Donor nerve selection in free gracilis muscle transfer for facial reanimation. A systematic review and meta-analysis of clinical outcomes

BACKGROUND

One of the critical factors in facial reanimation is selecting the donor nerve. The most favored neurotizers are the contralateral facial nerve with a cross-face nerve graft (CFNG) and motor nerve to the masseter (MNM). A relatively new dual innervation (DI) method has shown successful results. This study aimed to compare the clinical outcomes of different neurotization strategies for free gracilis muscle transfer (FGMT).

METHODS

The Scopus and WoS databases were queried with 21 keywords. Three-stage article selection was performed for the systematic review. Articles presenting quantitative data for commissure excursion and facial symmetry were included in meta-analysis, using random-effects model. ROBINS-I tool and Newcastle-Ottawa scale were used to assess bias and study quality.

RESULTS

One hundred forty-seven articles containing FGMT were systematically reviewed. Most studies indicated CFNG as the first choice. MNM was primarily indicated in bilateral palsy and in elderly. Clinical outcomes of DI studies were promising. 13 studies including 435 observations (179 CFNG, 182 MNM, 74 DI) were eligible for meta-analysis. The mean change in commissure excursion was 7.15 mm (95% CI: 4.57-9.72) for CFNG, 8.46 mm (95% CI: 6.86-10.06) for MNM, and 5.18 mm (95% CI: 4.01-6.34) for DI. In pairwise comparisons, a significant difference was found between MNM and DI (p = 0.0011), despite the superior outcomes described in DI studies. No statistically significant difference was found in resting and smile symmetry (p = 0.625, p = 0.780).

CONCLUSIONS

CFNG is the most preferred neurotizer, and MNM is a reliable second option. Outcomes of DI studies are promising, but more comparison studies are needed to draw conclusions. Our meta-analysis was limited by incompatibility of the assessment scales. Consensus on a standardized assessment system would add value to future studies.

Staged upper and lower lip reanimation following facial palsy: Peer-reviewed, patient-rated and objective outcomes

BACKGROUND

One approach to reanimating both upper and lower lips following facial palsy is through staged surgery: cross-face nerve grafting at stage I, free gracilis muscle transfer to levators at stage II and pedicled anterior belly of digastric muscle transfer (ABDMT) to depressors at stage III. The results of this approach were hitherto unquantified.

METHODS

This study retrospectively assessed peer-reviewed, patient-rated and objective outcomes following staged reanimation in adults between 2010 and 2020. Demographics, palsy characteristics and surgery details were recorded. Pre- and postoperative videos were rated by independent assessors using Terzis' aesthetic and symmetry scale. Photographs were analysed using Emotrics and patients completed the Glasgow Benefit Inventory (GBI) patient-rated outcome measure.

RESULTS

Ten patients [mean age = 34 (SD = 12.48)] were eligible. All regained lip elevation and depression. All markers of symmetry improved after gracilis transfer. All markers were also improved after ABDMT except for lower lip height when smiling with teeth showing (p > 0.05). Five patients (50%) responded to the GBI (mean score = +39.44). No patients reported detriment from the reanimations. Mean Terzis' scores preoperatively and after stages II and III were 1.5, 2.26 and 2.39, respectively (p < 0.05). Nine patients underwent aesthetic refinements [lipofilling to lower lip notches (n = 5), debulking of gracilis bulk (n = 6), repositioning of muscle insertion (n = 5) and facelifts (n = 2)].

CONCLUSION

The outcomes were positive objectively and as judged by peers and patients themselves. Aesthetic refinements may also be required to enhance these results.

Controversies in Contemporary Facial Reanimation

Facial palsy is a devastating condition with profound functional, aesthetic, and psychosocial implications. Although the complexity of facial expression and intricate synergy of facial mimetic muscles are difficult to restore, the goal of management is to reestablish facial symmetry and movement. Facial reanimation surgery requires an individualized treatment approach based on the cause, pattern, and duration of facial palsy while considering patient age, comorbidities, motivation, and goals. Contemporary reconstructive options include a spectrum of static and dynamic procedures. Controversies in the evaluation of patients with facial palsy, timing of intervention, and management decisions for dynamic smile reanimation are discussed.