Cerebral vasospasm patterns following aneurysmal subarachnoid hemorrhage: an angiographic study comparing coils with clips.

BACKGROUND AND PURPOSE: Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (aSAH) results in significant morbidity due to ischemia. Subarachnoid hematoma evacuation during aneurysm clipping reduces the incidence of vasospasm. However, studies comparing endovascular coiling with open clipping have reported similar rates of spasm. We addressed the question of how coiling produces similar (if not less) vasospasm without the benefit of clot evacuation by evaluating vasospasm patterns among patients with aSAH. We hypothesize that cerebrospinal fluid (CSF) circulation plays a major role in clearing blood breakdown products, and that coiling may preserve CSF flow in the subarachnoid space. METHODS: A retrospective chart review identified 36 (18 coiled/18 clipped) patients with aSAH who developed angiographic vasospasm. The degree of spasm was quantified using an ordinal scale from 0 (none) to 5 (severe) for 26 anatomic vessel segments evaluated on 164 successive angiograms. Statistical analysis was performed using the Fisher exact test for proportions and the Wilcoxon and Student t tests on ordinal/continuous measures. Quadratic regression was also used as a model for spasm activity versus post-bleed days. RESULTS: In both the coiling and clipping groups the most severely spastic vessels were located adjacent to aneurysm rupture. Perianeurysmal spasm affected all subjects. However, whereas spasm remained largely confined in patients treated by clipping, those who underwent coiling developed stepwise progression distally over time. The distal vasospasm severity scores were higher among subjects treated by coiling, particularly in the most dependent regions of the subarachnoid space. CONCLUSIONS: Patients with aSAH treated by endovascular coiling and surgical clipping demonstrate distinct vasospasm patterns. While both initially exhibit perianeurysmal spasm, patients treated by coiling go on to develop stepwise progression distally over time. This finding may reflect dispersion of blood breakdown products along preserved CSF egress pathways in patients treated by endovascular coiling.

Prevención de la recurrencia peritoneal en el tratamiento quirúrgico del cáncer gástrico / Prevention of peritoneal recurrence of gastric cancer

The peritoneal cavity is the main site of gastric cancer recurrence after curative surgery. When this recurrence occurs, patients may experience bowel obstruction, dehydration and multiple hospital admissions. The therapeutic options that may decrease the rate of peritoneal recurrence and increase five years survival are intraoperative hyperthermic chemotherapy, extensive intraoperative peritoneal lavage and routine bursectomy. We herein review the oncological results of curative surgery for gastric cancer, its failure patterns and the risk factors for peritoneal recurrence. We also review the studies aiming to prevent peritoneal carcinomatosis.

La recurrencia peritoneal en el cáncer gástrico avanzado, luego de una cirugía con intención curativa es un problema que debe ser considerado una prioridad en nuestro país, debido a la alta proporción de pacientes con compromiso de la serosa gástrica al momento del diagnóstico, siendo el peritoneo el principal sitio de recurrencia luego de una cirugía con intención curativa en este grupo. Luego de la recurrencia peritoneal, los pacientes presentan un deterioro importante de la calidad de vida, principalmente por episodios de obstrucción intestinal, deshidratación y rehospitalizaciones. Se han realizado múltiples estudios en el extranjero de potenciales medidas que se pueden realizar durante la cirugía inicial con intención curativa que previenen la recurrencia. Algunas de estas medidas han disminuido la recurrencia peritoneal y aumentado la sobrevida a 5 años, como son la quimioterapia hipertérmica intraoperatoria, el lavado peritoneal extensivo y la bursectomía rutinaria, en pacientes seleccionados. El objetivo de la presente revisión es mostrar los resultados oncológicos de la cirugía curativa, los patrones de falla luego de una cirugía curativa, los factores de riesgo para una recurrencia peritoneal y los estudios que se han realizado en relación a la prevención de la carcinomatosis peritoneal.

