**2.1. Patient population**

Between Jul 2003 and Dec 2009, 232 consecutive patients with 239 wide-neck aneurysms underwent stent-assisted coil embolization at our institution. Therapeutic alternatives were

© 2012 Gao and Liang, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

discussed between neurosurgical and neurointerventional teams. Informed consent from the patients and institutional review board approval was obtained. The medical records, radiographic studies and endovascular procedure reports were reviewed. Patient and aneurysm characteristics are summarized in table 1.


**Note:** SAH, subarachnoid hemorrhage; TIA, transient ischemic attack; PcomA, posterior communicating artery; AcomA, anterior communicating artery; Acho: anterior choroidal artery; ICA, internal carotid artery; ACA , anterior cerebral artery; BA, basilar artery; VA, vertebral artery; VB, vertebrobasilar; PICA, posterior inferior cerebellar artery, small, <10 mm; large, >10-25 mm; giant, >25 mm.

**Table 1.** Patient and aneurysm characteristics

#### **2.2. Treatment procedures**

270 Aneurysm

discussed between neurosurgical and neurointerventional teams. Informed consent from the patients and institutional review board approval was obtained. The medical records, radiographic studies and endovascular procedure reports were reviewed. Patient and

No. of patients 232

Mean 55.1 Range 18-81

Female 142 Male 90 Ruptured aneurysms (%) 129 (54.0)

I 39 II 46 III 34 IV 7 V 3 Unruptured aneurysms (%) 110 (46.0) Headache 35 Previous SAH 29 Incidental 22 CN paisy 13 TIA 11

Anterior Circulation 195 (81.6) PcomA 49 AcomA 12 Paraclinoid ICA 41 Cavernous ICA 20 Ophthalmic 37 ICA bifurcation 14 AchoA 17 A1 segment of ACA 5 Posterior Circulation 44 (18.4) BA 18 VA 12 VB junction 9 PICA 5

 Small 164(68.6) Large 43(18.0) Giant 32(13.4)

 Mean 5.9 Range 2-24 **Note:** SAH, subarachnoid hemorrhage; TIA, transient ischemic attack; PcomA, posterior communicating artery; AcomA, anterior communicating artery; Acho: anterior choroidal artery; ICA, internal carotid artery; ACA , anterior cerebral artery; BA, basilar artery; VA, vertebral artery; VB, vertebrobasilar; PICA, posterior inferior cerebellar artery,

aneurysm characteristics are summarized in table 1.

Hunt and Hess grade

Aneurysm location (%)

Aneurysm size (%)

Neck size (mm)

small, <10 mm; large, >10-25 mm; giant, >25 mm. **Table 1.** Patient and aneurysm characteristics

Age (y)

Gender

All procedures were performed under general anesthesia. Patients having unruptured aneurysms were premedicated with antiplatelet therapy consisting of aspirin 300 mg and clopidogrel 75 mg for 3 days before the procedure. Patients with SAH were loaded with aspirin 300 mg and clopidogrel 225 mg via nasogastric tube after general anesthesia. All patients received systemic heparinization to raise the activated clotting time (ACT) at about 300 seconds and continuous intravenous infusion of Nimodipine, 2mg/hour to prevent vasospasm during the procedure. In patients with ruptured aneurysms, heparinization started before puncture, and in patients who presented with acute SAH, heparinization started after aneurysm catheterization. A full three- or four-vessel cerebral angiogram was performed to permit a complete evaluation of the aneurysm, measure the aneurysm neck, width, and height, and measure the parent artery proximal and distal to the aneurysm. A 6F or 8F sheath was introduced in the right femoral artery following a standard Seldinger puncture. A 6F or 8F Envoy guiding catheter (Johnson & Johnson) was then guided into either the cervical internal carotid or vertebral artery, depending on the location of the aneurysm. The microcatheters were Prowler series (Johnson & Johnson), Excelsior SL-10, or Excelsior 1018 (Boston Scientific/Target Therapeutics). In all cases, embolization was completed by packing the aneurysm sac with a variety of commercially available coils. After the procedure, the patient was moved to the neurosurgery intensive care unit for monitoring and received low-molecular weight heparin calcium 4000IU/12h for the next 48 hours. Clopidogrel 75 mg each day was orally taken for an additional 30 days, and aspirin 100 mg for 6 months.

