Multicenter study of the safety and effectiveness of intracranial aneurysm treatment with the p64MW-HPC flow modulation device.

BACKGROUND AND PURPOSE: The new p64 flow diverter with hydrophilic polymer coating (HPC) was designed to reduce thrombogenicity. To date, it is unclear how antithrombogenic surface modifications affect neoendothelialization and thrombus formation in patients with unruptured intracranial aneurysms. The purpose of this study was to evaluate the safety and effectiveness of the p64MW-HPC in the treatment of unruptured aneurysms of small to giant size and of both the anterior and posterior circulation. MATERIALS AND METHODS: Between March 2020 and October 2022 all patients with unruptured intracranial aneurysms treated with the p64MW-HPC were included at five neurovascular centers. Demographic data, aneurysm characteristics, antiplatelet therapy, procedural complications, and clinical and angiographic outcomes were recorded. RESULTS: A total of 100 patients with 100 unruptured intracranial aneurysms met the inclusion criteria. Eighty-three aneurysms were classified as saccular, 12 aneurysms were fusiform, 4 aneurysms dissecting, and 1 aneurysm was blister-like. Dual antiplatelet therapy with Clopidogrel and Aspirin was given in 68 cases, and with Ticagrelor and Aspirin in 24 cases. Technical issues with deployment were encountered in 14 cases (torsion (n = 3), foreshortening (n = 8), and incomplete opening (n = 3)). Ischemic stroke occurred in a total of seven cases. In one patient a wire perforation and subsequent severe ICH occurred. Complete aneurysm occlusion at angiographic follow-up (mean time = 7 months) was seen in 73% and adequate occlusion in 93%. CONCLUSION: This study is the largest multicenter study to date documenting the safety and effectiveness of the new antithrombogenic p64MW-HPC in the treatment of unruptured intracranial aneurysms of the anterior and posterior circulation.

Flow Diversion for ICA Aneurysms with Compressive Neuro-Ophthalmologic Symptoms: Predictors of Morbidity, Mortality, and Incomplete Aneurysm Occlusion.

BACKGROUND AND PURPOSE: Flow diversion is an effective treatment for aneurysms of the ICA with compression-related neuro-ophthalmologic symptoms, especially when treatment is initiated early after symptom onset and aneurysm occlusion is complete. However, non-negligible complication rates have been reported. Our aim was to identify risk factors for morbidity/mortality and incomplete aneurysm occlusion. MATERIALS AND METHODS: We performed a secondary analysis of a previous publication, which included all patients treated with flow diversion for an unruptured aneurysm of the ICA with compression-related symptoms. RESULTS: Fifty-four patients with 54 aneurysms (48 women, 88.9%; mean age, 59.2 [SD, 15.9] years; range, 21-86 years) treated with flow diversion were included. We observed morbidity and mortality rates of 7.4% and 3.7%. Increasing age (OR per decade, 3.2; 95% CI, 1.23-8.49; P = .02) and dual-antiplatelet therapy with ticagrelor (OR, 13.9; 95% CI, 1.16-165.97; P = .04) were significantly associated with morbidity/mortality. After a median follow-up of 13.3 [SD, 10.5] months, the rates of complete aneurysm occlusion, neck remnant, and aneurysm remnant were 74%, 14%, and 12%. Incomplete occlusion at follow-up was less frequently observed in aneurysms treated with additional coil embolization (OR, 0.1; 95% CI, 0.01-0.86; P = .04). CONCLUSIONS: Although a promising treatment for compressive ICA aneurysms, flow diversion carries a relevant risk for complications and incomplete aneurysm occlusion. Our results may help identify patients in which flow diversion may not be the ideal treatment method. Additional coil embolization increased the likelihood of complete aneurysm occlusion at follow-up.

Aneurysm Treatment in Acute SAH with Hydrophilic-Coated Flow Diverters under Single-Antiplatelet Therapy: A 3-Center Experience.

