Functioning Muscle Transplantation Research Articles

The Role of Length of Nerve Grafts in Combination with Free Functional Muscle Transplantation for Brachial Plexus Injury: A Single-Center Experience.

Extensive lesions of the brachial plexus, or late cases, require free functional muscle grafts because the expected recovery time exceeds the critical threshold of 1.5 years, beyond which irreversible damage may be expected in the distal nerve stump and in the muscle. The reconstructive concept consists of a two-stage procedure where, in the first step, a nerve transfer is performed (from ipsi- or contralateral donor nerves). In the second step, after successful axonal regeneration within the graft has been confirmed, a free muscle transfer is performed. These grafts often exceed 40 cm in length, particularly for contralateral transfers. The purpose of this study was to assess whether robust motor recovery could be supported by such long nerve grafts. From April 2004 to April 2023, a total of 327 free functional muscle transfers were performed, the nerve graft length ranging from 0 cm (direct coaptation) to 90 cm (serial grafts). Motor recovery was evaluated 1.5 years after surgery according to the MRC scale. A total of 208 patients were available for follow up. Direct coaptation yielded the best results, with 83% of patients reaching an M3 or M4 level of muscle strength. With the application of long (30-60 cm) grafts, 73% of the patients were classified as M3 or M4. The application of serial nerve grafts, however, only resulted in 18% of patients achieving a motor recovery rating of M3. These findings demonstrate that robust motor regeneration is supported by long (30-60 cm) nerve grafts, whereas serial nerve grafting results in a marked reduction in the quality of regeneration.

Outcomes of Functioning Free Gracilis Muscle Transplantation to Restore Elbow Flexion in Late Brachial Plexus Birth Injury.

Restoring elbow function is challenging after late presenting brachial plexus birth injury (BPBI). Free functioning muscle transplantation (FFMT) using the gracilis muscle is a reliable procedure to restore elbow flexion in patients with impaired function after spontaneous recovery or failed surgical reconstruction. A retrospective review was performed on BPBI patients more than 2 years of age who received a FFMT between January 1993 and January 2018, with the aim of improving elbow flexion as the primary or secondary functional goal. Patients with preoperative elbow flexion Medical Research Council (MRC) grades less than 3 with more than or equal to 18 months of follow-up duration were included in the analysis. Patient demographic information and pre/postoperative clinical parameters including elbow flexion MRC scale, passive elbow range of motion, and complications were recorded. Surgical data including donor nerve choice, site of the FFMT tendon attachment, and necessity of concomitant procedures or reoperation were also analyzed. Fifty-six FFMTs were performed for the primary (29 patients) or secondary (26 patients) objective of restoring elbow flexion. The mean age at the time of the procedure was 9.6 years (standard deviation [SD] = 6.29, R = 3-35). Mean follow-up was 7.9 years (SD = 5.2). Elbow flexion improved from a median MRC grade 2 to 4 after a FFMT (p < 0.05). Patients who had a FFMT to restore two functions had 86% lower elbow flexion MRC grades than those who had a FFMT to restore flexion only (p < 0.05). Patients less than 12 years old at the time of surgery had more complications, reoperations, and rates of a flexion contracture more than or equal to 30 degrees than those aged more than 12 years (p < 0.05). FFMT is a reliable option for upper extremity reanimation. Patients aged less than 12 years old at the time of FFMT had significantly more complications, reoperations, and rates of postoperative elbow flexion contracture more than or equal to 30 degrees, but equivalent elbow flexion MRC grades. III.

