The Experimental Study On Vessel Wall Of Autogenous Venule Graft

Objective To establish an animal model for repairing arteriole defect withautogenous venule graft in rats and to observe the patency rate and the change inultrastructure of vessel wall after replantation.Methods 40 male Wistar rats were randomly assigned into four groups:arteria femoralis(A group, n=10), vena femoralis autograft(B group, n=10), arteriasaphena(C group. n=10), saphena autograft(D group, n=10). Evaluate the patency rateof different groups at 1 month following operation by cut down the distal vessel. Theother 56 male Wistar rats were randomly assigned into two groups: arteriafemoralis(A group, n=28), vena femoralis autograft(B group, n=28). Each rat of groupA underwent right arteria femoralis transaction and anastomosed directly. Each rat ofgroup B underwent right arteria femoralis transaction but keep a 5mm defect, thenthese defects were repaired with vena femoralis from the other side membra, thelength of the vena femoralis is 4mm. Evaluate the change in ultrastruction of vesselwall at 1,3 days and 1,2,4,6,8 weeks after venous transplantation by using Dopplerdetection, gross observation,histological and morphologic assessment.Results 1. The immediate patency rate reached 100％when utilizing venulesautograft to bridge arteria femoralis and arteria saphena defects in rats. After a monththe patency rate remained 100％in vena femoralis autograft and 50％in saphena autograft. The immediate patency rate is 100％in the group of direct anastomosis ofarteria femoralis and arteria saphena. After a month the patency rate remained 100％and 80％in arteria saphena. 2. The grafted vessel wall get gradually thicker. The wallthickness at the end of 4th weeks reaches the maximum. From then on, the thicknessdon't continue to increase, 1th～2rd week postperatively, medial SMC contain littlemyofilament and dense body, but with rich sereting organells.These indicated thatSMCs phenotype have changed from contractile phenotype to synthetic one. At theend of 4th weeks, secreting organells of SMC are less than that at 1th～2rd week butmedial collagen fiber is getting much. From 6th～8th week, SMCs also graduallychanged from synthetic phenol type to contractile one.Conclusions 1. The patency rate in repair of arteriole defect using venule(0.7mm～0.9mm in outer diameter)autograft is as high as that by direct anastomosis,but the patency rate in repair of arteriole defect using venule (0.4mm～0.5mm inouter diameter)autograft is lower than that by direct anastomosis. 2.4th～6th weekafter autogenous grafting, the wall thickness is rnaximum, 1th～2nd week after graftingthe phenotype change and proliferation of medial SMC are the most apparent, muchmicrovilli were seen.