Vastus lateralis vascularized nerve graft in facial nerve reconstruction: An anatomical cadaveric study and clinical implications

Anatomic and histomorphometric study of the nerve to the vastus lateralis in cadaver for its clinical application in facial reanimation

BACKGROUND

The innervated vastus lateralis flap (IVLF) is a barely used possibility for facial palsy reconstruction because of its thickness compared to the gracilis, latissimus dorsi, and pectoralis minor flaps. The aim of this study is to perform a precise description of the intramuscular distribution of the nerve motor branches and its relationship with the vascular pedicle in order to harvest a segmental muscle flap with the best contractile strength to restore facial reanimation.

METHODS

The study was performed on 16 adult cadaver thighs identifying the vastus lateralis muscle and the distribution and relationships of its neurovascular pedicle and branches. We evaluated where the nerve pierced the muscle and the course of the nerve within it. Transverse segments of the nerve were obtained from the proximal and distal ends of the nerve and stained using anti-ChAT (Choline acetyltransferase) antibodies which are specific of motor neurons.

RESULTS

A nerve for the vastus lateralis from the posterior division of the femoral nerve divided into 2 branches in 56% of cases; the principal branch coursed along the vascular pedicle and pierced the muscle more proximally than the respective vessels, and a minor branch that pierced the muscle 25-60 mm proximally. There were 3 main intramuscular branches. The nerve length (mean 132.65 ± 22.89 mm) allowed to reach the contralateral side of the face in almost all cases (95%). The mean ChAT positive fibers was 351.0 ± 92.4/mm² at the proximal end, and 270.3 ± 87.9/mm² at the distal end (p = 0.49). The number of ChAT negative fibers was higher than ChAT positive in both proximal and distal ends of the nerve.

CONCLUSION

We propose the IVLF as a one-step surgical flap for facial paralysis reanimation due to the constant neurovascular pattern and lengthy pedicle. The amount of motor fibers in several segments of the nerve is appropriate to produce a powerful contraction for dynamic reconstruction.

A Comprehensive Approach to Facial Reanimation: A Systematic Review

Purpose: To create a systematic overview of the available reconstructive techniques, facial nerve grading scales, physical evaluation, the reversibility of paralysis, non-reconstructive procedures and medical therapy, physical therapy, the psychological aspect of facial paralysis, and the prevention of facial nerve injury in order to elucidate the gaps in the knowledge and discuss potential research aims in this area. A further aim was to propose an algorithm simplifying the selection of reconstructive strategies, given the variety of available reconstructive methods and the abundance of factors influencing the selection. Methodological approach: A total of 2439 papers were retrieved from the Medline/Pubmed and Cochrane databases and Google Scholar. Additional research added 21 articles. The primary selection had no limitations regarding the publication date. We considered only papers written in English. Single-case reports were excluded. Screening for duplicates and their removal resulted in a total of 1980 articles. Subsequently, we excluded 778 articles due to the language and study design. The titles or abstracts of 1068 articles were screened, and 134 papers not meeting any exclusion criterion were obtained. After a full-text evaluation, we excluded 15 papers due to the lack of information on preoperative facial nerve function and the follow-up period. This led to the inclusion of 119 articles. Conclusions: A thorough clinical examination supported by advanced imaging modalities and electromyographic examination provides sufficient information to determine the cause of facial palsy. Considering the abundance of facial nerve grading scales, there is an evident need for clear guidelines regarding which scale is recommended, as well as when the postoperative evaluation should be carried out. Static procedures allow the restoral of facial symmetry at rest, whereas dynamic reanimation aims to restore facial movement. The modern approach to facial paralysis involves neurotization procedures (nerve transfers and cross-facial nerve grafts), muscle transpositions, and microsurgical free muscle transfers. Rehabilitation provides patients with the possibility of effectively controlling their symptoms and improving their facial function, even in cases of longstanding paresis. Considering the mental health problems and significant social impediments, more attention should be devoted to the role of psychological interventions. Given that each technique has its advantages and pitfalls, the selection of the treatment approach should be individualized in the case of each patient.

