Keywords coiling - double microcatheter - technique - broad-necked intracranial aneurysm -
outcome
Introduction
The treatment of aneurysms by the endovascular method was developed in 1990 with the
arrival of the Guglielmi detachable coil system and established a new era in the neurointervention
field with multiple randomized clinical trials reporting the safety and effectiveness
of coiling.[1 ] Small-necked intracranial aneurysm has presented a higher frequency of obtaining
complete aneurysmal sac occlusion.[2 ] Treatment of broad-necked intracranial aneurysm by endovascular therapy (defined
as neck diameter ≥4 mm and dome-to-neck ratio <2) still prevails technically troublesome
because of the increased risk of coils migration or entrenchment into parent vessels.[3 ]
[4 ]
[5 ] Numerous new endovascular tools and techniques have been evolved to overwhelm these
constraints such as three-dimensional (3D) coils,[6 ] balloon remodeling method,[7 ] and stent-assisted coils embolization.[8 ] The treatment of ruptured or unruptured aneurysm with intracranial stent has a higher
complication rate because of stent predisposing to thrombosis and requires antiplatelet
therapy which may increase the possibility of bleeding in postoperative period.[9 ]
[10 ] Therefore, double microcatheter (MC) is another technique for ruptured or nonruptured
broad-necked intracranial aneurysm treatment. In our study, it tried to assess the
safety and efficacy of this technique.
Materials and Methods
Patient Sample
This study included 16 patients with 16 broad-necked ruptured intracranial aneurysms
who underwent double MC coil embolization between December 2021 and December 2023
at our center. There were seven males and nine females with a male-to-female ratio
of 1:1.3. The mean age of patients was 51.3 years (range 35–70 years). Broad-necked
aneurysm was defined as a neck diameter ≥4 mm and dome-to-neck diameter less than
2 mm. The mean neck diameter was 4.5 (range 4–5.3) mm. Demographic information including
the patient's age and sex, clinical manifestations (Hunt and Hess grade), and aneurysm
morphology (neck, dome, and height) were carefully reviewed ([Table 1 ]). Modified Rankin scale (mRS) score at the time of discharge and follow-up was applied
to evaluate the clinical outcome. The angiographic results were classified according
to Raymond–Roy occlusion classification system[11 ] as follows: class 1: no filling of aneurysm neck or dome; class 2: residual filling
of neck but not dome; and class 3: residual filling of neck and dome. Large aneurysm
with wide neck can be treated by single MC but chances of recurrence are more in such
cases, so we excluded this aneurysm. And double MCs are also dangerous to place in
very small aneurysm having dome diameter less than 4 mm with wide neck. So, we included
moderate-sized aneurysms with neck diameter >4 mm having dome to neck ratio <2. Initial
and angiographic follow-up also were reviewed. Overall, follow-up ranged from 2 to
10 months, with a mean of 4.8 months.
Table 1
Patient and aneurysm characteristics
Characteristics
Frequency (n = 16)
Age (y)
51.3 (35–70)
Sex
Male
7 (43.7%)
Female
9 (56.3%)
Mean admission GCS
10.9 (8–15)
Mean admission Fisher 's scale
1.8 (I–IV)
Mean admission Hunt and Hess grade
1.7 (1–4)
Aneurysm location
Anterior circulation
12 (75%)
AcomA
5 (41.7%)
PcomA
1 (8.3%)
DACA
1 (8.3%)
MCA
5 (41.7%)
Posterior circulation
Basilar artery
4 (25%)
Aneurysm size (mm)
Mean neck diameter
4.5 (4–5.3)
Mean fundus diameter
4.7 (4–6)
Mean height diameter
5.3 (4.5–6.6)
Medical history
HTN
5 (31.2%)
DM
1 (6.3%) %
HTN + DM
3 (18.8%)
No history
7 (43.7%)
Mean hospital stay (d)
8 (5–14)
Mean follow-up (mo)
4.8 (2–10)
Abbreviations: AcomA, anterior communicating artery; DACA, distal anterior cerebral
artery; DM, diabetes mellitus; GCS, Glasgow coma scale; HTN, hypertension; MCA, middle
cerebral artery; PcomA, posterior communicating artery.
Techniques
All aneurysms were performed on a monoplane angiography unit using a common femoral
approach under general anesthesia. A 3,000 IU heparin bolus was administered before
placement of the guiding catheter followed by a continuous infusion of 10 IU/kg/h.
The morphologic characteristics of the aneurysm were carefully evaluated including
the size of the neck, width and height; the diameter and tortuousness of the parent
artery; major branches originating from aneurysmal sac with digital subtraction angiography
along with 3D angiographic reconstruction technique. A hemostatic valve with three
ports was connected with a 6F long sheath (6 × 90; Cook). A long sheath was placed
in the common carotid artery/subclavian artery with the help of a 5F diagnostic catheter
(Vert, Cook) and 0.035-inch glide wire (Radio Focus, Terumo). We selected a catheter,
1.7F (distal) 2.4F (proximal) of excelsior SL-10 where two such MCs can be easily
accommodated and manipulated without any difficulties through a 6F guiding catheter.