Temporal correlation between wall shear stress and in-stent stenosis after Wingspan stent in swine model.

BACKGROUND AND PURPOSE: A recent randomized clinical trial on intracranial atherosclerosis was discontinued because of the higher frequency of stroke and death in the angioplasty and stent placement group than in the medical treatment group. An in-depth understanding of the relationship between biologic responses and flow dynamics is still required to identify the current limitations of intracranial stent placement. MATERIALS AND METHODS: Five Wingspan stents were deployed in tapered swine ascending pharyngeal arteries. Temporal wall shear stress distributions and in-stent stenosis were evaluated at days 0, 7, 14, and 28 after stent placement. The physiologic role of wall shear stress was analyzed regarding its correlation with in-stent stenosis. RESULTS: In-stent stenosis reached a peak of nearly 40% at day 14 and decreased mainly at the distal stent segment until day 28. The wall shear stress demonstrated a characteristic pattern with time on the basis of the in-stent stenosis change. The wall shear stress gradient increased from the proximal to distal segment until day 14. At day 28, the trend was reversed dramatically, decreasing from the proximal to the distal segment. A significant correlation between the in-stent stenosis growth until day 14 and low wall shear stress values just after stent placement was detected. In-stent stenosis regression between days 14 and 28 was also associated with the high wall shear stress values at day 14. CONCLUSIONS: These data suggest that the physiologic wall shear stress can control the biphasic in-stent stenosis change in tapered arteries.

Angioarchitectural characteristics associated with complications of embolization in supratentorial brain arteriovenous malformation.

BACKGROUND AND PURPOSE: Embolization is an important therapeutic technique in brain arteriovenous malformations; however, little has been reported on the factors contributing to complications. We retrospectively reviewed a large series of supratentorial brain AVMs to identify the angioarchitectural characteristics that might be associated with the complications of embolization and poor clinical outcomes. MATERIALS AND METHODS: The clinical and angiographic features of 130 consecutive patients with supratentorial brain AVMs embolized with ethylene-vinyl alcohol copolymer in our hospital from 2005-2008 were retrospectively reviewed. None of these patients had prior embolization. Complications were classified as transient neurologic deficits, persistent neurologic deficits, and death. Univariate and multivariate analyses were conducted to assess the angiographic features in patients with and without complications. RESULTS: Twenty-three complications occurred in 130 embolization procedures, 13 (10%) were transient neurologic deficits (9 ischemic and 4 hemorrhagic), 9 (6.92%) were persistent neurologic deficits (7 ischemic and 2 hemorrhagic), and 1 death occurred. By univariate analyses, eloquent cortex (OR, 2.57; 95% CI, 1.08-3.42) and exclusive deep venous drainage (OR, 4.56; 95% CI, 1.28-9.67) were correlated with procedural complications. The impaction of eloquent cortical location (P = .001) and exclusive deep venous drainage (P = .035) on complications were also demonstrated by multivariate analysis. Eloquent cortex mainly resulted in permanent ischemic neurologic deficit; occlusion of drainage vein was significantly correlated with periprocedural hemorrhage in supratentorial brain AVMs with subtotal and partial embolization. CONCLUSIONS: In a retrospective study on supratentorial brain AVMs with first-time embolization, 6.92% of patients had permanent neurologic deficit or death. Eloquent cortical location and exclusive deep venous drainage were associated with complications.

A swine model to analyze arterial structural changes induced by mechanical thrombectomy.

We report a novel swine model that allows direct visualization of cervical arteries undergoing mechanical thrombectomy. The model also facilitates evaluation of histologic changes observed in the arteries after treatment. Swine superficial cervical arteries, which are similar in size and branching pattern to the human middle cerebral artery, were surgically exposed, occluded with experimental thrombus, and subsequently treated with the Merci clot retriever device. Angiographic and histologic assessment were performed.

Middle cranial fossa sphenoidal region dural arteriovenous fistulas: anatomic and treatment considerations.

