Successful surgical treatment of mitral valve stenosis in a dog.

Abstract

To report the successful surgical management (open mitral commissurotomy, OMC) of mitral stenosis (MS), incorporating heart-beating cardiopulmonary bypass (CPB), in a 1-year-old dog. Clinical case. One-year-old Cairn Terrier with MS. Diagnosis of MS was confirmed by means of 2-dimensional, continuous-wave and color-flow Doppler echocardiography. Surgery was performed through a left intercostal thoracotomy. CPB was initiated and the heart was kept beating. The fused commissures of the mitral valve were incised to free the cusps of the valve. Left intercostal thoracotomy allowed easy observation of the mitral orifice during heart-beating OMC. Persistent bleeding from the atriotomy site required a second surgical procedure after which the dog had an uneventful recovery. Echocardiography at 2 weeks and 1 year postoperatively indicated substantial improvement in left ventricular filling (pressure half-time=187 ms before surgery, 105 ms [2 weeks] and 110 ms [1 year] after surgery). Enlargement of the left atrium resolved; however, moderate mitral valve regurgitation was still present. MS can be successfully treated by OMC, facilitated by use of CPB. Substantial improvement in cardiac function was evident by ultrasound and Doppler examination postoperatively. OMC under heart-beating CPB should be considered for the treatment of MS in the dog.