The Tokuhashi score: effectiveness and pitfalls.

PURPOSE: Accurate survival estimation is prerequisite to determine the most appropriate treatment for patients with metastatic spine disease. Several authors have proposed classification systems analyzing clinical and radiological parameters, such as, performance status, metastasis localization, and primary tumor histotype, but the modified Tokuhashi score (mTS) is the most widely used. Although it is regarded as one of the most complete and accurate systems, it does not take the effectiveness of new therapeutic strategies into consideration, contributing to a progressive loss of accuracy. The purpose of this review is to verify the ability of the mTS to accurately estimate metastatic spine patient survival, nearly 10 years after it was introduced. METHODS: A literature review was conducted to evaluate mTS accuracy to predict metastatic spine patient survival. RESULTS: Ten studies were selected, representing 1686 patients. The total predictive accuracy of the mTS was 63.00%; for patients expected to survive less than 6 months (group I), it was 64.10%; 6-12 months (group II), 55.32%; and more than 12 months (group III), 77.21%. A progressive decrease in accuracy over time was statistically significant in groups I and II. CONCLUSIONS: The mTS is suggestive of actual survival for patients with a good prognosis. It is less accurate for patients with an estimated survival of less than 12 months. The decreasing trend in mTS accuracy over time will likely further reduce mTS utility. An important opportunity exists to develop new instruments to assist spine surgeons and oncologists to choose appropriate surgical or non-surgical treatment modalities for patients with metastatic spine disease.

Residual neurological function after sacral root resection during en-bloc sacrectomy: a systematic review.

PURPOSE: Sacrectomy is a highly demanding surgery representing the main treatment for primary tumors arising in the sacrum and pelvis. Unfortunately, it is correlated with loss of important function depending on the resection level and nerve roots sacrificed. The current literature regarding residual function after sacral resection comes from several small case series. The goal of this review is to appraise residual motor function and gait, sensitivity, bladder, bowel, and sexual function after sacrectomies, with consideration to the specific roots sacrificed. METHODS: An exhaustive literature search was conducted. All manuscripts published before May 2015 regarding residual function after sacrectomy were considered; if a clear correlation between root level and functioning was not present, the paper was excluded. The review identified 15 retrospective case series, totaling 244 patients; 42 patients underwent sacrectomies sparing L4/L4, L4/L5 and L5/L5; 45 sparing both L5 and one or both S1 roots; 8 sparing both S1 and one S2; 48 sparing both S2; 11 sparing both S2 and one S3, 54 sparing both S3, 9 sparing both S3 and one or both S4, and 27 underwent unilateral variable resection. RESULTS: Patients who underwent a sacrectomy maintained functionally normal ambulation in 56.2 % of cases when both S2 roots were spared, 94.1 % when both S3 were spared, and in 100 % of more distal resections. Normal bladder and bowel function were not present when both S2 were cut. When one S2 root was spared, normal bladder function was present in 25 % of cases; when both S2 were spared, 39.9 %; when one S3 was spared, 72.7 %; and when both S3 were spared, 83.3 %. Abnormal bowel function was present in 12.5 % of cases when both S1 and one S2 were spared; in 50.0 % of cases when both S2 were spared; and in 70 % of cases when one S3 was spared; if both S3 were spared, bowel function was normal in 94 % of cases. When even one S4 root was spared, normal bladder and bowel function were present in 100 % of cases. Unilateral sacral nerve root resection preserved normal bladder function in 75 % of cases and normal bowel function in 82.6 % of cases. Motor function depended on S1 root involvement. CONCLUSION: Total sacrectomy is associated with compromising important motor, bladder, bowel, sensitivity, and sexual function. Residual motor function is dependent on sparing L5 and S1 nerve roots. Bladder and bowel function is consistently compromised in higher sacrectomies; nevertheless, the probability of maintaining sufficient function increases progressively with the roots spared, especially when S3 nerve roots are spared. Unilateral resection is usually associated with more normal function. To the best of our knowledge, this is the first comprehensive literature review to analyze published reports of residual sacral nerve root function after sacrectomy.

The surgical neurovascular anatomy relating to partial and complete sacral and sacroiliac resections: a cadaveric, anatomic study.

