Accuracy and inter-operator variability of small bowel length measurement at laparoscopy

Measurement of bowel length is an essential surgical skill for laparoscopic and open gastrointestinal surgery in order to achieve favorable outcomes and avoid long-term complications. Variations in accuracy between the two surgical approaches may exist. However, only few studies have tried to assess these differences. Our aim was to assess reliability and inter-rater variability of small bowel length assessment during laparoscopy in an in vivo porcine model.

This is a single-institution, double-blinded, technical assessment study in a porcine in vivo model. Fourteen participants (ten senior surgeons with >1000 laparoscopic procedures and four junior surgeons) had to assess and mark lengths of small bowel in both laparoscopic and open surgical approaches. Each participant was assigned to measure and mark specific, randomized distances (range 25-197 cm) in both laparoscopic and open approaches using color-coded vessel loops. Actual participant-marked distances were compared to the assigned distances followed by Bland-Altman plots and linear regression analysis to determine accuracy and proportional error trends. Study data were further compared to available data sets from previously published studies.

Laparoscopy measurements were significantly shorter than required (difference 33.8 ± 28.7 cm, P < 0.001, 95% CI 17.8-49.7). The measuring error was proportional to the length of the measured segment (63% of the required distances, IQR 58.9-79.0%, P = 0.02). At laparotomy, mean difference and standard deviation were lower (1.5 cm ± SD 15 cm) and not statistically significant (P = 0.7). Re-analysis of previously published data sets validated the observed errors in laparoscopic bowel measurement (P < 0.01).

Small bowel length assessment during laparoscopy is inaccurate and associated with substantial variability. There is a need to develop a standardized laparoscopic technique for measuring small bowel length which is simple, reproducible, and easy to learn.