Management of pseudoaneurysms in the intracranial segment of the internal carotid artery with covered stents specially designed for use in the intracranial vasculature: technical notes

Stent-assisted coiling of intracranial carotid ophthalmic segment aneurysm segment aneurysms: Long-term follow-up from a single center

Background

To evaluate the efficacy of stent-assisted coiling (SAC) for the treatment of carotid ophthalmic segment aneurysm segment aneurysms (OSAs) of the internal carotid artery (ICA) through detailed long-term follow-up of a large patient cohort.

Methods

We retrospectively analyzed 88 consecutive patients with OSAs between January 2009 and January 2020 ​at our center. Angiographic results were evaluated using the modified Raymond grading system and clinical outcomes were evaluated using the mRS scale. The primary endpoints were major aneurysm recurrence and poor clinical outcomes for at least 18 months of follow-up. The patients were asked to attend clinical follow-up assessments and possibly undergo DSA or MR via telephone.

Results

We enrolled 88 patients with 99 OSAs treated with coiling, of whom 76 were treated with SAC. The coiling procedures were successful in all 88 patients. Overall, complications occurred in 8 patients (9.1%). No procedure-related mortality was observed. 67 (76.1%) experienced immediate aneurysm occlusion at the end of the procedure. Long-term angiographic follow-up (18 months) was available in 45/88 aneurysms (51%) (average 18.7 ​± ​5.2 months). Four patients continued their follow-up for 5 years after initial aneurysm treatment. After a clinical follow-up time of 28.7 months (range, 12-51 months), 85 patients (95.5%) achieved favorable clinical outcomes (mRS scores of 0-2).

Conclusions

This study indicates that SAC treatment is a safe and effective therapeutic alternative for ruptured and unruptured OSAs. The procedural risks are low with relatively long-term effectiveness.

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 treatment for blood blister-like aneurysm: A meta-analysis of efficacy and safety

Background

Blood blister-like aneurysm (BBA) is a rare and special type of intracranial aneurysm with extremely high rates of rupture, morbidity, mortality, and recurrence. Willis Covered Stent (WCS) is a new device that is specifically designed for the treatment of intracranial complex aneurysms. However, the efficacy and safety of WCS treatment for BBA remain controversial. Thus, a high level of evidence is required to prove the efficacy and safety of WCS treatment.

Methods

A systematic literature review was performed using a comprehensive literary search in Medline, Embase, and Web of Science databases to identify studies related to WCS treatment for BBA. A meta-analysis was then conducted to incorporate the efficacy and safety outcomes, including intraoperative situation, post-operative situation, and follow-up data.

Results

Eight non-comparative studies containing 104 patients with 106 BBAs met the inclusion criteria. In the intraoperative situation, the technical success rate was 99.5% [95% confidence interval (CI), 0.958, 1.000], the complete occlusion rate was 98.2% (95% CI, 0.925, 1.000), and the side branch occlusion rate was 4.1% (95% CI, 0.001, 0.114). Vasospasm and dissection occurred in 9.2% (95% CI, 0.000, 0.261) and 0.1% (95% CI, 0.000, 0.032) of the patients, respectively. In the post-operative situation, the rebleed and mortality rates were 2.2% (95% CI, 0.000, 0.074) and 1.5% (95% CI, 0.000, 0.062), respectively. In the follow-up data, recurrence and parent artery stenosis occurred in 0.3% (95% CI, 0.000, 0.042) and 9.1% (95% CI, 0.032, 0.168) of the patients, respectively. Ultimately, 95.7% (95% CI, 0.889, 0.997) of the patients had a good outcome.

Conclusions

Willis Covered Stent could be effectively and safely applied for BBA treatment. The results provide a reference for clinical trials in the future. Well-designed prospective cohort studies must be conducted for verification.

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 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.

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.

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.

Endovascular treatment of blister aneurysms

Blister aneurysms are rare cerebrovascular lesions for which the treatment methods are reviewed here, with a focus on endovascular options. The reported pathogenesis of blister aneurysms varies, and hemodynamic stress, arterial dissection, and arteriosclerotic ulceration have all been described. There is consensus on the excessive fragility of blister aneurysms and their parent vessels, which makes clipping technically difficult. Open surgical treatment is associated with high rates of complications, morbidity, and mortality; endovascular treatment is a promising alternative. Among endovascular treatment options, deconstructive treatment has been associated with higher morbidity compared with reconstructive methods such as direct embolization, stent- or balloon-assisted direct embolization, stent monotherapy, and flow diversion. Flow diversion has been associated with higher technical success rates and similar clinical outcomes compared with non–flow diverting treatment methods. However, delayed aneurysm occlusion and the need for antiplatelet therapy are potential drawbacks to flow diversion that must be considered when choosing among treatment methods for blister aneurysms.

