An assessment of the variation in the practice of lumbar discectomy and its role in axial back pain.

Background: Lumbar discectomy is performed for symptomatic lumbar disc herniation and is one of the most widely performed spinal surgical procedures worldwide in a variety of ways. This survey aimed at providing an overview/perspective of different practice patterns and the impact of lumbar discectomy on axial back pain with or without sciatica. Methods: An online survey was performed using the application "Google Forms." The link to the questionnaire was distributed to neurosurgeons through personal E-mail and social media platforms. Results: We received 333 responses. The largest percentage of responses across five continents was from Asia (66.97%, n = 223). The mean age of the respondents was 40.08 ± 10.5 years. A total of 66 respondents (20%) had a spine practice of 7%-90%, and 28 respondents had a spine practice of 90%-100% (8.4%). The number of respondents who practiced microscopic discectomy using a tubular retractor (n = 143 respondents, 42.9%) was nearly equal to the number of respondents who practiced open discectomy (n = 142 respondents, 42.6%). An almost equal proportion of respondents believed discectomy does not help in relieving axial back pain. Only 20.4% (n = 68) of respondents recommend bed rest for a longer duration postoperatively. Conclusions: Our survey revealed that only 22.2% of spine surgeons recommended discectomy in patients with radiological disc herniation with axial back pain alone and preferred a minimally invasive method of discectomy. Almost half of them believed discectomy to be ineffective for axial low back pain and only a few recommended prolonged bed rest postoperatively.

Effect of topical and intraventricular antibiotics used during ventriculoperitoneal shunt insertion on the rate of shunt infection-a meta-analysis.

INTRODUCTION: The ventriculoperitoneal shunt is one of the most commonly performed neurosurgical procedures. One of the avoidable complications of shunt surgery is shunt infection. This PRISMA-compliant meta-analysis analysed the effectiveness of topical and/or intraventricular antibiotics in preventing shunt infections in patients undergoing shunt surgery. METHODS: Four databases were searched from inception to 30th June 2021. Only original articles comparing the rate of shunt infection with and without antibiotics were included. Random-effects meta-analysis was used to compare the effect of the use of antibiotics in preventing infection and subgroup analysis for finding differences in various antibiotics. RESULTS: The rate of shunt infection was 2.24% (53 out of 2362) in the topical antibiotic group in comparison to 5.24% (145 out of 2764) in the control group (p = 0.008). Subgroup analysis revealed that there is no significant difference between the antibiotics used. CONCLUSIONS: Our meta-analysis found that the risk of shunt infection is significantly reduced with the use of topical and intraventricular antibiotics without any serious adverse effect. No side effects of topical or intraventricular antibiotics were reported in the included studies. Further prospective studies are required to establish the safety and optimal dosage of topical antibiotics for them to be used routinely in neurosurgical practice. They can be used in patients at high risk of developing shunt infections till such studies are available.

Hybrid Workshops During the COVID-19 Pandemic-Dawn of a New Era in Neurosurgical Learning Platforms.

BACKGROUND: During the COVID-19 pandemic, disruption of surgical hands-on training has hampered the skills acquisition by budding neurosurgeons. Online and virtual classrooms have not been able to substitute the hands-on experience and learning via direct interaction with senior colleagues. To overcome these challenges, we organized a hybrid workshop where simulation-based learning modules, and direct and virtual interaction with surgeons during live surgeries or didactic lectures were utilized to help delegates in understanding the nuances of neurosurgery. METHODS: A 3-day hybrid workshop was held in March 2021, which was attended by 133 delegates. A structured questionnaire was utilized to record their feedback. RESULTS: An overwhelming majority of the respondents (94.1%, n = 64) found hybrid conferences to be better than an online conference. Most of the respondents (88.3%, n = 60) rated the utility of direct face-to-face interaction to be more satisfying as compared with online interaction with faculty during a webinar. Again, many the respondents (86.8%, n = 59) believed that similar hybrid events will be the new normal given the current situation of COVID-19 pandemic. A large majority (88.2%, n = 60) of the respondents reported that they will prefer a hybrid event over an online conference. CONCLUSIONS: In this era of the COVID-19 pandemic, "hybrid" microneurosurgery workshops offer unique opportunities to enhance surgical skills acquisition by hands-on simulation-based learning and observing live surgical demonstrations, apart from 2-way interactions with experts under one roof. This may be a stepping stone for what lies ahead in the future of neurosurgical training.

