Towards a new treatment paradigm for ruptured blood blister-like aneurysms of the internal carotid artery? A rapid systematic review

Interventions to treat patients with blood blister-like aneurysms of the internal carotid artery: a protocol for a network meta-analysis

INTRODUCTION

Blood blister-like aneurysm (BBA) is a special type of intracranial aneurysm with relatively low morbidity and high mortality. Various microsurgical techniques and endovascular approaches have been reported, but the optimal management remains controversial. For a better understanding of the treatment of BBA patients, a network meta-analysis that comprehensively compares the effects of different therapies is necessary.

METHODS AND ANALYSIS

This protocol has been reported following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. Related studies in the following databases will be searched until November 2022: PubMed, Embase, Scopus, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP and Wanfang. Randomised controlled trials (RCTs) and non-randomised studies comparing at least two different interventions in BBA patients will be included. Quality assessment will be conducted using Cochrane Collaboration's tool or Newcastle-Ottawa Scale based on their study designs. The primary outcome is the composite of the incidences of intraoperative bleeding, postoperative bleeding and postoperative recurrence. The secondary outcome is an unfavourable functional outcome. Pairwise and network meta-analyses will be conducted using STATA V.14 (StataCorp, College Station, Texas, USA). Mean ranks and the surface under the cumulative ranking curve will be used to evaluate every intervention. Statistical inconsistency assessment, subgroup analysis, sensitivity analysis and publication bias assessment will be performed.

ETHICS AND DISSEMINATION

Ethics approval is not necessary because this study will be based on publications. The results of this study will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42022383699.

Endovascular treatment of distal internal carotid artery aneurysms and vertebral artery dissecting aneurysms with the Willis covered stent: A single-center, retrospective study

BACKGROUND

More data is needed on the short- and medium-term efficacy and safety of the Willis covered stent in treating distal internal carotid artery (DICA) aneurysms and vertebral artery dissecting aneurysms (VADAs).

METHODS

Records of all 42 patients with DICA aneurysms or VADAs treated with the Willis covered stents at our institute between July 2014 and January 2019 were retrospectively examined. The patients' demographic information, symptoms, diagnosis, treatment procedure, immediate and follow-up clinical and angiographic outcomes were extracted.

RESULTS

46 Willis covered stents were successfully implanted in all of the 42 patients (total 43 aneurysms). Immediate complete aneurysm occlusion was achieved in 37 patients (38 aneurysms) (88.4%), and endoleak occurred to 5 patients (5 aneurysms) (11.6%). 2 patients died post-operatively from procedure-related complications, another one died from reasons unrelated to the procedure. Among the remaining 39 patients, non-lethal complications occurred in 4 patients including ptosis and diplopia of the right eye, intra-operative hemorrhage and carotid cavernous fistulas (CCF). Angiographic and clinical follow-ups (means ± standard deviation: 8.8 ± 5.3 months) were done for 32 patients (33 aneurysms). Complete occlusion was maintained in all of the 33 aneurysms. 2 of the 32 patients had significant though asymptomatic parent artery (PA) occlusion. No ischemic or hemorrhagic event occurred during the follow-up period. The modified Rankin Scale (mRS) score was 0 in 31 patients and 1 in the remaining 1 patient.

CONCLUSIONS

The Willis covered stent could be a safe and effective treatment for complex DICA aneurysms with excellent durability. In addition, the Willis covered stent treated all of the 3 cases of VADAs in the study with complete success without any complications, however, as the number of the VADA cases was small, more cases are needed to further confirm the efficacy and safety of the Willis covered stent in treating VADAs.

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.

Wrap-Clipping for Patients with Ruptured Blood Blister-Like Aneurysms of the Internal Carotid Artery: Case Series and Literature Review

OBJECTIVE

 Blood blister-like aneurysms (BBAs) of the internal carotid artery (ICA) are challenging to treat. We assessed the clinical and radiologic outcomes in patients with ruptured BBAs of the ICA treated with wrap-clipping.

METHODS

 From November 2016 to January 2020, the clinical and radiologic data of patients with subarachnoid hemorrhage (SAH) caused by ICA BBAs who underwent wrap-clipping were retrospectively analyzed. The clinical outcomes were evaluated according to the modified Rankin Scale (mRS). Radiologic follow-up examinations included digital subtraction angiography (DSA), computed tomography angiography (CTA), and magnetic resonance angiography (MRA).

RESULTS

 Seven patients were enrolled in this study. All BBAs were wrap-clipped successfully, including two BBAs that exhibited intraoperative bleeding and required balloon-assistance during surgery. All patients had favorable clinical outcomes during follow-up. Among the six patients who completed the radiologic follow-up visit, one patient presented ICA occlusion at the 6-month DSA follow-up, but no neurologic dysfunction was noted. We did not observe the progression of ICA stenosis in other patients.