Construction of an in vivo carotid siphon model for testing endovascular devices for neuro-interventions

Objective The aim of this study was to construct an in vivo carotid siphon model for testing neurovascular devices for endovascular interventions. Methods A model of a human carotid siphon was pre-shaped using a glass tube from a human cadaver and used to confine a segment of one side of the common carotid artery (CCA) in canines. This segment of CCA with the glass carotid siphon on was interposed end-to-end onto the contralateral CCA so as to simulate a human carotid artery siphon in vivo. Two weeks later, the siphon model was evaluated using computed tomography angiography and digital subtraction angiography, and the covered stent specially designed for intracranial vasculature was navigated through the siphon model for a longitudinal flexibility test. Results All dogs tolerated the procedures well, and the artificial siphon model in vivo provided realistic conditions for device testing. Two weeks later, the in vivo carotid siphon model remained patent with no thrombosis. Five covered stents were navigated to pass through five siphon models successfully, with vasospasm occurring in two siphons. Conclusion Construction of an in vivo siphon model in dogs with a glass tube is feasible and useful for the test of endovascular devices for treating neurovascular diseases.

Treatment of internal carotid artery dissection with Willis covered stent: A case report of recurrent limb weakness and no response to medical therapy

Internal carotid artery dissection (ICAD) is a major cause of ischemic stroke in young and middle-aged patients. Patients may be asymptomatic or present with symptoms ranging from headache and neck pain to severe cerebral ischemic events. Conventional treatment is medical anticlotting therapy or involves the use of interventional tools, such as endovascular treatment. Anticoagulation or antiplatelet therapy are the primary treatment modalities used to prevent thromboembolic complications from arterial dissections, however, they are unsuitable in certain cases of dissecting aneurysms. In the current study reports the case of a 52-year-old male patient presenting with the primary complaint of left limb weakness. Computed tomography angiography revealed a right ICAD located in the oropharyngeal segment. Subsequently, digital subtraction angiography was performed to assess the oropharyngeal segment. Antithrombotic therapy resulted in no improvement; therefore, endovascular treatment with the insertion of a Willis covered stent was performed, resulting in an improved outcome.

Flow-Diverting Devices versus Coil Embolization for Intracranial Aneurysms: A Systematic Literature Review and Meta-analysis

OBJECTIVE

To review the literature on flow-diverting device (FDD) treatments for intracranial aneurysms (IAs) and to compare the safety and efficacy of FDDs with coil embolization treatment (CET) for IAs using a meta-analysis of published studies.

METHODS

A systematic electronic search was conducted of PubMed, Springer Link, EBSCO, and the Cochrane Database on all accessible published articles through September 2015. Abstracts, full-text manuscripts, and the reference lists of retrieved articles were analyzed. Studies that explicitly compared FDD and CET approaches to the treatment of IAs were included. Odds ratios (ORs) and 95% CIs were calculated for the complete occlusion rate and the morbidity rate using a random-effects model.

RESULTS

Nine studies were included in the analysis, containing retrospectively collected data for 863 patients. FDD treatment showed a significantly higher complete occlusion rate than CET (OR = 3.13; 95% confidence interval [CI], 2.11-4.65) and the subgroup of stent-assisted coiling did (OR = 2.08; 95% CI, 1.34-3.24). FDDs did not achieve a significantly lower overall morbidity rate compared with CET (OR = 0.87; 95% CI, 0.45-1.69) or the SAC (stent-assisted coiling) subgroup (OR = 0.86; 95% CI, 0.33-2.26), and our results did not show a significant difference in mortality between the two techniques.

CONCLUSIONS

FDD treatment of IAs yielded satisfactory results in complete occlusion rate compared with CET. The FDD procedure is feasible and has no significant difference in morbidity risk. Despite the findings reported herein, further validation with well-designed, multicenter randomized controlled trials is needed.

Endovascular embolization is applicable for large and giant intracranial aneurysms: experience in one center with long-term angiographic follow-up

BACKGROUND

Endovascular treatment of large and giant intracranial aneurysms and long-term results of angiographic follow-up of these aneurysms treated endovascularly are not known currently.

PURPOSE

To investigate the outcome of endovascular treatment of large and giant aneurysms and the long-term angiographic follow-up results.

