Minimally invasive chylothorax: The Penn experience

Introduction:
Minimally invasive throacoscopic Thoracic duct ligation and laparoscopic cisterna chili ablation (w/ thoracoscopic pericardiectomy) is our current method of choice when indicated for the treatment of canine chylothorax. 

Patient positioning and port placement:
The entire hemithorax (3600) is prepared and left or right abdomen (flank region) is clipped aseptically prepared and widely draped. Dogs are positioned in sternal recumbency and can be tilted slightly to accommodate visualization of the TDL. The thoracic inlet and the pelvis are positioned to straddle sandbags, which enable the abdomen to hang in a pendulous manner. If possible two viewing monitors are used with cameral operators positioned on both sides of the patient. Video monitors are positioned on both sides of the patient if possible. Dogs: In the this authors opinion, 3 ports are best placed in the dorsal third of the right caudal thorax at approximately the 10, 9th and 8th intercostal rib spaces with the middle port being slightly more ventral and utilized for the angled telescope. It is beneficial for the left side of the chest to also have at least 2 ports positioned in the same manner one for a telescope and one for a instrument. The thoracic duct is typically not visualized immediately and dissection is necessary through the pleura. The dissection is made in the caudal thorax (caudal to the entrance of the azygos vein into the chest). The dissection is initially started with hook cautery or with Metzenbaum scissors. The location is centered between the brances of the intercostal arteries, and it is typically started ventral to the aorta and always kept immediately adjacent to its outer surface. The aorta may require ventral retraction. Once all the tissue dorsal to the aorta is free and the dissection is continued completely through to the adjacent side. The dissected tissue combined with the thoracic duct is ligated enbloc either by clips or with a suture. Methelyne blue, Indocynanine green (ICG) or intraoperative lymphangiography can be used to assess the success of the ligation.  [...]