Thomas Beez

Diagnostic Performance of 18F-FET PET in Newly Diagnosed Cerebral Lesions Suggestive of Glioma

The aim of this study was to assess the clinical value of O-(2-18F-fluoroethyl)-l-tyrosine (18F-FET) PET in the initial diagnosis of cerebral lesions suggestive of glioma. Methods: In a retrospective study, we analyzed the clinical, radiologic, and neuropathologic data of 174 patients (77 women and 97 men; mean age, 45 ± 15 y) who had been referred for neurosurgical assessment of unclear brain lesions and had undergone 18F-FET PET. Initial histology (n = 168, confirmed after surgery or biopsy) and the clinical course and follow-up MR imaging in 2 patients revealed 66 high-grade gliomas (HGG), 77 low-grade gliomas (LGG), 2 lymphomas, and 25 nonneoplastic lesions (NNL). In a further 4 patients, initial histology was unspecific, but during the course of the disease all patients developed an HGG. The diagnostic value of maximum and mean tumor-to-brain ratios (TBRmax/TBRmean) of 18F-FET uptake was assessed using receiver-operating-characteristic (ROC) curve analyses to differentiate between neoplastic lesions and NNL, between HGG and LGG, and between high-grade tumor (HGG or lymphoma) and LGG or NNL. Results: Neoplastic lesions showed significantly higher 18F-FET uptake than NNL (TBRmax, 3.0 ± 1.3 vs. 1.8 ± 0.5; P < 0.001). ROC analysis yielded an optimal cutoff of 2.5 for TBRmax to differentiate between neoplastic lesions and NNLs (sensitivity, 57%; specificity, 92%; accuracy, 62%; area under the curve [AUC], 0.76; 95% confidence interval [CI], 0.68–0.84). The positive predictive value (PPV) was 98%, and the negative predictive value (NPV) was 27%. ROC analysis for differentiation between HGG and LGG (TBRmax, 3.6 ± 1.4 vs. 2.4 ± 1.0; P < 0.001) yielded an optimal cutoff of 2.5 for TBRmax (sensitivity, 80%; specificity, 65%; accuracy, 72%; AUC, 0.77; PPV, 66%; NPV, 79%; 95% CI, 0.68–0.84). Best differentiation between high-grade tumors (HGG or lymphoma) and both NNL and LGG was achieved with a TBRmax cutoff of 2.5 (sensitivity, 79%; specificity, 72%; accuracy, 75%; AUC, 0.79; PPV, 65%; NPV, 84%; 95% CI, 0.71–0.86). The results for TBRmean were similar with a cutoff of 1.9. Conclusion: 18F-FET uptake ratios provide valuable additional information for the differentiation of cerebral lesions and the grading of gliomas. TBRmax of 18F-FET uptake beyond the threshold of 2.5 has a high PPV for detection of a neoplastic lesion and supports the necessity of an invasive procedure, for example, biopsy or surgical resection. Low 18F-FET uptake (TBRmax < 2.5) excludes a high-grade tumor with high probability.

Evolution of Management of Intracranial Aneurysms in Children: A Systematic Review of the Modern Literature

Pediatric intracranial aneurysms are rare. Management of their more common adult counterparts was profoundly influenced by recent high-quality clinical studies. The aim of this review was to aggregate the modern pediatric data published in the wake of these studies and to analyze their impact on management of aneurysms in children. A systematic PubMed search identified 135 publications published between 2000 and 2015, accounting for 573 children and 656 aneurysms. Descriptive statistical analyses revealed differences between children and adults concerning demographics and aneurysm characteristics. A significant proportion of patients were treated endovascularly, suggesting endovascular treatment has been established in the therapeutic armamentarium for pediatric aneurysms. However, these data highlight the unique nature of pediatric aneurysms, and neither this review nor generalization from adult data can replace high-quality clinical research. Multicenter registries and controlled trials are required to establish the natural history and evidence-based treatment of pediatric aneurysms.

