Aneurysm Coiling 動脈瘤彈簧圈栓塞

Key facts

Procedure definition:coil embolization of intracranial aneurysms.Clinical setting triggering procedure:intracranial aneurysm.Best procedure approach:transfemoral guide catheter placed in internal carotid artery with subsequent intra-aneurysmal microcatheter placement and coil embolization.

Most feared complications:aneurysm rupture,embolic stroke,branch vessel occlusion;coil prolapse into parent vessel.

Expected outcome:exclusion of aneurysm from cerebral circulation.

Pre-procedure

Indications

Clinical setting triggering procedure:ruptured or unruptured intracranial aneurysm with suitable aneurysm neck geometry and lack of incorporation of parent vessel branches.

Anterior communicating,basilar tip and paraclinoid aneurysms particularly suitable due to difficult surgical exposure.

MCA aneurysms often more suitable for clipping due to surgical accessibility and frequent incorporation of parent vessel branches.

Contraindications

Unfavorable aneurysm geometry/location;inability to access aneurysm due to proximal vascular occlusion;renal failure (relative);uncorrected coagulopathy(relative).

Methods

Imaging studies(CT,MR and prior angiography).Ventriculostomy catheter to be placed prior to coiling in patients with ruptured aneurysms and ventriculomegaly.

Ventriculostomy kit should be in room(readily available).

BUN,creatinine,PT,PTT,INR.

Availability of anesthesia(most cases are performed under general).

Medications:Clopidogrel (Plavix) 75 mg and aspirin 325 mg daily commencing 4 days prior to procedure(unruptured aneurysms).

Equipment list:(1)high quality angiography machine with biplane fluoroscopy;

(2)6 Fr sheath,5 Fr neuroangiocatheter and a 0.035" angled-tip glidewire;

(3)2 rotating hemostatic valves(RHV);(4)5 or 6 Fr guiding catheter;(5)0.038" extra stiff exchange wire;(5)Microcatheter with proximal (3 cm from tip) and distal markers:0.010" coil compatible and 0.018" coil compatible.(6)0.010"or 0.014" microwire;(7)0.010" or 0.018" detachable coils (10 coils for aneurysms ＜10 mm):3D framing coils and non－3D filling coils.

Fig 1 a)CTA,b)VR recon struction and c)sagittal enhanced T1WI showed narrow－necked spherical aneurysm(arrow)arising from pericallosal artery.d) and e)DSA showed the pericallosal aneurysm was successfully treated with coils (arrow).Fig 2 Illustration showing a microcatheter and coil placed within an aneurysm.The inset demonstrates proper alignment or the coil marker(gray) and the proximal microcatheter marker (black) prior to detachment.

Procedure

Patient position/location：angio suite with patient supine.

Radiopague marker is placed on head for measurements.

Equipment preparation

Flush all catheters/sheaths.

Activate hydrophilic coating on catheters/wires by immersion in saline.

Procedure steps

(1)Patient under general anesthesia and foley inserted.

(2)Access femoral artery and perform baseline angiogram.Measure aneurysm and select working view which optimally shows relationship of aneurysm neck to parent vessel.

(3)Heparinize (ACT twice baseline) if unruptured aneurysm.

(4)Ruptured aneurysm:heparinize after first coil is placed or not at all.

(5)Select ECA on side to be treated with glidewire and 5 Fr catheter.

(6)Anchor a 0.038" extra stiff exchange wire in external carotid artery and exchange for the 5 or 6 Fr guiding catheter which is placed below bifurcation.

(7)Select and advance guide to level of distal cervical internal carotid artery and attach RHV with heparinized/pressurized saline drip.

(8)Roadmap image obtained in working view.

(9)Insert microcatheter/wire and place tip of microwire in aneurysm and then carefully advance microcatheter into aneurysm.

(10)Tip of catheter should be near center of aneurysm－ if tip is against wall may rupture aneurysm when coil is placed.

(11)Place appropriate diameter/length 3D framing coil and perform angiogram.If angiogram shows no coil prolapse then electrolytically or hydrostatically detach coil.

(12)Aneurysm is then filled with increasingly smaller filling coils.After the 3D coil is placed subsequent coils can be placed using a roadmap performed without contrast to subtract－out initial coil mass.

(13)Final intracranial angiography to exclude embolic complication.

(14)Heparin discontinued and sheath removed when ACT＜180 (or closure device is used).

Alternative procedures/therapies:surgical clipping

Post-procedure

(1)Admit to ICU with close monitoring of neuro status and blood pressure;

(2)IV fluids (normal saline);(3)Plavix×6 weeks and aspirin for life in coiled unruptured aneurysms;(4)angiography at 6 and 12 months to exclude regrowth.

Common problems

Wide－necked aneurysms may require balloon/stent assisted technique.

Complications

Stroke (GP IIb/IIIa inhibitors useful in unruptured aneurysms).

Aneurysm rupture(have protamine sulfate available and be prepared to rapidly place additional coils).

醫學詞匯注釋與簡要講解

aneurysm 動脈瘤

【prefix】trans-經由、通過

transfemoral 經股動脈

transcranial 經顱的

complications 并發癥：動脈瘤破裂，異位栓塞，分支血管栓塞，彈簧圈脫落

anterior communicating 前交通支

basilar tip 基底動脈尖

【prefix】para-在旁邊，靠近

paraclinoid 床突旁的

paranasal 鼻旁的

parent vessel 載瘤血管

ventriculostomy 腦室切開術

【sufffix】-megaly 增大，腫大

ventriculomegaly 腦室擴大

splenomegaly 脾大

Clopidogrel 氯吡格雷

sheath 血管鞘

glidewire 滑行導絲

catheter 導管

exchange wire 交換導絲

microwire 微導絲

angio suite 造影床

【prefix】hydro－ 水的

hydrophilic 親水的

hydrocephalus 腦積水

heparinize 肝素化

electrolytically 電解地

hydrostatically 液體穩定地

clipping 夾閉術

protamine sulfate 魚精蛋白