With the development of endovascular technique and devices, large and giant intracranial aneurysms are increasingly being managed by this less invasive method. Here we discuss our experience on managing such aneurysms via endovascular technique.
Retrospective data on 42 patients with large and giant intracranial aneurysms managed by endovascular techniques between September 2015 to December 2017 at our neurosurgery institute were included in this analysis.
There were a total 42 patients with 9 giant and 33 large aneurysms in this study. Eight aneurysms were treated by parent vessel occlusion, 22 aneurysms with coils and rest 12 aneurysms were treated with stent assisted coiling. Following the procedure, Raymond class I occlusion was accomplished in 31 (73.8%) patients while class Ⅱ in 9 (21.4%) and class Ⅲ in 2 (4.8%) patients. Overall morbidity and mortality were 9.5% and 14.3% respectively and favorable outcome was seen in 80.9% patients. Significant correlation was observed with clinical outcome and initial neurological status.
The study indicates that endovascular intervention is a safe and effective method in managing large and giant intracranial aneurysms with lesser morbidity and mortality.
Large and giant aneurysms are defined as aneurysms between 15 to 25 mm and those having more than 25 mm respectively. They often manifest as a result of catastrophic hemorrhage, mass effect or due to episodes of thromboembolism [
It is a retrospective review of database of patients managed via endovascular technique from September 2015 to December 2017 at our institute. In 282 patients, 308 aneurysms were managed by endovascular technique. Of the total of 282 cases, 42 cases were identified as either large or giant (largest diameter more than 15 mm). Decision regarding whether to treat the cases by coiling or clipping was made by the treating neurosurgeons as both the procedures are performed in our department. However, the decision was predominantly made on the basis of morphology and characteristics of the feeder vessels with posterior circulation aneurysms, small neck, absence of large hematoma requiring evacuation, absence of vasospasm and multiple aneurysms some of the criteria used in favor of coiling. A patient’s demand for the endovascular procedure was even one of the criteria.
All patients at admission were evaluated neurologically using Hunt and Hess (H & H) grade and Glasgow coma scale. Clinical outcomes were evaluated according to modified Rankin Scale (mRS) score measured at 3rd month after the initial procedure. Achievement of mRS score of 0-2 was designated as favorable outcome while score of 3-6 was defined as unfavorable outcome.
Computed tomographic angiography and digital subtraction angiography (DSA) of the brain was performed in all patients at our department. On pre-operative DSA, routine note was made regarding the neck, width, height, location, morphology of the aneurysms and the cross flow.
The endovascular treatment of all aneurysms were performed with a standard technique under general anesthesia using 6-7 diagnostic catheter Cook (Cook Inc., Bloomington, IN, USA) and Cordis (Miami Lakes, FL, USA) and 7-F sheath, micro-guide wires of size 10 and 14 Transcend (Boston Scientific, Natick, MA, USA), Agility (Cordis, Miami Lakes, FL, USA) and Mirage (EV3, Plymouth, MN, USA) along with micro-catheter, Prowlers series and Prowler plus (Johnson & Johnson, Miami Lakes, FL, USA) as described by us in our previously published article [
The peri-operative antiplatelet therapy in ruptured aneurysms consisted pretreatment of 150 mg acetylsalicylic acid and 450 mg clopidogrel given 3-5 days before surgery as well as an hour after coil embolization via nasogastric tube and continued for a month when stentassisted coiling (SAC) was employed and for 6 months in parent vessel occlusion (PVO). We routinely used bolus of 5000 IU heparin immediately after insertion of femoral catheter intra-arterially followed by infusion of 1000 IU of heparin per 500 mL normal saline (0.9%) during the entire procedure. Continuous intravenous infusion of nimodipine at 5 mg/h was also administered throughout the procedure and continued post-procedure to prevent vasospasm. Large and giant aneurysms were defined as those with diameter greater than 15 mm and 25 mm respectively as measured by DSA. All patients were analyzed regarding the size and type of aneurysm.
