Julie S. Weinberg

Objective Outcomes Analysis Following Microvascular Gracilis Transfer for Facial Reanimation: A Review of 10 Years’ Experience

IMPORTANCE Objective assessment of smile outcome after microvascular free gracilis transfer is challenging, and quantification of smile outcomes in the literature is inconsistent. OBJECTIVE To report objective excursion and symmetry outcomes from a series of free gracilis cases and investigate the predictive value of intraoperative measurements on final outcomes. DESIGN, SETTING, AND PARTICIPANTS A retrospective medical chart review was undertaken of all patients who underwent microvascular free gracilis transfer for smile at our institution over the past 10 years. MAIN OUTCOMES AND MEASURES Outcome measures included the following: smile excursion, angle of smile with respect to the vertical midline, and facial symmetry during repose and with smile. Measurements were obtained using an automated tool for assessment of facial landmarks (FACE-Gram). An exhaustive set of intraoperative parameters including degree of recoil of the gracilis muscle following harvest, the degree to which the muscle foreshortened during stimulation of the obturator nerve, final stretched length of the inset muscle, surgeon assessment of neurorrhaphy and pulse pressure, ischemia time, number of sutures used during neurorrhaphy, nerve used to innervate the flap, and surgeon assessment of oral commissure overcorrection were recorded and placed into a linear regression model to investigate correlations with smile. RESULTS From March 2003 to March 2013, 154 microvascular free gracilis transfers were performed for facial reanimation at our institution, 14 (9%) of which were deemed failures. Of the remaining 140 flaps, 127 fulfilled inclusion criteria and constituted the study cohort. Smile excursion, angle excursion, and symmetry of the oral commissure at repose and with smile all improved following gracilis free flap (P < .05). Associations between selected outcomes measures and intraoperative gracilis measurements were identified. CONCLUSIONS AND RELEVANCE Facial reanimation using free gracilis transfer results in quantifiable improvements in oral commissure excursion and facial symmetry both at rest and with smiling. Associations between contractility and internal recoil of the flap and final outcome were identified. LEVEL OF EVIDENCE 4

The effect of electrical and mechanical stimulation on the regenerating rodent facial nerve

Investigators have long sought realistic methods to accelerate regeneration following nerve injury. Herein, we investigated the degree to which manual target muscle manipulation and brief electrical stimulation of the facial nerve, alone or in combination, affects recovery following rat facial nerve injury.

The success of free gracilis muscle transfer to restore smile in patients with nonflaccid facial paralysis.

BackgroundDevelopment of synkinesis, hypertonicity, and poor smile excursion after facial nerve insult and recovery contribute to disfigurement, psychological difficulties, and an inability to convey emotion via facial expression. Despite treatment with physical therapy and chemodenervation, some patients who recover from transient flaccid facial paralysis never spontaneously regain the ability to perform a meaningful smile. MethodsProspective evaluation was performed on 20 patients with nonflaccid facial paralysis who underwent free gracilis muscle transfer. Patients were evaluated using the quality-of-life (QOL) FaCE survey, Facial Nerve Grading Scale, and Facegram to quantify QOL improvement, smile excursion, and symmetry after muscle transfer. ResultsA statistically significant increase in the FaCE score was seen after muscle transfer (paired 2-tailed t test, P < 0.039). In addition, there was a statistically significant improvement in the smile score on the Facial Nerve Grading Scale (P < 0.002), in the lower lip length at rest (P = 0.01) and with smile (P = 0.0001), and with smile symmetry (P = 0.0077) after surgery. ConclusionsFree gracilis muscle transfer has become a mainstay in the management armamentarium for patients who develop severe reduction in oral commissure movement after facial nerve insult and recovery. The operation achieves a high overall success rate, and innovations involving transplanting thinner segments of muscle avoid a cosmetic deformity secondary to excess bulk. This study demonstrates a quantitative improvement in QOL and facial function after free gracilis muscle transfer in patients who failed to achieve a meaningful smile after physical therapy.

Good correlation between original and modified House Brackmann facial grading systems.