BACKGROUND AND PURPOSE: DAVFs rarely involve the sphenoid wings and middle cranial fossa. We characterize the angiographic findings, treatment, and outcome of DAVFs within the sphenoid wings. MATERIALS AND METHODS: We reviewed the clinical and radiologic data of 11 patients with DAVFs within the sphenoid wing that were treated with an endovascular or with a combined endovascular and surgical approach. RESULTS: Nine patients presented with ocular symptoms and 1 patient had a temporal parenchymal hematoma. Angiograms showed that 5 DAVFs were located on the lesser wing of sphenoid bone, whereas the other 6 were on the greater wing of the sphenoid bone. Multiple branches of the ICA and ECA supplied the lesions in 7 patients. Four patients had cortical venous reflux and 7 patients had varices. Eight patients were treated with transarterial embolization using liquid embolic agents, while 3 patients were treated with transvenous embolization with coils or in combination with Onyx. Surgical disconnection of the cortical veins was performed in 2 patients with incompletely occluded DAVFs. Anatomic cure was achieved in all patients. Eight patients had angiographic and clinical follow-up and none had recurrence of their lesions. CONCLUSIONS: DAVFs may occur within the dura of the sphenoid wings and may often have a presentation similar to cavernous sinus DAVFs, but because of potential associations with the cerebral venous system, may pose a risk for intracranial hemorrhage. Curative embolization through a transarterial or transvenous approach is the primary therapeutic strategy for these lesions. In incompletely embolized patients, exclusion of any refluxing cortical veins is necessary.

Effects of perianeurysmal environment during the growth of cerebral aneurysms: a case study.

BACKGROUND AND PURPOSE: The natural history of cerebral aneurysms is thought to be governed by multifactorial processes involving hemodynamics, biomechanics, mechanobiology, and perianeurysmal environment. The purpose of this study was to highlight the importance of considering the influence of contacts with perianeurysmal environment structures on the hemodynamics and geometric evolution of intracranial aneurysms. MATERIALS AND METHODS: A large aneurysm of the basilar artery in contact with bone and observed to grow during a 4-year follow-up period was selected for study. Anatomic models were constructed from longitudinal CTA images acquired at 1-year intervals during the observation period. Computational fluid dynamics simulations were carried out under pulsatile flow conditions to analyze the blood flow pattern and WSS distribution in the aneurysm during its evolution. RESULTS: The aneurysm was observed to grow against the bone, resulting in a geometric change of the proximal parent artery, which, in turn, induced substantial changes in the aneurysm hemodynamics. In particular, a region of elevated WSS created by the inflow streams was observed to shift locations around the place where the aneurysm enlarged in contact with the bone as the aneurysm progressed. In addition, a "notch" near the distal end of the aneurysm, away from the bone and subject to relatively high WSS, was observed to grow and, later, completely disappear. CONCLUSIONS: Contacts with perianeurysmal structures need to be considered and analyzed to assess whether they could exert a significant influence on the geometric evolution of each individual intracranial aneurysm and its hemodynamics.

In vitro and in vivo testing of a novel, hyperelastic thin film nitinol flow diversion stent.

A flexible, low profile, flow diversion stent could replace endovascular coiling for the treatment of intracranial aneurysms. Micropatterned-thin film nitinol (TFN) is a novel biomaterial with high potential for use in next-generation endovascular devices. Recent advancements in micropatterning have allowed for fabrication of a hyperelastic thin film nitinol (HE-TFN). In this study, the authors describe in vitro and in vivo testing of novel HE-TFN based flow diverting stents. Two types of HE-TFN with expanded pores having long axes of 300 and 500 µm were used to fabricate devices. In vitro examination of the early thrombotic response in whole blood showed a possible mechanism for the device's function, whereby HE-TFN serves as a scaffold for blood product deposition. In vivo testing in swine demonstrated rapid occlusion of model wide-neck aneurysms. Average time to occlusion for the 300-µm device was 10.4 ± 5.5 min. (N = 5) and 68 ± 30 min for the 500-µm device (N = 5). All aneurysms treated with bare metal control stents remained patent after 240 min (N = 3). SEM of acutely harvested devices supported in vitro results, demonstrating that HE-TFN serves as a scaffold for blood product deposition, potentially enhancing its flow-diverting effect. Histopathology of devices after 42 days in vivo demonstrated a healthy neointima and endothelialization of the aneurysm neck region. HE-TFN flow-diverting stents warrant further investigation as a novel treatment for intracranial aneurysms.

