UNIVERSIDADE ESTADUAL DE CAMPINAS FACULDADE DE...
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UNIVERSIDADE ESTADUAL DE CAMPINAS FACULDADE DE CIÊNCIAS MÉDICAS LEONARDO ABDALA GIACOMINI RECONSTRUÇÃO NEUROVASCULAR COM STENTS DIVERSORES DE FLUXO NO TRATAMENTO DE ANEURISMAS E DISSECÇÕES ARTERIAIS NEUROVASCULAR RECONSTRUCTION WITH FLOW DIVERTER STENTS IN THE TREATMENT OF ANEURYSMS AND DISSECTION Campinas 2015
Transcript of UNIVERSIDADE ESTADUAL DE CAMPINAS FACULDADE DE...
UNIVERSIDADE ESTADUAL DE CAMPINAS
FACULDADE DE CIÊNCIAS MÉDICAS
LEONARDO ABDALA GIACOMINI
RECONSTRUÇÃO NEUROVASCULAR COM
STENTS DIVERSORES DE FLUXO NO
TRATAMENTO DE ANEURISMAS E DISSECÇÕES
ARTERIAIS
NEUROVASCULAR RECONSTRUCTION WITH FLOW
DIVERTER STENTS IN THE TREATMENT OF
ANEURYSMS AND DISSECTION
Campinas 2015
LEONARDO ABDALA GIACOMINI
RECONSTRUÇÃO NEUROVASCULAR COM
STENTS DIVERSORES DE FLUXO NO
TRATAMENTO DE ANEURISMAS E DISSECÇÕES
ARTERIAIS
NEUROVASCULAR RECONSTRUCTION WITH FLOW
DIVERTER STENTS IN THE TREATMENT OF
ANEURYSMS AND DISSECTION
Dissertação de Mestrado apresentada à Faculdade de Ciências Médicas da
Universidade Estadual de Campinas como parte dos requisitos exigidos
para obtenção do título de Mestre em Ciências Médicas, área de
concentração em Neurologia.
Master dissertation submitted to the State University of Campinas School
of Medical Sciences as part of the requirements for obtaining the title of
master degree in Medical Sciences, neurology area.
Orientador: Prof. Dr. Helder Tedeschi
Co-orientação: Dr. Andrei F. Joaquim
Este exemplar corresponde à versão final da tese defendida pelo aluno Leonardo Abdala Giacomini e orientada pelo Prof. Dr. Helder Tedeschi
Campinas
2015
BANCA EXAMINADORA DA DEFESA DE MESTRADO LEONARDO ABDALA GIACOMINI
ORIENTADOR: HELDER TEDESCHI
COORIENTADOR: ANDREI FERNANDES JOAQUIM
MEMBROS:
1. PROF. DR. HELDER TEDESCHI
2. PROF. DR. ENRICO GHIZONI
3. PROF. DR. ROBERTO SERGIO MARTINS
Programa de Pós-graduação em Ciências Médicas da de Ciências Médicas da
Universidade Estadual de Campinas. A ata de defesa com as respectivas assinaturas
dos membros da banca examinadora encontra-se no processo de vida acadêmica do
aluno.
Data: DATA DA DEFESA [02/10/2015]
Dedico,
À minha esposa Paula, por sempre acreditar em mim e me incentivar em cada passo
da vida;
Ao meu pai Marco Aurélio e à minha mãe Nazira que sempre estiveram na torcida de
cada etapa de minha vida.
Agradecimentos,
Ao Prof. Dr. Helder Tedeschi, por abrir o mundo fascinante da neurocirurgia para
mim;
Ao Dr. Enrico Ghizoni, pelos ensinamentos sobre respeito e paciência durante as
cirurgias;
Ao Dr. Andrei Joaquim, pelo incentivo para o crescimento cientifico;
Ao Dr. Ronie Piske, pela ajuda e incentivo para escrever essa tese.
RESUMO
Introdução: Os stents diversores de fluxo representam uma nova opção terapêutica
no tratamento endovascular de aneurismas intracranianos complexos, como aqueles
grandes, gigantes, de colo largo ou fusiformes. A redução do fluxo de entrada e de
saída do aneurisma é o ponto chave das modificações hemodinâmicas causadas pelos
stents diversores de fluxo, resultando na trombose intraluminal do aneurisma, além de
servir como aparato para proliferação da camada neoíntima do vaso relacionado ao
aneurisma, levando ao seu remodelamento.
Método: Avaliação retrospectiva de 77 pacientes com 87 aneurismas submetidos ao
tratamento endovascular com dois tipos de stents diversores de fluxo (Pipeline
Embolization Device e SILK) em um centro de neuroradiologia intervencionista em
São Paulo, entre outubro de 2010 e setembro de 2013.
Resultados: Os stents diversores de fluxo foram aplicados com sucesso em 98% dos
casos levando a uma imediata estase de contraste na maioria das lesões. A taxa total
de oclusão após seguimento de 6 meses e 18 meses respectivamente foi de 80% e
84% respectivamente. A taxa de oclusão de aneurismas saculares, pequenos não
previamente tratados foi de 100%. Complicações sintomáticas ocorreram em 11
pacientes (14,3%), com morbidade em 8 (10,4%) e mortalidade em 3 (3,9%)
pacientes.
Conclusão: O uso de stent diversor de fluxo foi efetivo para o tratamento de
aneurismas intracranianos com boa taxa de oclusão e morbidade aceitável. Houve
grande sucesso do mesmo em aneurismas saculares pequenos. Estudos prospectivos
desenhados para avaliar as indicações mais precisas bem como as taxas de
recanalização e oclusão em longo prazo são necessários.
Palavras-chave: Aneurismas. Endovascular. Stents diversores de fluxo. Pipeline,
SILK.
ABSTRACT
Background: Flow diverter stents represent a new endovascular tool for treating
complex aneurysms, such as giant, large, wide necked and fusiform. The high dense
mash of these stents reduces inflow and outflow inside the aneurysm, resulting in
intra aneurysmal thrombosis and stent endothelialization.
Objectives: to present the results of the treatment of intracranial aneurysms with flow
diverter stents in a single center.
Methods: Retrospective review of 77 patients with 87 aneurysms treated using two
different types of flow diverter stents: the pipeline embolization device and the SILK
stent, between October 2010 and September 2013 in an interventional neuroradiology
center.
Results: Flow diverter stents placement was successful in 98% of the lesions and
resulted in an immediate major stasis within most of the treated aneurysms. The
overall aneurysm occlusion rate at 6-month and 18-month was 80% and 84%
respectively. Symptomatic complications occurred in 11 patients (14,3%) with
morbidity in 8 (10,4%) and mortality in 3 patients (3,9%).
Conclusion: Flow diversion is a promising technique for the treatment of challenging
intracranial aneurysms with acceptable morbidity. A high rate of complete occlusion
for small large-necked aneurysms, a low morbidity and mortality rate and no
recanalization encourage their use in these aneurysms. Further studies accessing long-
term aneurysm occlusion and recanalization are required.
