Atormac
Neurology India
Open access journal indexed with Index Medicus
  Users online: 1673  
 Home | Login 
About Current Issue Archive Ahead of print Search Instructions Online Submission Subscribe Videos Etcetera Contact
  Navigate Here 
 Search
 
  
 Resource Links
  »  Similar in PUBMED
 »  Search Pubmed for
 »  Search in Google Scholar for
 »Related articles
  »  Article in PDF (4,841 KB)
  »  Citation Manager
  »  Access Statistics
  »  Reader Comments
  »  Email Alert *
  »  Add to My List *
* Registration required (free)  

 
  In this Article
 »  Abstract
 » Methods
 » Results
 » Case Illustrations
 »  Pathological Ana...
 » Discussion
 » Conclusion
 »  References
 »  Article Figures
 »  Article Tables

 Article Access Statistics
    Viewed91    
    Printed1    
    Emailed0    
    PDF Downloaded13    
    Comments [Add]    

Recommend this journal

 


 
Table of Contents    
NI FEATURE: CENTS (CONCEPTS, ERGONOMICS, NUANCES, THERBLIGS, SHORTCOMINGS) - ORIGINAL ARTICLE
Year : 2018  |  Volume : 66  |  Issue : 6  |  Page : 1741-1757

Surgery for very large and giant intracranial aneurysms: Results and complications


1 Department of Neurosurgery, University of Washington, Seattle, Washington, USA
2 Department of Radiology, University of Washington, Seattle, Washington, USA
3 Department of Pathology, University of Washington, Seattle, Washington, USA

Date of Web Publication28-Nov-2018

Correspondence Address:
Dr. Laligam N Sekhar
Department of Neurosurgery, Harborview Medical Center University of Washington, 325 Ninth Ave. Box 359924 Seattle, WA 98104
USA
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0028-3886.246291

Rights and Permissions

 » Abstract 


Background: Results of and the complications encountered during surgery for very large and giant intracranial aneurysms are illustrated.
Objective: To analyze a consecutive series of patients with very large and giant aneurysms treated with microsurgery.
Methods: This retrospective study included seventy six very large and giant aneurysms which were managed by clipping and bypass technique. Sixty two (82%) aneurysms were located in anterior circulation, and 14 (18%) aneurysms were located in posterior circulation. The bypasses performed included local bypasses, extra-intracranial bypasses, double bypasses and combination techniques of external carotid-internal carotid (EC-IC) bypass and local bypasses.
Results: 73 patients with 76 aneurysms were treated over 13 years. There were 44 very large and 32 giant aneurysms. Twenty-four patients presented with subarachnoid hemorrhage [SAH] (32%) while forty nine patients with 52 aneurysms (68%) were unruptured. These 73 patients underwent 63 bypass procedures with aneurysm occlusion and 13 clipping procedures. Out of 62 anterior circulation aneurysms, bypass surgery was performed in 49 patients while 13 underwent clipping. In posterior circulation aneurysms, all patients were treated with bypass procedures with proximal occlusion or trapping. In the ruptured group, 16 (67%) patients had postoperative modified Rankin Scale (mRs) 0-2, six patients (25%) had mRs 3-5, and two patients (8.4%) died. In the unruptured group, 45 patients (87%) had mRs 0-2, 3 patients (6%) had mRs 3-5, and four patients (7.6%) died.
Conclusions: In this large series of very large and giant aneurysms treated with microsurgical clipping and bypasses, excellent results were obtained in the long term, in regards to aneurysm occlusion, functional status, and graft patency. Our experience will be very useful to other neurosurgeons who treat these complex lesions


Keywords: Aneurysm clipping, bypass surgery, complication, internal carotid artery, large and giant intracranial aneurysms, outcome, revascularization, ruptured aneurysm, subarachnoid hemorrhage, unruptured aneurysm, vertebral artery
Key Message: Very large (18-24mm) and giant (>25mm) aneurysms are associated with a high risk of subarachnoid hemorrhage and cerebral compression with mass effect. Their microsurgical treatment, consisting of clip reconstruction, bypass with clipping and trappin or proximal occlusion, along with the outcome and complications of surgical treatment have been illustrated.


How to cite this article:
Zeeshan Q, Ghodke BV, Juric-Sekhar G, Barber JK, Kim LJ, Sekhar LN. Surgery for very large and giant intracranial aneurysms: Results and complications. Neurol India 2018;66:1741-57

How to cite this URL:
Zeeshan Q, Ghodke BV, Juric-Sekhar G, Barber JK, Kim LJ, Sekhar LN. Surgery for very large and giant intracranial aneurysms: Results and complications. Neurol India [serial online] 2018 [cited 2018 Dec 10];66:1741-57. Available from: http://www.neurologyindia.com/text.asp?2018/66/6/1741/246291




Aneurysms can be classified as very small (≤5 mm), small (5–9 mm), large (10–17 mm), very large (18–24 mm) or giant (defined as those ≥25 mm).[1],[2] Very large (VL) and giant aneurysms are associated with a high risk of subarachnoid hemorrhage (SAH) and cerebral compression with mass effect. They are considered as one of the most challenging lesions to manage and have a poor outcome and prognosis. The outcome in the management of giant aneurysms are very poor because of the higher risk of rupture and mass effect, leading to a high morbidity and mortality.[1],[2],[3] Untreated giant aneurysms have a mortality rate of 68% and 85% at 2 and 5 years after diagnosis, respectively.[4]

According to the International Study of Unruptured Intracranial Aneurysms, the chances for rupture are significantly higher in giant aneurysms. In anterior circulation, the annual rate of bleeding for aneurysms sized 7-12 mm and 13-24 mm is 0.5% and 2.9%, respectively, which increases significantly to 8% for the aneurysms greater than 25 mm. In posterior circulation including the internal carotid artery-posterior communicating artery (ICA-PCOM), the annual rate of bleeding for aneurysms sized 7-12 mm and 13-24 mm is 2.9% and 3.7%, respectively, which increases significantly to 10% for the aneurysms greater than 25 mm. Location also plays a crucial role in dictating morbidity and mortality with posterior circulation aneurysms having a higher mortality rate than those found in the anterior circulation.[3] An advanced age and associated comorbidities also play a pivotal role in the prognosis of these patients.

According to the Japanese unruptured aneurysm study, the overall rate of rupture of cerebral aneurysms is 0.95% annually. The risk of rupture increases with the increasing size of the aneurysm. The hazard ratios for size categories for aneurysms in the size range of 5 to 6 mm was 1.13; for the size range of 10 to 24 mm was 9.09; and, for aneurysms sized 25 mm or larger, it was 76.26. Regarding the independent risk factors for rupture, aneurysms of 7 mm size or larger were associated with a significantly increased risk of rupture according to the multivariate analysis; and large and giant aneurysms were associated with a very high risk of rupture.[5]

These aneurysms can be treated by the endovascular methods (coiling, stent assisted coiling, stent and balloon assisted coiling and flow diversion stents). Microsurgical treatment consists of clip reconstruction, bypass with clipping and trapping or proximal occlusion. In this publication, we have reviewed the outcome and complications of surgical treatment by a single surgeon over a 13-year period.


