Factors associated with survival of epiploic foramen entrapment colic: A multicentre, international study

Retrospective evaluation of the effects of a single intraoperative dose of dexamethasone in horses undergoing exploratory laparotomy for small intestinal lesions (2008-2019): 240 cases

OBJECTIVE

To determine the effect of a single intraoperative dose of dexamethasone on the risk of postoperative reflux (POR) in horses undergoing small intestinal surgery and to investigate its association with incisional complications and short-term survival.

DESIGN

Retrospective cohort study over an 11-year period (2008-2019).

SETTING

UK-based private referral center.

ANIMALS

Two hundred and forty client-owned horses >6 months of age undergoing exploratory laparotomy for treatment of a small intestinal lesion.

INTERVENTIONS

Ninety-seven horses received a single intraoperative dose of dexamethasone (0.1 mg/kg, IV).

MEASUREMENTS AND MAIN RESULTS

Of 97 horses that received dexamethasone, 52 (53.6%) required small intestinal resection. Of 143 horses that did not receive dexamethasone, small intestinal resection was performed in 78 (54.5%). A total of 70 horses (29%) developed POR. There was no difference in the risk of POR between horses that received dexamethasone (25/97; 26%) and those that did not (45/143; 31%, P = 0.34). Risk factors associated with the development of POR included small intestinal resection (odds ratio [OR]: 4.55, 95% confidence interval [CI]: 2.27-9.11, P < 0.001), a PCV >40% 24 hours postoperatively (OR: 4.11, 95% CI: 2-8.45, P < 0.001), and a WBC count >10 × 109/L on admission (OR: 3.29, 95% CI: 1.47-7.41, P = 0.004). Dexamethasone was not associated with the odds of POR. Horses undergoing repeat laparotomy had a higher risk of incisional infection (OR: 8.07, 95% CI: 1.98-32.81, P = 0.004). Dexamethasone administration was not associated with incisional infection. The development of POR was negatively associated with short-term survival (OR: 0.07, 95% CI: 0.03-0.17, P ≤ 0.001). Dexamethasone administration was not retained in the final multivariable model for survival.

CONCLUSIONS

Intraoperative dexamethasone was not associated with the development of POR in this study population, nor did it have an effect on postoperative survival or incisional infection in horses undergoing surgical management of small intestinal disease.

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.

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.

Study design synopsis: Observational study design in equine research

When planning to conduct research, thorough consideration of the study design is essential to enable valid results and purposeful conclusions. A good study design will provide a strong basis for robust conclusions that can contribute to the evidence base. Conversely, a poor study design may unintentionally lead to invalid conclusions with inappropriate claims of the clinical importance. The purpose of this article is to review important aspects of observational study design, with an emphasis on observational clinical research. The value of an observational study can be manifold and the benefit of studying clinical cases can add substantial value to the evidence base and equine health and welfare, however this value will be diminished if study designs are flawed, or are inadequately reported. It is essential that clinicians have the skills to critically appraise observational studies, to determine strengths, limitations and the applicability to their clinical practice.

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.

Indicators of 'critical' outcomes in 941 horses seen 'out-of-hours' for colic

BACKGROUND

This study aimed to describe the presentation and outcomes of horses with signs of colic (abdominal pain) seen 'out-of-hours' in equine practice.

METHODS

This was a retrospective study of horses seen 'out-of-hours' with colic by two equine veterinary practices between 2011 and 2013. Case outcomes were categorised as 'critical' or 'not critical'. A critical outcome was defined as requiring medical or surgical hospital treatment, or resulting in euthanasia or death. A non-critical outcome was defined as resolving with simple medical treatment. A hierarchical generalised linear model was used to identify 'red flag' parameters (aspects of signalment, history and presenting clinical signs) associated with critical outcomes.

RESULTS

Data were retrieved from 941 cases that presented with colic; 23.9 per cent (n=225/941) were critical. Variables significantly associated with the likelihood of a critical outcome in the final multivariable model were increased heart rate (P<0.001), age of the horse (P=0.013) and abnormal mucous membrane colour (P<0.001). Overall 18 per cent (n=168/941) of cases were euthanased.

CONCLUSIONS

This study highlights the mortality associated with colic. The 'red flag' parameters identified should be considered an essential component of the primary assessment of horses with colic.

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.

