Free muscle transplants in dogs, with microsurgical neurovascular anastomoses

Free Functional Muscle Transfer-Technical Considerations

Free functional muscle transfers restore voluntary motion in extremities following the loss of local muscle-tendon units. Surgeons, at various levels of expertise, need to consider several technical aspects when performing this procedure. Successful and consistent outcomes can be attained by applying a combination of basic principles, drawing from techniques developed for successful tendon transfers and microsurgical free tissue transfers. Patient preparation through counseling and intensive rehabilitation is essential to achieve the optimal conditions before the transfer.

Functioning Free Muscle Transplantation to Restore Finger Movement for Sequalae of Volkmann Ischemic Contracture

Volkmann ischemic contracture (VIC) is a devastating condition that results from neglected compartment syndrome, which leads to prolonged ischemia, irreversible tissue necrosis, and various degrees of muscle and nerve damage, causing serious motor and sensory functional implications for the limb and a spectrum of diseases associated with worsening deformities. A thorough understanding of the anatomy and VIC pathophysiology is needed to plan an appropriate strategy. Functioning free muscle transplantation (FFMT) can restore finger movement in a paralyzed limb but requires a three-staged approach to maximize the benefits of FFMT, leading to meaningful finger extrinsic function.

Highly Aligned Ternary Nanofiber Matrices Loaded with MXene Expedite Regeneration of Volumetric Muscle Loss

Current therapeutic approaches for volumetric muscle loss (VML) face challenges due to limited graft availability and insufficient bioactivities. To overcome these limitations, tissue-engineered scaffolds have emerged as a promising alternative. In this study, we developed aligned ternary nanofibrous matrices comprised of poly(lactide-co-ε-caprolactone) integrated with collagen and Ti3C2Tx MXene nanoparticles (NPs) (PCM matrices), and explored their myogenic potential for skeletal muscle tissue regeneration. The PCM matrices demonstrated favorable physicochemical properties, including structural uniformity, alignment, microporosity, and hydrophilicity. In vitro assays revealed that the PCM matrices promoted cellular behaviors and myogenic differentiation of C2C12 myoblasts. Moreover, in vivo experiments demonstrated enhanced muscle remodeling and recovery in mice treated with PCM matrices following VML injury. Mechanistic insights from next-generation sequencing revealed that MXene NPs facilitated protein and ion availability within PCM matrices, leading to elevated intracellular Ca2+ levels in myoblasts through the activation of inducible nitric oxide synthase (iNOS) and serum/glucocorticoid regulated kinase 1 (SGK1), ultimately promoting myogenic differentiation via the mTOR-AKT pathway. Additionally, upregulated iNOS and increased NO- contributed to myoblast proliferation and fiber fusion, thereby facilitating overall myoblast maturation. These findings underscore the potential of MXene NPs loaded within highly aligned matrices as therapeutic agents to promote skeletal muscle tissue recovery.

Free functional muscle transfer for lower extremity reconstruction

BACKGROUND

Free functional muscle transfer is a reconstructive strategy for the reconstruction of lost muscle units in the lower extremity after oncologic resection, trauma, compartment syndrome, or severe nerve injuries. Under appropriate circumstances, free functional muscle transfer may be the only suitable reconstructive option. This article reviews the underlying principles of free functional muscle transfer, its application to lower extremity reconstruction, appropriate patient selection, and surgical techniques.

METHODS

The underlying principles of free functional muscle transfer, its application to lower extremity reconstruction, appropriate patient selection, and surgical techniques are presented. Commonly used donor muscles appropriate for each type of functional defect are discussed. A review of recent publications on free functional muscle transfer in the lower extremity was also performed.

RESULTS

Good functional recovery with a Medical Research Council grade of up to 4/5 and full range of motion can be attained with free functional muscle transfer. Clinical outcomes and specific parameters for published case series in lower extremity free functional muscle transfer are presented and an illustrative case.

CONCLUSION

Free functional muscle transfer is a suitable treatment for the appropriate patient to restore essential functions and potentially regain ambulation. However, additional published clinical outcomes are needed and represent a major area for further investigation.

Form and Function: Technique for Free Functional Gracilis Harvest With Greater Saphenous Vein for Large Skin Paddle

Free functional gracilis transfer is a technique for restoration of upper extremity function following brachial plexus injury, as well as muscle loss from traumatic, oncologic, and congenital causes. However, when used for the latter applications, a functional muscle as well as large skin paddle can be required. Historically, skin paddle size was limited by venous outflow of the gracilis flap, using 1 or 2 venae comitantes, and large unreliable skin paddles resulting in partial necrosis. Therefore, to restore form and function, we herein present a technique of free functional gracilis muscle harvest with inclusion of adjacent greater saphenous vein for inclusion of a large skin paddle with 2 venous drainage systems.

