Management and Complications Associated with Treatment of Cervical Oesophageal Perforations in Horses K
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EQUINE VETERINARY EDUCATION / AE / MAY 2013 247 Original Article Management and complications associated with treatment of cervical oesophageal perforations in horses K. Kruger and J. L. Davis* Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, North Carolina, USA. *Corresponding author email: [email protected] Keywords: horse; oesophageal perforation; enteral nutrition Summary depressed, tachycardic (84 beats/min), tachypnoeic (54 Six horses were evaluated for colic and anorexia, choke or breaths/min) and dehydrated (capillary refill time 3 s, suspected oesophageal rupture with and without tracheal prolonged skin tent). Complete blood count (CBC) revealed laceration. Clinical findings were variable, but a painful leucopenia characterised by neutropenia with a left shift, and ventral neck swelling was noted in all cases. Two of the horses polycythaemia. Serum chemistry revealed hypocalcaemia. had signs of dehydration and sepsis. Additional findings Palpation per rectum and abdominal ultrasound were within included evidence of previous trauma over the trachea and normal limits. A mild swelling was noted on the ventral aspect oesophagus, ventral neck abscessation, choke and aspiration of the neck that was painful to palpation. During ultrasound pneumonia. A diagnosis of oesophageal perforation was and radiography of the neck, gas was evident in the soft made using endoscopy. Two horses were subjected to tissues surrounding the trachea and oesophagus. Endoscopy euthanasia without treatment. All horses where treatment was revealed a 5 cm long full thickness linear perforation of the attempted received debridement of the oesophageal ventral oesophagus in the mid-cervical region. perforation and surrounding tissues with or without surgical Standing surgery was performed under sedation and local closure of the oesophageal defect. Other therapies included anaesthesia. One approximately 10 cm straight incision was broad spectrum antimicrobials, anti-inflammatory drugs, fluid made through the skin using sharp dissection with a number 10 and nutritional support as well as additional therapeutics for blade scalpel. Further blunt dissection was performed through sepsis and individual complications. Complications included the necrotic subcutaneous and deeper tissues down to the site diverticulum formation, thrombophlebitis, diarrhoea, laryngeal of oesophageal rupture on the ventrolateral aspect of the hemiplegia, azotaemia, aspiration pneumonia, oesophageal neck, approximately 3 cm left of the trachea, for debridement obstruction, weight loss and laminitis. All 4 treated horses and lavage. Another approximately 15 cm straight incision recovered from the oesophageal perforation and are was made directly under the initial incision but further ventrally able to eat a normal diet. Two of the 4 horses have had at the level of the thoracic inlet through the skin and infrequent episodes of recurrent choke. Oesophageal rupture subcutaneous tissue to allow continued drainage of blood should be considered as a differential diagnosis for horses with and debris. The oesophageal tear and surgical wounds were a painful swelling of the ventral neck. With surgical left open to heal by second intention. debridement and adequate supportive care, oesophageal The horse was treated with broad spectrum antibiotics perforation cases can have a fair to good long-term survival, (ampicillin, gentamicin and metronidazole), nonsteroidal although chronic complications can occur, therapy is anti-inflammatory drugs (flunixin meglumine) and anti- prolonged, and a significant economic commitment is endotoxaemic drugs (polymyxin B, hyperimmune plasma). required. Replacement and maintenance polyionic crystalloids, with added calcium gluconate, were administered until the horse was able to maintain hydration from oral water intake on Introduction Day 4. Culture of the affected muscle surrounding the Between 2001 and 2012, 6 horses presented to the North oesophageal tear yielded a heavy growth of Pasteurella Carolina State University Veterinary Teaching Hospital (VTH) multocida and Escherichia coli, both of which were sensitive to with oesophageal perforation in the proximal to mid-cervical ampicillin. region (Table 1). The management of 4 of the cases is Over the first 24 h, the horse remained depressed and described in detail below. The remaining 2 cases were uncomfortable. The heart rate increased to 132 beats/min and subjected to euthanasia without treatment, one at the request copious amounts of serum, mucus and saliva drained from the of his owners due to age (29 years) and financial constraints open wounds. Opioid analgesics (butorphanol) were added and