## ETP024

**USEFULNESS OF ELECTRICAL STABILIZATION OF LAPAROSCOPIC IMAGE AND DEPTH PERCEPTION BY MOVEMENT PARALLAX IN LAPAROSCOPIC SURGERY**, Tatsuo Igarashi MD,Yukio Naya MD,Harufumi Makino MD,Hideki Hayashi MD, Research Center forFrontier Medical Engineering, Chiba University

**Background:** Laparoscopic surgery is carried out under conditions without depth perception and somewhat turbulent vision by the scope handled by a scopist. Previous report proved movement parallax affords depth perception using monocular laparoscopy coupling with the head movements of the surgeon (Voorhorst FA, et al. Med Prog Technol 21:211-8, 1996-7). We found similar effect could be obtained by stabilizing video image of shaking monocular laparoscopy. We tested a new technology of electric stabilization of turbulent image of laparoscopy for possible application in laparoscopic surgery, with special attention to depth perception. Materials and Methods: Motion stabilization software is kindly provided from ProTrack Co. Video images of 3 laparoscopic surgeries (resection of colon, pyeloplasty of the kidney, nephrectomy) are used to test the software in cancellation of turbulent motion of the image and depth perception by movement parallax. Experimental surgery (cholecystectomy, anastomosis of stomach and intestine, nephrectomy) was carried out in an animal model under the stabilized vision.

**Results:** Cancellation of shaking motion is recognized in every video without interference of motion of the forceps. In the experimental surgery, the target organ is fixed in the allotted position of the monitor, and swing in accordance with the camera motion, thus affording the depth perception. In this way, the depth perception is possible and useful especially in suturing.

<figure><img src="image_210.png" /></figure>

**Conclusion:** Present electrical motion stabilization technology is useful and is directly applied to laparoscopic surgery in stabilizing of the image, and affords depth perception when required.

## ETP025

**TRANSCORPORAL MAGNETIC RETRACTION OF LUMINAL VISCERA**, Stephen Van Lue, DVM, DACVS, Anne Palsgaard-Van Lue, DVM, University of Copenhagen, Faculty of Life Sciences, Copenhagen, Denmark

**Objective:** Adequate retraction of the bowel and other luminal viscera is important in lower abdominal and pelvic surgery. The objective was to place magnetic elements discreetly at select locations within luminal viscera, and engage these elements at the level of the abdominal wall with an external magnet for precise manipulation of the tissues.

**Description/Results:** A magnetically permeable element was deployed intraluminally at the level of the mid-descending colon in canine and feline cadavers. External compression on the abdominal wall brought the anterior abdominal wall proximate to the descending colon. A magnet was then utilized directly on the external abdominal wall to elevate the colon by magnetically engaging the intraluminal magnetically permeable element. Inflating a Foley catheter balloon positioned in the urinary bladder with a magneto-rheologic fluid provided a similar means of manipulating the urinary bladder.

**Conclusions:** Transluminal magnetic retraction and manipulation of visceral structures was easily achieved. With a more linear colonic intraluminal component, a longer segment of bowel could be elevated and "driven" around the anterior body wall with precision. Visibility of, and access to the mesenteric vasculature was excellent. Laparoscopic or

direct endoscopic visualization during placement of the intraluminal component(s) may provide a means whereby a surgeon could precisely identify relevant pathology and so direct their ideal placement. By incorporating a light emitting feature to the intraluminal retractor components, additional utility of the intraluminal components may be realized. Use of a magnetically permeable fluid may enable deployment of retractor balloons endoscopically or may enable retractor elements to be injected into specific anatomical spaces or tissues directly through the body wall. With further refinement, the described techniques may enable an incisionless procedure, or provide for a reduction in the number of laparoscopic ports normally utilized to manipulate visceral structures. Further investigations are warranted in human cadavers.

## ETP026

**TRANSBRONCHIAL EVALUATION OF MEDIASTINAL LYMPH NODES: A SINGLE INSTITUTION'S EARLY EXPERIENCE WITH ENDOBRONCHIAL ULTRASOUND**, Shawn S Groth MD,Bryan A Whitson MD,Michael A Maddaus MD,Rafael S Andrade MD, University of Minnesota Department of Surgery

**Objective:** Mediastinoscopy, the gold standard for histological evaluation of mediastinal lymph nodes (MLNs), is invasive and allows access only to certain MLN stations (American Thoracic Society stations 2, 4, and 7). We present our initial experience using endobronchial ultrasound-guided fine needle aspiration (EBUS-FNA) to biopsy MLNs in patients with benign and malignant disease.

**Methods:** We perform the procedure under general anesthesia (endotracheal tube size > 7 mm) and use an Olympus EVIS EXERA® BF-UC160F-OL8 ultrasonic bronchofiberscope (Olympus Imaging American Inc., Center Valley, PA, U.S.A.). Using integrated Doppler to accurately distinguish vascular structures from MLNs, EBUS-FNA MLN biopsies from stations 2, 3, 4, 7, 10 or 11 are obtained with a 22-gauge aspiration needle (Vizishot®; Olympus Medical Systems Co., Tokyo, Japan) under real-time ultrasonographic guidance. Each target MLN is accessed 1 to 3 times using 15 needle passes. Immediate and permanent cytology are performed on each sample. Patients without a histological diagnosis of cancer on immediate cytology from EBUS-FNA undergo confirmatory MLN biopsy with either mediastinoscopy or thoracoscopy.

**Preliminary Results:** Between September 2006 and February 2007, 18 patients (9 with malignancy, 9 with benign pathology) underwent EBUS-FNA at our institution. There were no complications. EBUS-FNA has a sensitivity of 71.4%, a specificity of 100%, and an accuracy of 77.8% in the diagnosis of benign and malignant nodal disease. Of our first 9 patients, 4 had false negative results; there were no false negatives in the subsequent 9 patients. Biopsies of station 11 MLNs, which are otherwise only accessible via thoracotomy or thoracoscopy (not mediastinoscopy), correctly established the diagnosis in 62.5% of (5 out of 8) patients. The smallest MLN from which diagnostic tissue was obtained was 6.5 mm.

**Conclusions:** EBUS-FNA is a safe, minimally invasive technique that allows access to more MLNs than mediastinoscopy and is emerging as an important tool in the evaluation of mediastinal pathology. Until the results of larger numbers of patients allow for a more accurate determination of the sensitivity of EBUS-FNA, negative biopsies require confirmation with either mediastinoscopy or thoracoscopy.

## ETP027

**REAL-TIME IMAGING OF THE COMMON BILE DUCT USING INFRARED TECHNOLOGY IN A PORCINE MODEL**, Ben R McHone MD, Alexander Gorbach PhD, Jack Liu BA, Mehrdad Alemozaffar BA, Nadeem Dhanani MD, Fred Gage PhD, Peter Pinto MD, Eric Elster MD, National Cancer Institute, National Institute of Biomedical Imaging, Naval Medical Research Center

**Introduction:** Intraoperative cholangiograms (IOCs) confer both an added cost to the laparoscopic cholecystectomy
<figure><img src="image_211.png" /></figure>

SAGES EMERGING TECHNOLOGY POSTER ABSTRACTS

(LC) as well as radiation exposure to both patients and operating room personnel. We introduce the application of passive infrared (IR) imaging to intraoperative cholangiography as a feasible alternative to traditional fluoroscopic IOCs.

**Methods:** A porcine model was used in which the gallbladder, CBD, and duodenum were exposed and an 18 gauge angiocatheter was inserted into the cystic duct. IR emission was detected using a digital IR camera (Lockheed Martin Inc., Goleta, CA) positioned at ~50cm above the abdomen. IR images (~1/s) were taken in real-time during infusion of room temperature saline (IR-IOC). Thermoplastic polymer stones were then inserted into the CBD. Once the artificial stone was placed, saline was again injected. The experiment was concluded by a CBD injury via a lateral 2cm incision immediately proximal to the duodenum. At the completions of each case, a standard single shot IOC was obtained with the infusion of 15 cc Renograffin.

**Results:** A total of 8 pigs were used. Real-time IR imaging was able to capture a visible temperature decrease, outlining the lumen of the CBD. With the injection of saline a decrease in temperature was noted in the lumen of the duodenum, corresponding to saline flowing unobstructed through the CBD into the duodenum, which was visualized as a dark area. Real-time IR images displayed the injected bolus being slowed by the obstruction. Finally, after partial transection of the CBD, the IR camera visualized saline flowing from the site of injury into the peritoneal cavity. These findings were all correlated with IOCs.

**Conclusions:** CBD anatomy, obstruction, and injury can be clearly visualized with an IR camera. Ultimately, the integration of IR technology into a standard laparoscope would require a fusion of real-time IR and visible light images. Intraoperative IR imaging is an emerging approach being utilized in several surgical fields.

ETP028

DESIGN AND INSTRUMENTATION OF NEW DEVICES FOR
PERFORMING APPENDECTOMY AT COLONOSCOPY, Gerd

Silberhumer MD, Tudor Birsan MD, Ewald Unger
MD, Winfried Mayr MD, Johannes Zacherl MD, Gerhard
Prager MD, Christoph Gasche MD, Medical University
Vienna, Department of Surgery, Department of
Gastroenterology and Hepatology

**Introduction:** Appendectomy is the most common operation in the gastrointestinal tract. There is increasing interest in interval appendectomy as a treatment for refractory ulcerative colitis. A less-invasive flexible endoscopic method for removing the appendix might offer advantages especially for interval appendectomy in patients undergoing colonoscopy. Aim: To design, develop and test new devices for removing the appendix via Natural Orifice Transluminal Endoscopic Surgery (NOTES).

**Methods:** Tests were performed on the bench in 13 colons from adult human cadavers. Various prototypes were tested, which could be inserted into the appendiceal orifice to its tip and could invert the appendix at its base in a controlled fashion into the lumen of the cecum. The advantage of using a tubular structure as counter force to aid inversion of the appendix was evaluated. After partial inversion the growing strain was relieved by endoluminal incision of the mesenteric side of the appendix. Closure methods with endoloops, clips and thread ties were studied. Appendiceal resection was completed by snare diathermy leaving an inverted intraluminal stump.

**Results:** The position of the appendix was retroceal in seven cases, pelvic in two, and pre-ileal or post-ileal in one each. The median length and luminal diameter was 85mm (52-125mm) and 5.5mm (3-7mm) respectively. Partial obstruction of the lumen was present in 5/13 cases. It was possible to advance the guide-wires and retraction devices to the tip of the appendiceal lumen in all cases. Partial inversion of the appendix was successful in 11/13 tests. The median length of the inverted stump was 13mm (3-18mm). The tension and volume (due to fat deposit) of the mesoappendix was the main reason for incomplete inversion. Complete inversion was achieved by endoluminal incision in 11/13 tests. The mean volume of the resected tissue (invert-

ed appendix incl. its mesoappendix) was 6.8 ± 1.9ccm.

**Conclusions:** Despite high individual variability, appendectomy at flexible colonoscopy proved to be feasible and relatively easy. New devices to allow appendix inversion were successfully tested.

ETP029

ENDOSCOPIC ESOPHAGEAL MUCOSECTOMY USING A
MULTIPURPOSE THERAPEUTIC HOOD (TXHOOD), Tatsuyuki

Kawano MD, Shigeo Haruki MD, Tokyo Medical and Dental University Hospital

Endoscopic resection including endoscopic mucosectomy (endoscopic mucosal resection (EMR) and endoscopic sub-mucoal dissection (ESD)) is a minimally invasive treatment for patients with early esophageal carcinoma (EEC) because almost all EECs are curable by endoscopic mucosectomy, esophagi are preserved and precise diagnoses of esophageal tumors are confirmed by histological examination of the resected specimens. Nowadays, although EMR techniques involving one piece resection (OPR) are established for relatively small lesions (2cm in diameter or less), wider lesions are still resected by piecemeal resection (PMR) techniques. ESD is appropriate for mucosal lesions of any size; however, ESD techniques are relatively difficult and can lead to serious complications, e.g., perforation and massive bleeding are reported more frequently following ESD than EMR.

We devised a novel technique for ESD and performed basic experiments to ensure safety. The new ESD technique can be performed easily using a newly designed piece of equipment called a multipurpose therapeutic hood (TxHood). The TxHood includes various therapeutic tools, e.g., electric needle knife, snare wire, and injection needle, and the lines can be selected freely before insertion of an endoscope covered by a TxHood. The main techniques for the resection of the target mucosal and submucosal tissues are endoscopic submucosal saline injections on demand through a working channel of the endoscope or TxHood, cut or swing cut with a needle knife attached to the TxHood, and grasping of the target area with grasping forceps through a working channel of the endoscope.

