Morphologic Change of Flow-Related Aneurysms in Brain Arteriovenous Malformations after Stereotactic Radiosurgery.

BACKGROUND AND PURPOSE: The natural history of flow-related aneurysms after obliteration of brain arteriovenous malformations is poorly understood. The purpose of this study was to evaluate the angioarchitecture and morphologic change in flow-related aneurysms after gamma knife surgery of brain arteriovenous malformations. MATERIALS AND METHODS: During a 12-year period, 823 patients with brain arteriovenous malformations underwent gamma knife surgery at our institution with complete peritherapeutic angiographic evaluation. From this population, a series of 72 patients (8.8%) with 111 flow-related aneurysms were enrolled (1.5 aneurysms per patient). There were 43 men and 29 women; ages ranged from 18 to 72 years (mean, 43 years). The morphologic change of flow-related aneurysms was longitudinally evaluated before and after obliteration of brain arteriovenous malformations. After gamma knife surgery, angiographic follow-up varied from 26 to 130 months (mean, 58 months). RESULTS: All flow-related aneurysms were small (mean, 4.1 mm; range, 2-9 mm). There were 72 proximal flow-related aneurysms (mean size, 4.3 mm) and 39 distal flow-related aneurysms (mean size, 3.7 mm). Spontaneous thrombosis occurred more frequently in distal flow-related aneurysms than in proximal flow-related aneurysms (P < .001). Smaller flow-related aneurysms (<5 mm) tended to spontaneously occlude after obliteration of brain arteriovenous malformations (P = .036). Two patients had ruptures of proximal flow-related aneurysms at 27- and 54-month follow-ups, respectively. CONCLUSIONS: Spontaneous thrombosis occurred more frequently in distal flow-related aneurysms due to occlusion or normalization of distal feeders. Smaller flow-related aneurysms also tended to spontaneously thrombose after obliteration of brain arteriovenous malformations. The rate of flow-related aneurysm rupture in our series was similar to that of natural intradural aneurysms.

Peritherapeutic Hemodynamic Changes of Carotid Stenting Evaluated with Quantitative DSA in Patients with Carotid Stenosis.

BACKGROUND AND PURPOSE: Quantitative data from DSA have become important tools for understanding hemodynamic changes of intracranial lesions. In this study, we evaluated 8 hemodynamic parameters in patients before and after carotid artery angioplasty. MATERIALS AND METHODS: DSA images of 34 patients with carotid stenosis who underwent angioplasty and stent placement were retrospectively analyzed. Eleven ROIs (M1, M2, A1, A2, the parietal vein, superior sagittal sinus, internal jugular vein, and 4 in the ICA) were selected on color-coded DSA. Eight hemodynamic parameters (bolus arrival time, TTP, relative TTP, full width at half maximum, wash-in slope, washout slope, maximum enhancement, and area under the curve) were measured from the time-concentration curves of these ROIs. The dependent t test for paired samples was applied to these parameters before and after stent placement. RESULTS: We found that the treatment significantly reduced TTP, relative TTP, bolus arrival time, and washout slope at all arterial ROIs and full width at half maximum and area under the curve at some arterial ROIs. Bolus arrival time was significantly reduced after treatment for all arterial ROIs, the parietal vein, and the superior sagittal sinus. The maximum enhancement and wash-in slope did not show significant changes after treatment. After treatment, the relative TTP from the ICA to M1, M2, and the parietal vein returned to normal values. CONCLUSIONS: In addition to TTP and relative TTP, other parameters can be used to evaluate peritherapeutic cerebral hemodynamic changes. Bolus arrival time has the potential to evaluate brain circulation at arterial and venous sites, especially when TTP cannot be measured because of an incomplete time-concentration curve.

Evaluation of the outcomes of endovascular management for patients with head and neck cancers and associated carotid blowout syndrome of the external carotid artery.