Keywords: Aneurysm. Endovascular. Flow diverter stent, Pipeline, SILK
FIGURAS
Figure 1. Seventy-one year old female, presented with mild visual loss. (a) Initial
angiography showing an ophthalmic segment and a superior hypophyseal aneurysm.
(b) A 4.5 mm x 30 mm SILK device was applied, incorporating both aneurysms. (c)
Immediate occlusion of the superior hypophyseal aneurysm was observed.
Figure 2. Sixty-three years old male, presenting with visual impairment. Pre-treatment
(A) angiography shows a 15.3 mm carotid ophthalmic aneurysm. B. Six-month follow
up shows a complete occlusion of the aneurysm, preserving the ophthalmic artery’s
patency. The patient’s visual impairment improved post treatment.
Figure 3. Seventy-four years old female, presenting with a long-term headache. A:
MRI shows a 40 mm left middle cerebral artery (MCA) partially thrombosed
aneurysm. (b)–(f) Left internal carotid artery (ICA) pre treatment: a slow flow distally
from the aneurysm is observed, compared with the anterior cerebral artery flow. (g)–
(j) Left ICA post treatment. A significant change in the MCA flow distally from the
aneurysm. (k) A computed tomography (CT) scan was performed after the procedure.
The Pipeline Embolization Device and contrast material inside the aneurysm with no
bleeding are observed. (l) Two days after procedure, CT demonstrating a large
intraparenchymal hematoma far from the aneurysm. The hematoma was promptly
drained; however, the patient died in the third day post procedure. (m) Radiography
showing the stent and contrast inside the aneurysm.
TABELAS
Table 1. Clinical presentation at admission.
Table 2. Aneurysms location.
Table 3. The results stratified by type of aneurysm.
Table 4. Modified Rankin Scale pretreatment, at discharge and at six months
follow up.
LISTAS DE SIGLAS E ABREVIATURAS
ISAT International Subarachnoid Aneurysm Trial
FDS Flow Diverter Stent
PED Pipeline Embolization Device
DSA Digital Subtraction Angiography
ASA Acetylsalicylic Acid
MRA Magnetic Resonance Angiography
mRS Modified Rankin Scale
ICA Internal Carotid Artery
IPH Intraparenchymal Hemorrhage
MCA Middle Cerebral Artery
SUMÁRIO
1-INTRODUÇÃO .........................................................................................................1
2-OBJETIVOS………………….……………………………………………………..5
3-METODOLOGIA…………………………………………………………………...6
4-RESULTADOS – ARTIGO………………………………………………………...7
5-DISCUSSÃO GERAL …………………………………………………………….21
6-CONCLUSÃO .........................................................................................................24
7-REFERÊNCIAS........................................................................................................25
8-ANEXOS…………………………………………………………………………..28
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INTRODUÇÃO
Desde a publicação do International Subarachnoid Aneurysm Trial (ISAT)1
, o
manejo dos aneurismas intracranianos mudou significativamente. O tratamento
endovascular com coils (micro molas metálicas) de aneurismas saculares com colo
favorável é um procedimento seguro, e eficiente utilizado amplamente. Entretanto,
para aneurismas complexos, como os de colo largo, grandes, gigantes ou fusiformes
existe uma dificuldade técnica significativa para a embolização com o uso de coils
com baixas taxas de oclusão e taxas de recorrências que chegam a 80% dos casos2,3
.
Os stents diversores de fluxo (SDF) surgem como uma nova ferramenta para o
remodelamento vascular e oclusão desses aneurismas. A redução dos fluxos de
entrada e de saída dentro do aneurisma é o ponto chave das alterações hemodinâmicas
propiciadas pelos SDF, resultando na trombose intraluminal do aneurisma4
. Além
disso os stents funcionam como um aparato para proliferação da camada neoíntima do
vaso relacionado ao aneurisma, levando ao seu remodelamento. O tempo necessário
para ocorrer a oclusão do aneurisma permanece desconhecido, assim como a taxa de
oclusão tardia. Vários fatores individuais podem influenciar na taxa de oclusão, como
o tamanho, a localização, a morfologia, a geometria da artéria aferente, os parâmetros
de coagulação e o tipo de stent diversor de fluxo5
.
O primeiro SDF comercialmente disponível foi o stent SILK (Balt Extrusion,
Montmorency, France), que é um dispositivo de 48 aros de níquel e titânio com 4
marcadores de platina6
. Posteriormente, em 2011 foi desenvolvido o Pipeline
Embolization Device (Ev3, Irvine, CA, USA), com 48 aros individuais de cobalto,
cromo e platina7
. Esses dispositivos apresentam entre 30 a 35% de superfície metálica
quando estão abertos.
Dado ao potencial promissor dos SDF no manejo dos aneurismas complexos
avaliamos retrospectivamente os resultados de pacientes tratados com SDF do tipo
SILK ou Pipeline Embolization Device em um centro de neuroradiologia
intervencionista, considerando a taxa de oclusão dos aneurismas, os resultados
clínicos e as complicações.
19
Os stents diversores de fluxo, desenvolvidos a partir de 2007 com o SILK
stent (Balt Extrusion, Montmorency, France) e em 2011 com o Pipeline Embolization
Device (Ev3, Irvine, CA, USA) 6,7
, apresentaram-se como uma nova ferramenta
endovascular no tratamento de aneurismas que não possuíam uma boa resposta às
outras técnicas endovasculares presentes à época. Os aneurismas complexos, como os
de colo largo, grandes, gigantes ou fusiformes apresentam uma dificuldade técnica
significativa para o tratamento além de altas taxas de recorrências com a embolização
por coils 2,3
. Essas lesões habitualmente cursam com efeito de massa promovendo a
compressão de estruturas neurais ao seu redor, a exemplo os nervos cranianos.
A embolização de aneurismas intracranianos por coils foi a grande ferramenta
endovascular nos últimos 20 anos a partir do seu desenvolvimento por Guglielmi1
. A
oclusão completa, com a redução da pulsatilidade da lesão, pode ser apenas realizada
quando há a completa passagem de coils, entretanto em aneurismas de colo largo isso
se torna tecnicamente difícil e, as vezes, impossível8. O uso de Onyx (Micro
Therapeutics, Inc., Irvine, CA) HD, que é um material embólico líquido, reduz o
efeito de massa em alguns casos, atingindo uma taxa de oclusão de 80% para
aneurismas grandes e de apenas 50% para aneurismas gigantes9. Os stents diversores
de fluxo, como o nome sugere, divergem o fluxo sanguíneo dos aneurismas,
reduzindo o estresse mecânico na parede da lesão e promovendo a sua trombose. A
intensidade da redução do fluxo dentro da lesão depende da porosidade e da superfície
metálica do aparato10.
A partir de 2011 começaram a surgir estudos com o uso dos stents diversores
de fluxo em grandes centros de tratamento endovascular4,11-18. Os pacientes
selecionados para o tratamento, possuíam lesões com contra indicações relativas ou
absolutas para a embolização com coils, assistidos ou não com stents, como
aneurismas gigantes (>25mm), aneurismas de colo largo (>4mm), aneurismas com
relação domus/colo <1,5 a 2, aneurismas fusiformes, dissecções arteriais e aneurismas
com tratamento prévio sem sucesso4,11,15-18. Pelo fato do efeito biológico dos stents
diversores de fluxo não ser imediato, os aneurismas tratados foram os não rôtos.
