Microsurgical treatment of blood blister-like aneurysms: efficacy of clip-on-wrapping with autologous dura mater.

OBJECTIVE: To present a consecutive 20-year series of blood blister-like aneurysms (BBAs) to show that clip-on-wrapping with a Y-shaped autologous dura mater enables treatment of BBAs with a low complication rate and a satisfactory curative result. METHODS: A retrospective review was performed from patients with BBAs of the internal carotid artery (ICA) at the Affiliated Hospital of Qingdao University from 1999 to 2019. Diagnosis and treatment options were analyzed. Outcome was assessed using the modified Rankin scale (mRS). RESULTS: A total of 30 patients with BBAs of the ICA were included. Among these patients, 20 patients underwent microsurgical treatment (15 patients were treated by clip-on-wrapping with a Y-shaped autologous dura mater), the other 10 patients underwent endovascular treatment. All patients presented with subarachnoid hemorrhage (SAH). Four angiograms were initially negative. For all patients, intraoperative rupture occurred in five cases, but no postoperative aneurysm rupture occurred in this series. Three cases with clinical or radiologic cerebral infarctions were observed. The outcome was favorable in 26 patients. CONCLUSIONS: Clip-reinforced wrapping technique using a Y-shaped autologous dura mater may be an effective method for treating BBAs.

A propensity score-matched study on the short-term outcome of ruptured blood blister-like aneurysm treated by microsurgery or endovascular surgery: a single-center study of 155 cases.

Treating blood blister-like aneurysms (BBA) is a major neurosurgical challenge. Whether endovascular repair serves as a better strategy than microsurgery remains controversial. We aim to perform a propensity score-matched (PSM) retrospective study to analyze the short-term outcome in BBA patients who received microsurgery and endovascular treatment. One hundred fifty-five eligible patients with internal carotid artery BBA were retrospectively collected with demographic and angiographic baseline in a single center. Three-month outcome and adverse events were set as outcome endpoints. PSM was used to match the microsurgery and endovascular group. Matching effect was evaluated by distribution variation analysis and love plot. The outcome of neurosurgery and endovascular treatment was then compared before and after PSM. Better WFNS levels (p = .017) and modified Fisher grade (p = .027) were noted in endovascular group before matching. Other baseline including angiographic features were comparable between two groups. Before matching, the 3-month outcome of endovascular repair surgery was more favorable than microsurgery (p < .0001). The occurrence of adverse events was also higher in the microsurgery group (p = .0079). In PSM-adjusted groups, the superior outcome effect of endovascular treatment still existed but with a reduced significance (p = .004). Similar trend was also observed in the adverse event rate (p = .038). Fatality rate was comparable between two adjusted groups regardless of PSM adjustment. Endovascular surgery of BBAs exhibits overall more favorable short-term outcome regardless of PSM matching. Microsurgery does not cause a higher fatality rate, hence it could be considered a salvage plan for those high-grade BBA patients.

Application of the Willis covered stent in the treatment of internal carotid artery blood blister-like aneurysms.

The optimal treatment for blood blister-like aneurysm (BBA) has not yet been determined, and BBA has a high recurrence rate after stent-assisted embolization. The purpose of the present study was to evaluate the safety and feasibility of patients with BBA rupture in the acute phase or patients with BBA who have recurrence after stent-assisted coil embolization. Eight patients (8 women, mean age 50.3 ± 3.7 years) who presented with ruptured BBA or recurrence BBA that had been treated by stent-assisted embolization (5 patients after primary treatment of stent-assisted embolization) were retrospectively reviewed. Clinical follow-up was performed at 1 year after endovascular treatment. All patients were successfully treated with the WCS, and immediate postoperative angiography showed that the aneurysms were completely isolated. The ophthalmic artery was covered by WCS in one patient; however, this patient did not show any clinical visual field or vision symptoms. Procedure-related complications such as aneurysm rupture, vasospasm, acute thrombosis, or thromboembolism did not occur in any case. All patients were followed up for 1 year after endovascular treatment, and they were in good condition without recurrence. One patient developed delayed bleeding at the right temporal lobe. All patients had good clinical prognosis (modified Rankin Scale score ≤ 2). WCS implantation may be a safe and feasible strategy for patients with BBA rupture in the acute phase and patients with BBA who have recurrence after stent-assisted coil embolization and is a promising option worth exploring.

