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During routine anatomical dissection of the upper extremity of a 64-year-old cadaver for educational purposes, we observed variations in the brachial plexus on each side. On the right an anomaly of cord formation was present and on the left there was a communication between the musculocutaneous nerve (MCN) and median nerve (MN). On the right side the brachial plexus showed two trunks, superior (C5 and C6) and inferior (C7, C8, and T1); the middle trunk was absent. The superior trunk bifurcated into anterior and posterior divisions, the anterior division continued as the lateral cord forming the MCN. The posterior division gave off the subscapular branch. The inferior trunk trifurcated into radial, median, and ulnar nerves. The radial nerve gave off the axillary and thoracodorsal nerves. The ulnar nerve gave off the median cutaneous nerves of the arm and forearm. The median nerve received a small ascending branch from the MCN. On the right side, there was a communicating branch from the MCN to the MN in the lower third of the arm region. This communicating branch also gave rise to a muscular branch to the brachialis muscle and the lateral cutaneous nerve of forearm. No additional heads of the biceps brachii muscle were observed in either upper limb. Knowledge of the variations of the brachial plexus in humans can be valuable for operations of the shoulder joint and its repair for providing an effective block or treatment for anesthetists and also for explaining otherwise incomprehensible clinical signs for neurologists.

Increased angiogenic potential of cerebrovascular malformations during pregnancy may help to explain the complications of arteriovenous malformations (AVMs) in this group of patients. This experimental study investigated the effect of pregnancy on angiogenic activity of implanted AVM tissue samples.A subject group of 10 pregnant rats and 10 non-pregnant rats as controls were used. Surgical AVM resection samples were implanted into the micropocket created in both eyes of each animal. Vascular development was assessed by vessel count throughout the study period. In addition, immunohistochemical studies were done for vascular endothelial growth factor (VEGF), platelet derived growth factor (PDGF), and their receptors (VEGFR, PDGFR).Statistically significant increase in the number of vessels was found in both groups (P0.0001); however, the increase in the pregnant group was greater (P=0.0032). The difference between the two groups was evident at the 25th day of the experiment. Despite both groups showed increased level, there was no difference with the level of VEGF, VEGF receptor, PDGF, or PDGF receptor (P0.05 for all comparisons).Findings of this study suggest that angiogenic activity of AVM tissues may increase during late pregnancy, hence physicians should inform pregnant patients with AVM of the potential risk.

Aim The major aim of the present anatomical study was to demonstrate the anatomical structures that can be visualized using the supraorbital keyhole approach, both endoscopically and microscopically, from an eyebrow incision to intracranial structures. Furthermore, it defines an optimal craniotomy for surgery. Methods Fine dissection was performed on each side of 5 formalin-fixed adult cadavers according to the surgical procedures of the supraorbital keyhole approach, and each step was documented both endoscopically and microscopically. Furthermore, the distance between the superior temporal line and the supraorbital notch/foramen was measured from the 10 total sides of the 5 cadavers and from the 118 sides of the 59 autopsies. Results Tumors and aneurysms of the anterior cranial fossa can be visualized during the supraorbital keyhole approach. The average distance between the superior temporal line and the supraorbital notch/foramen was measured. The distance obtained from the autopsies on the 25 females was 31.56 ± 4.03 mm on the right side and 31.04 ± 5.40 mm on the left side. The average distance obtained from the autopsies on the 34 males was 34.00 ± 4.59 mm on the right side and 33.59 ± 5.41 mm on the left side. There was no statistically significant difference between right and left in the female and male autopsies or between sexes. Conclusions This anatomical study showed that structures in the anterior and middle cranial fossa can be reached via the supraorbital keyhole craniotomy approach with minimal brain retraction and adequate exposure and with minimal craniotomy size.

Anatomical and surgical textbooks give almost no attention to the intradural communications between dorsal rootlets of adjacent spinal nerves. These communications can be of significance in various neurosurgical procedures and clinical conditions of the region. The spinal cord of six formaldehyde-fixed cadavers was dissected from C1–S5. The dorsal rootlets of the spinal nerves were exposed via a posterior approach and communications between adjacent spinal nerves were documented. The frequency of communication between adjacent dorsal rootlets of the spinal nerves showed variations among spinal levels. Thirty-eight dorsal rootlet communications were observed in six cadavers (12 sides) and 20 (52.6 %) were at cervical levels, 14 (36.8 %) at thoracic levels, and four (10.5 %) at lumbar levels. The majority of communications were observed on the left side (65.8 %). Communications were most frequently observed at cervical (C4–C5, C5–C6) and upper thoracic (T1–T2) levels and seen least frequently at lower thoracic and lumbar levels. No communications were observed at sacral levels. Five types of communication were observed: I. oblique ascending, II. oblique descending III. short Y, IV. long Y and V shaped. None of the communication extended beyond one segment at any spinal level. The occurrence of such dorsal rootlet communications ranged from 3 to 7 for each cadaver and the mean was 4.8 ± 1.3. Histological sections from various levels of the dorsal rootlet communications showed that all consisted of myelinated fibers of varying diameters. Such communications may lead to misinterpretation of the pathology on the basis of clinical signs and symptoms and also should be considered in rhizotomy.

