Strangulating lesions of the small intestine associated with the greater omentum in horses: 32 cases

Background: Strangulating lesions of the small intestine involving the greater omentum (SSIGOs) have only rarely been reported. Furthermore, information pertaining to clinical descriptions, surgical findings and outcome is lacking. Objectives: The objective of this study was to describe the prevalence, clinical presentation, surgical findings, postoperative outcome and risk factors associated with SSIGOs. Study design: This is a retrospective case series of 32 horses with a diagnosis of SSIGOs. Methods: Data from hospital records of horses identified with SSIGOs between 2005 and 2020 including signalment, clinical findings at presentation, initial laboratory results, surgical findings, surgical procedures performed and postoperative survival were analysed. The prevalence of SSIGOs was determined. SSIGO was compared with small intestinal strangulating and nonstrangulating lesions and other types of colic to identify potential risk factors among signalment data and to determine outcome, using multiple logistic regression models. Results: SSIGOs were present in 2.3% (32/1413) of all horses undergoing exploratory laparotomy for colic, 4.7% of all horses with primary small intestinal lesions (32/683) and 5.6% of strangulating small intestinal lesions (32/570). Surgical findings included primary strangulation by the greater omentum with or without involvement of a lipoma-like mass originating from the greater omentum (15/32 [47%]), adhesions involving the greater omentum leading to strangulation of the small intestine (14/32 [44%]) and small intestine incarceration through an omental rent (3/32 [9%]). The short-term survival rate defined as survival until discharge was 53% (17/32) considering all SSIGO cases, and 85% (17/20) for SSIGO cases recovered from anaesthesia. Risk factors identified were increasing age and year of surgery. Main limitations: The limitations of this study are retrospective study design and the limited number of SSIGO cases reflecting the rarity of this condition. Conclusions: Numerous anatomical configurations of SSIGO exist, but clinical presentation is similar to other strangulating small intestinal lesions. Although uncommon, SSIGOs should be considered a potential cause of small intestine strangulation.