BACKGROUND AND PURPOSE: In certain clinical circumstances, dual-antiplatelet therapy can be problematic in patients with acute SAH. In some aneurysms, however, flow-diverting stents are the ideal therapeutic option. We report our experience with ruptured intracranial aneurysms treated with flow diverters with hydrophilic coating (p48 MW HPC and p64 MW HPC) under single-antiplatelet therapy. MATERIALS AND METHODS: Patients were treated with either flow-diverter placement alone or a flow diverter and additional coiling. Due to the severity of the hemorrhage, the potential for periprocedural rehemorrhage, and the potential for additional surgical interventions, a single-antiplatelet regimen was used in all patients. RESULTS: Thirteen aneurysms were treated in 10 patients. The median age was 62 years; 5 patients were male. All had acute SAH due to aneurysm rupture. Four blood-blister, 2 dissecting, and 7 berrylike aneurysms were treated. Seven aneurysms were adjunctively coiled. Eight of the 10 patients received a single-antiplatelet protocol of aspirin, 1 patient was treated with prasugrel only, and 1 patient was treated with tirofiban first and then switched to the aspirin single-antiplatelet protocol. One device-related complication occurred, a thrombosis of an overstented branch. All stents, however, remained open at DSA, CTA, or MRA follow-up. CONCLUSIONS: The implantation of flow diverters with reduced thrombogenicity due to hydrophilic surface coating under single-antiplatelet therapy seems to be an option in carefully selected cases of SAH due to aneurysm rupture.

WEB-DL Endovascular Treatment of Wide-Neck Bifurcation Aneurysms: Long-Term Results in a European Series.

BACKGROUND AND PURPOSE: Flow disruption with the WEB-DL device has been used safely for the treatment of wide-neck bifurcation aneurysms. The stability of aneurysm occlusion after this treatment was evaluated in the short and midterm, but not in the long term. This retrospective multicenter European study is the continuation of an already published series dealing with short- and midterm anatomic results and analyzes long-term data in patients treated with the WEB-DL. MATERIALS AND METHODS: Twelve European neurointerventional centers initially participated in the study. In addition to data collected for the initial publication, images obtained at long-term follow-up were collected and independently analyzed by the same experienced interventional neuroradiologist. RESULTS: Of the initial 45 patients, 26 (20 women and 6 men; 35-73 years of age; mean, 55.2 ± 10.6 years; median, 55.5 years) with 26 aneurysms treated with the WEB-DL device had long-term follow-up (median, 27.4 months). Three of 26 patients (11.5%) were retreated between short- and midterm follow-up, and none, between mid- and long-term follow-up. Long-term aneurysm occlusion in the 19 patients treated with the WEB only and not retreated during follow-up was complete occlusion in 13/19 patients (68.4%), including aneurysms with opacification of the proximal recess in 9/19 patients (47.4%), neck remnant in 3/19 patients (15.8%), and aneurysm remnant in 3/19 patients (15.8%). In all patients (100.0%), aneurysm occlusion was stable between midterm and long-term follow-up. CONCLUSIONS: The results suggest that WEB treatment of wide-neck bifurcation aneurysms offers long-term stable occlusion.

Single-Layer WEBs: Intrasaccular Flow Disrupters for Aneurysm Treatment­Feasibility Results from a European Study.