In our experiments, an electric needle knife was set parallel to the shaft of the endoscope and offered safety and ease of handling for dissecting procedures. We reported this new device and the results of experimental study at the SAGES 2006 Annual Meeting in Dallas and have successfully performed ESD using a TxHood for 20 lesions in 18 patients with superficial esophageal carcinoma.

We conclude from our experimental and clinical experiences of ESD using the newly devised TxHood and former experiences of endoscopic mucosectomy for EECs that the new ESD techniques with a TxHood provides a useful treatment for EEC, and may be applicable to all mucosal or submucosal tumors in the gastro-intestinal tract.

ETP030

RADIOFREQUENCY ABLATION FOR LUNG TUMORS,

Ghulam Abbas MD, Arjun Pennathur MD, Rodney J
Landreneau MD, James D Luketich MD, University of
Pittsburgh Medical Center

**Objective:** Surgery remains the mainstay of treatment for early stage lung cancer. Almost 20% of patients with early stage lung cancer do not undergo surgery because of medical co-morbidities and poor pulmonary reserves. Radiofrequency Ablation (RFA) is an alternate to surgical resection.

**Description and Method:** RFA involves the application of high frequency electric current to heat and coagulate target tissue. RFA consists of an alternating current, which moves from an active electrode, placed within the tumor to dispersive electrodes (bovie pads) placed on the patient. As the RF energy moves from the active electrode to the dispersive electrode and then back to the active electrode, ions within the tissue oscillate in an attempt to follow the change in the direction of alternating current, resulting in frictional heating of the tissue. As the temperature within the tissue rises > 60° C, instantaneous cell death begins due to protein denat-
uration and coagulation necrosis. RFA probe is inserted in the tumor percutaneously using image guidance by thoracic surgeons. Results: Among all the patients who had RFA for pulmonary tumors over last three years, 19 had stage I lung cancer. Median age was 78 years (range 68-88). An initial complete response was observed in 2 patients (10.5%), partial response in 10 (53%), and stable disease in 5 (26%). Early progression occurred in 2 patients (10.5%). During follow-up, local progression occurred in 8 nodules (42%) and the median time to progression was 27 months. The remaining eleven (58%) are locally progression-free at a median follow-up of 13.5 months (3.5-44). There were no procedure-related mortalities. The median follow-up in the remaining patients was 20 months. The probability of survival at 1 year was estimated to be 95% (CI .68-.91), median survival was not reached. Conclusion: RFA is innovative alternate to surgical resection for pulmonary tumors in selected patients. Combination therapy with other modalities like cyberknife stereotactic surgery may achieve better results.

## ETP031

**THE ESTABLISHMENT OF A LARGE ANIMAL SURVIVAL MODEL OF LAPAROSCOPIC ROUX-EN-Y GASTRIC BYPASS TO STUDY SUBSEQUENT GASTROJEJUNOSTOMY REDUCTION USING THE RESTORE SUTURING SYSTEM, David B Lautz MD, Cesar E Escareno MD, Ikram V Kureshi MD, Arthur Nedder, Ali Tavakkolizadeh MD, Kerri A Clancy RN, Ajay Maker MD, Michele Ryan MS, Christopher C Thompson MD, Brigham and Women's Hospital, Harvard Medical School, Boston MA**

**Objective:** Large animal survival models for laparoscopic Roux-en-Y gastric bypass (LRYGB) do not exist. The objective of this experiment was threefold: 1) to create a reliable RYGB large animal survival model 2) to demonstrate that laparoscopic RYGB in a porcine survival model was technically feasible and 3) to safely and effectively reduce the gastrojejunostomy (GJ) outlet size in the surviving animals endoscopically, using a novel suturing device developed for this purpose.

**Methods:** LRYGB was performed in five Yorkshire swine with a baseline mean weight of 32.3KG. Pancreaticobiliary length was 100 cm and Roux limb length was 200cm. The GJ was constructed with a stapled linear cutter technique and was intentionally oversized, with a target size of 2 cm, to accommodate later endoscopic reduction. Animals were recovered and maintained on a 1200 kilocalorie, high protein liquid diet. At 5 weeks the animals underwent an endoscopic GJ reduction using the RESTORE Suturing System (Davol Inc, Cranston, RI). This prototype device can be used with a standard gastroscope, and provides multi-stitch capabilities with a single endoscope pass. The animals were euthanized immediately post outlet reduction procedure.

**Results:** Four of five animals tolerated the procedure, with one intra-operative death secondary to a cardiac arrhythmia. Average operative time was 222 minutes. There were no postoperative deaths or complications, and the remaining four animals survived the five week study period. Mean weight loss was 0.8kg, in contrast to the typical rapid weight gain seen in adolescent swine. GJ outlet size ranged from 16-25mm on follow-up endoscopy. All GJ anastomoses were successfully reduced to an average diameter of 5.7mm with an average procedure time of 26 minutes.

**Conclusion:** This early work indicates that laparoscopic Roux-en-Y in a porcine survival model is technically feasible; and that the RESTORE Suturing System is safe and appears to be effective in the reducing GJ size in the model. This model will allow for future histologic studies of suture depth, which are not available from human clinical studies, but are very relevant to the efficacy, safety and longevity of post-RYGB endoscopic GJ reductions.

## ETP032

**LTS3E AUGMENTED REALITY LAPAROSCOPIC SIMULATOR, Andrée Sansregret MD, Paul Yarin MS, David Hananel BS, Harrith M Hasson MD, Univ. of Montreal, Blackdust Design, Medical Education Technologies, Inc., Univ. of New Mexico**

**Objective of Technology:** A turnkey augmented reality simulator capable of training and assessing laparoscopic technical skills.

**Description of Technology:** The LTS3e (LTS) is an integrated, self-contained computer enhanced interactive training system. Users are trained/tested performing validated exercises. Sensors embedded within physical modules assess performance based on metrics validated at McGill. The LTS, designed for ease of set-up and operation, is stored and transported in a compact configuration. Standard laparoscopic instruments are used. A digital camera captures and records video. Rotating the caramel provides access to 10 tasks including some that are repeated with the non-dominant hand. The tasks assess basic laparoscopic coordination skills, cannulation, cutting and suturing skills, including one that verifies knot integrity with a disruptive force of 1 kg. The administrative software supports enrolling users in a database, selecting and performing tasks, viewing and printing past and present test reports, watching tutorials and shutting down.

**Results:** The LTS-ISM60 (precursor to LTS3e model) was validated and compared with MISTELS in a study conducted at 3 Canadian universities: Montreal, McGill, and Dalhousie. It involved 124 participants including medical students, residents, fellows and attendings from surgery, gynecology and urology. They were grouped based on laparoscopic experience: novices, intermediates, competents and experts. All were tested on LTS, 66 also tested on MISTELS. A satisfaction questionnaire was filled after each performance. The LTS showed progression of scores with level of laparoscopic experience (p=0.001). Good correlation was found between LTS and MISTELS (0,82). Level of satisfaction was highest with LTS.

**Conclusion / Future Directions:** The LTS-ISM60 had a comparable discriminating capability for level of performance to MISTELS according to laparoscopic experience, with a higher degree of satisfaction among participants. The LTS3e model retains all exercises and embedded metrics of the LTS-ISM60 with all components integrated in a self-contained unit to better fit the needs of a skills lab. Future directions include evaluations of recorded performances and addition of features, i.e. camera navigation.

## ETP033

**DX PH MEASUREMENT SYSTEM. A SENSITIVE RADIOTELEMETRY DEVICE FOR DETECTING LIQUID AND AEROSOLIZED SUPRAESOPHAGEAL GASTRIC REFLUX (SEGR), Harry S Miller MD, Tomas Garibaldi-Hardy, H.G.R.#20 of The Instituto Mexicano del Seguro Social & Restech Corp. USA**

### 1. Objective of the technology or device

As Laryngopharyngeal reflux becomes more prevalent, it is still challenging to diagnose it definitively. The Dx pH Measurement System was developed in response to the poor sensitivity of traditional pH catheters when used outside of the esophagus. The Dx minimally invasive catheter for Supraesophageal Gastric Reflux detection is able to measure pH in either liquid or aerosolized droplets at the posterior oropharynx.

### 2. Description of the technology and method of its use or application

While we began evaluating a mask-based system initially, after performing over twenty concurrent esophageal pH studies with the mask, it became clear that the reflux had usually been completely neutralized before reaching the sensor that was held outside the mouth in a modified anesthesia mask. The engineers decided to change the design of the device completely, and they incorporated the sensor into the end of a nasal cannula that would be worn for the entire study period. This made it possible to monitor patients con-
<figure><img src="image_212.png" /></figure>

# SAGES EMERGING TECHNOLOGY POSTER ABSTRACTS

tinuously for up to forty-eight hours during their eating periods, while they were talking and while they were performing their normal activities. Characteristics of the probe - 1.5 mm diameter oropharyngeal catheter with wireless digital ZigBee transmitter that transmits to a monitor that is worn by the patient on the belt. The tip is a tear drop shaped tip with 3.2 mm diameter has a colored Light Emitting Diode (LED), for oral visualization. The tip of the probe (the sensor face) is oriented to face downward to better detect rising gaseous reflux.

### 3. Preliminary results if available

Basically Dr. Gregory Wiener's, study found that supraesophageal gastric reflux does exist and that it is usually a weakly acidic (pH 4-7).

### 4. Conclusions/Future directions

To further understand the role of reflux in conditions such as chronic cough, asthma, sleep apnea, and voice disorders. Clinical trials are being held, to further validate the system.

## ETP034

**ENDO-LAPAROSCOPIC INTRAGASTRIC TUMOR EXCISION (ELITE) - AN EMERGING CONCEPT OF SYNCHRONIZED LAPAROSCOPY-ENDOSCOPY APPROACH**, Simon K Wong MD, Michael Li MD, Department of Surgery, Pamela Youde Nethersole Eastern Hospital, Hong Kong

**Background:** In parallel with technology advancement is the changing concept of minimally invasive surgery. It is no longer confined to body cavity (laparoscopy) and modern surgical operating suite should equip and prepare for interventional endoscopy like endolumenal surgery, or even natural orifice transluminal endoscopic surgery (NOTES). Under the same contest, laparoscopic surgeons should fully utilize the technology in minimally invasive surgery and expand its application.

**Aim:** We propose an emerging concept in combining laparoscopic surgical technique and instrument in complex endoscopic procedure like endolumenal excision of gastric wall tumor.

**Method:** A case of large 4cm dysplastic gastric polyp was selected for Endo-Laparoscopic Intragastric Tumor Excision (ELITE). Operation was performed in Endo-Lap OR (Olympus). Stage I: Gastroscope (Olympus, GIF 2T160) was inserted and stomach was distended with carbon dioxide insufflation. Anterior gastric wall was anchored to anterior abdominal wall with transgastric sutures. Atraumatic detachable vascular clamp (Aesculap) was applied at proximal jejunum to avoid small bowel distension. Stage II: Three laparoscopic trocars (Autosuture, VersaStep) were placed into stomach by percutaneous method. Stage III: Endolumenal intragastric excision of gastric polyp was performed with laparoscopic instruments (ValleyLab, LigaSure II) under both laparoscopic and endoscopic image guidance. Intragastric homeostasis was achieved by both endoscopic and laparoscopic instrument, and mucosal defect was closed with intragastric suturing. Plastic bag was placed into the stomach and specimen was retrieved transorally by endoscopy. Stage IV: Transgastric trocars were removed and gastric wall defects were closed with laparoscopic suturing.

**Results:** The operating time was 95 minutes and procedure was performed without complications.

**Conclusion:** ELITE is a promising method for excision of both mucosal and submucosal gastric wall tumors.

## ETP035

**MICROWAVE ABLATION OF LIVER TISSUE: THE FUTURE OF HEPATIC TUMOR ABLATION**, John P Cullen MD, David W Easter MD, Sonia Ramamoorthy MD, Brian Datnow MD, Santiago Horgan MD, Mark A Talamini MD, Yoav Mintz MD, University of California at San Diego

**Introduction:** Microwave (MW) ablation has several advantages over radiofrequency (RF) ablation including less charging, less pain, self-contained temperature control, decreased collateral damage, wider range of heating, less heat loss due to nearby blood vessels, and no need for a grounding pad. The Medwaves Microwave Ablation system

® features an array of disposable catheters of varying sizes (5 Fr to 12 Fr in diameter and up to 2 meters in length) and flexibilities to facilitate ablation in a number of modalities.

