The hypoglossal–facial nerve repair as a method to improve recovery of motor function after facial nerve injury

Extradural contralateral S1 nerve root transfer for spastic lower limb paralysis

The current study aims to ascertain the anatomical feasibility of transferring the contralateral S1 ventral root (VR) to the ipsilateral L5 VR for treating unilateral spastic lower limb paralysis. Six formalin-fixed (three males and three females) cadavers were used. The VR of the contralateral S1 was transferred to the VR of the ipsilateral L5. The sural nerve was selected as a bridge between the donor and recipient nerve. The number of axons, the cross-sectional areas and the pertinent distances between the donor and recipient nerves were measured. The extradural S1 VR and L5 VR could be separated based on anatomical markers of the dorsal root ganglion. The gross distance between the S1 nerve root and L5 nerve root was 31.31 (± 3.23) mm in the six cadavers, while that on the diffusion tensor imaging was 47.51 (± 3.23) mm in 60 patients without spinal diseases, and both distances were seperately greater than that between the outlet of S1 from the spinal cord and the ganglion. The numbers of axons in the S1 VRs and L5 VRs were 13414.20 (± 2890.30) and 10613.20 (± 2135.58), respectively. The cross-sectional areas of the S1 VR and L5 VR were 1.68 (± 0.26) mm 2 and 1.08 (± 0.26) mm 2, respectively. In conclusion, transfer of the contralateral S1 VR to the ipsilateral L5 VR may be an anatomically feasible treatment option for unilateral spastic lower limb paralysis.

Direct Hemi-Hypoglossal Nerve and Hypoglossal Nerve for Suprascapular Nerve/Proximal Brachial Plexus Neurotization: A Cadaveric Feasibility Study

Introduction Partial restoration of shoulder function is important in upper brachial plexus lesions, and the suprascapular nerve is often the target for such neurotization procedures. Although there is an extensive history of peripheral nerve surgeons using the hypoglossal nerve for various local nerve transfers, some have reported using this nerve as a donor for upper brachial plexus grafting procedures. We discuss our anatomical findings for the use of a direct hypoglossal to suprascapular nerve transfer. Materials and methods Fifteen adult cadavers (30 separate sides) were dissected to reveal the hypoglossal nerve in the neck and the supraclavicular brachial plexus in the supraclavicular region. On 15 sides, the hypoglossal nerve was dissected anteriorly to the midline, cut, and transposed toward the supraclavicular region in half of the dissections. On the remaining sides, the nerve was hemisected longitudinally into two equal parts, and the cut inferior portion also swung inferiorly toward the supraclavicular region. The cut end of the hypoglossal nerve was brought toward the proximal suprascapular nerve, the fifth (C5) and sixth (C6) cervical nerve roots, and the upper trunk. Measurements included the length and diameter of the cervical portion of the hypoglossal nerve and the diameter of the suprascapular nerve. Results The mean diameter and length of the hypoglossal nerve were 2.1 millimeters (mm) and 72.8 mm, respectively. The mean diameter of the proximal suprascapular nerve was 2.7 mm. Successful, tension-free transposition to the C5 and C6 nerve roots was achieved on all sides. The average extra length of the hypoglossal nerve for a C5 root transposition was 8 mm and 5.2mm for a C6 root transposition. The distal hypoglossal nerve reached the upper trunk on all but two sides (6.7%). The distal hypoglossal nerve reached the proximal suprascapular nerve on all but four sides (13.3%). Of the 87% of sides (n=26) where the hypoglossal nerve reached the proximal suprascapular nerve, 58% of these (n=15) required some manipulation of the suprascapular nerve from its origin at the upper trunk. This technique resulted in a mean additional length to the suprascapular nerve of 35 mm. No differences were found between the completely cut hypoglossal nerves and hemisected nerves in regard to working length. Conclusions To our knowledge, the use of the hypoglossal nerve as a transpositional graft for direct suprascapular nerve neurotization has not been previously described. Based on our study, we propose that the hypoglossal nerve, or hemi-hypoglossal nerve, should be considered as a donor nerve to restore suprascapular nerve function in the majority of patients. Additionally, the hypoglossal nerve may be transferred to the C5 and C6 roots and upper trunk of the brachial plexus for direct neurotization.