BACKGROUND AND PURPOSE: The safety and efficiency of the dual-layer Woven EndoBridge (WEB) device has already been published. However, this international multicenter study sought to evaluate the safety of single-layer devices, which are the newest generation of the WEB intrasaccular flow-disrupter family. They have been designed to offer smaller-sized devices with a lower profile to optimize navigability and delivery, which may, in turn, broaden their range of use. MATERIALS AND METHODS: Data from all consecutive patients treated with a single-layer WEB device, in 10 European centers from June 2013 to May 2014 were included. Clinical presentations, technical details, intra- and perioperative complications, and outcomes at discharge were recorded. Clinical and angiographic data at last follow-up were also analyzed when available. RESULTS: Ninety patients with 98 WEB-treated aneurysms were included in this study. In 93 cases (95%), WEB placement was possible. Complete occlusion at the end of the procedure was obtained in 26 instances (26%). Additional treatment during the procedure (coiling and/or stent placement) was necessary in 12 cases (12.7%). Procedure-related complications occurred in 13 cases, leading to permanent neurologic deficits in 4 patients (4.4%). Early vascular imaging follow-up data were available for 44 patients (57%), with an average time interval of 3.3 months. Treatment-related morbidity and mortality rates at last follow-up were 2.2% and 1.1%, respectively. CONCLUSIONS: In this study, the feasibility and safety of the single-layer WEB device was comparable with that of the double-layer. However, further studies are needed to evaluate long-term efficacies.

Intrasaccular Flow Disruption in Acutely Ruptured Aneurysms: A Multicenter Retrospective Review of the Use of the WEB.

BACKGROUND AND PURPOSE: Use of the WEB intra-aneurysmal flow-disruption device in unruptured wide-neck bifurcation aneurysms has proven safety and efficacy. However, ruptured aneurysms are underrepresented in existing studies. This retrospective multicenter study describes the use of the WEB in patients with a ruptured intracranial aneurysm. MATERIALS AND METHODS: Ten centers contributed to this study. Clinical and procedural data of 47 patients with 52 aneurysms were analyzed retrospectively together with follow-up angiographies. RESULTS: There were 37 anterior and 15 posterior circulation aneurysms with a neck size of ≥4 mm in 49 of 52 (94%) aneurysms; 45 (87%) aneurysms were <10 mm, and 2 were partially thrombosed. Successful placement of the WEB was possible in every case. Adjunctive devices were used in 8 of 52 (15%) aneurysms. Thromboembolic events were observed in 4 of 52 (8%) patients. Adverse events occurred in 15 patients with 16 aneurysms, 9 of which were potentially related to the WEB procedure (3 thromboembolic events, 5 protrusions, and 1 perforations; 2 perforations were caused by the wire or catheter), but none had a clinical impact. Four patients were retreated. Short-term follow-up in 25 of 39 patients revealed complete occlusion in 15 of 25 (60%), 5 of 25 (20%) with residual neck, and 5 of 25 (20%) with residual aneurysm filling. Short- to midterm imaging in 9 of 25 patients revealed complete occlusion in 5 (55.6%), residual neck in 2 (22%), and residual aneurysm filling in 2 (22%). Of 47 patients, 23 (49%) had an mRS score of 0, 1, or 2; 13 (28%) had an mRS score of 3 or 4; and none had an mRS score of 5 at discharge. CONCLUSIONS: This retrospective series showed good procedural safety, feasibility, and stability of midterm occlusion in ruptured wide-neck bifurcation aneurysms.

Double solitaire mechanical thrombectomy in acute stroke: effective rescue strategy for refractory artery occlusions?

BACKGROUND AND PURPOSE: Mechanical thrombectomy by using a single stent retriever system has demonstrated high efficacy for recanalization of large-artery occlusions in acute stroke. We aimed to evaluate the feasibility, safety, and efficacy of a novel double Solitaire stent retriever technique as an escalating treatment for occlusions that are refractory to first-line single stent retriever mechanical thrombectomy. MATERIALS AND METHODS: All patients treated with the double stent retriever technique by using the Solitaire system were retrospectively selected from 2 large neurointerventional centers. Time to recanalization, angiographic (TICI) and clinical outcomes (mRS), and complications were assessed. RESULTS: Ten patients (median NIHSS score, 16; mean age, 70 years) with MCA M1 segment (n = 5) and terminal ICA (n = 5 including 2 ICA tandem) occlusions were included. Prior single stent retriever mechanical thrombectomy had been performed in 9 patients (median number of passes, 3). Median time to recanalization was 60 minutes (interquartile range, 45-87 minutes). Procedure-related complications occurred in 1 patient; overall mortality was 20%. Recanalization of the target vessel (TICI 2b/3) was achieved in 80%. Good clinical outcome (mRS 0-2) was 50%. CONCLUSIONS: In this preliminary feasibility study, the double Solitaire stent retriever technique proved to be an effective method for recanalization of anterior circulation large-artery occlusions refractory to standard stent retriever mechanical thrombectomy.

