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.     

A retrospective analysis of left dorsal displacement of the large colon treated with phenylephrine hydrochloride and exercise in 12 horses (1996-98)

AIM: To review the outcome of cases of left dorsal displacement of the large colon (LDDLC) treated with phenylephrine HCl and mild exercise. METHODS: Physical parameters, laboratory data, ultrasonographic findings and outcome were analysed in a retrospective study of 12 horses with a confirmed diagnosis of LDDLC which were treated with phenylephrine HCl and mild exercise. RESULTS: Administration of phenylephrine HCl and mild exercise resulted in the resolution of LDDLC in 11 of 12 treated horses. One horse failed to resolve the entrapment and required surgical correction. CONCLUSION: Administration of phenylephrine HCl appears to be an effective treatment for horses with confirmed diagnosis of LDDLC presented with mild to moderate colonic distention.     

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.     

Serum gamma glutamyl transferase activity in horses with right or left dorsal displacements of the large colon

The purpose of this study was to test the hypothesis that horses with right dorsal displacement of the large colon (RDDLC) have elevations in serum gamma glutamyl transferase (GGT) activity when compared with horses with left dorsal displacement of the large colon (LDDLC). Medical records from 37 horses with RDDLC and 48 horses with LDDLC were reviewed. Horses were included for study if the RDDLC or LDDLC was confirmed by exploratory laparotomy or postmortem examination and if a serum GGT measurement was obtained within 24 hours before surgery. The proportion of horses with GGT activity within or above the reference range was determined. Of 37 horses, 18 (49%; exact binomial 95% confidence interval, 32-66%) with RDDLC and, of 48 horses, 1 (2%; 95% CI, 0-11%) with LDDLC had GGT above the reference range. Horses with RDDLC had higher serum GGT than did horses with LDDLC. Of 37 horses, 36 (97%) with RDDLC were discharged with a good prognosis and none returned as a result of hepatic disease. Evaluation of surgical and postmortem examinations revealed that positioning of the colon in horses with RDDLC results in compression of the bile duct, which can cause extrahepatic bile duct obstruction and a subsequent elevation in serum GGT activity.     

Colopexy in broodmares: 44 cases (1986-1990).

Colopexies were performed in 44 broodmares requiring abdominal surgery for large colon volvulus or right dorsal displacement of the large colon. Colopexies were performed by suturing the lateral bands of the left and right ventral colon to the ventral abdominal wall. Forty-seven percent of the mares in which a colopexy was performed had previous surgery for a large colon volvulus or right dorsal displacement of the large colon. Postoperative complications considered directly associated with the colopexy procedure were intermittent abdominal pain in 7, reoperation in 5, subcutaneous fistulous tracts in 1, and catastrophic rupture of the left ventral colon in 2 horses. Thirty-six horses survived greater than 6 months after colopexy, 34 of which had complete follow-up examinations. Twenty-seven mares have foaled at least once subsequent to the colopexy procedure, totalling 40 foals. Colopexy was considered a viable technique to prevent recurrence of large colon displacement or volvulus in selected predisposed populations.     

Laparoscopic closure of the nephrosplenic space for prevention of recurrent nephrosplenic entrapment of the ascending colon

OBJECTIVE: To evaluate outcome after laparoscopic closure of the nephrosplenic space in horses that had previous nephrosplenic entrapment of ascending colon (left dorsal displacement of the left colon; LDDLC). STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Horses that had previous LDDLC. METHODS: Medical records of horses that had LDDLC and subsequent laparoscopic nephrosplenic space closure between 2002 and 2004 were retrieved. Follow-up information was obtained by telephone interview of owners. Preoperative versus postoperative comparisons were: incidence of LDDLC, incidence of colic signs, and incidence of ventral celiotomy. Data were analyzed using a chi2-square test with significance set at P<.05. RESULTS: Ten horses met the inclusion criteria. Mean follow-up was 22 months. No horses had recurrence of LDDLC; however, 3 horses had colic signs subsequently that required surgical intervention. Over the follow-up period there was a significant decrease in the total incidence of colic and ventral celiotomy. Technique modifications included use of different cannula site locations, use of polyglyconate suture material for nephrosplenic space closure, and development of a custom cannula. CONCLUSIONS: Laparoscopic nephrosplenic space closure prevented recurrence of LDDLC, and significantly lowered the overall incidence of colic and ventral celiotomy. The custom-designed cannula provided good access to the operative site and no complications were encountered with use of polyglyconate suture material for nephrosplenic space closure. CLINICAL RELEVANCE: Closure of the nephrosplenic space will prevent LDDLC; however, other surgical lesions can occur.     

