Indications, surgical technique, and long-term experience with laparoscopic closure of the nephrosplenic space in standing horses

OBJECTIVE: To describe surgical technique and outcome after laparoscopic closure of the nephrosplenic space for treatment of recurrent left dorsal displacement of the left colon (LDDLC) in standing horses. STUDY DESIGN: Retrospective study. ANIMALS: Forty-four horses with LDDLC. METHODS: Laparoscopic portals were located in the left flank region. After administration of etilefrin intravenously to contract the spleen, the dorsal splenic margin was sutured to the nephrosplenic ligament to obliterate the nephrosplenic space. Horses were re-examined (< or = 3 years) for history of recurrence. In addition, medical records of 4,852 horses treated for colic over 16 years were evaluated to establish incidence of LDDLC and recurrence after treatment. RESULTS: Splenic contraction facilitated suture placement and closure of the nephrosplenic space was achieved without complications. LDDLC recurrence did not occur although 5 horses had subsequent episodes of colic; 4 horses had displacement of the ascending colon between the spleen and body wall. Review of medical records revealed an incidence of LDDLC of 6% and recurrence of 21% in a population of horses with signs of colic. CONCLUSION: Laparoscopic closure of the nephrosplenic space, facilitated by etilefrin-induced splenic contraction can be efficiently performed in standing horses. CLINICAL RELEVANCE: Laparoscopic ablation of the nephrosplenic space should be considered in horses that are predisposed to recurrent LDDLC.     

Use of Ultrasound In Horses for Diagnosis of Left Dorsal Displacement of the Large Colon and Monitoring its Nonsurgical Correction

During a 28 month period, 82 horses with clinical signs of abdominal pain were examined for left dorsal displacement of the large colon (LDDLC) using percutaneous ultrasound. Left dorsal displacement of the large colon was diagnosed when a gas echo dorsal to the spleen obliterated the dorsal splenic border, or when the colon was observed lateral to the spleen. In 42 horses, ultrasound confirmed a diagnosis of LDDLC and 40 horses had no evidence of LDDLC. There were five false negative results and no false positives. In four horses with LDDLC, the colon was displaced between the spleen and body wall; three of these colic episodes resolved with medical therapy and the fourth required a celiotomy to relieve a sand impaction. The remaining 38 horses had a renosplenic entrapment; surgical correction was elected in 4 horses, 21 horses were corrected by a nonsurgical rolling procedure, 12 were corrected at surgery after an unsuccessful rolling attempt, and one was corrected by rolling but required surgery later because of an additional lesion. Percutaneous abdominal ultrasound was a valuable aid in the diagnosis of LDDLC and in confirming correction of the displacement after a nonsurgical rolling procedure.     

Comparison of surgical versus medical treatment of nephrosplenic entrapment of the large colon in horses: 19 cases (1992-2002)

OBJECTIVE: To compare the outcome of horses with nephrosplenic entrapment of the large colon (NSELC) treated surgically or medically by rolling, administration of phenylephrine hydrochloride (or both), and exercise. DESIGN: Retrospective study. ANIMALS: 11 medically treated horses and 8 surgically treated horses with NSELC. PROCEDURE: Medical records of horses with nephrosplenic entrapment between 1992 and 2002 were reviewed. Medically treated horses were included if diagnosis and outcome of treatment of nephrosplenic entrapment were confirmed via transrectal examination and ultrasonographic examination. Surgically treated horses were included if the diagnosis was confirmed by exploratory laparotomy. Horses in which the large colon was entrapped between the spleen and body wall were not included. RESULTS: Significant differences in mean age, heart rate, and duration of colic prior to treatment were not detected between horses treated surgically or medically. Ten medically treated horses recovered without complications, and 1 died. In the surgically treated group, 6 of 8 horses recovered without complications and 2 died. Mortality rate did not differ between treatments. Duration of hospitalization for medically treated horses was significantly shorter and the cost significantly less than for surgically treated horses. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that medical treatment of horses with NSELC via administration of phenylephrine hydro-chloride, rolling during general anesthesia, or both appears to be as effective as and less expensive than surgical treatment.     

