Association between hemodynamic conditions and occlusion times after flow diversion in cerebral aneurysms.

BACKGROUND: Evaluation of flow diversion treatment of intracranial aneurysms is difficult owing to lack of knowledge of the target hemodynamic environment. OBJECTIVE: To identify hemodynamic conditions created after flow diversion that induce fast aneurysm occlusion. METHODS: Two groups of aneurysms treated with flow diverters alone were selected: (a) aneurysms completely occluded at 3 months (fast occlusion), and (b) aneurysms patent or incompletely occluded at 6 months (slow occlusion). A total of 23 aneurysms were included in the study. Patient-specific computational fluid dynamics models were constructed and used to characterize the hemodynamic environment immediately before and after treatment. Average post-treatment hemodynamic conditions between the fast and slow occlusion groups were statistically compared. RESULTS: Aneurysms in the fast occlusion group had significantly lower post-treatment mean velocity (fast=1.13 cm/s, slow=3.11 cm/s, p=0.02), inflow rate (fast=0.47 mL/s, slow=1.89 mL/s, p=0.004) and shear rate (fast=20.52 1/s, slow=32.37 1/s, p=0.02) than aneurysms in the slow occlusion group. Receiver operating characteristics analysis showed that mean post-treatment velocity, inflow rate, and shear rate below a certain threshold could discriminate between aneurysms of the fast and slow occlusion groups with good accuracy (84%, 77%, and 76%, respectively). CONCLUSIONS: The occlusion time of cerebral aneurysms treated with flow diverters can be predicted by the hemodynamic conditions created immediately after device implantation. Specifically, low post-implantation flow velocity, inflow rate, and shear rate are associated with fast occlusion times.

Curative endovascular reconstruction of cerebral aneurysms with the pipeline embolization device: the Buenos Aires experience.

OBJECTIVES: The 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. METHODS: Patients 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. RESULTS: Fifty-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. CONCLUSION: Endovascular 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.

Urgent endovascular stent-graft placement for traumatic penetrating subclavian artery injuries.

Penetrating injuries may infrequently cause pseudoaneurysms, lacerations and arteriovenous fistulas involving the subclavian artery. These injuries present with life-threatening bleedings, associated regional injuries and critical limb ischemia and although surgery has been considered the treatment of choice, subclavian injuries pose a real surgical challenge. We prospectively examined data of six patients presenting with penetrating subclavian artery injuries that were treated by urgent endovascular stent-graft placements. All stent-grafts were deployed successfully achieving complete exclusion of the pseudoaneurysm, control of bleeding and reconstruction of the injured artery. No procedural complications, stent thrombosis or stent infections occurred during hospitalization. One patient developed stenosis at 7 months, which required angioplasty. The series mean clinical and ultrasound-CTA follow-up is 38+/-19.7 months (range 11-60 months) and 28+/-19.1 months (range 6-58 months), respectively. This series shows the feasibility of endovascular repair by means of stent-grafts for selected patients with acute penetrating injuries of the subclavian arteries. This approach proved to be safe and effective in restoring the arterial lumen and patency, excluding the pseudoaneurysms and controlling the bleeding caused by subclavian lacerations. Mid-term follow-up on stent-graft patency rates are encouraging.

Evolución de la angiografía digital cerebral / Evolution of th digital cerebral angiography

Premio Nobel que fue reconocido por sus trabajos en tratamientos radicales en enfermedades mentales, pero no por la intervención de la angiografía, Antonio Caetano de Abreu Freire Egaz Moniz, se le acredita la inción de la angiografía. Sin embargo el impacto importante que tuvo en el desarrollo de este campo de la Medicina, que sobresali+o en sus trabajos, se le negó el Premio Nobel por circunstancias de la época. Por muchos años fue olvidada por parecer una técnica misteriosa. Hoy en día continúa cumpliendo un importante rol en el campo de la medicina vascular. La radiología se inicia como disciplina en los años treinta del siglo veinte, cuando se crea la Sociedad Norteamericana de Radiología, la cuál impulsa la relación entre enfermedad e imagen. La neurorradiología, inexistente como disciplina independiente, pertenecía a los clínicos, unos pocos la adoptaron como una discilplina comenzando con el estudio sistematizado de la anatomía y procesos patológicos del sistema nervioso a través de la imagen. Ésta se desarrolla vertiginosamente en Suecia, particularmente en en Instituto Karolinska de Estocolmo, y en Nueva York. La neurorradiología atribuible a Word en los albores de los años cincuenta, se concreta por el Dr. Juan M. Taveras en 1955, en la Universidad de Nueva York. Este artículo, refleja el comienzo de la angiografía, con Egas Moniz, y su evolución en el tiempo.

