EQUINE VETERINARY EDUCATION / AE / MAY 2015


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oesophagus such as a vascular ring anomaly, intramural stricture or a functional abnormality. Initial treatment included intravenous isotonic fluids


(lactated Ringer’s solution) with 2.5% dextrose supplementation, ampicillin (20 mg/kg bwt, i.v., t.i.d., Penibrin4), amikacin (22.5 mg/kg bwt, i.v., s.i.d., Amikacin- Fresenius5), ranitidine (6.6 mg/kg bwt, through the feeding tube, t.i.d., Zanidex6) and mare’s milk feeding through the feeding tube. In order to try to facilitate oesophageal relaxation, oxytocin (0.11 u/kg bwt, i.v., b.i.d., Partovet7) and N-butylscopolammonium (0.9 mg/kg bwt, i.v., b.i.d., Buscopan compositum8) were administered for 2 days.


Fig 1: Image from the first endoscopy of the oesophagus, on the day of admission. The stricture site is indicated by the arrow. The abnormal appearance of the proximal oesophagus is clearly demonstrated by the irregular luminal dilation and the absence of the normal longitudinal muscular folds.


Additional tests, further treatment and case progression


Fig 2: Left lateral chest radiograph on the day of admission. The arrows indicate the dilation of the proximal oesophagus. The feeding tube ends at the site of the stricture. Interstitial and alveolar patterns are demonstrated in the cranial and caudodorsal lung fields, indicative of the aspiration pneumonia.


Since the lumen of the oesophagus at the stricture site was almost completely closed (as is evident in Fig 1), endoscopic guidance was necessary to position the feeding tube correctly in the centre of the stricture and eventually the tube was passed through and reached the stomach. Radiopaque contrast material (iohexol 300 g/l, Omnipaque 3003) that was subsequently injected through the feeding tube seemed to flow freely into the stomach. A contrast radiograph of the whole oesophagus was not performed. The initial tentative diagnosis was of congenital oesophageal stenosis or stricture with concurrent proximal nonfunctioning megaoesophagus. The cause for the abnormality was not clear at this point. The main differential diagnosis was external pressure on the


During the first 3 days of hospitalisation, the filly became stronger and more alert; her vital signs were within the normal ranges, but she had profound bruxism and foaming from the mouth and nostrils (regurgitation of saliva) with occasional coughing. On the third day, repeated endoscopy revealed no significant changes compared to the initial examination. The oesophageal dilatation and stricture were still present and a large amount of foamy saliva was present in the proximal oesophagus. An attempt to dilate the stricture with the use of balloon bougienage was made (Dilation Balloon10, balloon diameter 20 mm, length 55 cm, volume 25 ml, catheter diameter 7 French and length 180 cm). This procedure is usually done under general anaesthesia; however, due to concerns with the use of general anaesthesia in light of the severe aspiration pneumonia, the procedure was performed under sedation alone (diazepam 0.1 mg/kg bwt, i.v.; Assival9). The feeding tube was removed before the procedure, after aspiration of most of the saliva that was present in the proximal oesophagus. Under endoscopic guidance, the balloon catheter was inserted into the constricted lumen until the stricture site was located at the centre of the length of the balloon. After positioning of the catheter, the balloon was inflated with saline. Dilatation attempts with the balloon were met with firm resistance at the stricture site and the balloon constantly slipped orally or aborally when distended with saline. The balloon could not be fully distended with the maximum volume of 25 ml, and only 15–20 ml were injected before the balloon would slip out of the stricture site. Due to this problem, the balloon was kept in place for only several seconds at each attempt. Additionally, the insertion of the balloon catheter into the very narrow opening in the stricture was difficult and frustrating at times. This was complicated by the presence of the foamy saliva that could not be aspirated completely and was constantly obscuring the stricture opening and interfering with the positioning of the balloon catheter. Furthermore, the procedure was painful and the filly would move when the balloon was distended. This dilatation attempt was eventually deemed unsuccessful for the most part. The only observed improvement was the ability to pass the scope through the stricture. The stricture seemed to extend for approximately 2 cm and the distal oesophagus and the stomach appeared to be normal with no signs of gastro-oesophageal reflux or ulceration. On the seventh day of hospitalisation a computed tomography (CT) scan was performed under general anaesthesia with the filly positioned in dorsal recumbency. Sequential, 6.5mm slices with 3.5mm slice intervals of the chest were helically acquired with settings of 120 Kvp and 200 mAs. Following an initial survey scan,


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