Endovascular treatment of blood blister-like aneurysms of the internal carotid artery

The unusual angiographic course of intracranial pseudoaneurysms

Although rare, traumatic intracranial pseudoaneurysms remain one of the most difficult vascular lesions to diagnose and treat. A 55-year-old male patient underwent endoscopic endonasal transphenoidal resection for a pituitary macroadenoma. The operation was complicated by an arterial bleed. The initial angiogram revealed pseudoaneurysm of the anterior choroidal artery. Although the pseudoaneurysm completely disappeared on the second angiogram, it was surprisingly found to have enlarged on the third angiogram. The lesion was successfully treated with flow-diversion using a pipeline embolization device. The present case demonstrates that the natural history of iatrogenic pseudoaneurysms may be unpredictable and misleading. Traumatic pseudoaneurysms should, therefore, be carefully followed when conservative treatment is elected or when the lesion seems to have spontaneously regressed. Flow-diversion seems to be a reasonable treatment option.

Management of Proximal Anterior Cerebral Artery Aneurysms: Anatomical Variations and Technical Nuances

OBJECTIVE

The proximal segment of the anterior cerebral artery (A1) is among the most uncommon locations for occurrence of an intracranial aneurysm. These aneurysms may be missed if small or misinterpreted when they are near the internal cerebral artery bifurcation or Anterior Communicating Artery region. The association with congenital vascular anomalies and multiplicity makes them unique.

METHODS

Seventeen A1 aneurysms were diagnosed in sixteen patients between January 2000 and October 2014 in our institution. A retrospective review of the clinical, radiological, and management (microsurgical and endovascular) details of these patients was conducted.

RESULTS

The incidence of A1 aneurysm was 1.71% of all patients harboring aneurysms and 1.19% of all aneurysms. Half of these patients exhibited subarachnoid hemorrhage. Fourteen aneurysms underwent microsurgical or endovascular intervention. All patients recovered well, except for one patient who died in the postoperative period.

CONCLUSIONS

A1 aneurysms are rare, with wide anatomic variations. In this article, we discuss those variations in detail with illustrative cases and pictures. We also discussed the microsurgical and endovascular strategies to encounter them highlighting the technical challenges.

Long-term Patient Outcomes After Microsurgical Treatment of Blister-Like Aneurysms of the Basilar Artery

BACKGROUND

Blister-like aneurysms (BLAs) are challenging lesions that require unique microsurgical strategies. BLAs are predominantly found along the internal carotid artery; however, BLAs of the basilar artery are a rare subset that requires a modified treatment strategy.

OBJECTIVE

To discuss the microsurgical management and review the long-term outcomes of patients with BLAs of the basilar artery.

METHODS

We retrospectively reviewed the surgical technique, postoperative results, and long-term outcomes of all patients with basilar artery BLAs treated at our institution from 2005 to 2011.

RESULTS

Four patients with basilar artery BLAs were identified over this 6-year interval. All 4 patients were treated by direct microsurgical clipping. A thin layer of cotton reinforcement was used beneath the clip tines to minimize the risk of clip slippage in 2 of 4 patients; 1 patient required adjunctive endovascular stent placement for residual aneurysm after clipping. Complete obliteration of all aneurysms was achieved, and there has been no recurrence at mean clinical follow-up of 72 months (median, 74.5; range, 37-103) and imaging follow-up of 48 months (median, 54; range 12-72).

CONCLUSION

Direct clipping with or without cotton reinforcement can obliterate basilar BLAs with excellent long-term outcomes. Clip wrapping is not an option for these lesions given the proximity to perforating branches. Endovascular techniques provide a useful adjunctive strategy; however, risks with antiplatelet therapy in the acute subarachnoid hemorrhage period must be considered.

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.

