Cost-effectiveness of surgery for degenerative cervical myelopathy in the United Kingdom.

PURPOSE: Degenerative cervical myelopathy (DCM) is the commonest cause of adult spinal cord dysfunction worldwide, for which surgery is the mainstay of treatment. At present, there is limited literature on the costs associated with the surgical management of DCM, and none from the United Kingdom (UK). This study aimed to evaluate the cost-effectiveness of DCM surgery within the National Health Service, UK. MATERIALS AND METHODS: Incidence of DCM was identified from the Hospital Episode Statistics (HES) database for a single year using five ICD-10 diagnostic codes to represent DCM. Health Resource Group (HRG) data was used to estimate the mean incremental surgery (treatment) costs compared to non-surgical care, and the incremental effect (quality adjusted life year (QALY) gain) was based on data from a previous study. A cost per QALY value of <£30,000/QALY (GBP) was considered acceptable and cost-effective, as per the National Institute for Health and Clinical Excellence (NICE) guidance. A sensitivity analysis was undertaken (±5%, ±10% and ±20%) to account for variance in both the cost of admission and QALY gain. RESULTS: The total number of admissions for DCM in 2018 was 4,218. Mean age was 62 years, with 54% of admissions being of working age (18-65 years). The overall estimated cost of admissions for DCM was £38,871,534 for the year. The mean incremental (per patient) cost of surgical management of DCM was estimated to be £9,216 (ranged £2,358 to £9,304), with a QALY gain of 0.64, giving an estimated cost per QALY value of £14,399/QALY. Varying the QALY gain by ±20%, resulted in cost/QALY figures between £12,000 (+20%) and £17,999 (-20%). CONCLUSIONS: Surgery is estimated to be a cost-effective treatment of DCM amongst the UK population.

Can AI pass the written European Board Examination in Neurological Surgery? - Ethical and practical issues.

Introduction: Artificial intelligence (AI) based large language models (LLM) contain enormous potential in education and training. Recent publications demonstrated that they are able to outperform participants in written medical exams. Research question: We aimed to explore the accuracy of AI in the written part of the EANS board exam. Material and methods: Eighty-six representative single best answer (SBA) questions, included at least ten times in prior EANS board exams, were selected by the current EANS board exam committee. The questions' content was classified as 75 text-based (TB) and 11 image-based (IB) and their structure as 50 interpretation-weighted, 30 theory-based and 6 true-or-false. Questions were tested with Chat GPT 3.5, Bing and Bard. The AI and participant results were statistically analyzed through ANOVA tests with Stata SE 15 (StataCorp, College Station, TX). P-values of <0.05 were considered as statistically significant. Results: The Bard LLM achieved the highest accuracy with 62% correct questions overall and 69% excluding IB, outperforming human exam participants 59% (p = 0.67) and 59% (p = 0.42), respectively. All LLMs scored highest in theory-based questions, excluding IB questions (Chat-GPT: 79%; Bing: 83%; Bard: 86%) and significantly better than the human exam participants (60%; p = 0.03). AI could not answer any IB question correctly. Discussion and conclusion: AI passed the written EANS board exam based on representative SBA questions and achieved results close to or even better than the human exam participants. Our results raise several ethical and practical implications, which may impact the current concept for the written EANS board exam.

Early management of adult traumatic spinal cord injury in patients with polytrauma: a consensus and clinical recommendations jointly developed by the World Society of Emergency Surgery (WSES) & the European Association of Neurosurgical Societies (EANS).

BACKGROUND: The early management of polytrauma patients with traumatic spinal cord injury (tSCI) is a major challenge. Sparse data is available to provide optimal care in this scenario and worldwide variability in clinical practice has been documented in recent studies. METHODS: A multidisciplinary consensus panel of physicians selected for their established clinical and scientific expertise in the acute management of tSCI polytrauma patients with different specializations was established. The World Society of Emergency Surgery (WSES) and the European Association of Neurosurgical Societies (EANS) endorsed the consensus, and a modified Delphi approach was adopted. RESULTS: A total of 17 statements were proposed and discussed. A consensus was reached generating 17 recommendations (16 strong and 1 weak). CONCLUSIONS: This consensus provides practical recommendations to support a clinician's decision making in the management of tSCI polytrauma patients.