Staged Phrenic Nerve Elongation and Free Functional Gracilis Muscle Transplantation–A Possible Option for Late Reconstruction in Chronic Brachial Plexus Injury

In patients with late brachial plexus birth injuries, sequelae after acute flaccid myelitis, or chronic adult brachial plexus injury, donor nerves for functioning muscle transplantation are often scarce. We present the results of a potential strategy using the phrenic nerve with staged free gracilis transplantation for upper extremity reanimation in these scenarios. A retrospective review was performed on an institutional database of brachial plexus injury or patients with palsy. All patients underwent a staged reconstruction in which the ipsilateral phrenic nerve was extended by an autogenous nerve graft (PhNG), followed by free-functioning gracilis transplantation (PhNG-gracilis). Nine patients (6 cases of late brachial plexus birth injuries, 2 of acute flaccid myelitis, and 1 of adult chronic brachial plexus injury) were included in this study. The median follow-up period following the PhNG-gracilis procedure was 27 months (range, 12-72 months). The goals of the staged PhNG and PhNG-gracilis were primarily finger extension or finger flexion. In some patients, the technique was used to improve both elbow and finger function, tunneling the muscle through the flexor compartment of the upper arm and under the mobile wad at the elbow. All patients exhibited improvement of muscle strength, including in finger extension (4 patients) from M0 to M2; finger flexion (3 patients) from M0 to M3; elbow extension (1patient) from M0 to M2; and elbow flexion (1 patient) from M2 to M4. A 2-stage PhNG-gracilis may restore or enhance the residual elbow and/or finger paralysis in chronic brachial plexus injuries. A minimum follow-up period of 3 years is recommended. This technique may remain useful as one of the last reconstructive options to increase power in patients with scarce donor nerves. Therapeutic V.

Facial Nerve Trauma: Clinical Evaluation and Management Strategies.

The field of facial paralysis requires the reconstructive surgeon to apply a wide spectrum of reconstructive and aesthetic principles, using a comprehensive array of surgical tools, including microsurgery, peripheral nerve surgery, and aesthetic facial surgery on the road to optimize patient outcomes. The distinct deficits created by different anatomical levels of facial nerve injury require a fundamental understanding of facial nerve anatomy. Palsy duration, followed by location and mechanism, will determine mimetic muscle salvageability, by means of either direct repair, grafting, or nerve transfers, whereas longer palsy durations will necessitate introducing a new neuromuscular unit, whether by muscle transfer or free functional muscle transplant. A thorough history, physical examination, and basic understanding of ancillary studies, emphasizing palsy duration, location, and mechanism of injury, are critical in evaluation, prognostication, and treatment strategies in traumatic facial palsy patients. The importance of ancillary and aesthetic procedures cannot be overstated. Although these do not provide motion, they constitute essential tools in the treatment of facial paralysis, providing both protective and improved aesthetic outcomes, yielding the highest impact in final surgeon and patient satisfaction, bringing our patients to smile not only on the outside, but also on the inside.

A preliminary study on B -mode ultrasonic evaluation of muscle recovery after functional gracilis muscle transplantation

Objective To investigate the value of the B-mode ultrasound method for muscle recovery after transplantation. Methods From January, 2009 to January, 2014, 35 patients of functioning free gracilis muscle transplantation for brachial plexus injury were involved. Using B-mode ultrasound to determine the cross-sectional area (CSA) of transplanted gracilismuscle at rest and contraction state. The contraction ratio (CR) and the muscle bulk ratio (MBR) was calculated based on the CSA. Then the CR and MBR were analysised statistically with manual muscle strength and joint range of motion (ROM) to investigate the correlation. Results The followed-up time was 8-24 months, averaged of 22.4 months. The CR of the transplated muscle was (1.23±0.15), which was significantly correlated with muscle strength and joint ROM (P 0.05). There was no statistically significant difference in muscle strength and ROM between patients with MBR greater than 1 and those with MBR less than 1 (P= 0.054, P=0.284, respectively). Conclusion The transplanted muscle recovery can be quantitatively reflected by the CR. CR enlargement of the transplanted gracilis muscle indicated a better recovery of muscle contraction function. MBR is not suitable for evaluating function recovery of transplanted muscles. Key words: Gracilis; Functional muscle transplantation; B-mode ultrasound; Muscle contraction; Muscle strength