DORSAL DISPLACEMENT OF THE LEFT VENTRAL AND DORSAL COLON IN TWO HORSES

This paper describes the clinical signs and surgical treatment of 2 cases of dorsal displacement of the left ventral and dorsal colon. The condition, in which the colon becomes enclosed in the space bounded by the base of the spleen, the dorsal aspect of the suspensory ligament of the spleen (phrenicosplenic ligament), the left kidney and the adjacent body wall, is characterised by moderate to severe pain, minimal signs of shock, no response to medical therapy and a tendency for a ventral midline abdominal paracentesis to enter the spleen. Both horses recovered after surgical replacement of the colon, one case requiring a second laparotomy because of a recurrence of the displacement.     

Equine Colic: Seventy-six Cases Resulting from Incarceration of the Large Colon by the Suspensory Ligament of the Spleen

Incarceration of the large colon by the suspensory ligament of the spleen was diagnosed and surgically corrected on exploratory celiotomy in 76 horses exhibiting abdominal pain. The condition was diagnosed most frequently during the winter months in mature males of mean age 4.7 years. Clinical signs progressed slowly and included mild to moderate abdominal pain and distension with moderate tachycardia. The mean duration of colic prior to surgical intervention was 20.7 hours. The mild nature of the colic, the findings on palpation per rectum, and the continued passage of feces in 40% of horses, frequently led to the diagnosis and treatment of colonic impaction prior to admission. The condition was correctly diagnosed prior to exploratory celiotomy, by palpation per rectum, in only 18% of cases. Two types of displacement were identified. Sixty-six (86.8%) animals survived and were discharged from the hospital; the longterm survival rate was 78.9%.     

Ultrasonographic visualization of colonic mesenteric vasculature as an indicator of large colon right dorsal displacement or 180�� volvulus (or both) in horses

Visualization of colonic mesenteric vasculature during transabdominal ultrasonographic examination of horses with colic can be a predictor of right dorsal displacement of the large colon or 180° large colon volvulus, or both. Medical records of 82 horses having had surgical treatment of colic and having received a transabdominal ultrasonographic examination on admission were reviewed. Colonic mesenteric vessels were sonographically identified coursing laterally on the right side of the abdomen in 24 of the 82 cases. Horses with colonic vessels identified on ultrasound were 32.5 times more likely to be diagnosed at surgery with either large colon right dorsal displacement or 180° large colon volvulus than those in which vessels were not seen (P < 0.001). Visualization of colonic mesenteric vessels on ultrasound provided a sensitivity of 67.7%, specificity of 97.9%, positive predictive value of 95.8%, and negative predictive value of 81% for large colon right dorsal displacement or 180° large colon volvulus, or both.     

Colopexy of the equine large colon: comparison of two techniques

A study was designed to evaluate 2 colopexy techniques (A and B) in 8 clinically normal horses to determine which technique would prevent recurrence of large-colon displacement and/or volvulus. For technique A, 35 cm of the lateral free band of the left ventral colon was sutured to the abdominal wall, 6 cm to the left of ventral midline. For technique B, the medial free band of the left ventral colon was sutured to the medial free band of the right ventral colon, and 8 cm of the lateral free band of the left ventral colon was sutured to the abdominal wall, 6 cm to the left of ventral midline. One horse from each group was euthanatized at 6 months, and another at 12 months after surgery. The position of the large colon, the integrity of the colopexy, and other adhesions within the abdominal cavity were evaluated. At necropsy, attempts were made to manually create displacement and volvulus of the large colon. The remaining horses in each group were anesthetized 6 months or 12 months after surgery, and the integrity of the colopexy was evaluated. After a 60-day recovery period, these horses were exercised for 2 months. Although each horse initially lost weight, the weight of all but 2 was acceptable at the conclusion of the study. Two horses that had technique-B colopexies had progressive weight loss serious enough to warrant euthanasia. Both colopexy techniques prevented manual creation of large-colon displacement and large-colon volvulus centered at the sternal and diaphragmatic flexures. Technique-A colopexy also prevented manual creation of volvulus of the large colon centered at its base.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cecocolic Anastomosis for the Surgical Management of Cecal Impaction in Horses

