Effect of Narrow Chest on Minimally Invasive Mitral Valve Surgery via Right Minithoracotomy.

Background: The effect of a narrow chest on minimally invasive mitral valve surgery (MIMVS) is unclear.Methods and Results: We enrolled 206 MIMVS patients and measured anteroposterior diameter (APD) between the sternum and vertebra, transverse thoracic diameter (TD), right and left APD of the hemithorax (RD and LD, respectively), and the Haller index (HI; TD/APD ratio) on computed tomography. Preoperative characteristics and operative outcomes were compared between patients with a narrow chest (Group N; HI >2.5; n=53) and those with a normal chest (control [C]; HI ≤2.5; n=153), and the correlations of these measurements with operation time were evaluated in 133 patients undergoing an isolated mitral procedure. Groups N and C differed significantly in APD (89.4 vs. 114.3 mm, respectively; P<0.001), TD (251.5 vs. 240.3 mm, respectively; P=0.002), RD (152.5 vs. 172.5 mm, respectively; P<0.001), LD (155.0 vs. 172.4 mm, respectively; P<0.001), and HI (2.84 vs. 2.12, respectively; P<0.001). Procedural characteristics were comparable, except for a longer aortic cross-clamp time (ACCT) in Group N (118.7 vs. 105.8 min; P=0.047). Rates of surgical death, re-exploration, cerebral infarction, and prolonged ventilation were comparable between the 2 groups. TD was significantly correlated with ACCT (R²=0.037, P=0.028) in patients undergoing an isolated mitral procedure.

Conclusions: Early MIMVS outcomes in patients with narrow chests are satisfactory. TD prolongs ACCT during MIMVS.