 » Methods Top


All patients were operated on by LNS with assistance in some patients by LJK or BVJ. The record review was performed by ZQ following approval from the institutional review board, University of Washington. Pathological examination of the removed aneurysmal wall was done by GJS, a neuropathologist. Record review included evaluation of the patients’ charts, radiographic studies, and follow up. The patient demographics, clinical presentation, preoperative imaging (computed tomographic angiography [CTA], magnetic resonance imaging [MRI], digital subtraction angiography [DSA]), the decision making process (based on clinical history, location/size/morphology of the aneurysm and peri-aneurysmal vessels; availability of donor or conduit vessels), intra- and post-operative imaging (indocyanine green [ICG], DSA, MRI, computed tomography [CT]), hospital course, clinic and outpatient follow up (complications and outcomes assessed by mRs) and delayed imaging (CTA, MRA, DSA looking for occlusion of the aneurysm, bypass and recipient vessel patency, and final stroke territories if any) were reviewed retrospectively. In all cases, an operative drawing by the senior author (LNS) was converted into a drawing by a medical illustrator. Statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) software.

In many cases, an experienced neuro-interventionist was involved in the decision making strategy as well as patient counseling when required. If there was a strong likelihood of a bypass during the operation, the patients were given 325 mg of aspirin orally, or 150 mg of clopidogrel, if an allergy to aspirin was present. During surgery, the patient was placed in burst suppression by the anesthesiologist to protect the brain; and, the blood pressure was kept normal (in the case of ruptured aneurysms), or elevated 20% (in the case of unruptured aneurysms). The patient was given 2,500 to 3,000 units of intravenous heparin during the bypass. Neurophysiological monitoring of somatosensory evoked potentials (SSEPs), and motor evoked potentials (MEPs) was used in all but a few emergent cases (in the latter cases, it was not available).

The decision to proceed with the cerebral revascularization was done on the basis of the preoperative aneurysm characteristics. The choice of the grafting procedure and bypass conduit was based on the flow required, the complexity of surgery, and the artery being replaced. The techniques used for the bypasses by the senior author have been presented in other papers.[6],[7],[8],[9],[10],[11]

The patients operated recently underwent an indocyanine green angiogram, and micro Doppler studies intraoperatively, and in all patients, a postoperative intra-arterial digital subtraction angiogram (IADSA) was performed as well as the duplex ultrasonographic imaging of the graft.

Modified Rankin score scale (mRs) was used to measure the preoperative and postoperative functional status of patients, in those patients with an unruptured aneurysm. In the cases with an ruptured aneurysm, the preoperative Hunt and Hess grade and the mRs scores were measured. The patients were followed up with regular clinic visits at eight weekly intervals for 6 months, and then at six months interval thereafter.


 » Results Top


A total of 703 aneurysms were operated upon between 2005 to 2018 by the senior author with VL or giant aneurysms being present in 76 cases. VL and giant aneurysms made up 11% of the total aneurysms operated during this time span. Overall, there were 44 VL and 32 giant aneurysms – 62 were in the anterior circulation (35 in the internal carotid artery, 17 in the middle cerebral artery, 8 in the anterior communicating artery, and 2 in the anterior cerebral artery), while 14 were found in the posterior circulation (3 in the vertebral artery, 8 in the basilar artery and 3 in the posterior cerebral artery) [Table 1], [Table 2], [Table 3].
Table 1: Number of aneurysms operated between 2005-2018 (n=703)

Click here to view
Table 2: Demographics of patients with aneurysms operated between 2005.2018 (n=703)

Click here to view
Table 3: Location of aneurysms

Click here to view


Twenty-four patients presented with SAH (32%); while in forty-nine patients, 52 aneurysms (68%) were unruptured. Out of a total of 76 aneurysms, 63 aneurysms were treated with a bypass procedure and aneurysm occlusion, and 13 aneurysms were treated by microsurgical clipping. Out of 62 anterior circulation aneurysms, the bypass surgery was performed in 49 patients and 13 underwent clipping. In the posterior circulation, all aneurysms were treated with the bypass procedure with aneurysm occlusion [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10]. Sixty-nine of the aneurysms presented de novo; 3 were recurrent after the patients harboring them had already undergone previous surgery for clipping the aneurysm; and, 4 were recurrent, as the patients harboring them had already undergone prior coiling or flow diversion procedures.
Table 4: Treatment of very large and giant aneurysms in relation to location (n=76)

Click here to view
Table 5: Outcome of unruptured aneurysms (n=52)

Click here to view
Table 6: Outcome of ruptured aneurysms (n=24)

Click here to view
Table 7: Outcome of studied patients (n=76)

Click here to view
Table 8: Complications of studied aneurysms (n=76)

Click here to view
Table 9: Treatment and outcome of anterior circulation aneurysms (n=62)

Click here to view
Table 10: Treatment and outcome of posterior circulation aneurysms

Click here to view


Unruptured aneurysms: There were 31 (60%) patients with the preoperative mRs score from 0-2, and 21 (40%) patients with the mRs score from 3-5. Postoperatively, 45 patients (87%) had an mRs score of 0-2, 3 patients (6%) had an mRs score of 3-5, and four patients (7%) died [Table 5].

Ruptured aneurysms: There were five (21%) patients with the preoperative Hunt and Hess grade being 3-5, and all had a poor outcome, with 3 patients having the postoperative mRs 3-5, while two expired. Of the 19 (79%) patients who had the preoperative Hunt and Hess grade 1-2, sixteen patients had an mRs score of 0 -2 and only three patients had an mRs score of 3-5 at the last follow up [Table 6].

On the long-term follow up visit, 99% of the aneurysms were found to be occluded. The mean clinical follow up duration was 32.3 months (range: 2 -118 months) and the mean radiological follow up was 29 months (range: 2-104 months).

Statistical analysis

The preoperative and postoperative mRs score for the unruptured cases were compared statistically by dichotomizing mRs scores at 0-2 and 3-6 and using a McNemar two-sided exact test. It concluded from this evaluation that the postoperative mRs was significantly better (P = 0.004) than the preoperative mRs, denoting a good outcome in patients with unruptured aneurysms treated by microsurgery [Table 5].

The relationship between the preoperative Hunt and Hess grade and the postoperative mRs score in the ruptured cases was assessed using a Kruskal-Wallis two-sided exact test. The preoperative Hunt and Hess grade was significantly related to the postoperative mRs score (P < 0.001), as the patients with the preoperative mRs score of 1-2 had a much lower postoperative mRs than the patients who had the preoperative mRs score of between 3-5. This analysis demonstrates that the outcomes after surgery were strongly correlated to the preoperative Hunt and Hess grade for ruptured giant aneurysms [Table 6].

Complications

Ruptured aneurysms: Four patients suffered a brain infarction, out of which two made a good recovery and two expired. One patient had an intraoperative rupture of the aneurysm after the induction of anesthesia prior to dural incision. This patient had a postoperative mRs score of 4 at follow up of two years. One patient developed wound infection and bone flap necrosis, which was managed by wound debridement. One patient developed postoperative extradural hematoma, which was managed conservatively. Three patients had graft-related complications. Out of these 3 patients, two patients required revision of the graft; and, one patient required balloon angioplasty of the graft.