At our institute, we perform balloon test occlusion (BTO) whenever permanent PVO is required and the patient should tolerate the procedure before he is deemed fit for PVO. We performed BTO in awake, heparinized patients under local anesthesia and assessed the neurological status of the patient post-procedure and noted the angiographic status of the vessels. A delay of >4s of venous drainage between the territories of the artery that has been injected and the occluded hemisphere was considered as cutoff for ineligibility for PVO, as described in another study [
Comparisons among different groups were analyzed by the use of paired t tests and statistical significance was defined as a probability value 0.05. Statistical analysis was done by SPSS (version 19.0, IBM Corp., Armonk, NY, USA).
There were total 42 patients with 42 large or giant aneurysm. Of them, 15 (35.7%) were male and 27 (64.3%) were female with a mean age of 47.8 years. There were 9 patients with giant aneurysms and 33 patients with large aneurysms. Six patients were admitted with symptoms associated with unruptured aneurysm and 36 patients were admitted with symptoms of subarachnoid hemorrhage. According to H & H grading 6 patients were in Grade 0, 11 in Grade I, 8 in Grade Ⅱ, 9 in Grade Ⅲ and 8 in Grade Ⅳ (
There was a total of 35 (83%) aneurysms, either giant or large that were located in anterior circulation and 7 (27%) aneurysms that were located in posterior circulation. In the anterior circulation, internal carotid artery (ICA) supraclinoid aneurysms were present in 20 (47.62%) patients whereas basilar top aneurysms topped the list in posterior circulation found in 5 (11.9%) patients (
All the 42 patients underwent endovascular management with the aim of alleviating symptoms and controlling further aneurysmal growth and a possible future bleed and mass effect due to the aneurysm. Eight aneurysms were treated by PVO, 22 aneurysms with coils and rest 12 aneurysms were treated with SAC. Immediately after the procedure, Raymond class I occlusion was accomplished in 31 (73.8%) patients while class Ⅱ in 9 (21.4%) and class Ⅲ in 2 (4.8%) patients. After recoiling was attempted in 2 of the class Ⅲ giant aneurysm patients, class Ⅱ result was obtained in one of them. Categorically, class I occlusion was achieved in 8 out of 8 (100%) of PVO cases, 9 out of 12 (75%) SAC cases and 14 out of 22 (63.6%) of coiling alone cases (
No intra-procedural mortality, iatrogenic dissection or aneurysmal rupture was seen in this study; however, stent-associated vasospasm was seen in 2 patients and coil protrusion was seen in 3 patients.
Every patient underwent angiographic evaluation after the procedure to assess the aneurysm obliteration and patency of the parent vessels. Follow-up angiographic studies were obtained for 1-34 months (mean, 10.6 months). The mRS score at 3rd month post the initial procedure ranged between 0-2 in 32 (80.9%) and 3-6 in 10 (19.1%) patients respectively. Overall morbidity and mortality were 4 (9.5%) and 6 (14.3%) respectively and favorable outcome was seen in 32 (80.9%) patients. In all the 6 unruptured aneurysm cases, there was good clinical and angiographic outcome. Of the 6 patients who died in the hospital, 4 had massive brain edema with increased intracranial pressure due to initial subarachnoid hemorrhage and not because of procedure related complications; on admission they had a poor H & H grade and were taken up for coiling due to large aneurysm size with massive subarachnoid hemorrhage. Delayed thrombotic occlusion occurred in two patients for which they underwent decompressive hemicraniectomy. Both the patients however died later.
In 3 patients there were partially thrombosed aneurysms and both were in anterior circulation. In 2 of them, PVO was performed and in one it was coiled. The latter patient developed infarction probably due to thromboembolism and decompressive hemicraniectomy was performed later.
