Thoracoscopy for Persistent Right Aortic Arch (PRAA) addresses the ligament that compresses the esophagus and blocks the movement of food and water into the stomach. This ligament is normal; however, the aorta is normally on the left, placing it and the ligament on the same side of the esophagus. The aorta can accidentally develop on the right side, rather than the left, as a fetus grows. This means that the ligament crosses over the esophagus from right to left, compressing it against the heart and trachea (windpipe). Food cannot get through this narrowed area, causing regurgitation and poor growth. It also puts the pet at risk for aspiration pneumonia, in which food, water, or saliva can enter the lungs because material does not travel normally to the stomach. It is important to note that other vascular malformations can exist and cause compression of the esophagus; however, 95% of the time it is PRAA.


Why it’s done

Your veterinarian may recommend PRAA surgery if your pet has:

  • Regurgitation
  • Failure to thrive, grow, and gain weight In addition, your veterinarian may recommend surgery to decrease the risk of future pneumonia.

How to prepare for your pet’s procedure

Before your pet’s procedure, you will meet with one of our specialists to talk about the procedure and what to expect.

When you meet with our team, please bring a list of all medications that your pet is currently taking, including over the counter medications, vitamins, and herbal supplements. Before your pet’s procedure, you may be asked to discontinue giving certain medications that can increase the risk of bleeding.

This is a good time to ask questions about the procedure and make sure you understand the risks and benefits.

Preoperative diagnostics and tests

Before your pet’s surgery the following may be indicated:

  • Radiographs (chest x-rays)
  • Barium swallow to evaluate the esophagus for compression
  • CT scan, if the diagnosis is not certain
  • Comprehensive blood work

General Instructions for the Day of Surgery

  • Please remove your pet’s access to food when instructed. Some young puppies will require feeding in the early morning hours to avoid low blood sugar.
  • Please allow your pet to have water all night long.
  • Please arrive for pet’s admission promptly at your scheduled arrival time.
  • You will be asked to sign both a Surgical Consent Form aswell as an Estimate, indicating your understanding of the procedure, risks, and associated costs.

What happens during athoracoscopic PRAA procedure?

Your pet will be given a general anesthetic. An endoscope will be passed down the esophagus to confirm the diagnosis of the aorta appearing on the right side. If the diagnosis cannot be confirmed, surgery may be postponed. If PRAA is seen, special instruments, including a camera, are passed through small ½ incisions into the chest. The ligament is identified, occluded, and divided. Associated fibrous bands are also freed from the esophagus.


Complications associated with thoracoscopic division of the ligament include the following:

  • Anesthetic need to convert to open surgery due to poor ventilation (oxygen exchange)
  • Need to convert for poor visualization due to patient size or adhesions
  • Bleeding
  • Infection

After the procedure

  • Following the procedure, you will be given a phone call with an update on your pet’s recovery.
  • Please plan for your pet to remain hospitalized for pain management, supportive care, and monitoring for 1-2 days post operatively.
  • You will be given daily updates regarding your pet’s progress during their stay.
  • A scheduled discharge will be coordinated when your pet is able to go home.
  • Once discharged, please remove the bandage from your pet’s intravenous catheter site 10 to 15 minutes after arriving home.
  • Some chest tenderness is common for 3-5 days following thoracoscopic surgery.
  • It is important to restrict your pet’s activity for the next 3-5 days while the incision is healing. Walks should be short and your pet should always be on a leash. Please do not let your pet rough house with other animals during this time.
  • Some patients will vomit or have diarrhea following anesthesia. If the vomiting or diarrhea persists more than 24 hours, please call Salt River. In contrast, some patients may be constipated or may not have a bowel movement for up to 72 hours following anesthesia. If your pet is straining to defecate after 72 hours, please call Salt River.
  • Suture removal in 10-14 days is necessary
  • Please monitor the incision for any signs of heat, pain, swelling, or discharge. Should you notice any of these signs, it may be an indication of infection. Please call Salt River if you notice a problem.
  • Licking or scratching at the incision will dramatically increase the chances of an infection or that the incision will open up. To prevent this from happening, please watch your pet closely for scratching or licking at the incision. If this occurs, an e-collar should be placed.


Many pets do very well following the procedure and can handle more solid foods. Initially, you will feed your pet meatballs of canned food in an upright body position. After suture removal, further changes in feeding will be discussed. The esophagus may not return to normal size, but removing the ligament is typically associated with a good result in most pets.

Follow up

A recheck appointment is required in 1-2 week.