Unuptured aneurysms: Four patients developed brain infarction. Out of these, two made a good recovery and two expired. Two patients with an unstable aneurysm had an intraoperative rupture of the aneurysms, and both died. Two patients had postoperative wound infection and two patients developed a subdural hematoma. Five patients suffered from graft-related complications; four underwent graft revision, and in one patient, balloon angioplasty of the graft was performed. The outcome and complications seen in the study are summarized in [Table 7] and [Table 8]. The analysis of patients with the postoperative mRs score of 3-5 is summarized in [Table 11], [Table 12], [Table 13]. The analysis of patients with the postoperative mRs 6 is summarized in [Table 14] and [Table 15].
Table 11: Analysis of patients with postoperative modified Rankin scale (mRS) 3-5

Click here to view
Table 12: Analysis of patients with postoperative modified Rankin scale (mRS) 3-5

Click here to view
Table 13: Analysis of patients with postoperative modified Rankin scale (mRS) 3-5

Click here to view
Table 14: Analysis of patients with anterior circulation aneurysms with postoperative modified Rankin scale (mRS) 6

Click here to view
Table 15: Analysis of patients with posterior circulation aneurysms with postoperative modified Rankin Scale (mRS) 6

Click here to view



 » Case Illustrations Top


Case 1: Giant anterior communicating artery aneurysm, clipping and A3-A3 side-to-side intracranial bypass

This 21-year old woman had a prior history of fibrous dysplasia and had undergone multiple surgeries in other institutions, which were complicated by bilateral blindness and panhypopituitarism. She presented to us with subarachnoid hemorrhage with her Hunt and Hess grade being 4. Neurological examination revealed an absence of light perception in both her eyes and right facial paresis. Cerebral angiography revealed a giant aneurysm arising from the left A2 vessel, projecting into the right frontal lobe with a large hemorrhage around the neck of the aneurysm. Clipping of the aneurysm along with A3-to-A3 bypass was planned. In the meantime, the patient had another rebleed with left frontal and left intraventricular hemorrhage and neurological deterioration. The patient underwent a bifrontal craniotomy, right orbital osteotomy, A3-to-A3, side-to-side anastomosis via an interhemispheric approach and trapping of the aneurysm [Figure 1]. She had a complex postoperative course with persisting vasospasm and the occurrence of cardiomyopathy requiring endovascular angioplasty and an intra-aortic balloon counterpulsion, respectively. She recovered without any additional neurological deficits and was discharged to domiciliary care. At a follow up of 5 years, she was doing well without any recurrence of the aneurysm.
Figure 1: (a and b) Axial and sagittal CT angiogram showing a large partially thrombosed anterior communicating artery aneurysm with calcification. (c) Three dimensional rotational angiographic reconstruction showing a multilobulated, irregular aneurysm. (d) Three dimensional illustration showing the A3-A3 bypass. (e) Three dimensional illustration showing clipping of the aneurusm and intraoperative rupture. (f) Postoperative DSA, right internal carotid artery injection showing A3-A3 bypass with clipped aneurysm with filling of both anterior cerebral arteries

Click here to view


Case 2: Giant anterior communicating artery aneurysm, temporary trapping to remove the clot, and clip reconstruction

This 62-year man presented with worsening headache. He had a history of having presented with a large anterior communicating artery aneurysm 3 years ago. Over the last three years, the aneurysm had significantly increased in size. It was bilobed, projecting toward the ventricle on both the sides, the right lobe being larger than the left. The aneurysmal sac was heavily thrombosed. The overall dimension of the aneurysm was 43 mm in the transverse axis, 23 mm in the superior/inferior axis, and 27 mm in the anteroposterior axis. When assessed by the angiographic images, the filling portion of the aneurysm measured 7.8 × 9.7 × 14.2 mm, with a very broad neck that measured 11 mm. The aneurysm was filling predominantly via the large left A1 artery, although there was also a small right A1 vessel. The patient underwent a bifrontal craniotomy, an orbitofrontoethmoidal osteotomy with an interhemispheric and basal frontal approach [Figure 2]. Microsurgical clipping of the aneurysm was done after its temporary trapping and removal of the clot. The patient had a good recovery without any deficit. At a follow up of seven years, he has been asymptomatic without aneurysm recurrence.
Figure 2: (a and b) Magnetic resonance imaging and maximum intensity projection rendering sequence showing the partially thrombosed lobulated anterior communicating artery aneurysm. (c) DSA, right internal carotid artery injection, anteroposterior view showing the non thrombosed portion of the aneurysm with both anterior cerebral artery filling. (d) DSA showing the hypoplastic right anterior cerebral artery with both arteries cerebral arteries filling from the left internal carotid artery. (e) DSA oblique view after left internal carotid artery injection showing neck of the aneurysm. (f and g) Three dimensional illustration showing the operative anatomy. (h) Three dimensional illustration showing aneurysmorraphy with clipped aneurysm. (i) Three dimensional rotational angiographic reconstruction showing the clip reconstruction of the aneurysm

Click here to view


Case 3: Double M1-middle cerebral artery aneurysm, resection with interposition graft

This 4-year old girl presented with episodes of severe headaches for two months. Cerebral angiogram revealed two fusiform middle cerebral artery (MCA) aneurysms measuring 25 mm and 14 mm and involving the M1 segment, straddling the anterior temporal artery. She underwent a right frontotemporal craniotomy and orbitotomy, and resection of the two aneurysms. A radial artery graft was placed as an interposition graft. The anterior temporal artery was occluded, and no lenticulostriate artery was seen arising from the M1 segment [Figure 3]. Her postoperative mRs score was 0. She recovered completely and remains normal neurologically for 5 years. At a five-year follow up, she is asymptomatic, has not had a recurrence of the aneurysm and also has a patent graft.
Figure 3: (a and b) Brain MRI showing the partially thrombosed M1-middle cerebral artery aneurysms. (c) DSA showing the lateral view of right internal carotid artery. (d) Three dimensional illustration showing the fusiform, partially thrombosed middle cerebral artery aneurysms involving the anterior cerebral artery and the bifurcation with no lenticulostriate perforators around the aneurysms. (e) Resection and end-end anastomosis of aneurysms with radial artery graft (RAG). (f) Postoperative DSA, right internal carotid atery injection, showing complete obliteration of the aneurysms with filling of distal middle cerebral artery branches with radial artery jump graft

Click here to view


Case 4: Superior hypophyseal artery aneurysm, clipping

This 61-year-old woman had presented with severe headaches during radiation treatment for adenocarcinoma of the lung and had been discovered to have a unruptured large internal carotid artery-superior hypophyseal artery aneurysm. Cerebral angiogram showed an aneurysm that was pointing medially, 14 × 10 mm in dimension with a neck dimension of 5 mm. The patient underwent a right frontotemporal craniotomy, posterolateral orbitotomy, anterior clinoidectomy and optic nerve decompression. Microsurgical clip reconstruction of the aneurysm was performed, and another small internal carotid artery aneurysm was clipped. Clipopexy was done to relieve kinking of the internal carotid artery caused by the clips [Figure 4]. The patient was relieved of her symptoms and was without any complications postoperatively.
Figure 4: (a) DSA, right internal carotid artery injection anteroposterior view, and (b) Three dimensional rotational angiographic reconstruction showing a lobulated aneurysm arising from supraclinoid portion of internal carotid artery and projecting medially. (c) DSA, right internal carotid artery injection anteroposterior view, and (d) Three dimensional rotational angiographic reconstruction showing clip reconstruction of the aneurysm