A taxa de oclusão nas grandes séries foi extremamente variável, entre 52% e
93%4,11-18 no seguimento de 6 meses após o tratamento. Talvez o dado mais
importante é o fato da taxa de oclusão aumentar ao longo do seguimento, como
20
demonstrando por O’Kelly et al em um estudo Canadense onde descreveram uma
taxa de oclusão de 65% em 6 meses, seguida por oclusão de 90% em 12 meses em 97
aneurismas tratados com stents diversores de fluxo11. Um seguimento mais longo é
necessário para avaliar a real taxa de oclusão dessas lesões15,17.
Pelo fato dos stents diversores de fluxo não promoverem a imediata oclusão
dos aneurismas, as séries foram realizadas selecionando-se lesões não rôtas e
consequentemente a maioria dos pacientes avaliados foram diagnosticados de forma
incidental. Isso explica o fato da maioria dos estudos terem como foco apenas na taxa
de oclusão e complicações do uso de stents em detrimento do status neurológico
anterior e posterior ao tratamento. A exceção seriam os aneurismas não rôtos que por
sua localização e tamanho promovessem a compressão de estruturas neurais
adjacentes como os nervos cranianos. No estudo ISAT os aneurismas que promoviam
compressão de nervos cranianos eram excluídos do tratamento com embolização por
coils, por existir evidência de piora da compressão sintomática após o seu uso,
principalmente relacionada ao nervo óptico 1. Sahlein DH et al, avaliaram 39
pacientes com compressão de nervo/quiasma óptico (com avaliação por campimetria)
por aneurismas não rôtos de segmento cavernoso ou oftálmico. Após o uso de stents
diversores de fluxo obtiveram 64% de melhora objetiva após o tratamento, resultados
esses, não vistos em outras métodos de tratamento endovascular24.
As complicações relacionadas ao tratamento são divididas em complicações
isquêmicas e hemorrágicas. A taxa de formação de hematomas intraparenquimatosos
varia entre 0% e 8,5%4,11,12,15,19,21. Em publicações recentes, a incidência parece ser
maior em comparação ao pacientes tratados com uso de coils concomitante com stents
comuns. A coorte de 284 paciente tratados com stent Neuroform (Boston Scientific,
Natick, Massachusetts) demonstrou uma taxa de 1,1% (3/284) de hematomas
intraparenquimatosos após o tratamento23. Essa taxa é similar ao uso de anti-
agregação plaquetária dupla em pacientes com prevenção secundária de acidentes
vasculares cerebrais. Esses dados em conjunto sugerem que o hematomas
intraparenquimatosos após o procedimento são um fenômeno associado aos stents
diversores de fluxo21.
As complicações isquêmicas são em sua grande maioria relacionadas à
oclusão de artérias perfurantes, fato esse visto de forma mais evidente em aneurismas
fusiformes e de circulação posterior. Phillips TJ et al em uma série de 32 aneurismas
21
de circulação posterior apresentaram uma taxa de 14% de isquemia sintomática em
pacientes submetidos ao tratamento por stents diversores de fluxo25.
22
OBJETIVOS
• Objetivo primário
Avaliação da eficácia (taxa de oclusão) e da segurança (efeitos adversos e
complicações) dos stents diversores de fluxo como uma ferramenta endovascular no
tratamento de aneurismas complexos
• Objetivos secundários
Determinar os fatores associados à resposta ao tratamento
Identificar os aneurismas com a melhor e a pior respostas ao uso de stents
diversores de fluxo
23
METODOLOGIA
Análise retrospectiva dos pacientes com diagnóstico de aneurisma ou
dissecções intracranianas tratados com dois diferentes tipos de stent diversor de fluxo
(pipeline embolization device e SILK) entre outubro de 2010 e setembro de 2013 em
um centro único de neuroradiologia intervencionista no Hospital Beneficência
Portuguesa de São Paulo.
24
ARTIGO
ARTIGO ORIGINAL EM REVISTA
Interventional Neuroradiology
Interv Neuroradiol. 2015 Jun;21(3):292-9.
ISSN 1591-0199
Neurovascular reconstruction with flow diverter stents for the treatment of 87 intracranial aneurysms: Clinical
results
Leonardo Giacomini1, MD; Ronie Leo Piske2, MD, PhD; Carlos Eduardo
Baccin3, MD; Marcelo Barroso4, MD; Andrei Fernandes Joaquim5, MD, PhD;
Helder Tedeschi6, MD, PhD;
1- Post-Graduation Neurosurgeon– Universidade Estadual de Campinas
(UNICAMP), Campinas, SP, Brazil
2- Director Interventional Neuroradiologist - Centro de NeuroAngiografia (CNA),
Hospital Beneficencia Portuguesa de Sao Paulo, SP. Brazil.
3- Interventional Neuroradiologist - Centro de NeuroAngiografia (CNA), Hospital
Beneficencia Portuguesa de Sao Paulo,SP, Brazil
4- Post-Graduation Neurosurgeon - Centro de NeuroAngiografia (CNA), Hospital
Beneficencia Portuguesa de Sao Paulo, SP, Brazil
5- Neurosurgeon – Universidade Estadual de Campinas (UNICAMP), Campinas, SP,
Brazil
6- Professor of Neurosurgery – Universidade Estadual de Campinas (UNICAMP),
Campinas, SP, Brazil
Corresponding adress: Rua Arruda Alvim 423, apt 153. São Paulo, São Paulo, Brazil.
Zip code 05410020. Work Telephone Number +55 11 985588280 E-mail:
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Abstract
Background: Flow diverter stents represent a new endovascular tool to treat complex
aneurysms, such as giant, large, wide- necked and fusiform. The highly dense mash of
these stents reduces inflow and outflow inside the aneurysm, resulting in intra
aneurysmal thrombosis and stent endothelialization.���
Objectives: To present the results of treatment of intracranial aneurysms with flow
diverter stents in a single center.
Methods: Retrospective review of 77 patients with 87 aneurysms treated using two
different types of flow diverter stent, the Pipeline Embolization Device and SILK
stent, between October 2010 and September 2013 in an interventional neuroradiology
center.���
Results: Flow diverter stent placement was successful in 98% of the lesions and
resulted in an immediate major stasis within most of the treated aneurysms. The
overall aneurysm occlusion rate at six months and 18 months was 80% and 84%
respectively. Symptomatic complications occurred in 11 patients (14.3%) with
morbidity in eight (10.4%) and mortality in three patients (3.9%).���
Conclusion: Flow diversion is a promising technique for treatment of challenging
intracranial aneurysms with acceptable morbidity. A high rate of complete occlusion
for small large necked aneurysms, a low morbidity and mortality rate and no
recanalization encourage their use in these aneurysms. Further studies accessing long-
term aneurysm occlusion and recanalization are required.
