Bernd E. Will

Do antibiotic-impregnated shunts in hydrocephalus therapy reduce the risk of infection? An observational study in 258 patients

BackgroundShunt infection in hydrocephalus patients is a severe, even life-threatening complication. Antibiotic-impregnated shunts (AIS) have been developed in an attempt to reduce rate of shunt infection. The study was performed to analyze if AIS can diminish the rate of shunt infection. The pathogenic nature of shunt infection in patients with AIS systems and those without antibiotic impregnated shunts (non-AIS) was compared.MethodsOver a period of 24 months in the Department of Neurosurgery at University Hospital of Tübingen shunt surgery was performed in 258 patients. In 86 patients AIS systems were implanted. Shunt catheters were commercially impregnated with clindamycin and rifampicin. Analysis of the clinical data included sex, age, classification of hydrocephalus, shunt types and risk factors for shunt infection [age (< 1 year and > 80 years), prematurely born patients, external ventricular drainage, former shunt infection, former systemic infection, disturbance of consciousness, former radiation-/chemotherapy]. Infection rates and underlying bacterial pathogens of patients with AIS were compared to patients with implanted non-AIS systems (172 patients).ResultsAIS and non-AIS patients did not differ in sex, etiology of hydrocephalus and the shunt type. In the AIS group 72 out of 86 patients had at least one risk factor (83.7 %), compared to 126 patients in the non-AIS group (73.3 %). There was no significant difference between the two groups (p = 0.0629; Fishers exact test). In patients with no risk factors, only one patient with non-AIS suffered from shunt infection. In patients with one or more risk factors the rate for shunt infection was 7.14 % in patients with non-AIS and 6.94 % in patients with AIS. Former shunt infection (p = 0.0124) was related to higher risk for shunt infection. The use of AIS had therefore no significant advantage (p = 0.8611; multiple logistic regression).Significantly related to a shunt infection was the number of shunt surgeries. 190 interventions in the AIS group (2.21 interventions per patient) and 408 in the non-AIS group (2.37 interventions per patient) had been performed (p = 0.3063; Wilcoxon). There was no shunt infection in the group of patients on whom only one shunt surgery was performed. In patients with at least two shunt surgeries the infection rate was 9%. The infection rate in AIS patients was 5/52 (9.6 %) and in the non-AIS 10/114 (8.77 %), (p = 1.0; Fishers exact test). Staphylococcus epidermidis was the most frequent pathogen for shunt infection. Fourteen out of 15 infections occurred within the first 6 months of surgery. The most frequent pathogen for shunt infection was S. epidermidis. No toxic or allergic complications were seen using the AIS shunt systems. The presented data show a remarkably low infection rate of 5.8 % in the non-AIS group compared to other studies which demonstrated a significant decrease in the infection rate by AIS.ConclusionAIS did not significantly reduce shunt infection in hydrocephalus patients in the presented study. In the AIS group three patients suffered from shunt infections caused by skin ulceration or neurosurgical procedures with exposure of the cerebrospinal liquor after shunt implantation. AIS was not developed to prevent infection in such cases, therefore an advantage of AIS can not be excluded. In view of the presented data and the small number of reported studies a prospective randomized multicenter study is required.

Objective criteria for successful transsphenoidal removal of suprasellar nonfunctioning pituitary adenomas. A prospective study.

SummaryBackground. Despite ample experience with transsphenoidal surgery, objective data on which suprasellar tumour expansion and growth pattern allows for radical adenoma resection are still sparse. Hence, we have performed a prospective study to establish the predictive value of tumour dimension and shape for the intra-operative descent of the diaphragma, the completeness of tumour resection and the outcome of patients harbouring pituitary adenomas with suprasellar extension.Method. Included in the study were 105 patients with nonfunctioning pituitary adenomas and suprasellar extension who underwent primary transsphenoidal surgery between January 1998 and December 2005. The precise suprasellar extension, the degree of dumbbell-shape, the configuration of the adenomas and the depth of the pituitary fossa were evaluated. Completeness of resection was assessed by MRI at 3 months postoperatively.Findings. The mean cranio-caudal diameter of the tumours was 28.0 mm (range 9.2–57.8 mm). On average, the suprasellar extension measured 11.9 mm (range 2.1–25.8 mm). Total removal of the suprasellar tumour was accomplished in 83% (87 of 105) of the patients. A second operation for residual adenoma was only indicated in 2 cases. The vertical intracranial extension was the strongest independent predictor of subtotal resection (p < 0.001). Irregular and multilobular configuration was a second highly-significant and independent predictor for incomplete resection (p < 0.003). In contrast, dumbbell-shape and shallow pituitary fossa were not independent predictive factors for incomplete tumour resection. The complication rate was very low. None of our patients suffered postoperative rhinorrhea, meningitis or visual deterioration.Conclusions. One-stage transsphenoidal surgery allows total or near-total resection of most suprasellar pituitary adenomas with low surgical morbidity. Quantitative assessment of tumour dimension and configuration contributes to establishing guidelines for the selection of the appropriate approach and prediction of surgical outcome.