PURPOSE: Pelvic and sacral surgeries are considered technically difficult due to the complex multidimensional anatomy and the presence of significant neurovascular structures. Knowledge of the key neurovascular anatomy is essential for safe and effective execution of partial and complete sacral resections. The goal of this anatomic, cadaveric study is to describe the pertinent neurovascular anatomy during these procedures. METHODS: Three embalmed human cadaveric specimens were used. Sacrectomies and sacroiliac joint resections were simulated and the structures at risk were identified. Both anterior and posterior approaches were evaluated. RESULTS: During sacroiliac joint resection, L5 nerve roots are at high risk for iatrogenic injury; the vasculatures at greatest risk are the common iliac vessels and internal iliac vessels with L5-S1 and S1-S2 high sacrectomies. Minor bleeding risk is associated with S2-S3 osteotomy because of the potential to damage superior gluteal vessels. S3-S4 osteotomy presents a low risk of bleeding. Adjacent nerve roots proximal to the resection level are at high risk during higher sacrectomies. CONCLUSIONS: Several sacrectomy techniques are available and selection often depends on the specific case and surgeon preference; nevertheless, anatomic knowledge is extremely important. Considering the highly variable anatomic relations of the vascular bundles, a preoperative evaluation with CT or MRI with vascular reconstruction may be helpful to decrease bleeding risk by preemptively binding the internal iliac vessels in cases where higher tumors are present. To decrease the risk of damaging nerve roots, it is recommended to perform the resection as close to the involved foramina as possible.

The surgical vascular anatomy of the minimally invasive lateral lumbar interbody approach: a cadaveric and radiographic analysis.

PURPOSE: The minimally invasive (MI) lateral lumbar interbody fusion (LLIF) approach has become increasingly popular for the treatment of degenerative lumbar spine disease. The neural anatomy of the lumbar plexus has been studied; however, the pertinent surgical vascular anatomy has not been examined in detail. The goal of this study is to examine the vascular structures that are relevant in relation to the MI-LLIF approach. METHODS: Anatomic dissection of the lumbar spines and associated vasculature was performed in three embalmed, adult cadavers. Right and left surgeon perspective views during LLIF were for a total of six approaches. During the dissection, all vascular elements were noted and photographed, and anatomical relationships to the vertebral bodies and disc spaces were analyzed. In addition, several axial and sagittal MRI images of the lumbar spine were analyzed to complement the cadaveric analysis. RESULTS: The aorta descends along the left anterior aspect of lumbar vertebra with an average distance of 2.1 cm (range 1.9-2.3 cm) to the center of each intervertebral disc. The vena cava descends along the right anterior aspect of lumbar vertebrates with average distance of 1.4 cm (range 1.3-1.6 cm) to the center of the intervertebral disc. Each vertebral body has two lumbar arteries (direct branches from the aorta); one exits to the left and one to the right side of the vertebral body. The lumbar arteries pass underneath the sympathetic trunk, run in the superior margin of the vertebral body and extend all the way across it, with average length of 3.8 cm (range 2.5-5 cm). The mean distance between the arteries and the inferior plate of the superior disc space is 4.2 mm (range 2-5 mm) and mean distance of 3.1 cm (range 2.8-3.8 cm) between two arteries in adjacent vertebrae. One of the cadavers had an expected normal anatomical variation where the left arteries at L3-L4 anastomosed dorsally of the vertebral bodies at the middle of the intervertebral disc. CONCLUSIONS: Understanding the vascular anatomy of the lateral and anterior lumbar spine is paramount for successfully and safely executing the LLIF procedure. It is imperative to identify anatomical variations in lumbar arteries and veins with careful assessment of the preoperative imaging.

The role of minimally invasive lateral lumbar interbody fusion in sagittal balance correction and spinal deformity.

PURPOSE: The recent proliferation of minimally invasive lateral lumbar interbody fusion (LLIF) techniques has drawn attention to potential for these techniques to control or correct sagittal misalignment in adult spinal deformity. We systemically reviewed published studies related to LLIF use in adult spinal deformity treatment with emphasis on radiographic assessment of sagittal balance. METHODS: A literature review was conducted to examine studies focusing on sagittal balance restoration in adult degenerative scoliosis with the LLIF approach. RESULTS: Fourteen publications, 12 retrospective and 2 prospective, reported data regarding lumbar lordosis correction (1,266 levels in 476 patients) but only two measured global sagittal alignment. CONCLUSION: LLIF appears to be especially effective when the lumbar lordosis and sagittal balance correction goals are less than 10° and 5 cm, respectively. However, the review demonstrated a lack of consistent reporting on sagittal balance restoration with the MIS LLIF techniques.

