Chylothorax after coronary artery bypass grafting using the right internal thoracic artery.

Chylothorax is a rare but serious complication of coronary artery bypass grafting (CABG) that results from disruption of the thoracic duct while harvesting the internal thoracic artery (ITA). A 78-year-old woman developed a large-volume milky pleural effusion 3 days after CABG. Biochemical analysis of the fluid resulted in a diagnosis of chylothorax. After failure of conservative medical treatment, including stopping her oral intake and starting total parenteral nutrition, surgical repair was performed via repeat median sternotomy. Intraoperative exploration revealed disruption of the thoracic duct or one of its tributaries close to the proximal portion of the right ITA, which was closed with interrupted sutures. In the majority of previous reports of chylothorax after CABG, the left ITA was used. However, harvesting of either the left or right ITA risks disruption of the thoracic duct and its tributaries, because of the high degree of anatomic variability of the thoracic duct system.