Tratamiento endovascular de aneurismas de arterias viscerales. Experiencia de 10 años en un solo centro / Endovascular treatment of visceral artery aneurysms. A single center 10-year experience

RESUMEN Antecedentes : los aneurismas de arterias viscerales (AAV) tienen una frecuencia baja (0,1 a 2%). Hasta un 25% puede presentarse como rotura, con una alta mortalidad (hasta 70%). La terapia endovascular ha ganado terreno y se recomienda como primera opción según las últimas guías. Hoy en día, es posible adaptarse a casi cualquier anatomía utilizando tecnología cerebral. Objetivo : describir la experiencia y enfoque en el manejo endovascular de AAV, con resultados a corto, mediano y largo plazo. Material y métodos : llevamos a cabo una evaluación retrospectiva de pacientes tratados por AAV verdaderos por vía endovascular en un solo centro entre 2010 y 2020, con un seguimiento mínimo de 6 meses. Resultados : analizamos 19 procedimientos en 18 pacientes (9 hombres y 9 mujeres). La edad promedio fue 61,9 años; el promedio de tiempo de internación fue 1,94 días y el promedio de seguimiento de 40 meses. La arteria más involucrada fue la esplénica (n = 9, 50%). El tamaño aneurismático promedio fue 30,1 mm. La estrategia terapéutica más utilizada fue colocación de diversor de flujo (n = 8, 42,1%). Dos pacientes fueron reintervenidos (11,1%). Las tasas de exclusión completa fueron del 47,4%, 68,4% y 94,7% a los 3, 6 y 12 meses, respectivamente. No hubo casos de mortalidad a 30 días ni mortalidad relacionada con el aneurisma durante el seguimiento. Conclusión : el tratamiento endovascular de los AAV es seguro y eficaz. Sin embargo, se debe contar con la tecnología adecuada, para la planificación preoperatoria y el tratamiento.

ABSTRACT Background : the prevalence of visceral artery aneurysms (VAAs) is low (0.1 to 2%). Up to 25% may present as rupture which is associated with high mortality (up to 70%). Endovascular treatment has gained ground and is even considered the first option according to the most recent recommendations. Nowadays, almost any anatomy can be approached with endovascular techniques used to treat intracranial aneurysms. Objective : the aim of our study was to describe the experience and approach for the endovascular management of VAAs with short-, mid-, and long-term results. Material and methods : we conducted a retrospective evaluation of patients with true VAAs undergoing endovascular treatment in a single center between 2010 and 2020 who were followed up for a minimum of 6 months. Results : we analyzed 19 procedures in 18 patients (9 men and 9 women). Mean age was 61.9 years; mean length of hospital stay was 1.94 days and mean follow-up was 40 months. The splenic artery was the vessel most affected (n = 9, 50%). Mean aneurysm size was 30.1 mm. Flow diversion was the strategy most used (n = 8, 42.1%). Two patients required reintervention (11%). Complete exclusion rate was 38.4%, 47.4%, 68.4% and 94.7% at 3, 6 and 12 months, respectively. There were no cases of mortality within the first 30 days and no aneurysm-related mortality during the follow-up period. Conclusion : endovascular treatment of VAAs is a safe and efficient strategy but requires adequate technology for preoperative planning and treatment.

Effects from Side Branch Diameter of Intracranial Aneurysm on Hemodynamic Parameters after Flow Diverter Implantation / 医用生物力学

Objective To comprehensively consider the effect of low diverter (FD) implantation on aneurysmal sac and its branches, so as to provide references for making a more reasonable surgical strategy for intracranial aneurysm embolization in clinical practice. Methods Based on computational fluid dynamics (CFD) method, the FD implantation procedure was simulated by using porous media model innovatively. Changes in hemodynamic parameters of aneurysmal sac and side branch with different diameters before and after FD implantation were compared and analyzed, such as blood flow field, velocity, wall pressure and wall shear stress (WSS). Results FD changed the hemodynamic characteristics of aneurysms. The blood flow velocity decreased significantly. The WSS on aneurysmal neck increased, while the difference of WSS between proximal and distal cervical area reduced conversely. Different side branch diameters of vessels had different effects on hemodynamic characteristic changes. The larger diameter would cause the greater blood flow reduction in side branch after FD implantation, but the decrease in velocity of aneurysmal sac and pressure on aneurysmal roof became smaller simultaneously. Meanwhile, the increase of WSS on aneurysmal neck was inversely proportional to the diameter of side branch. Conclusions The larger branch diameter of vessels would cause the worse effect of FD embolization therapy for intracranial aneurysm, worse atherosclerosis improvements and greater possibilities of branch occlusion or other ischemic complications. Doctors should pay more attention to such cases in FD interventional intravascular embolization in clinic.

