Disruption of the blood-brain barrier by intra-arterial administration of papaverine: a technical note

Introduction: Various endovascular techniques can be used to treat cerebral vasospasm after aneurysmal subarachnoid haemorrhage (SAH) including intra-arterial administration of vasodilator drugs such as papaverine or nicardipine and balloon dilatation of the affected vessel segment. Papaverine is known to have side effects, and we report a possible new one. Materials and methods: After the treatment of cerebral vasospasm in a SAH patient by intra-arterial administration of papaverine into the left posterior cerebral artery, severe mesencephalic extravasation of blood and contrast media was detected. Results: After reviewing the literature, the authors conclude that interruption of the blood-brain barrier by papaverine most likely combined with a secondary hyperperfusion phenomena, and perhaps a direct toxic effect on brain tissue was the mechanism of this major complication. Conclusion: In treating vasospasm in areas with a high density of perforating arteries, especially in the posterior circulation, papaverine should be used cautiously because a safe regimen has yet to be established. In this situation, alternative agents such as calcium channel blockers could be considered, but evidence-based data are still missin

Posterior epistaxis: endonasal exposure and occlusion of the branches of the sphenopalatine artery

Intractable posterior epistaxis (PE) is a frequent emergency for which different treatment modalities are available. While nasal packing causes extreme discomfort and angiography with consecutive selective embolization is not available everywhere, recent studies emphasize the value of sphenopalatine artery (SPA) occlusion by different techniques and indicate success rates of 13-33%. In our institution, previously endoscopic management of PE consisted either of isolated coagulation of an identified bleeding source (group A) or cutting and coagulation of arterial branches running through the sphenopalatine foramen (SPF) (group B). According to our neuroradiological and rhinological experience we developed a modification of SPA transsection and coagulation following identification of the division in conchal and septal branches of the SPA (group C). During a 26-month period the success rates of these three techniques in 95 patients were compared prospectively. The three modalities revealed a re-bleeding rate of 3 out of 21 (21%) in group A, 1 in 6 (16.7%) in group B and 3 in 69 (4.3%) in group C. At the level of the SPF, 36 out of 69 patients had one conchal branch, whereas 30 (43.5%) had two and 3 (4.4%) had three. If SPA transsection and coagulation for intractable PE is adopted the anatomic varieties of the SPA with its division in conchal and septal branches have to be taken into account. According to our experience the septal branch of the SPA plays a major role in PE. Its occlusion significantly improves the success rate of PE treatmen

Endovascular treatment of 170 consecutive cranial dural arteriovenous fistulae: results and complications

This study aims to evaluate a single-center experience with endovascular treatment of cranial dural arterievenous fistulae (CDAVF). The clinical and radiological records of 170 consecutive patients harboring a CDAVF and treated endovascularly in a 16-year period were reviewed. A variety of data related to demographics, features of the lesion, treatment, outcome, and follow-up were analyzed with emphasis to the results and complications. Half of the lesions had cortical venous drainage (CVD) in the initial angiographic investigation, whereas 26% had exclusively CVD. Sixty-seven percent of our patients presented with benign symptoms and 33% with aggressive symptoms. In 60.5% of the patients with benign lesion (without CVD), an anatomic cure in the immediate postinterventional angiogram without complication or permanent morbidity was achieved, whereas 69% of the patients with aggressive lesions (with CVD) had an anatomic cure in the postinterventional final angiogram with all permanent-morbidity cases belonging to this group. The average of endovascular operation sessions per patient was 1.2. In a mean follow-up period of 2.8years, the overall complete occlusion rate was 85.5% (78% for the benign group and 89.5% for the aggressive group) and clinical cure and/or improvement rate of 93%. The operative mortality was zero, and permanent neurologic morbidity was 2.3%. In 73% of our cases, N-butyl cyanoacrylate (NBCA) was used as the only or main embolic material. Endovascular embolization is the treatment of choice for CDAVF. High rates of good anatomical and clinical results, associated with very low operative complication rate can be achieved with few embolization sessions. Although mastering of a permanent embolic material is important, the therapeutic strategy should be individulized and not material based

Impact of fMRI-guided advanced DTI fiber tracking techniques on their clinical applications in patients with brain tumors

Introduction: White matter tractography based on diffusion tensor imaging has become a well-accepted non-invasive tool for exploring the white matter architecture of the human brain in vivo. There exist two main key obstacles for reconstructing white matter fibers: firstly, the implementation and application of a suitable tracking algorithm, which is capable of reconstructing anatomically complex fascicular pathways correctly, as, e.g., areas of fiber crossing or branching; secondly, the definition of an appropriate tracking seed area for starting the reconstruction process. Large intersubject, anatomical variations make it difficult to define tracking seed areas based on reliable anatomical landmarks. An accurate definition of seed regions for the reconstruction of a specific neuronal pathway becomes even more challenging in patients suffering from space occupying pathological processes as, e.g., tumors due to the displacement of the tissue and the distortion of anatomical landmarks around the lesion. Methods: To resolve the first problem, an advanced tracking algorithm, called advanced fast marching, was applied in this study. The second challenge was overcome by combining functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) in order to perform fMRI-guided accurate definition of appropriate seed areas for the DTI fiber tracking. In addition, the performance of the tasks was controlled by a MR-compatible power device. Results: Application of this combined approach to eight healthy volunteers and exemplary to three tumor patients showed that it is feasible to accurately reconstruct relevant fiber tracts belonging to a specific functional system. Conclusion: fMRI-guided advanced DTI fiber tracking has the potential to provide accurate anatomical and functional information for a more informed therapeutic decision makin

