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Shouldn't Have Put A Ring On It...

In honor of my dog Tommy's 10th birthday, I will let you in on a secret that not everyone knows..... Tommy was born with a congenital vascular ring anomaly meaning he was born with abnormal blood vessel remnants in his chest that led to encircling or entrapment of vital structures. This was the reason he came into my life in the first place - he was abandoned at the shelter at approximately 5 weeks of age because of frequent regurgitation.

Let me explain this more clearly...

Tommy was born with a condition called a Persistent Right Aortic Arch (PRAA), a type of vascular ring anomaly seen in dogs and rarely cats and other animal species. Most people are familiar with the aorta which is the major artery that leaves the heart to supply oxygenated blood to rest of the body. The aorta comes off the left side of the heart and makes a beautiful arch as it makes its initial exit from the heart. Well what if I told you that in-utero, we have both a left aorta with an arch and a mirror image of it to the right? Don't believe me? Well it's true! As we develop, the right arch should regress, and any branches that come after the arch, which are already plugged into the right heart, become smaller diameter blood vessels such as the right subclavian artery that feeds the right arm/forelimb. This is very simplistic as there are multiple paired aortic arches present in the fetus that undergo a coordinated effort to either persist, regress, and/or combine with other arches and vessels to form the blood vessels we all know and need.

In patients with a persistent right aortic arch, the persistent arch along with another blood vessel that has been forced to cross midline in an attempt to send blood to or receive blood from the arch, make up the encircling "ring." Fortunately, the vessel crossing midline either closes completely after birth forming a "ligamentum" or it stays open as a small bore artery where there is typically collateral circulation. This will be important to remember when it comes to treatment for this condition. Yet again I am simplifying things here as there are nine types of persistent aortic arch + ligamentum/vessel combos and they don't all lead to entrapment, however, the most common types do, and this was the case with Tommy.

Typically patients with a persistent right aortic arch have regurgitation as their primary symptom. This is due to entrapment of the esophagus at the level of the base of the heart where the aorta we all know arises from. Aspiration pneumonia can develop from a patient inhaling these contents and lead to additional symptoms such as fever, labored breathing, coughing, decreased or lack of appetite, weakness, lethargy, etc.

Diagnosis of this condition often involves visualization of a dilated esophagus from the throat/neck to the level of the base of the heart typically with radiographs/X-rays. This suggests that something outside of the esophagus is causing an obstruction due to entrapment. This differs from the diagnosis of megaesophagus which involves visualizing a diffusely dilated esophagus from the throat/neck to the stomach, which is due to by a motility disorder of the esophagus. Endoscopy, fluoroscopy, CT, and MRI can also be used for diagnostic purposes and have varying abilities to help diagnose, confirm the diagnosis, and even pin-point the exact type and origin of the vascular ring anomaly.

The treatment is always surgical for these patients. Surgery involves ligating the ligamentum or small bore artery to essentially open the "ring" so that the esophagus will no longer be trapped. Doing this as early as possible prevents permanent damage from occurring to the esophagus. Once this damage becomes permanent, it is possible that the patient may continue to have symptoms of regurgitation and be at-risk for aspiration pneumonia even after the vascular ring anomaly has been addressed.

Tommy was brought to the shelter at approximately 5 weeks old. He would regurgitate any solid food and so he was brought to the specialty center that I was during my specialty training at. The shelter staff was suspicious for a persistent right aortic arch immediately given his age. I fell in love with Tommy immediately. We diagnosed his condition with radiographs and endoscopy. Because it was an exceptionally slow day, he spent a lot of time with me and he snuggled in my jacket. He had surgery the following day with one of our excellent board certified surgeons and was released without complications a day later to the shelter staff. Fortunately he was too young to recover in the shelter and went home with a very very caring foster. He had a rocky recovery due to having gut parasites and picking up kennel cough at some point. Fortunately he pulled through all of that, and I was waiting for him on the other side of it all.

Tommy was lucky enough to have found his way to the right people at the right time. He has required some lifetime feeding adjustments such as being fed a bit more slowly than his brothers over the years, I was set on him eating solid kibble which would not have been a possibility without surgery. He has grown to his expected body size and is still doing amazingly well 10 years later despite all of the other hurdles he has had to face.

I am so appreciative of all the shelter and his foster did for him. I still keep in touch with his foster and keep her updated. I also got him pet insurance considering his rough start and it has more than paid off!

For more information on this condition including illustrations and radiographic images, check out these other sites:

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