33rd Annual Scientific Meeting proceedings

Introduction
A cranial left-sided approach to the thoracic duct where it coalesces into a single vessel may enable successful ligation with fewer thoracotomy incisions. Thoracic duct ligation and pericardiectomy at this site has potential to reduce morbidity and anesthesia time for idiopathic chylothorax patients.

Materials and Methods
CT lymphangiograms were evaluated retrospectively to determine location and branching of the thoracic duct at the left 4th intercostal space. A cadaveric study evaluated efficacy of thoracic duct ligation and pericardiectomy at this site. Following methylene blue mesenteric lymph node injection, thoracic ducts were identified through a left 4th intercostal thoracotomy, ligated, and sealed. Pericardiectomy was performed through the same incision. CT scans were performed to determine success of ligation.

Results
Lymphangiogram review revealed a single left-sided thoracic duct in 10/13 clinical cases at the proposed surgical site. Thoracic duct ligation via left 4th intercostal thoracotomy was successfully performed in 9/10 cadavers. A single left-sided branch was noted in 6/10, and two branches were noted in 4/10 cadavers, respectively. No branches were observed on the right side of the esophagus.

Conclusions
Thoracic duct ligation and subphrenic pericardiectomy utilizing a cranial left-sided approach was successfully performed in 9/10 canine cadavers and appeared feasible in 10/13 clinical cases. This approach allows clear visualization of the thoracic duct. A surgical approach with fewer thoracotomy incisions may reduce morbidity for chylothorax patients.