Major Nerve Research Articles

An Anatomic Appraisal of Biplanar Muscle-Splitting Breast Augmentation.

Biplanar muscle-splitting (BMS) breast augmentation is a relatively new technique for which the safe regions of dissection have not been delineated. The authors performed cadaver dissections to elucidate the surgical anatomy of the BMS pocket and to infer the safety of this method. The breasts and chest regions of 5 female cadavers were dissected to identify anatomic landmarks and to ascertain the optimal split site in the pectoralis major. CS was defined as the lateral junction of the middle and caudal one-third of the sternum, and the sternal index was defined as the ratio of the length of the sternum to the distance from CS to the most medial major nerve branch. Initiating the muscle split at CS is likely to avoid nerve injury. The mean distance from CS to the most medial nerve branch was 15.36 cm. The sternal index is a reproducible marker of the extension of the nerve branches in relation to chest size. The sternal length and the cranio-caudal length of the pectoralis major were similar, enabling reliable planning of the muscle split site. If dissection is limited to the safe regions delineated herein, BMS breast augmentation is likely to be a safe procedure for most patients. By maintaining the connections between the pectoralis major and its origins, a breast deformity associated with muscle contraction may be avoidable.

Obstacles to the Care of Patients With Multicomponent Volar Wrist Lacerations at a County Hospital.

Multicomponent volar wrist lacerations of "spaghetti wrist" injuries are devastating injuries of the upper extremity. These patients require long-term commitment to rehabilitation. Patients presenting to our county hospital represent a unique and complex patient population in terms of psychosocial considerations. We aimed to identify obstacles to care and optimal recovery in this patient population. A patient database was queried for ICD-9 codes related to major upper extremity nerve injuries, which were treated by plastic surgery faculty at San Francisco General Hospital from 2008 to 2014. A retrospective chart review was performed to identify patients with spaghetti wrist injuries. Charts were reviewed for patient demographics including age, occupation, handedness, psychiatric illness, isolated versus polytrauma, and employment status. Injuries were categorized for mechanism of injury, structures involved, and timing and method of surgical treatment. Outcomes were assessed for motor recovery, sensory recovery, and tendon function. We identified 18 patients with multicomponent volar wrist lacerations. Average patient age was 31 years. The most common mechanism of injury was accidental/work-related (n = 9, 50%), followed by self-inflicted (n = 4, 22%). Thirty-nine percent (n = 7) of patients had a psychiatric diagnosis, most commonly depression (n = 4, 22%). Eighty-nine percent (n = 16) of patients had an isolated injury to the upper extremity, and 39% (n = 7) had an injury to the dominant hand. Fifty percent (n = 9) of patients were lost to follow-up, with 28% (n = 5) having no known care plan. Motor, sensory, and tendon function outcomes for those with adequate follow-up were comparable to previously published studies. Multicomponent volar wrist lacerations can be devastating, and although we are able to provide patients with appropriate timely surgical care, these patients require long-term care far beyond the operating room for optimal outcomes. Psychiatric illness, socioeconomic limitations, poor patient compliance, and irregular follow-up are obstacles to care. These issues highlight the need for better social support systems and mental health care to provide access to the services necessary to optimize recovery.

Microstimulation of the lumbar DRG recruits primary afferent neurons in localized regions of lower limb.

Patterned microstimulation of the dorsal root ganglion (DRG) has been proposed as a method for delivering tactile and proprioceptive feedback to amputees. Previous studies demonstrated that large- and medium-diameter afferent neurons could be recruited separately, even several months after implantation. However, those studies did not examine the anatomical localization of sensory fibers recruited by microstimulation in the DRG. Achieving precise recruitment with respect to both modality and receptive field locations will likely be crucial to create a viable sensory neuroprosthesis. In this study, penetrating microelectrode arrays were implanted in the L5, L6, and L7 DRG of four isoflurane-anesthetized cats instrumented with nerve cuff electrodes around the proximal and distal branches of the sciatic and femoral nerves. A binary search was used to find the recruitment threshold for evoking a response in each nerve cuff. The selectivity of DRG stimulation was characterized by the ability to recruit individual distal branches to the exclusion of all others at threshold; 84.7% (n = 201) of the stimulation electrodes recruited a single nerve branch, with 9 of the 15 instrumented nerves recruited selectively. The median stimulation threshold was 0.68 nC/phase, and the median dynamic range (increase in charge while stimulation remained selective) was 0.36 nC/phase. These results demonstrate the ability of DRG microstimulation to achieve selective recruitment of the major nerve branches of the hindlimb, suggesting that this approach could be used to drive sensory input from localized regions of the limb. This sensory input might be useful for restoring tactile and proprioceptive feedback to a lower-limb amputee.

