The risk peaked at A4, A3 and B2, when the screw length was 40 mm and diameter was 5.0 mm, and the direction error was 30 degrees, while the risk was lowest at the apical level 14.3% (0%-40.7%) in any scenarios. CONCLUSIONS In patients with severe and rigid scoliosis, the aorta shifted more laterally and posteriorly, and the injury risk was lower at the apical level, compared with moderate scoliosis. Most of potential risks can be minimized by carefully preoperative planning and the assistance of intraoperative navigation or robotics. BACKGROUND Artificial dural substitute made from an expanded polytetrafluoroethylene (ePTFE) sheet have been widely used in surgical application. CASE DESCRIPTION We describe a 19-year-old woman in whom massive ossification with hematopoietic marrow was noted on both surfaces of an ePTFE sheet during epilepsy surgery. At the age of 8 years, she underwent decompressive craniectomy for a ruptured arterio-venous malformation in the right frontal lobe, followed by duraplasty with an ePTFE sheet and autologous cranioplasty fixed with titanium miniplates. CONCLUSIONS Since the ossification was prominent in the wrinkle dents of the ePTFE sheet and fibrotic membrane with repetitive hemorrhagic events was noted under the ePTFE sheet, the most plausible mechanism of ossification development is the organization of epi- and sub-artificial dural hematoma. Surgeons should be aware of the possibility of ossification development when working with ePTFE sheets for duraplasty. BACKGROUND Whether early enteral nutrition with probiotics can reduce the mortality and infection rate of severe craniocerebral injury (SCI) patients, improve their gastrointestinal function and shorten the length of stay in intensive care unite (ICU) have not been determined. METHODS PubMed, China National Knowledge Infrastructure, Embase were electronically searched for the purpose of identifying the randomized controlled trials investigated the potential of early enteral nutrition supplemented with probiotics on patients with SCI from the establishment of databases to August 26, 2019. STATA software (Version 12.0; Stata Corporation) was used to perform meta-analysis. RESULTS Totally 39 trials enrolling 3387 patients were included. Early enteral nutrition supplemented with probiotics was associated with decreased risk of infection (pooled RR=0.486, 95%CI 0.394-0.599). Decreased risk of the 7-day, 14-day and 28-day mortality (pooled RR=0.415, 0.497 and 0.385; 95% CIs 0.196-0.878, 0.297-0.833 and 0.197-0.751, respectively), decreased risk of gastrointestinal complications (pooled RR=0.363, 95%CI 0.274-0.481). Shortened the time course recovery of enteral function. Shortened the length of stay in hospital and length of ICU stay (SMDs = -3.327 and -1.461; 95% CIs -6.213–0.440, and -2.111–0.811, respectively). CONCLUSION Enteral nutrition supplemented with probiotics effectively decreases the risk of mortality, gastrointestinal complications, and infection, as well as shortens the stays in ICU, and thus it should be extensively adopted to manage these given patients. BACKGROUND Lesions of the skull make up a small but important part of neurosurgical practice. Selleck XL184 Several systemic disorders may involve the cranial vault including neoplastic and non-neoplastic conditions. Sarcoidosis of the skull is a little-known cause of calvarial involvement that has been rarely reported in the literature. The available information about skull sarcoidosis (SS) is sparse and is not well described; for this reason, we consider that a detailed description of this uncommon condition is necessary. METHODS An illustrative case of SS is presented; in addition, a PubMed and Scopus search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed to include studies reporting patients with SS. Different information was analyzed in these cases to describe the characteristics of this condition. Also, different. sources of literature were analyzed to complete the description of this clinical entity. RESULTS The search yielded 22 cases of patients with SS showing a variety of clinical manifestations. All studies were case reports. Most patients diagnosed with SS had no previous history of systemic sarcoidosis. Different characteristics of SS are analyzed and described in this paper. CONCLUSIONS The information collected from this review shows that SS is a rare condition that frequently is observed in patients without previous diagnosis of sarcoidosis. SS may manifest in different ways, and even may be found incidentally in some patients. The diagnosis of SS should be considered when multiple lytic skull lesions are observed, especially in cases of patients without a previous history of malignancy. BACKGROUND Metal hypersensitivity is a rare complication after spinal implant placement but is related to significant clinical challenges including implant failure and poor wound healing. The incidence is likely underreported secondary to challenges with diagnosis and retreatment options. CASE We present a case of a 41 year old woman with metal hypersensitivity 6 years status post Anterior Lumbar Interbody Fusion (ALIF) after a previously failed revision procedure who presented with low back pain and abdominal pain with food intolerance. Diagnostics revealed presacral fluid collection which was negative for infection. A detailed work-up ruled out other possible differential diagnoses and confirmed hypersensitivity to Nickel. Intraoperatively, the interbody was loose but difficult to remove secondary to scar tissue. Ultimately, it was successfully replaced with a PEEK interbody, which did not contain nickel. DISCUSSION Metal hypersensitivity is likely an underreported complication in spine literature that is associated with poor outcomes. Further research to create evidence based guidelines on diagnosis and retreatment options will facilitate diagnosis, reduce time to revision surgery and ultimately decrease patient suffering. OBJECTIVE Purpose of the present study is to investigate the existence and/or prevalence of clinical practice variation in management of aneurysmal subarachnoid hemorrhage (aSAH) and to determine need for long-term follow-up. MATERIALS AND METHODS Single-center study of aSAH patients over a 5-year period divided into two halves (2.5 years each) before and after addition of a dually trained cerebrovascular neurosurgeon. In-hospital clinical practice, clinical outcome (mortality, discharge destination) and long-term outcome (modified Rankin scale, mRS and telephone interview for cognitive status, TICS) were compared using descriptive summaries and non-parametric tests. RESULTS Among 251 aSAH patients admitted, 115 (45.8%) were prior to the index event, while 136 (54.2%) were during the later period. The aneurysm securing procedure changed from coil embolization to clip ligation [12/115 (10.4%) vs. 84/136 (61.8%), p less then 0.0001] during the latter years. Interventional treatment for cerebral vasospasm has decreased [58/115 (50.