Initial evaluation of a technique for complete cecal bypass in the horse

OBJECTIVE: To describe a novel stapling technique for creation of a complete cecal bypass, without ileal transection in horses. STUDY DESIGN: Experimental study. ANIMALS: Four adult horses. METHODS: Through a ventral median celiotomy, jejunocolostomy was made with an intraluminal anastomosis device (ILA-100) and oversewn with a Cushing pattern to reinforce the staple line. Immediately distal to the anastomosis, 4 rows of staples were applied using a thoracoabdominal stapling device (TA-90) to occlude the lumen of the distal jejunum and proximal ileum. Necropsy exams were performed at least 60 days after surgery. RESULTS: No intraoperative complications occurred. Cecal bypass was functional in all horses at necropsy. The most oral staple line across the ileum partially failed in 1 horse; however cecal bypass was functional. CONCLUSIONS: Complete cecal bypass without ileal transection is a viable alternative to traditional methods of complete cecal bypass. Two sets of staple lines across the ileum are recommended. Longer term follow-up is warranted before clinical use of this technique. CLINICAL RELEVANCE: Cecal bypass without ileal transection is technically simple and effectively bypasses the cecum. It also should intuitively require less time and have a reduced risk of contamination compared with complete cecal bypass with ileal transection.     

Surgical diseases of the equine cecum

Cecal impaction and cecal perforation, the two most common equine cecal diseases, are thought to develop after slowing or interruption of a single progressive motility pattern, which begins in a pacemaker area near the apex, occurs once every 3 minutes, and propels ingesta from the cecum to the right ventral colon. Rectal examination in horses with cecal impaction is the most useful technique to grade the severity of the condition. Medical treatment is undertaken if the impaction is judged to be mild to moderate. Surgical correction of cecal impaction in severe cases requires a ventral midline celiotomy, and exploration reveals a large ingesta-filled cecum and relatively empty large colon. Currently, the techniques of typhlotomy with manual evacuation of ingesta, combined with a complete bypass of the cecum by use of a jejunocolostomy, is the preferred method of surgical management. The use of a cecocolic anastomosis remains a viable alternative surgical procedure. Cecal perforation (CP), a uniformly fatal disease of horses, most often develops when the subtle signs of cecal impaction are missed or are masked by the administration of nonsteroidal antiinflammatory agents. CP can occur in mares around the time of foaling and, in this form, is not associated with cecal outflow dysfunction. Surgical management of cecocecal or cecocolic intussusception is required and involves resection of the diseased portion of cecum, either with extra- or intraluminal techniques. Both the side-to-side and end-to-side jejunocecal anastomoses are useful and successful techniques for bypass of simple or strangulating lesions of the ileum.     

Obstruction of the cecocolic orifice by ileocecocolic intussusception following jejunocecostomy in a horse

A 4-year-old Thoroughbred stallion was referred for signs of mild to moderate colic, anorexia, and decreased water intake of 3 weeks' duration. Ultrasonographic examination revealed an intussusception, the most common of which would be a cecal inversion or ileocecal intussusception. Surgical exploration identified an ileocecocolic intussusception with extension of the intussusceptum into the right ventral colon; however, the cause of the intussusception could not be identified. The intussusception could not be surgically corrected, and the horse was euthanatized. A side-to-side jejunocecostomy that had been performed previously was identified at necropsy. The ileal stump had intussuscepted into the right ventral colon and become hypertrophied, causing partial obstruction of the cecocolic orifice and clinical signs of colic. In horses requiring an ileocecal or jejunocecal anastomosis, the ileal stump may be left to slough within the cecum as part of the treatment for an irreducible ileocecal intussusception or intentionally inverted into the cecum when the ileal stump is necrotic and cannot be exteriorized and resected. Efforts should be made to minimize the size of the ileal stump to reduce the liklihood of intussusception.     

