Objective:To investigate the impact of flow diverter (FD) malapposition at the aneurysm neck on clinical outcomes and complications of intracranial aneurysms, and identify the influencing factors for intraoperative FD malapposition.Methods:A retrospective study was performed; 153 patients with unruptured saccular aneurysms at the C4-C7 segments of the internal carotid artery accepted single FD implantation at Department of Interventional Radiology, First Affiliated Hospital of Zhengzhou University from June 2022 to March 2024 were chosen. Intraoperative high-resolution C-arm CT was utilized to assess FD apposition at the aneurysm neck. (1) Based on FD apposition at the aneurysm neck as shown, these 153 patients were divided into a malapposition group ( n=23, including 16 patients with malapposition being identified as residual malapposition after intraoperative corrective measures such as microwire massage and 7 patients with malapposition being newly detected in this study) and a complete apposition group ( n=130). Perioperative and follow-up complications were recorded. Clinical outcomes were assessed using modified Rankin Scale (mRS) at the final follow-up (mRS score of 0-2 as favorable outcome), and angiographic outcomes were evaluated by DSA at the final follow-up. Differences in clinical and angiographic outcomes and complication rate were compared between the malapposition group and complete apposition group. (2) Based on FD apposition at the aneurysm neck as shown, these 153 patients were divided into an intraoperative malapposition group ( n=74, including 67 patients with malapposition being detected during surgery and 7 patients with malapposition being newly detected in this study) and an intraoperative complete apposition group ( n=79). Univariate analysis was performed to compare the clinical variables between the intraoperative malapposition group and intraoperative complete apposition group; multivariate Logistic regression was further employed to identify the independent influencing factors for FD malapposition at the aneurysm neck. Results:(1) Four patients (all from the malapposition group) developed perioperative acute in-stent thrombosis. Nine patients experienced ischemic or hemorrhagic stroke during the follow-up, including 6 from the malapposition group and 3 from the complete apposition group; the complication rate in the malapposition group (6/23, 26.1%) was significantly higher than that in the complete apposition group (3/130, 2.3%) during the follow-up ( P<0.05). At the final follow-up, 2 patients (both from the malapposition group) had poor clinical outcome, while the remaining 151 patients had favorable outcome. Proportion of patients with favorable outcome between the two groups was statistically different (91.3%[21/23] vs. 100.0%[130/130], P<0.05). Delayed occlusion was detected in 46 patients (12 from the malapposition group and 34 from the complete apposition group) at the final angiographic follow-up. FD restenosis/re-occlusion was noted in 10 patients, including 6 from the malapposition group and 4 from the complete apposition group. Significant difference in delayed occlusion rate (52.2%[12/23] vs. 26.2%[34/130]) and long-term in-stent stenosis/occlusion rate (26.1%[6/23] vs. 3.1%[4/130]) was observed between the two groups ( P<0.05). (2) Significant difference in aneurysm neck diameter, FD angulation, parent artery stenosis, parent artery diameter ratio>1.2, and presence of branching vessels at the FD implantation site was noted between the intraoperative complete apposition group and intraoperative malapposition group ( P<0.05). Multivariate Logistic regression indicated that aneurysm neck diameter ( OR=1.431, 95% CI: 1.096-1.868, P=0.008), parent artery diameter ratio>1.2 ( OR=2.199, 95% CI: 1.083-4.463, P=0.029), and FD angulation ( OR=1.019, 95% CI: 1.002-1.036, P=0.027) were independent influencing factors for FD malapposition at the aneurysm neck. Conclusion:In FD implantation for intracranial aneurysms, FD malapposition at the aneurysm neck adversely affects delayed occlusion rate and complication rate; aneurysms with wider aneurysm neck diameter, parent artery diameter ratio>1.2, and greater FD angulation are trend to have FD malapposition at the aneurysm neck.

