Relationship of Spinal Accessory Nerve with Internal Jugular Vein, Internal Carotid Artery, and Sternocleidomastoid in Head-and-Neck Carcinoma Patients in Indian Population

Introduction: Head-and-Neck Cancers in India have emerged as a dominant public health problem in recent years. Neck dissection with lymphadenectomy is commonly done to prevent the spread of metastasis. Spinal accessory nerve (SAN) is frequently injured during neck dissections, which leads to shoulder syndrome. Objectives: The aim is to study the relationship of SAN with Internal Jugular Vein (IJV), Internal Carotid Artery (ICA), and sternocleidomastoid (SCM) in neck in the patients undergoing lymphadenectomy. Materials and Methods: Surgical neck dissections were performed on 41 patients (38 males and 3 females). Results: SAN was lying deep (posterior/medial) to IJV in 8.1% neck surgery patients, whereas superficial (lateral/anterior) to IJV and ICA in 91.9%. The SAN was seen penetrating the SCM in 87.8% cases, and in 12.2%, it did not penetrate the SCM. In 4 cases, the SAN was sacrificed in neck surgery patients due to extensive lymphadenopathy/matted lymph nodes. Conclusion: The relationship of SAN with IJV and ICA at the level of the posterior belly of the digastric muscle and below it in the Carotid Triangle has been noted. The SAN was lying lateral to the IJV and ICA in the majority of cases. However, in some cases, SAN lying posterior to the IJV was observed. It was also noted that SAN pierced the SCM in the majority of cases. A detailed knowledge of variations, relations and branching pattern of SAN is of great surgical importance for the surgeons performing neck dissections in patients suffering from head-and-neck carcinoma to prevent any injury to SAN.