Endoscopic mucosal StO₂ imaging in ESG and LSG: a pilot study on tissue perfusion and weight loss

Bariatric procedures, including endoscopic sleeve gastroplasty (ESG) and laparoscopic sleeve gastrectomy (LSG), are established weight loss interventions. Recent advances in endoscopic technology enable real-time measurement of mucosal tissue oxygen saturation (StO₂) in the gastrointestinal tract, providing insight into tissue perfusion.

This pilot study aimed to establish baseline StO₂ values across gastrointestinal regions in uncomplicated post-LSG patients and to investigate changes in gastric StO₂ pre- and post-ESG and their relationship with weight loss outcomes.

This prospective, single-center pilot study enrolled 14 adults (6 LSG, 8 ESG).

In the LSG group, StO₂ was measured in the esophagus, proximal sleeve, distal sleeve, and duodenum. In the ESG group, gastric mucosal StO₂ was recorded immediately before and after the procedure. Demographics, clinical history, and one-month post-ESG weight loss data were also collected. Paired t-tests compared StO₂ values, and multivariable linear regression assessed the association between StO₂ change and weight loss. In LSG patients, the proximal gastric sleeve showed higher StO₂ (82%) than the distal sleeve (59%), with the esophagus recording the lowest value (31%). In the ESG group, mean gastric StO₂ decreased significantly from 54 ± 12% pre-procedure to 21 ± 7% post-procedure (p < 0.001). Average one-month weight loss was 4.58 kg. Multivariable regression identified StO₂ change as a negative predictor of percentage total weight loss (p = 0.0454), meaning greater StO₂ reduction correlated with less weight loss.

This study established baseline StO₂ values for uncomplicated LSG anatomy and demonstrated that excessive reduction in gastric mucosal perfusion during ESG negatively predicts early weight loss outcomes.