History of Microsurgery: The Legacy of Harry J. Buncke, MD

A historical review of the history of Microsurgery including the important influence and contributions of Harry J. Buncke MD considered by many to be the "Father of Microsurgery". An chronological list of Historic Replants and "Free Flap" and microvascular transplants is included. Those who lived through the age of the birth of this new surgical specialty were fortunate.

Upper Extremity Free Flap Transfers: An Analysis of the National Surgical Quality Improvement Program Database

Introduction  We evaluated the demographics, flap types, and 30-day complication, readmission, and reoperation rates for upper extremity free flap transfers within the National Surgical Quality Improvement Program (NSQIP) database. Materials and Methods  Upper extremity free flap transfer patients in the NSQIP from 2008 to 2016 were identified. Complications, reoperations, and readmissions were queried. Chi-squared tests evaluated differences in sex, race, and insurance. The types of procedures performed, complication frequencies, reoperation rates, and readmission rates were analyzed. Results  One-hundred-eleven patients were selected (mean: 36.8 years). Most common upper extremity free flaps were muscle/myocutaneous (45.9%) and other vascularized bone grafts with microanastomosis (27.9%). Thirty-day complications among all patients included superficial site infections (2.7%), intraoperative transfusions (7.2%), pneumonia (0.9%), and deep venous thrombosis (0.9%). Thirty-day reoperation and readmission rates were 4.5% and 3.6%, respectively. The mean time from discharge to readmission was 12.5 days. Conclusion  Upper extremity free flap transfers could be performed with a low rate of 30-day complications, reoperations, and readmissions.

Reconstruction of Large Full-Thickness Abdominal Wall Defects Using a Free Functional Latissimus Dorsi Muscle

Introduction

The large full-thickness abdominal wall defect has to be treated by considering anatomical and functional requirements. The abdominal wall must regain total physiological function, which means that the full thickness abdominal wall defect must be reconstructed anatomically, not only according to the anatomical requirements but also maintaining the functional dynamic voluntary movement. Defects in the abdominal wall alter respiratory mechanics and can impair the diaphragm function. Additionally, muscles of the anterolateral abdominal wall increase the stability of the lumbar region of the vertebral column by tensing the thoracolumbar fascia and by increasing intraabdominal pressure.

Materials and Methods

The timing and method of reconstruction must be chosen depending upon the etiology of the defect. Severe traumatic injuries, abdominal wall infections, necrotizing soft tissue loss, or sepsis needs to undergo staged reconstruction following adequate debridement to control the infectious process, establish the zone of injury, and for proper treatment of intraabdominal pathology, thereby achieving temporary primary closure using split-thickness skin grafting to the viscera. At the time of definitive reconstruction, deep skin graft dermabrasion give us a facial-like layer with adequate strength to stabilize the static abdominal wall. This dermal layer is supported by free functional (innervated) latissimus dorsi muscle (fLDM), giving full anatomical coverage and functional stability. After oncologic resections full-thickness abdominal wall reconstruction was performed immediately with a combination of fLDM flaps and meshes.

Results

A total of 14 patients underwent abdominal wall reconstruction using the fLDM flap. Staged reconstruction was applied in 8 cases. In the remaining six cases, two had no mesh support, three had synthetic mesh, and one had a fascial graft, which were covered with fLDM flap. There were no free flaps failure. One flap revision due to venous anastomosis thrombosis was performed. Donor site seromas occurred in 5 cases and were treated with punction and direct doxycycline injection. Electromyographic testing postoperatively confirmed reinnervation of transplanted LDM.

Conclusion

Using fLDM as a definitive solution, we are not only able to repair soft tissue defects, but also reconstruct voluntary contractility and dynamic natural functional abdominal wall. Transplanted LDM offers enough contractile capacity and strength to replace the function of the missing abdominal wall muscles.

Free functional muscle transfer for upper limb paralysis - A systematic review

BACKGROUND

Functional restoration of upper limb paralysis represents a major reconstructive challenge. Free functional muscle transfer (FFMT) enables reanimation in patients with a lack of local donor tissues or delayed presentation. This systematic review summarises the evidence for FFMT in the reconstruction of upper limb paralysis.

METHODS

A comprehensive search of MEDLINE and EMBASE was performed with a systematic review using methodology adapted from the Cochrane Handbook and the PRISMA statement. Data from included studies were compiled and narratively synthesised. Studies were assessed for risk of bias.

RESULTS

A total of 1155 records were screened, with 39 observational studies of 904 patients included. The most common aetiology was brachial plexus injury (736, 81.4%). Mean time from injury to intervention was 26 months. Restoration of elbow flexion was the commonest reconstructive goal. The most common donor muscle was gracilis (91.5%). Reported outcomes were heterogeneous with patient-reported outcome measures (PROMs) available in only 7 of 39 studies. Nearly half of FFMTs had a post-operative MRC grade of <4 and 18.1% had an MRC <3. Mean flap failure rate was 3.6% (range 0-10.5%). All studies were at high risk of bias.

