Needles, Herbs, and Electricity: A Meta-Analysis of Traditional Eastern Medicine in the Management of Facial Paralysis.

In Eastern nations, interventions like acupuncture and herbal medicine are often first-line for patients presenting with facial paralysis. Despite the rising popularity of Eastern medicine in Western nations, the literature assessing whether Eastern medicine interventions should be recommended for patients with facial paralysis is lacking. This meta-analysis aims to define what Eastern medicine interventions exist for the management of facial paralysis and assess whether current research supports these approaches as safe and effective. The PubMed and Cochrane databases were reviewed in accordance with PRISMA guidelines. Inclusion criteria consisted of peer-reviewed studies published between 2000 and 2023 that reported on Eastern medicine, also described as, "complementary" or "alternative" interventions for facial paralysis. Effective and cured rates were the primary outcomes extracted from the literature. Interventions within these studies were categorized into six groups: (1) standard acupuncture, (2) special needle therapies, (3) needle therapy + other alternative treatments, (4) herbal medicine, (5) alternative treatments + Western medicine, and (6) Western medicine alone. A multiple-treatment meta-analysis was performed to assess differences in effective and cured rates. Fifteen studies involving Eastern medicine for the treatment of facial paralysis met the inclusion criteria. No significant differences were found in effective and cured rates across groups. Multiple quality concerns were noted, such as the lack of control groups, blinding, and randomization noted in several studies. Many studies failed to report complications, preventing conclusions from being drawn on the safety of these Eastern medicine interventions. This meta-analysis was unable to support the recommendation of Eastern medicine approaches for patients with facial paralysis. No Eastern medicine treatments, combination of Eastern medicine treatments, or Eastern medicine treatments given with Western medicine were seen to be more effective than Western medicine alone.

A Scoping Review of Quality-of-Life Assessments Employed in Abdominal Wall Reconstruction.

INTRODUCTION: Surgeons use several quality-of-life instruments to track outcomes following abdominal wall reconstruction (AWR); however, there is no universally agreed upon instrument. We review the instruments used in AWR and report their utilization trends within the literature. METHODS: This scoping review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis extension for Scoping Reviews guidelines using the PubMed, Embase, Web of Science, ClinicalTrials.gov, and Cochrane databases. All published articles in the English language that employed a quality-of-life assessment for abdominal wall hernia repair were included. Studies which focused solely on aesthetic abdominoplasty, autologous breast reconstruction, rectus diastasis, pediatric patients, inguinal hernia, or femoral hernias were excluded. RESULTS: Six hernia-specific tools and six generic health tools were identified. The Hernia-Related Quality-of-Life Survey and Carolinas Comfort Scale are the most common hernia-specific tools, while the Short-Form 36 (SF-36) is the most common generic health tool. Notably, the SF-36 is also the most widely used tool for AWR outcomes overall. Each tool captures a unique set of patient outcomes which ranges from abdominal wall functionality to mental health. CONCLUSIONS: The outcomes of AWR have been widely studied with several different assessments proposed and used over the past few decades. These instruments allow for patient assessment of pain, quality of life, functional status, and mental health. Commonly used tools include the Hernia-Related Quality-of-Life Survey, Carolinas Comfort Scale, and SF-36. Due to the large heterogeneity of available instruments, future work may seek to determine or develop a standardized instrument for characterizing AWR outcomes.

Free Functional Platysma Transfer for Restoration of Spontaneous Eye Closure in Facial Paralysis.