Click here to view


Case 5: Giant internal carotid artery (ICA) aneurysm, radial artery graft bypass, clip reconstruction

This 40-year old physician presented with complaints of rapidly progressive visual loss and severe headache. Neurological examination revealed a left homonymous hemianopsia. Cerebral angiography demonstrated a giant ICA aneurysm involving the terminal ICA segment. Collaterals from the contralateral ICA were poor because of a small caliber anterior cerebral artery on the ipsilateral side. The patient underwent a radial artery graft bypass from the external carotid artery to the MCA, and the aneurysm was clipped with preservation of flow to the anterior choroidal artery [Figure 5]. Postoperatively, the patient had a mild hemiparesis, which resolved after 3 days. He has been back to work as a physician and has been without any deficit for 10 years. The follow up CT angiogram demonstrated graft patency without evidence of aneurysmal recurrence.
Figure 5: (a) Preoperative angiogram revealing the aneurysm involving the terminal internal carotid artery. (b) Angiogram revealing poor collateral flow from the contralateral internal carotid artery. (c) Three dimensional illustration showing the radial artery graft from the external carotid artery to the middle cerebral artery. (d) Three dimensional illustration revealing preservation of the anterior choroidal artery through the clip reconstruction. (e) Postoperative angiogram showing the patent radial artery graft from the external carotid artery to the middle cerebral artery. (f) Postoperative angiogram showing patent anterior choroidal artery flow

Click here to view


Case 6: P1/P2 junction aneurysm with brainstem compression, bypass with trapping

This 46-year old man presented with several weeks of episodes of headaches, which were progressively worsening. On neurological examination, he was found to have anisocoria along with visual changes in the form of worsening of sight in the near field and hyperopia. Cerebral angiography showed a partially thrombosed fusiform, 14.9 × 15.4 × 6.4 mm aneurysm at the left P1/P2 junction with the aneurysm neck incorporating the native PCA and with severe compression of the brainstem. The patient underwent a left temporal and retrosigmoid craniotomy, posterior transtemporal-transpetrosal approach and partial resection of the inferior temporal gyrus to approach the aneurysm. Proximal occlusion of the aneurysm was done followed by the placement of a radial artery graft from the occipital artery to the P2 segment of the posterior cerebral artery distal to the aneurysm [Figure 6]. The patient had a good postoperative recovery without any deficit, and had no recurrence at a one-year follow-up visit.
Figure 6: (a) Brain MRI. (b) Right vertebral artery DSA. (c) Three dimensional rotational angiographic reconstruction showing an aneurysm of P1 segment of the left posterior cerebral artery. (d) Postoperative right vertebral artery injection DSA, lateral view, showing complete obliteration of the aneurysm. (e) Left external carotid angiogram showing the bypass from the occipital artery to the posterior cerebral artery

Click here to view


Case 7: A giant vertebral artery aneurysm, with posterior inferior cerebellar artery (PICA) not filling from the contralateral vertebral artery (VA), bypass and trapping

This 21-year old man, suffering from Marfan's syndrome, had undergone endovascular occlusion of a giant right ICA aneurysm at 9 years of age at another institution. He presented to us with a giant right vertebral artery aneurysm. He also had a small aneurysm of the right posterior communicating (PCOM) artery, which was supplying the entire right middle cerebral artery territory. A balloon test occlusion of the right vertebral artery did not cause clinical deficit, but the right PICA was not filling from the contralateral vertebral artery injection. Due to the concern about a possible PICA infarct after endovascular occlusion of VA, surgery was elected. The patient underwent a suboccipital craniotomy, far lateral approach, and occlusion of the aneurysm with occipital artery to PICA bypass. The patient had already exhibited early aneurysmal changes in the right posterior communicating artery, which was the collateral source to the right middle cerebral artery. In addition, following the last procedure, the patient had developed an asymptomatic watershed infarct in the right parietal area. Both these findings indicated that the patient would benefit from additional revascularization of the right side of the brain in order to reduce the incidence of aneurysm formation as well as to reduce the chances of right brain ischemia [Figure 7]. Due to this fact, a radial artery graft bypass from the external carotid artery to the M2 segment of middle cerebral artery was performed in this patient. He recovered well without any deficit. Thus, this patient was not eligible for an endovascular flow diversion stent due to the unusual location of the PICA (at its origin from the vertebral artery) in close proximity to the giant vertebral artery aneurysm.
Figure 7: (a and b) Three dimensional angiogram showing a giant right vertebral artery aneurysm, which involved the distal V3 and V4 segments. (c) Initial view of the aneurysm after the far lateral approach. (d) Three-dimensional illustration showing the occipital-posterior inferior cerebellar artery (PICA) anastomosis and proximal occlusion and clipping of the aneurysm. (e) Postoperative angiogram showing the occipital to PICA bypass and saphenous vein graft bypass. (f) Postoperative angiogram after the second surgery showing the external carotid artery (ECA) to right middle cerebral artery (MCA) radial artery graft (RAG)

Click here to view


Case 8: Lower basilar artery aneurysm; sephanous vein graft to the posterior cerebral artery, proximal clipping and endovascular coiling

This 10-year old boy, who underwent multiple coiling procedures for a lower basilar trunk aneurysm, presented with episodic severe headaches and hemiparesis. The preoperative cerebral angiography revealed that the aneurysm had recurred and was filling through both vertebral arteries that had a right-sided dominance. The posterior communicating arteries were not adequate to support the endovascular occlusion of the basilar artery and a flow diversion stent was not available at that time. The patient underwent a right-sided combined far lateral and transpetrosal approach, with a saphenous vein graft from the right V3 segment of the vertebral artery to the P2 segment of the posterior cerebral artery. Both vertebral arteries just proximal to the aneurysm were occluded using a clip. Postoperative angiography demonstrated the persistent filling of the aneurysm through the contralateral vertebral artery, around the clip blades. Six weeks later, the remaining vertebral artery and the base of the aneurysm were obliterated with coils [Figure 8]. The follow-up at 1 year showed no evidence of aneurysm recurrence. The patient has an mRs score of 0 at a 12-year follow up period.
Figure 8: (a and b) Complex basilar trunk aneurysm filling predominantly through a right vertebral artery (VA) injection. (c) Postoperative angiogram showing the vertebral artery to posterior cerebral artery bypass using a saphenous vein graft (SVG). (d) Postoperative three-dimensional angiogram showing the persistent filling of the aneurysm through the opposite vertebral atery. (e) Endovascular coiling of the residual aneurysm via the left vertebral artery. (f) Endovascular coiling of the residual aneurysm via the left vertebral artery. (g) One-year follow-up angiogram showing the patent bypass graft and completely occluded aneurysm.