Objective:To investigate and summarize the imaging and pathological features of non-acute occlusion following flow diverter (FD) implantation in animal models.Methods:Four experimental pigs (experimental group) that experienced non-acute occlusion (occlusion time exceeding 24 hours) within the FD stent implanted in the common carotid artery, and 19 pigs (control group) that did not experience stent occlusion during the same period were involved. Using an interventional approach under digital subtraction angiography (DSA), the 4 occluded FD lumens were mechanically opened. Optical coherence tomography (OCT), intravascular ultrasound (IVUS) and histopathological examinations were performed to evaluate the intraluminal composition and characteristics of the occlusive tissues. These findings were compared with non-occluded FD stents to summarize the imaging and pathological changes within the occluded FD lumen.Results:The occlusion times of the FD stents in the 4 experimental pigs were 16 weeks, 20 weeks, 20 weeks, and 24 weeks postoperatively. All occluded stents were successfully recanalized under DSA, with a technical success rate of 4/4. Among the 19 non-occluded FD stents, OCT and IVUS revealed uniform (16 stents) or non-uniform (3 stents) neointimal coverage of the stent struts, presenting as homogeneous high/slightly high signal intensity or medium echogenicity. Histopathological examination indicated that the neointima was primarily composed of smooth muscle cells and a small amount of fibrous connective tissues. In contrast, the 4 occluded FD stents demonstrated excessive neointimal proliferation and plaque formation, leading to luminal loss, as shown by OCT and IVUS. The occlusion tissues predominantly presented as homogeneous high signal intensity with weak attenuation (fibrous plaques) on OCT, with some regions showing blurred low signal intensity and strong attenuation (lipid plaques). IVUS presented homogeneous echogenicity (fibrous plaques) and hypoechogenic zones (lipid plaques). Histopathological examination showed that the occlusion tissues mainly consisted of smooth muscle cells, fibrous connective tissues, and lipids, accompanied by numerous foam cells and a minor presence of inflammatory cells.Conclusions:Histopathological examinations confirm that non-acute occlusion of FD is mainly caused by excessive hyperplasia of intima along with the formation of fibrous plaques and lipid plaques. OCT and IVUS have typical finding in imaging that can assist in determining the cause of stent occlusion as well as the lesion's nature, thereby providing crucial guidance for subsequent clinical treatment and drug selection.

Objective:To investigate and summarize the imaging and pathological features of non-acute occlusion following flow diverter (FD) implantation in animal models.Methods:Four experimental pigs (experimental group) that experienced non-acute occlusion (occlusion time exceeding 24 hours) within the FD stent implanted in the common carotid artery, and 19 pigs (control group) that did not experience stent occlusion during the same period were involved. Using an interventional approach under digital subtraction angiography (DSA), the 4 occluded FD lumens were mechanically opened. Optical coherence tomography (OCT), intravascular ultrasound (IVUS) and histopathological examinations were performed to evaluate the intraluminal composition and characteristics of the occlusive tissues. These findings were compared with non-occluded FD stents to summarize the imaging and pathological changes within the occluded FD lumen.Results:The occlusion times of the FD stents in the 4 experimental pigs were 16 weeks, 20 weeks, 20 weeks, and 24 weeks postoperatively. All occluded stents were successfully recanalized under DSA, with a technical success rate of 4/4. Among the 19 non-occluded FD stents, OCT and IVUS revealed uniform (16 stents) or non-uniform (3 stents) neointimal coverage of the stent struts, presenting as homogeneous high/slightly high signal intensity or medium echogenicity. Histopathological examination indicated that the neointima was primarily composed of smooth muscle cells and a small amount of fibrous connective tissues. In contrast, the 4 occluded FD stents demonstrated excessive neointimal proliferation and plaque formation, leading to luminal loss, as shown by OCT and IVUS. The occlusion tissues predominantly presented as homogeneous high signal intensity with weak attenuation (fibrous plaques) on OCT, with some regions showing blurred low signal intensity and strong attenuation (lipid plaques). IVUS presented homogeneous echogenicity (fibrous plaques) and hypoechogenic zones (lipid plaques). Histopathological examination showed that the occlusion tissues mainly consisted of smooth muscle cells, fibrous connective tissues, and lipids, accompanied by numerous foam cells and a minor presence of inflammatory cells.Conclusions:Histopathological examinations confirm that non-acute occlusion of FD is mainly caused by excessive hyperplasia of intima along with the formation of fibrous plaques and lipid plaques. OCT and IVUS have typical finding in imaging that can assist in determining the cause of stent occlusion as well as the lesion's nature, thereby providing crucial guidance for subsequent clinical treatment and drug selection.