All the 36 surviving patients were clinically followed for a mean of 12.7 months (range, 6-34 months) after the procedure. During this follow-up period, two patients had major recanalization between 10 and 16 months and both were successfully re-treated by coiling alone. Clinical outcome of the patients was related to neurological status at admission with mRS 6 seen only with Hunt and Hess grade 5 or 6 (p=0.02) while outcome of the procedure was not significantly related to the size of the aneurysm sac (p>0.05). Two illustrative cases are shown in
Large and giant intracranial aneurysms pose a major treatment challenge for the cerebrovascular neurosurgeons. These aneurysms in the internal carotid segment have a high blood flow velocity and are difficult to treat. In the posterior circulation, basilar top aneurysms have a wide neck and coiling of these aneurysms may become technically difficult sometimes requiring stents for support. Patients who present with ischemic symptoms secondary to hemodynamic insufficiency due to aneurysm in anterior circulation treated by permanent ICA occlusion can be improved by external carotid-internal carotid bypass done before the occlusion procedure as found in one study [
In view of the recent development of new endovascular devices these large or giant ICA aneurysms can be treated with low morbidity and mortality. SAC is emerging as an alternate method for PVO as the latter is not tolerated in a vast number of cases [
Framing a treatment strategy for large and giant aneurysms is difficult because of lack of large clinical trials and both open microsurgical and endovascular approaches exist. Microsurgical options are effective in immediate dome occlusion but are associated with significant morbidity [
Coiling, however cannot abate the mass effect due to compression of some large aneurysms [
Balloon and SAC techniques have been one of the milestones in the endovascular treatment of complex intracranial aneurysms but at present flow-diversion devices represent the latest revolution in treatment of endovascular aneurysms and the treatment is changing from aneurysm embolization to parent vessel reconstruction specially in fusiform aneurysms [
In partially thrombosed aneurysms the PVO was a better procedure as there was no morbidity following it. In one case where the partially thrombosed aneurysm was occluded by coils, thromboembolism occurred which would have been due to the dislodgment of a part of thrombus during placement of microcatheter or when the coils were deployed.
Coiling or SAC of large and giant aneurysms is associated with reasonably low morbidity and mortality in good H & H grade patients. The flow diversion devices are a promising method to treat such aneurysms but the drawback of them are that they are costly and out of reach to the common man. Better yet inexpensive endovascular devices are needed to obtain more secure occlusion.
The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
(A) Non-contrast computed tomography brain showing a slightly hyperdense area anterior to the midbrain. (B) CT Angiography brain showing a giant saccular aneurysm but the site of origin could not be established. (C) DSA showing a basilar top aneurysm filling from the left vertebral artery. (D) Post coiling DSA showing decreased filling. CT, computed tomography; DSA, digital subtraction angiography.
(A) DSA showing a large saccular aneurysm arising from left cavernous segment directed antero-medially. (B) Post-SAC procedure showing satisfactory obliteration of the sac. DSA, digital subtraction angiography; SAC, stent-assisted coiling.
Demography and aneurysm characteristic of the studied patients
S. No. | Age/Sex | Diagnosis | Size (mm)/Shape | Aneurysm status | H & H grade | mRS |
---|---|---|---|---|---|---|
1 | 40Y/M | Right ICA supraclinoid | 16×18 mm, saccular | R | 3 | 3 |
2 | 42Y/F | Left ICA supraclioid | 19×22 mm, saccular, multilobular | R | 2 | 2 |
