Ruben Dammers

Risk factors for infections related to external ventricular drainage

SummaryBackground. External ventricular drainage (EVD) is frequently used in neurosurgery for cerebrospinal fluid (CSF) drainage in patients with raised intracranial pressure. The major complication of this procedure is an EVD-related infection, i.e., meningitis or ventriculitis. The purpose of the present retrospective single centre study is to assess the possible causes of these infections.Patients and methods. Two hundred and twenty-eight patients were included in the period from January 1993 until April 2005. Patient and disease demographics, as well as EVD data, and the occurrence of infection were reviewed, compared, and included in a risk-analysis study.Results. The population’s mean age was 56 ± 15 years and the sexes were equally distributed. Most frequently, the indication for EVD was hydrocephalus due to intraventricular haemorrhage (48.2%). An infection was documented in 23.2% of all patients. Duration of EVD drainage appeared to be a risk factor for infection (>11 days: OR 4.1; 95% CI 1.8–9.2, p = 0.001). CSF sampling frequency was also a significant risk-factor (no sampling: OR 0.2, 95% CI 0.2–0.5, p = 0.003).Conclusions. We found a relatively high percentage of EVD-related infections. After multivariate analysis there appears to be a relation with duration of drainage and frequent CSF sampling. As a result, a new EVD protocol is proposed in our institution that we believe will decrease the number of EVD-related infections to a minimum.

Safety and efficacy of frameless and frame-based intracranial biopsy techniques

SummaryBackground. Frameless stereotaxy or neuronavigation has evolved into a feasible technology to acquire intracaranial biopsies with good accuracy and little mortality. However, few studies have evaluated the diagnostic yield, morbidity, and mortality of this technique as compared to the established standard of frame-based stereotactic brain biopsy. We report our experience of a large number of procedures performed with one or other technique. Patients and methods. We retrospectively assessed 465 consecutive biopsies done over a ten-year time span; Data from 391 biopsies (227 frame-based and 164 frameless) were available for analysis. Patient demographics, peri-operative characteristics, and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and of it being followed by death. Results. On average, nine tissue samples were taken with either stereotaxy technique. Overall, the biopsy led to a diagnosis on 89.4% of occasions. No differences were found between the two biopsy procedures. In a multiple regression analysis, it was found that left-sided lesions were less likely to result in a non-diagnostic tissue sample (p = 0.023), and cerebellar lesions showed a high risk of negative histology (p = 0.006). Postoperative complications were seen after 12.1% of biopsies, including 15 symptomatic haemorrhages (3.8%). There was not a difference between the rates of complication after either a frame-based or a frameless biopsy. Overall, peri-operative complications (p = 0.030) and deep-seated lesions (p = 0.060) increased the risk of biopsy-related death. Symptomatic haemorrhages resulting in death (1.5% of all biopsies) were more frequently seen after biopsy of a fronto-temporally located lesion (p = 0.007) and in patients with a histologically confirmed lymphoma (p = 0.039). Conclusions. The diagnostic yield, complication rates, and biopsy-related mortality did not differ between a frameless biopsy technique and the established frame-based technique. The site of the lesion and the occurrence of a peri-operative complication were associated with the likelihood of failure to achieve a diagnosis and with death after biopsy. We believe that using intraoperative frozen section or cytologic smear histology is essential during a stereotactic biopsy in order to increase the diagnostic yield and to limit the number of biopsy specimens that need to be taken.

The role of corticosteroids in the management of chronic subdural hematoma: a systematic review

The role of corticosteroids in the management of chronic subdural hematoma (CSDH) remains a matter of debate. Standard surgical treatment has recurrence rates reported between 4 and 26%. We reviewed the safety and effectiveness of corticosteroids both as a monotherapy and as an adjunct to surgery in patients with CSDH. PubMed‐MEDLINE, EMBASE and Cochrane databases were searched in July 2011 for randomized controlled trials and for prospective and retrospective cohort studies, reporting on 10 or more adult patients with CSDH. Quality was assessed according to the STROBE checklist. Corticosteroid monotherapy and surgery with corticosteroids as an adjunct were compared with no treatment or surgery only, with regard to lethality, neurological outcome, secondary intervention and complications. Five observational studies were included in this review. There was no randomized allocation of treatment in any study. Secondary intervention rates ranged from 3 to 28%, lethality rates ranged from 0 to 13%, and good outcome was seen in 83–100%. Hyperglycemia occurred more often in patients treated with corticosteroids. In only two studies, one case of gastrointestinal bleeding was observed. Five observational studies suggest that corticosteroids might be beneficial in the treatment of CSDH; however, there is a lack of well‐designed trials that support or refute the use of corticosteroids in CSDH. These results encourage further randomized clinical trials to establish the role of corticosteroids in CSDH.