Pipeline embolization for definitive endoluminal reconstruction of blister-type carotid aneurysms after clip wrapping

Background

Ruptured blister aneurysms of the carotid artery are difficult to safely treat. We present a novel strategy of microsurgical clip wrapping of internal carotid artery blister aneurysms in the setting of acute rupture, followed by delayed placement of a pipeline embolization device for definitive treatment.

Clinical presentation

We present two cases of ruptured blister aneurysms of the internal carotid artery treated by wrapping of the diseased segment of the vessel, followed by delayed deployment of a flow diverting stent once the patient was out of the vasospasm window but during the same hospitalization.

Results

Clip wrapping followed by flow diversion in a delayed fashion results in anatomic remodeling of the diseased artery without a high morbidity.

Conclusions

A combined approach of acute surgical stabilization followed by definitive endovascular reconstruction may reduce hemorrhagic complications while improving long term treatment durability.

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.

Formal protocol for emergency treatment of ruptured intracranial aneurysms to reduce in-hospital rebleeding and improve clinical outcomes

OBJECT

While the incidence of a recurrent hemorrhage is highest within 24 hours of subarachnoid hemorrhage (SAH) and increases with the severity of the clinical grade, a recurrent hemorrhage can occur anytime after the initial SAH in patients with both good and poor clinical grades. Therefore, the authors adopted a 24-hour-a-day, formal protocol, emergency treatment strategy for patients with ruptured aneurysms to secure the aneurysms as early as possible. The incidences of in-hospital rebleeding and clinical outcomes were investigated and compared with those from previous years when broadly defined early treatment was used (<3 days of SAH).

METHODS

During an 11-year period, a total of 1224 patients with a ruptured aneurysm were managed using a strategy of broadly defined early treatment between 2001 and 2004 (Period B, n=423), a mixture of early or emergency treatment between 2005 and 2007, and a formal emergency treatment protocol between 2008 and 2011 (Period A, n=442). Propensity score matching was used to adjust the differences in age, sex, modified Fisher grade, World Federation of Neurosurgical Societies (WFNS) clinical grade at admission, size and location of a ruptured aneurysm, treatment modality (clip placement vs coil embolization), and time interval from SAH to admission between the two time periods. The matched cases were allotted to Group A (n=280) in Period A and Group B (n=296) in Period B and then compared.

RESULTS

During Period A under the formal emergency treatment protocol strategy, the catheter angiogram, endovascular coiling, and surgical clip placement were started at a median time from admission of 2.0 hours, 2.9 hours, and 3.1 hours, respectively. After propensity score matching, Group A showed a significantly reduced incidence of in-hospital rebleeding (2.1% vs 7.4%, p=0.003) and a higher proportion of patients with a favorable clinical outcome (modified Rankin Scale score 0-3) at 1 month (87.9% vs 79.7%, respectively; p=0.008). In particular, the patients with good WFNS grades in Group A experienced significantly less in-hospital rebleeding (1.7% vs 5.7%, respectively; p=0.018) and better clinical outcomes (1-month mRS score of 0-3: 93.8% vs 87.7%, respectively; p=0.021) than the patients with good WFNS grades in Group B.

CONCLUSIONS

Patients with ruptured aneurysms may benefit from a strategy of emergency application of surgical clip placement or endovascular coiling due to the reduced incidence of recurrent bleeding and improved clinical outcomes.

Endovascular management of intracranial blister aneurysms: spectrum and limitations of contemporary techniques

Background

Intracranial blister aneurysms are rare lesions that are notoriously more difficult to treat than typical saccular aneurysms. High complication rates associated with surgery have sparked considerable interest in endovascular techniques, though not well-studied, to treat blister aneurysms.

Objective

To evaluate our experience using various endovascular approaches to treat blister aneurysms.

Methods

All consecutive blister aneurysms treated using an endovascular approach by the study authors over a 3-year period were retrospectively analyzed. A literature review was also performed.

