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Background: Intracorporeal anastomoses in totally laparoscopic gastrectomy (TLG) remain technical challenges to many surgeons, although the intracorporeal jejunojejunal or gastrojejunal anastomosis is an essential procedure during TLG. Standardized, reproducible and simple circular-stapled anastomosis in open gastrectomy is limited in TLG due to the difficulties of intracorporeal purse-string suture or anvil placement. An optimal procedure for intracorporeal anastomosis in TLG remains to be established., Methods: Between February 2018 and January 2019, 31 consecutive patients with gastric cancer underwent totally laparoscopic total gastrectomy (TLTG) or totally laparoscopic distal gastrectomy (TLDG) using the novel u-shaped parallel purse-string suture technique along the jejunum for anvil placement. The intracorporeal circular-stapled jejunojejunostomy of Roux-en-Y reconstruction in TLTG and gastrojejunostomy of Billroth II in TLDG were, respectively, performed., Results: The total mean  ± SD operative time was 214.7 ± 48.6 minutes. The time required for purse-string suture and anvil placement was 2.3 ± 0.5 and 4.4 ± 1.1 minutes, respectively. There were no instances of postoperative jejunojejunal or gastrojejunal anastomosis-related complications observed during the median follow-up period of 5.5 months., Conclusions: The novel procedure conceptionally and technically changes the conventional circular-shaped purse-string suture into a much simpler way, u-shaped parallel purse-string suture. This could be the simplest published intracorporeal pure-string suture technique., (© 2019 Wiley Periodicals, Inc.)

Background: Anastomotic stricture following esophagogastrectomy (EG) can lead to significant dysphagia, necessitating interventions such as endoscopic dilatation. These post-operative complications gain importance with the increased survival rate of patients after EG. This study aimed to assess the outcomes of both circular-stapled (CS: 25 and 29 mm) and hand-sewn (HS) anastomoses after EG., Methods: We reviewed prospectively accrued data from December 2004 to December 2014 identifying all patients undergoing EG for esophageal cancer. Immediate post-operative and long-term complications were noted. Primary outcome measures included anastomotic leak and stricture, dysphagia, and subsequent., Results: A total of 142 patients were identified for analysis. The method used for reconstruction was noted: CS-EEA-25 mm (n = 30), CS-EEA-29 mm (n = 30), and HS (n = 82). Demographics, tumor pathology, and tumor locations were similar in each group. All groups experienced similar rates of anastomotic leak, stricture, and dysphagia. Furthermore, post-operative dilations for symptomatic dysphagia were required in 3 (10%), 4 (13%), and 9 (11%) patients, P = 0.91., Conclusion: In this cohort, the method of anastomotic construction had no bearing on the rate of complications after EG for the treatment of esophageal cancer. Furthermore, long-term need for dilations for symptomatic dysphagia was equal among all groups., (© 2017 Wiley Periodicals, Inc.)

Objectives: Uncontrolled hypertension, whether due to drug resistance or poor adherence and persistence, remains a problem in many patients. The ROX coupler is a novel technology designed to reduce arterial blood pressure consequent to the predicted physical effects of reducing vascular resistance and improving arterial compliance. This article describes the technical aspects of the device and implantation procedure, results from a preclinical study, patient selection criteria, and potential complications of this therapy for uncontrolled hypertension., Background: The coupler is a self-expanding, stent-like device that exploits the mechanical effects of the creation of a low-resistance, high-compliance venous segment to the central arterial tree, and can be implanted in a standard catheterization laboratory under fluoroscopic guidance., Methods: Preclinical studies were conducted in sheep with acute or chronic hypertension. The devices were implanted in the aorta for up to 12 months. The anastomoses were evaluated for patency, healing, conformation into the artery and vein, and complications., Results: Deployment of the anastomotic device in ovine aortas for up to 12 months showed optimal anastomotic patency in all animals with proper healing and conformation of the device into the artery and the vein. There was no significant residual mural thrombus and minimal to moderate intimal thickening at the vein outflow, consistent with expected arterialization., Conclusions: A novel arteriovenous coupler for percutaneous placement in the iliac vasculature is under clinical investigation as a potential treatment modality for selected patients with uncontrolled hypertension. Initial results from patients with uncontrolled hypertension are expected in Autumn 2014., (© 2014 Wiley Periodicals, Inc.)

