The inner laryngeal lymphatics. A lymphangioscopical and electron microscopical study

Area of Science:

• Anatomy and Physiology
• Surgical Oncology
• Head and Neck Surgery

Background:

• Understanding laryngeal lymphatic drainage is crucial for head and neck cancer staging and treatment.
• Previous studies have suggested distinct lymphatic compartments within the larynx, impacting metastasis patterns.
• Detailed anatomical and functional insights into laryngeal lymphatics are needed.

Purpose of the Study:

• To investigate the detailed structure and drainage pathways of the laryngeal lymphatic system.
• To evaluate the concept of strict compartmentation of laryngeal lymphatic drainage.
• To identify the role of lymphatic collaterals in laryngeal lymph flow.

Main Methods:

• Lymphangioscopy was employed to visualize the lymphatic vessels in situ.
• Ultrastructural analysis was performed to examine the morphology of lymphatic capillaries and collecting vessels.
• The study focused on the distribution and interconnections of lymphatic structures within the larynx.

Main Results:

• A comprehensive lymphatic capillary and collecting vessel system was identified in the larynx.
• Collecting vessels possess characteristic features, including luminal valves and elastic components.
• Strict compartmentation of laryngeal lymphatic drainage is generally not supported, except for the true vocal cord margins, due to extensive anastomoses.

Conclusions:

• The laryngeal lymphatic system is characterized by numerous anastomoses between capillaries and collecting vessels.
• These connections allow for midline and vertical plane lymphatic drainage, bypassing physiological blockades.
• The findings challenge the notion of rigid laryngeal lymphatic compartments and highlight the importance of collateral pathways in maintaining lymph flow.