Results

Nine patients with blister aneurysms underwent 11 endovascular interventions. In various combinations, stents were used in 8/11, coils in 5/11, and Onyx in 3/11 procedures. At mean angiographic follow-up of 200 days, 8/9 aneurysms were completely occluded by endovascular means alone requiring no further treatment and 1/9 aneurysms required surgical bypass/trapping after one failed surgical and two failed endovascular treatments. At mean clinical follow-up of 416 days, modified Rankin Scale scores were improved in six patients, stable in two, and worsened in one patient. One complication occurred in 11 procedures (9%), resulting in a permanent neurologic deficit. No unintended endovascular parent vessel sacrifice, intraprocedural aneurysmal ruptures, antiplatelet-related complications, post-treatment aneurysmal re-ruptures, or deaths occurred.

Conclusion

This series highlights both the spectrum and limitations of endovascular techniques currently used to treat blister aneurysms, including a novel application of stent-assisted Onyx embolization. Long-term follow-up and experience in larger studies are required to better define the role of endovascular therapy in the management of these difficult lesions.

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.

Stenting as monotherapy for uncoilable intracranial aneurysms

BACKGROUND

Small, blister-like aneurysms (BLAs), by virtue of their unique morphology, are difficult to treat with conventional modalities. The use of oversized self-expanding stents as monotherapy for BLAs is a relatively new and promising concept that warrants further investigation.

OBJECTIVE

To clarify the role of oversized self-expanding stents as monotherapy for BLAs.

METHODS

Five consecutive patients were treated for BLAs with oversized self-expanding stents alone by the senior author (K.R.B.). We report on their clinical and radiographic outcomes.

RESULTS

All 5 patients in our series were discharged in good clinical condition. Complete aneurysm occlusion was observed in all patients at the time of most recent radiographic follow-up. Mean follow-up time was 13.6 months (range, 1 month to 4.5 years).

CONCLUSION

The use of oversized self-expanding stents to redirect flow away from aneurysms is an effective option for patients with BLAs. This approach represents an alternative to the use of flow diverters.

Pipeline Embolization Device as primary treatment for blister aneurysms and iatrogenic pseudoaneurysms of the internal carotid artery

BACKGROUND

Blood blister type aneurysms (BBAs) and pseudoaneurysms create a unique treatment challenge. Despite many advances in open surgical and endovascular techniques, this subset of patients retains relatively high rates of morbidity and mortality. Recently, BBAs have been treated with flow-diverting stents such as the Pipeline Embolization Device (PED) with overall positive results.

METHODS

Four patients presented with dissecting internal carotid artery (ICA) aneurysms treated with the PED (two BBAs presenting with subarachnoid hemorrhage (SAH), two pseudoaneurysms after injury during endoscopic trans-sphenoidal tumor surgery).

RESULTS

Three patients had a successful angiographic and neurological outcome. One patient with a BBA re-ruptured during initial PED placement, again in the postoperative period, and later died. Primary PED treatment involved telescoping stents in two patients and coil embolization supplementation in one patient.

CONCLUSIONS

The PED should be used selectively in the setting of acute SAH. Dual antiplatelet therapy can complicate hydrocephalus management, and the lack of immediate aneurysm occlusion creates the risk of short-term re-rupture. PED treatment for iatrogenic ICA pseudoaneurysms can provide a good angiographic and neurological outcome.

Treatment of Blister-Like Aneurysms With the Pipeline Embolization Device

BACKGROUND:

Endovascular vessel reconstruction with the pipeline embolization device (PED) has become common practice. Data on the safety and efficacy of the PED in blister-like aneurysms (BLAs) are limited.

OBJECTIVE:

To retrospectively present our experience with use of the PED in BLAs.

METHODS:

A total of 8 patients harboring 8 BLAs were treated with the PED at our institution between November 2011 and April 2013.

