Cross-facial nerve grafts and microneurovascular free muscle transfer for long established facial palsy

Outcomes of Free Flap Transfer in Facial Reanimation: A Review

Free functional muscle transfer is is an option for reanimating the face in chronic facial nerve paralysis. The optimal outcome in these patients is the ability to restore a spontaneous smile in response to emotion. We discuss the role of free functional muscle transfer in facial paralysis treatment, the choices of nerve used in reconstruction surgery, and the application of different types of muscle flaps in facial reanimation. In this paper, we review the relevant and up-to-date academic literature regarding the outcomes of free functional muscle flap transfer in facial paralysis patients.

Age-related outcomes of facial reanimation surgery using gracilis free functional muscle transfer innervated by the masseteric nerve: A retrospective cohort study

BACKGROUND

The free functional muscle gracilis transfer is an established approach in facial reanimation surgery; however, the significance of its neurotization and the patient's age is still inconclusive. Several donor nerves are available for facial reanimation using the free functional gracilis muscle transfer.

OBJECTIVE

This retrospective cohort study investigates whether the masseteric nerve is an equally reliable donor nerve in both older and younger patients.

METHODS

We included 46 patients (13-71 years, male and female) who underwent nerve-to-masseter (NTM)-driven free functional muscle transfer (FFMT) between January 2008 and December 2019. Patients were distributed into three cohorts according to their age at surgery. We assessed the facial symmetry before and after surgery using the pupillo-modiolar angle. Commissure height and excursion deviation were measured with the Emotrics software. Patient-reported outcome measurements were taken using the Facial Clinimetric Examination (FaCE) scale.

RESULTS

All patients had successful flap innervation, except for one patient in the middle-aged cohort (31-51 years). The postoperative facial symmetry at rest, smiling, and laughing was analyzed with the pupillo-modiolar angle and the Emotrics software and showed similar results between all cohorts. The FaCE scale showed similar scores for the middle-aged (31-51 years) cohort and the senior cohort (52-71 years). The social function score in the senior cohort was higher than in the middle-aged cohort, without statistical significance. One patient in the middle-aged (31-51 years) cohort and the senior cohort (52-71 years), respectively, underwent emergency revision due to impaired flap perfusion and could be salvaged.

CONCLUSIONS

NTM-driven FFMT for facial reanimation is a safe and reliable procedure across all age groups of patients.

Gracilis Muscle-Free Flap Objective Improvement of Oral Commissure Excursion in Facial Palsy Reanimation Surgery: Systematic Review and Meta-Analysis

Background: Facial palsy patients face significant challenges. Gracilis free flap transfer is a key procedure in facial reanimation. Objective: This study aims to analyze oral commissure excursion improvement after gracilis free flap transfer and the differences regarding donor nerve: cross-facial nerve graft (CFNG), hypoglossal or spinal accessory nerves, motor nerve to masseteric (MNTM), and most recently, double anastomosis using both the MNTM and CFNG. Methods: A systematic review and meta-analysis were conducted of studies reporting oral commissure excursion improvement after free gracilis muscle transfer. Pooled proportions were calculated using a random-effects model. Results: Eighteen studies, 453 patients, and 488 free gracilis flaps were included. The mean change in perioperative oral commissure excursion was 7.0 mm, for CFNG 7.2 mm, for MNTM 7.7, and for double anastomoses 5.5 mm. Conclusions: There is a significant improvement in oral commissure excursion after gracilis muscle-free flap. Unfortunately, we could not make definitive conclusions regarding the optimal choice of donor nerve.

Microvascular Gracilis Free Flap: Single and Double Innervation

Facial paralysis (FP) is a devastating condition that can lead to significant aesthetic, social, and emotional morbidities for patients. For some patients with FP, free gracilis muscle transfer (FGMT) is the best option for smile restoration. Masseteric-driven FGMT produces a reliable voluntary smile. Cross-face nerve graft-driven FGMT can produce a spontaneous smile, but this technique has higher failure rates. Early studies suggest dual-innervation FGMT can produce a spontaneous smile while maintaining the reliability of masseteric-driven procedures. Great care should be taken during FGMT surgery to minimize facial bulk and place medial inset sutures that create a natural-appearing smile.

MODIFIED GRACILIS MUSCLE FLAP IN FACIAL REANIMATION: U-SHAPED DESIGN

BACKGROUND

Surgical treatment of long-term facial palsy has been reported using various techniques, including functioning muscle-free flaps. The free gracilis muscle flap is the most common because of its many advantages. Our study presents a modified way of shaping the gracilis muscle for transfer to the face to improve the restoration of natural smiles.

METHODS

This retrospective study assessed 5 patients who received the classical technique and 43 patients who received modified, U-shaped, free gracilis muscle flap for smile reanimation from 2013 to 2018. The surgery is single-staged. Preoperative and postoperative photos were taken. Functional outcomes were evaluated using the Terzis and Noah score and the Chuang smile excursion score.

RESULTS

The mean patient age at the time of operation was 31 years. The length of gracilis muscle harvested was 12-13 cm. Of the 43 patients who received U-shaped design-free gracilis muscle, results were excellent for 15 (34.9%), good for 20 (46.5%), and fair for 8 (18.6%) followed the Terzis and Noah score. The Chuang smile excursion score was 2 for 16.3%, 3 for 46.5%, and 4 for 37.2% of 43 patients. Of the 5 patients who underwent classical technique, there are no excellent results based on the Terzis and Noah score. The Chuang smile excursion score was only 1 and 2.

CONCLUSIONS

The U-shaped modification to the gracilis muscle-free flap is a simple and effective technique to help restore a symmetrical and natural smile in patients with facial palsy.