Lumbar disc herniation: level increases with age

BACKGROUND Prompted by the clinical impression that L4 radicular syndrome and disc herniations at L3-4 occurred at older ages we studied the correlation between age and level of herniated discs. METHODS We retrospectively correlated mean age and level of disc herniation of patients suffering from lumbar disc herniation. Data from 1431 patients were obtained from the neurologic database of the Atrium Medical Center Heerlen from 1995 through 1998. Nonparametric data were analyzed with the Mann-Whitney U test, and correlation was analyzed using linear regression. RESULTS Mean ages of the patients with disc herniation at L5-S1, L4-5, L3-4, and L2-3 were 44.1 +/- 0.5 years, 49.5 +/- 0.6 years, 59.5 +/- 0.9 years, and 59.6 +/- 2.7 years, respectively. Mean ages were significantly higher with herniation levels at L4-5, L3-4, and L2-3 compared to L5-S1 (p < 0.0001). Analogously, the mean age of patients with disc herniation at L3-4 was significantly higher compared to those with herniation at L4-5 (p < 0.0001). No difference in mean age was seen between L3-4 and L2-3 (p = 0.815). A strong correlation was observed between the level of herniation and increasing age (R = 0.371; p < 0.0001). CONCLUSION These results indeed prove that with increasing age, lumbar disc herniation is more cranially localized. It may help in understanding the patho-anatomic process of disc herniation, and in recognizing higher level radicular syndromes in advanced age.

Clinical factors associated with outcome in chronic subdural hematoma: a retrospective cohort study of patients on preoperative corticosteroid therapy.

BACKGROUND: Chronic subdural hematoma (CSDH) is commonly seen in neurosurgical practice, and the incidence is increasing. Treatment results are highly variable with respect to recurrences and complications. OBJECTIVE: To report our single-center experience with the surgical treatment of CSDH in patients on preoperative corticosteroids and to assess possible predictors of outcome. METHODS: The medical reports of 496 consecutive patients with CSDHs treated with burr hole craniostomy were analyzed retrospectively. Patient demographics, medication, hematoma, treatment characteristics, and laboratory values were scored in relation to outcome. Data were analyzed with the &khgr;2 test, independent t test, and multivariate backward regression. RESULTS: Mean age was 71.5 ± 13.3 years (range, 18.6-95.4 years); the male-to-female ratio was 3:1. A decreased Glasgow Coma Scale (GCS) was observed in 63.1%, and GCS motor score on admission was < 6 in 25.2%. Recurrence and mortality rates were 11.9% and 5.3%, respectively. Multivariate analysis showed a longer period of preoperative dexamethasone administration (odds ratio [OR], 0.93 per day; P = .02), GCS motor score within 1 week after surgery of 6 (OR, 0.54; P = .02), postoperative complications (OR, 5.3; P < .001), and a left-sided hematoma (OR, 0.42; P = 0.010) to be significantly related to recurrence risk. CONCLUSION: The present data suggest that in surgical treatment of CSDH with burr hole craniostomy, extended preoperative corticosteroid administration is associated with a lower recurrence rate. The use of corticosteroids does not seem to be related to a higher incidence of complications and treatment-related death compared with the current literature.

Towards improving the safety and diagnostic yield of stereotactic biopsy in a single centre

BackgroundPreviously, we reported on our single centre results regarding the diagnostic yield of stereotactic needle biopsies of brain lesions. The yield then (1996–2006) was 89.4%. In the present study, we review and evaluate our experience with intraoperative frozen-section histopathologic diagnosis on-demand in order to improve the diagnostic yield.MethodsOne hundred sixty-four consecutive frameless biopsy procedures in 160 patients (group 1, 2006–2010) were compared with the historic control group (group 2, n = 164 frameless biopsy procedures). Diagnostic yield, as well as demographics, morbidity and mortality, was compared. Statistical analysis was performed by Students t, Mann–Whitney U, Chi-square test and backward logistic regression when appropriate.ResultsDemographics were comparable. In group 1, a non-diagnostic tissue specimen was obtained in 1.8%, compared to 11.0% in group 2 (p = 0.001). Also, both the operating time and the number of biopsies needed were decreased significantly. Procedure-related mortality decreased from 3.7% to 0.6% (p = 0.121). Multivariate analysis only proved operating time (odds ratio (OR), 1.012; 95% confidence interval (CI), 1.000–1.025; p = 0.043), a right-sided lesion (OR, 3.183; 95% CI, 1.217–8.322; p = 0.018) and on-demand intraoperative histology (OR, 0.175; 95% CI, 0.050–0.618; p = 0.007) important factors predicting non-diagnostic biopsies.ConclusionsThe importance of a reliable pathological diagnosis as obtained by biopsy must not be underestimated. We believe that when performing stereotactic biopsy for intracranial lesions, next to minimising morbidity, one should strive for as high a positive yield as possible. In the present single centre retrospective series, we have shown that using a standardised procedure and careful on-demand intraoperative frozen-section analysis can improve the diagnostic yield of stereotactic brain biopsy procedures as compared to a historical series.

