Advances in Endovascular Neurosurgery Techniques: Toyama

Hospital Experience

Steven Tandean

Department of Neurosurgery, Universitas Sumatera Utara, Medan, North Sumatera, Indonesia

Keywords: Endovascular, Angiography, Anastomosis, Moya-Moya Disease.

Abstract: Advance developing technologies of neurosurgery field in the world especially endovascular treatment and

vascular surgery. Endovascular treatment has new technique in internal carotid stenosis, basilar tip aneurysm,

and carotid cavernous aneurysm. Effectiveness and safety of endovascular treatment not inferior compare to

open surgery and for some cases more superior. The only management for moyamoya disease is surgical

revascularization by direct bypass, indirect bypass, and combined bypass. Most of the previous procedures

were aimed on MCA territory so EDMAPS was developed to revascularize ACA territory by using frontal

pericranial flap for additional indirect bypass through medial frontal craniotomy. Studies demonstrates STA-

MCA anastomosis and EDMAPS is safe and effective to improve long term prognosis in moyamoya disease.

1 INTRODUCTION

Vascular neurosurgery has remarkable of

neurosurgical advances that require decision making,

critical care support, microsurgical skill, and

advanced technology. This field has evolved for this

past several decades and changed the nature of this

subspecialty of neurosurgery. In 1937 the first

aneurysm clipping procedure was performed by

Walter Dandy and evolved progression of devices

and techniques. Aneurysm sac obliteration by

endovascular insertion of silver wire was reported in

1941. Evolution of endovascular treatment was

continue by development of detachable device,

balloon and stent-assisted coiling, and recently flow

diverter. Vascular neurosurgery should be a field

oriented on disease and not procedure. At present,

vascular neurosurgery requires extraluminal and

endoluminal approach. The extraluminal approach is

an open cranial microsurgical technique involves

clipping, cortical mapping, and anastomosis. The

endoluminal approach is a technique requires

microcatheter, coils, balloon systems, embolic

materials, and stent technology

(Tjoumakaris et al,

2011; Crocker, 2007).

2 ENDOVASCULAR

NEUROSURGERY

2.1 Internal Carotid Artery Stenosis

Many clinical trials have been done to compare

carotid endarterectomy with carotid artery stenting

(CAS) in regard to their effectiveness and safety.

Most studies show that CAS is not inferior compare

to carotid endarterectomy. Currently there are three

types of cerebral embolic protection devices (EPD):

Flow preservation devices with distal filters, distal

occlusion devices, and proximal protection device by

flow stasis or flow reversal. Neurosurgery department

of Toyama University hospital has policy that

asymptomatic carotid artery >80% treat by CAS

(Gahremanpour, 2012).

Carotid stenosis cases will be analyzed by

magnetic resonance imaging (MRI) and diagnostic

digital subtraction angiography (DSA). DSA will be

performed with addition of three-dimensional

rotational angiography and 3D shaded surface

displays (SSDs). Two imaging modalities will

improve accuracy of the diagnosis and plan for

treatment. DSA can evaluate the entire carotid artery

system about tandem atherosclerotic disease, plaque

morphology, collateral circulation, and lesion

associated with atherosclerotic disease can be done

Tandean, S.

Advances in Endovascular Neurosurgery Techniques: Toyama Hospital Experience.

DOI: 10.5220/0010087607550759

In Proceedings of the International Conference of Science, Technology, Engineering, Environmental and Ramiﬁcation Researches (ICOSTEERR 2018) - Research in Industry 4.0, pages

755-759

ISBN: 978-989-758-449-7

755

by DSA. MRI was used to evaluate consistency of the

plaque by T1 and TOF (Adla, 2015).

Figure 1: A. Plaque in T1 sagittal MRI image (arrow). B.

Plaque in TOF axial MRI image (arrow). C. ICA stenosis

showed by 3D angiography (arrow). D. Lateral unsbtracted

angiographic view during angioplasty using du protection

with flow reversal: CCA (arrowhead) and ECA (small

arrow) occluded with balloon and distal filter (big arrow).

E. CCA angiography after stenting.

Carotid stenosis with large and soft plaque

(unstable plaque) was treated using dual protection

device (simultaneous flow reversal and distal filter)

and blood aspiration. Using EPD with only distal

filter or proximal balloon protection by flow stagnant

or flow reversal might not be sufficient to prevent

debris migrating to intracranial artery because

potential distal embolization by large and soft plaques

is high. Dual protection during CAS can cause debris

floating between the distal filter and the proximal end

of the stent so blood aspiration was performed after

post-dilation stent (Sakamoto, 2015).