Click here to view


Case 9: Giant basilar tip aneurysm after multiple coilings, sephanous vein graft bypass, and basilar artery occlusion

A 62-year old woman had undergone four coiling procedures for an unruptured basilar tip aneurysm. The procedures had started in 2003. She presented with progressive decline in her neurological status. She was restricted to a wheelchair and her neurological examination was positive for global cognitive dysfunction, expressive aphasia, and spastic quadriparesis. She also had difficulty in swallowing for which a gastrostomy was done. Her preoperative mRs was 5.

The brain MRI scan demonstrated a large cyst adjacent to the aneurysm, which was extending into the third and lateral ventricles, and a coil mass which was severely compressing the midbrain. The aneurysm was measuring 26 × 26 × 24 mm in size. Cerebral angiography showed the continued filling of the aneurysm from the basilar artery with the maximum dimension (the height of the aneurysm) of the portion that still had a patent circulation being 17 mm. The patient had an absent posterior communicating artery artery on the left side and a moderate-sized posterior communicating artery (of 1 mm diameter) on the right side. She underwent surgery in three stages; in first stage, the cyst was fenestrated endoscopically. In the second stage, exposure of V2 and V3 segments of the vertebral artery and decompression of the sigmoid sinus and facial nerve were performed by the transtemporal and transpetrosal approaches. The third stage consisted of the bypass procedure with placement of the saphenous vein graft from the vertebral artery (V3 segment) to the right PCA (P2 segment), followed by clip occlusion of the upper basilar artery. During this surgery, the aneurysm could not be visualized due to the coil mass.

The patient made a good recovery without any postoperative complications. The postoperative angiogram demonstrated the aneurysm neck filling slightly from the right posterior communicating artery, and through the bypass and a patent graft [Figure 9]. At a 3-year follow-up period, the patient had considerably improved. She was able to speak a few words, walk a few steps with assistance, and her swallowing had improved significantly followed by removal of gastrostomy tube. At a 3-year follow-up visit, her angiogram showed a patent graft with good flow in both posterior cerebral arteries, one supported by the sephanous vein graft and other through the posterior communicating artery. A small stable aneurysm neck remnant was also seen. Thus, due to a single, moderate sized, posterior communicating artery, the endovascular occlusion of the basilar artery was not done[12] A sephanous veing graft was placed because the radial arteries could not be used due to their utilization in the prior operations.
Figure 9: (a) Sagittal and (b) axial MRI showing the cyst in relation to the giant basilar tip aneurysm. (c) Angiogram, vertebral injection—lateral view, showing the giant aneurysm with coils in its sac. (d) Three-dimensional illustration showing the patent sephanous vein graft from the vertebral artery to the P2 segment of the posterior cerebral artery, with the clip on the basilar artery in place. (e) Angiogram, lateral view, vertebral injection (at an 18-month follow-up visit) shows the aneurysmal neck remnant. (f) Postoperative DSA image showing the clipping on the basilar artery. (g) Angiogram anterior–posterior view showing the patent graft vessel

Click here to view


Case 10: Vertebrobasilar junction aneurysm, bypass and subsequent endovascular occlusion of aneurysm; patient developed brain stem stroke

This 69-year female patient presented with sixth nerve palsy. Cerebral angiogram showed a 20 mm, partially thrombosed, aneurysm just above the vertebrobasilar junction, with both the vertebral arteries joining the proximal aspect of the neck of the aneurysm. The aneurysm was causing significant brain stem compression and could not be treated with simple endovascular coiling because both the vertebral arteries were joining the aneurysm at the inferior aspect of its sac, and the basilar artery had no collaterals from the posterior communicating artery. Due to this, the patient was offered either of the two choices, either an endovascular treatment utilizing a flow diversion device; or, a bypass to the right posterior cerebral artery followed by endovascular occlusion of the aneurysm. The patient chose to have microsurgery. She underwent a right temporal and retrosigmoid craniotomy, mastoidectomy with presigmoid petrosal approach and a radial artery graft was placed from the external carotid artery to the posterior cerebral artery on the right side. She did well initially after the bypass procedure. Coil embolization of the giant mid-basilar artery aneurysm, and both vertebral arteries was performed subsequently. After the coiling, however, her condition deteriorated, most likely due to the occlusion of perforators. The brain MRI demonstrated multiple ventrolateral pons and medullary infarcts [Figure 10]. Eventually, the patient developed respiratory failure and expired due to the development of brain stem infarcts. For such patients, there is no consistently good solution at present. In other patients with similar aneurysms, we have done bypass followed by proximal occlusion of the major inferior artery, or distal occlusion with good results. Flow diversion embolization has also been done but with variable results.[13]
Figure 10: (a and b) Three dimensional rotational angiographic reconstruction showing the giant vertebro-basilar junction aneurysm with both vertebral arteries entering the proximal aspect of the neck of the aneurysm. (c and d) Postoperative angiogram showing the radial artery graft (RAG) from the external carotid artery (ECA) to the posterior cerebral artery. (e) Coil embolization of the aneurysm and both vertebral arteries. (f) Brain MRI showing post coil embolization and the brainstem infarct

Click here to view


Case 11: Giant internal carotid artery aneurysm; rupture on induction of anesthesia

This 39-year old female patient presented with 2 months of blurred vision, worst in the left inferior quadrant of her visual fields. The cerebral angiogram showed a giant supraclinoid internal carotid artery aneurysm measuring 40 mm. The preoperative balloon occlusion test showed a 35% reduction of transcranial Doppler velocity in the middle cerebral artery, so a permanent endovascular occlusion was not done. She underwent a right frontotemporal craniotomy and orbitozygomatic osteotomy. The patient had an intraoperative rupture of the aneurysm spontaneously upon induction of anesthesia. We decided to proceed with treatment despite the absence of evoked potentials because of her young age. A CT scan showed significant intraventricular and subarachnoid hemorrhage, mass effect and cerebral edema in the right hemisphere and signs of central herniation syndrome. Frontal and temporal lobectomies were done and the aneurysm was trapped. An extracranial-to-intracranial bypass was performed using a radial artery graft, from the external carotid artery to the middle cerebral artery. This was followed by a decompressive craniectomy [Figure 11]. Postoperatively, she did not improve and died. This case demonstrates the presence of a very unstable aneurysm. Perhaps rupture could have been prevented by inducing hypotension during the induction of anesthesia until the aneurysm was occluded.
Figure 11: (a) Right ICA injection DSA, lateral view, and (b) three dimensional rotational angiographic reconstruction showing the giant supraclinoid internal carotid artery aneurysm with slow flow out in the middle cerebral artery. (c) Left internal carotid artery injection, DSA anteroposterior view, showing a good cross flow across the anterior communicating artery. (d) CT scan showing the intraparenchymal and intraventricular hemorrhage after intraoperative rupture of the aneurysm

Click here to view


Case 12: Giant internal carotid artery aneurysm with bypass; occlusion of the large posterior communicating artery; the patient developed a stroke

This 77-year old male patient presented to us with progressive visual decline in the right eye with complete visual loss. This manifestation was accompanied by headaches for six weeks. An MRI demonstrated a giant, right-sided supraclinoid internal carotid artery aneurysm measuring 26 mm, with compression on the optic nerve apparatus. The angiogram showed that the aneurysm was heavily thrombosed but the basal portion was still filling. The posterior communicating artery was fetal but with some communication through a tiny P1 segment and was arising from the neck of the aneurysm. All endovascular options were considered, which were not applicable due to the nearly fetal posterior communicating artery and a poor collateral circulation. The patient underwent a right frontotemporal craniotomy with orbital osteotomy. A radial artery bypass graft was placed from the common carotid artery to the M2 segment of the middle cerebral artery. The aneurysm was opened, a lot of thrombus and abnormal material was removed. The internal carotid artery was reconstructed with two fenestrated clips, and the posterior communicating artery appeared to be patent on evaluation using the indocyanine green angiogram and micro-Doppler studies.

