Number Of Fascicles Research Articles

Anatomical description of the ventral and dorsal cervical rootlets in rats: A microsurgical study.

ABSTRACTPurpose:To describe the anatomical aspects of the cervical rootlets and to quantify the number of rootlets that compose C1 to T1.Methods:Twenty male rats were used in this study. The dorsal rootlets from C1 to T1 were analyzed. To study the ventral rootlets, the posterior root avulsion was performed using a microhook, allowing exposure of the ventral roots through manipulation of the denticulate ligament and arachnoid mater. The parameters analyzed were the number of ventral and dorsal rootlets by side and level.Results:The formation of the respective spinal nerve was observed in the spinal roots the union of the ventral and dorsal roots. In four animals the C1 spinal root had no dorsal and/or ventral contribution. There is no normal pattern of numerical normality of the dorsal and ventral rootlets. The average number of fascicles per root was 4.08, with a slight superiority on the left side. There was a slight superiority of the dorsal rootlets compared to the ventral rootlets.Conclusions:This investigation was the first to study cervical rootlets in rats. In 20% of the sample studied, the dorsal root of C1 was absent mainly on the left side. There is a nonlinear numerical increase from C1 to T1 in the rootlets. There is a numerical predominance of cervical fascicles on the left side, confronting several studies related to the functional predominance of right laterality, requiring new studies that correlate these variables.

The Larval Scaffold Controls Fascicle Number But is Not Required for Formation of the Dorsolongitudinal Flight Muscles in Manduca Sexta

The Larval Scaffold Controls Fascicle Number But is Not Required for Formation of the Dorsolongitudinal Flight Muscles in Manduca Sexta

The terminal segment of the human phrenic nerve as a novel implantation site for diaphragm pacing electrodes: Anatomical and clinical description

BackgroundDiaphragm pacing allows certain ventilator-dependent patients to achieve weaning from mechanical ventilation. The reference method consists in implanting intrathoracic contact electrodes around the phrenic nerve during video-assisted thoracic surgery, which involves time-consuming phrenic nerve dissection with a risk of nerve damage. Identifying a phrenic segment suitable for dissection-free implantation of electrodes would constitute progress. Study designThis study characterizes a free terminal phrenic segment never fully described before. We conducted a cadaver study (n = 14) and a clinical observational study during thoracic procedures (n = 54). ResultsA free terminal phrenic segment was observed on both sides in 100% of cases, "jumping" from the pericardium to the diaphragm and measuring 60 mm [95% confidence interval; 48–63] and 72.5 mm [65–82] (right left, respectively; p = 0.0038; cadaver study). This segment rolled up on itself at end-expiration and became unravelled and elongated with diaphragm descent (clinical study). Three categories of fat pads were defined (type 1: pericardiophrenic bundle free of surrounding fat; type 2: single fatty fringe leaving the phrenic nerve visible until diaphragmatic entry; type 3: multiple fatty fringes masking the site of penetration of the phrenic nerve) that depended on body mass index (p = 0.001, clinical study). Hematoxylin-eosin and toluidine blue staining (cadaver study) showed that all of the phrenic fibers in the distal, pre-branching part of the terminal segment were contained within a single epineurium containing a variable number of fascicles (right: 1 [95%CI 0.65–4.01]; left 5 [3.37–7.63]; p = 0.03). ConclusionDiaphragm pacing through periphrenic electrodes positioned on the terminal phrenic segment should be tested.

The Myth of Median Nerve in Forearm and Its Role in Double Crush Syndrome: A Cadaveric Study.

