Incidence, risk factors, and clinical impact of subcutaneous emphysema following laparoscopic totally extraperitoneal inguinal herniorrhaphy: a retrospective cohort study

We aimed to determine the incidence of subcutaneous emphysema following laparoscopic totally extraperitoneal (TEP) inguinal herniorrhaphy and to evaluate its associated factors and clinical impact. In this retrospective cohort study, we included consecutive patients who underwent laparoscopic TEP inguinal herniorrhaphy between 2020 and 2023. The primary outcome was any SE, assessed using palpation method and radiographic imaging. Secondary outcomes were severe SE, defined as the SE extending to the area of the nipple and above. We also evaluated key postoperative recovery indices, comparing patients with and without SE. Among the 829 included patients, 161 (19.4%) developed any SE, and 98 (11.8%) developed severe SE. Four independent risk factors were identified for any SE: lower body mass index [adjusted odds ratios (aORs): 0.84, 95% confidence interval (CI): 0.77–0.90], higher peak airway pressure (aOR: 4.98, 95% CI: 1.53–16.17, on base-2 logarithmic scale), higher peak partial pressure of end-tidal carbon dioxide (aOR: 250.18, 95% CI: 73.41–852.59, on base-2 logarithmic scale), and use of volume-controlled ventilation (pressure- vs. volume-controlled ventilation: aOR: 0.40, 95% CI: 0.22–0.75) (c-statistic = 0.790). The safe threshold for any SE was peak airway pressure < 25 cm H2O and peak partial pressure of end-tidal carbon dioxide < 45 mm Hg. Patients with SE showed a higher need for supplemental oxygen after surgery. Independent factors associated with SE following laparoscopic TEP herniorrhaphy were identified and may facilitate timely recognition and management. SE can be accompanied by transient respiratory changes but is generally self-limited.