Experimental Studies On Calcification Resistance Of The Bovine Jugular Conduits With Valves Stabilized By Glutaraldehyde And Chromium Sesquioxide

Background:Glutaraldehyde(GA) cross-linked bovine jugular vein conduits(BJVC) is a new type of valved conduit to right ventricular outflow tract(RVOT) reconsruction.The clinical researches showed that the hemodynamic properties of this valved conduits were as well as the homograft valved conduits and were superior to porcine xenografts at early period.It maybe a preferable substitute of homograft valved conduit.Glutaraldehyde has been used extensively for the fixation and preservation of valved bovine jugular vein conduits(BJVC) as a kind of classical cross-linked reagent,reducing the host inflammatory reaction and amphfrng the bioprosthetic stabilization and durability.However,many experimental and clinical researches showed that glutaraldehyde cross-linking was the major factor for the bioprsthetic calcification and finally led to bioprostheis failure.Recently,it was found that the glutaraldehyde cross-linking followed by chromium sesquioxide treatment was effective in preventing calcification of some bioprsthetics.It seems that the glutaraldehyde cross-linking followed by chromium sesquioxide maybe reduce calcification and improve longevity of the bovine jugular vein conduits.This experiment will try to proof-test it.Objective:To observe the physiochemical properties and calcification resistance of the bovine jugular conduits with valves stabilized by glutaraldehyde and chromium sesquioxide seek better biological-materical for RVOT reconstruction.Method:The fresh bovine jugular veins with a natural valve were obtained from a local slaughterhous.Both of GA-cross-linked BJVC with heparin bonded and GA-cross-linked BJVC were implanted subcutaneously in back of weanling SD rats.90 days after the treatment,calcium concentration analysis,histologic examination,electron microscopy were tested.Results:The valves and wails of heparin-bonded BJVC showed less calcification singnificantly as compared with the valves and wall of GA-cross-linked BJVC after 60 calcium content(1.37±0.61) versus days implantation mean valves (3.95±1.36)ptg/mg dry weight,P＜0.05;mean walls calcium content(174.81±28.37) verus(215.43±26.19)ltg/mg dry weight,P＜0.05;Pathohistologic examinations demonstrated a prominent intrinsic collagen disruption in the GA- cross-linked BJVC.The heparized BJVC cross-linked by GA maintained morphologic integrity. Conclusion:(1) Glutaraldehyde-treated bioprostheses is easy to lead calcified; (2) Heparin coupling is efective in preventing calcification of GA cross-linked BJVC implanted in the back of rats.