Andreas K. Demetriades

Malignant transformation of acoustic neuroma/vestibular schwannoma 10 years after gamma knife stereotactic radiosurgery.

Only a handful of cases of de-novo malignancies of the vestibulocochlear nerve have been reported. Even rarer is the malignant transformation of a previously histologically diagnosed benign vestibular schwannoma. We present the case of a young adult who had combined operative/Gamma knife treatment for a benign vestibular schwannoma, followed by further surgery 2 years later. He represented 10 years after original diagnosis with facial numbness and ataxia, MRI showing gross tumor recurrence. After radical resection, histology showed malignant transformation to a malignant peripheral nerve sheath tumor. Within 3 months there was rapid, aggressive recurrence with brainstem compression, requiring further surgery for brainstem decompression. Histology confirmed further de-differentiation to an anaplastic sarcoma. While awaiting radiotherapy the tumor recurred again, the patient succumbing. The patient had no features of neurofibromatosis type 2. In the literature there are 13 other cases of malignant vestibular schwannomata. Only six had radiotherapy and of these only two had histological confirmation of a benign lesion preradiotherapy. Neither of these had neurofibromatosis. Three other cases had histological proof of malignancy postradiosurgery, but with no preradiotherapy histology; of these, two were positive for neurofibromatosis. The tumor biology of vestibular schwannomata as well as the radiobiology in the context of malignant transformation is discussed.

Radiation exposure to the surgeon and the patient during posterior lumbar spinal instrumentation: a prospective randomized comparison of navigated versus non-navigated freehand techniques.

Study Design. A prospective randomized study. Objective. To compare occupational radiation exposure to the surgeon, as well as the patient, during posterior lumbar spine instrumentation in 10 navigated cases (navigated) versus 11 cases using the freehand technique (non-navigated). Summary of Background Data. The use of navigation increases the accuracy of posterior lumbar instrumentation. A further speculated benefit of navigation is the reduction of radiation exposure of the surgeon. However, this has so far not been evaluated in such comparative manner. Methods. Radiation exposure to the surgeon was measured by digital dosimeters placed at the level of the eye, chest, and dominant forearm. Radiation exposure was measured from the time of positioning of the patient to the end of the procedure both for navigated (intraoperative 3-dimensional [3D] fluoroscopy-based) and non-navigated (2-dimensional fluoroscopy-guided) freehand posterior lumbar spine instrumentations. A 3D fluoroscopic scan was routinely performed at the end of the procedure for all patients. Results. Patients were distributed evenly in the 2 groups in terms of sex, age, body mass index, and the number of operated levels. The accumulated radiation dose for the surgeon was significantly higher in the non-navigated group; up to 9.96 times. The radiation dose for the patient was higher with the freehand technique, 1884.8 cGy·cm2 (non-navigated) versus 887 cGy·cm2 (navigated), without reaching a statistically significant level. Conclusion. Radiation exposure to the surgeon during pedicle screw placement with the freehand technique is up to 9.96 times greater than with the use of navigation. In the latter group, the only radiation exposure comes from the preoperative-level control and positioning of the 3D C-arm before 3D fluoroscopic acquisition. Furthermore, neuronavigation also reduces the cumulative dose for the patient. Level of Evidence: 2

3D printing of patient-specific anatomy: A tool to improve patient consent and enhance imaging interpretation by trainees.

We report the use of three-dimensional or 3D printed, patient-specific anatomy as a tool to improve informed patient consent and patient understanding in a case of posterior lumbar fixation. Next, we discuss its utility as an educational tool to enhance imaging interpretation by neurosurgery trainees.

Working time of neurosurgical residents in Europe--results of a multinational survey.

