Impact of Intraoperative Gravity-Dependent Atelectasis Following Laparo scopic Liver Resection Performed in the Lateral Position

Author(s): Ryoichi Miyamoto, Toshiro Ogura, Amane Takahashi, Kei Kitamura, Hiroyuki Ishida, Shinichi Matsudaira and Yoshiyuki Kawashima

Laparoscopic liver resection (LLR) is currently an acceptable approach to liver surgery in select patients. The correlation between the intraoperative position and the presence of gravity-dependent atelectasis (GDA) has been well discussed. However, LLR is performed in the left half lateral position, and the relationship between this position and the presence of GDA remains unclear. We evaluated the extent to which the intraoperative left half lateral position affects the presence of GDA. Furthermore, univariate and multivariate analyses were performed to identify potential risk factors for postoperative complications after LLR with a special emphasis on the presence of GDA by comparing various patient-, liver- and surgeryrelated factors in a retrospective cohort. We retrospectively evaluated 129 patients who underwent LLR in the left half lateral position at the Saitama Cancer Center in Saitama, Japan, between March 2011 and July 2020. The frequency and duration of GDA were investigated. We divided the cohort into groups with GDA and without GDA based on a cutoff value (≥ 5 days, n = 61 and < 5 days, n = 68, respectively). Using multivariate analysis, the duration of GDA and several risk factors for postoperative complications after LLR were independently assessed. Postoperative GDA was observed in 61 patients (47%) and lasted for 1 to 8 days in these patients. The mean duration of GDA was 4.3 days. Multivariate logistic regression analysis revealed that a GDA duration of 5 days or more (odds ratio [OR], 2.03; p = 0.001) and an operating time > 388 minutes (OR, 5.31; p < 0.001) were independent risk factors for postoperative complications after LLR. The incidence and duration of postoperative GDA are considered useful predictors of postoperative complications, and these predictors should be assessed to improve the short-term outcomes of patients undergoing LLR.