Nerve Trunk Research Articles

Effect of Forward and Reverse Suturing on Nerve Regeneration Following Facial Nerve Axotomy

Background/Objectives: When the facial nerve is severed and a nerve graft is required, motor nerves are typically connected in the forward direction, while sensory nerves are connected in the reverse direction. However, there is limited research on the effects of reversing this connection, and no studies have been conducted using the same facial nerve. This study aimed to investigate the effects of forward and reverse suturing on nerve regeneration following facial nerve axotomy. Methods: The facial nerve trunk of male Sprague Dawley rats was incised to induce facial nerve injury, and autografts were sutured using both forward and reverse methods. Behavioral tests, including whisker reflex and eye blink tests, were conducted. Histological analyses, including toluidine blue staining and transmission electron microscopy (TEM), were performed to evaluate axon recovery. Results: Behavioral experiments showed signs of recovery at 3–4 weeks in both the forward and reverse suture groups, with no significant differences between the two methods (p < 0.01). Histological analysis showed partial recovery by 8 weeks in both groups. Toluidine blue staining indicated a reduction in the number of axons at 4 weeks, with partial recovery at 8 weeks (p < 0.001) in both groups. TEM analysis revealed that myelin fiber thickness was restored in both the forward and reverse suture groups, though it remained thinner compared to normal (p < 0.01). Conclusions: Our results suggest that the direction of nerve suturing (forward vs. reverse) does not significantly impact nerve regeneration or functional recovery. Both suturing methods demonstrated similar recovery effects, with no significant differences in microstructural regeneration. Future studies should investigate the molecular mechanisms underlying nerve regeneration and extend the observation period to provide a more comprehensive understanding of this process.

Identification of peripheral nerve functional fascicles in Sprague-Dawley rats by the carbon quantum dot-Annexin V antibody complex

To explore a method to identify the sensory and motor fascicles of the peripheral nerve to achieve accurate peripheral nerve functional fascicle suture. The peripheral nerve Sunderland V injury model, muscle branch of the femoral nerve and saphenous nerve were established in the bilateral femoral nerves of Sprague-Dawley (SD) rats. The specific samples were grouped as follows: the main trunk of the femoral nerve was exposed bilaterally and cut with microscopic scissors in the main trunk of the femoral nerve to prepare a model of Sunderland V injury in the mixed fascicle of peripheral nerves; the muscle branch of the femoral nerve was exposed bilaterally and cut in the middle section of the muscle branch of the femoral nerve to prepare a model of Sunderland V injury in the motor fascicle of peripheral nerves; the saphenous nerve was exposed bilaterally and cut at 1 cm below the patella to prepare a model of Sunderland V injury to the sensory fascicle of the peripheral nerves. A carbon quantum dot (CD)-annexin V antibody complex was prepared and applied to the distal and proximal nerve stumps of the peripheral nerve Sunderland V injury model groups of SD rats. Under the excitation light source of a 380 nm uv lamp, fluorescence color development was observed under a fluorescence microscope after 5, 10, 15, and 20 min. At 5 min, sections of the bilateral femoral nerve trunk, muscular branches of the femoral nerve, and Sunderland V lesion of the saphenous nerve in SD rats were only dark in color under the microscope, and there was no difference in fluorescence. The intensity of the staining increased significantly for 10–20 min. The sensory fascicles and saphenous nerves of the femoral nerve trunk showed blue fluorescence under the CD-Annexin V antibody complex staining, while the motor fascicles and muscle branches of the femoral nerve trunk showed no fluorescence. Fluorescence intensity gradually decreased after 20 min of staining. There was no significant difference in the staining intensity at 5, 10, 15, and 20 min in each group. Our results suggest that the CD-Annexin antibody complex can be used to identify functional fascicles of peripheral nerves in SD rats.