Ultrasound and gross anatomy of the brachial plexus and major nerves of the forelimb. An anesthetic approach using the domestic rabbit (Oyctolagus cuniculus) as an experimental model1.

To update the gross and sonographic anatomy and propose landmarks to perform ultrasound-guided (US-guided) axillary brachial plexus block (BPB) in rabbits. Forty New Zeeland's rabbit (NZR) cadavers were dissected and the nerves were trimmed, identified, measured, and photographed. Additionally, in twenty NZRs, sonographic images of brachial plexus (BP) were performed through a simple-resolution ultrasound device. The US-guided block was achieved through a minimum volume of lidocaine necessary to surround the BP roots. The effectiveness of the brachial plexus block was assessed on sensitivity and motor functions. The BP resulted from connections between the ventral branches of the last four cervical spinal nerves and the first thoracic spinal nerve. In the axillary sonoanatomy, the BP appeared as an agglomerate of small, round hypoechoic structures surrounded by a thin hyperechoic ring. The amount of time and the minimum volume required to perform was 4.3 ± 2.3 min and 0.8 ± 0.3ml, respectively. The gross and sonographic anatomy of the BP showed uncommon morphological variations. Moreover, from sonographic landmarks, we showed complete reproducibility of the axillary US-guided brachial plexus block with simple resolution equipment and small volume of anesthetics required.

Laparoscopic Omohyoid Muscle Transection Surgery

Laparoscopic Omohyoid Muscle Transection Surgery

EUS - Fine- Needle Aspiration Biopsy (FNAB) in the Diagnosis of Pancreatic Adenocarcinoma: A Review.

Solid masses of the pancreas represent a variety of benign and malignant neoplasms of the exocrine and endocrine tissues of the pancreas. A tissue diagnosis is often required to direct therapy in the face of uncertain diagnosis or if the patient is not a surgical candidate either due to advanced disease or comorbidities. Endoscopic ultrasound (EUS) is a relatively new technology that employs endoscopy and high-frequency ultrasound (US). EUS involves imaging of the pancreatic head and the uncinate from the duodenum and imaging of the body and tail from the stomach. It has been shown to be a highly sensitive method for the detection of pancreatic masses. It is superior to extracorporeal US and computed tomographic (CT) scans, especially when the pancreatic tumor is smaller than 2-3 cm. Although EUS is highly sensitive in detecting pancreatic solid masses, its ability to differentiate between inflammatory masses and malignant disease is limited. Endoscopic retrograde cholangiopancreatography (ERCP) brushing, CT-guided biopsies, and transabdominal ultrasound (US) have been the standard nonsurgical methods for obtaining a tissue diagnosis of pancreatic lesions, but a substantial false-negative rate has been reported. Transabdominal US-guided fine-needle aspiration biopsy (US-FNAB) has been used for tissue diagnosis in patients with suspected pancreatic carcinoma. It has been shown to be highly specific, with no false-positive diagnoses. With the advent of curvilinear echoendoscopes, transgastric and transduodenal EUS-FNAB of the pancreas have become a reality EUS with FNAB has revolutionized the ability to diagnose and stage cancers of the gastrointestinal tract and assess the pancreas. Gastrointestinal cancers can be looked at with EUS and their depth of penetration into the intestinal wall can be determined. Any suspicious appearing lymph nodes can be biopsied using EUS/FNAB. The pancreas is another organ that is well visualized with EUS. Abnormalities such as tumors and cysts of the pancreas can be carefully evaluated using EUS and then biopsied with FNAB. There are many new applications of EUS using FNAB. Researchers are looking to deliver chemotherapeutics into small pancreatic cancers and cysts. Nerve blocks using EUS/FNAB to inject numbing medicines into the celiac ganglia, a major nerve cluster, are now routinely performed in patients with pain due to pancreatic cancer. The aim of this study is to perform a review of the literature regarding the usefulness of EUS/FNAB in the diagnosis of pancreatic adenocarcinoma.

