Association of iliopsoas muscle cross-sectional area with postoperative complications in older lung cancer patients: a retrospective study

Sarcopenia was correlated with increased postoperative complications and poor outcomes in patients with lung cancer. The cross-sectional area of the iliopsoas muscle on computed tomography is a relevant indicator of sarcopenia. This study aimed to investigate whether the preoperative cross-sectional area of the iliopsoas muscle is associated with the incidence of postoperative complications after lobectomy. This retrospective study included 584 consecutive patients aged 70 years or older who underwent curative resection for non-small cell lung cancer between 2016 and 2020. The cross-sectional area of the iliopsoas muscle was measured at the level of the third lumbar vertebra, and the cumulative area of both sides was evaluated. Univariable and multivariable analyses were performed to identify the predictors of early postoperative complications (≥ grade II by the Clavien-Dindo classification) along with the preoperative iliopsoas muscle cross-sectional area. The patients were divided into two groups according to the Clavien-Dindo grade: 125 patients (21%) had ≥grade II complications, whereas 459 patients (79%) had < grade II complications. The median iliopsoas muscle area was 1009 mm2 [range, 412–2455 mm2] in patients with < grade II complications and 797 mm2 [range, 307–1755 mm2] in those with ≥grade II complications, with significant differences (P < 0.01). The calculated cut-off value for the iliopsoas muscle cross-sectional area was 800 mm. The multivariable analysis showed that sex (P < 0.01) and an iliopsoas muscle area of < 800 mm2 (P < 0.01) were independent factors associated with postoperative complications. The most common complications were prolonged air leakage, pneumonia, atrial fibrillation, empyema, and acute exacerbation of interstitial pneumonia. Patients with an iliopsoas muscle area of < 800 mm2 had significantly more prolonged air leakage and atrial fibrillation than those with an iliopsoas muscle area of ≥ 800 mm2 (all P = 0.04). The cross-sectional area of the iliopsoas muscle is a valuable predictor of postoperative complications after lobectomy. Notably, patients with an iliopsoas muscle cross-sectional area < 800 mm² had significantly higher risks of pulmonary fistula and atrial fibrillation. For patients with a smaller iliopsoas muscle area, limited resection should be considered and more careful perioperative management may be necessary.