Ancient cervical vagal schwannoma and an interposition great auricular to vagus nerve graft

Introduction: Schwannomas of the cervical vagus nerve are exceedingly rare and have a myriad of clinical presentations depending on the tumor size and its proximity to neurovascular structures. We report a rare case of a cervical vagal schwannoma that was successfully treated with en bloc resection and reconstruction with a great auricular to vagus nerve graft. Case Report: A 42-year-old male presented with an asymptomatic, right lateral neck mass. Magnetic resonance imaging revealed a lesion 2.4 cm × 1.4 cm × 4.0 cm in size, located between the carotid arteries and internal jugular vein displacing the internal carotid artery anteromedially. En bloc resection of the lesion and reconstruction of the vagus nerve with a great auricular interposition graft was performed. Conclusion: Vagal schwannomas are rare, benign neurogenic tumors. Complete surgical excision is the mainstay of treatment. When a safe surgical plane cannot be identified between the neurogenic tumor and the main nerve trunk, en bloc resection with reconstruction should be considered.

Enhanced Understanding of Facial Nerve Anatomy and Arborization in the Indian Population: Implications for Surgical Procedures.

The anatomy and arborization patterns of the extraparotid facial nerve show considerable variation among different populations, impacting surgical approaches in plastic, head and neck, and ENT surgeries. This study focuses on the Indian population to provide a detailed understanding of these variations, specifically highlighting the Davis type IV arborization pattern's prevalence and its clinical relevance. We conducted a comprehensive dissection of 16 formalin-preserved Indian cadaveric hemifaces. The study meticulously mapped the facial nerve trunk (FNT), its furcation points, and branches. Key anatomical landmarks for locating these nerve structures were identified, including the tip of the mastoid process, the angle of the mandible, and a novel line between the lateral palpebral fissure and otobasion superioris. The most common arborization pattern observed was Davis type IV (31.3%). The study provided precise measurements for locating the FNT and its branches, using identifiable landmarks. These findings facilitate more accurate surgical planning, crucial for procedures involving nerve repair or grafting. This research offers vital insights into the facial nerve anatomy specific to the Indian population, with significant implications for surgical precision and patient outcomes. By establishing reliable anatomical landmarks and elucidating the predominant arborization pattern, the study enhances the understanding of facial nerve behavior during surgical interventions, particularly in the context of facial paralysis treatment and reconstructive surgeries. Due to the small sample size, however, this study only acts as a pilot for further research.

Microscopical anatomy of the peripheral nervous system: An essential notion for understanding the pathophysiology of very early classic Guillain-Barré syndrome.

The aim of this paper is to analyze the pathophysiological mechanisms acting in very early classic Guillain-Barré syndrome (GBS) (≤4 days of symptomatic onset). In this inaugural period, both in GBS and its animal model, experimental autoimmune neuritis, the outstanding pathological feature is inflammatory edema predominating in proximal nerve trunks, particularly spinal nerves, and possibly in preterminal nerve segments. Nerve trunks external to the subarachnoid angle possess epi- perineurium that is relatively inelastic and of low compliance. Here such edema can increase endoneurial fluid pressure that, when sufficiently critical, may stretch the perineurium and constrict transperineurial microcirculation, compromising blood flow and producing the potential for ischemic nerve injury, whose consequence is rapid partial or complete loss of nerve excitability. These histopathological features correlate well with electrophysiological and imaging findings reported in early GBS stages. Spinal nerve edema and ischemia help to understand the pattern of Wallerian-like degeneration observed in the axonal form of GBS, predominating in motor spinal roots at their exit from the dura matter (spinal nerves) with centrifugal distribution in more distant motor nerve trunks, and centripetal extension to the distal portion of intrathecal roots. The similarity of initial pathogenic mechanisms between demyelinating and axonal forms of GBS explains why an early increase of serum biomarkers of axonal damage is detected in both forms. In conclusion, knowledge of the microscopic anatomy of the peripheral nervous system is an essential step for a reliable understanding of pathophysiological mechanisms operating in the early phase of any classic GBS subtype.

The use of electrical stimulation to enhance recovery following peripheral nerve injury.