Subjective scales of facial function were plagued with reporting variations until the House‐Brackmann scale was described in 1985. Despite its utility, weaknesses were identified, including noninclusion of synkinesis phenomena and insensitivity to segmental weakness. Therefore, the scale was recently revised to address these weaknesses. The objective of this investigation was to determine agreement between the original and the updated House‐Brackmann scales.

Optimizing Total Facial Nerve Patient Management for Effective Clinical Outcomes Research

IMPORTANCE Assessment of outcomes in patients with facial paralysis is challenging owing to the lack of objective tools to evaluate facial function and suboptimal data collection. OBJECTIVE To describe a methodology for prospective evaluation of patients with facial paralysis that permits optimal assessment of clinical outcomes. DESIGN, SETTING, AND PARTICIPANTS At the Massachusetts Eye and Ear Infirmary, we have treated over 2000 patients with facial nerve injury since 2002. To better quantify and improve our outcomes, we have developed what we now believe represents a systematic method for the previsit evaluation, intake, management, and follow-up of our facial nerve patients to optimize data collection for the purposes of clinical outcome studies, as detailed in this retrospective descriptive study. RESULTS Data collection is often poor if there is not a specific individual delegated to the task and is particularly challenging in the intraoperative setting. Retrospective acquisition of data are inherently less accurate and time consuming. A user-friendly searchable database is required to use the collected data. CONCLUSIONS AND RELEVANCE Clinical outcomes research in the field of facial paralysis requires meticulous attention to comprehensive data collection at appropriate time points, precision photography, and the use of available quality of life and objective measurement tools. Ideally, a standardized approach for data collection would be adopted that would permit multi-institutional data analysis to improve the quality of outcomes research currently available. LEVEL OF EVIDENCE NA.

Facial nerve repair: fibrin adhesive coaptation versus epineurial suture repair in a rodent model

Repair of the transected facial nerve has traditionally been accomplished with microsurgical neurorrhaphy; however, fibrin adhesive coaptation (FAC) of peripheral nerves has become increasingly popular over the past decade. We compared functional recovery following suture neurorrhaphy to FAC in a rodent facial nerve model.

Functional recovery after facial nerve cable grafting in a rodent model.

IMPORTANCE Cable grafting is widely considered to be the preferred alternative to primary repair of the injured facial nerve; however, quantitative comparison of the 2 techniques has not been previously undertaken in a rodent model. OBJECTIVE To establish functional recovery parameters after interposition autografting in a rodent facial nerve model. DESIGN, SETTING, AND PARTICIPANTS Prospective randomized animal study at a tertiary care facial nerve center using 16 female Wistar Hannover rats. INTERVENTION The experimental group received reversed autograft reconstruction of a 20-mm neural gap, and the control group received facial nerve transection and primary repair. MAIN OUTCOME AND MEASURE Whisker excursion was measured weekly for 70 postoperative days using laser micrometers. RESULTS The control group exhibited the most rapid recovery, with substantial return of whisker movement occurring during the third postoperative week. The experimental group demonstrated return of function beginning in the fourth postoperative week, eventually achieving a degree of function comparable to that of the control group by the sixth postoperative week (P = .68). CONCLUSIONS AND RELEVANCE Recovery of facial function after cable grafting seems to be slower than, but eventually similar to, recovery after primary neurorrhaphy in a rodent model. In the present study we have established a benchmark for recovery of whisker movement across a 20-mm rodent facial nerve gap, which will be used for comparison of different facial nerve gap bridging materials in future studies. LEVEL OF EVIDENCE NA.

The Effects of Potential Neuroprotective Agents on Rat Facial Function Recovery Following Facial Nerve Injury