Background: Lymphatic supermicrosurgery, lymphaticovenular anastomosis (LVA), is becoming a treatment option for progressive lymphedema with its effectiveness and minimal invasiveness. It is important to detect and anastomose large functional lymphatic vessels for LVA surgery. This study aimed to evaluate usefulness of a near-infrared illumination system-integrated microscope for lymphatic supermicrosurgery., Methods: We performed LVA on 12 lower extremity lymphedema (LEL) patients with or without intraoperative microscopic indocyanine green (ICG) lymphography guidance. An operating microscope equipped with an integrated near-infrared illumination system (OME-9000; Olympus, Tokyo, Japan) was used for intraoperative microscopic ICG lymphography guidance. Feasibility, anastomosis patency, and treatment effect of the method were evaluated., Results: Forty LVAs were performed (24 LVAs with intraoperative microscopic ICG lymphography-guidance on 7 limbs, and 16 LVAs without the guidance on 5 limbs). Lymphatic vessels were enhanced by intraoperative microscopic ICG lymphography in 11 of 12 skin incision sites. Time required for detection and dissection of lymphatic vessels in cases with intraoperative microscopic ICG lymphography guidance was significantly shorter than that in cases without the guidance (2.3 ± 1.7 min vs. 6.5 ± 4.0 min, P = 0.010). There was no statistically significant difference in LEL index reduction between cases with and without intraoperative microscopic ICG lymphography guidance (18.3 ± 5.5 vs. 15.0 ± 5.5, P = 0.337)., Conclusions: Intraoperative microscopic ICG lymphography visualized lymphatic vessels, which helps a lymphatic supermicrosurgeon to find and dissect lymphatic vessels earlier., (Copyright © 2013 Wiley Periodicals, Inc.)

Background: Autologous microvascular breast reconstruction is an increasingly common procedure. While arterial anastomoses are traditionally being hand-sewn, venous anastomoses are often completed with a coupler device. The largest coupler size possible should be used, as determined by the smaller of either the donor or recipient vein. While its efficacy has been shown using 3.0-mm size and greater couplers, little is known about the consequences of using coupler sizes less than or equal to 2.5 mm., Methods: A retrospective chart review of patients undergoing autologous breast reconstruction was conducted at NYU Medical Center between November 2007 and November 2011. Flaps were divided into cohorts based on coupler size used: 2.0 mm, 2.5 mm, and 3.0 mm. Outcomes included incidence of arterial or venous insufficiency, hematoma, fat necrosis, partial flap loss, full flap loss, and need for future fat grafting., Results: One-hundred ninety-seven patients underwent 392 flaps during the study period. Patients were similar in age, type of flap, smoking status, and radiation history. Coupler size less than or equal to 2.0 mm was found to be a significant risk factor for venous insufficiency (P = 0.038), as well as for development of fat necrosis (P = 0.041) and future need for fat grafting (P = 0.050). In multivariate analysis, body mass index was found to be an independent risk factor for skin flap necrosis (P = 0.010) and full flap loss (P = 0.035)., Conclusions: Complications were significantly increased in patients where couplers of 2.0 mm or less were used, therefore to be avoided whenever possible. When needed, more aggressive vessel exposure through rib harvest, the use of thoracodorsal vessels or hand-sewing the anastomosis should be considered in cases of internal mammary vein caliber of 2.0 mm or less., Clinical Question: Therapeutic., Level of Evidence: Level III., (Copyright © 2013 Wiley Periodicals, Inc.)

Background and Objectives: Laser-based repairing techniques offer several advantages respect to standard suturing in microsurgery. In this work we evaluate the applicability and feasibility of two innovative laser-based approaches for microvascular repair and anastomoses: (1) laser-assisted vascular repair (LAVR); (2) laser-assisted end-to-end vascular anastomosis (LAVA). All these procedures have been executed by the use of diode laser irradiation and chitosan-patches infused with Indocyanine Green (ICG)., Study Design/materials and Methods: Experiments were performed on 30 rabbits. Twenty animals underwent LAVR and 10 end-to-end LAVA procedures. In the LAVR group, a 5-mm longitudinal cut was performed on the common carotid artery (CCA), then an ICG-infused chitosan patch was topically applied and laser-soldered over the arterial lesion. In the LAVA group the end-to-end anastomosis was executed on CCA by means of application of the three interrupted sutures and subsequent laser soldering of the ICG-infused patch. Animals underwent different follow-up periods (2, 7, 30, and 90 days). At the end of every follow-up, the animals were re-anesthetized and a microdoppler analysis was performed in order to check patency of the treated vessels. Then soldered segments were excised and subjected to histological and ultrastructural evaluations., Results: At the end of surgery no bleeding from the treated segment was observed; all the treated vessels were patent. At the end of follow-up periods, no signs of perivascular haemorrhage were found. An intraoperative microdoppler evaluation assessed the patency of all the treated vessels. Histology showed a good reorganization of the vascular wall structures and an early endothelial regeneration was observed by SEM., Conclusions: Our study demonstrated the efficacy of laser tissue soldering by means of ICG-infused chitosan patches for the in vivo repairing of microvascular lesions and end-to-end anastomoses. This approach offers several advantages over conventional suturing methods and is technically easy to perform, minimizing the surgical trauma to vessels., (Copyright © 2013 Wiley Periodicals, Inc.)

