456 EQUINE VETERINARY EDUCATION / AE / SEPTEMBER 2013 Original Article Treatment of cervical oesophageal rupture in horses C. M. Whitfield-Cargile*, P. C. Rakestraw† and J. Hardy Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas, USA. *Corresponding author email: [email protected]. Present addresses: *Texas Equine Hospital, 13688 S. State Hwy, 6 Bryan, Texas 77807, USA; and †Dubai Equine Hospital, Dubai, UAE. Keywords: horse; oesophagus; oesophagostomy; cervical fasciotomy Summary (Demoor et al. 1979), damage to the vagosympathetic trunk Oesophageal rupture in horses has only been previously or recurrent laryngeal nerve (Craig et al. 1989), rupture of the described in detail in isolated case reports. The objectives of this common carotid artery (Risnes and Mair 2003), electrolyte study were to describe the clinical findings, specific treatment derangements due to loss of saliva (Stick et al. 1981b), and outcome of oesophageal rupture in horses. Medical endotoxaemia and peritonitis (Hardy et al. 1992) and records of horses diagnosed with oesophageal rupture development of nonhealing oesophageal fistulas (Craig et al. between 1994–2008 were reviewed. Clinical findings, treatment 1989). and outcome were recorded. Seven horses with cervical There have previously been isolated case reports of oesophageal perforations were included in the study. Two oesophageal ruptures in horses (Raker and Sayers 1958; horses were subjected to euthanasia without treatment and 5 Demoor et al. 1979; Wingfield-Digby and Burguez 1982; Lunn were treated surgically. Treatment involved a fasciotomy of and Peel 1985; Dechant et al. 1998; Read et al. 2002; Risnes the cervical musculature and oesophageal tube placement. and Mair 2003) and one report of 61 horses with oesophageal Three of 5 horses survived long-term (>one year). Our study disorders (Craig et al. 1989) that briefly describe treatment. To showed that surgical treatment of cervical oesophageal the authors’ knowledge, there are no published reports rupture involving fasciotomy and oesophagostomy tube detailing the clinical signs, diagnosis, treatment and outcome placement can be successful with 3/5 of treated horses of horses with cervical oesophageal rupture. The objectives of surviving more than one year. this paper were to describe the clinical findings, complications, treatment and outcome of horses with cervical oesophageal rupture. Introduction Rupture of the oesophagus in horses is an uncommonly Materials and methods encountered disorder (Risnes and Mair 2003) usually The records of all horses that presented to Texas A&M associated with a poor prognosis (Lane 2002). Causes of Veterinary Medical Teaching Hospital between April 1994 and oesophageal rupture include external trauma (Lunn and Peel January 2008 were reviewed. Horses of all ages were included 1985), nasogastric intubation (Hardy et al. 1992), perforation of in this study if a clinical diagnosis of ruptured cervical chronic oesophageal ulcers (Dechant et al. 1998), extension oesophagus was made and confirmed by surgical exploration of surrounding infection and mural necrosis secondary to of the affected area or by necropsy. Horses were excluded long-standing oesophageal obstructions (Craig et al. 1989; from this study if the oesophagus ruptured secondary to a Read et al. 2002). Treatment of oesophageal rupture varies surgical procedure, if the clinical diagnosis was not confirmed and depends on the location and extent of the perforation, by necropsy or surgical evaluation, or if the ruptured portion of the duration of perforation and the degree of surrounding the oesophagus was in the thorax. infection. In one report examining 61 cases of oesophageal disorders in horses, 11 of which were oesophageal ruptures, Data collection medical management resulted in a survival rate of 0% (0 of 7) Information obtained from the medical records included while surgical management resulted in a 50% (2 of 4) survival case details, history, physical examination findings upon rate; therefore, the authors concluded that surgical presentation, diagnostics, treatment and outcome. management was preferable (Craig et al. 1989). Surgical Information obtained from the history included, cause of the treatment consists of primary closure if there is minimal rupture, duration of any oesophageal obstruction and contamination of the tissues (Stick 2006). This technique has treatment prior to arrival at the referral clinic. Information previously been used successfully (Demoor et al. 1979; obtained upon presentation included physical examination Wingfield-Digby and Burguez 1982). However, minimal abnormalities, findings of oesophageal endoscopic contamination of the surrounding soft tissues is unlikely