IntroductionThe introduction of the European Working Time directive 2003/88/EC has led to a reduction of the working hours with distinct impact on the clinical and surgical activity of neurosurgical residents in training.MethodsA survey was performed among European neurosurgical residents between 06/2014 and 03/2015. Multiple logistic regression was used to assess the relationship between responder-specific variables (e.g., age, gender, country, postgraduate yearxa0(PGY)) and outcome (e.g., working time).ResultsA total of 652 responses were collected, of which nu2009=u2009532 responses were taken into consideration. In total, 17.5, 22.1, 29.5, 19.5, 5.9, and 5.5xa0% of European residents indicated to work <40, 40–50, 51–60, 61–70, 71–80, or >80xa0h/week, respectively. Residents from France and Turkey (OR 4.72, 95xa0% CI 1.29–17.17, pu2009=u20090.019) and Germany (OR 2.06, 95xa0% CI 1.15–3.67, pu2009=u20090.014) were more likely to work >60xa0h/week than residents from other European countries. In total, 29xa0% of European residents were satisfied with their current working time, 11.3xa0% indicated to prefer reduced working time. More than half (55xa0%) would prefer to work more hours/week if this would improve their clinical education. Residents that rated their operative exposure as insufficient were 2.3 times as likely as others to be willing to work more hours (OR 2.32, 95xa0% CI 1.47–3.70, pu2009<u20090.001). Less than every fifth European resident spends >50xa0% of his/her working time in the operating room. By contrast, 77.4xa0% indicate to devote >25xa0% of their daily working time to administrative work. For every advanced PGY, the likelihood to spend >50xa0% of the working time in the OR increases by 19xa0% (OR 1.19, 95xa0% CI 1.02–1.40, pu2009=u20090.024) and the likelihood to spend >50xa0% of the working time with administrative work decreases by 18xa0% (OR 0.84, 95xa0% CI 0.76-0.94, pu2009=u20090.002).ConclusionsThe results of this survey on >500 European neurosurgical residents clearly prove that less than 40xa0% conform with the 48-h week as claimed by the WTD2003/88/EC. Still, more than half of them would chose to work even more hours/week if their clinical education were to improve; probably due to subjective impression of insufficient training.

Neurosurgical resident education in Europe--results of a multinational survey.

IntroductionNeurosurgical training aims at educating future generations of specialist neurosurgeons and at providing the highest-quality medical services to patients. Attaining and maintaining these highest standards constitutes a major responsibility of academic or other training medical centers.MethodsAn electronic survey was sent to European neurosurgical residents between 06/2014 and 03/2015. Multiple logistic regression analysis was used to assess the effect size of the relationship between responder-specific variables (e.g., age, gender, postgraduate year (PGY), country) and the outcomes (e.g., satisfaction).ResultsA total of 652 responses were collected, of which nu2009=u2009532 were taken into consideration. Eighty-five percent were 26–35 years old, 76xa0% male, 62xa0% PGY 4 or higher, and 73.5xa0% working at a university clinic. Satisfaction rates with theoretical education such as clinical lectures (overall: 50.2xa0%), anatomical lectures (31.2xa0%), amongst others, differed largely between the EANS member countries. Likewise, satisfaction rates with practical aspects of training such as hands-on surgical experience (overall: 73.9xa0%), microsurgical training (52.5xa0%), simulator training (13.4xa0%), amongst others, were highly country-dependant. In general, 89.1xa0% of European residents carried out the first surgical procedure under supervision within the first year of training. Supervised lumbar-/cervical spine surgeries were performed by 78.2 and 17.9xa0% of European residents within 12 and 24xa0months of training, respectively, and 54.6xa0% of European residents operate a cranial case within the first 36xa0months of training. Logistic regression analysis identified countries where residents were much more or much less likely to operate as primary surgeons compared to the European average. The caseload of craniotomies per trainee (overall: 30.6xa0% ≥10 craniotomies/month) and spinal procedures (overall: 29.7xa0% ≥10 spinal surgeries/month) varied throughout the countries and was significantly associated with more advanced residency (craniotomy: OR 1.35, 95xa0% CI 1.18–1.53, pu2009<u20090.001; spinal surgery: OR 1.37, 95xa0% CI 1.20–1.57, pu2009<u20090.001).ConclusionsTheoretical and practical aspects of neurosurgical training are highly variable throughout European countries, despite some efforts within the last two decades to harmonize this. Some countries are rated significantly above (and others significantly below) the current European average for several analyzed parameters. It is hoped that the results of this survey should provide the incentive as well as the opportunity for a critical analysis of the local conditions for all training centers, but especially those in countries scoring significantly below the European average.