Intraoperative Indocyanine Green–Based Cortical Perfusion Assessment in Patients Suffering from Severe Traumatic Brain Injury

OBJECTIVES The pathophysiology of traumatic brain injury (TBI) largely involves the brains vascular structural integrity. We analyzed the value of an intraoperative cortical indocyanine green (ICG) angiography in patients with severe TBI and acute subdural hematoma who underwent decompressive craniectomy. METHODS ICG-derived fluorescence curves of cortex and cerebral vessels were recorded by the use of software integrated into a surgical microscope in 10 patients. The maximum intensity, rise time (RT), time to peak, and residual fluorescence intensity (FI) were estimated from cortical arteries, the parenchyma, and veins. RESULTS ICG-derived fluorescence parameters were correlated with the short-term outcome 3 months after discharge. Five patients had a favorable and 5 an unfavorable outcome. Patients with a favorable outcome showed a significant longer RT in the arteries and a trend towards a significant longer RT in the veins. Overall mean residual FI was 47.5 ± 6.8% for the arteries, 45.0 ± 7% for the parenchyma and 57.6 ± 6% for the veins. The residual FI of the parenchyma and the veins was significantly greater in patients with an unfavorable clinical outcome. CONCLUSIONS Patients with an unfavorable clinical outcome showed an altered shape of the ICG-derived fluorescence curve, a shorter increase of the ICG-derived fluorescence intensity in the cortical arteries, and significantly greater residual fluorescence intensity. These observations are likely a correlate of an increased intracranial pressure, a capillary leak, and venous congestion. Intraoperative quantification of the ICG-derived fluorescence might help to appreciate the clinical outcome in patients with severe TBI.

The influence of decompressive craniectomy for major stroke on early cerebral perfusion.

OBJECT Multiple trials have shown improved survival and functional outcome in patients treated with decompressive craniectomy (DC) for brain swelling following major stroke. It has been assumed that decompression induces an improvement in cerebral perfusion. This observational study directly measured cerebral perfusion before and after decompression. METHODS Sixteen patients were prospectively examined with perfusion CT within 6 hours prior to surgery and 12 hours after surgery. Preoperative and postoperative perfusion measurements were compared and correlated. RESULTS Following DC there was a significant increase in cerebral blood flow in all measured territories and additionally an increase in cerebral blood volume in the penumbra (p = 0.03). These changes spread as far as the contralateral hemisphere. No significant changes in mean transit time or Tmax (time-to-peak residue function) were observed. CONCLUSIONS The presurgical perfusion abnormalities likely reflected local pressure-induced hypoperfusion with impaired autoregulation. The improvement in perfusion after decompression implied an increase in perfusion pressure, likely linked to partial restoration of autoregulation. The increase in perfusion that was observed might partially be responsible for improved clinical outcome following decompressive surgery for major stroke. The predictive value of perfusion CT on outcome needs to be evaluated in larger trials.

Perioperative Measures to Improve Outcome After Subarachnoid Hemorrhage—Revisiting the Concept of Secondary Brain Injury

Progress in the management of aneurysmal subarachnoid hemorrhage (SAH) is reflected most clearly in a continuously decreasing case fatality rate over the last decades. The purpose of the present review is to identify the relevant factors responsible for this progress and to outline future possibilities of improvement. Although data on intracerebral hemorrhage and ischemic stroke are less homogeneous, the respective data suggest that reduction of case fatalities could also be achieved with these types of stroke. Therefore, advances of general neurocritical care may be the common denominator responsible for the decreasing case fatality rates. Additionally, a change in practice with regard to treatment of elderly patients that is more active may also be a factor. Regarding SAH, the majority of unfavorable outcomes is still related to early or delayed cerebral injury. Therefore, efforts to pharmacologically prevent secondary neuronal damage are likely to play a certain role in achieving improvement in overall outcome. However, the data from previous randomized clinical trials conducted during the last three decades does not strongly support this. A clear benefit has only been proven for oral nimodipine, whereas other calcium antagonists and the rho-kinase inhibitors were not conclusively shown to have a significant effect on functional outcome, and all other tested substances disappointed in clinical trials. Regarding ischemic stroke and traumatic brain injury, intensive clinical research has also been conducted during the last 30 years to improve outcome and to minimize secondary neuronal injury. For ischemic stroke, treatment focusing on reversal of the primary pathomechanism, such as thrombolysis, proved effective, but none of the pharmacological neuroprotective concepts resulted in any benefit. To date, decompressive hemicraniectomy has been the only effective effort focused at reducing secondary damage that resulted in a clear reduction of mortality. In the case of traumatic brain injury, none of the pharmacological or other efforts to limit secondary damage met our hopes. In summary, although limited, pharmacotherapy to limit delayed neuronal injury is more effective for SAH than for ischemic stroke and traumatic brain injury. The disappointing results of most trials addressing secondary damage force one to question the general concept of mechanisms of secondary damage that do not also have a positive side in the natural course of the disease. For example, in the case of SAH, the data from the Cooperative Study from the 1960s showed that vasospasm to some degree protects against rerupture of unsecured aneurysms. Thus, one could argue from an evolutionary standpoint that the purpose of vasospasm was not exclusively a detrimental or suicide pathomechanism, but an attempt to protect against life-threating aneurysm rerupture. Because of the above-discussed arguments, SAH may indeed differ from ischemic stroke and traumatic brain injury with regard to the usefulness of blocking secondary mechanisms pharmacologically. Further efforts to limit vasospasm should therefore be made, and the most promising drugs, calcium antagonists, deserve further development. Because, with various drugs, systemic side effects counteracted the local beneficial effect, future efforts should focus on topical administration of drugs instead of systemic administration. Furthermore, efforts for a better understanding of the variations of the calcium channels and the interplay between the different types of calcium channels should be made.