Objective assessment of postural ergonomics in neurosurgery: integrating wearable technology in the operating room.

OBJECTIVE: Physical stress associated with the static posture of neurosurgeons over prolonged periods can result in fatigue and musculoskeletal disorders. Objective assessment of surgical ergonomics may contribute to postural awareness and prevent further complications. This pilot study examined the feasibility of using wearable technology as a biofeedback tool to address this gap. METHODS: Ten neurosurgeons, including 5 attendings (all faculty) and 5 trainees (1 fellow, 4 residents), were recruited and equipped with two wearable sensors attached to the back of their head and their upper back. The sensors collected the average time spent in extended (≤ -10°), neutral (> -10° and < 10°), and flexed (≥ 10°) static postures (undetected activity for more than 10 seconds) during spine and cranial procedures. Feasibility outcomes aimed for more than 70% of accurate data collection. Exploratory outcomes included the comparison of postural variability within and between participants adjusted to their demographics excluding nonrelated surgical activities, and postoperative self-assessment surveys. RESULTS: Sixteen (80%) of 20 possible recordings were successfully collected and analyzed from 11 procedures (8 spine, 3 cranial). Surgeons maintained a static posture during 52.7% of the active surgical time (mean 1.58 hrs). During spine procedures, all surgeons used an exoscope while standing, leading to a significantly longer time spent in a neutral static posture (p < 0.001, partial η2 = 0.14): attendings remained longer in a neutral static posture (36.4% ± 15.3%) than in the extended (9% ± 6.3%) and flexed (5.7% ± 3.4%) static postures; trainees also remained longer in a neutral static posture (30.2% ± 13.8%) than in the extended (11.1% ± 6.3%) and flexed (11.9% ± 6.6%) static postures. During cranial procedures, surgeons intermittently transitioned between standing/exoscope use and sitting/microscope use, with trainees spending a shorter time in a neutral static posture (16.3% vs 48.5%, p < 0.001) and a longer time in a flexed static posture (18.5% vs 2.7%, p < 0.001) compared with attendings. Additionally, longer cranial procedures correlated with surgeons spending a longer time (r = 0.94) in any static posture (extended, flexed, and neutral), with taller surgeons exhibiting longer periods in flexed and extended static postures (r = 0.86). Postoperative self-assessment revealed that attendings perceived spine procedures as more difficult than trainees (p = 0.029), while trainees found cranial procedures to be of greater difficulty than spine procedures (p = 0.012). Attendings felt more stressed (p = 0.048), less calmed (p = 0.024), less relaxed (p = 0.048), and experienced greater stiffness in their upper body (p = 0.048) and more shoulder pain (p = 0.024) during cranial versus spine procedures. CONCLUSIONS: Wearable technology is feasible to assess postural ergonomics and provide objective biofeedback to neurosurgeons during spine and cranial procedures. This study showed reproducibility for future comparative protocols focused on correcting posture and surgical ergonomic education.

Epidemiology of the reported severity of copperhead (Agkistrodon contortrix) snakebite.

OBJECTIVE: The goal of this study was to analyze trends in the annual rates of reported medical outcomes of US copperhead (Agkistrodon contortrix) snakebites published in the annual reports of the American Association of Poison Control Centers in the course of 26 years. METHODS: This was a retrospective analysis of medical outcomes for copperhead snakebite victims who developed fatal, major, moderate, minor, or no effects. The annual rates for these medical outcomes were calculated by dividing the annual number of patients in each outcome category by the total annual number of people reported as being bitten by copperheads. Poisson and negative binomial regression were used to examine trends in annual rates. RESULTS: From 1983 through 2008, the incidence rate of copperhead snakebites causing no effect significantly decreased by 12.1%/year (incidence rate ratio [IRR] 0.879; 95% confidence interval [CI] 0.848-0.911]. From 1985 through 2008, the incidence rate of minor outcomes significantly decreased by 2.3%/year (IRR 0.977; 95% CI 0.972-0.981), whereas the rate of moderate outcomes significantly increased by 2.8%/year (IRR 1.028; 95% CI 1.024-1.033). The rate of major outcomes did not significantly change. One fatality was reported in 2001. CONCLUSIONS: Annual rates of copperhead snakebites producing no effects and minor outcomes significantly decreased, those producing moderate outcomes significantly increased, and those producing major outcomes did not significantly change in a 26-year period.