Stenosis detection in forearm hemodialysis arteriovenous fistulae by multiphase contrast-enhanced magnetic resonance angiography: preliminary experience.

To assess the feasibility and accuracy of multiphase contrast‐enhanced magnetic resonance angiography (CE‐MRA) in patients with dysfunctioning hemodialysis arteriovenous fistulae (AVF), using digital subtraction angiography (DSA) as the standard of reference.

Antiepileptic drug therapy in the perioperative course of neurosurgical patients

Purpose of review Antiepileptic agents are widely used in the perioperative course of neurosurgical patients – for prophylactic and therapeutic reasons. However, the evidence supporting their use is extremely small and adverse events are common. This review highlights the current controversies. Recent findings Prophylactic use of antiepileptic agents is unfavorable for patients with subarachnoid hemorrhage. In patients with brain tumors, prophylactic use is not recommended. If the drugs are used nevertheless, stopping after the first postoperative week must be strongly recommended. After traumatic brain injury, early prophylactic use might prevent late post-traumatic seizures. The new antiepileptic drug levetiracetam seems to have a better safety profile, which makes it more suitable for prophylactic use. However, in all groups, evidence concerning the choice of drugs and duration of prophylaxis is lacking. Current research is focusing on prevention of epileptogenesis. Therapeutic use of antiepileptic drugs is supported by evidence. These drugs should be continued perioperatively. However, they might induce severe adverse events during adjuvant treatments like radiotherapy or chemotherapy in patients with brain tumors. Summary Despite lacking evidence, prophylactic antiepileptic drug use is common in the perioperative course of neurosurgical patients. More research is needed to deal better with epileptogenesis and to define the right drug for the right patient at the right time.

Brachial artery shear stress is independent of gender or age and does not modify vessel wall mechanical properties

The objective of the present study was to obtain brachial artery (BA) baseline shear stress (SS) values in healthy volunteers and to relate this to gender and age. Peak and mean wall shear rate (SR) were noninvasively measured in 30 healthy subjects using an SR estimation system. Arterial diameter and wall characteristics were obtained with a wall tracking system. SS was estimated from SR and calculated whole blood viscosity. Intrasubject variability and the effects of age and gender were assessed. Intrasubject variability of BA peak and mean SR were 16.2% and 28.6%. Baseline peak ( approximately 3.0 +/- 0.7 Pa) and mean SS ( approximately 0.5 +/- 0.2 Pa) were not gender-dependent, nor were they influenced by age. No vessel wall parameter related to BA SS. No differences in BA SS were observed between the genders and no influence of age was apparent. Our results indicate that the BA adequately responds to chronic changes in blood flow.

The incidence of postoperative thromboembolic complications following surgical resection of intracranial meningioma. A retrospective study of a large single center patient cohort

BACKGROUND Patients with meningiomas carry an increased risk for postoperative venous thromboembolic complications (VTE) including deep venous thrombosis (DVT) and pulmonary embolism (PE). OBJECTIVE In the present retrospective study we investigated the incidence of VTE and the risk factors involved, in a large cohort of patients surgically treated for an intracranial meningioma at our institution. METHODS During the period from January 1997 to January 2009, 581 consecutive patients underwent craniotomy for intracranial meningioma. All patients received low-molecular weight heparins as thromboembolism prophylaxis. Patient demographics and tumor characteristics were gathered via retrospective chart review. Postoperative VTE and hemorrhages were noted. Backward stepwise logistic regression was used to determine the risk factors. RESULTS 80.6% of meningiomas were WHO grade 1; 15.1% WHO grade 2; 4.3% WHO grade 3. Postoperative VTE were observed in 41 patients (7.2%). Of these, DVT was seen in 20 (3.5%) and PE in 26 patients (4.6%). The thromboembolic complication appeared on average 21.1±29.2 days post surgery. The 90-day mortality rate after VTE was 11.2% (23.1% for PE and 5.0% for DVT). Postoperative hemorrhages requiring surgical treatment were found in 2.9% of patients. Risk factors for VTE were body mass index (p=0.015) for DVT; weight (p=0.001) and bedridden postoperatively (p=0.001) for PE; and weight (p=0.004) and bedridden postoperatively (p=0.003) for VTE in general. There was no relation between tumor grade and thromboembolic complications. CONCLUSION The major risk factors for postoperative VTE found in our single center study are patient weight and a bedridden status postoperatively. Prophylactic intervention for this potentially fatal complication should be evaluated against the relative lower risk of postoperative hemorrhages.