**Objective:** To evaluate the Medwaves system's ability to ablate liver tissue in open, laparoscopic and natural orifice approaches

**Methods:** 4 farm pigs were anesthetized. Catheters were placed via laparoscopic, MIS, and NOTES approaches. Various powers, times, and temperature ranges were used. The Pringle maneuver was applied during several attempts to determine the effect of reduced blood flow. The lesions were evaluated macroscopically after surgery and microscopically by histology. Preliminary Results: Lesions ranged from 1-3 cm. The best results were obtained at ten minutes time with 25 watts and max temperature 120 degrees C. There was no hemorrhage or other complication. Placement of multiple catheters in parallel increased the volume of necrosis.

**Conclusions:** The Medwaves MW ablation system can be easily used in an open, laparoscopic, or natural orifice surgical approach to treat liver lesions. MW has several distinct advantages over RF ablation. Survival studies and ablation of lesions under US guidance will guide future endeavors. Figure 1 shows sections of ablated liver.

<figure><img src="image_213.png" /></figure>

## ETP036

**EVALUATION OF THE USE OF A NEW IMPEDANCE CONTROLLED BIPOLAR DEVICE WITH MONOPOLAR**

**CAPABILITY**, Thomas M Schmelzer MD, William W Hope MD, William L Newcomb MD, Keith S Gersin MD, David A Iannitti MD, B. Todd Heniford MD, Carolinas Medical Center This study evaluates a new electrosurgical device that combines an advanced electrosurgical bipolar sealing device with a monopolar electrode. This combination of devices in a single instrument facilitates dissection and improves surgical time by eliminating the need to exchange instruments. A single instrument can be used for tissue dissection as well as blood vessel and lymphatic sealing in several laparoscopic and open operations. Examples include colon and small bowel resections, splenectomy, appendectomy, cholecystectomy, and liver resection. Traditionally, these operations require the use of multiple devices. We have successfully used this device for these operations in a porcine model. We have evaluated the ability of this multiple capability device to seal human cystic ducts ex vivo following a cholecystectomy. Bursting pressures were measured (n = 4) with a mean bursting pressure of 262.4 mmHg (range 110-381 mmHg). The mean time needed to seal and cut the duct was 6.3 seconds (range 5-8 seconds). Sealed ducts also underwent histologic evaluation for thermal spread and demonstrated 1.1 mm of thermal spread. In vivo survival testing is required to evaluate the efficacy and the integrity of the bile duct seal over time. The speed and versatility of this new device make it useful for a variety of laparoscopic and open surgical procedures

## ETP037

**IRREVERSIBLE ELECTROPORATION FOR THE ABLATION OF MALIGNANT HCC TUMORS**, Brett Sheppard MD, Douglas Faigel MD, Gary Long PhD, Dave Plescia MS, Christie Cunningham BS, Phil Long PhD, NOTES Development Group, Oregon Health Sciences University (OHSU), Portland OR Ethicon Endo-Surgery Cincinnati OH, Vet Path Services, Inc Mason, OH

**Background:** Patients with non-resectable hepatocellular carcinoma (HCC) and colorectal metastases in the liver are cur-
rently being treated with radio frequency ablation (RFA). RFA techniques rely on the input energy to raise the temperature of the tissue for a sufficiently long period of time to cause necrosis of the entire tumor (tens of minutes). Irreversible electroporation (IE) is a technique by which an increase in the trans-membrane voltage of a cell can cause a rupture of the cell wall leading to apoptosis and subsequent cell death. The rapid treatment (1 to 2 seconds) allows for quick re-deployment of simple needle electrodes to treat large volumes of tissue. A side effect of IE is stimulated contractions of muscle.

**Methods:** A finite element (FE) model of tissue was built to map electric field lines. Three experiments were performed on in-vivo porcine livers with a two-needle probe which applied short period pulses (0.1-20 milliseconds) at high DC voltages (500-700VDC). The animals were survived for 3 and 6 hours. The histological results of the extent of damage in the porcine liver were compared to the FE model.

**Results:** Shorter, higher voltage pulses reduced the intensity of muscular contractions (observation). No heart arrhythmias were observed during the treatments. Histological analysis showed that a zone containing apoptotic/necrotic cells of approximately 1 cm by 0.7 cm by 1 cm deep into the tissue was achieved with multiple 0.4 millisecond pulses at 700 VDC. This treatment took approximately 1 second and could be quickly repeated as the electrodes were redeployed. A laparoscopic device is under development to continue testing this technique.

## ETP038

**A COMPARISON OF BURST PRESSURES OF GASTROJEJUNAL ANASTOMOSES WITH OR WITHOUT BUTTRESSING IN A PORCINE MODEL**, William W Hope MD, Marc Zerey MD, B. Lauren Paton MD, William L Newcomb MD, Albert Y Chen MD, Jessica J Heath BS, Richard D Peindl PhD, Amy E Lincourt PhD, Timothy S Kuwada MD, B. Todd Heniford MD, Keith S Gersin MD, Carolinas Medical Center

Anastomotic leaks and bleeding cause the greatest concern for the gastrointestinal surgeon. Anastomotic staple line buttressing materials could possibly reduce these complications. The purpose of our study was to compare the bursting pressure of a buttressed versus a non-buttressed gastrojejunal anastomosis in a porcine model.

Antecolic antegastric gastrojejunal anastomoses were constructed using a Proximate ILS® mechanical circular stapling device (Ethicon Endo-Surgery, Cincinnati, OH) with and without a buttressing material, polyglycolic acid/trimethylene carbonate (W.L. Gore, Flagstaff, AZ). Half of the animals (acute) were euthanized after the anastomosis was created and burst pressure testing was performed. The remaining half (chronic) underwent a Roux-en-Y procedure and were survived for one week. The gastrojejunal anastomoses were then resected and burst pressure testing performed.

Acute and chronic burst pressure testing with buttressing was performed on 5 animals with an average burst pressure of 1.37 and 2.24 PSI respectively. Acute and chronic burst pressure measurements without buttressing were performed on 6 animals with an average burst pressure of 0.39 and 3.86 PSI respectively. Initial burst pressures were significantly higher with polyglycolic acid/trimethylene carbonate (1.37 vs. 0.39 PSI, p=.0075). Burst pressures at one week were significantly lower with polyglycolic acid/trimethylene carbonate (2.24 vs. 3.86 PSI, p=0.0353), however, both readings were well above expected normal physiologic intestinal pressures.

A significant increase in staple line strength is noted acutely when polyglycolic acid/trimethylene carbonate is applied as a buttress to a circular stapled anastomosis. Further study is needed to evaluate long term effects of buttressing material on anatomoses.

## ETP039

**EARLY CLINICAL RESULTS USING GORE SEAMGUARD® BIOABSORBABLE STAPLE LINE REINFORCEMENT (CBSG) FOR CIRCULAR STAPLERS**, Wesley B Jones MD, Katherine M Myers, Eric S Bour MD, Greenville Hospital System University Medical Center, Department of Surgery, Greenville, SC, USA

Linear surgical staple line reinforcement has been shown to increase anastomotic tensile strength and reduce the incidence of staple line bleeding and anastomotic leaks. The benefits of staple line reinforcement on circular stapled anastomoses in foregut surgery remain unreported in the literature. The purpose of this study was to compare the incidence of anastomotic bleeding, leak, and stricture in laparoscopic gastric bypass patients with circular staple line reinforcements to those with no circular staple line reinforcement.

Since May, 2006, 90 consecutive patients have undergone laparoscopic Roux-en-Y divided gastric bypass with a 25mm circular stapled gastrojejunal anastomosis using GORE SEAMGUARD® staple line reinforcement. The incidence of anastomotic bleeding, leak, and stricture was compared to 269 patients who underwent surgery prior to May 2006 without gastrojejunal reinforcement.

In the patients with no circular staple line reinforcement, the incidence of anastomotic bleeding, anastomotic leak, and anastomotic stricture was 1.1%, 1.9% and 9.3%, respectively. There have been no incidents of anastomotic bleeding, anastomotic leak, or anastomotic stricture in patients with the GORE SEAMGUARD® circular staple line reinforcement over the 8 month course of this investigation.

In conclusion, early results indicate that the use of circular staple line reinforcement at the gastrojejunal anastomosis in patients undergoing laparoscopic gastric bypass decreases the incidence of anastomotic leak, bleeding, and stricture. On this basis, strong consideration should be given to the routine use of GORE SEAMGUARD® staple line reinforcement in patients undergoing laparoscopic divided gastric bypass with a circular stapled gastrojejunal anastomosis.

## ETP040

**REPAIR OF INGUINAL HERNIA IN DEVELOPING COUNTRIES**, Tehemton E Udwadia, Breach Candy and Hinduja Hospitals, Mumbai.

**Objective:** Tension free mesh hernioplasty, open or laparoscopic, is considered the ideal treatment for hernia. In large parts of the world commercially available mesh is way beyond the reach of a population whose average income would be $1 - $2 a day. To study application of the currently accepted ideal method of hernia repair – the tension free open mesh repair for the poor in the developing world, using mosquito-net which is freely available there.

**Technology:** The composition of mosquito-net is linear low density polyethelene, has a tensile strength of Newton 192n and a melting point of 122o C. One square yard of mosquito net costs Rs. 40 (90 cents). When cut to size for mesh repair the cost per mesh per patient would be Rs. 2/- (5 cents).

**Method:** No claims whatsoever are made of originality in the use of this material for hernia repair. Surgeons in rural India commenced using mosquito-net for tension free open mesh repair for their poor patients in 1996. (Indian J Surg (2003) 65:89-95). This study lacks adequate statistical analysis. A similar study with 20 cases in each arm has been reported (W.J.S.(2006) 30:1784-1789.) This mesh has anecdotally been used for laparoscopic hernia repair, but no study is reported. We are conducting a controlled trial of mosquito-net vis-à-vis commercially available mesh with meticulous statistical evaluation. Standard Lichtenstein repair is done in both arms.

**Results:** With 22 and 23 cases in the two arms in our study to date and a follow up of less than one year, our results are at best, preliminary. All post operative evaluation parameters are identical for both mesh.

**Conclusions:** If controlled trials can convincingly demonstrate that mosquito-net has similar results as commercial mesh, this would help ensure that the poor in the develop-
<figure><img src="image_214.png" /></figure>

# SAGES EMERGING TECHNOLOGY POSTER ABSTRACTS

ing world could afford to have the benefit of what on current evidence is accepted as the best form of hernia repair. Laparoscopic surgery is well established in the developing world. This mesh would be compatible for use in laparoscopic hernia repair. For decades surgeons have pursued high technology which has propelled our science to reach for the stars. It may be appropriate to have the humility to accept a technology which permits our science to reach for needy humans.

## ETP041

**ARTICULATING NEEDLE HOLDER DESIGN, Tim Frank**
PhD, Stuart Brown PhD, Alfred Cuschieri, Department of Surgery and Molecular Oncology, University of Dundee, UK and Cuschieri Skills Centre, University of Dundee, UK

**Objective:** Suturing is one of the most difficult laparoscopic surgical tasks. Furthermore, standard straight instruments can only readily be used to suture a line that is approximately parallel to the instrument shaft. These problems may be alleviated if needle holders are designed to incorporate a distal joint that angulates and also transmits axial jaw rotation through the angulation. Such a device can be used for a wide range of suturing directions and may reduce the difficulty of complex manoeuvres such as knot tying.

**Technology:** The articulating joint is placed 20-40mm from the instrument jaws and adds two degrees of freedom to the four degrees that standard instruments have. Joint design must allow angulations of 70° or more with preferably continuous axial rotation. In common with most types of surgical needle holder, the jaws should be latchable. Design options are described that provide adequate needle latching force, maintain this force during rotation and angulation movements, and transmit force and torque across the articulation without excess laxity or frictional resistance. The instrument handle must provide control of the additional degrees of freedom and possible ways achieving this are discussed.

**Conclusions:** Typical specifications and specific designs are presented and discussed. Stress analysis and prototype construction demonstrate that an instrument of 10mm diameter can meet the specifications. Furthermore, it is shown that the instrument can be constructed at 5mm diameter within, but near to, the limit of construction material properties. It has been shown that six-degree-of-freedom robots are very effective for previously difficult laparoscopic suturing tasks. However, the cost and complexity of these will limit their widespread use. Thus the articulating needle holder, while being perhaps the most complex laparoscopic instrument to date, could have a very significant place in laparoscopic instrumentation.