AIM: To evaluate factors related to the technical and haemostatic outcomes of endovascular management in patients with head and neck cancers (HNC) associated with carotid blowout syndrome (CBS) of the external carotid artery (ECA). MATERIALS AND METHODS: Between 2002 and 2011, 34 patients with HNC with CBS involving branches of the ECA underwent endovascular therapy. Treatment included embolization with microparticles, microcoils, or acrylic adhesives. Fisher's exact test was used to examine demographic features, clinical and angiographic severities, and clinical and imaging findings as predictors of endovascular management outcomes. RESULTS: Technical success and immediate haemostasis were achieved in all patients. Technical complications were encountered in one patient (2.9%). Rebleeding occurred in nine patients (26.5%). Angiographic vascular disruption grading from slight (1) to severe (4) revealed that the 18 patients with acute CBS had scores of 2 (2/18, 11.1%), 3 (3/18, 16.7%), and 4 (13/18, 72.2%). The 16 patients with impending and threatened CBS had scores of 1 (1/16, 6.25%), 2 (5/16, 31.25%), and 3 (10/16, 62.5%; p = 0.0003). For the 25 patients who underwent preprocedural computed tomography (CT)/magnetic resonance imaging (MRI) examinations within 3 months of treatment, the agreement between clinical and imaging findings reached the sensitivity, specificity, and kappa values for recurrent tumours (1, 0.7143, 0.7826), soft-tissue defect (0.9091, 0.3333, 0.2424), and sinus tract/fistula (0.4737, 0, 0.4286). CONCLUSION: Endovascular management for patients with CBS of the ECA had high technical success and safety but was associated with high rebleeding rates. We suggest applying aggressive post-procedural follow-up and using preprocedural CT/MRI to enhance the periprocedural diagnosis.

Can iterative reconstruction improve imaging quality for lower radiation CT perfusion? Initial experience.

BACKGROUND AND PURPOSE: Initial results using IR for CT of the head showed satisfactory subjective and objective imaging quality with a 20-40% radiation dose reduction. The aim of our study was to compare the influence of IR and FBP algorithms on perfusion parameters at standard and lowered doses of CTP. MATERIALS AND METHODS: Forty patients with unilateral carotid stenosis post-carotid stent placement referred for follow-up CTP were divided into 2 groups (tube currents were 100 mAs in group A and 80 mAs in group B). Datasets were reconstructed with IR and FBP algorithms; and SNRs of gray matter, white matter, and arterial and venous ROIs were compared. CBF, CBV, and MTT means and SNRs were evaluated by using linear regression, and qualitative imaging scores were compared across the 2 algorithms. RESULTS: The mean effective radiation dose of group B (2.06 mSv) was approximately 20% lower than that of group A (2.56 mSv). SNRs for ROIs in the dynamic contrast-enhanced images were significantly higher than those for the FBP images. Correlations of the SNRs for CBF, CBV, and MTT across the 2 algorithms were moderate (R² = 0.46, 0.23, and 0.44, respectively). ROIs in gray matter rather than the IR algorithm predicted increasing SNRs in all CBF, CBV, and MTT maps. Two cases of significant restenosis were confirmed in both algorithms. CBV, CBF, and MTT imaging scores did not differ significantly across algorithms or groups. CONCLUSIONS: Lower dose CTP (20% below normal dose) without IR can effectively identify oligemic tissue in poststenting follow-up. IR does not alter the absolute values or increase the SNRs of perfusion parameters. Other methods should be attempted to improve SNRs in settings with low tube currents.

In-room assessment of cerebral blood volume for guidance during intra-arterial thrombolytic therapy.

In acute ischemic stroke, the ability to estimate the penumbra and infarction core ratio helps to triage those who will potentially benefit from thrombolytic therapies. Flat-panel post-contrast DynaCT imaging can provide both vasculature and parenchymal blood volume within the angio room to monitor hemodynamic changes during the endovascular procedures. We report on an 80-year-old woman who suffered from an acute occlusion of the right distal cervical internal carotid artery. She was transferred to the angio room where in-room post-contrast flat-panel DynaCT imaging (syngo Neuro PBV IR) was performed to access the ischemic tissue, followed by successful mechanical thrombolytic therapy.

Preventive vertebroplasty for adjacent vertebral bodies: a good solution to reduce adjacent vertebral fracture after percutaneous vertebroplasty.

BACKGROUND AND PURPOSE: Adjacent VCF frequently occurs after percutaneous vertebroplasty. Our aim was to evaluate PrVP in the prevention of PVNO-adjacent VCF. MATERIALS AND METHODS: Radiographs of 68 patients who initially presented with a single-level unhealed fracture and underwent vertebroplasty were retrospectively reviewed for the occurrence of PVNO fracture. Patients in the nonpreventive group (n = 33) underwent TVP only for a vertebra with an unhealed fracture. The preventive group (n = 35) underwent PrVP combined with TVP. We injected bone cement into the caudal part of the superior adjacent vertebra and the cephalic part of the inferior adjacent vertebra to perform PrVP. RESULTS: The incidences of PVNO fracture in adjacent vertebra next to a vertebra cemented at the patient's first vertebroplasty (within 6 months: 24% versus 3%, P = .012; within 1 year: 30% versus 3%, P = .006; >4 years: 39% versus 3%, P = .006) markedly decreased in the preventive group compared with the nonpreventive group. PVNO fracture was found in 26% of vertebrae adjacent to the first TVP level in the nonpreventive group and in 2% of vertebrae adjacent to a PrVP level in the preventive group after inclusion of all PrVP procedures. Approximately 33% of patients in the nonpreventive group underwent repeat vertebroplasty, mainly due to adjacent fractures. Only 3% of patients in the preventive group underwent repeated procedures. None of the vertebrae cemented for PrVP or TVP developed PVNO refracture. CONCLUSIONS: Preventive vertebroplasty for the adjacent vertebra combined with TVP for the fractured vertebra is effective in the prevention of propagation of PVNO adjacent fractures, thus reducing the necessity of multiple repeat vertebroplasty procedures.

Direct puncture of a prematurely detached balloon in the supraclinoid ICA via the optic canal during embolisation of a traumatic carotid-cavernous fistula.

We report a patient with traumatic carotid-cavernous fistula associated with an isolated internal carotid artery in whom, after trans-arterial balloon embolisation, premature balloon detachment occurred with balloon migration to the supraclinoid carotid artery, leading to total occlusion of the blood flow. The carotid flow was eventually restored by direct puncture of the detached balloon via the optic canal and by deploying a coronary stent to fix the balloon in the vascular wall. The fistula was eventually occluded by using detachable coils. He was discharged with a mild hemiparesis and decreased acuity in the left eye.

Stent management of coil herniation in embolization of internal carotid aneurysms.

BACKGROUND AND PURPOSE: Coil herniation into the parent artery after detachment is an uncommon complication of embolization of the intracranial aneurysm. We report our experience with stent reconstruction of the lumen and flow of the internal carotid artery (ICA) after coil herniation during embolization for intracranial ICA aneurysms and the possible mechanisms of coil herniation. MATERIALS AND METHODS: A series of 216 consecutive patients was treated by endovascular coil embolizations for intracranial aneurysms. Of these patients, there were 9 (4 men, 5 women; 32-68 years of age) complicating with coil herniation into the ICA and undergoing stent deployment to reconstruct the ICA lumen (n = 8) or both lumen and flow (n = 1). Wide-neck aneurysms were found in 8 and narrow-neck, in 1. Aneurysms were in the posterior communicating artery (n = 5) and the paraophthalmic (n = 3) and cavernous portions (n = 1) of the ICA. Self-expandable stents were deployed in the ICA in 6; balloon-mounted stents were selected in 3. RESULTS: The causes of coil herniation appeared to be coil instability after detachment (n = 6), excessive embolization (n = 1), microcatheter-related problems (n = 1), or being pushed by subsequent coil embolization (n = 1). Endovascular stent placement to reconstruct the lumen and/or flow of the ICA was technically successful in all 9 patients; 1 needed a second stent due to further coil migration. No significant procedure-related complications were found. Clinical follow-up was 8-35 months. CONCLUSION: Coil herniation occasionally occurs during endovascular embolization of ICA aneurysms because of coil instability after detachment, excessive embolization, microcatheter-related problems, or pushing by subsequent coil embolization. In this small series, stent placement was safe and effective in the reconstruction of the arterial lumen and/or restoration of flow past a herniated coil mass.

Bilateral traumatic carotid-cavernous fistulae: Strategies for endovascular treatment.

BACKGROUND: Most traumatic carotid-cavernous fistula/e (TCCF) are unilateral, and simultaneous bilateral TCCF are uncommon. The purpose of this study was to evaluate the angiographic architecture of bilateral TCCF and report our experience with their endovascular management. METHOD: Over 15 years, 252 consecutive patients with TCCF were referred to our institute for endovascular treatment. Bilateral TCCF occurred in 5 men and 2 women with a mean age of 31 years. The angiographic architectures of bilateral TCCF were evaluated with cerebral angiography. All patients underwent a single session of transarterial embolisation by using various permanent embolic materials and were followed up clinically or with angiography for a mean of 22 months (range 9-36 months). FINDINGS: All patients presented with neuro-ophthalmic symptoms and signs. No new instances of cerebrovascular ischemia or intracranial haematoma resulted from bilateral TCCF. All fistulae were associated with partial arterial steal and were successfully occluded by using a detachable balloon and/or a detachable coil with or without a liquid adhesive. Of 14 TCCF, 9 were completely obliterated with preserved flow of the internal carotid artery (ICA). In the other 5 fistulae, the ICA had to be sacrificed to achieve occlusion because the anatomy of the fistula was complex. All fistula related symptoms resolved immediately or gradually during clinical follow up. No clinically significant procedure related neurological complications or recurrent fistulae were observed. CONCLUSIONS: All bilateral TCCF were associated with a partial arterial steal phenomenon. Single session endovascular treatment using various embolic materials was effective in managing these high-flow fistulae. In all patients, it was possible to preserve one or both ICAs.

Carotid blowout syndrome in patients with head-and-neck cancers: reconstructive management by self-expandable stent-grafts.

BACKGROUND AND PURPOSE: Some reports of reconstructive management of carotid blowout syndrome (CBS) with stent-grafts are promising, but some are unfavorable. This study sought to evaluate the hemostatic efficacy, safety, and outcome of reconstructive, endovascular stent-graft placement in patients with head-and-neck cancers in association with CBS. METHODS: Eight patients with head-and-neck cancers with CBS were treated with self-expandable stent-grafts. We evaluated the initial hemostatic results, complications, and outcomes by assessing the clinical and imaging findings. RESULTS: Immediate hemostasis was achieved in all patients. Initial complications included stroke in 1 patient and asymptomatic thrombosis of the carotid artery in 2 patients. Delayed complications included rebleeding, delayed carotid thrombosis, and brain abscess formation. Rebleeding was noted in 4 patients and was successfully managed with a second stent-graft and embolization in 2 of them. Delayed carotid thrombosis with follow-up after 3 months was found in 3 patients, 1 of whom had associated brain abscesses. CONCLUSION: Although stent-grafts achieved immediate and initial hemostasis in patients with head-and-neck cancers and CBS, long-term safety, stent patency, and permanency of hemostasis appeared unfavorable. This treatment may be for temporary or emergency purposes rather than serving as a permanent measure. We suggest its applications in patients with acute CBS that precludes performance of an occlusion test, as well as when carotid occlusion poses an unusually high risk of neurologic morbidity. We also propose prophylactic antibiotic treatment and combined embolization of pathologic vascular feeders to improve outcomes.

Transarterial balloon-assisted n-butyl-2-cyanoacrylate embolization of direct carotid cavernous fistulas.

BACKGROUND AND PURPOSE: Transarterial detachable balloon embolization of direct carotid cavernous fistulas (DCCFs) has become an optimal treatment. In a few cases, the parent artery has to be sacrificed to achieve morphologic cure. We present our experience with transarterial balloon-assisted n-butyl-2-cyanoacrylate (n-BCA) embolization of DCCFs in which there was failure to achieve angiographic cure and preservation of parent arteries. METHODS: Of 141 patients with traumatic DCCFs who had been treated by transarterial embolization with occlusion of the fistula and parent artery preservation, 18 received transarterial balloon-assisted n-BCA embolization-6 for residual fistula after the balloons detached, 7 for recurrent fistula because of premature balloon deflation or migration, and 5 for repeated puncture of the detachable balloon by the bony fragment at the cavernous sinus. A total of 27 procedures were performed with an average 1.5 attempts per patient, and the volume of the n-BCA mixture varied from 0.5 to 2.3 mL with a mean of 0.83 mL. RESULTS: All DCCFs were successfully occluded by the n-BCA mixture with preservation of parent arteries. One patient with a giant cavernous sinus varix had a fatal subarachnoid hemorrhage. One had a recurrence and was treated by internal carotid artery (ICA) occlusion. Five had asymptomatic pseudoaneurysms at the parent artery. There was no adhesion of the n-BCA mixture to the protective balloon or the microcatheter or n-BCA reflux into the parent arteries. CONCLUSION: Transarterial balloon-assisted n-BCA embolization is a feasible, efficient, and safe treatment for DCCFs when angiographic cure and ICA preservation are not achieved by transarterial detachable balloon embolization.

Brain abscess formation: a delayed complication of carotid blowout syndrome treated by self-expandable stent-graft.

A patient with hypopharyngeal cancer developed carotid blowout syndrome (CBS) treated by self-expandable stent-graft in the left carotid artery. CT scan for progressive right hemiparesis 4 months later showed multiple left cerebral abscesses and left carotid thrombosis. Although deployment of stent-grafts for CBS can achieve initial hemostasis in patients with head-and-neck cancer, the placement of a stent-graft in a field of necrosis and infection is associated with poor long-term outcome. We recommend the use of prophylactic antibiotics if endovascular foreign materials are placed in a contaminated field.

Percutaneous vertebroplasty for patients with osteoporosis: a one-year follow-up.

PURPOSE: To evaluate changes in height and wedge angle of treated vertebral bodies and kyphosis angle 1 year after vertebroplasty. MATERIAL AND METHODS: We reviewed radiographs of 95 vertebral bodies treated with vertebroplasty in 60 patients with osteoporosis. Only vertebral bodies with imaging evidence of a new fracture or avascular necrosis received vertebroplasty. Images were obtained for evaluation before vertebroplasty (B), within 2 weeks after vertebroplasty (T), and after 1 year (T1). RESULTS: The mean wedge angle decreased by 5.4 degrees from B to T1. Mean of the anterior, central, and posterior heights of the fractured bodies increased by 12.6%, 9.6%, and 3.1%, respectively, from B to T1. The kyphosis angle improved by 3.2 degrees initially from B to T, but the improvement later disappeared. In 48% of these patients, a new fracture developed after vertebroplasty, and 63% of the fractures were adjacent to a vertebroplasty-treated vertebral body. CONCLUSION: The increase in height and wedge angle of the vertebral bodies generally lasted at least 1 year. Improvement in kyphosis angles was lost 1 year after vertebroplasty because new fractures occurred in 48% of these patients. Prevention of new fractures after vertebroplasty remains an important task.

Intraspinal leakage of bone cement after vertebroplasty: a report of 3 cases.

We report 3 cases of vertebroplasty-induced intraspinal leakage of bone cement that were referred to us for management. Two patients received decompressive surgery, and one received rehabilitation. The gross surgical finding of yellowish dura mater and intradural fibrosis, adhesion, and microscopic finding of arachnoid membrane fibrosis are suggestive of late effect of thermal injury. These patients had residual lower extremity weakness and urinary and stool problems 13 months, 3 years, and 4.75 years post-vertebroplasty, respectively.

Evaluation of clinical and MR findings for the prognosis of spinal epidural haematomas.

AIM: The potential of MR and clinical findings of spinal epidural haematomas (SEHs), particularly the early MR findings, to help minimize delays in diagnosis, to aid prognosis and as a reference for conservative treatment, are evaluated. METHODS: Retrospectively 20 patients with SEHs (14 men and 6 women) were examined to record their neurological deficit, MR findings, management, clinical outcome, and interval between symptom onset and MRI or surgery. Two-tailed Fisher's exact test was used for these analyses. RESULTS: Of 8 patients with severe neurological deficit at the onset of symptoms, none had obvious clinical improvement after either surgical or conservative management. Of 12 patients with mild to moderate deficits, 11 (92%) showed improvement or recovery of clinical symptoms. T2-weighted images revealed myelopathy or infarction of the compressed spinal cord in 9 patients, 7 (78%) of whom had no improvement in neurological deficit with either conservative or surgical management. Images in 6 patients showed contrast enhancement in the haematomas. CONCLUSION: Poor clinical outcomes were observed mainly in those with severe neurological deficit and hyperintensity on T2-weighted images of the involved spinal cord. Surgery did not appear to improve outcome in many of these patients. In acute SEHs, MRI showed characteristic findings, such as contrast enhancement, which should not be confused with signs of inflammatory or neoplastic epidural disease.