Figure 2: A. A 9 Fr occlusion balloon-guiding catheter in

femoral artery connected to 4 Fr sheath in femoral vein via

filter and line for manual blood aspiration (asterisk). B.

Visible debris captured by the filter from AV shunt line.

(Image used with permission from Akioka N. (2016).

Textbook of JSNET educational seminar, Kobe).

All CAS procedures were performed under local

anesthesia and using heparin to maintain activated

clotting time between 250-300 seconds. Purpose of

using local anesthesia is to enable neurologic

examination during procedure. A 4 Fr sheath was

placed into the left femoral vein and 9 Fr occlusion

balloon-guiding catheter (OPTIMO; Tokai Medical

Products, Aichi, Japan) was introduced into the

common carotid artery (CCA) via right femoral

artery. An external arteriovenous (AV) shunt line was

created by connecting 9 Fr occlusion balloon-guiding

catheter with 4 Fr sheath via the blood filter to capture

debris. The line from AV shunt line was made for

manual blood aspiration. The balloon wire system

(GuardWire; Medtronic, Minneapolis, MN, USA)

was introduced into the external carotid artery (ECA)

and continuously inflated during procedure. Blood

flowed to venous circulation through AV shunt line

was confirmed after occlusion in the CCA and ECA

because of difference pressure of arterial and venous

(flow reversal). Distal filter using FilterWire EZ

(Boston Scientific, Natick, MA, USA) passed

through stenotic lesion and deployed into distal

internal carotid artery (ICA). After dual protection

was created with simultaneous flow reversal, stenotic

lesion was pre-dilated then performed blood

aspiration manually through AV shunt line about 30

cc using 50 cc syringe. Balloon in CCA was deflated

after aspiration to reduce duration of brain ischemia.

After inflation of CCA balloon, self-expanding stent

(Carotid Wallstent; Boston Scientific or PRECISE;

Johnson & Johnson, Miami Lakes, FL, USA) was

deployed from distal stenotic lesion to the CCA and

post-dilatation was performed. Manual blood

aspiration through AV shunt line about 30 cc using 50

cc syringe was performed repeatedly until absence of

debris from aspirated blood then CCA and ECA

balloon deflated. EC balloon and distal filter was

retrieved and the CAS procedure was completed.

2.2 Basilar Tip Aneurysm

Aneurysms in posterior circulation are considered as

the most hazardous location and also been long

considered as the most difficult lesion to treat by

surgery. Treatment of posterior circulation aneurysms

has shifted from microsurgery to endovascular during

past decade. Microsurgical clipping in this region

need aggressive cranial base resection and has high

risk of perforator infarction and cranial nerves

neuropathy. While endovascular treatments using

coils with stent or balloon assistance are considered

easier and more benign. Microsurgical clipping is

considered as secondary alternative when

ICOSTEERR 2018 - International Conference of Science, Technology, Engineering, Environmental and Ramiﬁcation Researches

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endovascular treatment is not possible especially for

both ruptured and unruptured aneurysms at basilar

trunk, proximal anterior inferior cerebellar artery, or

vertebrobasilar junction region (Sanai, 2008).

Important issue for endovascular treatment is

aneurysm recanalization, with approximately 20%

recanalized and 10% need retreatment. Quality of

aneurysm occlusion was mostly depended on the

neck size. Wide-neck aneurysm was treated with stent

assisted coiling and study show significantly decrease

need to retreatment and increase long-term

anatomical stability. For recent years, wide-necked

aneurysm on bifurcation artery like basilar tip was

treated using Y-stenting technique. Y-stenting

technique is Y-configuration double stent using

combination of open-open, open-closed, or closed-

closed stent with preserving parent artery circulation.

This technique shown good outcomes with low

complications but it’s technically complex and has

various challenges. Invention of braided stent with

compliant and flexible closed-cell design enable to

perform single stent assisted coiling at the wide-neck

bifurcation aneurysm (Alghamdi, 2016; Du, 2016).