DHI Increases the Proliferation and Migration of Schwann Cells Through the PI3K/AKT Pathway and the Expression of CXCL12 and GDNF to Promote Facial Nerve Function Repair

The facial nerve is one of the vulnerable nerves in otolaryngology. Repair and recovery of facial nerve injury have a high priority in clinical practice. The proliferation and migration of Schwann cells are considered of great significance in the process of nerve injury repair. Danhong injection (DHI), as a common drug for cardiovascular and cerebrovascular diseases, has been fully certified in neuroprotection research, but its role in facial nerve injury is still not clear. Our study found that DHI can promote the proliferation and migration of RSC96 cells, a Schwann cell line, and this effect is related to the activation of the PI3K/AKT pathway. LY294002, an inhibitor of PI3K, inhibits the proliferation and migration of RSC96 cells. Further studies have found that DHI can also promote the expression of CXCL12 and GDNF at gene and protein levels, and CXCL12 is, while GDNF is not, PI3K/AKT pathway-dependent. Animal experiments also confirmed that DHI could promote CXCL12 and GDNF expression and promote facial nerve function recovery and myelin regeneration. In conclusion, our in vitro and in vivo experiments demonstrated that DHI could promote the proliferation and migration of Schwann cells through the PI3K/AKT pathway and increase the expression of CXCL12 and GDNF to promote facial nerve function repair.

LncRNA RMRP knockdown promotes proliferation and migration of Schwann cells by mediating the miR-766-5p/CAND1 axis

The proliferation and migration of Schwann cells (SCs) promote nerve regeneration after facial nerve injury. In recent years, the role of long noncoding RNAs (lncRNAs) in regulating SC proliferation and migration has been gradually uncovered. However, there is little evidence on the function of lncRNA RMRP (lnc-RMRP) in SC growth. In the present study, we performed loss-of-function and overexpression assays to explore the function of lnc-RMRP in SCs. The relationships between lnc-RMRP, miR-766-5p and CAND1 (cullin-associated and neddylation-dissociated 1) were analyzed using bioinformatics analysis, luciferase detection, RNA binding protein immunoprecipitation and RNA pulldown methods. CCK-8, EdU, Transwell and wound healing assays were utilized for the detections of cell proliferation and migration. We found that lnc-RMRP silencing enhanced cell proliferation and migration of SCs, while lnc-RMRP overexpression showed the opposite effect. Mechanistically, lnc-RMRP directly bound to and negatively modulated the expression of miR-766-5p. MiR-766-5p knockdown decreased cell viability, proliferation and migration of SCs, and also reversed the effects of lnc-RMRP silencing. In addition, lnc-RMRP positively regulated CAND1 expression by sponging miR-766-5p. Upregulation of CAND1 rescued the function of lnc-RMRP knockdown in regulating SC proliferation and migration. These data suggested that lnc-RMRP played a significant role in SC proliferation and migration, indicating that lnc-RMRP might be a potential therapeutic target for the treatment of facial nerve injury.

Facial reanimation using the hypoglossal nerve and ansa cervicalis: a short-term retrospective analysis of surgical outcomes

Background

Transferring the hypoglossal nerve to the facial nerve using an end-to-end method is very effective for improving facial motor function. However, this technique may result in hemitongue atrophy. The ansa cervicalis, which arises from the cervical plexus, is also used for facial reanimation. We retrospectively reviewed cases where facial reanimation was performed using the ansa cervicalis to overcome the shortcomings of existing techniques of hypoglossal nerve transfer.

Methods

The records of 15 patients who underwent hypoglossal nerve transfer were retrospectively reviewed. Three methods were used: facial reanimation with hypoglossal nerve transfer (group 1), facial nerve reanimation using the ansa cervicalis (group 2), and sural nerve interposition grafting between the hypoglossal nerve and facial nerve (group 3). In group 1, the ansa cervicalis was coapted to neurotize the distal stump of the hypoglossal nerve in a subset of patients. Clinical outcomes were evaluated using the House-Brackmann (H-B) grading system and Emotrics software.

