Preoperative serum protein concentration as a predictor of staple-line leak after sleeve gastrectomy: a retrospective cohort study.

Background: Staple-line leak is the most frequent post-operative complication after sleeve gastrectomy (SG). Low serum protein concentration (SPC), a condition associated with malnutrition, is common among people with obesity. Whether low SPC represents a risk factor for staple-line leak has been actually not extensively investigated. The objective of this study is to assess the relationship between low SPC and staple-line leak in patients undergoing SG.

Methods: A prospectively collected database was queried for consecutive patients who underwent SG between January 1st 2010 and December 31st 2022 at a single institution.

Primary endpoint: to investigate the relationship between low pre-operative SPC and staple-line leak occurred within 30 days. Secondary endpoint: to investigate other patients' and surgeon's related risk factors for leak.

Results: 1669 patients were included in the study. Staple-line leak occurred in 53 patients (3.2%). Patients with staple-line leak had a significantly lower SPC than patients with a normal post-operative course (median 6.8 vs. 7.1 g/L; p < 0.001). High values of SPC significantly reduced the risk of leak (OR 0.20; 95% CI 0.09-0.45; p = 0.001). Major intraoperative bleeding and need of blood transfusions were significantly associated with a higher rate of leak (OR 3,58, 95% CI 1,45-8,86; p = 0,006; OR 9,79, 95% CI 3,66-26,22; p < 0,001) at a multivariable analysis.

Conclusion: The occurrence of staple-line leak after SG is directly related to pre-operative low SPC, an index of malnutrition. Nutritional assessment and optimization of protein intake could potentially reduce the rate of leak.