## ETP042

**NEW 2 MM INSTRUMENTS NOT REQUIRING TROCARS FOR MINIMALLY INVASIVE SURGERY, Ashutosh kaul**
MD, Ravi Kumar MD, New York Medical College

**Objective:** These devices aim to aid minimally invasive surgery in a cost effective cosmetic manner.

**Description:** This line of 2 mm instruments made of special alloy can be introduced through a small skin nick into the abdominal or thoracic cavity without use of trocars. Introduction is aided by veress needle like mechanism and they can then be deployed. They have external stabilizers to support their deployment at the skin level, and locking mechanism, which allows them to be, used as self-retaining retractors they allow use of electric source via an insulated channel. The instrument line includes bowel grasping, dissectors, Maryland like tips, fan and rake like retractors and hook dissectors.

**Preliminary results:** We have used these instruments in an animal model to do the following procedures with the aid of a 5 mm camera, They include diagnostic laparoscopic, laparoscopic cholecystectomy, grasping and running the small bowel, appendectomy, tubal ligation, hemostasis after liver biopsies.

As they require no trocars they can be cost effective besides being cosmetically advantageous. As they have stabilizers

with locking mechanism they can aid solo surgeons by providing a stable retraction in easily adjustable directions. The use of veress like mechanism for introduction minimizes tissue trauma.

**Conclusions:** This line of instruments can be used to do procedures like cholecystectomy and appendectomy in a cosmetic and cost effective manner. As they are self stabilizing they can also be used for temporary tissue retraction instead of introducing another trocar and the need for additional personal.

## ETP043

**EFFICACY OF FULLY COVERED SELF-EXPANDING NITINOL STENTS IN THE TREATMENT OF DYSPHAGIA FOR PATIENTS WITH REFRACTORY ANASTOMOTIC STRICTURES AFTER ESOPHAGECTOMY, Rajnish Mishra MD, Paul**
Yeaton MD, Michel Kahaleh MD, Vanessa Shami MD, University of Virginia Health System

**Background:** Esophageal stents have been widely used to treat malignant dysphagia. Fully covered stents offer the potential of removability, permitting treatment of benign esophageal stenosis. The purpose of this study is to assess the efficacy of this fully covered nitinol stent in patients with dysphagia due to refractory anastomotic strictures after esophagectomy for esophageal cancer.

**Methods:** Covered nitinol stents were implanted in five patients who had dysphagia after esophagectomy secondary to refractory anastomotic strictures (see table). All five patients had undergone esophagectomy for primary esophageal cancer and were unresponsive to serial (>3) endoscopic balloon dilations.

<table><thead><tr><th>Study</th><th>Case 1<br>(64/M)</th><th>Case 2<br>(68/M)</th><th>Case 3<br>(77/F)</th><th>Case 4<br>(75/M)</th><th>Case 5<br>(82/M)</th></tr></thead><tbody><tr><td>Surgery</td><td>Transhiatal</td><td>Transhiatal</td><td>Ivor-Lewis</td><td>Ivor-Lewis</td><td>Transhiatal</td></tr><tr><td>Prior Dilations</td><td>4</td><td>5</td><td>6</td><td>4</td><td>3</td></tr><tr><td>Stent Type (mm)</td><td>Alimax 18x70</td><td>Alimax 18x70</td><td>Alimax 18x70</td><td>Alimax 18x70</td><td>Alimax 18x70</td></tr><tr><td>Stent Duration</td><td>14.3y weeks</td><td>2.0y weeks</td><td>4y weeks</td><td>4y weeks</td><td>2y weeks</td></tr><tr><td>Complications</td><td>None</td><td>Ustest Train</td><td>None</td><td>None</td><td>Migration</td></tr></tbody></table>

**Results:** Placement of the stent was successful in all 5 patients. There was marked improvement in dysphagia in all 5 patients with 4 of these having long-term resolution of their symptoms after stent removal. In one patient the stent was found to have migrated distally into the stomach on two occasions, with resolution of the stricture and dysphagia the second time. In all patients, the stent was easily removed with a foreign body forceps.

**Conclusion:** Placement of covered nitinol stents in patients with refractory post operative benign esophageal anastomotic strictures appears safe and efficacious. Dysphagia was alleviated in all patients. Further studies need to be performed to define the duration of stent implantation to achieve resolution of the stenosis.

## ETP044

**A DIRECT DRIVE ENDOSCOPIC SYSTEM FOR COMPLEX ENDOLUMINAL AND NOTES APPLICATIONS, C C**
Thompson, R I Rothstein, N J Soper, M Ryou, D G Fong, R D Pai, P J Smith, B D Weitzner, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Dartmouth Hitchcock Medical Center, Dartmouth Medical School, Hanover, NH, USA; Northwestern University, Chicago, IL, USA; Boston Scientific, Marlborough, MA, USA

**OBJECTIVE:** This Direct Drive Endoscopic System is a multitasking platform created for endoluminal and NOTES applications. The system was developed to enhance the dexterity of the standard end-effectors required for complex endoscopic procedures, without the need for computer-assisted robotics.

**DESCRIPTION:** The unit consists of a rail platform and a three-lumen lockable, articulating guide sheath. The sheath accepts a small-caliber endoscope and two 4mm instruments. The drive handles are connected to long, interchangeable instruments that pass down the guide sheath. These handles run on the rail platform and transmit hand motion to the instrument tip, imparting five degrees of freedom. The guide sheath provides an additional two degrees
of freedom, for a total of seven. The unit was initially used in a series of calibration and training exercises, including passing rings between forceps and placing them on spikes. Graspers, scissors, and needle drivers were then used in ex-vivo porcine stomachs to attempt more complex procedures, including EMR, accurately place sutures, and knot tying. Video records were maintained.

**RESULTS:** The independent instrument movement with wide range of motion allowed the device to perform several complex tasks. The direct drive system was able to grasp tissue and hold it under tension, cut through layers of porcine stomach in a controlled fashion, suture, and tie knots.

**CONCLUSION:** Preliminary results suggest the Direct Drive Endoscopic System can perform complex endoscopic tasks that have traditionally been impossible to perform. The system's ability to operate through narrow flexible channels puts new capabilities for endoluminal and NOTES procedures in the interventionalist's hands.

## ETP045

**BUILDING VIRTUAL REALITY HAPTIC INTERFACES: THE CONTRIBUTIONS OF OPERATIVE EXPERIENCE**, *Allan Okrainec MD, Heather Carnahan PhD, Liya Ni PhD, David Wang PhD, Adam Dubrowski PhD*, University of Toronto and University of Waterloo

**Objective:** The "holy grail" of virtual reality simulation is the development of the most realistic representation of the operative environment. Psychophysics, which deals with the relationship between physical stimuli and their subjective percepts suggests that this may be a suboptimal approach. To date little is known about the tactile psychophysical experiences of practicing surgeons and how they should be represented in virtual reality simulators. The objective of our technology is to enable the experienced surgeon to determine the "feel of the tissues" to be simulated.

**Technology:** Hardware: a laptop and a PHANTOM 3 Degrees of Freedom Omni haptic device. Software (proSENSE and MATLAB): a 3D virtual organ model and representation of the PHANTOM (surgical) device. The user interface has slider-bars with which the surgeon can create haptic effects of the virtual tissues by first selecting a region of interest (such as a tumor) on an organ with a stylus and then adjusting psychophysical parameters such as "stiffness" and "roughness" corresponding to the physical parameters "compliance" and "texture". The values of these estimates for a selected organ region are recorded in a lookup table.

**Preliminary results:** We have recently presented a set of preliminary results at Medicine Meets Virtual Reality (Ni et al., 2007) conference. In summary, the pilot data show that four general surgeons adjust parameters of normal and cancerous tissues differently with low inter and intra-individual variability.

**Conclusions/Future directions:** Our haptic interface and software allows a surgeon to use memorial representations of the psychophysical properties of tissues to assist in the design of virtual reality haptic devices. Future technological development will focus on increasing the number of degrees of freedom of the device, to include rotations and opening and closing of simulated pincers. We will also aim to increase the number of psychophysical parameters describing the tissues. Future uses of this technology will include placing our haptic device and software in the operating room, allowing surgeons to correlate their intraoperative assessment of tissue properties with the haptic parameters set on our device. This would allow us to validate memory based psychophysical properties with intraoperative judgment of tissue properties.

## ETP046

**EFFECTIVENESS OF VIRTUAL INSTRUCTOR FEEDBACK ON NOVICE LEARNER PERFORMANCE USING THE GI MENTOR II GASTROINTESTINAL ENDOSCOPY SIMULATOR**, *James G Bittner IV MD, Adeline M Deladisma MD, Michael A Edwards MD, Edward J Kruse DO, John D Mellinger MD, Mary Anne Park MSc, Bruce V MacFadyen Jr. MD, D. Scott Lind MD, Department of Surgery, Medical College of Georgia School of Medicine

**OBJECTIVE:** SAGES is currently addressing the need for a comprehensive, standardized basic endoscopic assessment tool complete with a validated curriculum and appropriate real-time feedback. The overall goal then is to develop, evaluate, and refine an innovative, virtual endoscopy simulator with a validated curriculum and a skill-enhancing, interactive virtual instructor. These two educational tools, an interactive life-sized virtual instructor and high-fidelity endoscopy simulator, will synergize to produce an innovative, fully immersive, curriculum-based training environment with skill-enhancing feedback. Surgical and endoscopic simulation combined with real-time, interactive virtual instructors and feedback will increase trainee exposure to difficult or uncommon cases. This educational technology, based on validated curricula and simulation equipment, will improve basic laparoscopic and endoscopic operative skills, serve a crucial role in minimally invasive and endoscopic surgery curricula, and identify trainees who will require more training based on measured outcomes of simulated tasks and procedures. Simulation with interactive virtual instructors may decrease patient exposure to untrained individuals thereby lowering overall risk and lessening the time and financial burdens on attending faculty involved.

**METHODS:** Thirty medical students at the Medical College of Georgia School of Medicine will be randomly assigned to one of three groups. All participants will complete the same three simulated cases in sequential order using the GI Mentor II (Simbionix USA Corp., Cleveland, OH). The control group (n=10) will complete three cases with no real-time or summative feedback during or after each simulated case. Group 1 (n=10) will receive real-time, virtual and summative feedback currently provided by the GI Mentor II. Group 2 (n=10) gets real-time, virtual and summative feedback plus a digitally projected, interactive, virtual instructor. Data collected for the groups will include time to complete each virtual module, percent amount of mucosa visualized on each virtual module, efficiency of performance, and percent pathologies identified.

**CONCLUSION:** We believe that a real-time, interactive virtual instructor and simulator-based feedback employed simultaneously during simulated upper gastrointestinal endoscopy using the GI Mentor II will improve novice learner performance in all evaluated metrics compared to complete absence of feedback or simulator-based feedback alone.

## ETP047

**DECISION AIDS IN LAPAROSCOPIC CHOLECYSTECTOMY**, *Dawit Worku Gebrehiwot MD*, St. Bartholomew's and The London School of Medicine and Dentistry

Over the last two decades, laparoscopic cholecystectomy (LC) has gained worldwide acceptance and considered as "gold standard" in the surgical management of symptomatic cholelithiasis. However, despite the expertise gained in performing the procedure, complications such as bile duct injuries continue to occur at unacceptable rates, higher than that for open cholecytectomies.

Dynamic decision study in Laparoscopic Cholecytectomy has identified Situation Awareness (SA) and Recognition-Primed Decision (RPD) as important mental models utilized by surgeons performing LC. Such studies also highlight the need for decision support techniques and technologies for use in difficult cases of LC and by inexperienced surgeons. A number of practical and innovative techniques have been suggested that could help as decision aids, in order to reduce some of the complications retated with LC. One such technique is direct coloration of the cystic duct, the common
<figure><img src="image_215.png" /></figure>

# SAGES EMERGING TECHNOLOGY POSTER ABSTRACTS

bile duct and the gallbladder with intraoperative injection of methylene blue dye into the gallbladder fundus. The clinical use of ultrasoic doppler instrument (SonoDoppler (R)) for detection of blood flow during laparoscopic procedures also has an important potential in accessing and clarifying anatomical structures. Finally, intraoperative transillumination of the extrahepatic biliary ducts and vessels can be helpful in identifying the stuructures better.

