Skeletal Muscle Depletion: A Risk Factor for Pneumonia following Gastric Endoscopic Submucosal Dissection in Elderly Patients

Introduction: Endoscopic submucosal dissection (ESD) is an effective treatment for gastric neoplasms in elderly patients; however, it involves several adverse events, including pneumonia. This study aimed to investigate whether skeletal muscle depletion (SMD) was associated with the development of pneumonia in elderly patients who underwent gastric ESD. Methods: This retrospective observational cohort study included 157 patients (>= 80 years) who had undergone gastric ESD. The skeletal muscle cross-sectional area was measured by CT, and the value of the third lumbar vertebra skeletal muscle index (L3 SMI) was evaluated. The SMD was defined as an L3 SMI value <= 38.0 cm(2)/m(2) for women and <= 42.0 cm(2)/m(2) for men. Pneumonia was also diagnosed using CT to identify all included patients. Results: Among 157 patients, 66 (42.0%) showed SMD. In the SMD group, the incidence of pneumonia was 21.2%, whereas it was 7.7% in the non-SMD group (p = 0.018). The longest hospitalization duration was 19 days. Antibiotics were administered in 61.9% of the patients. Procedure time was not significantly different between the groups (72 +/- 54 min vs. 62 +/- 44 min, p = 0.201). On multivariate analysis, SMD was an independent risk factor for the development of pneumonia (odds ratio = 3.16, 95% confidence interval, 1.18-8.50, p = 0.023). Conclusions: SMD was not a rare entity in patients aged >= 80 years with gastric neoplasms. SMD was a significant risk factor for pneumonia related to gastric ESD in elderly patients.