WEB-DL endovascular treatment of wide-neck bifurcation aneurysms: short- and midterm results in a European study.

BACKGROUND AND PURPOSE: Flow disruption with the WEB-DL device has been used safely for the treatment of wide-neck bifurcation aneurysms, but the stability of aneurysm occlusion after this treatment is unknown. This retrospective multicenter European study analyzed short- and midterm data in patients treated with WEB-DL. MATERIALS AND METHODS: Twelve European neurointerventional centers participated in the study. Clinical data and pre- and postoperative short- and midterm images were collected. An experienced interventional neuroradiologist independently analyzed the images. Aneurysm occlusion was classified into 4 grades: complete occlusion, opacification of the proximal recess of the device, neck remnant, and aneurysm remnant. RESULTS: Forty-five patients (34 women and 11 men) 35-74 years of age (mean, 56.3 ± 9.6 years) with 45 aneurysms treated with the WEB device were included. Aneurysm locations were the middle cerebral artery in 26 patients, the posterior circulation in 13 patients, the anterior communicating artery in 5 patients, and the internal carotid artery terminus in 1 patient. Forty-two aneurysms were unruptured. Good clinical outcome (mRS < 2) was observed in 93.3% of patients at the last follow-up. Adequate occlusion (complete occlusion, opacification of the proximal recess, or neck remnant) was observed in 30/37 patients (81.1%) in short-term follow-up (median, 6 months) and in 26/29 patients (89.7%) in midterm follow-up (median, 13 months). Worsening of the aneurysm occlusion was observed in 2/28 patients (7.1%) at midterm follow-up. CONCLUSIONS: The results suggest that the WEB endovascular treatment of wide-neck bifurcation aneurysms offers stable occlusion in a class of aneurysms that are historically unstable. Additionally, our data show that opacification of the WEB recess can be delineated from true neck or aneurysm remnants.

Dynamic magnetic resonance angiography for localization of hyperfunctioning parathyroid glands in the reoperative neck.

OBJECTIVES: To evaluate the use of dynamic magnetic resonance angiography for localization of hyperfunctioning parathyroid glands in the reoperative neck. METHODS: We retrospectively evaluated the head-neck MRIs of 30 patients with a history of hyperparathyroidism, prior head-neck surgery, and intraoperative proven adenomas. The protocol included conventional imaging with T2-weighted STIR sequences, T1w axial and coronal prior to and after contrast media administration, and dynamic magnetic resonance angiography. We compared the results from MRI, dynamic magnetic resonance angiography with 99m-Tc-Sestamibi with intraoperative findings as the gold standard. RESULTS: In conventional MRI 19/30 true positives were detected with a sensitivity and specificity of 63.3% and 100%, respectively. However, by adding dynamic magnetic resonance angiography the detection rate increased to 28/30 true positives. Based on intraoperative findings, the sensitivity and specificity of dynamic magnetic resonance angiography were 93.3% and 100%, respectively. 99m-Tc-Sestamibi detected 24/30 true positives, sensitivity was 80%. CONCLUSION: The diagnostic value of MRI including dynamic magnetic resonance angiography is superior to MRI alone and superior to that of 99m-Tc-Sestamibi in the diagnostic workup of hyperfunctioning parathyroid glands when compared against intraoperative findings.

Intrasaccular flow-disruption treatment of intracranial aneurysms: preliminary results of a multicenter clinical study.

