The surgical anatomy of the supraclavicular lymph node flap: A basis for the free vascularized lymph node transfer.

BACKGROUND: Vascularized lymph node transfer is an effective surgical method in reducing lymphedema. This study provides the first detailed description of the surgical anatomy of the supraclavicular lymph node flap in regard to pedicle length, pedicle diameter, and the number of lymph nodes and their exact location inside the flap. METHODS: Bilateral supraclavicular dissections of nine fresh cadavers (five female) were performed. Before the dissection, the exact number of lymph nodes was determined sonographically by an experienced radiologist, and their distance from the jugular notch was measured. After anatomic dissection, the vascular pedicle's diameter and length were measured. RESULTS: The mean number of lymph nodes was 1.5 ± 1.85 on the right side and 3 ± 2.26 on the left. Their mean distance from the jugular notch was 8.29 ± 2.15 cm on the right and 6.10 ± 1.21 cm on the left. The pedicle's length was 4.72 ± 1.03 cm on the right and 4.86 ± 0.99 cm on the left, and its diameter 2.03 ± 0.83 on the right and 1.80 ± 0.77 on the left. CONCLUSION: The pedicle length and diameter of the supraclavicular lymph node flap are suitable for a microvascular tissue transfer. J. Surg. Oncol. 2017;115:60-62. © 2016 Wiley Periodicals, Inc.

The Spinal Accessory Nerve for Functional Muscle Innervation in Facial Reanimation Surgery: An Anatomical and Histomorphometric Study.

INTRODUCTION: Facial reanimation surgery is performed in severe cases of facial palsy to restore facial function. In a 1-stage procedure, the spinal accessory nerve can be used as a donor nerve to power a free gracilis muscle transplant for the reanimation of the mouth. The aim of this study was to describe the surgical anatomy of the spinal accessory nerve, provide a guide for reliable donor nerve dissection, and analyze the available donor axon counts. METHODS: Dissections were performed on 10 nonembalmed cadavers (measurements of 20 nerves). Surgical anatomy of the spinal accessory nerve was described and distances to important landmarks were measured. Nerve biopsies were obtained of the main nerve trunk distal to the skull base, caudoposterior to the sternocleidomastoid muscle, proximal to the trapezius muscle and at the level of donor nerve harvest to analyze the myelinated axon count throughout the course of the spinal accessory nerve. The donor nerve length and available donor nerve axon count were the primary outcome parameters in this study. RESULTS: The mean donor nerve length was 11.6 cm. The spinal accessory nerve was transferred to the mandibular angle without tension for ideal coaptation to the free muscle transplant. After retraction of the trapezius muscle, a small distal nerve branch that leaves the main nerve trunk at a 90-degree angle medially was used as a landmark to indicate the level of donor nerve transection. On average, 1400 myelinated donor axons were available for innervation of the gracilis muscle transplant. CONCLUSIONS: This study gives a practical guide for spinal accessory nerve dissection for its application in facial reanimation as a motor source for the innervation of a free muscle transplant.

ErbB2 blockade with Herceptin (trastuzumab) enhances peripheral nerve regeneration after repair of acute or chronic peripheral nerve injury.

OBJECTIVE: Attenuation of the growth supportive environment within the distal nerve stump after delayed peripheral nerve repair profoundly limits nerve regeneration. Levels of the potent Schwann cell mitogen neuregulin and its receptor ErbB2 decline during this period, but the regenerative impact of this change is not completely understood. Herein, the ErbB2 receptor pathway is inhibited with the selective monoclonal antibody Herceptin (trastuzumab) to determine its significance in regulating acute and chronic regeneration in a rat hindlimb. METHODS: The common peroneal nerve of Sprague-Dawley rats was transected and repaired immediately or after 4 months of chronic denervation, followed by administration of Herceptin or saline solution. Regenerated motor and sensory neurons were counted using a retrograde tracer 1, 2, or 4, weeks after repair. Distal myelinated axon outgrowth after 4 weeks was quantified using histomorphometry. Immunofluorescent imaging was used to evaluate Schwann cell proliferation and epidermal growth factor receptor (EGFR) activation in the regenerating nerves. RESULTS: Herceptin administration increased the rate of motor and sensory neuron regeneration and the number of proliferating Schwann cells in the distal stump after the first week. Herceptin also increased the number of myelinated axons that regenerated 4 weeks after immediate and delayed repair. Reduced EGFR activation was observed using immunofluorescent imaging. INTERPRETATION: Inhibition of the ErbB2 receptor with Herceptin unexpectedly enhances nerve regeneration after acute and delayed nerve repair. This finding raises the possibility of using targeted molecular therapies to improve outcomes of peripheral nerve injuries. The mechanism may involve a novel inhibitory association between ErbB2 and EGFR. Ann Neurol 2016;80:112-126.

Enhancement of facial nerve motoneuron regeneration through cross-face nerve grafts by adding end-to-side sensory axons.