26
Introduction
Since the publication of the International Subarachnoid Aneurysm Trial
(ISAT), management of intracranial aneurysms has changed significantly.1
Endovascular treatment with coiling of saccular aneurysm with a favorable neck has
been acceptable as a safe and efficient procedure. However, complex aneurysms, such
as large and giant ones, wide-necked and fusiform aneurysms, remains technically
challenging for coiling, with a low occlusion and high recurrence rate of up to 80%.2,3
The advent of flow diverter stents (FDSs) brings a new endovascular tool for
reconstructive treatment and vascular remodeling for these challenging aneurysms.
Two proprieties of the FDS are new in treatment of aneurysms. The highly dense
mash of the FDS reduces inflow and outflow on the aneurysm, resulting in intra
aneurysmal thrombosis.4 The device works as a scaffold for strong neointimal
proliferation resulting in remodeling the parent artery and curing the neck. The time
course of the intra aneurysmal thrombosis remains unclear, as well as long-term
occlusion recanalization rates. Many individual factors may influence complete
occlusion, such as aneurysm size, location and morphology, parent vessel geometry,
blood coagulation parameters, previously regular stent use as well as the type of flow
diversion and resulting flow changes.5
The first FDS commercially available was the SILK stent (Balt Extrusion,
Montmorency, France) in 2007, a braided device with 48 high-attenuation nickel and
titanium alloy wires with four platinum markers.6 Later, the Pipeline Embolization
Device (PED) (Ev3, Irvine, CA, USA) was developed, a cylindrical mesh device
composed of 48-braided individual cobalt chromium and platinum strands.7 The
device has about 30% to 35% metal surface area coverage when fully deployed. The
safety of flow diversion stents and their reliability as a permanent cure are yet to be
determined.
In this study, we present a single center series of 77 consecutive patients with
87 intracranial vascular lesions treated with SILK or PED, describing early results,
clinical outcome and complications.
27
Material and Methods
Study design
We performed a retrospective review of patients treated using two different
types of FDS, the PED and the SILK device, from October 2010 to September 2013
in a single interventional neuroradiology center (Hospital Beneficência Portuguesa) in
Sao Paulo, Brazil.
Indications for treatment with FDS were wide-necked aneurysms (neck > 4
mm) or a domus-to-neck ratio <2, large and giant aneurysms, high likelihood of
failure with conventional endovascular or surgical techniques, remnants of aneurysms
after surgical or endovascular treatment, partially thrombosed aneurysms, fusiform
aneurysms, and dissected vessels. The decision between each FDS in individual cases
was based on clinical and anatomical considerations. The SILK stent indications
were: similar diameter of pre and post segment of the artery (<1 mm of diameter
difference), parent artery diameter up to 5mm and a high likelihood to redeploy the
stent due to catheter instability. The PED indications were: parent artery with
different diameter of pre and post segment (>1mm of diameter difference), diameter
of parent artery <5mm and if stent shortening was not wanted.
Endovascular procedure
Procedures were performed on a biplane digital subtraction angiography
(DSA) unit (Philips Integris BV 5000).
All procedures were carried out under general anesthesia, using regular
techniques with a triaxial catheter system. Patients received a daily dose of 100 mg
acetyl-salicylic acid (ASA) and 75 mg of clopidogrel starting seven days prior to the
treatment. Clopidogrel assays were checked on all patients and platelet aggregation
was required to be lower than 30%. Four patients were found to be hyporesponders to
clopidogrel and were given Ticagrelor instead. Clopidogrel was maintained for the
next six months, and thereafter 100mg of ASA for 36 months.
Follow up
28
Each patient was scheduled for a DSA after six months. DSA was repeated at
18 and 36 months in the case of no occlusion. After complete occlusion, angiographic
image control was performed with magnetic resonance angiography (MRA) at 18 and
36 month after the treatment and then every three years. The DSA follow-up results
were classified as complete or incomplete aneurysmal occlusion. The incomplete
occlusion group was also divided into two groups: >95% occlusion group (near
complete occlusion) and <95% occlusion group (residual aneurysm).
Results
Clinical presentation and aneurysm morphology
A total of 77 patients (19 men and 58 women) with 87 aneurysms were
treated. The PED was used in 36 cases and the SILK device in 41 cases. The age of
patients ranged from 18 to 82 years old (mean of 52.5 years). Table 1 shows the
clinical presentation at admission.
The series comprises a total of 73 (84%) saccular aneurysms, eight (9%)
fusiform, three (4%) arterial dissections, two (2%) pseudoaneurysms and one carotid
segmental dysplasia (1%). Both pseudoaneurysms resulted from a carotid cavernous
iatrogenic injury during an endoscopic pituitary tumor resection.
A total of 76 (87%) treated lesions were located in the anterior circulation and
11 (13%) were located in the posterior circulation. Among the eight fusiform
aneurysms, six were located in the basilar artery, one in the cervical carotid segment
and one in the carotid cavernous segment. Table 2 shows the location of the
aneurysms.
Fifteen aneurysms had been treated previously: five with previous coiling; five
with coiling and stenting; four with Onyx and one with surgical clipping. Twenty-two
aneurysms (25%) were treated with coiling concomitant FDS deployment. The
number of FDSs used ranged from one to four, with one stent used in 68 (88%)
patients, two stents in eight (10%) and four stents in one (2%) patient.
The average diameter of 73 saccular aneurysms was 12.6mm (range from 1.8
to 40.0mm). Thirty aneurysms (41%) were small (<10mm), 32 (44%) were large (10
29
to 25mm) and 11 (15%) were giant (>25mm). The mean neck diameter of the
aneurysm was 5.14 mm (range from 1.4 to 16.0 mm). The mean domus-to-neck ratio
was 1.6 (range to 0.8 to 6.8). Both criteria (which classify the aneurysm as unsuitable
for treatment with coiling alone) were found in 70 of 73 saccular aneurysms. The
three lesions without these criteria were positioned in the carotid siphon making good
coil packing unlikely due to instability of the microcatheter.
Follow up
Immediate angiography following FDS deployment demonstrated major stasis
of contrast material in 82 aneurysms (94%). Four aneurysms (5%) had no flow
changes and one aneurysm (1%) had a complete occlusion – small, wide-neck,
superior hypophyseal aneurysm (Figure 1).
Table 3 shows the results for all lesions and also stratifies them by type and
size. A six-month DSA control was available in 66 patients (86%) with 75 aneurysms
(86%) and showed complete occlusion in 60 aneurysms (Figure 2) (80% occlusion
rate), near complete occlusion in six lesions (8%) and residual aneurysm in nine
(12%).
A second DSA follow-up was performed approximately 18 months (range
from 7 to 22 months) after the procedure in 14 patients with 14 lesions. Nine of them
were completely occluded aneurysms at the first DSA with no alteration at the second
DSA, three were near complete (all saccular aneurysms – two small and one giant)
and evolved to complete occlusion and two were classified as residual aneurysms
(both were saccular – one small and the other one large) and remain with residual
aneurysm. At 18 months post treatment control, 63 lesions were completely occluded
(84% – over-all rate of total occlusion).