BACKGROUND AND PURPOSE: The endovascular treatment of intracranial aneurysms with unfavorable anatomy (large aneurysms, wide-neck) is frequently challenging and is also associated with a high incidence of significant recurrences. The WEB, an intrasaccular flow disrupter, was designed for use in this type of aneurysm. We report our early experience with this device in this multicenter study. MATERIALS AND METHODS: Twenty patients with 21 aneurysms were treated by using the WEB in 3 European centers. The ability to successfully deploy the WEB, immediate posttreatment angiographic results, adverse events, clinical outcome, and angiographic follow-up results were recorded. RESULTS: Aneurysm location was the ICA (4/21, 19.1%), MCA (8/21, 38.1%), AcomA (5/21, 23.8%), and BA (4/21, 19.1%). No treatment failures were reported. Treatment was performed exclusively with the WEB in 16/21 (76.2%) patients. Additional treatment (coiling and/or stent placement) was used in 5/21 (23.8%) patients. One patient (4.8%) experienced transient clinical worsening (mRS 1 at 1 month, mRS 0 at 3 months) related to a thromboembolic event. Inadvertent detachment of the WEB was observed, and the WEB was retrieved in 1 patient, without adverse effects. In the short-term follow-up (2-8 months), adequate occlusion (total occlusion or neck remnant) was observed in 80.0% of aneurysms. CONCLUSIONS: Intrasaccular flow disruption is a new endovascular approach for aneurysm treatment. In our preliminary experience, this treatment was feasible and mostly used in bifurcation aneurysms (MCA, BA, ICA) with unfavorable anatomy. Further studies are needed to precisely evaluate the indications, safety, and efficacy of this new technique.

Very late thrombosis of flow-diverting constructs after the treatment of large fusiform posterior circulation aneurysms.

BACKGROUND AND PURPOSE: The PED is a new endoluminal construct designed to exclude aneurysms from the parent cerebrovasculature. We report the very late (>1 year) thrombosis of PED constructs in 2 patients. RESULTS: Two patients with very large fusiform basilar trunk aneurysms underwent parent artery reconstruction with the PED. Both patients were maintained on dual antiplatelet therapy throughout the first year following treatment. Follow-up conventional angiography, performed 12 months after treatment, demonstrated, in both patients, thrombosis of most of the aneurysm with minimal residual flow through the construct and into the aneurysm fundus. In response to the residual filling, clopidogrel was discontinued (aspirin therapy was maintained). Both patients presented with symptomatic acute occlusions of the PED constructs within 14 days of clopidogrel discontinuation. DISCUSSION: Patient 1 presented with constitutional symptoms that progressed to severe headache without other neurologic signs or symptoms. Occlusion of the PED construct was confirmed with conventional angiography. MR imaging demonstrated no evidence of infarction or parenchymal injury. The headaches were managed successfully with steroid therapy. Patient 2 presented with a syndrome of acute basilar occlusion with brain stem stroke. Complete occlusion was confirmed on angiography. Emergent thrombolysis with mechanical revascularization was performed successfully; however, the patient ultimately succumbed to the infarction. CONCLUSIONS: It appears that flow-diverting constructs built across large circumferential aneurysms may remain thrombogenic for much longer than conventional intracranial or peripheral bare metal stents. Constructs in these patients may remain susceptible to very late thrombosis, >1 year after implantation. These patients likely require long-term dual antiplatelet therapy (>1 year) to provide adequate prophylaxis against thrombosis. If these types of aneurysms demonstrate persistent residual filling months after PED reconstruction, operators should consider the placement of additional devices as an alternative to the discontinuation of 1 of the antiplatelet medications.

An Empirical Analysis of the Current Need for Teleneuromedical Care in German Hospitals without Neurology Departments.

