Experimental laser-assisted end-to-side microvascular anastomosis

The authors present a new technique of end-to-side microvascular anastomosis in a rat carotid artery model, employing a milliwatt CO2 laser. Both carotid arteries were isolated and approximated in an end-to-side fashion by the placement of four 10-0 nylon stay sutures. The milliwatt CO2 laser was used to effect vessel anastomosis between the sutures, using 70-100 mW of power. Animals were killed 8 weeks postoperatively. Angiography of each anastomosis was performed in all animals. All anastomoses were then harvested, and submitted for histological analysis. Anastomotic patency was 100%, both intraoperatively and angiographically. There was no evidence of intravascular thrombus, anastomotic stenosis, or pseudoaneurysm formation. Early in the experiment, some anastomoses showed localized dilatation at the anastomotic site. The histologic changes at the anastomotic site are described. Laser-assisted microvascular anastomosis is a feasible technique, and a potential alternative to conventional suture techniques.     

Clinical experience with non-penetrating vascular clips in free-flap reconstructions.

To date, the gold standard for performing a microvascular anastomosis has been the penetrating suture with attached needle. During the last two decades, non-penetrating techniques have been introduced, including the Unilink system for end-to-end anastomoses, and the VCS clip-applier system for both end-to-end and end-to-side anastomoses. The aim of this study was to compare the results of different techniques used to create microvascular anastomoses in free-flap reconstructions. Between January 1995 and October 1999, we performed 474 microvascular anastomoses in 216 consecutive free-tissue transfers. The anastomosis techniques included manual sutures (42%), Unilink rings (34%) and VCS clips (24%). Seven combined sutured-clipped anastomoses were excluded from further analysis. The mean anastomotic time when rings were applied was significantly shorter than when using clips (P 0.0001) or sutures (P 0.0001). Venous anastomoses using clips took less time than those using sutures (P 0.05). There were 19 anastomotic failures, all of which lead to early flap failure. Ten flaps were salvaged by early reoperation; nine flaps were lost. Three more flaps were lost as a result of other causes, bringing the flap survival rate down to 94.4%. Early flap failure was caused by failure of the arterial anastomosis in eight cases; all of them were sutured (these represented 5% of all arterial anastomoses with sutures). None of the clipped arterial anastomoses failed. Early flap failure was caused by failure of the venous anastomosis in 11 patients. Three of these anastomoses were sutured (representing 6% of all venous anastomoses with sutures), seven were anastomosed with rings (representing 5% of all venous anastomoses with rings) and one was clipped (representing 2% of all venous anastomoses with clips). Both the VCS clip-applier system and the Unilink system are easy to handle and allow fast microvascular anastomoses without intraluminal penetration. The patency rate of clipped vessels is at least as good as the patency rates of vessels anastomosed using sutures or rings.     

An automated interrupted suturing device for coronary artery bypass grafting: automated coronary anastomosis

BACKGROUND: The purpose of this study was to have a preliminary assessment of the safety and efficacy of an automated vascular suturing device. METHODS: The device (Heartflo, Perclose/Abbott Labs, Redwood City, CA), which delivers 10 interrupted 7-0 polypropylene sutures between side-to-side arteriotomies, was evaluated in animals (8 Yorkshire pigs). RESULTS: Tissue edge capture and quality of anastomosis were highly rated. Time of anastomoses averaged 22 minutes. This time was prolonged primarily due to suture management, tying of interrupted sutures, and learning curve effects. Six of the anastomoses were hemostatic and two required an additional stitch each. Angiography and histology of the anastomosis confirmed patency and quality of the anastomosis. CONCLUSIONS: Our preliminary results indicate that the Heartflo automated anastomotic device is safe and effective. Preclinical and clinical studies to validate its acute and long-term effectiveness will commence shortly.     

Who needs extra time? Amniotic membrane wrapped pauci-suture model for rapid anastomoses*

An ideal anastomosis method will obtain the highest post-anastomotic vessel patency and will repair the vessel anatomically with minimal thrombosis in an easier, faster and cheaper fashion. To achieve these goals an anastomosis model using an amniotic membrane is introduced. The study was performed on the femoral arteries of 22 Wistar Albino rats (11 control group, 11 experimental group). In the experiment group, the microvascular anastomosis was completed with three sutures and a patch of amniotic membrane which was wrapped around the anastomotic site. The conventional anastomosis technique with eight sutures was performed in the control group. The effects of the model on the patency and histological structure of the vessels were evaluated. As a result, normal patency was determined radiologically and macroscopically in all of the anastomoses. No thrombosis or aneurysm was detected in any of the anastomoses. In the angiographic study, vessel patency was detected in both the control and experimental groups. The average time to complete the arterial anastomosis was 18.14 (±2.84) and 10.39 (±2.45) minutes in the control and the experiment groups respectively. In the histological studies, anti-eNOS staining revealed that endothelin levels were significantly higher in the experimental group. This method describes a new anastomosis model in microvascular surgery with promising results that call for additional experimental studies and further clinical implementations. We believe that this experimental technique can be put into clinical practice as an alternative to the conventional microvascular anastomosis technique.     

