Methods and apparatuses for full-thickness hollow organ biopsy

A method for obtaining a full thickness biopsy of the wall of a hollow organ, comprising obtaining an apparatus comprising a cannula comprising a proximal cannula end comprising a cutting edge; and a distal cannula end comprising a biased spring, the biased spring being coupled to a needle carrier and a releasable lock; and a needle disposed within the cannula and carried on the needle carrier, the needle comprising: a tip; a flange; a notch portion comprising a notch thickness; and a shaft comprising a shaft thickness; where the shaft thickness is greater than the notch thickness and the releasable lock is configured to hold the cannula in a withdrawn position relative to the needle; obtaining a patient having skin, a first wall, and a second wall; creating an incision through the skin of the patient; inserting the apparatus into the incision; advancing the apparatus through the first wall and the second wall; withdrawing the cannula relative to the needle; locking the cannula with the releasable lock; aligning the notch portion such that the notch portion straddles the second wall; releasing the releasable lock such that the cutting edge of the cannula passes completely through the second wall creating a full-thickness biopsy; and withdrawing the apparatus from the patient.

FIELD OF THE INVENTION

This invention relates generally to field tissue sample collection. Specifically, methods and apparatuses for taking tissue samples from hollow organs are disclosed.

BACKGROUND

Current designs for biopsy guns for soft tissue applications use a cutting cannula to collect the tissue sample. The most commonly used method has the cannula sliding over a stable or retracting inner needle which contains a notch for collection of the tissue. The cannula is a hollow cylinder with a sharp leading edge. These designs are oriented toward solid soft tissues (e.g., liver, prostate) and tumors that arise from them.

Current methods and devices for obtaining soft tissue samples from hollow organs (e.g., stomach, intestines) require laparoscopy or laparotomy. These methods and devices often fail to collect the portions of interest in the target organ. In addition, these methods and devices have a high perforation rate, leading to patient injury and increased healing time. The following are incorporated by reference:“Percutaneous endoscopically assisted transenteric full-thickness gastric biopsy: initial experience in humans.” Andrews C N, Mintchev P, Neshev E, Fraser H F, Storr M, Bathe O F, Urbanski S J. Gastrointest Endosc. 2011 May; 73(5):949-54. Epub 2011 Mar. 9.“The London Classification of gastrointestinal neuromuscular pathology: report on behalf of the Gastro 2009 International Working Group.” Knowles C H, De Giorgio R, Kapur R P, Bruder E, Farrugia G, Geboes K, Lindberg G, Martin J E, Meier-Ruge W A, Milla P J, Smith V V, Vandervinden J M, Veress B, Wedel T. Gut. 2010 July; 59(7):882-7“Absence of the interstitial cells of Cajal in patients with gastroparesis and correlation with clinical findings,” J Gastrointest Surg, 2005; 9(1):102-8, Forster J, Damjanov I, Lin Z, Sarosiek I, Wetzel P, McCallum R W.“A deficiency of gastric interstitial cells of Cajal accompanied by decreased expression of neuronal nitric oxide synthase and substance P in patients with type 2 diabetes mellitus,” J Gastroenterol, 2006; 41(11):1076-87, Iwasaki H, Kajimura M, Osawa S, Kanaoka S, Furuta T, Ikuma M, Hishida A.“Distribution of interstitial cells of Cajal and nitrergic neurons in normal and diabetic human appendix,” Neurogastroenterol Motil, 2008; 20(4):349-57, Miller S M, Narasimhan R A, Schmalz P F, Soffer E E, Walsh R M, Krishnamurthi V, Pasricha P J, Szurszewski J H, Farrugia G.“Remodeling of networks of interstitial cells of Cajal in a murine model of diabetic gastroparesis,” Diabetes, 2000; 49(10):1731-9, Ordog T, Takayama I, Cheung W K, Ward S M, Sanders K M.“Diabetic gastroparesis,” N Engl J Med, 2007; 356(8):820-9, Camilleri M.“Evaluation of endoscopic approaches for deep gastric-muscle-wall biopsies: what works?” Gastrointest Endosc, 2008; 67:297-303, Rajan E, Gostout C J, Lurken M S, et al.“Endoscopic ‘no hole’ full-thickness biopsy of the stomach to detect myenteric ganglia,” Gastrointest Endosc, 2008; 68:301-7, Rajan E, Gostout C J, Lurken M S, et al.