Fourteen horses with cecal impaction were treated by cecocolic anastomosis. In nine horses, the anastomosis followed enterotomy and evacuation of the cecal contents, and in two horses it followed saline infusion and massage of the cecum. In three horses, the anastomosis was the only surgical procedure performed. Cecocolic anastomosis was performed between the lateral and dorsal cecal teniae, and the lateral and medial free teniae of the right ventral colon. The anastomosis was hand sutured in five horses. In all other horses, the GIA surgical stapling instrument was used in combination with hand sutured seromuscular layer closures and became the preferred surgical technique. The anastomosis allowed an alternative route for the transit of ingesta from the cecum to the right ventral colon.
Twelve of the 14 horses survived 2 months or longer after surgery (short-term survival rate, 86%) and 10 horses survived 12 months or longer after surgery (long-term survival rate, 71%). Early postoperative complications included mild abdominal pain (6 horses), wound infections (3 horses), fatal peritonitis (2 horses), and large colon distention necessitating reoperation (2 horses).     

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.     

Vascular Injury Associated with Naturally Occurring Strangulating Obstructions of the Equine Large Colon

Ten horses were euthanatized before, during, or after surgery to correct severe volvulus of the large colon. At surgery, the colonic serosa changed from blue-gray, blue or purple toward a more normal pink in seven horses after the volvulus was corrected. The mucosa consistently remained black or dark red. Results of postmortem colonic microangiography revealed perfusion of the serosa and the circular and longitudinal muscle layers, but mucosal perfusion was limited by thrombosis in the muscularis mucosae and submucosa. There was evidence of thrombosis of the mesenteric colic vessels in six horses. Damage to the colonic vascular system, especially thromboembolism in the submucosa, may be an important limitation to colonic viability after surgical correction of volvulus of the large colon.     

Use of ultrasound to evaluate outcome following colic surgery for equine large colon volvulus

Reasons for performing study: The post operative response of the large colon wall after a surgically corrected large colon volvulus (LCV) has not been investigated. Objectives: To use transabdominal ultrasound to monitor the post operative change in large colon wall thickness following surgical correction of LCV. Hypothesis: A prolonged period to colon wall involution is correlated with an increased rate of post operative morbidity and mortality. Methods: A prospective clinical study including horses that presented to the North Carolina State University Veterinary Teaching Hospital for colic between September 2006 and March, 2008, had surgically diagnosed and corrected LCV (at least 360°) without resection and recovered from anaesthesia. Ultrasound of the ventral large colon was performed at the time of anaesthetic recovery and every 6–8 h until the colon wall returned to normal thickness (≤5 mm). Outcome was evaluated using a one‐way ANOVA to compare average time to colon wall involution between: 1) survivors and nonsurvivors; and 2) horses that developed multiple organ dysfunction syndrome (MODS) during the post operative period and those that recovered without evidence of MODS. Results: Sixteen horses that recovered without evidence of MODS had a significantly shorter period to colon wall involution (≤5 mm) compared to those diagnosed with MODS (mean ± s.e. 19.6 h ± 2.5 and 39.7 h ± 6.7 respectively, P = 0.006). There was no significant difference in mean period to colon wall involution between survivors and nonsurvivors (26.2 ± 4.9 and 33.2 ± 7.8 h, respectively). Conclusions: A shorter time to colon wall involution was associated with decreased post operative morbidity in horses presented for surgical correction of large colon volvulus without resection. Potential relevance: Ultrasonographic monitoring of colon wall involution after surgical correction of LCV may aid in identifying those cases at risk of MODS. Further investigation of colon wall involution time using a larger number of horses is warranted.     

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.     

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.     