However, around this time, the motor evoked potential from the left arm and leg was suddenly lost and could not be recovered even with clip readjustment.

Postoperatively, the patient developed left-sided hemiplegia. His angiogram showed the occlusion of fetal posterior communicating artery from the internal carotid artery but forward filling of the posterior cerebral artery and the posterior communicating artery from the basilar artery. The MRI scan showed hypothalamic, medial temporal and thalamic infarcts [Figure 12]. At a three year follow up visit, his left-sided hemiplegia has improved with a power of 3/5 in both his extremities. His mRs was 3. An option in this patient would have been to perform the bypass followed by proximal occlusion of the aneurysm without trapping or clipping. This case was still difficult for a pipeline embolization device placement due to the presence of a significant thrombus within the aneurysm and the fetal origin of the posterior cerebral artery from the aneurysm.
Figure 12: (a and b) Brain MRI showing a partialy thrombosed internal carotid artery aneurysm. (c) Three dimensional rotational angiographic reconstruction showing the filling of the aneurysm and the fetal posterior communicating artery arising from the neck of the aneurysm. (d1) Three-dimensional illustration showing the partially thrombosed aneurysm and the fetal posterior communicating artery. (d2) Excision of aneurysm with clip reconstruction and radial artery bypass graft. (e and f) Postoperative three dimensional rotational angiographic reconstruction showing filling of the left posterior cerebral artery and a hypoplastic posterior cerebral artery on the right side. (g) Postoperative angiogram showing a radial artery graft from the common carotid artery to the M2 segment of middle cerebral artery. (h) CT scan coronal view after 2 years showing the resolved medial temporal, hypothalamic and thalamic infarcts

Click here to view



 » Pathological Analysis Top


The histopathologic examination was performed in the resected 10 very large and 11 giant aneurysms. These aneurysms demonstrated various structural abnormalities, including intimal denudation or fibrous hyperplasia, absence or prominent disruption of the internal elastic lamina, loss of smooth muscle cells of the tunica muscularis with associated variable areas of fibrosis, areas of atherosclerotic change, blood breakdown products, variable primarily lymphocytic mural infiltrates and microcalcifications. Five aneurysms demonstrated abundant thrombosis with organization and an occasional recanalization (as was evident in one case in the present study) [Figure 13].
Figure 13: Histopathology of one very large aneurysm (0.18 cm in greatest dimension) of the left middle cerebral artery resected in a 67-year old man. (a) Cross sectioned non-ruptured thrombosed enlarged vascular structure with occasional calcifications largely located in the inner portion of the wall (arrowhead); (b)The wall demonstrates intimal degeneration/denudation in association with an organizing thrombosis and hemosiderin-laden macrophages, significant loss of smooth muscle cells, and dense lympho-plasmacytic infiltrates involving most of the external portion of the vascular structure; (c) The internal elastic lamina is not detected. (inset shows a higher magnification of the vascular structure depicted in b and c). Hematoxylin and eosin stain: a and b; Verhoeff-Van Gieson (VVG) stain: c; Scale bars: 3.2 mm (a) and 100 μm (b and c)

Click here to view



 » Discussion Top


Over the years, there has been a tremendous evolution in microsurgical and endovascular techniques for managing these difficult lesions.[14],[15],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29] In the case of ruptured aneurysms, the microsurgical techniques are favored. The role of endovascular modalities is limited due to the need for administration of antiplatelet agents, although coiling followed by placement of a stent after 6 weeks is being used in many centers. Moreover, giant aneurysms with a mass effect, ruptured aneurysms, or bifurcation and trifurcation aneurysms cannot be treated with flow diversion embolization devices. Microsurgical techniques include clip reconstruction and bypasses. Calcification within the aneurysmal neck, the presence of severe atherosclerotic changes in the vessel wall, and excessive thrombosis within the aneurysm may preclude a clipping procedure; under these circumstances, the bypass techniques play a crucial role.

In unruptured aneurysms, the endovascular options must be considered. The procedure of coiling has a high recurrence rate. The occasional occlusion of perforators and herniation of the coils within the arterial lumen pose a formidable challenge.[30] The placement of flow diverters has emerged as a ground-breaking procedure although their efficacy, long term complications and results still need to be established in the coming years.[31],[32],[33],[34],[35],[36],[37],[38],[39],[40] Some of the unruptured aneurysms treated in this series may be addressed currently by endovascular means using flow diverters. The crucial issues regarding the endovascular management of aneurysms are the long-term outcome, durability and cost of these procedures, particularly in developing countries. Moreover, patients treated by endovacular methods need to be on a constant follow up while microsurgery provides a definitive treatment with a similar risk and outcome.

In our series, good results were achieved with microsurgical procedures but these results may be improved further. Majority of the very large and giant aneurysms treated here were with bypass and proximal occlusion/trapping. Poor outcomes correlated with a poor neurological condition after SAH, or even with the presence of unruptured aneurysms. Two aneurysms ruptured while anesthetic induction was being carried out reflecting a very unstable condition of the aneurysmal sac. Many cases were very difficult to manage, with multiple comorbidities, making them high risk candidates for rupture of the aneurysm.

Multiple published trials in the literature regarding microsurgical management of giant aneurysms show that an excellent to good outcome (mRs score 0–3) was obtained in 58% to 84% of the patients, and a mortality rate of 14% to 22% was observed.[41],[42],[43],[44],[45],[46]

This series has good outcome in 80% of the patients having a very large and giant aneurysm that was treated with microsurgery, with a mortality rate of 8% (6/73) and a morbidity rate of 12% (9/73).

However, the overall good results of 80% (mRs 0-2) are excellent, and can be improved upon if one pre-selects patients for surgery and does not treat patients in a poor preoperative condition. Yet, the pre-selection presents an ethical dilemma since some of these patients in poor condition can be improved after surgery, especially in those with unruptured cases.