CONCLUSIONS

FFMT may be an effective surgical intervention for upper limb paralysis; however, the current evidence has significant shortcomings. There is no consensus regarding outcome measures nor is it possible to identify prognostic factors for its effectiveness. This review highlights a need for improved study design with pre-operative assessment, standardisation in outcome reporting, and the use of PROMs to determine the effectiveness of FFMT in upper limb paralysis.

Single incision thenar muscle reconstruction using the free functional pronator quadratus flap

Background

Injuries to the thenar muscle mass or the thenar branch of the median nerve and resulting loss of thumb opposition lead to a massive impairment of hand function. For decades, reconstructive approaches were based on tendon transfers. To broaden the reconstructive repertoire, we present the free functional pronator quadratus flap as a viable alternative for functional reconstruction and provide a specification for its indication. We demonstrate our surgical technique to a single incision reconstruction using the free functional pronator quadratus flap. Based on a series of three patients, which were analyzed for hand function using Kapandji’s score and the angle of Bourrel, grip strength and nerve conduction velocity in a two year follow up, we present an indication algorithm.

Results

After successful reinnervation of all flaps, we found an improvement of Kapandji’s score from 4.3 ± 0.94 preoperatively, to 8.7 ± 0.47 after two years. Accordingly, the angle of Bourrel decreased from 75.75 ± 3.45 degrees to 36.96 ± 3.68 degree. Grip strength also improved from 14 ± 2.2 kg to 26.2 ± 1.2 kg. No impairment of wrist pronation was observed.

Conclusion

We found excellent functional recovery of thumb opposition and strength, showing similar or even superior results compared to results from tendon transfers. With the benefit of a single incision surgery and therefore minimal donor site morbidity, this free functional muscle transfer is a viable alternative to classic tendon transfers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01308-x.

The Anatomic Feasibility of a Functional Chimeric Flap in Complex Abdominal Wall Reconstruction

BACKGROUND

Dynamic and functional abdominal wall reconstruction (FAWR) remains a complex challenge. The ideal flap should have a minimal donor-site morbidity and cover a large surface area with motor and sensory capabilities. The goal was to investigate the feasibility of using a free chimeric flap with anterolateral thigh (ALT) and rectus femoris (RF) components pedicled only on the motor nerve branch.

METHODS

Ten fresh cadavers were dissected with a designed chimeric thigh flap including ALT and RF flaps. Anterolateral thigh was designed and raised with the lateral femoral cutaneous nerve integrated, and the descending branch of the lateral circumflex femoral artery was preserved. Rectus femoris was elevated and the common pedicle was dissected up to the femoral origin. Accompanying motor nerve branches were carefully dissected to their femoral origin.

RESULTS

Twenty RF flaps were dissected and 9 were harvested as a true chimeric flap with ALT. The mean number of neurovascular bundles associated with RF flap was 2.11 ± 0.47, and the mean primary motor nerve average length was 9.40 ± 2.42 cm. The common vascular bundle in all 9 chimeric flaps was ligated, and the flap was rotated toward the abdomen pedicled only by primary motor nerve of the RF muscle. Nerve length was adequate for reach up to xiphoid area in all 20 flaps.

CONCLUSIONS

This study demonstrates the feasibility of the chimeric ALT/RF muscle free flap pedicled only by the motor nerve branch, with adequate flap rotation. Even with the limitations in a live patient, this flap would be an excellent option for FAWR in the right patient.

Facial Reanimation With Free Latissumus Dorsi Muscle Transfer, a Comparative Study Between Lateral and Supine Approach

ABSTRACT

In this article, the authors present the versatility of the Latissmus dorsi muscle as a donor option in facial reanimation and compare between different approaches in harvesting this muscle.The study included 24 Latissimus Dorsi (LD) functional muscles were transferred for smile reanimation of complete facial palsy. The patients were classified into 2 groups in which the muscle either harvested with supine or lateral (trans-axillary) approach. Muscle harvesting time, total operating times, blood loss, and bulkiness of the flap were analyzed and compared. The hypoglossal nerve was used in 14 cases, the masseteric nerve in 4 cases, and the lower trunk of the facial nerve was used in 6 cases as adonor nerve. No microvascular complications were observed, hematoma occurred in 2 cases only. No donor site complications in any of the cases.The trans-axillary approach provides less operative time, blood loss, and donor site morbidity, while the classic approach is easier and has the advantage of skin paddle in complex cases.

Brachial Plexus Injuries - Review of the Anatomy and the Treatment Options

Brachial plexus injuries are still challenging for every surgeon taking part in treating patients with BPI. Injuries of the brachial plexus can be divided into injuries of the upper trunk, extended upper trunk, injuries of the lower trunk and swinging hand where all of the roots are involved in this type of the injury. Brachial plexus can be divided in five anatomical sections from its roots to its terminal branches: roots, trunks, division, cords and terminal branches. Brachial plexus ends up as five terminal branches, responsible for upper limb innervation, musculocutaneous, median nerve, axillary nerve, radial and ulnar nerve. According to the findings from the preoperative investigation combined with clinically found functional deficit, the type of BPI will be confirmed and that is going to determine which surgical procedure, from variety of them (neurolysis, nerve graft, neurotization, arthrodesis, tendon transfer, free muscle transfer, bionic reconstruction) is appropriate for treating the patient.