## ETP048

**2-DIMENSIONAL GEL PLASMA PROTEOMICS: A TOOL FOR THE ASSESSMENT OF THE PLASMA PROTEIN RESPONSE TO ILLNESS AND SURGICAL INTERVENTION**, John M Bennett BA, Abigail C Polley PhD, Mike Rhodes MD, Ian T Johnson PhD, Fran Mulholland PhD, Institute of Food Research

**Objective:** To develop techniques to optimise the detection and analysis of plasma proteins, ranging from global analysis of plasma protein expression to more focused analysis of protein sub-classes. The analysis of these plasma protein responses to both acute and chronic illness, and to medical and surgical interventions can reveal new information about the metabolic response to disease and treatment. We describe the development and optimisation of proteomic techniques for the analysis of changes in the plasma proteins in patients undergoing laparoscopic adjustable gastric banding for the treatment of morbid obesity.

**Description:** A variety of techniques are available for the separation and identification of plasma proteins but plasma samples must first be depleted of high abundance proteins (e.g. albumin) that would otherwise saturate the detection system. We compared two different methods for protein depletion: the Amersham Albumin/IgG depletion kit® and the Beckman plasma depletion column, which removes an additional eight abundant proteins. The depleted plasma was then subjected to isoelectric focusing on pH gradient strips followed by gel separation on 10% homogenous polyacrylamide gels. The pH gradient can be varied in the range 3-11 to enable more complete separation of different protein groups. The resultant images were digitised and examined using ProteomWeaver® software. Selected protein "spots" were then removed from the gels using a robotic spot-picking system and identified by MALDI-TOF and Q-TOF mass spectrometry. Differences in protein expression (spot-density) between controls and trial subjects, controls and disease groups, and individual subjects over time following surgical intervention were quantified and assessed statistically.

**Preliminary Results:** Our initial results demonstrate both the feasibility and importance of achieving consistent patterns of protein depletion using the commercial kits currently available for processing human plasma. Having optimised this approach we have obtained evidence for consistent changes in plasma protein expression in a pilot group of 5 morbidly obese patients before, and at three and six months post laparoscopic adjustable gastric banding.

**Conclusion and Future Direction:** Proteomic analysis can be utilised to develop a "systems biology" approach to the plasma metabolic changes related to diseases and medical interventions. We are conducting further development of plasma depletion techniques to allow analysis of less abundant proteins, and work also continues on the development of gels with pH ranges tailored for the optimal separation and quantification for different target proteins.

## ETP049

**TROCAR FOR LAPAROSCOPIC PLACEMENT OF CATHETER FOR PERITONEAL DIALYSIS**, Zoran Cala PhD, Ivo Soldo PhD, Irena Senecic-Cala MSc, Visnja Nesek-Adam MSc, Univ Dpt of Surgery GH Sveti Duh, Univ Dpt of Pediatrics CH Rebro, Zagreb, Croatia

**Aim:** The aim of our work is to improve the technique of peritoneal catheter placement substituting open with endoscopic operation. For this purpose we constructed original device Cala's trocar. After several models, now we have trocar that fulfills all our needs for this operation. This trocar consists of two essential parts. The outer part is a cannula

which can be separated longitudinally in two symmetric parts. The inner metal part has pyramid shaped tip.

**Method:** Endoscopic placement is performed under general anesthesia in the operating room using equipment for laparoscopic operation. After pneumoperitoneum is achieved and laparoscope introduced, the catheter trocar is passed obliquely through the abdominal wall and directed into the pelvis, with the laparoscopic monitoring of the trocar tip. The catheter is introduced through trocar canulla. The canulla is dismantled longitudinally and removed while the catheter tip is kept into the pelvis by the forceps.

**Results:** From December 1993 until January 2007 catheter for peritoneal dialysis was placed laparoscopically in 198 cases using our own trocar constructed for this purpose. There were no intraoperative or postoperative complications.

**Conclusion:** Laparoscopic placement of catheter for peritoneal dialysis using specially constructed Cala's trocar is a simple, quick, efficient and patient convenient technique.

## ETP050

**THORACOSCOPIC AND MINI-LUMBAR VERTEBRAL BODY STAPLING USING SHAPE MEMORY ALLOY (NITINOL) IN THE TREATMENT FOR SCOLIOSIS IN CHILDREN**, Harsh Grewal MD, Randal R Betz, Linda P D'Andrea, Section of Pediatric Surgery, Temple University Children's Medical Center and Orthopedic Surgery, Shriner's Hospitals for Children, Philadelphia

**Introduction:** In skeletally immature children (< 13 years in girls, <15 in boys) with progressive scoliosis (but curve <45 degrees) vertebral body stapling of the anterior spine may keep the curve from progressing while preserving movement and flexibility and provide a better alternative to bracing or fusion.

**Objective:** To describe initial results of thoracoscopic and mini-lumbar vertebral body stapling using a shape memory alloy (NITINOL) staple for the treatment of scoliosis in children.

**Description:** A retrospective review of children undergoing vertebral body stapling using a shape memory alloy (NITINOL) staple. Thoracic curves were stapled using a thoracoscopic technique with single lung ventilation, fluoroscopic control, usually requiring 3 to 4 ports. Lumbar curves were stapled using a mini-incision retroperitoneal exposure with fluoroscopic control.

**Results:** A minimally invasive vertebral body stapling was performed in 59 children with 78 curves (thoracic-30, lumbar-7, both curves-22). The curves stapled ranged from T2-L4. All children had their curves successfully stapled without any intra-operative neurological injuries. Mean estimated blood loss was 255 ml (50-1500). Postoperatively there were 6 complications (chylothorax-1, pancreatitis-1, diaphragmatic hernia-1, atelectasis-3). None of the staples were dislodged, there were four broken staple, and none of the staples moved. In one patient staples were removed because of persistent pain. Preliminary results reveal stability of curves (< 10 degrees) in 75% of the adolescent idiopathic scoliosis patients at one year.

**Conclusion:** A new treatment in children utilizing thoracoscopic and mini-lumbar vertebral body stapling appears to be a safe alternative to bracing or fusion in skeletally immature children with idiopathic scoliosis.

## ETP051

**A NOVEL DEVICE FOR DEFOGGING, HEATING, WHITE-BALANCING, PROTECTING AND CLEANING THE LAPAROSCOPE**, Sandy Heck MD, Alexander Gomez, Brian Jacob MD, Alfons Pomp MD, Weill Cornell Medical College, New Wave Surgical Corp.

**OBJECTIVE:** Considerable efforts are spent during laparoscopy to maintain adequate visualization, including lens wiping, defogging and color balancing. We hypothesized that a multifunction device capable of addressing these problems could significantly improve surgical efficiency. To meet this demand, we developed a single-use Defogging Heated Endoscopic Lens Protector (DHELP) device.
**DESCRIPTION:** DHELP contains a reservoir of heated anti-fog solution, a white-balancing target that blocks light interference, a microfiber surface for cleaning the lens, and a foam shell to protect the scope from damage and eliminate the fire hazard when the scope is outside of the body. Upon activation, a reservoir of anti-fog surfactant heats above body temperature in one minute, and remains heated for five hours. An adhesive bottom flap secures the device to the drapes so that the scope can be quickly inserted, defogged, and cleaned at any point.

<figure><img src="image_216.png" /></figure>

**RESULTS:** In a porcine animal study that measured time-to-fog after scope insertion into the abdomen, DHELP was compared in a randomized fashion to an anti-fog solution, heated water, and controls. At all time points and at all temperatures, time-to-fog was longest for DHELP. In trials where the scope remained inside DHELP for &gt;5 sec, no fogging resulted at all. A prospective, controlled human study is underway to further study DHELP&#x92;s potential for improving efficiency.

**CONCLUSION:** To our knowledge, DHELP is the first device to combine heat and anti-fog solution to definitively address the fogging problem. DHELP is also the first device specifically intended for white-balancing, protecting or cleaning the laparoscope during the procedure. By focusing on the most pervasive visualization problems, DHELP may significantly increase laparoscopic surgical efficiency.

## ETP052

### THE LAPAROSCOPIC VASCULAR TRANSILLUMINATOR: EFFICACY OF A BLOOD VESSEL IDENTIFICATION DEVICE USING INFRARED EMISSION DIODE, Kozo Konishi

MD,Kazuo Tanoue MD,Satoshi leiri MD,Shohei Yamagchi MD,Etsuko Kobayashi MD,Ichiro Sakuma MD,Takeyoshi Dohi MD,Makoto Hashizume MD, 1.Graduate School of Medicine, Kyushu University; 2. Graduate School of Information Science and Technology Medicine, The University of Tokyo

**Background:** In the laparoscopic surgery, because of the lack of tactile sensation, it is difficult to recognize and localize blood vessels intraoperatively. Especially in the surgery for obese or fatty patients, if we can identify the blood vessels which are buried among fat tissue and cannot be seen with normal laparoscopy, operative safety is expected to improve. The device which we applied mechanism of pulse oxymetry is newly developed for the detection and recognition of blood vessels in laparoscopic surgery. The purpose of this study was to investigate the performance and possibilities of the device.

**Method:** The device's performance and features were tested in ex vivo conditions and in simulated laparoscopic surgical conditions. We installed LED array in the back of a piece of meat buried with vascular model and photographed a transmitted light image with a CCD camera and analyzed by image processing software. We also evaluated the usefulness in vascular detection using organs of a pig.

**Results:** In ex vivo study with pieces of meat, the vascular detection up to 20mm in tissue thickness and up to 4mm in depth were possible. In animal study, the blood vessels which were invisible to the naked eye were detected with a transmitted light image by back irradiation of infrared LED array. The thickness of tissue which could arrow infrared transmission was up to 10mm.

**Conclusion:** The blood vessel detecting device that we had developed was feasible to be supplemented the lack of information on laparoscopic surgery, and to contribute to the improvement of the safety of laparoscopic surgery.

## ETP053

### EFFECTIVE APPETITE MANAGEMENT BY PROXIMAL GAS-TRIC ELECTRIC STIMULATION, B. A Zikria MD,Leaque

Ahmad MD,Joseph F Zikria BA,M Al-Sawwaf MD,Arthur Cooper MD, Harlem Hospital Medical Center, Columbia University, New York

Morbid obesity has become the third killer in the United States. $39 billion are spent for its treatment and another $38 billion dollars are spent for weight reduction annually.

**Objective:** The purpose of our device is to depress the appetite center by electric stimulation via gastric fundus (upper top) in deference to the earlier attempts of distal stomach (lower bottom) stimulations which have not been very effective.

**Methodology:** Research has supported the hypothesis that the afferent vagal stimuli from the stomach via the Nucleus Tactus Solitarius are relayed to the medial nucleus of satiety center in the hypothalamus which in turn depress the lateral nucleus of appetite center, thus turning off the appetite and achieving the state of satiety. Normally when an empty stomach is filled with air, fluid and food, distends and stretches more the fundic wall, the upper top with air, thus stimulating the stretch fundic receptors sending the message via left vagus to the hypothalamus to say, "I am full. I have to stop!"

**Preliminary Results:** Laparoscopic placement of two leads to the fundus of the stomach and stimulation with a pace maker in a hungry dog has given us impressive results. Further research is required to prove the validity of this hypothesis.

**Future Directions:** By such a method, if proven effective, we could achieve eating behavior modification with lasting weight loss results, less invasively and with less cost in lives and finances.

## ETP054

### ROBOTIC TELEPRESENCE OFFERS AN ALTERNATIVE PARA-DIGM FOR POST-RESIDENCY SURGICAL EDUCATION, Alex

Gandsas MD,John S Koppman MD,Christina Li MD,Stuart Shindel MD,Michael Schweitzer MD,Sergio Cantarelli MD,Gabriel Egidì MD, Sinai Hospital of Baltimore and Johns Hopkins Bayview Medical Center

**Introduction:** Traditional post-residency surgical training programs, which teach new procedures/techniques, are offered as didactic courses assisted by live video or as on-site preceptorship programs. This usually requires travel to an out of town facility that can be both time consuming and expensive. Using the RP7 robot (Intouch Health, Santa Barbara, USA) as a mobile, real-time telecommunication platform, the surgical education paradigm can be changed to one where actual attendance is replaced by robotic telepresence.