Sensitivity Analysis of Flow Diverter Treatment of Intracranial Aneurysm Using Porous Media Model / 医用生物力学

Objective To simulate the hemodynamic effects of different flow diverters (FD) parameters by using computational fluid dynamics (CFD) technology, so as to develop a more reasonable FD embolization strategy before operation. Methods The porous media model was used to simulate the process of FD implantation into aneurysms, and the initial values of its own unique porous media momentum source parameters (permeability and inertial resistance) were calculated for a specific FD (Tubridge).The changes of hemodynamic parameters such as blood flow velocity, wall shear stress (WSS), volume flow and pressure of aneurysm-roof were compared under different situations (initial values of 80%, 90%, 100%, 110% and 120%), and the sensitivity analysis on hemodynamic parameters of patient-specific intracranial aneurysms (IA) for the porous media model was further conducted. Results The sensitivity of IA hemodynamic parameters to the permeability of porous media model was as follows: WSSparent-artery＞WSSaneurysm＞paneurysmal-roof, but the sensitivity to inertia resistance was relatively lower. Conclusions By using the porous media model, different metal coverages (MC) of FD could be simulated by choosing different permeability parameters, so it is necessary to adjust specific permeability settings during modeling of FD with different MC.

Reconstrucción endovascular de aneurisma intracraneal mediante dispositivo diversor de flujo Pipeline®. Reporte de 2 casos y revisión de la literatura / Endovascular reconstruction of intracranial aneurysm using a Pipeline® flow diversifier device

Resumen Introducción: Los aneurismas intracraneales son anomalías vasculares cerebrales con una prevalencia aproximada a nivel mundial del 2-3%. Son la principal causa de hemorragia subaracnoidea no traumática, el diagnóstico y tratamiento preventivo de esta entidad puede reducir considerablemente la morbimortalidad que de ella deviene. Con la aparición de nuevos dispositivos de terapia endovascular cerebral como los diversores de flujo se ha logrado ofrecer al paciente un procedimiento menos invasivo que no requiere cirugía convencional, y una importante reducción en el número de días de estancia intrahospitalaria y de recuperación, con alto grado de seguridad. El tratamiento endovascular para aneurismas intracraneales ha evolucionado sustancialmente en las últimas dos décadas, convirtiéndose en el tratamiento de elección en diversas situaciones clínicas. Reporte de caso: Caso 1: Varón de 62 años edad que ingresa a unidad hospitalaria después de sufrir un traumatismo craneoencefálico moderado con pérdida transitoria del estado de alerta y cefalea holocraneana. Se realizó una tomografía de cráneo simple y con contraste ante la sospecha de hemorragia subaracnoidea. Se evidenció la presencia de un aneurisma intracraneal en la arteria carótida interna izquierda, segmento comunicante posterior de 4 x 3 mm con cuello de 3 mm. Se realizó tratamiento mediante la colocación de dispositivo diversor de flujo Pipeline®, así como control angiográfico a los 3 meses post-tratamiento con una evolución satisfactoria. Caso 2: Mujer de 59 años de edad que acudió por presentar hemiparesia facial y brazo ipsilateral, con incremento gradual de la intensidad y duración. Se inició protocolo de estudio con resonancia magnética. Se evidenció la presencia de aneurisma intracraneal de 15 mm de diámetro en el segmento comunicante de la arteria carótida interna derecha y otro de 8 mm contralateral. Fue programada para colocación de dispositivo diversor de flujo Pipeline® con adecuada evolución. Conclusión: El uso de dispositivos diversores de flujo es una excelente alternativa para el tratamiento de aneurismas intracraneales incidentales, con importantes ventajas de costo-efectividad, reduciendo tiempos quirúrgicos, de estancia hospitalaria y de recuperación. Además de tener un porcentaje de curación superior al 95% a 5 años.

