ORIGINAL ARTICLE Year : 2022  |  Volume : 30  |  Issue : 1  |  Page : 1-4

Determination of facial reanimation patients who can be transferred muscle after crossfacial nerve graft

Nijat Majidov, Osman Akdag, Mustafa Sutcu, Zekeriya Tosun
Department of Plastic Reconstructive and Aesthetic Surgery, Selcuk University Faculty of Medicine, Konya, Turkey

Date of Submission30-Apr-2021Date of Acceptance23-Oct-2021Date of Web Publication25-Dec-2021

Correspondence Address:
Dr. Nijat Majidov
Selçuk Üniversitesi Tıp Fakültesi, Allaeddin Keykubat Kampüsü, Department of Plastic Reconstructive and Aesthetic Surgery, Selcuk University Faculty of Medicine, 42030 Selçuklu, Konya
Turkey

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/tjps.tjps_26_21

Aims: The aim of facial reanimation isto restore facial symmetry in spontaneous, mimic, and emotional movements. One of the important reconstructive treatment options in patients with long-term facial paralysis is free muscle transfers. The first stage in two-stage muscle transfers is the cross facial nerve graft (CFNG). In this study, our aim is to investigate the importance of Tinel's sign and EMG in the selection of patients who have had CFNG due to long-term facial paralysis and who can undergo muscle transfer repair and investigate the effectiveness of these methods. Patients and Methods: Ten patients who underwent crossfacial nerve grafting for long-term facial nerve paralysis between 2012 and 2018 were prospectively included in the study. Results: No complications were observed during the operation and follow-up of the patients. The reliability of EMG is lower than the Tinel's sign when making a muscle transfer decision in patients who undergo CFNG. Conclusions: In conclusion, the etiology of facial paralysis (severity of injury in traumatic paralysis), age of patients, comorbid conditions, surgical experience, postoperative physical therapy process and patient compliance play an active role in providing reinnervation.

Keywords: Cross-facial nerve graft, EMG, facial paralysis, muscle transfer, Tinel's sign

How to cite this article:
Majidov N, Akdag O, Sutcu M, Tosun Z. Determination of facial reanimation patients who can be transferred muscle after crossfacial nerve graft. Turk J Plast Surg 2022;30:1-4
How to cite this URL:
Majidov N, Akdag O, Sutcu M, Tosun Z. Determination of facial reanimation patients who can be transferred muscle after crossfacial nerve graft. Turk J Plast Surg [serial online] 2022 [cited 2021 Dec 25];30:1-4. Available from: http://www.turkjplastsurg.org/text.asp?2022/30/1/1/333751   Introduction 

Loss of facial expression after facial paralysis affects patients' lives cosmetically, functionally, socially, psychologically, and economically. The aim of facial reanimation is to restore facial symmetry in spontaneous, mimic, and emotional movements.[1],[2],[3] One of the important reconstructive treatment options in patients with long-term facial paralysis is free muscle transfers.[4],[5] Muscle transfers can be performed in one and two stages. The first stage in two-stage muscle transfers is the cross-facial nerve graft (CFNG), and it is one of the reconstructive options used to provide coordinated, spontaneous, and mimic movements in patients with long-term facial paralysis. It is very important to determine the time required for muscle transfer, which is the second stage, and to evaluate whether the nerve impulses pass to the opposite side, that is, the paralyzed side. For this, methods such as Tinel's sign and EMG are frequently used in practice. In this study, our aim is to investigate the importance of Tinel's sign and EMG in the selection of patients who have had CFNG due to long-term facial paralysis and who can undergo muscle transfer repair and to investigate the effectiveness of these methods.

