Cerebral aneurysms.
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Biomedical subjects
Publications and source records attributed to Joon K Song.
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In patients with vein of Galen malformations, high-flow shunting decreases cerebral perfusion. By reducing or eliminating these shunts, transarterial embolization can improve cerebral perfusion and clinical outcomes. Quantifying pre- and postembolization shunt blood flow may help determine the optimal timing and efficacy of embolization and may provide prognostic information. The authors used magnetic resonance imaging noninvasive optimal vessel analysis as a novel modality to measure volumetric blood flow through vein of Galen malformation shunts in a neonate and an infant before and after transarterial embolization.
OBJECTIVE: To study the incidence and clinical outcomes of intraoperative aneurysm rupture (IOR) during endovascular coil embolization at a single large volume center and to review the literature on this subject to determine whether IOR rupture rate and mortality correlate with volume of aneurysms treated at a given center and years since the institution of Guglielmi detachable coils as a treatment modality. METHODS: We reviewed the aneurysm database at the Center for Endovascular Surgery since its inception (1997-2003) and reviewed 600 consecutively treated intracranial aneurysms in which coiling was attempted. All patients who sustained an IOR were studied. Procedural and follow-up angiograms as well as clinical outcomes were retrospectively reviewed. A literature review was conducted. RESULTS: Six patients (1.0%) experienced IOR (1.4% in acutely ruptured lesions, 0% in unruptured). All six had presented with diffuse subarachnoid hemorrhage (Fisher Grade 3) and in good clinical grade (Hunt & Hess Grades 1-3). One patient was rendered permanently disabled secondary to delay in controlling the IOR. All others were neurologically unchanged. A review of the literature revealed a trend in correlation between volume of aneurysms treated and IOR rate; no statistically significant correlation was found between volume of aneurysms treated or years since the introduction of GDC technology and IOR rates or mortality. CONCLUSION: IOR remains a serious risk of endosaccular coiling of intracranial aneurysms, with aneurysms presenting with subarachnoid hemorrhage at greater risk for this complication. This risk can be minimized with very low associated morbidity and mortality (incidence 1%, 17% morbidity, 0% mortality at our institution).
Aneurysmal subarachnoid hemorrhage in a neonate is exceedingly uncommon. The authors report the case of a neonate with a large anterior communicating artery aneurysm, accessory left middle cerebral artery aneurysm, and left internal carotid artery (ICA) fusiform aneurysm. The neonate suffered from occlusion of the left ICA and aneurysm rupture. The large aneurysm was treated with detachable coils and the patient made a significant recovery. Of the 15 case reports of cerebral aneurysms in neonates that have been published, none has contained a description of multiple aneurysms or a discussion of endovascular treatment.
OBJECT: The authors characterize the clinical presentation and imaging features of paraspinal nonvertebral arteriovenous fistulas (AVFs) along the segmental nerve and describe their endovascular treatment. METHODS: The authors undertook a retrospective review of medical records, imaging, and treatment of patients with endovascular problems spanning the period from 1985 to 2003. Five pediatric patients (2-3 years of age) received diagnoses of nonvertebral paraspinal AVFs along the segmental nerve. All patients presented with an incidentally discovered continuous murmur over the paraspinal or parasternal regions. All patients were neurologically intact; two patients had cardiomegaly. The AVF was found in the midthoracic level in four patients and at L-3 in one patient. All AVFs were high-flow single-hole fistulas at the neural foramen with venous drainage into paraspinal and epidural veins but without intradural reflux. All fistulas were endovascularly occluded in the same session as diagnostic angiography took place. The fistula was completely occluded, with detachable coils in one case and with N-butyl-cyanoacrylate (NBCA) in four cases. Before NBCA injection, the flow through the fistula was decreased either by placing coils distal to the fistula or by inflating a balloon proximally. No signs of recanalization appeared on short-term follow-up magnetic resonance imaging in all patients. All patients remained neurologically intact at the last available follow-up session (mean 6 years). CONCLUSIONS: Nonvertebral paraspinal AVFs along the segmental nerve are specific disease entities seen in children presenting with bruit and cardiomegaly. Endovascular embolization should be the treatment of choice for this rare disease.