Factors affecting incisional complication rates associated with colic surgery in horses: 78 cases (1983-1985)

From May 1, 1983 to April 1, 1985, 142 operations were performed on horses with signs of acute abdominal pain (colic), using a ventral midline incision. Seventy-eight horses lived for at least 15 days after surgery or had acute dehiscence and were included in the study. Seventy horses had surgery once, and 8 horses had surgery 2 or more times. Six-month follow-up evaluation was obtained for 66 horses that had 1 surgery and for 6 horses that had multiple surgeries. Incisional complications included drainage (including infection), acute dehiscence, hernia, and suture sinus formation. The effects of preoperative peritoneal fluid presence, enterotomy or resection, suture material and pattern used in the linea alba, type of skin closure and use of a sutured-on stent bandage on the incidence of incisional complications were investigated. The complication of incisional infection rate associated with a near-far-far-near suture pattern vs simple interrupted pattern in the linea alba was the only statistically significant (P less than 0.05) difference observed.     

Complications associated with left dorsal displacement of the large colon in the horse

Four horses operated on for left dorsal displacement of the large colon (LDDLC) had major intraoperative or postoperative complications. One horse was euthanatized during surgery because of extensive necrosis of the large colon. Three horses that were discharged after surgical correction of LDDLC were readmitted with signs of abdominal pain between 5 weeks and 13 months after surgery. Two horses had recurrence of LDDLC, and the third horse had an omental adhesion attached to and obstructing the pelvic flexure. The displacements were corrected, the adhesion was broken down, and the horses were discharged. One horse was readmitted a third time 16 months after the second surgery and required a third surgical correction of LDDLC.     

Further experiences with non-surgical correction of nephrosplenic entrapment of the left colon in the horse

Non-surgical correction of nephrosplenic entrapment of the left colon was attempted in 27 cases. In two cases the method failed and a laparotomy was necessary. Two other horses had a recurrence, one of which underwent laparotomy because of torsion of the caecal body.     

Incisional Hernias in the Horse Incidence and Predisposing Factors

Medical records of 210 horses that survived ventral midline celiotomy for at least 4 months were examined and owners were queried to determine factors contributing to incisional hernia formation. The incidence rate of incisional hernias within 4 months was 16%. Factors significantly associated with occurrence of incisional hernias were incisional drainage, closure of the linea alba with chromic gut suture material, previous midline celiotomy, excessive incisional edema, castrated male sex, postoperative leukopenia, and postoperative pain (colic). Factors not significantly associated with occurrence of incisional hernias were suture pattern used for linea alba closure, concurrent enterotomy or intestinal resection, postoperative bandage or stent, postoperative fever, hypoproteinemia, diarrhea, respiratory disease (coughing), and peritonitis. Hernias developed in horses within 12 weeks of surgery, with the earliest hernia recognized at week 2. Of 30 horses for which information was available, only one hernia developed in 24 (80%) and two or more hernias developed in 6 (20%) along the incision. Multiple hernias tended to be smaller than single hernias.     

Retrospective study of the risk factors and prevalence of colic in horses after orthopaedic surgery

The records of 496 orthopaedic operations on 428 horses were reviewed to estimate the prevalence of, and identify the risk factors for, the development of colic in horses after surgery. Colic was defined as any recognised sign of abdominal pain that could not be attributed to a concurrent disease. Fourteen of the horses developed colic; eight of them were undiagnosed, three were classified as impactions, one as tympanic colic of the colon, one as incarceration of the small intestine in the epiploic foramen, and one as left dorsal displacement of the colon in the nephrosplenic space. Morphine was associated with a four-fold increased risk of colic compared with the use of no opioid or butorphanol, and out-of-hours surgery was also associated with an increased risk.     

