Surgical treatment of blood blister–like aneurysms of the supraclinoid internal carotid artery with extracranial–intracranial bypass and trapping

Comparative analysis of characteristics, management, and clinical outcome of blood blister-like aneurysms treated with flow diverter devices: a systematic review and meta-analysis of 30 studies

BACKGROUND AND AIM

Because of relatively little data for blood blister-like aneurysms (BBAs) treated with flow diverter (FD) devices, existing studies failed to provide comprehensive analysis for the characteristics, management, and clinical outcome of the disease. Therefore, the authors collected and analyzed current evidence aiming to provide quantitatively pooled results for the management, complication, clinical, and angiographic outcomes as well as the risk factors of prognosis of BBAs treated with FD devices.

METHODS

A systematic search of PubMed, Cochrane Library, and Web of Science up to 1 May 2024 was conducted for relevant studies. The primary outcomes were to expound the management, characteristics, and clinical outcomes of BBAs treated with FD devices. The secondary outcomes were to determine the difference of characteristics and outcomes, as well as the risk factors of BBAs treated with FD devices. Two reviewers assessed trial quality and extracted the data independently. All statistical analyses were performed using the standard statistical procedures provided in Review Manager 5.2 and Stata 12.0.

RESULTS

A total of 30 reports with 311 of 783 BBA patients were identified. The pooled results indicated that 76.3% BBAs were located in the internal carotid artery (ICA), and 85 and 84% patients experienced complete occlusion and a modified Rankin scale (mRS) score 0-2, respectively, at follow-up time. Female BBAs patients (69.9%) were more prevalent and 88.5% patients experienced a favorable outcome at discharge. The overall and periprocedural complications account for 16.8 and 9.1%, respectively. The pooled results showed that the incidence of complete occlusion was 50% (95% CI: 31-69%), 80% (95% CI: 67-92%), and 84% (95% CI: 77-91%) at immediate, short, and long-term angiographic results, respectively. In addition, the favorable, moderate, and poor clinical outcomes evaluated with mRS were 89% (95% CI: 85-94%), 13% (95% CI: 5-21%), and 8% (95% CI: 3-13%), respectively. The authors found that compared to moderate or poor outcomes, patients with good outcomes experienced significantly lower preoperative scores (MD -1.24; 95% CI: -1.94 to -0.53), more complete occlusion (OR 5.17; 95% CI: 1.26-21.15) and less complications (OR 0.20; 95% CI: 0.08-0.47), respectively. It was observed that patients who experienced a complication had a higher onset Hunt-Hess scale (MD 0.49; 95% CI: 0.03-0.96) and Fisher's score (MD 1.43; 95% CI: 0.72-2.13), respectively. Patients with good outcomes experienced younger age (MD -5.76 years; 95% CI: -11.31 to -0.21) and lower onset Hunt-Hess scale (MD -0.96; 95% CI: -1.45 to -0.47), respectively.

CONCLUSIONS

BBA was middle-aged female predominant and common in ICA. The majority of patients generally experienced favorable outcomes with a low incidence of periprocedural complications. In addition, good outcomes benefited from lower preoperative scores, more complete occlusion, less complications, and younger age. Higher onset Hunt-Hess scale and Fisher's score may increase the risk of complications. Future studies with enough sample size and long follow-up are required to clear the management, long-term outcomes, and risk factors of BBAs.

Long-term follow up of surgical management of blood blister-like aneurysms at non-branching sites of the internal carotid artery

To describe long-term follow-up of 25 patients who presented with subarachnoid hemorrhages due to blood blister-like aneurysms (BBAs) treated with direct clipping or clip reinforcement with or without direct neck repair. Between June 1993 and July 2009, 25 consecutive patients with ruptured BBAs of the supraclinoid internal carotid artery were retrospectively reviewed. The mean age of patients was 39.5 ± 11.3 years. The mean duration of clinical follow-up was 128.9 months (range, 85-196 months). All aneurysms were located in the supraclinoid portion of the internal carotid artery. The mean aneurysm diameter was 4.04 ± 1.3 mm on intra-operative microscopic field. Tearing of the aneurysmal neck during dissection occurred in 8 (32%) patients. Six of 7 patients with neck tearing underwent direct neck repair. Surgeons treated aneurysms via direct clipping with a Bemsheet® in 5 (20%) patients or by clip reinforcement with a silicone sheet in 20 (80%) patients. Clinical outcomes were favorable (modified Rankin Scale [mRS]: 0-2) in 21 (84%) of 25 patients. Four (16%) patients had an unfavorable outcome (mRS: 3-6). The patient with severe disability (mRS: 4) was treated with clip reinforcement and direct neck repair. Mild stenosis, moderate stenosis, and total occlusion of the parent artery were confirmed in 10 (40%) patients, 6 (24%) patients, and 1 (4%) patient, respectively. Although surgical treatment of BBAs was associated with varying degrees of parent vessel patency loss, long-term follow-up results for more than 10 years showed that direct surgical clipping or clip reinforcement with a silicone sheet appeared to be a curative surgery.

Early surgical versus endovascular repair of ruptured blood-blister aneurysm of the internal carotid artery: a single-center 20-year experience

OBJECTIVE

Early repair of ruptured blood-blister aneurysms (BBAs) of the internal carotid artery (ICA) remains challenging. Although both surgical and endovascular therapies have been established, their relative superiority remains debated. The authors assessed their single-center experience and compared early deconstructive versus reconstructive repair and early reconstructive surgical versus endovascular repair of ruptured BBAs of the ICA.

METHODS

The study included patients who underwent repair of ruptured BBAs of the ICA within 1 week after the ictus during a 20-year period. Multiple variables were recorded, including clinical state, severity of subarachnoid hemorrhage (SAH), characteristics of the BBA, treatment details, complication profile, need for secondary treatment, and clinical outcome.

