Outcome Prediction after Surgical Management of Prosthetic Mitral Valve Dysfunction; a single center experience

Abstract

Background: Prosthetic Mitral valve dysfunction is a serious complication associated with a high mortality rate particularly in obstructive cases. The number of cases undergoing redo mitral valve surgery is increasing. This study aims to identify the risk factors of mortality and morbidity in patients who underwent redo mitral valve surgery for prosthetic mitral valve dysfunction. Methods: This study was conducted on 80 patients who underwent re-operation for management of prosthetic mitral valve dysfunction from December 2014 to February 2018. Patients' age ranged between 21 and 58 years with a mean of 36.8±9.60 years, and 53 patients (66.3%) were males. The causes of mitral valve malfunction were thrombus in 67 patients (83.7%) and pannus in 13 patients (16.3%). Results: 53 patients (66.25%) had urgent surgical intervention. Thrombectomy or pannus resection was done in 75 patients (93.75%) and valve replacement in 5 patients (6.25%). Re-exploration was required in 11 patients (13.75%) and was significantly associated with diabetes (p= 0.004), preoperative liver dysfunction (p= 0.04), elevated INR (p= 0.006), trial of thrombolysis (p<0.001) and prolonged ischemic time (p= 0.01). Postoperative renal failure occurred in 11 patients (13.75%) and was associated with diabetes (p< 0.001), preoperative renal dysfunction (p< 0.001), prolonged cardiopulmonary bypass and ischemic times (p< 0.001). 17 patients (21%) required prolonged mechanical ventilation and it was significantly associated with chronic obstructive lung disease (p< 0.001), pulmonary edema (p <0.001), low systolic blood pressure (p <0.001), low ejection fraction (p<0.001) and thrombectomy (p<0.001). Operative mortality occurred in 13 patients (16%) and was significantly associated with preoperative stroke, renal dysfunction, low blood pressure and acute pulmonary edema (p <0.001). Conclusion: Reoperation for prosthetic mitral valve dysfunction is associated with high morbidity and mortality. Outcomes can be predicted based on preoperative clinical status and operative times. Thrombectomy and pannus resection with the repair of the paravalvular leak is a simple and easy technique for management of those patients with a reduction of cardiopulmonary bypass and cross-clamp times.