Assessing the Efficacy of Anastomosis between Ansa Cervicalis and Facial Nerve for Patients with Concomitant Facial Palsy and Peripheral Neuropathy

Background: For decades, patients with facial asymmetry have experienced social interaction difficulties, leading them to seek treatment in the hope of restoring facial symmetry and quality of life. Researchers evaluated numerous surgical techniques, but achieving results remains a significant hurdle. Specifically, anastomosis between the ansa cervicalis (AC) and facial nerve (FN) can hinder the patient's physical appearance. Objective: Our study goal was to examine the efficiency of anastomosis between AC and FN for facial motor function recovery even in the presence of peripheral neuropathy. Materials and Methods: Four patients diagnosed with facial palsy grade VI on the House & Brackmann Scale (HB) after vestibular schwannoma (VS) resection (Koos grade IV) via the retrosigmoid approach underwent AC and FN anastomosis. Outcomes were related to tumor grade, previous therapy, and the time between postoperative facial palsy and anastomosis. Images and neurophysiological data were evaluated. Results: After vs. resection, all four patients demonstrated HB grade VI facial palsy for an average of 17 months. During the follow-up program, lasting between 6 and 36 months, two patients were evaluated as having HB grade III facial palsy; the other two patients were diagnosed with grade IV HB facial palsy. None of the patients developed tongue atrophy, speech disorder, or masticatordys function. Conclusions: Anastomosis between the AC and FN is a safe and effective treatment for facial paralysis after cerebellopontine tumor resection. Nerve reanimation may be feasible even for patients with peripheral polyneuropathy. This study also offers a new option for patients with a progression-free status.

Super-resolved fluorescence imaging of peripheral nerve

Traditional histopathologic evaluation of peripheral nerve employs brightfield microscopy with diffraction limited resolution of ~ 250 nm. Though electron microscopy yields nanoscale resolution of the nervous system, sample preparation is costly and the technique is incompatible with living samples. Super-resolution microscopy (SRM) comprises a set of imaging techniques that permit nanoscale resolution of fluorescent objects using visible light. The advent of SRM has transformed biomedical science in establishing non-toxic means for investigation of nanoscale cellular structures. Herein, sciatic nerve sections from GFP-variant expressing mice, and regenerating human nerve from cross-facial autografts labelled with a myelin-specific fluorescent dye were imaged by super-resolution radial fluctuation microscopy, stimulated emission depletion microscopy, and structured illumination microscopy. Super-resolution imaging of axial cryosections of murine sciatic nerves yielded robust visualization myelinated and unmyelinated axons. Super-resolution imaging of axial cryosections of human cross-facial nerve grafts demonstrated enhanced resolution of small-caliber thinly-myelinated regenerating motor axons. Resolution and contrast enhancement afforded by super-resolution imaging techniques enables visualization of unmyelinated axons, regenerating axons, cytoskeleton ultrastructure, and neuronal appendages of mammalian peripheral nerves using light microscopes.

Age-related outcome of facial reanimation surgery using cross face nerve graft and gracilis free functional muscle transfer-A retrospective cohort study

BACKGROUND

Free functional muscle transfer has become the criterion standard for the treatment of long-standing flaccid facial paralysis. Clinical experience suggests that a two-stage approach using a cross-face nerve graft (CFNG) as a donor nerve for free functional muscle transfers (FFMT) is less successful in older patients when compared to the pediatric population. However, clear data and scientific evidence are still rare. This study examines the age-related outcome of CFNG-driven FFMT.

METHODS

Twenty-eight patients with a mean age of 20.73 years (ranging 5-51 years) who received two-stage facial reanimation with CFNG-driven gracilis FFMT at our institution from 1998 to 2019 were included. The ipsilateral sural nerve was used as CFNG. After 12 months, the ipsilateral gracilis muscle was used as FFMT. Patients were distributed equally into three cohorts according to their age. We assessed facial symmetry before and after facial reanimation measuring the angle between the interpupillary and the intermodiolar line (pupillo-modiolar angle). Additionally, the commissure height was measured using the Emotrics software.

RESULTS

The mean follow-up of the pediatric, young adults and the middle-aged cohort was 29.5 ± 7.3, 24.9 ± 6.3, and 25.5 ± 12.4 months, respectively. One patient suffered flap loss due to flap ischemia. Four patients suffered insufficient innervation of the FFMT. Otherwise no major complication occurred. The likelihood of successful innervation of the FFMT was significantly higher in patients younger than 31 years (100% vs. 50%; p = .003). Smiling facial symmetry (pupillo-modiolar angle) significantly improved in the pediatric cohort (5-16 years; 8.68° ± 0.69° to 1.48° ± 0.67°; p < .001) and the young adults' cohort (17-30 years; 11.55° ± 1.95° to 4.62° ± 1.08°; p = .005), but improved only slightly in the middle-aged cohort (31-51 years; 11.77° ± 1.16° to 9.4° ± 1.8° p = .27). The postoperative smiling symmetry showed a significant correlation with increasing age (r = .62, p < .001). The smiling commissure height deviation significantly improved in the pediatric cohort (5-16 years; 6.5-2.3 mm; p = .006) and the postoperative result was significantly better than the middle-aged group (31-51 years; 2.3 vs. 7.5 mm; p = .02).

CONCLUSIONS

The outcome of CFNG-driven gracilis FFMT is age-related. Static as well as dynamic facial symmetry after two-stage facial reanimation was best in the pediatric and young adult population. For older patients, other approaches like the nerve-to-masseter-driven FFMT should be considered.

