Surgical treatment of active infective mitral valve endocarditis. 
Although infective endocarditis is primarily treated conservatively with antimicrobial therapy, early surgical intervention is often mandatory when various complications arise.  These include intractable heart failure, persistent uncontrollable infection, large mobile vegetations, peripheral embolism and prosthetic valve endocarditis.  Optimal timing of surgical intervention in patients with infected heart valves results in reduced early and late mortality.  In the context of healed infective endocarditis, mitral regurgitation is treated with mitral valve repair, which produces long-term results similar to those seen for treatment of degenerative mitral regurgitation.  Mitral valve repair should also be considered for patients with mitral regurgitation due to active infective endocarditis.  Superficial infection without valve destruction is the best candidate for valve repair.  Discrete vegetations on the valve leaflets are excised along with underlying leaflet tissue (vegetectomy).  Although valve lesions can be repaired by standard techniques, particular care (e.g., reinforcement with a pericardial patch) should be taken to avoid excess tension on the suture line.  The feasibility of valve repair depends on the extent of tissue destruction.  Large defects of the anterior leaflet, due to transmural infection or lesions that encompass greater than one-third of the entire posterior leaflet with annular abscess, are not amenable to repair.  Also, the involvement of the aortic valve frequently necessitates valve replacement.  Further, unstable preoperative hemodynamics leads to the decision to perform valve replacement immediately rather than complicate valve repair in an attempt to avoid prolonged operation time for life salvage.  In the context of the feasibility of valve repair, timely surgical intervention and precise repair technique are essential.