BACKGROUND: Facial palsy patients experience an array of problems ranging from functional to psychological issues. With regard to the eye, lacrimation, lagophthalmos, and the inability to spontaneously blink are the main symptoms and, if left untreated, can compromise the cornea and vision. This article reports the outcomes of 23 free functional vascularized platysma transfers used for reanimation of the eye in unilateral facial paralysis. METHODS: Data were collected prospectively for all patients undergoing reanimation of the paralyzed eye using free functional platysma transfer. The only exclusion criterion was that a minimum of a 2-year follow-up was required. Patients were assessed preoperatively and postoperatively and scored using the eFACE tool focusing on eye-symmetry with documentation of blink reflex. RESULTS: A total of 26 free functional platysma transfers were completed between 2011 and 2018; three patients were excluded because of inadequate follow-up. The mean age was 9.1 ± 7.1 years and there were 12 boys and 11 girls. Preoperatively, no patients had evidence of a blink reflex in comparison to 22 patients at 2-year follow-up. There was a statistically significant improvement in palpebral fissure ( P < 0.001) and full eye closure ( P < 0.001) scores at 2-year follow-up; however, there was no statistically significant difference in gentle eye closure ( P = 0.15). CONCLUSIONS: This is the first report of free functional platysma long-term outcomes in eye reanimation. The results demonstrate that successful restoration of the blink reflex can be achieved and full eye closure is obtainable following surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Evaluation of peripheral nerve regeneration in Murphy Roths Large mouse strain following transection injury.

Aim: Murphy Roths Large (MRL/MpJ) mice have demonstrated the ability to heal with minimal or no scar formation in several tissue types. In order to identify a novel animal model, this study sought to evaluate whether this attribute applies to peripheral nerve regeneration. Materials & methods: This was a two-phase study. 6-week-old male mice were divided into two interventional groups: nerve repair and nerve graft. The MRL/MpJ was compared with the C57BL/6J strain for evaluation of both functional and histological outcomes. Results: MRL/MpJ strain demonstrated superior axon myelination and less scar formation, however functional outcomes did not show significant difference between strains. Conclusion: Superior histological outcomes did not translate into superior peripheral nerve regeneration in MRL/MpJ strain.

A Systematic Review of the Reported Complications Related to Facial and Upper Extremity Vascularized Composite Allotransplantation.

INTRODUCTION: Twenty three years after the first successful upper extremity transplantation, the role of vascularized composite allotransplantation (VCA) in the world of transplantation remains controversial. Face and upper extremity reconstruction via transplantation have become successful options for highly selected patients with severe tissue and functional deficit when conventional reconstructive options are no longer available. Despite clear benefit in these situations, VCA has a significant potential for complications that are more frequent when compared to visceral organ transplantation. This study intended to perform an updated systematic review on such complications. MATERIALS AND METHODS: MEDLINE database via PubMed, Embase and Cochrane Library were searched. Face and upper extremity VCA performed between 1998 and 2021 were included in the study. Relevant media and press conferences reports were also included. Complications related to face and upper extremity VCA were recorded and reviewed including their clinical characteristics and complications. RESULTS: One hundred fifteen patients underwent facial (43%) or upper extremity (57%) transplantation. Overall, the surgical complication rate was 23%. Acute and chronic rejection was identified in 89% and 11% of patients, respectively. Fifty eight percent of patients experienced opportunistic infection. Impaired glucose metabolism was the most common immunosuppression-related complication other than infection. Nineteen percent of patients ultimately experienced partial or complete allograft loss. CONCLUSIONS: Complications related to VCA are a significant source of morbidity and potential mortality. Incidence of such complications is higher than previously reported and should be strongly emphasized in patient consent process. Strict patient selection criteria, complex preoperative evaluation, consideration of alternatives, and thorough disclosure to patients should be routinely performed prior to VCA indication.

Twenty Years of Abdominal Wall Allotransplantation: A Systematic Review of the Short- and Long-Term Outcomes.

BACKGROUND: Abdominal wall allotransplantation following intestinal and multivisceral transplant procedures has proven to be successful in achieving adequate closure in patients in whom other techniques have proven inadequate. Thus far, the focus of these abdominal wall allotransplants has been on graft and overall patient survival following surgery and the implementation of immunosuppression. The purpose of this study was to review the outcomes of abdominal wall allotransplantation reported in the literature. METHODS: The PubMed database was queried, and 2595 articles were found. Search criteria used were "abdominal wall transplant" and "abdominal wall allotransplant." Of these, eight met inclusion/exclusion criteria. RESULTS: In the present study, eight publications were identified reporting abdominal wall allotransplants, for a total of 38 full-thickness abdominal wall allotransplantations performed worldwide. All studies reported abdominal wall allotransplantation in combination with visceral organ allotransplantation. Abdominal wall allotransplantations reported thus far have been nonneurotized. Abdominal wall allotransplantations have proven to be beneficial both in terms of abdominal wall closure and acting as a sentinel marker for rejection for underlying visceral organ allotransplantation. The success of abdominal wall allotransplants and their long-term survival has introduced the question of functionality and long-term durability. Cadaveric studies have shown that it is possible to neurotize abdominal wall allotransplants, and future direction toward neurotized abdominal wall allotransplantation requires tools to assess functional outcomes of these transplants. CONCLUSIONS: Abdominal wall allotransplantation is an important reconstructive option when abdominal wall closure is challenging and should be considered in combination with visceral organ allotransplantations. There may be potential benefit in neurotizing the abdominal wall allotransplant for functional use, and future studies should aim to include functional outcomes.