Treatment of acetabular fractures involving the anterior column through the paramedian approach

Objective To explore the surgical techniques and clinical efficacy of the paramedian approach in the treatment of acetabular fractures involving the anterior column. Methods From August 2013 to December 2014, 56 patients with acetabular fracture were treated through the paramedian approach. They were 34 men and 22 women, aged from 29 to 58 years (average, 38 years) . According to Letournel-Judet classification, 12 cases were anterior column fracture, 18 cases fracture of anterior column plus posterior hemitransverse, 9 cases transverse fracture, 6 cases T-shape fracture, and 11 cases both column fracture. All patients were treated by open reduction and internal fixation through the paramedian approach after general anesthesia. After an abdominal midline longitudinal incision was made, the rectus abdominis anterior sheath was cut longitudinally 2-3 cm para-linea alba. After the rectus abdominis was retracted to the lesion side, the rectus abdominis posterior sheath was cut to expose the deep pelvic fracture. In the 12 patients who had been complicated with iliac wing fracture, an additional iliac fossa approach was used. Results The mean surgical time was 105 min (range, from 96 to 188 min) ; the mean blood lose was 400 mL (range, from 200 to 800 mL) ; red cell transfusion was 2.4 units (range, from 0 to 4 units) . The 56 patients were followed up for an average of 16 months (range, from 6 to 22 months) . According to the Matta's fracture reduction assessment, 38 cases were excellent, 11 good, 4 fair, and 3 poor, giving a good-to-excellent rate of 87.5%. All factures healed within 3 months. According to the modified Merle d'Aubigne & Postel scoring at the end of follow-up, the hip joint function was rated as excellent in 34 cases, good in 12, fair in 6 and poor in 4, giving a good-to-excellent rate of 82.1%. No abdominal wall hernias, wound infection or injury to major nerves or vessels was observed during follow-up. Conclusions In the treatment of acetabular fractures involving the anterior column, the paramedian approach can fully reveal anterior wall, anterior column and posterior column of the acetabulum. It is easy to handle and unlikely to injure major vessels and nerves. It also leads to less blood loss. This approach can be used for the majority of acetabular fractures involving the anterior column. Key words: Acetabulum; Fractures, bone; Fracture fixation, internal; Paramedian approach

Major Peripheral Nerve Injuries After Elbow Arthroscopy

To survey the American Society for Surgery of the Hand membership to determine the nature and distribution of nerve injuries treated after elbow arthroscopy. An online survey was sent to all members of the American Society for Surgery of the Hand under an institutional review board-approved protocol. Collected data included the number of nerve injuries observed over a 5-year period, the nature of treatment required for the injuries, and the outcomes observed after any intervention. Responses were anonymous, and results were securely compiled. We obtained 372 responses. A total of 222 nerve injuries were reported. The most injured nerves reported were ulnar, radial, and posterior interosseous (38%, 22%, and 19%, respectively). Nearly half of all patients with injuries required operative intervention, including nerve graft, tendon transfer, nerve repair, or nerve transfer. Of the patients who sustained major injuries, those requiring intervention, 77% had partial or no motor recovery. All minor injuries resolved completely. Our results suggest that major nerve injuries after elbow arthroscopy are not rare occurrences and the risk of these injuries is likely under-reported in the literature. Furthermore, patients should be counseled on this risk because most nerve injuries show only partial or no functional recovery. With the more widespread practice of elbow arthroscopy, understanding the nature and sequelae of significant complications is critically important in ensuring patient safety and improving outcomes.

Risk of nerve injury during arthroscopy portal placement in the elbow joint: A cadaveric study.

Background:Elbow arthroscopy has become a routine procedure now. However, placing portals is fraught with dangers of injuring the neurovascular structures around elbow. There are not enough data documenting the same amongst the Indians. We aimed to determine the relative distances of nerves around the elbow to the arthroscopy portals and risk of injury in different positions of the elbow.Materials and Methods:Six standard elbow arthroscopy portals were established in 12 cadaveric upper limbs after joint distension. Then using standard dissection techniques all the nerves around the elbow were exposed, and their distances from relevant portals were measured using digital vernier caliper in 90° elbow flexion and 0° extension. Descriptive statistical analysis was used for describing distance of the nerves from relevant portal. Wilcoxon-signed rank test and Friedman's test were used for comparison.Results:There was no major nerve injury at all the portals studied in both positions of the elbow. The total incidence of cutaneous nerve injury was 8.3% (12/144); medial cutaneous nerve of forearm 10/48 and posterior cutaneous nerve of forearm 2/24. No significant changes were observed in the distance of a nerve to an individual portal at 90° flexion or 0° extension position of the elbow.Conclusion:This study demonstrates the risk of injury to different nerves at the standard portals of elbow arthroscopy. In practice, the actual incidence of nerve injury may still be lower. We conclude that elbow arthroscopy is a safe procedure when all precautions as described are duly followed.