RESULTS

In total, 27 patients underwent early surgical (n = 16) or endovascular (n = 11) repair of BBAs at a median of 24 hours (range 9-120 hours) after the ictus during the period from September 2000 to June 2021 (20.4 years). Primary deconstructive repair (n = 6) without bypass was accompanied by middle cerebral artery (MCA) territory infarction in 5 of 6 (83%) patients and a high mortality rate (4/6 [67%]). Among the 21 patients who underwent early reconstructive repair, surgery was performed in 11 patients (clipping in 6 and clip-wrapping in 5 patients) and endovascular repair in 10 patients (flow diversion in 7 and stent/stent-assisted coiling in 3 patients). No differences were found in complication profiles or clinical outcomes between the surgical and endovascular groups. The mortality rate was low (2/21 [9.5%]), with 1 fatality in each group.

CONCLUSIONS

From the authors' experience, both surgical and endovascular approaches permitted reconstructive repair of ruptured BBAs of the ICA, with no modality proving superior. Reconstructive treatment is preferable to ICA sacrifice, and if sacrifice is chosen, it should be accompanied with bypass surgery or delayed to the phase when cerebral vasospasm has resumed. The rare occurrence of this disease calls for prospective multicenter studies to improve treatment and delineate which modality is preferable in individual cases.

Comparison of Blister Aneurysm Treatment Techniques: A Systematic Review and Meta-Analysis

OBJECTIVE

Blood blister aneurysms are small, thin-walled, rapidly growing side-wall aneurysms that have proved particularly difficult to treat, and evidence-based guidance for treatment strategies is lacking. A systematic review and meta-analysis was performed to aggregate the available data and compare the 3 primary treatment modalities.

METHODS

We performed a comprehensive literature search according to PRISMA guidelines followed by an indirect meta-analysis that compares the safety and efficacy of surgical, flow-diverting stents (FDS), and other endovascular approaches for the treatment of ruptured blood blister aneurysms.

RESULTS

A total of 102 studies were included for quantitative synthesis, with sample sizes of 687 treated surgically, 704 treated endovascularly without FDS, and 125 treated via flow diversion. Comparatively, FDS achieved significantly reduced rates of perioperative retreatment compared with both surgical (P = 0.025) and non-FDS endovascular (P < 0.001). The FDS subgroup also achieved a significantly lower incidence of perioperative rebleed (P < 0.001), perioperative hydrocephalus (P = 0.012), postoperative infarction (P = 0.002), postoperative hydrocephalus (P < 0.001), and postoperative vasospasm (P = 0.002) compared with those patients in the open surgical subgroup. Although no significant differences were found among groups on the basis of functional outcomes, angiographic outcomes detailed by rates of radiographic complete occlusion were highest for surgical (90.7%, 262/289) and FDS (89.1%, 98/110) subgroups versus the non-FDS endovascular subgroup (82.7%, 268/324).

CONCLUSIONS

Flow diversion seems to be an effective treatment strategy for ruptured blood blister aneurysms, with lower rates of perioperative complications compared with surgical and other endovascular techniques, but studies investigating long-term outcomes after flow diversion warrant further study.

Meta-analysis on the treatment options and outcomes of carotid blood blister aneurysms

OBJECTIVE

Carotid blister aneurysms remain a formidable surgical challenge with varied surgical options. There have been significant advancements in the endovascular management of these aneurysms with the introduction of flow diverters. The comparative risk profiles for different endovascular options compared to surgical management of these lesions is not completely understood.

METHODS

The study is a comprehensive systematic review and meta-analysis on the treatment of carotid blood blister aneurysms. Pubmed searches were used to identify relevant articles and patient level data was extracted. Two and three group analyses were conducted comparing surgical and endovascular strategies and surgical, stent coil and flow diversion techniques respectively. Patient outcomes were graded on the modified Rankin Scale with a score of 2 or less defined as favorable.

RESULTS

In total, 83 studies (41 and 42 studies on surgical and endovascular interventions, respectively) with 1119 patients met our inclusion criteria. A statistically significant difference (at the 5% level of significance) in the effect among three different interventions was not found (Q = 3.41, p = 0.1815) under the random-effect model. Our results did show summary proportions of favorable outcomes were higher in the stent coil (0.87, 95% CI: 0.79 - 0.94) and flow diversion (0.87, 95% CI: 0.75 - 0.96) than that of surgery (0.76, 95% CI: 0.71 - 0.83).

CONCLUSIONS

Our results suggest a trend towards improved patient outcomes with endovascular techniques compared to surgical strategies but statistical significance was not achieved. We also found that endovascular techniques compare favorably. Increasing retreatments were found to negatively affect patient outcomes.

Microsurgical Clip Reconstruction of a Ruptured Internal Carotid Artery Terminus Blister Aneurysm Using a Reverse Picket Fence Technique

BACKGROUND

Blister aneurysms are rare, technically challenging lesions that are typically ill defined and arise at nonbranch points of arteries.

OBJECTIVE

To describe the microsurgical treatment of a ruptured blister aneurysm at the internal carotid artery (ICA) terminus using the reverse picket fence clipping technique.

METHODS

The patient was a 60-yr-old male. He presented with a Hunt and Hess Grade 2, Fisher Grade 3 subarachnoid hemorrhage located in the bilateral sylvian fissures (right > left) and suprasellar cisterns. Computed tomography angiography demonstrated 2 aneurysms: a 2-mm right middle cerebral artery (MCA) aneurysm and a 2.5-mm right internal carotid artery (ICA) terminus blister aneurysm. Transradial cerebral angiography was undertaken which showed these similar sized aneurysms. Microsurgical treatment was chosen, and the patient underwent a right pterional craniotomy for clipping of his aneurysms. The patient consented to the procedure.

RESULTS

The combination of stacked fenestrated clips repaired the vessel, with intraoperative fluorescein and indocyanine green angiography demonstrated normal filling of the MCA and ICA circulation with no delay. Intraoperative angiography confirmed induced moderate stenosis of the ICA terminus at about 50%, which is essential to close the blister aneurysm site by utilizing a portion of the normal vessel wall.

CONCLUSION

Ruptured blister aneurysms at the ICA terminus can be safely repaired using the reverse picket fence technique for clipping.