Pre-operative masseter muscle EMG activation during smile predicts synchronicity of smile development in facial palsy patients undergoing reanimation with the masseter nerve: A prospective cohort study✰

Synchronicity of the oral commissure movement of a bilateral smile is a significant goal for reconstruction in facial reanimation and may only be guaranteed with use of the facial nerve as a donor nerve. Yet over the years several studies report some degree of spontaneity in certain patients when using a non-facial donor nerve, which indicates that synchronous initiation of the smile might be achievable with other donor nerves. We designed a prospective cohort study to evaluate whether pre-operative involuntary activation of the masseteric nerve during smile predicts development of a synchronous smile development when using the masseteric nerve for reanimation. In a prospective cohort study unilateral long-standing facial palsy patients scheduled for dynamic smile reanimation with a free functional muscle transplant using the masseteric nerve as a donor nerve were preoperatively evaluated via EMG for involuntary activation of the masseter muscle upon smiling, which we called coactivation. Postoperatively, six months after noting the first muscle contraction smile synchronicity was evaluated. We analyzed the synchronicity of the bilateral smile development by analyzing slow-motion video sequences of the patients that were taken while the patients were watching funny video sequences. Results were then correlated with the pre-operative EMG. 30 patients were recruited for this prospective study and underwent facial reanimation surgery with a free gracilis transfer innervated by the masseteric nerve. 19 patients demonstrated involuntary coactivation of the masseter muscle upon smiling and 11 did not. Postoperatively all patients could demonstrate a voluntary smile. 94% of patients who had preoperative coactivation showed a synchronous movement of the oral commissure when smiling. In those patients, that did not show activation of the masseter muscle upon smiling 0% showed synchronicity. The preoperative coactivation of the masseter muscle is able to predict the outcome regarding synchronicity of the smile with a sensitivity of 99.7%, a specificity of 88.5% and 92.5% positive predictive value and 99.6% negative predictive value (p<0.001 for all). The lack of masseter co-activation with smile predicts a lack of spontaneous involuntary smile after dynamic smile reconstruction using the masseteric nerve.

An Anatomical Study of the Length of the Neural Pedicle after the Bifurcation of the Thoracodorsal Nerve

ABSTRACTBackground: Latissimus dorsi muscle is considered as a key stone most important muscle in plastic surgery used for many reconstructive surgical procedures varying from facial reanimation and breast reconstruction to lower limb reconstruction. it is essential to have knowledge about The branching pattern and length of the thoracodorsal nerve which is the nerve supply of this precious latissimus dorsi distal to the splitting of this nerve. For innervated functional muscle transplant procedures, the length of nerve pedicles available for nerve anastomosis is crucialAim of the Work: Is to investigate the topography and branching pattern of the thoracodorsal and also measure its length distal to its splitting.Materials and Methods: Sixteen latissimus dorsi muscles were dissected in eight adult embalmed human specimens in Anatomy department Faculty of medicine Alexandria university. The thoracodorsal neurovascular bundle was dissected and the pattern of branching of the thoracodorsal nerve was identified The branches were dissected up to the latissimus dorsi muscle and further intramuscularly. All lengths were measured using a vernier caliber. Surgically, in total, 10 patients with recurrent squamous cell carcinoma were undergone surgery permitting simultaneous cancer resection and harvesting of latissimus dorsi flap in Plastic surgery department, Faculty of medicine, Menufia University, Informed written individual consent was obtained for all the patients.Results: The median length of the medial branch was 3.45 cm (range, 1.80 to 5.5 cm; mean, 3.60 cm; SD, 1.04 cm). As regard the branching pattern of the thoracodorsal nerve distal to its splitting it varied from three branches pattern in 75%, two branches pattern in 23% of the specimens and in one case continued as one branch on the lateral border of latissimus dorsi muscle In one other specimen thoracodorsal nerve distal to its split gave many branches and in this specimen abreast mass was noticed on the corresponding side of this thoraco dorsal nerve. The veins and arteries showed a similar pattern, with a median length that is similar to that of the thoracodorsal nerve.The median length of the middle branch was3.50 cm (range, 2.4 5 to 4.65 cm; mean3.45 cm; SD, 0.88 cm), The lateral branch showed a median length of 3.99 cm (range, 2.5 5 to 5.95 cm; mean, 3.85 cm; SD, 0.95 cm). The mean length of the thoracodorsal nerve measured from the posterior root to the split was 12.5 cm.Surgically, by surface area the latissimus dorsi is the largest muscle in the body. It can be as large as 20 x 40cms, enabling latissimus dorsi flaps to cover very large defects after resection of squamous cell carcinoma in head and neck region especially in temporal and scalp regions.Conclusions: The separate neurovascular branches and its minimal pedicle length make the latissimus dorsi muscle very suitable for single functional free muscle transfer, using only the lateral part of the latissimus dorsi muscle, and double functional free muscle transfer using only one vascular pedicle. This suggests the possibility of a multiple, segmentally innervated latissimus dorsi muscle transfer. And actually this is facilitated by this branching pattern of the thoracodorsal nerve.There may be association between the multiple branch pattern of the thoracodorsal nerve and presence of breast mass, an issue which need more research. From surgical points of view, there is strong need for preoperative diagnostic tools to predict the pattern of branching of neuro vascular bundle of latissimus muscle, to help preoperative planning especially in cases as facial reanimation, also in cases that we need more than one muscular functional units, also in cases that we might need to leave portion of muscle for better esthetics and better function of limb movements.