Expression of interleukin-16 by tumor-associated macrophages/activated microglia in high-grade astrocytic brain tumors

Abstract.IntroductionMacrophages/microglial cells are considered as immune cells in the central nervous system. Interleukin (IL)-16 is a proinflammatory cytokine produced by activated monocytic cells.Materials and MethodsExpression of IL-16 was analyzed by immunohistochemistry in human astrocytic brain tumors and the rat C6 glioblastoma tumor model. IL-16 was detected in both human astrocytic brain tumors and rat C6 glioma.ResultsCompared with human control brains, a significant increase in the percentages of parenchymal IL-16+ macrophages/microglia was observed already in grade II astrocytomas, indicating that IL-16+ immunostaining could be a descriptor of a macrophage/microglia subset in astrocytic brain tumors. A further increase was observed at the transition from grade II to III astrocytomas. This increase in IL-16 immunoreactivity correlated with WHO grades of human astrocytic brain tumors.ConclusionsTherefore, IL-16 might be a so far unknown factor in the regulation of the local inflammatory milieu of human and experimental astrocytomas.

Multifocal dysembryoplastic neuroepithelial tumor with signs of atypia after regrowth

We report the case of a multifocal dysembryoplastic neuroepithelial tumor (DNT) in a 7‐year‐old girl with local tumor regrowth 6 years later. The tumor was localized in the right parietal lobe extending from the cortex into the periventricular white matter. After subtotal resection of a histopathologically confirmed DNT we observed unexpected tumor progression in long‐term follow‐up. Therefore, a second surgery was performed when the patient was 14 years of age. In neuropathological examination of the second specimen the tumor showed an increased cellularity and pleomorphism, microvascular proliferations, an elevated proliferative activity (MIB1‐index focally up to 10%) and cellular atypia not typical for WHO grade I DNT. Furthermore, MRI studies showed additional supratentorial and infratentorial lesions which remained stable over years and are also well consistent with DNTs. Thus, an unusual form of a DNT with multifocal lesions, local regrowth and morphological transformation is supposed.

ICP monitoring with a re-usable transducer: Experimental and clinical evaluation of the Gaeltec ICT/b pressure probe

SummaryIntracranial pressure monitoring requires reliable transducers at a justifiable price. At present, transducers for single or repeated use are available. We examined the Gaeltec model ITC/b solid state miniature transducer experimentally and clinically. Measurement accuracy was assessed in vitro at increasing steps of 5 mmHg from 0 to 80 mmHg. While new and recently serviced probes revealed minimal deviations from the preset values, frequently used transducers differed up to 7 mmHg. This occured especially in the high pressure range above 50 mmHg. Additionally the drift was investigated at different pressure levels. After 24 hours we already found drifts of 2 mmHg with new and serviced probes and up to 4 mmHg with used ones. In clinical practice we implanted 150 transducers in 121 patients from 1983 until 1995. The probes were re-used up to twelve times, the average time being 7 times, 32.7% of all measurements were regarded as not reliable. Dislocation (16.7%), inability to calibrate (3.3%) and defect pressure probes (3.3%) were the most common complications. Repeated use of the Gaeltec ICT/b probe also seemed to result in an additional decay of measurement quality.The strain of frequent cleaning and sterilizing may have caused changes of the physical properties of the probes with time. Whether these results also apply to other types of ICP probes for repeated use needs further evaluation.

Predictive factors for neurocognitive function and Quality of Life after surgical treatment for Cushing’s disease and acromegaly

Background: Cushing’s disease (CD) and acromegaly (AC) are associated with impairment in quality of life (QoL) and neurocognition that can persist after successful treatment. Aim: To investigate the influence of current disease status (remission vs no remission) on neurocognitive function and QoL in treated CD and AC patients and to determine predictive factors (e.g. demographic, clinical, neurosurgical, endocrinological) for post-operative neurocognition and QoL. Subjects and methods: Twenty-four CD and 37 AC patients underwent neuropsychological testing 1 to 10 yr following surgical therapy. Additionally, QoL was assessed. An overnight 2-mg dexamethasone suppression test in CD and IGF-I and GH levels in AC patients were assessed to determine current disease status. The results were compared with 28 sex-, education- and age-matched healthy controls (HC). Results: Impaired QoL was more pronounced than neurocognitive decrease in both pathologies compared to HC. This finding was independent of the current status of disease. In AC, persistent comorbidities were associated with impaired QoL (p<0.05). Older age at operation in AC patients was a significant predictor for adverse effects on psychomotor speed and attentional functions (p<0.05). In CD persistent hypocortisolism, not hypercortisolism, had adverse effects on neurocognition (p<0.01). Conclusions: The current status of disease plays a subordinate role in postoperative outcome concerning QoL and neurocognition in either pathology. A possible explanation might be the considerably improved endocrinopathy after treatment compared to untreated patients, even if no cure is achieved. The lasting impairments might be explained by irreversible changes that have occurred during the active phase of the disease.