Evolución de la angiografía digital cerebral / Evolution of th digital cerebral angiography

Premio Nobel que fue reconocido por sus trabajos en tratamientos radicales en enfermedades mentales, pero no por la intervención de la angiografía, Antonio Caetano de Abreu Freire Egaz Moniz, se le acredita la inción de la angiografía. Sin embargo el impacto importante que tuvo en el desarrollo de este campo de la Medicina, que sobresali+o en sus trabajos, se le negó el Premio Nobel por circunstancias de la época. Por muchos años fue olvidada por parecer una técnica misteriosa. Hoy en día continúa cumpliendo un importante rol en el campo de la medicina vascular. La radiología se inicia como disciplina en los años treinta del siglo veinte, cuando se crea la Sociedad Norteamericana de Radiología, la cuál impulsa la relación entre enfermedad e imagen. La neurorradiología, inexistente como disciplina independiente, pertenecía a los clínicos, unos pocos la adoptaron como una discilplina comenzando con el estudio sistematizado de la anatomía y procesos patológicos del sistema nervioso a través de la imagen. Esta se desarrolla vertiginosamente en Suecia, particularmente en en Instituto Karolinska de Estocolmo, y en Nueva York. La neurorradiología atribuible a Word en los albores de los años cincuenta, se concreta por el Dr. Juan M. Taveras en 1955, en la Universidad de Nueva York. Este artículo, refleja el comienzo de la angiografía, con Egas Moniz, y su evolución en el tiempo.(AU)

Percutaneous vertebroplasty: technique and results in 192 procedures.

Percutaneous vertebroplasty with acrylic cement (usually polymethylmethacrylate) consists of injecting cement into vertebral bodies weakened by osseous lesions. The objective of this procedure is to obtain an analgesic effect by mechanical stabilization in destructive lesions of the spine. The three major indications are aggressive vertebral hemangiomas, severe or refractory pain related to osteoporotic vertebral fractures, and malignant vertebral tumors. Complications are infrequent, but occur essentially in patients with vertebral malignant tumors. We present our experience with 148 patients that underwent 192 percutaneous PMMA vertebroplasties for the treatment of painful osteoporotic compression fractures (76 patients, 105 vertebral levels), hemangiomas (31 patients, 43 vertebral levels) and neoplasms (31 patients, 43 vertebral levels). In a vast majority of appropriately selected cases and especially in osteoporotic cases, vertebroplasty constitutes a relatively simple procedure with a very high rate of success.

Reconstructive endovascular approach for a cavernous aneurysm in infancy.

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 to risky. A combined endovascular approach using stent and coils was performed. A 4 x 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.

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

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.

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 x 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.

Angioplasty and stent placement in intracranial atherosclerotic stenoses and dissections.

BACKGROUND AND PURPOSE: Stent placement has been shown to increase the safety and effectiveness of balloon angioplasty in cervical carotid disease. Here, the authors investigated the feasibility, safety, and short-term outcome of stent-assisted angioplasty for the treatment of intracranial stenoses. METHODS: Thirty-four patients (age range, 12-77 years; mean age, 54 years) with symptomatic intracranial atherosclerotic lesions and dissections that produced stenosis of more than 50% were selected and treated with stents. Eighteen lesions (53%) were located in the anterior circulation, and 16 (47%) were in the vertebrobasilar complex. The mean stenosis was 75%. RESULTS: At follow up, 21 patients (62%) improved clinically, 11 (32%) remained stable, and the condition of two patients (6%) deteriorated. In all patients, the angiographic degree of stenosis was reduced to less than 30%. In 10 patients (29%), two or more stents were implanted: Two stents were implanted in six patients, and three, in four patients. The transient procedural morbidity rate was 12%, and the transient neurologic morbidity rate was 6%. One patient had hemorrhagic transformation due to reperfusion and died, and another patient had a massive myocardial infarction after 5 months. Twenty patients were followed up with angiography for at least 6 months, and none required repeat angioplasty. CONCLUSION: Endovascular revascularization of intracranial arteries by means of stent-assisted angioplasty is technically feasible, effective, and safe in selected patients.

