Towards a better mouse model of vertical sleeve gastrectomy.

Background: The gold standard for treatment of obesity remains bariatric surgery. The mechanisms underlying the effectiveness of these operations remain incompletely understood. Rodent models of these surgeries have proven essential to efforts to elucidate these mechanisms. The most commonly used such model is the mouse vertical sleeve gastrectomy (VSG).

Objective: This study aimed to evaluate technical approaches and complications of mouse VSG.

Setting: Academic research laboratory, United States.

Methods: Wild-type male mice were subjected to variations of VSG. Important metabolic outcomes, including body weight, body composition, and glucose tolerance, were assessed at relevant time points postoperation. A necropsy was performed on all mice at 2 months postsurgery to evaluate the gastric sleeve for any complications.

Results: Chronic, contained gastric leak is a relatively high-frequency complication after mouse VSG. A scoring system was developed to quantify and sort mice with leaks. Data from mouse cohorts performed by different methods demonstrate that no surgical approach used in the study could prevent the risk of leak. It shows that significant leaks impact commonly measured metabolic parameters after VSG, likely secondary to the effects of chronic local and systemic inflammation.

Conclusions: The presence of chronic gastric leak is common after mouse VSG. The effects of these leaks are likely to confound data analysis when using this surgical model. The use of the scoring and sorting approach developed and described in this study provides an important tool for quality control of murine VSG studies. Careful elimination of mice with this complication enables the effective and reliable use of this surgical model.