At neurosurgery department of Toyama

University hospital, unruptured basilar tip aneurysms

are treated with single stent assisted-coil jailed-

catheter technique using Low-profile Visualized

Intraluminal Support Junior device (LVIS Jr;

MicroVention-Terumo, Tustin, California, USA) that

are dedicated for small parent artery from 2 to 3.5

mm. Single stent assisted coiling using LVIS Jr can

be obtained by placing from one of the branch arteries

to the parent artery with pull and push technique. All

procedure was performed in general anesthesia and

by using heparin to maintain activated clotting time

between 250-300 seconds. Procedures were using

standard 6 Fr guiding catheter from one or both

femoral arteries depend on the vertebral artery

diameter, for small size vertebral artery both femoral

artery will be used.

Figure 3: A. Wide-necked basilar tip aneurysm showed by

3D angiography (arrow). B. Coil (arrowhead) was partially

inserted to the sac and stent (arrow) was deployed use ‘push

and pull’ technique until cover all the neck. C. Stent (arrow)

was fully deployed and embolizing with coils (arrowhead).

D. Complete occlusion of Aneurysm (arrowhead).

Headway 21 microcatheter (Microvention-

Terumo) will be used for LVIS Jr stent. First,

Headway 21 microcatheter will be accessed to one of

distal arteries. After that, other microcatheter that

used to coil will be place in the aneurysm sac. Once

both microcatheters were placed, the coil was

partially inserted to aneurysm sac and stent was

deployed three quarters until cover all aneurysm

orifice. Unsheathing first centimeter of the stent by

withdraw the microcatheter. After that, deployment

of stent was by pushing on the pusher wire of the stent

and pulling the microcatheter. The stent deployed 1

mm at a time and continued until the stent pooch at

the neck of aneurysm and form a shape like shelf.

After the stent was considered shape satisfactory, the

rest of the stent was deployed three quarters using

standard technique. Then by using dyna-CT, the stent

was checked for the opening and absence of twisting.

Now, the microcatheter containing coil was

constrained between deployed stent and parent artery

wall. Coils continued to deploy until aneurysm sac

was completely packed, then stent can also be

deployed completely. After aneurysm sac was

completely occluded, microcatheter for coil was

pulled slowly with microguidewire. Packed coils

have been encaged between the aneurysm sac and

stent to prevent migration out of the sac.

2.3 Carotid Cavernous Aneurysm

Natural history of aneurysms from cavernous

segment was thought to be more benign and low

tendency to rupture than other vascular territories.

Due to dysplastic nature and anatomical morphology,

treatment options including surgical clipping, parent

artery occlusion with or without bypass, and

endovascular coiling was difficult to achieve

complete occlusion and have varying risk of

morbidity and mortality. Treatment was only

indicated for carotid cavernous aneurysm (CCA) that

symptomatic (opthalmoplegia or intractable retro-

orbital neuralgia), large size, and evidence of growth.

Because of endovascular technology advances, new

treatment option by using endoluminal device was

offered with a promising clinical outcome and also

low morbidity and mortality (Tanweer, 2014).

Endoluminal device or flow diversion is use to

exclude aneurysm segment of the parent artery by

implanting a metal scaffolding of low porosity (small

pore size) across the aneurysm neck. The idea of flow

diversion is to reduce intra-aneurysmal flow by

redirect blood flow along the parent artery. Reduction

of inflow jet velocity and level of shear stress on

aneurysm wall will initiate thrombosis in the

aneurysm sac. Ultimately, endothelization process

will begin with neointima and endothelium

Advances in Endovascular Neurosurgery Techniques: Toyama Hospital Experience

757

overgrowth of the stent that covered the aneurysm

neck. Adjacent branch vessel with uninterrupted

perfusion will not be affected. Thrombus in aneurysm

sac will be resorbed gradually via scavenger-cell-

mediated process and aneurysm mass will collapse.

This process begins immediate after stent deployment

and evolves over weeks to months. Currently, flow

diversion that approved by FDA is Pipeline

Embolization Device (PED; ev3-Covidien, Irvine,

CA) (Krishna, 2014).

PED is cylindrically shaped, self-expanding, and

made of 75% cobalt chromium alloy and 25%

platinum filament to impart greater radiopacity. PED

has low porosity (65-70%) and available in 10-35 mm

lengths and 2.5-5 mm diameters. Multiple PEDs can

be telescoped within each other to increase length or

to augment stent porosity over the aneurysm neck.

