Vascular Ring Anomaly

Rachelle has been asking me to blog since she started blogging and I've yet to do so. So for the 7 of you out there who might read this, here it is: a post about a case I saw today, structured in the way I try to think when I approach a "work up". It's a very interesting case and an easy diagnosis to make if you know to look for it. It is also rare, I may never see one of these again in my career. My boss has been practicing for 40 years and has never diagnosed one. The owners sound like they will perform the surgical correction, they are taking some time to think about it. I hope they choose to do the surgery, I am very excited to cut this one if they'll let me.

Patient: 8 week old male sled dog pup

Chief Complaint: Since weaning he can't hold any food down. He eats vigorously and almost immediately afterward the food passively comes back up, which he then eats again, and the process repeats itself.

Physical exam: BAR, temp. 100.1, pulse 100 bpm, no murmurs, regular rhythm, lungs auscult clear, mm pink, body condition score 3/9, both testes descended, no abdominal hernias palpable, normal bite occlusion, oral palate normal.

Problem list: Regurgitation (this is not the same as vomiting), thin body condition.

Specific rule outs: Congenital megaesophagus, congenital esophageal stricture, vascular ring anomaly, hiatal hernia, pericardio-peritoneal diaphragmatic hernia, dysphagia, achalasia, gastrointestinal parasites.

First line diagnostics: Offer food and observe.

Assessment: Pup eats ravenously, swallows fine, immediately seems uncomfortable, within 1 minute regurgitates all food.

Second line diagnostics: Radiographs, contrast esophagram with barium.

Assessment of radiographs: Esophageal stricture at heart base, dilated esophagus cranial to stricture, cardiac silhouette wnl, lung fields clear, no evidence of aspiration pneumonia.

Diagnosis: Vascular Ring Anomaly. There are multiple types of vascular ring anomalies described, by far the most common is a persistent 4th right aortic arch.

Plan: Preanesthetic bloodwork and surgery, left 4th intercostal thoracotomy, ligation and transection of the ligamentum arteriosum. Feed high calorie gruel while holding pup upright until day of surgery.

Prognosis: Good to excellent given that there don't appear to be any other congenital defects or secondary aspiration pneumonia.

So there it is, a blog. If interested in pictures and a description of the condition, see this link.

Hope you found this interesting,

Sam Smith, DVM