Adipose-Derived Stem Cells Enhance Axonal Regeneration through Cross-Facial Nerve Grafting in a Rat Model of Facial Paralysis.

Cross-face nerve grafting combined with functional muscle transplantation has become the standard in reconstructing an emotionally controlled smile in complete irreversible facial palsy. However, the efficacy of this procedure depends on the ability of regenerating axons to breach two nerve coaptations and reinnervate endplates in denervated muscle. The current study tested the hypothesis that adipose-derived stem cells would enhance axonal regeneration through a cross-facial nerve graft and thereby enhance recovery of the facial nerve function. Twelve rats underwent transection of the right facial nerve, and cross-facial nerve grafting using the sciatic nerve as an interpositional graft, with coaptations to the ipsilateral and contralateral buccal branches, was carried out. Rats were divided equally into two groups: a grafted but nontreated control group and a grafted and adipose-derived stem cell-treated group. Three months after surgery, biometric and electrophysiologic assessments of vibrissae movements were performed. Histologically, the spectra of fiber density, myelin sheath thickness, fiber diameter, and g ratio of the nerve were analyzed. Immunohistochemical staining was performed for the evaluation of acetylcholine in the neuromuscular junctions. The data from the biometric and electrophysiologic analysis of vibrissae movements, immunohistochemical analysis, and histologic assessment of the nerve showed that adipose-derived stem cells significantly enhanced axonal regeneration through the graft. These observations suggest that adipose-derived stem cells could be a clinically translatable route toward new methods to enhance recovery after cross-facial nerve grafting.

Facial Paralysis Grading System

Various facial paralysis grading systems have been introduced to evaluate the results of both spontaneous recovery and facial palsy reconstruction. The aim of the present study was to introduce and evaluate an objective new and quick Smile Excursion Score system which is readily applicable and easy to follow. It has been applied over the past 25 years for preoperative and postoperative result evaluation of smile reconstruction at Chang Gung Memorial Hospital. A standardized evaluation method was described for the assessment of the upper lip movement preoperatively and postoperatively with at least 1 year follow-up after functioning muscle transplantation. The evaluation was scored by the number of maxillary teeth exposed when smiling with teeth showing. Reliability of this technique was assessed by using 3 independent examiners who each evaluated the smiles of 34 unilateral facial paralysis patients 4 times, creating 408 sets of measurements. The intraclass correlation coefficients for interrater and intrarater reliability exceeded 0.94, which is considered as excellent and reliable. Chuang's Smile Excursion Score system is simple, quick, and accurate in evaluating smile after reanimation of paralyzed face effecting free functional muscle transplantation with no additional tools.

