bluuebunny/crossref_metadata_2025 huggingface dataset:
Transverse or longitudinal arteriotomies in end‐to‐side microvascular anastomoses for small vessels (1–2 mm)
Authors: Storrie Ann , McGeachie John , Samuels Roslyn , Hunneybun Bernadine , Bartlett Natasha
Published: March 2007

This investigation quantitatively compared lumenal dimensions of 1 mm end‐to‐side anastomoses with longitudinal or transverse arteriotomies into host arteries 1.5‐2 mm in diameter. In 27 rats, 6–7 mm sections of iliac arteries (1 mm in diameter) were sutured as small bypasses onto abdominal aortae (1.5‐2 mm in diameter). Half the anastomoses were performed on transverse, and half on longitudinal arteriotomies. Between 1 and 20 weeks following surgery intravascular methacrylate casts were made of the aortae and bypasses, and detailed measurements taken from the casts. The success rate (patency) of the bypasses was 78%; 18 successful casts (36 anastomotic sites) were analysed; 6 failed due to stenosis (3 other successful bypasses were used to develop the techniques). From these, five sites developed small dilations (“aneurysms”), which did not occur preferentially on either longitudinal or transverse arteriotomy sites. Despite a trend towards a greater diameter in the transverse compared with the longitudinal arteriotomies, they were not statistically different. Therefore, the authors recommend for technical reasons that for small end‐to‐side vascular anastomoses the transverse arteriotomy is preferable: it produces a simple incision which opens the artery and facilitates suturing. With a longitudinal arteriotomy in such small vessels it is often necessary to remove an elliptical area of tissue, which may produce an excessive defect.
Comparative study of mouse heart and heart‐lung transplantations
Authors: Han Duck Jong , Khang Shin Kwang , Pai Soo Tong , Yoon Dai Won
Published: March 2007

Heart transplantation in mice using a double anastomosis technique has become the standard method regardless of its technical difficulty. Heart‐lung transplantation performed by single anastomosis in rats was also applied to mice, showing the identical operative result in addition to the advantage of easy applicability. We compared the heart transplant made by double anastomosis with the heart‐lung transplantation using single aortic anastomosis in terms of graft survival and histologic features. The results were as follows: (1) During the follow‐up period of 100 days after the transplantation in mice that survived 7 days after the operation, there were no deaths among the hosts and no evidence of nonfunction of the grafts in the six mice in each group. (2) In terms of monocyte infiltration perivascularily or interstitially, myocyte necrosis, interstitial hemorrhage, neutrophilic infiltration, and endocardial changes, histologic changes in the grafts were less in single anastomosis of heart‐lung transplants than in double anastomosis. As a result, we can deduce that heart‐lung transplantation using the single anastomosis technique is a good experimental model for the study of transplant reaction.
Experience in rat pancreas transplantation at meikai university
Authors: Nozawa Masumi , Otsu Ichiro
Published: March 2007

A review of rat pancreatic transplantation conducted at Meikai University is presented. It was found that pancreas transplantation normalized the endocrine based metabolic disturbances of diabetes. Arginine‐induced serum insulin, glucagon, and somatostatin responses in the grafted pancreas were similar to those in normal pancreas. Urine amylase was found to be a more sensitive marker in graft rejection as compared with blood glucose using a urinary drainage model. The value of pancreas transplantation in diabetic nephropathy was dependent upon the timing of the transplantation; performed early in the course of diabetes (less than 4 months, post‐diabetes), it was able to reverse the nephropathy.
Rat kidney transplantation update with special reference to vesical calculi
Authors: D'Silva Milbhor , Gittes Ruben F. , Wolf Paul , Pirenne Jacques , Munger Karen , Pascual Juan , Lee Sun
Published: March 2007

A technical update on rat kidney transplantation is given. In this study, the bladder‐bladder union was made using silk, polyglycolic acid (Dexon), polyglactin (Vicryl), and chromic catgut. The propensity of these sutures to form vesical calculi was investigated in both first and second generation transplants. The results of our study indicate that there is no significant difference (P > 0.01) in their calculogenic ability. Special problems attendant with first and second generation kidney transplants are described. The concept and technique of second generation kidney transplants are also described.
An in vivo method for studies of traumatic vasospasm
Authors: Wadström Jonas , Lindbom Lennart , Wik Ove , Gerdin Bengt
Published: March 2007

A study was undertaken to develop a model for investigations of traumatically induced vasospasm. The left ear of the rabbit was denervated under short anesthesia. With the animal under light sedation, spasm of the central ear artery was repeatedly induced with a clip applying forceps. To evaluate the vasospasm, the vessel was transilluminated with cold light, and the internal diameter was continuously measured. The spasm was assessed in terms of its duration, intensity (reduction of initial diameter) and severity (integrated change in diameter over time). Repetitive application of the forceps on the same vessel segment shortened the spasm duration. With prolonged pinch duration, the spasm duration was lengthened. The preparation was stable for at least 3 hours. This model was effective for manipulating small vessels and producing spasm and is of potential value for studying the treatment of vasospasm by topical local intra‐arterial and systemic methods.
Vasodilator action of prostaglandin E1 on microcirculation of rat cremaster muscle
Authors: Chen Long‐En , Seaber Anthony V. , Urbaniak James R.
Published: March 2007

