Surgical treatment of epiploic foramen entrapment in 142 horses (2008–2016)

Flowmetry and spectrophotometry for the assessment of intestinal viability in horses with naturally occurring strangulating small intestinal lesions

BACKGROUND

Ancillary diagnostic methods to enhance the accuracy of viability assessment have not been established for use in clinical practice.

OBJECTIVES

To assess intestinal microperfusion measured by Laser Doppler Flowmetry and Spectrophotometry (LDFS) in naturally occurring small intestinal strangulations of different origins and to compare this between viable and non-viable segments.

STUDY DESIGN

Prospective clinical trial.

METHODS

Forty horses undergoing colic surgery for naturally occurring small intestinal strangulations were included. Tissue oxygen saturation (tSO2), haemoglobin (tHB) and blood flow (tBF) were determined by LDFS before and after release of the strangulation. Intestinal biopsies were taken in cases that underwent intestinal resection or intraoperative euthanasia and assessed using a semi-quantitative mucosal injury score (MIS). The LDFS measurements were compared between the different categories of strangulation causes and histopathological injury using parametric and non-parametric tests (p < 0.05).

RESULTS

Strangulations by pedunculated lipomas had lower tBF (13.9 ± 18 arbitrary units [AU]) than epiploic foramen entrapments (65.2 ± 61 AU; CI -1.697 to -0.2498; p = 0.005). Segments with MIS > 5 showed lower tBF during strangulation than segments with MIS < 4 (mean difference 61.1 AU; CI -1.119 to -0.07361; p = 0.03). This did not differ significantly following release of strangulation. Furthermore, there was a positive correlation between the inflammatory cell count and tBF during strangulation (r 0.34; CI 0.01 to 0.60; p = 0.04). The tSO2 and tHB did not differ between the different categories of lesions or injury.

MAIN LIMITATIONS

No biopsies could be taken from the intestinal segments that did not undergo resection. The duration of strangulation could not reliably be ascertained.

CONCLUSIONS

Blood flow measurements in naturally occurring strangulating lesions show a varying degree of ischaemia in different causes of strangulation. Intestinal blood flow measurements prior to release of the strangulation could potentially contribute to the identification of mucosal injury, yet a high individual variability and other contributing factors need to be considered.

Epiploic foramen entrapment in a dog

OBJECTIVE

To report small intestinal herniation through the epiploic foramen in a dog.

ANIMALS

Nine-year-old male castrated Shih Tzu.

STUDY DESIGN

Case report.

METHODS

The dog presented with an 8-year history of vomiting and regurgitation and acute onset of melena, lethargy, anorexia, anemia, and suspected gastrointestinal mass or obstruction on prereferral imaging. Abnormalities on abdominal radiographs included a large, midcaudal soft tissue structure and cranial displacement and segmental dilation of the small intestine. On abdominal ultrasound, severe gastric dilation, jejunal tortuosity and stacking, and peritoneal effusion were observed. Epiploic herniation of the small intestine and segmental jejunal devitalization was diagnosed on exploratory laparotomy, and the dog underwent hernia reduction, jejunal resection and anastomosis, and nasogastric tube placement.

RESULTS

Severe gastric distention and atony persisted 24 h after surgery, despite medical management. The dog was taken to surgery for decompressive gastrotomy and placement of gastrostomy and nasojejunostomy tubes for postoperative decompression and feeding, respectively. Three days after the original surgery, the dog developed a septic abdomen from anastomotic dehiscence and underwent jejunal resection and anastomosis and peritoneal drain placement. Gastric dysmotility gradually resolved with the administration of motility stimulants, removal of gastric residual volume, and nutritional support via nasojejunostomy tube feedings. Three months after discharge, the dog was clinically normal.

CONCLUSION

Epiploic foramen entrapment should be considered a type of herniation in dogs. Clinical suspicion should be raised in dogs with unresolving regurgitation and vomiting, visceral displacement, and stacking and distension of small intestine.

Colic Surgery: Recent Updates

The following article provides an overview of the last 5 years of research and innovation within the field of equine colic surgery, focusing on new techniques, new or recently described lesions, prevention of lesion recurrence or postoperative complications, and updates in prognoses. Early surgical intervention is an important factor in horse survival.

Surgical enlargement of the epiploic foramen in horses

OBJECTIVE

To assess the safety and efficacy of a method for digitally enlarging the caudal aspect of the epiploic foramen (EF).

STUDY DESIGN

Healthy horses and clinical cases of EF entrapment (EFE).

ANIMALS

Fourteen healthy horses and three clinical cases.

METHODS

Through a ventral midline celiotomy under general anesthesia, the EF was enlarged by digital separation of the caudal attachments of the caudate lobe of the liver from right dorsal colon, right kidney, gastropancreatic fold, and pancreas. Healthy horses were euthanized under anesthesia, and the enlarged EF was measured at necropsy.

