Obstruction of the Ascending Colon in Cattle: II. An Experimental Model of Partial Bypass of the Large Intestine

Four dairy calves were subjected to partial bypass of the large intestine by uniting the ileum to the distal centrifugal coil of the spiral loop of the ascending colon (spiral colon). Digesta bypassed the distal ileum, cecum, proximal loop of the ascending colon, and the centripetal coils of the spiral colon. The calves survived the surgical procedure and were healthy throughout the 4-week postoperative experimental period. Feces were loose immediately after bypass, but fecal dry matter (DM) gradually increased over the subsequent 2 weeks (P < 0.01), indicating adaptation of remaining bowel to absorb more water. There was no significant change in serum concentration of sodium or chloride. The calves continued to grow and gain weight at acceptable rates after bypass. Necropsy of 3 of the calves demonstrated a decrease in size of the bypassed bowel.     

Myoelectric activity in the intestine of cows with strangulating obstruction of the distal small intestine

Myoelectric activity in 2 cows instrumented with permanent electrodes in the ileum, cecum, proximal loop of the ascending colon (PLAC), and spiral colon was analyzed after an obstruction developed in the distal small intestine. Results were compared with patterns from a group of 7 normal cows. Myoelectric activity in the ileum immediately orad to the occlusion was characterized by abolition of the migrating myoelectric complex (MMC) and a constant pattern of strong spike bursts of long duration. Cyclic activity was present in all parts of the large intestine, and propagation of phase III activity was evident from proximal to distal. A slight degree of disorganization in phase III propagation was restricted to the spiral colon. Activity cycles tended to be shorter in the cecum and PLAC of both cows with colic than in normal cows, and the intensity of spiking activity was generally lower. Changes in duration of the MMC in the spiral colon (bovine colonic MMC, bcMMC) were inconsistent, but the intensity of spiking activity tended to be lower in phases I and II of both cows compared to controls. The organization of phase III in several spindles typical of the bovine spiral colon was not disrupted, but phase IV of the bcMMC occurred only infrequently. Organized cyclic activity occurred in the large intestine of both cows despite complete disruption of the small intestinal MMC, indicating the presence of mechanisms able to initiate and regulate coordinated myoelectric patterns in the large intestine independent of the small intestine.     

Myoelectric activity in the intestines of healthy dairy cows during the recovery period after implantation of permanent electrodes

OBJECTIVE: To describe myoelectric patterns in the intestines of cows after electrode implantation. ANIMALS: 7 lactating Simmental-Red Holstein cows. PROCEDURE: Cows were implanted with 7 pairs of bipolar silver electrodes (1 each in the ileum, cecum, and proximal loop of the ascending colon (PLAC) and 4 in the spiral colon). Myoelectric activity was monitored during 10 periods within the first 3 weeks after surgery. Recordings from the first 2 weeks were compared with recordings from the third week, which was considered a steady-state condition. RESULTS: Significant changes over time were detected for 18 of 57 variables, including 3 variables describing myoelectric activity of the ileum, 6 variables of the cecum, 6 variables of the PLAC, and 3 variables of the spiral colon. Compared with values for the steady-state condition, 16 variables differed significantly for the 14-day period after surgery (7 variables until day 11, 2 variables until day 8, 4 variables until day 5, 1 variable until day 3, and 2 variables until day 2 after electrode implantation). None of the variables had significant changes that lasted only 1 day after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Significant changes were observed for several variables of myoelectric activity in all intestinal segments until as late as 11 days after electrode implantation, whereas a steady-state condition was reached 14 days after surgery. Effects of drugs, manipulations, or nutrition regimens on myoelectric activity of the bovine digestive tract should be evaluated no sooner than 2 weeks after electrode implantation.     