Vascular spasm is often present after microsurgical procedures, and its presence or absence can greatly influence the success rate of such operations. Prostaglandin E1 (PGE1) is known to be a potent vasodilator and antiaggregator of small blood vessels. Using intravital videomicroscopy in the rat cremaster model, this study visually and quantitatively monitored changes in vessel diameter to observe the effect of PGE1 on the microcirculation and compared its action with that of 1% lidocaine. The results suggest that PGE1 (10 μg/ml) can significantly relieve epinephrine‐induced vasoconstriction at the terminal arteriole, arteriole, and small artery level (vessel diameters 10–50 μm). The vasodilatory action of PGE1 is reflected by an increase in vessel diameter, and PGE1 may have a role in reversing vascular spasm after microsurgery, enhancing the survival rate of replanted extremities.
Time of low‐dose acetylsalicylic acid administration influences in vivo platelet function and thrombus formation following arteriotomy and intimectomy; an experimental study in small arteries of Rabbits
Authors: Salemark Lars , Wieslander Jan B. , Dougan Peter , Arnljots Björn
Published: March 2007

To investigate if low‐dose acetylsalicylic acid (ASA), 4 mg/kg b.w., infused peroperatively or 10 hours preoperatively has antithrombotic effects, the central arteries of rabbit ears were prepared and 32P‐labeled platelets injected. Arteriotomy and intimectomy were performed and blood flow was restored. Bleeding times at the sites of arteriotomy/intimectomy, in vivo accumulations of isotope‐labeled platelets, amounts of red thrombotic material, and patency were recorded. Bleeding times following arterial puncture and the effect of ASA on thromboxane production were studied separately. Ten hours after ASA administration, bleeding times were shortened at the sites of arteriotomy/intimectomy but were prolonged following arterial puncture. Platelet accumulations were lower in patent vessels in this group than in an untreated control group. Peroperative ASA treatment increased but treatment 10 hours prior to blood flow restoration did not significantly affect the number of occlusions. Thromboxane production in ASA‐treated rabbits is largely inhibited even 14 hours after administration.
Angled side wall microarteriotomy scissors: A new end‐to‐side microvascular anastomosis instrument
Authors: Korber Kenneth E. , Kraemer Bruce A. , Li Zhang
Published: March 2007

Creation of a smooth side wall arteriotomy for an end‐to‐side microsurgical anastomosis can at times be difficult and time consuming. To facilitate this maneuver, a new end‐to‐side microarteriotomy scissor was designed for creation of recipient vessel openings from 0.5–2 mm in size. These new scissors and their recommended use are described.
Sensory recovery following digital replantation
Authors: Glickman Laurence T. , Mackinnon Susan E.
Published: March 2007

The recovery of sensibility following digital replantation is essential in the restoration of hand function. We reviewed 12 series of digital replantations between 1977 and 1989. Three hundred sixty‐seven fingers and 87 thumbs were successfully replanted. Mean age was 32.5 years. Mean follow‐up was 33.5 months. Mean static two‐point discrimination (S2PD) was 9.3 mm in clean thumbs vs. 12.1 mm in crush/avulsion thumb replantations. Mean S2PD was 8 mm in clean finger vs. 15 mm in crush/avulsion finger replantations. Overall mean S2PD was 11 mm in thumb and 12 mm in finger replantations. Sixty‐one percent of replanted thumbs and 54% of replanted fingers regained useful S2PD (<15 mm or ≥ S3 + ). Factors that influenced digital sensibility following replantation included patient's age, level and mechanism of injury, digital blood flow, cold intolerance, and postoperative sensory reeducation. Recovery of sensibility in the replanted digit is comparable to simple nerve repair and to nerve grafting techniques. Further emphasis should be on elucidating the mechanism of cold intolerance, which was a significant complaint for most replanted digits. The universal practice of postoperative sensory reeducation will continue to improve digital sensibility following replantation.
One hundred eleven thumb amputations: Replantation vs revision
Authors: Goldner Richard D. , Howson M. Patricia , Nunley James A. , Fitch Robert D. , Belding Nancy Regan , Urbaniak James R.
Published: March 2007

One hundred eleven patients who sustained isolated, complete thumb amputation between 1971 and 1985 were reviewed to assess results of replantation and to compare these with results of amputation revision. Routine postoperative evaluation was performed in 69 successful replant patients and in 42 with revision. Twenty‐five of the replant group and 18 of the revision group returned for additional testing that consisted of interview and physical examination, test of activities of daily living, Jebsen test of hand function, and both static and dynamic testing on the BTE work simulator. Ninety percent of replantations were between the metacarpophalangeal (MCP) joint and the proximal third of the distal phalanx. Shortening averaged 11 mm, and range of motion was 42% ± 28% that of the uninjured thumb. One‐half of the patients could touch the MP of their ring finger, and one‐fourth could touch the proximal interphalangeal (PIP) joint. Twenty‐one percent had 7 mm or less two‐point discrimination, and 38% had between 8 and 20 mm. Eighty percent of both groups were able to perform activities of daily living at 80% of their uninjured side. Grip strength was approximately 84% of that of the uninjured hand in each group. Lateral pinch averaged 68% ± 26% of that of the normal side in the replant group and 91% + 9% in the amputation group. Work simulator assessment of lateral and three‐point pinch was better in the revision group. Scores on Jebsen testing were slightly better for those with replanted thumbs, but in general neither replant nor revision patients functioned as well as did Jebsen's normals. In this group of patients, with the methods noted above, we were not able to demonstrate uniform superiority of replantation over revision.
Free flap circulation and modes of arterial insertion: An experimental study
Authors: Nyström Ake , Hanel Douglas P. , Scheker Luis , Schwartz Kenneth S. , Lister Graham D.
Published: March 2007