SUMMARY

One embodiment of the invention comprises a biopsy collection apparatus comprising a cannula comprising a proximal cannula end comprising a cutting edge, and a distal cannula end comprising a biased spring, the biased spring being coupled to a needle carrier and a releasable lock; and a needle disposed within the cannula and carried on the needle carrier, the needle comprising: a tip, a flange, a notch portion comprising a notch thickness, and a shaft comprising a shaft thickness, where the shaft thickness is greater than the notch thickness and the releasable lock is configured to hold the cannula in a withdrawn position relative to the needle.

In certain embodiments, the flange is angled away from the tip. In other embodiments, the flange is angled toward the tip. In still further embodiments, the notch portion further comprises graduated markings.

Another embodiment comprises a biopsy collection apparatus comprising a cannula comprising a proximal cannula end comprising a cutting edge and a distal cannula end comprising a biased spring coupled to a needle carrier and a releasable lock; and a needle disposed within the cannula and carried on the needle carrier, the needle comprising: a guide portion having a guide thickness, a tapered portion, and a shaft portion having a shaft thickness, where the shaft thickness is greater than the guide thickness and the releasable lock is configured to hold the cannula in a withdrawn position relative to the needle.

Some embodiments comprise a method for obtaining a full thickness biopsy of the wall of a hollow organ, comprising obtaining an apparatus comprising a cannula comprising a proximal cannula end comprising a cutting edge; and a distal cannula end comprising a biased spring, the biased spring being coupled to a needle carrier and a releasable lock; and a needle disposed within the cannula and carried on the needle carrier, the needle comprising: a tip; a flange; a notch portion comprising a notch thickness; and a shaft comprising a shaft thickness; where the shaft thickness is greater than the notch thickness and the releasable lock is configured to hold the cannula in a withdrawn position relative to the needle; obtaining a patient having skin, a first wall, and a second wall; creating an incision through the skin of the patient; inserting the apparatus into the incision; advancing the apparatus through the first wall and the second wall; withdrawing the cannula relative to the needle; locking the cannula with the releasable lock; aligning the notch portion such that the notch portion straddles the second wall; releasing the releasable lock such that the cutting edge of the cannula passes completely through the second wall creating a full-thickness biopsy; and withdrawing the apparatus from the patient.

Other embodiments comprise a method for obtaining a full thickness biopsy of the wall of a hollow organ, comprising: obtaining an apparatus comprising: a cannula comprising: a proximal cannula end comprising a cutting edge; and a distal cannula end comprising a biased spring coupled to a needle carrier and a releasable lock; and a needle disposed within the cannula and carried on the needle carrier, the needle comprising: a needle tip; a guide portion having a guide thickness; a tapered portion; and a shaft portion having a shaft thickness; where the shaft thickness is greater than the guide thickness and the releasable lock is configured to hold the cannula in a withdrawn position relative to the needle; obtaining a patient having skin, a first wall, and a second wall; creating an incision through the skin of the patient; inserting the apparatus into the incision; advancing the apparatus through the first wall; withdrawing the cannula relative to the needle; locking the cannula with the releasable lock; tenting the second wall with the needle tip; releasing the releasable lock such that the cutting edge of the cannula passes completely through the second wall creating a full-thickness biopsy; and withdrawing the apparatus from the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are “coupled” may be integral with each other. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The terms “substantially,” “approximately,” and “about” are defined as largely but not necessarily wholly what is specified, as understood by a person of ordinary skill in the art.

The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method that “comprises,” “has,” “includes” or “contains” one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps. Likewise, a connector that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those elements. For example, in a needle comprising a tip and a notch portion, the needle includes the specified elements but is not limited to having only those elements. For example such a needle could also comprise graduated markings.

The term “patient” may include any human patient or any animal patient with hollow organs.

While exemplary embodiments of the present invention have been shown and described in detail below, it will be clear to the person skilled in the art that changes and modifications may be made without departing from the scope of the invention. As such, that which is set forth in the following description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined by the following claims, along with the full range of equivalents to which such claims are entitled.