Radiofrequency Procedures to Relieve Chronic Knee Pain

Chronic knee pain from osteoarthritis or following arthroplasty is a common problem. A number of publications have reported analgesic success of radiofrequency (RF) procedures on nerves innervating the knee, but interpretation is hampered by lack of clarity regarding indications, clinical protocols, targets, and longevity of benefit from RF procedures. We reviewed the following medical literature databases for publications on RF procedures on the knee joint for chronic pain: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Google Scholar up to August 9, 2015. Data on scores for pain, validated scores for measuring physical disability, and adverse effects measured at any timepoint after 1 month following the interventions were collected, analyzed, and reported in this narrative review. Thirteen publications on ablative or pulsed RF treatments of innervation of the knee joint were identified. A high success rate of these procedures in relieving chronic pain of the knee joint was reported at 1 to 12 months after the procedures, but only 2 of the publications were randomized controlled trials. There was evidence for improvement in function and a lack of serious adverse events of RF treatments. Radiofrequency treatments on the knee joint (major or periarticular nerve supply or intra-articular branches) have the potential to reduce pain from osteoarthritis or persistent postarthroplasty pain. Ongoing concerns regarding the quality, procedural aspects, and monitoring of outcomes in publications on this topic remain. Randomized controlled trials of high methodological quality are required to further elaborate role of these interventions in this population.

Surgical Techniques for operating on Large Adherent Cervical Nodal Metastases from Thyroid Cancer causing Severe Neck Pain and Compression Effects and encasing Major Vessels

ABSTRACT Aim We aim to refine and define surgical techniques for doing difficult adherent bulky cervical nodal metastases from thyroid cancer to help surgeons do dissections with better curability and lesser morbidity. Background Patients with thyroid cancer with large nodal metastases presenting with severe neck pain due to compression effects and encasing carotid artery and other major vessels pose a challenge to surgeons to do complete resections while preserving important structures in the neck. Materials and methods We define surgical planning and road map to dissect difficult bulky adherent cervical nodes encasing carotid artery and jugular vein by splaying the plane over carotid sheath by doing adventitial level dissection and dissecting medial and lateral to carotid sheath the large nodal mass adherent to adjacent structures preserving the major vessels and nerve plexus. Conclusion By appropriate surgical planning and meticulous dissection techniques, we can do major neck dissections with complete resections and same time preserving important structures in the neck minimizing morbidity. Clinical significance: By doing neck dissections with complete oncological resections and saving vital structures in the neck, we aim to offer best possible chance of cure to the patient along with reduced morbidity at same time. How to cite this article Ramakant P, Singh KR, Rana C, Mishra AK. Surgical Techniques for operating on Large Adherent Cervical Nodal Metastases from Thyroid Cancer causing Severe Neck Pain and Compression Effects and encasing Major Vessels. World J Endoc Surg 2016;8(3):217-219.

Morphological and morphometric analysis of the distal branches of the rat brachial plexus

The rat brachial plexus has gained interest recently in neuro-regenerative research due to the advancement of neurosurgical equipment and techniques, but moreover in that it provides a model that can closely resemble the common peripheral nerve injuries seen in humans. The aim of this study was to provide a systematic baseline quantification for fibre type and morphology of the major terminal nerve branches of the rat brachial plexus (radial, ulnar and median) at four surgically accessible sites, through the forelimb. We applied a microstructural and immunohistological analysis of 12 rat brachial plexuses using three forms of micro-visualisation: electron microscopy; whole mount; and immunohistology. The three distal nerves studied showed a similar patterning in terms of the number and size of myelinated fibres, with all proportionally decreasing when moving distally. The fibre types of both the median and ulnar nerve appeared to be homogenously mixed throughout their trajectory, while the radial nerve had a more distinct patterning, especially distal to the elbow, with the entire nerve’s main branch appearing to consist of sensory fibres only. Our microstructural analysis of the rat brachial plexus provides important normative reference data for future peripheral nerve research using the forelimb of the rat.