BACKGROUND: In unilateral facial palsy, cross-face nerve grafts are used for emotional facial reanimation. Facial nerve regeneration through the grafts takes several months, and the functional results are sometimes inadequate. Chronic denervation of the cross-face nerve graft results in incomplete nerve regeneration. The authors hypothesize that donor axons from regional sensory nerves will enhance facial motoneuron regeneration, improve axon regeneration, and improve the amplitude of facial muscle movement. METHODS: In the rat model, a 30-mm nerve graft (right common peroneal nerve) was used as a cross-face nerve graft. The graft was coapted to the proximal stump of the transected right buccal branch of the facial nerve and the distal stumps of the transected left buccal and marginal mandibular branches. In one group, sensory occipital nerves were coapted end-to-side to the cross-face nerve graft. Regeneration of green fluorescent protein-positive axons was imaged in vivo in transgenic Thy1-green fluorescent protein rats, in which all neurons express green fluorescence. After 16 weeks, retrograde labeling of regenerated neurons and histomorphometric analysis of myelinated axons was performed. Functional outcomes were assessed with video analysis of whisker motion. RESULTS: "Pathway protection" with sensory axons significantly enhanced motoneuron regeneration, as assessed by retrograde labeling, in vivo fluorescence imaging, and histomorphometry, and significantly improved whisker motion during video analysis. CONCLUSION: Sensory pathway protection of cross-face nerve grafts counteracts chronic denervation in nerve grafts and improves regeneration and functional outcomes.

Macroscopic in vivo imaging of facial nerve regeneration in Thy1-GFP rats.

IMPORTANCE: Facial nerve injury leads to severe functional and aesthetic deficits. The transgenic Thy1-GFP rat is a new model for facial nerve injury and reconstruction research that will help improve clinical outcomes through translational facial nerve injury research. OBJECTIVE: To determine whether serial in vivo imaging of nerve regeneration in the transgenic rat model is possible, facial nerve regeneration was imaged under the main paradigms of facial nerve injury and reconstruction. DESIGN, SETTING, AND PARTICIPANTS: Fifteen male Thy1-GFP rats, which express green fluorescent protein (GFP) in their neural structures, were divided into 3 groups in the laboratory: crush-injury, direct repair, and cross-face nerve grafting (30-mm graft length). The distal nerve stump or nerve graft was predegenerated for 2 weeks. The facial nerve of the transgenic rats was serially imaged at the time of operation and after 2, 4, and 8 weeks of regeneration. The imaging was performed under a GFP-MDS-96/BN excitation stand (BLS Ltd). INTERVENTION OR EXPOSURE: Facial nerve injury. MAIN OUTCOME AND MEASURE: Optical fluorescence of regenerating facial nerve axons. RESULTS: Serial in vivo imaging of the regeneration of GFP-positive axons in the Thy1-GFP rat model is possible. All animals survived the short imaging procedures well, and nerve regeneration was followed over clinically relevant distances. The predegeneration of the distal nerve stump or the cross-face nerve graft was, however, necessary to image the regeneration front at early time points. Crush injury was not suitable to sufficiently predegenerate the nerve (and to allow for degradation of the GFP through Wallerian degeneration). After direct repair, axons regenerated over the coaptation site in between 2 and 4 weeks. The GFP-positive nerve fibers reached the distal end of the 30-mm-long cross-face nervegrafts after 4 to 8 weeks of regeneration. CONCLUSIONS AND RELEVANCE: The time course of facial nerve regeneration was studied by serial in vivo imaging in the transgenic rat model. Nerve regeneration was followed over clinically relevant distances in a small number of experimental animals, as they were subsequently imaged at multiple time points. The Thy1-GFP rat model will help improve clinical outcomes of facial reanimation surgery through improving the knowledge of facial nerve regeneration after surgical procedures. LEVEL OF EVIDENCE: NA.

The ErbB2 inhibitor Herceptin (Trastuzumab) promotes axonal outgrowth four weeks after acute nerve transection and repair.

Accumulating evidence suggests that neuregulin, a potent Schwann cell mitogen, and its receptor, ErbB2, have an important role in regulating peripheral nerve regeneration. We hypothesized that Herceptin (Trastuzumab), a monoclonal antibody that binds ErbB2, would disrupt ErbB2 signaling, allowing us to evaluate ErbB2's importance in peripheral nerve regeneration. In this study, the extent of peripheral motor and sensory nerve regeneration and distal axonal outgrowth was analyzed two and four weeks after common peroneal (CP) nerve injury in rats. Outcomes analyzed included neuron counts after retrograde labeling, histomorphometry, and protein analysis. The data analysis revealed that there was no impact of Herceptin administration on either the numbers of motor or sensory neurons that regenerated their axons but histomorphometry revealed that Herceptin significantly increased the number of regenerated axons in the distal repaired nerve after 4 weeks. Protein analysis with Western blotting revealed no difference in either expression levels of ErbB2 or the amount of activated, phosphorylated ErbB2 in injured nerves. In conclusion, administration of the ErbB2 receptor inhibitor after nerve transection and surgical repair did not alter the number of regenerating neurons but markedly increased the number of regenerated axons per neuron in the distal nerve stump. Enhanced axon outgrowth in the presence of this ErbB2 inhibitor indicates that ErbB2 signaling may limit the numbers of axons that are emitted from each regenerating neuron.

