A single-center experience in the endovascular treatment of carotid siphon aneurysms using the Willis covered stent: a retrospective analysis

Impact of Stent Size Selection and Vessel Evaluation on Skull Base Cerebrovascular Diseases Treated With Willis Covered Stents: A Multicenter Retrospective Analysis

PURPOSE

This study aimed to evaluate the impact of the diverse stent size selection on the clinical and angiographic outcomes of Willis covered stent (WCS) for the treatment of skull base cerebrovascular diseases.

MATERIALS AND METHODS

A total of 147 patients with 151 skull base cerebrovascular diseases treated with WCS in 3 centers between January 2015 and July 2022 were included in this study. Several parameters depicting stent size and parent artery condition were incorporated into the analysis of the outcomes.

RESULTS

Complete occlusion was found in 106 cases (68.2%) immediately after deployment and 126 cases (83.4%) after technical adjustment. In the multivariate logistics analysis, the difference between stent diameter and parent artery diameter (DD) was significantly associated with immediate endoleak without adjustment (odds ratio [OR]=0.410; p=0.005) and late endoleak (OR=0.275; p=0.028). In addition, differences between stent diameter and parent artery diameter at wide landing point (DSW) and differences between stent diameter and parent artery diameter at narrow landing point (DSN) was also was significant associated with immediate endoleak without adjustment and balloon re-dilation respectively.

CONCLUSIONS

This study demonstrated that the diameter selection of the WCS was associated with the occurrence of endoleak during the treatment of skull base cerebrovascular diseases. Precise selection and evaluation of stent size and vessel condition were significant factors for skull base cerebrovascular diseases treated by WCS.

CLINICAL IMPACT

This study demonstrates a significant association between the diameter selection of the Willis covered stent (WCS) and the occurrence of endoleak in the management of skull base cerebrovascular diseases. The results offer valuable medical evidence that can inform stent selection for WCS. The study emphasizes the significance of precise evaluation of stent size and vessel condition as crucial factors in WCS procedures. These findings underscore the importance of meticulous consideration and individualized approaches to stent selection, ultimately improving treatment outcomes in clinical practice.

Comparison of a covered stent and pipeline embolization device in intracranial aneurysm: a propensity score matching analysis

BACKGROUND

The Willis covered stent (WCS) and pipeline embolization device (PED) have partly overlapping therapeutic indications. However, the differences of effect between these two treatments remain unclear.

OBJECTIVE

To compare clinical outcome, angiographic outcome, and complications following treatment with a WCS versus PED.

METHODS

Patients with intracranial aneurysms treated by a WCS or PED between January 2015 and December 2020 were included. The primary outcomes were complications, clinical outcome (modified Rankin Scale score >2), and angiographic outcome (incomplete aneurysm occlusion). Propensity score matching was conducted to adjust for potential confounding factors.

RESULTS

A total of 94 aneurysms treated by WCS and 698 aneurysms by PED were included. Compared with the PED group, patients in the WCS group are younger, a greater number have a poor condition at admission, a larger proportion of ruptured, non-saccular, and anterior circulation aneurysms, a smaller aneurysm neck width, and less coiling assistance is required. A total of 42 (44.7%) branches were covered by WCS. After adjustment for age, sex, aneurysm type, rupture status, neck size, aneurysm location, and coiling, 50 WCS and PED pairs were examined for internal carotid artery aneurysms. No significant differences were observed in clinical (10.4% vs 2.1%, P=0.206) and angiographic outcomes (12.8% vs 18.2%, P=0.713). However, 27 branches covered by WCS, including 22 ophthalmic arteries and five posterior communicating arteries. Patients in the WCS group had a higher intraoperative complication rate than those in the PED group (28% vs 6%, P=0.008), especially in the occlusion rate of covered branches (51.9% vs 11.1%, P<0.001).

CONCLUSION

The comparable clinical and angiographic outcomes of WCS or PED demonstrate the therapeutic potential of WCS as a viable alternative for aneurysms. However, the complication of occlusion of covered branches might not be negligible.

Intra-arterial microguidewire electrocoagulation to treat intracranial vascular diseases

OBJECTIVE

To investigate the therapeutic effect of intra-arterial microguidewire electrocoagulation on intracranial vascular diseases.

METHODS

Data from 10 patients with cerebral aneurysms between May 2018 and September 2022 were analysed. Patients were treated with endovascular coil embolisation and microguidewire electrocoagulation. XperCT scans were conducted to identify new intracranial haemorrhage, infarction and hydrocephalus. Follow-up examinations were conducted 1, 3, 6 and 12 months after discharge.

