| 이철¹, 박천수¹, 이창하¹, 곽재건¹, 김수진², 심우섭², 송진영², 최은영², 이상윤² |
Objectives: Pulmonary valve replacements (PVR) using a bioprosthesis are frequently performed during repair of various congenital heart diseases. However, durability of bioprosthetic valves in the pulmonary position is not well defined. We examined the durability of bioprosthetic valves in the pulmonary position and risk factors associated with bioprosthetic pulmonary valve failure.
Methods: Between 1993 and 2004, 181 patients underwent initial PVR using bioprostheses. Patients who underwent valved conduit or homograft implantation were excluded. Mean age was 14.2 ± 9.8 years. Fundamental diagnoses were TOF (n = 97), PA with VSD (n = 39), DORV (n = 10), TGA (n = 9), PS (n = 8), cc-TGA (n = 6), absent pulmonary valve syndrome (n = 6), and others (n = 6). Indications for PVR were PR (n = 112), PS (n = 43), PSR (n = 14), and as a part of corrective surgery (n = 12). Types of bioprosthesis used were Hancock Ⅱ (n = 83), Perimount (n = 53), Freestyle (n = 23), Carpentier-Edwards porcine valve (n = 18), and others (n = 4). Median valve size was 23 mm (range, 19-27 mm). Prosthetic valve failure was defined as the need for redo PVR or interventional catheter procedure. Prosthetic valve dysfunction was defined as a peak pressure gradient equal to or greater than 40 mmHg or at least moderate amount of pulmonary regurgitation on the latest echocardiography.
Results: There were 3 early and 7 late deaths. Follow-up completeness was 88.6% and mean follow-up duration was 7.3 ± 2.9 years. Forty three patients underwent redo PVR. The median time interval between initial PVR and redo PVR was 6.4 years (range, 0.5-13.6 years). Overall freedom from redo PVR at 5 and 10 years was 93.9 ± 1.9% and 51.7 ± 8.6%, respectively. Overall freedom from both valve failure and valve dysfunction at 5 and 10 years was 92.2 ± 2.1% and 20.2 ± 6.7%, respectively. In multivariable analysis, younger age at operation, diagnosis of PA with VSD, and use of stentless valve were identified as risk factors for redo PVR.
Conclusions: Durability of bioprosthetic valves in pulmonary position was suboptimal. Valve function was maintained stable until 5 years after operation. By 10 years, however, about 80% will require reoperation or manifest valve dysfunction. Younger age and diagnosis of PA with VSD were identified as independent risk factors for redo PVR. In our experience, stentless valve was less durable than stented valves.
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