Cecal amputation within the right ventral colon for surgical treatment of nonreducible cecocolic intussusception in 8 horses

OBJECTIVES: To report a surgical technique for treatment of nonreducible cecocolic intussusception and outcome in 8 horses. STUDY DESIGN: Retrospective study. ANIMALS: Eight horses with nonreducible cecocolic intussusception treated by cecal amputation through a right ventral colotomy. METHODS: Data were obtained from medical records and telephone conversations by using a standardized questionnaire. The large colon was exteriorized and, if necessary, evacuated of its contents through a pelvic flexure enterotomy. A second colotomy was made on the ventral surface of the right ventral colon (RVC) centered over or immediately distal to the intussusceptum. In most horses, attempts to manually reduce the intussusception by pushing the cecum from within the RVC through the cecocolic orifice were unsuccessful. Invaginated cecum was then pulled into the RVC and amputated; the cecum was either ligated with umbilical tape or sutured proximal to the site of amputation. After amputation, the remainder of the invaginated cecum was reduced. After further resection to healthy tissue, the typhlectomy was closed with a double-inverting suture pattern. RESULTS: The median horse age was 2 years (range, 1 to 8 years). Duration of colic ranged from 6 hours to 6 months. Median surgical time was 180 minutes (range, 135 to 300 minutes). Median duration of antibiotic therapy was 7 days (range, 5 to 14 days). Median duration of hospitalization was 12 days (range, 6 to 21 days). All horses survived to hospital discharge. One horse died 3 months postoperatively; however, the remainder survived (median survival, 30 months; range, 6 to 96 months) and returned to or exceeded previous function. CLINICAL RELEVANCE: Despite some contamination during surgery, horses with nonreducible cecocolic intussusception that underwent this method of surgical treatment had a good prognosis.     

Elective inversion of the distal ileal stump into the caecum of the horse

The distal 30 to 40 cm of the ileum cannot be exteriorized through a midline laparotomy incision because of its close anatomical association with the base of the caecum. A method was developed to deal with those cases where this segment of small intestine was involved in an avascular, necrotic process and therefore required resection. The technique involves inverting the distal stump of ileum into the lumen of the caecum and then performing a routine ileocaecal or jejunocaecal anastomosis. This avoids the risk of peritonitis if a Parker-Kerr oversew of the necrotic ileal stump should dehisce. The technique was performed on five clinically normal horses and on four horses in which the terminal 30 to 40 cm of the ileum was necrotic. The postoperative clinical findings and autopsy results of these horses are discussed.     

Ileocecal intussusception corrected by resection within the cecum in two horses.

Irreducible ileocecal intussusceptions pose a difficult surgical problem. Strangulating ileocecal intussusceptions involving the ileum and jejunum were identified in 2 horses undergoing exploratory laparotomy because of colic. Surgical correction in both horses was achieved by amputation of the ileocecal intussusception from within the cecal lumen, via typhlotomy. The inverted ileal stump was blindly stapled near the ileocecal orifice after pulling the intussusceptum into the cecum. A jejunocecostomy was performed to reestablish intestinal continuity.     

Strangulating obstruction caused by intestinal herniation through the proximal aspect of the cecocolic fold in 9 horses

OBJECTIVE: To report the clinical and surgical findings and outcome for horses with strangulating obstruction caused by herniation through the proximal aspect of the cecocolic fold. STUDY DESIGN: Retrospective study. ANIMALS: Nine horses. METHODS: Medical records were reviewed for clinical signs, surgical findings and technique, and outcome. Cadaver ponies and necropsy specimens were also used to study the regional anatomy of the cecocolic fold. RESULTS: The ileum and distal jejunum were strangulated in 8 horses, whereas in 1 horse the small intestine and the left ascending colons were incarcerated in a rent in the cecocolic fold. Two horses were euthanatized at surgery, 6 horses had a small intestinal resection (mean length, 3 m; range, 1.5-6.4 m) and an end-to-side jejunocecostomy, and the entrapment was reduced without resection in the horse that had small intestine and ascending colon incarceration; cecocolic fold defects were not closed. One horse was euthanatized 36 hours after surgery because of endotoxemia. Six horses were discharged; 4 were available for long-term follow-up, of which 2 were euthanatized, and 2 were euthanatized 12 and 18 months after surgery because of colic signs. Variations in thickness of the cecocolic fold were observed in specimens obtained from necropsy of other horses and ponies. CONCLUSIONS: Reasons for this defect are unknown, although observed anatomic differences in cecocolic fold thickness may contribute to the development of defects. CLINICAL RELEVANCE: Reduction of the entrapped bowel is easiest when traction is placed on the bowel at a 90 degrees to the base of the cecum. Intestinal incarceration through rents within the proximal part of the cecocolic fold should be considered as a differential diagnosis for strangulating obstruction in horses.     