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.

Using overlapping low-profile visualized intraluminal support stent-assisted coil embolization for treating blood blister-like aneurysms of the internal carotid artery.

Blood blister-like aneurysm (BBA) of the internal carotid artery (ICA) is highly challenging to treat owing to its variable morphology and tendency for rupture and regrowth. In this study, we attempted to discuss the key techniques for overlapping low-profile visualized intraluminal support (LVIS) stent-assisted coil embolization, which is used for treating BBAs in our center. Clinical characteristics, endovascular treatment details, outcomes, and follow-up results of 13 patients with BBA treated at our center were retrospectively evaluated in this study. Overlapping LVIS stent-assisted coil embolization was successfully performed in all 13 patients of ruptured BBAs located in the ICAs. Recurrence of aneurysm was observed in 4 cases (30.8%) during the angiographic follow-up; in 2 of these cases, spontaneous healing was observed after discontinuation of antiplatelet therapy. Further, 2 patients with recurrence underwent endovascular treatment with complete obliteration of the aneurysm in one and occlusion of the parent artery after Onyx embolization and stent placement in the other. The overall obliteration rate of the BBAs was 92.3% (12/13). One patient (7.7%) developed intraoperative rupture of the aneurysm with coils protruding outside; however, no severe hemorrhage or neurological dysfunction occurred owing to timely embolization. Overlapping LVIS stent-assisted coil embolization is effective for management of BBA of the ICA. Appropriate adjustment in antiplatelet therapy may improve healing in recurrent cases.

Comparison of clinical and histopathological characteristics of short-term progressive and non-progressive blood blister-like aneurysms.

BACKGROUND: Many blood blister aneurysms (BBAs) have been documented with a rapid progression history in repeated angiography. The underlying mechanism and clinical significance remained elusive. This current study aims to clarify the clinical and histopathological differences between short-term progressive BBA and non-progressive BBAs. METHODS AND MATERIALS: Eighty-one patients with BBAs were consecutively included for this single-center retrospective analysis. Clinical and radiological data on these patients were retrieved from 2017 to 2019. BBAs were defined as either progressive or non-progressive based on observed growth based on repeated imaging. Histopathological examinations of a saccular aneurysm, a progressive BBA, and a non-progressive BBA were conducted using representative aneurysm samples. RESULTS: Among all enrolled patients, 26 of the them were identified with progressive BBAs, while the other 55 with non-progressive BBAs. Progressive BBAs were diagnosed significantly earlier in angiography (3.36 ± 0.61 vs. 6.53 ± 1.31 days, p < 0.05) and showed a higher presence rate of daughter sacs (61.5 vs. 38.2%, p < 0.05). Three different progression patterns were identified. BBAs that developed daughter sac enlargement are diagnosed significantly later than BBAs exhibiting other progression patterns. Patients with progressive and non-progressive BBAs exhibited similar overall clinical outcomes and incidence for complications. For patients with non-progressive BBAs, microsurgery appears to be inferior to endovascular treatment, while for patients with progressive BBAs, the short-term outcomes between microsurgery and endovascular treatment were identical. Histopathological analysis revealed that both subtypes shared a similar pseudoaneurysms structure, but non-progressive BBAs had more histologically destructed aneurysm wall with less remnant fibrillar collagen in adventitia. CONCLUSIONS: Progressive and non-progressive BBAs may not be distinct pathological lesions but represent different stages during the BBA development. Early intervention, regardless of treatment methods, is recommended for salvageable patients with progressive BBAs, but microsurgery should be performed with caution for non-progressive BBAs due to increased surgical risk.

Clip-wrapping of ruptured blood blister-like aneurysms of the internal carotid artery.