Objective:To investigate the impact of flow diverter (FD) malapposition at the aneurysm neck on clinical outcomes and complications of intracranial aneurysms, and identify the influencing factors for intraoperative FD malapposition.Methods:A retrospective study was performed; 153 patients with unruptured saccular aneurysms at the C4-C7 segments of the internal carotid artery accepted single FD implantation at Department of Interventional Radiology, First Affiliated Hospital of Zhengzhou University from June 2022 to March 2024 were chosen. Intraoperative high-resolution C-arm CT was utilized to assess FD apposition at the aneurysm neck. (1) Based on FD apposition at the aneurysm neck as shown, these 153 patients were divided into a malapposition group ( n=23, including 16 patients with malapposition being identified as residual malapposition after intraoperative corrective measures such as microwire massage and 7 patients with malapposition being newly detected in this study) and a complete apposition group ( n=130). Perioperative and follow-up complications were recorded. Clinical outcomes were assessed using modified Rankin Scale (mRS) at the final follow-up (mRS score of 0-2 as favorable outcome), and angiographic outcomes were evaluated by DSA at the final follow-up. Differences in clinical and angiographic outcomes and complication rate were compared between the malapposition group and complete apposition group. (2) Based on FD apposition at the aneurysm neck as shown, these 153 patients were divided into an intraoperative malapposition group ( n=74, including 67 patients with malapposition being detected during surgery and 7 patients with malapposition being newly detected in this study) and an intraoperative complete apposition group ( n=79). Univariate analysis was performed to compare the clinical variables between the intraoperative malapposition group and intraoperative complete apposition group; multivariate Logistic regression was further employed to identify the independent influencing factors for FD malapposition at the aneurysm neck. Results:(1) Four patients (all from the malapposition group) developed perioperative acute in-stent thrombosis. Nine patients experienced ischemic or hemorrhagic stroke during the follow-up, including 6 from the malapposition group and 3 from the complete apposition group; the complication rate in the malapposition group (6/23, 26.1%) was significantly higher than that in the complete apposition group (3/130, 2.3%) during the follow-up ( P<0.05). At the final follow-up, 2 patients (both from the malapposition group) had poor clinical outcome, while the remaining 151 patients had favorable outcome. Proportion of patients with favorable outcome between the two groups was statistically different (91.3%[21/23] vs. 100.0%[130/130], P<0.05). Delayed occlusion was detected in 46 patients (12 from the malapposition group and 34 from the complete apposition group) at the final angiographic follow-up. FD restenosis/re-occlusion was noted in 10 patients, including 6 from the malapposition group and 4 from the complete apposition group. Significant difference in delayed occlusion rate (52.2%[12/23] vs. 26.2%[34/130]) and long-term in-stent stenosis/occlusion rate (26.1%[6/23] vs. 3.1%[4/130]) was observed between the two groups ( P<0.05). (2) Significant difference in aneurysm neck diameter, FD angulation, parent artery stenosis, parent artery diameter ratio>1.2, and presence of branching vessels at the FD implantation site was noted between the intraoperative complete apposition group and intraoperative malapposition group ( P<0.05). Multivariate Logistic regression indicated that aneurysm neck diameter ( OR=1.431, 95% CI: 1.096-1.868, P=0.008), parent artery diameter ratio>1.2 ( OR=2.199, 95% CI: 1.083-4.463, P=0.029), and FD angulation ( OR=1.019, 95% CI: 1.002-1.036, P=0.027) were independent influencing factors for FD malapposition at the aneurysm neck. Conclusion:In FD implantation for intracranial aneurysms, FD malapposition at the aneurysm neck adversely affects delayed occlusion rate and complication rate; aneurysms with wider aneurysm neck diameter, parent artery diameter ratio>1.2, and greater FD angulation are trend to have FD malapposition at the aneurysm neck.