Abstract Introduction: Intracranial aneurysms are cerebral vascular anomalies with an approximate global prevalence of 2 to 3% and are the main cause of non-traumatic subarachnoid hemorrhage. Diagnosis and preventive treatment of this entity can considerably reduce morbidity and mortality. With the advent of new devices for cerebral endovascular therapy such as flow diverters, the patient now has the option of choosing a less invasive procedure, which does not require conventional surgery. This represents a significant reduction in the number of days of in hospital stay and recovery. The procedure has showed a high degree of security. The endovascular treatment for intracranial aneurysms has evolved substantially in the last two decades, and has become the treatment of choice. Case report: Case 1: A 62-year-old male was admitted in the hospital after a moderate cranioencephalic trauma with transient loss of conscious and a holocranial headache. A cerebral angiography was performed to rule out subarachnoid hemorrhage. The angiography showed an intracranial aneurysm. It was localized in left internal carotid-posterior communicating artery. The measures were of 4mm X 3mm with a 3mm neck. The treatment was performed with a pipeline flow-diverting device, as well as an angiographic control 3 months after the treatment with a satisfactory evolution. Case 2: A 59-year-old female patient with facial hemiparesis and ipsilateral arm, that showed a gradual increase in intensity and duration. A magnetic resonance study protocol was initiated and an intracranial aneurysm was observed in the communicating segment of the right internal carotid artery. The diameter of the aneurysmal sac was of 15 mm and also, a contralateral of 8 mm. Placement of a flow-diverting device was programmed. Conclusion: The use of flow-diverting devices is an excellent alternative for the treatment of incidental intracranial aneurysms, with important cost-effectiveness advantages, surgical time, hospital stay and recovery reduction. In addition to having a recovery percentage of 95% in 5 years.

Endovascular treatment of a traumatic carotid pseudoaneurysm with the Tubridge stent; A case report / 中国脑血管病杂志

Traumatic intracranial pseudoaneurysm is usually caused by blunt or penetrating head injuries. It lacks of real blood vessel wall and is covered only by a fragile connective tissue layer. Traumatic intracranial pseudoaneurysm mainly occurs in the carotid, cavernous and petrous segments of the internal carotid artery. A case of traumatic internal carotid artery pseudoaneurysm successfully treated with Tubridge flow diverter device was reported. The 32-year-old male patient was diagnosed as a pseudoaneurysm of the left internal carotid artery after a traffic accident, and received treatment with Tubridge flow diverter device one month later. After stents release, angiography showed obviously retained contrast agent in pseudoaneurysm, decreased aneurysm size and well-opened stents. The size of the pseudoaneurysm was found reduced by magnetic resonance angiography reexamination on the 4th day after the operation,and a further decrease on the 10th day by digital subtraction angiography (DSA) reexamination. Four months after the operation, DSA showed the aneurysm was completely cured.

Treatment of Intracranial Aneurysms with the Pipeline Embolization Device Only: a Single Center Experience / 신경중재치료의학

PURPOSE: The aim of this study was to evaluate the technical feasibility and rate of mid-term occlusion in aneurysms treated solely with the Pipeline Embolization Device (PED) in a German tertiary care university hospital. MATERIALS AND METHODS: Forty-nine non-consecutive intracranial aneurysms underwent endovascular treatment using the PED exclusively between March 2011 and May 2017 at our institution. Primary endpoint was a favorable aneurysm occlusion defined as OKM C1-3 and D (O'Kelly Marotta Scale). Secondary endpoints were retreatment rate and delayed complications. Median follow-up was 200 days. RESULTS: The mean aneurysm size was 7.1 ± 5.3 mm. Forty-four aneurysms were located in the anterior circulation (90%). Ten aneurysms were ruptured (20%). Branching vessels from the sac were observed in 11 aneurysms (22%). Favorable obliteration immediately after PED placement was seen in 13/49 aneurysms (27%), of those nine aneurysms were completely occluded (18%). Angiographic and clinical follow-up was available for 45 cases (92%); 36/45 aneurysms (80%) were occluded completely and 40/45 aneurysms (89%) showed a favorable occlusion result. A branching vessel arising from the aneurysm sac was associated with incomplete occlusion (P < .05). All electively treated patients had good outcome (mRS 0). Three aneurysms (6%) required additional treatment due to aneurysm recurrence. CONCLUSION: In our series, treatment of intracranial aneurysms with the PED was associated with favorable occlusion rates and low complication rates at mid-term follow-up. The presence of branching vessels arising from the aneurysms sac was predictive for an incomplete occlusion.

