Ex vivo biomechanical evaluation of tissue construct strength in an equine colopexy model

OBJECTIVE

To compare strength of left paramedian colopexies using various techniques in equine ex vivo models.

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Equine cadavers euthanized for nongastrointestinal pathology (36 specimens derived from 9 horses).

METHODS

Colopexies were performed after euthanasia. Suture pattern (horizontal mattress vs. cruciate) and incorporation of dorsal sheath of the rectus abdominis (partial-thickness) versus incorporation of dorsal and ventral sheath of the rectus abdominis (full-thickness) were evaluated. Single cycle load to failure, work to peak load, stiffness, and mode of failure of colopexy tissue constructs were assessed.

RESULTS

Mean load to failure of all constructs ranged from 102.26 to 166.38 N. Partial-thickness bites demonstrated a mean load to failure and standard deviation (SD) of 111.91 (35.88) N and 102.26 (30.06) N (p < .05) which was significantly lower than the mean and SD of full-thickness bites (166.3 [72.42] N and 163.21 [51.40 N]), respectively. All full-thickness bites regardless of suture pattern and over half of partial-thickness bites failed at the colonic wall. There was no significant difference in load to failure compared to mode of failure.

CONCLUSION

A stronger colopexy was achieved with a full-thickness bite regardless of the suture pattern. The most common mode of failure was the colon wall.

CLINICAL SIGNIFICANCE

Incorporating ventral and dorsal fascia of the rectus abdominus provided a stronger colopexy structure, which may necessitate a second incision or subcutaneous palpation of the needle when performing a colopexy. The lateral band of the colon failed in most constructs (77%) regardless of technique, which could weaken the colonic wall and risk colonic rupture.

Outcomes of pregnant broodmares treated for colic at a tertiary care facility

OBJECTIVE

To evaluate, following colic admission during pregnancy, (1) broodmare survival; (2) the frequency of recurrent colic in broodmares and its associated variables, and (3) pregnancy outcome and the variables associated with a negative pregnancy outcome.

STUDY DESIGN

Ambidirectional observational cohort study.

ANIMALS

One hundred and four client-owned broodmare admissions.

METHODS

Admissions of pregnant mares from June 2010 until October 2016 were included. Data were collected until November 2017. Cox proportional hazards regression analysis was performed to evaluate variables associated with broodmare survival. Logistic regression analysis was used to examine the variables associated with recurrent colic and pregnancy outcome.

RESULTS

Broodmares from 73/104 (70.2%) admissions were discharged alive. Lesion category, admission hyperlactatemia (hazard ratio (HR) 3.24, 95%, CI 1.28-8.22, P = .013), and admission high packed cell volume (HR 2.89, 95% CI 1.29-6.47, P = .010) were associated with reduced survival. Recurrent colic was observed in broodmares from 33/70 admissions (47.1%). The final multivariable model for recurrent colic included Thoroughbred breed (OR 5.09, 95% CI 1.58-16.4, P = .006) and age (OR .876, 95% CI .747-1.03, P = .105). Overall, negative pregnancy outcome was 14/65 (21.5%). Lesion category, evidence of systemic inflammatory response syndrome (SIRS) in hospital (OR 31.2, 95% CI 2.09-466.5, P = .013), and diarrhea in hospital (OR 379.3, 95% CI 97.1-1482.0, P < .001) were associated with increased negative pregnancy outcome. Altrenogest administration was inversely associated with negative pregnancy outcome (OR 0.029, 95% CI .004-.222, P = .001).

CONCLUSION

Pregnant broodmares admitted for colic had lower survival than anticipated and were at risk of recurrent colic. Markers of broodmare disease severity were associated with pregnancy outcome.

CLINICAL SIGNIFICANCE

Lesion category, hematologic variables (packed cell volume and l-lactate concentration), evidence of SIRS, and diarrhea were useful for predicting broodmare and pregnancy outcomes.

Managing Reproduction Emergencies in the Field: Part 2: Parturient and Periparturient Conditions

Selected conditions affecting broodmares are discussed, including arterial rupture, dystocia, foal support with ex utero intrapartum treatment, uterine prolapse, postpartum colic, the metritis/sepsis/systemic inflammatory response syndrome complex, and retained fetal membranes. Postpartum colic beyond third-stage labor contractions should prompt comprehensive evaluation for direct injuries to the reproductive tract or indirect injury of the intestinal tract. Mares with perforation or rupture of the uterus are typically recognized 1 to 3 days after foaling, with depression, fever, and leukopenia; laminitis and progression to founder can be fulminant. The same concerns are relevant in mares with retention of fetal membranes.

Exploratory Celiotomy in the Horse Secondary to Acute Colic: A Review of Indications and Success Rates

To review indications and risk factors for exploratory celiotomy secondary to acute colic in the horse; decision making for and during surgery; and prognosis for return to function after exploratory celiotomy for the practicing veterinarian. Data sources included scientific reviews and original research publications from veterinary sources, as well as clinical data specifically in regard to underlying disease and survival rates from a tertiary referral hospital where exploratory celiotomy is commonly performed. There is a high positive predictive value of specific clinical preoperative parameters of the equine acute abdomen, many of which rely on techniques available to field practitioners, relative to the need for surgical intervention. Decision making regarding surgical procedure or even intraoperative euthanasia depends on owner expectations. Survival rates following exploratory celiotomy range from fair to excellent (60%-100%) depending on underlying lesion and return to athleticism following celiotomy is good to excellent (76%-90%). A knowledge base of indications for and rates of survival from colic requiring exploratory celiotomy in the horse is of paramount importance to the equine practitioner. Preconceived notions of poor survival rates are rampant among horse owners, and owners rely on their primary veterinarian's advice for continuation to referral center and in further treatment including exploratory celiotomy.