RESULTS:

Aneurysm size was 2.5 mm on average. Five patients had sustained a subarachnoid hemorrhage (SAH), 1 patient presented with sentinel headaches, and in 2 patients the aneurysm was incidentally discovered. Seven aneurysms arose from the ICA and 1 from the basilar artery. Placement of the PED was successful in all 8 patients. There were no procedural or perioperative complications in any of the patients. At the latest follow-up, all 8 patients achieved a favorable outcome (mRS 0-2). Angiographic follow-up was available for 6 patients at a mean time point of 3.9 months. Follow-up angiography showed 100% aneurysm occlusion in 5 patients and marked decrease in aneurysm size in 1 patient.

CONCLUSION:

The findings of this study suggest that the PED may be a safe and effective treatment for BLAs. Given the limitations of other treatment modalities and the challenging nature of BLAs, flow diversion may be a valuable option for these lesions.

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.

Endovascular exclusion of the anterior communicating artery with flow-diverter stents as an emergency treatment for blister-like intracranial aneurysms. A case report

Blood blister-like aneurysms (BLAs) are rare lesions, associated with diffuse subarachnoid hemorrhage (SAH). BLAs tend to rebleed quickly after first bleeding and must be treated as an emergency. Acute treatment is challenging using surgical and endovascular approaches due to the fragile aneurysm wall and small sac. Flow-diverter stents (FDSs) may offer a new option for the treatment of difficult small aneurysms. We describe a case of a ruptured BLA on the anterior communicating artery (AComA) treated in the acute phase of SAH by endovascular exclusion of the AComA with deployment of two FDSs in the A1/A2 junctions of both anterior cerebral arteries (ACAs). A 61-year-old man was admitted for diffuse SAH with a focal interhemispheric hematoma. Angiography revealed multiple arterial wall irregularities on the AComA and both ACAs. We performed an endovascular shunt of the AComA by deploying two FDSs in both A1/A2 junctions. Immediate control injections confirmed flow diversion in the A1/A2 segments of the ACAs with decreased blood flow in the AComA. The patient's course in hospital was uneventful. A three-month follow-up angiogram confirmed complete exclusion of the aneurysms, complete exclusion of the AComA, and patency of the two ACAs without any persistent arterial wall irregularity. Endovascular bypass using an FDS for a ruptured BLA has never been described. It establishes a new therapeutic option despite the need for antiplatelet therapy. Endovascular AComA exclusion using an FDS may be a solution when no other treatment is available for a ruptured BLA.

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.

Reconstructive Treatment of Ruptured Blood Blister–like Aneurysms With Stent and Coil

BACKGROUND:

Controversy remains about the optimal treatment for blood blister--like aneurysms (BBAs).

OBJECTIVE:

To evaluate clinical and angiographic outcomes after reconstructive treatment for BBA with stent and coil.

METHODS:

Thirty-four patients (6 men, 28 women; mean age, 47.3 years) with ruptured BBAs underwent reconstructive treatment with stent and coil. Posttreatment courses and outcomes were retrospectively evaluated.

RESULTS:

Initial treatments were ≥ 2 overlapping stents with or without coiling (n = 28) and single stent with coiling (n = 6). Three BBAs rebled on days 9, 11, and 15 after treatment, resulting in 1 death. Except for 3 patients who died early, 31 patients were followed up for 7 to 80 months (median, 32 months). One patient recovered completely but died of complications of systemic lupus erythematosus at 25 months. Of the remaining 30 patients, 25 had favorable outcomes (modified Rankin scale, 0-2) and 5 had unfavorable outcomes. Angiographic follow-up was available in the 32 BBAs. Eight (25.0%) recurred, all within 5 weeks. In the multiple stents group (n = 26), 22 BBAs showed improvement or complete healing, but 4 (15.4%, 2 rebleedings) had recurrence. In the single stent with coiling group (n = 6), 2 BBAs were stable but 4 (66.7%, 1 rebleeding) had recurrence. Single stent with coiling and Hunt and Hess grade ≥ 4 were 2 independent risk factors for recurrence (P &lt; .05).