Brachial Plexus Injuries in Sport Medicine: Clinical Evaluation, Diagnostic Approaches, Treatment Options, and Rehabilitative Interventions

The brachial plexus represents a complex anatomical structure in the upper limb. This "network" of peripheral nerves permits the rearrangement of motor efferent fibers, coming from different spinal nerves, in several terminal branches directed to upper limb muscles. Moreover, afferent information coming from different cutaneous regions in upper limb are sorted in different spinal nerves through the brachial plexus. Severe brachial plexus injuries are a rare clinical condition in the general population and in sport medicine, but with dramatic consequences on the motor and sensory functions of the upper limb. In some sports, like martial arts, milder injuries of the brachial plexus can occur, with transient symptoms and with a full recovery. Clinical evaluation represents the cornerstone in the assessment of the athletes with brachial plexus injuries. Electrodiagnostic studies and imaging techniques, like magnetic resonance and high-frequency ultrasound, could be useful to localize the lesion and to define an appropriate treatment and a functional prognosis. Several conservative and surgical techniques could be applied, and multidisciplinary rehabilitative programs could be performed to guide the athlete toward the recovery of the highest functional level, according to the type of injury.

Redefining the Anatomic Boundaries for Safe Dissection of the Skin Paddle in a Gracilis Myofasciocutaneous Free Flap: An Indocyanine Green Cadaveric Injection Study

The gracilis free flap remains a versatile option in the reconstructive ladder. The flap itself can be harvested with or without a skin paddle. The gracilis myocutaneous free flap, however, is known for partial skin flap necrosis, especially in the distal one-third of the skin island. The gracilis myofasciocutaneous flap has been previously described as a technique to improve perfusion to the skin by harvesting surrounding deep fascia in a pedicled flap. However, limitations to this study required injection of multiple pedicles to demonstrate its perfusion. We demonstrate a novel technique using a cadaveric model that shows perfusion through injection via a single dominant pedicle (medial circumflex) with a large cutaneous paddle (average 770 cm²) with included deep fascia, using indocyanine green and near-infrared imaging. For comparison, we are also able to confirm the lack of perfusion to the distal cutaneous paddle when the fascia is not harvested, correlating with previous findings and ink injection studies. This novel technique is versatile, relatively inexpensive, and can demonstrate perfusion patterns via perforasomes that were otherwise not possible from previous techniques. Additionally, real-time imaging is possible, helping to elucidate the sequence of flow into the flap and potentially predict areas of flap necrosis.

Functional pectoralis minor myocutaneous flap transplantation for reconstruction of thumb opposition: An anatomic study with clinical applications

OBJECTIVE

To develop a myocutaneous flap for reconstruction of thumb opposition function in patients with loss of the thenar muscles and skin.

METHODS

An anatomic experiment on the dimensions of the pectoralis minor muscle and its neurovascular supply in 10 adult human cadavers was conducted to evaluate the feasibility of microsurgical transplantation using part of the muscle for thumb opposition reconstruction. Based on these results, we performed surgical thenar reconstruction with a pectoralis minor myocutaneous flap in seven patients (34.7 ± 9.8 years of age) from December 2007 to October 2010.

RESULTS

The transferred muscle was reinnervated with the third lumbrical branch of the ulnar nerve. Six to twelve months after the surgery, follow-up assessment showed that all patients had recovered functional opposition of the carpometacarpal joint with survival of the skin and a muscle power of M4 to M5.

CONCLUSION

Our results support the use of this new technique for thenar and opposition reconstruction in patients with severe loss of the thenar muscles and skin and damage to the median nerve and who wish to improve the appearance of the thenar eminence.

One plus one: Two free flaps from same donor thigh for simultaneous coverage of two different defects

Introduction:

Primary microvascular reconstruction of multiple defects is challenging particularly if it has to be simultaneous. In trauma cases, harvesting two independent free flaps from different sites is very time-consuming and adds to morbidity. To eliminate these disadvantages, we sought to find out a reliable alternative method of harvesting two independent free flaps based on the descending branch of circumflex femoral artery, i.e., one anterolateral thigh (ALT) flap and one rectus femoris muscle flap.

Aim:

To study the feasibility of transferring two free flaps, i.e., ALT and rectus femoris muscle flap simultaneously from the same thigh for coverage of two different limb defects.

Materials and Methods:

From 2003 to 2012, five patients with two defects each were managed with a total of ten flaps harvested from five donor sites based on independent pedicles of descending branch of lateral circumflex femoral artery and used to cover severe injuries of extremities. Three cases had both lower limb defects and two cases had one upper limb and one lower limb defect. In each case, one ALT flap and one rectus femoris muscle flap were used for coverage.