Facial synkinesia before and after surgical reanimation of the paralyzed face.

BACKGROUND: Facial synkinesia is a common sequela of facial palsy, affecting 15 to 20 percent of patients. The rate of postoperative synkinesia after facial reanimation is not clearly established. The severity and type of synkinesia determine the degree of clinical relevance. METHODS: One hundred sixty-seven patients with facial palsy were included in this retrospective cohort study. Three-dimensional video analysis of facial movements was performed preoperatively and 18 months after facial reanimation. The severity of synkinesia was rated subjectively on a four-degree severity scale. Objective three-dimensional analysis of synkinesia was performed on patients with 18-month follow-up times. RESULTS: Preoperatively, 84.4 percent of patients were not affected by synkinesia, 9 percent presented with mild synkinesia, 4.2 percent presented with moderate synkinesia, and 2.4 percent presented with severe synkinesia. Postoperatively, 51 percent of all patients presented with facial synkinesia (41.8 percent mild, 17.3 percent moderate, and 1 percent severe synkinesia; some patients had more than one type). Patients treated with territorially differentiated gracilis muscle transplantation were most frequently affected (69.8 percent), followed by patients treated with gracilis muscle transplantation in combination with temporalis muscle transposition to the eye (51.8 percent). Oculo-oral synkinesia was the most frequent form of synkinesia. CONCLUSIONS: After surgical reanimation of the paralyzed face, half of the patients presented with synkinesia. The majority of patients developed mild or moderate forms of synkinesia; therefore, the clinical relevance of synkinesia has to be seen in the context of total facial function. Because of the high prevalence of synkinesia, it should be documented and addressed in patients undergoing facial reanimation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Comparison of three-dimensional surface-imaging systems.

BACKGROUND: In recent decades, three-dimensional (3D) surface-imaging technologies have gained popularity worldwide, but because most published articles that mention them are technical, clinicians often have difficulties gaining a proper understanding of them. This article aims to provide the reader with relevant information on 3D surface-imaging systems. In it, we compare the most recent technologies to reveal their differences. METHODS: We have accessed five international companies with the latest technologies in 3D surface-imaging systems: 3dMD, Axisthree, Canfield, Crisalix and Dimensional Imaging (Di3D; in alphabetical order). We evaluated their technical equipment, independent validation studies and corporate backgrounds. RESULTS: The fastest capturing devices are the 3dMD and Di3D systems, capable of capturing images within 1.5 and 1 ms, respectively. All companies provide software for tissue modifications. Additionally, 3dMD, Canfield and Di3D can fuse computed tomography (CT)/cone-beam computed tomography (CBCT) images into their 3D surface-imaging data. 3dMD and Di3D provide 4D capture systems, which allow capturing the movement of a 3D surface over time. Crisalix greatly differs from the other four systems as it is purely web based and realised via cloud computing. CONCLUSION: 3D surface-imaging systems are becoming important in today's plastic surgical set-ups, taking surgeons to a new level of communication with patients, surgical planning and outcome evaluation. Technologies used in 3D surface-imaging systems and their intended field of application vary within the companies evaluated. Potential users should define their requirements and assignment of 3D surface-imaging systems in their clinical as research environment before making the final decision for purchase.

Evolution of the 3-dimensional video system for facial motion analysis: ten years' experiences and recent developments.

Since the implementation of the computer-aided system for assessing facial palsy in 1999 by Frey et al (Plast Reconstr Surg. 1999;104:2032-2039), no similar system that can make an objective, three-dimensional, quantitative analysis of facial movements has been marketed. This system has been in routine use since its launch, and it has proven to be reliable, clinically applicable, and therapeutically accurate. With the cooperation of international partners, more than 200 patients were analyzed. Recent developments in computer vision--mostly in the area of generative face models, applying active--appearance models (and extensions), optical flow, and video-tracking-have been successfully incorporated to automate the prototype system. Further market-ready development and a business partner will be needed to enable the production of this system to enhance clinical methodology in diagnostic and prognostic accuracy as a personalized therapy concept, leading to better results and higher quality of life for patients with impaired facial function.

3D video analysis of facial movements.

This article presents a review of 3D video analysis for use in patients with facial paralysis. The difficulties inherent in quantifying the degree of facial paralysis and the effect of therapeutics that has led to the use of videos and computer-assisted 3D analysis are discussed, which can yield quantifiable results of treatment, allow the description and quantification of facial paralysis, and become a tool in the planning of operative procedures. The authors provide a step-by-step overview of video analysis, and present case studies from two specific techniques they have used in reconstruction surgery.