RESULTS

After the patients received electrocoagulation for different durations, Raymond Grade 1 embolisation was achieved in all 10 patients. No complications, such as haemorrhage, infarction or hydrocephalus, were found during or after surgery. Ten patients were followed up for 6-12 months, and none had any symptoms or new neurological dysfunction 1 month after their operation. Among them, nine were followed up for 12 months, and digital subtraction angiography showed no recurrence of aneurysms or occlusion of parent arteries.

CONCLUSION

Intra-arterial microguidewire electrocoagulation can be used as a supplementary treatment for cerebral aneurysms. In cases of incomplete lesion embolisation and cases where tamponade treatment cannot continue, immediate thrombosis may occur. Thus, intra-arterial microguidewire electrocoagulation can help achieve patients' treatment goals.

Endovascular treatment strategies and a new classification for multiple aneurysms of the ipsilateral ophthalmic segment of the internal carotid artery

OBJECTIVE

Aneurysms occurring in the ophthalmic segment (C6) of the internal carotid artery (ICA) have complex anatomy. This poses a challenge for the use of traditional open surgery, which is gradually being replaced by endovascular treatment (EVT). However, multiple aneurysm (MA) EVT, especially in MAs occurring ipsilaterally, has not been specifically described or discussed. The present study aimed to propose a more concise clinical classification standard for ipsilateral C6 ICA MAs and report on the clinical experience with EVT.

METHODS

The cases of 18 patients with ipsilateral C6 ICA MAs treated with EVT were retrospectively reviewed. The treatment results and procedure-related complications were recorded, and clinical and angiographic follow-ups were performed at least six months after surgery.

RESULTS

A total of 38 ipsilateral C6 ICA aneurysms were treated during the study period and classified into four main types and six total subtypes based on anatomical features. There was a failure to coil through the stent in one aneurysm, while the remaining 37 were successfully treated using various EVT methods. Of these, 36 were completely concluded. One aneurysm had a size reduction, and one had no changes during the angiographic follow-up. All Tubridge flow diverter stents were patent. All patients achieved satisfactory clinical outcomes and were independent at the final follow-up.

CONCLUSION

EVT may be safe and feasible for the treatment of C6 ICA MAs. Traditional stent-assisted coiling methods, the Willis covered stent, and the double-layered low-profile visualized intraluminal support stent all achieved favorable results. The flow diverter stent is also considered a safe and efficient option for selected aneurysms, but the visual deficit risk should be considered. The present study introduces a new EVT classification option based on the anatomical features of an aneurysm.

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.

Case report: Covered stent placement to treat delayed aneurysmal rupture after flow diverter-assisted coil embolization

INTRODUCTION

Flow diverter (FD) placement is widely accepted as a treatment for large saccular intracranial aneurysms. Delayed aneurysmal rupture (DAR) after FD placement is potentially catastrophic and difficult to treat. To our knowledge, using a Willis covered stent (WCS) to treat DAR after placement of a Pipeline Flex embolization device (PFED) combined with coiling has not been previously reported.

CASE PRESENTATION

A 49-year-old woman with an incidental asymptomatic large right supraclinoid internal carotid artery aneurysm was treated with PFED placement and adjunctive coiling. DAR causing subarachnoid hemorrhage occurred 11 hours after the procedure. Treatment using a WCS was successful and resulted in a favorable clinical outcome (modified Rankin scale score 2).

CONCLUSION

DAR after FD implantation requires isolation of the aneurysm from the cerebral circulation as soon as possible. WCS placement can achieve this immediately and occlude the aneurysm. We hope our case could provide new idea for similar cases in the future.

Use of covered stents to treat complex cerebrovascular diseases: Expert consensus

The treatment of complex cerebrovascular diseases (CCVDs) at the skull base, such as complex intracranial aneurysms, carotid-cavernous sinus fistulas, and intracranial artery traumatic injuries, is a difficult clinical problem despite advances in endovascular and surgical therapies. Covered stents or stent graft insertion is a new concept for endovascular treatment that focuses on arterial wall defect reconstruction, differing from endovascular lesion embolization or flow diverter therapies. In recent years, covered stents specifically designed for cerebrovascular treatment have been applied in the clinical setting, allowing thousands of patients with CCVDs to undergo intraluminal reconstruction treatment and achieving positive results, even in the era of flow diverters. Since there is no unified reference standard for the application of covered stents for treating CCVDs, it is necessary to further standardize and guide the clinical application of this technique. Thus, we organized authoritative experts in the field of neurointervention in China to write an expert consensus, which aims to summarize the results of covered stent insertion in the treatment of CCVDs and propose suitable standards for its application in the clinical setting. Based on the contents of this consensus, clinicians can use individualized intraluminal reconstruction treatment techniques for patients with CCVDs.