Using electromagnetic flowmetry, the circulation through free flaps was studied in an experimental animal model. It was demonstrated that the total circulation of blood through a free flap is not affected by the establishment of an arterial through‐flow or end‐flow model in the recipient bed.
Microarterial synthetic graft repair: Interstitial cellular components
Authors: Joos Karen M. , Sandra Alexander
Published: March 2007

Although the histologic changes occurring during healing on the lumen surface of large vessel synthetic vascular grafts have been well characterized, the cells populating the interstices of microvascular grafts have not been examined in detail. Since microvascular grafts are required to provide vascular continuity under quite different physiological and hemodynamic conditions as compared with large vessel grafts, these interstitial cells within the synthetic graft material may also vary as a function of graft size. Monoclonal antibodies, light microscopy, and scanning and transmission electron microscopy were used in this study to identify the cells present within the 30‐μm pores of 1 ‐mm diameter polytetrafluoroethylene and replamineform silicone rubber grafts. Identified cells included few capillary endothelial cells enclosing erythrocytes, rare proliferating endothelial cells, few macrophages, rare foreign body giant cells, and a majority of fibroblasts. There was no evidence of smooth muscle cells or myofibroblasts within the interstices of these microvascular prostheses 12 weeks after implantation in the rabbit central ear artery. The graft types differed by the presence of foreign body giant cells and more densely packed collagen between cells in the replamineform silicone rubber graft interstices.
Reverse‐flow vascularized fibular graft: A new method
Authors: Minami Akio , Itoga Hideya , Suzuki Katsunori
Published: March 2007

The reverse‐flow island flap is a relatively recent concept. We have applied this concept to the vascularized bone graft. We report a new method of the reverse‐flow vascularized fibular graft for two patients with a pseudarthrosis and massive bone defect of the tibia. The peroneal artery and venae comitantes were severed proximally and elevated with the fibula while maintaining distal vascular continuity. The reverse‐flow vascularized fibula was grafted to the posterior aspect of the bone defect of the tibia. Bony union was obtained in both cases. The reverse‐flow vascularized fibular graft has many advantages compared with free vascularized fibular graft.
Comparative study of secretion by vagotomized and isotransplanted stomachs in the Rat
Authors: Ueda Toshisada , Kunitaka Toratani , Tanaka Takasi , Sakabe Takasi
Published: March 2007

An acute observation of gastric secretion by syngeneic stomach transplants in Lewis male rats was compared to the gastric secretory fate of normal, pylorus‐ligated, vagotomized, and combined pylorus ligation and vagotomized Lewis rats. A 5 day observation was sufficient before sympathetic fibers and vagal channels could be regenerated. A total of 36 rats were divided into five groups of which group I (ten normals), group II (five vagotomized), group III (pylorus‐ligated), group IV (six vagotomized and pylorus‐ligated), and group V (five syngeneic stomach‐transplanted, five animals served as donors), and those stomachs were intubated to collect gastric juice by housing animals in Bollman cages. Whereas group V animals secreted a mean 24 hr gastric juice volume of 12.5 ± 6.4 ml with free acid secretion of 0.15 ± 0.01 mEq/24 hr, animals in groups I, II, III, and IV secreted 24.4 ± 2.9 ml, 23.3 ± 1.1 ml, 25.5 ± 3.4 ml, 22.4 ± 0.5 ml, respectively, for 24 hr periods with free acid secretions of varying rates. From these observations, the transplanted stomach mean secretory rate averaged half that of the normal stomach.
A tribute to the late Dr. Ryo Shimazu: A chronic bowel allograft model in the Rat
Authors: Shimazu Ryo , Raju Seshadri , Grogan James B.
Published: March 2007

A chronic model of bowel allotransplantation is described. End‐to‐end microvascular anastomosis between superior mesenteric vessels was utilized. The recipient splenic vein was preserved to avoid postoperative pancreatitis. Euro‐Collins solution was used to flush the vasculature in the lumen of the transplant. Low‐dose cyclosporine was used for immunosuppression. With experience, 89% long‐term survival was achieved.
Small bowel transplantation
Authors: Schroeder Peter , Gundlach Matthias , Schweizer Eva , Deltz Eberhard
Published: March 2007

Small intestinal transplantation has had several clinical attempts based on extensive experimental work during the past two decades. Several models, such as auxiliary (heterotopic) or orthotopic models, have been developed in regard to problems with graft immunology and function. The question of mesenteric‐portal or mesenteric‐caval graft drainage was raised, and the answer seems to be open. Concerning lipid absorption, interest was directed to the reconstitution of lymphatic vessels, because orally administered cyclosporine A is absorbed by the lipid mechanism. Carbohydrate digestion and absorption are used for determination of graft function and for monitoring graft rejection. This article summarizes these problems and deals with the surgical procedure of small bowel transplantation in the rat.
Small bowel transplantation in the rat with immediate restoration of intestinal continuity
Authors: Moore Gail H. , Roza Allan M. , Johnson Christopher P. , Telford Gordon L. , Adams Mark B.
Published: March 2007