To evaluate the safety and validity of microsurgical Gore-Tex clip-wrapping for ruptured blood blister-like aneurysms (BBAs) of the internal carotid artery (ICA). Single-surgeon series. Retrospective study. Data analyzed were patient age, sex, Hunt and Hess grade (H&H), Fisher grade, time from rupture to hospitalization, aneurysm size and location, collateral capacity of the circle of Willis, time from hospitalization to aneurysm repair, aneurysm obliteration, complications, and modified Rankin scale (mRS) at follow-up. Six patients (2 males, 4 females) with ICA BBAs underwent clip-wrapping between 2011 and 2016. Median age was 50.0 years (range 31.7-54.0). H&H was grade 1 or 2 in 5 patients and grade 4 in 1 patient. All aneurysms were small (≤ 0.3 cm), without relation to vessel bifurcations, and located anteromedially, anterolaterally, and superomedially on the ICA trunk. Right side was most frequent (66%). All aneurysms could be clip-wrapped without intraoperative ruptures and all parent arteries could be preserved in the acute phase. Clip-wrapping completely eliminated the BBAs in five patients, whereas one patient underwent additional stent-assisted coiling. There were no re-ruptures, delayed infarctions, or deaths postoperatively. After a median follow-up of 57 months (range 20-90), outcome was favorable (mRS score 0-2) in all patients without radiographic signs of recurrences. Using the Gore-Tex clip-wrapping technique for ruptured ICA BBAs, the aneurysm could be treated without intraoperative ruptures or parent artery sacrifice in the acute phase. The outcomes were similar to other SAH patients and on follow-up, there were no aneurysm recurrences, indicating a durable long-term outcome.

Flow diverter treatment of cerebral blister aneurysms.

PURPOSE: Blood blister-like aneurysms (BBA) are small, friable, broad-based aneurysms that represent high risk for rerupture. Treatment of BBA is challenging, and may include surgical wrapping, clipping, multiple overlapping stents, and/or coiling. Flow diversion is a rapidly evolving treatment strategy for intracranial aneurysms, but the evidence for its use in cases of BBA is scarce. METHODS: A retrospective review of flow-diverter-treated, ruptured BBA cases at our tertiary care institution was undertaken. Clinical, imaging, procedural, and mid-term follow-up data on the patients were collected. RESULTS: Eight patients underwent flow-diverter stent treatment for ruptured BBA. Median age at time of treatment was 49 years (interquartile range [IQR] 42-57) with five females (62.5%). The most common location of the BBA was the supraclinoid segment of the internal carotid artery. The median Hunt-Hess score was 2 (IQR 1.7-3.2). All patients were treated with dual anti-platelet therapy. Good clinical outcomes (modified Rankin score 0-2) were seen in 6/7 (85.7%) patients with available follow-up at 1 year. Complete occlusion of the aneurysm on latest angiogram (7) or MRI (1) was seen in 6/8 (75%) patients (at a median of 8 months). No patient had rerupture, retreatment, or recurrence of the aneurysm. CONCLUSION: Flow-diverter stents may be a feasible treatment option for BBAs. They offer high occlusion and low retreatment rates with good mid-term outcomes, but the long-term efficacy remains unknown. Also, dual anti-platelet therapy in the acute ruptured setting can be challenging.

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.

What are the treatment options for blister-like aneurysms?

Treatment of blood blister-like aneurysms (BBAs) of the supraclinoidal internal carotid artery (ICA) is challenging and the optimal treatment is yet to be defined. The treatment options for ICA BBAS are microsurgery, endovascular therapy, or a combination of the two. The microsurgical armamentarium consists mainly of direct aneurysm clipping with or without protective EC-IC bypass, clip-wrapping, or trap ligation with ICA sacrifice with or without EC-IC bypass. The endovascular treatment options are mainly endovascular ICA ligation, multiple overlapping stents (≥ 3) with or without coiling, covered stents, or flow diverters. In four recent meta-analyses of BBAs, neither microsurgical nor endovascular therapy had an impact on clinical outcome in multivariate analysis. Microsurgery offered aneurysm obliteration rates superior to endovascular techniques, but came at a higher risk of intraoperative bleeding. Endovascular therapy increased the likelihood of a second treatment, conversion to another treatment modality, and incomplete aneurysm obliteration. In this review, we discuss pros and cons of the above approaches while adding our own viewpoints to the discussion.

[Endovascular Treatment of Blood Blister-like Aneurysms in Internal Carotid Artery].