Strangulating obstruction of the small intestine by a fibrous band originating on the nephrosplenic ligament

During a laparotomy for colic signs in a 2-year-old male Thoroughbred, a portion of approximately 7 m of the jejunum was found entrapped in a fibrous band originating from the nephrosplenic ligament. The entrapped jejunum was necrotic and was removed. Two months after the first surgery, a laparoscopy was performed to close the nephrosplenic space and it was possible to identify several fibrous bands bridging from the renal capsule to the splenic capsule and a fibrotic plate over the spleen. This is the first report of a strangulating obstruction of the jejunum in the nephrosplenic space and of fibrous bands bridging from the nephrosplenic ligament to the spleen. The fibrous bands were likely due to inflammation caused by previous, multiple left dorsal displacements of the bowel, which resolved spontaneously.     

Left dorsal displacement of the large colon in the horse

Left dorsal displacement of the large colon is a condition unique to the horse that results in an obstruction of the colon and signs of colic. This condition may be successfully treated medically with analgesia, i.v. or oral fluids and feed restriction, exercise with or without administration of phenylephrine, or rolling under general anaesthesia with or without administration of phenylephrine, or a combination of these conservative options. Surgical correction via standing left flank laparotomy or, more commonly, ventral midline laparotomy under general anaesthesia, is required in cases where conservative therapy is unsuccessful. Recurrence rates range from 3.2% to 21%. Surgical attempts to prevent recurrence of this condition include large colon resection, colopexy, and ablation of the nephrosplenic space.     

The use of phenylephrine in the treatment of nephrosplenic entrapment of the large colon in horses

Nephrosplenic entrapment is a commonly diagnosed cause of acute colic that may be corrected using surgical or non-surgical methods and has a good prognosis for survival. Intravenous administration of phenylephrine at doses ranging from 20–60 μg/kg given over 5–15 min often followed by forced exercise, various rolling techniques under general anaesthesia, or a combination of therapies has been reported. Correction of the entrapment via exploratory celiotomy may be challenging in certain cases and is hampered by marked splenic enlargement. The case report by Loomes and Anderson (2019) in this issue described a novel method of reducing the size of the spleen by direct intra-splenic injection of phenylephrine, in a case non-responsive to intravenous phenylephrine administration, which facilitated surgical correction of the nephrosplenic entrapment.     

Ulceration and stricture of the right dorsal colon after phenylbutazone administration in four horses

Four cases of ulceration and stricture of the right dorsal colon were encountered. Ulceration of the right dorsal colon is generally associated with nonsteroidal anti-inflammatory drug (NSAID) toxicosis but there are few reports of stricture following ulceration. All four horses had recent phenylbutazone use: three had been given doses well in excess of the recommended dose and in one the dose was marginally above those recommended but was combined with administration of other NSAIDs. All four horses presented with intermittent low-grade colic, weight loss and ventral oedema. Diarrhoea was also seen in three of them. All had hypoproteinaemia due to severe hypoalbuminaemia, and hyperfibrinogenaemia. Hypoalbuminaemia was less severe in one horse and this horse was successfully managed medically. Two cases were definitively diagnosed at exploratory celiotomy and two at necropsy. Exploratory celiotomy was performed in two horses: one was euthanased at surgery and one was managed successfully with medical treatment and remained normal 1 year after surgery. Medical management included feeding of a low-roughage pelleted ration, corn oil, psyllium mucilloid, and discontinuation of NSAID administration.     