Compared with other rat transplant models, small bowel transplantation (SBT) is associated with higher peritransplant morbidity and mortality. We describe a two‐stage technique of SBT in the rat that minimizes perioperative complications and also allows immediate restoration of intestinal continuity. Inbred Lewis strain rats were used as donors and recipients. A one‐stage technique was originally adopted whereby the distal 50% of the jejunoileum was transplanted followed by near‐total resection of the native small intestine and restoration of intestinal continuity. Among 20 rats transplanted with this technique, only one survived longer than 30 days. With the two‐stage technique, transplantation of the donor jejunoileum in continuity was performed, followed by native enterectomy 7 days later. With the two‐stage technique 17 of 20 rats survived indefinitely (>50 days). Other important technical modifications are described. In the hands of a skilled microvascular surgeon, the two‐stage SBT technique results in consistently improved survival and minimal morbidity.
Influence of the length of the small bowel graft on the severity of graft versus host disease
Authors: Pirenne Jacques , D'Silva Milbhor , Hamoir Etienne , Lardinois Frederic , Fridman Viviana , Mahieu Philippe , Honore Pierre , Meurisse Michel , Jacquet Nicolas
Published: March 2007

The influence of the length and origin of a small bowel graft on graft versus host disease (GVHD) was studied in 33 (Lewis × brown Norway) F1 hybrids transplanted with different types of Lewis small bowel grafts. Recipients of an entire small bowel graft (N = 9), a jejunal graft (N = 6), or an ileal graft (N = 6) displayed a similar acute lethal GVHD, with 100% mortality rate and equivalent survival time (15 ± 0.7, 16.8 ± 0.9, and 16 ± 0.6 days, respectively) (P> 0.01). On the other hand, 80% of the recipients of a segmental jejunal graft (N = 10) recovered from a transitory form of GVHD and regained weight similarly to the isografted rats (N = 4). It was concluded that the entire small bowel, jejunum, and ileum can provoke an equivalent GVHD after transplantation, whereas a segment of jejunum decreases the intensity of GVHD, probably by reducing the amount of transplanted lymphoid tissue.
Cervical small bowel transplantation in the Rat: A useful tool
Authors: Sonnino Roberta E. , Teitelbaum Daniel H. , Harmel Richard P.
Published: March 2007

Orthotopic intestinal transplantation in the rat is highly successful, but circumstances may require an extraabdominal graft location. We describe a microsurgical technique for cervical intestinal transplantation in the rat, which has been used to investigate the immune status of hosts already bearing an intraabdominal bowel transplant. A 10 cm segment of donor jejunum is harvested on a pedicle of superior mesenteric artery and superior mesenteric vein. In the recipient, the carotid artery (CA) and external jugular vein (EJV) are isolated. The venous anastomosis is performed end to end to the medial EJV branch, and the arterial anastomosis is completed end to side to the CA. Both anastomoses are performed with interrupted 10‐0 nylon. The bowel is placed in a subcutaneous pocket in the neck, with both ends exteriorized. The procedure was performed in 11 donor‐recipient pairs planned to elicit rejection, graft‐vs.‐host disease (GVHD) or graft acceptance. No technical complications were encountered. All rats survived long term, and their grafts were monitored histologically. The expected immune responses were observed, but rejection and GVHD were not fatal to the host with this model. We conclude that this technique is feasible and reliable to monitor the progress of isolated intestinal transplants. The location in the neck does not disrupt normal intestinal function of the recipient and may have multiple applications in the study of intestinal transplant immunology and physiology.
Neovascularisation of the epiphysis
Authors: Binns Malcolm , Pho Robert W. H.
Published: March 2007

Two experiments in the rabbit model have been carried out to see if a vascular pedicle placed in a growing epiphysis would establish new capillaries. In one, the vascular pedicle of peroneus longus muscle was placed in the proximal fibula epiphysis. In the other, the proximal fibula was excised and the epiphysis placed across the saphenous artery and vein in the groin. After 3 months, histological examination of the epiphyses in both experiments showed that no new vessels had grown from the vascular pedicle. Cartilage is known to inhibit vascularisation, and these results suggest that attempts to revascularise the epiphysis, for example, following Perthes' disease, may fail. For the same reason, attempting to supplement the epiphyseal vessels by implanting a new vessel before or after epiphyseal transfer may fail.
Mural repair following obliteration of aneurysms. Part III: Pathomorphological effects of Nd: YAG laser on aneurysm obliteration
Authors: Guity Afrassiab , Young Paul H. , Fischer Vernon W. , Albanna Faisal J. , Kennedy David G.
Published: March 2007