CONCLUSION:

Reconstructive treatment with stent and coil appears a viable option for BBAs. Single stent with coiling and Hunt and Hess grade ≥ 4 were 2 independent risk factors for recurrence. Follow-up angiography should be considered mandatory soon after treatment.

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 efficacy of endovascular treatment of ruptured blood blister-like aneurysms using stent-assisted coil embolization

We report our experience with endovascular treatment and follow-up results of a ruptured blood blister-like aneurysm (BBA) in the supraclinoid internal carotid artery. We performed a retrospective review of ruptured blood blister-like aneurysm patients over a 30-month period. Seven patients (men/women, 2/5; mean age, 45.6 years) with ruptured BBAs were included from two different institutions. The angiographic findings, treatment strategies, and the clinical (modified Rankin Scale) and angiographic outcomes were retrospectively analyzed. All seven BBAs were located in the supraclinoid internal carotid artery. Four of them were ≥ 3 mm in largest diameter. Primary stent-assisted coiling was performed in six out of seven patients, and double stenting was done in one patient. In four patients, the coiling was augmented by overlapping stent insertion. Two patients experienced early re-hemorrhage, including one major fatal SAH. Complementary treatment was required in two patients, including coil embolization and covered-stent placement, respectively. Six of the seven BBAs showed complete or progressive occlusion at the time of late angiographic follow-up. The clinical midterm outcome was good (mRS scores, 0 -1) in five patients. Stent-assisted coiling of a ruptured BBA is technically challenging but can be done with good midterm results. However, as early re-growth/re-rupture remains a problem, repeated, short-term angiographic follow-up is required so that additional treatment can be performed as needed.

Unruptured non-branching site aneurysms located on the anterior (dorsal) wall of the supraclinoid internal carotid artery: aneurysmal characteristics and outcomes following endovascular treatment

BACKGROUND

This study was undertaken to evaluate the aneurysmal characteristics and clinico-radiological outcomes of unruptured non-branching site aneurysms located on the anterior (dorsal) wall of the supraclinoid internal carotid artery (ICA).

METHODS

The data of 34 patients that underwent endovascular treatment for 36 unruptured ICA anterior wall aneurysms were reviewed. ICA anterior wall aneurysms were defined as aneurysms that projected superiorly from the anterior wall of the ICA ophthalmic (n = 35) or communicating (n = 1) segment on lateral angiograms, without any branch vessel relationship. In addition, aneurysmal characteristics and treatment outcomes were compared with those of 60 unruptured aneurysms originating from the posterior (ventral) wall of the ICA ophthalmic segment.

RESULTS

Patients with an ICA anterior wall aneurysm frequently had a mirror aneurysm on the contralateral side (14.7 % versus 3.3 %) or another ICA aneurysm (35.3 % versus 15 %). Two of the 36 ICA anterior wall aneurysms exhibited ICA narrowing suggestive of dissection, and another five had dysplastic ICA dilatation around the neck. Stent-assisted embolization was more frequently performed for ICA anterior wall aneurysms (66.7 % versus 36.7 %) because of unfavorable dome/neck (mean, 1.21) and aspect (mean, 1.15) ratios, and because of microcatheter instability associated with superior aneurysmal projections against the abrupt curvature of the carotid siphon. Procedure-related thromboembolic complications occurred in three patients in the anterior aneurysm group, but no patient deteriorated clinically. Immediate radiological outcomes were more unfavorable for ICA anterior wall aneurysms (residual sac, 36.1 % versus 16.7 %). Nevertheless, rates of recanalization (2.9 % versus 5.2 %) and progressive occlusion (24.7 % versus 8.1 %) during follow-up slightly favored ICA anterior wall aneurysms. Two stent-treated ICA anterior wall aneurysms developed asymptomatic ICA steno-occlusion (8.3 %).