Clinical Utility of Intravascular Ultrasound (IVUS) in Carotid Artery Interventions: A Systematic Review and Meta-analysis.

BACKGROUND: Carotid plaque morphology plays an important role in determining outcome of carotid artery stenting (CAS). Intravascular ultrasound (IVUS) and its extension VH (Virtual Histology)-IVUS evaluate plaque characteristics in real time and guide decision making during stenting. To date, there is no consensus about indications of IVUS and its validated methods. This systematic review and meta-analysis aims to evaluate the clinical utility of IVUS in carotid artery interventions (CAS) and develop a future consensus for research and practice parameters. METHODS: A systematic review and meta-analysis was performed of the English literature articles published till February 2021. Studies reporting on IVUS parameters and findings and also its performance compared with other imaging modalities were included in review. Pooled prevalence with 95% confidence intervals (CI) was calculated. The statistical analysis was conducted in R version 3.6.2. RESULTS: A total of 2015 patients from 29 studies were included. Proportional meta-analysis was performed on 1566 patients from 11 studies. In 9 studies, stroke/transient ischemic attack (TIA) had a pooled prevalence of 4% (95% CI 3%-5%) while asymptomatic stroke had a pooled prevalence of 46% (95% CI 31%-62%) in 4 studies following IVUS. Two studies reported that IVUS detected more plaque protrusion compared with angiography (n=33/396 vs 11/396). IVUS led to stent type or size change in 8 of 48 cases which were missed on angiography in 3 other studies. Concordance between VH-IVUS and true histology was good at 80% to 85% reported in 2 studies. CONCLUSIONS: This systematic review and meta-analysis showed, though IVUS fared better to computed tomography (CT)/magnetic resonance (MR) angiography for better stent selection during CAS, with low to moderate risk of bias in the studies included. However, large scale, preferably randomized controlled studies are needed to predict its role in determining clinical outcome.

Effect of statins on functional outcome and mortality following aneurysmal subarachnoid hemorrhage - Results of a meta-analysis, metaregression and trial sequential analysis.

OBJECTIVE: Cerebral vasospasm (CVS) and delayed ischemic neurological deficits (DIND) are a common cause of morbidity following aneurysmal subarachnoid hemorrhage (SAH). Statins have been shown to decrease CVS. The objective of this article was to ascertain the effect of statins on functional outcome and mortality following aneurysmal SAH by performing meta-analysis. METHODS: A comprehensive search of different databases was performed to retrieve randomized controlled trials. Meta-analysis with subgroup analysis and metaregression was done. Trial sequential analysis (TSA) was performed to determine if the cumulative sample size was appropriately powered for the obtained pooled effect values and to avoid random error. RESULTS: Twelve articles were selected for meta-analysis. Pooled OR for the change in favorable outcome, mortality, CVS, DIND and elevated transaminases was 1.07 (p = 0.55), 0.78 (p = 0.17), 0.58 (p = 0.0004), 0.54 (p = 0.0293) and 0.68 (p = 0.1774) respectively. Further, subgroup analysis and metaregression showed that the use of different statin or dose did not result in significant variation in results in the parameters studied. TSA showed that more trials and patients are required to reach to a definitive conclusion regarding any effect on statins on functional outcome and mortality as the current studies neither reached the level of confidence nor crossed the futility boundary. CONCLUSION: Use of statins in patients with aneurysmal SAH resulted in marginal but non-significant favorable impact on functional outcome and mortality. TSA showed that more studies are required to get conclusive evidence in this regard.

Neurosurgery and Neurology Practices during the Novel COVID-19 Pandemic: A Consensus Statement from India.