Twenty‐four experimental aneurysms were created in rat carotid arteries using the venous pouch technique. Four to twelve weeks later, these aneurysms were totally obliterated by the external application of Nd:YAG laser. The aneurysmal dome and neck were both exposed to the laser using low amplitude (1–2 W) at continuous or repeat intervals (0.3 sec on/0.1 sec off). Small aneurysms were easily obliterated without external signs of necrosis, whereas aneurysms larger than 2 mm required complete coagulation resulting in a charcoal‐like appearance. At varying intervals (30 min, 7 days, 3 weeks, 6 weeks), the obliterated aneurysms were harvested and evaluated using the scanning electron microscope and standard histological techniques. The results indicate that the effects of the laser on the aneurysm and parent vessel are similar to those encountered following the application of bipolar coagulation with massive coagulation necrosis of the aneurysmal neck and dome. Notably, however, the extension of this process onto the parent vessel involving especially the endothelium surrounding the aneurysm orifice (commonly seen with bipolar coagulation) is minimal following laser coagulation. There appears to be a protective effect on the parent vessel endothelium by blood flow through the vessel. On this basis, it appears that the laser may be an alternative method of aneurysmal coagulation; the use of laser entails less manipulation of the aneurysm. The Nd:YAG laser may be a useful adjunct in the surgical obliteration of clinical cerebral artery aneurysms, especially small ones.
Simultaneous comparison of pre‐ and post‐microanastomotic hemodynamic profiles using a Tandem Doppler Probe
Authors: Tuchler Robert E. , Zhang Ling , Siebert John W. , Shaw William W.
Published: March 2007

The use of High‐Frequency Pulsed Doppler Ultrasound (HFPDU) for evaluation of microvascular hemodynamics is well established. Due to technical limitations of existing probes, quantitation of anastomotic stenoses and detailed waveform analyses are difficult to perform and impractical for clinical use. We present a new Tandem Doppler Probe (TDP) for simple and accurate study of blood flow in vessels smaller than 1 mm in diameter. Its unique ability to compare the pre‐ and post‐anastomotic waveforms simultaneously allows for quantitative detection of anastomotic narrowing of as little as 5%, as well as identification of subtle pathologic anastomotic waveform changes not seen with single probes. Such early and precise delineation of anastomotic problems in the operating room can provide an invaluable, objective assessment of the technical adequacy of the anastomoses as well as an important baseline for later post‐operative monitoring of free‐tissue transfers with implantable Doppler devices.
Rat femoral vein‐to‐vein grafts as a microvascular practice model: Factors that influence patency
Authors: Cooley Brian C. , Lan Ma , Gould John S.
Published: March 2007

The rat femoral vein has become a standard model for microvascular anastomosis practice as well as for research investigations into various manipulative influences upon venous patency. Although vein grafts to the rat artery are the focus of many experimental studies, few reports have investigated vein‐to‐vein grafts. This study examines the short‐term patency (1–3 days) of vein grafts interpositioned to the rat femoral vein. Several factors are studied for their ability to alter the patency rate. The results indicate that patency is difficult to achieve following the creation of a second serial anastomosis (construction of a vein‐to‐vein graft). Systemic heparin consistently improves patency rates, and trends toward increased patency are seen for reduction in longitudinal tension of the repaired vessel. It is also implied that a deeper understanding of venous hemodynamics and thrombotic events may lead to improved methodologies in the clinical applications of microvenous repairs. These results indicate that rat vein‐to‐vein grafts may provide a challenging microvascular training model, while introducing the novice microsurgeon to some of the complicating factors encountered with microvascular grafting.
Inhibition of epinephrine‐induced vasospasm with adrenoreceptor blockade in the rat cremaster muscle
Authors: Hartsock Langdon A. , Seaber Anthony V. , Urbaniak James R.
Published: March 2007

This study demonstrates that intravenous epinephrine causes arterial vasospasm, but not venous constriction, in the microcirculation of the rat cremaster muscle. This effect can be blocked by a smooth muscle relaxant such as papaverine or an alpha receptor antagonist such as phentolamine. Circulating vasospastic agents such as epinephrine are important determinants of microcirculatory blood flow, and inhibition by pharmacologic means may enhance blood flow and survival in microvascular surgery.
Coupled suturing: A new technique for microvascular anastomosis
Authors: Cheng‐Da Huang , Sharkey Neil A. , Szabo Robert M.
Published: March 2007

The left carotid artery of 12 Sprague‐Dawley rats was sectioned and anastomoses immediately performed utilizing a new technique termed coupled suturing. Patency and constriction were assessed immediately postoperatively and at 1, 2, and 3 weeks. Specimens were also evaluated by light microscopy and scanning electron microscopy. Vessels healed well with excellent patency and edge eversion. With the development of a specialized needle, coupled suture could prove to be a reasonable alternative to current methods of anastomosis. Its main advantage is better intimal eversion, which decreases the risk of thrombosis.
Comparison of nerve regeneration through different types of neural prostheses
Authors: Gibson Karen L. , Remson Laura , Smith Andrea , Satterlee Nancy , Strain George M. , Daniloff Joanne K.
Published: March 2007

Rat sciatic nerve regeneration through three synthetic neural prostheses was compared with regeneration through nerve allografts. The synthetic prostheses were either nonpermeable nonabsorbable (Silastic), permeable absorbable (polyglactin mesh), or permeable nonabsorbable (polypropylene mesh). Animals were evaluated at 10, 24, and 90 days. Functional analysis of nerve regeneration was performed by noninvasive methods: electromyography and walking tracks. Nerve tissue was examined with routine histologic and immunofluorescent techniques. A compressive neuropathy developed with the use of the Silastic implant. A neutrophilic inflammatory infiltrate was consistently associated with implantation of the polyglactin mesh. A strong connective tissue response was noted around the polypropylene mesh. Early recovery of nerve function was seen with the Silastic implants, however, overall nerve function was best in the nerve allograft and polypropylene mesh groups. Polyglactin implantation increases the local inflammatory response and should not be used for nerve anastomoses. If Silastic entubulation is used, it should be removed between 24 and 90 days.
Experimental study of the influence of arterial trauma on dependent distal tissue survival
Authors: Cooley Brian C. , Lan Ma , Groner Jeffrey P. , Hoer Steven R. , Dollinger Beth M. , Hanel Douglas P.
Published: March 2007