MATERIAL AND METHODS

A retrospective analysis of all patients with endovascular treatment of large and giant aneurysms between 1998 and 2009 was performed. There were 90 large or giant aneurysms treated with coiling alone, stent-assisted coiling, covered-stent deployment, or parent artery occlusion (PAO) in 88 patients (female/male, 54/34; age range, 23-92 years; mean age, 56 years).

RESULTS

Immediately after the initial endovascular embolization procedure, complete occlusion was achieved in 56.7%, near complete occlusion in 37.8%, and incomplete occlusion in 5.5%. The total periprocedural complication rate excluding subarachnoid hemorrhage (SAH)-induced vasospasm was 10.2% with a mortality rate of 2.3%. Follow-up angiography was performed in all of the aneurysms with the longest follow-up duration of 131 months. Among 38 aneurysms initially treated with coiling alone and 17 initially treated with stent-assisted coiling, 22 (57.9%) and four (23.5%) recurred, respectively, during follow-up. No recurrence occurred in aneurysms initially treated with covered-stent deployment or PAO. Aneurysm recurrence was predominantly seen in older and female patients, in larger aneurysms, and in aneurysms treated with coiling alone. Twenty-three aneurysms were successfully retreated endovascularly.

CONCLUSION

Endovascular intervention with coiling alone or stent-assisted coiling for large and giant cerebral aneurysms is not very effective, while covered stents are more promising. Better endovascular devices are needed to obtain more secure closure.

Development of microporous self-expanding stent grafts for treating cerebral aneurysms: designing micropores to control intimal hyperplasia

Treatment of large (diameter 12-25 mm) or giant (diameter >25 mm) cerebral aneurysms with a broad neck in the cranio-cervical area is difficult and carries relatively high risks, even with surgical and/or endovascular methods. To this end, we have been developing a high-performance, self-expanding stent graft which consists of a commercially available NiTi stent (diameter 5 mm, length 20 mm) initially covered with a thin microporous segmented polyurethane membrane fabricated by the dip-coating method. Micropores are then created by the excimer laser ablation technique, and the outer surface is coated with argatroban. There are 2 types of micropore patterns: circular-shaped pore type (pore: diameter 100 μm, opening ratio 12.6%) and the bale-shaped pore type (pore: size 100 × 268 μm, opening ratio 23.6%). This self-expanding stent graft was tested on side-wall aneurysms of both canine carotid arteries that were experimentally induced using the venous pouches from the external jugular veins, with the self-expanding stent graft on one side and a bare self-expanding stent on the other side. All carotid arteries were patent and free of marked stenosis after 1 month. All aneurysms were occluded by stent grafts, while patent in those treated with bare stents. Histologically, the stent grafts with bale-shaped micropores and a high opening ratio were associated with less intimal hyperplasia (187 ± 98 μm) than the bare stents (341 ± 146 μm) or the stent grafts with circular micropores and a low opening ratio (441 ± 129 μm). A pore ratio of 23.6% was found to control intimal growth.

Covered Stent Implantation for the Treatment of Direct Carotid-Cavernous Fistula and Its Mid-Term Follow-up

SUMMARY

Carotid-cavernous fistulas are abnormal arteriovenous communications either directly between the internal carotid artery and the cavernous sinus or between the dural branches of the internal and external carotid arteries. These fistulas predominantly present with ocular manifestations and they are treated mainly by endovascular techniques in most cases. A detailed review of the literature allowed us to make a complete analysis of the information available on the topic. We describe a case of a direct carotid-cavernous fistula occluded by endovascular implantation of a covered stent, showing the persistence of results after three years.

Surgical construction of a novel simulated carotid siphon in dogs

Object

The development and preclinical assessment of new endovascular devices necessitate readily available and reproducible animal models. The purpose of this study was to develop an in vivo carotid siphon model for testing the properties of covered stents specially designed for the intracranial vasculature.

Methods

Six carotid siphon–shaped devices were created. Six dogs underwent surgery to expose and isolate both common carotid arteries (CCAs). The right CCA origin was ligated and incised distal to the ligation point after temporary constriction of the distal right CCA. The distal left CCA was ligated and incised proximal to the ligation point after the left CCA origin was temporarily clamped. The proximal isolated left CCA was passed through the shaped device and then anastomosed end-to-end to the distal isolated right CCA. Finally, the shaped device was fixed and embedded in the neck. Intraarterial digital subtraction angiography was performed at 7 days, 2 weeks, and 1 month postprocedure. All models underwent endovascular interventional simulation. The carotid siphon models were evaluated.