Results:

All reconstructive procedures were completed without any major complications. All flaps survived well. There were no re-explorations and no complications related to donor sites.

Conclusion:

We conclude that our approach of simultaneous harvest of ALT and rectus femoris muscle from the same thigh offers two flaps for two different defects in terms of economy of donor site and operating time.

Polymer therapeutics in surgery: the next frontier

Polymer therapeutics is a successful branch of nanomedicine, which is now established in several facets of everyday practice. However, to our knowledge, no literature regarding the application of the underpinning principles, general safety, and potential of this versatile class to the perioperative patient has been published. This study provides an overview of polymer therapeutics applied to clinical surgery, including the evolution of this demand‐oriented scientific field, cutting‐edge concepts, its implications, and limitations, illustrated by products already in clinical use and promising ones in development. In particular, the effect of design of polymer therapeutics on biophysical and biochemical properties, the potential for targeted delivery, smart release, and safety are addressed. Emphasis is made on principles, giving examples in salient areas of demand in current surgical practice. Exposure of the practising surgeon to this versatile class is crucial to evaluate and maximise the benefits that this established field presents and to attract a new generation of clinician–scientists with the necessary knowledge mix to drive highly successful innovation.

Free Flap Functional Muscle Transfers

Free functional muscle transfers remain a powerful reconstructive tool to restore upper extremity function when other options such as tendon or nerve transfers are not available. This reconstructive technique is commonly used for patients following trauma, ischemic contractures, and brachial plexopathies. Variable outcomes have been reported following free functional muscle transfers that are related to motor nerve availability and reinnervation. This article highlights considerations around donor motor nerve selection, dissection, and use of the gracilis muscle, and the surgical approach to performing a free functional muscle transfer to restore elbow flexion and/or digit flexion.

Free Functional Muscle Transfers to Restore Upper Extremity Function

Free functional muscle transfer provides an option for functional restoration when nerve reconstruction and tendon transfers are not feasible. To ensure a successful outcome, many factors need to be optimized, including proper patient selection, timing of intervention, donor muscle and motor nerve selection, optimal microneurovascular technique and tension setting, proper postoperative management, and appropriate rehabilitation. Functional outcomes of various applications to the upper extremity and the authors' algorithm for the use of free functional muscle transfer are also included in this article.

Temporalis pull-through vs fascia lata augmentation in facial reanimation for facial paralysis

Objectives:

Surgical rehabilitation of facial palsy is challenging as each case is unique and success rate is often unpredictable. In one technique, temporalis is elevated from origin preserving vessels, and this elevation increases the length which is tunneled into buccal tissues (pull-through technique, Group A). In the other technique, a harvested fascia lata is attached to temporalis after a coronoidectomy release and the fascia lata is attached to the modiolus (Group B). The aim of this study is to compare the two different surgical techniques.

Materials and Methods:

Case records of 22 cases, 15 females, and 7 males who were operated between 2008 and 2012 for facial palsy with at least 1-year follow-up, using either of the techniques were assessed for pull of muscle, postoperative pain, recovery time, motor control, and symmetry at rest. Descriptive statistics are presented.

Results:

The Group A (n = 7) and Group B (n = 15) formed the study group. In the Group A, residual asymmetry (n = 3), poor postoperative muscle pull (n = 2) were noticed while in the modified group it was 2 and 3, respectively. The technique used in Group B had better pull of muscle, symmetry, faster recovery time, and better motor control at 1-year follow-up than the conventional technique.

Discussion and Conclusion:

The difference between the two groups is due to preservation of original muscular architecture, vascular channel supply. As the muscle is not traumatized, no fibrosis occurs aiding regaining of normal function. In addition, the facial reanimation is more successful in the Group B. The mechanism and success behind the technique used in Group B is discussed elaborately in terms of localregional anatomy and physiology

Functional free muscle transfer for upper extremity reconstruction

BACKGROUND

Functional losses in the upper extremity that cannot be restored by nerve or tendon transfer present a treatment dilemma to the reconstructive surgeon. Common indications for functional free muscle transfer include late reconstruction of brachial plexus injuries, traumatic muscle loss, Volkmann ischemic contracture, loss resulting from oncologic resection, and congenital absence of motor function as seen in arthrogryposis.

METHODS

This article reviews the authors' experience in upper extremity reconstruction using functional free muscle transfer. The indications and technique for functional free muscle transfer in the upper extremity are reviewed. Surgical details for sites of reconstruction and the nuances of harvesting the main donor muscles are presented.

RESULTS

Specific cases and outcome reviews for several series of functional free muscle transfers are presented.

CONCLUSION

Functional free muscle transfer is the best and final option for restoring function in an otherwise nonreconstructible limb.

What has changed in brachial plexus surgery?