Background: Since the birth of reconstructive microvascular surgery, attempts have been made to shorten the operative time while maintaining patency and efficacy. Several devices have been developed to aid microsurgical anastomoses. This article investigates each of the currently available technologies and attempts to provide objective evidence supporting their use., Methods: Techniques of microvascular anastomosis were investigated by performing searches of the online databases Medline and Pubmed. Returned results were assessed according to the criteria for ranking medical evidence advocated by the Oxford Centre for Evidence Based Medicine. Emphasis was placed on publications with quantifiable endpoints such as unplanned return to theatre, flap salvage, and complication rates., Results: There is a relative paucity of high-level evidence supporting any form of assisted microvascular anastomosis. Specifically, there are no randomized prospective trials comparing outcomes using one method versus any other. However, comparative retrospective cohort studies do exist and have demonstrated convincing advantages of certain techniques. In particular, the Unilink™/3M™ coupler and the Autosuture™ Vessel Closure System® (VCS®) clip applicator have been shown to have level 2b evidence supporting their use, meaning that the body of evidence achieves a level of comparative cohort studies., Conclusion: Of the available forms of assisted microvascular anastomoses, there is level 2b evidence suggesting a positive outcome with the use of the Unilink™/3M™ coupler and the Autosuture™ VCS® clip applicator. Other techniques such as cyanoacrylates, fibrin glues, the Medtronic™ U-Clip®, and laser bonding have low levels of evidence supporting their use. Further research is required to establish any role for these techniques., (Copyright © 2011 Wiley-Liss, Inc.)

Background: Microvascular anastomotic coupling devices have been available to microsurgeons for over 20 years. Many studies have validated the efficacy of these devices for venous anastomosis. To date, there have been no large reports of their success in the anatomical region with the highest free flap failure rate, the lower extremity., Methods: A retrospective review of 67 consecutive patients who underwent lower extremity microvascular reconstruction performed from August 2003 to September 2010 was performed. Patient charts were reviewed for age, sex, medical comorbidities, etiology of defect, location of defect, flap type, anastomotic technique, complications, flap survival, and limb salvage outcome., Results: No patients returned to the operating room to have an arterial or venous anastomosis revised. Despite 100% vascular anastomosis patency rates in 67 consecutive lower extremity free flaps, flap survival rate was 95.5%. Total complication rate (13.4%) was due to two partial and one complete flap loss, three infections, two skin graft loses, and one hematoma. There were no intraoperative or perioperative complications involving the use of a microvascular anastomotic coupling device itself. Thirty-day and long term limb salvage rate was 97% and 92.5%, respectively., Conclusion: Microvascular anastomotic coupling devices create effective venous anastomoses in lower extremity microvascular reconstruction. Thus, it presents an important tool in the armamentarium for lower extremity microsurgical reconstruction., (Copyright © 2011 Wiley-Liss, Inc.)

Background: While modern reconstructive surgery was revolutionized with the introduction of microsurgical techniques, microsurgery itself has seen the introduction of a range of technological aids and modern techniques aiming to improve dissection times, anastomotic times, and overall outcomes. These include improved preoperative planning, anastomotic aides, and earlier detection of complications with higher salvage rates. Despite the potential for substantial impact, many of these techniques have been evaluated in a limited fashion, and the evidence for each has not been universally explored. The purpose of this review was to establish and quantify the evidence for each technique., Methods: A search of relevant medical databases was performed to identify literature providing evidence for each technology. Levels of evidence were thus accumulated and applied to each technique., Results: There is a relative paucity of evidence for many of the more recent technologies described in the field of microsurgery, with no randomized controlled trials, and most studies in the field comprising case series only. Current evidence-based suggestions include the use of computed tomographic angiography (CTA) for the preoperative planning of perforator flaps, the intraoperative use of a mechanical anastomotic coupling aide (particularly the Unilink® coupler), and postoperative flap monitoring with strict protocols using clinical bedside monitoring and/or the implantable Doppler probe., Conclusion: Despite the breadth of technologies introduced into the field of microsurgery, there is substantial variation in the degree of evidence presented for each, suggesting the role for much future research, particularly from emerging technologies such as robotics and modern simulators., (Copyright © 2010 Wiley-Liss, Inc.)