  Materials and Methods 

Ten patients who underwent cross-facial nerve grafting for long-term facial nerve paralysis between 2012 and 2018 were prospectively included in the study. The duration of facial paralysis in all patients included in the study was more than 2 years and all were unilateral. The mean age of the patients and the etiology of facial paralysis were determined. CFNG (cross-facial sural graft) was applied to selected patients. The nerve graft was coapted to the buccal branch of the intact side of the facial nerve, tunneled, and passed to the opposite, paralyzed side, and left there until the graft showed signs of regeneration. Hospitalization and average follow-up periods of the patients were saved. Later, at 3, 6, and 9 months, it was evaluated according to Tinel's sign and EMG tests. In patients who were thought to have reinnervation, usually 6–12 months later (depending on the length of the graft), the motor nerve of the muscle flap which transferred in the second stage was coapted to the distal part of the nerve graft and appropriate muscle transfers were performed. The average time between the 1st and 2nd surgeries was calculated. EMG was performed in the 6th month of the patients who underwent muscle transfer, and facial tone was evaluated after resting and laughing.

The Tinel's sign was performed by gently tapping the nerve along the trace to reveal the sensation of electrification in the distribution of the nerve.[6] When the Tinel's sign was positive in the preauricular region of the paralyzed side, the operation was decided for muscle transfer. Results were evaluated by two independent plastic surgeons.

The first stage, CFNG, was evaluated according to the results of the EMG study (amplitude, polyphasia, Motor Unit Potential [MUP]) at the 3rd, 6th, and 9th months. Small-amplitude polyphasic MUP was considered to indicate the ongoing reinnervation process.[7] CMAP (combined muscle action potential) values were measured in EMG in the 6th month after muscle transfer. The amplitude of CMAP is determined by the number of muscle fibers it innervates and is one of the most useful indicators for nerve regeneration studies.[8] Results were evaluated by one neurologist and two independent plastic surgeons.

The facial tone of the patients who underwent muscle transfer 6 months after the 2nd surgery was compared with the healthy side at rest and after laughing. These results were evaluated according to Terzis's Functional and Aesthetic Grading System classification [Table 1].

  Results 

Two of the patients were congenital, one was iatrogenic, two were posttraumatic, and five were idiopathic facial paralysis, six of them were female, and four were male. Their average age was 31.8 (22–56 years). The average age of patients with only CFNG repair was 36.6 (25–56 years), whereas the average age of patients who underwent muscle transfer with CFNG was 27 (18–43 years). The patients were followed up for an average of 38 months (16–65 months). In patients who underwent two-stage repair, the mean time between the first and second operations was 13 (7–18 months) months.

No complications were observed during the operation and follow-up of the patients. After CFNG, weakness was not found in the intact facial nerve. Average hospitalization period in patients who underwent CFNG was 2.4 days (2–4 days). Postoperative patients were referred to a physiotherapist for physical rehabilitation. Tinel's sign was determined as negative in five patients and positive in five by two independent plastic surgeons. Small-amplitude polyphasic MUP was evaluated as positive in four patients in electrodiagnostic studies by the neurologist and two independent plastic surgeons, which was also accepted as a sign of regeneration [Figure 1]. Amplitudes compared with intact side. In four EMG-positive patients, Tinel's sign was also positive.

Figure 1: Above - small-amplitude polyphasic MUP after CFNG on the side with facial paralysis, below - normal MUP values on the intact side after CFNG are shown

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Free muscle transfers were performed in four patients who had positive Tinel's sign findings and also showed signs of regeneration in amplitude values after CFNG. While Tinel's sign was positive in one patient, muscle transfer was performed although the sign of regeneration was not observed in electromyographic studies. One of these muscle flaps is free serratus anterior muscle flap, and four are free extensor digitorum brevis muscle flaps. In the other five patients, only CFNGs were performed. CMAP values were measured in EMG in the 6th month after muscle transfer. Regeneration was evaluated by calculating innervated muscle fibers by the nerve. Regeneration findings were detected in five patients who underwent muscle transfer.

In the postoperative 6th month after muscle transfer, five patients (who underwent muscle transfer) were evaluated according to Terzis's Functional and Aesthetic Grading System classification. One of the patients was determined as Grade 5, and four of them were determined as Grade 4 [Table 2]. Pictures of the patient before CFNG, after CFNG, and after muscle transfer are shown below [Figure 2].