In addition, one of ordinary skill in the art will appreciate upon reading and understanding this disclosure that other variations for the invention described herein can be included within the scope of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present disclosure are directed to methods and apparatuses for obtaining a full-thickness biopsy in a hollow organ. Current methods and devices for obtaining soft-tissue samples do not allow a user (e.g. a surgeon) to access all portions of a hollow organ.

For example, in some instances a surgeon may desire access to the enteric nervous system of the stomach. Because the enteric nervous system lies within the myenteric plexus between the muscle layers of the stomach, it is not accessible by standard biopsy forceps. Thus, tissue must be obtained by laparoscopy or laparotomy, procedures that are more invasive than a biopsy. In addition to being more invasive than biopsies, laparoscopic and laparotomic procedures are also more likely to puncture the stomach wall, leading to increased incidents of injury and potentially extending patient recovery time.

Turning now to the figures,FIG. 1illustrates one embodiment of a biopsy collection apparatus10with the cannula in the cocked position. Apparatus10comprises a cannula20which surrounds an inner needle30. Needle30and cannula20are configured to move relative to one another for the collection of a tissue sample.

Cannula20is hollow and substantially cylindrical in shape, and comprises a proximal end22and a distal end26. Proximal end22is configured to be inserted into an incision made in the skin of a patient (not shown). Proximal end22comprises a cutting edge24that is configured to cut through the tissue of a target organ. In some embodiments, cannula may be a 14-gauge or a 12-gauge cannula.

In the illustrated embodiment, cannula20comprises a needle carrier50, a biased spring52, and a releasable lock54, all located at distal end26. Shaft38of needle30is coupled to needle carrier50. Releasable lock54is configured to hold biased spring52in a cocked position. Biased spring52may comprise any suitable elastic material, including but not limited to alloyed metals or elastic polymers. When apparatus10is cocked, needle30is advanced from cannula20and cannula20is withdrawn relative to needle30. Releasable lock54may be engaged to release cannula20, placing apparatus20in an uncocked position. When apparatus10is in an uncocked position, notch portion36of needle30is withdrawn into cannula20, and cannula20is advanced relative to needle30.

Needle30is disposed within cannula20such that each moves relative to the other. Needle30comprises a tip32configured to puncture tissue walls (e.g., a patient's abdominal wall or stomach wall). Needle30comprises a notch portion36comprising a notch thickness46and a shaft portion38comprising a shaft thickness48, with shaft thickness48being greater than notch thickness46. Notch portion36is defined on one end by a flange34. In the embodiment shown, flange34is angled toward tip32of needle30, forming an obtuse angle between flange34and notch portion36. As shown in the illustrated embodiment, flange34may be contoured to allow for repositioning of needle30after apparatus10is cocked but before cannula20is fired.

Turning now toFIG. 2, an alternative embodiment of apparatus10is shown. In most respects, the embodiment depicted inFIG. 2is equivalent to the embodiment depicted inFIG. 1. One difference in the embodiment shown inFIG. 2is the angle of flange34: in the embodiment shown inFIG. 2, flange34is angled away from tip32of needle30, such that an acute angle is formed between flange34and notch portion36. This is so because in some applications, the target tissue may slide off notch portion36when cannula20is fired. In embodiments where flange34faces rearward, the target tissue is more likely to stay in place. In some embodiments, flange34may comprise a sharp edge. In still other embodiments, flange34may be such that a right angle is formed between flange34and notch portion36.

In certain embodiments, other mechanisms may be used to store potential energy instead of biased spring52and releasable lock54. For example, a shape memory alloy configured to rapidly advance cannula20toward tip32of needle30may be used. Or pneumatic or electro-mechanical actuators may be used to withdraw and advance cannula20relative to tip32of needle30.

Still other embodiments may omit releasable lock54. In such embodiments, an operator (such as a surgeon) may withdraw cannula20relative to needle30, hold it in place by hand, then release cannula20.

Turning now toFIGS. 3A-3D, a step-by-step process of using the apparatus is shown. First, an incision is made in the skin of a patient (not shown). As shown inFIG. 3A, apparatus10, in the uncocked position, is inserted into the incision and through a first wall100and a second wall102. In the embodiments discussed below, first wall100is the abdominal wall, while second wall102is the stomach. For ease of understanding, and in no way limiting the uses of the disclosed embodiments, the remainder of the discussion will refer to abdominal wall100and stomach wall102. The disclosed invention may be used on other hollow organs such as the intestines, for example.