Objective:To summarize the imaging features of severe unilateral transverse sinus and sigmoid sinus thromboses, and evaluate the efficacy and safety of intravascular interventional therapy in them.Methods:Thirty-seven patients with severe unilateral transverse sinus and sigmoid sinus thromboses clinically mainly manifested as intracranial hypertension and accepted endovascular intervention in Department of Interventional Radiology, First Affiliated Hospital of Zhengzhou University from June 2012 to September 2022 were chosen; their clinical data were retrospectively analyzed and imaging features were summarized. Short-term efficacy was evaluated according to blood flow restoration degrees and pressure gradient reduction in the occlusive sinus and modified neurological symptoms before and after endovascular intervention. Hospitalized complications were observed; safety and long-term efficacy were evaluated according to postoperative clinical follow-up and imaging results 6-12 months after endovascular intervention.Results:(1) Preoperative brain MRI and (or) CT showed different degrees of swelling of the brain tissues, with the affected side as the target; mixed signals/density shadow could be seen in the blocked transverse sinus and sigmoid sinus; venous cerebral infarction or post-infarction cerebral hemorrhage could be combined in some patients. MRV, CTV and DSA showed poor or completely occluded transverse sinus and sigmoid sinus while normal in the contralateral side; obvious thrombus filling-defect was observed in the occluded venous sinus after mechanical thrombolysis. (2) Occlusive sinus blood flow was restored in all patients after endovascular intervention, and pressure gradient of the occlusive segment decreased from (16.6±3.3) mmHg before to (2.8±0.8) mmHg after endovascular intervention. Before discharge, clinical symptoms of all patients were significantly improved (modified Rankin scale [mRS] scores of 0 in 30 patients, 1 in 5 patients, 2 in 1 patient and 3 in 1 patient), and 2 patients had unilateral limb movement disorder (muscle strength grading III and IV, respectively). All patients received clinical follow-up for (9.6±3.0) months. At the last follow-up, neurological function obviously improved compared with that before endovascular intervention, without new neurosystem-related symptoms (mRS scores of 0 in 30 patients, 1 in 6, and 2 in 1 patient). In 34 patients received MRV or DSA follow-up, 28 had complete recanalization of occlusive sinus and 6 had partial recanalization, without obvious stenosis or recurrent occlusion.Conclusions:Severe unilateral transverse sinus and sigmoid sinus thrombosis can cause local intracranial venous blood stasis, and then cause "increased regional venous sinus pressure", which is manifested as unilateral brain tissue swelling and even venous cerebral infarction or post-infarction cerebral hemorrhage. Early diagnosis and endovascular intervention can obviously improve the prognosis of these patients, enjoying good safety.

Methods:From February 2018 to January 2022, the clinical data of 1 123 patients who underwent Starclose vascular closure device, Angio-Seal and Exoseal vascular occlusion devices and Perclose ProGlide vascular suture device at femoral artery puncture hemostasis after neuro-intervention, in the Department of Interventional Radiology (Eastern District), The First Affiliated Hospital of Zhengzhou University, were retrospectively analyzed. The patients were divided into three groups based on the intervention method: the closure group (Starclose, n=271), the occlusion group (Angio-Seal, n=327 and Exoseal, n=352) and the suture group (ProGlide, n=173). Next, the hemostatic efficacy and complications associated with the three devices were analyzed and compared. Additionally, regression analysis was conducted to identify any relevant factors that may contribute to complications. Results:Three vascular hemostatic devices demonstrated effective hemostasis and the success rate were 92.6% in the closure group (Starclose), 93.4% in the occlusion group (Angio-Seal 93.0% and Exoseal 93.8%) and 89.6% in the suture group (ProGlide). There was no statistically significant difference( χ2=3.026, P=0.388). Single or multiple complications were observed in 102 patients (9.1%), including local oozing (16 cases in the closure group, 39 cases in the occlusion group, 13 cases in the suture group), local hematoma (14 cases in the closure group, 31 cases in the occlusion group, 11 cases in the suture group), pseudoaneurysm (13 cases in the closure group, 35 cases in the occlusion group, 10 cases in the suture group), local infection (2 cases in the closure group, 3 cases in the occlusion group, 1 case in the suture group). There were no statistically significant differences ( P>0.05). Moreover, serious complications such as femoral artery occlusion, embolus shedding and permanent nerve injury weren′t observed in the three groups. Multivariate logistic regression analysis revealed that overweight ( OR=1.562,95% CI 1.023—2.385, P=0.039), femoral artery with calcified plaque ( OR=1.934,95% CI 1.172-3.189, P=0.010), combined use of multiple antiplatelet drugs ( OR=1.769,95% CI 1.103—2.839, P=0.018), use of an 8F sheath( OR=2.824,95% CI 1.406—5.671, P=0.004) and the operator′s proficiency ( OR=0.508,95% CI 0.328—0.788, P=0.002) were the independent factors influencing complications, of which the first four were identified as risk-promoting factors for complications while the operator′s rich experience and high proficiency were the protective factors. Conclusions:Three hemostatic devices demonstrate effective hemostasis and comparable rates of complications at femoral artery puncture hemostasis after neuro-intervention. Overweight, femoral artery with calcified plaque, combined use of multiple antiplatelet drugs, use of an 8 F sheath and the operator′s proficiency were independent factors influencing complications.Ojective:To investigate the efficacy and complications associated with vascular suture, closure and occlusion devices at femoral artery puncture hemostasis after neuro-intervention.