Ileocecal intussusception in horses: 26 cases (1981-1988)

The case records of 26 horses with ileocecal intussusception over a 7-year period were reviewed to determine clinical features of the disease and response to treatment. The median age of horses with ileocecal intussusception was 1 year and ranged from 2 weeks to 19 years. There was no apparent gender or breed predisposition to this disease. An acute form of ileocecal intussusception was diagnosed in 19 horses with signs of moderate to severe abdominal pain of less than or equal to 24 hours' duration, and a chronic form was diagnosed in 7 horses with signs of intermittent, mild to moderate abdominal pain of more than 3 days' duration. Horses with chronic ileocecal intussusception had a history of weight loss or failure to gain weight, slow growth, poor appetite, low-grade pyrexia, and postprandial signs of abdominal pain. At surgery, the involved segments of intestine (intussusceptum and intussuscipiens) in chronic cases were 2 to 10 cm long, and the ileum and much of the distal portion of the jejunum were flaccid, dilated, and thick walled. In the acute cases, the length of involved intestine ranged from 6 to 457 cm. Whereas only 1 of 7 chronic intussusceptions (14%) could be reduced, 9 of 19 (47%) acute intussusceptions were reducible. Surgical treatment included resection and jejunocecostomy (6 horses), partial resection through a cecotomy and a side-to-side jejunocecostomy (2 horses), and a side-to-side ileocecostomy or jejunocecostomy without resection (12 horses, 7 of which had chronic intussusception). Six horses with acute intussusception were euthanatized before or during surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

The characteristics of intestinal injury peripheral to strangulating obstruction lesions in the equine small intestine.

Recent studies suggest that horses requiring surgical correction of strangulating intestinal obstruction may develop post operative complications as a result of ischaemia/reperfusion injury. Therefore, the mucosal and serosal margins of resected small intestine from 9 horses with small intestinal strangulating lesions were examined for evidence of ischaemia/reperfusion injury. Severe mucosal injury and marked elevations in myeloperoxidase activity were detected at ileal resection margins (n = 4), whereas the mucosa from proximal jejunal (n = 9) and distal jejunal (n = 5) resection margins was normal. However, the serosa from jejunal resection margins had evidence of haemorrhage and oedema, and the proximal jejunal serosa had significantly increased numbers of neutrophils. Histological injury in ileal stumps is indicative of the inability fully to resect the ileum in horses with distal small intestinal strangulations. One of 4 horses subjected to ileal resection was subjected to euthanasia and found to have a necrotic ileal stump. Evidence of serosal injury and neutrophil infiltration in the proximal jejunal resection margins may predispose horses to post operative adhesions. Four of 8 horses discharged from the hospital suffered from recurrent colic in the post operative period.     

Complete caecal bypass without ileal transection for caecal impaction in horses: seven clinical cases (1997-2007)

Objectives To report the clinical outcome in seven horses following use of a newly described surgical technique for treating caecal impaction. Methods The medical records of seven horses with caecal impaction treated surgically using a stapling technique to create a complete caecal bypass without ileal transection were reviewed. Data were obtained from the records and through telephone interviews with case-associated personnel. Results The mean age was 10 years (range 2–22 years) and duration of colic ranged from 24 h to 2 weeks. Five horses had type II motility dysfunction and the remaining two had type I. Mean surgical time was 185 min (range 146–245 min) and the horses were hospitalised for a mean of 12.4 days (range 9–22 days); 71% (5/7) were discharged from hospital and all five were alive 60 days from the surgery date. One horse was lost to follow-up. The four (66.7%) available remaining horses were alive ≥ 1 year (long-term survivors). Conclusions Complete caecal bypass without ileal transection for clinical cases of caecal impaction had comparable outcomes to complete bypass with ileal transection. The technique is easy to perform, has the potential to reduce surgical time, compared with traditional bypass techniques, and may reduce the risk of intraoperative abdominal contamination. It is recommended for use in clinical cases in which caecal bypass is desirable.     