Although the devices for large-caliber vessel (>2-mm diameter) anastomosis are available, there are no devices for performing anastomosis of small-caliber vessels. We designed a hooked device composed of a bioabsorbable polymer for sutureless anastomosis of small-caliber vessels. The efficacy of this device was evaluated by in vitro degradation and arterial-fixation strength tests as well as in vivo transplantation experiments with common carotid arteries of growing SD rats. A nonabsorbable device without hooks served as the control in the fixation strength and animal experiments. The tensile strength of the bioabsorbable device decreased to 27 and 9% of the initial value after 8- and 24-week incubation, respectively. The fixation strength was greater and the anastomotic time was shorter with this device than with the control. The transplantation experiments showed complete endothelial bridging in both devices at 2 weeks after surgery (n = 6). The control device created a considerable protrusion into the arterial lumen at 8 postoperative weeks, whereas the experimental device did not (n = 6). Arterial diameter measurements detected a significant difference between the inner diameters at the respective anastomotic sites (n = 6, P < 0.05) and demonstrated that the control device hindered the vessel growth while the experimental device did not. Therefore, the bioabsorbable hooked device was an effective tool for anastomosis of small-caliber arteries (ca. 1-mm diameter).

Background and Objectives: Microvascular surgery associates intricate surgical techniques to join tiny blood vessels and help transfer large amount of tissues. Successful venous anastomosis remains the main challenge because inadequate blood flow correlates with a major risk of free flaps venous congestion and thrombosis. The aim of this study is to assess blood flow after laser-assisted microvascular anastomosis (LAMA) using a 1.9-microm diode laser., Study Design/materials and Methods: LAMA was performed on a series of 10 external jugular veins of Wistar rats. Two stay sutures and a standard laser tissue welding technique (lambda: 1.9 microm; power: 110 mW) were used. Similarly, a series of 10 conventional venous anastomosis were performed (CSMA). In both groups, contralateral non-operated jugular veins were used as control. MRI was used to perform positioning, anatomical, angiographic blood flow sequences, 1 day post-procedure and at 1, 4 and 8 weeks., Results: Venous patency rate was 100% at the time of surgery. Mean clamping time was 7.9 minutes in the LAMA group compared to 11.4 minutes in the CSMA group. In the angiographic sequence, there were no aneurysms in both groups for all observation periods. At post-operative day 1, mean loss of blood flow at the level of anastomosis in the LAMA group was 7% compared with 22% in the CSMA group. At 1, 4 and 8 weeks, blood flow reduction was greater in the CSMA group: 34%, 38% and 41%, respectively, compared to 12%, 15% and 16% in the LAMA group. Moreover, three cases of thrombosis were observed in the venous anastomosis performed with the conventional technique at 1 (n = 2) and 3 months (n = 1)., Conclusion: The flow-MRI further demonstrates that 1.9 microm diode LAMA is a consistent, reliable and reproducible technique, capable of improving blood flow in veins when compared to conventional surgery., ((c) 2010 Wiley-Liss, Inc.)

Autologous breast reconstruction with microsurgical free tissue transfer has become routine, and perforator-based adipocutaneous flaps are recognized as an excellent option for many patients. Current efforts to optimize patient outcomes focus on minimizing operative morbidity both at the donor and recipient sites. The DIEAP flap avoids most of the abdominal wall morbidity associated with the TRAM. At the recipient site, however, partial rib resection, for access to the internal mammary (IM) artery and vein as recipient vessels, has a risk of chest wall pain, deformity, and pneumothorax. Perhaps more importantly, sacrifice of the IM vessels precludes their use for potential future coronary revascularization. To avoid this, the intercostal perforating branches from the internal mammary system may be used as recipient vessels for microanastomosis. This has been well described using suture technique, although the use of a mechanical coupling device for arterial anastomosis to the perforator has not been reported. We report nine cases whereby a mechanical coupling device was used to perform both the arterial and venous anastomoses of DIEAP and SIEA flap pedicles to IM intercostal perforating vessels. Flap ischemia time was shorter in all cases, allowed ease of anastomosis for vessel size mismatch, and is technically easier in deep wounds. This technique is a further refinement to free flap breast reconstruction and is a powerful application of the coupling device., ((c) 2008 Wiley-Liss, Inc.)