Purpose: This study aims to histologically compare the median nerve in the arm, forearm, and wrist, to help understand how cervical radiculopathy in a double crush phenomenon causes distal nerve dysfunction at the carpal tunnel and median nerve with concurrent absence of symptoms at the forearm.Methods: The study was performed on 12 fresh cadaveric upper limbs free from any injury or operation. Male cadavers in the age range of 35–40 years were used. The dissection of the median nerve and the histological examination of the specimens from the arm, forearm, and wrist were conducted to evaluate variations in the epineurium thickness (μm), perineurium thickness (μm), number of fascicles per nerve trunk, area percent of myelin covering, and area percent of neurolemmal sheath.Results: Morphometric and statistical results of the cadaveric median nerve trunk revealed that the mean epineurium and perineurium thickness measured in H&E-stained sections in the forearm were significantly greater than those in the arm and wrist specimens. Further, the mean percent area of the myelin covering in the forearm was significantly lower than that in the arm and wrist specimens in the sections stained with osmium oxide (p < 0.001). There were, however, no significant differences in the neurolemmal sheath among the arm, forearm, and wrist specimens in the silver-stained sections.Conclusion: The histological differences explained the high concomitant occurrence of carpal tunnel syndrome (CTS) and cervical radiculopathy and the concurrent absence of symptoms at the forearm. Hence, we suggest cautious evaluation of patients with upper limb symptoms, since the management of these conditions requires a different approach.

Straight Form of Calcaneofibular Ligament as a Three-Dimensional Magnetic Resonance Imaging Sign in Diagnosis of Calcaneofibular Ligament and Anterior Talofibular Ligament Inferior Fascicle Injury

The present study was performed to investigate the morphological characteristics of the calcaneofibular ligament (CFL) and evaluate its relationship to the anterior talofibular ligament (ATFL) in patients with lateral ankle ligament injury using 3-dimensional magnetic resonance imaging (3D-MRI). This retrospective study involved 35 patients with lateral ankle ligament injury and 24 patients without a history of ankle trauma and a bone abnormality as controls. Reconstructed 3D-MRI was used to classify the form of the CFL as curved, wavy, or straight. The presence/absence of continuity between the fibula and CFL was evaluated in the 35 patients with injury, who were divided into 2 groups (continuity and discontinuity groups). The number of fascicles in the ATFL and the continuity between the distal end of the fibula and the proximal end of the ATFL were then evaluated. Among the patients with injury, 54.3% had the curve type of CFL, 34.3% had the wave type, and 11.4% had the straight type. In the control group, 62.5% had the curve type, 37.5% had the wave type, and none had the straight type. Continuity between the fibula and CFL was seen in 88.6%, and discontinuity was seen in 11.4%. Additionally, 85.7% had double fascicles in the ATFL. Inferior fascicle discontinuity between the ATFL and fibula was found in 13.3% with a double-fascicle ATFL; in all of these patients, the form of the CFL was straight and exhibited inferior fascicle discontinuity. The straight form of CFL could be a 3D-MRI sign in the diagnosis of CFL and ATFL inferior fascicle injury.

Comparison of the histological structure of the tibial nerve and its terminal branches in the fresh and fresh-frozen cadavers.

The aim of this study was to compare the histological structure (cross-sectional area [CSA] and number of nerve fascicles) of the distal part of the tibial nerve (TN) and its terminal branches (medial plantar nerve [MPN], lateral plantar nerve [LPN]) in the fresh and fresh-frozen cadavers using computer assisted image analysis. The TNs with terminal branches (MPN and LPN) were dissected from the fresh and fresh-frozen cadavers. Each nerve was harvested 5 mm proximally and respectively 5 mm distally from the TN bifurcation, marked, dehydrated, embedded in paraffin, sectioned at 2 μm slices and stained with haematoxylin and eosin. Then the specimens were photographed and analysed using Olympus cellSens software. The fresh cadavers' group comprised 60 feet (mean age 68.1 ± 15.2 years). The mean CSA and the number of nerve fascicles were respectively 15.25 ± 4.6 mm2, 30.35 ± 8.45 for the TN, 8.76 ± 1.93 mm2, 20.75 ± 7.04 for the MPN and 6.54 ± 2.02 mm2, 13.40 ± 5.22 for the LPN. The fresh-frozen cadavers' group comprised 21 feet (mean age 75.1 ± 9.0 years). The mean CSA and the number of nerve fascicles were respectively 13.71 ± 5.66 mm2, 28.57 ± 8.00 for the TN, 7.55 ± 3.25 mm2, 18.00 ± 6.72 for the MPN and 4.29 ± 1.93 mm2, 11.33 ± 1.93 for the LPN. Only LPNs showed statistical differences in the CSA and the number of nerve fascicles between examined groups (p = 0.000, p = 0.037, respectively). A positive correlation was found between donors age and tibial nerve CSA in the fresh cadavers group (r = 0.44, p = 0.000). A statistical difference was found between the MPN and LPN both in the CSA and the number of nerve fascicles (p < 0.001, p < 0.001, respectively). The CSA and the number of nerve fascicles of the tibial and medial plantar nerves were similar in the fresh and fresh-frozen cadavers whilst different in the LPN. The TN showed increasing CSA with the advanced age in the fresh cadavers. The MPN had larger CSA and more nerve fascicles than the LPN.