It is difficult to compare the complications encountered within various series published in the literature due to the differences in the morbidities encountered in dealing with anterior and posterior circulation aneurysms, and the variable definition of a good outcome.[47],[48],[49],[50],[51],[52],[53],[54],[55] [Table 16] summarizes the previous reports of very large and giant aneurysms treated by microsurgery and compares the results of those studies to our study.
Table 16: Review of previous studies with very large and giant aneurysms treated by microsurgery

Click here to view



 » Conclusion Top


Due to their poor natural history and associated complexities in management, the treatment of very large and giant aneurysms is associated with a higher morbidity than that seen in small intracranial aneurysms. The retrospective analysis of our cases shows that a good outcome can be achieved with microsurgical techniques. Endovascular flow diversion is preferred for unruptured internal carotid artery-cavernous sinus and many para-ophthalmic intracranial aneurysms. For ruptured giant intracranial aneurysms, both endovascular and microsurgical treatment should be considered. Bypass with aneurysmal occlusion, followed by clip reconstruction are the main microsurgical treatments for these aneurysms. Therefore, continuing to learn and teach bypass techniques to future generations of neurosurgeons should be a mandatory feature of training programs in neurosurgery.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
 » References Top

1.
Locksley HB, Sahs AL, Sandler R. Report on the cooperative study of intracranial aneurysms and subarachnoid hemorrhage. 3: Subarachnoid hemorrhage unrelated to intracranial aneurysm and A-V malformation: A study of associated diseases and prognosis. J Neurosurg 1966;24:1034-56.  Back to cited text no. 1
    
2.
Sahs AL, Perret G, Locksley HB, Nishioka H. Intracranial Aneurysms and Subarachnoid Hemorrhage: A Cooperative Study. Philadelphia, PA: Lippincott; 1969.  Back to cited text no. 2
    
3.
Wiebers DO, Whisnant JP, Huston J 3rd, Meissner I, Brown RD Jr, Piepgras DG, et al. International Study of Unruptured Intracranial Aneurysms Investigators. Unruptured intracranial aneurysms: Natural history, clinical outcome, and risks of surgical and endovascular treatment. Lancet 2003;362:103-10.  Back to cited text no. 3
    
4.
Misra BK, Warade A, Purandare H. Giant intracranial aneurysms: Microsurgery. In: Singh VP, Nair MD, editors. Progress in Clinical Neuroscience Vol 29. Thieme; Delhi 2014. P 122-42.  Back to cited text no. 4
    
5.
Morita A, Kirino T, Hashi K, Aoki N, Aoki N, Fukuhara S, et al. UCAS Japan Investigators: The natural course of unruptured cerebral aneurysms in a Japanese cohort. N Engl J Med 2012 Jun 28;366:2474-82.  Back to cited text no. 5
    
6.
Sekhar LN, Chandler JP, Alyono D. Saphenous vein graft reconstruction of an unclippable giant basilar artery aneurysm performed with the patient under deep hypothermic circulatory arrest: Technical case report. Neurosurgery 1998;42:667-72.  Back to cited text no. 6
    
7.
Sekhar LN, Bucur SD, Bank WO, Wright DC. Venous and arterial bypass grafts for diffcult tumors, aneurysms, and occlusive vascular lesions: Evolution of surgical treatment and improved graft results. Neurosurgery 1999;44:1207-23.  Back to cited text no. 7
    
8.
Sekhar LN, Stimac D, Bakir A, Rak R. Reconstruction options for complex middle cerebral artery aneurysms. Neurosurgery 2005;56 (1, Suppl):66-74.  Back to cited text no. 8
    
9.
Ramanathan D, Hegazy A, Mukherjee SK, Sekhar LN. Intracranial in situ side-to-side microvascular anastomosis: Principles, operative technique, and applications. World Neurosurg 2010;73:317-25.  Back to cited text no. 9
    
10.
Sekhar LN, Du JM, Kalavakonda C, Olding M. Cerebral revascularization using radial artery grafts for the treatment of complex intracranial aneurysms: Techniques and outcomes for 17 patients. Neurosurgery 2001;49:646-58.  Back to cited text no. 10
    
11.
Ramanathan D, Temkin N, Kim LJ, Ghodke B, Sekhar LN. Cerebral bypasses for complex aneurysms and tumors: Long-term results and graft management strategies. Neurosurgery 2012;70:1442-57.  Back to cited text no. 11
    
12.
Steinberg GK, Drake CG, Peerless SJ. Deliberate basilar or vertebral artery occlusion in the treatment of intracranial aneurysms: Immediate results and long-term outcome in 201 patients. J Neurosurg 1993;79:161-73.  Back to cited text no. 12
    
13.
Natarajan SK, Lin N, Sonig A, Rai AT, Carpenter JS, Levy EI, et al. The safety of pipeline flow diversion in fusiform vertebrobasilar aneurysms: A consecutive case series with longer-term follow-up from a single US center. Neurosurg 2016;125:111-9.  Back to cited text no. 13
    
14.
Hanel RA, Spetzler RF. Surgical treatment of complex intracranial aneurysms. Neurosurgery 2008;62(6 suppl 3):1289-97.  Back to cited text no. 14
    
15.
Ponce FA, Albuquerque FC, McDougall CG, Han PP, Zabramski JM, Spetzler RF. Combined endovascular and microsurgical management of giant and complex unruptured aneurysms. Neurosurg Focus 2004;17:E11.  Back to cited text no. 15
    
16.
Lawton MT, Spetzler RF. Surgical strategies for giant intracranial aneurysms. Neurosurg Clin N Am 1998;9:725-42.  Back to cited text no. 16
    
17.
Lawton MT, Daspit CP, Spetzler RF. Technical aspects and recent trends in the management of large and giant midbasilar artery aneurysms. Neurosurgery 1997;41:513-20.  Back to cited text no. 17
    
18.
Sundt TM Jr, Piepgras DG, Fode NC, Meyer FB. Giant intracranial aneurysms. Clin Neurosurg 1991;37:116-54.  Back to cited text no. 18
    
19.
Chen L, Kato Y, Sano H, Watanabe S, Yoneda M, Hayakawa M. Management of complex, surgically intractable intracranial aneurysms: The option for intentional reconstruction of aneurysm neck followed by endovascular coiling. Cerebrovasc Dis 2007;23:381-7.  Back to cited text no. 19
    
20.
Jahromi BS, Mocco J, Bang JA, Gologorsky Y, Siddiqui AH, Horowitz MB, et al. Clinical and angiographic outcome after endovascular management of giant intracranial aneurysms. Neurosurgery 2008;63:662-74.  Back to cited text no. 20
    
21.
Wehman JC, Hanel RA, Levy EI, Hopkins LN Giant cerebral aneurysms: Endovascular challenges. Neurosurgery 2006;59 (5 suppl 3):S125-38.  Back to cited text no. 21
    
22.
Standard SC, Guterman LR, Chavis TD, Fronckowiak MD, Gibbons KJ, Hopkins LN. Endovascular management of giant intracranial aneurysms. Clin Neurosurg 1995;42:267-93.  Back to cited text no. 22
    
23.
Guterman LR, Hopkins LN. Endovascular treatment of cerebral aneurysms: Diagnosis and treatment. Clin Neurosurg 1993;40:56-83.  Back to cited text no. 23
    
24.
Wong GK, Kwan MC, Ng RY, Yu SC, Poon WS. Flow diverters for treatment of intracranial aneurysms: Current status and ongoing clinical trials. J Clin Neurosci 2011;18:737-40.  Back to cited text no. 24
    
25.
Thornton J, Dovey Z, Alazzaz A. Surgery following endovascular coiling of intracranial aneurysms. Surg Neurol 2000;54:352-60.  Back to cited text no. 25
    
26.
Drake CG, Peerless SJ. Giant fusiform intracranial aneurysms: Review of 120 patients treated surgically from 1965 to 1992. J Neurosurg 1997;87:141-62.  Back to cited text no. 26
    
27.
Peerless SJ, Drake CG. Treatment of giant cerebral aneurysms of the anterior circulation. Neurosurg Rev 1982;5:149-54.  Back to cited text no. 27
    