Brachial plexus injuries, in all their severity and complexity, have been extensively studied. Although brachial plexus injuries are associated with serious and often definitive sequelae, many concepts have changed since the 1950s, when this pathological condition began to be treated more aggressively. Looking back over the last 20 years, it can be seen that the entire approach, from diagnosis to treatment, has changed significantly. Some concepts have become better established, while others have been introduced; thus, it can be said that currently, something can always be offered in terms of functional recovery, regardless of the degree of injury. Advances in microsurgical techniques have enabled improved results after neurolysis and have made it possible to perform neurotization, which has undoubtedly become the greatest differential in treating brachial plexus injuries. Improvements in imaging devices and electrical studies have allowed quick decisions that are reflected in better surgical outcomes. In this review, we intend to show the many developments in brachial plexus surgery that have significantly changed the results and have provided hope to the victims of this serious injury.

Functional neuro-vascularized muscle transfer for oncological reconstruction of extremity sarcoma

The strategy of limb salvage following surgical resection of skeletal tumor has led to an increased demand for more complex reconstructive options in order to achieve better functional outcomes. Functional neuro-vascularized muscle transfer (FMT) is a beneficial tool for restoring joint movement involving the reconstruction of "movement" in the affected extremity. Until now, however, the clinical application of FMT was mainly limited to trauma cases and to date, very few studies have focused on musculoskeletal oncology. In this study, we reviewed patients who underwent wide resection for extremity sarcoma and functional reconstruction using FMT and discussed the advantages, indications and complications of the procedure.

Free functional muscle transfer for the upper extremity

Free functional muscle transfers are an excellent treatment option in patients when significant time has passed after a nerve injury. In addition, they are the treatment of choice for reconstruction of established Volkmann's ischemic contracture, muscle loss from trauma, or tumor resection, and in congenital muscle absence. In cases where there is both soft tissue and functional muscle loss, free functional muscle transfers can address these problems together. This article focuses on the key principles for functional reconstruction of the upper extremity with free functional muscle transfers.

Functional pectoralis minor muscle flap transplantation for reconstruction of thumb opposition: an anatomic study and clinical applications

In this report, we present the results of an anatomic study on the dimensions of the pectoralis minor muscle and its neurovascular supply in 10 adult human cadavers, in attempt to evaluate the feasibility of microsurgical transplantation of a part of the muscle for thumb opposition reconstruction. A series of five patients consequently underwent thenar reconstruction with the pectoralis minor muscle flap from December 2004 to October 2006. The transferred muscle was reinnervated with the third lumbrical branch of the ulnar nerve. Follow-up assessment showed that the patients recovered functional opposition of carpometacarpal joint with 24 degrees of pronation, and a muscle power with M4 to M5. All patients were satisfied with the appearance of reconstructed thenar eminence. We recommend this new technique for thenar and opposition reconstruction in patients who have severe loss of thenar muscles, injury to the median nerve, and wish to improve the appearance of thenar eminence.

Reanimation of the middle and lower face in facial paralysis: review of the literature and personal approach

Facial paralysis refers to a condition in which all or portions of the facial nerve are paralysed. The facial nerve controls the muscles of facial expression, paralysis which results in a lack of facial expression which is not only an aesthetic issue, but has functional consequences as the patient cannot communicate effectively. The treatment of long-standing facial paralysis has challenged plastic surgeons for centuries, and still the ultimate goal of normality of the paralysed hemi-face with symmetry at rest as well as the generation of a spontaneous symmetrical smile with corneal protection has not yet fully been reached. Until the end of the 19th century, the treatment of this condition involved non-surgical means such as ointments, medicines and electrotherapy. With the advent and refinement of microvascular surgical techniques in the latter half of the 20th century, vascularised free muscle transfers coupled with cross-facial nerve grafts were introduced, allowing the possibility of spontaneous emotion being restored to the paralysed face became reality. The aim of this article is to revisit the surgical evolution and current options available as well as outcomes for patients suffering from facial paralysis concentrating on middle and lower face reanimation.

History of microsurgery

In the mid-1500s, the techniques of vascular ligature and vascular suture were developed sporadically by several pioneers in this field. However, vascular surgery became realistic experimentally as a result of the work by Carrel and Guthrie in the early 1900s, in which they performed replantations and transplantations of several composite tissues and organs, including amputated limbs, kidneys, and others using experimental animals. In contrast, the development of heparin by Howell and Holt in 1918 accelerated the rate of these types of operations being performed with increasing success in humans. Since the first use of a monocular microscope for ear surgery by Nylen in 1921 and a binocular microscope by Holmgren in 1923, in addition to the timely developments of the Zeiss operating microscope, microsurgical instruments, and suture materials, microsurgery was born in several surgical disciplines in the ensuing 50-year period. The application of microvascular surgery and microneurosurgery in the fields of hand, plastic, and reconstructive surgery resulted in revolutionary advances in clinical replantation and transplantation of composite tissues and more allotransplantations.