Results

All patients in group 1 (n = 4) achieved H-B grade IV facial function and showed improvements in the oral commissure angle at rest (preoperative vs. postoperative difference, 6.48° ± 0.77°) and while smiling (13.88° ± 2.00°). In groups 2 and 3, the oral commissure angle slightly improved at rest (group 2: 0.95° ± 0.53°, group 3: 1.35° ± 1.02°) and while smiling (group 2: 2.06° ± 0.67°, group 3: 1.23° ± 0.56°). In group 1, reduced tongue morbidity was found in patients who underwent ansa cervicalis transfer.

Conclusion

Facial reanimation with hypoglossal nerve transfer, in combination with hypoglossal nerve neurotization using the ansa cervicalis for complete facial palsy patients, might enable favorable facial reanimation outcomes and reduce tongue morbidity. Facial reanimation using the ansa cervicalis or sural nerve for incomplete facial palsy patients did not lead to remarkable improvements, but it warrants further investigation.

Motor Relearning After Hypoglossal-Facial Nerve Anastomosis

ABSTRACT

Facial paralysis is a clinical condition associated with significant functional and psychosocial morbidity (Facial Plast Surg FPS. 2011;27(4):346-57). The management paradigm for this condition continues to evolve with the use of both surgical and nonsurgical strategies (Facial Plast Surg FPS. 2011;27(4):346-57). Hypoglossal-facial nerve anastomosis is a surgical technique whereby the hypoglossal nerve acts as a donor motor nerve to restore facial muscle reinnervation via movements of the tongue (Plast Reconstr Surg. 1979;63(1):63-72). This case describes a 33-yr-old woman with unilateral facial paralysis who underwent hypoglossal-facial nerve anastomosis and 14 wks of postoperative rehabilitation. This report highlights the details of her rehabilitation regimen including the specific techniques used to enhance motor relearning of facial expression through movement of the tongue.

Facial Nerve Repair by Muscle-Vein Conduit in Rats: Functional Recovery and Muscle Reinnervation

The facial nerve is the most frequently damaged nerve in head and neck traumata. Repair of interrupted nerves is generally reinforced by fine microsurgical techniques; nevertheless, regaining all functions is the exception rather than the rule. The so-called "postparalytic syndrome," which includes synkinesia and altered blink reflexes, follows nerve injury. The purpose of this study was to examine if nerve-gap repair using an autologous vein filled with skeletal muscle would improve axonal regeneration, reduce neuromuscular junction polyinnervation, and improve the recovery of whisking in rats with transected and sutured right buccal branches of the facial nerve. Vibrissal motor performance was studied with the use of a video motion analysis. Immunofluorescence was used to visualize and analyze target muscle reinnervation. The results taken together indicate a positive effect of muscle-vein-combined conduit (MVCC) on the improvement of the whisking function after reparation of the facial nerve in rats. The findings support the recent suggestion that a venal graft with implantation of a trophic source, such as autologous denervated skeletal muscle, may promote the monoinnervation degree and ameliorate coordinated function of the corresponding muscles.

Split hypoglossal facial anastomosis for facial nerve palsy due to skull base fractures: A case report

Introduction

Traumatic brain injury (TBI) is the most prevalent causes of morbidity and mortality worldwide. The biomechanics of primary TBI involve a direct impact, practically extended to the base of the skull, and most of the skull base fractures (SBF) are identified in anterior and medial cranial fossa. Furthermore, those predicted in the medial area are related to fissures from temporal bones.

Presentation of case

We report two cases of right facial nerve palsy initiated by SBF's, which were diagnosed and treated at our institution. The 3D CT evaluation in our first case showed a longitudinal fracture of the right petrosal bone, which was longitudinal and transverse for the second case. Two cases of facial nerve palsy were managed with split hypoglossal facial anastomosis to restore functional reanimation. All patients were adequately achieved after the procedure, and the hypoglossal nerve function was preserved.

Conclusion

Split hypoglossal facial anastomosis technique was used to treat patients with facial nerve paralysis resulting from SBF's. This was to achieve good recovery outcome, in terms of facial reanimation and preservation of tongue function.

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A skull base fracture (SBF) is about 4% of all cases Traumatic brain injury (TBI).

