Prevention of Pulmonary Edema after Minimally Invasive Cardiac Surgery with Mini-Thoracotomy Using Neutrophil Elastase Inhibitor

Abstract

Purpose: Unilateral re-expansion pulmonary edema (RPE) is a rare but one of the most critical complications that may occur after re-expansion of a collapsed lung after minimally invasive cardiac surgery (MICS) with mini-thoracotomy.

Methods: We performed a total of 40 consecutive patients with MICS by right mini-thoracotomy with single-lung ventilation between January 2013 and June 2016. We divided the patients into control group (n = 13) and neutrophil elastase inhibitor group (n = 27). Neutrophil elastase inhibitor group received continuous intravenous infusion of neutrophil elastase inhibitor at 0.2-0.25 mg/kg per hour from the start of anesthesia until extubation during the perioperative period.

Results: There were no relations with operative time, cardiopulmonary bypass (CPB) time, aortic clamp time, and intraoperative water valances for postoperative mechanical ventilation support time. Compared with the neutrophil elastase inhibitor group, the control group had significantly higher initial alveolar-arterial oxygen gradient and significantly lower initial ratio of partial pressure of arterial oxygen to fraction of inspired oxygen at the intensive care unit (ICU). The control group had significantly longer postoperative mechanical ventilation support time and hospital stay compared with the neutrophil elastase inhibitor group.

Conclusions: Neutrophil elastase inhibitor may have beneficial effects against RPE after MICS with mini-thoracotomy.

Keywords: minimally invasive cardiac surgery; neutrophil elastase inhibitor; re-expansion pulmonary edema.

Figures

Fig. 1. Correlations with operation time (A), CPB time (B), and aortic clamp time (C) and also intraoperative water valances (D) postoperative mechanical ventilation support time. There were no correlations with perioperative factors for postoperative mechanical ventilation support time. CPB: cardiopulmonary bypass

Fig. 2. Correlations between initial A-aDO2 (A) and FiO2 ratio (PFR) (B) with ventilation support time. There were strong correlations between initial A-aDO2 and PFR with ventilation support time. A-aDO2: alveolar-arterial oxygen difference; FiO2: fraction of inspired oxygen; PFR: partial pressure of arterial oxygen to fraction of inspired oxygen ratio

Fig. 3. Imaging findings 1 day after in a 59-year-old male (Case 1) who underwent minimally invasive cardiac surgery (A and B). (A) Chest radiography 1 day after operation shows unilateral pulmonary edema on the right. (B) Computed tomography shows obvious unilateral change with alveolar consolidation on the right. Imaging findings 6 months after minimally invasive cardiac surgery (C and D). (C) Chest radiography shows improvement in the unilateral right-sided pulmonary edema. (D) Computed tomography shows disappearance of the unilateral changes and alveolar consolidation.