Residency program trainee-satisfaction correlate with results of the European board examination in neurosurgery.

IntroductionSubstantial country differences in neurosurgical training throughout Europe have recently been described, ranging from subjective rating of training quality to objective working hours per week. The aim of this study was to analyse whether these differences translate into the results of the written and oral part of the European Board Examination in Neurological Surgery (EBE-NS).MethodsCountry-specific composite scores for satisfaction with quality of theoretical and practical training, as well as working hours per week, were obtained from an electronic survey distributed among European neurosurgical residents between June 2014 and March 2015. These were related to anonymous country-specific results of the EBE-NS between 2009 and 2016, using uni- and multivariate linear regression analysis.ResultsA total of nu2009=u20091025 written and nu2009=u200963 oral examination results were included. There was a significant linear relationship between the country-specific EBE-NS result in the written part and the country-specific composite score for satisfaction with quality of theoretical training [adjusted regression coefficient (RC) −3.80, 95xa0% confidence interval (CI) -5.43–7u2009-2.17, pu2009<u20090.001], but not with practical training or working time. For the oral part, there was a linear relationship between the country-specific EBE-NS result and the country-specific composite score for satisfaction with quality of practical training (RC 9.47, 95xa0% CI 1.47–17.47, pu2009=u20090.021), however neither with satisfaction with quality of theoretical training nor with working time.ConclusionWith every one-step improvement on the country-specific satisfaction score for theoretical training, the score in the EBE-NS Part 1 increased by 3.8xa0%. With every one-step improvement on the country-specific satisfaction score for practical training, the score in the EBE-NS Part 2 increased by 9.47xa0%. Improving training conditions is likely to have a direct positive influence on the knowledge level of trainees, as measured by the EBE-NS. The effect of the actual working time on the theoretical and practical knowledge of neurosurgical trainees appears to be insignificant.

Are internet sites providing evidence-based information for patients suffering with Trigeminal Neuralgia?

Trigeminal neuralgia has a variety of treatments with variable efficacy. Sufferers present to a spectrum of disciplines. While traditional delivery of medical information has been by oral/printed communication, up to 50–80% patients access the internet for information. Confusion, therefore, may arise when seeking treatment for trigeminal neuralgia. We evaluated the quality of information on the internet for trigeminal neuralgia using the DISCERN© instrument. Only 54% websites had clear objectives; 42% delivered on these. A total of 71% provided relevant information on trigeminal neuralgia, 54% being biased/unbalanced; 71% not providing clear sources of information. No website detailed the side-effect profile of treatments; 79% did not inform patients of the consequences/natural history if no treatment was undertaken; it was unclear if patients could anticipate symptoms settling or when treatment would be indicated. Internet information on trigeminal neuralgia is of variable quality; 83% of sites assessed were of low-to-moderate quality, 29% having ‘serious shortcomings.’ Only two sites scored highly, only one being in the top 10 search results. Websites on trigeminal neuralgia need to appreciate areas highlighted in the DISCERN© instrument, in order to provide balanced, reliable, evidence-based information. To advise patients who may be misguided from such sources, neurosurgeons should be aware of the quality of information on the internet.

The teaching of neurosurgery in UK medical schools: a message from British medical students

