Analysis of complications following surgical treatment of benign parotid disease.

Background: The objective of the study was to study the incidence of, and risk factors for developing complications following parotidectomy for benign disease, to improve preoperative patient counselling and better inform future surgical management.

Methods: An 11-year retrospective review of 162 parotidectomies for benign disease, collecting and analysing data about presentation, investigations, surgical treatment, postoperative facial nerve function, Frey's syndrome and other surgical complications.

Results: The mean age at presentation was 58 years. The commonest pathology was benign pleomorphic adenoma (43%), followed by Warthin's tumour (30%) and chronic sialadenitis (22%). Sialadenitis was a significant risk factor for facial nerve palsy and increased the incidence of salivary fistulas. Parotid duct ligation increased the risk of nerve palsy in the distribution of zygomatic and buccal branches. Operations for Warthin's tumour were associated with an increased risk of dysfunction of the cervical branch of the nerve. Half the patients had intraoperative facial nerve stimulation and this did not influence the likelihood of facial paresis. The recovery of facial nerve function showed a biphasic distribution, with 90% of patients having normal function within 12 months, followed by a slower recovery rate for up to 2 years.

Conclusion: The incidence of postoperative complications was influenced by the pathology, with inflammatory lesions significantly increasing the risk of facial nerve dysfunction and other complications, but also by variations in surgical practice, such as parotid duct ligation. Overall, the incidence of permanent facial paralysis was less than 2%, but temporary nerve palsy was common at 40%, with most patients regaining normal function within 1 year of the operation.