Bon H Verweij

University Medical Center Utrecht | UMC Utrecht · Department of Neurosurgery

Background and purpose: Aneurysm volume pulsation is a potential predictor of intracranial aneurysm rupture. We evaluated whether 7T MR imaging can quantify aneurysm volume pulsation. Materials and methods: In Stage I of the study, 10 unruptured aneurysms in 9 patients were studied using a high-resolution (0.6-mm, isotropic) 3D gradient-echo seq...

Background and purpose: Induced hypertension is widely used to treat delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage, but a literature review shows that its presumed effectiveness is based on uncontrolled case-series only. We here report clinical outcome of aneurysmal subarachnoid hemorrhage patients with DCI included in a...

Background: Recent studies suggest that gadolinium-enhancement of the aneurysm wall may reflect aneurysm wall inflammation, which might increase the risk of aneurysm growth or rupture. Objective: To determine the prevalence of gadolinium-enhancement and its determinants in patients with predominantly small (<7 mm) unruptured intracranial aneurys...

Insight into processes leading to rupture of intracranial aneurysms (IAs) may identify biomarkers for rupture or lead to management strategies reducing the risk of rupture. We characterized and quantified (ultra)structural differences between unruptured and ruptured aneurysmal walls. Six unruptured and 6 ruptured IA fundi were resected after micros...

Background: Intracranial aneurysm rupture prediction is poor, with only a few risk factors for rupture identified and used in clinical practice. Objective: To provide an overview of all the risk factors (including genetic, molecular, morphological, and hemodynamic factors) that have potential for use in clinical practice. Methods: We systemati...

The excimer laser assisted non-occlusive anastomosis (ELANA) technique is used to make anastomoses on intracerebral arteries. This end-to-side anastomosis is created without temporary occlusion of the recipient artery using a 308-nm excimer laser with a ring-shaped multi-fiber catheter to punch an opening in the arterial wall. Over 500 patients hav...

Background and purpose: Analyzing genes involved in development and rupture of intracranial aneurysms can enhance knowledge about the pathogenesis of aneurysms, and identify new treatment strategies. We compared gene expression between ruptured and unruptured aneurysms and control intracranial arteries. Methods: We determined expression levels w...

Background and purpose: Both hemodynamics and aneurysm wall thickness are important parameters in aneurysm pathophysiology. Our aim was to develop a method for semi-quantitative wall thickness assessment on in vivo 7T MR images of intracranial aneurysms for studying the relation between apparent aneurysm wall thickness and wall shear stress. Mate...

Background and purpose: The presumed effectiveness of induced hypertension for treating delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage is based on uncontrolled case-series only. We assessed the effect of induced hypertension on cerebral blood flow (CBF) in aneurysmal subarachnoid hemorrhage patients with delayed cerebral ischem...

The eventual goal of preventive treatment of unruptured intracranial aneurysms is to increase the number of life years with high life satisfaction. Insight in the time with reduced functioning, working capacity, and life satisfaction after aneurysm treatment is pivotal to balance the pros and cons of preventive aneurysm occlusion. We sent a questio...

Genetic risk factors for intracranial aneurysm (IA) are not yet fully understood. Genomewide association studies have been successful at identifying common variants; however, the role of rare variation in IA susceptibility has not been fully explored. In this study, we report the use of whole exome sequencing (WES) in seven densely-affected familie...

BACKGROUND: Risk prediction of rupture of intracranial aneurysms is poor and is based mainly on lumen characteristics. However, characteristics of the aneurysm wall may be more informative predictors. The limited resolution of currently available imaging techniques and the thin aneurysm wall make imaging of wall thickness challenging. OBJECTIVE: To...

BACKGROUND: Risk prediction of rupture of intracranial aneurysms is poor, and mainly based on lumen characteristics. However, characteristics of the aneurysm wall may be more informative predictors. The limited resolution of currently available imaging techniques, and the thin aneurysm wall, make imaging of wall thickness challenging. OBJECTIVE: To...

No class I evidence exists about the optimal treatment of chronic subdural hematoma (CSDH). The aim of this study was to evaluate current practice of CSDH patients with different neurological grades, and probable ambivalence towards various treatment paradigms, especially primary treatment with high-dose corticosteroids, among vascular neurologists...

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 Co...

The purpose of this study was to assess flow, patency, and endothelialization of bypasses created with the sutureless Excimer Laser Assisted Non-occlusive Anastomosis (SELANA) technique in a pig model. In 38 pigs, a bypass was made on the left common carotid artery (CCA), using the right CCA as a graft, with 2 SELANAs. Bypass flow was measured usin...