Seminal Studies in Facial Reanimation Surgery: Consensus and Controversies in the Top 50 Most Cited Articles

ABSTRACT

Facial paralysis can impair one's ability to form facial expressions that are congruent with internal emotion. This hinders communication and the cognitive processing of emotional experience. Facial reanimation surgery, which aims to restore full facial expressivity is a relatively recent undertaking which is still evolving. Due in large part to published techniques, refinements, and clinical outcomes in the scientific literature, consensus on best practice is gradually emerging, whereas controversies still exist.Taking stock of how the discipline reached its current state can help delineate areas of agreement and debate, and more clearly reveal a path forward. To do this, the authors have analyzed the 50 seminal publications pertaining to facial reanimation surgery. In longstanding cases, the free gracilis transfer emerges as a clear muscle of choice but the nerve selection remains controversial with prevailing philosophies advocating cross facial nerve grafts (with or without the support of an ipsilateral motor donor) or an ipsilateral motor donor only, of which the hypoglossal and nerve to masseter predominate. The alternative orthodoxy has refined the approach popularized by Gillies in 1934 and does not require the deployment of microsurgical principles. Although this citation analysis does not tell the whole story, surgeons with an interest in facial reanimation will find that this is a good place to start.

Neurotization Preferences in Smile Reanimation: A Discrete Choice Experiment

BACKGROUND

Common donor nerve options in smile reanimation include ipsilateral trigeminal motor or contralateral facial nerve branches. Neurotization preference may be influenced by multiple factors, whose relative importance remains poorly understood. In this article, decision-making in smile reanimation is assessed using a stated preference model.

METHODS

Qualitative interviews with facial palsy patients identified five relevant attributes for study: smile type ("smile when biting" versus "smile spontaneously" as proxies for trigeminal versus cross-facial neurotization), number of operations, success rates, complication rates, and side effects. Community volunteers (n = 250) completed a discrete-choice experiment relevant to free muscle transfer for smile reanimation. Preoperative and postoperative states were demonstrated through video vignettes, together with explanation of surgical risks, consequences, and benefits. Attribute importance was modeled using hierarchical Bayes estimation.

RESULTS

Two hundred forty-one responses met quality controls. Attribute importance ranked as follows: chance of success, 37.3 percent; smile type, 21.4 percent; side effects, 13.9 percent; complication rates, 13.8; and number of operations, 13.6 percent. All attributes significantly correlated with decision making (p < 0.0001). An aggregate response model revealed most participants (67.6 percent; standard error, 3.0 percent) preferred smile reanimation by cross-facial (assuming a success rate of 80 percent) as opposed to ipsilateral trigeminal motor branch neurotization. When the success rate for cross-facial neurotization was reduced below 67 percent, trigeminal neurotization was preferred.

CONCLUSIONS

Despite a higher risk of failure, most respondents preferred a cross-facial as opposed to trigeminal neurotization strategy for smile reanimation. These findings highlight the complexity of decision-making and need for individualized risk tolerance assessment in the field of facial reanimation.

Temporalis Tendon Transfer Versus Gracilis Free Muscle Transfer: When and Why?

Temporalis tendon transfer (T3) and gracilis free muscle transfer (GFMT) are popular techniques in lower facial rehabilitation when reinnervation techniques are unavailable. T3 involves a single-stage outpatient procedure resulting in immediate improvement in resting symmetry and a volitional smile. GFMT allows a spontaneous smile, customized vectors, and increased excursion but requires longer surgical time, a delay before movement, and specialized equipment. Ultimately, shared decision making between the clinician and patient should focus on the patient's goals and unique medical condition.

Lessons from Gracilis Free Tissue Transfer for Facial Paralysis: Now versus 10 Years Ago

Outcomes following free gracilis muscle transfer have steadily improved during the past decade. Areas for continued improvement include re-creating natural smile vectors, improving midface symmetry, minimizing scarring, improving spontaneity, and increasing reliability using various neural sources. Outcome standardization, pooled data collection, and remote data acquisition methods will facilitate comparative effectiveness research and continued surgical advancements.

Transfacial transmandibular approach to the masticator space: Excision of odontogenic myxoma arising from the mandibular condyle

Odontogenic myxomas are an uncommon benign odontogenic tumor that can present with a wide variety of symptomatology depending on location and potentially be locally destructive. The present case describes a 66-year-old female who presented with left lower facial paresthesia, left aural fullness and hearing loss. She was found to have an odontogenic myxoma that involved the condylar head and extended into the masticator space. In this report we detail our surgical approach utilizing a preauricular transfacial transmandibular approach to the masticator space. In addition, we will discuss various approaches to the masticator space and infratemporal fossa along with considerations on how to manage facial nerve paralysis, facial contour deformities, and post-operative rehabilitation for permanent unilateral condylar head disarticulation.

The reverse flow extensor digitorum brevis flap for dorsal foot defects-A single center study

BACKGROUND

Defects on the dorsum of the foot remain a reconstructive challenge for plastic surgeons. There are very few pedicled flaps that have a reach up to the distal foot and those too with a threat of poor perfusion. Very often distal foot has to be resurfaced with free flap even with small defects. This study describes our experience with the reverse extensor digitorum brevis muscle (EDB) flap for small- to medium-sized defects on the dorsum of the foot.

METHODS

The study was conducted on 12 patients between February 2018 and March 2020 who presented with defects on the dorsum of the foot. The mean age of the patients was 30.8 years and the mean defect size was 20.17 cm². The EDB was applied on 10 male and 2 female subjects and resurfaced with a split thickness skin graft. The donor site was closed primarily.

RESULTS

All flaps survived well. Two patients had small graft loss and 2 partial wound dehiscence of donor site, all of which healed on conservative treatment. Three patients had temporary sensory disturbance which resolved in few weeks.

CONCLUSION

The reverse EDB flap is a reliable flap for the coverage of small- to medium-sized dorsal foot defects. The flap has the advantage of robust vascularity, expendable muscle with little donor site morbidity, an easy to learn technique, short operating time, and acceptable esthetic outcome, and it can be used as the primary option in cases of small to medium dorsal foot defects.