An experimental model was developed combining arterial trauma with island flap creation using the rat groin flap system. Flap arteries were subjected to crush/avulsion injuries with subsequent microvascular repair. A second series involved resection 4 hr after thrombosis of injured flap arteries and interpositional vein grafting to reestablish circulation. A single bolus of systemic heparin was administered to half of the animals from each series on a blinded, randomized basis. Arterial patency at 7 days correlated with flap survival. There was no case of partial flap loss. Patencies improved in the first series from 31% to 71% with heparin administration (P < 0.05) and from 58% to 90% in the second (not significantly different). A third series involving immediate resection of traumatized vessel and vein graft replacement achieved a patency of 92% (without heparinization). These results support the value of replacement of all traumatized arterial tissue with vein grafts and indicate the efficacy of systemic heparin (in single bolus) for enhancing the likelihood of maintaining patency. Furthermore, it is suggested that the occurrence of a thrombogenic site in the arterial inflow to a region of dependent tissue does not lead to partial tissue loss, and thus thromboembolic events may not be responsible for this clinical phenomenon.
Nervous influence on traumatic vasospasm in the rabbit ear artery
Authors: Wadström Jonas , Gerdin Bengt
Published: March 2007

The effects of partial denervation, partial denervation with additional nervous blockade with bupivacaine, and total denervation achieved by amputation and replantation of the ear on traumatic vasospasm were studied in the rabbit. The central ear artery was exposed and compressed in a standardized fashion. The inner diameter was determined by in vivo microscopy using transillumination with cold light. The resulting spasm was assessed in terms of its duration, intensity (reduction of initial diameter), and severity (integrated change in diameter over time). None of the types of denervation had any influence on the vasospasm. The results suggest that the vasospasm is a local phenomenon of the vascular smooth muscle and is not modified by the nervous system.
The observation of endothelial cells in vein grafts by the en face silver staining method
Authors: Isogai Noritaka , Hashizume Keito , Uegaito Kaoru , Kamiishi Hiroshi
Published: March 2007

The introduction of en face silver staining to microsurgery has provided useful, detailed information about endothelial cells with regard to their size, shape, and number. With this staining method, endothelial cells of rat vein grafts have been morphologically investigated following division of the site of observation into three areas: the recipient artery, the proximal part of the vein graft, and the midportion of the vein graft. The results show that the arterial endothelial cells are small and spindle‐shaped, whereas the cells in the proximal vein graft location are larger. Finally, large, rounded endothelial cells are seen in the midportion of the graft. These results are quantitated through a computerized graphic analysis system, which provides estimations of the cell size, Feret's diameters, and irregularities in the cell borders. The combination of en face silver staining and computerized graphic analysis has been especially useful for comparing minute changes that occur in recovering/regenerating endothelial cells.
Anatomy and circulation of the canine skin
Authors: Pavletic Michael M.
Published: March 2007

The skin of the dog has several anatomic differences from human skin. Skin thickness, hair growth, and circulation vary regionally in the dog and between breeds to some degree. Direct cutaneous arteries supply the canine skin. The deep or subdermal layer is closely associated with the panniculus muscle (where present) and should be elevated with the overlying skin during routine flap elevation or undermining procedures. Flaps in the dog elevated without inclusion of a direct cutaneous artery and vein have been termed subdermal plexus flaps to avoid confusing them with random flaps in the human based on musculocutaneous vessels. Axial pattern flaps developed for veterinary clinical use are discussed, several of which have potential for free flap transfer in cutaneous reconstructive surgery.
Free tissue transfer of digital foot pads for reconstruction of the distal limb in the dog
Authors: Basher Anthony W. P. , Fowler J. David , Bowen C. Vaughan A.
Published: March 2007

Reconstructive procedures used in salvaging distal limb injuries in the dog are reviewed. Techniques employed to resurface the distal weight‐bearing surface include local reconstruction using pedicle flap transposition of foot pads. The development of a previously described free microneurovascular digital foot pad flap is reviewed; the experimental results and potential for clinical use of the free flap are discussed.
Microsurgical free bone transfer in the dog
Authors: Fowler J. David , Levitt Lyndell , Bowen C. Vaughan A.
Published: March 2007

Bone grafts have been used extensively for the reconstruction of skeletal injury in dogs. Cancellous and corticocancellous chip autografts are used for their osteoinductive and osteoconductive properties. Fresh, fresh‐frozen, freeze‐dried, and ethylene oxide‐sterilized cortical allografts have been recommended for the reconstruction of segmental cortical defects. Donor sites for microsurgical bone transfer have been identified experimentally in the dog, but these remain to be used clinically. This paper reviews the anatomy and structural characteristics of donor sites for microsurgical bone transfer. Potential clinical indications for microsurgical bone transfer in the dog are described.
Pedicled radial forearm flaps for recalcitrant defects about the elbow
Authors: Meland N. Bradly , Clinkscales Carlton M. , Wood Michael B.
Published: March 2007