A comparison of CO2 laser-assisted venous anastomoses and conventional suture techniques: patency, aneurysm formation, and histologic differences

The expected patency and the potential complications of CO2 laser-welded end-to-end venous anastomoses have not been well established despite increasing clinical interest in the subject. To further study this relatively new technique we used the internal jugular veins (1.0 to 1.4 mm diameter) of 15 New Zealand White rabbits weighing 2.5 to 3.5 kg. On one randomly selected side, a laser-welded end-to-end anastomosis was performed in all animals by placing three equidistant stay sutures followed by welding the vein edges with a CO2 laser (spot size of 0.27 mm, power of 100 mW, and power density of 175 W/cm2). On the contralateral side, the vein was anastomosed with interrupted 10-0 nylon sutures in 10 animals, and in the remaining five animals a continuous 10-0 nylon suture technique was used. All anastomoses were surgically assessed at 30 days after operation. A significantly lower 30-day patency rate (p less than 0.05, Fisher's Exact Test) was found in anastomoses constructed by use of the continuous technique (20%) compared with either interrupted (90%) or the laser-assisted technique (87%). No significant difference was observed in 30-day patency between laser-assisted and conventional interrupted anastomoses. Anastomoses performed with the continuous and the laser-assisted technique required 12.5 +/- 1.3 and 12.9 +/- 3.0 minutes, respectively, whereas those constructed with interrupted technique required 19.1 +/- 4.5 minutes (p less than 0.05, Student-Neuman-Keuls' Test). No evidence of false or true aneurysm was noted in any of the animals. Histologic evaluation of laser-assisted anastomoses demonstrated early full-thickness coagulation necrosis of the wall with reendothelialization by 7 days and complete healing by 30 days after the procedure. Conventional anastomoses showed reendothelialization and minimal necrosis near the sutures at 7 days, but healing was complete by 30 days after the procedure. The patency rate of vein anastomoses performed with the CO2 laser is excellent and superior to the one obtained with continuous sutures, and except for less operating time, the former technique does not appear to offer any significant advantage over the conventional interrupted suture technique for small vein anastomosis in this animal model up to 1 month of follow-up.     

A comparison of para-anastomotic compliance profiles after vascular anastomosis: nonpenetrating clips versus standard sutures

PURPOSE: Anastomotic compliance is an important predictive factor for long-term patency of small diameter vascular reconstruction. In this experimental study we compare the compliance of continuous and interrupted sutured vascular anastomoses with those using nonpenetrating clips. METHODS: Both common carotid arteries in nine goats (average weight, 57 +/- 5.7 kg) were transected, and end-to-end anastomoses were constructed with nonpenetrating clips or polypropylene sutures. The latter were applied with both interrupted and continuous techniques. Intraluminal pressure was measured with a Millar Mikro-tip transducer, and vessel wall motion was determined with duplex ultrasound equipped with an echo-locked wall-tracking system. Diametrical compliance was determined. Environmental scanning electron microscopy was performed on explanted anastomoses. RESULTS: There was a reduction in anastomotic compliance and associated proximal and distal para-anastomotic hypercompliant zones with the use of all techniques. However, compliance loss was significantly less in those anastomoses with clips and interrupted sutures when compared with continuous suture (P <.001). Furthermore, the total compliance mismatch across anastomoses with continuous sutures was significantly greater than those with clips or interrupted sutures (P <.05). The mean time for constructing clipped anastomoses was 5.7 +/- 1.4 minutes, which was significantly less than either continuous (P <.0001) or interrupted sutures (P <.0001). Furthermore, environmental scanning electron microscopy demonstrated minimal intimal damage with good intimal apposition in the clip group. CONCLUSION: Anastomoses performed with nonpenetrating clips resulted in improved para-anastomotic compliance profiles and reduced intimal damage when compared with those with polypropylene sutures. These benefits may enhance long-term graft patency by reducing the risk of anastomotic intimal hyperplasia.     