Lesion Trapping with High-Flow Bypass for Ruptured Internal Carotid Artery Blood Blister-Like Aneurysm Has Little Impact on the Anterior Choroidal Artery Flow: Case Series and Literature Review

OBJECTIVE

To examine the relationship between trap location and cerebral infarction in the anterior choroidal artery (AChA) region and associated risks in ruptured internal carotid artery blood blister-like aneurysm (BLA) treatment with high-flow bypass and lesion trapping.

METHODS

We included 26 patients diagnosed with BLAs and treated with high-flow bypass and trapping. We examined clinical characteristics including age, aneurysm trap location, final prognosis, cerebral infarction on postoperative magnetic resonance imaging, and modified Rankin Scale score at discharge. We also searched the literature for similar studies.

RESULTS

The modified Rankin Scale score at discharge was 0-2 in 20 patients, 3-5 in 2 patients, and 6 in 2 patients. In 19/26 patients (73.1%), the trapped segment was between the posterior communicating (PcomA) and the ophthalmic arteries. In 2 patients (7.7%), the trapped segment included the PcomA and the AChA; in 4 patients (15.4%), the trapped segment was within the PcomA. In these patients, the PcomA was occluded, and blood from the high-flow bypass flowed out to the AChA alone. No patient showed cerebral infarction. Our systematic review identified 70 patients. Of all 96 patients, 12 had AChA cerebral infarction; however, the infarction affected the prognosis of only 2 patients.

CONCLUSIONS

When treating BLAs with high-flow bypass and lesion trapping, the frequency of AChA cerebral infarction is low even when the PcomA is occluded, leaving the AChA as the only outflow vessel during high-flow bypass. However, PcomA occlusion may be associated with risks when treating patients with advanced arteriosclerosis near C1-2.

The role of EC-IC bypass in ICA blood blister aneurysms-a systematic review

To perform a systematic review of extracranial-to-intracranial (EC-IC) bypass surgery with parent vessel trapping for blood blister–like aneurysms (BBAs) of the internal carotid artery (ICA) according to PRISMA guidelines. Search of PubMed using “bypass” [all fields] and “ICA” [all fields] or “internal carotid artery” [all fields] and (“blood blister–like aneurysm” [MeSH terms]. Thirty-four original articles were identified, of which 21 were excluded (treatment not including bypass or insufficient details on complications or clinical outcomes). Thirteen articles published between 2008 and 2019 were included, totaling 98 patients, with a median of 7.5 patients per article (range 1–17). Mean age was 53.3 years (range 23–80). The main techniques were external carotid artery to middle cerebral artery (ECA-MCA) in 81% and superficial temporal artery to MCA (STA-MCA) in 19%. The most common grafts were radial artery (74%) and STA (19%). The risk of intraoperative rupture varied from 0 to 75%, with a mean of 12%. With respect to clinical outcomes, the modified Rankin Scale (mRS) was not stated in 30% of the cases. When stated, mRS was ≤ 2 in 79%, mRS was 3–5 in 10%, and 4% had mRS 6 (death). We identified only 13 articles, with no prospective studies. Outcomes were better than generally reported for ruptured aneurysms, both with respect to poor outcome (mRS > 2) and in-hospital mortality, perhaps reflecting a selection bias. In general, the data reporting quality was low, precluding any firm conclusions, but EC-IC bypass with ICA trapping may be a valid treatment option for ruptured ICA BBAs.

Blister aneurysms of the internal carotid artery: Surgical treatment and management outcome from a single center experience

OBJECTIVE

Blood-blister aneurysms (BBAs) of the internal carotid artery (ICA) are rare entities, but clinically important cause of subarachnoid hemorrhage (SAH). Several surgical and endovascular strategies have been attempted for these heterogeneous lesions. In this study, the authors analyzed the treatment strategy and outcomes in a series of cases of ICA blister aneurysms treated microsurgically.

PATIENTS AND METHODS

We retrospectively reviewed 15 consecutive cases of patients harboring ruptured BBAs, microsurgically treated at our institution between 2014 and 2018. We performed an analysis of the clinical and surgical aspects, as well as post-operative angiograms and outcomes.

RESULTS

Fifteen patients were identified; 9 (60%) were female. The mean age of presentation was 43,8 years. Most patients presented in good clinical conditions (Hunt-Hess 1-3 = 86%). The most common Fisher grade at presentation was 3 (60% of cases). All patients underwent digital subtraction angiography (DSA), revealing broad-based aneurysms at non-branching sites on the dorsal wall of the ICA. Intraoperatively, BBAs were confirmed in all cases. The lesions were approached through pterional (11-73%) or lateral supraorbital (4-27%) craniotomy. Direct clipping was performed in all but one lesion, in which case the clip-wrapping technique was used. Final angiographic control revealed complete occlusion in 14 cases. One patient required reoperation due to residual aneurysm filling. At discharge, a good outcome (Glasgow Outcome Scale [GOS] 4 or 5) was observed in 12 (80%) patients. Three patients were discharged with a GOS of 3.

CONCLUSION

Blood-blister-type aneurysms are rare and challenging lesions. Preoperative knowledge and careful surgical planning can prevent poor clinical outcomes. Surgical treatment remains an effective and safe option in this context.

Blood Flow Diversion as a Primary Treatment Method for Ruptured Brain Aneurysms-Concerns, Controversy, and Future Directions

Flow diversion is a novel treatment for brain aneurysms that works by redirecting blood flow away from the aneurysm. Immediately after placement of the stent, blood flow stagnates within the aneurysm dome and it undergoes thrombosis. Over time, a new endothelium develops across the neck, thereby reconstructing the parent vessel and curing the aneurysm. The use of this treatment method for ruptured aneurysms has two specific concerns: 1) risk of hemorrhage from the aneurysm after treatment because of potential delayed aneurysm occlusion; and 2) hemorrhagic complications from antiplatelet use, which is required to prevent thromboembolic complications from the device. In this review, we explore these two concerns based on the emerging published literature. Optimal peri-procedural management of these issues in the neurocritical care setting is vital to improving outcomes. We also identify ongoing clinical trials of flow diversion for the treatment of ruptured aneurysms. Flow diversion is an alternative to clipping or coiling for many ruptured aneurysms and may be potentially more efficacious in certain aneurysm subtypes.