Figure 2: (a) -Before CFNG, (b) - after CFNG, (c) - after muscle transfer

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  Discussion 

Dynamic and static treatment methods are available in facial paralysis.[9] One of the dynamic treatment methods is free muscle transfers. Irreversible atrophy develops in denervated facial muscles if they are not innervated within 2 years. Therefore, in long-term facial paralysis, muscle transfer is required with reinnervation.[10] In the first stage of facial paralysis, the cross-facial, ipsilateral trigeminal, and hypoglossal nerves can be used as the receiving nerve. The purpose of cross-facial nerve grafting is to use the intact contralateral facial nerve and reinnervate the paralyzed side to provide spontaneous and synchronized facial expression.[1] Using of intact contralateral facial nerve is thought to be very important in terms of symmetrical movement of the face, as it provides both a new and similar source of motor innervation.[11] In patients who fail this surgery, the second stage should not be applied (as it is thought that there will not be innervation of the muscle after muscle transfer) or the 5th (trigeminal nerve) or 12th cranial nerve (hypoglossal nerve) (babysitter procedure) must be transferred [Figure 3]. The disadvantage of second-stage muscle transfer is that it takes a long time for axon regeneration after cross-facial nerve grafting, resulting in prolonged muscle denervation and atrophy.[1] This does not constitute a disadvantage in the patients included in our study, since facial paralysis was more than 2 years and muscle atrophy developed. Another disadvantage is the risk of impairment of innervation on the donor side. This can be minimized using nondominant branches of the donor nerve.[12] Moreover, in our study, complications did not develop on the donor side because the buccal branches of the facial nerve were used. In the study conducted by Rab et al. in 2006, similar functional results were found in two-stage and single-stage muscle transfers.[13]

The average age of the patients who were included in the study and who underwent only CFNG was found to be higher than the average age of patients who underwent CFNG and muscle transfer, which indicates that age is important in nerve recovery. Another factor affecting nerve healing is the etiology of facial paralysis. Hence, nerve healing findings were not observed in severe posttraumatic injuries and in some patients with idiopathic facial paralysis, whereas in patients with iatrogenic, congenital, and some patients with idiopathic facial paralysis, nerve healing findings were detected. Both Tinel's sign and electromyography results are valuable in the evaluation of reinnervation. Tinel's sign is an indicator of nerve regeneration and is used to monitor whether axons reach the desired area.[11] It is performed by gently tapping on the nerve to reveal a sensation of electrification in the distribution of the nerve.[6] EMG can be evaluated according to the MUP results. However, EMG results alone may be insufficient. The main reason for this is the lack of experienced physicians who can follow up dynamic facial paralysis surgery electromyographically. Clinical Tinel's sign is more valuable for patients undergoing free muscle transfer. In our study, five patients were found to be Tinel's sign-positive, whereas four of these patients had positive EMG results, but muscle transfer was performed in five patients with Tinel's sign-positive. In the 6th month after muscle transfer, the CMAP in five patients was positive and in the same five patients were Grade 5 and 4 according to the Functional and Aesthetic Grading System classification of the Terzis's. It shows once again that Tinel's sign is more valuable.

MUP and CMAP occur due to muscle contraction during EMG. Therefore, EMG is a valuable test to determine the prognosis in acute peripheral facial paralysis.[14] However, MUP and CMAP do not occur in patients with long-term facial paralysis since there is not muscle contraction due to muscle atrophy. Small amplitude MUP on the side with facial paralysis during EMG in patients undergoing CFNG occurs due to spontaneous symmetrical movements. Because of all these, the reliability of EMG is lower than the Tinel's sign when making a muscle transfer decision in patients who undergo CFNG.

  Conclusion 

In conclusion, the etiology of facial paralysis (severity of injury in traumatic paralysis), age of patients, comorbid conditions, surgical experience, postoperative physical therapy process, and patient compliance play an active role in providing reinnervation.

Declaration of patient consent

The authors declare that they have obtained consent from patients. Patients have given their consent for their images and other clinical information to be reported in the journal. Patients understand that their names will not be published and due efforts will be made to conceal their identity but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 

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  [Figure 1], [Figure 2], [Figure 3]
 
 
  [Table 1], [Table 2]