Early failure of decellularized xenogenous pulmonary valve conduit (Matrix-P-Plus) for reconstruction of the right ventricular outflow tract in the ross procedure

Objectives: To analyse the early to mid-term performance of the decellularized pulmonary valve conduit Matrix-P-Plus as an alternative to a pulmonary homograft in the Ross procedure.

Methods: Between April 2007 and October 2008 twenty-one patients (mean age 49 years, range: 33-56 years) underwent a Ross procedure using the Matrix-P- Plus conduit (mean conduit size 27 mm) for reconstruction of the right ventricular outflow tract in our clinic.

Results: At a median follow up of 56.2 months (range: 49-64 months) one patient died of liver failure. Echocardiography demonstrated severe pulmonary stenosis necessitating reintervention in 9 patients (42.9%; five had their conduits explanted and replaced with a pulmonary homograft, two had a transcatheter pulmonary valve implantation and two are scheduled for reoperation within the next months). One patient showed asymptomatic pulmonary stenosis (max. pressure gradient 47 mmHg, mean pressure gradient 25 mmHg) and the remaining 11 patients (52.3%) had no signs of valve dysfunction or stenosis. Intraoperatively the explanted valves showed scarring stricture of the pulmonary wall in the pericardial tube. This lead to predominantly postvalvular stenosis. Histological examination showed massive inflammatory reaction and necrosis. The cusps showed no calcification and no migration of any cells into the decelluarized tissue.

Conclusions: Because of a massive inflammatory reaction that may lead to early graft stenosis the Matrix-P-Plus biological conduit cannot be recommended for reconstruction of the right ventricular outflow tract in adults. Furthermore, it is no alternative to a pulmonary homograft in the Ross procedure.