A machine learning-based method for estimating the number and orientations of major fascicles in diffusion-weighted magnetic resonance imaging.

Accurate modeling of diffusion-weighted magnetic resonance imaging measurements is necessary for accurate brain connectivity analysis. Existing methods for estimating the number and orientations of fascicles in an imaging voxel either depend on non-convex optimization techniques that are sensitive to initialization and measurement noise, or are prone to predicting spurious fascicles. In this paper, we propose a machine learning-based technique that can accurately estimate the number and orientations of fascicles in a voxel. Our method can be trained with either simulated or real diffusion-weighted imaging data. Our method estimates the angle to the closest fascicle for each direction in a set of discrete directions uniformly spread on the unit sphere. This information is then processed to extract the number and orientations of fascicles in a voxel. On realistic simulated phantom data with known ground truth, our method predicts the number and orientations of crossing fascicles more accurately than several classical and machine learning methods. It also leads to more accurate tractography. On real data, our method is better than or compares favorably with other methods in terms of robustness to measurement down-sampling and also in terms of expert quality assessment of tractography results.

Microanatomic analyses of extratemporal facial nerve and its branches, hypoglossal nerve, sural nerve, and great auricular nerve

ObjectiveTo investigate microanatomic organizations of the extratemporal facial nerve and its branches, hypoglossal nerve, sural nerve, and great auricular nerve. MethodsNerve samples were dissected in 12 postmortem autopsies, and histomorphometric analyses were conducted. ResultsThere was no significant difference between the right and left sides of the nerve samples for the nerve area, fascicle area, number of fascicles and average number of axons. The lowest mean fascicle number was found in the hypoglossal nerve (4.9 ± 1.4) while the highest was in great auricular nerve (11.4 ± 6.8). The highest nerve area (3,182,788 ± 838,430 μm2), fascicle area (1,573,181 ± 457,331 μm2) and axon number (14,772 ± 4402) were in hypoglossal nerve (p < 0.05). The number of axons per unit nerve area was higher in the facial nerve, truncus temporofacialis, truncus cervicofacialis and hypoglossal nerve, which are motor nerves, compared to the sural nerve and great auricular nerve, which are sensory nerves (p < 0.05). The number of axons per unit fascicle area was also higher in motor nerves than in sensory nerves (p < 0.05). ConclusionIn the present study, it was observed that each nerve contained a different number of fascicles and these fascicles were different both in size and in the number of axons they contained. All these variables could be the reason why the desired outcomes cannot always be achieved in nerve reconstruction.

Importance of cone beam computed tomography in the recognition of the trajectory and anatomical variants of the mandibular canal. A review of the literature

The objective of this study was to provide an updated review of the literature on the importance of the use of cone beam computed tomography (CBCT) in the recognition of the trajectory and variants of the mandibular canal (MCV).CBCT allows obtaining high quality images and visualization with an accuracy of approximately 94%, compared to 53% with periapical intraoral radiography (RIP) and 17% with panoramic extraoral radiography (REP), making CBCT an important diagnostic tool.The incidences of MCV in CBCT studies were between 1.3% and 69%, with differences between patients of different ethnic origins and within the same ethnic population, and in the types and configurations of MCV within each ethnic group. The studies available in the literature provide a histological description of the content of MCV. The presence of nerve and artery bundles of different calibers suggests that patients present clinical symptoms only if the neurovascular bundle reaches a certain size and number of fascicles. This review provides a description of the different classifications available and updated with CBCT.

The terminal branch of the posterior interosseous nerve: an anatomic and histologic study.