Technical difficulties hamper the widespread use of intestinal transplantation in rats. We evaluated the feasibility in training this microsurgical model for medical students. Thirty eight students were assessed. After information about intestinal transplantation in rats, they spontaneously agreed to be trained for this procedure. The course consisted of 4-h weekly lessons during 4-month period. The teaching process includes assessment in four phases: I) conception of intestinal transplantation and rat anatomy; II) basic microsurgery training; III) donor operation; IV) donor/recipient operation. Wistar rats were used as donors and recipients in one-step small bowel transplantation. All students (100%) reached phase II, seven students (18.42%) reached phase III and two students (5.26%) reached phase IV. Decreased interest about the theme, lack of time and patience, frustration and/or inability were all reasons given by the student that may have contributed to the low rate of success. Medical students achieved a low rate of completion for training in rat intestinal transplantation microsurgical procedures.

Free microvascular tissue transfers have become today a key instrument for the surgical treatment of wide loss of tissue. These procedures can provide definitive treatment in a single operation but they are expensive and require specialized practitioners. The operating microscope traditionally has provided this requirement; our study is focusing on the prospect of using a new visual system-Varioscope M5-in the reconstructive microsurgery field. Varioscope M5 (Life Optics, Vienna, Austria) has been employed in 21 microvascular anastomoses, where different free flaps were used in head and neck reconstruction. The necessity to operate in a different department, not provided with an operating microscope, brought along the idea of exploring an alternative procedure to classical visualization systems. Specific advantages such as reduced cost, freedom of movement, autofocus, minimal upkeep, a variable range of magnification from 2x to 9x are some of the reasons that convinced the authors to use this new type of magnification system. Increasing interest in microsurgery magnification highlights the need for further technical development in that field. We consider Varioscope M5 a future mean of anastomotic magnification in most free-tissue transfers with specific characteristics that combine the microscope and loupe philosophies., ((c) 2007 Wiley-Liss, Inc.)

Renal transplantation is a potential treatment for irreversible renal failure in pet cats. Our aim is to reduce warm ischemic time by using nonpenetrating vascular closure staples (VCS), thereby improving graft survival. Experimental cats were divided into the VCS group (n = 4; autotransplantation) or suture group (n = 6; allotransplantation). The renal artery was anastomosed with the external iliac artery in an end-to-end fashion, and the renal vein was attached to the external iliac vein in an end-to-side fashion. Warm ischemic time as well as arterial and venous anastomotic times were measured. Cats in the suture group were administrated cyclosporine and prednisolone orally after transplantation. Ischemic and anastomotic times in the VCS group were significantly reduced compared with the suture group. Two of 6 allografts had a ureteral anastomotic stricture, and 4 allografts were rejected. Histological findings of autografts showed normal structure. In conclusion, VCS staples were useful in feline renal transplantation., (Copyright 2006 Wiley-Liss, Inc.)

Microvascular anastomosis is a demanding skill requiring technical excellence and a thorough knowledge of anatomy and physiology. Every suture placed in a microvascular anastomosis should be considered critical as each has the potential to compromise the delicate reconstruction. As such, any device that can facilitate microvascular suture placement deserves thorough evaluation. The U-clip (Coalescent Surgical, Sunnyvale, CA) is such a device in that it eliminates the often time consuming process of tying knots. We evaluated use of the U-clip in microvascular anastomosis of a 1.5 mm artery. We found the U-clip to offer some advantages including ease of use, traditional feel of directed suture placement (as compared to couplers), and elimination of time needed for knot tying. Its shortcomings include size (in diameter, the "pop-off" section of the device appears larger than standard 8-0 suture), the significant force required to "pop-off" the device and difficulty removing the device., (Copyright (c) 2006 Wiley-Liss, Inc.)