RESULTS

The method used for enlarging the EF did not cause clinically relevant hemorrhage, as determined by visual inspection of the EF in 14 horses at necropsy and by vital parameters under anesthesia in all horses. In clinical cases, EFE was reduced following enlargement of the EF, and no intraoperative complications were encountered. In one clinical case, necropsy at 30 days confirmed partial closure of the enlarged EF.

CONCLUSION

The method proposed enlarged the EF safely and effectively. Limitations of the study include the small number of clinical cases and the lack of postoperative follow-up on the healthy horses.

CLINICAL SIGNIFICANCE

Enlargement of the EF at its caudal extent should be considered in selected cases of EFE in which manual reduction is difficult or protracted. Although the procedure was safe in this study, knowledge of the anatomy, practice on cadavers, and careful selection of cases with greatest need are recommended before clinical use.

Clostridioides (Clostridium) difficile-associated disease, epiploic foramen entrapment, and gastric rupture in a Thoroughbred racehorse: case report and literature review

Epiploic foramen entrapment (EFE) is a common cause of small intestinal colic in horses and may lead to intestinal strangulation. Strangulating intestinal obstruction impairs the gastrointestinal outflow and can lead to secondary gastric rupture and endotoxemia. Clostridioides difficile can cause enterotyphlocolitis with colic in horses of all ages, and the process is commonly referred to as C. difficile-associated disease (CDAD). Here we report the results of the postmortem examination of a 7-y-old Thoroughbred racehorse with concurrent CDAD, EFE, and gastric rupture that was euthanized following a history of colic over several days. A segment of distal jejunum and proximal ileum had passed through the epiploic foramen, and the intestinal wall was thickened and dark-red. The remaining small intestinal loops were distended and filled with blood-tinged contents. Peritonitis had resulted from escape of gastric contents into the abdominal cavity through a tear in the major curvature of the stomach. Histologically, the incarcerated segment had acute transmural hemorrhage with congestion and mucosal necrosis; neutrophilic infiltrates with fibrin thrombi were in the mucosa of the non-incarcerated small intestinal segments. C. difficile toxins were detected in the small intestinal contents, and C. difficile was isolated from the small intestine, colon, and cecum.

Performance of predictive models of survival in horses undergoing emergency exploratory laparotomy for colic

Objective

To evaluate previously published predictive survival models in a population of horses undergoing colic surgery in the midwestern United States.

Study design

Retrospective cohort study; single referral hospital.

Animals

A total of 260 horses met the inclusion criteria.

Methods

Medical records of horses undergoing surgical treatment for colic were reviewed. Previously published models were applied to cohort data to predict outcome. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for prediction of short‐term survival were calculated.

Results

Single‐variable and multivariable models performed similarly for prediction of survival, with a mean 79% sensitivity (range: 44%–94%), 48% specificity (range: 22%–83%), 63% PPV (range: 56%–72%), 73% NPV (range: 60%–83%), and 64% accuracy (range: 59%–72%). Blood lactate ≤6 mmol/l and the colic severity score (CSS) were highly sensitive for prediction of survival; however, both had poor specificity.

Conclusion

Single‐variable and multivariable predictive models did not perform as well for prediction of survival in the study cohort compared to original reports, suggesting that population‐specific factors contribute to patient survival.

Clinical significance

Predictive models of survival developed in one population may be less reliable when used to predict outcome in horses undergoing colic surgery from an independent population. Additional model testing and refinement using data from multiple surgical centers could be considered to improve prediction of outcome for horses undergoing laparotomy for treatment of colic.

Multi-Institutional Retrospective Case-Control Study Evaluating Clinical Outcomes of Foals with Small Intestinal Strangulating Obstruction: 2000–2020

Simple Summary

Lower survival rates have been reported in foals than adults with severe colic lesions obstructing blood flow to the small intestine, but this has not been compared directly. These survival rates are important to horse owners making medical decisions surrounding colic, for both the foal’s wellbeing and the owner’s finances. In this retrospective case-control study, hospital records of surgical colic cases were collected from five US academic referral hospitals to directly compare foal and adult survival following surgery for specific colic lesions. It was hypothesized that foals would exhibit lower survival than case-matched adults. This study was limited by incomplete medical and surgical records, relatively small sample size, and lack of long-term follow-up. Short-term survival in foals was not significantly different than in adults with comparable colic lesions and may have been partly driven by decision-making on the farm prior to referral. More optimism toward surgical treatment of foals with suspected SISO may be warranted.

Abstract

Lower survival has been reported in foals than adults with small intestinal strangulating obstruction (SISO), but age-dependent outcomes have not been examined directly. Hospital records were collected from five US academic referral hospitals. It was hypothesized that foals would exhibit lower survival than case-matched adults. Foal cases 6-months-of-age or younger, and adult cases between 2- and 20-years-of-age were collected. Data revealed 24 of 25 (96.0%) foals and 66 of 75 (88.0%) adults that were recovered from surgery for SISO survived to hospital discharge. Sixteen of the total 41 (39.0%) foals studied were euthanized intraoperatively, whereas 30 of 105 (28.6%) adults were euthanized intraoperatively. Common lesions in foals that were recovered from surgery were volvulus (n = 13) and intussusception (n = 5), whereas common lesions in adults were volvulus (n = 25) and strangulating lipoma (n = 23). This study was limited by incomplete medical records, relatively small sample size, and lack of long-term follow-up. Unexpectedly, short-term survival tended to be higher in foals than adults and may have been partly driven by case selection prior to referral or surgery or decision-making intraoperatively. More optimism toward surgical treatment of foals with SISO may be warranted.