Nerve grafts in head and neck reconstruction

PURPOSE OF REVIEW

This article reviews recent literature on repair of peripheral nerve injuries in the head and neck with a focus on autografts, allografts, nerve conduits, and technical considerations.

RECENT FINDINGS

Contemporary nerve grafting techniques offer the potential to improve peripheral nerve outcomes and reduce donor site morbidity. A variety of donor nerves autografts have been described that offer favorable outcomes for segmental reconstruction of facial nerve defects. Recent studies have demonstrated promising results in repair of inferior alveolar nerve injuries with human allografts. Animal models describe successful reinnervation of small defects with neural conduits. The latest data do not favor protocolled nerve graft polarity or use of a motor versus sensory donor nerves.

SUMMARY

Interposition nerve grafting is the gold standard for repair of peripheral nerve injuries when a tension-free primary neurorrhaphy is not possible. Autografts are the work-horse for the majority of head and neck neural defects, however, can result in some degree of donor site morbidity. Recent developments in allografting and neural conduits have the potential to further diversify the head and neck reconstructive surgeon's armamentarium. It is unclear if nerve graft makeup or polarity affect functional outcome.

The application of venous nerve conduit trap in the immediate repair and reconstruction of facial nerve in parotid gland tumor: an attempt of a new technique

OBJECTIVE

To introduce the application of venous nerve conduit in the immediate repair and reconstruction of facial nerve in parotid gland tumor.

METHODS

Three patients with parotid gland tumor in Sichuan Provincial Cancer Hospital were reviewed. All patients were found that the tumor encased and invaded the facial nerve which was difficult to be separated during the operation when all patients were treated with facial nerve repair and reconstruction with the venous nerve conduit trapping technique.

RESULTS

After 1-year follow-up, all patients recovered well in facial nerve function.

CONCLUSION

The venous nerve conduit trapping technique is an effective attempt in the immediate repair and reconstruction of facial nerve in parotid gland tumor, but it needs to be further confirmed by multiple studies.

Usefulness of a template-based anterolateral thigh flap for reconstruction of head and neck defects

BACKGROUND

One of the challenges in head and neck reconstruction is to have an adequate understanding of the three-dimensionalities of the defects created after resections due to the high variability of clinical scenarios. Consequently, it is essential to design the flap to match the requirements of the defect in order to facilitate the insetting and to achieve a successful outcome. The anterolateral thigh flap (ALT) is a robust and versatile flap commonly used in head and neck reconstruction. In this study the authors use a hand-made template as a tool to customize ALT flaps and its variations to fit more accurately the different shapes, volume, and components of the resulting defects. The aim of this study is to describe in detail this surgical approach and present the clinical experience in 100 consecutive cases using a template-based ALT flaps in head and neck reconstruction.

METHODS

A retrospective review was performed on all microvascular head and neck reconstruction cases between January 2013 and December 2017 in our institution where a template-based ALT flap design was performed. We describe in detail the surgical technique used and present the clinical outcomes. In addition, we analyzed the use of different designs of the ALT flaps including different flap components in relation to the location of the defect.

RESULTS

One hundred reconstructions for head and neck defects were performed in 97 patients. Seven types of ALT free flaps were performed: fasciocutaneous (46%), suprafascial (8%), adipofascial (9%), vastus lateralis muscle (3%), composite fasciocutaneous/adipofascial (9%), chimeric flaps (21%), and vascularized nerve grafts (4%). Oropharyngeal and periauricular defects were mostly reconstructed with fasciocutanoues design. In more complex three-dimensional defects such as skull base or midface defects, a chimeric flap was selected. In all cases the used of template facilitated the insetting of the free flap. The total flap loss was 2%.

