A Novel Method for Evaluating Postoperative Adhesions in Rats

ABSTRACT

Purpose/Aim: Postoperative adhesions remain an undesirable and commonly symptomatic side effect of abdominopelvic surgeries. Animal models of postoperative adhesions typically yield heterogeneous adhesions throughout the abdominal cavity and are not easily quantified. Here we present a novel method of postoperative adhesion assessment and report its reliability and measurement error. Materials and Methods: A model of cecal abrasion with partial sidewall attachment was performed on female rats. After 1, 2, 4, or 7 days of recovery, the rats were euthanized and their abdominopelvic cavities were systematically evaluated for postoperative adhesions. The necropsy was recorded through the surgical microscope. Four raters were trained to use a ballot to capture key factors of the adhesions as they viewed the recordings. Their ratings were compared for measurement error and reliability (using Bland-Altman plots and intraclass correlation coefficients, respectively) and for the ability to discriminate differences in experimental groups. A subset of the data was analyzed to determine practical utility. Results: The rating system was shown to have low measurement error and high inter-rater reliability for all parameters measured. Applied practically, the system was able to discriminate groups in a manner that was expected. Conclusions: We have developed and validated a rating system for postoperative adhesions and shown that it can detect group differences. This method can be used to quantify postoperative adhesions in rodent models.

Keywords::

• postoperative adhesions
• reliability
• gastrointestinal surgery
• rat
• bowel obstruction
• infertility

Funding

Research reported in this publication was supported by the National Institute General Medical Sciences of the National Institutes of Health under Award Number R01GM108041 to GMB. The content does not necessarily represent the views of the National Institutes of Health.

AUTHOR CONTRIBUTIONS

GMB and SLC designed the rating methods, EB, JH, and GMB designed and performed the data analysis, and all authors contributed to the writing of the manuscript.