Non-Invasive Targeted Peripheral Nerve Ablation Using 3D MR Neurography and MRI-Guided High-Intensity Focused Ultrasound (MR-HIFU): Pilot Study in a Swine Model.

PurposeUltrasound (US)-guided high intensity focused ultrasound (HIFU) has been proposed for noninvasive treatment of neuropathic pain and has been investigated in in-vivo studies. However, ultrasound has important limitations regarding treatment guidance and temperature monitoring. Magnetic resonance (MR)-imaging guidance may overcome these limitations and MR-guided HIFU (MR-HIFU) has been used successfully for other clinical indications. The primary purpose of this study was to evaluate the feasibility of utilizing 3D MR neurography to identify and guide ablation of peripheral nerves using a clinical MR-HIFU system.MethodsVolumetric MR-HIFU was used to induce lesions in the peripheral nerves of the lower limbs in three pigs. Diffusion-prep MR neurography and T1-weighted images were utilized to identify the target, plan treatment and immediate post-treatment evaluation. For each treatment, one 8 or 12 mm diameter treatment cell was used (sonication duration 20 s and 36 s, power 160–300 W). Peripheral nerves were extracted < 3 hours after treatment. Ablation dimensions were calculated from thermal maps, post-contrast MRI and macroscopy. Histological analysis included standard H&E staining, Masson’s trichrome and toluidine blue staining.ResultsAll targeted peripheral nerves were identifiable on MR neurography and T1-weighted images and could be accurately ablated with a single exposure of focused ultrasound, with peak temperatures of 60.3 to 85.7°C. The lesion dimensions as measured on MR neurography were similar to the lesion dimensions as measured on CE-T1, thermal dose maps, and macroscopy. Histology indicated major hyperacute peripheral nerve damage, mostly confined to the location targeted for ablation.ConclusionOur preliminary results indicate that targeted peripheral nerve ablation is feasible with MR-HIFU. Diffusion-prep 3D MR neurography has potential for guiding therapy procedures where either nerve targeting or avoidance is desired, and may also have potential for post-treatment verification of thermal lesions without contrast injection.

Detailed reconstruction of the nervous and muscular system of Lobatocerebridae with an evaluation of its annelid affinity.

BackgroundThe microscopic worm group Lobatocerebridae has been regarded a ‘problematicum’, with the systematic relationship being highly debated until a recent phylogenomic study placed them within annelids (Curr Biol 25: 2000-2006, 2015). To date, a morphological comparison with other spiralian taxa lacks detailed information on the nervous and muscular system, which is here presented for Lobatocerebrum riegeri n. sp. based on immunohistochemistry and confocal laser scanning microscopy, supported by TEM and live observations.ResultsThe musculature is organized as a grid of longitudinal muscles and transverse muscular ring complexes in the trunk. The rostrum is supplied by longitudinal muscles and only a few transverse muscles. The intraepidermal central nervous system consists of a big, multi-lobed brain, nine major nerve bundles extending anteriorly into the rostrum and two lateral and one median cord extending posteriorly to the anus, connected by five commissures. The glandular epidermis has at least three types of mucus secreting glands and one type of adhesive unicellular glands.ConclusionsNo exclusive “annelid characters” could be found in the neuromuscular system of Lobatocerebridae, except for perhaps the mid-ventral nerve. However, none of the observed structures disputes its position within this group. The neuromuscular and glandular system of L. riegeri n. sp. shows similarities to those of meiofaunal annelids such as Dinophilidae and Protodrilidae, yet likewise to Gnathostomulida and catenulid Platyhelminthes, all living in the restrictive interstitial environment among sand grains. It therefore suggests an extreme evolutionary plasticity of annelid nervous and muscular architecture, previously regarded as highly conservative organ systems throughout metazoan evolution.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-015-0531-x) contains supplementary material, which is available to authorized users.

Telltale signs of peripheral neurogenic tumors on magnetic resonance imaging.

Peripheral nerve sheath tumors are categorized into benign and malignant forms, comprising of neurofibroma and schwannoma in the benign category and malignant peripheral nerve sheath tumors in the malignant category. Magnetic resonance imaging plays an important role in the diagnosis of these lesions. The various imaging features and signs that help to identify and characterize a nerve sheath tumor are, distribution of the tumor along a major nerve, an entering or exiting nerve sign, target sign, a fascicular sign and a split-fat sign.

Relationship Between the Superior Gluteal Vessels and Nerve at the Greater Sciatic Notch.