The Blood Blister Like-aneurysm: Usefulness of Sundt Clip

Objective

Blood blister-like aneurysm (BBA) is a kind of dorsal wall aneurysm and it is small, sessile, fragile and hazardous because of its high mortality and morbidity. Many challenges tried to establish the management or strategy. But so far, there is no optimal treatment of choice for the BBA. In this article, 17 cases of the ruptured BBA in one institute were analyzed retrospectively. The operative options were correlated with surgical and clinical outcomes.

Materials and Methods

During 14 years between October, 2002 and October, 2016, 23 patients were treated for subarachnoid hemorrhage with ruptured dorsal wall aneurysms. There were various strategies for treatment and different outcomes revealed. BBA were 17 (74%) cases and 6 (26%) cases were saccular aneurysm. By excluding saccular aneurysm, BBA was sorted and classified with its morphological characteristics, and the outcome of treatment in each case investigated retrospectively.

Results

Among 17 BBA-cases, 8 cases get microsurgical operation by Sundt clip. 5 cases get operation by conventional Yasargil clip, 1 case treated by Yasargil clip with wrapping, and 2 cases underwent endovascular management with coiling, and 1 case was managed by endovascular trapping of involved internal cerebral artery. Clinical outcomes were analyzed with modified Rankin Scale, Glasgow outcome scale and post-operative complications.

Conclusion

As the optimal management, operation using Sundt clip had much significance in treatment BBA. And, a thorough analysis of the angiography is essential to prepare for the treatment of BBA.

Nontraumatic, posterior circulation pseudoaneurysm of the basilar artery summit with complete spontaneous resolution: Case report and literature review

Background:

Intracranial pseudoaneurysms are rare vascular defects of arterial walls that are classically the result of traumatic injury, iatrogenic causes, or infection. Idiopathic pseudoaneurysms are seen even less frequently and are often related to atherosclerosis. Pseudoaneurysms are most commonly found along the distal wall of the internal carotid artery, however, can occur at any location in the cerebrovascular circulation. Treatment of these arterial defects is often challenging due to their frail nature.

Case Description:

A 61-year-old male with a history of hypertension presented with a severe, atypical headache without history of trauma. Computed tomography (CT) and computed tomography angiography (CTA) demonstrated diffuse subarachnoid hemorrhage. Imaging demonstrated a 3.5 mm pseudoaneurysm projecting distally from the basilar artery at the apex. Repeated imaging (CTA, digital subtraction angiography) demonstrated decreased size and flow associated within the aneurysm over the following 2 weeks; as such, the patient was managed conservatively. The patient was discharged in neurologically intact condition when imaging at 14 days confirmed complete and spontaneous resolution of the pseudoaneurysm.

Conclusion:

Idiopathic pseudoaneurysms that are commonly associated with atherosclerosis are most commonly managed surgically or endovascularly. Conservative approach may be considered in a select group of patients that exhibit decreased size and/or flow within the aneurysm in repeated imaging; spontaneous resolution was seen in the present case.

Microsurgical versus endovascular interventions for blood-blister aneurysms of the internal carotid artery: systematic review of literature and meta-analysis on safety and efficacy

OBJECTIVE Blood-blister aneurysms (BBAs) of the internal carotid artery (ICA) have a poor natural history associated with high morbidity and mortality. Currently, both surgical and endovascular techniques are employed to treat BBAs; thus, the authors sought to perform a meta-analysis to compare the efficacy and safety of these approaches. METHODS A literature search of PubMed, MEDLINE, and Google Scholar online databases was performed to include pertinent English-language studies from 2005 to 2015 that discussed the efficacy and safety of either surgical or endovascular therapies to treat BBAs. RESULTS Thirty-six papers describing 256 patients with BBAs treated endovascularly (122 procedures) or surgically (139 procedures) were examined for data related to therapeutic efficacy and safety. Pooled analysis of 9 papers demonstrated immediate and late (mean 20.9 months) aneurysm occlusion rates of 88.9% (95% CI 77.6%-94.8%) and 88.4% (95% CI 76.7%-94.6%), respectively, in surgically treated patients. Pooled analysis of 12 papers revealed immediate and late aneurysm obliteration rates of 63.9% (95% CI 52.3%-74.1%) and 75.9% (95% CI 65.9%-83.7%), respectively, in endovascularly treated aneurysms. Procedure-related complications and overall poor neurological outcomes were slightly greater in the surgically treated cases than in the endovascularly treated cases (27.8% [95% CI 19.6%-37.8%] vs 26.2% [95% CI 18.4%-35.8%]), indicating that endovascular therapy may provide better outcomes. CONCLUSIONS Blood-blister aneurysms are rare, challenging lesions with a poor prognosis. Although surgical management potentially offers superior aneurysm obliteration rates immediately after treatment and at the long-term follow-up, endovascular therapy may have a better safety profile and provide better functional outcomes than surgery. A registry of patients treated for BBAs may be warranted to better document the natural course of the disease as well as treatment outcomes.

Hybrid procedure combining clip on wrapping and stent placement for ruptured supraclinoid blood blister-like aneurysm of the internal carotid artery

Blood blister-like aneurysms of the supraclinoid portion of the internal carotid artery are rare, fragile, and thin-walled lesions with a higher rate of rebleeding. Our case underwent a hybrid procedure combining direct surgical and endovascular approach.

Blister Aneurysms of the Internal Carotid Artery: Microsurgical Results and Management Strategy

BACKGROUND: Blister aneurysms of the supraclinoid internal carotid artery (ICA) are challenging lesions with high intraoperative rupture rates and significant morbidity. An optimal treatment strategy for these aneurysms has not been established.

OBJECTIVE: To analyze treatment strategy, operative techniques, and outcomes in a consecutive 17-year series of ICA blister aneurysms treated microsurgically.

METHODS: Seventeen patients underwent blister aneurysm treatment with direct clipping, bypass and trapping, or clip-reinforced wrapping.

