Level I Neck Dissection Techniques and Implications for Surgery of the Skull Base, Paranasal Sinuses and Salivary Glands

Background: Neck dissection is often considered for cancers of the paranasal sinuses, salivary glands and skull base. The extent of neck dissection for these cancers remains controversial in the literature. The situation is further complicated by the heterogeneity of tumor locations and histologic diagnoses. Level I of the neck is particularly relevant in these cancers not only for oncological reasons, but because it allows identification of the facial vessels for free flap reconstruction.

Objectives: To evaluate the pathological results of level I neck dissection in tumors of the salivary glands, skull base and paranasal sinuses.

Methods: Level I neck dissection surgical techniques included dissection of the perivascular nodes as well as level IA. The technique allows preservation of the facial artery and veins as recipient vessels. Level I neck dissections were oriented as follows: Level IA was divided into IAa (contralateral) and IAb (ipsilateral). Level IB was divided into IBc (prevascular), IBd (postvascular), IBe (preglandular), IBf (postglandular), IBg (submandibular gland) and IBh (deep to submandibular gland). A single surgeon who delivered the specimen to the pathologist oriented all specimens.

Results: During the initial one-year period of this study, 119 patients underwent neck dissection including level I. We identified 13 patients who represented the cohort for this study. Preliminary results indicate that our system which divides Level I into the substations described increases the nodal yield with a maximum node count of 19 nodes in level I of the specimen. Substation node counts within level I were feasible and relevant in a variety of cancers regardless of clinical or pathological N stage.

Conclusion: We describe our method of dissection and orientation of level I of the neck and preliminary node count data. Specific techniques used during the neck dissection and specimen orientation lead to increased node counts. We believe that more reliable pathological results may be obtained using this technique, which will serve to guide future neck dissections for this heterogeneous group of malignancies. Of particular relevance are the prevascular and postvascular nodes. Our results suggest that our technique of dissecting these nodes and orienting the specimens to analyze these substations increases the nodal yield and may well have an impact that resembles sentinel node mapping by more specifically directing the pathologist. We have found that the technique is reproducible and has a positive impact on training of residents and fellows as well.