Deep lymphatic vessel

Deep lymphatic vessels are lymphatic channels located beneath the deep fascia, typically accompanying arteries and deep veins. They drain lymph from muscles, joints, and internal organs into regional lymph nodes and larger lymphatic trunks.

Location and Pathways: Deep lymphatic vessels are found within deep tissues such as muscles, tendons, joints, and visceral organs. They run parallel to major arteries and deep veins, draining into deep lymph nodes (e.g., iliac, para-aortic, mediastinal). These vessels converge into lymphatic trunks, which then empty into the thoracic duct or right lymphatic duct, ultimately returning lymph to the venous circulation.

Structure: Deep lymphatic vessels have thicker walls than superficial lymphatics. They are surrounded by smooth muscle that contracts rhythmically and contain valves that maintain unidirectional flow. Lymph flow is facilitated by arterial pulsations and skeletal muscle contractions.

Functions: Deep lymphatic vessels drain lymph from deep structures, including muscles, bones, and viscera. They transport immune cells and antigens from internal organs to lymph nodes and provide pathways through which systemic infections or malignancies can spread via the lymphatic system.

Clinical Relevance:

• Cancer spread: Deep lymphatic vessels serve as key routes for the metastasis of visceral cancers (e.g., prostate, colon, lung).

• Surgical importance: Understanding deep lymphatic drainage is essential in oncologic surgery and cancer staging.