Amyotrophic lateral sclerosis after embolization of cerebral arterioveneous malformations

Cerebral arterioveneous malformations (AVM) can cause neurological symptoms and carry a risk of hemorrhage. Therapeutic options to cure or reduce AVM include surgery, embolization, irradiation, and combinations thereof. Prompted by three index cases treated in our center, we studied whether AVM embolization is associated with an increased risk of subsequent amyotrophic lateral sclerosis (ALS). In a monocenter series, we retrospectively analyzed the new development of ALS in patients who had been treated with embolization of cerebral AVM from 1986 to 2010 (n=1,114). After a median follow-up of 11years (range, 0-25years) after first embolization, seven patients developed ALS with a median latency of 14years (range, 12-17years) and a median age of ALS onset of 38years (range, 28-52years). In all cases, the initial limb of ALS symptom onset was ipsilateral to the AVM. Five patients died within the follow-up period, with a range of 1-4years after the onset of ALS symptoms. The seven patients belonged to a subgroup of 34 patients who had in common a rare AVM architecture characterized by significant perinidal angiogenesis. All cases were partially treated by at least three embolization sessions. As there is no known association between AVM and ALS, AVM embolization must be taken into account to have contributed to the development of ALS in the seven patients with this rare AVM architecture. Searching for underlying mechanisms, we compared frozen serum samples that were available from four of the patients who developed ALS, from eight patients with AVM of other architecture, and less than three embolizations who did not develop ALS, and of 20 controls. The concentration of vascular endothelial growth factor (VEGF) in the serum was lowest in AVM patients who developed ALS (245±154pmol/l) and highest in controls (409±178pmol/l). Although this difference was not statistically significant in the small sample, it suggests that low VEGF production by AVM with significant angiogenesis, possibly due to multiple embolization procedures, might have contributed to ALS development. ALS should be considered as a late complication of multiple embolizations of cerebral AVM characterized by significant perinidal angiogenesis

Silicone models as basic training and research aid in endovascular neurointervention—a single-center experience and review of the literature

The rapid development and wider use of neurointerventional procedures have increased the demand for a comprehensive training program for the trainees, in order to safely and efficiently perform these procedures. Artificial vascular models are one of the dynamic ways to train the new generation of neurointerventionists to acquire the basic skills of material handling, tool manipulation through the vasculature, and development of hand-eye coordination. Herein, the authors present their experience regarding a long-established training program and review the available literature on the advantages and disadvantages of vascular silicone model training. Additionally, they present the current research applications of silicone replicas in the neurointerventional arena

Amyotrophic lateral sclerosis after embolization of cerebral arterioveneous malformations

Cerebral arterioveneous malformations (AVM) can cause neurological symptoms and carry a risk of hemorrhage. Therapeutic options to cure or reduce AVM include surgery, embolization, irradiation, and combinations thereof. Prompted by three index cases treated in our center, we studied whether AVM embolization is associated with an increased risk of subsequent amyotrophic lateral sclerosis (ALS). In a monocenter series, we retrospectively analyzed the new development of ALS in patients who had been treated with embolization of cerebral AVM from 1986 to 2010 (n = 1,114). After a median follow-up of 11 years (range, 0-25 years) after first embolization, seven patients developed ALS with a median latency of 14 years (range, 12-17 years) and a median age of ALS onset of 38 years (range, 28-52 years). In all cases, the initial limb of ALS symptom onset was ipsilateral to the AVM. Five patients died within the follow-up period, with a range of 1-4 years after the onset of ALS symptoms. The seven patients belonged to a subgroup of 34 patients who had in common a rare AVM architecture characterized by significant perinidal angiogenesis. All cases were partially treated by at least three embolization sessions. As there is no known association between AVM and ALS, AVM embolization must be taken into account to have contributed to the development of ALS in the seven patients with this rare AVM architecture. Searching for underlying mechanisms, we compared frozen serum samples that were available from four of the patients who developed ALS, from eight patients with AVM of other architecture, and less than three embolizations who did not develop ALS, and of 20 controls. The concentration of vascular endothelial growth factor (VEGF) in the serum was lowest in AVM patients who developed ALS (245 ± 154 pmol/l) and highest in controls (409 ± 178 pmol/l). Although this difference was not statistically significant in the small sample, it suggests that low VEGF production by AVM with significant angiogenesis, possibly due to multiple embolization procedures, might have contributed to ALS development. ALS should be considered as a late complication of multiple embolizations of cerebral AVM characterized by significant perinidal angiogenesis

Silicone models as basic training and research aid in endovascular neurointervention-a single-center experience and review of the literature

The rapid development and wider use of neurointerventional procedures have increased the demand for a comprehensive training program for the trainees, in order to safely and efficiently perform these procedures. Artificial vascular models are one of the dynamic ways to train the new generation of neurointerventionists to acquire the basic skills of material handling, tool manipulation through the vasculature, and development of hand-eye coordination. Herein, the authors present their experience regarding a long-established training program and review the available literature on the advantages and disadvantages of vascular silicone model training. Additionally, they present the current research applications of silicone replicas in the neurointerventional arena