Prevalence of nodal metastases in the submuscular recess (Level IIb) during selective neck dissection

Objectives: To determine the prevalence of nodal metastases in the submuscular recess (SMR) in patients undergoing selective neck dissection (SND) and to identify potential risk factors for the presence of metastatic disease in the SMR. Design: Prospective cohort study. Setting: Academic tertiary care referral center. Patients: Consecutive patients undergoing SND for squamous cell carcinoma of the head and neck between January 5, 1998, and November 23, 2001, were prospectively analyzed. Patients with a history of neck dissection or whose pathology reports did not clearly distinguish the SMR from other nodal levels were excluded from the study. Interventions: Patients underwent SND based on the primary tumor site and well established regional lymphatic drainage patterns. Main Outcome Measure: Presence of histopathologically proven nodal disease in the SMR. Results: Seventy-four patients underwent 90 SNDs, 16 of which were bilateral. The prevalence of metastases in the SMR was 1.6% (1/63) in clinically NO necks and 11.1% (3/27) in clinically node-positive necks, with an overall incidence of 4.4% (4/90). There was a statistically significant association between SMR metastases and advanced pathologic N stage (P=.003), particularly with positive nodal disease in level IIa (P=.001). Extracapsular tumor spread was also shown to have a statistically significant association with metastases in the SMR (P=.01). No significant associations were observed between SMR metastases and primary tumor site (P=.06), clinical N stage (P=.09), a history of primary tumor recurrence (P=.52), or previous radiation therapy (P=.68). Conclusion: The results of the present study suggest that nodal metastases in the SMR are rare in head and neck cancer patients undergoing SND.