Use of pelvic flexure biopsies to predict survival after large colon torsion in horses

Objective-To determine if morphologic evaluation of intraoperative biopsies of the large colon could be used to accurately predict outcome in horses w ith large colon torsion. Study Design-Clinical study. Animals-Fifty-four horses with large colon torsion. Methods-A full-thickness biopsy was collected from the pelvic flexure of th e ascending colon after correction of naturally occurring colonic torsion. Morphologic changes were evaluated and graded for interstitial tissue to cr ypt ratio (I:C ratio), percentage loss of superficial and glandular epithel ium, and the degree of hemorrhage and edema. These variables were then used to predict survival. Results-Morphologic variables could be used to correctly predict survival o r death in 51 horses (P <.0001). This corresponded to a sensitivity of 95.1 % (82.2%-99.28; 95% CI) and a specificity of 92.3% (62.0%-99.6%; 95% CI). O f 6 horses that had colonic resection, 5 survived; an accurate prediction o f outcome based on morphologic criteria was made for each horse. Conclusions-Interpretation of changes in colonic morphology can be used to accurately predict postoperative survival in horses with large colon torsio n. Clinical Relevance-Use of frozen colonic tissue sections is a rapid, reliab le, and relatively inexpensive method for assessing morphologic damage asso ciated with large colon torsion during surgery. Intraoperative evaluation o f pelvic flexure biopsies can aid in the prediction of survival and guide s urgical judgment as to the need for colonic resection. (C) Copyright 2000 b y The American College of Veterinary Surgeons.