CONCLUSIONS

Customization of ALT flaps using intraoperative templates is a useful method for flap design which facilitates fitting of the flap to a variety of defects in head and neck reconstruction.

Contemporary Concepts of Primary Dynamic Facial Nerve Reconstruction in the Oncologic Patient

Transection of the facial nerve and its branches during extensive ablative procedures in the oncologic patient causes loss of control of facial mimetic muscles with severe functional and aesthetic sequelae. In such patients with advanced tumorous disease, copious comorbidities, and poor prognosis, rehabilitation of the facial nerve has long been considered of secondary priority. However, recent advances in primary facial nerve reconstruction after extensive resection demonstrated encouraging results focusing on rapid and reliable restoration of facial functions. The authors summarize 3 innovative approaches of primary dynamic facial nerve reconstruction by using vascularized nerve grafts, dual innervation concepts, and intra-facial nerve transfers.

Use of Vascularized Sural Nerve Grafts for Sciatic Nerve Reconstruction After Malignant Bone and Soft Tissue Tumor Resection in the Lower Legs

BACKGROUND

Vascularized nerve grafting is normally associated with a good outcome, but can be difficult to use for nerve reconstruction in patients with long defects of the sciatic nerve given the graft thickness. We report 3 cases of large defect sciatic nerve reconstruction using the bilateral sural nerves of the lower legs harvested together with the fascia and lesser saphenous vein to form a vascularized flap.

METHODS

The subjects were 3 patients who required the reconstruction of a 10-cm or longer segment of the sciatic nerve. Priority was given to restoring sensation in the plantar region such that reconstruction of the sensory nerves corresponding to the tibial region.

RESULTS

Two patients were followed up for long term. There was some persistent perceptual deficit in the foot, minimal protective sensation had been achieved.

CONCLUSIONS

We were able to selectively reconstruct the sensory nerves to achieve sensation in the soles of the feet by using sural nerve grafts from both legs. As the prognosis for the underlying condition in cases necessitating this procedure is often poor, the costs and benefits of reconstruction should always be weighed carefully for each individual patient.

Distal Extension of the Anterior Approach to the Hip Using the Femoral Interbundle Technique: Surgical Technique and Case Series

BACKGROUND

The direct anterior approach (DAA) is becoming more popular as the standard surgical approach for primary total hip arthroplasty. However, it has been associated with an increased incidence of intraoperative femoral fractures in particular during the learning curve. Distal extension of the approach may be needed in case of intraoperative complications. The aim of the present study is to describe the distal extension of the DAA using the femoral interbundle technique.

METHODS

A stepwise approach based on a cadaveric study to extend the DAA distally is presented. The interval between the neurovascular bundles running to the vastus lateralis is used to gain access to the femur. Clinical and electromyography results of 5 patients undergoing a revision of the femoral component through an extended anterior approach are reported.

RESULTS

In 2 cases, the proximal bundle was exposed whereas in 3 cases the interval between the proximal and distal bundle was developed and cerclage wires were applied around the isthmus of the femur. All fractures had healed at 6 months of follow-up. Four cases had a normal electromyography, and 1 case demonstrated a neuropraxia of a branch to the vastus lateralis. All cases had a 5/5 extension power of the quadriceps muscle clinically.

CONCLUSION

The interbundle technique is an alternative way to gain additional exposure of the femur during the DAA and is based on precise knowledge of the periarticular neurovascular structures. This approach can be helpful to safely deal with intraoperative complications such as fractures requiring proximal femoral cerclage wiring during the anterior approach.

Distal Extension of the Direct Anterior Approach to the Hip: A Cadaveric Feasibility Study

BACKGROUND

The direct anterior approach (DAA) is becoming more popular as the standard surgical approach for primary total hip arthroplasty. However, femoral complications of up to 2.8% have been reported. Therefore, it is important for surgeons to understand the periarticular neurovascular anatomy in order to safely deal with intraoperative complications.