Symptomatic Post Endarterectomy Common Carotid Artery Pseudoaneurysm Treated with Combination of Flow Diverter Implantation and Carotid Stenting / 신경중재치료의학

A 74-year-old male developed cervical carotid artery psuedoaneurysm 8 months after carotid endarterectomy. The patient was successfully managed with dual implantation of flow-diverter and conventional carotid stent. Flow-diverter was placed across the neck of pseudoaneurysm to provide flow diversion while carotid stent was implanted within the lumen of the expanded flow-diverter to approximate and hold the flow diverter proximal and distal to the pseudoaneurysm. Follow-up ultrasonography revealed complete resolution of the pseudoaneurysm.

Kinking of Flow Diverter in a Giant Wide-Necked Supraclinoid Internal Carotid Artery Aneurysm / 신경중재치료의학

We report here a rare complication in the form of kinking of flow diverter in a case of giant wide-necked supraclinoid internal carotid artery (ICA) aneurysm 48 hours after the procedure. This 28-year female presented with giant wide-necked right supraclinoid ICA aneurysm which was managed by flow diversion. On 2nd post-op day, patient developed weakness of left side with altered sensorium - angiography and CT showed kinking of flow diverter at the neck of the aneurysm with poor distal flow. Eventually, the patient developed right middle cerebral artery infarct for which decompressive hemicraniectomy was done. The likely cause of development of kink is because the aneurysm was wide-necked, the hemodynamic forces have resulted in inward buckling of the flow diverter at the aneurysm neck. This case shows that kinking of flow diverter can still happen 48 hours post-procedure.

First Human Evaluation of Endothelial Healing after a Pipeline Flex Embolization Device with Shield Technology Implanted in Posterior Circulation Using Optical Coherence Tomography / 신경중재치료의학

A 64-year-old female presented with an incidentally-discovered right posterior inferior cerebral artery (PICA) aneurysm, initially treated in 2015 by simple coiling. Follow-up demonstrated significant coil compaction that required retreatment. Retreatment was done uneventfully using a Pipeline embolization device (PED) shield deployed starting from the basilar artery and ending at the V4 segment of the vertebral artery. Eight-weeks post-deployment, a follow-up digital subtraction imaging (DSA) and intravascular imaging with optical coherence tomography were obtained. The intravascular imaging demonstrated that the flow diverter had good wall apposition and concentric neointimal growth over the braid with exception to the areas that the PED was not in contact with the endothelial wall, such as at the right PICA ostium and at the vertebrobasilar junction. The entire procedure was safe, and the patient had no complications. In this article, we describe for the first time the assessment of the status of endothelial “healing” of the PED shield at 8-weeks.

Nationwide Mortality Data after Flow-Diverting Stent Implantation in Korea

OBJECTIVE: To investigate nationwide statistics on flow-diverting stent usage for cerebral aneurysm treatment and related mortality data.METHODS: We requested data extraction from the National Health Insurance Service claims database using electronic data interchange codes (J3207064, J3207073). Patient and hospital information as well as death statistics were collected from the database.RESULTS: A total of 169 procedures were performed using flow-diverting stents for cerebral aneurysm treatment from November 2014 to December 2016 in Korea. The majority of primary diagnosis was unruptured intracranial aneurysm. During the study period, nine subjects died, including one patient initially diagnosed with subarachnoid hemorrhage. The crude mortality rate was 5.3%. Five patients died within one month after the procedure; therefore, the estimated periprocedural mortality rate was 3.0±1.3%. The mortality rate as of the last day of 2016 was 6.3±2.1%.CONCLUSION: In a 171 person-year follow-up in a Korean series, nine deaths occurred after flow-diverting stent treatment. The crude mortality rate in Korea (5.3%) was higher than that reported in a previous meta-analysis (3.8%).

