Echocardiographic assessment in minimally invasive mitral valve surgery

Due to limited exposure, removal of intracavitary air and visual assessment of cardiac function during minimally invasive procedures are not always possible. We analysed the utility of intraoperative transesophageal echocardiography (TEE) and postoperative transthoracic echocardiographic (TTE) in minimally invasive mitral valve (MV) procedures.

We evaluated data from 163 consecutive patients undergoing isolated minimally invasive MV replacement (n=40) or repair (n=123) via small right anterolateral thoracotomy (121 complex mitral procedures). Cardioplegic arrest was achieved using either endoaortic (n=23) or transthoracic aortic clamp (n=140). In addition to preoperative TTE, TEE was used intraoperatively before and after cardiopulmonary bypass (CPB). Postoperative TTE was performed to monitor valve function at 3 and 12 months, and at 5-year follow-up.

Pre-CPB TEE was useful to assess valve dysfunction and assist in placement of the arterial and venous cannulas. During CPB, placement and positioning of the endoclamp were guided effectively in all but 4 patients, in whom recurrent balloon migration necessitated secondary transthoracic aortic clamping. TEE detected one acute retrograde aortic dissection and one circumflex artery occlusion. After 18.7+/-10.6 months follow-up, all patients except three improved symptomatically and had consistently good valve function.

Intraoperative TEE is essential for minimally invasive MV surgery, because it allows immediate control of valve function before and after surgery. It is useful to detect unexpected complications requiring immediate remedy. Postoperative echocardiographic results show that minimally invasive MV surgery is a good alternative to conventional surgery even in complex MV repairs.