Objective:To assess the efficacy and safety of overlapping braided carotid artery stent (Wallstent) implantation in large extracranial internal carotid artery aneurysms (15 mm≤diameter<25 mm) and giant ones (diameter≥25 mm).Methods:A retrospective study was performed; the clinical data of 23 patients with large or giant extracranial internal carotid artery aneurysms accepted overlapping Wallstent stent implantation in Department of Interventional Radiology, First Affiliated Hospital of Zhengzhou University from August 2015 to June 2023 were collected. Immediately after implantation, DSA was used to evaluate the retention of contrast agent within the aneurysms and high-resolution C-arm CT (HR-CBCT) was used to detect the apposition between the two stents and between the stents and inner wall of the blood vessel. Perioperative complications were recorded. Clinical follow-up was performed bi-monthly via outpatient visits or telephone, and modified Rankin scale (mRS) was used to assess the prognoses (mRS scores of 0-2 as good prognosis) at the last follow-up; aneurysm occlusion was evaluated in a 6-month follow-up by DSA and in-stent restenosis in a final imaging follow-up by DSA or CTA according to the OKM grading. Results:Twenty-two patients had successful overlapping implantation of 2 Wallstent stents; blood flow was restricted in one patient due to carotid artery dissection at the distal end of the aneurysm during stent implantation and restored after a Neuroform EZ stent and 2 Wallstent stent implantation from the distal-proximal lesion; technical success rate of 95.7% (22/23) was obtained. DSA immediately after implantation showed obvious contrast medium retention in all aneurysms. HR-CBCT indicated good stent apposition in 21 patients and mild incomplete stent apposition in 2. Clinical follow-up was finished in 23 patients, ranged 6-31 months (mean 11.5±6.3 months); all patients had good prognosis at the last follow-up. Imaging follow-up, including at least once DSA, was conducted for all patients, with intervals ranging from 6 to 15 months (mean 10.4±3.4 months); DSA 6 months after implantation showed complete aneurysm occlusion in 19 patients (OKM grading D) and a bit of residual contrast in 4 patients (OKM grading C); final imaging follow-up (DSA in 2 and CTA in 21) revealed in-stent stenosis in 2 patients (stenosis rates of 51% and 87%) with obvious improved stenosis after balloon angioplasty and patent stents in 21 patients without evidence of aneurysm opacification.Conclusion:Overlapping braided carotid artery stent (Wallstent) implantation is an effective and safe approach for managing large or giant extracranial carotid artery aneurysms.