Peripheral nerve injury is common and can have devastating consequences. In severe cases, functional recovery is often poor despite surgery. This is primarily due to the exceedingly slow rate of nerve regeneration at only 1-3 mm/day. The local environment in the distal nerve stump supportive of nerve regrowth deteriorates over time and the target end organs become atrophic. To overcome these challenges, investigations into treatments capable of accelerating nerve regrowth are of great clinical relevance and are an active area of research. One intervention that has shown great promise is perioperative electrical stimulation. Postoperative stimulation helps to expedite the Wallerian degeneration process and reduces delays caused by staggered regeneration at the site of nerve injury. By contrast, preoperative "conditioning" stimulation increases the rate of nerve regrowth along the nerve trunk. Over the past two decades, a rich body of literature has emerged that provides molecular insights into the mechanism by which electrical stimulation impacts nerve regeneration. The end result is upregulation of regeneration-associated genes in the neuronal body and accelerated transport to the axon front for regrowth. The efficacy of brief electrical stimulation on patients with peripheral nerve injuries was demonstrated in a number of randomized controlled trials on compressive, transection and traction injuries. As approved equipment to deliver this treatment is becoming available, it may be feasible to deploy this novel treatment in a wide range of clinical settings.

Cranial nerve palsies in leprosy: a systematic review of published case reports and case series.

In leprosy, peripheral nerve involvement is well-documented, cranial nerve impairment in leprosy is less frequently reported, often through isolated case reports. This review aims to elucidate the pattern and spectrum of cranial nerve involvement in leprosy patients, enhancing understanding about pathogenesis and management. Adhering to PRISMA guidelines, we conducted a systematic review of case reports and series documenting cranial nerve involvement in leprosy. Searches were performed across PubMed, Scopus, Embase, and Google Scholar up to February 2, 2024, without language restrictions. We identified 40 documents reporting on 49 patients, with a mean age of 41.3 years and a predominance of male patients (87.6%). Cranial nerve involvement included the trigeminal nerve (28.6%), facial nerve (38.8%), and instances of multiple cranial nerve palsies (10.2%). Magnetic resonance imaging findings indicated nerve T2/FLAIR hyperintensity/enhancements. Neuroimaging abnormalities extended up to brain stem. Approximately 30% of patients experienced lepra reactions, with 51% showing improvement following treatment. Following mutidrug therapy (MDT), neuroimaging abnormalities were vanished. Cranial nerve involvement in leprosy primarily affects the trigeminal and facial nerves, with multiple cranial nerves also being implicated. Exaggerated inflammation during lepra reaction involve nerve trunks and/or brainstem nuclei.

Оценка результатов лечения больных с синдромом шейного ребра в послеоперационном периоде

The pectoral exit syndrome is of undoubted interest for surgeons, angiosurgeons and neurologists due to the possible compression of the vascular-nervous plexus, causing certain symptoms and reducing work abilities. Objective To conduct an analysis of the results of the treatment of patients with cervical rib syndrome in the short and remote observation periods in the postoperative period. Material and methods 138 patients with abnormal cervical ribs were the clinical material and the object for the study, abnormal cervical ribs caused the extravasal compression of the vascular bunch of the upper extremities at the exit from the chest. These patients were treated and were operated on in the vascular surgery department of the Republican Scientific Center of Cardiovascular Surgery from January 1990 to May 2020. Results Good postoperative results were observed in 89.1 % of patients in the short postoperative period. Intraoperative complications were noted in 5 (3.6 %), and in the short postoperative period – in 10 (7.2 %) patients. In the remote period, relapse of preoperative symptoms of the disease was noted in 8 (5.8 %) of all 138 patients observed. Relapse (or renewal of the symptoms of Reino) was mainly observed in the period of up to 3 years. At different times of observation, 5 patients were lost from sight. In the remote period, in terms of up to 1 year of observation, a good result was 97.2 %, from 2–3 years to more than 5 years – 90.6 %. Conclusions The early identification of intraoperative and postoperative complications allows to timely eliminate these complications. In the nearest postoperative period, only the hemodynamic effect of decompression operations and selective cervical-breed sympathctomy is obvious. Neurological symptoms regressed gradually in the remote period. In this case, it is necessary to emphasize the importance of timely rehabilitation therapy, the implementation of the recommendations of a specialist, since the restoration of dystrophic changes in the nerve trunks is a long process.

