Thrombectomy for Prosthetic Heart Valve Obstruction

Abstract

Emergency surgery with valve replacement is the preferred treatment for prosthetic heart valve obstruction (PHVO), with a reported perioperative mortality of up to 17.5% in patients with New York Heart Association (NYHA) class IV before surgery.We followed up 11 patients who had thrombectomy between 1994 and 2004 for the treatment of PHVO (nine thrombi involving mitral and two thrombi involving aortic prosthetic valves). All patients were in NYHA classes III and IV. Immediate surgery was indicated for clinical presentations that included pulmonary edema, low cardiac output, congestive heart failure, and embolism. In all cases, the cause for PHVO was inadequate anticoagulation. None of the patients had underlying clotting disorders.Operations were performed using standard cardiopulmonary bypass with ante-and retrograde cold blood cardioplegia. Both sides of the obstructed valves were inspected. The left atrium was opened in cases involving the aortic, and aortotomy was performed in cases involving the mitral prosthetic valves. The thrombi were removed and the heart cavities rinsed with saline. The lower surfaces of the valves were then inspected with a cardioscope (Storz, Tuttlingen, Germany) to ensure that there were no residual thrombi.Early mortality occurred in one of 11 patients. An 80-year-old patient in NYHA IV with multiple morbidities died on the first postoperative day after mitral prosthetic valve thrombectomy. The cause of death was multiorgan failure. The surviving patients and their physicians were interviewed by telephone with a standardized questionnaire. The mean follow-up time was three years. All survivors were in NYHA class I or II at time of follow-up, and were sufficiently anticoagulated with warfarin. None of the patients required repeat surgery following thrombectomy.In our opinion PHVO does not necessarily require valve replacement. Thrombectomy without valve replacement reduces bypass time, thereby decreasing mortality. It should be considered when managing PHVO, especially for patients in higher NYHAclassification. Awareness of clinical consequences due to insufficient anticoagulation is extremely vital amongst physicians. Figure 1. Thrombosed mechanical mitral valve in situ.

Diagnostic accuracy of two-dimensional and three-dimensional transesophageal echocardiography in detecting pannus and thrombus in left mechanical valve obstruction

“…Differentiating between thrombus and pannus in LMVO is important, even in patients not indicated for thrombolytic therapy due to severe symptoms and large masses. Specifically, thrombus debridement might be favored over replacement, especially in a patient with high surgical risk to reduce the cardiopulmonary bypass time, and debridement might have a lower mortality rate 4 . In regards to patients with pannus, valve replacement is preferred because the fibrotic tissues can continue growing over mechanical valve surfaces 5 .…”