European Journal of Cardio-Thoracic Surgery, Vol 10, 1090-1096, Copyright © 1996 by European Association for Cardio-thoracic Surgery
New approach for replacement of degenerated mitral bioprostheses
AS Geha and JH Lee
Division of Cardiothoracic Surgery, Case Western Reserve University School of Medicine, Cleveland, OH 44106-5011, USA.
OBJECTIVE: The most common indication for reoperation in patients with a
mitral bioprosthetic valve is primary tissue failure. Explanation of the
bioprosthesis is time-consuming and may be complicated by cardiac rupture
at the atrioventricular junction or the posterior left ventricular wall
where a strut is imbedded, injury to the circumflex artery and late
perivalvular leak. A new approach to avoid these complications by excising
only the bioprosthetic tissue and attaching a reversed aortic St. Jude
valve to the intact stent has been developed and evaluated. METHODS: We
have replaced degenerated mitral bioprostheses with a St. Jude valve in 73
patients during the last 12 years. In 57, including all who had their
operation before 1991, explantation was used. The stent was preserved in 16
patients; in the first four we implanted a mitral St. Jude valve (SJM)
within the stent, but this only allows a SJM 6-8 mm smaller than the
bioprosthesis. We evolved our approach in the last 12 patients to suture a
reversed aortic St. Jude valve with extended cuff to the atrial side of the
bioprosthetic cuff; this allows the use of a St. Jude valve 2 mm smaller
than the bioprosthesis with exact matching of the orifice sizes. The
demographic and clinical profiles of the two groups were similar. RESULTS:
Operative mortality was 8/57 (14%) in the explantation group and none in
the stent-preservation group. Three late perivalvular leaks occurred in the
explanation group, and none in the stent-preservation group. Thirteen late
deaths occurred in the explanation group, with a 5-year survival rate of
68%, and one late death (cancer) in the stent-preservation group, but the
follow-up is significantly shorter. CONCLUSIONS: Leaving the mitral
bioprosthetic stent and cuff intact eliminates the need for extensive
dissection, thus shortening and simplifying the procedure and diminishing
its attendant mortality and morbidity. It offers a safe and logical
approach to replacement of a degenerated mitral bioprosthesis with a St.
Jude valve of comparable size which projects into the left atrium, rather
than a smaller one jammed into the orifice of the bioprosthetic stent.