28.
Drake CG. Giant intracranial aneurysms: Experience with surgical treatment in 174 patients. Clin Neurosurg 1979;26:12-95.  Back to cited text no. 28
    
29.
Darsaut TE, Darsaut NM, Chang SD, Silverberg GD, Shuer LM, Tian L, et al. Predictors of clinical and angiographic outcome after surgical or endovascular therapy of very large and giant intracranial aneurysms. Neurosurgery 2011;68:903-15.  Back to cited text no. 29
    
30.
Vishteh AG, David CA, Spetzler RF. Giant aneurysms. In: Sekhar LN, Fessler R, editors. Atlas of Neurosurgical Techniques. Vol. I. Stuttgart: Thieme; 2006. p. 212-21.  Back to cited text no. 30
    
31.
Karsy M, Guan J, Brock AA, Amin A, Park MS. Emerging technologies in flow diverters and stents for cerebrovascular diseases. Curr Neurol Neurosci Rep 2017;17:96.  Back to cited text no. 31
    
32.
Kiyofuji S, Graffeo CS, Perry A, Murad MH, Flemming KD, Lanzino G, et al. Meta-analysis of treatment outcomes of posterior circulation non-saccular aneurysms by flow diverters.J Neurointerv Surg 2018;10:493-99.  Back to cited text no. 32
    
33.
Miyachi S, Hiramatsu R, Ohnishi H, Yagi R, Kuroiwa T. Usefulness of the pipeline embolic device for large and giant carotid cavernous aneurysms. Neurointervention 2017;12:83-90.  Back to cited text no. 33
    
34.
Rajah G, Narayanan S, Rangel-Castilla L. Update on flow diverters for the endovascular management of cerebral aneurysms. Neurosurg Focus 2017;42:E2.  Back to cited text no. 34
    
35.
Madaelil TP, Moran CJ, Cross DT 3rd, Kansagra AP. Flow diversion in ruptured intracranial aneurysms: A meta-analysis. AJNR Am J Neuroradiol 2017;38:590-95.  Back to cited text no. 35
    
36.
Wong GK, Kwan MC, Ng RY, Yu SC, Poon WS. Flow diverters for treatment of intracranial aneurysms: Current status and ongoing clinical trials. J Clin Neurosci 2011;18:737-40.  Back to cited text no. 36
    
37.
Sanai N, Zador Z, Lawton MT. Bypass surgery for complex brain aneurysms: An assessment of intracranial-intracranial bypass. Neurosurgery 2009;65:670-83.  Back to cited text no. 37
    
38.
Sanai N, Tarapore P, Lee AC, Lawton MT. The current role of microsurgery for posterior circulation aneurysms: A selective approach in the endovascular era. Neurosurgery 2008;62:1236-49.  Back to cited text no. 38
    
39.
Lv X, Ge H, He H, Jiang C, Li Y. A systematic review of pipeline embolization device for giant intracranial aneurysms. Neurol India 2017;65:35-38.  Back to cited text no. 39
[PUBMED]  [Full text]  
40.
Kumar VRR, Subramaniam SB, Murugan ABG, Bapu KRS. Endovascular pulmonary artery inflatable balloon-induced hypotension: A novel technique for clipping giant intracranial aneurysms. Neurol India 2017;65:566-9.  Back to cited text no. 40
[PUBMED]  [Full text]  
41.
Lawton MT, Quinones-Hinojosa A, Sanai N, Malek JY, Dowd CF. Combined microsurgical and endovascular management of complex intracranial aneurysms. Neurosurgery 2008;62 (6 suppl 3):1503-15.  Back to cited text no. 41
    
42.
Kato Y, Sano H, Imizu S. Surgical strategies for treatment of giant or large intracranial aneurysms: Our experience with 139 cases. Minim Invasive Neurosurg 2003;46:339-43.  Back to cited text no. 42
    
43.
Abdulrauf SI, Sweeney JM, Mohan YS, Palejwala SK. Short segment internal maxillary artery to middle cerebral artery bypass: A novel technique for extracranial-to-intracranial bypass. Neurosurgery 2011;68:804-9.  Back to cited text no. 43
    
44.
Sano H, Kato Y, Shankar K, Kanaoka N, Hayakawa M, Katada K, et al. Treatment and results of partially thrombosed giant aneurysms. Neurol Med Chir (Tokyo) 1998:38(suppl):58-61.  Back to cited text no. 44
    
45.
Khandelwal P, Kato Y, Sano H, Yoneda M, Kanno T. Treatment of ruptured intracranial aneurysms: Our approach. Minim Invasive Neurosurg 2005;48:325-29.  Back to cited text no. 45
    
46.
Sekhar LN, Tariq F, Kim LJ. Unyielding progress: Treatment paradigms for giant aneurysms. Neurosurgery 2012;59,6-21.  Back to cited text no. 46
    
47.
Peerless SJ, Wallace MC, Drake CG. Giant intracranial aneurysms. In: Youmans JR (Editor). Neurological Surgery. Philadelphia, PA: W. B. Saunders Co.;1990:1742-63.  Back to cited text no. 47
    
48.
Hosobuchi Y. Giant intracranial aneurysms. In: Wilkins RH, Rengachary SS (Editors). Neurosurgery. New York City: McGraw-Hill; 1985:1404-14.  Back to cited text no. 48
    
49.
Sundt TM Jr. Results of surgical management. In: Sundt TM Jr (Editor). Surgical techniques for saccular and giant intracranial aneurysms. Baltimore, MD: Williams and Wilkins; 1990:19-23.  Back to cited text no. 49
    
50.
Lawton MT, Spetzler RF. Surgical management of giant intracranial aneurysms: Experience with 171 patients. Clin Neurosurg 1995;42:245-66.  Back to cited text no. 50
    
51.
Hauck EF, Wohlfeld B, Welch BG, White JA, Samson D. Clipping of very large or giant unruptured intracranial aneurysms in the anterior circulation: An outcome study. J Neurosurg 2008;109:1012-18.  Back to cited text no. 51
    
52.
Sharma BS, Gupta A, Ahmad FU, Suri A, Mehta VS. Surgical management of giant intracranial aneurysms. Clin Neurol Neurosurg 2008;110:674-81.  Back to cited text no. 52
    
53.
Sano H. Treatment of complex intracranial aneurysms of anterior circulation using multiple clips. Acta Neurochir Suppl (Wien) 2010;107:27-31.  Back to cited text no. 53
    
54.
Cantore G, Santoro A, Guidetti G, Delfinis CP, Colonnese C, Passacantilli E. Surgical treatment of giant intracranial aneurysms: Current viewpoint. Neurosurgery 2008; 63(4, Suppl 2):279-89.  Back to cited text no. 54
    
55.
Xu BN, Sun ZH, Romani R, Jiang JL, Wu C, Zhou DB, et al. Microsurgical management of large and giant paraclinoid aneurysms. World Neurosurg 2010;73:137-46.  Back to cited text no. 55
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10], [Table 11], [Table 12], [Table 13], [Table 14], [Table 15], [Table 16]



 

Top
Print this article  Email this article
   
Online since 20th March '04
Published by Wolters Kluwer - Medknow