Treatment of Equine Gastric Impaction by Gastrotomy R

EQUINE VETERINARY EDUCATION / AE / april 2011 169

Case Reporteve_165 169..173 Treatment of equine gastric impaction by gastrotomy R. A. Parker*, E. D. Barr† and P. M. Dixon Dick Vet Equine Hospital, University of Edinburgh, Easter Bush Veterinary Centre, Midlothian; and †Bell Equine Veterinary Clinic, Mereworth, UK.

Keywords: horse; colic; gastric impaction; gastrotomy

Summary Edinburgh with a deep traumatic shoulder wound of 24 h duration. Examination showed a mildly contaminated, A 6-year-old Warmblood gelding was referred for treatment of 15 cm long wound over the cranial aspect of the left a traumatic shoulder wound and while hospitalised developed scapula that transected the brachiocephalicus muscle a large gastric impaction which was unresponsive to and extended to the jugular groove. The horse was sound medical management. Gastrotomy as a treatment for gastric at the walk and ultrasonography showed no abnormalities impactions is rarely attempted in adult horses due to the of the bicipital bursa. limited surgical access to the stomach. This report describes The wound was debrided and lavaged under standing the successful surgical treatment of the impaction by sedation and partially closed with 2 layers of 3 metric gastrotomy and management of the post operative polyglactin 910 (Vicryl)1 sutures in the musculature and complications encountered. simple interrupted polypropylene (Prolene)1 skin sutures, leaving some ventral wound drainage. Sodium benzyl Introduction penicillin/Crystapen)2 (6 g i.v. q. 8 h), gentamicin (Gentaject)3 (6.6 mg/kg bwt i.v. q. 24 h), flunixin 4 Gastric impactions are rare in horses but, when meglumine (Flunixin) (1.1 mg/kg bwt i.v. q. 12 h) and 5 encountered, may carry a grave prognosis. Medical tetanus antitoxin (7500 iu subcut) were administered and management is the preferred first line therapy and involves the horse admitted for observation. gastric lavage via nasogastric tube (Barclay et al. 1982). Approximately 24 h later, signs of colic were noted This technique may be unsuccessful in more severe cases consisting of the horse spending long periods in lateral prompting the use of surgical methods such as transgastric recumbency and faecal output was reduced. The horse lavage and massage during laparotomy (Honnas and was quiet, alert and responsive with a heart rate of 40 Schumacher 1985). Gastrotomy as a treatment for gastric beats/min, respiratory rate 12 breaths/min and rectal 6 impactions is described in foals (Blikslager and Wilson 2006; temperature 37.8°C. Hyoscine butylbromide (Buscopan) Coleman et al. 2009) and smaller breeds (Clayton-Jones (80 mg i.v.) was administered to aid rectal examination et al. 1972; Owen et al. 1987) while discrete Persimmon which revealed formed faeces in the rectum and marked concretions have also been successfully removed via caudal and ventral displacement of the spleen which lay gastrotomy (Kellam et al. 2000). Removal of large immediately cranial to the pelvic brim. Passage of a impactions is rarely attempted in larger adult horses due to nasogastric tube yielded no reflux and 5 l of electrolytes the limited surgical access to the stomach. This report were administered. Food was withheld and the previously describes the successful surgical treatment of a large described antimicrobial therapy was continued along with gastric impaction in a large breed of horse by gastrotomy flunixin meglumine (1.1 mg/kg bwt i.v. q. 24 h). and the post surgical complications encountered. By the following day there was little change in clinical parameters and gastroscopy identified a large mass of Case report impacted food material in the stomach. Transabdominal ultrasonography revealed the stomach wall to be visible History and case details over a greater number of intercostal spaces than normal and the spleen to be displaced ventrally and caudally. A 6-year-old Warmblood gelding, weighing 552 kg, Using a nonfenestrated nasogastric tube and a stomach presented to the Dick Vet Equine Hospital, University of pump, the stomach was repeatedly lavaged with warm water in an attempt to soften and remove the impacted *Corresponding author email: [email protected] material via the nasogastric tube but little gastric contents

