SRS214 - Decoding the anatomy of preauricular lymph nodes: a cadaveric exploration

Abstract Purpose Primary lymphedema presents with a variety of symptoms, including swelling in the extremities, trunk, and face. This condition can lead to significant facial and orbital swelling resulting from impaired lymphatic drainage, which underscores the importance of preauricular lymph nodes (LNs) in treatment strategies. This study aims to clarify the precise anatomical positioning of the preauricular LNs. Methods A total of 12 cadaver dissections were performed to locate the preauricular LNs. Dissections focused on identifying lymph nodes at the sub-SMAS (Superficial Musculoaponeurotic System) level, particularly in relation to the superficial temporal artery (STA), superficial temporal vein (STV), and tragus. Results Preauricular lymph nodes (LNs) were identified in 16 of the 22 preauricular regions examined across 12 cadavers. The average size of the lymph nodes measured 4.56 mm, with an average distance of 11.75 mm anterior to the tragus. The lymph nodes were consistently located at the sub-SMAS level, positioned superficial and posterior to the superficial temporal vein (STV), with afferent and efferent lymphatic vessels also found at this plane. Initial dissections took an average of 2 h to locate the lymph nodes, while subsequent dissections, with refined techniques, reduced the time required to 30 min. Conclusions Preauricular lymph nodes are most consistently located at the sub-SMAS level, approximately 10–15 mm anterior to the tragus, with an average size of 4.56 mm. A thorough understanding of these anatomical landmarks and refined dissection techniques can substantially decrease the time needed for node identification, thereby enhancing surgical strategies in the preauricular area.