Envoy 6F guiding catheter (Envoy, Codman) through which two MCs can be advanced was
positioned in the C3 segment of the internal carotid artery/V3 segment of the vertebral
artery with the help of a guiding wire. Then MC (Excelsior SL 10, Stryker) was placed
in the sac of an aneurysm with the support of 0.014-inch microwire (Synchro 2, Stryker).
Another Excelsior SL 10 was placed in the sac of an aneurysm below the first MC ([Fig. 1 ]). Soft helical (Target 360 Ultra, Stryker or Optima, Balt) or 3D coil (Axium 3D,
eV3) was first attempted into the aneurysm to form a relatively stable frame. Actually,
we used to deploy both coils simultaneously or one or two loops of first coil followed
by second coil loops so that both coils interlock with each other preventing prolapse
of coils loop into the parent vessel. So, depending on this method rather than choosing
the first long coils, we choose two coils of similar dimensions approximately half
of the coils' dimension chosen in the case of a single coil to be used for simple
coiling. After a stable frame was obtained, one of the two coils was detached, and
the next smaller coil was advanced to fill the frame. This process was continued alternatively
until the aneurysms were as densely packed as possible.
Fig. 1 Angiography of a 66-year-old woman with a ruptured aneurysm. (A, B) The vertebral
artery angiogram shows lateral and cranial views of the basilar artery aneurysm. I
3D reconstruction image shows wide-necked basilar tip aneurysm (neck fundus × height:
5.2 × 5.9 × 6.1 mm). (D) Two microcatheters are positioned in aneurysm sac. First
coil, complex-10, supersoft (Optima, Balt) 5 mm × 10 cm was advanced from the first
microcatheter but not detached. Frame complex (Axium Prime, eV3) 3.5 mm × 8 cm was
advanced from the second microcatheter and the coil from the first microcatheter was
detached. Then, bare platinum (Axium Prime) 3 mm × 6 cm, complex-10, supersoft 2.5 mm × 4 cm,
and complex-10, supersoft 2 mm × 6 cm were deployed. (E) Immediately after coil embolization,
the angiogram shows compact occlusion of aneurysmal sac. (F) Six months after embolization,
the angiogram shows no interval changes and stable coils.
Results
A total of 16 patients were treated with double MC technique between December 2021
and December 2023; 43.7% were male and 56.3% were female with a mean age of 51.3 years.
Seven patients (43.7%) had no medical history; three patients (18.8%) had both hypertension
(HTN) and diabetes mellitus (DM) history; five patients (31.2%) and one patient (6.3%)
% had only a history of HTN and DM, respectively. We reported that eight patients
(50%) had Hunt and Hess grade 1, five patients (31.2%) had Hunt and Hess grade 2,
two patients (12.5%) had Hunt and Hess grade 3, and one patient (6.3%) had Hunt and
Hess grade 4 at the time of admission.
The majority of aneurysms (75%) were located in anterior location, including anterior
communicating artery (n = 5, 41.7%), distal anterior cerebral artery (n = 1, 8.3%), posterior communicating artery (n = 1, 8.3%), and middle cerebral artery (n = 5, 41.7%). Four aneurysms (25%) were located in posterior circulation of basilar
artery. The mean neck diameter, mean dome diameter, and mean height diameter were
4.5 (4–5.3) mm, 4.7 (4–6) mm, and 5.3 (4.5–6.6) mm, respectively. Immediately postprocedure,
Raymond–Roy occlusion class I in 13 patients (81.2%) and occlusion Raymond–Roy occlusion
class II in 3 patients (18.8%) were noted. There were eight patients who had mRS score
0, five patients had mRS score 1, two patients had mRS score 2, and one patient had
mRS score 3 during discharge period ([Table 2 ]). One patient developed aphasia in next day of coils embolization. We performed
angiography, but no procedural-related complication was found. Patient improved in
aphasia after 4 days. No any procedure-related complications and recanalization of
aneurysms were found at the follow-up period.
Table 2
Procedure-related clinical and angiographic outcomes at discharge as well as follow-up
period
Characteristics
Frequency
Raymond–Roy scale (at procedure time)
Class I
13 (81.2%)
Class II
3 (18.8%)
Class III
0 (0%)
Raymond–Roy scale (at follow-up)
Class I
14 (87.5%)
Class II
2 (12.5%)
Class III
0 (0%)
Modified Rankin score (at discharge time)
0
8 (50%)
1
5 (31.2%)
2
2 (12.5%)
3
1 (6.3%)
4
0 (0%)
5
0 (0%)
6
0 (0%)
Modified Rankin score (at follow-up)
0
11 (68.7%)
1
5 (31.3%)
2
0 (0%)
3
0 (0%)
4
0 (0%)
5
0 (0%)
6
0 (0%)
Complication
0 (0%)
Discussion
Before the evolution of endovascular technique, surgical management was the most common
method to treat aneurysm by the use of clip across the neck of aneurysm. An Italian
neurosurgeon, Guido Guglielmi in 1990 first introduced detachable platinum coils for
the management of intracranial aneurysm by endovascular technique. Aneurysm treatment
by the endovascular method has comparatively lower morbidity and mortality than surgical
clipping.[12 ] However, permanent morbidities and mortality, incomplete aneurysmal occlusion or
coils breach into parent vessels, or recanalization leading to required retreatment
for management of broad-necked intracranial aneurysm by endovascular technique have
been described.[3 ]
[13 ]
[14 ] Treatment for broad-necked intracranial aneurysm has been reported with various
techniques such as balloon remodeling techniques[7 ] and intracranial stent[8 ] and multiple MC technique[15 ] have been described in the literature.