PEDs are supplied loaded within a removable sheath

an mounted on delivery microwire. The PED is

delivered through 0.027inch inner diameter

microcatheters so PED can be reconstructed to any

location that can be accessed with a 0.027inch inner

diameter microcatheter. Microcatheter can be

advanced to either capture delivery wire or relocated

distally for additional of PED deployment in a

telescoping fashion (Krishna, 2014).

Figure 4: A. Cavernous carotid aneurysm showed by 3D

angiography. B. Immediate angiography post flow diverter

placement showed stasis of contrast within aneurysm sac.

C. CT showed good position of device. D. Axial TOF MRI

after oneweek treatment showed trombosis in aneurysm

sac.

3 COMPARISON APPROACH

Endovascular therapy in 3 months at Toyama hospital

was 33 cases compare to vascular surgery only 12

cases. For vascular lesion, there are great swift from

vascular surgeries to endovascular therapies. So,

endovascular therapies 2.75 times more than vascular

surgeries. This is caused by improvement in

endovascular technology that made endovascular

therapies were effective and safe. Endovascular

therapies need a lot of cost depend on how

complicated the case and device that needed.

Sometimes endovascular therapies more expensive

than vascular surgeries.

Table 1: Approach list for vascular lesion.

Procedure Sum Type

Carotid angioplasty

Stentin

14 Endovascular

Coiling 12 Endovascula

Embolization 7 Endovascula

Clipping 8 Vascula

Vascular

Anstomosis

4 Vascular

4 CONCLUSION

Training with a different work culture at Toyama

University Hospital was an excellent experience. It

gave a broad perspective of different ways of to

approach similar conditions. This training also made

me more familiar with state-of-the-art neurosurgical

equipment and procedures in endovascular and

vascular neurosurgery.

ACKNOWLEDGEMENTS

I would like to acknowledge Prof Kuroda and Prof

Kuwayama for the opportunity to study endovascular

and vascular neurosurgery in Toyama University

Hospital and constant help during my training.

REFERENCES

Adla, T., Adlova, R., 2015. Multimodality imaging of

carotid stenosis. Int J angiol, 24, pp. 179-184.

Alghamdi, F., Mine, B., Morais, R., Scillia, P., Lubicz, B.,

2016. Stent-assisted coiling of intracranial aneurysms

located on small vessels: midterm results with the LVIS

ICOSTEERR 2018 - International Conference of Science, Technology, Engineering, Environmental and Ramiﬁcation Researches

758

junior stent in 40 patients with 43 aneurysms.

Neuroradiology, 58, pp. 665-671.

Crocker, M., Tolias, C., 2007. What future for vascular

neurosurgery? Vascular Health and Risk Management,

3(3), pp. 234-244.

Du, E. H. Y., Shankar, J. J. S., 2016. LVIS Jr ‘shelf’

technique: an alternative to Y stent assisted aneurysm

coiling. J NeuroInterv Surg,8(12), pp: 1256-1259.

Gahremanpour, A., Perin, E. C., Silva, G., 2012. Carotid

artery stenting versus endarterectomy.

Tex Heart Inst J, 39(4), pp: 474-487.

Krishna, C., Sonig, A., Natarajan, S. K., Siddiqui, A. H.,

2014. The expanding realm of endovascular

neurosurgery: Flow diversion for cerebral aneurysm

management. MDCVJ, X(4), pp: 214-219.

Sakamoto, S., Kiura, Y., Okazaki, T., Shinagawa, K.,

Ichinose, N., Shibukawa, M., et al, 2015. Usefulness of

dual protection combined with blood aspiration for

distal embolic protection during carotid artery stenting.

Acta Neurochir, 157, pp: 371-377.

Sanai, N., Tarapore, P., Lee, A. C., Lawton, M. T., 2008.

The current role of microsurgery for posterior

circulation aneurysms: A selective approach in

endovascular era. Neurosurgery, 62(6), pp: 1236-1253.

Tanweer, O., Raz, E., Brunswick, A., Zumofen, D.,

Shapiro, M., Riina, H. A., et al, 2014. Cavernous

carotid aneurysms in the era of low diversion: A need

to revisit treatment paradigms. AJNR Am J

Neuroradiol, 35, pp: 2334-2340.

Tjoumakaris, S. I., Jabbour, P. M., Gonzales, L. F.,

Dumont, A. S., Randazzo, C. G., Rosenwasser, R. H.,

2011. The evolution of future directions of

neuroendovascular therapy: From clips to coils to?

Clinical Neurosurgery, 58, pp: 42-50.

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