Facial Animation With Free Functional Gracilis Transfer Innervated by the Cross-Facial Nerve Graft

BACKGROUND

The treatment of long-standing facial paralysis has always been a challenge for plastic surgery. The purpose of this study was to demonstrate that the free functional gracilis transfer innervated by the cross-facial nerve graft (CFNG) is still an ideal option, even though there are many new surgical options available.

METHODS

A retrospective survey was made on 12 patients who received free functional gracilis transfer innervated by the CFNG. A modified version of the House-Brackmann scale was used to evaluate the movement of the corners of mouth after surgery. Patients were also asked about their satisfaction with the operation. In addition, an objective test was performed to assess the postoperative angle improvement by measuring the angle formed between the horizontal line of both corners of the lips and the vertical midline.

RESULTS

All grafts survived well. No severe complication occurred. Three patients received further surgical operations for aesthetic reasons. The movement of the corners of mouth was classified as excellent in 8 cases, good in three cases, and fair in one cases. The static angle and dynamic angle of postoperation improved and the range of dynamic angle improvement was larger than that of static angle.

CONCLUSION

Free functional gracilis transfer innervated by the CFNG is an ideal technique for facial paralysis. It can effectively improve the facial dynamic of the affected side.

Modern Management of Facial Nerve Disorders

Facial paralysis is a devastating condition, encompassing a spectrum of disorders, with resultant psychosocial, functional, and aesthetic sequelae. With this in mind, an individualized treatment approach based on the cause, pattern, and duration of palsy is necessary. Treatment options include pharmacologic agents, corneal protective interventions, physical therapy, and surgical procedures. The use of steroids and antivirals in the setting of idiopathic facial paralysis or virus-associated facial paralysis is well supported. Despite the diversity of surgical interventions described, there is a lack of consensus regarding optimal treatment. This article provides an overview of the current management of facial paralysis. Medical, surgical, and physical treatment options are discussed with a review of the relevant literature.

Hypoglossal-Facial Side-to-End Neurorrhaphy With Concomitant Masseteric-Zygomatic Nerve Branch Coaptation and Muscle Transfer for Facial Reanimation: Technique and Case Report

BACKGROUND

Hypoglossal-facial direct side-to-end neurorrhaphy has become widely used for facial reanimation in patients with irreversible facial nerve damage. Although this procedure achieves good restoration of facial function, it has disadvantages such as mass movement and lack of spontaneity.

OBJECTIVE

To present a new facial reanimation technique using hypoglossal-facial direct side-to-end neurorrhaphy with concomitant masseteric-zygomatic nerve branch coaptation and secondary muscle transfer to reduce mass movement and achieve a spontaneous smile in patients with facial paralysis.

METHODS

This article describes a novel facial reanimation technique that employs hypoglossal and masseteric nerve transfer combined with secondary vascularized functional gracilis muscle transfer.

RESULTS

Details of the technique are reported in a patient with complete facial paralysis after brain surgery. The hypoglossal nerve was partially served and connected to the mastoid segment of the facial nerve by side-to-end anastomosis to restore facial symmetry. A nerve supplying the masseter muscle was coapted with a zygomatic branch by end-to-end anastomosis to restore voluntary movement of the oral commissure, as well as to assist with eye closure. A cross face sural nerve graft was connected to zygomatic branches on the healthy side. In the second stage, a vascularized functional gracilis muscle graft was transplanted using the cross face nerve graft as the donor nerve to restore a natural smile.

CONCLUSION

Hypoglossal-facial neurorrhaphy with concomitant masseteric-zygomatic nerve branch coaptation and muscle transfer is an alternative facial reanimation technique that reduces mass movement and achieves a natural smile.

Powering the Gracilis for Facial Reanimation: A Systematic Review and Meta-analysis of Outcomes Based on Donor Nerve

Importance

Free gracilis transfer for dynamic reanimation in chronic facial paralysis is the gold standard, but there remains a need to better understand outcomes with respect to the donor nerve.

Objective

To characterize outcomes in adults undergoing primary gracilis transfer for facial paralysis stratified by donor nerve used for neurotization.

Data Sources

Search strategies were used in Ovid MEDLINE (1946-2019), Embase (1947-2019), Scopus (1823-2019), Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov (1997-2019).

Study Selection

Inclusion and exclusion criteria were designed to capture studies in adults with unilateral chronic facial paralysis undergoing single-paddle free gracilis transfer. All study types were included except case reports. Abstracts and full texts were reviewed in duplicate. Of 130 unique citations, 10 studies including 295 patients were included after applying inclusion and exclusion criteria. Data were analyzed between November 2018 and December 2019.

Data Extraction and Synthesis

PRISMA guidelines were followed. The Newcastle-Ottawa scale was used to assess study quality, and the Cochrane Risk of Bias tool was used to assess risk of bias. Independent extraction by 2 authors (P.M.V. and J.J.C.) was performed. Data were pooled using a random-effects model.

Main Outcomes and Measures

Owing to heterogeneity in reporting of facial reanimation outcomes, we first performed a systematic review, and then compiled available outcomes for meta-analysis. Outcomes studied for meta-analysis were oral commissure excursion and facial symmetry.

Results

Meta-analysis of masseteric nerve (MN) (n = 56) vs cross-facial nerve graft (CFNG) (n = 52) in 3 retrospective studies showed no statistical heterogeneity between these studies (I2 = 0%), and the standardized mean difference (SMD) was greater for MN (0.55; 95% CI, 0.17 to 0.94). Meta-analysis of angles of symmetry in 2 retrospective studies comparing MN (n = 51) to CFNG (n = 47) both at rest (-0.22; 95% CI, -0.63 to 0.18) and with smiling (-0.14; 95% CI, -0.73 to 0.46) were better with MN, though the difference was not statistically significant.