RESULTS: Twelve aneurysms (71%) were treated with direct surgical clipping. Three patients required bypass: 1 superficial temporal artery to middle cerebral artery bypass, 1 external carotid artery to middle cerebral artery bypass, and 1 ICA to middle cerebral artery bypass. One patient was treated with clip-reinforced wrapping. Initial treatment strategy was enacted 71% of the time. Intraoperative rupture occurred in 7 patients (41%), doubling the rate of a poor outcome (57% vs 30% for patients with and without intraoperative rupture, respectively). Severe vasospasm developed in 9 of 16 patients (56%). Twelve patients (65%) were improved or unchanged after treatment, and 10 patients (59%) had good outcomes (modified Rankin Scale scores of 1 or 2).

CONCLUSION: ICA blister aneurysms can be cautiously explored and treated with direct clipping as the first-line technique in the majority of cases. Complete trapping of the parent artery with temporary clips and placing permanent clip blades along normal arterial walls enables clipping that avoids intraoperative aneurysm rupture. Trapping/bypass is used as the second-line treatment, maintaining a low threshold for bypass with extensive or friable pathology of the carotid wall and in patients with incomplete circles of Willis.

Current status of the treatment of blood blister-like aneurysms of the supraclinoid internal carotid artery: A review

Currently, the treatment of blood blister-like aneurysms (BBAs) of the supraclinoid internal carotid artery (ICA) is challenging and utilizes many therapeutic methods, including direct clipping and suturing, clipping after wrapping, clipping after suturing, coil embolization, stent-assisted coil embolization, multiple overlapping stents, flow-diverting stents, covered stents, and trapping with or without bypass. In these therapeutic approaches, the optimal treatment method for BBAs has not yet been defined based on the current understanding of BBAs of the supraclinoid ICA. Therefore, in this study, we aimed to review the literature from PubMed to discuss and analyze the pros and cons of the above approaches while adding our own viewpoints to the discussion. Among the surgical methods, direct clipping was the easiest method if the compensation of the collateral circulation of the intracranial distal ICA was sufficient or direct clipping did not induce stenosis in the parent artery. In addition, the clipping after wrapping technique should be chosen as the optimal surgical modality to prevent rebleeding from these lesions. Among the endovascular methods, multiple overlapping stents (≥3) with coils may be a feasible alternative for the treatment of ruptured BBAs. In addition, flow-diverting stents appear to have a higher rate of complete occlusion and a lower rate of retreatment and are a promising treatment method. Finally, when all treatments failed or the compensation of the collateral circulation of the intracranial distal ICA was insufficient, the extracranial-intracranial (EC-IC) arterial bypass associated with surgical or endovascular trapping, a complex and highly dangerous method, was used as the treatment of last resort.

Surgical Management of Intracranial Artery Dissection

Intracranial artery dissection (IAD) is a relatively rare cause of stroke, but it has been recognized increasingly with recent advances of the neuroimaging technique. Since rebleeding occurs frequently in the acute stage in the ruptured IAD, urgent surgical treatment should be performed to prevent rebleeding. On the other hand, surgical treatment for unruptured IAD is controversial because it has little risk for bleeding. However, surgical treatment for unruptured IAD may be considered if the formation or enlargement of the aneurysmal dilatation has been confirmed. Since there are several proposed surgical strategies for IAD, it is important to select an appropriate strategy on a case-by-case basis. If the risk of infarction due to vessel occlusion is high, combined bypass surgery should be considered.

Cerebral Blood Flow after Acute Bypass with Parent Artery Trapping in Patients with Ruptured Supraclinoid Internal Carotid Artery Aneurysms

BACKGROUND

Bypass with parent artery trapping is an alternative treatment method for ruptured internal carotid artery (ICA) aneurysms when clipping or coiling is contraindicated. However, the efficacy and safety of this strategy during the acute stage of subarachnoid hemorrhage (SAH) is undetermined.

METHODS

A retrospective review of 955 consecutive patients presenting SAH between 2006 and 2014 identified 17 patients with ruptured ICA aneurysms treated by bypass with parent artery trapping within 72 hours after the bleeding (bypass group). The 26 cases with ruptured posterior communicating artery aneurysms treated with clipping during the same period were defined as a control group (clipping group). Postoperative cerebral blood flow (CBF) was evaluated by single photon emission computed tomography (SPECT). We analyzed the postoperative hemodynamic status, surgical complications, and the clinical outcomes.

RESULTS

Postoperative rebleeding did not occur in any of the cases. CBF in the first postoperative week in the bypass group was lower than that in the clipping group (P = .0165). This CBF decrease improved in the second postoperative week and did not differ from that of the clipping group. The incidence of acute ischemic complications was significantly higher in the bypass group (P = .0284), but the incidence of delayed cerebral ischemia did not differ between the 2 groups. The incidence of favorable outcomes at 6 months was 82.4% in the bypass group and 81% in the clipping group.

CONCLUSIONS

Although the transient CBF decrease with acute ischemic complications should be noted, acute bypass with parent artery trapping is safe and effective for unclippable/uncoilable ruptured ICA aneurysms.

Morphological aspects of blister aneurysms and nuances for surgical treatment

OBJECT

Blister aneurysms of the supraclinoid part of the internal carotid artery (ICA) are known for their high morbidity and mortality rates related to treatment, regardless of whether the treatment is surgical or endovascular. However, this grim prognosis is based on results that indiscriminately group all blister aneurysms together without taking into account the heterogeneous appearance of these lesions. The goal of this study was 2-fold: to determine whether different blister aneurysm morphologies present different pitfalls, which would then require different surgical strategies, as well as to determine whether there are identifiable subgroups of these types of aneurysms based on morphology.

METHODS

The authors reviewed the charts, cerebral catheter angiograms, surgical reports, and intraoperative videos of all ICA blister aneurysms treated surgically at the Centre Hospitalier de l'Université de Montréal from 2005 to 2012 to investigate whether there was a relationship between morphology and pitfalls, and whether different surgical strategies had been used according to these pitfalls. During this review process the authors noted 4 distinct morphological aspects. These 4 aspects led to a review of the English and French literature on blister aneurysms in which imaging was available, to determine whether other cases could also be classified into the same 4 subgroups based on these morphological aspects.