Long-term outcomes of free-muscle transfer for smile restoration in adults

BACKGROUND

The cross-facial nerve grafting/free-muscle transfer strategy for smile restoration is superior to static reconstruction or regional muscle transposition. The purpose of this study was to evaluate the long-term outcomes of this technique in adult patients.

METHODS

Eighty-one adult patients received a free-muscle transfer for midface reanimation in the authors' center. Of this group, the authors identified 24 cases with follow-up of 5 years or longer. Smile symmetry and function were evaluated at three points: preoperatively, early postoperatively, and at long-term follow-up. To better evaluate the effect of time, patients were divided into groups according to the length of follow-up: group A, 5 to 6 years; group B, 7 to 10 years; group C, 11 to 15 years; and group D, more than 15 years. Four independent observers rated each patient's smile using a five-category scale ranging from poor to excellent. Panelists were asked to comment on whether the patient's smile weakened over time.

RESULTS

All patients obtained higher scores at 2 years from free-muscle transfer in comparison with their preoperative rates (p < 0.0001). Late outcomes demonstrated that muscle regeneration continues beyond the initial 2 years, with a further increase of the scores and motor units on electromyography at the late follow-up (p < 0.0001, p = 0.0313). No significance was found when comparing both variables among the four groups, indicating that time does not have a differential effect on muscle function. In 80 percent of the evaluations, the four observers agreed on maintained smile symmetry over time.

CONCLUSIONS

Cross-facial nerve grafting/free-muscle transfer is an effective technique for smile restoration in late facial paralysis. These data indicate maintenance of effective muscle function and progressive improvement with time.

Late reconstruction for brachial plexus injury

Traumatic brachial plexus injuries are devastating and management is complex. Treatment involves a multidisciplinary approach. Primary reconstruction involves nerve repair, grafting, and transfer techniques. Secondary reconstruction includes microneurovascular free-functioning muscle transfer, tendon transfers, and arthrodesis to improve or restore function. These procedures are indicated when patients present more than 12 months from injury or when primary reconstruction procedures fail, and should focus on elbow flexion and shoulder stability. A free-functioning muscle transfer is often indicated for elbow flexion, with double free-functioning muscle transfers providing possible prehension. Shoulder reconstruction focuses on restoring stability to the glenohumeral joint and restoring abduction. This article outlines these techniques, their principles, and important details.

Free functional gracilis muscle transfer in children with severe sequelae from obstetric brachial plexus palsy

We present 4 children between 6 and 13 years suffering from severe sequelae after a total obstetric brachial plexus lesion resulting in a hand without functional active long finger flexion. They had successfully reanimated long finger flexion using a free functional gracilis muscle transfer. These children initially presented a total obstetric brachial plexus palsy without neurotisation of the lower trunk in an early microsurgical nerve reconstruction procedure.

We describe our indications for this complex microsurgical procedure, the surgical technique and the outcome.

Functional muscle transfer and the variance of reinnervating axonal load: part II. Peripheral nerves

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

Increasing the axonal load to a functional muscle transplant beyond that of its indigenous motor nerve does not improve outcome.

New technique of total phalloplasty with reinnervated latissimus dorsi myocutaneous free flap in female-to-male transsexuals

From December 2001 to September 2005, the technique of total penile reconstruction with a reinnervated free latissimus dorsi myocutaneous flap was used in 22 patients (24-38 years old) with gender dysphoria. These patients were followed up for at least 11 months (range, 11-44 months). All flaps survived. Complications include hematoma (7 cases), vascular thrombosis (2 cases), partial necrosis (1 case), excessive swelling of the neophallus (3 cases), and skin graft loss at the donor site (1 case). Of the 19 patients included in the final evaluation, the transplanted muscle was able to obtain contraction in 18 (95%) cases and 8 patients (42%) had sexual intercourse by contracting the muscle to stiffen and move the neopenis. The described technique of neophalloplasty proved to be a reliable technique and the muscle movement in the neophallus can be expected in almost all cases. The muscle contraction in the neophallus leads to "paradox" erection-stiffening, widening, and shortening of the neopenis, which allows for sexual intercourse in some patients. Subsequent reconstruction of the urethra is possible.

Microvascular Reconstruction of the Upper Extremity

BACKGROUND

Upper extremity composite tissue defects may result from trauma, tumor resection, infection, or congenital malformations. When reconstructing these defects the ultimate objectives are to provide adequate soft tissue protection of vital structures, and to provide optimal functional and esthetic outcomes. The development of clinical microsurgery has added a large number of treatment options to the trauma surgeon's armamentarium - primarily replantation of amputated tissues and transplantation of vascularized tissues from distant donor sites. Since the early 1970s, considerable refinement in microsurgical tools and techniques together with a better understanding of the anatomy and physiology of microcirculatory tissue perfusion led to the introduction of a variety of thin, pliable and versatile-free flap designs.