The aim of this study was to evaluate the terminal branch of the posterior interosseous nerve (PIN) by anatomically and histologically assessing the number, dimension, and area of its individual fascicles, by determining the dimension and area of the whole nerve itself, and by calculating the nerve density ratio (ratio of the sum of the areas of individual fascicles to the area of the whole nerve) of the terminal branch of the PIN. Twenty-eight terminal branches of the PIN nerve samples were collected from patients undergoing partial denervation of the wrist. The nerve samples were fixed in 10% buffered formalin and stained with haematoxylin and eosin to visualise their nerve bundles. Quantitative analysis of individual fascicles and the whole nerve itself were carried out. Ten nerve samples (35.7%) had one single fascicle (group 1) while the remaining 18 nerve samples (64.3%) contained 2-9 fascicles (group 2). The difference in the sum of the areas of individual fascicles between the two groups did not constitute a statistical difference. Statistically significant between-group differences (p < 0.05) were seen in the area of whole nerve, the ratio of fascicle area to the nerve cross-sectional area and the cross-section maximum nerve length and width. The number of nerve fascicles in the terminal branch of the PIN does not affect the overall size of the nerve. The majority of the volume of multi-fascicle nerves, therefore, primarily consists of the internal perineurium. However, due to the low number of nerves, this question cannot be clearly answered. This sets a further direction for further research on a larger group.

Accurate automated diagnosis of carpal tunnel syndrome using radiomics features with ultrasound images: A comparison with radiologists’ assessment

PurposeUltrasonography is the most common imaging modality used to diagnose carpal tunnel syndrome (CTS). Recently artificial intelligence algorithms have been used to diagnose musculoskeletal diseases accurately without human errors using medical images. In this work, a computer-aided diagnosis (CAD) system is developed using radiomics features extracted from median nerves (MN) to diagnose CTS accurately. MethodThis study is performed on 228 wrists from 65 patients and 57 controls, with an equal number of control and CTS wrists. Nerve conduction study (NCS) is considered as the gold standard in this study. Two radiologists used two guides to evaluate and categorize the pattern and echogenicity of MNs. Radiomics features are extracted from B-mode ultrasound images (Ultrasomics), and the robust features are fed into support vector machine classifier for automated classification. The diagnostic performances of two radiologists and the CAD system are evaluated using ROC analysis. ResultsThe agreement of two radiologists was excellent for both guide 1 and 2. The honey-comb pattern clearly appeared in control wrists (based on guide 1). In addition, CTS wrists indicated significantly lower number of fascicles in MNs (based on guide 2). The area under ROC curve (AUC) of the radiologist 1 and 2 are 0.658 and 0.667 based on guide 1 and 0.736 and 0.721 based on guide 2, respectively. The CAD system indicated higher performance than two radiologists with AUC of 0.926. ConclusionThe proposed CAD system shows the benefit of using ultrasomics features and can assist radiologists to diagnose CTS accurately.

Feasibility of Medial Pectoral Nerve to Musculocutaneous Nerve Transfer Using Medial Antebrachial Cutaneous Nerve of Forearm Graft: Histopathologic and Anatomical Evaluation.

To evaluate the compatibility of medial antebrachial cutaneous nerve of the forearm (MACN) with medial pectoral (MPN) and musculocutaneous (MCN) nerves for the anastomosis from anatomical and histopathologic aspects. Ten brachial plexus specimens from five cadavers were dissected. The distances of the distal ends of MPN and MACN and proximal ends of MACN and MCN were measured from coracoid. Histopathologic slides from the four mentioned nerve ends were provided. The number of fascicles, cross-section diameter, and area of each nerve ends were measured. The distance of proximal and distal ends of MACN were adjacent to MPN and MCN. The mean number of fascicles (4.5 ± 1.2 vs. 2.9 ± 1.0), area (6.0 ± 2.5 vs. 2.8 ± 2.4) and diameter (2.7 ± 0.6 vs. 1.8 ± 0.7) of the distal end of MACN was significantly more than MCN. The mean number of fascicles (4.4 ± 1.4 vs. 2.6 ± 0.5), area (5.6 ± 2.4 vs. 2.0 ± 1.0) and diameter (2.6 ± 0.6 vs. 1.6 ± 0.4) of the proximal end of MACN was significantly more than MPN. The mentioned parameters were similar between MCN and MPN. Our study reveals that MACN is not a proper graft for MCN and MCN anastomosis due to the incompatibility of its diameter, area, and number of fascicles.