#### **2.3. Stenting strategies**

Stent deployment was successful in 237 of 239 aneurysms, and failed in two aneurysms. Strategies used regarding the sequence of stenting and coiling in 237 treated aneurysms were the following:


**Figure 1.** Three dimensional reconstruction (A) of the right ICA in anteroposterior view demonstrated a posterior communicating artery aneurysm. The Neuroform stent delivery system was brought up over the exchange microguidewire to cross the aneurysm neck. The stent was partly deployed to narrow the aneurysm neck after aneurysm catheterization (B). Homogeneous coil framing was achieved without coil prolapse by the limitation of the partially-deployed stent. (C). After several coils were placed, the stent was fully deployed and coiling continued using traditional jailing technique (D). Postprocedure angiogram (E) revealed complete occlusion. 13 months follow-up right common carotd artery angiogram (F) revealed high-grade stenosis within the stented segments of right ICA. Collateralisation was seen over the anterior communicating artery from the left side (G). Superselective angiogram (H) demonstrated that right ICA was not completely occluded. Then, balloon angioplasty of the right ICA was performed (I). Postangioplasty control angiography demonstrated substantial improvement in the caliber, but flow to right cerebral anterior artery was still delayed (J).

b. Stenting before coiling in a second session in 14 aneurysms (5.9%). The main reason for using this option was the difficulties of accessing the aneurysm for coiling after initial stent placement, especially when the parent artery was tortuous, or the aneurysm was small. The coiling procedure was usually performed from 1 to 2 months after the stenting procedure.


**Figure 2.** Angiography demonstrated a basilar trunk aneurysm in a 38-year-old woman with SAH (A B). A Neuroform stent (4.5 × 20 mm) was deployed across the aneurysm neck, and coil embolization was postponed to a second session due to difficulty in trans-stent aneurysm catheterization (C). Oneyear follow-up angiography demonstrated complete occlusion (D E).

#### **2.4. Data collection**

All patients underwent CT scanning within 6 hours after the procedure. During the hospital stays, physicians performed neurological examinations of the patients once each day. After discharge, clinical follow-up data were collected by clinic visitation, follow-up angiography, or telephone interview. Clinical outcome was graded according to modified Rankin score (mRS), as follows: excellent (mRS 0-1), good (mRS 2), poor (mRS 3-4) and death (mRS 5). For each patient, 6 months, 1 year, 3 year and 5 year follow-up angiogram were recommended. The pre-embolization, post-embolization and follow-up (if possible) angiograms were reviewed and compared by 2 senior endovascular neurosurgeons not involved in the procedure for initial and follow-up occlusion grade, which was classified as class 1: complete occlusion (no contrast filling the aneurysmal sac); class 2: neck remnant (residual contrast filling the aneurysmal neck); class 3: residual flow (residual contrast filling the aneurysmal body). 5 Recanalization was defined as more than 10 % increase in contrast filling of the aneurysm; less than 10 % increased filling was defined as unchanged. 6

Angiographic results and clinical outcome were evaluated. Cases with complications were analyzed, including radiological findings, clinical presentations, management experience and clinical sequelae.

#### **2.5. Statistical analysis**

SPSS 11.0 software (SPSS, Inc, Chicago, IL) was used for statistical analysis. A chi-square test was used to compare the incidences of intraprocedural rupture and thromboembolic complications between ruptured unruptured aneurysms and to compare the incidences of complete occlusion rate between different stenting strategies.