Tip32of needle30punctures abdominal wall100and stomach wall102, allowing both cannula20and needle30to be inserted into the stomach cavity104. As shown inFIG. 3B, once apparatus10has been inserted into stomach cavity104, apparatus10is placed in the cocked position. When the apparatus is in the cocked position, needle30is advanced from cannula20, and cannula20is withdrawn with respect to needle30. Releasable lock54engages biased spring52, needle carrier50, or both to maintain apparatus10in cocked position until releasable lock54is triggered.

Apparatus10is now in an uncocked position, and biopsy106is enclosed in cannula20between notch portion36and the inner wall of cannula20. Apparatus10may be removed from stomach cavity104. In some embodiments, biopsy106may be collected by cocking apparatus10, removing biopsy106from notch portion36, and returning apparatus10to the uncocked position.

AlthoughFIGS. 3A-3Dillustrate apparatus10in use in minimally-invasive biopsy context, the apparatus may be used during open surgery as well. In open surgery, the hollow organ may be directly exposed to the surgeon, such that the apparatus may not need to be inserted through an incision and abdominal wall100. In such applications, an operator may place apparatus10in the uncocked position such that cannula20is advanced relative to needle30. Tip32of needle30punctures stomach wall102, allowing both cannula20and needle30to be inserted into the stomach cavity104. Apparatus10may then be cocked and positioned as discussed above, such that notch portion36of needle30straddle stomach wall102and cutting edge of cannula20is outside stomach wall102. Releasable lock54may then be triggered such that biased spring54propels cutting edge24of cannula20through stomach wall102toward tip32of needle30. Similar to the procedure described above, as cannula20passes through stomach wall102and advances past notch portion36, a full-thickness biopsy106is removed from stomach wall102.

FIG. 4illustrates another alternative embodiment of apparatus10, which operates in a similar fashion to the apparatus illustrated inFIGS. 1 and 2above except that a different needle is used. In the illustrated embodiment, apparatus10comprises tracking needle60. Tracking needle60comprises a tip62, a guide portion64, a tapered portion66, and a shaft portion68.

The embodiment ofFIG. 4is used in a similar fashion as the embodiments discussed above. However, unlike the embodiments shown inFIGS. 3A-3B, in the embodiment inFIG. 4, tracking needle60is inserted into the incision in a cocked position. Tip62pierces abdominal wall100allowing guide portion64to pass through abdominal wall100. Tip62is inserted into stomach wall102, or “tents” it, but tip62does not pass through stomach wall102. In certain embodiments, tip102may comprise a bulb, balloon, or umbrella configured to tent stomach wall102. Once tip62abuts stomach wall102, releasable lock54may be triggered. Cutting edge24of cannula20is projected past tip62and through stomach wall102, collecting biopsy106within cannula20. Apparatus10may then be withdrawn from the patient with biopsy106within cannula20. In some embodiments, biopsy106may be removed from apparatus10by placing apparatus10in a cocked position, removing biopsy106from around guide portion64.

Two practical applications of the disclosed invention will now be discussed.

Example I

Animal Trial

Gastroparesis is a motility disorder of the stomach characterized by symptoms of delayed gastric emptying. These symptoms may include nausea, vomiting, bloating, and abdominal pain. Diagnosis is made by typical clinical history and confirmation with a gastric emptying test after exclusion of structural abnormalities or malignancy.

The pathophysiology of gastroparesis is complex. Recent evidence has shown histopathologic disruption of the enteric nervous system (ENS) in full-thickness stomach specimens of patients with gastroparesis. Altered mediators of oxidative stress have also been found in animal models of gastroparesis. Because the myenteric plexus (which contains the majority of ENS neurons and interstitial cells of Cajal) is sandwiched between the circular and longitudinal muscles of the stomach, it is not accessible with standard mucosal biopsy forceps. Obtaining gastric ENS tissue, to date, has typically required a laparoscopy or laparotomy. Experimental endoscopic approaches have either failed to access ENS tissue or had a high perforation rate.