OBJECTIVES: To study the feasibility and effectiveness of endovascular treatment to blood blister-like aneurysms (BBA) in internal carotid artery. METHODS: Retrospective analyzed the clinical features, outcomes, and complications of 20 cases of BBA treated with endovascular intervention techniques from 2013-2015 in our center. RESULTS: The patients were treated with covered stent, internal carotid artery balloon occlusion, and stents assisted coiling, respectively. One death occurred after the patient accepted covered stent treatment, another 2 death was due to vasospasm after internal carotid artery balloon occlusion, and double stents assisted coiling, respectively. The modified Rankin Scale (mRS) score when patients being discharged were 0-2 in 15 cases, and 3-4 in 2 cases. There were 17 cases with clinical follow-up from 1 to 26 months (9.3 months on average), the mRS scores were all less than 2 points. 16 cases accepted angiographic review. 14 cases had BBA totally occluded, 1 case had stable neck residue, and 1 case had incompleted occlusion and the aneurysm dwindled at follow-up. CONCLUSIONS: Stent-assisted coiling is feasible and effective in the treatment of BBA in internal carotid artery.

Endovascular treatment of ruptured blood blister-like aneurysms with multiple (≥3) overlapping Enterprise stents and coiling.

BACKGROUND: Blood blister-like aneurysms (BBAs) are difficult to treat both surgically and endovascularly, and the optimal treatment remains controversial. The aim of this study was to evaluate the clinical and angiographic feasibility of multiple overlapping stents (≥3) with coiling for treating BBA. METHODS: A retrospective review from four institutions identified ten patients with ruptured BBAs who were treated with multiple overlapping stents (≥3). We included both the patients who were initially treated with more than three stents and those who eventually had more than three stents as a consequence of retreatment. Angiographic results (Raymond scale), clinical outcomes (mRS) and treatment courses were evaluated. RESULTS: Initially, seven patients were treated with triple stents and three with double stents. Immediate angiographic results revealed that six aneurysms were Raymond grade 1, three were grade 2, and one was grade 3. Complementary treatment was required in four patients. All three patients who were initially treated with double stents required complementary treatment (100 %). One patient required complementary treatment among the seven patients who were initially treated with three stents (14.3 %). The last follow-up angiography (mean, 12.2 ± 14.7 months; range, 1-44 months) revealed grade 1 in all ten patients. Clinical data (mean follow-up period, 18.2 ± 20.1 months; range, 1-62 months) revealed eight patients with a mRS score of 0-2 and two with mRS 3-5. CONCLUSIONS: Even in the era of flow diverter stents, multiple overlapping stents (≥3) with coiling could be a feasible alternative for treating ruptured BBAs. Additional experience and follow-up are needed in a larger series to state the long-term efficacy of this treatment.

Specific and helpful intraoperative indocyanine green videoangiography finding of blood blister-like aneurysm of internal carotid artery.

BACKGROUND: Blood blister-like aneurysms (BBAs) account for 0.5-2.0 % of ruptured intracranial aneurysms. Because of their rarity, the natural history and pathophysiology of such aneurysms are not fully understood. We present two patients with BBAs treated with Bemsheets-covered clipping and discuss their pathophysiological characteristics, through the intraoperative and specific indocyanine green (ICG) video angiography (VA) findings. CASE REPORT: A 34-year-old male and a 53-year-old female were admitted to our emergency room with suddenly reduced levels of consciousness. Brain imaging studies demonstrated a blood blister-like aneurysm of the supraclinoid segment of the right ICA. Craniotomy and an attempt of surgical clipping were performed. ICG-VA showed the filling defect of dye in aneurysm in the operative field. The BBAs were clipped after being covered by Bemsheets (Kawamoto Corporation, Osaka, Japan) and then confirmed by the ICG-VA. Postoperatively, both patients showed transient neurological deficit due to vasospasms and recovered to their normal statuses within a few months after their respective operations. CONCLUSIONS: ICG-VA showed the filling defect of dye in BBAs, which supported that BBAs have been a pseudoaneurysm. In addition, although not routinely recommended in the treatment of BBAs, we believe that Bemsheet-covered clipping is a safe and effective treatment option for BBAs.

Compatibility of the semijailing technique with extremely soft i-ED coils for ruptured blood blister-like and dissecting aneurysms: patient series.