A prospective evaluation of interrupted nitinol surgical clips in arteriovenous fistula for hemodialysis

BACKGROUND: The use of a self-closing nitinol surgical clip (Coalescent Surgical U-Clip) is a novel technique of creating an interrupted vascular anastomosis, which also eliminates the knot tying associated with a conventional vascular anastomosis. The purpose of this study was to compare the clinical outcome of arteriovenous fistulae (AVF) for hemodialysis as constructed using interrupted U-Clip devices and conventional continuous polypropylene sutures. METHODS: We prospectively studied the clinical course of 132 patients (149 access) undergoing either forearm autologous arteriovenous fistula (FAVF, n = 69) or upper arm autologous arteriovenous fistula (UAVF, n = 80) or creations during a 39-month period. Among the FAVF, U-Clips and polypropylene sutures were used in 37 and 32 anastomoses, respectively. Among the UAVF, U-Clips and polypropylene sutures were used in 41 and 30 anastomoses, respectively. Primary patency, complication, and maturation rates were analyzed. RESULTS: Clipped FAVF had an improved maturation rate at 6 weeks (32 of 37, 86%) when compared with sutured FAVF (22 of 32, 69%, P <0.05). There was no difference in the maturation rate among UAVF constructed with either U-Clips or sutures (88% versus 87%, not significant). The primary patency rates at 12, 24, and 36 months were 91%, 84%, and 75% for the clipped FAVF; and 83%, 74%, and 61% for the sutured FAVF (P <0.05) There was no difference in the patency rate of UAVF constructed with either U-Clips or polypropylene sutures at either 12, 24 or 36 moths (91%, 80%, and 75% versus 83%, 77%, and 69%, respectively). CONCLUSIONS: The U-Clips are a viable alternative to sutures for creating vascular anastomosis. It provides a improved maturation and patency rates when compared with the conventional sutured AVF in the forearm. The clinical benefit of the U-Clips may be due in part to the improved compliance created by the interrupted anastomotic technique.     

Microvascular anastomoses: a comparison of the end-to-end and the telescoped techniques in rats

The end-to-end anastomotic technique and the telescoped anastomotic technique were compared in a paired experimental study of 200 primarily patent anastomoses in the femoral arteries and veins of rats. It was found that the arterial telescoped anastomosis was faster and simpler to perform and had a significantly lower frequency of late thrombotic deposition (13%) than the arterial end-to-end anastomosis (41%), although the patency rates at 1 week were equal (88%). Aneurysms at the site of the anastomosis were not observed in the arterial telescoped anastomoses, while initial stages of probable aneurysms were observed in 24% of the arterial end-to-end anastomoses. The venous telescoped anastomoses were also less time-consuming and simpler to construct. Although equal patency rates at 1 week were obtained (84%-88%), the venous telescoped anastomoses displayed a significantly more pronounced incidence of thrombotic deposition at the site of the anastomosis.     

The Heartflo device for distal coronary anastomoses: clinical experiences in 60 patients

BACKGROUND: The Heartflo anastomotic device automates the suturing process with simultaneous delivery of 10 standard polypropylene sutures through the graft and the coronary vessel wall to construct the anastomosis. We performed clinical testing in 60 patients undergoing coronary artery bypass grafting. METHODS: One automated distal coronary anastomosis was initially placed in each patient, the other anastomoses were created with standard running sutures. After a "flat foot"-shaped prototype was deployed in 30 patients (group I), the design of the foot was modified and deployment of the new device performed in the next 30 patients (group II). RESULTS: In group I, automated anastomoses were completed in 16 patients (53%) using 1.7 +/- 1 additional stitches. In 26 group II patients (86%), a hemostatic anastomosis using 1.2 +/- 1 additional stitches was achieved. Anastomoses were completed in 19.0 +/- 3 minutes in group I and in 15.6 +/- 2 minutes in group II. CONCLUSIONS: We have shown the feasability of coronary anastomoses using the Heartflo device. The modified version improved tissue capture, resulting in a higher rate of completed anastomoses. Because anastomotic time is still prolonged, an easier suture management is mandatory in the next developmental step.     