Results

The animals tolerated the surgical procedure well. The mean time for surgical construction of the model was 90 minutes. The morphology and endovascular manipulation of the siphon models were similar to those in humans. Stenosis of anastomotic stoma occurred in 2 models, and mural thrombosis of anastomotic stoma occurred in 1 model; however, all models were patent at postprocedural follow-up angiography.

Conclusions

Surgical construction of an in vivo carotid siphon model in dogs with carotid siphon–shaped devices is feasible and potentially useful for testing neurovascular devices.

Stent graft treatment of cerebrovascular wall defects: intermediate-term clinical and angiographic results

OBJECTIVE

Endovascular stent graft (SG) deployment offers a useful vessel-preserving strategy for vascular wall lesions such as pseudoaneurysms and fistulae. Although deployment of expanded polytetrafluoro-ethylene-covered SGs within the carotid and vertebral arteries is technically feasible, data on long-term efficacy, safety, and patency rate remain sparse.

METHODS

Six patients with traumatic (n = 4), iatrogenic (n = 1), or spontaneous (n = 1) internal carotid and vertebral artery injuries (direct carotid-cavernous fistula, n = 2; pseudoaneurysms, n = 4) were treated with nine balloon-mounted coronary expanded polytetrafluoro-ethylene SGs. Angiographic (mean, 2.3 yr; range, 1.7-4.2 yr) and neurological follow-up (mean, 2.7 yr) was performed for all patients.

RESULTS

Complete angiographic exclusion of the lesion was achieved by the initial procedure in five of the six patients; one ruptured cavernous carotid aneurysm leading to a direct carotid-cavernous fistula showed persistent slow shunting despite tandem deployment of two SGs. All six patients revealed complete and persistent angiographic obliteration at delayed follow-up, with minimal in-stent stenosis (<20%) seen in two instances. Difficulty with SG navigation was encountered in five patients, resulting in one instance of guide catheter-induced intimal dissection. Type I endoleak was observed in five patients, requiring secondary angioplasty in four patients and deployment of an additional tandem SG in three.

CONCLUSION

Technical challenges in current-generation SG deployment include sizing, navigation, positioning, and propensity for endoleak. When managed successfully, stent grafting provides a valuable approach for the treatment of vascular wall defects for which vessel preservation is preferred. Intermediate-term safety is satisfactory, with no delayed complications and minimal in-stent stenosis in follow-up periods of more than 2 years.

Endovascular treatment of giant intracranial aneurysms with willis covered stents: technical case report

OBJECTIVE

To evaluate the efficacy of endovascular treatment of giant intracranial aneurysms with Willis covered stents (Micro-Port, Shanghai, China).

CLINICAL PRESENTATION

The endovascular treatment of two cases of giant intracranial aneurysm was successfully accomplished by the placement of Willis covered stents specially designed for intracranial use. Both patients presented with symptoms of cavernous mass effect that resulted from a giant aneurysm in the cavernous segment of the internal carotid artery.

INTERVENTION

Three Willis covered stents were successfully placed in two patients. Immediate postprocedure angiograms demonstrated some endoleak of the aneurysms. In one patient, the endoleak was eliminated and complete exclusion of the aneurysms was confirmed with follow-up angiography. However, the other patient required the placement of a new Willis covered stent.

CONCLUSION

The use of covered stents in intracranial vascular structures is a feasible method to treat selected cases of intracranial giant aneurysms. It is suggested that patients who present with compressive mass effect caused by large or giant aneurysms are the best candidates for covered stent placement, but potential complications should be considered carefully before the stenting procedure.

The feasibility and efficacy of treatment with a Willis covered stent in recurrent intracranial aneurysms after coiling

BACKGROUND AND PURPOSE

Aneurysm recurrence is an innate problem after coiling, and the recurrence rate is higher in complicated aneurysms. We evaluated the feasibility and efficacy of using the Willis covered stent in treating recurrent aneurysms after coil embolization.

MATERIALS AND METHODS

Eight aneurysms in 8 patients treated with detachable coils had confirmed recurrent aneurysms: 3 giant, 1 large, 1 dissecting, and 3 small wide-necked. The recurrent aneurysms involved C3 in 1 patient, C4 in 1, C7 in 5, and V4 in 1. A total of 11 covered stents were implanted into 8 target arteries. Follow-up angiography was performed 1-16 months after the procedure. Clinical follow-up data were collected and retrospectively analyzed, grading as fully recovered, improved, unchanged, or aggravated.