Occurrence of Incisional Complications After Closure of Equine Ventral Midline Celiotomies With 2 Polyglycolic Acid in Simple Interrupted Suture Pattern

The aim of this retrospective study was to describe the use of simple interrupted suture pattern for the closure of the abdomen after ventral midline celiotomy in horses and to evaluate the prevalence of resulting incisional complications. Seventy horses undergoing abdominal surgery (2006–2015) and surviving at least 30 days were included in the study. Closure technique of the abdominal wall was performed on three layers. Linea alba was closed with a simple interrupted pattern using number two coated braided absorbable polyglycolic acid suture. Follow-up information was recovered at the 90th day postoperatively. Incisional complications considered included drainage, infection, dehiscence, and herniation. The complications observed in the present study using simple interrupted suture pattern were 4.29% (3 of 70), lower than reported in literature with different suture pattern. Simple interrupted suture pattern could be a valid option for the closure of linea alba after ventral midline celiotomy in horses.     

Congenital retrosternal (Morgagni) diaphragmatic hernias in three horses

CASE DESCRIPTION: 3 Horses were examined and treated because of sudden onset of signs of abdominal pain. CLINICAL FINDINGS: All horses had a retrosternal (Morgagni) hernia involving the right side of the diaphragm. In each horse, the large colon was incarcerated in a right muscular defect in the diaphragm with a large hernial sac. TREATMENT AND OUTCOME: Definitive surgical repair of the hernia was not performed during the initial celiotomy. The hernia was repaired with mesh herniorrhaphy, but without resection of the hernia sac in 2 horses. For 1 horse, conservative management was applied. In the 2 horses treated with surgical correction, no major postoperative complications developed, and all 3 horses have been free of signs of abdominal pain. CLINICAL RELEVANCE: Horses with retrosternal hernias involving the diaphragm can develop clinical signs of intermittent obstruction of the large colon and chronic colic. In horses, retrosternal diaphragmatic hernias appear to develop exclusively in the right ventral aspect of the diaphragm and could represent an embryologic defect of diaphragm formation. Affected horses can be successfully treated with mesh herniorrhaphy or, in some instances, with conservative management.     

Difference in incisional complications following exploratory celiotomies using antibacterial‐coated suture material for subcutaneous closure: Prospective randomised study in 100 horses

Reasons for performing study: Incisional complications are a major post operative challenge following ventral midline exploratory celiotomy for abdominal pain in horses. They lead to discomfort, prolonged hospitalisation, longer recovery times and increased cost; therefore, investigation of preventative procedures are warranted. Objectives: To determine the clinical effect of antibacterial (triclosan) coated 2‐0 polyglactin 910 suture material on the likelihood of incisional infections when used for closure of subcutaneous tissue following ventral midline celiotomies in horses. Methods: One hundred horses undergoing exploratory celiotomy assigned at random to one of 2 groups. In the control group coated 2‐0 polyglactin 910 (Vicryl) was used for apposition of the subcutaneous tissue in a simple continuous pattern and, in the study group, antibacterial (triclosan) coated 2‐0 polyglactin 910 suture material (Vicryl Plus) was used. Post operatively an elastic adhesive abdominal bandage was applied, changed and the incision was inspected by a clinician blinded to the study protocol at 24–36 h and 6–9 days post operatively. Outcomes of interest were evidence of incisional pain, incisional oedema, sheath/udder oedema, incisional drainage, hernia formation and dehiscence. Results: Antibacterial‐coated suture material did not decrease the likelihood of incisional complications in 100 horses. Conclusions: A beneficial effect on ventral midline incisions in 100 horses was not evident by using antibacterial‐coated suture material. Potential relevance: Lack of effectiveness of antibacterial‐coated suture material in equine ventral midline closure after exploratory celiotomy and the observed potential adverse effects suggest that further clinical investigations are needed before using such material routinely on horses.     