Conclusions and Relevance

Owing to heterogeneity in reported outcomes from facial reanimation, we were unable to make definitive conclusions regarding the optimal donor nerve. Establishing a reporting standard at peer-reviewed journals to improve results reporting is one method to allow for improved collaboration in the future. Standardizing follow-up times, assessing spontaneity in an objective and reproducible fashion, and use of consistent outcome measures would allow for future meta-analyses and better understanding of options for facial reanimation.

Impact of increasing age on functioning free muscle transplantation for facial palsy reconstruction

BACKGROUND

Management of facial paralysis in older patients is controversial. The purpose of this study is to evaluate the impact of increasing age on functioning free muscle transplantation (FFMT).

PATIENTS AND METHODS

Twenty-nine facial paralysis patients over 50 years old received FFMT. A separate group of patients aged 41-50 years old were included as control. Outcome assessments included use of the SMILE evaluation system for excursion, a cortical adaptation scoring system for brain plasticity, and a subjective satisfaction assessment score. Meta-analysis of literature over the past 50 years was also performed to examine the impact of older age.

RESULTS

The mean change in excursion movement was 13.39 ± 5.49 mm. Weakest excursion was found in the oldest age group (11.74 ± 4.84 mm, p = .097), in concordance with the meta-analysis. There was significant difference between the three different neurotizers (p = .036). Excursion and satisfaction score were significantly worse in the older cohort with the cross face-nerve graft FFMT.

CONCLUSIONS

FFMT is a viable option in the elderly patient group but performs weaker in excursion. The choice of neurotizer is dependent on the patient's goals and the suitable age at which the benefits outweigh the risks.

Obturator Nerve Split for Gracilis Free-flap Double Reinnervation in Facial Paralysis

The use of a double-powered free muscle transfer for facial reanimation has been reported by several authors with different types of nerve coaptation. A new nerve coaptation strategy is presented herein. We performed a 1-stage double-powered free gracilis muscle flap transfer in a patient with long-standing facial paralysis by splitting the obturator nerve and anastomosing the 2 free ends to the contralateral facial nerve (through a sural graft) and to the masseteric nerve. Voluntary movement of the transferred muscle with teeth clenching was observed at 6 months after the operation and a symmetric smile with bilateral elevation of the mouth angle at 10 months. Our limited experience suggests that in case of a large cross-section of the obturator nerve, the latter can be split and sutured to the ipsilateral masseteric nerve and to the contralateral facial nerve with a sural graft by double end-to-end anastomosis.

A Rapid Protocol for Intraoperative Assessment of Peripheral Nerve Myelinated Axon Count and Its Application to Cross-Facial Nerve Grafting

BACKGROUND

Donor nerve myelinated axon counts correlate with functional outcomes in reanimation procedures; however, there exists no reliable means for their intraoperative quantification. In this article, the authors report a novel protocol for rapid quantification of myelinated axons from frozen sections, and demonstrate its applicability to surgical practice.

METHODS

The impact of various fixation and FluoroMyelin Red staining strategies on resolved myelin sheath morphology from cryosections of rat and rabbit femoral and sciatic nerves was assessed. A protocol comprising fresh cryosection and rapid staining was developed, and histomorphometric results were compared against conventional osmium-postfixed, resin-embedded, toluidine blue-stained sections of rat sciatic nerve. The rapid protocol was applied for intraoperative quantification of donor nerve myelinated axon count in a cross-facial nerve grafting procedure.

RESULTS

Resolution of myelinated axon morphology suitable for counting was realized within 10 minutes of tissue harvest. Although mean myelinated axon diameter appeared larger using the rapid fresh-frozen as compared to conventional nerve processing techniques (mean ± SD; rapid, 9.25 ± 0.62 μm; conventional, 6.05 ± 0.71 μm; p < 0.001), no difference in axon counts was observed on high-power fields (rapid, 429.42 ± 49.32; conventional, 460.32 ± 69.96; p = 0.277). Whole nerve myelinated axon counts using the rapid protocol herein (8435.12 ± 1329.72) were similar to prior reports using conventional osmium processing of rat sciatic nerve.

CONCLUSIONS

A rapid protocol for quantification of myelinated axon counts from peripheral nerves using widely available equipment and techniques has been described, rendering possible intraoperative assessment of donor nerve suitability for reanimation.

Innervation of an engineered muscle graft for reconstruction of muscle defects

Autologous muscle flaps are commonly used to reconstruct defects that involve muscle impairment. To maintain viability and functionality of these flaps, they must be properly vascularized and innervated. Tissue-engineered muscles could potentially replace autologous muscle tissue, but still require establishment of sufficient innervation to ensure functionality. In this study, we explored the possibility of innervating engineered muscle grafts transplanted to an abdominal wall defect in mice, by transferring the native femoral nerve to the graft. Six weeks posttransplantation, nerve conduction studies and electromyography demonstrated increased innervation in engineered grafts neurotized with the femoral nerve, as compared to non-neurotized grafts. Histologic assessments revealed axonal penetration and formation of neuromuscular junctions within the grafts. The innervation process described here may advance the fabrication of a fully functional engineered muscle graft that will be of utility in clinical settings.