CONCLUSIONS

Stent-assisted embolization is safe and effective for the treatment of unruptured ICA anterior wall aneurysms exhibiting unfavorable aneurysmal geometries and projections for coil embolization.

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.

Superciliary keyhole approach for small unruptured aneurysms in anterior cerebral circulation

BACKGROUND

Neurovascular surgeons have been trying to find a solution to the problem of surgical invasiveness by applying minimally invasive keyhole approaches.

OBJECTIVE

To evaluate the feasibility and surgical outcomes of a superciliary keyhole approach for unruptured intracranial aneurysms (UIAs) as an alternative to a pterional approach.

METHODS

The authors report on a consecutive series of patients who underwent a superciliary approach for clipping UIAs smaller than 15 mm arising at the supraclinoid internal carotid artery (ICA), A1 segment, anterior communicating artery (ACoA), and M1 segment including the middle cerebral artery (MCA) bifurcation. The data were compared with a historical control group (n = 90) who underwent a pterional approach for UIAs.

RESULTS

A total of 120 aneurysms were successfully clipped in 102 patients with a mean age of 58 years. There was no direct mortality related to the surgery, and only 1 (1.0%) patient developed significant morbidity adversely affecting the Glasgow Outcome Scale score. The superciliary approach demonstrated statistically significant advantages over the pterional approach, including a shorter operative duration (mean, 120 min), no intraoperative blood transfusion, and extremely rare postoperative epidural hemorrhages. In addition, temporalis atrophy was rare and palsy of the frontalis persisting more than 6 months only occurred in 6 patients (5.9%) and was resolved within 2 years. The overall cosmetic outcome was excellent.

CONCLUSION

A superciliary approach can be a reasonable alternative to a pterional approach for small (<15 mm) UIAs arising at the supraclinoid ICA, A1, ACoA, and M1 segment including the MCA bifurcation.

Salvage surgical treatment for failed endovascular procedure of a blood blister-like aneurysm

The blood blister-like aneurysm (BBA) of the internal carotid artery (ICA) is a rare but clinically important cause of subarachnoid hemorrhage (SAH), which accounts for 0.5% of incidences of ruptured intracranial aneurysms. BBA is a thin-walled, broad-based aneurysm that lacks an identifiable neck and is one of the most difficult lesions to treat. In this paper, a case is presented of a 57-year-old woman with SAH. Her cerebral angiography demonstrated a small BBA on the dorsal wall of her right ICA. Endovascular treatment that consisted of a stent-within-a-stent was attempted, but the replacement of the second stent failed, and the aneurysm became bigger. Surgery was performed by clipping the BBA with a Sundt slim-line encircling graft clip. The patient completely recovered with no complications. This treatment may be a salvageable option for BBA, especially when endovascular treatment has failed.

Stent-assisted coil trapping in a manual internal carotid artery compression test for the treatment of a fusiform dissecting aneurysm

Internal carotid artery (ICA) trapping can be used for the treatment of giant intracranial aneurysms, blood blister-like aneurysms, and fusiform dissecting aneurysms. Fusiform dissecting aneurysms are challenging to treat surgically and endovascularly because of no definite neck and critical perforators. Surgical or endovascular trapping of the ICA with or without an extracranial-intracranial bypass has commonly been used as an effective method to treat these lesions, but balloon test occlusion (BTO) must be performed. Here, we report a case of a ruptured fusiform dissecting aneurysm of the distal ICA, which was successfully treated using an endovascular ICA trapping with a manual ICA compression test instead of BTO.

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.

Immediate and midterm results following treatment of recently ruptured intracranial aneurysms with the Pipeline embolization device

BACKGROUND AND PURPOSE

A number of flow-diverting devices have become available for endovascular occlusion of cerebral aneurysms. This article reports immediate and midterm results in recently ruptured aneurysms treated with the PED.

