The surgery is begun with the dog in right lateral recumbency and under general anesthesia. A heating pad is used to maintain body temperature. Drapes are positioned to reveal the left 4th intercostal space.

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Dog being prepared for surgery.

The incision is made straight down from the caudal angle of the scapula. Blood vessels are isolated and ligated and the opening of the thorax follows normal procedure.

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Once the thorax has been opened the left apical lung is visible. The lung is retracted caudally and held in place with a moistened gauze sponge to reveal the heart

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The heart is exposed with its pleural covering. The left vagus nerve and phrenic nerve are now visible. The air-filled esophagus is apparent, as is the constriction formed by the ligamentum arteriosum extending between the pulmonary artery and the right aortic arch. In cases where the ligamentum cannot be seen readily, it may be felt as a tight band in a similar position.

praa11-n	praa11a-n Left vagus nerve highlighted in yellow.
praa11b-n Phrenic nerve, highlighted in yellow.	praa11c-n Constriction of the esophagus, visible above the heart base.
praa11d-n Ligamentum arteriosum, highlighted in green, at the level of the stricture.	praa11e-n Main pulmonary artery highlighted in purple.
praa11f-n Part of the descending aorta, highlighted in red, on the far side of the esophagus.

The vagus nerve is isolated by blunt dissection and retracted ventrally by placement of a temporary ligature.

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The pleura is incised over the lateral aspect of the ligamentum arteriosum. If the ligamentum is not visible it may be localized by digital palpation.

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Dissection is continued to expose the ligamentum arteriosum. The vagus and left recurrent laryngeal nerves are retracted ventrally with a temporary ligature to avoid damage.

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In some patients the ligamentum arteriosum will be partially patent and may bleed when transected. For this reason a transfixing suture is placed at both ends of the ligamentum before transecting it. The sutures in this photo demonstrate the actual length of the ligamentum.

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praa15a-n Ligamentum arteriosum, highlighted in green, is isolated and ligatures are applied at either end.

As soon as the ligamentum is cut the esophagus expands and the stricture is relieved. The esophagus is then dissected a few centimeters in each direction to make sure that no fibrous bands still constrict it.

After the esophagus expands a stomach tube is passed to ensure no constrictions remain. In this clip you can see the esophagus widen as the tube passes to the stomach and narrow again as it is withdrawn.

The temporary sutures are removed from the vagus and recurrent laryngeal nerves. The pleura is left open over the esophagus to prevent constriction.

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The ligamentum arteriosum has been severed.

Next the lungs are repositioned and inflated to eliminate atelectasis.

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Tension sutures are placed at 1/2 inch intervals behind the 5th rib and in front of the 4th rib. A rib approximator may be used in larger dogs to help hold the ribs together as these sutures are tied.

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A pleural cavity drainage tube is inserted through the 6th intercostal space by making a small incision 2-3 cm caudal to the primary incision, inserting a hemostat, and withdrawing the tube. A number of extra holes are made in the end of the tube to prevent blockage. The chest tube is aspirated every 15 minutes until less than 1 cc of air or fluid per 10 lbs of body weight is removed per hour.

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After the chest tube is inserted and the tension sutures are tied, the latissimus dorsi muscle is closed with a semi-continuous suture. The pleural cavity is aspirated to remove all air and the skin incision is sutured in usual fashion. A mattress suture is placed around the chest tube exit to be tied when the tube is removed.

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Post operative care consists of injectable antibiotics for three days and long term vitamin supplementation. Small amounts of baby food are given 5-6 times daily for 2 weeks and then experimentation begins to decide the type of food the patient will tolerate best.

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This barium esophagram was done after the procedure and shows only slight constriction over the base of the heart, and essentially normal esophageal function.

After the surgery the dog should be fed small amounts of solid food 3-4 times a day. Some dogs are better able to eat in a vertical position because gravity helps them swallow.

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This dog recovered full function of his esophagus and had no noticeable effects 8 months after surgery.

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