Transcutaneous sentinel lymph node detection in cutaneous melanoma with indocyanine green and near-infrared fluorescence: A diagnostic sensitivity study.

Sentinel lymph node (SLN) biopsy with preoperative radiocolloid-based lymphoscintigraphy and blue dye injection is considered the standard procedure for staging nodal metastases in early-stage cutaneous melanoma patients with clinically uninvolved lymph nodes. While this combination renders good accuracy in SLN detection, radiation exposure and the frequent allergic reactions to the blue dye are considered drawbacks of this technique. Indocyanine green (ICG) is a water-soluble fluorescent dye that can be identified through near-infrared fluorescence imaging (NIRFI). The aim of this prospective diagnostic sensitivity study was to assess the feasibility of ICG and NIRFI to identify SLNs in melanoma transcutaneously ("before skin incision") and to analyze the various factors influencing detection rate, in comparison to lymphoscintigraphy. This study included 93 patients undergoing SLN biopsy for cutaneous melanoma. The region and the number of the SLNs identified with lymphoscintigraphy and with ICG were recorded. Patients' characteristics, as well as tumor details were also recorded preoperatively. One hundred and ninety-four SLNs were identified through lymphoscintigraphy. The sensitivity of ICG for transcutaneous identification of the location of the SLNs was 96.1% overall, while the sensitivity rate for the number of SLNs was 79.4%. Gender and age did not seem to influence detection rate, but a body mass index >30 kg/m2 was associated with a lower identification rate of the number of SLNs (P = .045). Transcutaneous identification of SLNs through ICG and NIRFI technology is a feasible technique that could potentially replace in selected patients the standard SLN detection methodology in cutaneous melanoma.

Axonal Regeneration Through Autologous Grafts: Does the Axonal Load Influence Regeneration?

INTRODUCTION: Two-stage free functional muscle transfers for long-standing facial palsy can yield unpredictable results. Earlier studies have demonstrated incomplete regeneration across neurorrhaphies in native nerve and higher donor axonal counts correlating with improved outcomes but axonal count in nerve grafts have not been as thoroughly reviewed. To investigate the impact of varying axonal counts in autologous grafts on functional outcomes of repair. MATERIALS AND METHODS: Animals were allocated into three groups: Direct Nerve Repair (DNR, n = 50), Small Nerve Graft (SNG, n = 50), and Large Nerve Graft (LNG, n = 50). All grafts were inset into the Posterior Auricular Nerve with ear movement recovery (EMR) monitored as functional outcome. At various postoperative weeks (POWs), excised specimens were imaged with electron microscopy. Axonal counts were measured proximal to, distal (DAC) to, and within grafts. Total Success Ratio (TSR) was calculated. RESULTS: In DNR, DAC was significantly lower than proximal axonal counts at all POWs, with maximum TSR of 80%. TSR for LNG and SNG were significantly lower at all POWs when compared to DNR, with maximums of 56% and 38%, respectively. LNG had a significantly larger DAC than SNG at POW12 and beyond. A direct relationship was present between DAC and EMR for all values. CONCLUSIONS: Higher native axonal count of autologous nerve grafts resulted in higher percentage of regeneration across neurorrhaphies.

Evolution and Transformation of Uterine Transplantation: A Systematic Review of Surgical Techniques and Outcomes.

