The Shaw scalpel and development of facial nerve paresis after superficial parotidectomy.

OBJECTIVE To evaluate the independent relationship of the Shaw scalpel on the development of facial nerve injury in patients undergoing superficial parotidectomy. METHODS A retrospective review of 77 cases between 1991 and 1996. Forty-eight percent of the surgical procedures were performed using the Shaw scalpel, and 52% were performed using a cold knife. To assess whether use of the Shaw scalpel is an independent predictor of facial nerve injury, both univariate analysis and regression analysis were used in the statistical analysis of the data. RESULTS Fifty-four percent of the patients who underwent a parotidectomy in which the Shaw scalpel was used developed postoperative facial weakness, compared with 14% of those who underwent a cold knife parotidectomy (P=.002). CONCLUSION Multivariate analysis revealed that use of the Shaw scalpel represents an independent risk factor for development of facial nerve weakness after parotidectomy (P=.01), even after other risk factors are controlled for.