Free functional muscle transplantation of an anomalous femoral adductor with a very large muscle belly: a case report

We report the case of a 34-year-old man with a total brachial plexus injury that was treated by free functional muscle transplantation to restore simultaneously elbow flexion and finger extension. The muscle had a very large muscle belly (12 cm width), which was considered anatomically to be a fusion of the gracilis and the adductor longus muscles. Although the muscle possessed two major vascular pedicles with almost equal diameters, only the proximal vascular pedicle was anastomosed to the recipient vessels during the transplantation surgery, resulting in partial necrosis of the muscle. Several authors have reported on the successful simultaneous transplantation of the gracilis and adductor longus muscles, because they are supplied generally by a single common vascular pedicle. However, the present study suggests that when a surgeon encounters an aberrant femoral adductor with a very large muscle belly that can be considered to be a fusion of these muscles, the surgeon should assess intraoperatively the vascularity of the muscle using Doppler sonography, indocyanine green fluorescence injection, or other techniques.

Prinzipien und Möglichkeiten der Defektedeckung im distalen Unterschenkeldrittel und Sprunggelenkbereich

The lower leg is the most often severely injured part of the lower extremity. Despite improved operative techniques, soft tissue defects alone or in combination with bone defects that cannot be closed by secondary suture still present a complex diagnostic and therapeutic problem. Modern treatment of severe trauma to the distal lower leg requires a global defect management which is based on: 1) profound basic knowledge, 2) multidisciplinary treatment team using a “common language” concerning diagnosis, classification and treatment, and 4) an integrated treatment concept. Adequate primary defect reconstruction is the basis of any successful treatment. For function improvement a variety of secondary operations like muscle/tendon transfer, tenodesis, capsulodesis, arthrodesis or ultimatively free functional muscle transplantation alone or in combination are available. Moreover adjuvant procedures such as orthesis, orthopaedic shoes, etc. may be useful at any time of treatment.

Subdivision of the sural nerve: Step towards individual facial reanimation

Long term facial paralysis is a serious affliction and upsetting for the patient. Dynamic facial reanimation has become the treatment of choice. Various techniques that use different donor muscles have been developed since the first functional muscle transplant for facial paralysis more than 30 years ago. The concept of using a single muscle was refined into the use of dividable muscle slips such as serratus muscle or separate muscular subunits to avoid the resulting mass movements. Because the results are still not satisfactory, efforts were put into also dividing the donor nerve transplant into corresponding subunits to create a continuous line of individual action. Twenty human cadaveric sural nerves were successfully dissected into three completely separate subunits, transecting the interfascicular bridges. This anatomical study gives the potential to allow an independent triple innervation of three separate serratus anterior muscle slips, so decreasing further the mass movement after facial reanimation.

An Anatomical Study of the Length of the Neural Pedicle after the Bifurcation of the Thoracodorsal Nerve: Implications for Innervated Free Partial Latissimus Dorsi Flaps

