Novel surgical ablation through a septal-superior approach for valvular atrial fibrillation: 7-year single-centre experience.

Objectives: We previously reported favourable short-term results of our 'trans-septal maze procedure', a novel technique for creating biatrial lesions through a septal-superior approach during mitral valve surgery. Here, we reviewed the mid-term results of this procedure and determined the impact of restored left atrial (LA) contraction on late outcomes.

Methods: We examined clinical data of 50 patients with persistent (n = 7) or long-standing persistent atrial fibrillation (AF) (n = 43) (mean period of rhythm disturbance 77 ± 78 months) who underwent a trans-septal maze procedure concomitant with mitral valve surgery and were followed postoperatively for at least 24 months. The mean preoperative LA dimension was 59 ± 9 mm (40-85 mm). The presence of an A wave in Doppler echocardiography was considered to indicate evidence of LA mechanical contraction. Serial echocardiography was performed to evaluate left ventricular and LA dimensions, degree of valvular regurgitation and estimated systolic pulmonary artery (PA) pressure. Follow-up was completed with a mean duration of 59 ± 17 months (27-92 months).

Results: There were no ablation-related complications and 48 patients (96%) were free from AF immediately after the operation. At the latest follow-up, 39 patients (78%) were free from AF, while 28 (56%) presented LA mechanical contraction. Patients who restored LA mechanical contraction were less likely to experience postoperative thromboembolic events (4 vs 23%, P = 0.075), as compared with those who did not restore it. Serial echocardiography showed that patients with restored LA contraction showed improvement in Doppler-derived systolic PA pressure to a greater degree and less incidence of significant tricuspid regurgitation (7 vs 41%, P = 0.006). The Cox proportional hazards models with adjustments for all other covariates revealed LA dimension >60 mm at baseline as an independent risk factor for lack of LA mechanical contraction (adjusted hazards ratio 3.9, 95% confidence interval 1.1-14, P = 0.035).

Conclusions: Our trans-septal maze procedure may be an effective alternative surgical treatment for eliminating AF during mitral valve surgery. In patients with valvular AF, early surgery is warranted to restore sinus rhythm with LA mechanical contraction, before severe LA dilatation occurs. The impact of LA contraction recovery conferred by AF ablation on postoperative haemodynamic improvements and thromboembolic events remains to be determined.