Microsurgical Cervical Lymphaticovenous Anastomosis: A Novel Mouse Model for Brain Lymphatic Outflow

Background: Cervical lymphaticovenous anastomosis (LVA) has recently emerged as an innovative surgical approach to enhance brain lymphatic clearance for the treatment of Alzheimer's disease (AD). While early clinical findings are promising, the absence of a reproducible preclinical model has hindered mechanistic investigations and translational advancements. Objective: This study aimed to establish the first mouse model for cervical LVA, addressing technical challenges and providing a standardized platform for preclinical research on lymphatic clearance and its role in neurodegeneration. Methods: Mice underwent bilateral cervical LVA using high-magnification supermicrosurgical techniques. Following identification of the deep cervical lymph nodes, end-to-side anastomosis was performed between the deep cervical lymphatic vessels and the external jugular vein. Anastomotic patency was confirmed intraoperatively by direct visualization without leakage. Indocyanine green (ICG) lymphangiography, performed via nasal administration, demonstrated fluorescence drainage into the external jugular vein. Results: With progressive refinement of microsurgical skills and improved anatomical familiarity, procedural stability was achieved. In the final cohort of five mice, all LVA procedures resulted in successful anastomotic patency. Intraoperative indocyanine green (ICG) lymphangiography confirmed real-time lymphatic drainage into the venous system in all cases. Conclusion: This study demonstrates that lymph node-venous anastomosis (LNVA) is a feasible approach for cervical lymphaticovenous anastomosis (LVA) in mice, overcoming previous technical limitations. As LNVA is also the predominant LVA technique now used in Alzheimer's disease patients in China, this model provides a valuable platform for investigating its role in brain lymphatic drainage and neurodegeneration. Additionally, we propose nasal ICG lymphangiography as an effective imaging method for assessing lymphatic flow, offering a more effective alternative to local injection. This model lays the groundwork for future studies on LNVA's impact on glymphatic clearance and potential clinical applications.