Surgical Management of the Spinal Nerve in Modified Radical Neck Dissection

Abstract

In 1906, Crile (1906) first reported radical neck dissection as a surgical technique for the treatment of neck lymph-node metastasis of head and neck cancer. It began to be used more widely after the report of Martin et al. (1951). The basic technique for neck dissection involves excising the neck lymphatic tissue, together with the accessory nerve, sternocleidomastoid muscle, and internal jugular vein, although this results in marked postoperative morphological and functional disorders. In particular, severing the accessory nerve is associated with postoperative shoulder dysfunction. Various techniques for functional (conservative) neck dissection have been introduced to prevent such dysfunction, and these techniques have been modified in various ways (Bocca & Pignataro, 1967; Bocca et al., 1980; Eisele et al., 1991; Medina & Lore, 2005; Suarez, 1963). The original approach to functional neck dissection was reported by Osvaldo Suarez in 1963. Unlike radical neck dissection, functional neck dissection can prevent postoperative morphological and functional disorders by preserving the accessory nerve, sternocleidomastoid muscle, and internal jugular vein. Over the past 40 years, there has been ongoing development of various nerve-, vein-, and muscle-preserving techniques. The most recent development is selective neck dissection, based on site-specific lymph drainage patterns. These conservative procedures have attempted to alleviate neck and shoulder morbidity and to ensure that oncological safety is not compromised (Bocca & Pignataro, 1967; Bocca, 1975; Bocca et al., 1980; Eisele et al., 1991; Medina & Lore, 2005; Suarez, 1963). Damage to the spinal accessory nerve generally leads to the condition known as “sloping shoulder syndrome” (Salgarelli et al., 2009), which consists of: numbness over the angle of the jaw and around the ear due to the associated injury to the transverse cervical and great auricular nerves; paralysis of the trapezius muscle, resulting in shoulder droop and difficulty in shoulder movement, especially abduction, although some patients retain almost full movement; pain, often the worst consequence of injury, resulting from traction of the unsupported shoulder on the brachial plexus or even a sensory element in the spinal accessory nerve; winging of the scapula, which occurs because trapezius paralysis allows the medial border of the scapula to lift off the chest wall.