BACKGROUND: The COVID-19 infection outbreak has aroused increasing attention and affected thousands of people nationwide. The long incubation period, high infectious rate, varied manifestation, and absence of effective treatment make it difficult to manage the disease transmission. OBJECTIVE: The intended goals are to encourage efficient management of neurological and neurosurgical patients, resource utilization, and protecting the healthcare provider during the COVID-19 epidemic. Herein, we present a consensus statement from various centers in India. METHODOLOGY: In addition to the literature review, recommendations were included from neurologists and neurosurgeons from various centers in India. RESULTS: Every patient presenting for treatment should be treated as a potential asymptomatic infected case. Patients should be categorized based upon the priority as acute (require immediate treatment/surgery within 24 h), sub-acute (requiring treatment within a maximum of 7-10 days), or chronic (requiring treatment within a month). Non-essential elective surgeries and outpatient clinics should be avoided after informing the patient(s). There is a high risk of aerosol dispersion during intubation and certain neurosurgical procedures particularly those involving drills and endoscopes. These procedures should be performed wearing full personal protective equipment. The workflow of the operating rooms should also be modified significantly. Minor modifications in personal and professional lifestyles and routine training to use the PPE will ensure efficient management of resources. CONCLUSION: These recommendations could be used to mitigate the risks and reduce exposure to other patients, public, and healthcare staff.

An institutional review of 10 cases of spinal hemangiopericytoma/solitary fibrous tumor.

BACKGROUND: Spinal hemangiopericytoma is very rare tumors with only a few case reports and one case series. We have treated ten patients between 2004 and 2017 and, thus, present a retrospective review of our patients with a focus on clinical presentation, radiological features, management, pathology, and outcome. MATERIALS AND METHODS: Histopathological data were reviewed in all the cases and clinical and follow-up details were collected from data available in our department. RESULTS: There were five males and five females, including one pediatric patient. The mean age of the patients was 34.7 years (Range 12-52 years). Dorsal, cervical, and lumbar spine involvement were found in five, four, and one patient, respectively. Intradural extramedullary tumor was the most common tumor and all patients presented motor weaknesses. Gross total resection of the tumor was done in seven patients and six patients received postoperative radiotherapy. Histopathology showed anaplastic tumor in two cases with high MIB-1 labelling index. Most patients were positive for CD34, vimentin, mic-2, and bcl-2. While the seven patients who underwent gross total resection improved significantly and were self-ambulatory in the follow-up period, two patients who underwent subtotal resection expired due to tumor metastasis. CONCLUSION: Spinal hemangiopericytoma is a very rare tumor. We present a series of cases treated at our institute for the same. Gross total resection is the goal and radiotherapy should be given in case of residual tumor or high-grade tumors. Prognosis is good after gross total excision and functional recovery can be expected in most patients.

Thiol-to-amine cyclization reaction enables screening of large libraries of macrocyclic compounds and the generation of sub-kilodalton ligands.

Macrocyclic compounds are an attractive modality for drug development, but the limited availability of large, structurally diverse macrocyclic libraries hampers the discovery of leads. Here, we describe the discovery of efficient macrocyclization reactions based on thiol-to-amine ligations using bis-electrophiles, their application to synthesize and screen large libraries of macrocyclic compounds, and the identification of potent small macrocyclic ligands. The thiol-to-amine cyclization reactions showed unexpectedly high yields for a wide substrate range, which obviated product purification and enabled the generation and screening of an 8988 macrocycle library with a comparatively small effort. X-ray structure analysis of an identified thrombin inhibitor (K i = 42 ± 5 nM) revealed a snug fit with the target, validating the strategy of screening large libraries with a high skeletal diversity. The approach provides a route for screening large sub-kilodalton macrocyclic libraries and may be applied to many challenging drug targets.

Detection of metabolic pattern following decompressive craniectomy in severe traumatic brain injury: A microdialysis study.