Neck remodeling technique with balloon or stent has previously been performed to treat
broad-necked aneurysm that helps the formation of coils compactness by preventing
coils migration into parent vessels; however, there are some limitations and technical
troubles in carrying out them. Some studies reported raised risk of aneurysm rupture
because of compressive pressure created by balloon inflation; raised the risk of distal
ischemic complication by temporary vessel occlusion, dissection of vessels, and thromboembolic
complication by balloon remodeling technique.[7 ]
[16 ]
[17 ] Overall incidences of thromboembolic events with balloon- and stent-assisted techniques
ranging from 4 to 14%[18 ]
[19 ] and from 0 to 21%,[20 ]
[21 ]
[22 ]
[23 ]
[24 ] respectively, have been mentioned. A study done for wide-necked aneurysm treatment
with dual MC technique described that thromboembolic complication and intraoperative
aneurysmal rupture were found in six (10.7%) patients and one (1.8%) patient, respectively.[25 ] Similarly, Lee et al reported that thromboembolic complication in 11 (14.6%) patients,
permanent neurological deficit in 1 (1.3%) patient, and coils migration in 2 (2.7%)
patients were noted.[26 ]
Double MC technique is new concept that helps to make stable coils frame under support
of a MC such as balloon- and stent-assisted techniques for wide-necked intracranial
aneurysm. However, this technique has also minimal likelihood in increased risk of
thromboembolic complication with the use of double MC as compared with multiple balloon-
and stent-assisted techniques. Continuous catheter infusion with systemic heparinization
(10 IU/kg/h) should be used to prevent from thromboembolic complication. We did not
find any thromboembolic event in our patients. One of the drawbacks of ruptured or
nonruptured aneurysm with stent-assisted coiling is that dual antiplatelet therapy
is inevitably needed pre- and postoperatively because stent has property of generation
of thrombus,[20 ]
[21 ] lead to tendency of bleeding complication at postoperative period. But, double MC
technique does not require long-term antiplatelet therapy. Therefore, we can believe
that the treatment of ruptured broad-necked intracranial aneurysm is safe and effective
by double MC.
A good clinical outcome (mRS score, 0–2) was observed in 93.7% patients at the time
of discharge in our case series, whereas 64.3% patient had good outcome (mRS score,
0–2) at the time of discharge.[25 ] Durst et al explained that an excellent clinical outcome (mRS score, 0–2) was noted
in 93% of patients at long-term follow-up period, whereas 100% patients had excellent
clinical outcome (mRS score, 0–2) at the follow-up period (range, 2–10 month) in our
study.[27 ] Xu et al described total occlusion (Raymond–Roy occlusion class I) in 46 (79%) aneurysm,
a neck remnant (Raymond–Roy occlusion class II) in 7 (13%), and body filling (Raymond–Roy
occlusion class III) in 5 (8%); and complication rate associated with technique was
5% (3/58); procedure-related mortality was 0%, and recanalization developed in 3 (9%)
at the mean follow-up of 12.5 months.[28 ] Similarly, Yoon et al described that total occlusion (Raymond–Roy occlusion class
I) in 27 (48.2%) aneurysms, contrast filling neck of aneurysm (Raymond–Roy occlusion
class II) in 15 (26%), and contrast filling the sac of aneurysm (Raymond–Roy occlusion
class III) in 14 (25%), and technique-related complication rate was 5% (3/58), procedure-related
mortality was 0%, and recanalization developed in 21 (56.8%) at the mean follow-up
of 20.6 months.[25 ] In our case, there was no re-canalization reported at the mean follow-up of 4.8
months. However, our case report has some limitations such as number of cases are
too small size; angiographic follow -up period is too short, and it is retrospective
nature of the study. Therefore, larger numbers of case series with longer angiographic
follow-up information are required to evaluate safety and validity of double MC technique
for management of ruptured broad-necked intracranial aneurysms.
Conclusion
In this case study, it presents that the double MC technique is safe and effective
for management of ruptured broad-necked intracranial aneurysm with dual MC technique
when there is a probability of failure of coil compactness due to coils migration
or impingement. And it also replaces stent- and balloon-assisted coils embolization.
Therefore, double MC technique can be considered as an alternative option in broad-necked
intracranial aneurysm.
