Renner J, et al. - Here, the researchers decided to retrospectively examine patients scheduled for minimally invasive mitral valve surgery (MICS) in their institution. The analysis led us to hypothesize the possibility of an inflammatory disposition for unilateral pulmonary oedema (UPE) in accordance with the rarely available literature regarding UPE after MICS. In this patient population, the role of pulmonary hypertension remained unclear.

Methods

• The researchers examined 256 MICS patients after approval by their institutional review board.
• They defined a newly developed UPE, radiographically evident within the first 24 h postoperatively as part of the primary end-point.
• The length of stay in the intensive care unit, length of stay in the hospital and in-hospital mortality were the secondary end-points.
• In this study, chest radiographs were analyzed by an independent consultant of radiology.

Results

• In the 1st postoperative chest radiography performed in the intensive care unit, 51 (19.9%) patients showed increased right-sided pulmonary vascular congestion.
• After admission to the intensive care unit, 5 (1.95%) patients immediately required extracorporeal life support.
• In the UPE group, cardiopulmonary bypass time was significantly longer [UPE vs non-UPE 213 (49) vs 196 (43) min; P=0.013].
• A preoperative increase of C-reactive protein >0.4265 mg/dl (P=0.05) was observed in more patients with UPE.
• In logistic regression analysis, the researchers determined a preoperative increase in C-reactive protein >0.4265 mg/dl as well as a prolonged cardiopulmonary bypass time (odds ratio 1.009, 95% confidence level 1.002–1.016; P=0.014) independent risk factors, significantly associated with the development of UPE (odds ratio 2.583, 95% confidence interval 1.275–5.233; P=0.008), a prolonged cardiopulmonary bypass time (odds ratio 1.009, 95% confidence interval 1.002–1.016; P=0.014).
• Regarding the genesis of UPE, the presence of pulmonary hypertension (odds ratio 0.273, 95% confidence interval 0.08–0.84; P=0.02) seemed to be a protective factor.