The excimer laser-assisted nonocclusive anastomosis (ELANA) technique facilitates the construction of an end-to-side anastomosis between a donor vessel and a recipient artery without the need to temporarily occlude the recipient artery. To test whether the surgically difficult ELANA technique can be simplified. In 42 rabbits, with the aorta as the...

A key element in the Excimer Laser Assisted Non-occlusive Anastomosis (ELANA) technique is the retrieval of a disc ("flap") of artery wall from the anastomosis by the laser catheter tip. We assessed if the flap retrieval rate could be optimized. We used a specially designed in vitro model using rabbit aortas. We tested three essential elements of t...

To define the safety and clinical value of giant aneurysm clipping under protection of an excimer laser-assisted non-occlusive anastomosis (ELANA) bypass. We report 32 patients with an uncoilable intracerebral giant aneurysm, operated on with the aid of an ELANA protective bypass between January 1, 1994, and January 1, 2008. We retrospectively coll...

Pulmonary edema (PED) is a severe complication after aneurysmal subarachnoid hemorrhage (SAH). PED is often treated with diuretics and a reduction in fluid intake, but this may cause intravascular volume depletion, which is associated with secondary ischemia after SAH. We prospectively studied intravascular volume in SAH patients with and without P...

Massive intraventricular haemorrhage (IVH) complicating aneurysmal subarachnoid haemorrhage (SAH) is associated with a poor prognosis. Small observational studies suggest favourable results from fibrinolysis of the intraventricular blood. We performed an observational study on IVH in a large series of patients with SAH to assess the proportion of p...

Conventional parameters used to guide fluid therapy after aneurysmal subarachnoid hemorrhage (SAH) are poorly related to blood volume. In a prospective controlled study we assessed whether fluid management guided by daily measurements of blood volume (BV) reduces the incidence of severe hypovolemia compared to conventional fluid balance guided flui...

In a recent study on nurses' ability to predict volume status after subarachnoid haemorrhage, we found very low predictive values [1]. In a letter to the editor, Dane [2] argued that an error in statistics 'makes any reasonable conclusions impossible'. Because Dr Dane was the statistical reviewer of our manuscript, both the authors and the editors...

Excimer laser-assisted nonocclusive anastomosis (ELANA) is a technique that can be used for extracranial-to-intracranial (EC-IC) bypasses, without the necessity of temporary occlusion of the donor or recipient artery. Information on predictors of patency of EC-IC bypasses in general and the ELANA bypass in particular is sparse. The authors studied...

Patients treated for aneurysmal subarachnoid hemorrhage (SAH) often report a loss of smell. To discriminate between the effects of aneurysmal rupture and treatment, the authors assessed the occurrence of anosmia after clipping and coiling of unruptured aneurysms as well as after the coiling of ruptured aneurysms. The authors interviewed patients in...

Patients who have suffered aneurysmal subarachnoid haemorrhage (SAH) often have derangements in blood volume, contributing to poor outcome. To guide fluid management, regular assessments of volume status must be conducted. We studied the ability of nursing staff to predict hypovolaemia or hypervolaemia, based on their interpretation of available ha...

Patients with Neurofibromatosis type 1 (NF1) have an increased risk of developing neoplasms. The most common brain tumors, found in 15%-20% of NF1 patients, are hypothalamic-optic gliomas, followed by brainstem and cerebellar pilocytic astrocytomas. These tumors generally have a benign nature. NF1 patients are predisposed to a 5-fold increased inci...

To define the clinical value of the flow replacement bypass using the excimer laser-assisted nonocclusive anastomosis (ELANA) technique in the treatment of patients with a noncoilable, nonclippable giant intracranial aneurysm of the middle cerebral artery (MCA). Between 1999 and 2006, 22 patients with a giant intracranial aneurysm of the MCA were t...

To define the clinical value of the high-flow replacement bypass using the excimer laser-assisted nonocclusive anastomosis technique in the treatment of patients with a noncoilable, nonclippable giant or large intracranial aneurysm of the internal carotid artery (ICA). We studied 34 patients with a giant intracranial aneurysm of the ICA proximal to...

Cerebral vasospasm continues to be a major cause of poor outcome in patients with ruptured aneurysms. Prophylactic Transluminal Balloon Angioplasty (pTBA) appeared to prevent delayed ischemic neurological deficit in a pilot study. A phase II multicenter randomized clinical trial was subsequently designed. One hundred and seventy patients with Fishe...