Role of Navigation in the Surgery of Spine Tumours.

Computer-assisted navigation has emerged in neurosurgery as an approach to improve intraoperative orientation and achieve better surgical results with lower complication rates. While the initial use was focused around precise identification of the surgical target, the current applications are much wider and continue to rapidly expand.Here we report our review of the main applications of navigation in spine surgery with a focus on the surgery of spine tumours operated in Sheffield Teaching Hospitals in the past 10 years (2010-2020). In our unit, intraoperative navigation became a helpful and routine adjunct to the modern armamentarium of a spinal surgeon and is currently used not just for accurate placement of the implants but also for precise demarcation of the tumour margins, as well as for identification of important anatomical structures that must be preserved.Conclusion: Intraoperative navigation is a technology that helped us to improve intraoperative orientation to the unexposed anatomy and reduce the risk of iatrogenic complications; achieve better tumour resection; improve the spinal biomechanical construction; provide a safer learning environment for the spinal surgical trainees; minimise radiation exposure of the surgical team and shorten the operating time. In our opinion, it was helpful not only to reduce the risk of complications but also to perform procedures, which without navigation would have been considered inoperable or very high risk.

Factors Influencing Surgical Decision-Making in the Posterior Laminectomy With Fixation for Degenerative Cervical Myelopathy (POLYFIX-DCM) Trial: Survey Study.

BACKGROUND: Degenerative cervical myelopathy (DCM) is estimated to affect 2% of the adult population. DCM occurs when degenerative processes cause compression and injure the spinal cord. Surgery to remove the stress caused by the compression of the spinal cord is the mainstay of treatment, with a range of techniques in use. Although various factors are described to inform the selection of these techniques, there needs to be more consensus and limited comparative evidence. OBJECTIVE: The main objective of this survey was to explore the variation of practice and decision-making, with a focus on laminectomy versus laminectomy and fusion in posterior surgery of the cervical spine. We present the results of a survey conducted among the principal investigators (PIs) of the National Institute for Health and Care Research (NIHR) randomized controlled trial on posterior laminectomy with fixation for degenerative cervical myelopathy (POLYFIX-DCM). METHODS: A series of 7 cases were shared with 24 PIs using SurveyMonkey. Each case consisted of a midsagittal T2-weighted magnetic resonance imaging and lateral cervical x-rays in flexion and extension. Surgeons were asked if their preferred approach was anterior or posterior. If posterior, they were asked whether they preferred to instrument and whether they had the equipoise to randomize in the NIHR POLYFIX-DCM trial. Variability in decision-making was then explored using factors reported to inform decision-making, such as alignment, location of compression, number of levels operated, presence of mobile spondylolisthesis, and patient age. RESULTS: The majority of PIs (16/30, 53%) completed the survey. Overall, PIs favored a posterior approach (12/16, 75%) with instrumentation (75/112, average 66%) and would randomize (67/112, average 62%) most cases. Factors reported to inform decision-making poorly explained variability in responses in both univariate testing and with a multivariate model (R2=0.1). Only surgeon experience of more than 5 years and orthopedic specialty training background were significant predictors, both associated with an anterior approach (odds ratio [OR] 1.255; P=.02 and OR 1.344; P=.007, respectively) and fusion for posterior procedures (OR 0.628; P<.001 and OR 1.344; P<.001, respectively). Surgeon experience also significantly affected the openness to randomize, with those with more than 5 years of experience less likely to randomize (OR -0.68; P<.001). CONCLUSIONS: In this representative sample of spine surgeons participating in the POLYFIX-DCM trial as investigators, there is no consensus on surgical strategy, including the role of instrumented fusion following posterior decompression. Overall, this study supports the view that there appears to be a clinical equipoise, and conceptually, a randomized controlled trial appears feasible, which sets the scene for the NIHR POLYFIX-DCM trial.