Cecília Meireles e a revista Távola Redonda: a busca pelo graal da poesia

A revista Távola Redonda circulou em Portugal entre 15 de janeiro de 1950 e julho de 1954, e teve David Mourão-Ferreira como um dos principais nomes à sua frente. Esboçando uma reação ao neorrealismo e ecoando dis­cursos manifestados na antecessora revista Presença, reivindicava uma literatura pautada pela subjetividade e pela expressão individual do au­tor. A publicação estabeleceu, assim, uma clara oposição aos neorrealistas que priorizavam uma poesia comprometida com seu momento histórico e social, ou seja, acima das nuances do “eu”. Nesse contexto e inserido no meio literário português, surge o nome de Cecília Meireles, que integrou esse rol de poetas “acolhidos” com simpatia e, mais do que isso, admiração pelas páginas da Távola. O fascículo número 12, de 29 de fevereiro de 1952, publicou quatro poemas que apareceram com o título de “Poesias inédi­tas”, além de um texto crítico, “Cecília Meireles, acerca da sua poesia”, de autoria de David Mourão-Ferreira. Dessa forma, destacam-se as forças motrizes da publicação e as proximidades que levaram a poeta brasileira a figurar na revista, salientando-se a importância de sua participação no periódico e o diálogo luso-brasileiro ali estabelecido.

Quantified Morphology of the Cervical and Subdiaphragmatic Vagus Nerves of Human, Pig, and Rat.

It is necessary to understand the morphology of the vagus nerve (VN) to design and deliver effective and selective vagus nerve stimulation (VNS) because nerve morphology influences fiber responses to electrical stimulation. Specifically, nerve diameter (and thus, electrode-fiber distance), fascicle diameter, fascicular organization, and perineurium thickness all significantly affect the responses of nerve fibers to electrical signals delivered through a cuff electrode. We quantified the morphology of cervical and subdiaphragmatic VNs in humans, pigs, and rats: effective nerve diameter, number of fascicles, effective fascicle diameters, proportions of endoneurial, perineurial, and epineurial tissues, and perineurium thickness. The human and pig VNs were comparable sizes (∼2 mm cervically; ∼1.6 mm subdiaphragmatically), while the rat nerves were ten times smaller. The pig nerves had ten times more fascicles—and the fascicles were smaller—than in human nerves (47 vs. 7 fascicles cervically; 38 vs. 5 fascicles subdiaphragmatically). Comparing the cervical to the subdiaphragmatic VNs, the nerves and fascicles were larger at the cervical level for all species and there were more fascicles for pigs. Human morphology generally exhibited greater variability across samples than pigs and rats. A prior study of human somatic nerves indicated that the ratio of perineurium thickness to fascicle diameter was approximately constant across fascicle diameters. However, our data found thicker human and pig VN perineurium than those prior data: the VNs had thicker perineurium for larger fascicles and thicker perineurium normalized by fascicle diameter for smaller fascicles. Understanding these differences in VN morphology between preclinical models and the clinical target, as well as the variability across individuals of a species, is essential for designing suitable cuff electrodes and stimulation parameters and for informing translation of preclinical results to clinical application to advance the therapeutic efficacy of VNS.