Characteristics of anti-contactin1 antibody positive autoimmune nodopathies combined with membranous nephropathy

BackgroundAutoimmune nodopathy (AN) is a very rare new disease entity, especially when combined with membranous nephropathy (MN). MethodsAntibodies against nodal-paranodal cell adhesion molecules in the serum were detected using cell-based assays. Antibody subtypes against contactin-1 (CNTN1) were confirmed. Cases of anti-CNTN1 antibody-positive AN with and without MN were retrieved through a literature search to compare clinical and electrophysiological characteristics. ResultsA 65-year-old male patient with MN developed limb numbness and weakness, along with walking instability. Serum CNTN1 antibodies were positive, primarily those of the IgG4 subtype. Electromyography showed prominent demyelination patterns in both the proximal and distal segments of the nerves compared to the middle nerve trunk. Magnetic resonance imaging revealed enlargement of the bilateral brachial and lumbosacral plexuses and local hyperintensity of the right C5-C6 nerve roots. Thirty-five cases with anti-CNTN1 antibody-positive AN with MN and 51 cases with anti-CNTN1 antibody-positive AN without MN were compared. Furthermore, the proportion of patients with MN combined with AN presenting with acute or subacute onset was higher than that observed in the MN without AN group. Nevertheless, no substantial differences were noted between the two groups concerning the clinical and electrophysiological characteristics, which were mainly elderly men, manifested as sensory ataxia, IgG4 antibody subtype, electrophysiological demyelination, and a certain effect on immunotherapy. ConclusionIn cases of electrophysiological manifestation of demyelinating peripheral neuropathy, especially in distal and poximal segments of nerves, AN should be considered, and further screening for renal function should be performed. Concomitant MN does not aggravate or alleviate peripheral nerve symptoms.

Epineurectomy of extracranial facial nerve trunk for non-flaccid sequelae following Bell's palsy: A single-arm trial.

Non-flaccid facial palsy sequelae manifest as sequelae following Bell's palsy. Currently, there are no effective remedies for addressing this issue. In this study, we proposed a new surgical solution, epineurectomy of the extracranial facial nerve trunk, and assessed its safety and efficacy as a potential remedy.. In this single-arm trial, adult patients with non-flaccid facial palsy sequelae were enrolled and subjected to epineurectomy of the extracranial facial nerve trunk. The primary efficacy endpoint was the Sunnybrook scores at months 12 postoperatively. The secondary endpoints included non-flaccid facial palsy sequelae symptom scores, such as facial tightness or facial stiffness, facial synkinesis, eyefissures narrowing or difficulty in opening the eyes, House-Brackmann grade scale, and Facial Disability Index. A total of 22 patients were enrolled between July 2020 and January 2021. One patient was lost to follow up. One year after surgery, the Sunnybrook score was 72.0 (63.0 - 75.0) at 12 months versus 68.0 (58.0 - 70.8) at baseline. The mean difference was -5.4 (-7.2 to -3.6). The scores of facial tightness or facial stiffness, synkinesis, eye fissures narrowing or difficulty in opening eyes were 0.0 (0.0 - 1.0), 1.0 (1.0 - 1.0), 1.0 (1.0 - 2.0) at 12 months versus 3.0 (1.3 - 3.0), 2.0 (1.0 - 2.8), 2.0 (2.0 - 3.0) at baseline, respectively. The median (IQR) values of the Facial Disability Index physical function were 92.0 (90.0 - 95.0) at months 12, and the mean difference (95% CI) was -32 (-38 to -26) compared to baseline. The mean difference (95% CI) in the Facial Disability Index social/well-being function between month 12 and baseline was -38 (-46 to -31). Epineurectomy of the extracranial facial nerve trunk can effectively and safely alleviate the sequelae of non-flaccid facial palsy.

Facial Nerve Injury after Extracapsular Dissection for Benign Parotid Tumors with and without Intraoperative Monitoring: A Retrospective Study of a Single Center.