Methods

This protocol was approved by the University of Calgary Animal Care Committee. Three healthy, mongrel dogs (2 female, average weight 17.6 kg) were fasted overnight. One prophylactic dose of antibiotic (enrofloxacin, 5 mg/kg intravenously; Bayer, Montreal, QC) was administered before the procedure. General anesthesia was induced with thiopental sodium, 20 mg/kg intravenously (Vetoquinol; Lavaltrie, QC) and maintained with 1% to 3% isoflurane inhaled (Halocarbon Laboratories, River Edge, N.J.).

The Percutaneous Endoscopically Assisted Transenteric Technique

Each dog underwent upper endoscopy, and a suitable biopsy area was chosen, based on indentation of the ventral antral wall by external finger pressure on the abdomen and by transillumination with the endoscope. By using a sterile technique, local anesthesia was administered (lidocaine 1%; AstraZeneca, Montreal, QC) in the skin and along the tract to the stomach. Confirmation of a direct tract was made by visualizing the anesthetic needle penetrating the stomach. A 3-mm incision was made through the abdominal skin with a scalpel. The stomach was then fully distended with air.

A 14-gauge biopsy needle set (9-cm length, 20-mm throw; Quick-Core Biopsy Needle Set, Cook Medical Inc, Bloomington, Ind.) was used. This set contains an internal needle with a notch on the shaft for collecting tissue, surrounded by a spring-loaded, cutting, 14-gauge cannula. The set was passed, uncocked, into the stomach under direct visualization. The spring was then cocked, and the internal needle containing the biopsy notch was exposed. The needle set was withdrawn until the cannula left the stomach, and the notch appeared to straddle the stomach wall. This was confirmed by tenting of the gastric wall by the cannula pushing from the serosal side. The needle was then fired, taking a full-thickness gastric biopsy specimen.

The needle set was then withdrawn, and the biopsy tissue collected. The needle set was then passed again through the same abdominal incision and the procedure repeated three more times at adjacent regions of the antrum at least 10 mm apart. No mucosal or full-thickness closure interventions were planned or performed. Skin incisions were closed with tissue glue (methacrylate; Ted Pella, Redding, Calif.), and the dogs were recovered from anesthesia.

All dogs received buprenorphine, 0.02 mg/kg (Schering-Plough, Montreal, QC), for pain control before, and ten hours after, the procedure. All dogs were monitored daily for symptoms of peritonitis, bleeding, or fever (rectal temperature and hemoglobin daily for the first two days postoperatively).

Dogs were followed for four weeks. Dogs then had repeat endoscopy (all dogs), and laparoscopy (1 dog) under general anesthesia as previously done and were then killed with sodium barbital, 2 mL/4.5 kg (Bimeda-MTC, Cambridge, ON), followed by necropsy. Biopsy material was immediately fixed in 10% formalin and later paraffin was embedded and sectioned. Material was stained for hematoxylin and eosin (for general assessment and muscle), c-kit (for interstitial cells of Cajal), PGP9.5 (for neuronal cells), and S-100 (for glial cells) by using standard methods.

Results

Each dog had four gastric biopsy specimens taken at the initial endoscopy. Although a small mucosal defect was often seen shortly after biopsy upon removal of the needle set, this spontaneously sealed within 10 seconds.FIG. 5shows a photograph of this mucosal defect. Similarly, an insignificant amount of oozing blood was seen after biopsy, but this stopped spontaneously. No hematoma was seen at any of the biopsy sites.

All dogs survived the four-week follow-up period. No signs of peritonitis or pain were observed either immediately after the operation or during the following four weeks. During the first two postoperative days, all dogs were fed with canned (wet) dog food, and two of the dogs had looser stools during this period. After we switched them to a dry dog food, their stools normalized. All dogs maintained their initial weights.

In all dogs, at week four, the abdominal skin incision was barely discernable. Repeat endoscopy showed no perceptible scarring in two dogs, and a suggestion of mild mucosal deformity in the region of biopsy in one dog. The gastric mucosa was completely healed in all cases, with no evidence of inflammation, ulceration, or perforation. There was no evidence of adhesion formation between the abdominal wall and the stomach, and minimal scarring was seen on the parietal peritoneum of the abdominal wall, as shown inFIG. 6. No scarring could be perceived visually on the serosal aspect of any of the stomachs in the collapsed (ie, undistended) state, either at laparoscopy (one dog) or after en bloc resection with detailed inspection at necropsy (all dogs).