the other due to a poor prognosis. This horse had 4 for additional pain control. Wounds were flushed twice daily separate areas of oesophageal ulceration and tears and signs with sterile saline. Despite continued saliva and serum loss, of severe sepsis, as well as a history of repeated choke. serum electrolytes remained within normal limits. Cellulitis became evident in the pectoral area 3 days after Case 1 presentation. The skin and subcutaneous tissues over this area An 11-year-old Tennessee Walking Horse was referred to VTH proceeded to slough, leaving an open, draining wound. In for an 18 h history of anorexia and colic that did not resolve addition, a malodorous infection developed in the tissues with medical therapy administered by the primary deep to the oesophagus. The tissues were debrided and the veterinarian. On presentation, the horse was moderately wounds were subsequently cleaned twice daily and a dilute © 2013 EVJ Ltd 248 EQUINE VETERINARY EDUCATION / AE / MAY 2013 TABLE 1: Summary of cases presented to the North Carolina State University Veterinary Teaching Hospital with a diagnosis of oesophageal rupture Age (years), Days in Complications Complications Case breed, gender Description of rupture hospital (acute) (chronic) Outcome 1 11, Tennessee Walking 5 cm; ventral 30 Endotoxaemia Recurrent choke Survived Horse, gelding oesophagus; Cellulitis mid-cervical 2 1, Quarter Horse, filly 5 cm; ventral 20 Phlebitis Diarrhoea Survived oesophagus; Diarrhoea Left laryngeal mid-cervical Pyrexia hemiplegia Left laryngeal hemiplegia 3 5, Thoroughbred, mare 1 cm; ventral 37 Subcutaneous – Survived oesophagus; proximal emphysema cervical Periesophageal abscess 4 1.5, Tennessee Walking Two 10 cm; ventral 44 Endotoxaemia Recurrent choke Survived Horse, gelding oesophagus; Cellulitis Laminitis mid-cervical Choke Left laryngeal Aspiration pneumonia hemiplegia Left laryngeal hemiplegia Laminitis Azotaemia 5 29, Quarter Horse 2 cm; lateral oesophagus; <1 – – Subjected to gelding proximal, 3–4 cm distal euthanasia to the larynx 6 1.5, Warmblood, 4 cm; dorsal oesophagus; <1 – – Subjected to gelding distal cervical; multiple euthanasia ulcerations present iodine solution was applied. Debridement was performed as complication. The neck wounds were manually cleaned of necessary afterwards until the wounds had healed. food particles twice daily and lavaged with water. Surgical After an initial 48 h of fasting, an indwelling nasogastric gauze soaked in dilute iodine solution was packed into the tube was placed and enteral feeding initiated using high fibre large tissue defect surrounding the oesophageal tear. Pectoral pellets soaked in water with added corn oil. Partial parenteral wounds were cleaned daily with chlorhexidine scrub and nutrition consisting of 8.5% amino acids at 250 ml/h as well as necrotic tissue debrided as needed. Wounds were sprayed 10% dextrose in 0.45% NaCl with 10 ml of vitamin B complex with dilute iodine solution on an hourly basis. By Day 26 the added to each litre at 250 ml/h was also started in addition horse had gained back 55 kg. to the abovementioned fluids and continued for 3 days. Despite maintaining a fairly good attitude, a severe, This was designed to provide an additional 25% of the prolonged, neutropenia with a left shift developed after the horse’s maintenance energy requirements (approximately discontinuation of polymyxin B on Day 21. In addition, 8.25 kcal/kg bwt/day). On Day 5, the nasogastric tube was tachycardia persisted at 60–70 beats/min until Day 25 and only removed because of fears that it might be interfering with decreased to 48–52 beats/min at discharge. These healing of the oesophageal rupture. The horse was offered the abnormalities were attributed to continued endotoxaemia as soaked pelleted feed, which he only ate well for the first 24 h, a result of Gram-negative bacterial sepsis. The neutropenia after which his appetite became poor. Metronidazole resolved by Day 27, but the left shift was present until administration was switched to per rectum at this point. Within discharge. Mild anaemia developed on Day 22, and persisted 36 h, the horse became severely depressed and developed until discharge. a thrombocytopenia. Prothrombin time, activated The contracting external skin incision had to be extended thromboplastin time and fibrinogen degradation products approximately 5 cm on Day 27 to re-establish adequate were within normal limits. A stallion catheter was placed drainage. Excessive granulation tissue was also debrided at through the oesophageal wound into the stomach in order to this time. The horse was discharged on Day 30. His diet administer oral medications. The horse’s attitude and platelet consisted of pellets and 30 min of hand grazing several times a count improved over a period of 48 h. The neutropenia day. Flunixin