A DSA follow-up was available in 10 of 15 saccular aneurysms previously
treated, with five complete occlusions (50%). We observed 55 completely occluded
aneurysms among 65 without previous treatment (85% occlusion rate).
In the saccular aneurysm group, DSA follow-up was available in 67 of the 73
aneurysms (92%), with 56 completely occluded lesions at six-month follow-up (84%
occlusion rate) and 59 completely occluded lesions at 18-month follow-up (88%
occlusion rate). The occlusion rate was 93% for small (26 of 28), 90% for large (26 of
30
29) and 70% for giant aneurysms (7 of 10) at 18-month follow-up. Considering the
previous untreated saccular aneurysms, the occlusion rate was 95% (54 of 57), with
100% for small (25 of 25), 96% for large (24 of 25) and 71% for giant aneurysms (5
of 7) at 18-month follow-up – see Table 3.
Of eight fusiform aneurysms, four performed a six- month DSA control with
one complete occlusion (25%). A DSA was also available in one of two
pseudoaneurysms (with complete occlusion), in two dissecting aneurysms (complete
occlusion on both lesions) and in the carotid dysplasia (incomplete occlusion).
Among the aneurysms treated concomitantly with FDS and coiling 20
performed a DSA control with 17 demonstrating a complete occlusion (85%).
Clinical outcome and complications
In Table 4, we present the clinical outcome, before and after treatment,
according to the Modified Rankin Scale (mRS).
Symptomatic complications occurred in 11 patients (14.3%) with morbidity in
eight patients (10.4%) and the mortality in three (3.9%). Hemorrhagic complications
occurred in five patients, all of them with large or giant aneurysms, four in the
anterior and one in the posterior circulation. The cause of bleeding was: secondary to
ischemic event in one, probably due to hyperperfusion in one (Figure 3), rupture of
other aneurysm (contralateral to the treated one) in one and unknown in two cases.
Ischemic complication occurred in four patients and was related to internal
carotid artery (ICA) and stent thrombosis in one case of large aneurysm (hemispheric
infarct and dead) and perforator occlusion in three, all of them in basilar fusiform
aneurysm.
Cranial nerve compression was the clinical presentation in 18 patients. After
the procedure, we observed an improvement in 10 cases, including optic nerve, III,
IV, V, VI and lower cranial nerves compression (Figure 2). No changes were
observed in six patients and two patients got worse.
Transient motor deficit was observed in four patients due to a thromboembolic
event. Those patients were treated with enoxaparin and volemic expansion, with a
good outcome.
31
Discussion
The advent of FDS offers a new endovascular therapeutic modality for the
treatment of challenging aneurysms such as large, giant and fusiform. Such
aneurysms often present with mass effect and corresponding compression syndrome
on the neighboring neural tissue. Aneurysm coiling has been the main endovascular
treatment modality for the past 20 years. Aneurysm occlusion and pulsation reduction
can only be achieved if completely sealed with coils; however, most of these lesions
have a wide neck, making complete occlusion unlikely, even impossible.8 The use of
Onyx HD (Micro Therapeutics, Inc., Irvine, CA, USA) reduces the mass effect in
some cases, but can induce new symptoms and reach a complete rate of occlusion of
80% in large and 50% in giant aneurysms.9 FDS, as the name suggests, diverts the
flow away from the aneurysm, reducing the shear stress on the aneurysm wall,
promoting stasis and thrombosis. The extent of intra aneurysmal flow depends on the
porosity and metal surface coverage.10
Angiographic findings
All lesions were successfully accessed in this series, and successful
deployment of the devices was achieved in all but one procedure (retreatment of a
giant wide-necked ophthalmic aneurysm previously treated with coil and stent. The
microcatheter did not distally progress the stent). O’Kelly et al. also demonstrated
failed distal progress of the microcatheter in two patients with wide-neck giant
aneurysms.11 An internal carotid occlusion was performed after the patient passed a
balloon test occlusion and tolerated the permanent vessel occlusion.
Immediately after the FDS deployment, a variable contrast stasis occurred in
all lesions. Although this observation is expected, it is unlikely at this time complete
aneurysm obliteration, considering the hemodynamic changes caused by FDSs12
(Figure 1).
At least one follow-up DSA was available in 66 patients (86%) with 75 lesions
(86%). As expected from a series of this size, some patients were lost to follow-up for
various reasons and nine patients (12%) did not complete the six-month period for the
32
first follow-up DSA. We had an 80% and 84% complete occlusion rate after six-
month and 18-month DSA, respectively. The occlusion rate in other series is
extremely variable raging from 52% to 93%.4,11–18
Considering the near complete occlusion cases, the occlusion rate in our study
is even higher (88%). Also, three aneurysms with near complete occlusion on the first
DSA improved to complete occlusion in the 18- month follow-up DSA. O’Kelly et al.
described a 65% complete occlusion and near complete occlusion after six-month
follow-up and 83% at 15 months in 97 aneurysms after PED treatment.11 There are no
available data about the rupture risk of a near complete occluded aneurysm treated
with FDS.
The identification of aneurysmal or procedural features predisposing complete
occlusion or persistent perfusion is not clear yet; however, there are some aspects that
could influence the final outcome, including the aneurysm morphology, porosity of
the FDS in the neck and presence of a branch rising from the aneurysm wall.
A complete occlusion rate improvement is observed depending on the type of
aneurysm. If only saccular aneurysms are considered we had 84% complete occlusion
rate for all lesions, 88% for all saccular aneurysms and 100% for small, not
previously treated lesions. Nelson et al., in a multicenter trial, had a 93% aneurysmal
occlusion on the six-month follow-up after treatment with PED of saccular
aneurysms.14 Thromboembolic and hemorrhagic complications occurred only in large
and giant lesions in our series. Complete occlusion occurred also in all
pseudoaneurysms and dissections.
Our series includes 15 lesions treated previously with conventional
techniques. At six-month DSA follow-up, 50% complete occlusion was observed in
that group compared with 85% with no previous treatment. McAuliffe et al
corroborate this observation, in an Australian multicenter prospective study.19 A six-
month occlusion rate of 92% was achieved in the group with no previous treatment
compared with 50% in the aneurysms previously treated with other endovascular
techniques. The presence of a previously deployed stent may reduce the biological
effect of a FDS, because the stent may affect the intimal changes that FDS is
purposed to make.12
A six-month DSA follow-up was available in seven of 11 posterior circulation
aneurysms, with an occlusion rate of 57% (four cases). Six patients had a fusiform
33
aneurysm (four with a DSA control, presenting one complete occlusion) and three
dissecting (both complete occlusion). These data suggest that the complete occlusion
of fusiform aneurysm is more difficult with FDS. Chalouhi et al. presented 42%
complete occlusion at six months in a small series of unruptured posterior circulation
aneurysms. Besides a lower occlusion rate, there is substantial morbidity and
mortality associated with the treatment of these lesions.20
Siddiqui et al., in a small series of seven patients with vertebro-basilar
fusiform aneurysms, reported four deaths, one patient severely disabled, and only two
patients with good outcome.18 Substantial morbidity and mortality associated with
few options of treatment and the natural history brings up the use of FDS as a
treatment option for fusiform aneurysm. However, there is not sufficient outcomes
data showing FDS as a well-defined safe procedure for the treatment of these
aneurysms.21
Clinical Outcome and Complications
In our series, morbidity and mortality rate were 8% and 4% respectively.