Spinal cord stimulation for genitofemoral neuropathy: A case report and review of the literature.

Background: Chronic testicular pain due to genitofemoral neuropathy often becomes refractory to conservative medical therapy. Neurostimulation is a potentially useful treatment option, should the neuropathic pain remain refractory to more invasive procedures such as orchiectomy. We provide a case report of spinal cord stimulation (SCS) for successful treatment of genitofemoral neuropathy and have also reviewed the literature to find similar cases which required a similar treatment paradigm. Case Description: A 42-year-old male underwent SCS for refractory testicular and groin pain. SCS through a four-column, 2 × 8 contact neurostimulator paddle lead, was implanted in the mid-thoracic-9 (T9) vertebral level, providing > 50% testicular pain relief with a decrease in visual analog scale scores from 8-10/10 to 3-4/10. The patient required one adjustment to the stimulation parameters at the time of the 6 weeks follow-up visit due to over-stimulation. He then continued to experience >50% resolution in pain 9 months later. A review of the literature yielded only two similar cases that successfully utilized SCS for treatment of chronic testicular pain. Conclusion: SCS should be considered as a possible treatment option for patients with chronic testicular pain localized to the genitofemoral nerve distribution.

Laparoscopically Assisted Ventriculoperitoneal Shunt Placement Is not Cost-Effective nor Preventive for Distal Shunt Malfunction.

BACKGROUND: Laparoscopy for ventriculoperitoneal shunt creation might offer smaller incisions and more reliable placement. We assessed the reliability and cost-effectiveness of this technique compared with mini-laparotomy shunt placement. METHODS: All patients undergoing ventriculoperitoneal shunt creation between November 2013 and September 2017 at a single academic institution were evaluated. Individual cases were assessed for the use of laparoscopy for peritoneal shunt placement (laparoscopy) versus mini-laparotomy for peritoneal shunt placement (open). The direct hospital costs for the laparoscopy and open groups were compared for elective shunt placement from the Vizient database. These direct costs were the proportion of the admission cost attributed to surgery. The primary endpoints included costs and revision of the peritoneal catheter within 12 months of the index procedure. RESULTS: A total of 68 patients met the inclusion criteria. Most cases (n = 40; 58.8%) had been performed with laparoscopy, with 28 performed using an open peritoneal approach. Three patients had required ≥1 distal shunt revision: 2 laparoscopy patients (5.0%; 1 had required a second revision) and 1 open patient (3.6%). No statistically significant differences were found for the patients requiring distal shunt revision between the 2 groups (P = 1.000; Fisher's exact test). The direct cost ($9461) of ventriculoperitoneal shunt creation with laparoscopy was greater than that with an open approach ($8247; P = 0.033). CONCLUSIONS: Both laparoscopy and open peritoneal shunt creation are safe procedures, with a 12-month distal revision rate in the present series of ~4%. Laparoscopy provided no relative improvement in safety or complication avoidance but had resulted in a mean increase in costs of >$1200 per patient.

Brain boosters: Evaluating a pilot program for memory complaints in veterans.

This study investigated the feasibility and preliminary effectiveness of a pilot program designed to address subjective memory complaints among Veterans. The program, Brain Boosters, consisted of 10 once-weekly group sessions, during which psychoeducation and cognitive enhancement strategies were used to target memory concerns and related processes, specifically attentional difficulties. Given that memory complaints often are associated with psychiatric comorbidities, sessions also incorporated strategies for reducing symptoms of depression, posttraumatic stress, and insomnia. Controlling for age, we examined pre- to posttreatment change in symptom ratings for 96 Veterans (aged 22 to 87 years) who participated in the Brain Boosters program. The effect of Brain Boosters on memory complaints interacted with age: younger (but not older) Veterans reported reductions in memory impairment from pre- to posttreatment. Additionally, irrespective of age, from pre- to posttreatment Veterans reported fewer attentional difficulties and fewer depression symptoms. Ratings of posttraumatic stress and insomnia symptoms did not change, although insomnia was negatively associated with age. Linear regression controlling for age revealed that reductions in attention problems predicted reductions in perceived memory impairment. Findings from this exploratory, uncontrolled pilot study suggest that a psychoeducational cognitive enhancement group is feasible to conduct in a heterogeneous Veteran population, and may be associated with improvements in perceived memory functioning for younger Veterans, and in attention and depression symptoms for Veterans across age groups. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Neurotrauma From Border Wall Jumping: 6 Years at the Mexican-American Border Wall.

