Contrast-enhanced ultrasound-guided precision fibrinolysis for refractory loculated chylothorax after lung transplantation: a case report.

Background: Pleural complications remain a major source of morbidity after lung transplantation, with chylothorax posing particular therapeutic challenges. When complicated by fibrinous septation, effective drainage becomes difficult, often necessitating intrapleural fibrinolytic therapy (IPFT). However, in the early post-transplant period, blind fibrinolysis carries substantial risks, including hemorrhage and disruption of fragile bronchial anastomoses or lymphatic vessels. Case Description: We report a 31-year-old woman with pulmonary lymphangioleiomyomatosis (PLAM) who developed refractory loculated chylothorax 39 days after bilateral lung transplantation. Initial chemical pleurodesis was ineffective and subsequently induced a honeycomb-like, non-communicating pleural effusion that was not amenable to conventional drainage. To balance the need for septation lysis against the risk of bleeding, contrast-enhanced ultrasound (CEUS) was integrated as a real-time guidance tool. CEUS facilitated the precise differentiation between avascular fibrin septa and vascularized pleural tissue, allowing targeted low-dose urokinase injection into isolated locules. The restoration of inter-locule communication was directly visualized, permitting early termination of fibrinolytic exposure. Subsequent drainage and repeat pleurodesis resulted in full lung re-expansion without recurrence. Conclusions: To our knowledge, this is the first case utilizing CEUS to guide precision fibrinolysis in a lung transplant recipient. This case provides a proof-of-concept that CEUS-guided precision fibrinolysis can transform a traditionally blind and high-risk intervention into a controlled, visualization-driven procedure. By enabling targeted intervention and real-time efficacy assessment, this approach offers a safer salvage strategy for high-risk patients.