The endovascular treatment of wide-necked intracranial aneurysms is evolving. We report our initial experience in treating seven wide-neck intracranial aneurysms by using a new self-expanding stent, the Neuroform, in combination with a new generation of coils that incorporate a self-expandable hydrophilic lining, the HydroCoil.
We developed an experimental canine model in which four types of aneurysm--bifurcation, side-wall, small branch-artery, and arterial-stump--were surgically created in the same animal. These experimental aneurysms are exposed to simultaneous but different hemodynamic stresses correlating to human intracranial aneurysms in different locations. Because this model allowed for the creation of four aneurysms, each with different hemodynamic features, it seems to offer advantages from ones previously described. This model may foster investigation of new and current endovascular devices.
BACKGROUND AND PURPOSE: This study evaluated the safety and efficacy of aggressive mechanical clot disruption (AMCD) in acute stroke patients with persisting middle cerebral artery (MCA) or internal carotid artery (ICA) occlusion after thrombolytic therapy. METHODS: Retrospective case series were used from a prospectively collected stroke database on consecutive acute ischemic stroke patients treated with intra-arterial (IA) thrombolytics and mechanical clot disruption during a 5-year interval. Thrombolytic dosage, endovascular techniques, immediate and final recanalization rates, symptomatic hemorrhage, mortality, and outcome were determined. RESULTS: Thirty-two patients received AMCD. Median baseline National Institutes of Health Stroke Scale (NIHSS) score was 18, and median time to initiation of IA treatment was 261 minutes from symptom onset. ICA occlusion was noted in 16 patients and MCA occlusion in 16 patients: 22 received combined IV/IA thrombolytics, 3 received IV thrombolytics, 6 received IA thrombolytics, and 1 patient received no thrombolytics before AMCD. No immediate periprocedural complications were noted. Immediate recanalization was achieved in 38% (50% MCA, 25% ICA) and final recanalization in 75% (88% MCA, 63% ICA) of patients. Favorable outcome occurred in 19 (59%) patients, symptomatic cerebral hemorrhage in 3 (9.4%) patients, and mortality in 4 (12.5%) patients. CONCLUSIONS: AMCD can be performed safely with comparable intracerebral hemorrhage and mortality rates to other IA therapies even after use of intravenous thrombolytics in selected patients. Early deployment of this technique leads to immediate recanalization in one third of patients. AMCD may potentially shorten the time to flow restoration and improve overall recanalization rates achieved with IA therapy.
The treatment of ruptured cerebral aneurysms in patients presenting with vasospasm remains a particular challenge. The authors treated two patients harboring Hunt and Hess Grade 1 subarachnoid hemorrhages from middle cerebral artery (MCA) aneurysms associated with severe local angiographically demonstrated yet asymptomatic vasospasm on presentation. Because both aneurysms had wide necks and were located at the MCA bifurcation, they were believed to be anatomically suitable for microsurgical clip application. Severe M, vasospasm was believed to be a relative contraindication to open surgery, however. An intentionally staged endovascular and microsurgical treatment strategy was planned in each patient. Partial coil occlusion of the aneurysmal dome was performed to prevent the lesion from rebleeding and was followed by balloon angioplasty of the spastic vessel. Early treatment of the severe spasm appeared to prevent significant delayed neurological ischemic deficit. Following resolution of the vasospasm, definitive clipping of the aneurysms was performed on Day 13 post embolization. One patient had a good clinical recovery and was discharged without neurological deficit. The other patient's hospital course was complicated by the occurrence of a postoperative posterior temporal infarct requiring partial temporal lobectomy, although she eventually had a good recovery with only a small visual field deficit. Based on data obtained in these two patients, one can infer that ruptured wide-necked MCA aneurysms associated with severe local vasospasm may best be treated using a staged combined treatment plan. Delayed clip application might be performed more safely 4 to 6 weeks postocclusion, or later, than at 2 weeks.