Racing performance following the laryngeal tie-forward procedure: a case-controlled study

REASONS FOR PERFORMING STUDY: The laryngeal tie-forward procedure (LTFP) is becoming widely used for correction of dorsal displacement of the soft palate (DDSP) despite the absence of an evidence-based assessment of its efficacy. HYPOTHESES: The LTFP returns racing performance to preoperative baseline levels and to that of matched controls; and post operative laryngohyoid position is associated with post operative performance. DESIGN AND POPULATION: Case-controlled study of racehorses undergoing a LTFP for dorsal displacement of the soft palate at Cornell University between October 2002 and June 2007. METHODS: The presence of at least one post operative start and race earnings ($) were used as outcome variables. Controls were matched by age, breed and sex from the third race prior to surgery. A novel radiographic reference system was used to determine laryngohyoid position pre- and post operatively. Data for definitively and presumptively diagnosed cases were analysed separately. RESULTS: During the study interval, 263 racehorses presented, of which 106 were included in the study; 36 had a definitive diagnosis of DDSP and 70 a presumptive diagnosis. Treated horses were equally likely to race post operatively as controls in the equivalent race. Treated horses had significantly lower earnings in the race before surgery than matched controls. The procedure moved the basihyoid bone dorsally and caudally and the larynx dorsally and rostrally. A more dorsal post operative basihyoid position and more dorsal and less rostral laryngeal position were associated with an increased probability of racing post operatively. CONCLUSIONS: Horses undergoing a LTFP are as likely to race post operatively as matched controls. The procedure restores race earnings to preoperative baseline levels and to those of matched controls. POTENTIAL RELEVANCE: This study provides strong evidence supporting the use of the LTFP in racehorses. Further work is needed to determine the relationship between laryngohyoid conformation and nasopharyngeal stability in horses.     

Transendoscopic contact neodymium:yttrium aluminum garnet laser correction of epiglottic entrapment in standing horses

Fifty-seven Standardbred and 44 Thoroughbred racehorses and 1 Thoroughbred polo mare with primary clinical signs of exercise intolerance or respiratory tract noise or combined exercise intolerance and respiratory tract noise were referred for laser correction of epiglottic entrapment. Significantly (P less than 0.001) more Standardbred than Thoroughbred racehorses were affected, compared with the observed hospital population during the same period. At referral, 14 horses did not have evident epiglottic entrapment and were returned to exercise without development of entrapment after treatment, which consisted of 1 week of rest and administration of anti-inflammatory medication. In 88 standing horses under sedation and topical anesthesia, epiglottic entrapment was corrected transendoscopically by use of a contact neodymium:yttrium aluminum garnet laser. In these 88 horses, 98% of entrapments were persistent, 92% were thick, 97% were wide, and 45% were ulcerated. Thirty-one percent of the horses had endoscopic evidence of epiglottic hypoplasia, and 8% had deviated epiglottic axis. Complete correction was achieved in 97% of the horses, Persistent dorsal displacement of the soft palate in 1 horse and severe epiglottic hypoplasia with thick, chronic entrapping membranes in 2 horses precluded successful transendoscopic correction with the horses in standing position. Most horses were treated on an outpatient basis, and all were able to be returned to exercise after 7 to 14 days of rest and treatment with anti-inflammatory medication. Entrapment recurred in 4 horses (5%), 3 of which had hypoplastic epiglottis. Dorsal displacement of the soft palate developed after surgery in 9 horses (10%) and continued in 4 horses (5%) that had displaced soft palate before surgery. All these horses had epiglottic hypoplasia. Laser correction of epiglottic entrapment in standing horses was safe, well tolerated, and effective. Laser surgery was an alternative to conventional surgery, and eliminated the need for general anesthesia and laryngotomy. It also reduced convalescence and postoperative complications.     

Determination of the acid-base status in 50 horses admitted with colic between December 1998 and May 1999

The purpose of the present study was to investigate the acid-base status and the concentration of organic acids in horses with colic caused by various disorders. Blood samples were collected from 50 horses with colic and from 20 controls. No intravenous fluids had been given prior to sample collection. Identified causes of colic included gastric ulceration, small intestinal volvulus, cecal intussusception, cecal rupture, colonic impaction, left dorsal colon displacement, right dorsal colon displacement, colonic volvulus, colitis, peritonitis, and uterine torsion. Thirty-seven horses recovered from treatment of colic, 8 horses were euthanized, and 5 died. Most cases were not in severe metabolic acidosis. In previous studies, most horses presented for diagnosis and treatment of colic were in metabolic acidosis and in shock.