Roles of Pipeline embolization device in combination with coils in the treatment of large and giant unruptured internal carotid artery aneurysms / 中国脑血管病杂志

Objective To investigate the roles of Pipeline embolization device ( PED) in combination with coils in the treatment of large and giant unruptured internal carotid artery aneurysms. Methods From January 2014 to December 2016,51 patients with large (diameter 10-25 mm) and giant (diameter >25 mm) internal carotid artery aneurysms treated at the Department of Neurosurgery,Xuanwu Hospital,Capital Medical University were analyzed retrospectively. Among them,35 were females and 16 were males, the average age was 53 ±13 years (range 15-71). They were divided into a PED group (n=31) and a PED combined with coil group (n=20) according to whether using coils for packing aneurysm cavity or not. The treatment of two groups of patients and ≥6 months of imaging follow-up effect were analyzed. The embolic rate was evaluated by Raymond grade. Results Thirty-one patients with 32 aneurysms ( mean diameter 15 ± 3 mm) in the PED group were treated with 33 PEDs,including 15 with cavernous sinus aneurysm and 17 with supraclinoid aneurysm;20 patients with 21 aneurysms ( mean diameter 17 ± 4 mm) were treated with 22 PEDs in the PED combined with coil group,including 10 cavernous sinus aneurysms and 11 supraclinoid carotid aneurysms. Six months after procedure,imaging follow-up revealed that the incidence of residual aneurysm ( Raymond grade Ⅱ-Ⅲ) in the PED group was significantly higher that that in the PED combined with coil group (9. 7% [n =3] and 0％,respectively). The incidence of thrombosis in PED combined with coil group was significantly higher than that in the PED group,there was significant difference between two groups (P<0. 05). Conclusions When using PED to treat large and giant internal carotid artery aneurysms,packing aneurysm cavity in combination with coils can reduce the incidence of residual aneurysm,but it may have a higher risk of thrombotic events. A prospective randomized controlled trial of large samples is still needed to prove it.

Nationwide Mortality Data after Flow-Diverting Stent Implantation in Korea

OBJECTIVE: To investigate nationwide statistics on flow-diverting stent usage for cerebral aneurysm treatment and related mortality data. METHODS: We requested data extraction from the National Health Insurance Service claims database using electronic data interchange codes (J3207064, J3207073). Patient and hospital information as well as death statistics were collected from the database. RESULTS: A total of 169 procedures were performed using flow-diverting stents for cerebral aneurysm treatment from November 2014 to December 2016 in Korea. The majority of primary diagnosis was unruptured intracranial aneurysm. During the study period, nine subjects died, including one patient initially diagnosed with subarachnoid hemorrhage. The crude mortality rate was 5.3%. Five patients died within one month after the procedure; therefore, the estimated periprocedural mortality rate was 3.0±1.3%. The mortality rate as of the last day of 2016 was 6.3±2.1%. CONCLUSION: In a 171 person-year follow-up in a Korean series, nine deaths occurred after flow-diverting stent treatment. The crude mortality rate in Korea (5.3%) was higher than that reported in a previous meta-analysis (3.8%).

Usefulness of the Pipeline Embolic Device for Large and Giant Carotid Cavernous Aneurysms / 신경중재치료의학

PURPOSE: Conventional coil embolization for large carotid cavernous aneurysms (CCAs) has limited utility due to its inability to prevent recurrences and reduce mass effect. Trapping of the parent artery may have a risk of ischemic complications due to intracranial perfusion disorders. We successfully treated 24 patients with large CCAs using a flow diverter (Pipeline™ embolic device: PED), and this report discusses the safety and efficacy of this method. MATERIALS AND METHODS: Twenty four patients (23 females, mean age 71.5 years old) with large CCAs, including 6 giant CCAs, were treated with a PED over three years. Under sufficient dual anti-platelet management, the PED was deployed over the orifice of the aneurysm. Two patients required multiple telescoping stents. Clinical and radiological states were checked with MRI at 1, 3 and 6 months post-surgically. Angiographic follow-up was performed at 6 months. RESULTS: In all patients, PED was appropriately deployed. Stagnation of contrast with eclipse signs was observed post-angiogram in 21 cases. One patient requiring 5 telescoping stents experienced temporary ischemic symptoms. Fourteen patients experienced improvement of ocular motor impairment deficiency, including 6 patients who recovered. Angiograms at 6 months follow-up showed complete occlusion in 63% (12/19) of patients, and MRI showed reduction of aneurysm volume in 89% (17/19) of patients. CONCLUSION: Flow diverters for large CCAs showed promising clinical and radiological efficacy. They can shrink the aneurysm and improve symptoms without sacrificing the parent artery. It will be necessary to summarize the cases and to verify the long-term results.

