Efficacy of Neck Dissection: Are Surgical Volumes Important?

Objectives/Hyphothesis: Surgical volumes have been shown in many fields to reflect expertise and to be associated with improved clinical outcomes. We sought to test similar hypotheses that neck dissection is a volume-sensitive procedure wherein the number of lymph nodes harvested and clinical outcomes are correlated with the number of neck dissections performed. Methods: We conducted a retrospective analysis of 375 neck dissections. The number of nodes harvested was examined by multiple linear regression before and after mathematical correction for pathologists' variation over time. The prior experiences of the surgeons were also averaged, depending on whether there was regional recurrence after at least 9 months of follow-up. Results: More nodes were found by the pathologists over time, with 2.1 more nodes being found on average for each successive year (P < .001). After correcting for this effect of time, there remained a significant relationship between surgeons' experience and number of nodes harvested (P < .003). Additionally, cases that recurred were operated by less-experienced surgeons (P = .02). Conclusions: We have demonstrated that there is a learning curve for neck dissection. Our most experienced surgeon harvested on average 11 more nodes than similar specimens submitted by the group of inexperienced surgeons. The effect of experience remains significant even without adjusting for time (P < .001). Surgical experience also affects clinical outcome months after the dissection. This retrospective review supports surgical volume as an indicator of expertise in neck dissection that could be used to assess trainees' progress and for quality assurance in large head and neck units.