BACKGROUND: Uterine transplantation (UTx) is acknowledged to be on the second (2A) of five steps of development in accordance with the staging system for the evaluation of surgical innovations. Accordingly, we aimed to systematically review the available evidence of the surgical techniques and outcomes of UTx in terms of graft survival. METHODS: A comprehensive search was conducted across PubMed Medline, Cochrane-EBMR, Scopus, Web of Science, and CENTRAL through November 2020. RESULTS: Forty studies, reporting 64 recipients and 64 donors, satisfied inclusion criteria. The surgical time and the estimated blood loss were 515 minutes and 679 mL for graft procurement via laparotomy, 210 minutes and 100 mL for laparoscopic-assisted graft harvest, and 660 minutes and 173 mL for robotic-assisted procedures, respectively. Urinary tract infections (n = 8) and injury to the urinary system (n = 6) were the most common donor complications. Using the donor's internal iliac system, two arterial anastomoses were performed in all cases. Venous outflow was accomplished through the uterine veins (UVs) in 13 cases, a combination of the UVs and the ovarian/uteroovarian veins (OVs/UOVs) in 36 cases, and solely through the OVs/UOVs in 13 cases. Ischemia time was 161 and 258 minutes when using living donors (LD) and deceased donors (DD), respectively. Forty-eight uteri were successfully transplanted or fulfilled the purpose of transplantation, 41 from LDs and 7 from DDs. Twenty-five and four live childbirths from LDs and DDs have been reported, respectively. CONCLUSION: UTx is still experimental. Further series are required to recommend specific surgical techniques that best yield a successful transplant and reduce complications for donors and recipients.

Abdominal Wall Vascularized Composite Allotransplantation: A Scoping Review.

BACKGROUND: Abdominal wall vascularized composite allotransplantation (AW-VCA) is a novel reconstructive technique used for large abdominal wall defects in combination with intestinal transplantation (ITx) or multivisceral abdominal transplantation (MVTx). Since the introduction of this procedure, several studies have been published reporting their experience. This study aims to present a scoping review looking at all available evidence-based medicine information to understand the most current surgical techniques and clinical outcomes. METHODS: This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) extension for scoping reviews checklist. A comprehensive research strategy of several databases was conducted. RESULTS: A total of 31 studies were included in this review, which comprised animal, cadaveric, and human studies. In human studies, four surgical techniques with high flap survival rates and low complication rates were found. In cadaveric studies, it was shown that the use of iliofemoral cuff-based flaps provided adequate tissue perfusion to the abdominal wall graft. Also, the use of thoracolumbar nerves have been described to provide functionality to the AW-VCA and prevent long-term muscle atrophy. CONCLUSION: AW-VCA is a safe and efficient alternative for patients with large and complex abdominal wall defects. The future holds a promising evolution of a functional AW-VCA, though surgeons must face and overcome the challenge of distorted anatomy frequently present in this population. Forthcoming studies with a better level of evidence are required to evaluate functionality and differences between surgical techniques.

Presence of Donor Lymph Nodes Within Vascularized Composite Allotransplantation Ameliorates VEGF-C-mediated Lymphangiogenesis and Delays the Onset of Acute Rejection.

BACKGROUND: The lymphatic system plays an active role in modulating inflammation in autoimmune diseases and organ rejection. In this work, we hypothesized that the transfer of donor lymph node (LN) might be used to promote lymphangiogenesis and influence rejection in vascularized composite allotransplantation (VCA). METHODS: Hindlimb transplantations were performed in which (1) recipient rats received VCA containing donor LN (D:LN+), (2) recipient rats received VCA depleted of all donor LN (D:LN-), and (3) D:LN+ transplantations were followed by lymphangiogenesis inhibition using a vascular endothelial growth factor receptor-3 (VEGFR3) blocker. RESULTS: Our data show that graft rejection started significantly later in D:LN+ transplanted rats as compared to the D:LN- group. Moreover, we observed a higher level of VEGF-C and a quicker and more efficient lymphangiogenesis in the D:LN+ group as compared to the D:LN- group. The presence of donor LN within the graft was associated with reduced immunoactivation in the draining LN and increased frequency of circulating and skin-resident donor T regulatory cells. Blocking of the VEGF-C pathway using a VEGFR3 blocker disrupts the lymphangiogenesis process, accelerates rejection onset, and interferes with donor T-cell migration. CONCLUSIONS: This study demonstrates that VCA LNs play a pivotal role in the regulation of graft rejection and underlines the potential of specifically targeting the LN component of a VCA to control graft rejection.