Working in low- and middle-income countries: Learning from each other.

•Barriers may limit LMICs-HICs collaborations: infrastructure, equipment's lack/inadequacy, political issues, brain drain.•Local training is crucial for universal health coverage; several activities are headed by Global Neurosurgery organisations.•The â€‹EANS Global and Humanitarian Neurosurgery Committee aims to become a gateway for partnerships between HICs and LMICs.

Safety and feasibility of same-day discharge following lumbar decompression surgery: A systematic review.

Introduction: Lumbar decompression (LD) surgery, with or without discectomy, is a commonly performed surgical procedure. Despite the concept of day-case LD being reported as early as the 1980s, day-case LD is yet to become routine clinical practice. Research question: This systematic review aimed to examine the published literature on the safety and complication rates of day-case LD. Secondary outcome measures, including the economic impact and patient satisfaction of day-case LD, were also examined. Materials and methods: A systematic electronic search was carried out on PubMed, EMBASE and the Cochrane Library between 1999 and January 2022. Studies were screened against predefined inclusion/exclusion criteria with the quality of included studies subsequently being assessed. Results: In total, 15 studies were included in this review. The majority of studies were undertaken in the USA (n â€‹= â€‹8, 53%) and were of a case series design (n â€‹= â€‹9, 60%). Reported complication rates ranged from 0% to 7.8%, with nine studies reporting a complication rate of <4%. Readmission rates ranged from 0% to 7.7%. Seven studies quoted a readmission rate of 0%. Five studies found cost saving benefits of day-case LD in comparison to inpatient LD of up to $27,984 (USD). Patient acceptability of day-case LD was consistently high across the six studies that assessed it. Discussion and conclusion: Day-case LD surgery is a safe and economically efficient surgical option in appropriately selected patients.

Clinical-Instrumental Results and Analysis of Functional Activity Restoration in Professional Athletes After Lumbar Total Disk Replacement.

OBJECTIVE: To analyze the clinical and biomechanical outcome of professional athletes after lumbar total disk replacement, with a focus on restoration of the functional activity. METHODS: This nonrandomized retrospective single-center study included 11 professional athletes who underwent lumbar disc replacement surgery using the prosthesis M6-L (Spinal Kinetics, Schaffhausen, Switzerland). The average postoperative follow-up was 3.18 ± 1.14 years. The following outcomes were evaluated: intensity of pain in the lumbar spine and lower limbs, Oswestry Disability Index, Short-Form 36, complications, time of return to previous sports activity, range of movement, degree of lumbar lordosis, degenerative changes of the adjacent levels, and degree of heterotopic ossification. RESULTS: The operated patients reported significant decrease of pain on visual analog scale (P < 0.001) as well as significant improvement of Oswestry Disability Index (P = 0.001) and Short-Form 36 (P < 0.001). For the duration of follow-up, the patients maintained segmental range of motion at L4-L5 (P = 0.04) and L5-S1 (P = 0.03) levels. There was also some statistically insignificant increase of global lumbar lordosis (P = 0.84). We did not identify any significant degeneration of the adjacent intervertebral disks (P > 0.05) or progression of the facet joint degenerative changes at the implantation level and in the adjacent segments (P > 0.05). One patient (9.1%) developed grade I heterotopic ossification 5 years after surgery and in 1 patient (9.1%), a lesion of superior hypogastric plexus was recorded. The average time of return to previous sports activity was 9.72 ± 3.03 weeks. CONCLUSIONS: Total lumbar disc replacement using M6-L prosthesis in professional athletes made it possible to achieve statistically significant reduction of pain and facilitated early return to normal sports activities. In our opinion, preservation of movement of the operated lumbar segment can help to reduce the mechanical stress with beneficial impact on the rate of degeneration of the adjacent level.

