Application of dual Willis covered stents in the management of large fusiform carotid aneurysms in a canine model

Covered Stent Treatment for Direct Carotid-Cavernous Fistulas: A Meta-Analysis of Efficacy and Safety Outcomes

BACKGROUND

Direct carotid-cavernous fistulas (dCCFs) involve the abnormal shunting of blood between the internal carotid artery and the cavernous sinus. The use of covered stents (CSs) has been reported for the treatment of complex carotid artery lesions. However, the efficacy and safety of CS treatment for dCCFs remain controversial. Thus, we performed a systematic review and meta-analysis to evaluate these efficacy and safety endpoints.

METHODS

A systematic literature review was performed by comprehensively searching the Medline, Embase, and Web of Science databases to identify studies that were related to CS treatment for dCCFs. Then, a meta-analysis was conducted to pool the efficacy and safety outcomes from these studies based on perioperative and follow-up data.

RESULTS

Fourteen noncomparative studies enrolling 156 patients with 160 dCCFs met the inclusion criteria. When analyzing perioperative outcomes, the technical success rate was 98.5% [95% confidence interval (CI), 0.948; 1.000], and the immediate complete occlusion rate was 90.9% (95% CI, 0.862; 0.959). Vasospasm and dissection occurred in 32.2% (95% CI, 0.238; 0.463) and 0.1% (95% CI, 0.000; 0.012) of patients, respectively. The in-stent acute thrombus formation rate was 0.1% (95% CI, 0.000; 0.013). Postoperatively, the mortality rate was 0.1% (95% CI, 0.000; 0.013). Based on available follow-up data, the final complete occlusion and parent artery stenosis rates were 99.3% (95% CI, 0.959; 1.000) and 18.6% (95% CI, 0.125; 0.277), respectively.

CONCLUSIONS

CS placement can be used to safely and effectively treat dCCFs. These results provide a reference for future clinical trials.

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.

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.

Closure of an unusual morphology patent ductus arteriosus with a covered stent in a dog

Patent ductus arteriosus (PDA) with unusual morphology was diagnosed in a 3-year-old German shepherd presented for exercise intolerance. Two interventional PDA closure procedures with various Amplatzer devices and one surgical ligation were attempted to close the PDA. However, PDA closure failed with both methods due to the unusual morphology and the severe enlarged ductus ampulla. Therefore, the patient underwent an aortic covered stent placement, and successful closure of the PDA was achieved. Eight months after the procedure, the dog was free of clinical signs and no residual flow was identified through the PDA on transthoracic echocardiography. Moreover, computed tomography angiography demonstrated correct stent positioning, with no evidence of thrombus formation, damage to the stent, nor any aortic wall abnormalities. Aortic covered stent placement is a viable option in dogs with unusual PDA morphology.

Case Report of Late Type IIIb Endoleak with Willis Covered Stent (WCS) and Literature Review

OBJECTIVE

We report a case of late type IIIb endoleak with Willis covered stent (WCS) developed 14 months after endovascular paraclinoid aneurysm repair.

METHODS

A 52-year-old woman presented with episodic headache, caused by a giant paraclinoid aneurysm. She underwent a successful 3.5 x 16mm WCS positioning to treat the aneurysm. Fourteen months later, the patient was admitted with the same symptoms. Digital subtraction angiography examination showed recurrence of the aneurysm, which was similar to the preoperative one. DynaCT (Siemens, Erlangen, Germany) indicated the intact of the metal structure of the stent without migration. Type IIIb endoleak (defect in the graft fabric) was confirmed with a whole aneurysm neck located in the middle part of the stent. The type IIIb endoleak was treated with another WCS (4.0 x 16mm). The immediate digital subtraction angiography imaging indicated that the endoleak disappeared and the aneurysm was completely occluded. Re-examination done 1 year after the second treatment showed a complete exclusion of the aneurysm sac.

CONCLUSIONS

Type IIIb endoleaks can be safely treated by the endovascular positioning of another WCS. Continuous surveillance after endovascular paraclinoid aneurysm repair for intracranial aneurysms is warranted to make ensure the safety of WCS.

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

OBJECTIVE

To report the clinical results and initial clinical experience of endovascular isolation with the Willis covered stent for carotid siphon aneurysms.

METHODS

Between November 2013 and December 2016, a total of 57 patients who presented with carotid siphon aneurysms were treated with the Willis covered stent. Results of the procedures, technical events, and complications were recorded. Clinical and imaging follow-ups were performed at 3 months following the endovascular procedures.

RESULTS

Placement of the Willis covered stent was successful in all patients. Immediate angiography revealed complete exclusion of aneurysms in 48 patients (84%), while endoleak occurred in nine patients (16%). Procedure-related complications occurred in three cases, including displacement of the covered stent in one patient, acute in-stent thrombosis in one patient, and microwire-related intracranial hemorrhage in one patient. Angiographic follow-ups were done in 49 patients, with complete exclusion of aneurysms in 47 patients. Endoleak was present in two patients. No aneurysm recurrence occurred. Forty-four patients showed good parent artery patency, while the other five patients showed mild to moderate asymptomatic in-stent stenosis. During the follow-up period, no ischemic or hemorrhagic event occurred. The modified Rankin Scale scores at follow-up were 0-2 in 56 patients and >2 in one patient.

CONCLUSIONS

The treatment of siphon aneurysms with Willis covered stent implantation resulted in satisfactory clinical outcomes. The Willis covered stent seems safe and feasible for the treatment of siphon aneurysms, which still needs to be confirmed by longer follow-up periods and controlled studies with larger samples.

Efficacy and Safety of Willis Covered Stent for Treatment of Internal Carotid Artery Aneurysms

OBJECTIVE

The purpose of this study was to evaluate the clinical and short-term outcome of patients who underwent covered stent treatment for internal carotid artery aneurysms.

METHODS

Twelve cases patients with internal carotid artery aneurysms were treated with Willis covered stents during the period from December 2010 to January 2016. The guiding catheter was placed as high as possible to facilitate the delivery of the covered stent system.

RESULTS

Covered stent placement was successful in 11 of 12 case patients (91.6%), embolization was successful in 11 of 12 patients (91.6%), the treatment in 1 patient of 12 cavernous aneurysms patients was performed covered stents +ONYX + plastic coil embolization, and the other was used Willis covered stents. The results indicated that only 1 of 12 patients underwent postoperative massive cerebral infarction, but was successfully rescued. The angiographic following-up of patients using covered stent suggested that 12 cases patients were complete occlusion and the parent artery patency. Clinical follow-up results also demonstrated that clinical neurologic symptoms fully recovered in 11 of 12 cases patients, another case improved and were not aggravated in any patient before discharge and had aggravated symptoms.

CONCLUSION

Willis covered stents are effective for treatment of internal carotid artery aneurysms with good safety and short-term outcomes.

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.