Effect of sodium butyric acid, sodium valerianic acid, and osmolarity on contractility of specimens of intestinal wall obtained from the cecum and spiral colon of healthy cows

OBJECTIVE: To compare the effect of various concentrations of sodium butyric acid and sodium valerianic acid, as well as various osmolarities, on contractility of ex-vivo intestinal wall specimens obtained from the cecum and spiral colon of each of several healthy cows. SAMPLE POPULATION: Full-thickness preparations of intestinal wall, dissected parallel to the longitudinal smooth muscle layers, harvested from freshly slaughtered healthy cows. PROCEDURE: Specimens of intestinal wall were incubated for 5 minutes with various concentrations of sodium butyric acid and sodium valerianic acid as well as various osmolar concentrations of NaCl, using a crossover design. Isometric contractions were induced 7 times with carbachol (CH; 5 X 10(-6) mol/L). Contractility was defined as the maximum amplitude of contraction and the amplitude of contraction 2 minutes after addition of CH. RESULTS: Repeated addition of CH did not result in a significant effect on contractility of specimens from the cecum and spiral colon. Contractility after addition of CH was not significantly affected by prior incubation with various concentrations of sodium butyric acid or sodium valerianic acid or after an increase of osmolarity. Maximum amplitude of contraction was significantly higher in specimens from the spiral colon, compared with specimens from the cecum. CONCLUSIONS: Increases in concentrations of sodium butyric acid or sodium valerianic acid and increases in osmolarity did not inhibit contractility of intestinal wall specimens from the cecum and spiral colon of a group of healthy cows.     

Effects of an abrupt increase of starch-rich concentrates in the diet of dairy cows on concentrations of volatile fatty acids in the rumen and large intestine and on myoelectric activity of the spiral colon

OBJECTIVES: To describe the effects of an abrupt increase of concentrates in the diet of dairy cows on myoelectric activity of the spiral colon and on fermentation patterns in the rumen and large intestine. ANIMALS: 6 healthy lactating Simmental x Red-Holstein cows. PROCEDURES: The diet of 6 cows implanted with bipolar electrodes in the spiral colon was changed from hay only to a ration of 50% hay:50% starch-rich concentrates during a period of 60 hours. Myoelectric activity of the spiral colon, concentrations of absolute and undissociated volatile fatty acids (VFA), and pH of ruminal and large intestinal contents were monitored before, during, and after the dietary change. RESULTS: Significant changes in patterns of myoelectric activity of the spiral colon were restricted to phases III and IV of the bovine migrating myoelectric complex and to propagation velocity. Significant alterations were not observed in pH or VFA concentrations in ruminal fluid, but pH decreased and VFA concentrations increased significantly in fecal specimens after the change of diet. CONCLUSIONS AND CLINICAL RELEVANCE: Although rumen fluid is of limited value for measurement of certain indicators of fermentation, fecal samples can be used for measurement of pH and VFA concentrations, which serve as indicators of fermentation patterns in the large intestine. Increased concentrations of VFA and low pH in large intestinal digesta have a minimal influence on myoelectric activity of the spiral colon. Increased luminal VFA concentrations are unlikely to play an important role in the etiopathogenesis of motility disorders of the large intestine in cattle.     

Abdominal adhesions after small intestinal surgery in the horse

One hundred thirteen of 172 horses (66%) undergoing exploratory celiotomy for a small intestinal lesion survived 4 or more days after surgery. Intra-abdominal adhesions causing clinical problems requiring additional surgery or euthanasia were documented in 25 horses (22.1%). Problems developed in significantly more males than females. The most common initial small bowel lesion was ileal impaction (12 horses); 21 horses underwent small intestinal resection or bypass. However, there was no significant difference in the incidence of intra-abdominal adhesions between horses that underwent intestinal resection or bypass and those that did not. Only 4 of the 25 horses (16%) with problems associated with postoperative adhesions survived. The mean interval between surgical procedures or between the initial procedure and euthanasia for all horses was 84 days (range, 7-512 days; median, 25 days). However, 70% of the subsequent celiotomies were performed within 60 days of the previous surgery. The mean interval between celiotomies was 221 days (range, 9-512 days) for the survivors and 61 days (range, 7-358 days) for the nonsurvivors. These results indicated that most of the problems related to postoperative intra-abdominal adhesions occurred within 2 months of the initial small intestinal surgery. Furthermore, the earlier development of postoperative adhesions was associated with a poorer prognosis for survival.     