OBJECTIVE: The aim of the study was to detect mitochondrial dysfunction and ischaemia in severe traumatic brain injury and their relationship with outcome. METHODS: Forty-one patients with severe traumatic brain injury (TBI) who underwent decompressive craniectomy were prospectively monitored with intracerebral microdialysis catheters (MD). Variables related to energy metabolism were studied using microdialysis. RESULTS: Twentysix patients (63.4%) had a good outcome in terms of Glasgow outcome score (GOS) at 6 months while the rest (15 patients) had poor GOS at 6 months. Mitochondrial dysfunction was defined as Lactate Pyruvate ratio (LP ratio) > 25 and pyruvate <70 while ischaemia was defined as LP ratio > 25 and pyruvate >70. The poor outcome group showed significantly higher proportion of mitochondrial dysfunction 65.9% vs. 55.9% (p<0.001) and ischemia 13.9% vs. 7.2% (p<0.001) Conclusions: After decompressive craniectomy in severe TBI, patients with higher incidence of mitochondrial dysfunction and ischaemia were more likely to have poorer outcome with ischaemia having a more profound effect. ABBREVIATIONS: Traumatic brain injury (TBI), microdialysis (MD), lactate pyruvate ratio (LP ratio), Glasgow coma scale (GCS), Glasgow outcome scale (GOS), cerebral perfusion pressure (CPP), intracranial pressure (ICP), mitochondrial transition pore (MTP), non-contrast computed tomography (NCCT), traumatic axonal injury (TAI).

A clinicopathological study of primary central nervous system lymphomas & their association with Epstein-Barr virus.

BACKGROUND & OBJECTIVES: Primary central nervous system lymphomas (PCNSLs) are relatively uncommon, accounting for 2-3 per cent of primary brain tumours. Majority of these are diffuse large B cell lymphomas (DLBCL) occurring both in immunocompromised and immunocompetent patients. We undertook this study to classify PCNSL into germinal centre (GC) and non-germinal centre (NGC) type based on Hans classification and to find the role of Epstein-Barr virus (EBV) in pathogenesis both by conventional immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH). METHODS: The consecutive cases of PCNSL during a 10 years period were analysed by IHC for CD45, CD20, CD3, B-cell lymphoma 2 and 6 (Bcl-2 and Bcl-6), B-cell specific octamer binding protein-1 (BOB-1), multiple myeloma oncogene-1 (MUM-1), EBV latent-membrane protein 1 (LMP-1), cyclin-D1, CD10, CD5 and CD23, as well as by CISH for EBV. RESULTS: During a period of 10 years, 65 PCNSL were diagnosed which comprised 0.69 per cent (65/9476) of all intracranial tumours. The mean age of presentation was 49 yr with sex ratio (M:F) of 1.4:1. Most common location was supratentorial region with predominant involvement of frontal lobe. Single lesions were seen in 38 (58.4%) and multifocal lesions in 27 (41.5%) patients. None of the patients were immunocompromised. All cases were B cell immunophenotype and were DLBCL except one case of follicular lymphoma. According to Hans classification, majority of them were NGC (n=51, 79.6%) and 13 (20.3%) were GC type. Bcl-2 expression was noted in 34 (52.3%) tumours. EBV was positive in three (4.6%) cases; two were detected both by IHC and CISH and one case by CISH only. INTERPRETATION & CONCLUSIONS: In Indian population, PCNSL occurs mainly in immunocompetent patients, and a decade earlier than in western population. Immunophenotyping revealed that all cases were DLBCL with predominance of NGC type. No prognostic difference was seen between GC and NGC DLBCL. Association of EBV was rare and this virus was possibly not involved in the pathogenesis of PCNSL in immunocompetent individuals. CISH was an easy, economical and less cumbersome method for detection of EBV in PCNSL.

Early versus delayed decompression in acute subaxial cervical spinal cord injury: A prospective outcome study at a Level I trauma center from India.