For innervated functional muscle transplant procedures, it is essential to have knowledge about the length of nerve pedicles available for nerve anastomosis. For the latissimus dorsi muscle, the thoracodorsal nerve divides into two funicles that separately innervate the medial and lateral portions of the muscle. This suggests the possibility of a multiple, segmentally innervated latissimus dorsi muscle transfer. The branching and length of the thoracodorsal nerve distal to the bifurcation have not been described. This surgical-anatomical study presents anatomical data on these practical/clinical issues. Eleven latissimus dorsi muscles were dissected in eight adult embalmed human specimens. The thoracodorsal neurovascular bundle was dissected from insertion to proximal of the bifurcation. Measurements were taken indirectly from standardized photographic images and analyzed with ImageJ and standard spreadsheet software. The mean age of the specimens was 66 years. The median pedicle length of the lateral part of the muscle was 3.8 cm (range, 2.41 to 5.93 cm). The median length of the medial branch was 3.49 cm (range, 1.7 to 5.12 cm). Proximal branching of the medial pedicle of the bifurcation was identified in approximately two-thirds of the specimens and had a median of 3.55 cm (range, 2.54 to 4.68 cm). The veins and arteries showed a similar pattern, with a median length slightly less than that of the thoracodorsal nerve. The separate neurovascular branches and its minimal pedicle length make the latissimus dorsi muscle very suitable for single functional free muscle transfer, using only the lateral part of the latissimus dorsi muscle, and double functional free muscle transfer using only one vascular pedicle.

Bewährte und innovative operative Techniken zur Reanimation des gelähmten Gesichtes

This overview on the currently most effective reconstructive techniques for reanimation of the unilaterally or bilaterally paralysed face includes all important techniques of neuromuscular reconstruction as well as of supplementary static procedures, which contribute significantly to the efficiency and quality of the functional overall result. Attention is paid to the best indications at the best time since onset of the facial palsy, depending on the age of the patient, the cause of the lesion, and the compliance of the patient for a long-lasting and complex rehabilitation programme. Immediate neuromuscular reconstruction of mimic function is favourable by nerve suture or nerve grafting of the facial nerve, or by using the contralateral healthy facial nerve via cross-face nerve grafting as long as the time since onset of the irreversible palsy is short enough that the paralysed mimic muscles can still be reinnervated. For the most frequent indication, the unilateral irreversible and complete palsy, a three-stage concept is described including cross-face nerve grafting, free functional gracilis muscle transplantation, and several supplementary procedures. In patients with limited life expectancy, transposition of the masseteric muscles is favoured. Bilateral facial palsy is treated by bilateral free gracilis muscle transplantation with the masseteric nerve branches for motor reinnervation. Functional upgrading in incomplete lesions is achieved by cross-face nerve grafting with distal end-to-side neurorrhaphy or by functional muscle transplantation with ipsilateral facial nerve supply.

Brachial Plexus Injury: Nerve Reconstruction and Functioning Muscle Transplantation

Adult brachial plexus injury remains a dilemma to a reconstructive microsurgeon, especially when attempting to reconstruct cases of total root avulsion. Different degrees and different levels of injury require different strategies of reconstruction. The purpose of this article is to illustrate the author's reconstructive strategy in correlation with the injury level of classification. Nerve transfer, functioning free muscle transplantation, and other palliative surgery are reconstructive options for level 1 injuries. Neurolysis, nerve repair, nerve grafts (free nerve graft or vascularized ulnar nerve graft), nerve transfer if associated with level 1 lesion in other spinal nerves, and palliative reconstruction are chosen options for level 2, 3, and 4 lesions. A clavicle osteotomy is often required in level 3 lesions. Nerve grafts are frequently applied in level 4 lesions, which result in less aberrant reinnervation and a better prognosis.

Free Functional Gracilis Muscle Transplantation for Reconstruction of Active Elbow Flexion in Posttraumatic Brachial Plexus Lesions