One-stage reconstruction by dual-innervated double muscle flap transplantation with the neural interconnection between the ipsilateral masseter and contralateral facial nerve for reanimating established facial paralysis: A report of 2 cases

The authors developed a one-stage double-muscle reconstruction technique for facial paralysis using a latissimus dorsi (LD) flap and a serratus anterior (SA) flap, which were dually reinnervated by the contralateral facial nerve (FN) and ipsilateral masseter nerve (MN). The procedure was performed for 61-year-old man 3-years after resection of a malignant tumor and a 24-year-old woman 10-years after temporal fracture with facial paralysis. A double-muscle flap comprising left LD and SA flaps was harvested, a 15-cm thoracodorsal nerve (TN) section was attached to the LD flap, and 5-cm and 1-cm sections of the long thoracic nerve (LTN) were attached to the proximal and distal sides of SA flap. The LD flap and SA flap were sutured along the direction of motion of the zygomaticus major and risorius muscles, respectively. The contralateral FN and ipsilateral MN were interconnected by nerve suturing: the medial branch of TN to the distal end of LTN, the proximal end of LTN to the ipsilateral MN, and the buccal branch of contralateral FN to the main trunk of TN. After surgery, good contraction of the transferred flaps resulted in reanimation of a natural symmetrical smile; no complications were observed during the 12-month follow-up period.

Free Gracilis Transfer and Static Facial Suspension for Midfacial Reanimation in Long-Standing Flaccid Facial Palsy

This article presents an approach to reanimation of the midface in long-standing flaccid facial palsy by means of functional free gracilis transfer and static facial suspension.

Evaluation of the effects of a polyglycolic acid-collagen tube in the regeneration of facial nerve defects in rats

PURPOSE

The purpose of this study was to assess the utility of a polyglycolic acid-collagen tube and to investigate its possible application in the field of facial nerve reconstruction.

METHODS

Wistar rats were used in this study. In the operation, a periauricular incision was made to expose the buccal and marginal branches of the facial nerve. Gaps of 10 mm were created by resection of a part of the nerve into the marginal branches and the buccal branch of the left facial nerve. The left marginal branch gap was bridged with a 10-mm polyglycolic acid-collagen tube or an autograft. At 12 weeks after the operation, nerve regeneration was assessed based on clinical, histopathological, and electrophysiological evaluations.

RESULT

The functional recovery of the vibrissal muscle was observed with the polyglycolic acid-collagen tube. However, the functional recovery obtained with the use of the polyglycolic acid-collagen tube was inferior to that obtained with an autograft.

CONCLUSION

We found that polyglycolic acid-collagen tubes could be applied in facial nerve gap reconstruction. However, further improvements will be necessary to achieve results that are equivalent to those obtained with autografts.

Qualitative and Quantitative Analysis of Smile Excursion in Facial Reanimation: A Systematic Review and Meta-analysis of 1- versus 2-stage Procedures

Background:

Free functional muscle transfer has become a common treatment modality for smile restoration in long-lasting facial paralysis, but the selection of surgical strategy between a 1-stage and a 2-stage procedure has remained a matter of debate. The aim of this study was to compare the quantitative and qualitative outcomes of smile excursion between 1-stage and 2-stage free muscle transfers in the literature.

Methods:

A comprehensive review of the published literature between 1975 and end of January 2017 was conducted.

Results:

The abstracts or titles of 2,743 articles were screened. A total of 24 articles met our inclusion criteria of performing a quantitative or qualitative evaluation of a free-functioning muscle transfer for smile restoration. For the purpose of meta-analysis, 7 articles providing quantitative data on a total of 254 patients were included. When comparing muscle excursion between 1-stage and 2-stage procedures, the average range of smile excursion was 11.5 mm versus 6.6 mm, respectively. For the purpose of systematic review, 17 articles were included. The result of the systematic review suggested a tendency toward superior functional results for the 1-stage procedure when comparing the quality of smile.

Conclusions:

The results of this review must be interpreted with great caution. Quantitative analysis suggests that 1-stage procedures produce better excursion than 2-stage procedures. Qualitative analysis suggests that 1-stage procedures might also produce superior results when based on excursion and symmetry alone, but these comparisons do not include one important variable dictating the quality of a smile—the spontaneity of the smile. The difficulty in comparing published results calls for a consensus classification system for facial palsy.

Simultaneous Surgical Treatment for Smile Dysfunction and Lagophthalmos Involving a Dual Latissimus Dorsi Flap

Paralytic lagophthalmos and smile dysfunction are serious complications of facial paralysis and various reconstructive procedures have been developed to treat them. Among these procedures, there is no doubt that dynamic procedures are more effective than static ones. The 1-stage simultaneous surgical treatment of these 2 dysfunctions with a dynamic procedure involving a single muscle would be ideal, but no such methods have been reported. In this article, we present a 1-stage method for the simultaneous surgical treatment involving the use of a dual latissimus dorsi muscle flap. In this method, 2 muscle flaps based on the descending and transverse branches of the thoracodorsal vessels are transferred to the face. The descending and transverse branches of the thoracodorsal nerve are sutured to separate branches of the masseteric nerve. Using this method, complete eyelid closure during strong clenching and voluntary smiling during weak clenching without eyelid closure were achieved. Although our method does not result in spontaneous smiling, we believe that it is a good option for some patients with long-standing facial paralysis.

An Anatomical study for localisation of Zygomatic branch of Facial nerve and Masseteric nerve - An aid to nerve coaptation for facial reanimation surgery: A cadaver based study in Eastern India

CONTEXT

In cases of chronic facial palsy, where direct neurotisation is possible, ipsilateral masseteric nerve is a very suitable motor donor. We have tried to specifically locate the masseteric nerve for this purpose.

AIMS

Describing an approach of localisation and exposure of both the zygomatic branch of Facial nerve and the nerve to masseter, with respect to a soft tissue reference point over face.

SETTINGS AND DESIGN

Observational cross sectional study, conducted on 12 fresh cadavers.

SUBJECTS AND METHODS

A curved incision was given, passing about 0.5cms in front of the tragal cartilage. A reference point "R" was pointed out. The zygomatic branch of facial nerve and masseteric nerve were dissected out and their specific locations were recorded from fixed reference points with help of copper wire and slide callipers.

STATISTICAL ANALYSIS USED

Central Tendency measurements and Unpaired "t" test.