Patients with aneurysmal subarachnoid haemorrhage (SAH) often have disturbed autoregulation of cerebral blood flow. A reduction in systemic blood pressure during surgery may therefore lead to delayed cerebral ischaemia (DCI). To assess the incidence and severity of intra-operative hypotension, we performed a retrospective cohort study in 164 patien...

Anosmia has an important impact on well-being but is often neglected by physicians. In patients with subarachnoid hemorrhage (SAH), anosmia has mainly been reported after surgery for aneurysms of the anterior communicating artery. We studied the prevalence, predisposing factors (aneurysm site and type of treatment), impact, and prognosis of anosmia...

Cerebral aneurysms that cannot be treated by clip or coil placement can be treated with high-flow bypass surgery using techniques such as the excimer laser-assisted nonocclusive anastomosis (ELANA). To simplify the technique, a sutureless ELANA (SELANA) was developed in combination with an expanded polytetrafluoroethylene (ePTFE) graft. In 18 rabbi...

Before energy metabolism can take place, brain cells must be supplied with oxygen and glucose. Only then, in combination with normal mitochondrial function, sufficient energy (adenosine tri-phosphate (ATP)) can be produced. Glucose is virtually the sole fuel for the human brain. The brain lacks fuel stores and requires a continuous supply of glucos...

Patients with complex craniocerebral pathophysiologies such as giant cerebral aneurysms, skull base tumors, and/or carotid artery occlusive disease are candidates for a revascularization procedure to augment or preserve cerebral blood flow. However, the brain is susceptible to ischemia, and therefore the excimer laser-assisted nonocclusive anastomo...

The poor prognosis for traumatic acute subdural hematoma (ASDH) might be due to underlying primary brain damage, ischemia, or both. Ischemia in ASDH is likely caused by increased intracranial pressure (ICP) leading to decreased cerebral perfusion pressure (CPP), but the degree to which these phenomena occur is unknown. The authors report data obtai...

Oxygen supply to the brain is often insufficient after traumatic brain injury (TBI), and this results in decreased energy production (adenosine triphosphate [ATP]) with consequent neuronal cell death. It is obviously important to restore oxygen delivery after TBI; however, increasing oxygen delivery alone may not improve ATP production if the patie...

Abnormal accumulation of intracellular calcium following traumatic brain injury (TBI) is thought to contribute to a cascade of cellular events that lead to neuropathological conditions. Therefore, the possibility that specific calcium channel antagonists might exert neuroprotective effects in TBI has been of interest. The focus of this study was to...

Determining the efficacy of a drug used in experimental traumatic brain injury (TBI) requires the use of one or more outcome measures such as decreased mortality or fewer neurological and neuropsychological deficits. Unfortunately, outcomes in these test batteries have a fairly large variability, requiring relatively large sample sizes, and adminis...

We recently demonstrated that posttraumatic administration of the N-type calcium channel blocker SNX-111 (S) and a novel blood-brain barrier penetrating antioxidant U-101033E (U), significantly alleviated mitochondrial dysfunction induced by traumatic brain injury (TBI) in rats. The present study was designed to determine whether a combination of S...

Permanent congenital brachial plexus palsy is a recognized serious complication associated with shoulder dystocia. The timing and etiology of this injury remains controversial. Previous authorities have used adult-derived, non-brachial plexus data to extrapolate the anticipated timing for electromyographic denervation changes to date such injuries...

Despite medical and technological advances in neurosurgical intensive care, severe traumatic brain injury still carries a poor prognosis. Invasive monitoring of cerebral oxygenation has recently been proposed as a means for the detection and prevention of cerebral ischemia in comatose patients; however, it has not proven to influence the patient's...

We have recently demonstrated in a rat model that traumatic brain injury induces perturbation of cellular calcium homeostasis with an overload of cytosolic calcium and excessive calcium adsorbed on the mitochondrial membrane, consequently the mitochondrial respiratory chain-linked oxidative phosphorylation was impaired. We report the effect of a se...

We have recently demonstrated in a rat model that traumatic brain injury induces perturbation of cellular calcium homeostasis with an overload of cytosolic calcium and excessive calcium adsorbed on the mitochondrial membrane, consequently the mitochondrial respiratory chain-linked oxidative phosphorylation. was impaired. We report the effect of a s...

Research has demonstrated that much of the mortality and morbidity in severely head-injured patients is due to secondary injury. The development of techniques to monitor cerebral blood flow, arteriovenous difference of oxygen or saturation of jugular venous blood flow with oxygen, and cerebral metabolic rate of oxygen has led to recognition, treatm...