Reconstruction of powerful active elbow flexion. Reconstruction of missing muscle unit by neurovascular pedicled functional muscle transplantation. Treatment of last choice for --secondary reconstruction of active elbow flexion in case of complete lesion of the brachial plexus or musculocutaneous nerve (M0 muscle function = replacement indication), partial but incomplete lesion of the brachial plexus or musculocutaneous nerve (M1-(3) muscle function = augmentation indication); --replacement of the elbow flexor muscles in case of primary muscle loss (tumor, trauma). Concomitant lesions of the axillary artery. No adequate donor nerve. Relative: no sensibility at all at the forearm and hand. Free functional biarticular myocutaneous transplantation of gracilis muscle. A myocutaneous gracilis flap is raised at the thigh. At the upper arm the flap is fixed proximally to the coracoid process or the lateral clavicle. The distal insertion is sutured to the distal biceps tendon. Vascular anastomoses are carried out in end-to-side fashion with the brachial artery and vein. Nerval coaptation is done in end-to-end technique using the muculocutaneous nerve. Complete immobilization for 6 weeks. Dorsal upper arm splint until sufficient muscle power (M(4)). Progressive increase of active range of motion for another 6 weeks. Continuation of physiotherapy for 12-18 months. Postoperative standardized compression therapy, combined with scar therapy (silicone sheet). Functionally useful results can be expected in 60-75% of patients, especially if there is some residual function (M1 or M2) left ("augmentation indication"). Early free functional muscle transplantation shows best results in patients with direct muscle defect, because all vascular and neuronal structures are still available, and no secondary changes such as fibrosis or joint stiffness are present yet. There are inconsistent results for patients with neurologic insufficiency (i.e., total brachial plexus palsy) or mixed neuromuscular insufficiency, such as compartment syndrome. Especially in complete brachial plexus lesion, free functional muscle transfer is often the only treatment option. Provided there is a good patient selection, satisfactory results can be achieved for elbow flexion. Whether a higher number of axons, as provided by the contralateral C7 transfer, will lead to better results is the topic of an ongoing study.

Three-Dimensional Video Analysis of the Paralyzed Face Reanimated by Cross-Face Nerve Grafting and Free Gracilis Muscle Transplantation: Quantification of the Functional Outcome

Surgeons have found it difficult to quantify facial paralysis and its improvement by reconstructive surgery. This article presents the results achieved by free functional muscle transplantation for reconstruction of the paralyzed face, registered by three-dimensional video analysis of facial movements. Of patients treated consecutively between 1997 and 2006, two groups were constituted: group 1 comprised 22 patients with reinnervation completed after a single cross-face nerve graft and a free gracilis muscle graft for reconstruction of the smile; group 2 comprised nine patients treated with two cross-face nerve grafts followed by a territorially differentiated gracilis muscle transplant for reconstruction of the smile and eye closure. Smiling with showing teeth, maximal showing of teeth, and closing the eyes as in sleep were analyzed in detail. In group 1, static asymmetry was reduced from 12.19 +/- 8.73 mm preoperatively to -1.84 +/- 7.67 mm at 18 months postoperatively. Smile amplitude increased from 9 to 60 percent of that on the healthy side in 10 incomplete facial palsies of this group, and from 0 to 62 percent in eight functionally successful muscle grafts among 11 patients with complete lesions. In group 2, static asymmetry improved from 7.24 +/- 12.64 mm to -5.36 +/- 9.07 mm; the overcorrection was intentional. Movement was improved in eight cases. Smile amplitude reached 68 +/- 43 percent of that on the normal side. Lagophthalmus improved from 7.21 +/- 3.59 mm to 1.38 +/- 2.49 mm. All improvements were statistically significant (p <or= 0.05). Three-dimensional video analysis provided an exact quantitative documentation of the degree of facial palsy preoperatively and the reconstructed movements. The value of free functional gracilis muscle transplantation was demonstrated for both variations of the technique.

Functional Muscle Transfer and the Variance of Reinnervating Axonal Load: Part II. Peripheral Nerves