OBJECT: The authors investigated whether HydroCoils decreased coil compaction and aneurysm recanalization in a canine model of a large, wide-necked, high-flow bifurcation aneurysm. METHODS: Eleven experimental aneurysms were created. Two aneurysms were untreated (Group 1); three were treated with standard platinum coils (Guglielmi Detachable Coils; Group 2); and six were treated with platinum framing coils and filling HydroCoils (Group 3). Comparative angiographic and histopathological data were analyzed at 2 weeks and again at 3 months. At 3 months, the Group 1 aneurysms remained patent without spontaneous thrombosis. After coil placement the percentage of aneurysm filling by volume ranged from 59 to 90% (mean 75.4%) for Group 3 (HydroCoil-treated) and 34.3 to 48.9% (mean 39.6%) for Group 2 (GDC-treated) (p < 0.05). At 14 days, two of the three Group 2 aneurysms exhibited coil compaction and aneurysm recanalization at the neck; in both cases the condition worsened at 3 months. At 14 days and 3 months, five of the six Group 3 aneurysms were 100%, and one of six was 90% occluded and remained stable. At 3 months, the neointima of the aneurysm neck was significantly thicker in the Group 3 lesions, which had been treated by HydroCoils (0.329 +/- 0.191 mm), than in Group 2 lesions, which had been treated with GDCs (0.026 +/- 0.018 mm) (p < 0.001). No thrombus formation occurred in Group 2; however, in two of the six aneurysms in Group 3, thrombus formed at the coil-neck interface. CONCLUSIONS: The experimental canine bifurcation aneurysm model overcomes the limitations of side-wall aneurysm models. In this model, HydroCoils resulted in significantly denser coil packing, less follow-up coil compaction, and thicker neointimal tissue at the neck of the lesion. HydroCoils also appeared more thrombogenic at the aneurysm neck-parent artery interface.
BACKGROUND AND PURPOSE: The management of thrombus formation during coil placement in an intracranial aneurysm is important in minimizing periprocedural morbidity and mortality. We report on seven cases in which the primary treatment for thrombus formation during such coil placement was intra-arterial abciximab infusion. METHODS: Clinical and radiologic records of 100 consecutive patients who underwent coil placement in intracranial aneurysms at our institution during a 1-year period were reviewed. We identified seven cases (four ruptured aneurysms, three unruptured aneurysms) in which thrombus formation occurred during the procedure. RESULTS: Intra-arterial abciximab infusion, up to 5 mg, completely dissolved the thrombus in four of seven patients and almost completely dissolved it in two. In one patient with distal emboli, recanalization was not achieved. In two patients, an intravenous bolus of abciximab without 12-hour infusion was also given adjunctively. In one patient, leakage of contrast material occurred; this was related to the intra-arterial infusion. Clinically, no new neurologic deficits were directly related to the intra-arterial abciximab infusion. Six patients had good clinical outcome, and one patient died. CONCLUSION: Relatively low-dose, intra-arterial abciximab infusion can immediately dissolve an acute thrombus that forms during intracranial aneurysm coil placement. Although neither the optimal dose of intra-arterial abciximab nor the need to supplement the intra-arterial infusion with intravenous administration was established, we preliminarily found that low-dose intra-arterial abciximab infusion may be relatively effective and safe in this setting, even in patients with acute subarachnoid hemorrhage.
BACKGROUND AND PURPOSE: The best strategy for treatment of subarachnoid hemorrhage due to ruptured cerebral aneurysm is obliteration of the aneurysm as soon as possible. Early surgery is desirable if the patient does not develop severe vasospasm or is clinically stable. However, if the patient has already developed severe vasospasm on admission, surgery may carry the risk of increasing the severity. We evaluated the safety and effectiveness of combined Guglielmi detachable coil (GDC) embolization and angioplasty in a single session for the treatment of ruptured aneurysms associated with symptomatic vasospasm. METHODS: From January 1992 to January 2001, 12 consecutive patients with ruptured aneurysms associated with symptomatic vasospasm were treated. Patients were classified as Hunt and Hess grade 2 (n = 1), 3 (n = 6), 4 (n = 4), or 5 (n = 1) and Fisher CT group 2 (n = 1), 3 (n = 10), or 4 (n = 1). They underwent GDC aneurysm occlusion and balloon angioplasty (n = 6), intraarterial papaverine infusion (n = 2), or both (n = 4) in a single session. In nine patients, aneurysm coil occlusion was performed first. RESULTS: Complete GDC occlusion was achieved in eight patients, a small neck remnant persisted in three, and embolization was incomplete in one patient. In all patients, angiographic improvement of vasospasm was obtained. In one patient, a thromboembolic complication occurred and was treated with urokinase. Clinical outcomes at discharge were good recovery in six, moderate disability in two, severe disability in three, or death in one. CONCLUSION: Endovascular treatment can be the first therapeutic option for ruptured aneurysms associated with severe vasospasm on admission. It offers some advantages over surgery in this setting, but these are balanced by the risk of thromboembolism.
