A new antithrombogenic RV-PA valved conduit.

A new antithrombogenic right ventricular (RV)-pulmonary artery (PA) valved conduit was developed using a bovine jugular vein containing a natural valve. To maintain the natural and mechanical properties of the venous tissue, a hydrophilic cross-linking reagent, glycerol polyglycidyl ether polyepoxy compound (PC) was used instead of glutaraldehyde (GA). Moreover, to induce antithrombogenicity, heparin was bonded to the inner surface of the bovine jugular vein cross-linked with PC. Conduits of 18 to 20 mm inner diameter (ID) were implanted between the RV and PA in nine dogs weighing 7-17 kg, with the native main PA being ligated proximally. The handling and suturing of the graft was easy and adaptable, and the anastomosis was completed with excellent coaptation and no blood leakage at the suture lines. All animals were chronic survivors, but one animal died of hematemesis on the 438th postoperative day. Grafts were explanted from 182 to 385 days after implantation. The luminal surface of the conduits were white, glistening, and smooth with good coaptation of the cusps, without calcification or degenerative changes except for one cusp that showed a minimal deformation with a small thrombus. Macroscopic and microscopic observation showed that there were no thrombi at the anastomotic lines, but small thrombi on the luminal surface of the conduits near the cusps and in some cusps. Endothelium-like cells were noticed on the luminal surface of the graft, except in the area near the cusps, and on one cusp at 196 days after surgery. These results indicated that the new RV-PA valved conduit provided adequate antithrombogenicity by temporary slow heparin release, followed later by endothelialization of the graft in a low pressure system at 1 year after implantation.