BACKGROUND: Optimal treatment options for ruptured blood blister-like aneurysms (BBAs) and dissecting aneurysms (DAs) have not yet been established. Endovascular treatment may achieve vessel reconstruction with the preservation of antegrade blood flow; however, securing curative hemostasis at the fragile rupture point remains a major concern. OBSERVATIONS: Two ruptured BBAs and two ruptured DAs treated by stent-assisted coiling with the semijailing technique in the last 2 years are described herein. The devices used were braided stents and i-ED coils, which are new low-memory shape and extremely soft coils. Neither rebleeding nor ischemic complications were observed. All patients had a favorable outcome and showed no recurrence after treatment. LESSONS: All aneurysms were treated without ischemic complications or rebleeding. The good compatibility of braided stents and the new concept coils in stent-assisted coiling by the semijailing technique provides insight into these intractable hemorrhagic vascular pathologies.

Multimodal Management of Ruptured Internal Carotid Artery Blood Blister-like Aneurysm: Technical Notes and Case Series of Surgical Muscle Wrapping and Fenestration Clipping Combined with Flow-Diverter Embolization.

OBJECTIVE: To evaluate the effects of a multimodal management technique combining surgical muscle wrapping, clipping, and flow-diverter stent (FDS) placement in patients with ruptured blood blister-like aneurysms (BBAs) in the internal carotid artery (ICA). METHODS: In a retrospective case series review from 2020 to 2023, 3 patients with ruptured ICA BBAs underwent multimodal management, an approach combining muscle wrapping, surgical clipping, and FDS embolization. The aneurysm sac was initially packed and wrapped with multiple tailored temporalis muscle grafts and then secured using fenestration clips, with good preservation of the ICA branches. The FDS was placed 2-3 weeks after the clipping. RESULTS: All 3 patients had right ICA BBAs (mean age, 52 years). The modified Hunt and Hess grades ranged from 2 to 3, and the Fisher grades ranged from 3 to 4. The mean angiography follow-up time was 27.7 months (15, 31, and 37 months). There were no instances of symptomatic vasospasm or visible ischemic stroke during follow-up computed tomography. No patient required cerebrospinal fluid shunt implantation, and all achieved favorable neurological outcomes (modified Rankin scale 0-1). Follow-up digital subtraction angiography revealed no evidence of aneurysm recurrence or significant ICA stenosis. CONCLUSIONS: We discuss a promising multimodal management approach for ruptured ICA BBAs combining muscle wrapping, surgical clipping, and FDS embolization. This technique was safe and effective in preventing re-rupture, achieving positive short-term clinical outcomes. Further research and more extensive studies are required to validate the long-term efficacy of this approach.

Considerations and Literature Review for Treating Subarachnoid Hemorrhage due to Blood Blister-Like Aneurysms.

Objective: Subarachnoid hemorrhage (SAH) due to blood blister-like aneurysm (BBA) is rare but very risky during treatment. Moreover, there is no established treatment method. In this study, we performed endovascular treatment (EVT) as the first-line treatment on patients with SAH during the subacute phase, and cases were analyzed in this series. Methods: Patients with SAH due to BBA who visited our hospital between April 2021 and March 2023 were enrolled in this study. We waited as long as possible during the acute phase and performed EVT during the subacute phase. We performed stent-assisted coiling (SAC) as the first-line treatment and performed DSA approximately 6 months after treatment. Results: Ninety-six patients with SAH visited our hospital during the study period and six had SAH due to BBAs. There were two males and four females aged 56.2 ± 14.6 years. We performed SAC in five patients, and one died owing to rebleeding before treatment. Two patients received treatments because of rebleeding. One patient died on the day after rebleeding, whereas the other experienced rebleeding and treatments twice and achieved a good outcome. Four patients had good outcomes (modified Rankin scale [mRS]: 0). The surviving patients achieved complete occlusion at follow-up DSA. However, two patients had poor outcomes (mRS: 6). Conclusion: Patients with SAH due to BBA treated in the subacute phase may achieve good outcomes; however, there is a risk of rebleeding during the waiting period, which often causes poor outcomes.

Advantages of 3D High-Resolution Vessel Wall Imaging in a Patient With Blood Blister-Like Aneurysm: A Case Report and Literature Review.