CONCLUSION

 All BBAs in this study were wrap-clipped successfully and completely occluded. Wrap-clipping is effective for BBAs of the ICA and has favorable clinical outcomes. A multicenter study with a large sample size and a longer radiologic follow-up is necessary.

High-flow bypass using saphenous vein grafts with trapping of ruptured blood blister-like aneurysms of the internal carotid artery: patient series

BACKGROUND

Trapping an aneurysm after the establishment of an extracranial to intracranial high-flow bypass is considered the optimal surgical strategy for ruptured blood blister-like aneurysms (BBAs) of the internal carotid artery (ICA). For high-flow bypass surgeries, a radial artery graft is generally preferred over a saphenous vein graft (SVG). However, SVGs can be advantageous in acute-phase surgeries because of their greater length, easy manipulability, ability to act as high-flow conduits, and reduced risk of vasospasms. In this study, the authors presented five cases of ruptured BBAs treated with high-flow bypass using an SVG followed by BBA trapping, and they reported on surgical outcomes and operative nuances that may help avoid potential pitfalls.

OBSERVATIONS

After the surgeries, there were no ischemic or hemorrhagic complications, including symptomatic vasospasms. In three of the five cases, postoperative modified Rankin scale scores were between 0 and 2 at the 3-month follow-up. In one case, the SVG spontaneously occluded after surgery while the protective superficial temporal artery (STA) to middle cerebral artery (MCA) bypass became dominant, and the patient experienced no ischemic symptoms.

LESSONS

High-flow bypass using an SVG with a protective STA-MCA bypass followed by BBA trapping is a safe and effective treatment strategy.

Endovascular treatment of ruptured blister-like aneurysms: A case report and review of the literature

A ruptured blister-like aneurysm of the internal carotid artery is a rare event with a high risk of recurrence and mortality. Selecting an appropriate treatment modality remains challenging due to a lack of consensus or specific recommendations in the literature. In this article, we present the case of a 68-year-old man who presented with ruptured blister-like aneurysms in the supraclinoid portion of the internal carotid artery. The patient was diagnosed and successfully managed using an endovascular coil embolization technique at our hospital. We aim to illustrate and share our experiences with this rare occurrence, which may assist in the treatment of similar cases in the future.

Application of covered stent graft in the treatment of complex carotid artery lesions: A single center experience

PURPOSE

To assess the clinical efficiency and imaging outcome of applying covered stent grafts for the treatment of complex carotid artery lesions.

METHOD

A total of 39 consecutive patients with carotid artery lesions treated with covered stent grafts at our institution from December 2016 to December 2019 were reviewed. Two kinds of stent including self-expandable covered stent (Viabahn; W. L. Gore & Associates) and balloon-expandable covered stent (Willis; Microport) were applied. The angiograms immediately after the procedure, perioperative complications, and follow-up outcomes were recorded.

RESULT

Based on imaging features, 11 patients exhibited pseudoaneurysms, 23 patients had blood blister-like aneurysms (BBAs), and five patients were carotid cavernous fistulas. A total of 40 stent implantations were performed, including nine Viabahn stents and 31 Willis stents. Two patients received double implants of Willis stents. Stent failed to perform for one patient due to tortuous parent artery. The angiography reports immediately after the procedure showed that the lesions in 36 patients were completely occluded, whereas two patients had minimal endoleaks. With respect to the occurrence of procedural complications, an aneurysm ruptured during the procedure in one case, which resulted in CCF, and acute in-stent thrombosis occurred in another case. Clinical and angiographic follow-up (11.2±2.4 months) sessions were conducted for 38 patients and a complete lesion exclusion was achieved in 36 patients. The minimal endoleak persisted in one patient and another patient experienced recurrence with stent migration, leading to ipsilateral blepharoptosis. However, none of the patients developed hemorrhage or ischemia and in-stent stenosis was not observed.

CONCLUSION

Covered stent grafts appear to be a safe and feasible for the treatment of complex carotid artery lesions. Despite the potential for stent delivery failure as well as endoleak and procedure-related complications, covered stent grafts should be considered when selecting the optimal treatment strategy.

Endovascular treatment of blood blister-like aneurysms of internal carotid artery: Stent-assisted coiling and pipeline flow diversion

OBJECTIVE

To report the stent-assisted coil embolization and flow diversion treatments of blood-blister-like aneurysms based on the theory of acute dissection of the internal carotid artery.

PATIENTS AND METHODS

From July 2016 through July 2020, 27 patients presenting with subarachnoid hemorrhage (SAH) due to rupture of internal carotid artery blood blister-like aneurysms were subjected to endovascular treatment with stent-assisted coiling or Pipeline flow diversion. Clinical outcomes were evaluated using modified Rankin Scale score (mRS).