The impact of thromboemboli histology on the performance of a mechanical thrombectomy device.

BACKGROUND AND PURPOSE: Recently we published a novel method of thrombus preparation for use in a swine model for evaluation of thrombectomy designs. The clot (fibrin rich clot) is characterized by its similarity in histologic characteristics to the thromboemboli recovered from stroke patients. The purpose of this latest study was to evaluate if the performance of a mechanical thrombectomy device was affected by the histologic characteristics of thromboembolus. Erythrocyte rich clot, which was created using exogenous thrombin, and the novel experimental clot with abundance of fibrin/cellular component were used for comparison. The Merci clot retriever was used for the evaluation and the angiographic outcomes were analyzed. MATERIALS AND METHODS: Two histologically different types of experimental clot, a conventionally used thrombin-induced clot (erythrocyte-rich clot) and a novel experimental clot that is similar in histologic characteristics to the thromboemboli recovered from patients with stroke (fibrin-rich clot), were prepared. Eight extracranial arteries in swine were occluded with erythrocyte-rich clot (group A), and 8 were occluded with fibrin-rich clot (group B), and MT by using the Merci clot retriever device was performed. Angiographic results in each group were evaluated. RESULTS: A total of 48 attempts at MT were made. The average number of attempts to achieve TIMI grade II or III recanalization was 2.75 times in group A and 4.5 times in group B (P < .001), respectively. The mean time to achieve recanalization was 15.5 minutes in group A and 81.5 minutes in group B (P < .01). Every vessel in group A showed recanalization (100%), whereas only 3 of 8 samples (37.5%) achieved recanalization in group B. CONCLUSIONS: In this model, arteries occluded by fibrin-rich clot demonstrated a significantly lower recanalization rate, lower final TIMI score, and a longer mean recanalization time than did arteries occluded by erythrocyte-rich clot. The angiographic outcome of MT by using the Merci clot retriever system was influenced by the histologic characteristics of the occluding thromboembolus.

Partial recanalization of concomitant internal carotid-middle cerebral arterial occlusions promotes distal recanalization of residual thrombus within 24 h.

OBJECTIVES: Acute, simultaneous, concomitant internal carotid artery (ICA) and middle cerebral arteries (MCA) occlusions almost invariably lead to significant neurological disability if left untreated. Endovascular therapy is frequently the method of treatment in such situations but there remains a chance of incomplete recanalization. Successful recanalization of the proximal aspect of the occlusion may allow for endogenous thrombolysis and facilitate further endogenous recanalization of any residual MCA occlusion. METHODS: Consecutive patients with acute ischemic stroke undergoing endovascular therapy for tandem extracranial ICA-MCA or contiguous intracranial ICA-MCA occlusions were retrospectively analyzed. Rates of facilitated endogenous recanalization at 24 h (FER(24)) were compared by imaging within the immediate post-intervention 5-24 h period in those with proximal recanalization and in those without. RESULTS: 17 patients were included in the analysis. 12 patients had good initial proximal recanalization but a residual partial or total occlusion of the MCA while five patients failed any recanalization. Seven patients (58.3%) in the first group and none in the second had FER(24) on interval imaging after intervention (p=0.04). The probability of death and disability at discharge was less in patients with FER(24) than those without (p=0.05). CONCLUSIONS: More than half of all patients who present with both ICA and MCA occlusions who are only partially recanalized will undergo facilitated endogenous recanalization within the subsequent 24 h following intervention.