In search of the "perfect" anastomosis

Forty-five end-to-side microvascular anastomoses were completed in rat carotid arteries of 0.7-0.8 mm diameter (anastomosing the distal end of the left common carotid to the side of the right common carotid). For comparison both 10-0 and 11-0 sutures were utilized in different anastomotic techniques: interrupted, direct-continuous, and diagonal-continuous sutures, plus total mural thickness vs. partial mural thickness (piercing only the adventitia and outer media, excluding the intima). Anastomoses were evaluated for patency and scanning electron microscopic appearance after 10 to 12 weeks. The results indicate complete patency in all anastomoses. Ultrastructural observations revealed nearly normal intimal appearance in the partial medial technique and only minimal evidence of intimal injury in the other techniques. It is concluded that 100% patency can be obtained regardless of suture size or anastomotic technique. The most important factor in anastomotic patency is the operator's technical skill.     

Venous thrombosis in coupled versus sutured microvascular anastomoses

BACKGROUND: The anastomotic coupling device (ACD) is currently used for microsurgical venous anastomoses as an alternative to sutures and can reduce anastomotic time. METHODS: We reviewed the microsurgical procedures performed at the University of Texas M. D. Anderson Cancer Center over a 40-month period. Procedures were performed for elective reconstruction of the breast, head or neck, or extremities after tumor excision. Thrombosis and ultimate flap salvage rates were compared between cases using ACDs and those using sutures for the venous anastomoses. RESULTS: Seven hundred twenty-three free flaps were included in the study. There were no intraoperative technical complications using the ACD. Overall, the venous thrombosis rates were not significantly different between the ACD (1.4%, 2/139 cases) and sutured (3.3%, 19/584 cases) groups. Salvage rates following venous thrombosis were not significantly different for venous anastomoses performed with an ACD (50%, 1 of 2 cases salvaged) compared with venous anastomoses performed with sutures (68.4%, 13 of 19 cases salvaged). CONCLUSION: The ACD is a useful alternative to sutured venous anastomoses that can reduce anastomotic time while achieving similar patency rates.     

Are mechanical microvascular anastomoses easier to learn than suture anastomoses?

Sutured anastomoses of small vessels are considered difficult to learn. Mechanical anastomosis systems allow a more rapidly performed anastomosis. In order to compare the process of learning to perform sutured and mechanical microvascular anastomoses, two surgeons, with limited microvascular experience, performed 30 aortic and 30 femoral vein anastomoses in 30 Wistar rats. The methods compared were conventional suture, vascular closure system (VCS) and microvascular anastomatic coupler system (MAC). There were no inter-surgeon differences regarding patency or time to perform anastomoses. The average time to perform a suture anastomosis was 39 min (patency 80%). Anastomoses with the VCS system took 24 min (patency 25%), whereas the MAC couplers took 13 min to perform (patency 95%). There was a significant learning effect with sutures, but no obvious reduction in time to perform MAC coupler or VCS clip anastomoses was seen. MAC couplers were easiest to use, and allowed us to perform rapid anastomoses with high patency.     

A new combined "interrupted-continuous" microvascular anastomotic technique. Experimental study and clinical application

A new combined interrupted-continuous microvascular anastomotic technique is introduced, using four interrupted stay stitches and continuous suturing in between. Its efficacy is compared with the simple interrupted and continuous techniques. Microanastomoses were performed in the femoral artery and vein of rats. The patency, anastomosis time, and blood loss from the suture line of all anastomoses were recorded. Also, the sites of all anastomoses were harvested and histologically examined for lumen stenosis, media regeneration, and endothelial lining. Experimentation findings showed 100% patency rate in all groups. The combined and the continuous techniques were significantly faster and watertight compared with the simple interrupted. The only difference in pathology findings was the development of significant lumen stenosis in vein anastomoses performed with the continuous technique, compared with the other two techniques. The combined technique was clinically used in 16 free flap transfers and ensured 100% patency in all arterial and vein anastomoses, as well as survival of all flaps. In conclusion, the combined technique was found to be fast and easy to perform and ensured the same patency rate as the simple interrupted and continuous techniques. It also diminished the lumen stenosis effect of the continuous technique in vein anastomoses. Therefore, we suggest its use in both experimental studies and clinical cases.     

Low power CO2 laser-assisted microvascular anastomosis: an experimental study

Low power CO2 laser-assisted microvascular anastomosis (LAMA) was used for saphenous artery autotransplantation in 40 rabbits. Eighty end-to-end anastomoses were performed by three methods (conventional interrupted suture, stay suture + laser, laser without stay suture). The long term patency rate in the three types of anastomosis is 93%, 93%, and 100%, respectively. The time needed for the laser procedure is half to one-third of that required for the interrupted suture method. The tensile strength of the bonding site can withstand up to 250 mm Hg of arterial pressure. We have demonstrated that the CO2 laser can be used in microvascular anastomosis with or without stay sutures. Aneurysm formation is a potential risk of LAMA. Accurate coaptation of the transected vessel, precise control of laser energy, and minimal area exposed to the laser beam are the key points for further improving anastomotic quality.     