Indroduction. At present, modern telemedicine methods are being introduced, that may contribute to reducing lack of qualified stroke patient care, particularly in less populated regions. With the help of video conferencing systems, a so-called neuromedical teleconsultation is carried out. Methods. The study included a multicentered, completely standardized survey of physicians in hospitals by means of a computerized on-line questionnaire. Descriptive statistical methods were used for data analysis. Results. 119 acute hospitals without neurology departments were included in the study. The most important reasons for participating in a teleneuromedical network is seen as the improvement in the quality of treatment (82%), the ability to avoid unnecessary patient transport (76%), easier and faster access to stroke expertise (72%) as well as better competitiveness among medical services (67%). The most significant problem areas are the financing system of teleneuromedicine with regard to the acquisition costs of the technical equipment (43%) and the compensation for the stroke-unit center with the specialists' consultation service (31%) as well as legal aspects of teleneuromedicine (27%). Conclusions. This investigation showed that there is a high acceptance for teleneuromedicine among co-operating hospitals. However these facilities have goals in addition to improved quality in stroke treatment. Therefore the use of teleneuromedicine must be also associated with long term incentives for the overall health care system, particularly since the implementation of a teleneuromedicine network system is time consuming and associated with high implementation costs.

Imaging of pheochromocytoma and paraganglioma.

Paragangliomas are tumours that arise within the sympathetic nervous system originating from the neural crest. These tumours can be found anywhere from the neck to the pelvis in locations of sympathetic ganglions. Although in the majority of paragangliomas the diagnosis is based on measuring catecholamines and metabolites in plasma or urine, imaging plays an important preoperative role. Today, there are several morphological and radionuclide imaging methods available that predict tumour localisation and tumour extent and give anatomic information to the surgeon. MRI is the morphological imaging modality of choice in localising pheochromocytomas and extra-adrenal paragangliomas. It provides excellent anatomic detail and has the advantage of lacking ionising radiation. The overall accuracy of computed tomography (CT) in detecting primary adrenal pheochromocytomas is very high, but CT lacks in specificity as difficulties may occur in distinguishing between paragangliomas and other tumour entities. The major advantages of radionuclide imaging are very high specificity and routinely performed whole-body scanning. Furthermore, metabolic imaging is not influenced by artifacts like scar tissue or metallic clips in post-surgical follow-up. Currently, a reported specificity of 99% and a cumulative sensitivity of about 90% in paragangliomas make (123)I-MIBG the most important nuclear imaging method. However, (18)F-DOPA-PET seems to be a very promising procedure which offers higher accuracy. The higher spatial resolution of PET-scanners enables the detection of small lesions not visualised with (123)I-MIBG. Both use of radiolabelled somatostatin analogue like (111)In-pentetreotide and (18)F-FDG is limited due to low specificity of the tracers and should be restricted to MIBG- and F-DOPA-negative cases.

Dynamic 3D MR angiography of intra- and extracranial vascular malformations at 3T: a technical note.

Time-resolved, contrast-enhanced 3D MR angiography combined with parallel imaging at 3T was applied to an intracranial arteriovenous malformation, a dural arteriovenous fistula, and an extracranial facial arteriovenous malformation. The temporal resolution was one image every 1.5 seconds. Arterial feeders were depicted in all three cases. Early venous drainage was observed in the intracerebral arteriovenous malformation and the dural arteriovenous fistula, but not in the facial arteriovenous malformation. All findings were concordant with conventional angiography.

Fulminant acute disseminated encephalomyelitis mimicking acute bacterial menigoencephalitis.

Most patients with acute disseminated encephalomyelitis (ADEM) recover quickly under corticosteroid treatment and have a favourable long-term prognosis. We report on a young woman with acute onset of an extensive and solitary white-matter lesion in the left hemisphere. Fever, high pleocytosis and elevated protein in cerebrospinal fluid initially suggested bacterial meningoencephalitis. The patient died from brain herniation despite maximal conservative therapy. Histological changes in necropsy were consistent with the diagnosis ADEM. Treatment options of fulminant ADEM are discussed.

Diffusion-weighted MRI during early global cerebral hypoxia: a predictor for clinical outcome?