Wall shear stress distribution inside growing cerebral aneurysm.

BACKGROUND AND PURPOSE: Hemodynamic stimulation has been suggested to affect the growth of cerebral aneurysms. The present study examined the effects of intra-aneurysmal hemodynamics on aneurysm growth. MATERIALS AND METHODS: Velocity profiles were measured for 2 cases of AcomA aneurysms. Realistically shaped models of these aneurysms were constructed, based on CT angiograms. Flow fields and WSS in the models were measured by using particle image velocimetry and LDV. In 1 case, hemodynamic changes were observed in 4 stages of growth over a 27-month period, whereas no development was observed in the other case. RESULTS: The growing model had a smaller and more stagnant recirculation area than that in the nongrowth model. The WSS was markedly reduced in the enlarging region in the growing models, whereas extremely low WSS was not found in the nongrowth model. In addition, a higher WSSG was consistently observed adjacent to the enlarging region during aneurysm growth. CONCLUSIONS: The results indicated that the flow structure of recirculation itself does not necessarily lead to high likelihood of cerebral aneurysm. However, WSSG and WSS were distinctly different between the 2 cases. Higher WSSG was found surrounding the growing region, and extremely low WSS was found at the growing region of the growing cerebral aneurysm.

3D quantitative evaluation of atherosclerotic plaque based on rotational angiography.

BACKGROUND AND PURPOSE: Atherosclerosis is a systemic disease that has been shown to cause various cardiovascular diseases and stroke. However, technologies to evaluate the volume of atherosclerotic plaque are limited. We present a method for determination of 3D plaque volume based on RA. MATERIALS AND METHODS: 3DRA images obtained from patients were used to evaluate the plaque. Six patients who were diagnosed with atherosclerotic lesions were included. The PR model developed for 3DRA was applied to analyze the geometry of the vessel and calculate the plaque volume. To validate the present method, we tested computer-generated phantoms with different degrees of stenosis. RESULTS: Application of PR to clinical cases allowed the estimation of plaque morphology and quantification of plaque volume. Technique validation showed that on average, PR can rebuild 92% of the plaque and provide satisfactory determination of plaque volume. CONCLUSIONS: A new approach to obtain plaque volume based on 3DRA is presented. The initial tests in 6 clinical cases and validation with different phantoms showed that this method is feasible. Further validation in a larger clinical series is required to assess the ultimate value of the present technique.

Endovascular management of anterior cranial fossa dural arteriovenous malformations. A technical report and anatomical discussion.

Dural arteriovenous fistulas (dAVFs) of the anterior cranial fossa have traditionally been treated by open surgical disconnection. Safe navigation through the ophthalmic artery or fragile cortical veins has historically provided a barrier to effective endovascular occlusion of these lesions. Using current microcatheter technology and embolic materials, safe positioning within the distal ophthalmic artery, beyond the origin of the central retinal artery, is achievable. We describe two cases in which anterior cranial fossa dAVFs were treated by exclusively endovascular strategies, and highlight the pertinent technical and anatomic considerations. We discuss the clinical symptoms resulting from the differing venous drainage patterns.

The risk of acute radiocontrast-mediated kidney injury following endovascular therapy for acute ischemic stroke is low.