were retrieved by this method. The horse was kept on wood shavings (its usual bedding material), allowed ad libitum water and starved in an attempt to allow the impacted material to be passed into the intestines. The horse remained bright throughout a period of complete starvation for 7 days during which time a muzzle was placed as it was noted that the horse was consuming shavings. After 7 days, trickle feeding of haylage (approximately 0.5 kg q. 4 h) was introduced. Mild colic signs persisted, including occasional periods of lateral recumbency and teeth grinding. Intestinal sounds remained normal or mildly reduced in all quadrants. Haematology and clinical chemistry examinations 4 days post admission were within normal limits. Repeated gastroscopy and gastric lavage under mild sedation with romifidine (Sedivet)6 (20 mg i.v.) was performed at 2 day intervals during the 11 day period but retrieved little solid material; 5 l of oral electrolytes were administered after each lavage. Visual inspection by gastroscopy revealed no change in the consistency of the stomach contents Fig 1: Visualisation of the enlarged stomach (black arrow) protruding to the level of the laparotomy incision. The edge of the while daily ultrasonography revealed no obvious change spleen can be seen caudal to the stomach (white arrow). in the size of the impaction. Faecal output was reduced with intermittent scant soft faeces passed. During this period, the shoulder wound initially developed some local emphysema and drainage but then healed well with antimicrobial therapy being discontinued after 7 days.

Treatment and outcome

Because of the failure of the gastric impaction to respond to medical treatment along with continued signs of abdominal pain, surgical evacuation of the stomach was attempted on Day 13 of hospitalisation. Sodium benzyl penicillin, gentamicin and metronidazole7 (15 mg/kg bwt per os q. 8 h) were administered prior to surgery. Following premedication with romifidine (Sedivet) (0.1 mg/kg bwt i.v.), general anaesthesia was induced with ketamine (Vetalar)8 (2.2 mg/kg bwt i.v.) and diazepam9 (100 mg/kg bwt i.v.) and maintained with inhaled sevofluorane 10 11 (Sevoflo) ; morphine sulphate (120 mg i.v.) was also Fig 2: Four partial thickness Polyglactin stay sutures have been administered as analgesia during surgery. The animal was placed in the greater curvature of the stomach to allow later placed in dorsal recumbency and a midline laparotomy elevation of the gastrotomy wound edges. made originating just caudal to the xiphoid process and extending approximately 30 cm caudally. The enlarged 15 cm linear gastrotomy incision created, exposing the stomach (c. 60 cm diameter) and spleen were gastric contents that consisted of slightly moist wood immediately visualised (Fig 1) and routine exploration of shavings overlying dry masticated forage. Initial attempts the remaining abdominal contents was unremarkable. to manually remove the contents showed them to be Four 4 metric Polyglactin 910 stay sutures with a 2–3 cm loose and they fell apart during removal, causing some bite were placed c. 10 cm apart and also c.10cmon contamination of the immediate surgical area including each side of the proposed gastrotomy incision site on the the loose packing drapes and exposed serosa. greater curvature where the distended stomach was In order to minimise further contamination, 2 closest to the laparotomy incision (Fig 2). The stay sutures overlapping saline soaked drapes were placed 10 cm were placed through the serosa, muscularis and within the gastrotomy site to form a funnel and kept in submucosa of the greater curvature of the stomach to position with simple transfixing sutures through the drapes later allow elevation of the edges of the gastrotomy site and stomach wall. The other ends of these drapes lay and help reduce abdominal contamination. The outside the laparotomy incision on the edge of the surrounding area was packed with sterile drapes and a abdomen. The stomach contents were then manually