Laparoscopic repair of a small intestinal mesenteric rent in a broodmare

OBJECTIVES : To describe standing laparoscopic repair of mesoduodenal rent inaccessible by ventral median celiotomy. STUDY DESIGN : Clinical case report. SAMPLE POPULATION : A 6-year-old Thoroughbred broodmare with a right displacement of the dorsal colon and small intestinal incarceration in a mesoduodenal rent. METHODS : Two days after correction of a right dorsal displacement of the ascending colon, small intestinal incarceration, and partial closure of mesoduodenal rent, standing left and right flank laparoscopy was used to explore the abdomen to identify the mesoduodenal defect. The mesenteric rent was repaired from right flank portals by approximation with hemostatic clips. RESULTS : Approximation of the mesoduodenal rent was achieved with laparoscopic clips. No further complications or signs of abdominal pain occurred over the following year. CONCLUSIONS : Mesenteric rents in the mesoduodenum can be repaired by laparoscopic techniques in the standing horse. CLINICAL RELEVANCE : Use of laparoscopic techniques in the standing horse should be considered for mesoduodenal rents that are not accessible form a ventral median celiotomy.     

Surgical treatment of colic in the miniature horse: a retrospective study of 57 cases (1993-2006)

REASONS FOR PERFORMING STUDY: It has been suggested that the rate of post operative abdominal adhesions in miniature horses is higher than that for other breeds. However, few reports exist in the veterinary literature describing complications and long-term survival following surgical treatment of colic in these horses. OBJECTIVES: To determine the prevalence of surgical lesions in miniature horses with acute abdominal disease in terms of clinical signs, surgical management, post operative treatment and complications, as well as short- and long-term survival. METHODS: Medical records of 57 American Miniature Horses undergoing surgical treatment for acute abdominal pain at the Michigan State University Large Animal Veterinary Teaching Hospital 1993-2006 were evaluated for clinical information. Owners and trainers were contacted to gain information regarding long-term survival. RESULTS: The most common surgical lesion was a faecalith (38/57 cases) located primarily within the descending colon and most frequently diagnosed in horses age <6 months (19/38 cases). Short-term survival to hospital discharge for horses recovered from anaesthesia was 98% (55/56) with the most common post operative complications being diarrhoea and inappetance. Intra-abdominal adhesions were identified in 2/8 horses requiring a second celiotomy. Long-term follow-up was available for 45 horses and 87% (39/45) were alive at least 12 months after surgery. CONCLUSIONS: As previously reported, faecalith obstruction is a frequent surgical lesion in the miniature horse and is most common in miniature horses age <6 months. The incidence of adhesion formation may be lower than previously reported.     

Colopexy of the Left Large Colon to the Right Large Colon in the Horse

Three colopexy techniques were examined in 11 normal horses to determine which would prevent recurrence of targe colon displacement and volvulus. The medial free band of the left ventral colon was sutured to the medial free band of the right ventral colon (technique A). The free band of the left dorsal colon was sutured to the free band of the right dorsal colon (technique B). In technique C, both the ventral and dorsal colon were sutured as in techniques A and B, and the pelvic flexure was sutured to the mesocolon between the right dorsal and right ventral colon. Absorbable (surgical gut) and nonabsorbable (polypropylene) suture material were compared.
One horse from each group was euthanized 2 weeks and 6 months after surgery. The position of the colon and the integrity of the colopexy were examined. At necropsy, attempts were made to produce displacement and volvulus of the colon. In the remaining horses, exploratory celiotomy 1 year after surgery was used to examine the integrity of the colopexy.
Although all horses initially lost weight after surgery, all but one began gaining weight 2 to 4 weeks later and had attained their preoperative weight by 6 months. The horse that continued to lose weight was euthanized 2 months after surgery. Numerous small colon, omental, and large colon adhesions were found at necropsy.
For all colopexy techniques, the colopexy adhesion remained short and intact at polypropylene suture sites. At surgical gut sites, the adhesion had lengthened by 6 months and was absent at 1 year. At necropsy, all colopexies prevented manual displacement of the large colon and volvulus of the colon at the sternal and diaphragmatic flexures. The colopexies did not prevent manual creation of volvulus at the base of the colon. Technique A was the easiest to perform.