RESULTS

A proximal stenosis caused by angiopathology adjacent to aneurysms were found on internal carotid artery angiograms in all 27 cases. The angiopathology combining with the aneurysms implement that acute dissection of the supraclinoid segment of the internal carotid artery indicated the pathogenesis of blood blister-like aneurysm formation. All aneurysms were treated successfully with alleviation of the adjacent angiopathology after stenting on angiograms. During 1-12 months, mean 3.5 months, complete aneurysm obliteration without adjacent stenosis were found in 25(92.6%) patients. Two (7.4%) cases of recanalization were retreated with complete obliteration at 1 week and 3 months after initial treatment. Clinical mRS 0 and 1 outcomes were observed in 23(85.2%) patients, mRS 2 in 3(11.1%) patients and mRS 6 in 1(3.7%) not related to aneurysm treatment during follow-up.

CONCLUSIONS

Acute focal dissection of supraclinoid segment of internal carotid artery underlies the development of blood blister-like aneurysm. Stent-assisted coiling and flow diversion treatments constitute appropriate treatment based on the arterial dissection pathology.

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.

The formation mechanism of acute dissection of blood blister-like aneurysm and its implication of endovascular treatment

BACKGROUND

Acute mural dissection of the anterior wall of the internal carotid artery which may contribute to the development of blood blister-like aneurysms (BBLAs) was postulated, and stenting or flow diversion treatment across the soi-disant aneurysm was reported in this study.

METHODS

From December 2016 to December 2018, 8 patients presenting with subarachnoid hemorrhage (SAH) due to BBLA were subjected to endovascular treatment with stent-assisted coiling. Clinical outcomes were evaluated using a clinical outcome score scale.

RESULTS

Based on angiograms, pathologic change involving the supraclinoid segments of the internal carotid artery (ICA) adjacent to BBLA was found in all patients. This pathologic change meant a focal dissection of the supraclinoid segment of the ICA which constituted the pathogenesis of BBLAs. Closed-cell, open-cell, and braided stents were used in 1, 1, and 6 patients, respectively. Complete obliteration was achieved following endovascular treatment among all 8 patients harboring BBLA. One re-bleeding successive to a closed-cell stent across the aneurysmal neck was observed. Follow-up angiograms revealed stable complete exclusion of all BBLAs from the parent vessel at 3 to 8 months. All patients had a favorable clinical outcome score of 0-1.

CONCLUSIONS

Acute dissection of a focal point of the intracranial vessels underlies the development of BBLAs. Open-cell and braided-cell stent-assisted coiling may constitute appropriate treatment due to good apposition against the vascular walls. Adjunctive coils may facilitate immediate complete occlusion of BBLAs.

Supraclinoid internal carotid artery blister-like aneurysms: hypothesized pathogenesis and microsurgical clipping outcomes

BACKGROUND

Blister-like aneurysms (BLAs) on the supraclinoid segment of the internal carotid artery (ICA) are an enigma of cerebrovascular disease. Neither has a definite pathogenesis been so far identified, nor have uniform treatment guidelines been established for them. Our aim was to develop a hypothesis regarding the evolution of BLAs according to their macroscopic morphologies and to evaluate the efficacy of microsurgical clipping.

METHODS

The clinical data and morphological features of 15 consecutive patients with 16 BLAs on the supraclinoid ICA were retrospectively reviewed. The treatment strategies were analyzed, and functional outcomes were evaluated using the modified Rankin scale (mRS). Favorable outcomes were defined as a mRS score of 0-2.

RESULTS

Morphologically, aneurysm growth with expansion of the aneurysm neck before the surgical procedure occurred in two ruptured and one unruptured aneurysm. Daughter bleb formation was observed in two ruptured and five unruptured aneurysms. A varied degree of parent artery sclerosis was observed in nine patients. Thirteen patients were treated with direct surgical clipping, one patient was treated with clipping and wrapping, and the remaining patient was treated with an encircling clipping graft. Favorable and unfavorable outcomes were observed in 13 and two cases, respectively. Follow-up angiograms revealed 4 cases of stenosis with respective degree of mild, 30%, 50%, and 80% without any neurological dysfunction.

CONCLUSIONS

We suggest a hypothesis that BLAs on the supraclinoid ICA may share different evolving mechanisms between ruptured and unruptured lesions. A majority of them can be reliably and safely obliterated by direct clipping technique, except for the aneurysms accompanied with severely atherosclerotic parent walls.