Jejunoileal anastomosis following small intestinal resection in horses: seven cases (1999-2001)

OBJECTIVE: To report the postoperative outcome in horses undergoing jejunoileal anastomosis performed with a 2-layer simple continuous technique. DESIGN: Retrospective study. ANIMALS: 7 horses. PROCEDURE: Information regarding signalment, clinical signs, findings at surgery, and postoperative complications was obtained from medical records of horses that underwent exploratory ventral midline celiotomy, small intestinal resection, and jejunoileal anastomosis to correct various small intestinal strangulating lesions. Follow-up information was obtained via telephone conversations with owners or trainers. RESULTS: Six males and 1 female of various breeds aged 10 months to 27 years and weighing 312 to 785 kg (686.4 to 1,727 lb) were included. The most common complications were mild to moderate tachycardia and mild to moderate signs of abdominal pain. Two horses developed incisional infections and soft, fluctuant swelling at the incision site following resolution of the infection. Follow-up time ranged from 7 to 17 months after surgery. Owners reported no further colic episodes and no diet change necessary following surgery. All horses had returned to their intended level of use. CONCLUSIONS AND CLINICAL RELEVANCE: Advantages to the jejunoileal technique include maintaining the normal ileocecal valve and a postoperative recovery period similar to that described following other small intestinal anastomoses. Jejunoileal anastomosis is a viable alternative to ileal bypass. This technique appears to result in a postoperative complication rate similar to that reported following jejunojejunostomy procedures.     

Clinical assessment and outcome of three techniques for jejunal resection and anastomosis in horses: 59 cases (1989-2000)

OBJECTIVE: To compare postoperative complications, short- and long-term survival, and surgical times for hand-sewn end-to-end (EE), stapled functional end-to-end (FEE), and stapled side-to-side (SS) anastomotic techniques for jejunal resection in horses. DESIGN: Retrospective study. ANIMALS: 59 horses. PROCEDURE: Medical records were reviewed to obtain signalment, diagnosis, treatment, and outcome for horses that underwent jejunojejunostomy in our hospital. Only horses that recovered from anesthesia were included in the study. RESULTS: Among the 59 horses, there were 33 EE, 15 FEE, and 11 SS anastomoses. No difference was found in duration of surgery among the 3 techniques. The most common postoperative complications were colic episodes (56%), ileus (53%), diarrhea (20%), and adhesions (15%). Horses with SS anastomosis had a significantly shorter duration of postoperative ileus than the EE group did. No significant difference in duration of postoperative ileus was found among the other groups. No difference was found among the 3 anastomotic techniques in regard to survival rate at the time of discharge, 6 months after surgery, or 1 year after surgery. Overall survival rates after jejunal anastomosis were 88% at the time of discharge, 65% at 6 months after surgery, and 57% at > or = 1 year after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: The hand-sewn EE, stapled FEE, and stapled SS anastomotic techniques should be considered equivalent methods for small intestinal anastomosis in the horse. However, the stapled SS technique may be preferred because of possible decreased duration of postoperative ileus.     

Bypass Surgery for Intestinal Occluding Abscesses in the Equine: A Report of Two Cases

The medical management of two horses with small intestine occluding abdominal abscesses was supported by surgical bypasses. In the first case the small intestine was transected proximal to the abscess and an end-to-side anastomosis performed distally; in the second case a side-to-side anastomosis was performed without bowel transection. The results suggest bowel transection with an end-to-side anastomosis to be the preferred procedure.     

Handsewn Semiclosed Single‐Layer Jejunocecal Side‐To‐Side Anastomosis in the Horse

