External aortic clamping versus endoaortic balloon occlusion in minimally invasive cardiac surgery: a systematic review and meta-analysis.

OBJECTIVES: Minimally invasive cardiac valve surgery is safe, effective and increasingly popular. It is performed worldwide with the use of either external aortic clamping or endoaortic balloon occlusion.

METHODS: We conducted a literature search using MEDLINE, EMBASE, Scopus and Web of Science. Primary outcomes included aortic dissection, conversion to sternotomy, mortality, stroke and cross-clamp time. Secondary outcomes included atrial fibrillation, acute kidney injury, reoperation for bleeding, cardiopulmonary bypass times, myocardial infarction, use of intra-aortic balloon pump and length of hospital stay. The random effects model was used to calculate the outcomes of both binary and continuous data.

RESULTS: Thirty retrospective studies were included in the meta-analysis. The incidence of aortic dissection (pooled odds ratio = 3.88, 95% confidence interval = 1.06-14.18; P =0.04) and conversion to sternotomy (pooled odds ratio = 3.07, 95% confidence interval = 1.33-7.10; P = 0.009) was higher in the endoaortic balloon occlusion group than in the external aortic clamping group, in whom a direct comparison was possible. The remaining observational studies did not show any significant differences in either group. There was no significant difference in 30-day mortality (P = 0.37), stroke (P = 0.26), cross-clamp time (P = 0.20), atrial fibrillation (P = 0.18), acute kidney injury (P = 0.49), reoperation for bleeding (P = 0.24), cardiopulmonary bypass time (P = 0.06), myocardial infarction (P = 0.74), use of intra-aortic balloon pump (P = 0.11) or length of hospital stay (P = 0.47).

CONCLUSIONS: External aortic clamping may be safer than endoaortic balloon occlusion with respect to aortic dissection and conversion to sternotomy. However, mortality, length of stay, stroke, cross-clamp time and other cardiovascular complication rates were similar between the 2 techniques.