Current Knowledge of and Perspectives about the Pathogenesis of Blood Blister-like Aneurysms of the Internal Carotid Artery: A Review of the Literature

Blood blister-like aneurysms (BBAs) are rare and usually appear at nonbranching sites in the supraclinoid portion of the internal carotid artery (ICA). Because it is difficult to obtain histological specimens of the aneurysm wall and because experimental models are challenging to establish, the pathogenesis of BBAs remains uncertain. In this paper, we reviewed the diagnostic, radiological, and pathophysiological characteristics of patients with BBAs. We also summarized the existing evidence and potential mechanisms related to the causes of BBAs. Current evidence indicates that atherosclerosis and dissection are the main prerequisites for the formation of BBAs. Hemodynamics may play a role in the process of BBA formation due to the unique vascular anatomy of the supraclinoid ICA. Further research on histopathology and hemodynamics is warranted in this field.

Treatment of Anterior Circulation Aneurysms in the Internal Carotid Artery With Flow Diverters

Several studies have shown the efficacy and feasibility of flow diversion for the endovascular treatment of wide-necked and otherwise anatomically challenging intracranial aneurysms (IA). Technological advances have led to successful long-term occlusion rates and a safety profile for flow-diverter stents that parallels other endovascular and open surgical options for these lesions. With growing indications for use of the Pipeline Embolization Device (PED, Medtronic, Dublin, Ireland) to include IAs up to the internal carotid artery (ICA) terminus, understanding the nuances of this technology is increasingly relevant. Furthermore, there is a growing body of literature on the use of flow diversion to treat distal (up to A2, M2, and P2), ruptured, and posterior circulation aneurysms, although these applications are "off-label" at present. In this manuscript, we discuss the expanding role of flow diversion in the ICA and compare this technique with other endovascular options for the treatment of ICA IAs. We also discuss technical nuances of the deployment of flow diverters for the treatment of challenging lesions and in difficult and tortuous anatomy.

Treatment of Ruptured Blister-Like Aneurysms with the FRED Flow Diverter: A Multicenter Experience

BACKGROUND AND PURPOSE

Treatment of ruptured blister-like aneurysms is technically challenging. This study aimed at analyzing the safety and efficacy of the Flow-Redirection Endoluminal Device (FRED) in the treatment of ruptured blister-like aneurysms.

MATERIALS AND METHODS

In a retrospective multicenter study, all patients treated with the FRED due to a ruptured intracranial blister-like aneurysm between January 2013 and May 2019 were analyzed. The primary end points for clinical safety were mRS 0-2 at 6 months after treatment and the absence of major ipsilateral stroke or death. The primary end points for efficacy were the absence of rebleeding after treatment and complete angiographic occlusion according to the O'Kelly-Marotta classification at 6 months after treatment.

RESULTS

In total, 30 patients with 30 ruptured blister-like aneurysms were treated. Immediate complete aneurysm obliteration (O'Kelly-Marotta classification D) with the FRED was achieved in 10 patients (33%). Of the 26 patients with follow-up, complete obliteration was achieved in 21 patients (80%) after 6 months and in 24 patients (92%) in the final follow-up (median, 22 months). Twenty-three patients (77%) achieved mRS 0-2 at 6 months. Major stroke or death occurred in 17%. Two patients died due to pneumonia, and 2 patients died due to infarction following cerebral vasospasm. There was no case of rebleeding after FRED implantation. There was 1 case of delayed asymptomatic stent occlusion.

CONCLUSIONS

Treatment of ruptured blister-like aneurysms with the FRED is safe and effective.

Comparison of Bypass and Non-Bypass Surgical Treatments for Internal Carotid Artery Blood Blister-Like Aneurysms: A Meta-Analysis of Efficacy, Safety, and Outcomes

BACKGROUND

The optimal surgical strategy for treating internal carotid artery (ICA) blood blister-like aneurysms (BBAs) has remained unclear. Although some have preferred bypass surgery, others have favored less-demanding surgical methods. The aim of the present meta-analysis was to assess the efficacy, safety, and outcomes of bypass and non-bypass surgical methods when intended as primary treatment of ICA BBAs.

METHODS

Studies reporting data on the outcomes of interest for surgically treated patients with ICA BBAs were searched for in the PubMed/MEDLINE, Evidence-Based Medicine Reviews, Cochrane Central, ProQuest, and Scopus databases. The data were analyzed using random effects modeling.

RESULTS

Seven observational studies involving 140 patients met the inclusion criteria. The patients treated with bypass surgery, compared with those treated with non-bypass techniques, had lower odds of poor outcomes (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.28-2.02; P = 0.57; I² = 0%), postoperative vasospasm (OR, 1.73; 95% CI, 0.38-7.92; P = 0.48; I² = 19%), intraoperative bleeding (OR, 3.37; 95% CI, 0.82-13.90; P = 0.09; I² = 0%), postoperative bleeding (OR, 1.91; 95% CI, 0.47-7.76; P = 0.36; I² = 0%), and postoperative recurrence of BBAs (OR, 2.16; 95% CI, 0.54-8.66; P < 0.28; I² = 0%). No comparison, however, achieved statistical significance.