RESULTS

Zygomatic branch of the Facial nerve was located within a small circular area of radius 1 cm, the centre of which lies at a distance of 1.1 cms (±0.4cm) in males and 0.2cm (±0.1cm) in females from the point, 'R', in a vertical (coronal) plane. The nerve to masseter was noted to lie within a circular area of 1 cm radius, the centre of which was at a distance of 2.5cms (±0.4cm) and 1.7cms (±0.2cm) from R, in male and female cadavers, respectively. Finally, Masseteric nerve's depth, from the masseteric surface was found to be 1cm (±0.1cm; male) and 0.8cm (±0.1cm; female).

CONCLUSIONS

This novel approach can reduce the post operative cosmetic morbidity and per-operative complications of facial reanimation surgery.

Extensor Digitorum Brevis Flap for the Coverage of Ankle and Dorsal Foot Wounds: A Technical Trick

Soft tissue wounds overlying the dorsum of the foot and ankle are difficult to treat, and historically have been treated with free tissue transfer. Advances in surgical technique have expanded the use of pedicle perforator flaps to avoid free tissue transfer in certain situations. The authors describe a technique for using an extensor digitorum brevis flap to provide soft tissue coverage for wounds of the ankle and foot. In the senior authors' experience, the use of this flap has achieved wound coverage in 100% of patients with smaller wounds (≤45 cm) of the ankle.

Masseteric-facial nerve neurorrhaphy: results of a case series

OBJECTIVE Facial palsy is a well-known functional and esthetic problem that bothers most patients and affects their social relationships. When the time between the onset of paralysis and patient presentation is less than 18 months and the proximal stump of the injured facial nerve is not available, another nerve must be anastomosed to the facial nerve to reactivate its function. The masseteric nerve has recently gained popularity over the classic hypoglossus nerve as a new motor source because of its lower associated morbidity rate and the relative ease with which the patient can activate it. The aim of this work was to evaluate the effectiveness of masseteric-facial nerve neurorrhaphy for early facial reanimation. METHODS Thirty-four consecutive patients (21 females, 13 males) with early unilateral facial paralysis underwent masseteric-facial nerve neurorrhaphy in which an interpositional nerve graft of the great auricular or sural nerve was placed. The time between the onset of paralysis and surgery ranged from 2 to 18 months (mean 13.3 months). Electromyography revealed mimetic muscle fibrillations in all the patients. Before surgery, all patients had House-Brackmann Grade VI facial nerve dysfunction. Twelve months after the onset of postoperative facial nerve reactivation, each patient underwent a clinical examination using the modified House-Brackmann grading scale as a guide. RESULTS Overall, 91.2% of the patients experienced facial nerve function reactivation. Facial recovery began within 2-12 months (mean 6.3 months) with the restoration of facial symmetry at rest. According to the modified House-Brackmann grading scale, 5.9% of the patients had Grade I function, 61.8% Grade II, 20.6% Grade III, 2.9% Grade V, and 8.8% Grade VI. The morbidity rate was low; none of the patients could feel the loss of masseteric nerve function. There were only a few complications, including 1 case of postoperative bleeding (2.9%) and 2 local infections (5.9%), and a few patients complained about partial loss of sensitivity of the earlobe or a small area of the ankle and foot, depending on whether great auricular or sural nerves were harvested. CONCLUSIONS The surgical technique described here seems to be efficient for the early treatment of facial paralysis and results in very little morbidity.

Modification of the Labbé Procedure: Integration of the Deep Temporalis Fascia Turnover Flap

Modification of the lengthening temporalis myoplasty for reanimation of facial paralysis is presented. A patient experienced traumatic laceration of the left facial nerve resulting in left hemifacial paralysis. Multiple attempts at nerve repair were unsuccessful. For smile restoration, a Labbé procedure was performed. Because of inadequate length, the temporalis tendon could not be directly secured to the modiolus. Therefore, an inferiorly based temporalis fascia flap was recruited from the deep temporal fascia and reflected inferiorly to provide additional length by which the tendon could be secured to the modiolus. This technique provided immediate smile restoration and required no additional donor site.

A new paradigm in facial reanimation for long-standing palsies?

Background:

A chance observation of return of excellent facial movement, after 18 months following the first stage of cross-face nerve grafting, without free functional muscle transfer, in a case of long-standing facial palsy, lead the senior author (RBA) to further investigate clinically.

Patients and Methods:

This procedure, now christened as cross-face nerve extension and neurotization, was carried out in 12 patients of very long-standing facial palsy (mean 21 years) in years 1996-2011. The mean patient age and duration of palsy were 30.58 years and 21.08 years, respectively. In patients, 1-5 a single buccal or zygomatic branch served as a donor nerve, but subsequently, we used two donor nerves. The mean follow-up period was 20.75 months.

Results:

Successive patients had excellent to good return of facial expression with two fair results. Besides improved smile, patients could largely retain air in the mouth without any escape and had improved mastication. No complications were encountered except synkinesis in 1 patient. No additional surgical procedures were performed.

Conclusion:

There is experimental evidence to suggest that neurotization of a completely denervated muscle can occur by the formation of new ectopic motor end plates. Long-standing denervated muscle fibres eventually atrophy severely but are capable of re-innervation and regeneration, as validated by electron microscopic studies. In spite of several suggestions in the literature to clinically validate functional recovery by direct neurotization, the concept remains anecdotal. Our results substantiate this procedure, and it has the potential to simplify reanimation in longstanding facial palsy. Our work now needs validation by other investigators in the field of restoring facial animation.

Extensor digitorum brevis flap on the treatment of lower limb injuries

OBJECTIVE:

To describe our pioneer national experience with 11 patients with soft tissue defects in the distal 1/3 of the leg, ankle and forefoot treated with extensor digitorum brevis muscle flap (EDB).