BACKGROUND: The border between the United States (US) and Mexico is an international boundary spanning 3000 km, where unauthorized crossings occur regularly. We examine patterns of neurotrauma, health care utilization, and financial costs at our level 1 trauma center incurred by patients from wall-jumping into the US. OBJECTIVE: To determine the clinical and socioeconomic consequences from neurotrauma as a result of jumping over the US-Mexico border wall. METHODS: Medical records of patients at (Banner University of Arizona Medical Center - Tucson) were retrospectively reviewed from January 2012 through December 2017. Demographics, clinical status, radiographic findings, treatment, length of stay, and financial data were analyzed for all patients suffering neurotrauma during that time. RESULTS: Over 6 yr, 64 patients sustained cranial or spinal injuries directly from jumping or falling onto US soil from the border wall. Fifty (78%) suffered spinal injuries, 15 (23%) experienced cranial injury, and 1 patient had both. Total medical charges were available in 36 patients and summed $3.6 M, of which 22% was reimbursed, an amount significantly lower than expected from more conventional trauma. Neurotrauma steadily declined over the 6-yr observation period, dropping in 2017 to 6% of rates observed in 2012. CONCLUSION: In the Southern US, neurotrauma from unauthorized border crossings occurs commonly as a result of wall-jumping. These injuries represent a clinical and costly extreme of border-related trauma, and future efforts from both sides of the border wall are needed to decrease the detrimental impacts felt both by immigrants and surrounding health care systems.

Altered expression of signaling pathways regulating neuronal excitability in hippocampal tissue of temporal lobe epilepsy patients with low and high seizure frequency.

Despite recent advances in our understanding of synaptic transmission associated with epileptogenesis, the molecular mechanisms that control seizure frequency in patients with temporal lobe epilepsy (TLE) remain obscure. RNA-Seq was performed on hippocampal tissue resected from 12 medically intractable TLE patients with pre-surgery seizure frequencies ranging from 0.33 to 120 seizures per month. Differential expression (DE) analysis of individuals with low (LSF, mean = 4 seizure/month) versus high (HSF, mean = 60 seizures/month) seizure frequency identified 979 genes with ≥2-fold change in transcript abundance (FDR-adjusted p-value ö0.05). Comparisons with post-mortem controls revealed a large number of downregulated genes in the HSF (1676) versus LSF (399) groups. More than 50 signaling pathways were inferred to be deactivated or activated, with Signal Transduction as the central hub in the pathway network. While neuroinflammation pathways were activated in both groups, key neuronal system pathways were systematically deactivated in the HSF group, including calcium, CREB and Opioid signaling. We also infer that enhanced expression of a signaling cascade promoting synaptic downscaling may have played a key role in maintaining a higher seizure threshold in the LSF cohort. These results suggest that therapeutic approaches targeting synaptic scaling pathways may aid in the treatment of seizures in TLE.

A novel proposed grading system for cerebellar arteriovenous malformations.