Mechanical couplers are successfully used for microvascular venous anastomoses. The advantages include a simple and fast technique and a high patency rate. Couplers offer a secluded coaptation site, and might also be of use in peripheral nerve repair. The present study was designed to investigate coupler coaptation of the rat sciatic nerve, evaluating the number and locations of motor and sensory neurons projecting to the selected muscles as well as stimulation-induced muscle contraction force. Adult rats underwent either suture or coupler repair after left sciatic nerve transection. In all rats, the experimental side was compared to the healthy right side. Evaluation after 20 weeks included retrograde labeling of motoneurons and dorsal root ganglion neurons projecting to the tibial anterior muscle and to the tibial posterior muscle, histology, muscle contraction force (tibial anterior muscle and gastrocnemius muscle), and a pinch reflex test. The results show that the suture and the coupler groups did not differ significantly regarding the examined parameters, except for discrete signs of nerve compression at the coaptation site after coupler repair due to fibrous tissue ingrowth. However, this did not impair axonal regeneration. Importantly, axonal outgrowth from the repair site to the surrounding tissue was not observed after coupler coaptation, but it was observed after suture repair. These results suggest that couplers may be of value for repair of nerves in adjacency to avoid axonal crisscrossing between nerves during regeneration., (Copyright (c) 2005 Wiley-Liss, Inc.)

A recent advance in technology permits the creation of sutureless proximal aortic anastomosis during coronary artery bypass graft surgery. This new tool has significant potential benefit by minimizing aortic manipulation with subsequent reduction in neuroembolization. Implantation of a nitinol-based proximal aortic connector (Symmetry) has a potential to elicit intimal hyperplastic reaction analogous to restenosis after coronary stent placement. We report cases of early vein graft stenosis in association with the use of the Symmetry device. Three patients suffered from severe ostial stenosis within 6 months of bypass surgery with symptomatic presentation. Of these three patients, two underwent successful percutaneous revascularization. Fluoroscopic star-shaped appearance of the metallic Symmetry allows device recognition during angiography. We review current data regarding graft patency with the use of Symmetry device and discuss technical issues to address specific problems during percutaneous revascularization., (Copyright 2004 Wiley-Liss, Inc.)

In the search for better anastomosing techniques, an improved vascular stapler device (VCS clip applier system(R)) has been introduced. The system uses nonpenetrating clips to approximate everted vessel walls. The objective of this study was to determine the effects of nonpenetrating vascular clips on endothelial wound healing. Aortic end-to-end anastomoses were performed in male Wistar rats. A comparison was made between clipped (n = 12) and conventional hand-sewn (n = 6) anastomoses. Patency rates were verified at different time intervals (after 1, 4, and 8 weeks), after which the anastomotic sites were removed. Morphological evaluation was carried out using scanning electron microscopy. All rats survived the procedure. Closure with clips took less time than closure with conventional sutures, with decreasing aortic clamping times for the clipped procedures during the course of the experiments. Patency rates were 100% in both the "clipped" and "sutured" groups. Microscopic examination showed favorable endothelial healing at the clipped anastomotic sites, with less inflammatory reaction at 1 week, and a more complete endothelial regeneration at 4 and 8 weeks follow-up, as compared with the sutured anastomoses. The clip applier holds the promise of a useful device in anastomosing small-caliber vessels, since clip closure takes less time than suturing, while patency rates are identical, and morphological results are favorable. Training is mandatory to obtain technical skills and to achieve optimal results., (Copyright 1999 Wiley-Liss, Inc.)

In the rabbit, posterior facial vein segments were grafted to the femoral arteries using either conventional suture technique or a mechanical absorbable pinned-ring device. The purpose of this study was to compare patency rates and anastomotic times for the two different methods. The anastomoses were evaluated macroscopically and using light and scanning electron microscopy. The grafts anastomosed with the absorbable rings exhibited 100% patency, while only 83% of the sutured grafts were patent. The mean anastomotic time using the mechanical pinned-ring device was 18.1 min (range 9.8-30 min). The conventionally sutured anastomoses were completed in a mean time of 60 min (range 50-75 min). The experiment has confirmed that the absorbable pinned-ring device provides a safe and fast way to perform microvascular anastomosis.

