Re-expansion pulmonary oedema after minimally invasive cardiac surgery with right mini-thoracotomy

Re-expansion pulmonary oedema (RPO) sometimes occurs after minimally invasive cardiac surgery (MICS) with single-lung ventilation. However, it has not been widely recognized as a serious complication. The aim of this study is to evaluate the occurrence rate and risk factors of RPO. A total of 381 consecutive patients who underwent MICS with right mini-thoracotomy from March 2005 to October 2013 were retrospectively reviewed. RPO was observed in 8 (2.1%) patients. In the preoperative data, greater percentages of preoperative use of steroid or immunosuppressant were found in patients with RPO (25% [2/8] vs 1% [4/373]; P = 0.0056). In the operative data, significantly longer operation, cardiopulmonary bypass (CPB) and aortic cross-clamping (ACC) times as well as greater percentages of second CPB run were found in patients with RPO (388 ± 80 vs 272 ± 61 min; P < 0.0002, 253 ± 79 vs 158 ± 50 min; P = 0.0009, 162 ± 65 vs 108 ± 38 min; P = 0.020 and 38% [3/8] vs 1.3% [5/373]; P < 0.0003). The overall 30-day mortality rate was 0.8% (3/381) and the 30-day mortality rate of patients with RPO was 12.5% (1/8). Significantly prolonged initial ventilation time, intensive care unit and postoperative hospital stay were observed in patients with RPO ( P = 0.0022, <0.0001 and 0.0003, respectively). Multivariate logistic analysis detected preoperative use of steroid or immunosuppressant and prolonged ACC time (≥156 min) as independent risk factors for RPO after MICS (odds ratio [OR]: 87.6 [95% confidence interval, CI: 4.1–2463.8]; P = 0.006 and OR: 36.0 [95% CI: 4.8–731.4]; P < 0.001). RPO should be recognized as one of the most serious complications after MICS with right mini-thoracotomy. More accurate risk factors of prolonged lung malperfusion and steroid use on RPO after MICS should be investigated.