3 | 69Y/F | Basilar top | 18×22 mm, fusiform | R | 1 | 1 |
4 | 42Y/F | Left ICA supraclinoid | 252×7 mm, fusiform | R | 1 | 0 |
5 | 27Y/F | Left ICA ophthalmic | 45×42 mm, saccular | U | 0 | 0 |
6 | 34Y/M | Right ICA supraclinoid | 15×16 mm, saccular | R | 4 | 4 |
7 | 40Y/F | Right ICA cavernous | 26×30 mm, fusiform | R | 4 | 6 |
8 | 40Y/F | Basilar top | 27×29 mm, fusiform | R | 3 | 2 |
9 | 25Y/M | Left P1-Pcomm | 17×15 mm, saccular | R | 2 | 2 |
10 | 70Y/M | Left ICA supraclinoid | 20×22 mm, saccular | U | 0 | 0 |
11 | 57Y/F | Right ICA paraclinoid | 18×17 mm, saccular | R | 4 | 6 |
12 | 43Y/M | Right ICA paraclinoid | 18×16 mm, saccular | R | 3 | 6 |
13 | 55Y/F | Right MCA bifurcation | 22×25 mm, saccular | R | 1 | 0 |
14 | 32Y/M | Left ICA supraclinoid | 17×19 mm, saccular | R | 1 | 0 |
15 | 40Y/M | Right ICA paraclinoid | 20×22 mm, saccular | R | 2 | 1 |
16 | 30Y/M | Left MCA bifurcation | 18×17 mm, saccular | R | 1 | 0 |
17 | 54Y/F | Right ICA supraclinoid | 22×24 mm, saccular | R | 3 | 2 |
18 | 30Y/M | Left ICA supraclinoid | 16×19 mm, saccular | R | 2 | 0 |
19 | 44Y/F | Right MCA bifurcation | 16×17 mm, saccular | R | 4 | 3 |
20 | 46Y/F | Right ICA cavernous | 19×18 mm, saccular | R | 2 | 1 |
21 | 55Y/F | Anterior communicating artery | 16×18 mm, saccular | R | 1 | 0 |
22 | 64Y/F | Basilar top | 27×30 mm, fusiform | R | 4 | 6 |
23 | 60Y/F | Right MCA bifurcation | 16×18 mm, saccular | R | 4 | 6 |
24 | 40Y/F | Right ICA supraclinoid | 20×22 mm, saccular | R | 3 | 2 |
25 | 42Y/F | Left MCA bifurcation | 19×19 mm, saccular | R | 4 | 3 |
26 | 55Y/F | Right ICA cavernous | 17×18 mm, saccular | R | 1 | 1 |
27 | 45Y/F | Left ICA-posterior communicating artery | 18×19 mm, saccular | R | 3 | 2 |
28 | 28Y/M | Left ICA-posterior communicating artery | 16×14 mm, saccular, bilobed | R | 1 | 1 |
29 | 25Y/F | Left ICA bifurcation | 17×15 mm, saccular | R | 3 | 2 |
30 | 60Y/F | Left ICA cavernous | 23×14 mm, saccular | U | 0 | 0 |
31 | 65Y/F | Left ICA cavernous | 23×21 mm, saccular | U | 0 | 0 |
32 | 38Y/M | Right ICA cavernous | 18×14 mm, saccular | U | 0 | 0 |
33 | 52Y/M | Left ICA cavernous | 19×18 mm, fusiform | R | 2 | 2 |
34 | 65Y/F | Right MCA bifurcation | 22×24 mm, saccular | R | 3 | 1 |
35 | 65Y/F | Left MCA bifurcation | 27×25 mm, saccular | R | 1 | 0 |
36 | 70Y/F | Basilar top | 27×22 mm, fusiform | R | 4 | 6 |
37 | 65Y/F | Right PICA | 18×19 mm, saccular | R | 2 | 1 |
38 | 55Y/M | Right PCA | 18×20 mm, saccular | R | 3 | 1 |
39 | 40Y/M | Basilar top | 28×27 mm, saccular | R | 1 | 0 |
40 | 52Y/F | Right ICA bifurcation | 15×15 mm, saccular | R | 1 | 0 |
41 | 62Y/F | Left ICA ophthalmic | 27×26 mm, saccular | U | 0 | 0 |
42 | 45Y/M | Right ICA-posterior communicating artery | 22×23 mm, saccular | R | 2 | 0 |
H & H, Hunt and Hess; mRS, modified Rankin Scale; ICA, internal carotid artery; MCA, middle cerebral artery; PICA, posterior inferior cerebellar artery, PCA, posterior cerebral artery; R, ruptured; U, unruptured.
Anatomical location of the aneurysms
Location | Number |
---|---|
35 | |
1. Right carotid supraclinoid | 9 |
2. Left carotid supraclinoid | 11 |
3. Right carotid cavernous | 2 |
4. Left carotid cavernous | 3 |
5. Right posterior communicating | 2 |
6. Left carotid ophthalmic | 2 |
7. Right middle cerebral artery | 2 |
8. Anterior communicating artery | 2 |
9. Left middle cerebral artery | 1 |
10. Right distal anterior cerebral artery | 1 |
7 | |
1. Basilar top | 5 |
2. Right posterior inferior cerebellar artery | 1 |
3. Left vertebral artery | 1 |
4. Right posterior cerebral artery | 1 |
Degree of occlusion after the initial procedure
Degrees of occlusion | Coiling only |
Stent-assisted coiling |
PVO |
Total | |||
---|---|---|---|---|---|---|---|
Large aneurysm | Giant aneurysms | Large aneurysm | Giant aneurysms | Large aneurysm | Giant aneurysms | ||
Raymond class I | 12 | 2 | 8 | 1 | 5 | 3 | 31 |
Raymond class II | 5 | 1 | 3 | 9 | |||
Raymond class III | 2 | 2 |
PVO, parent vessel occlusion