MATERIALS AND METHODS

A prospective registry was established at 3 Australian neurointerventional sites to collect data on ruptured and unruptured aneurysms treated with PED during a 12-month period from August 2009. From this data base of 65 patients, 11 cases of recent aneurysmal SAH were examined. Relevant data including antiplatelet therapy, technical issues, complications, and imaging findings during at least a 6-month period of follow-up were collected and analyzed.

RESULTS

Eleven patients had acutely ruptured aneurysms with SAH. Clinical follow-up was available on all cases with imaging follow-up at 6 months in 9 patients. Two patients died from rebleeding during the acute illness. There was no other procedural or delayed significant symptomatic morbidity. Eight aneurysms were occluded with a single case of residual body filling.

CONCLUSIONS

PED should be used in SAH with caution, reserved for suitable patients concomitantly treated with endosaccular coiling if possible.

Acute endovascular treatment (< 48 hours) of uncoilable ruptured aneurysms at non-branching sites using silk flow-diverting devices

A blood blister-like (BBL) or dissecting aneurysm should be carefully considered if located at a non-branching site of the supra-clinoid internal carotid artery (ICA). Several surgical and endovascular treatment methods have been proposed but they all carry a relatively high risk of morbidity and mortality. This study evaluated the effectiveness of a novel Silk flow-diverting device (SFD) placed in the early acute stage. Three patients presenting with acute subarachnoid haemorrhage caused by small blister-like aneurysms of the carotid siphon were treated within 48 hours after admission by placement of SFDs. More than one device was placed to cover the lesion. None of the patients were premedicated and started anti-platelet therapy during the procedure. All aneurysms were successfully occluded. A good outcome was observed in two out of three treated patients. No thromboembolic or haemorrhagic event occurred during or after the procedures, or during follow-up (6-14 months). SFD prevented rebleeding and the use of these devices could be proposed as an option to treat fragile uncoilable BBL aneurysms, even in the early acute phase without anti-platelet premedication. Larger studies and long-terms results are necessary.

Ruptured symptomatic internal carotid artery dorsal wall aneurysm with rapid configurational change. Clinical experience and management outcome: an original article

BACKGROUND

Aneurysms located at non-branching sites, protruding from the dorsal wall of the supraclinoid internal carotid artery (ICA) with rapid configurational changes, were retrospectively reviewed in effort to identify and characterize these high-risk aneurysms.

METHODS

A total of 447 patients with 491 intracranial aneurysms were treated from March 2005 to August 2008, and of these, eight patients had ICA dorsal wall aneurysms. Four of them suffered subarachnoid hemorrhage (SAH), and all had aneurysms undergoing rapid configuration changes during the treatment course. Digital subtraction cerebral angiography (DSA) performed soon after the SAH events. Data analyzed were patient age, sex, Hunt and Kosnik grade, time interval from first DSA to second DSA, aneurysm treatment, and modified Rankin scale score after treatment for 3 months. Success or failure of therapeutic management was examined among the patients.

RESULTS

Digital subtraction cerebral angiography showed only lesions with small bulges in the dorsal walls of the ICAs. However, the patients underwent DSA again for re-bleeding or for post-treatment follow-up, confirming the SAH source. ICA dorsal wall aneurysms with rapid growth and configurational changes were found on subsequent DSA studies.

CONCLUSIONS

Among the four patients, ICA dorsal wall aneurysms underwent rapid growth with configurational change from a blister type to a saccular type despite different management. ICA trapping including the lesion segment can be considered as the first treatment option if the balloon occlusion test (BOT) is successful. If a BOT is not tolerated by the patient, extracranial-intracranial bypass revascularization surgery with endovascular ICA occlusion is another treatment option.