Effects of age, disease, and anastomosis on short- and long-term survival after surgical correction of small intestinal strangulating diseases in 89 horses

BACKGROUND

Although survival rates have been reported after small intestinal surgery for strangulating diseases in horses, none have followed survival for periods relevant to the long lifespan of horses and none have described effect of age, disease and surgical treatments over such long survival periods.

OBJECTIVES

To examine effects of age, disease, and type of surgery on long-term survival in horses after surgical treatment of small intestinal strangulating diseases over periods relevant to the expected lifespan of a horse.

STUDY DESIGN

Retrospective clinical study.

METHODS

Post-operative data were gathered from medical records and owner contact for 89 horses with small intestinal strangulation. Survival times from surgery to date of death or date of last follow-up were analysed by Kaplan-Meier statistics. Variables of interest were age, type of strangulating disease, and surgical correction. Cox proportional hazards regression was used to evaluate these variables.

RESULTS

Short-term survival was not affected by any of the variables measured. For long-term survival with Kaplan-Meier statistics, horses ≥16 years old had significantly shorter (P=0.002) median survival times (72 months; 95% C.I. 32.0-96.0) than younger horses (121.7 months; 95% C.I. 90.0-162), horses without resection had significantly longer (P=0.02) survival times (120 months; 95% C.I. 86-212) than horses that had jejunocecostomy (76.8 months; 95% C.I. 24-125), and horses with miscellaneous diseases had significantly longer (P=0.02) median survival times (161.9 months (95% C.I. 72.0-M) than horses with strangulating lipoma (79.8 months; 95% C.I. 32.0-120.0). In the multivariable Cox Proportional Hazard model, age (HR=2.67; 1.49-4.75, p<0.001) and anastomosis (HR=0.65; 0.46-0.92, P=0.02) had the most significant effect on median survival time.

MAIN LIMITATIONS

Limitations were small numbers in some categories, loss of cases to follow-up, owner recall failures, and lack of a control group.

CONCLUSIONS

The remaining lifespan of older horses at the time of surgery had the greatest effect on survival. Age could influence long-term survival studies after colic surgery, and therefore needs to be considered for survival analyses. Horses that did not require resection and anastomosis had favourable outcomes, underscoring the potential importance of early intervention to reduce the need for resection.

Equine colic associated with small intestinal epiploic foramen entrapment

Intestinal epiploic foramen entrapment (EFE) is an important differential diagnosis in horses with colic, but disappointing short- and long-term outcomes are reported in the scientific literature. Many horses are euthanased during surgery due to a predicted poor prognosis or due to uncontrollable intraoperative haemorrhage. The ileum is involved in the majority of cases. Several risk factors for the development of EFE are described; crib-biting/windsucking being the most important one. The recurrence rate of EFE is low despite the described risk factors, probably due to spontaneous closure of the EF after EFE colic surgery in about 40% of the cases. Safe laparoscopic techniques to obliterate the EF preventively in horses at risk or as part of surgical management of EFE at laparotomy are described. Methods for improved outcomes including utilising recently gained anatomical insights of the region while manipulating entrapped intestines, critical revision of anastomosis techniques and avoiding the occurrence of post-operative reflux are discussed.

Mesh closure of epiploic foramen by ventral laparotomy in 17 horses with entrapment

BACKGROUND

Epiploic foramen entrapment (EFE) of small intestine is a severe cause of strangulating small intestinal obstruction (SSI) with long-term survival seeming lower than for other causes of SSI in horses. Different techniques via laparoscopy or laparotomy for epiploic foramen (EF) closure have been developed.

METHODS

This study describes a technique of peroperative mesh closure of the EF in clinical cases and their long-term follow up.

RESULTS

In the study period of 5.5 years, 36 horses were admitted to the clinic with EFE. Of these, 17 horses had peroperative mesh closure, with resection anastomosis in 4 cases and enterotomy in 4 other cases. Fifteen of these survived to discharge. Long-term follow-up (one to three years, median three years) was favourable in all 15 horses not showing recurrence of EFE nor other related signs of colic. Laparoscopic evaluation of the EF was performed in two cases and showed integration of the mesh. One horse was euthanased 3.5 years after mesh placement for an unrelated cause and the mesh was well adherent obliterating the EF.

CONCLUSION

Mesh closure of EF during emergency coeliotomy did not cause short-term complications even in horses with resection or enterotomy and may reduce the risk of recurrence of EFE in horses.