OBJECTIVES: As prognostic assessment of prolonged cerebral hypoxia is often difficult on clinical grounds, a tool for an early prognosis of clinical outcome is desirable. PATIENTS AND METHODS: In a prospective study, we investigated the prognostic value of diffusion-weighted MRI (DWI) in 12 patients within 36 h after global cerebral hypoxia. Results of DWI including apparent diffusion coefficient maps (ADC) were analyzed and related to the clinical outcome after 6 months, in comparison with conventional magnetic resonance imaging (cMRI). RESULTS: Three patients with a short resuscitation time showed normal findings in cMRI and DWI and a good recovery. In seven patients, DWI revealed multiple large hyperintense areas although cMRI was normal. In two patients, large diffuse lesions were observed in DWI which were also found in cMRI. All of these nine patients developed a vegetative state in the follow-up examination. CONCLUSION: Pathological DWI during the early phase after cerebral hypoxia might be superior to cMRI as a predictor of a worse clinical outcome.

Parkes Weber or Klippel-Trenaunay syndrome? Non-invasive diagnosis with MR projection angiography.

Klippel-Trenaunay and Parkes Weber (Klippel-Trenaunay-Weber) syndromes consist of vascular malformations of the capillary, venous and lymphatic systems combined with soft tissue and bone hypertrophy of the affected extremity. Klippel-Trenaunay syndrome is a pure low-flow condition, while Parkes Weber syndrome is characterized by significant arteriovenous fistulas. The distinction of both entities is relevant, since the prognosis and therapeutic strategies differ significantly. Our purpose is to demonstrate that thick-slice dynamic magnetic resonance projection angiography (MRPA) is a non-invasive tool to detect arteriovenous shunting in Parkes Weber syndrome. Four patients underwent MR imaging and MRPA. MRPA demonstrated arteriovenous shunting in three patients. Arteriovenous shunting was characterized by early appearing draining veins. The time of arrival between normal arteries and pathological veins varied between less than 0.5 and 1.0 s. Therefore, the diagnosis in these cases could be specified as Parkes Weber syndrome. In all these cases, arteriovenous shunting was confirmed by intraarterial digital subtraction angiography. One patient showed normal results in MRPA and could be diagnosed as having Klippel-Trenaunay syndrome.

Cerebral arteriovenous malformations: influence of angioarchitecture on bleeding risk.

BACKGROUND: To evaluate the angioarchitecture of cerebral arteriovenous malformations (cAVMs) with special regard to its influence on the risk of intracranial haemorrhage. METHODS: Clinical and neuroradiological data of 171 patients with cAVMs, who were treated at our department, were analysed retrospectively. The angioarchitectonic data were obtained from angiographic series, cranial CT scans and MR images. A chi(2) test was conducted to correlate the parameters and determine the P values. FINDINGS: The following parameters correlate to an increased risk of haemorrhage: diameter of the nidus < or =2 cm (P<0.001), number of arterial feeders < or =2 (P<0.001), diameter of the main feeder < or =1 mm (P<0.0001), number of veins draining the nidus < or =2 (P<0.001), exclusive deep drainage (P<0.05), and low or middle flow-velocity (P<0.01). Specific angioarchitectonic features such as venous stenoses, varicose dilatation of the draining vein, arterial aneurysms of the feeding artery, arteriovenous fistula within the nidus, contralateral drainage and sinushypo/-aplasia did not alter the bleeding rate. INTERPRETATION: Various angiographic features were correlated with the occurrence of intracranial haemorrhage in patients with cerebral AVMs. In addition to the well-known factors influencing the bleeding risk of cAVMs like size, pattern of venous drainage and location within the brain our data demonstrate the importance to look at the diameter of the main feeder and the number of draining veins showing a better correlation.

Arteriovenous malformation in the temporalis muscle.

An 18-year-old man presented with an arteriovenous malformation (AVM) in the temporalis muscle. It was shown by magnetic resonance imaging (MRI) and confirmed by intra-arterial angiography. The lesion was completely resected and the defect reconstructed with titanium mesh and cancellous bone.