Objective. To evaluate whether a series of pharmacologic agents with potential neuroprotective effects accelerate and/or improve facial function recovery after facial nerve crush injury. Study Design. Randomized animal study. Setting. Tertiary care facility. Methods. Eighty female Wistar-Hannover rats underwent head restraint implantation and daily conditioning. Animals then underwent unilateral crush injury to the main trunk of the facial nerve and were randomized to receive treatment with atorvastatin (n = 10), sildenafil (n = 10), darbepoetin (n = 20), or a corresponding control agent (n = 40). The return of whisking function was tracked throughout the recovery period. Results. All rats initiated the return of whisking function from nerve crush by day 12. Darbepoetin-treated rats (n = 20) showed significantly improved whisking amplitude and velocity across the recovery period, with several days of significant pairwise differences vs comparable control rats (n = 16) across the first 2 weeks of whisking function return. In contrast, rats treated with sildenafil (n = 10) and atorvastatin (n = 10) did not show significant improvement in whisking function recovery after facial nerve crush compared to controls. By week 8, all darbepoetin-treated animals and comparable nerve crush control animals fully recovered whisking function and were statistically indistinguishable. Conclusion. Among the 3 potentially neuroprotective agents evaluated, only darbepoetin administration resulted in accelerated recovery of whisking parameters after facial nerve crush injury. Further efforts to define the mechanism of action and translate these findings to the use of darbepoetin in the care of patients with traumatic facial paralysis are needed.

Rat whisker movement after facial nerve lesion: evidence for autonomic contraction of skeletal muscle.

Vibrissal whisking is often employed to track facial nerve regeneration in rats; however, we have observed similar degrees of whisking recovery after facial nerve transection with or without repair. We hypothesized that the source of non-facial nerve-mediated whisker movement after chronic denervation was from autonomic, cholinergic axons traveling within the infraorbital branch of the trigeminal nerve (ION). Rats underwent unilateral facial nerve transection with repair (N=7) or resection without repair (N=11). Post-operative whisking amplitude was measured weekly across 10weeks, and during intraoperative stimulation of the ION and facial nerves at ⩾18weeks. Whisking was also measured after subsequent ION transection (N=6) or pharmacologic blocking of the autonomic ganglia using hexamethonium (N=3), and after snout cooling intended to elicit a vasodilation reflex (N=3). Whisking recovered more quickly and with greater amplitude in rats that underwent facial nerve repair compared to resection (P<0.05), but individual rats overlapped in whisking amplitude across both groups. In the resected rats, non-facial-nerve-mediated whisking was elicited by electrical stimulation of the ION, temporarily diminished following hexamethonium injection, abolished by transection of the ION, and rapidly and significantly (P<0.05) increased by snout cooling. Moreover, fibrillation-related whisker movements decreased in all rats during the initial recovery period (indicative of reinnervation), but re-appeared in the resected rats after undergoing ION transection (indicative of motor denervation). Cholinergic, parasympathetic axons traveling within the ION innervate whisker pad vasculature, and immunohistochemistry for vasoactive intestinal peptide revealed these axons branching extensively over whisker pad muscles and contacting neuromuscular junctions after facial nerve resection. This study provides the first behavioral and anatomical evidence of spontaneous autonomic innervation of skeletal muscle after motor nerve lesion, which not only has implications for interpreting facial nerve reinnervation results, but also calls into question whether autonomic-mediated innervation of striated muscle occurs naturally in other forms of neuropathy.

Quantitative Analysis of Muscle Histologic Method in Rodent Facial Nerve Injury

OBJECTIVE To describe denervation features of facial musculature following facial nerve injury in a rodent model. METHODS Six Wistar-Hannover rats underwent unilateral transection and immediate repair of the facial nerve. After 8 weeks, muscular bundles consisting of dilator naris and levator labii superioris from both sides were analyzed for mean muscle cell diameter and the percentage of muscle cell cross-sectional area using image processing software. The atrophic features of facial muscles were quantified and compared with the contralateral, healthy side of the face. RESULTS Weekly postoperative whisking assessment demonstrated the anticipated course of recovery. We observed significant differences between the normal side and the manipulated side, respectively, in the percentage of muscle specimen cross-sectional area attributable to muscle cell profiles (57% vs 29%; P = .006) and total fiber counts (1346 vs 794; P = .02). The mean cross-sectional area of individual muscle fibers was higher on the normal side (1129 vs 928 μm2; P = .39); however, this difference was statistically nonsignificant. CONCLUSION The objective, quantitative measures of muscle microstructure used in this report provide a valuable point of comparison for whisking function and electrophysiologic measures and can be used in future studies to assess muscle atrophic features associated with facial nerve injury and repair techniques.