Thoracoscopy Persistent Right Aortic Arch and PDA

Thoracoscopy is being more and more frequently in veterinary surgery to treat several conditions. Thoracoscopy has been used to transect the ligamentum arteriosum during the persistence of the 4th right aortic arch or ligate a patent ductus arteriosus.

Presistent Right Aortic Arch Approach
To perform minimally invasive PRAA correction the patient is placed in right lateral recumbency. Four portals will be required. Three portals are placed in the 7 or 8th intercostal space and the fourth cannula is placed in the one intercostal cranial in the ventral third of the space. A retractor or a palpation probe used as a retractor will be introduced in that portal.

Equipment Used
Five millimeters equipment can be used for the procedure. However, since most of the dogs are very young and less than 8 kg a pediatric set of equipment is more appropriate. Pediatric equipment is usually 2.7 mm in diameter. Five millimeter diameter cannulas are difficult to place in the intercostal space. One 5 mm cannula will still be need for introduction of vascular clip or vessel sealant device.

Surgical Technique
The left cranial lung lobe is retracted ventrally to expose the cranial mediastinum and the heart base. The first step of the procedure is to localize the ligamentum arteriosum. Usually the esophagus is fairly dilated and a narrowing can be noticed at the level of the base of the heart. A stomach tube can be placed in the esophagus to improve visualization of the ligamentum arteriosum. A palpation probe is used to further localize the ligamentum arteriosum.  [...]