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SBF which frequently occurs in the petrous part of the temporal bone, is implicated in facial nerve palsy.

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Split hypoglossal facial anastomosis technique showed good recovery of facial reanimation with HB scale assessment.

Assessment of axonal sprouting and motor performance after hypoglossal-facial end-to-side nerve repair: experimental study in rats

Hypoglossal-facial nerve anastomosis (HFA) aims to reanimate denervated mimic muscles with hypoglossal axons when the transected facial nerve is not accessible. The aim of this study was to evaluate the recovery of HFA using a "Y" tube in two variants: (1) the proximal stump of the hypoglossal nerve was entubulated to the "Y" tube (classic "Y" tube HFA) and (2) the "Y" tube was sutured to an epineurial window of a slightly damaged hypoglossal nerve (end-to-side "Y" tube HFA). A total of 48 adult female rats were divided into four groups: intact controls (group 1), sham operated (group 2), classic "Y" tube HFA (group 3) and end-to-side "Y" tube HFA (group 4). The abdominal aorta with both common iliac arteries of isogeneic male rats served as the Y-tube conduit. Animals from group 4 recovered better than those from group 3: the degree of collateral axonal branching (3 ± 1%) was significantly lower than that determined in group 3 (13 ± 1%). The mean deviation of the tongue from the midline was significantly smaller in group 4 (6 ± 4°) than that measured in animals from group 3 (41 ± 6°). In the determination of vibrissal motor function in group 3 and group 4, a decrease in amplitude was found to be - 66% and - 92%, respectively. No differences in the reinnervation pattern of the target muscles were detected. As a result, these surgical models were not determined to be able to improve vibrissal movements. It was concluded that performance of end-to-side "Y" tube HFA diminishes collateral axonal branching at the lesion site, which in turn, promotes better recovery of tongue- and vibrissal-motor performance.

Side-to-End Hypoglossal-Facial Neurorrhaphy for Treatment of Complete and Irreversible Facial Paralysis after Vestibular Schwannoma Removal by Means of a Retrosigmoid Approach: A Clinical and Anatomic Study

BACKGROUND

Facial paralysis secondary to a complete and irreversible anatomic or functional lesion of the facial nerve (FN) causes severe functional and psychological disorders for the patient. A large number of surgical techniques have therefore been developed for FN repair. Our objective was to propose a surgical FN reanimation protocol for patients with irreversible anatomic or functional postsurgical injury of the FN in the cerebellopontine angle after vestibular schwannoma resection.

METHODS

The clinical study included a total of 16 patients undergoing side-to-end hypoglossal-facial neurorrhaphy (SEHFN) since 2010, in which the FN injury was always secondary to vestibular schwannoma surgery in the cerebellopontine angle using a retrosigmoid approach. All patients had complete clinical facial paralysis at the time of the SEHFN. The anatomic study was conducted using 3 heads and necks (6 SEHFN).

RESULTS

Twelve months after surgery, FN function assessment with the House and Brackmann scale showed 2 patients with grade II, 13 patients with grade III, and only 1 patient with grade IV, and after 2 years, 4 patients had grade II, 11 patients had grade III, and 1 patient had grade IV. The average length of the anastomotic translocation portion of the FN in the anatomic study was 34.76 mm.

CONCLUSIONS

Side-to-end epineural suture of the FN, mobilizing its mastoid segment on the hypoglossal nerve with partial section of the dorsal aspect of the hypoglossal nerve, is a safe anatomic surgical technique for FN reanimation with outstanding clinical results.

Facial Nerve Injury and Repair: A Practical Review for Cutaneous Surgery

BACKGROUND

The facial nerve and its branches are at risk of injury during dermatologic surgery. Few publications in the dermatologic literature discuss facial nerve injury and management.

OBJECTIVE

To review facial nerve injury and management, including static and dynamic repair techniques, and to review outcomes in facial nerve reconstruction.

METHODS

Two detailed literature reviews were performed using PubMed. First, articles reporting facial nerve injury and/or management in the dermatologic literature were identified. In addition, articles pertaining to outcomes in facial nerve reconstruction with a minimum of 20 patients were included.

