Surgery is begun with the dog in right lateral recumbency and under general anesthesia.

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The dog is draped to expose the left 4th intercostal space and an incision is made straight down from the caudal angle of the scapula. Bleeders are isolated and clamped and the opening of the thorax follows normal procedure.

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Rib retractors are inserted and spread carefully to avoid damaging the lung. The lung is then pushed out of the way and held in place with a piece of moistened gauze to reveal the heart.

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With the heart exposed it is now possible to see the left vagus nerve, the left phrenic nerve, the main pulmonary artery, the arch of the aorta, and the ductus arteriosus.

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The pleura is opened with blunt dissection and the vagus nerve is retracted ventrally by encircling it with suture and retracting it with hemostats.

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The ductus is isolated from the aorta and pulmonary artery with blunt dissection. The most delicate part of this surgery is carefully separating the ductus from the closely apposed aorta.

Three ligatures are placed around the isolated ductus. In this case the outer two are umbilical tape and the middle is silk. All ligatures are placed before any are tied. The aortic end is tied first. The middle ligature is then tied as a transfixing suture-ligature.

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The ligature closest to the aorta is tied first to reduce the pressure inside the ductus so the other ligatures may be tied more easily. A transfixing suture is placed through the lumen of the ductus to promote scar formation.

Next the lungs are repositioned and inflated to eliminate atelectasis.

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Tension sutures are placed behind the 5th rib and in front of the 4th rib. A rib approximator may be used in large dogs to help hold the ribs together as these sutures are tied.

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A chest tube is inserted through the 6th intercostal space so that the pleural cavity can be 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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After the surgery dogs are given a course of antibiotics and kept in the hospital for 3 to 5 days. Exercise is restricted for 3 more weeks after discharge. Current success rate for this surgery is over 95%.

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