Application of the Willis Covered Stent in the Treatment of Blood Blister-Like Aneurysms: A Single-Center Experience

Objective

To evaluate the effectiveness of the Willis covered stent (WCS) in the treatment of ruptured blood blister-like aneurysms (BBAs) of the internal carotid artery (ICA).

Method

The clinical data of 16 patients consecutively treated with WCSs from December 2015 to January 2019 were retrospectively analyzed. Clinical data and angiographic findings were analyzed by two experienced neuroradiologists and neurosurgeons, including age, sex, Hunt and Hess (H&H) grade at admission, modified Rankin scale (mRS) score, aneurysm size, and location, the diameter of the patent artery in proximal and distal ends, stent size, rate of aneurysm occlusion, procedure-related complications, and follow-up.

Results

All the 16 patients (five males, 11 females) with ICA BBAs underwent WCS deployment successfully. The median age was 49 years (range, 29–72). All patients had complete aneurysm occlusion on immediate postoperative angiography. Anterior choroidal artery (AChA) was occluded in one patient accidentally while no obvious neurological dysfunction was observed. However, this patient underwent subarachnoid hemorrhage 1 day after the treatment; endoleak and aneurysm recurred, and the patient died 10 days later. Therefore, the effective rate of WCS treatment was 93.8% (15/16), and procedure-related complications rate was 6.3% (1/16). Moreover, one patient was urgently treated because of accidental aneurysm rupture after anesthesia, and external ventricular drainage was then performed postoperatively. Another patient developed coma and hemiplegia 3 days after treatment, with emergency angiography showing in-stent thrombosis and ICA occlusion which was recanalized with arterial rt-PA thrombolysis; the patient recovered completely. The clinical follow-up period was 3–30 months in 14 patients. The mRS scores were 0 in 12 patients (85.7%) and 4 in 1 case (7.1%), while 1 patient (7.1%) died 6 months postoperatively for unknown reasons. Angiographic follow-up was performed in 13 patients, and no recurrence was observed. However, ICA occlusion without neurological deficit was observed in one patient.

Conclusion

Based on careful preoperative evaluation, appropriate WCS size selection, and precise surgical operation, WCSs may provide an alternative and effective solution for blood BBAs via aneurysm isolation and ICA reconstruction immediately; However, further follow-up studies with larger samples are required.

Willis Covered Stent for Treating Intracranial Pseudoaneurysms of the Internal Carotid Artery: A Multi-Institutional Study

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).

CONCLUSION

WCSs are effective in treating intracranial PSAs of the ICA.

A heparin-rosuvastatin-loaded P(LLA-CL) nanofiber-covered stent inhibits inflammatory smooth-muscle cell viability to reduce in-stent stenosis and thrombosis

Background

An endovascular covered-stent has unique advantages in treating complex intracranial aneurysms; however, in-stent stenosis and late thrombosis have become the main factors affecting the efficacy of covered-stent treatment. Smooth-muscle-cell phenotypic modulation plays an important role in late in-stent stenosis and thrombosis. Here, we determined the efficacy of using covered stents loaded with drugs to inhibit smooth-muscle-cell phenotypic modulation and potentially lower the incidence of long-term complications.

Methods

Nanofiber-covered stents were prepared using coaxial electrospinning, with the core solution prepared with 15% heparin and 20 µM rosuvastatin solution (400: 100 µL), and the shell solution prepared with 120 mg/mL hexafluoroisopropanol. We established a rabbit carotid-artery aneurysm model, which was treated with covered stents. Angiography and histology were performed to evaluate the therapeutic efficacy and incidence rate of in-stent stenosis and thrombosis. Phenotype, function, and inflammatory factors of smooth-muscle cells were studied to explore the mechanism of rosuvastatin action in smooth-muscle cells.

Result

Heparin–rosuvastatin-loaded nanofiber scaffold mats inhibited the proliferation of synthetic smooth-muscle cells, and the nanofiber-covered stent effectively treated aneurysms in the absence of notable in-stent stenosis. Additionally, in vitro experiments showed that rosuvastatin inhibited the smooth-muscle-cell phenotypic modulation of platelet-derived growth factor-BB induction and decreased synthetic smooth-muscle-cell viability, as well as secretion of inflammatory cytokines.

Conclusion

Rosuvastatin inhibited the abnormal proliferation of synthetic smooth-muscle cells, and heparin–rosuvastatin-loaded covered stents reduced the incidence of stenosis and late thrombosis, thereby improving the healing rates of stents used for aneurysm treatment.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00867-8.