OBJECTIVE: The objective of this study was to evaluate the existing Spetzler-Martin (SM), Spetzler-Ponce (SP), and Lawton-Young (LY) grading systems for cerebellar arteriovenous malformations (AVMs) and to propose a new grading system to estimate the risks associated with these lesions. METHODS: Data for patients with cerebellar AVMs treated microsurgically in two tertiary medical centers were retrospectively reviewed. Data from patients at institution 1 were collected from September 1999 to February 2013, and at institution 2 from October 2008 to October 2015. Patient outcomes were classified as favorable (modified Rankin Scale [mRS] score 0-2) or poor (mRS score 3-6) at the time of discharge. Using chi-square and logistic regression analysis, variables associated with poor outcomes were assigned risk points to design the proposed grading system. The proposed system included neurological status prior to treatment (poor, +2 points), emergency surgery (+1 point), age > 60 years (+1 point), and deep venous drainage (deep, +1 point). Risk point totals of 0-1 comprised grade 1, 2-3 grade 2, and 4-5 grade 3. RESULTS: A total of 125 cerebellar AVMs of 1328 brain AVMs were reviewed in 125 patients, 120 of which were treated microsurgically and included in the study. With our proposed grading system, we found poor outcomes differed significantly between each grade (p < 0.001), while with the SM, SP, and LY grading systems they did not (p = 0.22, p = 0.25, and p = 1, respectively). Logistic regression revealed grade 2 had 3.3 times the risk of experiencing a poor outcome (p = 0.008), while grade 3 had 9.9 times the risk (p < 0.001). The proposed grading system demonstrated a superior level of predictive accuracy (area under the receiver operating characteristic curve [AUROC] of 0.72) compared with the SM, SP, and LY grading systems (AUROC of 0.61, 0.57, and 0.51, respectively). CONCLUSIONS: The authors propose a novel grading system for cerebellar AVMs based on emergency surgery, venous drainage, preoperative neurological status, and age that provides a superior prognostication power than the formerly proposed SM, SP, and LY grading systems. This grading system is clinically predictive of patient outcomes and can be used to better guide vascular neurosurgeons in clinical decision-making.

Current Status of the PulseRider in the Treatment of Bifurcation Aneurysms: A Systematic Review.

BACKGROUND: The PulseRider is an innovative stent-like device designed for the treatment of intracranial bifurcation aneurysms. The aim of this study was to assess the current evidence on safety and effectiveness of the PulseRider. METHODS: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The following databases were searched: PubMed, Ovid MEDLINE, and Scopus. The search strategy consisted of "pulserider," "bifurcation aneurysm," and "endovascular" in both AND and OR combinations. Studies included were original research articles in peer-reviewed journals. The manuscripts were thoroughly examined for study design, outcomes, and results. RESULTS: Three studies were identified describing use of the PulseRider device in the treatment of 63 patients with 63 bifurcation aneurysms. We identified 2 multicenter case series and 1 single-arm clinical trial. The majority of aneurysms treated were located at the basilar tip (37, 58.7%). All devices were successfully deployed, and there were 5 intraoperative complications (7.9%), including 2 intraoperative aneurysm ruptures, 1 vessel dissection, and 2 thrombus formations. Immediate complete aneurysm occlusion was achieved in 61.9% (39/63) of cases and at the 6-month imaging follow-up, 66.7% (42/63) achieved complete aneurysm occlusion. One recanalization was reported in 1 of the multicenter case series within the 6-month follow-up. CONCLUSIONS: The PulseRider is safe and probably effective for the treatment of intracranial bifurcation aneurysms, sometimes not amenable for stent-assisted coiling. However, current evidence is limited to a small sample and short follow-up. In addition, the device has not been compared with other treatment modalities.

The Unique Features and Outcomes of Microsurgically Resected Cerebellar Arteriovenous Malformations.

BACKGROUND: Cerebellar arteriovenous malformations (CAVMs) are challenging to treat given their close proximity to the brain stem, greater propensity for rupture, and greater rates of morbidity and mortality than other brain arteriovenous malformations. The present investigation sought to describe and characterize the features of these rare and unique lesions. METHODS: A retrospective review of CAVM cases treated at 2 tertiary medical centers was performed. Patients surgically treated at institution 1 from September 1999 to February 2013 and institution 2 from October 2008 to October 2015 were included. RESULTS: A total of 120 patients had been treated. Of the 120 patients, 85 (70.8%) had initially presented with hemorrhage, 45 (37.5%) of whom experienced hemorrhage requiring emergent surgery. A favorable neurological outcome was observed in 76 patients (63.3%; modified Rankin Scale score <3). The perioperative mortality was 2.5% (n = 3). The long-term mortality rate was 7.5% (n = 9). The mean follow-up time was 1.82 years. On average, the patients with large CAVMs (≥3 cm; P ≤ 0.001), who had received embolization before surgery (P = 0.04), did not have an associated aneurysm (P ≤ 0.001), or had a residual CAVM after surgery (P = 0.008) were significantly younger. Female patients had fewer CAVMs with deep venous drainage (54.3% vs. 72.3%; P = 0.049), experienced decreased mortality (1.4% vs. 16.7%; P = 0.003), and were less likely to have worse neurological status after treatment (P = 0.003). CONCLUSIONS: CAVMs are rare lesions that exhibit unique disease characteristics. Although most patients will experience a favorable outcome, CAVMs frequently present with hemorrhage, result in high rates of morbidity and mortality, and characteristically differ depending on patient age and gender.