CONCLUSIONS

For surgeons who use both bypass and non-bypass surgical strategies, the 2 methods seemed comparable in terms of the outcomes of interest, although the bypass technique appeared superior. However, comparisons with studies reporting bypass as the uniquely preferred technique have indicated that specialization in, and preference for, the bypass procedure has been associated with more favorable outcomes.

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.

Endovascular Intervention with a Low-profile Visualized Intraluminal Support Stent Versus Surgical Clipping for Blood Blister-like Aneurysms : A Retrospective Study

PURPOSE

Blood blister-like aneurysms (BBAs) have a high risk of early recurrence and postoperative rebleeding. This study compared the clinical outcomes and complications between endovascular intervention with low-profile visualized intraluminal support (LVIS) stent-assisted coiling and the surgical clipping in patients with BBAs.

METHODS

This retrospective study enrolled 39 patients with BBAs who underwent endovascular intervention with LVIS stent-assisted coiling (n = 21) or surgical clipping (n = 18) between January 2013 and July 2018. Primary outcomes were mortality and modified Rankin scale (mRS). Secondary outcomes were hospital stay, intensive care unit (ICU) stay and operation parameters. Complications were also retrospectively collated.

RESULTS

At baseline, the two groups were well balanced in patient characteristics. The hospital stays, ICU stays, operation time and intraoperative infusion volume were all significantly lower in LVIS group than that in clipping group (p < 0.05). A second operation was performed in 6 cases in the clipping group but none in the LVIS group (p = 0.006). The mean mRS score in the LVIS group was significantly lower than that of the clipping group both at hospital discharge and final follow-up (p < 0.001). Adverse outcomes occurred in 1 case in LVIS group and 7 in clipping group, with significant difference (p = 0.015). Complications were reported in 8 cases in LVIS group and 16 cases in clipping group, with significant difference (p < 0.001).

CONCLUSION

The endovascular intervention with LVIS stent-assisted coiling has better prognosis than surgical clipping. It decreased the risk of a second operation and procedure-related complications compared with surgical clipping.

Efficacy of pipeline endovascular device and Willis stent graft in the treatment of traumatic pseudo intracranial aneurysms

OBJECTIVE

To investigate the advantages and effects of pipeline embolization device (PED) or Willis stent, in treating traumatic pseudoaneurysms. Traumatic pseudo intracranial aneurysms (TPIA) can be caused by either direct trauma or iatrogenic injuries, usually caused by direct arterial wall injury or shear due to acceleration. We describe a series of patients with TPIA who received a PED or Willis stent.

MATERIALS AND METHODS

Retrospective analysis was performed on nine patients with TPIA admitted to the southern hospital of Southern Medical University from December 2017 to June 2019, of whom four were treated with PED and five were implanted with six Willis covered stents. The occlusive rate and complication in the two kinds of stents were compared by postoperative follow-up and modified rankin score (MRS).

RESULTS

After the implantation of PED, four patients showed an immediate stagnation of blood flow or a decreased filling in aneurysms, three out of four patients exhibited complete occlusion, and the remaining patient had nearly complete occlusion. Four out of five cases of Willis stent implantation were associated with immediate complete occlusion of aneurysms, and the modified rankin score of these patients ranged from 0 to 1. One patient died of unassociated complications.

CONCLUSION

For different types of TPIA in the internal carotid artery (ICA), PED and Willis stents provide significant advantages in treatment, with fewer postoperative complications and prognosis well.

A Patient with a Ruptured Blood Blister-like Aneurysm of the Internal Carotid Artery in Whom Two LVIS Stents Were Inserted

Objective

We report a case in which multiple overlapping low-profile visualized intraluminal support (LVIS) stents were used as monotherapy for ruptured blood blister-like aneurysm (BBA) of the internal carotid artery (ICA).

Case Presentation

A 48-year-old female presented to the emergency room with acute-onset headache. She was alert without neurological deficit with subarachnoid hemorrhage (SAH) Hunt and Kosnik grade I. Emergency angiography revealed a BBA from the supraclinoid ICA. This aneurysm had a small diameter, which makes coil embolization difficult. Therefore, we planned to use multiple overlapping LVIS stents as monotherapy for the ruptured aneurysm. The postoperative course was uneventful without rebleeding. The patient exhibited no neurological deficits on the clinical follow-up at 1 year.

Conclusion

Multiple overlapping LVIS stents as monotherapy is useful for ruptured BBAs of the ICA.