METHODS

Sources for this manuscript include a comprehensive literature search using the PUBMED and EMBASE databases along with relevant text books, Selected Readings in Plastic Surgery(®), and personal experiences of upper extremity reconstruction and microsurgery.

RESULTS

In this manuscript, we describe the primary microsurgical techniques used to reconstruct upper extremity tissue defects and discuss the basis for selecting one technique over another.

CONCLUSION

Where possible, the best results may be achieved by reattaching the amputated original tissues (microsurgical replantation). In noninfected, uncontaminated traumatic injuries resulting in composite soft tissue defects, Early free flap reconstruction of the upper extremities has important advantages over delayed (72 h-3 months) or late wound closure (3 months-2 years). In recent years, thin, pliable, and versatile fasciocutaneous flaps such as the anterolateral thigh (ALT) and lateral arm (LA) free flaps have been increasingly used with great success to reconstruct the upper extremity. The use of "spare parts" and functional reconstructions using osteomyocutaneous free flaps or toe to thumb transfers complete the armamentarium of the upper limb reconstructive microsurgeon.

Functioning free muscle transfers

Functioning free muscle transfer to the upper extremity is an extremely complex and difficult procedure. It is useful only in selected cases that require significant skeletal muscle replacement and fulfill stringent criteria. The operation itself is performed by means of a two-team approach. Attention to detail is paramount if success is to be achieved. Careful placement of the muscle origin and insertion under appropriate tension is a key feature of the procedure. Precise microvascular anastomoses and microneural coaptations must be done. A time-intensive rehabilitation program is needed to gain as much function from the muscle as possible. Although not perfect, free muscle transfer does provide substantial improvement from a functional standpoint for these unfortunate patients.

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.

Microneurovascular anatomy of the peroneus brevis muscle in the NZW-rabbit: a new model for free functional muscle transplantation

This study introduces the peroneus brevis muscle of the NZW-rabbit as a new model for free functional muscle transplantation. The muscle originates from the lateral aspect of the knee joint and inserts on the 5th metatarsal with a circumscript tendon. It can be harvested with a 7 cm long motor nerve branch. In a series of 22 animals divided in two groups with a body weight of 3.19 +/- 0.30 kg and 4.81 +/- 0.38 kg respectively, vessel diameter of the supplying artery was found to be 0.3-0.35 mm in group one and 0.40-0.45 mm in group two, the two concomitant veins were 1.1-1.4 mm in diameter in the first group and 1.2-1.6 mm in the second group. Histomorphometric analysis stained with NADH showed 3.67 +/- 3.21% type I fibers, 25.41 +/- 7.87% type IIa fibers, and 70.93 +/- 9.12% type IIb/d fibers.

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.

Temporary innervation of a primary coverage muscle: a new technique to optimize function in a subsequent functional microvascular muscle transplant

The author describes the simple technique of innervating the coverage muscle in the staged reconstruction of an upper-extremity crush-avulsion injury with a functional microvascular muscle transplant (FMMT). The thoracodorsal nerve was repaired to the mixed motor-sensory radial nerve above the elbow. Contraction of the latissimus muscle at 8 months after nerve repair signaled the adequacy of the 10-cm thoracodorsal nerve graft as a target motor nerve for the eventual FMMT. Excursion of the latissimus muscle created a septo-alveolar plane similar to the plane between two healthy muscles into which the FMMT could be placed. The author also discusses the potential advantages of early thoracodorsal nerve repair for successful nerve regeneration. This simple technique helped overcome the potential limitations to functional muscle transplantation in the severely traumatized upper extremity, and deserves applied study.

Rectus femoris muscle flap donor-site morbidity

Donor-site morbidity in four patients after reconstruction with free neurovascular rectus femoris muscle was examined through a series of strength tests in which the leg with rectus femoris muscle harvested was compared with the contralateral leg with an intact rectus femoris muscle. The tests were conducted with three testing devices: (1) the 'Con-Trex Leg-press' in which the force and power of right and left leg extensions at 0.2 and 0.4 m/s in a knee angle from 50 to 90 degrees were tested separately; (2) the isometric power tester, which enabled the unilateral evaluation of the isometric leg extension at three knee angles: 50, 70 and 90 degrees ; and (3) at the 'SP-Force Platforms' in which the patients performed a counter-movement jump where the amplitude of the ground reaction force, the parameters maximum force, and the jump height were calculated in order to compare the right and left leg during a single dynamic movement. Our results showed that the patients (with one exception) demonstrated a balanced relationship between the donor leg and the intact contralateral leg. The patient that primarily demonstrated a large strength deficit was retested 3 months later and showed, after an extensive rehabilitation and training program, an impressive increase in strength. The authors concluded that there is no significant limitation in the strength of the donor leg after removal of the rectus femoris muscle and consequently no significant functional donor-site morbidity. We believe that for the realisation of such results that the intraoperative linking of the vastus lateralis muscle with the vastus medialis muscle, especially in their lower third, and an extensive postoperative rehabilitation and training program are essential.