Replacement of valved right ventricular (RV) to pulmonary artery (PA) conduits – an observational study with focus on right ventricular geometry

Abstract

Objective: Timing of the operation for exchange of RV to PA conduits is a matter of considerable debate. We aimed to study the course of RV dimension in patients undergoing conduit exchange. Methods: We retrospectively studied patients who underwent implantation and or replacement of RV/PA conduits during the period between 1990 and 2005. Clinical and echocardiographic data were recorded as obtained at follow-up visits. Results: A total of 229 patients underwent surgery for implantation and or replacement of RV/PA conduits during the study period. Patients were assigned to three age groups including 37 infants, 125 children aged 1–10 years and 67 patients more than 10 years of age. 185 pulmonary (81%) and 44 aortic homografts (19%) were implanted. Fifty-eight of these patients (25%) required exchange of conduits after a median time of 6.4 [8 months –12 years]. The follow-up was 7.55 [0.1–17] years. The survival of the patients after homograft change was 98%. Age at conduit exchange (coefficient: –4.917; p<0.001) and RV end-diastolic dimension (RVDD) before conduit exchange (coefficient: 8.255; p<0.001) were related to RVDD as measured by M-mode echocardiography at follow-up. RVDD decreased in 48/58 patients, remained unchanged in 8/58 and increased in 2/59 patients. Conclusions: Reoperation for exchange of degenerated conduits should be performed early to prevent the development of irreversible structural myocardial changes and persistence of right ventricular dilatation.