Facial nerve injury (FNI) is the most common complication of parotid surgery and manifests as FN paralysis. The use of intraoperative facial nerve monitoring (IFNM) is becoming an established intraoperative aid for surgeons, assisting in the identification of the location and dissection of the facial nerve trunk or branches. The postoperative outcomes of parotid surgery with and without monitoring have been addressed in only a limited number of studies. The objective of this study is to evaluate the incidence of postoperative paralysis in patients undergoing extracapsular dissection (ED) for benign parotid tumors concerning the use or non-use of IFNM. The retrospective study was conducted at the Maxillo-Facial Department of the Magna Graecia University of Catanzaro. The patients were divided into two groups: Group 1 consisted of patients who underwent surgery without IFNM (1 January 2015 to 31 December 2018); Group 2, on the other hand, consisted of patients who underwent surgery with IFNM (1 January 2019 to 31 December 2022). Group 2 employed the Nerve Integrity Monitor (Medtronic's NIM®). To classify the FN function, we employed the modified House-Brackmann classification system. To evaluate the dependence between the "use of IFNM" and "postoperative paralysis", a descriptive analysis was conducted, including applying the Chi-squared test and calculating the Pearson correlation. Subsequently, a binary logistic regression model was applied to further evaluate the correlation between the latter. The level of statistical significance was set at p < 0.05. A total of 276 patients were included in the study: 120 subjects were assigned to Group 1 (43.5%, comprising 60 men and 60 women) and 156 subjects were assigned to Group 2 (56.5%, comprising 93 men and 63 women). In 91.7% of the cases (n. 253, precisely 105 in Group 1 and 148 in Group 2), no FNI occurred. In 8.33% of the cases (n. 23, specifically 15 in Group 1 and 8 in Group 2), postoperative paralysis was observed. Of these subjects, only two in Group 1 had permanent paralysis (8.69%); therefore, 91.31% had transient paralysis. As a result, 91.31% of the subjects exhibited transient paralysis. In the case of FNI, 78% of the cases involved the marginal mandibular branch (n. 18), 13% involved the temporo-zygomatic branch (n. 3), and 7% involved more than one branch (n = 2). The results of the multivariable binary logistic regression analysis demonstrated that the use of IFNM was a statistically significant influencing factor, with an estimated reduction in postoperative paralysis of approximately 62% (OR 0.378; 95% CI: 0.155-0.92). In Group 2, the occurrence of transient complications was significantly reduced (OR 0.387; 95% CI: 0.149-1.002 with p < 0.05). The use of IFNM in the ED for benign parotid tumors significantly reduces the rate of FNI and, consequently, postoperative FN paralysis. On the other hand, the use of monitoring systems must not replace the experience and anatomical knowledge of the surgeon.

Horner’s syndrome caused by the first rib fracture sustained during coronary artery bypass grafting: a case report and literature review

BackgroundHorner’s syndrome is a rare complication of cardiovascular surgery. A bone fragment and hematoma due to rib fracture after cardiac surgery may cause injury to the brachial nerve plexus and sympathetic nerve trunk, leading to neurologic disorders and Horner’s syndrome. However, few reports have revealed the etiology of Horner’s syndrome after cardiovascular surgery based on imaging. Herein we present a case in which a plain CT scan confirmed the etiology of Horner’s syndrome after coronary artery bypass grafting (CABG), reviewing 139 CABG cases retrospectively in our hospital and 6 case reports of Horner’s syndrome associated with cardiovascular surgery.Case presentationA 69-year-old woman with a history of percutaneous coronary intervention and total abdominal hysterectomy with bilateral salpingo-oophorectomy had chest pain on exertion. Coronary angiography showed severe triple vessel disease. She underwent off-pump coronary artery bypass grafting (CABG). A median sternotomy was performed, and the split sternums were widened using a sternal retractor. The bilateral internal thoracic arteries were harvested. A triple CABG was performed. She had left shoulder pain after surgery. She complained of anhidrosis involving the left face and hyperhidrosis involving the right face from postoperative day (POD) 6. Left ptosis and blurry vision appeared after discharge from the hospital, for which she saw a neurologist in our hospital on POD 48. Miosis could not be clearly confirmed. She was diagnosed with Horner’s syndrome. A plain CT scan revealed displaced fractures of the bilateral first ribs and left second rib. The bone fragment of the left first rib head was displaced 3 mm anteriorly compared to the left first rib head before surgery, which suggested that the fragment affected the stellate ganglion in the sympathetic trunk. The patient had regular follow-up evaluations. The anhidrosis persisted, but the ptosis improved, and the miosis was not confirmed at the 6-month follow-up evaluation.ConclusionsWe should recognize that Horner’s syndrome is one of the complications of cardiovascular surgery, especially CABG. Fracture of the first rib head with a displaced bone fracture was shown to be a contributor to ipsilateral Horner’s syndrome. When symptoms of Horner’s syndrome and other neurologic symptoms are noted after open heart surgery, a plain CT examination should be obtained.

