Purpose This review focuses on the etiology, incidence and therapy of delayed paralysis
of the facial nerve (DFP) after different types of middle ear surgery. Methods Retrospective
review of studies published in English from 1970 until 2019 reporting DFP after tympanoplasty,
tympanomastoid surgery, stapedotomy and stapedectomy. The search used the databases
of PubMed, Scopus and Cochrane Library. Studies reporting from adult patients and
DFP onset after 48 h after surgery were included. Studies dealing with iatrogenic
or preexisting facial palsy and case reports were excluded. The initial literature
search resulted in 52 studies. The relevance of the publications was verified using
title, abstract and full-text analysis. Data were analyzed with descriptive statistics
using median, simple sum and statistical significance. Results Ten studies having
12,161 patients could be included in this review. The incidence of DFP after the middle
ear surgeries varies between 0.2 and 1.9%. The surgical stress of the middle ear surgeries
is the main trigger for the development of DFP and leads to a virus reactivation and/or
neuronal edema. Patients with a dehiscence of the facial canal have a significantly
higher probability for a DFP. The recommended therapy of DFP based on the data of
the therapy of Bell's palsy, consists of the administration of a steroid. For patients
having a case history of previous viral infections, an antiviral prophylaxis is recommended.
Conclusion Overall, DFP has a very good prognosis, with mostly complete healing with
appropriate therapy. Viral reactivation is the most favored genesis of DFP. Immunization
or antiviral prophylaxis is recommended to those patients being at risk for a viral
reactivation.