Llif in the correction of degenerative scoliosis in elderly patients / Llif na correção da escoliose degenerativa em pacientes idosos / Llif en la corrección de la escoliosis degenerativa en pacientes de la tercera edad

ABSTRACT Objective The incidence of adult degenerative scoliosis (ADS) among individuals over 50 years old can be as high as 68%. Surgical interventions aimed at correcting the spinal deformity in elderly patients are accompanied by a high risk of complications. The use of lateral lumbar interbody fusion (LLIF) is associated with lower rates of complications when compared with open anterior or posterior fusions. Methods Ninety-three patients with ADS (23 men, 70 women) were operated at the Federal Neurosurgical Center. The average age was 63 (52 to 73 years). Results Back pain, measured according to the Visual Analogue Scale (VAS), decreased from 5.9/6 (4;8) (format - mean/median (1;3 quartile)) to 2.6/3 (1;3) points (p <0.0001). Leg pain according to the VAS decreased from 4.6/4 (3;7) to 1.4/1 (0;2) points (p < 0.0001). Functional adaptation according to the Oswestry Disability Index (ODI) improved from 47.8±17.4 to 38.5±14.5 (p < 0.0273). Pelvic tilt (PT) before the surgery was 23.9±12.2° whereas at 12 months follow-up it was 16.8±5.9° (p < 0.0001). PI-LL mismatch pre surgery was 12.1/13 (9;16)° whereas 12 months later it was 7.9/8 (6;10)° (p = 0.0002). Conclusions Restoration of local sagittal balance in ADS patients by short-segment fixation using LLIF technology leads to a statistically significant improvement in quality of life and increased functional adaptation. A lower incidence of early and late postoperative complications, less intraoperative blood loss and shorter hospital stay makes LLIF, in combination with minimally invasive transpedicular fixation, the method of choice to correct ADS in elderly patients. Level of evidence IV; Case series.

RESUMO Objetivo A incidência de escoliose degenerativa do adulto (EDA) entre indivíduos acima de 50 anos, pode chegar a 68%. As intervenções cirúrgicas destinadas a corrigir a deformidade da coluna vertebral em pacientes idosos são acompanhadas por um alto risco de complicações. A fusão intersomática lombar por via lateral (LLIF) está associado a uma taxa menor de complicações em comparação com as fusões anteriores ou posteriores abertas. Métodos Noventa e três pacientes com EDA (23 homens, 70 mulheres) foram operados no Centro Federal de Neurocirurgia. A média de idade foi de 63 anos (52 a 73 anos). Resultados A dor nas costas, de acordo com a escala visual analógica (EVA) diminuiu de 5,9/6 (4; 8 quartis) (formato média/mediana [1; 3 quartis]) para 2,6/3 (1; 3 quartis) (p < 0,0001). A dor nas pernas, também de acordo com a EVA, diminuiu de 4,6/4 (3; 7 quartis) para 1,4/1 (0; 2 quartis) (p < 0,0001). A adaptação funcional, de acordo com o Índice de Incapacidade de Oswestry (ODI) melhorou de 47,8 ± 17,4 para 38,5 ± 14,5 (p < 0,0273). A inclinação pélvica (PT) antes da cirurgia era de 23,9 ± 12,2°, enquanto nos 12 meses de acompanhamento era de 16,8 ± 5,9 (p < 0,0001). A incompatibilidade pré-cirúrgica de IP-LL foi de 12,1/13 (9; 16), enquanto 12 meses depois foi de -7,9/8 (6; 10) (p = 0,0002). Conclusões A restauração do equilíbrio sagital local em pacientes com EDA por fixação de segmento curto, usando a tecnologia LLIF, proporciona melhora estatisticamente significativa na qualidade de vida e aumenta a adaptação funcional. A menor incidência de complicações pós-operatórias precoces e tardias, a menor perda sanguínea intraoperatória e menor tempo de internação possibilitam que a LLIF, em combinação com a fixação transpedicular minimamente invasiva, seja o método de escolha para corrigir a EDA em pacientes idosos. Nível de evidência IV; Série de casos.