Rethinking Fistula Preservation in Anorectal Malformation Surgery: A Histopathological Perspective.

This study aims to assess the histopathological characteristics of the fistulous tissue in males with anorectal malformation (ARM) to determine its suitability for use in constructing a neoanus. This prospective observational study included male ARM patients with recto-urethral fistula. All other types were excluded. The tissue specimens comprised 0.5-2.0 cm of the most distal part of the rectal pouch and the fistulous tissue. Hematoxylin and eosin-stained sections were prepared. Histological features viz. internal sphincter, anal grand and crypts, ganglion cells, presence of subepithelial fibrosis, thickened nerve trunks, and metaplasia were evaluated. Of 65 patients of ARM admitted, 24 met the inclusion criteria. Gross and microscopic internal sphincter was not found in any sample. The anal mucosa was visualized in all cases; however, crypts were irregular and distorted architecture was seen in 4 (16.67%) samples. Urothelial metaplasia was identified in 10 (41.67%) cases. Adequate ganglion cells were seen only in 6 (25%) samples. Significant submucosal fibrosis was seen in all samples. Thickened nerve trunks were identified in 4 (16.67%) samples. All normal anal histological features could not be found together in the fistula tissue. With the absence of normal features, such as internal anal sphincter muscles, and the presence of abnormal histopathological features, such as subepithelial fibrosis, thickened nerve trunks, and metaplasia there are high chances of abnormal bowel function like constipation if the fistulous tissue is used for neoanus construction. It may have an impact on the quality of life of patients.

Feasibility of a cross-face reconstruction of the mental nerve—A cadaveric simulation study with histomorphometric analysis

IntroductionThe inevitable sacrifice of the inferior alveolar nerve (IAN) during oncologic resections results in substantial sensory impairment, impacting crucial functions such as speech, saliva retention, and mastication. This study investigates the feasibility of sensory restoration through cross-face reconstruction of the mental nerve via a contralateral mental nerve branch. MethodsThe cross-face reconstruction procedure was simulated in five formalin-fixed cadavers for both sides to evaluate the anatomic fundamentals and the nerve gap between the mental nerve main trunk and the transferred contralateral mental nerve branch. Furthermore, a histomorphometric analysis was performed to assess cross-sectional area and axon counts. ResultsThe mean gap distance between the main mental nerve trunk and the transferred contralateral branch was 15.3mm. End-to-end coaptation was achieved in 9 out of 10 simulations. The mean cross-sectional area was 0.996 mm2 at the main mental nerve trunk and 0.253mm2 at the coaptation site of the nerve branch. The mean donor-to-recipient axon ratio was found to be 0.3:1. ConclusionThe cadaveric simulation demonstrates the feasibility of a cross-face reconstruction of the mental nerve with only minimal gapping. Advantages of the proposed technique include the use of shorter nerve grafts, minimizing donor site morbidity and enabling fast reinnervation. This technique may offer a promising method for enhancing the quality of life for a patient group with increasing survival rates and life expectancy.

Collagen protein-chitosan nerve conduits with neuroepithelial stem cells promote peripheral nerve regeneration

The peripheral nervous system consists of ganglia, nerve trunks, plexuses, and nerve endings, that transmit afferent and efferent information. Regeneration after a peripheral nerve damage is sluggish and imperfect. Peripheral nerve injury frequently causes partial or complete loss of motor and sensory function, physical impairment, and neuropathic pain, all of which have a negative impact on patients’ quality of life. Because the mechanism of peripheral nerve injury and healing is still unclear, the therapeutic efficacy is limited. As peripheral nerve injury research has processed, an increasing number of studies have revealed that biological scaffolds work in tandem with progenitor cells to repair peripheral nerve injury. Here, we fabricated collagen chitosan nerve conduit bioscaffolds together with collagen and then filled neuroepithelial stem cells (NESCs). Scanning electron microscopy showed that the NESCs grew well on the scaffold surface. Compared to the control group, the NESCs group contained more cells with bigger diameters and myelinated structures around the axons. Our findings indicated that a combination of chitosan-collagen bioscaffold and neural stem cell transplantation can facilitate the functional restoration of peripheral nerve tissue, with promising future applications and research implications.