RESULTS

Fifty-three articles reporting outcomes in facial nerve reconstruction were identified and consist of retrospective reviews and case series. Most patients achieve improvement in facial symmetry and movement with nerve repair.

CONCLUSION

Timing of facial nerve repair is an important consideration in management of facial nerve injury, with earlier repairs achieving better outcomes. Facial nerve repair does not result in normal facial movement, and improvements may require a year or more to be realized. Many options exist for facial nerve reconstruction, and patients with long-standing facial nerve injuries may still benefit from treatment.

Effect of surgically guided axonal regrowth into a 3-way-conduit (isogeneic trifurcated aorta) on functional recovery after facial-nerve reconstruction: Experimental study in rats

BACKGROUND

The "post-paralytic syndrome" after facial nerve reconstruction has been attributed to (i) malfunctioning axonal guidance at the fascicular (branches) level, (ii) collateral branching of the transected axons at the lesion site, and (iii) intensive intramuscular terminal sprouting of regenerating axons which causes poly-innervation of the neuromuscular junctions (NMJ).

OBJECTIVE

The first two reasons were approached by an innovative technique which should provide the re-growing axons optimal conditions to elongate and selectively re-innervate their original muscle groups.

METHODS

The transected facial nerve trunk was inserted into a 3-way-conduit (from isogeneic rat abdominal aorta) which should "guide" the re-growing facial axons to the three main branches of the facial nerve (zygomatic, buccal and marginal mandibular). The effect of this method was tested also on hypoglossal axons after hypoglossal-facial anastomosis (HFA). Coaptational (classic) FFA (facial-facial anastomosis) and HFA served as controls.

RESULTS

When compared to their coaptation (classic) alternatives, both types of 3-way-conduit operations (FFA and HFA) promoted a trend for reduction in the collateral axonal branching (the proportion of double- or triple-labelled perikarya after retrograde tracing was slightly reduced). In contrast, poly-innervation of NMJ in the levator labii superioris muscle was increased and vibrissal (whisking) function was worsened.

CONCLUSIONS

The use of 3-way-conduit provides no advantages to classic coaptation. Should the latter be impossible (too large interstump defects requiring too long interpositional nerve grafts), this type of reconstruction may be applied. (230 words).

Hypoglossal-facial 'side'-to-side Neurorrhaphy Combined with Electrical Myostimulation for Facial Palsy in Rats

Introduction This study investigated the effect of combining hypoglossal-facial nerve “side”-to-side neurorrhaphy and electrical myostimulation in a rat model of facial palsy.

Methods Rats with facial nerve crush injury were subjected to control condition, monotherapy of either neurorrhaphy or electrical myostimulation, or bitherapy of the two treatments. After 1, 3, and 6 months, rats were performed the facial symmetry evaluation, electrophysiological examination and the retrograde labeling of motor neurons.

Results As early as 3 months after injury, face symmetry significantly improved in rats of the bitherapy group. At 3 or 6 months after injury, either the parameters of electrophysiological examination or the number of labeled motor neurons were significantly increased in the bitherapy group than in any other group.

Discussion The combination of neurorrhaphy and electrical myostimulation effectively promoted the functional recovery after facial nerve crush injury.

Stimulation of morphofunctional repair of the facial nerve with photobiomodulation, using the end-to-side technique or a new heterologous fibrin sealant

This research evaluated the influence of Photobiomodulation Therapy (PBMT) on lesions of the facial nerve repaired with the end-to-side technique or coaptation with a new heterologous fibrin sealant. Thirty-two Wistar rats were separated into 5 groups: Control group (CG), where the buccal branch of the facial nerve was collected; Experimental Suture Group (ESG) and Experimental Fibrin Group (EFG), in which the buccal branch was end-to-side sutured to the zygomatic branch on the right side of the face or coaptated with fibrin sealant on the left side; Experimental Suture Laser Group (ESLG) and Experimental Fibrin Laser Group (EFLG), in which the same procedures were performed as the ESG and EFG, associated with PBMT (wavelength of 830nm, energy density 6.2J/cm², power output 30mW, beam area of 0.116cm², power density 0.26W/cm², total energy per session 2.16J, cumulative dose of 34.56J). The laser was applied for 24s/site at 3 points on the skin's surface, for a total application time of 72s, performed immediately after surgery and 3 times a week for 5weeks. A statistically significant difference was observed in the fiber nerve area between the EFG and EFLG (57.49±3.13 and 62.52±3.56μm², respectively). For the area of the axon, fiber diameter, axon diameter, myelin sheath area and myelin sheath thickness no statistically significant differences were found (p<0.05). The functional recovery of whisker movement occurred faster in the ESLG and EFLG, which were associated with PBMT, with results closer to the CG. Therefore, PBMT accelerated morphological and functional nerve repair in both techniques.

