Mini-sternotomy aortic valve replacement: is it safe and effective? Comparison with standard techniques

Abstract

Background and aim of the study: Mini-sternotomy aortic valve replacement (MSAVR) has been increasingly performed at the authors' institution since October 2003. The study aim was to compare results obtained with MSAVR to those following AVR with conventional sternotomy (SAVR).

Methods: Between 1998 and 2008, a total of 143 consecutive patients (mean age: 67 +/- 12.5 years) underwent AVR at the authors' institution. Of these patients, 82 underwent SAVR, and 61 underwent MSAVR performed through a reversed-L-shaped median sternotomy with a transverse limb at the right fourth intercostal space. Ascending aortic and right atrial cannulation through the mini-sternotomy were employed for cardiopulmonary bypass (CPB).

Results: Typically, the MSAVR patients were slightly younger than SAVR patients (mean age: 67 +/- 16 years and 70 +/- 15 years, respectively; p = 0.037), had a lower incidence of diabetes (3% versus 18%, p = 0.008), and a slightly higher left ventricular ejection fraction (74.5 +/- 12% versus 71 +/- 12%, p = 0.019). There were no other inter-group preoperative differences. As expected, MSAVR required a slightly longer aortic cross-clamp time (49 +/- 19 min) compared to SAVR (44.5 +/- 16 min; p = 0.019), and longer CPB times (77 +/- 31 min versus 60 +/- 26 min; p <0.0001), though the overall operating times were similar (p = 0.38). Postoperatively, MSAVR patients were extubated at 3 +/- 5 h, similar to SAVR patients (4 +/- 5 h) (p = 0.13). The median intensive therapy unit stay was 1 +/- 1 days in both groups. The median hospital stay was comparable between groups (MSAVR, 7 +/- 5 days; SAVR, 8 +/- 4 days; p = 0.48). The MSAVR patients had a higher incidence of delayed pericardial effusions requiring pericardiocentesis (n = 4; p = 0.031), but this did not affect survival. The 30-day mortality was similar in both groups (MSAVR group, n = 1 (1.6%); SAVR group, n = 3 (3.7%); p = 0.64). At five years after surgery, freedom from cardiac-related death was 96 +/- 2.6% in MSAVR patients, and 89 +/- 4.9% in SAVR patients (p = 0.32).

Conclusion: Mini-sternotomy AVR is technically challenging with longer CPB and aortic cross-clamp times. However, with increasing surgical experience, it offers results comparable to those achieved with conventional AVR, and with acceptable cosmetic results.