Symptomatic communicating hydrocephalus in a contemporary cohort of high grade glioma patients

Abstract Introduction: High grade glioma (HGG) treatment has seen a paradigm shift with intensified regimes, but hospitalisation burden is partially attributed to side effects of therapy. Symptomatic communicating hydrocephalus (HC) is a potential complication. Aim of this study was to investigate its incidence, risk factors and treatment in a contemporary cohort. Methods: We performed a retrospective review of HGG patients. Patients with symptomatic communicating HC were identified and demographic, tumour and treatment variables extracted from hospital notes. Descriptive statistics were performed and odds ratios (OR) with 95% confidence intervals (CI) calculated. Results: From a cohort of 278 eligible HGG patients, 8 (3%) were diagnosed with symptomatic communicating HC. In the subgroup of patients with intraoperative opening of the ventricular system during previous surgery (N = 66), hydrocephalus developed in 10.6% of cases (N = 7). Symptoms were lethargy (N = 5), headache (N = 3), confusion (N = 3), gait disturbance (N = 3) and urinary incontinence (N = 1); three patients presented resembling normal pressure hydrocephalus. A higher rate of intraoperative opening of the ventricles was found in the HC group (p = .0002); all other variables were equally distributed. The increased odds for developing HC for patients with intraoperative opening of the ventricles reached statistical significance (OR = 25.0339, 95% CI = 3.0196–207.5449, p = .0028), whereas previous radiotherapy only increased odds by tendency. Hydrocephalic patients were treated with ventriculoperitoneal shunts and all but one patient improved. One patient had a complication attributed to the shunt procedure The median overall survival after shunting was 4 months. Conclusions: Symptomatic communicating hydrocephalus occurred in 3% of HGG patients and in 10.6% in the subgroup with previous intraoperative opening of the ventricles. Treatment with a ventriculoperitoneal shunt is effective and has a low complication rate.

Endoscopic Visualization of an Iatrogenic Valve Mechanism: Elucidating the Pathogenesis of Postoperative Tumor Bed Cysts

Space-occupying tumor bed cysts have been reported after resection of intracranial tumors, although the exact mechanism of their pathogenesis is unclear. Opening of the ventricular system during the tumor resection appears to be a risk factor. Occlusion of the surgical opening of the ventricle using fibrinogen-coated collagen fleece has been suggested to restore the integrity of the ventricular system. Here we present a clinical image depicting an iatrogenic valve mechanism caused by a fleece intended to seal a surgical opening of the lateral ventricle, leading to development of a space-occupying tumor bed cyst and cerebrospinal fluid fistula.