Gliosarcoma with chondroid and osseous differentiation

We present the case of a 65‐year‐old woman with a short‐term history of cognitive decline and neuropsychiatric symptoms. Neuroradiological examinations revealed a large left temporo‐occipital cystic and calcified tumor mass measuring 6 cm in diameter, which was suspicious for an oligodendroglioma or a choroid plexus carcinoma. Neuropathological investigations finally revealed a gliosarcoma with extensive mesenchymal differentiation. The tumor demonstrated a biphasic pattern consisting of focal anaplastic glial components with vascular proliferation and necrosis. Adjacent sarcomatous tissue displayed pleomorphic fibroblastic cells surrounding metaplastic cartilage and osseous formation. Accounting for only approximately 2% of glioblastomas, gliosarcomas represent a rare entity of intrinsic CNS neoplasms. Exceedingly rare, the mesenchymal part of the gliosarcoma undergoes metaplastic transformation. Interestingly, in our case, the tumor exhibited features of both cartilaginous and osseous differentiation and multifocally showed a sharp transformation zone between highly malignant gliosarcomatous tumor areas and well‐differentiated non‐proliferative metaplastic regions.

Magnetic resonance angiography of a complex occipital meningoencephalocele involving the confluence of sinuses. Case illustration.

occipital region in almost 70% of cases.2 These entities comprise complex intracranial anomalies usually associated with several other brain malformations.4 Among these anomalies, an abnormal venous system is frequently associated with occipital encephaloceles.4 This 2-day-old girl was admitted to our department after suffering from a closed complex occipital meningoencephalocele. Cranial magnetic resonance (MR) imaging revealed a complex meningoencephalocele containing prolapsed parts of the occipital and parietal lobes and portions of the third and lateral ventricles, as well as corpus callosum agenesis. On T2-weighted MR imaging, large abnormal veins could be seen. The venous phase of MR angiography showed large veins within the encephalocele but only 1 joining the transverse sinus (Fig. 1). This vein was interpreted as an anomaly of the vein of Galen draining the prolapsed brain. The straight sinus was atretic. During surgery, the malformation was mostly repaired, preserving all neural and vascular structures. The abnormal venous system of complex occipital meningoencephaloceles has been studied using conventional angiography.4 Due to the invasiveness and additional risks of using conventional angiography, however,3 MR angiography has become increasingly useful for studying the normal cerebral venous system in children.5 Concerning brain malformations, MR angiography has also been used twice to demonstrate an abnormal venous system in occipital encephaloceles,1,3 but only once for a large occipital meningoencephalocele involving the confluence of sinuses.3 The use of MR angiography instead of conventional angiography appears to be a reasonable option in surgical planning for large occipital meningoencephaloceles with a complex abnormal venous system, which can preclude additional risks for this group of patients. (DOI: 10.3171/PED/2008/1/3/261)

Specific technical aspects and clinical findings of neuroendoscopic procedures

SummaryA new endoscopic system for neurosurgical procedures is described. The neuroendoscope was designed for intracerebral endoscopy. Several changes were integrated into the system including: camera positioning in the nonsterile area; use of a smaller diameter; micro-drive and only one bundle leaving the operation field. To date, we have operated on 28 patients with cystic lesions and occlusive hydrocephalus with no intraoperative complications. Expectations regarding the safety of the system were met.

A neuroendoscopic approach to the ventral brainstem

SummaryThe microsurgical approach to the ventral brainstem is difficult and dangerous in most cases, the aim of neurosurgical treatment of brainstem tumours is to obtain a histological sample and decompress the cystic parts of the tumour We describe a new access to the ventral brainstem achieved using a combination of stereotaxy and endoscopy A 2% year old boy began to show a noticeable somatic standstill, with increasing ataxic gait and dysarthria MRI scans of the skull showed that the entire pons was taken over by a diffuse growing lesion, blocking the aqueduct We carried out a stereotactic-guided neuroendoscopicfenestration of the floor of the third ventricle A biopsy from the tumour was taken under vision through the stoma The histological diagnosis revealed a fibrillary astrocytoma The MRI control showed a sufficient ventriculostorny The hydrocephalus resolved postoperatively The boy died 15 months after the operation. A stereotactic-guided biopsy under neuroendoscopic vision can be performed with re...