Completion of the Circle of Willis Varies by Gender, Age, and Indication for Computed Tomography Angiography.

OBJECTIVE: The circle of Willis (CoW) is the foremost anastomosis and blood distribution center of the brain. Its effectiveness depends on its completion and the size and patency of its vessels. Gender-related and age-related anatomic variations in the CoW may play an important role in the pathogenesis of cerebrovascular diseases. In this study, we analyzed computed tomography angiograms (CTAs) to assess for differences in CoW completion related to gender, age, and indication for CTA. METHODS: A total of 834 CTAs were retrospectively analyzed for all CoW vessels to compare the incidence of complete CoW and variation frequency based on gender, age, and indication. RESULTS: The incidence of complete CoW was 37.1% overall. CoW completion showed a statistically significant decrease with increasing age for all age groups in both men (47.0%, 29.4%, 18.8%) and women (59.1%, 44.2%, 30.9%). Completion was greater in women (43.8%) than in men (31.2%) overall and for all age groups. These gender differences were all statistically significant except for the 18-39 years age group. The most frequent of the 28 CoW variations were absent posterior communicating artery (PCOM) bilaterally (17.1%), right PCOM (15.3%), and left PCOM (10.9%). Ischemic stroke and the 18-39 years age group of hemorrhagic stroke showed a statistically significant reduction in completion relative to trauma. CONCLUSIONS: The incidence of complete CoW is likely greater in women for all age groups and likely decreases with age in both genders. The most frequently absent vessel is likely the PCOM, either unilaterally or bilaterally. Completion may play a role in ischemic stroke and a subset of patients with hemorrhagic stroke.

Intracranial Hemorrhage in Patients with Durable Mechanical Circulatory Support Devices: Institutional Review and Proposed Treatment Algorithm.

BACKGROUND: Spontaneous intracranial hemorrhage (ICH) is frequently managed in neurosurgery. Patients with durable mechanical circulatory support devices, including total artificial heart (TAH) and left ventricular assist device (LVAD), are often encountered in the setting of ICH. Although durable mechanical circulatory support devices have improved survival and quality of life for patients with advanced heart failure, ICH is one of the most feared complications following LVAD and TAH implantation. Owing to anticoagulation and clinically relevant acquired coagulopathies, ICH should be treated promptly by neurosurgeons and cardiac critical care providers. We provide an analysis of ICH in patients with mechanical circulatory support and propose a treatment algorithm. METHODS: We retrospectively reviewed medical records from 2013-2016 for patients with a durable mechanical circulatory device at Banner-University of Arizona Medical Center Tucson. All patients with suspected ICH underwent computed tomography scan of the brain. Anticoagulation was managed by the cardiothoracic surgeon. RESULTS: In 58 patients, an LVAD (n = 49), TAH (n = 10), or both (n = 1) were implanted. Both acquired von Willebrand disease and spontaneous ICH were diagnosed in 5 patients (8.6%) who underwent LVAD implantation. Seven neurosurgical procedures were performed in 2 patients. The overall mortality rate was 60%. Two patients had little or no deficits after treatment with modified Rankin Scale score of 1 and 2, respectively. CONCLUSIONS: We propose a novel treatment algorithm to manage patients with a LVAD or TAH and ICH, implemented in a multidisciplinary manner to best avoid neurologic and cardiovascular complications.

Instability in Thoracolumbar Trauma: Is a New Definition Warranted?