METHODS

Anatomic dissections were performed on 20 cadaveric hips. The neurovascular structures anterior to the femur and distal to the intertrochanteric line were dissected and its position was described in relation to anatomic landmarks easily identified through the DAA: anterior superior iliac spine (ASIS), the insertion of the gluteus minimus (GM), and the lesser trochanter (LT).

RESULTS

Two clearly distinguishable neurovascular bundles running to the vastus lateralis were seen in 17 of 20 specimens. The average distances to the landmarks were as follows: ASIS-1st bundle = 12.3 cm (range, 9.7-14.5); GM-1st bundle = 3.2 cm (range, 2.2-4); LT-1st bundle = 1.6 cm (range, 0.7-2.8); 1st bundle-2nd bundle = 3.3 cm (range, 1.8-6.1).

CONCLUSION

A consistent pattern of 2 clearly distinguishable neurovascular bundles was seen in 85% of the specimens. Knowledge of the position of these neurovascular bundles in relation to the anatomic landmarks makes distal femoral extension of the DAA feasible. Further clinical studies are needed to confirm the safety of the extensile anterior approach.

Free anterolateral thigh flap and masseter nerve transfer for reconstruction of extensive periauricular defects: Surgical technique and clinical outcomes

BACKGROUND

Radical tumor ablation in the periauricular area often results in extensive soft tissue defects, including facial nerve sacrifice, bone and/or dura defects. Reconstruction of these defects should aim at restoring facial reanimation, wound closure, and facial and neck contours. We present our experience using free anterolateral thigh flap (ALT) in combination with masseter nerve to facial nerve transfer in managing complex defects in the periauricular area.

METHODS

Between 2011 and 2015 six patients underwent a combined procedure of ALT flap reconstruction and masseter nerve transfer, to reconstruct extensive, post tumor resection, periauricular defects. The ALT flap was customized according to the defect. For smile restoration, the masseter nerve was transferred to the buccal branch of the facial nerve. If the facial nerve stump was preserved, interposition of nerve grafts to the zygomatic and frontal branches was performed to provide separate eye closure. The outcomes were analyzed by assessing wound closure, contour deformity, symmetry of the face, and facial nerve function.

RESULTS

There were no partial or total flap losses. Stable wound closure and adequate volume replacement in the neck was achieved in all cases, as well as good facial tonus and symmetry. The mean follow-up time of clinical outcomes was 16.8 months. Smile restoration was graded as good or excellent in four cases, moderate in one and fair in one.

CONCLUSION

Extensive periauricular defects following oncologic resection could be adequately reconstructed in a combined procedure of free ALT flap and masseter nerve transfer to the facial nerve for smile restoration.

Reconstruction of facial nerve after radical parotidectomy

CONCLUSION

Most patients benefitted from immediate facial nerve grafting after radical parotidectomy. Even weak movement is valuable and can be augmented with secondary static operations. Post-operative radiotherapy does not seem to affect the final outcome of facial function.

OBJECTIVES

During radical parotidectomy, the sacrifice of the facial nerve results in severe disfigurement of the face. Data on the principles and outcome of facial nerve reconstruction and reanimation after radical parotidectomy are limited and no consensus exists on the best practice.

METHOD

This study retrospectively reviewed all patients having undergone radical parotidectomy and immediate facial nerve reconstruction with a free, non-vascularized nerve graft at the Helsinki University Hospital, Helsinki, Finland during the years 1990-2010. There were 31 patients (18 male; mean age = 54.7 years; range = 30-82) and 23 of them had a sufficient follow-up time.

RESULTS

Facial nerve function recovery was seen in 18 (78%) of the 23 patients with a minimum of 2-year follow-up and adequate reporting available. Only slight facial movement was observed in five (22%), moderate or good movement in nine (39%), and excellent movement in four (17%) patients. Twenty-two (74%) patients received post-operative radiotherapy and 16 (70%) of them had some recovery of facial nerve function. Nineteen (61%) patients needed secondary static reanimation of the face.