**Methods:** The system consists of a robotic unit placed in the operating room which is accessed remotely by the student using client software running on a Windows® based control station computer. The robot, equipped with a 15 inch flat screen, uses an advanced proprietary video conference system to access the public internet over a 802.11G wireless network. Video and audio stream from the robot is rendered by the client software in a 320 X 240 pixels window, with an encoding rate that ranges from 300 to 700 kilobits-per-second displaying video images up to 30 frames-per-second. This technology allows the student surgeon to log in to an operating room from his/her office and experience an individualized, on-site preceptorship of a given surgical procedure. Students watch live surgery, interact with an expert surgeon in real-time, and ultimately acquire the surgical knowledge necessary to meet surgical competency benchmarks for a given procedure/technique.

**Results:** From September 2006 to December, 2006 two laparoscopic surgeons in Bahia Blanca, Argentina logged in to a robot located in an operating room in Baltimore, USA and experienced customized preceptorships on laparoscopic gastric bypass. After completing a total of 19 sessions, the surgeons were expected to safely and independently perform a laparoscopic gastric bypass procedure at their own facility.
<figure><img src="image_217.png" /></figure>

# SAGES EMERGING TECHNOLOGY POSTER ABSTRACTS

**Conclusions:** By using robotic remote telepresence, barriers associated with traditional forms of education may be minimized while enhancing the educational experience by tailoring it to the students' needs in terms of content and timing. Widespread dissemination of this technology promises to change the paradigm for post-residency surgical education.

## ETP055

**COMPARISON OF TASK PERFORMANCE BETWEEN ARTICULATING AND CONVENTIONAL LAPAROSCOPIC INSTRUMENTS**, Prakash Gatta MD, Peter M Denk MD, Bin Zheng PhD, Lee L Swanstrom MD, Legacy Health System

**OBJECTIVE:** A new type of laparoscopic instrument was introduced recently with an ability to articulate the tip. While this instrument may offer the possibility of performing more complex tasks, the control of this instrument may be hampered by increased maneuverability. A study was designed to compare the task performance between the articulating instrument and conventional laparoscopic instruments. We also note that task performance on this new instrument may be a function of surgical experience. Tasks were therefore undertaken comparing two groups with distinct skill levels.

**DESCRIPTION:** Two teams of 8 each were tested based on skill level. One team had extensive surgical experience (surgeon) and the other with no experience (novice). Both groups were given 3 tasks to perform in a laparoscopic training box. The tasks were Peg transfer, left-right suturing & up-down suturing. Scoring on these tasks was based on movement speed and accuracy. These tasks and the scoring were adapted from the well validated Fundamentals of Laparoscopic Skills program. Both groups performed these tasks using conventional and articulating instruments. Novices and experts alike were then given a basic orientation on how to use the articulating instrument after which they were retested.

**RESULTS:** Not surprisingly the expert group scored significantly better than the novice group, (87 vs 53, p <0.001). Both groups combined, performed better with conventional instruments. However, after a basic orientation was given on use of the articulating instrument, the novice groups outscored the expert group in terms of net improvement of performance (47 to 59 for novice vs 81 to 80 for expert, p = 0.166). This was a 25% improvement in the novice group.

**CONCLUSIONS:** Articulating instruments can be used effectively by a surgeon experienced with use of conventional laparoscopic instruments. Adding flexibility to a laparoscopic tool did not degrade performance of surgical tasks in an expert group. Also, training using the articulating instrument can be started at an early stage of surgical training as lack of surgical experience does not affect the acquisition of new surgical skills using the articulating instrument. Further study is needed to determine the learning curve to achieving proficiency on the articulating instruments. An intriguing follow up to these studies would be to compare the performance of this flexible instrument to that of the surgical robot.

## ETP056

**MINIMALLY TRAUMATIC SUTURING DEVICE FOR LAPAROSCOPIC VENTRAL HERNIA REPAIR (LVHR)**, Brij B Agarwal MS, Krishna A Agarwal, Nayan Agarwal, Manish K Gupta MS, Sneh Agarwal, MS, Krishan C Mahajan MS, Sir Ganga Ram Hospital, Lady Hardinge Medical College & DPS, RK Puram, India

**BACKGROUND:** Transabdominal fixation of mesh in LVHR with a "suture passer" traumatizes parietal wall, pain at suture sites & significant morbidity. We propose to design a minimally traumatic instrument to pass sutures in laparoscopic surgery.

**DESIGN:** The instrument's Part-1 is 18 gauze metallic tube with a sharp tip to penetrate the abdominal wall through a skin puncture. A number 1 monofilament non absorbable suture can core through this tube to enter the peritoneal cavity from the skin puncture site. The tube is then withdrawn over the external portion of suture. Part-2, a 22 gauze stilet like rod with a flexible wire fused at its both ends to make a loose bow like a violin string. The sharp end of rod

goes through the abdominal wall with its wire loop. The intraperitoneal end of suture passed earlier is snared through the loop of part-2 and pulled out through the skin puncture site. The suture ends are now tied and buried in subcutaneous tissue. The skin puncture site doesn't need any closure. Trauma to parieties is negligible as only a needle like puncture is there. Pending production of this instrument we are using the same mechanism with the help of two spinal needles as explained in our paper on laparoscopic "Vest over Pant" closure of defect in LVHR.
(abstractID:14215)

**FUTURE DIRECTION:** This instrument ensures atraumatic suture fixation and ease of defect closure in LVHR.

<figure><img src="image_218.png" /></figure>

## ETP057

**OBJECTIVE MEASUREMENT OF FLS PRECISION CUTTING**

**TASK**, Derek Young, Fiona Slevin, Derek Cassidy, Donncha Ryan, Haptica Inc

The Precision-Cutting Task in the SAGES/ACS FLS Program requires the user to dissect a circle of specific size and shape from a marked piece of mesh.

Currently, measurement of the accuracy and area dissected is done by observation and by measuring the dissected mesh on a measurement grid.

Using advanced vision-tracking, the ProMIS surgical simulator takes an image of the dissected mesh and automatically generates a metric, indicating the accuracy of the shape and area dissected.

**Method**

1. Once the user has completed the Precision-Cutting Task, ProMIS takes an image of the dissected mesh. The image is converted to binary image and then scanned using a blob detection algorithm which produces a list of blobs.

2. The blob with the largest area is taken as the cut out area and the number of pixels are counted inside this area.

3. The actual measurement for area is given in cm². This is calculated by counting the number of pixels in a known area of the image and then using ratios to determine the area of the cut out. (Note: this calibration step is achieved by taking the tissue off the tray and running the blob detection and pixel count on the uncovered black foam of which the exact area is known)

<figure><img src="image_219.png" /></figure>

**Results:** Initial trials of the metrics on the FLS Precision-Cutting Task show that ProMIS is as accurate — and frequently more accurate — than the current human observation method.

## ETP058

**THE NOVEL USE OF SELF-EXPANDING, COVERED, PLASTIC ESOPHAGEAL STENTS (SEPS) IN THE MANAGEMENT OF BENIGN COLORECTAL ANASTOMOTIC STRICTURES,**

William J Peche MD, Kirsten B Wilkins MD, Kelly M Tyler MD, Theodore E Eisenstat MD, Gregory C Oliver MD, Joseph R Notaro MD, Daniel Simon* MD, Bertram T Chinn MD, Department of Colon and Rectal Surgery, UMDNJ-Robert Wood Johnson University Hospital, New Brunswick, NJ and \*Department of Radiology, Solaris Health Systems, Edison, NJ

**Purpose:** Colorectal anastomotic strictures occur in 3-30% of patients and carry significant morbidity including obstruc-
tion, fistula formation, and perforation. Treatment includes dilatation, stent placement, or surgery. Endoscopic dilatation is highly successful, but may be complicated by perforation and recurrent stricture. Reoperative surgery is usually successful, but it is not without morbidity and ostomy creation may be required. Self-expanding metallic stents (SEMS) have proven efficacy for malignant colorectal strictures, but are associated with tissue ingrowth and restenosis, and are considered permanent or are retrievable only by surgery. SEMS in benign disease is controversial, and may be associated with high complication rates. Retrievable SEPS have been developed and used in benign esophageal disease with low complication and high patency rates. We extrapolated the use of SEPS to treat benign colonic anastomotic strictures.

**Methods:** Two patients with strictures following diverticular resection had 3 SEPS placed. Each patient presented with obstructive symptoms due to stricture. Patient 1 was initially treated with endoscopic balloon dilatation followed by SEPS. Patient 2 required emergent hospitalization due to obstruction. CT demonstrated an anastomotic stricture/contained leak. This patient was initially treated with SEPS. In each case, SEPS were placed under endoscopic and fluoroscopic guidance.

**Results:** Initial successful placement was achieved in each patient without immediate complication. Both patients passed the SEPS spontaneously. Patient 1 passed the SEPS on the day of placement. One month later a second SEPS was successfully placed for a recurrent stricture. Patient 2 avoided emergent surgery for the obstruction/contained leak after SEPS placement. After 3 months, the stricture recurred and was successfully managed with endoscopic balloon dilatation.

**Conclusion:** We describe the novel use of SEPS for the relief of obstruction in two patients with benign colorectal anastomotic stricture without short-term complications. Due to the ease of placement and relief of symptoms, we advocate further studies to evaluate both short and long term complications and success of SEPS in benign colonic strictures. In select patients, SEPS may alleviate the need for redo surgery. Unlike SEMS, SEPS are potentially useful for the treatment of benign anastomotic strictures and fistulae due to their retrievable and covered nature.

## ETP059

**SURGICAL STAPLERS WITH MAGNETICALLY SECURED COMPONENTS**, Stephen Van Lue, DVM, DACVS, University of Copenhagen, Faculty of Life Sciences, Copenhagen, Denmark

**Background:** Surgical staplers in use today can be difficult to maneuver and position around tissue in many surgical applications. The necessity of having the anvil and cartridge components on opposing jaws, within a framework, or as separate components which must be manipulated by the operator to mechanically connect and align is problematic. Regarding circular staplers, the presence of the anvil rod limits mobility within the bowel lumen, and typically requires the hollow viscous to be perforated, as well as placement of a purse string suture, before the anvil and cartridge components are coupled.

**Objective:** The objective is to eliminate the use of opposing jaws, frames, anvil rods, and the necessity of purse string sutures in the use and application of surgical stapling devices.

**Description:** Magnetism may be utilized to provide a means of aligning and coupling stapler components across a tissue interface such that the components may be introduced from different access points (even dropped off endoscopically within a tissue space or lumen). With regard to circular staplers, the methods provide for an anvil without an anvil rod, and means of coupling components without the prior perforation of a luminal structure.

**Preliminary results:** Preliminary results in a porcine cadaver showed it was possible to fit the anvil portion of a circular stapler with a magnetic component, remove the anvil rod, place the anvil within the bowel, steer the anvil to a location with a magnetic laparoscopic probe, and connect the anvil to a stapler cartridge component across the bowel wall. The cartridge component was similarly fitted with a magnetic component.

**Conclusions:** The ability to deploy stapler components independently from one another, without the need for anvil rods, purse string sutures, or the use of opposing jaws and frames for alignment may have utility in the development of new, or refinement of existing, stapling procedures. Final mechanical alignment of the anvil and cartridge may take place after general alignment and coupling of the mechanically independent magnetic components. The methods may be applied to various tissue fixation devices apart from surgical staplers, including catheter based devices. The use of magnetic forces for the initial coupling and general alignment of these components, and transillumination as a targeting modality, may shorten procedural times, have value in reducing patient morbidity, and contribute to advancements in tissue stapling and repair.

## ETP060

**MAGNETIC OPTICAL SUTURING**, Stephen Van Lue, DVM, DACVS, University of Copenhagen, Faculty of Life Sciences, Copenhagen, Denmark

**Objective:** The objective of the technology is to enable the coaxial passage of a suture and needle across a tissue boundary, such that the needle may be captured on a "blind side" of the tissue, and then re-introduced at a desired location on the visible side of the tissue boundary, using a bead of light as a targeting modality.

**Description:** Using a columnar shaped magnetic element with a central lumen, an elongate surgical needle will tend to orient itself to the central lumen when brought proximate to the magnetic element. When on the blind side of a tissue interface, the central lumen of the magnetic element is utilized for the conduction of light, which serves as a targeting modality for both the introduction, and subsequent retrieval of the needle from the "blind side". In addition, the central lumen of the magnetic component may be utilized to pass suction, to stabilize the capture, or receiving component on a desired tissue plane.

**Preliminary results:** Depending on tissue thickness and magnetic field strength, the needle was oriented easily such that when the needle was urged toward the bead of light which was transilluminating the tissue, the needle oriented to the light, and the lumen of the magnetic component on the blind side of the tissue boundary was penetrated. In order to allow the needle to orient properly, the suture was held just behind the swedge point of the needle.

