Surgical interventions for management of benign parotid tumors: Systematic review and network meta-analysis

The impact of the extent of parotid surgery on postoperative complications has long been considered a topic of controversy. The aim of the current network meta-analysis (NMA) is to answer the following questions: (1) Does the extent of surgical resection of benign parotid tumors increase the risk of postoperative complications? (2) What is the best surgical intervention for treatment of benign parotid tumors that can provide an acceptable balance between tumor recurrence rate and other postoperative complications? A comprehensive search on PubMed, Embase, Scopus, and Cochrane library was conducted to identify the eligible studies. The outcome was the incidence of tumor recurrence, facial nerve weakness (temporary [TFW] or permanent [PFP]), Frey's syndrome (FS), sialocele, and salivary fistula. The Bayesian network meta-analysis (NMA) accompanied by a random effect model and 95% credible intervals (CrI) were calculated using the GeMTC R package. Forty-four studies with a total of 7841 participants were included in the current NMA comparing five surgical interventions, namely enucleation, extracapsular dissection (ECD), partial superficial parotidectomy (PSP), superficial parotidectomy (SP), and total parotidectomy (TP). Enucleation showed the highest recurrence rate compared to ECD, SPS, SP, and TP. No statistical differences were observed concerning the recurrence rate when ECD, PSP, SP, and TP were compared together. There was an increased incidence of TFW and FS with the increase in the extent of parotid resection, while no significant difference was found when comparing enucleation with ECD and PSP. SP showed the highest incidence of PFP, and salivary fistula compared to ECD, PSP, and TP. The tumor recurrence rates in enucleation, ECD, PSP, SP, and TP were 14.3%, 3.6%, 3.7%, 2.8%, and 1.4%, respectively. The current NMA demonstrated that the risk of TFW and FS increases with the increase in the extent of parotid resection and that ECD and PSP can be considered the treatment of choice for benign parotid tumors, as both provide an acceptable balance between the incidence of tumor recurrence and facial nerve dysfunction.