NEW PROPOSED CLASSIFICATION OF RETROMANDIBULAR AND EXTERNAL JUGULAR VENOUS VARIANTS – TWO CASE REPORTS WITH REVIEW OF LITERATURE AND CLINICAL IMPLICATIONS

Typically the retro‐mandibular vein contributes to formation of common facial and external jugular veins, via its anterior and posterior divisions. However, cervico‐facial venous variants are rather common. The cervico‐facial veins were studied in two successive dissections. In both cases the retromandibular vein was undivided. The first had external jugular vein draining into subclavian vein, but no common facial vein. The second had no external jugular vein, but had common facial vein draining into internal jugular vein. The first variant was characterized as Posterior Dominant Retromandibular External Jugular Vein with no Common Facial Vein. The second variant was characterized as Anterior Dominant Retromandibular Common Facial Vein with no External Jugular Vein. Each was sub‐classified as Typical or Atypical based on its final drainage pattern. Cervico‐facial venous variants often vary from case to case and side to side. Since these veins are used for clinical and surgical interventions, accurate preoperative classification of variations may preclude intra‐operative surprises and consequent complications. Support or Funding Information Not applicable New proposed classification of retromandibular external jugular and common facial venous variants *RMV Characterization Divisions of Retromandibular Vein (RMV) External Jugular Vein (EJV) Common Facial Vein (CFV)Typical Retromandibular Vein (RMV) Divisions presentAnterior Division: Unites with Facial Vein to form CFVPosterior Division: Unites with Posterior Auricular Vein to form EJVEJV present Drains into Subclavian Vein ***CFV present Drains into Internal Jugular Vein (IJV) ***Variant Retromandibular Vein (RMV) NO Division Posterior Auricular Vein unites with main RMV, but may drain elsewhere** Posterior Dominant: Whole RMV goes toward Posterior Triangle of Neck superficial to Sternocleidomastoid Muscle as External Jugular Vein (EJV) Typical: EJV present Drains into Subclavian VeinAtypical: Drains elsewhereTypical: CFV ABSENTOriginal Facial Vein drains into IJVAtypical: Drains elsewhere** Anterior Dominant: Whole RMV goes toward Anterior Triangle of Neck and forms Common Facial Vein (CFV) Typical EJV ABSENTAtypical: Other variation(s)Typical CFV present Drains into IJVAtypical: Drains elsewhere* This Characterization of variant Retromandibular Vein is proposed for adoption in clinical practice ** Anterior/Posterior Dominance of Undivided RMV is the linchpin of the Classification because of its clinical significance *** Copyright © Sanjoy Sanyal 2018–2019This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .