Biomedical subjects
Publications and source records attributed to Alessandra Biondi.
The outcome of intracranial aneurysms remains disastrous despite progress in diagnosis, management, care, and follow-up. This article discusses the pathology, the etiologies, the epidemiology and the classifications of intracranial aneurysms.
Cerebral vasospasm is a major cause of morbidity and mortality associated with subarachnoid hemorrhage (SAH). Advances in neuroimaging and development of newer intraparenchymal monitoring devices have improved the prediction and diagnosis of cerebral vasospasm significantly. Recent experimental and clinical trials have increased the armamentarium of preventive and treatment strategies for cerebral vasospasm. Vasospasm refractory to medical therapy usually is treated endovascularly with percutaneous transluminal balloon angioplasty (PTA) for proximal vessel vasospasm and vasodilator infusion for distal vessel vasospasm. Although vasospasm usually does not recur after PTA, recurrence is frequent after vasodilator infusion. The development of newer microballoon catheters has led to improvements in treatment of not only proximal but also distal vessel vasospasm with balloon angioplasty. This article reports on current knowledge in the diagnosis, prediction, prevention, and management of cerebral vasospasm.
Intracranial aneurysms (IAs) can be related to or associated with some vascular anatomic variations, lesions, diseases, or systemic disorders in which a causative or predisposing factor(s) in aneurysm formation can be identified. This article includes flow-related, infectious, traumatic iatrogenic, and neoplastic aneurysms and aneurysms related to systemic disorders and drug abuse. In some conditions, IAs associated with other disorders are true aneurysms. Most of them, however, are false aneurysms. Characteristics and management of these unusual aneurysms are discussed.
Aneurysms arising along the arterial trunk are uncommon and not well-characterized lesions in contrast to saccular aneurysms. According to pathological studies, most of spontaneous trunkal aneurysms are related to dissecting phenomena. On the basis of clinical presentation, dissecting aneurysms can be separated into acute or chronic lesions. Understanding of the underlying pathological mechanisms associated with these aneurysms is useful for planning appropriate treatment. This article reviews the etiopathogenesis, the angiographic aspects, and the endovascular treatment of dissecting aneurysms. Fusiform aneurysms and aneurysms in atherosclerotic disease also are discussed briefly.
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BACKGROUND AND PURPOSE: Internal carotid artery (ICA) dissection remains a major cause of stroke in the young. Although systemic anticoagulation and antiplatelet therapy allow healing of the dissection in most patients, medical treatment can fail or be contraindicated. In selected cases of carotid dissections, the use of endovascular stent-assisted angioplasty has been reported to permit reconstruction of the extracranial ICA. METHODS: We report a case of symptomatic spontaneous carotid dissection which progressively extended from the cervical to the supraclinoid segments of the ICA in a 48-year-old patient under anticoagulant therapy. Because of failed medical therapy and further transient ischemic attacks (TIAs), the patient was treated by 5 tandem stents deployed in an overlapping fashion from the terminal ICA to the cervical segment. RESULTS: Postprocedure angiography demonstrated reconstitution of the luminal diameter of the ICA. The patient progressively improved and no further TIAs were observed. At 8-month follow-up, the vessel remained patent with a slight intra-extracranial reduction in size suggesting myointimal hyperplasia. Neurological exam was normal. CONCLUSIONS: The successful angiographic and clinical results observed in our case of intra-extracranial stenting of a long dissection contributes to the literature of carotid dissection treated with multiple stents. The excellent mid-term follow-up in our patient confirms the efficacy of this treatment and good tolerance to multiple stents. To our knowledge this is the first case of spontaneous dissection treated with stenting including the distal supraclinoid segment, through an extensive proximally dissected artery.
