Neurological Complications in Benign Parapharyngeal Space Tumors - Systematic Review and Meta-Analysis.

 Parapharyngeal space tumors with complex anatomy and diverse histology have remained a challenging phenomenon for treating physicians.  We have conducted a comprehensive web search on the PubMed, Web of Science, EMBASE, Cochrane Library, Biomedical Literature Database (CBM), and Clinicaltrials.gov databases to determine the factors that are associated with postoperative complications in parapharyngeal space tumors.  Two researchers reviewed all identified articles independently with a third reviewer for adjudication. Patient demographics and other clinicopathological characteristics were explored. The systematic review has identified 631 benign parapharyngeal space tumors with neurogenic and salivary tissue histology in 13 studies, with a mean age of 42.9 ± 7.76 years old and a median follow-up of 40.98 ± 19.1 months. Salivary gland (50.8%) and neurogenic (49.1%) tumors were the most common histological entities. Tumor size, location, histology, deep parotid lobe involvement, and proximity to great vessels or to the skull base were the deciding factors in selecting the surgical approach. The factors considered to select the surgical approach do not seem to have a correlation with the outcome in terms of neurological sequalae (  = 0.106). Tumors with neurogenic histology have significantly increased chances of developing neurological complication (OR 6.07;  = 0.001).  Neurologic complications are significantly associated with neurogenic benign tumors rather than surgical approach.