STUDY DESIGN: Review of the articles. OBJECTIVE: The objective of this study was to review all articles related to spinal instability to determine a consensus statement for a contemporary, practical definition applicable to thoracolumbar injuries. SUMMARY OF BACKGROUND DATA: Traumatic fractures of the thoracolumbar spine are common. These injuries can result in neurological deficits, disability, deformity, pain, and represent a great economic burden to society. The determination of spinal instability is an important task for spine surgeons, as treatment strategies rely heavily on this assessment. However, a clinically applicable definition of spinal stability remains elusive. MATERIALS AND METHODS: A review of the Medline database between 1930 and 2014 was performed limited to papers in English. Spinal instability, thoracolumbar, and spinal stability were used as search terms. Case reports were excluded. We reviewed listed references from pertinent search results and located relevant manuscripts from these lists as well. RESULTS: The search produced a total of 694 published articles. Twenty-five articles were eligible after abstract screening and underwent full review. A definition for spinal instability was described in only 4 of them. Definitions were primarily based on biomechanical and classification studies. No definitive parameters were outlined to define stability. CONCLUSIONS: Thirty-six years after White and Panjabi's original definition of instability, and many classification schemes later, there remains no practical and meaningful definition for spinal instability in thoracolumbar trauma. Surgeon expertise and experience remains an important factor in stability determination. We propose that, at an initial assessment, a distinction should be made between immediate and delayed instability. This designation should better guide surgeons in decision making and patient counseling.

Outcomes and Complications of Minimally Invasive Surgery of the Lumbar Spine in the Elderly.

INTRODUCTION: Minimally invasive spine (MIS) surgery is gaining popularity in the elderly. With aging population and a strong desire for all patients to remain physically active, this trend will likely continue. Previous studies have reported clinical outcomes in the elderly undergoing MIS surgery; however, most of these studies encompass multiple surgeons at different sites and thus present heterogeneous experiences. In this work, we investigate the clinical outcomes and complications of all lumbar MIS procedures performed in patients over 65 years of age by a single surgeon. METHODS: A retrospective analysis of a prospectively maintained database of spine surgeries was performed. Twenty-six patients who underwent 27 procedures were included. RESULTS: Mean age at surgery was 72 years (range 64-86). The mean BMI was 30.2 kg/m(2), patients had an average of 5 comorbidities, took 9 medications, and 15% were smokers. The mean symptoms duration was 40.6 months with the numeric rating scale (NRS) and the Oswestry disability index (ODI) prior to surgery of 7.68 and 50% respectively. Six different types of procedures were performed, the most common was the interlaminar decompression and fusion (ILIF) followed by MIS laminectomy, microdiscectomy and MIS lateral fusion (XLIF). 74% of the surgeries were done at a single level. Average blood loss was 43 mL, and the mean length of stay was 1.7 days. There were three complications (11.1%): one urinary tract infection, one pulmonary embolism, and one new, postoperative weakness. At six months follow-up, there was a mean improvement of 27% in ODI, and a 5.6 improvement in NRS (both p<0.05); 90% of patients stated they would have the surgery again. CONCLUSION: Minimally invasive lumbar spine surgery is both safe and highly effective in the elderly population. Patient selection is of utmost importance. This data will add to the existing literature on the overall safety and effectiveness of these procedures in the elderly population.

A computer-assisted navigation technique to perform bone tumor resection without dedicated software.

PURPOSE: In oncological orthopedics, navigation systems are limited to use in specialized centers, because specific, expensive, software is necessary. To resolve this problem, we present a technique using general spine navigation software to resect tumors located in different segments. MATERIALS AND METHODS: This technique requires a primary surgery during which screws are inserted in the segment where the bone tumor is; next, a CT scan of the entire segment is used as a guide in a second surgery where a resection is performed under navigation control. We applied this technique in four selected cases. To evaluate the procedure, we considered resolution obtained, quality of the margin and its control. RESULTS: In all cases, 1 mm resolution was obtained; navigation allowed perfect control of the osteotomies, reaching the minimum wide margin when desired. No complications were reported and all patients were free of disease at follow-up (average 25.5 months). CONCLUSIONS: This technique allows any bone segment to be recognized by the navigation system thanks to the introduction of screws as landmarks. The minimum number of screws required is four, but the higher the number of screws, the greater the accuracy and resolution. In our experience, five landmarks, placed distant from one another, is a good compromise. Possible disadvantages include the necessity to perform two surgeries and the need of a major surgical exposure; nevertheless, in our opinion, the advantages of better margin control justify the application of this technique in centers where an intraoperative CT scanner, synchronized with a navigation system or a dedicated software for bone tumor removal were not available.