Donor nerve graft assessment for covering thumb nerve defects: a cadaveric study

BackgroundEven though several studies reported donor autologous nerve grafts for digital nerve defects, there is no report in the literature regarding acceptable graft for thumb nerves. The purpose of this study is to provide guidelines for autologous nerve graft selection by detecting similarities between thumb nerve zones and donor nerve with regard to the number of fascicles and cross-sectional area.Materials and methods Five cadavers were used in this study. An anatomical zoning system was defined for thumb nerves (zones 1, 2, 3). Sural nerve (SN), medial antebrachial cutaneous nerve (MABCN), lateral antebrachial cutaneous nerve (LABCN), posterior interosseous nerve (PIN), and anterior interosseous nerve (AIN) were selected as donor nerve grafts. The number of fascicles and surface area (mm2) was defined.ResultsThe mean of the fascicle number in zone 1, zone 2, zone 3, AIN, PIN, LABCN, MABCN, and SN were 3.8, 4.7, 6.1, 2.2, 1.8, 4.5, 3.1, and 6.4, respectively. The mean of the surface area in zone 1, zone 2, zone 3, AIN, PIN, LABCN, MABCN, and SN were 2.19, 6.26, 4.04, 1.58, 0.71, 5.00, 3.01, and 8.06, respectively.ConclusionsLABCN is the best choice for all zones that has fascicular matching with all three zones of thumb nerves and caliber matching with zones 2 and 3. In zone 1, the best nerve graft is MABCN which has both suitable caliber and fascicle count.

A New Synthetic Conduit for the Treatment of Peripheral Nerve Injuries

BackgroundPeripheral nerve defects (PND) often cause lifelong physical disability, and the available treatment options are often not satisfactory. PND are usually bridged with an autologous nerve transplant or a nerve guidance conduit (NGC), when coaptation as preferred technique is not possible. The aim of this experimental study was to determine the effectiveness of a novel NGC for regeneration in the treatment of PND.Materials and methodsA conduit made of gelatin with an innovative interior structure was tested for the repair of a 6-mm gap versus direct microsurgical suture repair without gap.ResultsWe found that bridging the defect with this conduit was as effective as direct microsurgical coaptation without a defect.ConclusionsThis nerve conduit, effective in bridging neural defects, appears as an alternative to autologous nerve grafts, avoiding the problems related to nerve graft harvesting, host–donor differences in diameter, mismatches in number and pattern of fascicles, cross-sectional shape and area, and morbidity of the donor area.

Functional vagotopy in the cervical vagus nerve of the domestic pig: implications for the study of vagus nerve stimulation

Objective. Given current clinical interest in vagus nerve stimulation (VNS), there are surprisingly few studies characterizing the anatomy of the vagus nerve in large animal models as it pertains to on-and off-target engagement of local fibers. We sought to address this gap by evaluating vagal anatomy in the pig, whose vagus nerve organization and size approximates the human vagus nerve. Approach. Here we combined microdissection, histology, and immunohistochemistry to provide data on key features across the cervical vagus nerve in a swine model, and compare our results to other animal models (mouse, rat, dog, non-human primate) and humans. Main results. In a swine model we quantified the nerve diameter, number and diameter of fascicles, and distance of fascicles from the epineural surface where stimulating electrodes are placed. We also characterized the relative locations of the superior and recurrent laryngeal branches of the vagus nerve that have been implicated in therapy limiting side effects with common electrode placement. We identified key variants across the cohort that may be important for VNS with respect to changing sympathetic/parasympathetic tone, such as cross-connections to the sympathetic trunk. We discovered that cell bodies of pseudo-unipolar cells aggregate together to form a very distinct grouping within the nodose ganglion. This distinct grouping gives rise to a larger number of smaller fascicles as one moves caudally down the vagus nerve. This often leads to a distinct bimodal organization, or ‘vagotopy’. This vagotopy was supported by immunohistochemistry where approximately half of the fascicles were immunoreactive for choline acetyltransferase, and reactive fascicles were generally grouped in one half of the nerve. Significance. The vagotopy observed via histology may be advantageous to exploit in design of electrodes/stimulation paradigms. We also placed our data in context of historic and recent histology spanning multiple models, thus providing a comprehensive resource to understand similarities and differences across species.