AIMS: This study was done with the aim to compare the clinical outcome and patients' quality of life between early versus delayed surgically treated patients of acute subaxial cervical spinal cord injury. The current study was based on the hypothesis that early surgical decompression and fixations in acute subaxial cervical spinal cord trauma is safe and is associated with improved outcome as compared to delayed surgical decompression. MATERIALS AND METHODS: A total of 69 patients were recruited and divided into early decompression surgery Group A (operated within 48 h of trauma; n = 23) and late/delayed decompression surgery Group B (operated between 48 h and 7 days of trauma; n = 46). The patients in both groups were followed up, and comparative differences noted in the neurological outcome, quality of life, and bony fusion. RESULTS: The early surgery group spent lesser days in the intensive care unit and hospital (Group A 28.6 vs. Group B 35 days) had lesser postoperative complications (Group A 43% vs. Group B 61%) and a reduced mortality (Group A 30% vs. Group B 45%). In Group A, 38% patients had 1 American Spinal Injury Association (ASIA) grade improvement while 31% experienced >2 ASIA grade improvement. In Group B, the neurological improvement was 27% and 32%, respectively (P = 0.7). There was a significant improvement in the postoperative quality of life scores in both groups. CONCLUSION: Early surgery in patients with acute subaxial cervical spine injury should be considered strongly in view of the lesser complications, early discharge, and reduced mortality.

Tachycardia in breast reconstructive microsurgery: Affirmation of the IMA tachycardia syndrome.

INTRODUCTION: The internal mammary vessels are frequently chosen as recipient vessels for breast free flap reconstruction. We have noticed that when using the internal mammary recipients that these patients have a propensity for tachycardia that was not previously observed. Our aim was to investigate the factors related to perioperative tachycardia in the microsurgical breast reconstruction population and to address whether use of the internal mammary system is a causative factor in tachycardia. METHODS: A retrospective chart review was conducted to identify patients who underwent abdominal-based microvascular breast reconstruction at the Washington University School of Medicine between 2002 and 2012 to identify the presence of tachycardia. After application of exclusion criteria, 76 microvascular abdominal-based free flap reconstructions were identified. The internal mammary (IM) TRAM group (n = 24) and the thoracodorsal (TD) TRAM group (n = 52) were compared. A binomial logistic regression was performed with the presence of tachycardia as the dependent variable. RESULTS: There was a higher incidence of tachycardia in the IM TRAM group when compared to the TD TRAM group (p = 0.004). The variables predictive of tachycardia in our logistic regression model were IMA recipient (p = 0.04), need for transfusion (p = 0.03), and presence of fever (p = 0.01). CONCLUSION: Our study reaffirms that there are several factors that are predictive of tachycardia in the setting of microvascular breast reconstruction. The IMA syndrome should be a recognized cause of tachycardia as using these recipient vessels are shown to be predictive of postoperative tachycardia as shown in our study.

Indigenously developed multipurpose acrylic head phantom for verification of IMRT using film and gel dosimetry.

The purpose of this study was to validate the newly designed acrylic phantom for routine dosimetric purpose in radiotherapy. The phantom can be used to evaluate and compare the calculated dose and measured dose using film and gel dosimetric methods. In this study, a doughnut-shaped planning target volume (8.54 cm3) and inner organ at risk (0.353 cm3) were delineated for an IMRT test plan using the X-ray CT image of the phantom. The phantom consists of acrylic slabs which are integrated to form a human head with a hole in the middle where several dosimetric inserts can be positioned for measurement. An inverse planning with nine coplanar intensity-modulated fields was created using Pinnacle TPS. For the film analysis, EBT2 film, flatbed scanner, in-house developed MATLAB codes and ImageJ software were used. The 3D dose distribution recorded in the MAGAT gel dosimeter was read using a 1.5 T MRI scanner. Scanning parameters were CPMG pulse sequence with 8 equidistant echoes, TR = 5600, echo step = 22 ms, pixel size = 0.5 × 0.5, slice thickness = 2 mm. Using a calibration relationship between absorbed dose and spin-spin relaxation rate (R2), R2 images were converted to dose images. The dose comparison was accomplished using in-house MATLAB-based graphical user interface named "IMRT3DCMP". For gel measurement dose grid from the TPS was extracted and compared with the measured dose grid of the gel. Gamma index analysis of film measurement for the tolerance criteria of 2%/2mm, 1%/1 mm showed more than 90% voxels pass rate. Gamma index analysis of 3D gel measurement data showed more than 90% voxels pass rate for different tolerance criteria of 2%/2 mm and 1%/1 mm. Overall both 2D and 3D measurement were in close agreement with the Pinnacle TPS calculated dose. The phantom designed is cost-effective and the results are promising, but further investigation is required to validate the phantom with other 3D conformal techniques for dosimetric purpose.