Central versus peripheral nervous system regeneration: is there an exception for cranial nerves?

There exists a dichotomy in regenerative capacity between the PNS and CNS, which poses the question - where do cranial nerves fall? Through the discussion of the various cells and processes involved in axonal regeneration, we will evaluate whether the assumption that cranial nerve regeneration is analogous to peripheral nerve regeneration is valid. It is evident from this review that much remains to be clarified regarding both PNS and CNS regeneration. Furthermore, it is not clear if cranial nerves follow the PNS model, CNS model or possess an alternative novel regenerative process altogether. Future research should continue to focus on elucidating how cranial nerves regenerate; and the various cellular interactions, molecules and pathways involved.

Emerging electron microscopy and 3D methodologies to interrogate Staphylococcus aureus osteomyelitis in murine models.

Recent breakthroughs in our understanding of orthopaedic infections have come from advances in transmission electron microscopy (TEM) imaging of murine models of bone infection, most notably Staphylococcus aureus invasion and colonization of osteocyte-lacuno canalicular networks of live cortical bone during the establishment of chronic osteomyelitis. To further elucidate this microbial pathogenesis and evaluate the mechanism of action of novel interventions, additional advances in TEM imaging are needed. Here we present detailed protocols for fixation, decalcification, and epoxy embedment of bone tissue for standard TEM imaging studies, as well as the application of immunoelectron microscopy to confirm S. aureus occupation within sub-micron canaliculi. We also describe the first application of the novel Automated-Tape-UltraMicrotome system with three-dimensional reconstruction and volumetric analyses to quantify S. aureus occupation within the osteocyte-lacuno canalicular networks. Reconstruction of the three-dimensional volume broadened our perspective of S. aureus colonization of the canalicular network and, surprisingly, revealed adjacent noninfected canaliculi. This observation has led us to hypothesize that viable osteocytes of the osteocyte-lacuno canalicular networks respond and resist infection, opening future research directions to explain the paradox of adjacent uninfected canaliculi and life-long deep bone infection in patients with chronic osteomyelitis.

Regional Lymphatic Inclusion in Orthotopic Hindlimb Transplantation: Establishment and Assessment of Feasibility in a Rodent Model.

BACKGROUND: The lymphatic system may play an important role in local immunomodulation in vascularized composite allotransplantation (VCA). Currently, there is no standardized VCA model that includes the regional draining lymphatic tissue. The aim of this study was to develop a rapid and efficient orthotopic hindlimb transplantation model in rats that included the draining lymphatic basin to permit further evaluation of the lymphatic system's role in VCA. METHODS: Thirty transplantations from Brown Norway rats to Lewis rats were performed. To include the regional lymphatic tissue, the superficial epigastric vessels were preserved to allow retrieval of the corresponding inguinal lymph nodes, including the inguinal fat pad, with the hindlimb. A cuff technique was used for the vein, whereas the conventional microsurgical technique was used for the arterial anastomosis. Vascular patency was confirmed through laser Doppler analysis at postoperative day 1 and histological analysis after euthanasia. RESULTS: The presence and vascularization of the inguinal lymph nodes were verified with indocyanine green lymphoscintigraphy at the time of transplantation. Mean total ischemia time was 69 ± 24 minutes, and mean recipient operation time was 80 ± 19 minutes. Overall transplant survival rate was 93.3%. Laser Doppler analysis showed vascular (technical) success, indocyanine green lymphoscintigraphy confirmed the presence of lymph nodes and the histological analysis revealed patent anastomoses. CONCLUSIONS: We successfully developed an experimental orthotopic hindlimb transplantation model in rats that includes the draining inguinal lymphatic basin, which is an important asset in further research on lymphatic tissue and its role in VCA.

Pretest and Posttest Evaluation of a Longitudinal, Residency-Integrated Microsurgery Course.