Abdominal Adhesions after Small Intestinal Surgery in the Horse

One hundred thirteen of 172 horses (66%) undergoing exploratory celiotomy for a small intestinal lesion survived 4 or more days after surgery. Intra-abdominal adhesions causing clinical problems requiring additional surgery or euthanasia were documented in 25 horses (22.1%). Problems developed in significantly more males than females. The most common initial small bowel lesion was ileal impaction (12 horses); 21 horses underwent small intestinal resection or bypass. However, there was no significant difference in the incidence of intra-abdominal adhesions between horses that underwent intestinal resection or bypass and those that did not. Only 4 of the 25 horses (16%) with problems associated with postoperative adhesions survived. The mean interval between surgical procedures or between the initial procedure and euthanasia for all horses was 84 days (range, 7–512 days; median, 25 days). However, 70% of the subsequent celiotomies were performed within 60 days of the previous surgery. The mean interval between celiotomies was 221 days (range, 9–512 days) for the survivors and 61 days (range, 7–358 days) for the nonsurvivors. These results indicated that most of the problems related to postoperative intra-abdominal adhesions occurred within 2 months of the initial small intestinal surgery. Furthermore, the earlier development of postoperative adhesions was associated with a poorer prognosis for survival.     

Retrospective Evaluation of Repeat Celiotomy in 53 Horses with Acute Gastrointestinal Disease

Fifty-three of 648 horses (8.2%) treated surgically for acute gastrointestinal obstruction were subjected to repeat celiotomy. Forty horses (75%) recovered from anesthesia after repeat celiotomy, and 26 horses (49%) were discharged from the clinic. Excluding two horses lost to follow-up, 10 of 51 horses (20%) survived long term. Horses subjected to repeat celiotomy had a significantly lower long-term survival rate than horses subjected to a single celiotomy. Twenty-eight horses had mechanical obstructions, and 22 had functional obstructions at the second surgery. Significantly more horses with mechanical obstructions recovered from anesthesia, but there was no difference in short-term or long-term survival. Seventy-seven percent of horses were subjected to two celiotomies without being discharged from the clinic between procedures. The intervals between primary and repeat celiotomies ranged from less than 24 hours to 4 years, with 89% of them being less than 2 months. Horses with functional obstructions at the second surgery had a significantly shorter interval between surgeries than horses with mechanical obstructions. Twenty-three horses had sequelae of the primary celiotomy, 19 had progression of their original disease, 8 had recurrence of the same condition, and 3 had unrelated problems. Intestinal ischemic necrosis was the most common diagnosis at repeat celiotomy, and small intestinal obstruction by adhesions was the second most frequent.     

Retrospective evaluation of repeat celiotomy in 53 horses with acute gastrointestinal disease

Fifty-three of 648 horses (8.2%) treated surgically for acute gastrointestinal obstruction were subjected to repeat celiotomy. Forty horses (75%) recovered from anesthesia after repeat celiotomy, and 26 horses (49%) were discharged from the clinic. Excluding two horses lost to follow-up, 10 of 51 horses (20%) survived long term. Horses subjected to repeat celiotomy had a significantly lower long-term survival rate than horses subjected to a single celiotomy. Twenty-eight horses had mechanical obstructions, and 22 had functional obstructions at the second surgery. Significantly more horses with mechanical obstructions recovered from anesthesia, but there was no difference in short-term or long-term survival. Seventy-seven percent of horses were subjected to two celiotomies without being discharged from the clinic between procedures. The intervals between primary and repeat celiotomies ranged from less than 24 hours to 4 years, with 89% of them being less than 2 months. Horses with functional obstructions at the second surgery had a significantly shorter interval between surgeries than horses with mechanical obstructions. Twenty-three horses had sequelae of the primary celiotomy, 19 had progression of their original disease, 8 had recurrence of the same condition, and 3 had unrelated problems. Intestinal ischemic necrosis was the most common diagnosis at repeat celiotomy, and small intestinal obstruction by adhesions was the second most frequent.     