Other series demonstrated similar mortality and morbidity rates.4,11 The mechanism of
intraparenchymal hemorrhage (IPH) after FDS treatment is not clear yet; however,
there are some theories about the physiopathology aspect of this complication. Cruz et
al.21 proposed a hypothesis that artery reconstruction with a FDS could reduce the
local compliance of that vascular segment, changing the blood pressure waveform
transmitted to the distal cerebral vasculature. This blood pressure waveform
transmitted beyond the reconstructed segment might exhibit a higher systolic peak
and a lower diastolic trough and this alteration could contribute to delayed post-
procedural IPH.22 This theory could explain an IPH in two patients in our series
without a clear cause. Although this is a valid hypothesis it does not fully explain
these events because IPH rates are not uniform across multiple series.
In one of our patients presenting IPH post procedure (Figure 3),
hyperperfusion was the probable mechanism. A very slow flow distally from the
aneurysm is clearly observed on the pretreatment angiography. Immediately after
PED deployment there is a significant increase in the middle cerebral artery (MCA)
34
flow distally from the aneurysm. One patient had a hemorrhagic complication from an
ischemic area after the treatment and another patient from a contralateral MCA
aneurysm that had been clipped 12 years before and presented a residual aneurysm.
The IPH rate is variable raging from 0% to 8.5%.4,11,12,15,19,21 In recent
publications, the overall incidence of IPH appears to be greater in patients treated
with FDS than in patients treated with stent-assisted coil. A cohort of 284 patients
treated with the Neuroform stent (Boston Scientific, Natick, MA, USA) showed a
1.1% (3/284) rate of spontaneous IPH after treatment.23 This rate is similar to the IPH
rate due to double anti-aggregative treatment for secondary stroke prevention. These
data suggest that post-procedural IPH might be a phenomenon that is most associated
with FDS.21
Conclusions
Flow diversion is a promising technique for the treatment of intracranial
aneurysms. The results are excellent for small saccular wide-necked aneurysms with
near 100% complete occlusion rate and no complications. More challenging lesions,
such as large and giant aneurysms, also have a very good result with a relatively low
rate of complications.
The results for the challenging fusiform vertebro-basilar aneurysms, which
have a very poor long term prognosis, are promising; however, the rate of ischemic
events is still very high and mostly related to perforator occlusion.
There was no recanalization in this series and it seems that its occurrence is
very rare with FDS. More follow-up time is needed to prove that.
Our study suggests efficacy and safety of FDS in the treatment of complex
aneurysms. More studies are needed to further refine the possible indicators and the
technical aspects of this treatment to improve clinical results.
35
References
1- Molyneux AJ, Kerr RS, Yu LM, et al. International Subarachnoid Aneurysm
Trial (ISAT) Collaborative Group. International Subarachnoid Aneurysm Trial
(ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients
with ruptured intracranial aneurysms: a randomized comparison of effects on
survival, dependency, seizures, rebleeding, subgroups, and aneurysm
occlusion. Lancet. 2005;366:809–817.
2- Sluzewski M, Menovsky T, van Rooij WJ, Wijnalda D. Coiling of very large
or giant cerebral aneurysms: long-term clinical and serial angiographic results.
Am J Neuroradiol. 2003;24:257–262.
3- Thornton J, Debrun GM, Aletich VA, Bashir Q, Charbel FT, Ausman J.
Follow up angiography of intracranial aneurysms treated with endovascular
placement of Guglielmi detachable coils. Neurosurgery. 2002;50:239–249.
4- Fischer S, Vajda Z, Perez MA, et al. Pipeline embolization device (PED) for
neurovascular reconstruction: initial experience in the treatment of 101
intracranial aneurysms and dissections. Neuroradiology. 2012;54:369–382.
5- Kulcsar Z, Houdart E, Bonafe A, et al. Intra-Aneurysmal Thrombosis as a
Possible Cause of Delayed Aneurysm Rupture after Flow-Diversion
Treatment. Am J Neuroradiol. 2011;32:20–25.
6- Leonardi M, Dall'olio M, Princiotta C, Simonetti L. Treatment of carotid
siphon aneurysms with a microcell stent. A case report. Interv Neuroradiol.
2008;14:429–434.
7- Fiorella D, Woo HH, Albuquerque FC, Nelson PK. Definitive reconstruction
of circumferential, fusiform intracranial aneurysms with the Pipeline
embolization device. Neurosurgery. 2008;62:1115–1121.
8- vanRooij WJ, Sluzewski M. Unruptured large and giant carotid artery
aneurysms presenting with cranial nerve palsy: comparison of clinical
recovery after selective aneurysm coiling and therapeutic carotid artery
occlusion. Am J Neuroradiol. 2008;29:997–1002
9- Piske RL, Kanashiro LH, Paschoal E, Agner C, Lima SS, Aguiar PH.
Evaluation of Onyx HD-500 embolic system in the treatment of 84 wide-neck
intracranial aneurysms. Neurosurgery. 2009;64(5):865-875.
36
10- Szikora I, Berentei Z, Kulcsar Z, et al. Treatment of intracranial aneurysms by
functional reconstruction of the parent artery: the Budapest experience with
the pipeline embolization device. Am J Neuroradiol. 2010;31:1139–1147.
11- O’Kelly CJ, Spears J, Chow M, et al. Canadian Experience with the pipeline
embolization device for repair of unruptured intracranial aneurysms. Am J
Neuroradiol. 2013;34:381–387.
12- Lylyk P, Miranda C, Ceratto R, et al. Curative endovascular reconstruction of
cerebral aneurysms with the pipeline embolization device: the Buenos Aires
experience. Neurosurgery. 2009;64(4):632-642.
13- Saatci I, Yavuz K, Ozer C, Geylk S, Cekrge HS. Treatment of intracranial
aneurysms using the pipeline flow-diverter embolization device: a single-
center experience with long-term follow-up results. Am J Neuroradiol.
2012;33:1436–1446.
14- Nelson, P. Lylyk, I. Szikora, Wetzel SG, Wanke I, Fiorella D. The Pipeline
Embolization Device for the Intracranial Treatment of Aneurysms Trial. Am J
Neuroradiol. 2011;32:34-40
15- Szikora I, Marosfo M, Salomvary B, Berentei Z, Gubucz I. Resolution of
Mass Effect and Compression Symptoms following Endoluminal Flow
Diversion for the Treatment of Intracranial Aneurysms. Am J Neuroradiol
2013;34:935–939
16- Shankar JJ, Vandorpe R, Pickett G, Maloney W. SILK flow diverter for
treatment of intracranial aneurysms: initial experience and cost analysis. J
NeuroIntervent Surg 2013 Feb 19. [Epub ahead of print].
http://jnis.bmj.com/content/early/2013/02/18/neurintsurg-2012-010590.long.