Recent advancements in endovascular aneurysm repair, including bioactive and expansile coils and intracranial stents, hold promise for improved aneurysm occlusion rates. We report the immediate and midterm clinical and angiographic outcomes of a consecutive series of patients treated since the advent of these technologies. Clinical and radiological records of 134 patients with 142 aneurysms treated between 2001 and 2004 were retrospectively evaluated by an independent neurologist. Endovascular procedures were analyzed by an independent neuroradiologist blinded to all clinical information. Seventy-two ruptured and 60 un-ruptured saccular aneurysms, nine fusiform and one post-traumatic aneurysm were treated. Matrix coils were used in 53% of saccular aneurysms and HydroCoils in 13% of all aneurysms. Neuroform stents were deployed in 19% of aneurysms. Angiographic total or subtotal occlusion was achieved in 76% of cases and in 96% at last follow-up. Aneurysm recanalization was observed in 14% over a mean follow-up of 12 months, and 18% of aneurysms were retreated. Clinically relevant complications occurred in 6.0%, resulting in procedure-related morbidity of 0.6% and 0.6% mortality at 6 months. No aneurysm bled over a cumulative 1,347 months of observation. Newer embolization technologies can be exploited successfully even in more complex aneurysms with very low morbidity and mortality.
Wide-necked aneurysms remain difficult to treat by either open microneurosurgical or endovascular procedures. Recent advances in the latter technology, including intracranial stents and bioactive coils, now allow an endovascular treatment option for cases in which this was not previously available. In this report the authors describe the new developments in endovascular technologies that make the treatment of wide-necked aneurysms possible. This includes discussion of intracranial stents and bioactive coils designed to promote obliteration of the aneurysm lumen. In addition, methods for coil insertion in wide-necked aneurysms are described, including balloon remodeling and various stent placement procedures. Wide-necked aneurysms previously thought to be untreatable by endovascular means can now be obliterated, thanks to new devices specifically designed for intracranial use.
BACKGROUND AND PURPOSE: Hemangioblastomas (HBs) are rare lesions accounting for 1-5% of all spinal cord tumors. Seventy-five percent of spinal HBs are intramedullary. Lesions of the conus medullaris and the cauda equina are uncommon, and the filum terminale location is very rare. HBs of the lower spinal region are highly vascular tumors requiring surgery that is potentially complicated by excessive bleeding. In the literature, there are few reports concerning preoperative embolization of HBs, and only few cases are reported in spinal location. Presurgical embolization of HBs located in the lower spinal region has not been described. Although lower spinal HBs are predominantly fed by the anterior spinal artery (ASA), embolization of these lesions is possible and can reduce tumor vascular supply, thus facilitating surgery. We report our experience in four rare cases of solitary HBs occurring in the lower spinal region. METHODS: Clinical charts and radiologic studies of four patients with a preoperatively embolized HB of the lower spinal region were retrospectively reviewed. The lesions were located in the conus medullaris in one case, at the level of the cauda equina in another, and in the filum terminale in two. In the conus medullaris case, the neoplasm was associated with a syrinx. In three patients, the HB was sporadic, while the patient with the HB of the cauda equina had Von Hippel-Lindau disease. Devascularization of the tumor was performed through the ASA in all cases and also through the posterior spinal artery in one by using non reabsorbable calibrated microspheres in three cases and polyvinyl alcohol particles in the other one. RESULTS: Embolization caused no permanent complications, although one patient with a cauda equina HB mildly worsened after the endovascular procedure but recovered before surgery. At surgery, the tumor was completely removed in all cases. Blood loss was reported to be less than usually observed (100, 200, 200, and 400 mL). In addition, manipulation and removal of the tumor was reported to be easy in three of four tumors. Histologic examination confirmed the diagnosis. At 1-year postsurgical follow-up, two patient recovered completely from neurologic deficits, and two showed significant recovery. No tumor recurred during a follow-up period of 1-6 years (mean, 3.5 years). CONCLUSION: Our results indicate that preoperative embolization of HBs of the lower spinal region is an useful procedure in aiding surgical resection of these highly vascular tumors. With a meticulous technique, embolization can be performed through the ASA.
