2876 - Does Adjuvant Radiation Affect Facial Nerve Recovery? A Hidden Setback Following Total Facial Nerve Sacrifice
Presenter(s)
A. D. Williams1, M. Davis1,2, A. E. Simpson1, A. E. Martinez1, R. B. Appel1, A. Ha2, P. W. Gidley3, P. Yu2, and Z. H. Lee2; 1Division of Plastic and Reconstructive Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX, 2Department of Plastic and Reconstructive Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, 3Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, TX
Purpose/Objective(s): Facial nerve grafting is the reconstructive gold standard following oncologic facial nerve sacrifice. Studies have shown that adjuvant radiation does not significantly impact the final degree of facial nerve recovery in most cases. We hypothesize that patients who undergo total facial nerve sacrifice are more impacted by adjuvant radiation and experience worse functional recovery.
Materials/Methods: A retrospective chart review was conducted on patients who underwent oncologic parotidectomy with nerve grafting for total facial nerve sacrifice between Jul 2000 to Mar 2020 at one institution. Those who received static procedures in grafted regions were excluded. Subjects were divided into two cohorts: those who received adjuvant radiation and those who did not. The Facial Nerve Grading System (FNGS) classifies facial paralysis on a scale from I (normal) and VI (complete paralysis) across four regions: brow, eye, nasolabial fold (NF), and oral. To align FNGS scores with the main anatomical facial nerve branches, we categorized grafted regions as follows: brow = temporal-frontal; eye = zygomatic; NF = zygomatic or buccal; oral = buccal, marginal mandibular, or cervical. Final regional and overall FNGS scores were compared between cohorts using the Mann-Whitney U test. Linear regression was performed on all grafted regions combined to analyze the impact of adjuvant radiation age, preoperative palsy, smoking status, BMI, and diabetes mellitus on final FNGS score. A p-value <0.05 was considered statistically significant.
Results: 91 grafted facial regions across 44 patients were included (36, 16, 21, and 18 to the brow, eye, NF and oral regions, respectively). Of these, 31 patients (70.5%) received adjuvant radiation, with 70.3%) of grafts exposed to radiation. The average final FNGS score was significantly worse for patients who received adjuvant radiation than those who did not (4.27 vs. 3.42, p=0.0239). No significant changes were seen for any particular facial region. In linear regression, adjuvant radiation is associated with worse FNGS scores (ß=0.85753, p=0.0253). No other comorbidities were significantly associated with postoperative FNGS scores.
Conclusion: In patients who undergo grafting following total facial nerve sacrifice during oncologic parotidectomy, adjuvant radiation may negatively impact postoperative facial nerve recovery. Ongoing analysis aims to describe the impact of various radiotherapeutic treatment plans and explore potential differences in nerve recovery rates between radiation-based cohorts.
Abstract 2876 - Table 1
| Facial Region n patients | No Adjuvant Radiation Mean (SD) | Adjuvant Radiation Mean (SD) | p-value* |
| Brow n = 36 | 4.11 (1.96) | 4.41 (1.69) | 0.7330 |
| Eye n = 16 | 3.27 (1.74) | 3.97 (1.54) | 0.2582 |
| NF n = 21 | 3.91 (1.45) | 4.03 (1.64) | 0.7697 |
| Oral n = 18 | 4.09 (1.30) | 4.24 (1.55) | 0.7681 |
| Overall n = 91 | 3.42 (1.53) | 4.27 (1.58) | 0.0239 |