Use of fibrin glue to minimize bleeding of microvascular repairs in hypertensive rats.

The purpose of this study is to describe our technique of applying fibrin glue at the microvascular anastomotic site and to evaluate the effect of fibrin glue on anastomotic hemostasis and patency under various high pressure states using dopamine-induced acute hypertension in rats. A total of 72 male Wistar Kyoto rats, 10 weeks old, were used in this study. Under urethane anesthesia, end-to-end anastomosis of the left femoral artery was performed using 10-0 nylon suture by the standard interrupted suture technique. Pasteurized fibrin glue was then topically applied upon the suture line of the anastomosis. Thirty-six normotensive rats were divided into three groups based on the number of sutures (4, 6, or 8) used to complete the anastomosis. Groups were subdivided, half receiving fibrin glue application and half without. Thirty-six dopamine-induced acutely hypertensive rats were divided into three groups based on the blood pressure levels of 150, 200, and 250 mmHg, respectively. These groups were again subdivided, with half receiving glue applications. Microvascular anastomosis was performed using 6 nylon sutures. Patency rates and anastomotic bleeding were evaluated. The results revealed that successful anastomoses could be performed with fewer sutures when fibrin glue was used as a reinforcement at the anastomosis. Fibrin glue was also effective at the maximum blood pressure (250 mmHg) with no anastomotic leakage and no decrease in postoperative patency rate. These results suggest that conventional microsurgical suturing technique combined with fibrin glue would be effective in the prevention of leakage in microsurgical repairs, even under conditions of high blood pressure.     

Initial evaluation of absorbable polydioxanone suture for peripheral vascular surgery

The long-term integrity of an autogenous vascular anastomosis is primarily dependent on the strength of tissue healing; therefore permanent mechanical support of an autogenous anastomosis with sutures is unnecessary. In this study we evaluated monofilament absorbable polydioxanone as an alternative to polypropylene for suturing autogenous vascular tissue during adult peripheral vascular operations. We used polydioxanone suture for 21 vascular procedures in 20 patients. We evaluated suture handling characteristics during operation and then followed patients with clinical assessments and serial duplex scans to monitor for pseudoaneurysms, anastomotic narrowing, and vessel patency. Indications for surgery included limb salvage (67%), dialysis access (23%), traumatic arteriovenous fistula and claudication (5% each). The operative procedures included infrainguinal bypass (57%), arteriovenous fistula formation (24%), thromboembolectomy (14%), and arteriovenous fistula repair (5%). Polydioxanone sutures were placed in 39 separate test sites (35 arterial, 4 venous). No deaths occurred during operation. Polydioxanone suture was found to have handling characteristics similar to polypropylene. During mean patient follow-up of 7.2 +/- 0.6 months, we found no cases of anastomotic narrowing or pseudoaneurysms. Actuarial test site patency at 1, 3, and 6 months was 97%, 97%, and 86%, respectively. Polydioxanone suture has handling properties that are acceptable for use in vascular applications, and it provides adequate mechanical support for sutured vessels to heal. A randomized trial comparing polydioxanone with polypropylene suture will be necessary to determine whether the lack of permanent foreign material in vascular anastomoses can improve long-term patency.     

Cervical or thoracic anastomosis after esophageal resection and gastric tube reconstruction: a prospective randomized trial comparing sutured neck anastomosis with stapled intrathoracic anastomosis