Endovascular reconstruction of intracranial arteries by stent placement and combined techniques.

OBJECT: The authors investigated the feasibility, safety, and short-term outcome of stent treatment for intracranial aneurysms, stenoses, and dissections. METHODS: One hundred twenty-three consecutive patients with intracranial saccular, dissecting, and fusiform aneurysms, atherosclerotic lesions, and dissections were selected for intracranial stent implantation with or without adjunctive coil placement. One hundred eleven patients (mean age 47 years, range 3-73 years) underwent stent treatment; 12 patients (9.8%) were not treated. These 111 patients were divided into four groups: in Group 1 there were 62 patients with saccular aneurysms; Group 2 included nine patients (10 lesions) with dissecting or fusiform aneurysms; in Group 3 there were 36 patients with symptomatic intracranial atheromatous stenoses of more than 50%; and Group 4 included four patients with symptomatic intracranial dissections. All patients underwent computerized tomography scanning and/or magnetic resonance imaging and cerebral digital subtraction angiography preoperatively. Of the 72 aneurysms in Groups 1 and 2, 59 (82%) were treated with combined endovascular stent implantation and endosaccular coil placement. In 67 aneurysms (93%) we achieved complete or nearly complete obliteration. All patients with arterial narrowing achieved residual stenoses of less than 30% postangioplasty. One patient required repeated angioplasty. The morbidity rate in the series was 10.9% and the mortality rate was 6.3%. CONCLUSIONS: These findings indicate that stent treatment is feasible and seems to be an effective modality for arterial reconstruction. This versatile tool allows the treatment of a wide variety of challenging intracranial lesions.

Tratamiento endovascular de remanentes aneurismáticos / Endovascular treatment of partially clipped aneurysms

El pinzado ("clipado") parcial de un aneurisma ocurre en aproximadamente el 4 porciento de las intervenciones quirúrgicas. Debido al riesgo de crecimiento y ruptura del remanente aneurismático, se reconoce la necesidad de una intervención quirúrgica. Sin embargo, este procedimiento puede resultar técnicamente complejo y con un elevado índice de complicaciones . En este artículo describimos nuestra experiencia con 9 pacientes portadores de remanentes aneurismático postclipado tratados por vía endovascular. Cinco pacientes (88.9 porciento) se localizaron en la circulación anterior. La angiografía de control postoperatorio mostró la oclusión total del remanente aneurismático en 8 casos (88.9 porciento). El clipado parcial del cuello o cuerpo aneurismático puede permitir la colocación estable de coils. El clip puede limitar la adecuada visualización angiográfica del cuello aneurismático. No se presentaron complicaciones neurológicas asociadas al procedimiento ni hemorragias durante o posteriormente a la embolización. Concluimos que el tratamiento endovascular de remanentes aneurismáticos puede ser efetuado con seguridad y eficacia. Se identifican tipos de clipado que favorecen el tratamiento endovascular.

Tratamiento endovascular de remanentes aneurismáticos / Endovascular treatment of partially clipped aneurysms

El pinzado ("clipado") parcial de un aneurisma ocurre en aproximadamente el 4 porciento de las intervenciones quirúrgicas. Debido al riesgo de crecimiento y ruptura del remanente aneurismático, se reconoce la necesidad de una intervención quirúrgica. Sin embargo, este procedimiento puede resultar técnicamente complejo y con un elevado índice de complicaciones . En este artículo describimos nuestra experiencia con 9 pacientes portadores de remanentes aneurismático postclipado tratados por vía endovascular. Cinco pacientes (88.9 porciento) se localizaron en la circulación anterior. La angiografía de control postoperatorio mostró la oclusión total del remanente aneurismático en 8 casos (88.9 porciento). El clipado parcial del cuello o cuerpo aneurismático puede permitir la colocación estable de coils. El clip puede limitar la adecuada visualización angiográfica del cuello aneurismático. No se presentaron complicaciones neurológicas asociadas al procedimiento ni hemorragias durante o posteriormente a la embolización. Concluimos que el tratamiento endovascular de remanentes aneurismáticos puede ser efetuado con seguridad y eficacia. Se identifican tipos de clipado que favorecen el tratamiento endovascular. (AU)