Using the technique of radioactive 51Cr-labeled biological microspheres, this study evaluated arterial blood flow following small vessel anastomosis by CO2 laser welding and a dissolvable stent in the lumen. A total of 30 Sprague-Dawley rats were divided into two groups. Group A: 11 rats had their femoral arteries ligated on one side. The contralateral side served as a control, with the artery transected and repaired using conventional microsuturing. Group B: 19 rats had their femoral arteries transected and repaired using CO2 laser welding and an intraluminal dissolvable stent technique. The contralateral side was again used as a control using conventional microsuturing. At 1 hr postoperatively, 51Cr-labeled biological microspheres were injected centripetally into the left common carotid artery and the legs and thighs immediately harvested for measurement of radioactivity. All repaired arteries were patent (30/30 in the microsuturing group and 19/19 in the stented welding group), with no detectable stenosis or dilation at the repaired site. Statistical analysis showed that tissue radioactivity (cpm/g) in the ligated group (3,972 +/- 384 in thighs and 3,142 +/- 742 in legs) was significantly lower than in the microsuturing group (7,132 +/- 1,723 in thighs and 6,557 +/- 1,469 in legs) (P < 0.01). In the ligated group, a significant reduction of blood flow was seen in the legs when compared with the thighs (P < 0.05). There was no significant difference in radioactivity when comparing the microsuturing control with the stented welding group, in both thighs (7,064 +/- 2,599 and 7,006 +/- 2,406, respectively; P > 0.05) and legs (6,386 +/- 1,703 and 6,288 +/- 1,757, respectively; P > 0.05). This study provided evidence that the dissolvable stent placed intraluminally does not impair blood circulation and that when coupled with CO2 laser welding offers a high-quality alternative to conventional small vessel anastomosis.

With the introduction of endoscopy to surgery, it has become apparent that magnification similar to the magnification provided by the surgical microscope can be achieved with its use. Endoscopic techniques provide both magnification and the ability to operate at a distance, potentially increasing the applications of microsurgery. An endoscopic unit is significantly less expensive than the operating microscope. Furthermore, it enables invasive techniques utilizing smaller incisions. The purpose of this project was to investigate whether the visual assistance provided by the endoscope is sufficient to perform a microvascular anastomosis. An initial experiment with six rats is presented. The right femoral artery was isolated, divided, and reconstructed by standard microanastomosis with the visual assistance provided by a 4-mm endoscope. All anastomoses were patent at 7 days by microangiography and histology. The magnification provided by the endoscope is sufficient for the creation of a microvascular anastomosis.

The use of aorto-coronary graft markers has not been standard, presumably due to concern about possible adverse effects on subsequent graft patency. Our goal was to determine if there was any increased risk of graft occlusion in patients who received circumferential graft markers at the time of their coronary artery bypass (CAB) surgery. A retrospective review of angiograms was performed for patients with prior CAB. Cohorts with and without graft markers were compared. A total of 405 "unmarked" and 311 "marked" grafts were identified in 335 patients meeting inclusion criteria. Patency is reported in divisions of elapsed time since CAB. Overall patency in the "marked" group (71.1%) was significantly higher than in the "unmarked" group (58.0%, P < 0.001). In this retrospective population, there was no increased risk of graft occlusion in patients who received circumferential graft markers at the time of CAB surgery as compared to those patients who did not.

Objective: When coronary and graft angiography is required for patients with prior coronary artery bypass (CAB) graft surgery, it is often difficult to localize the proximal aorto-coronary graft anastamosis. Our goal was to quantify the potential benefit during subsequent angiography if the proximal anastamosis is marked by an aorto-coronary graft marker at the time of CAB., Methods: Retrospective review of 414 angiograms that were performed for patients with prior CAB. Cohorts with an without graft markers were compared., Results: In the group with aorto-coronary graft markers and > or = 2 aorto-coronary grafts, there were significant reductions in fluoroscopy time (30.5%, p < 0.0001), contrast volume (21.7%, p < 0.0001), and numbers of angiographic catheters used (17.0%, p = 0.0001). If only one aorto-coronary graft was placed and marked, a trend toward reduced fluoroscopy time was observed (23.8%, p = 0.07)., Conclusions: This study demonstrates the objective benefit supporting routine placement of circumferential aorto-coronary graft markers during CAB, particularly if > 1 graft is required.