examination, radiographic findings of the oesophageal region following a rupture of the oesophagus making primary closure and thorax, treatment, surgical findings, complications, unlikely to be successful. In these cases, ventral drainage of outcome and necropsy findings. the affected area, antimicrobials and oesophageal rest is Long-term outcome of at least one year was obtained by recommended to allow the oesophagus to heal by second telephone interview with the owner or referring veterinarian or intention (Craig et al. 1989; Fubini 2002). by re-evaluation at the clinic. Outcome was considered Complications associated with rupture of the oesophagus successful if the horse was discharged from the hospital and in horses include extension of the infection to the thorax resumed a normal lifestyle. © 2013 EVJ Ltd EQUINE VETERINARY EDUCATION / AE / SEPTEMBER 2013 457 Technique of fasciotomy and oesophagostomy tube placement Prior to surgical drainage and debridement, all horses were administered nonsteroidal anti-inflammatory drugs (flunixin meglumine 1.1 mg/kg bwt i.v.), broad-spectrum antimicrobials (procaine penicillin G 22,000 iu/kg bwt i.m., gentamicin 6.6 mg/kg bwt i.v.) and tetanus toxoid (1 ml i.m. once). Horses were sedated with detomidine (0.01–0.04 mg/kg bwt i.v.) and butorphanol (0.01–0.02 mg/kg bwt i.v.). Local anaesthesia was achieved by infiltrating 10–20 ml of mepivacaine over the palpable areas of cellulitis and fluid accumulation beneath the skin, usually on the ventral midline of the neck or ventral to the jugular vein. Skin incisions of appropriate lengths to allow adequate drainage were made over the area of palpable cellulitis and oedema. Blunt dissection was continued deeper between the sternocephalicus and jugular vein to allow adequate access to the contaminated areas. All feed material was flushed from the neck and necrotic tissue debrided as needed. Dissection and debridement were performed Fig 1: Exteriorised oesophagus incised prior to oesophagostomy diligently avoiding the carotid artery, vagosympathetic trunk tube placement. and recurrent laryngeal nerve. Throughout the course of hospitalisation, the procedure was repeated as needed to further debride the necrotic tissues or to allow access to developing pockets of cellulitis and infection. An oesophagostomy tube was placed concurrently with fasciotomy and debridement. A nasogastric tube was passed into the stomach preoperatively, once any obstruction had been resolved, to aid in identification of the oesophagus. Local anaesthesia was achieved with 5–10 ml of mepivacaine infiltrated for a distance of 4–8 cm just ventral to the left jugular vein. The location of this block depended on the location of the rupture but was usually at the junction of the middle and distal thirds of the neck or 5–10 cm distal (caudal) to the area of rupture. If the oesophageal defect was located too far distally (caudally) to have space to perform an oesophagostomy, then the oesophageal tube was placed in the oesophagus through the existing wound. A 6 cm skin incision was made just ventral and parallel to the jugular vein. The sternocephalicus and brachicephalicus muscles were identified and bluntly separated to expose the deep cervical Fig 2: Patient with oesophagostomy tube in place distal to site of fascia. The oesophagus, located deep to the cervical fascia rupture. over the dorsolateral aspect of the trachea, was exposed by a combination of sharp and blunt dissection being careful to avoid the common carotid artery, vagosympathetic trunk and the neck and suturing it to the skin with the use of several recurrent laryngeal nerve. Once the oesophagus was located, butterfly bandages constructed from tape (see Fig 2). The end it was gently elevated to the incision using blunt dissection. A of the tube was capped with a 3 cc syringe case to prevent air 0.635 cm penrose drain was passed around the oesophagus from entering the tube. The oesophagostomy tube was not and used as a retractor. A 3 cm full thickness longitudinal directly secured to the oesophagus at the oesophagotomy oesophageal incision was made using the previously placed site in order to preserve the integrity of the oesophageal nasogastric tube as a guide. If a nasogastric tube was unable musculature and vascular supply at the oesophagostomy site. to be passed due to concurrent obstruction, the muscularis of the oesophagus was incised and the submucosa and mucosa Post operative care grasped with tissue forceps and elevated out of the incision in Diet consisted of a commercially available complete pelleted the muscularis and a 3 cm incision made longitudinally feed (Equine Senior)1 soaked in water and made into a slurry through the submucosa and mucosa to enter