Factors Predicting Variability in Total Small Bowel Length (TSBL) in People With Obesity Undergoing Metabolic Bariatric Surgery

Variability in the length of the total small bowel has been published. There is no easy noninvasive method to measure the total small bowel length (TSBL), and intraoperative measures can be difficult and may lead to bowel injury. It is crucial to know the TSBL in patients undergoing bypass procedures for metabolic bariatric surgery (MBS). The present study aims to study the demographic, anthropometric and metabolic parameters that contribute to TSBL in patients undergoing MBS. Patients undergoing MBS at the single centre between Oct 2022-May 2025 were included. TSBL was measured from the duodenojejunal junction to the ileocaecal junction on unstretched bowel along the anti-mesenteric border by a single surgeon using lap instruments with markings. Data were statistically analyzed to find the correlation between TSBL and covariates. Weight loss and comorbidity outcomes were not measured for this study. Total 246 consecutive patients were included in the study with 150 females. The mean age was 42.7 years, the mean height was 163.4 cm and the mean BMI was 45.7 kg/m2. The mean TSBL in the study participants was 797.7 cm. Height (r = 0.399) and presence of T2DM (p-value < 0.05) positively correlated, but age negatively correlated (r = -0.178) with TSBL. Linear regression analysis using age, sex, height, weight, dyslipidemia and diabetes to predict TSBL was carried and after adjusting for other significant factors, only age, height and diabetes were statistically significant to predict TSBL (p-value < 0.05). There is significant variability seen in TSBL in people with obesity. Height, and the presence of T2DM significantly impacted the length of TSBL positively, whereas advancing age negatively impacted TSBL. This highlights the need to measure TSBL in patients having a bypass as that would affect weight loss and comorbidity outcomes.