Effects of MIAVS on Early Postoperative ELWI and Respiratory Mechanics

The effects of minimally invasive aortic valve surgery (MIAVS) on the early postoperative extravascular lung water index (ELWI) and respiratory mechanics have rarely been studied.

A total of 90 patients were divided into 3 groups: a conventional full sternotomy (CS) group (n=30), an upper ministernotomy (US) group (n=30), and a right anterior thoracotomy (RT) group (n=30). Hemodynamic and respiratory mechanics parameters were recorded at perioperative time points, including before skin incision (T(-1)); at sternum closing (T0); and 4 h (T4), 8 h (T8), 12 h (T12), and 24 h (T24) after the operation. The ventilator support time, ICU length of stay, and postoperative hospitalization time, as well as the thoracic drainage volume and blood transfusion volume, were recorded.

The ELWI and pulmonary vascular permeability index (PVPI) increased at T4, and the values were significantly lower in the US group than in the RT group and CS group (P<0.05). At T8, the ELWI and PVPI in the US group and RT group were significantly lower than in the CS group. At T12, there were no significant differences among the 3 groups. In addition, at T4 static lung compliance decreased, plateau airway pressure increased, and airway resistance changed non-significantly. There were no significant differences between the US group and the RT group, but both groups showed better results than the CS group did.

The ELWI and PVPI may transiently increase after aortic valve surgery with cardiopulmonary bypass. Compared with the 12 h required to recover from a conventional sternotomy operation, it may only take 8 h to recover from MIAVS.