A Novel Flow Diverter (Tubridge) for the Treatment of Recurrent Aneurysms: A Single-Center Experience

OBJECTIVE: The Tubridge flow diverter (FD) is a novel device aimed at reconstructing the parent artery and occluding complex aneurysms. Retreatment of recurrent aneurysms using the FD is challenging. We report our initial experience in the repair of aneurysm recurrence with the FD. MATERIALS AND METHODS: A database was reviewed prospectively, and 8 patients with 8 recurrent aneurysms (mean size, 16.7 mm) were identified. Four aneurysms had previously ruptured. The previous aneurysm treatment consisted of coiling in 1 aneurysm and single-stent-assisted coiling in 7 aneurysms. The procedural complications and clinical and angiographic outcomes were analyzed. RESULTS: Six aneurysms were treated by using a single Tubridge FD alone, while the remaining 2 were treated with FD + coiling. The immediate results of the 8 aneurysms were that they all showed incomplete occlusion. Neither major ischemic nor hemorrhagic complications occurred; however, 1 patient experienced a vasospasm. Follow-up angiographies were available for 7 aneurysms; the mean follow-up was 16.9 months (7–36 months). Five aneurysms were completely occluded, whereas 2 had a residual neck. Severe asymptomatic stenosis of 1 parent artery of a vertebral artery dissecting aneurysm was found. All visible branches covered by the FD were patent. All patients were clinically assessed as having attained a favorable outcome (modified Rankin Scale score ≤ 2) at discharge and follow-up. CONCLUSION: In selected patients, the Tubridge FD can provide a safe and efficient option for the retreatment of recurrent aneurysms. Nevertheless, attention should be paid to several technical points.

Pipeline Embolization Device for Large/Giant or Fusiform Aneurysms: An Initial Multi-Center Experience in Korea / 신경중재치료의학

PURPOSE: The purpose of this study was to assess the safety and early outcomes of the Pipeline device for large/giant or fusiform aneurysms. MATERIALS AND METHODS: The Pipeline was implanted in a total of 45 patients (mean age, 58 years; M:F=10:35) with 47 large/giant or fusiform aneurysms. We retrospectively evaluated the characteristics of the treated aneurysms, the periprocedural events, morbidity and mortality, and the early outcomes after Pipeline implantation. RESULTS: The aneurysms were located in the internal carotid artery (ICA) cavernous segment (n=25), ICA intradural segment (n=11), vertebrobasilar trunk (n=8), and middle cerebral artery (n=3). Procedure-related events occurred in 18 cases, consisting of incomplete expansion (n=8), shortening-migration (n=5), transient occlusion of a jailed branch (n=3), and in-stent thrombosis (n=2). Treatment-related morbidity occurred in two patients, but without mortality. Both patients had modified Rankin scale (mRS) scores of 2, but had an improved mRS score of 0 at 1-month follow-up. Of the 19 patients presenting with mass effect, 16 improved but three showed no changes in their presenting symptoms. All patients had excellent outcomes (mRS, 0 or 1) during the follow-up period (median, 6 months; range, 2-30 months). Vascular imaging follow-up (n=31, 65.9%; median, 3 months, range, 1-25 months) showed complete or near occlusion of the aneurysm in 24 patients (77.4%) and decreased sac size in seven patients (22.6%). CONCLUSION: In this initial multicenter study in Korea, the Pipeline seemed to be safe and effective for large/giant or fusiform aneurysms. However, a learning period may be required to alleviate device-related events.

