UNASSIGNED: Pseudoaneurysm (PSA) of internal carotid artery is a rare but severe cerebrovascular disease and difficult to repair surgically. A novel medical device called Willis covered stent (WCS) has been created especially for the treatment of complex cerebrovascular diseases. However, the efficacy and safety of WCS therapy for PSA are still debatable. Additional substantial proof is needed.
UNASSIGNED: To find research pertaining to WCS treatment for PSA, a systematic review of literature was conducted in the Medline, Embase, Web of Science, CNKI, Wanfang, and CBM databases. The results comprising the data of intraoperative situation, postoperative situation, and follow-up were then included in a meta-analysis.
UNASSIGNED: The criteria were met by 11 noncomparative studies with 152 patients and 157 PSAs. Technical success rate was nearly 100 % (>0.999 (95 % confidence interval (CI), 0.958, 1.000)), complete occlusion rate was 97.8 % (95 % CI, 0.932, 1.000), and side branch occlusion rate was 0.5 % (95 % CI, 0.001, 0.045). The rates of acute in-stent thrombosis (<0.001 (95 % CI, 0.000, 0.013)) and hemorrhage (<0.001 (95 % CI, 0.000, 0.005)) were both less than 0.1 %. In postoperative situation, surgery-related mortality rate was less than 0.1 % (<0.001 (95 % CI, 0.000, 0.005)). The rates of recurrence (<0.001 (95 % CI, 0.000, 0.002)) and parent artery stenosis (<0.001 (95 % CI, 0.000, 0.008)) were both less than 0.1 %, while late in-stent stenosis occurred in 1.3 % (95 % CI, 0.000, 0.053) of patients. In the end, 98.5 % (95 % CI, 0.943, 1.000) of patients had a good outcome.
UNASSIGNED: The application of WCS could be effective and safe for PSAs. The findings of this study could serve as a reference for upcoming clinical trials.

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.

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.

OBJECTIVE: This work aimed to retrospectively analyze Willis covered stent (WCS)\'s therapeutic efficacy in intracranial pseudoaneurysms (PSAs) of the internal carotid artery (ICA).
METHODS: Between June 2018 and July 2021, 56 individuals with intracranial PSAs of the ICA treated with WCS in three centers were included to analyze information regarding medical records, operative parameters, imaging findings and follow-up data.
RESULTS: All WCSs were successfully targeted to the ICA lesions. Total exclusion of PSA was found in 53 cases (94.6%) right upon surgery, and mild endoleak into the aneurysm remained in 3 cases (5.4%). Intraoperative thrombosis occurred in 1 case (1.8%), and tirofiban was utilized for recanalization. Follow-up by angiography showed total aneurysm occlusion in the total number of individuals, including in the 3 above cases with residual endoleak. In-stent stenosis occurred in 7 (12.5%) patients. No stent-related ischemic event was encountered. Predictive factors of late in-stent stenosis following WCS implantation in this patient group were irregular post-operative antiplatelet treatment (p = 0.015) and C4-C5 segment of the ICA (p = 0.043).
CONCLUSIONS: WCSs are effective in treating intracranial PSAs of the ICA.

UNASSIGNED: Symptomatic vertebral artery dissecting aneurysm (VADA) is a challenging disease with controversy on treatment strategy due to anatomic configuration and their nature. Moreover, the outcomes of reconstructive treatment have not been well established.
UNASSIGNED: To evaluate the safety and efficacy of reconstructive endovascular treatment (EVT) for symptomatic VADAs with Willis covered stent.
UNASSIGNED: We evaluated retrospectively 13 patients with symptomatic VADAs who treated with Willis covered stent, compared with stent-assisted coiling (SAC) on the characteristics, posttreatment course, angiographic and clinical follow-up outcomes at an average of 14.4 months (range, 3-48 months).
UNASSIGNED: A total of 33 patients with symptomatic VADAs were reviewed, 23 of these patients with ruptured VADAs. The technical successful rate is 100% respectively in Willis covered stent (Group A) and SAC (Group B, n ​= ​20). The initial complete occlusion rate was significant higher in group A (100%) than group B (30%) (p ​< ​0.01). Major procedure-related complications were not significant different in the two groups. Serial follow-up angiograms revealed 5 recurrent VADAs in group B and no recurrence in group A (p ​> ​0.05). No obvious in-stent stenosis and no re-hemorrhage and delayed ischemic symptoms during the follow-up period. The final angiograms of all survived patients demonstrated the complete occlusion rate was higher in group A (100%) than group B (80%), but no significant statistical difference (p ​> ​0.05). Clinical outcomes were favorable in 31 (93.9%), severe disability occurred in one in group B, and only one death in group A. The final clinical outcomes were also not significant difference in the two groups (p ​> ​0.05).
UNASSIGNED: Our initial result demonstrated reconstructive EVT with Willis covered stent provides a viable approach for selected symptomatic VADAs involving the intracranial and extracranial segments, which is similar to favorable results with SAC. However, an expanded clinical experiences and larger cohort studies are needed.

