The spinal lymphatic system: an emerging pathway bridging fluid homeostasis, immunity, and disease.

The lymphatic system, traditionally regarded as a unidirectional conduit for interstitial fluid and immune cell transport, has recently been redefined through the discovery of lymphatic networks along the spinal axis. These spinal lymphatic vessels, encompassing the spinal cord, vertebral bones, and intervertebral discs, challenge long-standing anatomical dogmas and introduce new perspectives on the interplay between the central nervous system (CNS) and the vertebral column. This review systematically summarizes the distribution and dual functions of the spinal lymphatic system in regulating cerebrospinal fluid drainage, maintaining tissue homeostasis, and mediating immune responses. Furthermore, we highlight emerging evidence linking spinal lymphatic dysfunction to spinal pathologies, neurological disorders, and vertebral degeneration. Based on these findings, we propose that the spinal lymphatic system constitutes a previously underappreciated pathway integrating spinal cord and vertebral physiology, with potential implications for both disease progression and therapeutic intervention. While research on the cranial lymphatic system has rapidly advanced, the spinal lymphatic system remains comparatively underexplored. We hope this review will catalyze further investigation into spinal lymphatic biology and inform the development of novel therapeutic strategies targeting spinal and neurological diseases.