17- Berge J, Biondi A, Machi P, et al. Flow-diverter SILK stent for the treatment
of intracranial aneurysms: 1-year follow-up in a multicenter study. Am J
Neuroradiol. 2012;33:1150–1155.
18- Siddiqui AH, Abla AA, Kan P, et al. Panacea or problem: flow diverters in
the treatment of symptomatic large or giant fusiform vertebrobasilar
aneurysms. J Neurosurg. 2012;116(6):1258-1266.
19- McAuliffe V, Wycoco H, Rice C, Phatouros C, Singh TJ, Wenderoth J.
Immediate and Midterm Results following Treatment of Unruptured
Intracranial Aneurysms with the Pipeline Embolization Device. Am J
Neuroradiol. 2012;33:164–170.
37
20- Chalouhi N, Tjoumakaris S, Dumont AS, et al. Treatment of Posterior
Circulation Aneurysms with the Pipeline Embolization Device. Neurosurgery.
2013;72(6):883-889.
21- Cruz JP, Chow M, O'Kelly C, et al. Delayed Ipsilateral Parenchymal
Hemorrhage Following Flow Diversion for the Treatment of Anterior
Circulation Aneurysms–Pipeline. AJNR 2012 33: 603-608
22- Velat GJ, Fargen KM, Lawson MF, Hoh BL, Fiorella D, Mocco J. Delayed
intraparenchymal hemorrhage following Pipeline embolization device
treatment for a giant recanalized ophthalmic aneurysm. J Neurointerv Surg
2011;4(5):e24. [Epub ahead of print].
http://jnis.bmj.com/content/4/5/e24.long.
23- Diener HC, Bogousslavsky J, Brass LM, et al. Aspirin and clopidogrel
compared with clopidogrel alone after recent ischemic stroke or transient
ischemic attack in high-risk patients (MATCH): randomized, double-blind,
placebo-controlled trial. Lancet. 2004;364:331–337.
38
DISCUSSÃO GERAL
Todas as lesões tratadas na série foram acessadas com sucesso e a deposição
do stent diversor de fluxo foi realizada em todos os casos à exceção de um aneurisma
gigante de artéria oftálmica, tratando previamente com coils e stent, onde o
microcateter não progrediu distalmente à lesão. O’Kelly et al demonstraram a falha na
progressão do microcateter em dois pacientes com aneurismas gigantes de colo
largo11. A oclusão da artéria carótida interna foi realizada após o paciente apresentar
tolerância ao teste de oclusão por balão.
Imediatamente após a introdução dos stents diversores de fluxo, a estase de
uma quantidade variável de contraste ocorreu em todas as lesões. Apesar desse
achado ser esperado, consideradas as mudanças hemodinâmicas desencadeadas pelo
aparato, é improvável que ocorra a obliteração dos aneurismas ocorram nesse
momento12 (figura 1).
Pelo menos uma angiografia digital foi realizada em 66 pacientes (86%) sendo
observadas 75 lesões (86%). Conforme esperado para uma série desse tamanho,
alguns pacientes perderam o seguimento por diferentes razões e 9 pacientes (12%)
não completaram a angiografia de controle no seguimento 6 meses após o tratamento.
Obtivemos uma taxa de oclusão de 80% em 6 meses de seguimento e de 84% em 18
meses de seguimento. A taxa de oclusão em outras séries variou, entre 52% a 93%4,11-
18.
Considerando-se os casos com oclusão parcial subtotal, a taxa de oclusão foi
de 88%, com 3 lesões com oclusão parcial no primeiro exame de controle evoluindo
para oclusão completa em 18 meses. Não existem dados disponíveis sobre o risco de
ruptura dos aneurismas com oclusão subtotal após o tratamento com stents diversores
de fluxo.
A taxa de oclusão observada foi elevada e dependente da morfologia e
tamanho dos aneurismas. Se apenas os aneurismas saculares forem considerados, a
taxa de oclusão foi de 88%, e chega a 100% para os aneurismas saculares e pequenos
sem tratamento prévio (menores de 10mm). Nelson et al, em um estudo multicêntrico
obtiveram uma taxa de oclusão de 93% em 6 meses de seguimento apenas com
aneurismas saculares,11 sugerindo um melhor resultado comparado aos aneurismas
fusiformes. Eventos tromboembólicos e hemorrágicos ocorreram apenas em lesões
39
grandes e gigantes na nossa série. Oclusão completa foi atingida nos
pseudoaneurismas e dissecções arteriais.
Nossa série incluiu 15 lesões que foram submetidas a algum tipo de
tratamento prévio, seja endovascular ou microcirúrgico. A taxa de oclusão para essas
lesões foi de apenas 50% em comparação a 85% de lesões sem tratamento prévio.
Essa observação foi corroborada por McAuliffe et al em um estudo multicêntrico e
prospectivo na Austrália19. O autor apresentou uma taxa de oclusão de 92% e 50%
para aneurismas sem e com tratamento prévio respectivamente. A presença do
material relacionado ao tratamento prévio provavelmente reduziu o efeito biológico
dos stents diversores de fluxo, diminuindo as mudanças da camada intima
esperadas12.
O seguimento de 6 meses com angiografia digital foi possível em 7 das 11
lesões de circulação posterior com taxa de oclusão de 57% (4 casos). Aneurismas
fusiformes foram vistos em 6 pacientes (apenas 4 pacientes realizaram seguimento
angiográfico em 6 meses com 1 oclusão) e 3 dissecções arteriais (com oclusão
completa). Esses dados corroboram outros estudos que sugerem uma taxa de oclusão
menor no tratamento de aneurismas fusiformes. Chalouhi et al apresentaram uma taxa
de oclusão de 42% em 6 meses em uma série de aneurismas fusiformes não rôtos de
circulação posterior. Além de uma taxa de oclusão menor, o autor sugere uma alta
taxa de morbidade e mortalidade no tratamento dessas lesões20.
Siddiqui et al, em uma série pequena de 7 pacientes com aneurismas
fusiformes de circulação posterior, apresentaram 2 pacientes com bons resultados e 4
mortes após tratamento com stents diversores de fluxo18. Altas taxas de morbidade e
mortalidade associadas a poucas opções de tratamento dessas lesões colocam os stents
diversores de fluxo como uma opção terapêutica. Apesar disso, ainda não existem
dados suficientes para definir o seu uso como método seguro no tratamento dessas
lesões desafiadoras21.
Avaliação clínica e complicações
A exemplo de outras séries, a taxa de morbidade e mortalidade foram baixas,
de 8% e 4% respectivamente4,11. Embora não exista na literatura uma explicação
adequada para o desenvolvimento de hematomas intraparenquimatosos após o
tratamento com o uso de stents diversores de fluxo, Cruz21 et al propuseram uma
40
hipótese em que ocorreria uma diminuição da complacência arterial no segmento
tratado, alterando a onda pressórica sanguínea transmitida para os vasos cerebrais
distais. A onda pressórica sanguínea apresenta um pico de pressão sistólica, mais
elevado, e um pico de pressão diastólica, menos elevado, contribuindo para a
formação de hematomas após o tratamento22. Essa teoria poderia explicar dois
hematomas em nossa série, sem origem aparente. Embora seja uma hipótese válida,
não explica de forma adequada alguns casos, pois a taxa de formação de hematomas
não é uniforme entre as múltiplas séries.