Peripheral limb reconstruction using functional muscle transfer following injury or tumor resection has been widely reported in the literature. Such procedures often fail to deliver the physiologic contractile strength that might be hoped for in relation to the size of the transplanted muscle. Pure motor nerves of differing sizes were used to reinnervate a constant-sized muscle flap to see whether functional results could be improved in an experimental model analogous to clinical peripheral limb reconstruction. Twenty-four New Zealand White rabbits were divided into two groups of 12 animals each. The rectus femoris muscle was raised as a free flap and transplanted back to the donor site orthotopically (coapted back to its original motor nerve) in the rectus femoris group or heterotopically (coapted to the larger motor nerve to the vastus lateralis-double the axonal load of the indigenous nerve) in the vastus lateralis group. Half the animals from each group were euthanized at 6 months, and the remaining animals were at 9 months. In all cases, the contralateral rectus femoris muscle served as a control. Physiologic assessment of the transplants for maximal tetanic contractural force was undertaken, together with immunohistochemical and histologic analysis of muscle and nerve tissue. Result analysis demonstrated that the double-sized nerve failed to produce significant improvements in physiologic outcome between the two groups at either the 6- or 9-month time point. The results were further endorsed by the histologic findings. Increasing the axonal load to a functional muscle transplant beyond that of its indigenous motor nerve does not improve outcome.

Technique of Harvesting the Gracilis for Free Functioning Muscle Transplantation

In this article, we describe our technique and experience in harvesting the gracilis muscle for free functioning muscle transplantation (FFMT). The gracilis is the most commonly used muscle for FFMT. The main indication for gracilis FFMT is traumatic brachial plexus injury. Gracilis muscle has a class 2 vascular pedicle, with a dominant vascular pedicle originating from the profunda femoris vessels and a single motor nerve originating from the obturator nerve. During gracilis harvest, it is important to include the entire fascia around the muscle to ensure vascularity of the skin paddle and enhance muscle gliding in its new bed. Mobilization of the adductor longus allows tracing of the pedicle to its origin from the profunda femoris vessels, hence, achieving the maximum available length of the pedicle. Lengthening of gracilis tendon with a periosteal strip provides a free gracilis long enough to span the distance from the clavicle to the distal forearm. The main complications are related to the wound, and these include delayed healing, infection, and scar-related problems. The functional deficit after gracilis harvest is negligible.

Free functional muscle transplantation for facial reanimation: experimental comparison between the one- and two-stage approach

To investigate functional results of either one- or two-staged free muscle transplantation the scutuloauricularis model in the New Zealand white rabbit was used. Thirty rabbits were allocated to two groups with 15 animals each. In Group 1 (one-stage approach) peroneus brevis (PB) was harvested as a free muscle graft with a 7cm long motor branch. The graft was positioned instead of right scutuloauricularis (SCUT) and its vascular supply microsurgically re-established. The motor branch was transferred to the contralateral side and its proximal end coapted to the cut facial motor branch to left SCUT. Before nerve coaptation biopsies were harvested from the cut motor branch for morphological analysis. In Group 2 (two-stage approach) a 7cm long saphenous nerve graft was taken and coapted to the cut motor branch of SCUT and crossed over to the contralateral side. Nerve specimens from the cut motor branch were taken. Eight months later the free transplantation of PB was performed and its motor branch coapted to the distal end of the cross-over nerve graft. After a total time period of 13 months the final experiments were carried out in each group. Maximal tetanic tensions in reinnervated PB were measured and biopsies of muscle grafts together with nerve biopsies from the distal part of the motor branch were harvested for morphological analysis. Muscle grafts of Group 1 revealed tetanic tension values of 12.5N (SD 3.1) in comparison to 10.6N (SD 3.5) obtained in Group 2. This difference was not statistically significant (p=0.303). In Group 1, the amount of regenerated nerve fibers counted at the distal motor branch site (mean: 2798, SD 1242) was significantly higher (p=0.008) than in Group 2 (mean: 1138, SD 1004). Muscle graft morphology revealed significantly less Type I fibers (p=0.016) and more Type IIb/d fibers (p=0.011) in Group 1 compared to Group 2. However, the overall amount of perimysial connective tissue showed no significant difference in both groups (p=0.478). Free muscle transplantation in a one-stage approach offers similar functional results in comparison to the two-stage approach. Although muscle grafts of the one-stage transplantation underwent a longer period of denervation similar contents of perimysial connective tissue could be observed.