Flow-diverting Stent-assisted Coil Embolization of a Ruptured Internal Carotid Artery Blister Aneurysm with the Pipeline Flex Embolization Device

Internal carotid artery (ICA) blister aneurysms are rare and challenging to successfully treat, using contemporary surgical or endovascular approaches, without partial or complete compromise of the parent vessel. We describe the use of a resheathable flow diverter, the Pipeline Flex Embolization Device (PFED) to perform stent-assisted coiling of a ruptured supraclinoid ICA blister aneurysm in a 56-year-old female who presented with a high-grade subarachnoid hemorrhage (SAH). The first PFED was deployed across the aneurysm neck to jail a microcatheter within the aneurysm dome, and then, two small coils were delivered into the aneurysm. After removing the coiling microcatheter, the second PFED was telescoped into the first PFED. There were no postprocedural complications, and follow-up magnetic resonance angiography 15 months after embolization showed complete aneurysm obliteration. Flow-diverting stent-assisted coiling should be considered as a reconstructive, vessel-preserving, endovascular treatment option for appropriately selected patients with ruptured ICA blister aneurysms. However, future studies are necessary to assess the periprocedural safety in the setting of acute SAH.

Efficacy and Safety of Willis Covered Stent for Treatment of Complex Vascular Diseases of the Internal Carotid Artery

BACKGROUND

Willis covered stents are used in clinical practice for some complex cerebrovascular diseases. However, the performance of the Willis covered stent requires further investigation. In this study, we investigate the safety and efficacy of Willis covered stents for the treatment of complex vascular diseases of the internal carotid artery (ICA).

METHODS

Thirteen patients with complex ICA diseases treated with the Willis covered stent system at our institution from October 2016 to January 2018 were analyzed retrospectively. Follow-up observation and digital subtraction angiography (DSA) examination were conducted at about 6-10 months after the treatment.

RESULTS

The complex vascular diseases of the ICA were successfully treated in 12 patients. The technical success rate was 92.3%. Pathologically, 13 lesions included blood blister-like aneurysm (n = 7), traumatic pseudoaneurysm (n = 1), traumatic carotid artery rupture (n = 1), and aneurysm with arteriovenous fistula (n = 4). Thirteen patients with complex vascular diseases of the ICA were treated with 15 Willis covered stents. The release sites of Willis covered stents were the C7 (n = 2), C6 (n = 1), C5 and/or C4 (n = 9), and the C2 (n = 3) segment of the ICA. DSA performed immediately after stent deployment revealed that complete occlusion of the lesion was achieved in 11 patients and endoleak was observed in 2 patients. Of the 11 patients, postoperative DSA examination indicated that the lesions were occluded completely. Among 2 patients, who had a second stent implantation at the break of the ICA, the traumatic ICA rupture was essentially completely obstructed in 1 patient. The endoleak remained in 1 patient with carotid cavernous sinus fistula because the placement of the second stent system was difficult with his ICA tortuosity. No recurrence of aneurysms, hemorrhagia, and other lesions was observed, and the patients' parent arteries were patent without stenosis. No procedure-related complications or deaths occurred during follow-up.

CONCLUSIONS

For the treatment of complex vascular diseases in the ICA, Willis covered stent implantation is safe and effective. However, longer follow-up, large-sample controlled studies, and multicenter studies are needed for further confirmation.

[The role of interventional neuroradiology in treatment of hemorrhagic stroke]

Treatment of hemorrhagic strokes necessitates hospitalization in an accommodated hospital offering the possibility of a multidisciplinary approach. In this setting, over recent years interventional radiology has become increasingly important from the diagnostic as well as the therapeutic standpoint. In the context of subarachnoid hemorrhage by intracranial aneurysm rupture, the NICE (National Institute for Health and Clinical Excellence) and ASA (American Stroke Academy) recommendations suggest that endovascular coiling should be considered as an alternative to surgical clipping (class I, level of evidence B). As stenting is associated with increased morbidity and mortality in the ruptured aneurysms, it should be avoided (class III, level of evidence C). The patient's clinical status on presentation should be taken into account when deciding on therapeutic management and determining prognosis. Long-term clinical outcome depends on several factors: clinical status on arrival, comorbidities, age, occurrence of operative complications and complications of subarachnoid hemorrhage such as hydrocephaly, vasospasm and delayed cerebral ischemia, as well as complications stemming from prolonged bed rest. In the event of vasospasm refractory to maximal medical therapy, endovascular treatment by intra-arterial injection of Nimodipine and angioplasty can be envisioned. In the event of intracerebral hemorrhage (ICH) by rupture cerebral dural arteriovenous fistula, once the diagnosis has been confirmed, and given the exceedingly high risk of rebleeding, first-line treatment will consist in emergency endovascular embolization. In the event of intracerebral hemorrhage (ICH) by arteriovenous rupture, treatment is decided on during a multidisciplinary meeting and either carried out immediately or delayed according to several factors: clinical conditions, age of the patient, angioarchitecture and ICH location.