RESULTS

The retrospective review of the authors' series of 10 patients allowed a division into 4 distinct subtypes: Type I (classic), Type II (berry-like), Type III (longitudinal), and Type IV (circumferential). These subtypes may at times be progressive stages in the arterial anomaly, and could represent a continuum. Each subtype described in this paper presented its own pitfalls and required specific surgical adaptations. Upon reviewing the literature the authors retained 35 studies involving a total of 61 cases of blister aneurysms, and all cases were able to be classified into 1 of these 4 distinct subtypes.

CONCLUSIONS

Although they share some common characteristics, blister aneurysms may be divided into distinct subtypes, suggestive of a continuum. Such a classification with a detailed description of each type of blister aneurysm would allow for better recognition to anticipate complications during intervention and better assess the different treatment strategies according to the subtypes.

Use of the sundt clip graft in a previously coiled internal carotid artery blister-like aneurysm

Owing to the focal wall defect covered with thin fibrous tissues, an aneurysm arising from the dorsal wall of the internal carotid artery (ICA) is difficult to manage either surgically or endovascularly and is often associated with high morbidity and mortality. Unfortunately, the definitive treatment modality of such highly risky aneurysm has not yet been demonstrated. Upon encountering the complex intracranial pathophysiology of such a highly precarious aneurysm, a neurosurgeon would be faced with a challenge to decide on an optimal approach. This is a case of multiple paraclinoid aneurysms including the ICA dorsal wall aneurysm, presented with spontaneous subarachnoid hemorrhage. With respect to treatment, direct clipping with a Sundt graft clip was performed after multiple endovascular interventions had failed. This surgical approach can be a treatment modality for a blood blister-like aneurysm after failed endovascular intervention(s).

Blood blister-like aneurysm with rupture point close to origin of anterior choroidal artery

If a ruptured blood blister-like aneurysm (BBA) arises from the lateral or superolateral wall of the internal carotid artery (ICA) at the level of the anterior choroidal artery (AChA), its proximity to the origin of the AChA presents a serious surgical challenge to preserve the patency of the AChA. Two such rare cases are presented, along with successful surgical techniques, including the application of a C-shaped aneurysm clip parallel to the ICA and a microsuture technique to repair the arterial defect. The patency of the AChA and ICA was successfully preserved without recurrence or rebleeding of the BBA during a 1-year follow-up after the operation.

How I do it: treatment of blood blister-like aneurysms of the supraclinoid internal carotid artery by extracranial-to-intracranial bypass and trapping

BACKGROUND

Blood blister-like aneurysms (BBAs) pose a significant challenge to neurosurgeons and neuro-interventionalists. These fragile broad-based aneurysms have a propensity to rupture with minimal manipulation during surgical or endovascular explorations because, unlike saccular aneurysms, they lack all layers of the arterial wall. Aneurysm trapping with extracranial-intracranial (EC-IC) bypass is a safe and durable treatment for BBAs.

METHODS

We describe our technique and the guiding principles for surgical bypass and trapping of BBAs of the supraclinoid internal carotid artery (ICA).

CONCLUSIONS

Treatment of BBAs of the supraclinoid ICA remains difficult. Aneurysm trapping with EC-IC bypass treats BBAs definitively by eliminating the diseased segment of the ICA. We have found the technique and principles described here to be safe and durable in our hands.

Blister-like aneurysms of middle cerebral artery: a multicenter retrospective review of diagnosis and treatment in three patients

Blood blister-like aneurysms (BBA) were described for the first time in the 1990s, as small hemispherical bulges arising from a very fragile arterial wall. Until 2008, it was thought that this type of aneurysm almost exclusively affected the internal carotid artery, in particular, its dorsal portion. Subsequently, it was discovered that a BBA may also be present on the anterior communicating artery and on the vessels of the posterior cranial fossa. However, we found no reports in English-language literature of BBA arising from the middle cerebral artery (MCA). In this article, we present three cases of MCA BBA and discuss the unique diagnostic and therapeutic aspects of this vascular lesion. In our retrospective, multicenter review of 1330 patients with non-traumatic subarachnoid hemorrhage admitted to our services from 2000 to 2013, we found three cases (all in men) of MCA BBA. The patients' outcome was assessed using the modified Rankin scale. All three patients underwent angio-computed tomography, which did not reveal any aneurysms. Digital subtraction angiography performed within 24-48 h after admission, in all cases, demonstrated a very small aneurysm (<2 mm), with a triangular shape and abroad base, at non-branching sites of MCA. All the aneurysms were treated: one by wrapping + clipping, one by wrapping + flow-diverter stent, and one with coils. At the time of surgery, the aneurysms appeared on the surface of the parent artery without any involvement of the branches. All presented as blister-like aneurysms that were thin-walled and lacked a surgical neck. At the time of discharge, the outcome was good in one patient and poor in the other two. Our cases demonstrate that BBA can also arise from the MCA, despite the lack of previous reports of this occurrence; a BBA should be suspected, particularly in cases of non-perimesencephalic subarachnoid hemorrhage in which the presence of a MCA aneurysm is suspected but not revealed by digital subtraction angiography or angio-computed tomography.

Combination treatment for rapid growth of a saccular aneurysm on the internal carotid artery dorsal wall: case report

Aneurysms arising from non-branching sites of the supraclinoid internal carotid artery (ICA) are considered rare, accounting for only 0.9-6.5% of all ICA aneurysms. They are thin-walled, broad-based, can easily rupture during surgery, and are referred to as dorsal, superior, anterior, or ventral wall ICA aneurysms, as well as blister-like aneurysms. Various treatment modalities are available for blister-like aneurysms, but with varying success. Here, we report on two cases of saccular shaped dorsal wall aneurysms. Both patients were transferred to the emergency department with subarachnoid hemorrhage because of an aneurysmal rupture. Computed tomography angiography and transfemoral cerebral angiography (TFCA) showed a dorsal wall aneurysm in the distal ICA. We performed clipping on the wrapping material (Lyodura®, temporal fascia). Follow-up TFCA showed rapid configuration changes of the right distal ICA. Coil embolization was also performed as a booster treatment to prevent aneurysm regrowth. Both patients were discharged without neurologic deficit. No evidence of aneurysm regrowth was observed on follow-up TFCA at two years. Dorsal wall ICA aneurysms can change in size over a short period; therefore, follow-up angiography should be performed within the short-term. In cases of regrowth, coil embolization should be considered as a booster treatment.

