Mechanism of hemolysis after mitral valve repair and new surgical management: prosthetic annuloplasty ring covered with autologous pericardium.

摘要

BACKGROUND AND AIMS OF THE STUDY: Hemolysis after mitral valve repair is a rare occurrence, but is one of the complications leading to reoperation. Since 1999, mitral valve repair at the authors' institution has been performed using a prosthetic annuloplasty ring covered with autologous pericardium to prevent this complication. The study aims were to investigate the mechanism of hemolysis after mitral valve repair and to describe the surgical management of this complication. METHODS: This retrospective study comprised 204 consecutive patients who underwent mitral valve repair using an annuloplasty ring between October 1991 and April 2000 at the authors' institution. Patients were allocated to the non-covered ring group (n = 174) and the covered ring group (n = 30), and compared for the degree of mitral regurgitation (MR), serum levels of lactate dehydrogenase (LDH), and occurrence of hemolysis. The degree and flow pattern of MR, and patient prognoses were described for hemolytic patients. RESULTS: Postoperative MR and serum LDH were not significantly high in either group. A total of seven patients presented with hemolysis; postoperative echocardiography revealed MR to be mild in two patients, moderate in three and severe in two. Collision of the regurgitant jet into the artificial ring was evident in all seven patients. A beta-blocker proved effective in treating hemolysis in three patients, mitral re-repair was performed in three, and a prosthetic mitral valve was inserted in one patient. None of the patients in the covered ring group presented with hemolysis. CONCLUSION: The major cause of hemolysis after mitral repair was collision of the regurgitant jet into the artificial ring. The simple technique used herein prevented contact of the regurgitant jet with the rough surface of the ring, and may in turn have prevented hemolysis. In selected patients, hemolysis was improved by beta-blocker administration.