Blood blister-like aneurysms (BBAs) are rare and challenging intracranial aneurysms. They pose significant diagnostic and surgical risks due to their delicate walls. Accounting for a small percentage of intracranial aneurysms, BBAs are pathologically pseudoaneurysms, often resulting from arterial dissection, with a high tendency to rupture. This report underscores the critical nature of BBAs by reviewing a case in which subarachnoid hemorrhage caused by a BBA rupture was difficult to diagnose with conventional imaging. We highlight the efficacy of three-dimensional (3D) high-resolution vessel wall imaging (VWI) in discerning the subtle vascular abnormality of BBAs. The integration of the black-blood imaging technique within VWI provides superior contrast between the aneurysm and surrounding tissues, facilitating clearer visualization of the aneurysmal wall. The use of 3D T1-weighted imaging provides intricate details of the vessel wall including its contrast enhancement, which is crucial for a comprehensive assessment of a ruptured aneurysm. This case is consistent with the existing literature, supporting the role of VWI in the identification of ruptured BBAs, an area with limited but growing information on its diagnostic value. VWI is precise and accurate in the preoperative diagnosis of BBAs, emphasizing its potential to improve patient management and outcomes, especially in conditions with high risks of morbidity and mortality.

Endovascular Treatment of Ruptured Blood Blister-like Aneurysms Using the LVIS EVO Stents.

Blood blister-like aneurysms (BBAs) are rare cerebrovascular lesions that face serious challenges in surgical as well as endovascular treatment. In this paper, we present our experience in treating BBAs using the LVIS EVO stents. A total of 10 patients (mean age of 56.1 years) with 13 BBAs, who were admitted to our university hospital between April 2020 and November 2021 with a subarachnoid hemorrhage (SAH) due to aneurysm rupture, were treated using the LVIS EVO stents. Treatment of the BBAs consisted of stent-assisted coiling in four patients and stenting in six patients. The aneurysms were located within ICA (84.6%), VA (7.7%), and MCA (7.7%). Placement of the LVIS EVO stents was successful in all patients. No technical complications were observed. One in-stent thrombotic event occurred during the procedure. MRA for one-year follow-up was performed in nine patients. One patient died (Hunt and Hess Grade IV). LVIS EVO stents may be a beneficial treatment option for BBAs, as they provide high occlusion rates. However, the long-term efficacy remains uncertain.

Willis covered stent in the treatment of a recurrent blood blister-like aneurysm after pipeline implementation: A case report.

Blood blister-like aneurysms (BBAs) are fragile and difficult to treat. However, the optimal treatment has yet to be determined. Pipeline embolization devices and Willis covered stent implementation are still controversial strategies for treating BBA. Herein, we report a case of recurrent BBA successfully treated with a Willis covered stent. A long-term follow-up angiography after the procedure indicated complete occlusion of the aneurysm. This case demonstrates the safety and efficacy of applying the Wills cover stent in the treatment of recurrent BBA after Pipeline implantation.

Long-Term Outcomes of Ruptured Blood Blister-Like Aneurysms with Multiple (≥2) Overlapping Stents and Coiling: A Single-Center Experience.

OBJECTIVE: To evaluate the long-term feasibility of multiple overlapping stents (≥2) with or without coiling for treating blood blister-like aneurysms (BBAs). METHODS: BBAs treated with stent-assisted coiling or stent-only therapy wasincluded. BBAs with atypical anatomical locations, other endovascular or surgical techniques performed, and delayed treatment (>48 hours) were excluded. Medical records of patients and procedures were retrospectively reviewed. RESULTS: Seventeen patients with BBAs were identified, and 15 were treated with stent-assisted coiling and 2 with stent-only therapy. Triple overlapping stents were performed in seven patients, double stents in nine, and a single stent with coiling in 1. One patient experienced in-stent fibrin formation and received intra-arterial tirofiban. Complementary treatment was required in four patients. Three patients were initially treated with double (3/9) and 1 with triple stents (1/7). Three recurred in the acute period (≤6 weeks) and 1 recurred 14 months after treatment. Three of 17 patients with Hunt Hess grade 5 died early. Thirteen patients were available for long-term angiographic follow-up (13.8 ± 8.9 months). Final angiography showed complete aneurysm occlusion in all patients without in-stent stenosis or perforating vessel occlusion. Clinical follow-up data were available for all 14 surviving patients (66.8 ± 40.9 months). Eight patients had favorable outcomes, five had unfavorable outcomes, and 1 died of a subarachnoid hemorrhage-unrelated cause. Delayed infarct or hemorrhage was not documented. CONCLUSIONS: Even in the era of flow diverter stents, the use of multiple overlapping stents with or without coiling can be a feasible alternative for treating ruptured BBAs.