Targeted Muscle Reinnervation in the Upper Arm: A Functional Anatomical Study

BackgroundThe aim of this study was to accurately locate the neural fascicle controlling hand movement in the upper arm, to enhance expression of motor intention after targeted muscle reinnervation. MethodsThe right sides of the median, ulnar and radial nerves were dissected from distal to proximal in 6 fresh cadaver specimens. The sectional location and diameter of the functional fascicle were measured at 10 and 20 cm below the acromion. The diameter of the main muscle branches of muscle reinnervation target muscles was measured. ResultsThe median nerve branch of finger and wrist flexion was mainly located between the 9 and 12 o’clock positions in the plane 10 and 20 cm below the acromion, where the diameter of the nerve fascicle was 2.07 and 2.04 mm, respectively. The ulnar nerve branch of finger and wrist flexion was mainly located between the 8 and 12 o’clock positions, with a diameter of respectively 1.80 and 1.99 mm. The radial branch of finger and wrist extension was mainly located between the 10 and 2 o’clock positions in the plane 10 cm below the acromion and between 6 and 12 o’clock in the plane 20 cm below the acromion, with a diameter of respectively 2.57 and 3.03 mm. ConclusionsThe nerve fascicles innervating the flexor and extensor fingers were distributed in relatively constant regions of the median, ulnar and radial nerve trunks, and their diameters closely matched the muscle branches of the target muscle.

Extratemporal Facial Nerve Interconnections and Trunk's Variability: A Systematic Review with Meta-Analysis.

The present systematic review with meta-analysis is a significant contribution to the understanding of the morphological variability of the facial nerve (FN) extratemporal segment, i.e., the facial trunk (FT) variability, its division, and terminal branching patterns. The study also provides a comprehensive overview of the clinical significance of the FN extracranial division. Four online databases were utilized to conduct the systematic review according to evidence-based anatomy guidelines. A meta-analysis of the studies included was carried out using R programming software. The combined prevalence of the FN variants was calculated, along with subgroup and cumulative analysis. From the systematic review, 29 studies were retrieved as eligible for our initial purpose. However, 19 studies followed the same classification system and were selected for the meta-analysis, with a total sample of 2453 nerves. The most common pattern of the FN morphology was the FT bifurcation (typical pattern), with a pooled prevalence of 94.1% and a single interconnection (IC) between the temporofacial and cervicofacial branches (23.1% pooled prevalence). Two ICs between these branches were the rarest pattern (8.9% pooled prevalence). Our findings underscore the extensive morphological variability of the FN extratemporal anatomy, which has led to confusion among researchers. While several classification systems have been developed, none accurately represent the typical and variant anatomy. Our meta-analysis provided a small range between 8.9-23.1% for the rarest and most common pattern; thus, diversity is the rule. Therefore, it is not safe to conclude the typical morphology of FN extratemporal anatomy for its whole distribution before the FT's division (proximally) and its terminal branches (distally). Nevertheless, the bifurcation of the FT can be considered the typical morphology, and it is far more constant than the distal branching pattern. These findings have significant implications for surgical procedures, particularly parotidectomy, where surgeons must exercise utmost caution due to the potential clinical implications of FN injury.

The effectiveness of intraoperative ultrasound control in removing foreign bodies of soft tissues in military personnel with fragmentation wounds at the stage of specialized surgical care