Fatal Ruptured Blood Blister-like Aneurysm of Middle Cerebral Artery Associated with Ehlers-Danlos Syndrome Type VIII (Periodontitis Type)

Objective To illustrate a unique instance of Ehlers-Danlos syndrome type VIII (EDS VIII) with blood blister–like aneurysm of the middle cerebral artery.

Design This is a single patient case report.

Setting University of Wisconsin-Madison Hospital.

Participants A 42-year-old woman with diagnosis of EDS VIII presented with a sudden onset severe headache and altered mental status. She was diagnosed with Hunt and Hess grade IV subarachnoid hemorrhage. Angiography demonstrated a blood blister–like aneurysm of the left middle cerebral artery. After an unsuccessful coiling attempt in another facility, the patient was operated on with the intention to perform extracranial to intracranial bypass and trapping of the diseased segment of the artery.

Results The patient's neurologic condition remained poor after surgery. On postoperative day 2, her neurologic examination unchanged, and care was withdrawn per the family's request.

Conclusions Individuals with EDS VIII may be at risk for catastrophic vascular events.

Endovascular internal carotid artery trapping for ruptured blood blister-like aneurysms: long-term results from a single centre

INTRODUCTION

Endovascular internal carotid artery (ICA) trapping was performed to treat ruptured blood blister-like aneurysms (BBAs). The aim of this study was to evaluate the procedural risks and long-term follow-up results.

METHODS

The records of 11 consecutive patients with BBAs who underwent endovascular ICA trapping between 2005 and 2010 were reviewed. Clinical outcomes were assessed with modified Rankin Scale (mRS) scores.

RESULTS

Endovascular ICA trapping was performed in 11 patients as either the primary treatment (7 patients) or the secondary treatment (4 patients) after the patient underwent other treatments. Three patients underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass when balloon test occlusion (BTO) revealed inadequate collateral circulation. In the primary ICA trapping group (seven patients), six patients had good outcomes (mRS 0 in five, mRS 1 in one), and one patient had a poor outcome (mRS 6: dead). In the secondary ICA trapping group (four patients), two patients had good outcomes (mRS 0), and two patients had poor outcomes (mRS 4, 5). All ten of the surviving patients were clinically stable during the follow-up period (mean 39 months). A radiological follow-up of nine patients (mean 22 months) demonstrated stable occlusion, with the exception of one reopening of the ICA because of coil migration. Perfusion studies of nine patients (mean: 23 months) demonstrated no perfusion decrease.

CONCLUSION

Endovascular ICA trapping is an effective and durable treatment for BBAs.

High incidence of ICA anterior wall aneurysms in patients with an anomalous origin of the ophthalmic artery: possible relevance to the pathogenesis of aneurysm formation

OBJECT

Surgery for aneurysms at the anterior wall of the internal carotid artery (ICA), which are also referred to as ICA anterior wall aneurysms, is often challenging. A treatment strategy needs to be determined according to the pathology of the aneurysm-namely, whether the aneurysm is a saccular aneurysm with firm neck walls that would tolerate clipping or coiling, a dissecting aneurysm, or a blood blister-like aneurysm. However, it is not always possible to properly evaluate the condition of the aneurysm before surgery solely based on angiographic findings.

METHODS

The authors focused on the location of the ophthalmic artery (OA) in determining the pathology of ICA anterior wall aneurysms. Between January 2006 and December 2012, diagnostic cerebral angiography, for any reason, was performed on 1643 ICAs in 855 patients at Saitama Medical Center. The authors also investigated the relationship between the origin of the OA and the incidence of ICA anterior wall aneurysms. The pathogenesis was also evaluated for each aneurysm based on findings from both angiography and open surgery to identify any correlation between the location where the OA originated and the conditions of the aneurysm walls.

RESULTS

Among 1643 ICAs, 31 arteries (1.89%) were accompanied by an anomalous origin of the OA, including 26 OAs originating from the C3 portion, 3 originating from the C4 portion, and 2 originating from the anterior cerebral artery. The incidence of an anomalous origin of the OA had no relationship to age, sex, or side. Internal carotid artery anterior wall aneurysms were observed in 16 (0.97%) of 1643 ICAs. Female patients had a significantly higher risk of having ICA anterior wall aneurysms (p = 0.026). The risk of ICA anterior wall aneurysm formation was approximately 50 times higher in patients with an anomalous origin of the OA (25.8% [8 of 31]) than in those with a normal OA (0.5% [8 of 1612], p < 0.0001). Based on angiographic classifications, saccular aneurysms were significantly more common in patients with an anomalous origin of the OA than in those with a normal OA (p = 0.041). Ten of 16 patients with ICA anterior wall aneurysms underwent craniotomies. Based on the intraoperative findings, all 6 aneurysms with normal OAs were dissecting or blood blister-like aneurysms, not saccular aneurysms.

CONCLUSIONS

There was a close relationship between the location of the OA origin and the predisposition to ICA anterior wall aneurysms. Developmental failure of the OA and subsequent weakness of the vessel wall might account for this phenomenon, as previously reported regarding other aneurysms related to the anomalous development of parent arteries. The data also appear to indicate that ICA anterior wall aneurysms in patients with an anomalous origin of the OA tend to be saccular aneurysms with normal neck walls. These findings provide critical information in determining therapeutic strategies for ICA anterior wall aneurysms.

Long-term Follow-up of Blister Aneurysms of the Internal Carotid Artery

BACKGROUND:

Blister aneurysms of the internal carotid artery (ICA) are uncommon. There is a paucity of data on the long-term outcomes of patients.