All biopsies except two of the first biopsies showed intact gastric wall with ENS elements. Full-thickness histology is shown inFIG. 4. Specific staining for interstitial cells of Cajal, neurons, and glia confirmed the presence of those tissue elements (not shown). Average fresh biopsy size was approximately 2 mm by 4 mm laid out on blotter paper.

Discussion

This study confirms the feasibility and safety of the novel percutaneous endoscopically assisted transenteric approach (PEATE) biopsy technique in a canine model. The technique is easily performed, similar in some aspects to insertion of a percutaneous gastrostomy feeding tube, a routine endoscopic procedure. PEATE gastric biopsy also reliably obtains ENS tissue and appears safe from animal data.

Potential risks of this procedure include peritonitis because of leakage of gastric content into the abdominal cavity after the biopsy specimen is taken. This likelihood is low because of the ability of the gastric muscle to contract and reduce the size of the defect; the function of the omentum to inhibit leakage; and mucosal clips that may be applied endoscopically if necessary. Although placing clips may be prudent in humans, the risk of peritonitis would be expected to be lower in humans because of the thicker stomach relative to the biopsy size. Peritonitis may also occur because of infection introduced by the percutaneous approach, but this is minimized by adhering to strict sterile technique for the procedure. The risk of bleeding is also minimized by the fact that this biopsy is not done blindly. If significant bleeding were to occur, it would be expected as soon as the needle set was passed into the stomach; thus, action could be taken before the cannula was fired to minimize damage. Bleeding that is not endoscopically visible (eg, into the peritoneal cavity) is typically minor, based on experience from percutaneous gastrostomy tube insertion. There are other risks of performing this procedure in humans with comorbidities (such as food retention, obesity, or immune deficiency), but these conditions would not be expected to pose an excessive risk.

Assessment of ENS histology or biomarkers appears promising in gastroparesis. This new technique may provide a valuable research tool in understanding gastric motility disorders in humans, which cause a huge morbidity burden. Furthermore, with the simplicity of this technique and the fact that it can be practiced by any endoscopist, routine assessment of ENS tissue easily could be adopted if shown to be of value in diagnosis.

Example II

Human Trial

This protocol was approved by University of Calgary Research Ethics Board, and all patients gave written informed consent. After an overnight fast, one prophylactic dose of antibiotic (cefazolin 2 g IV) was administered before the procedure. Conscious sedation with fentanyl and midazolam, or propofol was given as required.

Each patient underwent upper endoscopy and a suitable biopsy area was chosen based on indentation of the ventral antral wall by external finger pressure on the abdomen and by transillumination with the endoscope. Using sterile technique, local anesthesia (lidocaine 2%; Astrazeneca, Montreal, QC) was given in the skin and along the tract to the stomach. Confirmation of a direct tract was made by visualizing the anesthetic needle penetrating the stomach. A 3 mm incision was made through the abdominal skin with a scalpel. The stomach was then fully distended with air.

A 14 gauge (G) biopsy needle set (9 cm length, 20 mm throw; Quick-Core Biopsy Needle Set, Cook Medical Inc, Bloomington, Ind.) was used. This set contains an internal needle with a notch on the shaft to collect tissue surrounded by a spring-loaded cutting 14 G cannula. The set was passed, uncocked, into the stomach under direct visualization. The spring was then cocked and the internal needle containing the biopsy notch was exposed. The needle set was withdrawn until the cannula left the stomach and the notch appeared to straddle the stomach wall. This was confirmed by tenting of the gastric wall by the cannula pushing from the serosal side. The needle was then fired, taking a full-thickness gastric biopsy.

The needle set was then withdrawn and the biopsy tissue collected. The needle set was then passed again through the same abdominal incision and the procedure repeated 3 more times at adjacent regions of the antrum. No mucosal or full-thickness closure interventions were planned or performed. A sterile dressing (Op-Site) was placed over the skin incision for 24 hours. Patients were monitored for at least 3 hours post-operatively for signs of complications before being discharged.