OBJECTIVETo objectively evaluate the usefulness and the reliability of the perineural vascular plexus as a landmark for facial nerve as well as whether it will be a landmark for identification of the facial nerve in surgery for otology and neurotology by means of investigating the location of the facial nerve for prevention of iatrogenic facial palsy.

METHODSProspective case series were designed. Three hundred and eleven consecutive patients were studied which required tympanoplasty for chronic otitis media or microsurgery for facial nerve decompression and congenitally malformation of the ear from July 2002 to July 2005. All the patients were operated by the first author. Perineural vascular plexus as a landmark for identification of the facial nerve in surgery were observed to assess the utility.

RESULTSThe well recognized perineural vascular plexus were seen on the horizontal mesotympanic segment of the nerve in 95.8% of patients (298 cases), and only in 4.2% of the patients (13 cases), the vessel plexus was difficult to identify. The 95% confidence interval was from 93.6% to 98.0%.

CONCLUSIONSThe vascular plexuses around or over the horizontal portion of the facial nerve provide an early and direct indicator of the location of the facial nerve. The perineural vascular plexus could be a dependable and reliable landmark for the identification the horizontal part of the facial nerve in surgery for otology and neurotology.