Node counts in neck dissection: are they useful in outcomes research?

OBJECTIVES: We studied the unilateral nodal yields for procedures reported as standard or modified radical neck dissection (RND) to determine their applicability in outcomes research. METHODS: We analyzed the unilateral nodal yields for all procedures reported as RND for carcinoma of the oral cavity, pharynx, and larynx at our institution from 1985 to 1997 (n = 64, no prior treatment). These included both standard and modified techniques, encompassing levels I through V of the neck. Each side of a bilateral RND was treated as a separate case. This sample was compared with a similar population from the National Cancer Institute's Surveillance, Epidemiology, and End-Results (SEER) registry. Nodal yield was obtained for RND alone and for unspecified neck dissection with primary excision for the same diseases and time period (n = 1499). RESULTS: The mean nodal yield from 64 RND was 30 vs 27 in the SEER data. The standard deviation was 14.7 compared with 17.2 in the SEER data. Values ranged from 7 to 66 nodes whereas the SEER range was from 1 to 97 nodes. Although the SEER data contain nodal yields from regional or selective neck dissection, we corroborate our findings of large variance in nodal yield from our RND sample. CONCLUSIONS: Large variance in nodal yields from RND may have undefined effects on quality of life, cure rate, and survival. Until correlation of nodal yields with outcomes is examined, we cannot know how to relate RND to outcomes.

Comparison of topical anti-ischemic agents in the salvage of failing random-pattern skin flaps in rats.

OBJECTIVE: To determine the efficacy of topical anti-ischemic drug therapy in the salvage of failing, random-pattern skin flaps. DESIGN: Prospective, randomized, placebo-controlled, therapeutic trial. SETTING: Academic medical center. SUBJECTS: Sixty-one adult male Sprague-Dawley rats. INTERVENTION: Each experimental rat underwent a caudally based random-pattern skin flap using the modified McFarlane technique. Rats were randomized to 1 of 6 treatment groups: topical nifedipine, topical trolamine salicylate, topical nitroglycerin, topical trolamine salicylate-nitroglycerin combination, topical nifedipine-trolamine salicylate-nitroglycerin combination, or inert carrier ointment (control). Treatment was initiated immediately following flap closure and continued every 6 hours for 7 days. At the end of the treatment period, animals were euthanized and flap survival was determined for each one. RESULTS: Topical anti-ischemic drug therapy resulted in a statistically significant reduction in ischemic flap necrosis for each drug (or combination) tested relative to the 44.2% mean necrosis observed in control animals. Treatment with the combination of topical nitroglycerin and topical trolamine salicylate resulted in the best salvage response (25.2% mean necrosis) with a statistically significant improvement in flap survival relative to both controls and nitroglycerin alone. CONCLUSIONS: Topical anti-ischemic agents are effective in reducing ischemic necrosis of failing, random-pattern skin flaps in the rat model. Although nitroglycerin, trolamine salicylate, and nifedipine possess unique pharmacologic mechanisms of action, each drug produced a statistically significant improvement in flap survival. The results of this study suggest that topical drug therapy may play an important role in clinical salvage of the failing skin flap. Further studies are needed to explore the potential of combination drug therapy.

Comparison of the auditory-evoked brainstem response wave I to distortion-product otoacoustic emissions resulting from changes to inner ear blood flow.

OBJECTIVE/HYPOTHESIS: Examine and compare in detail the time courses of the auditory brainstem response (ABR) wave I amplitude and latency to the distortion-product otoacoustic emission (DPOAE) amplitude and phase measured in the rabbit model following deliberate obstruction of cochlear blood flow (CBF). METHODS: Using a posterior fossa craniotomy in five rabbits, the internal auditory artery (IAA) was compressed with a probe. ABR and otoacoustic emission were continuously monitored before, during, and after the compressions. RESULTS: ABR wave I amplitudes demonstrated measurable decreases at a mean of 28.3 s after IAA compression, whereas DPOAE amplitudes decreased after a mean of 14.8 s. Wave I latencies began to increase at a mean of 18.3 s after occlusion, while DPOAE phase measures changed after a mean of only 4.8 s following IAA compression. The time-course patterns were similar for the amplitudes of both ABR wave I and DPOAE. CONCLUSIONS: ABR wave I amplitude follows a similar, though delayed (by approximately 10 s) time-course pattern to that of the DPOAE following IAA compression. The implication of these findings for intraoperative auditory monitoring is that changes in many currently employed measures will lag actual surgically induced alterations in CBF by at least 20 to 30 s.