Neuroradiological findings in atypical teratoid/rhabdoid tumor of the central nervous system.

PURPOSE: To evaluate the computed tomography (CT) and magnetic resonance imaging (MRI) findings of atypical teratoid tumor/rhabdoid tumor (AT/RT) of the central nervous system (CNS). MATERIAL AND METHODS: Twenty cases of CNS AT/RT have been found over the past 23 years in our hospital; these involving 11 boys and 9 girls whose mean age at diagnosis was 5.5 years. Their clinical data, the CT, and MRI findings were reviewed retrospectively. RESULTS: AT/RT was located in the cerebellum in 15 cases. Four cases arose from the supratentorial region, while only one occurred primarily in the lumbar spinal cord. Almost all cases revealed heterogeneous intensity and heterogeneous enhancement. Peripheral cystic components were common. Survival time ranged from 2 months to 3 years, with a mean survival of 11.6 months. CONCLUSION: Most cases of AT/RT are located in the cerebellum. The radiologic manifestations are non-specific. The diagnosis mainly depends on the pathologic findings. However, AT/RT should still remain in the differential diagnosis of brain tumors in young children, especially those located in the cerebellar hemisphere and with eccentric cysts.

Carotid blowout treated by direct percutaneous puncture of internal carotid artery with temporary balloon occlusion.

SUMMARY: Direct percutaneous puncture of a cervical carotid pseudoaneurysm for coil placement or acrylic embolization is described for the endovascular management of acute carotid blowout. However, direct puncture of the internal carotid artery (ICA) for the endovascular management of carotid blowout has not been described. We report a difficult case of acute carotid blowout syndrome in a patient who had radiation- induced occlusion of the right common carotid artery with vasculopathy and pseudoaneurysm in the right cervical ICA. Collaterals from the branches of the controlateral external carotid artery (ECA) anastomosed with branches of right ECA supplied the vasculopathy. We performed direct percutaneous puncture of the bulb of the right ICA using a spinal needle and placed fiber coils to occlude antegrade flow of the artery. During the injection of a mixture of N-butyl cyanoacrylate and lipiodol oil for embolization of the remaining carotid bulb, we transiently inflated an occlusion balloon in the controlateral common carotid artery to further arrest antegrade flow in the ICA. The vasculopathy and pseudoaneurysm of the right cervical ICA were successfully embolized, with preservation of the distal branches of the right ICA.

MR findings of spontaneous intracranial hypotension.

PURPOSE: To present the MR features of spontaneous intracranial hypotension (SIH) and to discuss the correlation of MR features with clinical manifestations. MATERIAL AND METHODS: Between 1997 and 2000, 15 patients with SIH underwent brain MR investigation. Lumbar puncture for the measurement of cerebrospinal fluid (CSF) pressure was performed in 6 patients. Follow-up MR was obtained in 8 patients after the clinical symptoms had improved. We analyzed the MR findings of SIH, and discuss them in relation to CSF pressure and clinical manifestations. RESULTS: Fourteen of the 15 patients with SIH had abnormal MR findings. The imaging findings included: diffuse pachymeningeal enhancement in 13 patients; descent of the brain in 6 patients; and subdural effusion/hematoma in 2 patients. Low CSF pressure was shown at lumbar puncture in 5 out of 6 patients. Follow-up MR examination in the symptoms-relieved status demonstrated a recovery of the abnormal MR findings in 6 of 8 patients. CONCLUSION: Our data revealed that MR is sensitive in diagnosing SIH. The presence of characteristic clinical manifestations and MR features are virtually diagnostic for SIH syndrome. Invasive lumbar puncture is thus reserved for the equivocal cases.