Yellow nail syndrome with chylothorax after coronary artery bypass grafting

BACKGROUND: Yellow nail syndrome is a rare condition considered secondary to functional anomalies of lymphatic drainage. Yellow nail syndrome is diagnosed through the triad of intrathoracic findings (30% being pleural effusions), nail discoloration, and lymphedema, with any two features sufficient for diagnosis. We report the second case of post-operative yellow nail syndrome. CASE PRESENTATION: After coronary artery bypass grafting, our patient presented with chylothorax on post-operative day 13 and yellow toenail discoloration on post-operative day 28, diagnosing yellow nail syndrome. Initial conservative management with pigtail catheter drainage and low-fat diet with medium-chain triglycerides reduced chylous drainage from 350 mL/day on post-operative day 14 to < 100 mL/day on post-operative day 17. However, by post-operative day 18, drainage returned to 350 mL/day that persisted despite attempts to readjust the catheter position, replacement of catheter with chest tube, and transition to total parenteral nutrition and octreotide while nil per os. Lymphangiogram on post-operative day 32 did not identify the thoracic duct or cisterna chyli, precluding embolization. Talc and doxycycline pleurodeses performed on post-operative days 33 and 38, respectively, resolved his chylothorax and nail discoloration. CONCLUSIONS: Both yellow nail syndrome and chylothorax as a complication of coronary artery bypass grafting are rare entities. The proposed mechanism of post-operative chylothorax is iatrogenic injury to thoracic duct or collateral lymphatic vessels. Diagnosing yellow nail syndrome in patients with post-operative chylothorax (through co-existing yellow nail discoloration and/or lymphedema) may suggest predisposition to impaired lymphatic drainage, portending a difficult recovery and potentially indicating need for surgical management.