BACKGROUND AND PURPOSE: Endovascular therapy is an alternative for the treatment of AIS resulting from large intracranial arterial occlusions that depends on the use of iodinated RCM. The risk of RCM-mediated AKI following endovascular therapy for AIS may be different from that following coronary interventions because patients may not have identical risk factors. MATERIALS AND METHODS: All consecutive patients with large-vessel AIS undergoing endovascular therapy were prospectively recorded. We recorded the baseline kidney function, and RCM-AKI was assessed according to the AKIN criteria at 48 hours after RCM administration. We compared the rate of RCM-AKI 48 hours after the procedure and sought to determine whether any preexisting factors increased the risk of RCM-AKI. RESULTS: We identified 99 patients meeting inclusion criteria. The average volume of contrast was 189 ± 71 mL, and the average creatinine change was -4.6% at 48 hours postangiography. There were 3 patients with RCM-AKI. Although all 3 patients died as a result of their strokes, return to baseline creatinine levels occurred before death. There was a trend toward higher rates of premorbid diabetes mellitus, chronic renal insufficiency, preadmission statin and NSAID use, and a higher serum creatinine level on admission for the RCM-AKI group. The volume of procedural contrast was similar between groups (those with and those without RCM-AKI) (P = .5). CONCLUSIONS: In this small study, the rate of RCM-AKI following endovascular intervention for AIS was very low. A much larger study is required to determine its true incidence.

Higher rates of mortality but not morbidity follow intracranial mechanical thrombectomy in the elderly.

BACKGROUND AND PURPOSE: Mechanical thrombectomy is a promising means of recanalizing acute cerebrovascular occlusions in certain situations. We sought to determine if increasing age adversely affects prognosis. MATERIALS AND METHODS: We reviewed all Merci thrombectomy cases and compared patients younger than 80 years of age with older individuals. We compared these 2 age groups with respect to recanalization rates, hospital LOS, hemorrhagic transformation, and death and disability on discharge. RESULTS: Elderly patients were more likely to die from their stroke than those younger than 80 years of age, regardless of recanalization success (48% versus 15%; OR, 5.5; 95% CI, 2.1-14.1). Among survivors, there was no difference in the probability of having a good functional outcome (mRS,

A novel method of thrombus preparation for use in a swine model for evaluation of thrombectomy devices.

We report the development of a novel technique of thrombus preparation for use in a swine model for evaluation of thrombectomy devices. The experimental thrombus prepared using plain sedimentation showed mechanical stability due to its solid fibrin-rich component. The thrombus also showed histologic similarity to the typical thromboemboli recovered from patients with stroke in the course of therapeutic thrombectomy. This new technique may be beneficial for preclinical evaluation of thrombectomy devices.

Recanalization rates decrease with increasing thrombectomy attempts.

BACKGROUND AND PURPOSE: Use of the Merci retriever is increasing as a means to reopen large intracranial arterial occlusions. We sought to determine whether there is an optimum number of retrieval attempts that yields the highest recanalization rates and after which the probability of success decreases. MATERIALS AND METHODS: All consecutive patients undergoing Merci retrieval for large cerebral artery occlusions were prospectively tracked at a comprehensive stroke center. We analyzed ICA, M1 segment of the MCA, and vertebrobasilar occlusions. We compared the revascularization of the primary AOL with the number of documented retrieval attempts used to achieve that AOL score. For tandem lesions, each target lesion was compared separately on the basis of where the device was deployed. RESULTS: We identified a total of 97 patients with 115 arterial occlusions. The median number of attempts per target vessel was 3, while the median final AOL score was 2. Up to 3 retrieval attempts correlated with good revascularization (AOL 2 or 3). When >or=4 attempts were performed, the end result was more often failed revascularization (AOL 0 or 1) and procedural complications (P = .006). CONCLUSIONS: In our experience, 3 may be the optimum number of Merci retrieval attempts per target vessel occlusion. Four or more attempts may not improve the chances of recanalization, while increasing the risk of complications.