BackgroundA great variability exists in the clinical exposure of neurosurgery across all academic years in UK medical schools, although the effects of this on knowledge level and confidence in referring cases appropriately to specialists have not been reported.MethodsA cross-sectional study was carried out involving students in years 1–5 across nine British medical schools. An electronic questionnaire was sent out which consisted of questions concerning the teaching of the subject; and questions assessing the knowledge of basic neurosurgery through mini clinical scenarios testing which specialty should receive a referral.ResultsOf 417 participants, 60 were excluded due to incomplete participation. Senior years outperformed students in junior years for correctly answered questions on five neurosurgical scenarios (mean score: years 1–3 (184/357)u2009=u20093.33/5, years 4–5 (173/357)u2009=u20093.79/5, pu2009<u20090.05). Participants in years 1–5 with prior clinical exposure in neurosurgery scored higher than participants who had no exposure (mean score: exposed (247/357)u2009=u20094.21/5, not-exposed (110/357)u2009=u20093u2009·u200950/5, pu2009<u20090.05). Sixty-one percent prefer receiving neurosurgical teaching via increased exposure to operations. Students in years 4–5 with exposure in both classroom and operating theatre scored higher than students with classroom-only experience (mean classroom (69/131)u2009=u20093.62/5, mean classroom and operating theatre (62/131)u2009=u20094.21/5, pu2009<u20090.05); 33.3 % of final-year students reported difficulty in identifying patients that require neurosurgical referral.ConclusionsStudents with exposure to an operating theatre outperformed those students exposed to just classroom teaching. Students indicated an increased preference for teaching through the operating theatre scene. One in three final-year medical students had difficulty identifying the need for a neurosurgical referral.If neurosurgical teaching were further enhanced at medical school, it could lead to increased confidence and efficiency in junior-year doctors when facing the neurosurgical referral process. Increased exposure to clinical neurosurgery may significantly improve the ability of future doctors to tackle neurosurgical scenarios.

Aspirin therapy discontinuation and intraoperative blood loss in spinal surgery: a systematic review

The purpose of this study was to determine the effect of aspirin therapy discontinuation on intraoperative blood loss in spinal surgery. We searched Medline and Google Scholar 1946 to January 2017 inclusive for case-control studies, cohort studies, and controlled trials reporting intraoperative blood loss during spinal surgery in patients on pre-operative aspirin. Other outcome measures reported in the eligible studies were collected as secondary outcomes. Two reviewers independently screened and extracted data from each study. Five retrospective cohort and two case-control studies were eligible for inclusion. Of the 1173 patients identified, 587 patients were never on aspirin (Ax), 416 patients had aspirin discontinued before surgery (Ad), ranging from 3 to 10xa0days, and 170 patients had aspirin continued until surgery (Ac). Six out of seven studies reported no statistically significant difference in intraoperative blood loss irrespective of aspirin discontinuation. Meta-analysis was not possible due to high risk of bias. Of the secondary outcome measures, operative time and postoperative complications were most commonly reported. One of six studies evaluating operative time reported a significantly longer operative time in the Ad group compared with the Ac group. The overall risk of postoperative haematoma in Ax, Ad, and Ac groups is 0.2% (n/Nu2009=u20091/587), 0.2% (n/Nu2009=u20091/416), and 1.2% (n/Nu2009=u20092/170), respectively. No study reported a statistically significant difference in postoperative complications. There is no strong evidence demonstrating a difference in intraoperative blood loss, operation time, and postoperative complications, irrespective of aspirin discontinuation. This is, however, based on a limited number of studies and higher-quality research is required to answer this question with a higher degree of confidence.

Prevalence of concomitant traumatic cranio-spinal injury: a systematic review and meta-analysis

The biomechanical relationship between cranial and spinal structures makes concomitant injury likely. Concomitant cranio-spinal injuries are important to consider following trauma due to the serious consequences of a missed injury. The objective of this review was to estimate the prevalence of concomitant cranio-spinal injury in the adult trauma population. A systematic search of MEDLINE and EMBASE databases to identify observational studies reporting the prevalence of concomitant cranio-spinal injury in the general adult trauma population was conducted on 21 March 2017. The prevalence of concomitant cervical spinal injury in patients with a traumatic brain injury (TBI); the prevalence of concomitant spinal injury in patients with a TBI; the prevalence of concomitant TBI in patients with a cervical spinal injury; and the prevalence of concomitant TBI in patients with a spinal injury were calculated by meta-analysis. Twenty-one studies met the inclusion criteria and were included in this review. The prevalence of concomitant cervical spinal injury in patients with a TBI was found to be 6.5% (95% CI 6.0–7.1%); the prevalence of concomitant spinal injury in patients with a TBI to be 12.4–12.5%; the prevalence of concomitant TBI in patients with a cervical spinal injury to be 40.4% (95% CI 33.0–48.0%); and the prevalence of concomitant TBI in patients with a spinal injury to be 32.5% (95% CI 10.8–59.3%). This review reports the prevalence of concomitant cranio-spinal injury and highlights the importance of considering concomitant injury in patients with a cranial or spinal traumatic injury.