Objective: To report a technique for semiclosed 1‐layer side‐to‐side jejunocecal anastomosis in horses. Study Design: Experimental study and clinical reports. Sample Population: Part 1—In vitro: Intestinal specimens from 24 horses collected immediately after death at an abattoir. Part 2—Clinical cases: 10 horses with clinical signs of colic requiring jejunocecostomy. Methods: Mean time to perform twelve 2‐layer handsewn (HS2L) and 12 semiclosed 1‐layer modified handsewn (SC) jejunocecal anastomoses was compared. Mean bursting pressures of anastomoses measured with a modified tank inflation test were compared. The SC technique was used in 10 horses that required jejunocecal anastomosis with and without resection (complete or incomplete ileocecal bypass). Results: The SC technique was significantly quicker to perform than HS2L technique. Clinically, the technique appeared safe with a major complication, associated with obstruction from kinking of the anastomosis, occurring in 1 horse. Conclusions: The SC technique was easy to perform with very little mucosal exposure in comparison to the HS2L technique, and was safe and effective in restoring intestinal continuity in clinical cases. Clinical Relevance: The SC technique should be considered for jejunocecostomy in horses because it reduces anastomosis time and mucosal exposure compared with other techniques.     

Use of colonic luminal pressure to predict outcome after surgical treatment of strangulating large colon volvulus in horses

OBJECTIVE: To evaluate the relationship of colonic luminal pressure (CLP) measurements to outcome in horses with large colon volvulus (LCV) after either manual correction or large colon resection and anastomosis (LCRA). STUDY DESIGN: Retrospective study. ANIMALS: Horses (n=57) that had LCV. METHODS: Records for horses with LCV (March 1997-December 2003) were reviewed. Inclusion criteria were strangulating LCV proximal to the cecocolic ligament (>270 degrees), recorded CLP, and successful recovery from anesthesia. CLP measurements and survival/mortality rates were compared between horses that had manual correction (M) or LCRA (R). RESULTS: Of 57 horses, 27 had M and 30 had LCRA. For group M, CLP measurements had a sensitivity of 0.60 and specificity of 0.77 for predicting survival, whereas for group R, sensitivity was 0.50 and specificity was 0.54. CONCLUSION: In our LCV population, elevated CLP measurements had poor accuracy for predicting outcome in horses after surgical correction, especially after LCRA. CLINICAL RELEVANCE: CLP measurements based on a single hospital population of horses with LCV should be used with caution for other hospital populations of LCV. CLP may be only one of many variables needed for predicting outcome of horses with strangulating LCV, especially after LCRA.     

Large colon resection and anastomosis in horses

Large colon resection and anastomosis was performed in 11 horses at various levels of the colon, using several surgical methods. The level of resection ranged from the pelvic flexure to the cecocolic ligament. Nine of 11 horses survived and at follow-up (4 months to 7 years) were free of clinical signs referable to disease of the gastrointestinal tract. Seven horses could be evaluated as to athletic or reproductive function and all returned to original potential.     

Chronic ileocecal intussusception in horses

Ten young horses with signs of simple partial obstruction of the small intestine were found upon surgical exploration of the abdomen to have chronic intussusception of the distal ileum into the cecum. Poor general physical condition, intermittent or continual abdominal pain of varying degree, depression, and poor appetite were consistent clinical findings. Rectal palpation in eight animals was suggestive of an incomplete or intermittent obstruction of the small intestine. Laboratory determinations were not helpful in making a diagnosis. Dilatation and hypertrophy of the distal jejunum and ileum were associated surgical findings indicating chronicity of the problem. Surgical correction utilizing an end-to-side or a side-to-side anastomosis of small intestine to cecum resulted in recovery in 7 of 8 cases which could be followed long term. Failure to resect the abnormal segment of small intestine did not affect the outcome.     

Experimental Large Colon Resection at the Cecocolic Ligament in the Horse

Ten normal horses had approximately 95% of the length of the large colon resected with a side-to-side anastomosis between right ventral and right dorsal colon performed with surgical stapling equipment. Four horses died shortly after surgery of colitis (1 horse) or failure of the TA 90 transection staple line (3 horses). Another horse died 4 months after surgery from disseminated streptococcal infection but had recovered well from the colon resection. Five horses survived long term (18 months) with no clinical evidence of adverse effects of the resection. Surviving horses had weight loss and soft fecal consistency for 3 to 12 weeks after surgery but returned to preoperative values within 12 months. At a second surgery 1 year later (5 horses) or at necropsy 4 months later (1 horse), fibrous omental adhesions were present over the transection staple line in four horses and over the anastomotic staple line in two horses. Omental adhesions to the everted staple line were moderate but not associated with any clinical sequellae. An incisional hernia was present in one horse. The anastomotic stomata measured between 8 and 9 cm, which was 60% of the size of the original surgically created stomata. Failure of the transection staple line occurred in the first three of five horses in which the procedure was attempted due to improper configuration of the staples or crushing of the tissue between the staples. Experience corrected this complication.     