**Conclusions:** Magnetic optical suturing is plausible and facilitates coaxial suturing, blindly across a tissue boundary, as the respective components may be uncoupled - not necessarily relying on opposing jaws for passage and capture. The methods also have application on a larger scale for end-effector guidance - for example, inserting a laparoscopic instrument into a trocar without looking away from the video monitor. A relatively straight needle configuration was most effective, with modifications needed to enable the needle to be returned from the blind side of the tissue interface. The concepts may also enhance the application of minimally invasive suture techniques, where the suturing devices being utilized are currently limited to having the needle capture mechanism within the construction, or as part of, the opposing jaw of a single instrument.

## ETP061

**SUPPORT WHERE IT'S NEEDED: SMART ARM**, Stuart I Brown PhD, Ian Rutherford, University of Dundee, UK

**Objective:** An important role in endoscopic surgery is simply holding instrumentation: retractors or laparoscopes, for example. This may be done by a junior surgeon who is susceptible to fatigue, tremor and lapses of concentration. Some sort of assisting device may be employed, but these are often heavy, awkward, prone to slipping and difficult to sterilize. Most current assisting arms depend on friction to lock the arm in position. High forces are required in the mechanism to maintain this friction, particularly at the prox-
<figure><img src="image_220.png" /></figure>

SAGES EMERGING TECHNOLOGY POSTER ABSTRACTS

imal end, and any slippage results in scratches – a haven for
infective organisms. Adjustment is usually made using
knobs or levers.

The objective of the Smart Arm is a light, strong and use-
able assisting device with modular construction, suited to
various surgical uses.

**Description of the technology:** The Smart Arm avoids the pitfalls of friction by using a number of modular units with interdigitating features. The units may be assembled to create arms in any configuration required by the procedure. Adjustment of the joints may be made manually or, by using an optional simple pneumatic actuator, at the push of a button.

An optional distal joint uses a clamped ball and socket, again operated either manually or by pneumatics. Activation and release of the clamp has been automated with a touch sensor. This permits free motion of the surgical instrument when grasped by the surgeon, but locks in position immediately upon release. This functionality may be particularly useful for holding laparoscopes, for example, where frequent changes in position are required.

The entire system clips together without tools and is manu-
factured from lightweight materials. Tear-down for cleaning
or re-configuration is easily accomplished. The pneumatic
"tube actuator" is disposable.

**Preliminary results:** A 6 DoF Smart Arm system weighs 1.20 kg and will easily support an applied torque of 10Nm, while an equivalent system used at our Institution weighs 1.95kg but cannot support more than 1.5Nm. The tube actuator and touch sensor mechanisms work faultlessly.

Using interdigitating joints means that the arm is limited to
discrete positions. In practise however, even a 4DoF arm
offers eight hundred and ten thousand alternative positions,
so this presents no problem in use.

**Conclusions/Future directions:** The prototype Smart Arm continues to be evaluated in our training facility. The IP is protected by patent application.

ETP062

NEW CURRICULUM FOR ACQUIRING “SURGICAL SKILLS”
USING VIRTUAL REALITY SURGICAL SIMULATION., S
Ivanova MD,N Iqbal,T Albrani,B Patel, Academic Department
of Upper GI Surgery, Barts and The Royal London School of
Medicine and Dentistry. Queen Mary, University of London.
Institute of Cancer, Old Anatomy Building, Charterhouse
Square, London, United Kingdom, EC1M 6BQ.

**Objective of the Technology or Device:** Taking time-off surgical training in order to do a research for higher degree has always been accompanied with apprehension due to lack of contact with clinical work and deterioration of surgical skills. To date most academic centers offer limited exposure to clinical work during the research period. Surgical skills during and at the end of the research period are seldom assessed and if so had been shown to deteriorate. We designed this curriculum in order to afford the candidates opportunity to develop technical skills by simulation in Diagnostic Endoscopy, Laproscopic surgery and Intestinal Anastomosis during the research period.

**Description and Methods:** 10 students enrolled in a newly developed, intensive one year MSc course for surgical training, by simulation and research programme at Barts and The Royal London Hospital – Queen Mary University of London. In the course of the first six months the students were allocated to spend on an average 4 hours per week acquiring technical skills on simulators for Endoscopy and Laproscopic Skills and synthetic bowel for practicing bowel anastomosis. The remaining six months were focused on research activities for the MSc. Computer generated data of objective assessment obtained from Simbionix Lap-Mentor and GI-Mentor during the training period was retrieved at the end of the study period for analysis. Data was analysed by SPSS15 statistical package.

**Preliminary Results:** 10 MSc students training on simulators spent on an average 4 hours per week acquiring technical skills to perform Diagnostic Endoscopy and Laparoscopic Cholecystectomy. One of the criteria for successfully completing MSc was safely performing a Laparoscopic

Cholecystectomy on a simulator, which was observed by
experienced internal and external examiner. In addition all
the participants successfully completed the course.

**Conclusions/Future Directions:** The combination of Research and Virtual Reality Training, that this intensive 1 year MSc course offers is a unique opportunity for acquiring surgical skills on simulators and completing research for Higher degree.

ETP063

DEVELOPMENT OF SIMULATION FOR PRACTICING
LAPAROSCOPIC HERNIA REPAIRS AND GASTRIC BYPASS,
Yael Friedman PhD, Simbionix Corp.

Simbionix has developed two new modules of simulation enabling the real-time interactive practicing of Laparoscopic Hernia Repairs and Gastric Bypass. The modules will be add-on to the LAP Mentor, multi-disciplinary LAP surgery simulator enables simultaneous hands-on practice for a single trainee or a team. Simbionix Laparoscopic Incisional Hernia Repair module allows surgeons to perform a Hernia Repair procedure in a safe, controlled, real-life simulated environment. The module is designed to train surgeons with the necessary skills required to perform laparoscopic hernia repairs procedures, including adhesiolysis and handling and fixating intraperitoneal prosthetic mesh in a choice of shapes and sizes. It includes a variety of Hernia Repair Procedures in real-life scenarios. Surgeons perform simulated surgical procedures to treat a variety of hernia pathologies such as umbilical, periumbilical and epigastrium hernia. This virtual experience provides clinicians with an essential tool for practicing on realistic environment, using actual tools and choosing from a selection of mesh types and sizes. Additionally, the module provides a complete virtual environment of the external maneuvers required to learn and assess the principles of port placement, followed by the insertion and operation of the suture passer, that are unique to the incisional hernia repair procedure. The module features tools to measure skills assessment and training success. During the training session, all data is recorded and presented in a file. Important procedure information such as choice of mesh handling, safe dissection and complication management are measured during the session in order to assess skill levels. Simbionix Gastric Bypass module helps surgeons in performing and mastering the specific tasks of this procedure in a safe and monitored environment. This module provides real-life visual and tactile simulation of the key stages of the Gastric Bypass procedure: simulations of internal organs and bodily fluids, manipulation of tools and tool-organ interaction and deformation, including tissue cutting and anastomosis using a linear cutter. It also features an assisting tool that allows the introduction of three or even four instruments into the scene at once. The user is guided, case by case, through the entire gastric bypass procedure- creation of the gastric pouch, measurement and division of the jejunum, gastrojejunal anastomosis and enteroenterostomy anastomosis. A full array of virtual surgical instruments duplicates the activity and sensation of manipulating instruments in the various stages of the procedure. Video clips of the actual procedure are accessible throughout the simulation.

ETP064

ANTIMICROBIAL NANOPARTICLE SURFACE FUNCTIONAL-
IZATION TO PREVENT BIOFILM FORMATION ON MEDICAL
DEVICES, Roger Massengale, Bruce Gibbins PhD, Alan Dine
BS, I-Flow Corporation, Acrymed Inc.

**Background and Objective:** Surgical site infections (SSI) impart a heavy financial burden, costing U.S. hospitals in excess of $1.5 billion in additional medical treatment. The surfaces of medical devices do not normally have any inherent resistance to microbial colonization. The use of a novel process that causes the formation of nanoparticles of silver on the surface of a Soaker® Catheter used for the continuous administration of regional anesthesia to surgical wounds may reduce the risk of SSI.

**Technology and method of Application:** This new technology is a wet immersion process whereby medical devices are
submerged in an aqueous mixture of ionic silver salt, stabilizers. The addition of a catalyst initiates the formation of nanoparticles of silver that grow and bind tightly to the surface. The Soaker catheters are exposed to this process to impart antimicrobial properties due to the release of ionic silver through oxidation of the nanoparticles.

**Results.** Soaker catheters were treated to a range of 6-10 µg Ag/cm2. The silver was in the form of mono-dispersed 10 nm diameter nanoparticles. Microbial challenge testing showed the catheters possessed equivalent antimicrobial activity on both the external surface and lumen. Treated catheters showed 3 log reduction of bacterial counts after 10 days of saline elution. Testing against 6 strains each of 6 types of clinical isolates showed that the treated surfaces prevented biofilm formation. A biodistribution study in mice showed the majority of silver stayed either on the catheter or local skin site and that none accumulated in tissues.

**Conclusion.** Continuing investigation of the biology of infection at the surgical site and methods of prevention may allow us to further reduce the frequency, cost, and morbidity associated with SSI. This wet immersion technology is a novel method for deposition antimicrobial silver nanoparticles to the surface of a Soaker catheter used to deliver continuous incisional pain management. Nanoparticles serve as an ideal reservoir for sustained release of sufficient silver to prevent biofilm formation. This technology platform has been successfully commercialized in the ON-Q® PainBuster regional anesthesia delivery device.

## ETP065

### RADIOFREQUENCY ASSISTED LAPAROSCOPIC LIVER

**RESECTION: INITIAL EXPERIENCE WITH THE LAPAROSCOPIC HABIB DEVICE**, Alejandro Mejia MD, Stephen Cheng MD, THE LIVER INSTITUTE - METHODIST DALLAS

**INTRODUCTION:** The laparoscopic approach for resection of liver tumors is a technique in evolution. A limiting factor for wider applicability of the procedure has been the lack of efficient tools for parenchymal transection. The Habib device has offered new options in open resections and a newly released laparoscopic variation of the instrument has been tested at our center. **METHODS:** Five patients underwent a hand-assisted laparoscopic liver resection using the laparoscopic Habib device.

### RESULTS

<table><thead><tr><th>Patient #/AGE</th><th>Lesion/Location</th><th>EBL(cc)/OR time</th><th>LOS (days)</th></tr></thead><tbody><tr><td>1/64</td><td>Hemangioma/Rt I</td><td>500 / 342 min</td><td>4</td></tr><tr><td>2/48</td><td>FNH/Left lobe</td><td>200 / 381 min</td><td>4</td></tr><tr><td>3/47</td><td>FNH/Left lobe</td><td>250 / 248 min</td><td>2</td></tr><tr><td>4/52</td><td>FNH/Rt Lobe</td><td>600 / 432 min</td><td>3</td></tr><tr><td>5/37</td><td>Abscess/R lobe</td><td>200 / 411 min</td><td>3</td></tr></tbody></table>

**CONCLUSION:** The new laparoscopic Habib device offers a promising alternative for a safe parenchymal transection during laparoscopic liver resection cases. In our preliminary limited experience, the best results with the device are obtained when used in combination with a saline-enhanced electrocautery and endo-stapling techniques. Larger series may be warranted to maximize the safety of the laparoscopic approach for liver lesions.

## ETP066

### TEMPORARY STENT PLACEMENT AFTER COLORECTAL ANASTOMOSIS USING POLYFLEX SYSTEM: AN ANIMAL

**MODEL**, Zurab Tsereteli MD, Tim M Geiger MD, Christopher Edwards MD, Sharon Backman MD, Nitin Rangnekar MD, Brent Miedema MD, Klaus Thaler MD, University of Missouri-Columbia, Columbia, MO, Department of General Surgery

**Background:** The anastomotic leak rate after colorectal surgery continues to be clinically relevant. It goes further up with chemoradiation, low anterior resection and surgery for colorectal emergencies. Creation of a protective stoma requires a two-stage procedure with its intrinsic morbidity and increased costs. A temporary stent could protect anastomosis and eliminate the need for diverting stoma.

**Objective:** Test the feasibility and efficacy of temporary self-expanding covered stent to protect healing of a colorectal

anastomosis in an animal (porcine) survival model.