Facial reanimation using hypoglossal-facial nerve anastomosis after schwannoma removal

CONCLUSION

In this series, the split type hypoglossal-facial nerve anastomosis resulted in more favorable outcomes in terms of both facial function and tongue atrophy.

OBJECTIVE

This study compared surgical techniques for hypoglossal-facial nerve anastomosis after schwannoma removal and evaluated which technique achieves better facial outcomes and less tongue morbidity.

METHOD

This study included 14 patients who underwent hypoglossal-facial nerve anastomosis after schwannoma removal and were followed for more than 1 year. Three surgical techniques were performed: end-to-end, end-to-side, and split anastomoses. Facial palsy and tongue atrophy after anastomosis were evaluated using the scales suggested by House-Brackmann and Martins, respectively. Tumor volume and the time to surgery were also evaluated, and the effects on facial outcomes were analyzed.

RESULTS

Overall, nine of 14 (64.3%) patients had favorable facial outcomes, and eight of 14 (57.1%) had favorable tongue outcomes. Regarding facial palsy, five of seven (71.4%) end-to-end, three of four (75%) split, and only one of three (33.3%) end-to-side patients had favorable facial function. Regarding tongue atrophy, all three (100%) end-to-side, three of four (75%) split, and two of seven (28.6%) end-to-end patients had favorable tongue outcomes. The effects of tumor volume and time to surgery on facial outcome were not significant.

The new heterologous fibrin sealant in combination with low-level laser therapy (LLLT) in the repair of the buccal branch of the facial nerve

This study aimed to evaluate the effects of low-level laser therapy (LLLT) in the repair of the buccal branch of the facial nerve with two surgical techniques: end-to-end epineural suture and coaptation with heterologous fibrin sealant. Forty-two male Wistar rats were randomly divided into five groups: control group (CG) in which the buccal branch of the facial nerve was collected without injury; (2) experimental group with suture (EGS) and experimental group with fibrin (EGF): The buccal branch of the facial nerve was transected on both sides of the face. End-to-end suture was performed on the right side and fibrin sealant on the left side; (3) Experimental group with suture and laser (EGSL) and experimental group with fibrin and laser (EGFL). All animals underwent the same surgical procedures in the EGS and EGF groups, in combination with the application of LLLT (wavelength of 830 nm, 30 mW optical power output of potency, and energy density of 6 J/cm(2)). The animals of the five groups were euthanized at 5 weeks post-surgery and 10 weeks post-surgery. Axonal sprouting was observed in the distal stump of the facial nerve in all experimental groups. The observed morphology was similar to the fibers of the control group, with a predominance of myelinated fibers. In the final period of the experiment, the EGSL presented the closest results to the CG, in all variables measured, except in the axon area. Both surgical techniques analyzed were effective in the treatment of peripheral nerve injuries, where the use of fibrin sealant allowed the manipulation of the nerve stumps without trauma. LLLT exhibited satisfactory results on facial nerve regeneration, being therefore a useful technique to stimulate axonal regeneration process.

Hypoglossal-facial nerve 'side'-to-side neurorrhaphy using a predegenerated nerve autograft for facial palsy after removal of acoustic tumours at the cerebellopontine angle

TRIAL DESIGN

Hypoglossal-facial nerve (HN-FN) neurorrhaphy is a method commonly used to treat facial palsy when the proximal stump of the injured FN is unavailable. Since the classic HN-FN neurorrhaphy method that needs to section the injured FN is not suitable for incomplete facial palsy, we investigated a modified method that consists of HN-FN 'side'-to-side neurorrhaphy, retaining the remaining or spontaneously regenerated FN axons while preserving hemihypoglossal function.

