[Meta-analysis of surgical techniques for preventing Frey syndrome and a concave facial deformity after parotidectomy].

Objective: To explore the curative effects on surgical methods for the prevention of Frey syndrome and a concave facial deformity after parotidectomy.

Methods: A literature search was performed using the Wianfang Database, Chinese Biomedical Literature Disk Database, Chinese Digital Hospital Library and Chinese Scientific Journals Database of VIP from January 1989 to December 2008. Twenty-six Chinese language controlled studies involving surgical techniques for prevention of Frey syndrome and the concave facial deformity after parotidectomy were identified. Review manager 4.2 software was applied for Meta analysis.

Results: Meta-analysis for surgical techniques to prevent symptomatic Frey syndrome, a positive starch-iodine test, and contour deformity, favored intervention with a cumulative odds ratio (OR) of 0.14 [95% confidence interval (CI), 0.07-0.25]; OR, 0.21 (95% CI, 0.17-0.26); and OR, 0.09 (95% CI, 0.04-0.19), respectively. There was a significant difference in the incidence of these complications between surgical treatment groups and control groups (Z = 6.42, Z = 13.70, Z = 6.43, all P < 0.05). The application of a sternocleidomastoid muscle flap decreased the incidence of symptomatic Frey syndrome (Z = 2.33, P < 0.05), positive starch-iodine test (Z = 7.48, P < 0.05) and contour deformity (Z = 7.78, P < 0.05). The application of acellular dermal matrix decreased the incidence of symptomatic Frey syndrome (Z = 6.02, P < 0.05) and positive starch-iodine test (Z = 5.72, P < 0.05) but did not decrease the incidence of contour deformity (Z = 1.27, P > 0.05).

Conclusions: Meta-analysis of operative techniques to prevent symptomatic Frey syndrome, a positive starch-iodine test, and facial asymmetry suggests that such methods are likely to reduce the incidence of these complications and improve the quality of life after parotidectomy.