Congenital peritoneopericardial diaphragmatic hernia in an alpaca

An adult alpaca was presented because of abdominal pain and was diagnosed with an intestinal obstruction. The putative diagnosis at surgery was an intestinal obstruction caused by peritonitis and intra-abdominal adhesions. The cause of the inflammation was not determined at that time. The alpaca died soon after surgery from post-surgical complications and a peritoneopericardial diaphragmatic hernia that was not diagnosed until necropsy.     

Ultrasonographic findings in cows with dilatation, torsion and retroflexion of the caecum

Thirty cows with caecal dilatation underwent clinical and ultrasonographic examinations, followed by a right flank laparotomy and surgical correction. The intraoperative findings were compared with the results of the ultrasonographic examination. The appearance, position, dimensions, diameter and nature of the contents of the caecum and proximal and spiral ansa of the colon were determined with a 3.5 MHz linear transducer. The wall of the proximal ansa of the colon and of the dilated caecum closest to the abdominal wall was visible in all the cows and appeared as an echogenic semicircular line immediately adjacent to the peritoneum. The contents of the caecum and of the proximal and spiral ansa of the colon were not visible in 21, 25 and 25 cows, respectively, owing to gas. In the remaining cows, the contents were hypoechogenic to echogenic in appearance. In all of the cows, the dilated caecum was imaged from the right abdominal wall at the level of the tuber coxae. The caecum was imaged from the 12th, 11th and 10th intercostal spaces in 11, five and three cows, respectively. The caecum and proximal ansa of the colon were situated immediately adjacent to the right abdominal wall in 28 cows, but in the other two cows parts of these structures were pushed away from the abdominal wall by the liver or gall bladder. The diameter of the caecum, measured at various sites varied from 7.0 to 25.0 cm. Caecal dilatation was diagnosed on the basis of the results of rectal examinations in 28 of the cows, but in all 30 cows on the basis of the results of the ultrasonographic examinations. Dilatation and caudal displacement of the caecum were diagnosed in 18 cows; dilatation and cranioventral retroflexion of the caecum were diagnosed in six cows, and dilatation and craniodorsal retroflexion of the caecum were diagnosed in two cows. In the four other cows, the direction of the retroflexed caecum could not be determined. The diagnosis of caecal dilatation based on the ultrasonographic findings was confirmed in all the cows during exploratory laparotomy. The results of ultrasonography and exploratory surgery with regard to the position of the dilated and sometimes retroflexed or twisted caecum were in complete agreement in 18 cases, in partial agreement in eight cases, but in four cases did not agree.     

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.     

Abdominal surgery in foals: a review of 119 cases (1977-1994)