**Methods:** 12 adult pigs (80-120lbs) were used for this study. Under general anesthesia, all animals underwent an open transection of the rectum 15-20cm above the anal verge followed by reanastomosis with a 21mm circular stapler. Each animal then underwent endoscopic or fluoroscopic placement of a 21mm Polyflex self-expandable covered plastic stent with 25mm proximal flare and 12cm length. Stent placement was standardized with equal distance on both sides of the anastomosis. In the first 4 animals (Group A) anastomosis was left intact, but two of the stents were secured with 3 chromic sutures at the proximal end; in Group B (8 pigs), 1-2cm leak was created along the anterior portion of the anastomosis, and all stents were secured with 3 non-absorbable sutures. The animals were sacrificed after 2 weeks.

**Results:** In Group A, two pigs w/o suture fixation expelled stents on POD1 and the other 2 with chromic sutures sometime between POD3-14. All anastomotic sites were well healed. In Group B, one pig with 1cm leak was sacrificed on POD8 due to wound dehiscence; the stent was still in place and no clinical signs of leakage. Another pig with 2cm leak was sacrificed on POD7 because of bladder necrosis of unknown etiology; the stent was in place with remaining anastomotic defect <5mm. All other pigs from Group B expelled their stents between POD6 and 9. At necropsy, all anastomoses were healed clinically and none of the animals had signs of intrabdominal infection or fistula formation.

**Conclusion:** Preliminary data suggest that placement of a removable endoluminal covered stent across colorectal anastomosis is technically feasible and can be very efficient to protect anastomosis if stays in place until completion of the healing phase. Migration is most likely due to forceful physiologic peristalsis in this region. Further investigation needs to focus on improvement in fixation and stent design.

## ETP067

### PRELIMINARY RESULTS UTILIZING A BIOABSORBABLE OMEGA-3 FATTY ACID COATED LIGHTWEIGHT POLYPROPYLENE MESH FOR OPEN AND LAPAROSCOPIC VENTRAL

**AND INGUINAL HERNIA REPAIR**, Richard A Pierce

MD, Margaret M Frisella RN, Laura M Todt BS, Brent D Matthews MD, Washington University School of Medicine and Institute for Minimally Invasive Surgery, Saint Louis, Missouri, USA

**Introduction:** The purpose of this preclinical market outcomes study is to evaluate an FDA-approved, bioabsorbable omega-3 fatty acid coated lightweight polypropylene mesh (C-QUR, Atrium Medical Corp., Hudson, NH) for open and laparoscopic ventral and inguinal hernia repair. This novel, bioabsorbable adhesion barrier remains intact for more than 90 days, eventually undergoing hydrolysis in vivo, with conversion to naturally occurring components and resulting in absorption by local tissues and consumption via normal lipid metabolism.

**Methods:** The records for patients undergoing laparoscopic or open ventral or inguinal hernia repair with C-QUR mesh from May 2006 through December 2006 were evaluated. The type of hernia, technique for repair and short-term follow-up (4 - 8 weeks) were recorded. All handling and implantation characteristics were rated by the participating surgeons.

**Results:** Preliminary results from this multi-institutional study are based on 129 patients with 122 ventral/incisional hernias and 7 inguinal hernias. Twenty-six (20.2%) patients were treated for recurrent hernias. Laparoscopic hernia repair was performed in 88 patients and open hernia repair in 41 patients. Ninety-two (71.3%) patients have completed an 8 week follow-up visit. Seromas developed in 24 (26.1%) patients, hematomas in 2 (2.2%) patients, and wound infections in 8 (8.7%) patients. Six (6.5%) patients were still requiring treatment for postoperative pain. There were no recurrences. Surgeons rated the mesh to meet or exceed expectations when compared to commercially available meshes in regard to rolling the mesh and passing it through a trocar, unraveling the mesh after laparoscopic intra-abdominal placement, enhanced visibility through the mesh
<figure><img src="image_221.png" /></figure>

SAGES EMERGING TECHNOLOGY POSTER ABSTRACTS

while positioning/fixating, and manipulation and/or confor-
mation to position in 99%, 93%, 98%, and 96% of cases,
respectively. The textured side was distinguishable from the
smooth side during positioning in 94% of cases.

**Conclusion:** Preliminary results demonstrate this novel, bioabsorbable adhesion barrier coated lightweight polypropylene mesh is safe and effective in short-term follow-up with favorable handling and implantation characteristics compared to other currently marketed meshes in this clinical market evaluation.

ETP068

TWIN INPUT INSUFFLATOR, Krishna A Agarwal, Brij B Agarwal MS,Nayan Agarwal,Sneh Agarwal MS,Krishan C Mahajan MS, Sir Ganga Ram Hospital , Lady Harding Medical College & DPS-RKPuram, India

**BACKGROUND** - We do not use energy sources as a mandatory routine in laparoscopic surgery. We keep them as "stand by" for control of bleeding. Peritoneal insufflation is synonymous with capno-peritoneum. Carbon di-oxide is used for its anti-combustion property.

**TECHNOLOGY DESIGN** - We do not use energy sources routinely but keep them ready for any need. We would like to study the feasibility of using air or nitrous oxide in place of carbon dioxide. We propose to have an insufflator that can handle two gases simultaneously at the input level. The output option should be available to the surgeon. He should be able to switch between two gases. This can be achieved with a Y-attachment at the input. The two open stems of "Y" can take inon gas each i.e. air/nitrous oxide and carbon dioxide. The stem of "Y" can feed the output. The output can have a lever-switch to enable the flow of either gas, one at a time.This will allow the surgeon to operate under nitro/aero-peritoneum as long as he is not using energy sources like electrosurgery. If the surgeon needs to use the energy source he can shift to capno-peritoneum by moving the lever-switch to put on the required gas.The twin input insufflator should have a ligned indicator to show the gas being supplied at the output and being used. The indicator lights should follow the colour codes of the gases. It will add to its advantage if the utflow control switch is in the sterile zone and operable by the operating surgeon. This machine will help the surgon avoid or limit the insult from capno-peritoneum and its related physilogical disturbances.

**FUTURE DIRECTION / CONCLUSION** - Development of a dual input insufflator with a selective output will help in avoiding the harmfull effects capno-peritoneum.

ETP069

TRANSGASTRIC ENDOSCOPIC DIAGNOSTIC PERITO-
NEOSCOPY IN HUMANS, Jeffrey W Hazey MD, Scott Melvin
MD,Vimal K Narula MD,Peter Muscarella MD, Christopher
Ellison MD, The Ohio State University

**Objective:** Natural Orifice Transluminal Endoscopic Surgery (NOTES) has been proposed as a possible advancement for surgical interventions. We initiated a pilot study in humans to investigate the feasibility and develop the techniques and technology necessary for this type of surgery. Reported herein, is the first human clinical trial of NOTES, performing diagnostic peritoneoscopy via the transgastric route.

**Methods:** Patients participating in this IRB approved human trial were scheduled to undergo diagnostic laparoscopy for evaluation of presumed pancreatic cancer. The findings of traditional laparoscopy were compared to that of transgas- tric endoscopic peritoneoscopy after diagnostic evaluation of the abdomen was performed by a second surgeon, blind- ed to the previous findings, using an orally placed gastro- scope. Diagnostic findings, operative times and clinical course were recorded. Definitive care was rendered based on the findings of standard laparoscopy.

**Results:** Ten patients have completed the protocol with an average age of 67.6 years. All patients underwent diagnostic laparoscopy followed by successful transgastric access and diagnostic peritoneoscopy. The average time of diagnostic laparoscopy was 12.3 minutes compared to 24.8 for the transgastric route. Transgastric abdominal exploration cor- roborated traditional laparoscopic intra abdominal findings

in 9 of 10 patients. Peritoneal or liver biopsies were
obtained in 4 patients by traditional, and in 1 patient by
transgastric access routes. Nine patients underwent pancre-
aticoduodenectomy and one underwent palliative gastroje-
junostomy.

**Conclusions:** This study demonstrates the feasibility of a transgastric approach to diagnostic peritoneoscopy. Technical issues, including visualization, intraabdominal manipulation and gastric closure need further development. Advances in instrumentation and experience are necessary before recommending NOTES for routine human therapeu- tic interventions.

ETP070

GUIDELINE FOR CHOLECYSTECTOMY BY NOTES, Kiyoshi Hashiba PhD, Sergio Roll PhD, Marco A D'Assuncao MD,Pablo R Siqueira MD, Hospital Sirio Libanes, Gastrointestinal Endoscopy Unit, Sao Paulo, Brazil

**Objective:** the study was conducted in experimental sessions to find a way to perform a successful and totally endoscopic transgastric cholecystectomy by NOTES technique.

**Description of the technology and method of its use or application:** nine experimental sessions were conducted using different places and different techniques to perform the stomach perforation, its closure, and the cholecystectomy complemented by gallbladder removal through the stomach. The hot biopsy forceps and the probe for cystostomy were used for the gallbladder and the cystic duct dissection. One Maryland forceps was placed in the right upper abdomen. A 0,035-wire guide and a dilation balloon to treat biliary ducts stenosis allow to obtain the cholangiography. The closing of the gastric wall was performed using endoscopic clips placed after the presentation made by a foreign body extraction endoscopic forceps and an end adapter for the endoscope. The conventional one working channel endoscope was used.

**Preliminary results:** after nine experimental sessions with pigs the results allow us to bring up some viewpoints and suggestions. The preferential point in the stomach to gain access to the peritoneal cavity, to perform the procedure was the anterior wall of the gastric antrum. It allowed making the operation with a not-inverse image and always placing the endoscope distal end just near the gallbladder. The endoscopic accessories used allow performing the management of the organ, but they have to be improved or new instruments must be created, like aspirator and devices to grab the stones. A bag to keep the organ and an extractor will be fundamental in most cases. It is possible to close the gastrotomy with clips, but the placement of the devices is not easy when the perforation is in the gastric distal part. A local previous suture was desirable in this situation. Despite the visual absence of air or secretion from the stomach to the abdominal cavity, a local fence around the endoscope was planned.

**Conclusions/Future directions:** The transgastric endoscopic surgery is a new and involving approach that will require the cooperation of endoscopists and surgeons. The NOTES cholecystectomy is feasible with few desirable devices. The procedure would not lose the endoscopic characteristics and advantages due to the placement of only one transabdominal forceps.

ETP071

ANALYSIS OF PARAMEDIAN ABDOMINAL WALL DEFECTS
FOLLOWING INTENTIONAL ACCESS CANNULA MANIPULA-
TION IN SWINE, Rich Schiretz MS, Steve Izzo BS, Greg
Okoniewski BS, Russell Heinrich PhD, United States Surgical,

**Introduction/Objective:** After laparoscopic surgery, the size of the body wall defect left by trocars is thought to be positively correlated to herniation rate and is often used clinically to determine whether fascial closure is necessary. The rationale for analyzing size and character of the body wall defects was to develop a method of reliably quantifying the abdominal fascial sheath defect left by (1) the trocar - size, shape, bladed vs bladeless and (2) manipulation of the indwelling cannula.
SAGES EMERGING TECHNOLOGY POSTER ABSTRACTS

**Materials and Methods:** Various bladed and bladeless 12mm and 15mm trocars with ribbed cannulas were inserted using direct visualization in designated subcostal regions along the insufflated abdominal wall of female swine. Dilating tips were removed and cannulas were manipulated over a 3 hour period. Desufflation was then performed under anaesthesia. Cannulas were removed. Abdominal wall tissue preparation included euthanization, tissue excision with unhindered normal contraction, and preservation in formalin under no tension. Both anterior and posterior fascial defects were carefully exposed. Digital images were taken of the exposed defect sites and analyzed further using AxioVision LE 4.2 software for quantification of defect cross sectional area.

**Results:** Amongst device groups, preliminary data suggest no significant difference in anterior rectus sheath defects

(ANOVA (P>0.05). Differences between 12mm Excel clocking versus 12mm Excel no clocking and 15mm Prototype Radial Dilating Cannulas (PRDC) are noted in the posterior transverse sheath defects. (ANOVA (P<0.05).

**Conclusion/Future Direction:** This study demonstrates that tissue harvesting, sectioning and digital imaging are promising methods for measuring abdominal defect size. Preliminary data show that 15mm PRDC create similar ( anterior) and significantly smaller (posterior) defects vs 12mm device(s). Future studies will involve similar evaluations including real time defect analysis, chronic defect healing, and histopathological studies to better understand the clinical need for fascial closure and differentiating defects related to various trocar dilating tip and cannula designs.

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SAGES 2007