RESUMEN Objetivo La incidencia de escoliosis degenerativa del adulto (EDA) entre individuos con más de 50 años puede llegar a 68%. Las intervenciones quirúrgicas destinadas a corregir la deformidad de la columna vertebral en pacientes del grupo de la tercera edad son acompañadas por un alto riesgo de complicaciones. La fusión intersomática lumbar por vía lateral (LLIF) está asociada a una tasa menor de complicaciones en comparación con las fusiones anteriores o posteriores abiertas. Métodos Noventa y tres pacientes con EDA (23 hombres, 70 mujeres) fueron operados en el Centro Federal de Neurocirugía. El promedio de edad fue de 63 años (52 a 73 años). Resultados El dolor de espalda, de acuerdo con la escala visual analógica (EVA) disminuyó de 5,9/6 (4; 8 cuartiles) (formato promedio/mediana [1; 3 cuartiles) para 2,6/3 (1; 3 cuartiles) (p <0,0001). El dolor en las piernas, también de acuerdo con EVA, disminuyó de 4,6/4 (3; 7 cuartiles) para 1,4/1 (0; 2 cuartiles) (p <0,0001). La adaptación funcional, de acuerdo con el Índice de Incapacidad de Oswestry (ODI) mejoró de 47,8 ± 17,4 para 38,5 ± 14,5 (p <0,0273). La inclinación pélvica (PT) antes de la cirugía era de 23,9 ± 12,2°, mientras que en los 12 meses de acompañamiento fue de 16,8 ± 5,9 (p <0,0001). La incompatibilidad prequirúrgica de IP-LL fue de 12,1/13 (9; 16), mientras que 12 meses después fue de -7,9/8 (6; 10) (p = 0,0002). Conclusiones La restauración del equilibrio sagital local en pacientes con EDA por fijación de segmento corto, usando la tecnología LLIF, proporciona mejora estadísticamente significativa en la calidad de vida y aumenta la adaptación funcional. La menor incidencia de complicaciones postoperatorias precoces y tardías, la menor pérdida sanguínea intraoperatoria y un menor tiempo de internación posibilitan que la LLIF, en combinación con la fijación transpedicular mínimamente invasiva, sea el método de elección para corregir la EDA en pacientes de la tercera edad. Nivel de evidencia IV; Series de casos.

Comparison of Navigated versus Fluoroscopic-Guided Pedicle Screw Placement Accuracy and Complication Rate.

OBJECTIVES: Accurate placement of the pedicle screw is requisite for any successful spinal instrumentation procedure. Screw insertion can be achieved using free-hand and fluoroscopic- or navigation-guided techniques. We sought to assess the variation in accuracy between fluoroscopic- and navigation-guided techniques, which are both used in Sheffield Teaching Hospitals National Health Service Trust, a tertiary spine referral center. METHODS: Using a retrospective study design, we assessed all the pedicle screws placed between 2013 and 2018. Radiographic and clinical assessment of all cases was performed. RESULTS: We studied 176 spinal instrumented cases, with a total of 831 screws implanted, out of which 296 (35.6%) were navigated and 535 (64.4%) were fluoroscopic guided. Pathology treated included spinal stenosis, spondylolisthesis, tumors, and trauma. Suboptimal screw position was identified in 2.03% (n = 6) of the navigation-guided series and 4.11% (n = 22) of the fluoroscopic-guided series with an overall screw misplacement rate of 3.4%. Evaluating surgeons' individual accuracy rates revealed that suboptimal screw placement registered a higher variation for the fluoroscopy-guided technique, and the misplacement rate was higher for surgeons with a lower volume of cases. CONCLUSIONS: Use of navigation during spinal instrumentation helps lower the rate of screw misplacement for spinal surgeons who are at the beginning of their learning curve or do not frequently perform this kind of procedure. Navigation-guided spinal instrumentation is more accurate compared with fluoroscopic-guided techniques and appears to have a lower complication rate.

Giant spinal nerve sheath tumours - Surgical challenges: case series and literature review.