Bleeding from the superior gluteal (SG) blood vessels at the greater sciatic notch is frequently encountered during acetabular fracture surgery. The purpose of this study is to define the positional anatomy of the superior gluteal vessels and nerve (SGVAN) at the greater sciatic notch. Twenty-three hemipelvi were dissected in whole human cadavers. The greater sciatic notch and SGVAN were visualized via a posterior surgical approach, identified deep in the greater sciatic notch, and traced superficially. Branches of the SGVAN and their anatomical relationship to each other were recorded. In the notch, SG arteries comprised a single vessel in 18 (78%) of 23 specimens, with all of these dividing at varying distances (1-3.5 cm) along the lateral ilium after dividing into superior and inferior branches. The SG artery branches were contiguous with periosteum of the bony notch in all specimens. More than 1 SG nerve branch was seen in the greater sciatic notch of all specimens, including an inferior branch that exited caudal or caudal-superficial to the SG vessels. The caudal-most SG nerve branch was directly adjacent to the bony notch's periosteum in 15 (65%) of 23 specimens. The SGVAN are at risk in patients undergoing acetabular fracture surgery. Individuals performing surgery along the acetabulum's posterior column would expect to encounter a major SG nerve branch (deep inferior) before encountering the SG vessels in all cases. Iatrogenic injuries to the SGVAN might be prevented by avoiding use of cautery in this area if hemorrhage is encountered.

A Systematic Review of Contralateral C7 Transfer for the Treatment of Traumatic Brachial Plexus Injury: Part 1. Overall Outcomes.

Contralateral C7 (CC7) transfer has been used for treating traumatic brachial plexus injury. However, the effectiveness of the procedure remains a subject of debate. The authors performed a systematic review to study the overall outcomes of CC7 transfer to different recipient nerves in traumatic brachial plexus injuries. A literature search was conducted using PubMed and EMBASE databases to identify original articles related to CC7 transfer for traumatic brachial plexus injury. The data extracted were study/patient characteristics, and objective outcomes of CC7 transfer to the recipient nerves. The authors normalized outcome measures into a Medical Research Council-based (MRC) outcome scale. Thirty-nine studies were identified. The outcomes were categorized based on the major recipient nerves: median, musculocutaneous, and radial/triceps. Regarding overall functional recovery, 11 percent of patients achieved MRC grade M4 wrist flexion and 38 percent achieved MRC grade M3. Grade M4 finger flexion was achieved by 7 percent of patients, whereas 36 percent achieved M3. Finally, 56 percent achieved greater than or equal to S3 sensory recovery in the median nerve territories. In the musculocutaneous nerve group, 38 percent regained to M4 and 37 percent regained to M3. In the radial/triceps nerve group, 25 percent regained elbow or wrist extension strength to a MRC grade M4 and to M3, respectively. Outcome measures in the included studies were not consistently reported to uncover true patient-related benefits from the CC7 transfer. Reliable and validated outcome instruments should be applied to critically evaluate patients undergoing CC7 transfer.

Histologic features and fascicular arrangement of the inferior alveolar nerve

ObjectivesKnowledge of the various possible morphologies and courses of the inferior alveolar nerve and artery is important for successful and safe surgical procedures in the mandibular region. The purpose of this study was to verify the histologic features and fascicular arrangement of the inferior alveolar nerve and artery relative to tooth region. Materials and methodsTwenty embalmed dentulous hemimandibles were examined (eight males and two females; mean age, 58.2 years). The hemimandibles were prepared for routine histology and stained with hematoxylin–eosin and Masson’s trichrome. The histologic features, fascicular arrangement, courses, and areas of the inferior alveolar nerve and artery were investigated with the aid of a light microscope. ResultsThe inferior alveolar neurovascular bundle comprised the inferior alveolar nerve, which appeared as a large trunk comprising two major nerves (the mental and dental nerves), and the inferior alveolar artery, which occupied a relatively small portion of the bundle. The mental nerve was located inferolingually in the third molar region and turned to the buccal side in the first molar region, separating from the dental nerve before reaching the mental foramen. The mandibular incisive canal with a bony wall was not found in the lateral incisor region; instead, small dental nerve fascicles and arteries presented consistently in the intertrabecular spaces. The inferior alveolar artery traveled above the inferior alveolar nerve over the entire mandibular canal. ConclusionsThese results provide data that are relevant to treatment planning for operative procedures such as implant placement, endodontic treatment, and osteotomy in the mandibular region.