A New Flow-Diverter (the FloWise): In-Vivo Evaluation in an Elastase-Induced Rabbit Aneurysm Model

OBJECTIVE: We aimed to evaluate the efficacy and safety of a newly developed, partially retrievable flow-diverter (the FloWise) in an elastase-induced rabbit aneurysm model. MATERIALS AND METHODS: We developed a partially retrievable flow diverter composed of 48 strands of Nitinol and platinum wire. The FloWise is compatible with any microcatheter of 0.027-inch inner diameter, and is retrievable up to 70% deployment. The efficacy and safety of the FloWise were evaluated in the elastase-induced rabbit aneurysm model. The rate of technical success (full coverage of aneurysm neck) and assessment of aneurysm occlusion and stent patency was conducted by angiograms and histologic examinations at the 1-month, 3-month, and 6-month follow-up. The patency of small arterial branches (intercostal or lumbar arteries) covered by the FloWise were also assessed in the 5 subjects. RESULTS: We attempted FloWise insertion in a total of 32 aneurysm models. FloWise placement was successful in 31 subjects (96.9%). Two stents (6.2%) were occluded at the 3-month follow-up, but there was no evidence of in-stent stenosis in other subjects. All stented aneurysms showed progressive occlusion: grade I (complete aneurysm occlusion) in 44.4% and grade II (aneurysm occlusion > 90%) in 55.6% at 1 month; grade I in 90% and II in 10% at 3 months; and grade I in 90% and II in 10% at 6 months. All small arterial branches covered by the FloWise remained patent. CONCLUSION: A newly developed, partially retrievable flow-diverter seems to be a safe and effective tool of aneurysm occlusion, as evaluated in the rabbit aneurysm model.

Blood flow in intracranial aneurysms treated with Pipeline embolization devices: computational simulation and verification with Doppler ultrasonography on phantom models

PURPOSE: The aim of this study was to validate a computational fluid dynamics (CFD) simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms. METHODS: Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations. RESULTS: CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography. CONCLUSION: The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.

Persistent Aneurysm Growth Following Pipeline Embolization Device Assisted Coiling of a Fusiform Vertebral Artery Aneurysm: A Word of Caution! / 신경중재치료의학

The complex morphology of vertebrobasilar fusiform aneurysms makes them one of the most challenging lesions treated by neurointerventionists. Different management strategies in the past included parent vessel occlusion with or without extra-intracranial bypass surgery and endovascular reconstruction by conventional stents. Use of flow diversion has emerged as a promising alternative option with various studies documenting its efficacy and safety. However, there are various caveats associated with use of flow diversion in patients with fusiform vertibrobasilar aneurysms especially in patients presenting with acute subarachnoid hemorrhage (SAH). We report a rare case of persistent aneurysmal growth after coiling and placement of the Pipeline Embolization Device (PED; ev3, Irvine, California, USA) for SAH from a fusiform vertebral artery aneurysm. As consequences of aneurysm rupture can be devastating especially in patients with a prior SAH, the clinical relevance of recognizing and understanding such patterns of failure cannot be overemphasized as highlighted in the present case.

Pipeline Embolization Device for Giant Internal Carotid Artery Aneurysms: 9-Month Follow-Up Results of Two Cases

The pipeline(TM) embolization device (PED) is a braided, tubular, bimetallic endoluminal implant used for occlusion of intracranial aneurysms through flow disruption along the aneurysm neck. The authors report on two cases of giant internal carotid artery aneurysm treated with the PED. In the first case, an aneurysm measuring 26.4 mm was observed at the C3-C4 portion of the left internal carotid artery in a 64-year-old woman who underwent magnetic resonance imaging (MRI) for dizziness and diplopia. In the second case, MRI showed an aneurysm measuring 25 mm at the C4-C5 portion of the right internal carotid artery in a 39-year-old woman with right ptosis and diplopia. Each giant aneurysm was treated with deployment of a PED (3.75 mm diameter/20 mm length and 4.5 mm diameter/25 mm length, respectively). Nine months later, both cases showed complete radiological occlusion of the giant intracranial aneurysm and sac shrinkage. We suggest that use of the PED can be a therapeutic option for giant intracranial aneurysms.