OBJECTIVE: The purpose of the study was to compare in prospective randomized fashion a manually sutured esophagogastric anastomosis in the neck and a stapled in the chest after esophageal resection and gastric tube reconstruction. SUMMARY BACKGROUND DATA: Despite the fact that all reconstructions after esophagectomy will result in a cervical or a thoracic anastomosis, controversy still exists as to the optimal site for the anastomosis. In uncontrolled studies, both neck and chest anastomoses have been advocated. The only reported randomized study is difficult to evaluate because of varying routes of the substitute and different anastomotic techniques within the groups. The reported high failure rate of stapled anastomoses in the neck and the fact that most surgeons prefer to suture cervical anastomoses made us choose this technique for anastomosis in the neck. Our routine and the preference of most surgeons to staple high thoracic anastomoses became decisive for type of thoracic anastomoses. METHODS: Between May 9, 1990 and February 5, 1996, 83 patients undergoing esophageal resection were prospectively randomized to receive an esophagogastric anastomosis in the neck (41 patients) or an esophagogastric anastomosis in the chest (42 patients). To evaluate selection bias, patients undergoing esophageal resection during the same period but not randomized (n = 29) were also followed and compared with those in the study (n = 83). Objective measurements of anastomotic level and diameter were assessed with an endoscope and balloon catheter 3, 6, and 12 months after surgery. The long-term survival rates were compared with the log-rank test. RESULTS: Two patients (1.8%) died in hospital, and the remaining 110 patients were followed until death or for a minimum of 60 months. The genuine 5-year survival rate was 29% for chest anastomoses and 30% for neck anastomoses. The overall leakage rate was 1.8% (2 cases of 112) with no relation to mortality or anastomotic method. All patients in the randomized group had tumor-free proximal and distal resection lines, but 1 patient in the nonrandomized group had tumor infiltrates in the proximal resection margin. At 3, 6, and 12 months after operation, there was no difference in anastomotic diameter between the esophagogastric anastomosis in the neck and in the thorax (P = 0.771), and both increased with time (P = 0.004, ANOVA repeated measures). Body weight development was the same in the two groups. With similar results in randomized and nonrandomized patients, study bias was eliminated. CONCLUSIONS: When performed in a standardized way, neck and chest anastomoses after esophageal resection are equally safe. The additional esophageal resection of 5 cm in the neck group did not increase tumor removal and survival; on the other hand, it did not adversely influence morbidity, anastomotic diameter, or eating as reflected by body weight development.     

Classification and comparison of five techniques of end-to-end microarterial anastomoses in rats: A new proposed technique

We propose a new classification of five main techniques for microarterial anastomoses: interrupted, autogenous cuff, continuous, sleeve and partial sleeve. The last method was developed by the authors. A study was performed on 48 albino rats and comprised 20 anastomoses of each type (for a total of 100), performed on femoral and carotid arteries of average size 0.83 mm. These were compared with respect to patency, anastomosis time, leak, bleeding time, number of sutures (bites), microangiography, histopathology and scanning electron microscopy. The overall patency was 88%, and that of the partial sleeve technique was 100%, associated with 30% incidence of aneurysms. Clinical, histopathological and scanning electron microscopy findings showed better results for techniques with predominantly extraluminal sutures (sleeve and partial sleeve), which was particularly relevant in our situation, in which a larger sized needle (150 μm) had to be used. An overall aneurysm incidence of 17% was noted. © 1995 Wiley-Liss, Inc.     

Coupling the venous anastomosis: Safe and simple

Varous 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. © 1997 Wiley-Liss, Inc. MICROSURGERY 17:414–416 1996     

Comparison of arcuate-legged clipped versus sutured hepatic artery, portal vein, and bile duct anastomoses

Attempts at improving anastomoses have included the development of stapling techniques. Our purpose was to evaluate arcuate-legged clipped versus standard sutured anastomoses of the hepatic artery (HA), portal vein (PV), and bile duct in a porcine liver transplantation model. Two groups of pigs were studied intraoperatively and 1 day after liver transplantation. A control group underwent sutured anastomosis of PV and HA with polypropylene and of bile duct with polydioxanone (n = 8). An experimental group underwent anastomoses with arcuate-legged clips (n = 8). We analyzed the time to perform anastomosis and flows before and at various time points after anastomosis. In addition, patency and histology of the anastomoses were evaluated 1 day after operation, including a fibrin-thrombosis score, medial injury, and inflammation score. Times to complete HA and PV anastomoses were not different between clipped and sutured groups. However, the time was shorter to complete bile duct anastomosis with clips than with sutures (6.3 +/- 1.1 minutes and 13.3 +/- 2.0 minutes, respectively). Flows through HA anastomoses were not different between groups, but flow through the PV was higher in clipped compared with sutured anastomosis (P = 0.06). Patency was 100 per cent with no leaks for all three anastomoses in both groups. Histologic data were similar between vascular anastomotic groups. Sutured bile duct anastomoses revealed mild smooth muscle injury in 75 per cent whereas clipped bile duct anastomoses displayed no smooth muscle injury. We conclude that arcuate-legged clipped anastomosis represents a viable option to sutured anastomoses of the PV, HA, and bile duct anastomoses. Bile duct anastomoses were completed in less than half the time and with less tissue damage documented histologically.