A computed tomography-based morphometric study of the styloid process.

The styloid process (SP) refers to a cylindrical piece projecting from the inferior of the temporal bone, situated anterior to the stylomastoid foramen. It is an anatomic formation close to major vessels and nerves, and its excessive elongation results in pathologies leading to anatomical disorders, such as Eagle's syndrome. Several studies have been conducted on SP in relation to its close proximity to vessels and nerves, but there is no study that reveals its distance to important anatomical formations, such as the internal auditory meatus (IAM), carotid canal (CC), cochlea, tegmen tympani (TT) and tragus. In the current study, we aimed to investigate the incidence of Eagle's syndrome based on morphometric measurements of SP. The patient files archived in the Radiology Department of Adiyaman University Training and Research Hospital were retrospectively examined. The study was carried out on the data of patients for whom specialist radiologists found no pathology findings on the computed tomography images. A total of 77 individuals (36 females and 41 males) aged 22 to 54 years were included in the study. The length of SP and its distances to IAM, cochlea, CC, TT and tragus were obtained using computed tomography radiological measurements. When the individual measurements performed on computed tomography images were evaluated in men and women, no significant difference was found concerning the distance between SP and various anatomic structures in close proximity to SP (p > 0.05). However, there was a statistically significant difference between the genders in length of the right SP (p = 0.003) and left SP (p = 0.006). This anthropometric study revealed the standard morphometric measurements of SP. We believe that the data obtained will help clinicians to identify and diagnose pathologies more easily.

Targeted fascicular biopsy of the sciatic nerve and its major branches: rationale and operative technique.

OBJECT Nerve biopsy is typically performed in distal, noncritical sensory nerves without using imaging to target the more involved regions. The yield of these procedures rarely achieves more than 50%. In selected cases where preoperative evaluation points toward a more localized (usually a more proximal) process, targeted biopsy would likely capture the disease. Synthesis of data obtained from clinical examination, electrophysiological testing, and MRI allows biopsy of a portion of the major mixed nerves safely and efficiently. Herein, experiences with the sciatic nerve are reported and a description of the operative technique is provided. METHODS All cases of sciatic nerve biopsy performed between 2000 and 2014 were reviewed. Only cases of fascicular nerve biopsy approached from the buttock or the posterior aspect of the thigh were included. Demographic data, clinical presentation, and the presence of percussion tenderness for each patient were recorded. Reviewed studies included electrodiagnostic tests and imaging. Previous nerve and muscle biopsies were noted. All details of the procedure, final pathology, and its treatment implications were recorded. The complication rate was carefully assessed for temporary as well as permanent complications. RESULTS One hundred twelve cases (63 men and 49 women) of sciatic nerve biopsy were performed. Mean patient age was 46.4 years. Seventy-seven (68.8%) patients presented with single lower-extremity symptoms, 16 (14.3%) with bilateral lower-extremity symptoms, and 19 (17%) with generalized symptoms. No patient had normal findings on physical examination. All patients underwent electrodiagnostic studies, the findings of which were abnormal in 110 (98.2%) patients. MRI was available for all patients and was read as pathological in 111 (99.1%). The overall diagnostic yield of biopsy was 84.8% (n = 95). The pathological diagnoses included inflammatory demyelination, perineurioma, nonspecific inflammatory changes, neurolymphomatosis, amyloidosis, prostate cancer, injury neuroma, neuromuscular choristoma, sarcoidosis, vasculitis, hemangiomatosis, arteriovenous malformation, fibrolipomatous hamartoma (lipomatosis of nerve), and cervical adenocarcinoma. The series included 11 (9.9%) temporary and 5 (4.5%) permanent complications: 3 patients (2.7%) reported permanent numbness in the peroneal division distribution, and 2 patients (1.8%) were diagnosed with neuromuscular choristoma that developed desmoid tumor at the biopsy site 3 and 8 years later. CONCLUSIONS Targeted fascicular biopsy of the sciatic nerve is a safe and efficient diagnostic procedure, and in highly selected cases can be offered as the initial procedure over distal cutaneous nerve biopsy. Diagnoses were very diverse and included entities considered very rare. Even for the more prevalent diagnoses, the biopsy technique allowed a more targeted approach with a higher diagnostic yield and justification for more aggressive treatment. In this series, new radiological patterns of some entities were identified, which could be biopsied less frequently.