Background: Giant nerve sheath tumours (GNST) are rare and literature on their management is scant. Spinal GNST present as a surgical challenge due to the involvement of anatomical regions often outside the "comfort zone" of a spinal surgeon. This case series aims to identify challenges in the surgical management of GNSTs. Methods: Retrospective case note review of all spinal GNST cases from 2010 to 2016 managed in Sheffield Teaching Hospitals identified 8 patients, 3 of whom were incidental findings (kept under surveillance) and were excluded. 5 cases were treated surgically. Data collected included patient demographic, presenting symptom(s), radiological data, surgical approach to the tumour and challenges encountered, histopathology report and follow up. Results: Our cohort consisted entirely of females (N = 5) with a mean age of 56.4 years (range 45-70). Imaging studies and histopathological diagnoses confirmed 5 GNSTs (four benign schwannomas and one ganglioneuroma). A Single-stage anterior approach was adopted for three patients while a combined anterior-posterior approach was adopted for the remaining two. In one patient, a posterior approach was initially planned, but this was abandoned and converted to an anterior approach following onset of acute superior vena cava (SVC) syndrome secondary to SVC compression by the giant tumour on prone positioning of the patient. PET imaging of case 3 showed intense tracer uptake consistent with malignancy, however histology confirmed WHO grade 1 Schwannoma. The other three non-operated GNSTs are kept under yearly radiological and clinical surveillance. Conclusions: GNSTs are surgically challenging as they often invade territories that are beyond the comfort zone of one single specialty. A multidisciplinary approach with careful pre-operative surgical planning is recommended. Patients in whom a posterior approach is planned should have a trial of prone positioning pre-operatively. Careful interpretation of FDG-PET imaging is recommended due to the possibility of false positive result.

Using Intraoperative Ultrasonography for Spinal Cord Tumor Surgery.

BACKGROUND: Our aim was to evaluate the usefulness of modern intraoperative ultrasonography (iUS) in the resection of a wide variety of spinal intradural pathologic entities. METHODS: We evaluated patients with spinal cord disease treated between January 2006 and September 2015. Intraoperative standard B-mode images were acquired using a 3.5-MHz to 12-MHz ultrasonographic probes (linear and curvilinear) on various ultrasound machines. The benefits and disadvantages of iUS were assessed for each case. RESULTS: A total number of 158 intradural spinal lesions were operated on using iUS. Of these, 107 lesions (68%) were intradural extramedullary and 51 (32%) were intramedullary. All lesions were clearly visible using the ultrasound probe. The high-frequency linear probes (10-12 MHz) provided a better image quality compared with lower-frequency probes. Color and power-angiography modes were helpful in assessing the vascularization of the tumors and location of the major vessels in the vascular lesions. DISCUSSION: We document how iUS was used to facilitate safe and efficient spinal tumor resection at each stage of the operation. iUS was beneficial in confirmation of tumor location and extension, planning myelotomy, and estimation of degree of resection of the intramedullary tumors. It was particularly helpful in guiding the approach in redo surgeries for recurrent spinal cord tumors. CONCLUSIONS: iUS has a fast learning curve and offers additional intraoperative information that can help improve surgical accuracy and therefore may reduce procedure-related morbidity.

Hydrocephalus and Papilledema in Spinal Cord Tumors: A Report of Two Cases.

Background The association between spinal cord tumors and hydrocephalus is a rarely reported phenomenon. Diagnosis in this group of patients is difficult as they present with findings of an intracranial pathology and the symptoms of a spinal lesion may be absent. Case Report We report two cases of spinal cord tumors presenting with visual disturbance and findings of increased intracranial pressure. Discussions Mechanisms describing the relationship between spinal cord tumors and increased intracranial pressure have been explained. Most of the literature reported marked regression of these manifestations after tumor excision. Conclusions Spinal cord tumors associated with hydrocephalus and papilledema are rare conditions. The diagnosis of these conditions may be difficult or confusing because the symptoms referable to the spinal lesion may be minimal. Meticulous history taking, examination, and investigations are mandatory to diagnose this entity.