BACKGROUND AND PURPOSE: Acceleration of healing mechanisms is a promising approach to improve current limitations of endovascular aneurysm therapy with the use of platinum coils. We evaluated a new endovascular therapeutic, bioabsorbable polymeric material (BPM), which may promote cellular reaction in the aneurysms. METHODS: Four different concentrations of lactide/glycolic acid copolymer [poly(D-L-lactic-co-glycolic acid)] (PLGA), 85/15, 75/25, 65/35, and 50/50, were used as BPMs. Sixteen experimental aneurysms were created in 8 swine. Eight-millimeter-long spiral-shaped BPMs were surgically implanted in the aneurysms without tight packing (n=3 for each BPM). Guglielmi detachable coils (GDCs) were used as control (n=4). The animals were killed 14 days after embolization, and angiographic, histological, and immunohistochemical analyses were performed. RESULTS: Despite loose packing of aneurysms with BPMs, faster BPMs such as 50/50 or 65/35 PLGA demonstrated more mature collagen formation and fibrosis in the sac and neck of the aneurysm. One aneurysm treated with 65/35 PLGA, 1 treated with 75/25 PLGA, and all 3 treated with 85/15 PLGA showed a neck remnant on angiography. There was a linear relationship between collagen levels and polymer degradation properties (r=-0.9513). CONCLUSIONS: This preliminary animal study indicates that acceleration of aneurysm healing with the use of BPM is feasible. This concept can be applied to decrease and perhaps prevent aneurysmal recanalization after endovascular treatment of cerebral aneurysms.
The authors present the case of a 69-year-old man who suffered from bilateral cortical venous hypertension due to a brain pial arteriovenous malformation (AVM) with a high-flow fistula. The AVM became complicated by the development of a high-grade stenosis of the posterior superior sagittal sinus (SSS). A comparison of cerebral angiograms obtained at different times revealed that the severe SSS stenosis had developed within a 5-year period and was located distal to the nidus of the left parietal AVM nidus, away from the entrance of the dominant superior superficial cortical draining vein into the SSS. The high-flow fistula was occluded with detachable coils and the AVM nidus was further embolized with acrylic. The SSS stenosis was mechanically dilated by means of balloon angioplasty and stent placement. This case provides angiographic evidence to support the hypothesis that a pial arteriovenous fistula in an adult can cause high-flow occlusive venopathy in a major sinus within a relatively short time and that this acquired high-flow occlusive venopathy can develop at an atypical location distant from the nidus of the AVM.
Acute embolic occlusion of the intracranial internal carotid bifurcation is associated with a poor prognosis. Recanalization rates of this lesion with intravenous or intraarterial thrombolysis are exceedingly low. We describe the use of balloon angioplasty after failed thrombolysis to achieve immediate recanalization of acute carotid T occlusions in two patients. At 1-month follow-up, both patients were alive with neurologic deficits. For acute carotid T occlusion, balloon angioplasty should be considered a first-line endovascular therapy.
We simultaneously injected both internal carotid arteries (ICAs) during 3D rotational digital subtraction angiography in a patient with a ruptured anterior communicating artery (Acom) aneurysm and vasospasm. Shaded surface display (SSD) images from this acquisition provided more anatomic detail than did SSD images created from individual ICA 3D rotational digital subtraction angriography. In the evaluation of complex Acom aneurysms, this technique can facilitate the choice of optimal working projections for safer aneurysm coiling.
In our experience with the canine model, sidewall aneurysms made with an oblique-cut arteriotomy were less likely to thrombose than were those made with a standard technique.