Safety and Efficacy of Endovascular Therapy for Blood Blister-Like Aneurysms: Willis Covered Stents and Double Stents Assistant Coils-A Single Center Cohort Study

Objective: To summarize and discuss the application of Willis covered stents (WCSs) and double stent-assisted coils in the treatment of blood blister-like aneurysms (BBAs).

Materials and Methods: Thirty-two patients with BBAs treated from January 2015 to October 2020 were included in the study. Among them, 18 were treated using WCSs and 14 using double stents-assisted coils. The indications for treatment, perioperative findings, and postoperative follow-up results were collected and analyzed.

Results: All 32 patients had successful stent deployments. Complete aneurysm occlusion was achieved in all 18 patients treated with WCSs immediately. WCS-related adverse events included 2 cases of mild vasospasm and 4 aggressive procedure-related vasospasms during WCS deployment, a case of dissection after WCS deployment, and 1 death due to ipsilateral temporal lobe rebleeding at the sixth day after WCS deployment. In patients treated with double stent-assisted coils, there were 3 cases of neck remnants, 1 acute occlusion of the ipsilateral MCA branch, and 4 mild procedure-related intraoperative vasospasms. The mean follow-up period was 4.2±1.6 months (range 3–6 months). Follow-up imaging data were available for 25 patients (78.1%). In the first postoperative angiographic follow-up, all BBAs were completely occluded. Mild asymptomatic stent stenosis was observed in 3 patients treated with WCSs. Follow-up examination at 6 months after the employment of WCSs showed that the modified Rankin score (mRs) was 0 in 6 patients, 1 in 5 patients, 2 in 3 patients, 3 in 1 patient, 4 in 2 patients, and 6 in 1 patient. After treatment with double stents-assisted coils, the mRs was 0 in 4 patients, 1 in 5 patients, 2 in 3 patients, and 4 in 2 patients.

Conclusions: WCSs and double stent-assisted coils for the treatment of BBAs are both safe and efficient. WCSs provide a higher rate of immediate occlusion; however, there was no significant difference in the long term.

Endovascular Treatment of Complex Vascular Diseases of the Internal Carotid Artery Using the Willis Covered Stent: Preliminary Experience and Technical Considerations

Purpose: The Willis covered stent (WCS) is used to treat complex vascular diseases of the internal carotid artery; however, its performance requires further investigation. This study aimed to present our single-center clinical results and experience of endovascular repair of complex vascular diseases of the internal carotid artery using the WCS.

Methods: Patients who presented with complex vascular diseases of the internal carotid artery and who were treated with the WCS from December 2013 to September 2018 were retrospectively reviewed. Procedural results, perioperative complications, incidence of endoleak, and follow-up outcomes were analyzed.

Results: Sixty-five patients were enrolled. A total of 25 large aneurysms, 10 pseudoaneurysms, 14 blood blister-like aneurysms, 11 carotid–cavernous fistulas, and 5 surgical injuries were assessed. WCS placement was successful in all patients. Immediate angiography showed that complete repair of the target artery was achieved in 56 patients (86.2%). Endoleak was observed in nine patients, including seven type I endoleaks and two type II endoleaks. Occlusion of a side-branch vessel occurred in four patients. Acute in-stent thrombosis occurred in one patient. No ischemic or hemorrhagic events or other complications developed during the perioperative and follow-up periods. Angiographic follow-up (mean duration, 12 ± 3.29 months) was performed in 60 patients and showed complete target artery repair in 58 patients, and asymptomatic mild to moderate in-stent stenosis was observed in four patients. Slight endoleak persisted in two patients without enlargement or rupture of the residual lumen.

Conclusion: WCS implantation is safe, feasible, and efficacious for endovascular repair in patients with complex vascular diseases of the internal carotid artery, showing excellent short-term target artery patency and clinical outcomes.

Recurrence of an internal carotid artery aneurysm after complete exclusion by a Willis covered stent

Treatment of selective intracranial aneurysms treated with a Willis covered stent is safe and effective. We describe a previously unreported case of a large, irregular, carotid-ophthalmic aneurysm that was treated with a Willis covered stent. An immediate angiogram after the procedure showed complete occlusion of the aneurysm. However, a six-month follow-up angiogram demonstrated contrast media filling of the aneurysm neck. To the best of our knowledge, this is the first report of a recurrent aneurysm treated with a Willis covered stent because of a membrane partially isolated with the stent. This case suggests that an aneurysm that is treated with a Willis covered stent might recanalise, and the risk of aneurysm rupture persists when the membrane of the stent is isolated with the stent. Therefore, follow-up angiography is necessary, even if an immediate angiogram shows complete aneurysm occlusion. Long-term follow-up is required, and the final outcome of such a case is still unknown.