Role of simvastatin in prevention of vasospasm and improving functional outcome after aneurysmal sub-arachnoid hemorrhage: a prospective, randomized, double-blind, placebo-controlled pilot trial.

BACKGROUND: Vasospasm plays a major role in the morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). The preliminary studies suggest that statins protect against cerebral vasospasm. OBJECTIVE: The aim of the study was to determine the role of simvastatin in preventing clinical vasospasm and improving functional outcome in patients with aSAH. METHODS: All patients with aSAH admitted within 96 h of ictus were randomized to receive either Simvastatin or placebo - 80 mg/day for 14 days. Thirty eight patients were recruited in the study- 19 received Simvastatin and 19 placebo. All the patients underwent surgical clipping of the aneurysm. The primary outcome of the study was the development of clinical cerebral vasospasm. The secondary outcomes included Glasgow Outcome Score (GOS), Modified Rankin Scale (MRS) and Barthel Index Score (MBI) at follow-up at 1, 3 and 6 months. RESULTS: 16% of the patients in the simvastatin group had high Middle Cerebral Artery velocities (> 160 cm/sec) on transcranial Doppler on one or more than one day during the study duration as compared to 26% of the patients in the placebo group (p = 0.70). Neurological deterioration occurred in 26% and 42% of the patients in simvastatin group versus placebo group, respectively (p = 0.31). There was an improvement in the functional outcome in the simvastatin group at 1, 3 or 6 months in the follow-up; however, this difference was not statistically significant. CONCLUSIONS: There was benefit of simvastatin in terms of reduction in clinical vasospasm, mortality or improved functional outcome, however, this was not statistically significant.

Primary tethered cord syndrome--clinical and urological manifestations, diagnosis and management: a prospective study.

Primary tethered cord syndrome refers to a group of neural tube defects that are not externally obvious, and, if detected at an early age, surgical intervention may prevent the significant irreversible neurological deficits. This study was performed to evaluate the presenting clinical features of patients with primary tethered cord syndrome and the indications of surgery in such patients as well as the clinical and urological outcome. In all cases, the indication for surgery was the presence of a tethered cord on magnetic resonance imaging, the criteria for tethering being a low-lying conus (below L1-L2) and a thickened filum (>2 mm). Urodynamic studies were performed before detethering. Microsurgical detethering of low-lying cord was then performed, and the patients were then followed clinically and urologically for 6 months. Pain responded the most to detethering while limb weakness and urological symptoms responded the least. Clinical improvement in urological symptoms correlated with improvement in urodynamic parameters. A urodynamic study identified improvement in a larger number of patients and also deterioration in a few patients which was not visible clinically; this may point to its high sensitivity and usefulness in preceding clinical manifestations in a future follow-up.

Pediatric bony craniovertebral junction abnormalities: Institutional experience of 10 years.

OBJECTIVE: To study the clinical features and treatment outcome of pediatric patients with bony craniovertebral abnormalities. MATERIALS AND METHODS: The authors studied 189 consecutive cases of pediatric bony craniovertebral junction abnormalities operated between 2001 and March, 2010. RESULTS: The pathologies were developmental (n = 162), traumatic (n = 18) and tuberculous (n = 9). Surgical procedures included transoral decompression (n = 118), occipitocervical fusion (OCF, n = 139), C 1 -C 2 fusion (n = 45), and posterior fossa decompression (n = 5). Methods for OCF included contoured stainless steel rods (n = 86), titanium lateral mass screws and plates (n = 47) and steel wires (n = 6). Constructs of all patients of posterior fixation with contoured rods and wires or lateral mass screw and rod who could be followed up were either stable/fused or were fused and stable. No implant failure was noticed among these two surgical procedures. However, 6 patients with C 1-C 2 fusion had broken wires on follow-up requiring repeat posterior fixation. Good neurological outcome was observed even in poor-grade patients. No significant effect on the curvature or growth of the spine was observed at follow-up. CONCLUSIONS: Pediatric craniovertebral junction anomalies can be managed successfully with good outcomes using a low cost contoured rod and wires.