at the hospital post small intestinal enterotomy, followed by the introduction of small soft oat breakfast cereal feeds offered every 4 h for 24 h. Soaked grass nuts were then introduced every 4 h for a further 48 h prior to the introduction of increasing amounts of haylage reaching normal levels at 6 days post operatively. A variety of clinical complications were evident in the immediate and later post operative period. Colic signs were not seen post operatively but at 24 h the horse was quiet and displayed mild bruxism. Three days post operatively, the horse developed pyrexia (39.2°C) and increased digital pulses in all 4 feet and infection was noted at the cranial aspect of the laparotomy incision with serosanguinous discharge and diffuse, painful ventral oedema. Abdominal ultrasonography revealed small pockets of turbid fluid within the abdomen consistent with Fig 3: Impacted ingesta consisting of wood shavings and semi-dry peritonitis; abdominal paracentesis was not performed. forage recovered during gastrotomy. Gut sounds remained good throughout this period and the pyrexia had fully resolved by 8 days with the horse removed in large handfuls and any dropped contents becoming brighter. were prevented from contaminating the abdomen by the Further post operative complications included heat drapes. Deeper in the stomach, a full arm length was and swelling at the jugular catheter site (10 days post needed to remove the contents. A total of 25 kg of operatively), diarrhoea and pyrexia (12 days post impacted ingesta (Fig 3) was removed. operatively) and facial swelling (16 days post operatively). Following removal of the impacted material, the 2 Ultrasonography of both jugular veins at 10 days revealed internal drapes were removed and the gastric incision them to be patent with no thrombophlebitis; the swelling closed with a double layer of Cushing’s suture pattern, was present in the subcutaneous tissue. The catheter was using 4 metric Polyglactin 910. Following removal of the subsequently removed and bacterial culture of its tip external packing around the stomach the external drapes produced no growth. Following removal of the jugular were left in place but both surgeons changed gloves and catheter, as a precaution, antimicrobial therapy of oral gowns before the gastrotomy site and abdomen were metronidazole (at previous dose) and procaine penicillin lavaged with lactated Ringer’s solution. A new pack of (Depocillin)5 (22,000 iu/kg bwt i.m. q. 12 h) was continued, instruments was opened prior to the placement of 2 along with phenylbutazone (Equipalazone)14 (1 g per os q. paramedian, active closed intra-abdominal drains 5 cm 12 h) until 15 days post operatively. Faecal culture at 12 lateral to the midpoint of the midline incision (Nieto et al. days was negative for Salmonella sp.; haematology 2003). The laparotomy incision was closed using a simple revealed a mildly raised leucocyte count (15.5 ¥ 109 cells/l, continuous suture pattern of 5 metric braided lactomer 92% neutrophils) and both the diarrhoea and pyrexia (Polysorb)12 in the linea alba followed by 4 metric resolved within 48 h without additional treatment. Polyglactin 910 subcutaneous sutures and 4 metric Antimicrobial therapy with ceftiofur sodium (Excenel)8 polypropylene in a forward interlocking suture pattern skin (2 mg/kg bwt i.m. q. 12 h) and metronidazole along with sutures. A sterile stent was sutured to the wound and flunixin phenylbutazone (1 g per os q. 12 h) was resumed at 17 days meglumine (1.1 mg/kg bwt i.v.) and Polymixin B13 in response to the facial swelling. Repeat ultrasonography (5000 iu/kg bwt i.v.) were administered. Total surgery time of both jugular veins revealed no thrombus and the facial was 130 min. swelling resolved completely within 72 h. Ceftiofur sodium Recovery was uneventful, with the exception of minor and metronidazole administration were stopped after 5 corneal ulceration of the right eye that was successfully days and enrofloxacin (Baytril)15 (5 mg/kg bwt per os q. treated with topical antibiotics over the following 10 days. 24 h) administered. The horse was discharged 35 days after Post operative care included abdominal lavage with 20 l initial admission on a continuing course of enrofloxacin and of warmed sterile lactated Ringer’s solution infused into the phenylbutazone (1g per os q. 12 h) for a further 14 days. ventral abdominal drains at 6, 18, 36 and 48 h post The shoulder wound had healed completely during operatively followed by removal of the drains. A further 2 hospitalisation. Minor discharge was still present from the doses of Polymixin B were administered at 8 and 16 h post caudal aspect of the laparotomy wound at discharge operatively and the horse continued to receive i.v. sodium from the hospital; this had healed fully without further benzyl penicillin, gentamicin, flunixin meglumine and oral complication at re-examination 21 days later. metronidazole at the previous dosage until removal of the A telephone conversation with the owner 42 months jugular catheter at 10 days post surgery. Feed was withheld post operatively revealed that the horse was well and had in the initial 48 h post operatively as was standard practice shown no further signs of colic since discharge.

