Carlos Miranda

CURATIVE ENDOVASCULAR RECONSTRUCTION OF CEREBRAL ANEURYSMS WITH THE PIPELINE EMBOLIZATION DEVICE: THE BUENOS AIRES EXPERIENCE

OBJECTIVESThe Pipeline embolization device (PED) (Chestnut Medical Technologies, Inc., Menlo Park, CA) is a new microcatheter-delivered endovascular construct designed to achieve the curative reconstruction of the parent arteries giving rise to wide-necked and fusiform intracranial aneurysms. We present our initial periprocedural experience with the PED and midterm follow-up results for a series of 53 patients. METHODSPatients harboring large and giant wide-necked, nonsaccular, and recurrent intracranial aneurysms were selected for treatment. All patients were pretreated with dual antiplatelet medications for at least 72 hours before surgery and continued taking both agents for at least 6 months after treatment. A control digital subtraction angiogram was typically performed at 3, 6, and 12 months. RESULTSFifty-three patients (age range, 11–77 years; average age, 55.2 years; 48 female) with 63 intracranial aneurysms were treated with the PED. Small (n = 33), large (n = 22), and giant (n = 8) wide-necked aneurysms were included. A total of 72 PEDs were used. Treatment was achieved with a single PED in 44 aneurysms, with 2 overlapping PEDs in 17 aneurysms, and with 3 overlapping PEDs in 2 aneurysms. The mean time between the treatment and last follow-up digital subtraction angiogram was 5.9 months (range, 1–22 months). Complete angiographic occlusion was achieved in 56%, 93%, and 95% of aneurysms at 3 (n = 42), 6 (n = 28), and 12 (n = 18) months, respectively. The only aneurysm that remained patent at the time of the 12-month follow-up examination had been treated previously with stent-supported coiling. The presence of a preexisting endoluminal stent may have limited the efficacy of the PED reconstruction in this aneurysm. No aneurysms demonstrated a deterioration of angiographic occlusion during the follow-up period (i.e., no recanalizations). No major complications (stroke or death) were encountered during the study period. Three patients (5%), all with giant aneurysms, experienced transient exacerbations of preexisting cranial neuropathies and headache after the PED treatment. All 3 were treated with corticosteroids, and these symptoms resolved within 1 month. CONCLUSIONEndovascular reconstruction with the PED represents a safe, durable, and curative treatment of selected wide-necked, large and giant cerebral aneurysms. The rate of complete occlusion at the time of the 12-month follow-up examination approached 100% in the present study. To date, no angiographic recurrences have been observed during serial angiographic follow-up.

Partial aortic obstruction improves cerebral perfusion and clinical symptoms in patients with symptomatic vasospasm

Abstract Objective: Stroke studies in animals showed that aortic obstruction increases cerebral blood flow (CBF) and reduces infarct size. In this study we evaluate the safety and efficacy of a device providing partial and transitory aortic obstruction. Methods: We report the results in 24 selected patients with symptomatic vasospasm by aneurysmal subarachnoid hemorrhage treated by partial and transitory aortic obstruction with a novel device (NeuroFlo™, CoAxia, MN). Aneurysms were secured by coils prior to the procedure. We studied the adverse effects related to the aorta-obstructing device, and changes in CBF and neurological outcome. Results: Mean flow velocity increased in both middle cerebral arteries over 15%, and the score in the National Institute of Health Stroke Scale decreased ≥2 point in 20 patients (83%). During the procedure, three patients developed symptoms that were controlled. At 30 days follow-up, three patients had 6 points (unrelated death), three had 3 points, six had 1 point, and 12 had 0 points, in the modified Rankin scale. Discussion: Partial aortic obstruction was safe, the cerebral blood flow increased without inducing significant hypertension and the neurological defects improved in most of the patients. Efficacy with a better level of evidence will be determined by a randomized study.

Endovascular reconstruction by means of stent placement in symptomatic intracranial atherosclerotic stenosis.

Abstract Objective: Patients with intracranial atherosclerosis who fail antithrombotic therapy have a poor prognosis. The high rate of recurrent stroke warrants testing alternative treatments such as intracranial angioplasty. Methods: We present our experience in the treatment of 104 patients (age range, 54–82 years; mean age, 67 years) with symptomatic intracranial atherosclerotic stenoses despite medical therapy who underwent stent-assisted angioplasty. Patient records were retrospectively analysed for location and degree of stenosis, regimen of antiplatelet agents, devices used, procedure-related complications and adverse events. Clinical (Modified Rankin Scale) and radiographic outcomes were obtained 24 hours, 1 month and 3–6 months after treatment. Sixty-five lesions (62.5%) were located in the posterior circulation. Mean stenosis was 75.4%. Results: In all patients, the angiographic degree of stenosis was reduced to less than 30%. One stent was implanted in 66 patients (63%), and two or more in 38 patients (37%). Modified Rankin Scale (mR) was 1–2 in 67.5% of the cases, 3–4 in 25.9%, 5 in 2.8%, 6 in 3.8%. Procedural morbidity was 5.7% and procedural mortality was 3.8%. Angiographic follow-up was available in 58 patients (55.7%) and the restenosis rate was 12.5%. Discussion: In selected patients, endovascular revascularization of intracranial arteries by means of stent-assisted angioplasty is technically feasible, effective and safe.