Usefulness of a Point-of-Care Analyzer to Measure Cardiac Troponin I and D-Dimer Concentrations in Critically Ill Horses With Gastrointestinal Diseases

Point-of-care (POC) systems for the joint measurement of Troponin and D-dimers have not been studied in horses. The aim of this study was to perform the validation of a POC system (AQT90 FLEX) for the measurement of cardiac troponin I (cTnI) and D-dimers in the serum of horses with gastrointestinal diseases. The main objective was to evaluate whether or not this system can distinguish healthy animals from diseased animals. A sample of 33 horses was included in the study: control group (n = 10) and horses with gastrointestinal disorders (n = 21), which were classified according to their outcome in survivors (subgroup A = 9) and nonsurvivors (subgroup B = 12). Considering the diagnosis of the process, ill horses were classified into three groups: inflammatory (I = 7), obstructive (O = 9), and strangulating diseases (S = 5). The clinical usefulness of AQT90 FLEX was validated by the study of linearity, coefficient of variation, and detection limits. Later, concentrations of D-dimers and cTnI were measured. A significant increase in both parameters was detected in ill animals (cTnI: control: 0.014 ± 0.01 μg/mL, survivors: 0.27 ± 0.37 μg/mL, nonsurvivors: 0.60 ± 1.21 μg/mL; D-dimers: control: 104.90 ± 30.82 ng/mL, survivors: 1,217.22 ± 1,213.28 ng/mL, nonsurvivors: 1,613.67 ± 1,426.75 ng/mL), although there were no statistically significant differences in concentrations according to diagnosis and outcome. In conclusion, AQT90 FLEX POC analyzer can be used in horses with gastrointestinal diseases to measure cTnI and D-dimer concentrations. It is a quick, practical, and minimally invasive tool that helps in determining the severity of illness.

Use of perioperative variables to determine the requirement for repeat celiotomy in horses with postoperative reflux after small intestinal surgery

OBJECTIVE

To determine whether perioperative variables can be used to differentiate a medical vs a surgical reason for postoperative reflux (POR) after small intestinal (SI) surgery in horses.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Horses >1 year of age that recovered from SI surgery and had POR.

METHODS

Medical records of horses that underwent SI surgery and developed POR from 2009-2015 were reviewed. Surgical reasons for POR were defined as an anastomosis complication, mechanical obstruction, or nonviable intestine identified at repeat celiotomy/necropsy. A medical reason for POR was presumed when the POR improved with medical treatment or when no surgical reasons were identified at repeat celiotomy/necropsy. Perioperative variables were analyzed and used to develop a logistic regression model.

RESULTS

Fifty-one horses had POR after SI surgery. After initial SI surgery, 14 horses had surgical reasons for POR diagnosed at repeat celiotomy or necropsy. Thirty-seven horses were considered to have medical reasons for POR because their POR resolved with medical management or functional ileus was diagnosed at repeat celiotomy/necropsy. A greater volume and a greater duration of POR were not associated with a surgical reason for POR. Rather, a postoperative (PO) fever and the timing of colic in the PO period were associated with a surgical reason for POR.

CONCLUSION

Horses that developed a fever and colic in the PO period after SI surgery were more likely to have a surgical reason for POR.

CLINICAL SIGNIFICANCE

These findings may provide guidance for clinicians when they are making decisions about repeat celiotomy in horses with POR after SI surgery.

Encarceramento do intestino delgado em forame epiploico em equinos com hábito de aerofagia: relato de caso

RESUMO São relatados quatro casos de encarceramento de forame epiploico (EFE), entre os casos: três machos e uma fêmea; dois da raça Quarto de Milha, um SRD e um Brasileiro de Hipismo; idade média de 11 anos; altura média de cernelha de 160,5cm; massa corporal média de 465kg. Todos os animais possuíam o hábito de aerofagia. A presença de refluxo enterogástrico e intestino delgado distendido à palpação transretal foi variável na dependência do segmento intestinal aprisionado. À laparotomia exploratória constataram-se: dois casos de aprisionamento jejunoileal; um de jejuno; e o outro de íleo. Todos os animais apresentaram EFE da esquerda para a direita, representando o sentido horário. Apenas o animal que apresentava o íleo aprisionado sobreviveu; os demais foram submetidos à eutanásia no período transoperatório devido à extensa isquemia intestinal e às lesões vasculares decorrentes da manobra de redução. A aerofagia é o fator de risco que apresenta maior correlação positiva com o EFE, fato corroborado pelos casos apresentados. Apesar de ser descrito um bom prognóstico para o EFE na literatura, foi obtido um desfecho ruim entre os casos atendidos, e salienta-se que a extensão da lesão e o sangramento da veia porta no transoperatório contribuíram para esse resultado.