INTRODUCTION: Current microsurgical training courses average 5 consecutive 8-hour days and cost US $1500 to US $2500/individual, making training a challenge for residents who are unable to take leave from clinical duties. This residency-integrated microsurgery course was designed for integration with a residency program, averaging 3 hours/week over 7 weeks. This allows for one-on-one training, beginning with synthetic tissue and concluding with in vivo stimulation. This study was performed to validate this longitudinal training course. METHODS: After recruitment and before the start of coursework, subjects completed a baseline anastomosis without guidance and a survey regarding microsurgical experience. Subjects completed approximately 3 hours/week of practical exercises. Weeks 1 to 5 used synthetic models, whereas 6 to 7 used in vivo rodent models. Nine minimum anastomoses of increasing complexity were completed and assessed with the Anastomosis Lapse Index and the Stanford Microsurgery and Residency Training scale. Scoring was performed by 3 independent reviewers and averaged for comparison. RESULTS: Five subjects completed the course for study. Presurvey results showed an average confidence in theoretical knowledge of 2/5; technical ability to perform procedures, 1.8/5; and ability to manage complications, 1.8/5. Postsurvey revealed confidence in theoretical knowledge of 2.5/5; technical ability to perform procedures, 2.25/5; and ability to manage complications, 2.25/5. None of these differences were significant. Each individual component of the Stanford Microsurgery and Residency Training scale scoring system improved postcourse with P < 0.05, and overall performance score improved from an average of 2.6 to 3.9 (P = 0.006). The total number of errors recorded using the Anastomosis Lapse Index reduced from 6.58 to 3.41 (P = 0.02). Time to completion reduced from an average of 28 minutes, 8 seconds to 24 minutes, 5 seconds (P = 0.003). CONCLUSIONS: Despite a lack in significant confidence improvement, completion of the residency-integrated microsurgery course leads to significant and quantifiable improvement in resident microsurgical skill and efficiency.

A Retrospective Case Series Reporting the Outcomes of Avance Nerve Allografts in the Treatment of Peripheral Nerve Injuries.

BACKGROUND: Acellular nerve allografts are a viable treatment modality for bridging nerve gaps. Several small studies have demonstrated results equal to those of autologous grafts; however, there is information lacking with regard to outcomes for wider indications. The authors evaluated the outcomes of patients treated with a nerve allograft in a variety of clinical situations. METHODS: A retrospective chart analysis was completed between April of 2009 and October of 2017. Inclusion criteria were age 18 years or older at the time of surgery and treatment with a nerve allograft. Patients were excluded if they had not been followed up for a minimum of 6 months. The modified Medical Research Council Classification was used to monitor motor and sensory changes in the postoperative period. RESULTS: Two hundred seven nerve allografts were used in 156 patients; of these, 129 patients with 171 nerve allografts fulfilled the inclusion criteria. Seventy-seven percent of patients achieved a sensory outcome score of S3 or above and 36 percent achieved a motor score of M3 or above. All patients with chronic pain had improvement of their symptoms. Graft length and diameter were negatively correlated with reported outcomes. One patient elected to undergo revision surgery, and the original graft was shown histologically to have extensive central necrosis. Anatomically, allografts used for lower limb reconstruction yielded the poorest results. All chronic patients had a significantly lower postoperative requirement for analgesia, and allografts were effective in not only reducing pain but also restoring a functional level of sensation. CONCLUSIONS: This study supports the wider application of allografts in managing nerve problems. However, caution must be applied to the use of long grafts with larger diameters. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Outcome measures of facial nerve regeneration: A review of murine model systems.

Animal models of nerve function have been subject to extensive study in order to understand and investigate methods which may improve axon regeneration and promote functional outcomes following nerve injury and repair. As the facial nerve is a cranial nerve, there is mounting evidence that cranial nerve regeneration differs from peripheral, and outcome models specifically addressing the facial nerve are required. Murine models are the most commonly utilized, with a variety of methods employed to measure the actions of whisking, eye closure, or ear movement as indicators of facial nerve regeneration. Each method of measurement is reviewed in terms of validity, strengths, limitations, and the specific outcome data provided. The authors propose that prior to choosing an outcome model, the goals and objectives of a planned study should be well defined, as various outcome measures may be useful depending on the information which is desired. The aim of this paper, therefore, is to provide the reader with a concise review which may facilitate project design.