Background and Objective: Temperature feedback control (TFC) during laser-assisted tissue welding was implemented to eliminate exponential increases in the rate of denaturation associated with rapidly increasing temperatures. This study was undertaken to investigate and compare the weld strengths and healing responses of laser welded enterotomies with and without TFC using a cw Ho:YAG laser and to examine the effects of wavelength on weld strength and histology. The Ho:YAG experimental results were compared with a similar study using cw argon ion laser irradiation., Study Design/materials and Methods: An automated system was developed for temperature feedback controlled laser irradiation. An experimental device incorporating co-aligned laser delivery and temperature detection was used to perform cw Ho:YAG laser-welded enterotomies (with and without TFC). The weld strength and histology of laser welded and control sutured enterotomies were compared in an in vivo rat model (Ho:YAG, n = 42; argon, n = 41). Animals were sacrificed at 1, 3, 7, and 21 days postoperatively and the anastomotic site was removed for bursting/leaking pressure measurements and histological examination., Results: Argon and Ho:YAG laser-welds with and without TFC and the control sutured anastomoses healed comparably, although wound abscesses were more prevalent in the Ho:YAG group leading to delay in mucosal healing. Laser-welded anastomoses without TFC were associated with more spontaneous ruptures and leaks (argon: 4/6 ruptures; Ho:YAG: 1/4 leak, 2/4 ruptures, & 1/3 stenosis) during the survival period than those with TFC (argon: 1/3 leak; Ho:YAG: 1/5 rupture). Bursting pressures of the Ho:YAG welds were weaker at 1 week than the argon welds, but by 3 weeks, laser welds and suture anastomoses were equally strong., Conclusion: From the spontaneous failure rates encountered, it is believed that TFC improves the quality and stability of laser-assisted enterotomy closures in surviving animals. However, TFC does not provide a satisfactory method to identify completion of a weld.

Background and Objective: Thermal denaturation of proteins is recognized as a rate process governed by the local temperature-time response. Since rate processes are exponential with temperature, laser-assisted tissue welding was performed with and without temperature feedback control (TFC) to investigate the efficacy of temperature feedback in enhancing the photothermal welding process in vivo., Study Design/materials and Methods: An automated system was developed for temperature feedback controlled laser irradiation. An experimental device incorporating co-aligned laser delivery and temperature detection was used to perform argon laser welded (with and without TFC) enterotomies. The weld strength and histology of laser welded and control sutured enterotomies were compared in an in vivo rat model. Animals (n = 41) were sacrificed at 1, 3, 7, and 21 days postoperatively, and the anastomotic site was removed for bursting/leaking pressure measurements and histological examination., Results: Laser-welded (with and without TFC) and control sutured anastomoses in surviving animals healed comparably. Some laser-welded anastomoses without TFC ruptured spontaneously (4 out of 15) leading to the animals' death within the first 24-36 hours postoperatively. None of the animals in the other groups had this problem (control suture 0/6; laser with TFC 1 leak/8). The bursting/leaking pressures of the laser welded anastomoses were not significantly different than those of the sutured controls., Conclusion: TFC improves the quality of laser-welded rat intestinal anastomoses in vivo in the critical first postoperative 36 hours.

Various anastomotic coupling systems have been developed aiming to facilitate microvascular anastomoses. Of these only the 3M Precise Microvascular Anastomotic System (MAS) has recently gained increasing popularity. However, clinical studies on the use of the MAS are sparse. We report our clinical experience with the MAS in a two-centre study between 1991 and 1996. Of the 96 MAS coupling rings used, 50 were accessible for final analysis, and a 100% patency rate was obtained. The main indication is venous end-to-end anastomosis in vessels of minimal discrepancy. In selected cases in head and neck surgery even end-to-side venous anastomoses appear to be feasible. Although it is not universally applicable for microvascular anastomoses, we conclude that, if appropriate, the MAS coupling device leads to a reliable venous anastomosis in a greatly reduced operating time of less than 4 minutes.

Background and Objectives: Fistula and stricture formation at the site of sutured anastomoses are frequent complications of major urethroplasty. We performed urethroplasty using laser-welded skin tube grafts in the hope that in addition to being free of suture holes, grafts would be as strong as or stronger than sutured controls., Study Design/material and Methods: Scrotal skin was harvested from each of 11 rabbits and fashioned into tubes 3-4 cm in length using either conventional suture techniques or laser welding. Welding was performed using an 808-nm diode laser and a dye-enhanced solder composed of albumin and sodium hyaluronate. Laser power density was 15.9 watts/cm2. For each graft, leak pressure, and urethroplasty time (tube creation and anastomosis to native urethra) were measured., Results: Urethroplasty time was significantly shorter and initial leak pressures were seven times greater in the laser-welded group., Conclusions: The near-uniform occurrence of strictures in both groups suggests that the rabbit is not an ideal model for free tube graft urethroplasty. However, our data indicate that laser welding with albumin-based solder, when used in the appropriate setting, may offer the potential for the rapid creation of watertight grafts in reconstructive urology.