Valved bovine jugular venous conduits for right ventricular to pulmonary artery reconstruction

Various valved and nonvalved external right ventricle (RV) to pulmonary art ery (PA) conduits have been used to palliate congenital heart anomalies. Th e ideal conduit has not been found, Reasons for conduit failures include st enosis, thrombosis, calcification of the valve or graft wall, and developme nt of an obstructive peel. We evaluated valved and nonvalved conduits const ructed from a glutaraldehyde preserved segment of bovine jugular vein. Bovi ne jugular conduits (n = 31), 10-13 mm in diameter, were implanted into wei ght-matched adult mongrel dogs using a standard closed heart technique. Val ved conduits (VC, n = 17) were stented at the valve annulus with a Gore-Tex ring, whereas the nonvalved conduits (NC, n = 14) were stented at their mi dpoint. The proximal PA was tightly banded to 3 mm with a ligature, Cardiac output (CO) and hemodynamic gradients were measured at the time of inserti on and 8 months postoperatively, Pulmonary artery angiograms were used to a ssess bovine jugular conduit regurgitation. All xenografts were evaluated b y gross and histologic exam. Two dogs had conduits placed but died for reas ons unrelated to the conduit before evaluation. Valved conduit leaflets sho wed thickening, insignificant thrombus deposition in the base of one or mor e cusps, and a mild degree of regurgitation as assessed by angiograms. Exam ination of the NC showed mild conduit thickening and a moderate-to-severe d egree of regurgitation as assessed by angiograms. There was a significant d ifference observed in pulmonary outflow gradients between the VC (11 +/- 2 mm Hg) and NC (17 +/- 2 mm Hg) (p < 0.05), although neither group developed a hemodynamically significant gradient. On gross examination, VC ventricle s displayed significantly less evidence of volume and pressure overload com pared with the NC ventricle. Valved conduits demonstrated significantly les s obstruction and regurgitation. The potential clinical advantages of bovin e jugular conduits are their availability, potential durability evidenced b y lack of early calcification, and the advantage of not requiring a proxima l extension for the RV anastomosis, The presence of a durable and functiona l xenograft valve in valved conduits may prevent postoperative sequelae in some patients.