Pulmonary position cryopreserved homograft in non-Ross patients: how to improve the results?

Abstract

The outcomes of homografts (HGs) in the reconstruction of the right ventricular outflow tract (RVOT) in non-Ross patients are often considered disappointing, compared with Ross patients; and the risk factors for HG degeneration are still controversial. The objective of this study was to determine the durability and prognostic factors related to the HGs implanted in non-Ross patients and to propose potential ways to improve the results. A retrospective study (1993-2010) included 115 consecutive non-Ross patients who received a HG for RVOT reconstruction. The median age at implantation was 2.8 years (4 days-58 years). The main heart defects were pulmonary atresia with ventricular septal defect (n = 40; 34%), truncus arteriosus (n = 28; 24%) and tetralogy of Fallot (n = 23; 20%). Thirty-eight percent had preoperative pulmonary hypertension. A low-dose corticosteroid therapy was used during the postoperative period in patients displaying a HG-related inflammatory response (no septic context) (n = 11). The median diameter of the implanted HG was 22 mm (range 9-30 mm). The median age of the HG donor was 14 years (range 0.5-65 years). ABO compatibility rules were not systematically respected for the HG implantation: 43% of the implanted HGs were ABO compatible with the recipient. The endpoints were HG stenosis (peak gradient ≥20 mmHg), regurgitation (moderate or severe), dysfunction (peak gradient ≥ 50 mmHg or regurgitation moderate or severe) and failure (explantation or balloon dilation). Freedom from HG explantation and failure were 89 and 80% at 5 years, and 76 and 69% at 10 years, respectively. HG donor age <30 years [hazard ratio (HR): 2; P = 0.012], preoperative pulmonary hypertension (HR: 3; P = 0.02) and HG mismatch (HR: 5; P = 0.04) were multivariate risk factors for HG stenosis, regurgitation and failure, respectively. HG diameter <22 mm was a multivariate risk factor for HG regurgitation (HR: 8; P < 0.001), dysfunction (HR: 9; P = 0.02) and failure (HR: 5; P = 0.03). ABO incompatibility increased the risk of HG stenosis (HR: 4; P = 0.009) and dysfunction (HR: 2; P = 0.04). The use of corticosteroids significantly protected against the risk of HG regurgitation (HR: 0.08; P = 0.04) in the multivariate analysis. The cryopreserved HG implanted to reconstruct the RVOT in non-Ross patients remains one of the most acceptable options in this specific non-Ross population. The outcomes of HGs in non-Ross patients might be improved by implanting an ABO-compatible HG with an adapted diameter, coming from a donor >30 years and by optimizing the perioperative afterload of the HG.