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.

Clipping on Crossed Wrapping Method for Ruptured Blood Blister-Like Aneurysm of the Internal Carotid Artery: Technical Note and Long-Term Results

Background

We have been performing the clipping on crossed wrapping (COCW) method using 2 strips of cotton on patients with an internal carotid artery blood blister-like aneurysm (IC-BLA). This method is reliable in preventing the clips from slipping off and the aneurysm walls from being damaged during clipping, and it enables more appropriate and safer clipping. Here we report the technical details of this method and the long-term outcomes of patients receiving this procedure.

Methods

Fifteen of 1275 (1.5%) patients with a ruptured cerebral aneurysm who received treatment at the Saiseikai Kumamoto Hospital during the period from January 1, 1999, to December 31, 2016, had an IC-BLA. All 15 patients were treated with COCW, except for the first patient, who was treated using a single strip of cotton. The long-term outcome of the treatment was analyzed.

Results

The mean follow-up period was 74 months. The first patient experienced rerupture of an aneurysm 10 days after the operation. No complications or regrowth of an aneurysm were observed in the remaining 14 patients during the follow-up period, except for 1 patient who received a reoperation for the regrowth of an aneurysm. As the final outcome, the numbers of patients with a Modified Rankin Score of 0, 3, and 6 were 13, 1, and 1, respectively.

Conclusions

It is suggested that COCW is a treatment that enables safe and long-term management of lesions in IC-BLAs.

Pathogenesis of dorsal internal carotid artery wall aneurysms based on histopathologic examination and microscopic configuration

Blood blister-like aneurysms (BBAs) are an important cause of subarachnoid hemorrhage (SAH), but proper treatment is uncertain due to the poor prognosis of these aneurysms. The pathogenesis of BBAs remains unclear and few studies have reported on histological examinations of BBAs because it is difficult to obtain a specimen due to a high risk of intraoperative bleeding. In this report, BBAs were histopathologically examined in two patients who presented with SAH due to rupture of a BBA that was treated with surgical trapping and bypass surgery. BBA specimens including the adjacent internal carotid artery (ICA) walls were obtained intraoperatively. We suggest the pathogenesis of BBAs based on histopathologic examination and microscopic configuration.

Safety of Prasugrel loading in ruptured blister like aneurysm treated with a Pipeline device

OBJECTIVE

Blister like aneurysm (BLA) is extremely challenging to treat; endoluminal reconstruction has emerged as the most promising treatment method. When to treat after the ictus, the timing of administration of antiplatelet and causal relationship between platelet function testing results and thrombo-embolism is unclear. We theorized that Prasugrel with a lower incidence of resistance may be a safe suitable alternative to clopidogrel in patients treated with a flow diverter (FD).

METHODS

Prospectively collected data from consecutive patients treated for a ruptured blister with an FD was reviewed. Device deployment was timed to be at 2 h following Prasugrel loading. Thrombo-embolic and hemorrhagic complications, and occlusion rates were documented.

RESULTS

Nine patients were included. Most were females (55%); the median age was 55 (43, 65). The median Fischer grade was 3 (2, 4). A single pipeline device was deployed in all within 24 h of admission; the median time from ictus to device deployment was 4 days (2, 30). There were no thrombo-embolic or hemorrhagic complication. Complete occlusion was noted in 89% (n = 9).

CONCLUSION

Prasugrel loading timed 2 h prior to stent delivery did not increase thrombo-embolic or hemorrhagic complications. Single stent that is well apposed against the wall appears to be an effective treatment strategy to treat BLA. Advances in knowledge: Treatment of acutely ruptured BLA with a single pipeline device deployed at 2 h after Prasugrel loading appears to be safe.

Angiographic Appearance of Pulsatile Blister Aneurysm

A male with detected subarachnoid hemorrhage was admitted to our center. During the first angiography, a pulsatile blister aneurysm was revealed and the aneurysm was also noticeably enlarged during the surveillance angiography. The patient accepted balloon-assisted clipping successfully. Blister aneurysms are at a high risk of rupture, high risk of regrowth, and need for multimodal management.

