Experimental Study Of Microvascular Fish-mouth Shape Sleev Anastmosis Using Cyanoacrylate Adhesives

Objective: With the development of microsurgery, anasto- mosis techniques of small vascular have been enhanced greatly. But, how to improve the anastomosis technique has aroused more and more attention of many people. Microvascular anastomosis is crucial to free tissue transfer and replantation. Conventional microvascular anastomosis using sutures is a well-established and successful technique.However,it is tedious and time-consuming, requiring special trainng in microvascular surgery,leading to serious damage to vessel wall,especially to the intima and suturematerial expose into the vessel lumen,which would cause thrombocyte gathering and thrombogenesis.In an attempt to overcome these shortcomings, investigators have employed a variety of anastomotic techniques, including mechanical devices, laser welding,and tissue adhesives.The concept of using tissue adhesives for microvascular anastomosis is attractive,and synthetic cyanoacrylate adhesives have been examined by a number of investigators.However,experimental results on vascular anastomosis, using such adhesives have tended to be less than satisfactory, as the entry of adhesive into the lumen causes instant thrombosis. The aim of this study was to develop a more reliable technique for performing a microvascular anastomosis using Microvascular fish-mouth Shape Sleeve with Cyanoacrylate Adhesives,and the results are compared with the conventional suturing anastomosis technique To evaluate the feasibility and superiority of the method.Methods: In this study, 79 grown-up rabbits with body weights of 2500-3000 g were used as experimental animals, One side of the carotid arteries was divided and anastomosed by using Microvascular fish-mouth Shape Sleeve with Cyanoacrylate Adhesives as experimental group, the other side was anastomosed by using sutures as control group. Entobar(pentobarbital sodium) was used for anesthesia via vein injection at 30 mg/kg body weight. The anesthetized rabbits were shaved after immobilization in a supine position and then cleaned with alcohol.After the skin was incised, the carotid artery was carefully exposed while surrounding tissues were electrocauterized to prevent hematoma formation. Two microvascular clamps were placed on the exposed carotid artery, which was then cut with microscissors in the middle perpendicularly to the direction of blood flow after the external diameters were measured. The diameters of the arteries ranged from 2.0 to 2.5mm(mean: 2.2mm). The lumen of the divided vessel was carefully washed with heparinizedsaline solution (25 IU/ml), The experimental group was used Microvascular fish-mouth Shape Sleeve Cyanoacrylate Adhesives.The redundant adventitia of the proximal vessel end was trimmed to prevent it from entering the vessel lumen, and then the distal vessel wall was not trimmed at all. The distal segment of the artery was cut two gaps as if fish-mouth shape which was about 1 time the diameter of the vessel across the direction of blood flow at an angle 180.At the upper limit of two gaps two U-shaped sutures (9-0nylon) were inserted and tightened sufficiently to allow the cut vessel surface touch and so prevent the penetration of adhesive materral into the open lumen.The edges of the distal vessel end's wall were pulled over the adventitia of the proximal vessel end so that the wall of the two vessel ends overlapped. Care was taken to place the edges of the overlaying wall a small distance away from the cut ends of either the media or the intima.Once the walls of the two vessel ends were manually manipulated into an overlapping position, commercially available minimum Cyanoacrylate was applied to the surface of the vessel,using one needle tip as a paintbrush.With the anastomosis completed, the clamp and the suture were released with meticulous care. The control group was anastomosed by the conventional method of suturing with 9-0nylon.After recording the time-consuming for anastomosis ,postoperative carotid artery patency was checked by observation of the carotid pulse or by the milkine test. The skin was sutured with 3-0 nylon. The animals were anesthetized in the same pattern, and the anastomosed carotid arteries were exposed at the different time . The biodynamic changes of the anastomoses in rabbits were measured by biodynamic method at the 1st hour, 1st week, 2nd week, and 1st month . The vessel speciments were harvested at the same time and were analyzed by light microscopy and scanning electron microscopy.All the experimental data were statisticated.Results: After an initial familiarization period,an anastomosis with Cyanoacrylate Adhesives could be completed in 5 min (mean ) from the time that the vessel ends are cleaned and prepared for the anastomosis, until the time that the clamp is removed;An anastomosis by using sutures could be completed in 18 min (mean).there were no significantly differences of patency rate between the two methods at the 1st hour, 1st week after operation. there were no significant differences of AMSBF(the average maximal stretch breaking force)and AMBP(the average maximal breaking pressure)between the two methods within 30 days after operation. No distraction, leaks, or hemorrhages from the anastomoses were observed within 30 days after operation. The histological results indicate that the vessel wall healing of the anastomosis with Microvascular fish-mouth Shape Sleeve using Cyanoacrylate Adhesives is better than that with suturing.The endothelial cells regenerate earlier, and the intima is smoother.Conclusion: Our experimental results demonstrated that the OB adhesive did not caused thrombus, the vessel wall was injured lightly, especially to the intima,and the vessel wall healing of the anastomosis with Microvascular fish-mouth Shape Sleeve using Cyanoacrylate Adhesives is better than that with suturing . The foreign matters were not exposed into the lumen of the vessel and the probability of thrombogenesis was decreased. The microvascular anastomosis technique with Microvascular fish-mouth Shape Sleeve Cyanoacrylate Adhesives was proved to be rapid and easy.It is also safe and reli-able.This kind of microvascular anastomosis technique is feasible and generalizated easily application.