Endoscopic Lavage of Extensive Chronic Subdural Hematoma in an Infant After Abusive Head Trauma: Adaptation of a Technique From Ventricular Neuroendoscopy

Subdural fluid collections are frequently encountered in young children after non-accidental injury. In a subset of patients, these collections progress in size and ultimately require permanent drainage, which is commonly achieved with subdural-peritoneal shunts. However, excessive protein and cellular contents in the fluid are potential risk factors for shunt failure. Here, we describe the adaptation of an endoscopic lavage technique established for ventricular endoscopy with the aim of improving fluid condition prior to shunting. We present a case of subdural fluid collections secondary to non-accidental injury, where permanent shunting was required but could not be performed due to excessive protein and cellular levels in the subdural fluid despite conventional burr hole drainage. A two-month-old male infant presented with a bulging and tense fontanel, a reduced level of consciousness, bradycardia, and significant macrocephaly. Computed tomography (CT) demonstrated massive bilateral, low attenuation subdural fluid collections, reaching a diameter of 4.5 cm. Emergency burr hole washout and insertion of subdural drains was performed. Despite prolonged drainage over 10 days, the protein level remained at 544 mg/dl and the mean erythrocyte count at 6,493/µl. Continuous drainage was required to avoid clinical deterioration due to raised intracranial pressure; however, the fluid condition was still considered incompatible with permanent subdural-peritoneal shunting. We, therefore, performed an endoscopic subdural lavage with a careful evacuation of residual blood deposits. No complications were encountered. Postoperatively, mean protein level was 292 mg/dl and mean erythrocyte count was 101/µl. Endoscopic lavage could be safely performed in a case of extensive subdural low attenuation fluid collections, where conventional burr hole drainage failed to improve protein and cellular contents as a prerequisite for successful permanent shunting. We conclude that adaptation of this technique can be helpful in selected cases as an alternative procedure.

Pediatric neurosurgery malpractice claims in Germany

PurposeThere is limited data regarding malpractice claims in pediatric neurosurgery. Aim of this study was to analyze the rate, subject, and outcome of malpractice claims faced by pediatric neurosurgeons.MethodsWe analyzed malpractice claims in pediatric neurosurgical patients assigned to the review board of North Rhine Medical Council from 2012 to 2016. Claims were categorized as “medical error” or “adverse event, no medical error.” Severity was graded from negligible (grade 1) to death (grade 6).ResultsOf 391 pediatric malpractice claims, seven (1.8%) concerned pediatric neurosurgery. Claims were related to cranial surgery (N = 5), spinal surgery (N = 1), and a neuro-interventional procedure (N = 1). Of operative cases, three were shunt operations, two were cranioplasty procedures, and one was a spinal fusion. Complications of medical care (adverse events) had occurred in all cases. A medical error was detected in only one case. Severity of damage was grade 2 (transient minor) in three, grade 3 (transient major) in one, and grade 5 (permanent major) in three cases, respectively.ConclusionsPediatric neurosurgery accounted for 1.8% of all pediatric malpractice claims. In 14% of these claims, a medical error was confirmed. Malpractice claim rate thus appears to be lower than expected for a high-risk specialty. , adverse events were confirmed in all cases, a negligent medical error was rare. Adverse event rate appears to be a predictor for malpractice claim burden, highlighting the importance of surgical checklists, standard operating procedures and morbidity and mortality surveillance.

Headache and Shunt-Related Impact on Activities of Daily Life in Patients Growing Up with a Ventriculoperitoneal Shunt

Background/Aims Ventriculoperitoneal shunts (VPS) are a mainstay of treatment for hydrocephalus. Morbidity related to infection and dysfunction is well known, whereas data on psychosocial outcome and quality of life are scarce. Our aim was to assess headache burden and shunt‐related impact on daily life in children growing up with a VPS. Methods Patients between 3 and 21 years of age were identified and their families were contacted. A set of standardized questionnaires was used to assess headache and quality of life. Results Fifteen patients with a mean age of 12 years agreed to participate in this study. Satisfaction with the VPS and improvement of the patients condition was reported by 87%. A total of 67% denied negative impact on everyday life, reported a headache less than once a month, and never or rarely miss school. However, 53% take precautions before special activities. Conclusions The results demonstrate that modern VPS systems are tolerated very well and do not per se reduce quality of life. However, patients adapt to the presence of a VPS by avoiding risks and taking precautions. Chronic headache is not a major problem and not necessarily attributed to the VPS. Nevertheless, most patients asked for technical improvements, which might guide future research and the technical development of VPS.