METHODS

To improve axonal regeneration, we used for the first time a predegenerated sural autograft for performing HN-FN 'side'-to-side neurorrhaphy followed by postoperative facial exercise. We treated 12 patients who had experienced FN injury for 1-18 months as a result of acoustic tumour removal. All patients experienced facial grade V-VI paralysis according to the House-Brackmann scale, but their FN was anatomically preserved. No spontaneous facial reinnervation was detected before repair.

RESULTS

Although we did not perform fresh nerve grafts and HN-FN 'side'-to-end neurorrhaphy as controls for ethical reasons, the reparative outcomes after nerve reconstruction were remarkable: functional improvements were detected as soon as 3 months after repair, House-Brackmann grade II or III FN functions were achieved in five and four patients, respectively, and there were no apparent signs of synkinesis. The three patients who experienced less satisfactory outcomes had exhibited facial palsy for more than 1 year accompanied by muscle atrophy, consistent with a need for rapid surgical intervention.

CONCLUSIONS

Based on fundamental concepts and our experimental results, this new surgical method represents a major advance in the rehabilitation of FN injury.

TRIAL REGISTRATION NUMBER

JS2013-001-02.

Comparison of Direct Side-to-End and End-to-End Hypoglossal-Facial Anastomosis for Facial Nerve Repair

BACKGROUND

The hypoglossal facial anastomosis (HFA) is the gold standard for facial reanimation in patients with severe facial nerve palsy. The major drawbacks of the classic HFA technique are lingual morbidities due to hypoglossal nerve transection. The side-to-end HFA is a modification of the classic technique with fewer tongue-related morbidities.

OBJECTIVES

In this study we compared the outcome of the classic end-to-end and the direct side-to-end HFA surgeries performed at our center in regards to the facial reanimation success rate and tongue-related morbidities.

METHODS

Twenty-six successive cases of HFA were enrolled. In 9 of them end-to-end anastomoses were performed, and 17 had direct side-to-end anastomoses. The House-Brackmann (HB) and Pitty and Tator (PT) scales were used to document surgical outcome. The hemiglossal atrophy, swallowing, and hypoglossal nerve function were assessed at follow-up.

RESULTS

The original pathology was vestibular schwannoma in 15, meningioma in 4, brain stem glioma in 4, and other pathologies in 3. The mean interval between facial palsy and HFA was 18 months (range: 0-60). The median follow-up period was 20 months. The PT grade at follow-up was worse in patients with a longer interval from facial palsy and HFA (P value: 0.041). The lesion type was the only other factor that affected PT grade (the best results in vestibular schwannoma and the worst in the other pathologies group, P value: 0.038). The recovery period for facial tonicity was longer in patients with radiation therapy before HFA (13.5 vs. 8.5 months) and those with a longer than 2-year interval from facial palsy to HFA (13.5 vs. 8.5 months). Although no significant difference between the side-to-end and the end-to-end groups was seen in terms of facial nerve functional recovery, patients from the side-to-end group had a significantly lower rate of lingual morbidities (tongue hemiatrophy: 100% vs. 5.8%, swallowing difficulty: 55% vs. 11.7%, speech disorder 33% vs. 0%).

CONCLUSION

With the side-to-end HFA technique the functional restoration outcome is at least as good as that following the classic end-to-end HFA, but the complications related to the complete hypoglossal nerve transection can be avoided. Best results are achieved if this procedure is performed within the first 2 years after facial nerve injury. Patients with facial palsy of longer duration also have the chance for good functional restoration after HFA.

S, Rao V. B. To evaluate the feasibility of neurotisation of facial nerve branches with ipsilateral masseteric nerve: an anatomic study

CONTEXT

Facial palsy is a common problem encountered in clinical practice. These patients suffer serious functional, cosmetic & psychological problems with impaired ability to communicate. Functional problems around the eye are usually a first priority for the patient with facial palsy.The nerve to masseter as a direct nerve transfer to the zygomatic branch of facial nerve to reinnervate viable facial muscles within a year after the onset of paralysis has been scarcely reported. This study was contemplated to evaluate the feasibility of neurotisation of zygomatic branch of facial nerve with masseteric nerve branch of the trigeminal nerve Objectives: Establishing the anatomic relationship of masseteric nerve to masseteric muscle, determining feasibility of neurotisation of zygomatic branch of facial nerve using the nerve to the masseter and establishing fascicular correlation of the donor and the recipient nerves.