Imaging Peripheral Nerve Regeneration: A New Technique for 3D Visualization of Axonal Behavior.

BACKGROUND: Peripheral nerve assessment has traditionally been studied through histological and immunological staining techniques in a limited cross-sectional modality, making detailed analysis difficult. A new application of serial section electron microscopy is presented to overcome these limitations. METHODS: Direct nerve repairs were performed on the posterior auricular nerve of transgenic YFP-H mice. Six weeks postoperatively the nerves were imaged using confocal fluorescent microscopy then excised and embedded in resin. Resin blocks were sequentially sectioned at 100 nm, and sections were serially imaged with an electron microscope. Images were aligned and autosegmented to allow for 3D reconstruction. RESULTS: Basic morphometry and axonal counts were fully automated. Using full 3D reconstructions, the relationships between the axons, the Nodes of Ranvier, and Schwann cells could be fully appreciated. Interactions of individual axons with their surrounding environment could be visualized and explored in a virtual three-dimensional space. CONCLUSIONS: Serial section electron microscopy allows the detailed pathway of the regenerating axon to be visualized in a 3D virtual space in comparison to isolated individual traditional histological techniques. Fully automated histo-morphometry can now give accurate axonal counts, provide information regarding the quality of nerve regeneration, and reveal the cell-to-cell interaction at a super-resolution scale. It is possible to fully visualize and "fly-through" the nerve to help understand the behavior of a regenerating axon within its environment. This technique provides future opportunities to evaluate the effect different treatment modalities have on the neuroregenerative potential and help us understand the impact different surgical techniques have when treating nerve injuries.

Development of the interscutularis model as an outcome measure for facial nerve surgery.

INTRODUCTION: Animal models for the study of facial paralysis have been well developed, but concern has arisen regarding the accuracy of eye closure and whisker movement as outcome measures due to new data regarding interconnectivity between facial nerve branches and autonomic innervation. The posterior auricular nerve (PAN) is an isolated branch of the facial nerve which has been confirmed as the sole motor innervat or of the interscutularis muscle. This study was designed to develop a model for facial nerve palsy utilizing the PAN and interscutularis muscle. METHODS: A custom-made automated video capture system was built into a poly methyl methacrylate cage using a high definition monochrome digital camera and image sensor to record the animal as it drank from a water feeder. A copper floor pad and copper collar around the water feeder were connected to an electrical circuit for automatic saving of the video recording 10 s prior to and 30 s following the drinking event. A pre-operative baseline recording of ear movement during drinking was captured. Female YFP-16 mice at 6 weeks were assigned to sham (Sh, n = 5), nerve excision (Ex, n = 10), or nerve crush (Cr, n = 10) groups with all interventions performed on the right PAN. Sh mice were irrigated with 10 ml normal saline as were the Ex and Cr mice following operative intervention. In Ex mice, a 3 mm section of the PAN was sharply excised and nerve gap was confirmed with fluorescent microscopy. In Cr mice, the PAN was crushed 3 mm from the origin of the facial nerve trunk with size 5 jeweler's forceps for two periods of 20 s. Post-operative video recordings were collected on post-operative days (POD) 1, 10, 20, and 30. To determine the change in ear movement, the right ear was graphically compared to the left control side. RESULTS: Sh animals exhibited a statistically significant reduction in ear movement at POD01 compared to other POD recordings (p < 0.05), but no significant change in right ear movement following POD05. Ex animals had a significant reduction in right ear movement at all PODs in comparison to the left ear (p < 0.05) with no significant change in right ear movement during the study period (p = 0.94). Cr animals showed a significant reduction in right ear movement compared to the left at POD01, POD10, and POD20 (p < 0.05). At POD30, there was no significant difference between ear movement on either side (p = 0.35). There was a significant change in right ear movement during the data collection period (p < 0.05). CONCLUSION: The results show that significant differences were demonstrated between the experimental groups and that significant changes within the crush group were identifiable making this an acceptable model to develop as an accurate outcome measure following rodent facial nerve surgery.