Resultados perioperatorios y sobrevida alejada de la pancreatoduodenectomía con resección vascular / Pancreaticoduodenectomy with vascular resection: perioperative results and long-term survival

Background: Pancreaticoduodenectomy (PDD) with vascular resection (VR) of the portal and superior mesenteric vein for locally advanced periampullary tumors is controversial. Aim: To evaluate the perioperative results and long-term survival of PDD with VR. Patients and Methods: Retrospective study. We included patients with periampullary tumors who underwent a PDD with VR between 1990 and 2008. We compared perioperative results and long-term survival with PDD without VR during the same period. We compared survival with non resected patients. Results: One hundred and eighty eight patients underwent a PDD, a VR was performed in 8 (4 percent) patients (Age: 58 +/- 14 years, Male: 4). Morbidity for PDD with and without VR was 75 percent and 59 percent (p = ns). Surgical mortality for PDD with and without VR was 0 percent and 8 percent (p = ns). In 6 of 8 patients the diagnosis was pancreatic cancer and histopathologic confirmation of vascular invasion was present in 4 patients. Long-term survival for patients with PDD with and without VR was similar (median 25 and 16 months; p = ns). Survival for patients with PDD with VR was superior to non resected patients (median 25 and 3 months; p = 0.0001). Conclusions: PDD with VR has similar perioperative results and long-term survival to PDD without VR. The survival reached with this type of surgery is far superior to non resected patients.

Introducción: La pancreatoduodenectomía (PDD) con resección vascular (RV) cuando existe invasión de la vena porta o mesentérica superior (VP-VMS) es controversial. Objetivo: Evaluar los resultados del perioperatorio y la sobrevida alejada de los pacientes sometidos a esta técnica. Material y Método: Estudio retrospectivo que incluyó a los pacientes con un tumor periampular en quienes se realizó una PDD con RV entre 1990 y 2008. Se compararon los resultados del perioperatorio y de sobrevida alejada con el grupo sometido a una PDD sin RV durante el mismo período. Se comparó también la sobrevida con los pacientes no resecados. Resultados: Se realizaron 188 PDD, en 8 (4 por ciento) de estos pacientes se realizó PDD con RV (Edad: 58 +/- 14 años, Hombres: 4). La morbilidad postoperatoria para la PDD con y sin RV fue de 75 por ciento y 59 por ciento (p = ns). La mortalidad postoperatoria para los grupos con y sin RV fue de 0 por ciento y 8 por ciento (p = ns). En 6 de los 8 pacientes el diagnóstico fue cáncer de páncreas y en 4 se confirmó histopatológicamente la invasión de VP-VMS. La sobrevida del grupo con y sin RV no tuvo diferencia significativa (medianas 25 y 16 meses; p = ns). La sobrevida de los pacientes sometidos a una PDD con RV fue superior a los pacientes no resecados (medianas 25 y 3 meses; p = 0,0001). Conclusiones: La PDD con RV obtiene resultados perioperatorios y de sobrevida alejada comparables a una PDD sin RV. La sobrevida alcanzada con esta técnica es ampliamente superior a la de los pacientes no resecados.

Quantitative hemodynamic analysis of brain aneurysms at different locations.

BACKGROUND AND PURPOSE: Studies have shown that the occurrence of brain aneurysms and risk of rupture vary between locations. However, the reason that aneurysms at different branches of the cerebral arteries have different clinical presentations is not clear. Because research has indicated that aneurysm hemodynamics may be one of the important factors related to aneurysm growth and rupture, our aim was to analyze and compare the flow parameters in aneurysms at different locations. MATERIALS AND METHODS: A total of 24 patient-specific aneurysm models were constructed by using 3D rotational angiographic data for the hemodynamic simulation. Previously developed computational fluid dynamics software was applied to each aneurysm to simulate the blood-flow properties. Hemodynamic data at peak pulsatile flow were recorded, and wall shear stress (WSS) and flow rate in the aneurysms and parent arteries were quantitatively compared. To validate our method, a comparison with a previously reported technique was also performed. RESULTS: WSS and flow rate in the aneurysms at the peak of the cardiac cycle were found to differ in magnitude between different locations. Multiple comparisons among locations showed higher WSS and flow rate in middle cerebral artery aneurysms and lower WSS and flow rate in basilar artery and anterior communicating artery aneurysms. CONCLUSIONS: We observed changes in hemodynamic values that may be related to aneurysm location. Further study of aneurysm locations with a large number of cases is needed to test this hypothesis.