Discussion Surgical treatment of gastric impaction via laparotomy has been well described in foals with gastric outflow Gastric impaction, although rare, presents as a significant obstruction (Blikslager and Wilson 2006; Coleman et al. cause of morbidity and mortality in equine patients. The 2009). In adult horses, however, due to limited surgical aetiopathogenesis of the disorder is often obscure but may access to the stomach and the high potential for be due to primary conditions affecting only the stomach abdominal contamination and post operative peritonitis, a or secondary to diseases affecting other areas of the surgical approach is more rarely adopted. Some authors gastrointestinal tract and/or other body systems. Primary have advocated the use of transgastric lavage and causes include intrinsic ones such as motility dysfunction, softening of the impaction (Honnas and Schumacher 1985; defective gastric secretion or pyloric stricture (Barclay Blikslager 2005) but, if unsuccessful, this may necessitate a et al. 1982; Cummings et al. 1997) or extrinsic causes second surgery to perform gastrotomy. This technique was including poor dentition, foreign bodies, reduced water not performed in the current case due to the failure of intake or the ingestion of material which may swell in the repeated nasogastric lavage. Gastrotomy and removal of stomach (Sanchez 2004). Gastric impaction may also impacted ingesta has been reported in 2 adult ponies occur secondary to conditions such as equine grass (Owen et al. 1987) but this report did not detail any specific sickness and hepatic disease with up to 20% of the latter methods used to reduce abdominal contamination or cases presenting with this disorder (Milne et al. 1990; manage post operative complications. McGorum et al. 1999). The cause of the impaction in the A surgical approach was adopted in this case due to current case, as in many encountered in hospitalised the lack of response to medical therapy. Although it is patients, was not clear although the administration of possible that more aggressive medical therapy in the nonsteroidal anti-inflammatory medication and sedation early stages of the disease using carbonated soft drinks or may have altered gastric motility. DSS may have negated the need for surgery, the authors Detection of gastric impactions can be problematic think this unlikely given the chronic nature of the due to the nonspecific signs of this disorder which vary from impaction and the likelihood that there was a significant mild discomfort and inappetance to severe abdominal degree of gastric atony associated with the distension. pain coupled with the low prevalence of the condition. The large size of the impaction facilitated the surgical Similar to caecal or pelvic flexure impactions, this condition approach by bringing the gastric serosa close to the may develop in hospitalised horses being treated for other cranial abdominal wall. Stay sutures to maintain elevation disorders, lowering the suspicion that a concurrent gastric of the incised stomach wall close to the abdominal abnormality is present. A definitive diagnosis of equine incision were helpful in reducing abdominal gastric impaction is usually made during exploratory contamination. Furthermore, the use of a funnel of laparotomy in acute surgical colic cases or by using moistened drapes sutured within the stomach greatly gastroscopy and ultrasonography in chronic cases reduced the intra-abdominal spillage of gastric contents. (Fontaine et al. 1999; Blikslager 2005). As in this case, A similar technique involving a bag sutured externally to abnormal positioning of the spleen on rectal examination is the serosa was found to help reduce contamination also suggestive of a gastric distension due to the close during caecal amputation in cases of caecocolic apposition of the spleen and stomach. intussusception (Hubert et al. 2000). The earlier use of this Once detected, medical management is often the first technique may have prevented or greatly reduced the line of therapy for gastric impaction and may be successful intra-abdominal contamination that did occur, although in mild cases. As in the current case, food is withheld and it is recognised that some degree of abdominal gastric lavage carried out via a nasogastric tube in an contamination is inevitable with such surgery. attempt to soften the ingesta and allow reflux of the liquid Post operative intra-abdominal lavage was used in this (Barclay et al. 1982). Rodriguez-Hurtado et al. (2007) case in an effort to minimise the likelihood of septic described the use of a carbonated drink to aid medical peritonitis. Although there is debate over the efficacy of resolution of a persimmon bezoar causing gastric peritoneal lavage in the treatment of equine peritonitis impaction. This technique has been successful in man (Hawkins et al. 1993; Nieto et al. 2003; Mair and Smith 2005), (Ladas et al. 2002) and the beneficial effects were thought in cases where there is a high risk of contamination post to be a combination of the acidifying and carbonating enterotomy, lavage is likely to be useful as has been found effects of the beverage. Others have suggested the use of in the treatment of human diverticulitis and peritonitis compounds such as Dioctyl Sodium Sulphosuccinate (DSS) (Alamili et al. 2009). Peritonitis developed in this case to break down the impaction and facilitate its removal by despite lavage, possibly due to the level of contamination stomach tube (Murray 2002). This conservative approach experienced during surgery. may however be unsuccessful if the impaction is large, Other complications experienced in this case were long-standing or the material is not water soluble. Any cases jugular thrombophlebitis and diarrhoea. Mair and Smith undergoing medical management should be closely (2005) reported jugular thrombophlebitis in 8.3% of surgical monitored for deterioration of clinical signs, since gastric colic cases with increased incidence in horses that rupture is a life threatening sequel (Cummings et al. 1997). experienced post operative colic signs and shock. Horses

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