Reduction of occult metastatic disease by extension of the supraomohyoid neck dissection to include level IV.

Background: Patients with clinically N0 necks will undergo elective removal of lymphatic tissue from levels I, II, and III as part of their routine surgical management. Level IV is omitted on the basis that there is negligible chance of containing significant occult disease. Evidence to support this approach is minimal, and the aim of this study was to increase the yield of metastatically involved lymph nodes by simply extending the supraomohyoid neck dissection (SOHND) to include level IV.

Methods: The records of 49 patients with cancer of the oral cavity undergoing extended supraomohyoid neck dissection (ESOHND) during the period January 1996-March 1999 were reviewed. All patients were staged as having N0 disease. The follow-up period ranged from 12 to 36 months.

Results: Thirteen of 55 N0 stage necks showed occult metastasis (26.5%). Neck failure rate occurred in 4 of 49 patients (8.2%). Neck failure rate in the pN0 group was 5.4% and in the pN+ group was 16.6%. Complication rates of ESOHND were noted as 3.6%. No long-term morbidity arose. Occult metastasis in level IV occurred in 5 of 49 cases (10%). Two cases involved other surgical levels.

Conclusions: ESOHND as performed in this study removed occult level IV metastatic regional disease from an extra 10% of patients that, if the patients had undergone SOHND, would have remained undiscovered. No long-term morbidity is associated with this procedure that the authors now recommend as a first-line treatment in all patients with N0 necks.