Endovascular treatment using predominantly stent-assisted coil embolization and antiplatelet and anticoagulation management of ruptured blood blister-like aneurysms

BACKGROUND AND PURPOSE

BBA is a rare type of intracranial aneurysm that is difficult to treat both surgically and endovascularly and is often associated with a high degree of morbidity/mortality. The aim of this study was to present clinical and angiographic results, as well as antiplatelet/anticoagulation regimens, of endovascular BBA treatment by using predominantly stent-assisted coil embolization.

MATERIALS AND METHODS

Thirteen patients (men/women, 6/7; mean age, 49.3 years) with ruptured BBAs were included from 2 different institutions. Angiographic findings, treatment strategies, anticoagulation/antiplatelet protocols, and clinical (mRS) and angiographic outcome were retrospectively analyzed.

RESULTS

Eleven BBAs were located in the supraclinoid ICA, and 2 on the basilar artery trunk. Nine of 13 were ≤3 mm in the largest diameter, and 8/13 showed early growth before treatment. Primary stent-assisted coiling was performed in 11/13 patients, double stents and PAO in 1 patient, each. Early complementary treatment was required in 3 patients, including PAO in 2. In stent-placement procedures, altered periprocedural antiplatelet (11/12) and postprocedural heparin (6/12) protocols were used without evidence of thromboembolic events. Two patients had early rehemorrhage, including 1 major fatal SAH. Twelve of 13 BBAs showed complete or progressive occlusion at late angiographic follow-up. Clinical midterm outcome was good (mRS scores, 0-2) in 12/13 patients.

CONCLUSIONS

Stent-assisted coiling of ruptured BBAs is technically challenging but can be done with good midterm results. Reduced periprocedural and postprocedural antiplatelet/anticoagulation protocols may be used with a low reasonable risk of thromboembolic complications. However, regrowth/rerupture remains a problem underlining the importance of early angiographic follow-up and re-treatment, including PAO if necessary.

Endovascular treatment of blood blister-like aneurysms using multiple self-expanding stents

The surgical as well as endovascular treatment of blood-blister-like aneursysms (BBAs) is extremely difficult because of these pathological natures, such as small and the fragile necks. The optimal treatment of BBAs has remained uncertain. Stents are known to divert blood flow and induce thrombosis of intracranial aneurysms. We report 3 cases of successful obliteration of BBAs after multiple stents placement.

Endovascular coil embolization for saccular-shaped blood blister-like aneurysms of the internal carotid artery

BACKGROUND

Because of their fragile and thin wall, ruptured blood blister-like aneurysms (BBAs) at the anterior wall of the internal carotid artery (ICA) are difficult to manage, both surgically, as well as endovascularly. BBA is usually a tiny and broad-necked aneurysm, but it occasionally demonstrates a relatively saccular-like shape. In addition, the pseudoaneurysm sac often assumes a saccular shape. In this paper, the authors present their experience in treating these saccular-shaped BBAs endovascularly with coil packing.

METHOD

Nine saccular-shaped ruptured BBAs in nine patients (one male and eight females; mean age 51.3 years, range 38-76) were treated with coil packing of the lesion between January 2006 and August 2010 in Nagoya University and its affiliated hospitals. Clinical, procedural, and angiographic data were retrospectively evaluated.

FINDINGS

Seven BBAs were treated by balloon-assisted coil embolization. Two remaining BBAs were embolized without balloon inflation, though a balloon catheter was on standby at the ICA. In one case, in which a saccular coil embolization could not be achieved, ICA trapping was performed. Three (33.3%) were treated in acute, two (22.2%) in subacute, and four (44.4%) in chronic period. One (11.1%) intraoperative rupture occurred. Six (66.7%) had excellent clinical outcomes, while two (22.2%) proved fatal outcomes. During the follow-up period (mean 18.9 months, range 4-48), two out of seven (28.6%) aneurysms presented an angiographical recurrence, but both were treated by coil embolization without complications. The remaining five (71.4%) aneurysms were completely resolved.

CONCLUSIONS

Endovascular coil embolization can be considered as an alternative treatment option for selective saccular-shaped BBAs.