PURPOSE: To determine whether the blood flow abnormalities frequently associated with arteriovenous malformations (AVMs) can alter functional magnetic resonance (MR) imaging evaluation of language lateralization and whether reorganization of language function occurs in patients with brain AVMs. MATERIALS AND METHODS: Eleven patients with left-hemisphere brain AVMs and 10 age-matched control subjects were examined with 1.5-T blood oxygen level-dependent (BOLD) functional MR imaging. Verbal fluency, sentence repetition, and story listening tasks were performed. The functional MR imaging laterality index in the frontal and temporal lobes was defined as the (L - R)/(L + R) ratio, where L and R are the numbers of activated pixels in the left and right hemispheres, respectively. Statistical analyses were performed with Wilcoxon signed rank, Fisher exact, and Kruskal-Wallis tests. RESULTS: Control subjects had left-sided language dominance, although symmetric pixel counts were observed in the frontal lobes in two subjects and in the temporal lobes in one subject. Six patients had left-sided language dominance similar to that observed in control subjects. Five of these patients had AVMs outside frontal or temporal language areas, without flow abnormalities. Five patients had abnormally right-sided asymmetric indexes (below mean control subject value - 2 SDs), which suggested language reorganization (P <.05). Results of Wada examination and/or postembolization functional MR imaging performed in two of these patients showed that the abnormal laterality indexes were at least partly due to severe flow abnormalities that impaired detection of BOLD MR imaging signal intensity. CONCLUSION: These data suggest that flow abnormalities may interfere with language lateralization assessment with functional MR imaging.
BACKGROUND AND PURPOSE: Dural Carotid Cavernous Fistulas (CCFs) can be treated by transarterial and/or transvenous endovascular techniques. The venous route usually goes through the internal jugular vein (IJV) and the inferior petrosal sinus (IPS) up to the pathologic shunts of the cavernous sinus. In case a thrombosed IPS, catheterization through the obstructed sinus is not always possible and a puncture of the superior ophthalmic vein (SOV) can be performed often after a surgical approach. We report our results in the endovascular transvenous treatment of dural CCFs through the facial vein (retrograde catheterization of the IJV, facial vein, angular vein, SOV, and cavernous sinus). METHODS: A retrospective study of seven patients with a dural CCF treated with transvenous embolization via the facial vein was performed. In five patients, the IPS was thrombosed. In one patient, the IPS was patent, but there was not communication between the cavernous sinus compartment in which the CCF shunts were located and the IPS itself. In the only patient with the CCF draining through permeable IPS, the transvenous route through the IPS permitted the occlusion of the posterior CCF shunts and a second session was performed through the facial vein in order to occlude the shunts of the anterior compartment of the cavernous sinus. The other six patients underwent one embolization session only. RESULTS: In all seven cases, it was possible to navigate through the tortuous junction of the angular vein and the SOV. In one patient with a thrombosed SOV, the venous procedure was interrupted because the catheterization through the occluded SOV failed. In the other six patients, after transvenous catheterization of the cavernous sinus via the facial vein, placement of coils resulted in complete occlusion of the dural CCF with clinical cure in four patients and improvement in two. CONCLUSION: In the endovascular treatment of the dural CCFs, the transfemoral approach via the facial vein provides a valuable alternative to other transvenous routes. Catheterization of the cavernous sinus via the facial vein is usually successful. Although this technique requires caution, it allows a safe and effective treatment of these lesions.
BACKGROUND AND PURPOSE: Cerebral vasospasm remains a major problem in patients recovering from aneurysmal subarachnoid hemorrhage despite advances in medical, surgical, and endovascular care. Our purpose was to assess the efficacy of intra-arterial nimodipine, a calcium-channel blocker acting mainly on cerebral vessels, in preventing delayed neurologic deficits in patients with symptomatic vasospasm. METHODS: Clinical charts of 25 consecutively treated patients were retrospectively reviewed. A multifactorial decision tree was used to determine the indication for angiography and subsequent endovascular treatment. Nimodipine was infused intra-arterially via a diagnostic catheter in the internal carotid artery or vertebral artery at a rate of 0.1 mg/min. Angiographic vasospasm before endovascular treatment, immediate vessel caliber modifications, and short- and long-term clinical efficacy of the procedure were assessed. RESULTS: Thirty procedures were performed in 25 patients. Clinical improvement was observed in 19 (76%), 16 of whom improved after the first endovascular procedure, two after the second intra-arterial treatment, and one after the third. Of these 19 patients, only 12 (63%) had notable vascular dilatation at postprocedural angiography. Dilatation of infused vessels occurred in only 13 (43%) of 30 procedures. After follow-up of 3-6 months, 18 (72%) of 25 patients had a favorable outcome (Glasgow outcome scale score of 1-2 and modified Rankin scale score of 0-2). No complications were observed. CONCLUSION: Intra-arterial nimodipine is effective and safe for the treatment of symptomatic vasospasm after subarachnoid hemorrhage. Further prospective randomized studies of cerebral blood flow are needed to confirm these results.
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