Pipeline embolization device retraction and foreshortening after internal carotid artery blister aneurysm treatment

Background Subarachnoid hemorrhage (SAH) secondary to rupture of a blister aneurysm (BA) results in high morbidity and mortality. Endovascular treatment with the pipeline embolization device (PED) has been described as a new treatment strategy for these lesions. We present the first reported case of PED retraction and foreshortening after treatment of a ruptured internal carotid artery (ICA) BA. Case description A middle-aged patient presented with SAH secondary to ICA BA rupture. The patient was treated with telescoping PED placement across the BA. After 5 days from treatment, the patient developed a new SAH due to re-rupture of the BA. Digital subtraction angiography revealed an increase in caliber of the supraclinoid ICA with associated retraction and foreshortening of the PED that resulted in aneurysm uncovering and growth. Conclusions PED should be oversized during ruptured BA treatment to prevent device retraction and aneurysm regrowth. Frequent imaging follow up after BA treatment with PED is warranted to ensure aneurysm occlusion.

Treatment of ruptured blood blister aneurysms using primary flow-diverter stenting with considerations for adjunctive coiling: A single-centre experience and literature review

Objective The objective of this article is to conduct a single-centre evaluation and quick literature review of the effectiveness of primary flow-diverter (FD) treatment of ruptured blood blister aneurysms (BBAs), with additional relevance of adjunctive coiling. Methods Patients presenting with subarachnoid haemorrhage (SAH) due to ruptured BBAs and subsequently treated with FDs were retrospectively selected from June 2010 to January 2017. Treatment techniques, angiographic data on occlusion rates and procedural success as well as clinical outcomes using the modified Rankin Scale (mRS) were collated. Cross-reference of results were made with available literature. Results Thirteen patients harbouring 14 BBAs were recruited. Of the 14 aneurysms, five (35.7%) showed immediate complete occlusion after the procedure (four of these five patients had adjunctive coiling). All of the aneurysms showed complete occlusion by the six- to nine-month control diagnostic angiogram. No rebleed or retreatment was experienced. Twelve of 13 (92%) patients had an mRS score of 0-1 at the last clinical follow-up. From the pooled data of the literature review, eventual aneurysm occlusion was achieved in 48/56 patients, with five patients requiring further endovascular treatment. In the clinical follow-up period, an mRS of 0-2 was recorded for 83.3% (45/54) of patients. Conclusion Endovascular reconstruction of BBAs using FD treatment is an effective method with good final clinical outcomes. Adjunctive use of coiling achieves higher incidence of immediate complete occlusion of BBAs.

Current Treatment Strategies for Intracranial Aneurysms: An Overview

Intracranial aneurysm is a leading cause of stroke. Its treatment has evolved over the past 2 decades. This review summarizes the treatment strategies for intracranial aneurysms from 3 different perspectives: open surgery approach, transluminal treatment approach, and new technologies being used or trialed. We introduce most of the available treatment techniques in detail, including contralateral clipping, wrapping and clipping, double catheters assisting coiling and waffle-cone technique, and so on. Data from major trials such as Analysis of Treatment by Endovascular approach of Non-ruptured Aneurysms (ATENA), Internal Subarachnoid Trial (ISAT), Clinical and Anatomical Results in the Treatment of Ruptured Intracranial Aneurysms (CLARITY), and Barrow Ruptured Aneurysm Trial (BRAT) as well as information from other clinical reports and local experience are reviewed to suggest a clinical pathway for treating different types of intracranial aneurysms. It will be a valuable supplement to the current existing guidelines. We hope it could help assisting real-time decision-making in clinical practices and also encourage advancements in managing the disease.

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.

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.

Endovascular isolation of intracranial blood blister-like aneurysms with Willis covered stent

Objective

Intracranial blood blister-like aneurysm (BBA) is a rare type of aneurysm that lacks all layers of the arterial wall. These fragile aneurysms have the propensity to rupture with minimal manipulation, which makes them hazardous and difficult to treat. The present study evaluated the safety and feasibility of endovascular treatment of BBAs with the Willis covered stent.

Materials

Thirteen patients (7 men and 6 women, age range 28–68 years) who presented with ruptured BBAs and were treated with the Willis covered stent were retrospectively reviewed. Results of the procedures and treatment-related complications were recorded. Angiographic and clinical follow-ups were performed 4–6 months after the procedure.

Results

Placement of the covered stent was successful in all patients. Immediate angiography showed complete aneurysm occlusion in 12 patients while one patient showed a mild endoleak. This high rate of aneurysm exclusion ensured the security of postoperative antiplatelet treatment. Occlusion of the ophthalmic artery occurred in two patients and occlusion of the anterior choroidal artery occurred in one patient; however, none of them showed acute or delayed clinical symptoms. Thrombosis, aneurysm rupture, and other complications did not develop in any case. Angiographic follow-up showed complete aneurysm exclusion without aneurysm recurrence in any patients. Only two patients showed asymptomatic mild to moderate in-stent stenosis. All patients had satisfactory clinical outcomes (modified Rankin Scale score ≤1).

Conclusions

Willis covered stent implementation may be safe and feasible for BBAs. This strategy might be a promising option for this high-risk type of aneurysm.