“Lewis Hamilton” a 5 month male Maine Coon cat was referred to Northwest Veterinary Specialists from his primary care practice for further investigations into regurgitating his food after eating.
Lewis came to see one of our Soft Tissue Surgery Specialists Rachel Burrow. On his examination Lewis was very well in himself, in good body condition and very active, as to be expected with his young age.
His referring veterinary practice had taken some general radiographs (x-rays) of his chest and also performed a barium swallow radiographic study where a contrast material is given orally highlighting the oesophagus.
This procedure demonstrated Lewis had a dilation in his oesophagus in front of his heart which is commonly known as a megaoesophagus.
The suspected diagnosis for Lewis was a Persistent Right Aortic Arch but this needed to be confirmed via a Computed Tomography (CT) Scan first.
Lewis was admitted to the hospital the same day and an intravenous cannula was placed and blood samples were taken to check Lewis’s liver and kidney function prior to his anaesthetic procedure.
To perform a CT scan of Lewis’s chest cavity, a full general anaesthetic was required and this was not without risks. Due to Lewis’s history of regurgitating, he had an increased risk that he may regurgitate food material from his oesophagus and aspirate some of this material into his lungs which could result in pneumonia. He was also at risk of hypoglycaemia (low blood sugar) due to his young age. Both of these complications can potentially be fatal if unnoticed.
Luckily here at Northwest Veterinary Specialists we have a team of specialist Veterinary Anaesthetists that work closely with our Registered Veterinary Nurses (RVN) to provide “gold standard” care to all of our patients.
The CT images were analysed and confirmed the suspected diagnosis of Persistent Right Aortic 4th Arch, and after a discussion between Lewis’s owner and Rachel Burrow, it was decided that Lewis would be taken to theatre the following day for open chest surgery (thoracotomy) to correct the problem.
A Persistent Right Aortic Arch is a developmental abnormality that occurs due to abnormal blood vessel development in the foetus. This results in a blood vessel encircling the oesophagus (and sometimes the trachea too) near the heart and compresses these structures resulting in difficulty of passage of food through the obstruction into the stomach. In some cases breathing difficulties can be seen but this was luckily not seen in Lewis’s case.
The following morning Lewis was taken upstairs to our theatre suites and placed in a warm ward area while our team of surgical nurses and veterinary anaesthetists prepared for his procedure and general anaesthetic.
A thoracotomy (opening into the chest via surgery) is a painful procedure so a pain plan was discussed and implemented to provide sufficient pain control before, during and after the surgery ensuring Lewis remained as comfortable as possible. Lewis received a schedule 2 opioid (one of the strongest available for small animals in the UK) along with a sedative. He also received a local anaesthetic agent that was infiltrated around the surgery site before Rachel Burrow began his surgery. Lewis was placed on a mechanical ventilator to breathe for him during the operation and was carefully monitored throughout.
Rachel Burrow opened the chest wall and began the hour long procedure of dissecting away the left ligament arteriosum (the abnormal vessel) from the oesophagus. A tube was then placed into the oesophagus and slowly passed down to ensure there was sufficient dilation for food to pass through with ease.
Once the surgery was completed and Lewis’s chest was closed, a drain was placed into the chest cavity near the surgical site for drainage of any air or fluid build-up and to instil further pain relief agents to ensure a comfortable recovery for Lewis. He was then transferred into our recovery ward for further monitoring of his breathing and blood glucose along with regular assessments of his pain levels.
Lewis was exceptionally comfortable after his operation and was back to playing with one of his toys just 3 hours later! The drain in his chest was removed and he was discharged from the hospital 2 days later with guidelines for Lewis to be fed small amounts of soft food often.
Lewis returned to us 8 weeks later looking exceptionally well. He had grown in height and weight and is no longer having any problems with eating or with regurgitation. Rachel carried out a fluoroscopy examination to determine if he had any remaining problems with his oesophagus. This procedure involves feeding Lewis a barium (contrast) coated meal whilst at the same time, taking a live images similar to an X-ray using a special piece of highly technical equipment called fluoroscopy. The images were then assessed by Rachel, which highlighted the food moving through his oesophagus as expected. Lewis had this procedure performed whilst he was conscious and he was able to go home a couple of hours later and has now been completely discharged from the hospital. This is great news for Lewis and his family and a successful and interesting case for us all here at Northwest Veterinary Specialists!
This case report was written by Michelle Moran RVN.