Large colon volvulus is a severe form of intestinal strangulation that has been associated with poor survival rate in horses.1–4 Death is inevitable without surgical intervention. Injury to the colonic tissue is the result of vascular occlusion associated with the twisting of the colon around its mesenteric axis that commonly occurs near the base of the cecum. This causes obstruction of blood flow immediately distal to the site of strangulation. Delivery of oxygenated blood to the ascending colon of horses is derived from the arterial loop created by the colic branch of the ileocolic artery and the right colic artery. Within the ascending colon, the PF is anatomically farther away from its principal blood supply than is the DC. Therefore, it may be surmised that a gradient of increased injury would be present at sites more distant to the site of strangulation, particularly the PF. Although histomorphometric evaluations of PFBSs used to predict short-term outcome have indicated that PFBSs are representative of the entire affected portion of the colon,5–7 the optimal biopsy location continues to be debated.6 Therefore, the objective of the study reported here was to determine whether the degree of histomorphometric damage in DCBSs and PFBSs from horses with LCV differed and whether assessment of measurements of a DCBS from adjacent to the site of colonic resection more accurately predicts short-term outcome, compared with assessment of measurements of a PFBS, for those horses.
This work was partially funded by a grant from the North Carolina Horse Council. Additional support was provided by the NIH to Dr. Gonzalez (SERCA, K01OD019911). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.
The authors declare that there were no conflicts of interest related to this report.
Dorsal colon biopsy specimen
Large colon volvulus
Mucosal hemorrhage score
Pelvic flexure biopsy specimen
Receiver operating characteristic
Immuno-glo, MG Biologics, Ames, Iowa.
GraphPad Prism Software, version 8.4.3, La Jolla, Calif.
Emberson RM, Cook G, Hance SR, et al. Large colon volvulus: surgical treatment of 204 horses (1986-1995)(abstr), in Proceedings. 42nd Annu Meet Am Assoc Equine Pract 1996;254-255.
1. Driscoll N, Baia P, Fischer AT, et al. Large colon resection and anastomosis in horses: 52 cases (1996-2006). Equine Vet J 2008;40:342–347.
2. Ellis CM, Lynch TM, Slone DE, et al. Survival and complications after large colon resection and end-to-end anastomosis for strangulating large colon volvulus in seventy-three horses. Vet Surg 2008;37:786–790.
3. Suthers JM, Pinchbeck GL, Proudman CJ, et al. Survival of horses following strangulating large colon volvulus. Equine Vet J 2013;45:219–223.
5. van Hoogmoed L, Snyder JR, Pascoe JR, et al. Evaluation of uniformity of morphological injury of the large colon following severe colonic torsion. Equine Vet J Suppl 2000;32:98–100.
6. Levi O, Affolter VK, Benak J, et al. Use of pelvic flexure biopsy scores to predict short-term survival after large colon volvulus. Vet Surg 2012;41:582–588.
7. Gonzalez LM, Fogle CA, Baker WT, et al. Operative factors associated with short-term outcome in horses with large colon volvulus: 47 cases from 2006 to 2013. Equine Vet J 2015;47:279–284.
8. Hughes FE, Slone DE. A modified technique for extensive large colon resection and anastomosis in horses. Vet Surg 1998;27:127–131.
9. Snyder JR, Olander HJ, Pascoe JR, et al. Morphologic alterations observed during experimental ischemia of the equine large colon. Am J Vet Res 1988;49:801–809.
10. van Hoogmoed L, Snyder JR, Pascoe JR, et al. Use of pelvic flexure biopsies to predict survival after large colon torsion in horses. Vet Surg 2000;29:572–577.
11. Gonzalez LM, Moeser AJ, Blikslager AT. Animal models of ischemia-reperfusion-induced intestinal injury: progress and promise for translational research. Am J Physiol Gastrointest Liver Physiol 2015;308:G63–G75.
12. Hackett ES, Embertson RM, Hopper SA, et al. Duration of disease influences survival to discharge of Thoroughbred mares with surgically treated large colon volvulus. Equine Vet J 2015;47:650–654.