Fracture through fused cervical segments following trauma in a patient with Klippel-Feil syndrome.

Klippel-Feil syndrome (KPS) is a congenital spinal deformity characterised by the presence of at least one fused cervical segment. We report an unusual case of a fracture through fused cervical segment in a patient with KPS, who presented with quadriparesis and progressed on to develop respiratory failure and quadriplegia and who had a successful outcome following surgery. To the best of our knowledge, fracture through fused cervical segments in a Klippel-Feil patient has not been reported previously and this case report extends the spectrum of injuries seen in patients with KPS.

The value of intraoperative ultrasound in the recognition of pseudo-swelling of the spinal cord.

We present the case of a woman who presented with weakness of both legs due to a low grade tumor of the spinal cord. Excision of the tumor was performed and confirmed with intraoperative ultrasound. Prior to dural closure the spinal cord was found to be pushed dorsally with herniation of the cord through the dural defect. Intraoperative ultrasound showed a collection of cerebrospinal fluid in an anterior pocket giving the impression of the cord being swollen. Once cerebrospinal fluid was drained, the cord settled within the thecal space and closure of the dural defect was performed. Surgery for an intramedullary spinal cord tumor can cause a significant amount of swelling and either a duroplasty is required or the dura is left open with meticulous closure of the wound. Ultrasound is helpful to identify pathology anterior to the cord and prevents the potential complications associated with duroplasty or leaving the dura open.

A practical grading system of ultrasonographic visibility for intracerebral lesions.

BACKGROUND: Intraoperative ultrasound for intracranial neurosurgery was largely abandoned in the 1980s due to poor image resolution. Despite many technological advances in ultrasound since then, the use of this imaging modality in contemporary practice remains limited. Our aim was to evaluate the utility of modern intraoperative ultrasound in the resection of a wide variety of intracranial pathologies. METHODS: A total of 105 patients who underwent intracranial lesion resection in a contiguous fashion were prospectively included in the study. Ultrasound images acquired intraoperatively were used to stratify lesions into one of four grades (grades 0-3) on the basis of their ultrasonic echogenicity and border visibility. RESULTS: Forty-two out of 105 lesions (40 %) were clearly identifiable and had a clear border with normal tissue (grade 3). Fifty-five of 105 lesions (52 %) were clearly identifiable but had no clear border with normal tissue (grade 2). Eight of 105 lesions (8 %) were difficult to identify and had no clear border with normal tissue (grade 1). None (0 %) of the lesions could not be identified (grade 0). High-grade gliomas, cerebral metastases, meningiomas, ependymomas, and haemangioblastomas all demonstrated a median ultrasonic visibility grade of 2 or greater. Low-grade astrocytomas and oligodendrogliomas demonstrated a median ultrasonic visibility grade of 2 or less. CONCLUSION: Intraoperative ultrasound can be of tremendous benefit in allowing the surgeon to appraise the location, extent, and local environment of their target lesion, as well as to reduce the risk of preventable complications. We believe that our grading system will provide a useful adjunct to the neurosurgeon when deciding for which lesions intraoperative ultrasound would be useful.

Neuronavigation. Principles. Surgical technique.

Neuronavigation and stereotaxy are techniques designed to help neurosurgeons precisely localize different intracerebral pathological processes by using a set of preoperative images (CT, MRI, fMRI, PET, SPECT etc.). The development of computer assisted surgery was possible only after a significant technological progress, especially in the area of informatics and imagistics. The main indications of neuronavigation are represented by the targeting of small and deep intracerebral lesions and choosing the best way to treat them, in order to preserve the neurological function. Stereotaxis also allows lesioning or stimulation of basal ganglia for the treatment of movement disorders. These techniques can bring an important amount of confort both to the patient and to the neurosurgeon. Neuronavigation was introduced in Romania around 2003, in four neurosurgical centers. We present our five-years experience in neuronavigation and describe the main principles and surgical techniques.