The case records of 119 young horses (all less than age one year) that underwent an exploratory celiotomy during a 17 year period were examined to determine the surgical findings, short- and long-term outcome, and prevalence of small intestinal disease compared to previous reports in the mature horse. Physical and laboratory values were compared for long-term survivors vs. nonsurvivors and the frequency of post operative intra-abdominal adhesions was determined. The most common cause for exploratory celiotomy was small intestinal strangulation, followed by enteritis and uroperitoneum. Six horses died during surgery, 23 were subjected to euthanasia at the time of surgery due to a grave prognosis, and 17 horses died or were destroyed after surgery, prior to discharge from the hospital; the short-term survival was 61%. Nine horses were lost to follow-up. Forty-one horses survived long-term (at least 6 months after surgery), 15 died or were subjected to euthanasia after discharge for reasons related to the prior abdominal surgery, and 8 died or were destroyed after discharge due to unrelated reasons, making the long-term survival 45%. Fifty-three (45%) of the horses presented as neonates, and 66 (55%) presented age 3-12 months. Uroperitoneum and meconium impaction were the most common disease in the neonate. Intussusception and enteritis were the most common diseases in older foals. The overall prevalence of small intestinal disease was 44%. Significant elevations in packed cell volume, heart rate, nucleated cell counts and total protein in abdominal fluid and rectal temperature were observed in nonsurvivors compared to survivors. Nonsurvivors had significantly decreased serum bicarbonate, chloride, sodium, and venous pH values. There was no evidence that location of the lesion affected long-term survival. Horses with a simple obstruction had a higher survival percentage than those with a strangulating obstruction, and horses that underwent an intestinal resection had a lower long-term survival than those horses undergoing only intestinal manipulation. Nineteen (33%) of the foals examined after the original surgery had evidence of intra-abdominal adhesions. Nine of these (16%) had adhesions that caused a clinical problem.     

Surgical Treatment of Gastric Outflow Obstruction in 40 Foals

Objective— To report short- and long-term survival and factors affecting outcome of foals after surgical correction of gastric outflow obstruction.
Study Design— Case series.
Animals— Foals (n=40) aged 5–180 days.
Methods— Clinical signs, laboratory data, diagnostic imaging, surgical findings, surgical procedures, medical treatment, and necropsy findings were retrieved from medical records. Outcome was obtained by reviewing performance, sales, and produce records or by telephone conversations with the owners.
Results— Gastric outflow obstruction was treated by gastroduodenostomy or by gastrojejunostomy with or without jejunojejunostomy. Long-term follow-up was available for 36 of 39 foals that survived to hospital discharge; 25 (69%) survived >2 years. All 8 foals with pyloric obstruction survived >2 years, whereas only 11 of 21 (52%) foals with duodenal obstruction survived >2 years. Six of 8 foals with obstruction of the duodenum and pylorus survived >2 years. Obstruction of the duodenum, adhesions to the duodenum, and postoperative ileus were significantly associated with decreased long-term survival.
Conclusions— Long-term outcome after gastric bypass procedures was substantially improved compared with previous reports. Factors that may have contributed to improved survival include better case selection and performing the gastrojejunostomy with the jejunum aligned from left to right.
Clinical Relevance— The prognosis for long-term survival after surgical bypass of pyloric obstruction is excellent. The overall prognosis for long-term survival after surgical bypass of duodenal obstruction is fair but should be considered guarded in those with pre-existing duodenal adhesions.     

Surface oximetry of healthy and ischemic equine intestine

Measurements of jejunal, ileal, and large colon (pelvic flexure) surface O2 tension (PSO2) were made in halothane-anesthetized horses with a nonheated miniature oxygen polarographic electrode. Assisted ventilation with 100% O2 was used to maintain PaCO2 tension at 50 +/- 8 mm of Hg while mean arterial blood pressure was maintained greater than or equal to 70 mm of Hg. Mean +/- SD PSO2 for the intestinal segments were: jejunum (horses 1 to 4), 71 +/- 20 mm of Hg; ileum (horses 1 to 4), 61 +/- 8 mm of Hg; and pelvic flexure of the large colon (horses 1 to 10), 55 +/- 13 mm of Hg. The response of the sensor to intestinal ischemia was studied in the large colon of an additional 12 halothane-anesthetized horses, using 4 types of vascular occlusion: venous (4 horses); arterial and venous (4 horses); venous and intramural vascular obstruction (2 horses); and arterial, venous, and intramural obstruction (2 horses). Venous and arterial occlusions were maintained for 30, 60, 90, and 120 minutes, whereas intramural obstruction combined with either type of vascular obstruction was studied for 60 to 120 minutes. After vascular occlusion, PSO2 decreased to 8 +/- 7 mm of Hg for venous obstruction, 4 +/- 3 mm of Hg for arterial and venous obstruction, 6 +/- 0 mm of Hg for intramural and venous obstruction, and 3 +/- 0 mm of Hg after intramural and arterial and venous obstruction. Thirty minutes after release of the clamps, the PSO2 increased to greater than or equal to 50% of the preoccluded large colon value.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultrasonographic examination of the caecum and the proximal and spiral ansa of the colon of cattle