The Arterial Supply to the Ileum, Cecum and Proximal Loop of the Ascending Colon in the Ox*

This study describes in detail the arteries supplying the ileum, cecum and proximal loop of the ascending colon in the ox important to the veterinary surgeon treating disorders of these segments of the intestinal tract. The ileum was vascularized by the mesenteric ileal artery (from the ileocolic), the first ileal artery (from the cranial mesenteric) and by the ileal branches of the cecal artery which, by means of their anastomoses, form a row of antimesenteric arches in the ileal part of the ileocecal fold. The termination of the ileum was also supplied by twigs from the ileocecocolic arch. The ileum appears to be the most vascular part of the small intestine. The cecum was supplied mainly by the cecal branches of the cecal artery. The proximal end of the cecum was also vascularized by branches from the ileocecocolic arch. The proximal loop of the colon was vascularized by the three colic branches of the ileocolic. The first colic branch supplied the third part of the loop, the second colic branch supplied the first and the second parts of the loop and the third colic branch supplied the first part and, together with the first cecal branch of the cecal artery, formed the ileocecocolic arch at the dorsolateral surface of the ileocecocolic junction. The terminal branches of the arteries to the ileum, cecum and proximal loop of the colon detached lateral branches in the tunica muscularis which anastomosed with similar branches from neighboring arteries in an arcuate manner in the tunica submucosa. The terminal branches from both sides terminated in the free border, releasing branches which anastomosed with each other in the tunica submucosa. The colic lymph nodes were supplied by the colic branches of the ileocolic artery, die two largest nodes being perforated by some of the branches of the first two colic branches. The ileal lymph nodes were supplied by the ileal arteries of the cranial mesenteric. They were also perforated by these arteries. Cecal lymph nodes were seen only in the specimen from the calf. They were much smaller than the colic and ileal nodes and were supplied by the first two or three cecal branches of the cecal artery and also by twigs arising directly from the cecal artery.     

Differential survival in horses requiring end-to-end jejunojejunal anastomosis compared to those requiring side-to-side jejunocaecal anastomosis

REASONS FOR PERFORMING STUDY: Horses requiring different methods of intestinal anastomosis during equine colic surgery may have differences in mortality and morbidity. HYPOTHESES: Horses requiring side-to-side jejunocaecal anastomosis have a higher mortality and morbidity rate than those requiring end-to-end jejunojejunal anastomosis. Morbidity and mortality of handsewn vs. stapled side-to-side jejunocaecal anastomoses are not significantly different. METHODS: A prospective, nonrandomised, observational study was conducted. Clinical and surgical details were recorded during hospitalisation and survival data acquired by periodic telephone questionnaire. Differences in mortality and morbidity rate were evaluated by survival analysis. RESULTS: A total of 184 horses underwent end-to-end jejunojejunal anastomosis and 178 underwent side-to-side jejunocaecal anastomosis. Horses with a jejunocaecal anastomosis had a significantly higher mortality rate. The incidence of post operative colic in horses requiring side-to-side jejunocaecal anastomoses was greater than those requiring end-to-end jejunojejunal anastomoses. Within the group undergoing side-to-side jejunocaecal anastomosis there was no evidence of differential survival between horses with handsewn vs. stapled anastomoses. CONCLUSIONS: Mortality rate is higher in horses that have required side-to-side jejunocaecal anastomosis than in those that needed end-to-end jejunojejunal anastomosis; and post operative colic is more common after side-to-side jejunocaecal anastomosis. No difference in mortality was found between horses with handsewn and stapled side-to-side jejunocaecal anastomoses. POTENTIAL RELEVANCE: Surgeons should be aware of the increased mortality and morbidity in horses requiring side-to-side jejunocaecal anastomosis. Our finding of no difference in mortality between handsewn and stapled side-to-side jejunocaecal anastomoses justifies surgeons exercising personal preference in their selection of anastomosis method.