Background Despite the current availability of flow diverter devices (FDD), problems remains regarding optimal endovascular treatment (EVT) for blood blister-like aneurysms (BBAs) of the internal carotid artery (ICA). Objective To evaluate the safety and efficacy of EVT of BBAs in the ICA with a Willis covered stent. Methods 20 consecutive patients (5 men and 15 women) with ruptured BBAs underwent EVT using a Willis covered stent in two institutions from March 2013 to March 2018. Clinical observations, angiographic characteristics, and procedural and follow-up outcomes were retrospectively evaluated. Results 20 consecutive patients (5 men and 15 women) with ruptured BBAs underwent EVT using a Willis covered stent in two institutions from March 2013 to March 2018. Clinical observations, angiographic characteristics, and procedural and follow-up outcomes were retrospectively evaluated. Conclusion Our initial results demonstrate that reconstructive EVT using a Willis covered stent provides a viable approach to treat ICA BBAs. However, an expanded clinical evaluation and larger cohort are needed to confirm the results.

Objective: To investigate the safety and efficacy of Willis covered stents (WCS) in the treatment of traumatic pseudoaneurysm of the cranial internal carotid artery (CICA). Methods: Fifteen patients with traumatic pseudoaneurysm of the intracranial segment of the ICA treated with the WCS system at our institution from 2013 to 2019 were analyzed retrospectively. Follow-up observation and digital subtraction angiography (DSA) examination were conducted ~6 months after the treatment. Results: DSA performed immediately after stent deployment revealed that complete occlusion of the lesion was achieved in 13 patients and that endoleak occurred in two patients. In 12 patients, postoperative DSA examination indicated that the lesions were completely occluded. In two patients who had a second stent implantation at the break of the ICA, traumatic ICA rupture was essentially completely obstructed in 1 patient. The endoleak remained in one patient with carotid cavernous sinus fistula because the placement of the second stent system was difficult with his ICA tortuosity. No recurrence of aneurysms, hemorrhage, or other lesions was observed, and the patients\' parent arteries were patent without stenosis. No procedure-related complications or ischemic strokes occurred during the follow-up period of ~6 months. Conclusions: For treatment of traumatic pseudoaneurysm of the CICA, Willis covered stent implantation in some appropriate cases, is safe and effective. However, large-sample controlled studies and multicenter studies are needed for further confirmation.

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.

UNASSIGNED: The purpose of this study is to report the treatment approaches and postoperative outcomes of extracranial carotid artery aneurysms (ECAAs) and discuss the symptoms, related risk factors, etiology, diagnostic methods, treatments, and follow-up period complications.
UNASSIGNED: We describe three patients with symptomatic extracranial carotid artery aneurysms; one of them was treated with end-to-end anastomosis of the extracranial internal carotid artery (EICA) after the resection of the aneurysm, while the other two patients were deployed with Willis covered stents in the extracranial internal carotid artery. All of the patients were in good condition when discharged home. After a mean follow-up period of 8 months, all the patients were alive and only one of them had the neurologic deficit. Additionally, we reviewed the relative literatures.
UNASSIGNED: Both of the surgical and endovascular treatments have relatively satisfactory outcomes in ECAA patients. However, it is necessary to provide individualized treatments to different patients according to the characteristics of the aneurysms.

The purpose of this study was to retrospectively analyse the clinical and angiographic outcomes of Willis covered stent placement for unruptured aneurysms in internal carotid artery. Forty-six consecutive patients with internal carotid artery aneurysms (49 cases) were included to evaluate clinical and angiographic outcomes. Covered stent placement was successful in 47 cases, whereas stent navigation failed in 2 cases. Of the 49 aneurysms (mean aneurysm size, 7.9 mm), 5, 6, and 38 were located in the petrous, cavernous, and ophthalmic segments, respectively. Immediate angiography revealed complete aneurysm exclusion in 36 (76.6%) cases, whereas minimal endoleak was observed in 11 cases. Four patients had procedure-related complications, including 1 patient with acute in-stent thrombosis, 2 with a post-operative subarachnoid haemorrhage, and 1 with artery rupture. Angiographic and clinical follow-up was available for 36 patients (38 aneurysms). Complete aneurysm occlusion was achieved in 34 (89.5%) cases, endoleak was present in 2 cases, and aneurysm recurrence occurred in 2 cases. Asymptomatic in-stent stenosis was observed in 3 patients. No hemorrhagic or ischemic events occurred during the follow-up period. At follow-up, the modified Rankin scores were 0-2 for 35 patients and >2 for 1 patient. Satisfactory angiographic outcomes were achieved in our study. However, the risks of stent navigation failure, endoleak after balloon re-inflation, procedure-related complications and coverage of side branches should be considered when choosing the best therapeutic option for internal carotid artery aneurysms.