Moyamoya Syndrome in an Adolescent With Essential Thrombocythemia. Successful Intracranial Carotid Stent Placement

Background— Essential thrombocythemia (ET) is a chronic myeloproliferative disorder with increased frequency of thrombotic events, including transient ischemic attacks (TIAs) and stroke. Moyamoya syndrome is a rare cerebrovascular disease characterized by progressive occlusion of intracerebral arteries with a typical “puff of smoke” angiographic pattern. We report the development of moyamoya syndrome in a patient with ET. Case Description— The patient is an 18-year-old female who presented at age 13 with recurrent TIAs. Persistent thrombocytosis was found, a diagnosis of ET was made, and treatment with anagrelide was started. Despite normal platelet counts, she experienced recurrent TIAs and stroke. Severe stenosis of the supraclinoid segment of the left internal carotid artery (LICA) and abnormal collateral vessels were found, and moyamoya syndrome was diagnosed on the basis of the characteristic angiographic appearance. An intracranial stent was placed in the LICA, and since then, she has had an uneventful outcome after a 46-month follow-up. Conclusion— To our knowledge, the development of moyamoya phenomenon has not been reported in ET, and the relationship between these 2 disorders remains unclear. Besides, this is the first intracranial carotid stent implanted successfully in a patient with moyamoya.

Computational modelling of blood flow in side arterial branches after stenting of cerebral aneurysms

The major concern with the use of stents as flow diverters for the treatment of intracranial aneurysms is the potential occlusion of a perforating artery or other side branches which can cause ischemic strokes. This article presents image-based patient-specific models of stented cerebral aneurysms in which a small side artery has been jailed by the stent mesh. The results indicate that, because of the large resistances of the distal vascular beds which dominate the flow divisions among the different arterial branches, the flow reduction in jailed side branches is quite small even when a large percentage of the inlet area of these branches has been blocked. This suggests that unless the side branch is completely occluded, it will likely maintain its normal blood flow. Although this conclusion eases the concern of stenting cerebral aneurysms, a complete occlusion can still be caused depending on the conformability characteristics of the stents.

Partially Clipped Intracranial Aneurysm Obliterated with Combined Stent and Coil Implantation

Purpose: To report a case of endovascular stent placement to assist stable coil deployment in a symptomatic, wide-necked, partially clipped aneurysm. Case Report: A 48-year-old woman presented for endovascular treatment of a symptomatic posterior communicating artery aneurysm remnant that was surgically clipped 10 years ago. A 3.5-mm × 12-mm balloon-expandable stent was placed across the aneurysm orifice followed by complete obliteration of the remnant with coils implanted through the stent mesh. Digital subtraction angiography documented continued patency of the arterial lumen and complete obliteration of the aneurysm at 11 months. Conclusions: Partial aneurysm clipping may assist or complicate secondary interventional procedures and interfere with correct visualization of the neck. Stent placement obviates the need for the balloon-assist method of coil embolization for wide-necked aneurysm remnants, acting as a mechanical barrier to hold the coils in a very unfavorable anatomy.

Covered stent as an innovative tool for tumor devascularization and endovascular arterial reconstruction

Abstract A temporal paraganglioma was pre-operatively embolised with particles and due to the fact that the internal carotid artery was encased by the tumor and that multiple petrous feeders precluded safe embolization, we decided to implant a balloon-expandable covered stent. On immediate post-procedural angiography, the arterial diameter was restored and a complete devascularization of the tumor was achieved. The tumor was operated with minimal blood loss and the carotid artery was released from surrounding tumor using the frame of the stent as a surgical limit. Covered stents may become a valuable tool for pre-operative tumor devascularization and arterial reconstruction especially when dealing with hypervascular tumors of the cranial base that encase the carotid artery.

Reconstructive endovascular approach for a cavernous aneurysm in infancy

Abstract We report a unique case of endovascular arterial reconstruction using stent and coils in a symptomatic cavernous aneurysm presented in infancy. A 3-year-old infant presented with a partial cavernous sinus syndrome secondary to a bilobulate cavernous aneurysm with subarachnoid extension. Direct clipping represented a considerable challenge and trapping after bypass grafting was considered too risky. A combined endovascular approach using stent and coils was performed. A 4 × 18 mm balloon-expandable stent was then placed across the aneurysm orifice allowing the complete obliteration of the remnant with coils implanted through the stent mesh. Digital substraction angiography documented patency of the ICA lumen and complete obliteration of the aneurysm. A 24-months angiographic follow-up was performed confirming persistent aneurysm exclusion and patency of the parent vessel with no signs of in-stent de novo stenosis. Reconstructive endovascular technique using stent and coils allowed the treatment of a complex vascular condition. The cavernous lesion was excluded from the circulation while preserving normal flow through the parent vessel and its branches. Long-tern follow up is a major concern, specially in pediatric patients but the 24 months angiographic follow-up is encouraging.