Proteinase-activated receptor 2 distribution and expression in equine small intestine tracts following herniation through the epiploic foramen

Proteinase-activated receptor 2 (PAR₂) is a G-protein-coupled receptor for trypsin and mast cell tryptase; it is highly expressed at the intestinal level with multiple functions, such as epithelial permeability and intestinal motility. The aim of the study was to evaluate the distribution and expression of proteinase-activated receptor 2 in the small intestine during herniation through epiploic foramen. In this prospective clinical study, eight horses admitted for colic and which underwent exploratory laparotomy were considered. During surgery, the jejunum or the ileum was sampled by enterectomy. Morphological examination (histology, PAR₂ immunohistochemistry) and molecular biology analysis (western blot and quantitative polymerase chain reaction) were carried out on the resected intestinal samples. The Marginal Injured Tracts (MITs) and Central Injury Tracts (CITs) were defined as the oral and caudal marginal segments of the resected bowel tract and as the geometric centre of the intestinal ischaemic lesion length, respectively. The PAR₂ immunoreactivity was particularly evident in the epithelial cells, with higher immunoreactivity in the MIT rather than in the CIT. Moreover, a different immune localisation was observed in the MITs at the cell membrane level and in the CITs in the cytoplasm. No statistical difference was observed in PAR₂ mRNA and protein (44kDa) expression between the MIT and the CIT. The PAR₂ protein content in the intestinal tracts which were removed from horses with herniation was lower when compared with the control animals. This study provided data concerning the PAR₂ presence and distribution in horses with intestinal herniation through the epiploic foramen.

Long-term follow-up on recovery, return to use and sporting activity: a retrospective study of 236 operated colic horses in Finland (2006-2012)

BACKGROUND

Surgical treatment of colic is expensive and complications may occur. Information on the prognosis and the use of the horse after surgery for colic is important for surgeons and owners. Current literature on return to athletic function after celiotomy is limited. The present study reviewed surgical cases of the Veterinary Teaching Hospital, Helsinki, Finland for 2006-2012. The aim was to follow the population of horses of different breeds for surgical findings, postsurgical complications, long-term recovery and prognosis. The findings and their influence on survival, return to previous or intended use and performance were assessed.

RESULTS

Most of the operated horses (82.6%; 195/236) recovered from anesthesia and 74.9% (146/195) were discharged. The total follow-up time was 8 years and 10 months and the median survival time 79.2 months. Age of the horse, location of the abdominal lesion (small vs. large intestine), incidence of postoperative colic, surgical site infection, incisional hernia or convalescence time after surgery, did not significantly affect the probability of performing in the previous or intended discipline after the surgery. A majority of the discharged horses (83.7%) was able to perform in the previous or intended discipline and 78.5% regained their former or higher level of performance. Operated horses had 0.18 colic episodes per horse-year during the long-term follow-up. The incidence of colic was 20.0% within the first year after surgery. Horses operated for large intestinal colic were 3.3-fold more prone to suffer postoperative colic than horses operated for small intestinal colic. The majority of the owners (96.3%) were satisfied with the veterinary care and nearly all (98.5%) evaluated the recovery after the colic surgery to be satisfactory or above.

CONCLUSIONS

If the horse survives to discharge, prognosis for long-term survival and return to previous level of sporting activity and performance was good after colic surgery in a population of horses of different breeds. None of the factors studied were found to decrease the probability of performing in the same or intended discipline after surgery. The majority of horses were able to return to their previous activity and perform satisfactorily for several years after surgery.

Has intravenous lidocaine improved the outcome in horses following surgical management of small intestinal lesions in a UK hospital population?