METHODS:

Between November 2009 and July 2012 11 patients were operated with the flap technique. We operated nine men and two women aged between 10 and 66 years. The surgical indications were acute trauma in four patients and post-traumatic osteomyelitis in seven patients. The small defects were covered ranging from 3x3 to 6x3 cm. The patch was applied with proximal stalk in most cases.

RESULTS:

Complete healing and infectious cure were obtained in all cases, despite one loss.

CONCLUSION:

The EDB flap is a feasible and safe technique to repair foot, ankle and distal leg losses. Suffering, dehiscence and delayed healing of the EDB end flap donor area may, however, occur. L-shaped incisions should be avoided for muscle lifting. Level of Evidence IV, Case series.

Reinnervation of segmented latissimus dorsi muscle with the distal stump of the thoracodorsal nerve: A preliminary experimental study in rats

To date, nerve stumps have been dissected at the proximal side of the donor muscle for reinnervation of the muscle in free neurovascular muscle transfer. Herein, we examined the use of the distal thoracodorsal nerve, dissected from the muscle belly at the distal side of the latissimus dorsi muscle, for the reinnervation of muscle. The rat right latissimus dorsi muscle was employed as the model for our study. Twenty Wistar rats were used in this study. A rectangular muscle segment was dissected with the distal stump of dominant thoracodorsal nerve. After rotation of muscle, the distal nerve stump was sutured to a severed proximal recipient thoracodorsal nerve (n = 5). The degree of reinnervation through the distal nerve stump was compared with control groups that received proximal-to-proximal nerve sutures (n = 5), nerves that were not severed (n = 5), and severed nerves that were not sutured (n = 5) using electrophysiological, histological, and muscular volume assessments. Reinnervation of the distal nerve stump was confirmed by the contraction of the muscle following electrical stimulation and electromyography. Crossing of axons into motor endplates was confirmed by histology. Results of these assays were similar to that of the proximal nerve suture group. The volume of muscle in the distal nerve suture group was not significant different from that of the proximal nerve suture group (P = 0.63). It was demonstrated that the distal stump of the thoracodorsal nerve can be used to innervate segmented latissimus dorsi muscle. This novel procedure for the reinnervation of transplanted muscle deserves further investigations.

Anatomical Research of the Three-dimensional Route of the Thoracodorsal Nerve, Artery, and Veins in Latissimus Dorsi Muscle

BACKGROUND

The latissimus dorsi (LD) muscle flap has been widely used in facial reanimation surgery. However, there are no standards to what degree the muscle flap may be safely thinned because the three-dimensional positional relationship of thoracodorsal artery, vein, and nerve inside the LD muscle is poorly understood.

METHODS

From 18 formalin-fixed cadavers, we made 36 transparent specimens of LD muscles using a newly developed decoloration technique. In 26 specimens, nerve staining (Sihler's staining method) and silicone rubber (Microfil) injection to the thoracodorsal artery were performed, and the relationship of the artery and the vein was examined in 10 specimens.

RESULTS

The thoracodorsal artery and vein always ran parallel in a deeper layer compared to the nerve. The thoracodorsal nerve constantly existed in a deeper layer than half (50%) of the muscle in the range of use of the muscle flap in facial reanimation surgery.

CONCLUSIONS

The thoracodorsal nerves ran in a shallower layer, and the depth to the nerve in the muscle flap in actual facial reanimation surgery is safe enough to avoid damage to the nerves. The LD muscle may be thinned to half its original thickness safely.

Recycle of temporal muscle in combination with free muscle transfer in the treatment of facial paralysis

We experienced three patients with long-standing unilateral complete facial paralysis who previously underwent temporalis muscle transfer to the cheek for smile reconstruction. All patients complained of insufficient and uncomfortable buccal motion synchronised with masticatory movements and incomplete eyelid closure with ptotic eyebrow. To attain a near-natural smile and reliable eyelid closure, temporalis muscle was displaced from the cheek to the eyelid, and a neurovascular free latissimus dorsi muscle was transferred for the replacement of cheek motion. As a result, cheek motion synchronised with the contralateral cheek upon smiling and sufficient eyelid closure were obtained in all cases. Smile reconstruction using the temporal muscle is an easy and a versatile way in general. However, spontaneous smile is not achieved and peculiar movement of the cheek while eating is conspicuous in some cases. Replacement with neurovascular free latissimus dorsi muscle and recycling previously used temporalis muscle for eyelid closure are considered to be valuable for such cases.

Hemihypoglossal nerve transfer for acute facial paralysis

Object

The authors have developed a technique for the treatment of facial paralysis that utilizes anastomosis of the split hypoglossal and facial nerve. Here, they document improvements in the procedure and experimental evidence supporting the approach.

Methods

They analyzed outcomes in 36 patients who underwent the procedure, all of whom had suffered from facial paralysis following the removal of large vestibular schwannomas. The average period of paralysis was 6.2 months. The authors used 5 different variations of a procedure for selecting the split nerve, including evaluation of the split nerve using recordings of evoked potentials in the tongue.

Results

Successful facial reanimation was achieved in 16 of 17 patients using the cephalad side of the split hypoglossal nerve and in 15 of 15 patients using the caudal side. The single unsuccessful case using the cephalad side of the split nerve resulted from severe infection of the cheek. Procedures using the ansa cervicalis branch yielded poor success rates (2 of 4 cases).

Some tongue atrophy was observed in all variants of the procedure, with 17 cases of minimal atrophy and 14 cases of moderate atrophy. No procedure led to severe atrophy causing functional deficits of the tongue.

Conclusions

The split hypoglossal-facial nerve anastomosis procedure consistently leads to good facial reanimation, and the use of either half of the split hypoglossal nerve results in facial reanimation and moderate tongue atrophy.