The large intestine of 10 cows was examined from the right abdominal wall with a 3.5 MHz linear transducer. The cows were then slaughtered, and the organs were re-examined in a water bath. The caecum was visualised from the middle region of the abdominal wall. It ran caudo-cranially, varied in diameter from 5.2 to 18.0 cm and was situated immediately adjacent to the abdominal wall. The lateral wall of the caecum appeared as a thick, echogenic, crescent-shaped line. It could be visualised as far cranially as the 12th intercostal space. Although its junction could not be identified, the proximal ansa of the colon was recognised on the basis of its anatomical position and its diameter, which was smaller than that of the caecum. The spiral ansa of the colon and the descending colon were situated dorsal to the caecum and could be identified by moving the transducer horizontally along the abdominal wall to the last rib. The spiral ansa of the colon was situated ventral to the descending colon, and its walls appeared as thick echogenic lines. In a contracted state, the spiral colon had the appearance of a garland.     

Clinical and pathologic effects of spiral and total ring prostheses applied to the cervical and thoracic portions of the trachea of dogs

This study compared the short-term clinical and pathologic effects of spiral and total ring prostheses, applied to the cervical and thoracic portions of the trachea of dogs via a combined intercostal thoracotomy and ventral cervical midline approach. The effect of intraluminal placement of synthetic monofilament nonabsorbable suture also was evaluated. Eleven small-breed dogs were randomly allotted to 3 groups. Group 1 (n = 3) were controls that had been treated by sham operation, group 2 (n = 4) had polypropylene spiral prostheses applied to the cervical and thoracic portions of the trachea, and group 3 (n = 3) had total ring prostheses applied to the cervical and thoracic portions of the trachea. All dogs were euthanatized and necropsied 8 weeks after surgery. Clinical complications were minimal and limited to mild, short-term lameness and coughing. Three and 6 weeks after surgery, radiographs were within normal limits in all dogs. Tracheoscopy confirmed maintenance of tracheal lumen diameter and integrity of the mucosal epithelium in all dogs. Gross and microscopic postmortem findings were similar in groups 2 and 3. Mild adhesions were present between prostheses and adjacent structures. Similar adhesions were present where prostheses had been applied and subsequently removed in group-1 dogs. Histopathologic abnormalities included mild to moderate adventitial and periprosthetic fibrosis and mild advential inflammation associated with polypropylene spiral prostheses and total ring prostheses. The majority (70%) of intratracheal sutures evaluated were covered by microscopically normal ciliated mucosal epithelium by 8 weeks after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spiral colon bypass in a geriatric Vietnamese potbellied pig

An 8-year-old potbellied pig was evaluated for anorexia, decreased fecal production, signs of depression, inappetence, and abdominal distension. During hospitalization, a tooth root impaction and abscess were diagnosed, and abdominal radiography revealed severely distended, gas-filled large and small intestines. Exploratory laparotomy revealed a stricture of the proximal centripetal loop of the spiral colon and megacolon of the proximal portion of the spiral colon and cecum. A side-to-side spiral colon anastomosis was performed to create a partial bypass of the spiral colon. The success of this procedure suggests that spiral colon bypass is a treatment option for spiral colon stricture formation in potbellied pigs. Spiral colon stricture formation should be considered as a differential diagnosis in geriatric potbellied pigs that are anorectic, have abdominal distension, and have decreased fecal production.