Background

Pneumoperitoneum incidentally found on imaging following gastrointestinal surgery can be a challenging clinical phenomenon. No studies have evaluated postoperative pneumoperitoneum after minimally invasive bariatric surgery or the prognostic utility of defining pneumoperitoneum. The primary objective was to evaluate the incidence of pneumoperitoneum after minimally invasive bariatric surgery and imaging signs consistent with leak.

Methods

This is a retrospective study of patients who underwent primary bariatric surgery between July 2002 to December of 2022. CT imaging was obtained on post-operative days 0-13 of 335 patients who underwent laparoscopic bariatric surgery (including Roux-en-Y gastric bypass, sleeve gastrectomy, and duodenal switch). CT imaging with largest area of pneumoperitoneum graded as mild (0-5 mm), moderate (6-10 mm) or severe (> 10 mm).

Results

Univariate analysis shows increasing pneumoperitoneum on CT imaging (p = 0.023) and increasing days to post-operative CT scan (p = 0.001) were associated with a post-operative leak. Patients with a higher BMI and findings of pneumoperitoneum on CT were associated with a leak (p = 0.025). Multivariate analysis showed that pneumoperitoneum on CT, used as ordinal variable (Mild = 1 / Moderate = 2/ Severe = 3), as pneumoperitoneum increases, the risk of leak increases (p = 0.036) and increasing days to post-operative CT scan was associated with a leak (p = 0.039).

Conclusions

Following laparoscopic bariatric surgery, severe pneumoperitoneum (diameter 6-10 mm) increased the odds of a postoperative leak, and increasing days to post-operative CT scan with pneumoperitoneum present was associated with a leak.