Intra-operative Small Bowel Length Measurements

Ezra Teitelbaum, MD, Khashayar Vaziri, MD, Sara Zettervall, MD, Richard L Amdur, PhD, Bruce A Orkin, MD. George Washington University

Introduction: Few studies have measured small bowel length (SBL) in live humans and most surgery texts base their “normal” anatomic lengths on cadaver data. Here we present a single-surgeon series of intra-operative SBL measurements and analyze potential demographic predictors of increased length.

Methods: From May 1997 to December 2008, SBL (jenunum and ileum) was measured in 240 patients undergoing laparotomy for colorectal resections. The intestine was measured from the ligament of Treitz to the ileocecal value along its anti-mesenteric border with an umbilical tape immediately upon entering the peritoneal cavity. Patients with Crohn’s disease and those who had undergone prior bowel resections were excluded. Univariate Pearson’s correlation analysis was used to check individual associations of height, weight, and age with SBL. An unpaired t-test was used to compare SBL in men and women. A multivariate linear regression analysis was performed to evaluate whether patient gender, height, weight and age were predictive of increased SBL. Separate analyses were then performed within each gender subgroup.

Results: Of 240 patients, 127 (53%) were women. Mean age was 55 ±15 (range 20 – 86) years, mean height was 169 ±10 (range 138 – 196) cm, and mean weight was 77 ±19 (range 41 – 175) kg. Mean SBL from ligament of Treitz to ileocecal valve was 506 ±105 (range 285 – 845) cm. On univariate analysis, height was associated with increased SBL (p < .001) and men had a longer mean SBL than women (533 ±105 vs. 482 ±99; p < .001). A multivariate linear regression model using patient gender, age, height and weight was significant (p = .001) and the predictors explained 8% of the variance in SBL. In this model, only height was independently predictive of increased SBL (p < .05). Correlation results differed between genders. In men, height correlated with increased SBL (r = .20; p < .05), whereas in women it did not (r = .06; p = .51). In men, age did not correlate with SBL (r = .17; p = .08), whereas in women age had a negative correlation with SBL (r = -.18; p <.05).

Conclusions: This study describes the largest data set of in vivo SBL measurements in a non-bariatric patient population. We found a mean SBL of 506 cm in live patients as compared with the 600-700 cm range derived from cadaver measurements quoted by most surgical textbooks. Men had longer mean SBL than women and height was independently predictive of increased SBL. SBL may decrease with age in women but not in men. This surprising gender difference will need to be validated in future studies.
 

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