Owing to the increasing population of elderly patients, a large number of patients with degenerative spondylosis are currently being surgically treated. Although basic measures for decreasing postoperative surgical infections (PSIs) are considered, it still remains among the leading causes of morbidity and mortality. The aim of this retrospective analysis is to present possible causes leading to PSI in patients who underwent surgery for lumbar degenerative spondylosis and highlight how it can be avoided to decrease morbidity and mortality. The study included 540 patients who underwent posterior stabilization due to degenerative lumbar stenosis between January 2013 and January 2014. The data before and after surgery was retrieved from the hospital charts. Patients with degenerative lumbar stenosis who were operated upon in this study had >2 levels of laminectomy and facetectomy. For this reason, posterior stabilization was performed for all the patients included in this study. Determining the causes of postoperative infection (PI) following spinal surgeries performed with instrumentation is a struggle. Seventeen different parameters that may be related to PI were evaluated in this study. The presence of systemic diseases, unknown glove perforations, and perioperative blood transfusions were among the parameters that increased the prevalence of PI. Alternatively, prolene sutures, double-layered gloves, and the use of rifampicin Sv (RIS) decreased the incidence of PI. Although the presence of systemic diseases, unnoticed glove perforations, and perioperative blood transfusions increased PIs, prolene suture material, double-layered gloves, and the use of RIS decreased PIs.

Background: Only limited attention has been paid to the anatomy and clinical importance of the falcine venous plexus. The aim of this study was to evaluate the falcine venous plexus anatomically using scanning electron microscopy (SEM), and to provide guidance for neurosurgical approaches. Methods: Latex or ink was injected into the superior and inferior sagittal sinus. The falcine venous plexus lying within the connective tissue of the falx cerebri was observed by dividing the falx into thirds (anterior, middle and posterior). Further, the SEM appearance of the falcine venous plexus was evaluated. Results: The anterior third of the falx cerebri consisted of small diameter falcine venous vessels. These vessels were localized close to either the superior or inferior sagittal sinus, and none extended as far as mid-falx cerebri levels in any of the 16 cases. They communicated with either superior or inferior sagittal sinuses, but not with both of these sinuses. In the middle third of the falx cerebri, the majority of the vessels of the falcine venous plexus had larger diameter compared to those of the anterior third. These vessels extended the length of the falx cerebri levels. They communicated with both superior and inferior sagittal sinuses. In the posterior third of the falx cerebri, the vessels of the falcine venous plexuses had the largest diameter and were located at the junction of the inferior sagittal sinus and the straight sinus. They were localized at the lower two-thirds of the falx cerebri. In all cases, the dense venous networks communicated with the inferior sagittal sinus but not with the superior sagittal sinus. The falcine venous plexus observed in the posterior third of the falx cerebri was denser than in the anterior and middle portions. The SEM revealed small vessels whose diameter ranged between 42 and 138 µm. The vessels of the falcine venous plexus in the anterior third had a mean diameter of 0.42 ± 0.1 mm, in the middle third a mean diameter of 0.87 ± 0.17 mm, and in the posterior third, 1.38 ± 0.21 mm. Conclusion: The falcine venous plexus is a network of venous channels that exists within the connective tissue of the falx; the sizes and patterns of communication of these structures showed regional differences. Neurosurgeons should be aware of the regional differences when making an incision or puncturing the falx during a surgical approach.

It is widely believed that the main function of denticulate ligaments (DLs) is to stabilize the spinal cord within the vertebral canal. The aim of this study was to assess the anatomical and histological structure of the DLs and to document any regional differences. Five formalin-fixed adult cadavers were used. The DLs were exposed via the posterior approach, and detailed anatomy and histology of these structures were documented. The main findings were: (1) each DL is composed of a single narrow fibrous strip that extends from the craniovertebral junction to T12, and each also features 18–20 triangular extensions that attach to the dura at their apices; (2) the triangular extensions are smaller and more numerous at the cervical levels, and are larger and less numerous at the thoracic levels; (3) the apices of the extensions attach to the dura via fibrous bands at cervical levels (each band 3-5 mm long) and lower thoracic levels (21-26 mm long), whereas they attach directly to the dura at upper thoracic levels; (4) the narrow fibrous strip of the DL features longitudinally oriented collagen fibers, whereas the triangular extensions are composed of transverse and obliquely oriented collagen fibers. The collagen fibers are thicker and more abundant at the cervical than at the thoracic levels. DL histology and anatomy are strongly correlated with the function of this structure at different spinal levels. It is important to have accurate knowledge about DLs as these structures are relevant for clinical procedures that involve the spinal cord or craniovertebral junction.