Chronic, open wounds about the elbow frequently require flap coverage. Skin grafts, local transposition flaps, muscle transposition flaps, and two‐staged pedicled flaps from the chest and abdomen as well as free tissue transfers have all been reported. Recalcitrant elbow defects in patients in whom these previous flaps have failed are especially challenging to the upper extremity reconstructive surgeon. We have successfully employed pedicled radial forearm flaps in three patients in whom one or more previous flaps have failed.
Experience with calcium antagonists nitrendipine, diltiazem, and verapamil and β2‐agonist salbutamol in salvaging ischemic skin flaps in rabbits
Authors: Kawabata Hidehiko , Knight Kenneth R. , Coe Serena A. , Angus James A. , McC.o'brien Bernard
Published: March 2007

This study investigated the efficacy of selected agents in the salvage of experimental skin flaps in rabbits after 21 hours of 25°C ischemia. Calcium channel antagonists nitrendipine, diltiazem, and verapamil increased ischemic skin flap survival in rabbits from 33.3% for buffered saline infused controls to 71.4% (P < 0.05), 71.4% (P < 0.05), and 50.0% (not significant) respectively. The β2‐adrenoceptor agonist salbutamol produced an increase in survival to 64.3%, which narrowly missed statistical significance. All four test agents invoked a vasodilatory response (greatest for nitrendipine, diltiazem, and salbutamol), a slight fall in blood pressure, and a small increase in heart rate. It is concluded that the vasodilatory response in the microcirculation of the ischemic flap helped to minimize the risk of occlusion due to thrombosis or cell sludging during reperfusion, thus leading to improved flap survival.
Free vascularized whole joint transfer in children
Authors: Ishida Osamu , Tsai Tsu‐Min
Published: March 2007

Reconstruction of the traumatized finger joint with epiphyseal destruction has long been problematic. Since free vascularized whole joint transfer was introduced as a treatment for joint and epiphyseal destruction, this procedure has been selected as an alternative treatment because it may provide a growing epiphysis. We have reviewed our series of 19 joint transfers. Mean age at operation was 6.2 years (range 3 to 12). Average active range of motion was 31°/61° for the group with posttraumatic reconstruction (n = 12) and 21°/43° for the group with reconstruction of a congenital deformity (n = 7), with an overall average of 27°/54°. Average range of motion following transfer of an metatarsophalangeal (MTP) or metacarpophalangeal (MCP) joint to an MCP joint position was 39°/75° (n = 4); proximal interphalangeal (PIP) to PIP transfer was 22°/39° (n = 13); and PIP to MCP transfer was 38°/51° (n = 2). The proximal phalanges in MCP joints transferred to the MCP position grew an average of 7.0 mm, and the middle phalanges of joints transferred to the PIP position grew 4.3 mm. Almost normal growth was observed in all transferred joints except two that showed premature epiphyseal closure. Indications for this procedure and techniques to improve range of motion are described.
Major limb replantation in children
Authors: Daigle Jean Pierre , Kleinert James M.
Published: March 2007

This retrospective study evaluated patients under 18 years of age who underwent major limb replantation between 1976 and 1989 at Louisville Hand Surgery. The age of the 15 patients followed for between 1 and 8.5 years (mean 4.2 years) ranged from 2 to 17 years (mean 9.8). Of amputations, 40% were guillotine, 40% were limited crush‐avulsions, 7% were extended crushing, and eight were of an upper extremity and seven of a lower extremity. Average warm/total ischemia times were 4.8/14.8 hr in failures and 1.1/7.5 hours in successful replantation. Overall limb survival was 87%. Among the patients, 93% felt that their replanted limb functioned and looked better than a prosthesis; 87% of patients had a sensory recovery of more than S2 + in the lower extremity or S3 in the upper extremity; and 38% of upper extremity replantation patients had two‐point discrimination of less than 15 mm.
Replantation of severed fingers: Two unique cases
Authors: Zhou Guang‐Hen , Zhang Weng‐De
Published: March 2007

Two cases of amputated digits are reported. One involved a period of ischemia at freezing temperatures, and the other at unusually high temperatures. Both fingers survived upon replantation. The implications of extreme temperature upon ischemic tissues are discussed.
Root reconstruction for bladder reinnervation: An experimental study in rats
Authors: Chuang David Chwei‐Chin , Chang Phei‐Lang , Cheng Shaw‐Yi
Published: March 2007

Nerve transfer (or nerve crossover) is a well established technique for achieving reinnervation of a valuable sensory or motor territory by reconnection using a functional nerve of lesser value. Patients with lower spinal cord lesions causing neurogenic bladder dysfunction could theoretically benefit from such an approach for return of useful micturition. Based on the known anatomical details of the spinal nerve, a new reconstructive method was created to provide intradural ventral root transfer for pure motor‐to‐motor reinnervation and extradural postganglionic spinal nerve transfer for pure sensory‐to‐sensory reinnervation. Experimental studies in rats were performed, demonstrating the feasibility of this approach. A modified method is further suggested that would use nerve grafts for extradural approaches to pure motor and sensory transfers, without the need for extensive laminectomy and dura opening. This proposed approach is anticipated to minimize the associated morbidity and mortality with such spinal nerve reconstruction.
Refined technique for intestinal transplantation in the rat
Authors: Zhong Robert , Grant David , Sutherland Francis , Wang Pengzhi , Chen Huifang , Lo Steven , Stiller Calvin , Duff John
Published: March 2007

