Case: Thoracotomy for a vascular ring anomaly in a puppy
9th March 2014
Charlie, an 8 week old Labrador puppy presented with a history of regurgitation and vomiting once he made the change from liquid to solid food intake. Radiographs from the referring vet showed megaoesophagus (a dilated food filled oesophagus) forwards of the heart base. This history and radiographic finding was very suggestive of a vascular ring anomaly, where aberrant anatomy of the major blood vessels above the heart cause an encircling of the oesophagus which prevents food from passing down it to the stomach. Liquids can get through for larger boluses of food can’t and get regurgitated. There is a real risk that this regurgitated food can then be aspirated (inhaled into the airway) leading to aspiration pneumonia. Charlie was very bright at presentation and the appearance of his lungs on his chest x-rays was reasonable, but increased chest noise suggested some aspiration pneumonia was present. The difficulty in food getting to the stomach and the intestines makes malnutrition a real concern in these cases.
We passed an endoscope down Charlie’s oesophagus and confirmed megaoesophagus “upstream” of the level of the heart. The scope wouldn’t pass further.
A left sided intercostal thoracotomy (surgical approach into the chest between the ribs) was made and dissection revealed that the aorta was on the right side of the chest, not the left where it should have been. A blood vessel that should have closed down at the time of birth was still patent, and was pinching the oesophagus. This was ligated and cut to release the pressure on the oesophagus. A tube could now easily be passed down the oesophagus into the stomach. There was serious blood loss during this part of the procedure and a transfusion was required.
Charlie required close supervision in hospital for a few days post-operatively and he was fed via a gastrostomy feeding tube (a tube that passes directly into his stomach through the left body wall just behind the last left rib). He made excellent progress in the early post-operative period. Once he was stable, he was discharged for his owners to continue with the tube feeding, and for continued antibiotic and analgesic drug administration via the tube.
We weren’t sure to what degree, if any, his oesophagus would recover. Often the stretched part of the oesophagus never recovers properly and remains flabby, stretched, and unable to close around food particles and propel them downwards towards the stomach. We warned the owners that he was not yet “out of the woods”. Charlie would likely need long term management for megaoesophagus which requires feeding small meals regularly from a height to use gravity to assist the passage of food down the oesophagus.
Tiny amounts of food were offered by mouth a couple of weeks post-operatively, with the pup restrained in a “head-up” position. Sadly there were respiratory complications a few days later and Charlie succumbed to these. It was a very sad outcome for what had been a very satisfyingly successful case up to that point.