Em um de nossos pacientes que apresentou um hematoma
intraparenquimatoso após o tratamento (figura 3), a hiperperfusão foi o provável
mecanismo de formação. Um fluxo bem lento é observado nas imagens da angiografia
pré-tratamento. Imediatamente após a deposição do stent diversor de fluxo há um
aumento no fluxo distal ao aneurisma na artéria cerebral média. Um dos pacientes
apresentou um resangramento contralateral ao tratamento, onde 12 anos antes fora
clipado de forma parcial um aneurismas de artéria cerebral média.
41
CONCLUSÃO GERAL
O uso de stents diversores de fluxo constitui-se em uma nova ferramenta no
tratamento de aneurismas intracranianos e dissecções arteriais. Os resultados são
excelentes para aneurismas saculares, com alta taxa de oclusão e poucas
complicações. Lesões complexas como aneurismas fusiformes e gigantes apresentam
também bons resultados a despeito das maiores taxas de complicações e risco de
morte.
Estudos prospectivos são necessários para aprimorar as indicações dos stents
diversores de fluxo e melhorar o entendimento dessa nova modalidade de terapêutica
endovascular.
42
BIBLIOGRAFIA
1- Molyneux AJ, Kerr RS, Yu LM, et al. International Subarachnoid Aneurysm
Trial (ISAT) Collaborative Group. International Subarachnoid Aneurysm Trial
(ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients
with ruptured intracranial aneurysms: a randomized comparison of effects on
survival, dependency, seizures, rebleeding, subgroups, and aneurysm
occlusion. Lancet. 2005;366:809–817.
2- Sluzewski M, Menovsky T, van Rooij WJ, Wijnalda D. Coiling of very large
or giant cerebral aneurysms: long-term clinical and serial angiographic results.
Am J Neuroradiol. 2003;24:257–262.
3- Thornton J, Debrun GM, Aletich VA, Bashir Q, Charbel FT, Ausman J.
Follow up angiography of intracranial aneurysms treated with endovascular
placement of Guglielmi detachable coils. Neurosurgery. 2002;50:239–249.
4- Fischer S, Vajda Z, Perez MA, et al. Pipeline embolization device (PED) for
neurovascular reconstruction: initial experience in the treatment of 101
intracranial aneurysms and dissections. Neuroradiology. 2012;54:369–382.
5- Kulcsar Z, Houdart E, Bonafe A, et al. Intra-Aneurysmal Thrombosis as a
Possible Cause of Delayed Aneurysm Rupture after Flow-Diversion
Treatment. Am J Neuroradiol. 2011;32:20–25.
6- Leonardi M, Dall'olio M, Princiotta C, Simonetti L. Treatment of carotid
siphon aneurysms with a microcell stent. A case report. Interv Neuroradiol.
2008;14:429–434.
7- Fiorella D, Woo HH, Albuquerque FC, Nelson PK. Definitive reconstruction
of circumferential, fusiform intracranial aneurysms with the Pipeline
embolization device. Neurosurgery. 2008;62:1115–1121.
8- vanRooij WJ, Sluzewski M. Unruptured large and giant carotid artery
aneurysms presenting with cranial nerve palsy: comparison of clinical
recovery after selective aneurysm coiling and therapeutic carotid artery
occlusion. Am J Neuroradiol. 2008;29:997–1002
9- Piske RL, Kanashiro LH, Paschoal E, Agner C, Lima SS, Aguiar PH.
Evaluation of Onyx HD-500 embolic system in the treatment of 84 wide-neck
intracranial aneurysms. Neurosurgery. 2009;64(5):865-875.
43
10- Szikora I, Berentei Z, Kulcsar Z, et al. Treatment of intracranial aneurysms by
functional reconstruction of the parent artery: the Budapest experience with
the pipeline embolization device. Am J Neuroradiol. 2010;31:1139–1147.
11- O’Kelly CJ, Spears J, Chow M, et al. Canadian Experience with the pipeline
embolization device for repair of unruptured intracranial aneurysms. Am J
Neuroradiol. 2013;34:381–387.
12- Lylyk P, Miranda C, Ceratto R, et al. Curative endovascular reconstruction of
cerebral aneurysms with the pipeline embolization device: the Buenos Aires
experience. Neurosurgery. 2009;64(4):632-642.
13- Saatci I, Yavuz K, Ozer C, Geylk S, Cekrge HS. Treatment of intracranial
aneurysms using the pipeline flow-diverter embolization device: a single-
center experience with long-term follow-up results. Am J Neuroradiol.
2012;33:1436–1446.
14- Nelson, P. Lylyk, I. Szikora, Wetzel SG, Wanke I, Fiorella D. The Pipeline
Embolization Device for the Intracranial Treatment of Aneurysms Trial. Am J
Neuroradiol. 2011;32:34-40
15- Szikora I, Marosfo M, Salomvary B, Berentei Z, Gubucz I. Resolution of
Mass Effect and Compression Symptoms following Endoluminal Flow
Diversion for the Treatment of Intracranial Aneurysms. Am J Neuroradiol
2013;34:935–939
16- Shankar JJ, Vandorpe R, Pickett G, Maloney W. SILK flow diverter for
treatment of intracranial aneurysms: initial experience and cost analysis. J
NeuroIntervent Surg 2013 Feb 19. [Epub ahead of print].
http://jnis.bmj.com/content/early/2013/02/18/neurintsurg-2012-010590.long.
17- Berge J, Biondi A, Machi P, et al. Flow-diverter SILK stent for the treatment
of intracranial aneurysms: 1-year follow-up in a multicenter study. Am J
Neuroradiol. 2012;33:1150–1155.
18- Siddiqui AH, Abla AA, Kan P, et al. Panacea or problem: flow diverters in
the treatment of symptomatic large or giant fusiform vertebrobasilar
aneurysms. J Neurosurg. 2012;116(6):1258-1266.
19- McAuliffe V, Wycoco H, Rice C, Phatouros C, Singh TJ, Wenderoth J.
Immediate and Midterm Results following Treatment of Unruptured
Intracranial Aneurysms with the Pipeline Embolization Device. Am J
Neuroradiol. 2012;33:164–170.
44
20- Chalouhi N, Tjoumakaris S, Dumont AS, et al. Treatment of Posterior
Circulation Aneurysms with the Pipeline Embolization Device. Neurosurgery.
2013;72(6):883-889.
21- Cruz JP, Chow M, O'Kelly C, et al. Delayed Ipsilateral Parenchymal
Hemorrhage Following Flow Diversion for the Treatment of Anterior
Circulation Aneurysms–Pipeline.
22- Velat GJ, Fargen KM, Lawson MF, Hoh BL, Fiorella D, Mocco J. Delayed
intraparenchymal hemorrhage following Pipeline embolization device
treatment for a giant recanalized ophthalmic aneurysm. J Neurointerv Surg
2011;4(5):e24. [Epub ahead of print].
http://jnis.bmj.com/content/4/5/e24.long.
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