RESULTS

Willis covered stent placement succeeded technically in all of the aneurysms. No technique-related adverse event occurred. Total occlusion was achieved immediately in 6 aneurysms, and a small endoleak was observed in 2 aneurysms. No mortality or morbidity occurred during or after the procedures, including during the follow-up period. Follow-up angiograms revealed that all 8 of the recurrent aneurysms were completely isolated, and 8 parent vessels kept patency, except 1 with mild stenosis. Clinical neurologic symptoms fully resolved in 5 patients, improved in 1, and were unchanged in 2 at the end of the follow-up period.

CONCLUSIONS

In this small study with a middle-term follow-up, the Willis covered stent was used safely and effectively to occlude recurred aneurysms after coiling. Longer-term follow-up and additional clinical experience are needed to fully determine the safety and efficacy of the device.

A new covered stent designed for intracranial vasculature: application in the management of pseudoaneurysms of the cranial internal carotid artery

BACKGROUND AND PURPOSE

The management of intracranial pseudoaneurysms is controversial. The purpose of this study was to provide a preliminary evaluation of the clinical efficacy of a Willis covered stent specially designed for the intracranial vasculature in the management of a pseudoaneurysm of the cranial internal carotid artery (CICA).

MATERIALS AND METHODS

Eight patients with pseudoaneurysms of the CICA were treated with use of the Willis covered stent. The flexibility of the entire stent system was gauged from the resistance met when reaching the target lesion and was categorized as no resistance, no apparent resistance, or resistance that could be overcome. The apposition of the Willis stent after deployment was scored as excellent with no endoleak, good with a small endoleak, or bad with an apparent endoleak. Follow-up angiography was performed 3 to 12 months after placement of the stent, and angiographic assessments were categorized as endoleak, stenosis of the covered segment of vessel, or occlusion of parent arteries. Follow-up clinical evaluations were also performed, and outcomes were graded as full recovery, improvement, unchanged, and aggravation.

RESULTS

Endovascular treatment was technically successful in all aneurysms without procedural-related complications, and all of the stents were easily navigated to the targeted lesions in the CICA. Complete resolution of the pseudoaneurysm was observed in 6 patients immediately after the procedure, and a minimal endoleak into the aneurysm persisted in 2 patients. No morbidity or mortality and no technical adverse event occurred. A follow-up angiogram confirmed complete reconstruction of the internal carotid artery, with no recurrent aneurysmal filling and no occurrence of stenosis in the area of the stent. By the final follow-up visit, 4 patients had fully recovered, 3 had improved, and 1 patient's condition was unchanged.

CONCLUSION

On the basis of our preliminary experience, the Willis covered stent specially designed for the intracranial vasculature can manage a CICA pseudoaneurysm safely and effectively, but longer follow-up and expanded clinical trials are needed.

Endovascular treatment of giant or very large intracranial aneurysms with different modalities: an analysis of 20 cases

INTRODUCTION

The aim of this retrospective study was to evaluate the clinical efficacy and limitations of different endovascular modalities in the treatment of very large and giant intracranial aneurysms.

METHODS

A group of 20 patients with very large and giant intracranial aneurysms treated by endovascular approaches were retrospectively analyzed. Of the 20 patients, 9 had been treated by parent artery occlusion, 8 by coil embolization, and 3 with an intracranial covered stent. Two recurrent aneurysms initially treated with coil embolization were retreated with an intracranial covered stent. Patients were followed for 9-83 months after the procedure.

RESULTS

Endovascular treatment was technically feasible in all 20 patients. One patient died 7 days after the procedure from rebleeding caused by incomplete aneurysmal occlusion. Immediate postprocedural angiograms showed that complete occlusion was achieved in 11 aneurysms, subtotal occlusion in 7, and incomplete occlusion in 2. The final angiographic results in the other 19 surviving patients confirmed complete occlusion of 15 aneurysms, subtotal occlusion in 3, and incomplete occlusion in 1. Clinical evaluations performed at the final follow-up visit showed an excellent outcome in 11 patients and a good outcome in 8.

CONCLUSION

Endovascular treatment of giant intracranial aneurysms with coil embolization is often associated with a low complete occlusion rate and a high recanalization rate, and parent artery occlusion remains a practical option in selected patients. Based on our limited experience, the use of an intracranial covered stent appears to be a relatively simple and safe procedure for occluding very large and giant aneurysms while still maintaining the patency of the parent artery.