Comparison of Continuous and Intermittent Nerve Monitoring on Facial Nerve Outcomes in Parotidectomy

Sunday, October 12, 2025

1:48 PM - 1:54 PM EDT

Location: 242

Disclosure(s):

Christian R. Schaaff, BA:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Andrew D.P Prince, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

David WA Forner, MD MSc FRCSC:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Mark E. Prince, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Introduction: Intraoperative facial nerve monitoring (FNM) is crucial in parotidectomy to reduce the risk of facial nerve injury. This study compares FNM between an intermittent surgeon-operated nerve integrity monitoring system (NIMS) and continuous electromyography by trained audiologists (EMG).

Methods: A retrospective cohort study at a tertiary care center was conducted on patients undergoing parotidectomy with FNM for benign tumors from 2018-2023. Fisher exact tests were used for comparisons of demographic, surgical, and outcome variables. Logistic regression modeling controlled for confounders identified in bivariate analysis or selected a priori. Cases with preoperative facial nerve weakness or concurrent procedures were excluded.

Results: Among 334 tumors analyzed, 193 (57.8%) were in female patients, with a mean patient age of 55.3 years. FNM was performed with NIMS in 166 cases and EMG in 168. A greater proportion of NIMS cases were performed outpatient [NIMS: 113 (68.1%); EMG: 84 (50.0%); p=0.0009], but no other demographic or surgical differences were observed. There was no significant difference in transient [NIMS: 25 (15.1%); EMG: 35 (20.8%); p=0.1999] or permanent [NIMS: 2 (1.2%); EMG: 2 (1.2%); p=0.9999] facial nerve weakness. In bivariate analysis, perioperative complications were significantly lower in NIMS cases [NIMS: 29 (17.5%); EMG: 49 (29.2%); p=0.0139], driven by a difference in seroma formation when controlling for total parotidectomy, tumor size, and drain placement [OR=5.2;95%CI: (3.1, 34.2)]. NIMS was selected based on the surgeon preferences for each individual case.

Conclusions: In selected parotidectomy cases for benign tumors, surgeon-operated NIMS monitoring showed similar risk of postoperative facial nerve injury compared to continuous EMG monitoring.

Presenting Author(s)

Christian R. Schaaff, BA

Medical Student
University of Michigan Medical School
Ann Arbor, MI, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Co-Author(s)

AP

Andrew D.P Prince, MD

Otolaryngology Resident
University of Michigan
Ann Arbor, Michigan, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.
KO

Kimberly A. Oslin, MD

Resident
Henry Ford
Royal Oak, MI, United States

Disclosure information not submitted.
DF

David WA Forner, MD MSc FRCSC

Assistant Professor of Otolaryngology-Head and Neck Surgery
University of Michigan
Ann Arbor, Michigan, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.
Mark E. Prince, MD

Professor and Chair
University of Michigan
Ann Arbor, MI, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Senior Author(s)

Steven B. Chinn, MD

Associate Professor
University of Pittsburgh Medical Center
Pittsburgh, PA, United States

Disclosure information not submitted.