OBJECTIVE:

To review our experience with the treatment of these lesions.

METHODS:

We retrospectively reviewed all aneurysms treated at our institution between 1994 and 2005. Relevant operative notes, radiology reports, and inpatient/outpatient records were reviewed.

RESULTS:

Seventeen patients (3 male, 14 female) with 18 blister aneurysms of the ICA were identified. The mean age was 44.6 years (range, 17–72; median, 42 years). Twelve patients (70.6%) presented with aneurysmal subarachnoid hemorrhage. The mean admission Glasgow Outcome Scale score was 4.3 (range, 2–5; median, 5). All patients were initially treated using microsurgical technique with direct clipping (n = 15; 83.3%) or clip-wrapping with Gore-Tex (n = 3, 16.7%). There were 4 cases of intraoperative rupture, all associated with attempted direct clipping; all 4 cases were successfully clipped. Two cases rebled post-treatment. Both rebleeding episodes were managed with endovascular stenting. Follow-up angiography was available for 14 patients and revealed a new aneurysm adjacent to the site of clipping in 1 patient and in-stent stenosis in 2. At the mean follow-up of 74.5 months (median, 73; range, 7–165), the mean Glasgow Outcome Scale score was 4.6 (range, 2–5; median, 5).

CONCLUSION:

Microsurgical treatment of blister aneurysms of the ICA results in excellent outcome. In the evolution of treating these friable aneurysms, we have modified our clip-wrapping technique and use this technique when direct clipping is not feasible.

Changing Treatment Strategy From Clipping to Radial Artery Graft Bypass and Parent Artery Sacrifice in Patients With Ruptured Blister-Like Internal Carotid Artery Aneurysms

BACKGROUND:

Blood blister-like aneurysms (BBAs) are aneurysms with ill-defined fragile necks arising from an internal carotid artery (ICA) and associated with high mortality.

OBJECTIVE:

To describe strategies and outcomes in patients in whom radial artery (RA) graft bypass with ICA sacrifice was considered as the primary treatment during the acute phase of subarachnoid hemorrhage.

METHODS:

The authors analyzed the clinical records of 20 patients who were treated between 2004 and 2011 at their hospital and affiliate institutions.

RESULTS:

A majority of the patients were treated during the acute phase (&lt;24 hours, n = 15). A favorable outcome was achieved in 18 (90%) patients. The treatment strategies used were as follows: (1) ICA trapping/external carotid artery (ECA)-RA-middle cerebral artery (MCA) bypass (n = 13), (2) ICA trapping/superficial temporal artery-MCA bypass (n = 2), (3) aneurysm clipping with RA-MCA temporary bypass (n = 3), (3) aneurysm clipping with proximal ICA ligation and ECA-RA-MCA bypass (n = 1), and (4) direct clipping (n = 1). Postoperative infarction was observed in 6 patients and was ascribed to vasospasm (n = 1), retrograde thrombosis associated with trapping (n = 2), and reasons unrelated to the surgical procedures (n = 3).

CONCLUSION:

Trapping with RA graft bypass demonstrated favorable results in patients with internal carotid BBAs. Although trapping/RA graft bypass is a definitive treatment for BBAs located proximal to the origin of the posterior communicating artery, some distal BBAs preclude ICA trapping to spare the perforating arteries.

The pipeline flow-diverting stent for exclusion of ruptured intracranial aneurysms with difficult morphologies

BACKGROUND

The Pipeline Embolization Device (PED) is a flow-diverting stent that may represent a new therapeutic tool for difficult-to-treat intracranial aneurysms, including those that present with subarachnoid hemorrhage (SAH).

OBJECTIVE

To demonstrate the feasibility of utilizing the PED as a primary treatment for ruptured aneurysms with challenging morphologies.

METHODS

Three patients with ruptured intracranial aneurysms presented with SAH. Three distinct and difficult-to-treat aneurysm morphologies were encountered: (1) a small basilar trunk pseudoaneurysm, (2) a carotid artery blister aneurysm, and (3) an A1/A2 junction-dissecting-type aneurysm. All were treated with deployment of one or more PEDs across the aneurysm.

RESULTS

PEDs were successfully deployed in all 3 cases. Two patients were treated with 2 overlapping PEDs, and the third patient was treated with a single device. Aneurysm obliteration was achieved in all 3 cases with no early rehemorrhage or other clinically adverse event.

CONCLUSION

Endovascular treatment with the pipeline flow-diverting stent may be a viable treatment option for otherwise difficult-to-treat aneurysm morphologies in the context of acute SAH.

Blister-like aneurysms of the internal carotid artery - management considerations

Blood blister-like aneurysms (BBA) originate at non-branching sites of the internal carotid artery (ICA). These aneurysms present a fragile wall and a poorly defined broad-based neck. Recognition of the BBA is essential for proper management of these vascular lesions. Various surgical and endovascular strategies have been attempted for these heterogeneous lesions. These have been associated with significant morbidity and mortality including rebleeding, regrowth, ischemic and thromboembolic complications. The authors review the key elements important for diagnosis and management of BBA and review current treatment options.

Coiling of a residual internal carotid artery aneurysm via an extracranial-intracranial bypass graft following parent vessel occlusion

We report the case of a ruptured internal carotid artery (ICA) aneurysm that demonstrated significant persistent filling despite management with a common carotid to middle cerebral artery saphenous vein extracranial-intracranial bypass and subsequent permanent ICA balloon occlusion. The residual aneurysm was successfully embolised with detachable coils using a novel endovascular approach via the bypass graft.

The management of very small/blister internal carotid artery aneurysms

Blood blister aneuryms are uncommon lesions that have a poor natural history. Because there is no clear aneurysmal sac to treat they remain challenging lesions to manage whether the approach is endovascular or surgical. Although the management of intracranial cerebral aneurysms has changed subsequent to the results published by the ISAT trial, there still exist groups of aneurysms which do not lend themselves to endovascular management. There are recent reports of successful endovascular management using flow diverting approaches but experience is limited and relying on flow change may be insufficient to prevent re-rupture. Surgery when possible offers the advantage of immediate vessel wall reconstruction.