Extended vertical transseptal approach versus conventional left atriotomy for mitral valve surgery

Mitral valve surgery requires optimal exposure of the valvular apparatus, particularly when a conservative procedure is used. Retrospectively, we compared surgical results in patients who underwent mitral valve surgery using the vertical transseptal approach (which has been adopted routinely in our institute) with those in patients undergoing conventional left atriotomy.

A total of 172 consecutive patients operated on for mitral procedures were allocated to either group A (those operated on through a longitudinal left atriotomy; n = 62), or group B (mitral valve exposure achieved through an extensive vertical transseptal approach; n = 110).

In group A, there were 24 valvular reconstructions and 38 valvular replacements. Mean (+/- SD) cardiopulmonary bypass (CPB) time was 65.9 +/- 17 min and mean ischemia time 37.4 +/- 13 min. Total postoperative bleeding was 277 +/- 171 ml. There was no surgical re-exploration for bleeding. One patient in this group died (mortality rate 2%). Among 40 patients in atrial fibrillation preoperatively, four had one episode of temporary junctional rhythm, six had temporary sinus rhythm and two had stable sinus rhythm. Among patients with preoperative sinus rhythm, six (27%) had episodes of atrial fibrillation and two (9%) temporary atrioventricular block. In group B, 46 mitral reconstructions and 64 mitral replacements were performed. Mean CPB time was 67.9 +/- 20 min and mean ischemia time 48.1 +/- 17 min. Total postoperative bleeding was 400 +/- 189 ml. Three patients in this group died (mortality rate 2.7%). Among 60 patients with preoperative atrial fibrillation, six (10%) had one episode of temporary junctional rhythm, 14 (24%) had temporary sinus rhythm and two (3%) had conversion to stable sinus rhythm. Among those in sinus rhythm preoperatively, 16 (32%) had episodes of temporary junctional rhythm, two (4%) had temporary atrial fibrillations, and four (8%) had stable atrial fibrillation. In group B patients, the incidences of ischemia time and total postoperative bleeding (p = 0.004), and postoperative junctional arrhythmia in those with preoperative sinus rhythm (p < 0.001), were greater than in group A patients.

No technique-related deaths occurred; neither were causes of re-exploration for bleeding related to technique, and there was no evidence of residual interatrial shunt. In conclusion, transseptal extended atriotomy provides excellent exposure for mitral valve surgery. Disadvantages of minimally increased ischemia time and surgical bleeding are minor compared with the superior and more complete surgical reconstruction achieved. The advantages of the technique are undermined by the higher incidence of junctional arrhythmia which, even if temporary, requires strict postoperative monitoring.