Long-Term Results of Transseptal Atriotomy in Small Left Atrium

Background: Transseptal atriotomy provides better exposure to the mitral valve in challenging cases but has conflicting results with postoperative rhythm disturbances. We aimed to investigate long term results of limited transseptal atriotomy in cases with a small left atrium. Methods: From January 2010 through February 2014, 1214 patients underwent mitral valve surgery at the SBÜ Kartal Kosuyolu High Specialization Training and Research Hospital. Left atrium diameter on 2-dimensional (2-D) echocardiography defined in 119 patients who had small left atrium and met the inclusion criteria were enrolled in the study, of which 57 patients (47.9%) underwent transseptal atriotomy (Group TS), while 62 patients (52.1%) underwent a left atriotomy (Group LA). Data was retrospectively collected. Long-term analyses were performed based on survival. The mean follow-up duration was 10.7 ± 4.2 years. Results: Isolated mitral procedures were performed in 49 patients (41.2%). Concomitant tricuspid valve surgery was performed in 42 patients (35.3%), concomitant aortic valve surgery in 24 patients (20.2%), and concomitant coronary artery bypass grafting in 15 patients (12.6%). The procedure rates were comparable in both Groups (p > 0.05). There was no significant difference in pre-operative variables. Ischemic time and total perfusion time were found to be similar in the Group TS vs. Group LA (87.6 ± 33.5 vs. 77.4 ± 27.8 minutes and 117.2 ± 38.4 vs. 112.3 ± 33.8 minutes respectively; p > 0.05). New-onset arrhythmia was higher in the Group TS but did not reach statistical significance (26.3% vs. 19.4%; p = 0.5). The rate of permanent pacemaker insertion was similar (5.3% vs. 4.8%; p = 0.9). Follow-up was completed in all cases and survival rate was 64.7% (64 ± 7% in Group TS vs. 58 ± 7% in Group LA; p > 0.05). Log rank analyses shows similar survivals (Group TS: 11.7 ± 0.6 years, 95% CI: 10.5–12.9; Group LA: 11.8 ± 0.6 years, 95% CI: 10.6–12.9; p > 0.05). In the multivariate Cox regression analysis, age, obesity, procedure type, and left ventricular dysfunction were found to be independent risk factors for late mortality. Regardless of tricuspid valve surgery, concomitant coronary artery bypass grafting (CABG) had worse survival compared to isolated mitral procedures and concomitant aortic valve replacement (AVR) (12.5 ± 0.5 years for mitral, 11.4 ± 1 years for concomitant AVR, and 8.2 ± 1.2 years for concomitant CABG; p < 0.01). Conclusion: Limited transseptal atriotomy was not found to be inferior when compared to left atriotomy in cases with a small left atrium undergoing while mitral valve (MV) should be performed when the exposure is challenging.