Trypan blue intraoperative lymphography for thoracic duct ligation and cisterna chyli ablation with subtotal pericardiectomy in dogs

Abstract A 2.5‐year‐old, 45‐kg, intact male Rottweiler (case 1) and a 4‐year‐old, 30‐kg, intact male German Shepherd crossbreed (case 2) were referred for thoracic duct ligation, cisterna chyli ablation and subtotal pericardiectomy for the treatment of idiopathic chylothorax. Intraoperative lymphography was performed using trypan blue (TB). Mesenteric lymphatics were injected with 1.5 mL of non‐diluted 0.055% TB to facilitate visualisation of the thoracic duct (TD). There was no evidence of chylothorax recurrency in cases 1 and 2, 9 and 14 months after the surgery, respectively. The TB‐stained lymphatics were easily identified, and no side effects were detected. This is the first published case report describing the usage of TB for the visualisation of lymphatic vessels in dogs. TB lymphography is safe, readily available, non‐radioactive and effective for direct intraoperative visualisation of the TD without the use of specialised equipment.