Transfert du nerf obturateur vers le nerf tibial au moyen d’une greffe de nerf saphène pour le traitement des avulsions du plexus sacré : étude cadavérique

IntroductionIn cases of sacral nerve avulsion injuries, proximal nerve stumps are not available because of its protected position in pelvis, and results of nerve repair or graft are unsatisfactory. Nerve transfer can reduce the regeneration time and improve the results of recovery. HypothesisThe obturator nerve transfer to the tibial nerve via saphenous nerve graft is possible and feasible. Materials and methodsTen male adult cadaveric lower limbs dissected to identify the location of the anterior branch of obturator nerve, the saphenous nerve and the medial gastrocnemius branch. The saphenous nerve was cut from its origin and transferred to the anterior branch of obturator nerve. As well, it was cut distally and transferred to the medial gastrocnemius branch. After nerve coaptation, surface area and fascicle count were determined by histological methods. ResultsIn all limbs, the proximal and distal stumps of saphenous nerve were reached the anterior branch of obturator and the medial gastrocnemius branch, respectively without tension. The mean of fascicle number in the anterior branch of obturator nerve, proximal and distal stump of the saphenous nerve and stump of medial gastrocnemius nerve branch were 2.90±0.99, 4.50±2.70, 4.00±2.26 and 4.30±1.25, respectively. DiscussionThis study showed that it is possible to transfer the obturator nerve to the medial gastrocnemius branch via saphenous nerve bridge; and their histological parameters are match in a good manner. Therefore, this technique is suggested for patients with sacral nerve avulsion injuries. Level of evidenceIV, case series of cadaveric study.

Obturator to tibial nerve transfer via saphenous nerve graft for treatment of sacral plexus root avulsions: A cadaveric study

IntroductionIn cases of sacral nerve avulsion injuries, proximal nerve stumps are not available because of its protected position in pelvis, and results of nerve repair or graft are unsatisfactory. Nerve transfer can reduce the regeneration time and improve the results of recovery. HypothesisThe obturator nerve transfer to the tibial nerve via saphenous nerve graft is possible and feasible. Materials and methodsTen male adult cadaveric lower limbs dissected to identify the location of the anterior branch of obturator nerve, the saphenous nerve and the medial gastrocnemius branch. The saphenous nerve was cut from its origin and transferred to the anterior branch of obturator nerve. As well, it was cut distally and transferred to the medial gastrocnemius branch. After nerve coaptation, surface area and fascicle count were determined by histological methods. ResultsIn all limbs, the proximal and distal stumps of saphenous nerve were reached the anterior branch of obturator and the medial gastrocnemius branch, respectively without tension. The mean of fascicle number in the anterior branch of obturator nerve, proximal and distal stump of the saphenous nerve and stump of medial gastrocnemius nerve branch were 2.90±0.99, 4.50±2.70, 4.00±2.26 and 4.30±1.25, respectively. DiscussionThis study showed that it is possible to transfer the obturator nerve to the medial gastrocnemius branch via saphenous nerve bridge; and their histological parameters are match in a good manner. Therefore, this technique is suggested for patients with sacral nerve avulsion injuries. Level of evidenceIV, case series of cadaveric study.

Intramuscular pathway and fascicular characteristics of the segmental intercostal innervation to rectus abdominis.

Rectus abdominis is a muscle that is commonly used clinically as a muscle flap, especially in reconstructive surgery. Its intramuscular innervation, however, has rarely been examined in detail or accurately mapped. The purpose of this study was to use biopsied, histological specimens complemented with a staining technique to investigate intramuscular nerve connections and distribution of the rectus abdominis. Four fresh human cadavers were included in the study and rectus abdominis was dissected bilaterally. Nerve sections innervating the rectus abdominis were biopsied and histologically processed. Sections were viewed under the microscope, and axons within each fascicle were counted using imaging software. All specimens were stained with a modified Sihler's staining technique. Intramuscular innervation was observed and the number as well as distribution was recorded. Macroscopically stained specimens showed that the eighth, ninth, 10th and 12th intercostal nerves innervated the eight muscle bellies of rectus abdominis. The greatest number of minor nerve branching as well as intramuscular nerve communications originated from nerve roots T9 and T10. Minor nerve branches crossed tendinous intersections to communicate with adjacent nerves and innervate adjacent muscle bellies. Nerves originating from T9 had the greatest number of nerve fascicles and the highest axon count in each cadaver. The rectus abdominis is divided into four compartments with each receiving its own independent nerve supply. Minor nerve branches crossed tendinous intersections to communicate with adjacent muscle bellies and nerves suggesting that rectus abdominis can be used as a whole in innervated free flap transfer procedures.