BACKGROUND: The involvement of civilian medical institutions in medical care in military conflicts and counter-terrorism operations has become an important area of the medical support system. Modern methods of surgical navigation make possible minimal invasive, effective and safe removing foreign bodies from soft tissues. Clear understanding of injuries’ character allows better planning of procedures. AIM: Improving the results of treatment of military personnel with fragment wounds by taking into account the character of injury and the use of ultrasound control during removing soft tissue foreign bodies at the stage of specialized surgical care. MATERIAL AND METHODS: Data from 253 case histories who were treated at the State Budgetary Institution RO “Central City Hospital named Semashko”. Indications for the removal of fragments included the size of the fragment over 7 mm, localization near to large vessels and nerve trunks, and an acute purulent process. The patients were been randomized to two groups. Group I (control) included 118 patients in whom surgery was been performed in the traditional way. Group II (main) included 135 patients in whom procedures were performed with ultrasound navigation. The research methods are ultrasound, X-ray, clinical, and statistical. RESULTS: In 164 patients (64.8%), the wounds were of an isolated nature, where fragments were localized in various anatomical areas. 89 patients (35.2%) had combined shrapnel wounds. Of the 118 patients in group I, in whom surgery was performed in the traditional way, 65 patients (55.1%) underwent surgery under local anesthesia, 53 (44.9%) — under general anesthesia (anesthesia is always general). In 135 patients of group II, operations were performed by only one surgeon under local anesthesia. The duration of surgery, surgery invasion and wound infections rate were significantly lower in group II. CONCLUSION: The part of isolated fragment wounds is 64.8%, combined — 35.2%. The use of ultrasound navigation during surgery can significantly improve the effectiveness of surgical treatment of patients with fragmentation wounds: reduce the invasiveness and duration of surgery, blood loss, and the rate of wound infectious complications.

Multilevel neurium-mimetic individualized graft via additive manufacturing for efficient tissue repair

Complicated peripheral nerve injuries or defects, especially at branching sites, remain a prominent clinical challenge after the application of different treatment strategies. Current nerve grafts fail to match the expected shape and size for delicate and precise branched nerve repair on a case-by-case basis, and there is a lack of geometrical and microscale regenerative navigation. In this study, we develop a sugar painting-inspired individualized multilevel epi-/peri-/endoneurium-mimetic device (SpinMed) to customize natural cues, featuring a selectively protective outer sheath and an instructive core, to support rapid vascular reconstruction and consequent efficient neurite extension along the defect area. The biomimetic perineurium dictates host-guest crosslinking in which new vessels secrete multimerin 1 binding to the fibroin filler surface as an anchor, contributing to the biological endoneurium that promotes Schwann cell homing and remyelination. SpinMed implantation into rat sciatic nerve defects yields a satisfactory outcome in terms of structural reconstruction, with sensory and locomotive function restoration. We further customize SpinMed grafts based on anatomy and digital imaging, achieving rapid repair of the nerve trunk and branches superior to that achieved by autografts and decellularized grafts in a specific beagle nerve defect model, with reliable biosafety. Overall, this intelligent art-inspired biomimetic design offers a facile way to customize sophisticated high-performance nerve grafts and holds great potential for application in translational regenerative medicine.

Blocking Aδ- and C-fiber neural transmission by sub-kilohertz peripheral nerve stimulation.

We recently showed that sub-kilohertz electrical stimulation of the afferent somata in the dorsal root ganglia (DRG) reversibly blocks afferent transmission. Here, we further investigated whether similar conduction block can be achieved by stimulating the nerve trunk with electrical peripheral nerve stimulation (ePNS). We explored the mechanisms and parameters of conduction block by ePNS via ex vivo single-fiber recordings from two somatic (sciatic and saphenous) and one autonomic (vagal) nerves harvested from mice. Action potentials were evoked on one end of the nerve and recorded on the other end from teased nerve filaments, i.e., single-fiber recordings. ePNS was delivered in the middle of the nerve trunk using a glass suction electrode at frequencies of 5, 10, 50, 100, 500, and 1000 Hz. Suprathreshold ePNS reversibly blocks axonal neural transmission of both thinly myelinated Aδ-fiber axons and unmyelinated C-fiber axons. ePNS leads to a progressive decrease in conduction velocity (CV) until transmission blockage, suggesting activity-dependent conduction slowing. The blocking efficiency is dependent on the axonal conduction velocity, with Aδ-fibers efficiently blocked by 50-1000 Hz stimulation and C-fibers blocked by 10-50 Hz. The corresponding NEURON simulation of action potential transmission indicates that the disrupted transmembrane sodium and potassium concentration gradients underly the transmission block by the ePNS. The current study provides direct evidence of reversible Aδ- and C-fiber transmission blockage by low-frequency (<100 Hz) electrical stimulation of the nerve trunk, a previously overlooked mechanism that can be harnessed to enhance the therapeutic effect of ePNS in treating neurological disorders.