MATERIALS AND METHODS

Ninteen hemi-faces in ten fresh cadavers (6 Male and 4 Female)were dissected in a forensic morgue and access was by a standard preauricular incision and anterior skin flap is elevated in a subcutaneous plane. Facial nerve and its two main divisions are dissected in its full A*/extratemporal course. Zygomatic branch dissected upto zygomatic arch and the nerve to the masseter is identified within the masseter muscle, dissected proximodistally to isolate it. Feasibility of transfer of this masseteric nerve to the zygomatic branch without using nerve graft is determined. At the completion of dissection, the ends of both nerves are sent for HPE analysis to determine fascicular anatomy and count.

RESULTS

The dissection of massteric nerve was done taking into consideration of 3 axes, that is anteroposterior (x), vertical (y) axes and mediolateral(z) for locating the nerve and for standardization of the dissection. The nerve was cut and stored in glutaraldehyde solution and subjected to histopathologic examination after fixing and staining with Haematoxilin-eosin stain. Donor masseter neve has 7-10 fascicles. Recipient zygomatic branch has 2-3 fascicles. And the buccal branch has 5-6 fascicles.

CONCLUSION

The use of the nerve to masseter offers a simpler ipsilateral alternative for neurotisation of the facial nerve branches in patients who have an early facial nerve paralysis.

Bell's palsy and partial hypoglossal to facial nerve transfer: Case presentation and literature review

Background:

Idiopathic facial nerve palsy (Bell's palsy) is a very common condition that affects active population. Despite its generally benign course, a minority of patients can remain with permanent and severe sequelae, including facial palsy or dyskinesia. Hypoglossal to facial nerve anastomosis is rarely used to reinnervate the mimic muscle in these patients. In this paper, we present a case where a direct partial hypoglossal to facial nerve transfer was used to reinnervate the upper and lower face. We also discuss the indications of this procedure.

Case Description:

A 53-year-old woman presenting a spontaneous complete (House and Brackmann grade 6) facial palsy on her left side showed no improvement after 13 months of conservative treatment. Electromyography (EMG) showed complete denervation of the mimic muscles. A direct partial hypoglossal to facial nerve anastomosis was performed, including dissection of the facial nerve at the fallopian canal. One year after the procedure, the patient showed House and Brackmann grade 3 function in her affected face.

Conclusions:

Partial hypoglossal–facial anastomosis with intratemporal drilling of the facial nerve is a viable technique in the rare cases in which severe Bell's palsy does not recover spontaneously. Only carefully selected patients can really benefit from this technique.

Use of a Y-Tube Conduit After Facial Nerve Injury Reduces Collateral Axonal Branching at the Lesion Site But Neither Reduces Polyinnervation of Motor Endplates Nor Improves Functional Recovery

BACKGROUND:

Despite increased understanding of peripheral nerve regeneration, functional recovery after surgical repair remains disappointing. A major contributing factor is the extensive collateral branching at the lesion site, which leads to inaccurate axonal navigation and aberrant reinnervation of targets.

OBJECTIVE:

To determine whether the Y tube reconstruction improved axonal regrowth and whether this was associated with improved function.

METHODS:

We used a Y-tube conduit with the aim of improving navigation of regenerating axons after facial nerve transection in rats.

RESULTS:

Retrograde labeling from the zygomatic and buccal branches showed a halving in the number of double-labeled facial motor neurons (15% vs 8%; P &lt; .05) after Y tube reconstruction compared with facial-facial anastomosis coaptation. However, in both surgical groups, the proportion of polyinnervated motor endplates was similar (∼30%; P &gt; .05), and video-based motion analysis of whisking revealed similarly poor function.

CONCLUSION:

Although Y-tube reconstruction decreases axonal branching at the lesion site and improves axonal navigation compared with facial-facial anastomosis coaptation, it fails to promote monoinnervation of motor endplates and confers no functional benefit.