Unlike other solid organ transplants, intestinal transplantation (IT) remains a highly experimental procedure. Rejection, sepsis, and graft‐versus‐host disease have been the major barriers to successful IT in humans. These problems can be studied in the rat model, but this requires a reliable surgical technique that will produce high survival rates and excellent graft function. Herein, we review 400 consecutive IT in rats and describe important technical aspects of surgery. Technical modifications that have helped to reduce the morbidity after IT in rats include 1) minimizing mechanical and ischemic injuries to grafts during the donor procedure, 2) marking the portal vein and aortic conduit with sutures to ensure correct orientation of the graft, 3) using a macaroni noodle to stent the intestinal anastomosis, and 4) administering large volumes of crystalloid to maintain a normal blood pressure during the donor and recipient surgeries. The survival rate in 298 rats with accessory, heterotopic grafts was 90%. The survival rate in 102 rats with orthotopic (in continuity) graft (OIT) was 86%. Rats have survived more than 500 days after OIT, maintaining normal weights, intestinal function, and intestinal histology.
Use of anticoagulants in replantation and elective microsurgery
Authors: Siegel David B.
Published: March 2007

Clinical and experimental data support the adjunctive use of anticoagulant medication following microvascular anastomosis. Local irrigating solutions, oral and intravenous anticoagulants, thrombolytic agents, plasma expanders, vasodilators, and antiplatelet medications are currently used in patients undergoing microsurgery, but for some time there has been considerable controversy over the agent or combination of agents that should be used and the optimal time when administration should begin and end. Over the past 15 years, however, experience with microsurgery for replantation and elective reconstruction has increased dramatically. With this greater experience and refined operative technique, the indications for varying anticoagulant regimens have changed so that it is now possible to make specific recommendations for antithrombotic therapy in traumatic and elective situations.
Evaluation of the effect of pharmacologic agents on crush‐avulsion arterial injuries: A scanning electron microscopy study
Authors: Savoie F. H. , Cooley Brian C. , Gould John S.
Published: March 2007

This study was designed to investigate the short‐term formation and composition of thrombus occurring at sites of arterial intimal injury in rabbits. Anticoagulants, platelet anti‐aggregation agents, and fibrinolytic agents were evaluated for their influence upon the developing thrombus, utilizing scanning electron microscopy to determine thrombus surface composition. These agents included: heparin, aspirin, dextran 40, streptokinase, and prostacyclin. The results are consistent with the known nature of each of these agents. When two agents were given simultaneously, each acting on different aspects of thrombogenesis (platelets vs. fibrin), the outcome appeared synergistic, with substantial reduction in thrombus accumulation; clear inhibition of both platelet aggregation and fibrin polymerization was noted. These findings support the clinical use of two agents used simultaneously, one inhibiting fibrin strand formation and the other inhibiting platelet adherence/aggregation, for the prevention of micro‐arterial thrombosis.
Selective heparinization of venous anastomosis in latissimus dorsi free flaps to cover lower‐extremity soft‐tissue defects
Authors: Labosky David A.
Published: March 2007

Two groups of consecutive patients treated with latissimus dorsi free myocutaneous flaps to cover lower‐extremity soft‐tissue defects were compared for postoperative vascular occlusion. In the first group of 13 patients (group I), there were five (38%) venous occlusions and no arterial occlusions. The second group of 15 patients (group II) was treated with selective heparinization of each venous anastomosis via a 0.35′ catheter sutured into the serratus branch of the donor vein. In this group one patient suffered an arterial occlusion, but no patient suffered a venous occlusion. Statistical analysis using the Fisher exact probabilities test showed a significant decrease in vascular occlusion rate in group II, proving that selective heparinization had a beneficial effect on the venous patency rate.
International survey of current microvascular practices in free tissue transfer and replantation surgery
Authors: Salemark Lars
Published: March 2007

The replies to a questionnaire about current microvascular practice circulated to microsurgeons worldwide are summarized and discussed. The material comprises results of 6,594 procedures performed during 1989. The survey topics dealt with include overall success rates in free flap transfer and replantation surgery, antithrombotic therapy, frequency of thrombosis, and frequency of reoperation. At centres not using antithrombotic therapy, the frequency of thrombosis in free flap procedures was higher than at centres using antithrombotic therapy, the result being a higher reoperation rate at the former. However, the final success rates for free flap transfers were about the same (95‐96%). The success rate for replantation with antithrombotic therapy was 92%; few centres attempted replantation without such treatment, and at these centres, the success rate was 82%, and reoperation was not attempted. The same modes of antithrombotic therapy and postoperative monitoring are used worldwide.
A new technique for microvascular sleeve anastomosis
Authors: Zhang Ling , Tuchler Robert E. , Shaw William W. , Siebert John W.
Published: March 2007

This study describes our experience using an improved technique for microsurgical sleeve anastomosis of arteries. Modifications of previously described techniques include utilization of a sidecut and placement of the two stitches within separate vertical planes. In 40 arteries, we attained a patency rate of 97.5%. Histology, in vivo observation, and flow study using high‐frequency pulsed ultrasound Doppler at 2 hr to 8 weeks demonstrate that the sidecut sleeve anastomosis shows patency and flow characteristics similar to those of standard end‐to‐end anastomosis, but with a dramatic decrease in operative time.