Background

Perioperative lidocaine treatment is commonly used in horses that undergo surgical treatment of colic, to prevent or treat postoperative ileus and reduce the effects of intestinal ischaemia-reperfusion injury. However, its clinical efficacy has not been evaluated in a large population of horses undergoing small intestinal surgery. The aim of the current study was to evaluate whether systemic lidocaine administration reduced the prevalence, volume and duration of postoperative reflux and improved rates of survival following surgical treatment of small intestinal lesions. Data were collected as a part of two prospective studies investigating postoperative survival of surgical colic patients admitted to a UK equine referral hospital during the periods 2004–2006 and 2012–2014. Kaplan-Meier plots of cumulative probability of survival and the log-rank test were used to compare survival between horses that did or did not receive lidocaine. The Wilcoxon rank-sum test was used to compare the total reflux volume and duration of reflux between the groups. A multivariable Cox proportional hazards model was used to identify pre- and intraoperative risk factors for non-survival.

Results

Data from 318 horses were included in the final analysis. The overall prevalence of postoperative reflux was 24.5 %. This was significantly higher (34.8 %) in horses admitted in 2012–2014 compared to the 2004–2006 cohort (16.7). Perioperative lidocaine treatment had no effect on total reflux volume, duration of reflux or rates of postoperative survival nor was it a risk factor associated with altered postoperative survival. Variables identified to be associated with increased risk of postoperative mortality included packed cell volume on admission (hazard ratio [HR] 1.03 95 %, 95 % confidence interval [CI] 1.004–1.06, p = 0.024), heart rate on admission (HR 1.014, 95 % CI 1.004–1.024, p =0.008) and duration of surgery (HR 1.007, 95 % CI 1.002–1.01, p = 0.008).

Conclusions

Lidocaine therapy had no effect on the prevalence of postoperative reflux, total reflux volume and duration of reflux nor did it have any effect on postoperative survival in horses undergoing surgical management of small intestinal disease for treatment of colic. There is a need for a well-designed multicentre, prospective randomised controlled trial to fully investigate the efficacy of lidocaine across different hospital populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-016-0784-7) contains supplementary material, which is available to authorized users.

Prevention of post operative complications following surgical treatment of equine colic: Current evidence

Changes in management of the surgical colic patient over the last 30 years have resulted in considerable improvement in post operative survival rates. However, post operative complications remain common and these impact negatively on horse welfare, probability of survival, return to previous use and the costs of treatment. Multiple studies have investigated risk factors for post operative complications following surgical management of colic and interventions that might be effective in reducing the likelihood of these occurring. The findings from these studies are frequently contradictory and the evidence for many interventions is lacking or inconclusive. This review discusses the current available evidence and identifies areas where further studies are necessary and factors that should be taken into consideration in study design.

Surgical treatment of equine colic - a retrospective study of 297 surgeries in Norway 2005-2011

BACKGROUND

Colic, defined as pain originating from the abdomen, is a common condition in horses. Most of the cases resolve spontaneously or after medical treatment, but a few require surgical treatment. Surgical treatment of colic in horses is resource-demanding and expensive, and information on prognosis is therefore important for both owners and surgeons. In the present study, surgical cases in two equine hospitals in Norway between 2005 and 2011 were reviewed. The aim of the study was to describe associations between prognostic indicators, diagnoses and short term survival by use of random effects logistic regression.

RESULTS

In the present study, 162 out of 297 (54.5%) surgeries resulted in the horse being discharged from the hospital. Excluding cases euthanized during surgery, the overall short-term survival was 74.0% (162 out of 219 surgeries). Seventy-eight (26.3%) of the horses were euthanized during surgery, due to grave or poor prognosis. In univariable analyses, duration of colic signs, heart rate, capillary refill time, mucosal membrane appearance, intestinal sounds, affected gastrointestinal segment, hematocrit, intestinal resection, hospital and surgeon board-certification had P-value <0.20 and were assessed in multivariable analyses. Respiration rate, rectal temperature and lactate in blood also had univariable P <0.20, but were left out from multivariable analyses due to too high levels of missing values. A random effect of primary surgeon was included and breed, sex and age were tested in multivariable analyses as possible confounders; and hospital was included to control for hospital routine differences. In the final multivariable model the variables mucosal membrane appearance, affected gastrointestinal segment and surgeon board-certification significantly influenced survival. The random surgeon effect was not significant.

CONCLUSIONS

The present study showed that prognostic parameters and diagnoses of surgical treatment of horses with colic in Norway are in accordance with reports from other parts of the world. The significant effect of board-certification of surgeon is not reported in previous studies. The general short-term survival rate was somewhat lower than reported in other studies, partly due to more horses being euthanized intraoperatively in the present study. This might be because of economical or animal welfare reasons.