Objective:To explore the stent apposition and safety of Neuroform EZ and Enterprise 2 stents in treatment of symptomatic intracranial atherosclerotic stenosis (sICAS), and their influencing factors for in-stent restenosis.Methods:A total of 143 sICAS patients treated by Enterprise 2 stents (implanted 143 Enterprise 2 stents, E2 group) and 202 patients treated by Neuroform EZ stents (implanted 202 Neuroform EZ stents, EZ group) were selected from Department of Interventional Radiology, First Affiliated Hospital of Zhengzhou University from January 2017 to January 2022. Stent apposition was evaluated based on reconstructive images of high-resolution flat detector CT. The complications 30 d after surgery and during 6-24 months of follow-up were recorded. Based on DSA or CTA 6 months after surgery, the patency of the two stents was evaluated. Univariate analysis and multivariate Logistic regression analysis were used to determine the independent risk factors for in-stent restenosis.Results:(1) Forty-nine patients had incomplete stent apposition (ISA) after stent release: 24 patients with ISA in E2 group (16.8%, 24/143; 15 of type I and 9 of type II) and 25 with ISA in the EZ group (12.4%, 25/202, 11 of type I and 14 of type II) were found, without statistical difference ( χ 2=1.334, P=0.248); however, ISA incidence in the EZ group (19.0% and 10.3%) was significantly lower than that in the E2 group (41.4% and 25.6%) when the diameter ratio of anterior and posterior vessels of the stenosis lesions≥1.30 or the angle of stent≥75° ( χ 2=4.228, P=0.040; χ 2=4.531, P=0.033). (2) Within 30 d of stenting, 17 patients developed neurological dysfunction-related complications: 8 patients in EZ group and 9 in E2 group were noted, without significant difference ( P=0.324). Clinical follow-up was obtained in 317 patients, and 20 patients developed long-term stroke associated with responsible lesion vessels: 12 patients in EZ group and 8 in E2 group were noted, without significant difference ( P=0.995). (3) Totally, 298 patients received imaging follow-up 6 months after surgery, and 65 patients developed in-stent restenosis: 36 patients in EZ group and 29 in E2 group were noted, without significant difference ( χ 2=0.309, P=0.578). Multivariate Logistic regression analysis showed that diabetes ( OR=2.714, 95% CI: 1.437-5.126, P=0.002), stent apposition ( OR=3.435, 95% CI: 1.223-9.652, P=0.019), lesion stenosis length ( OR=1.176, 95% CI: 1.065-1.300, P=0.001) and immediate postoperative residual stenosis ( OR=1.038, 95% CI: 1.004-1.074, P=0.029) were independent influencing factors for in-stent restenosis. Conclusions:Enterprise 2 and Neuroform EZ stents have high stent apposition and safety in sICAS treatment, but in cases with large diameter ratio of the anterior and posterior vessels of the stenosis lesions (diameter ratio≥1.30) or large angle of the stent (≥75°), Neuroform EZ stent has better stent apposition. Patients with diabetes, ISA, long lesion stenosis or high residual stenosis may trend to have in-stent restenosis.

Objective:To compare the efficacies of Enterprise 1 stent and Enterprise 2 stent in treating symptomatic intracranial atherosclerotic stenosis (ICAS).Methods:From January 2018 to April 2021, 76 patients with symptomatic ICAS treated by Enterprise 2 stent (implanting Enterprise 2 stents, EP2 group) and 52 patients with symptomatic ICAS treated with Enterprise 1 stent (implanting Enterprise 1 stents, EP1 group) were chosen from Department of Interventional Radiology, First Affiliated Hospital of Zhengzhou University. DSA was performed immediately after stent implantation and residual vascular stenosis rate was analyzed and compared between the 2 groups. Stent apposition of the 2 groups were evaluated according to reconstruction images of high-resolution flat detector CT; patients were divided into incomplete stent apposition (ISA) group and complete stent apposition group, accordingly; their clinical data were compared. Multivariate Logistic regression was used to analyze the independent influencing factors for ISA. Incidences of perioperative complications and short-term in-stent restenosis (6 months after implantation) in the EP2 group and EP1 group were observed.Results:Intracranial stent was successfully implanted in all patients, with technical success rate of 100%. Significant difference was noted in EP1 group between pre-implanted vascular stenosis rate (80.85±12.14)% and post-implanted residual vascular stenosis rate ([21.44±8.11]%, P<0.05); significant difference was noted in EP2 group between pre-implanted vascular stenosis rate (81.83±12.85)% and post-implanted residual vascular stenosis rate ([21.53±7.76]%, P<0.05); no significant difference was noted in pre-implanted vascular stenosis rate, post-implanted residual stenosis rate, or angles of stent between EP1 group and EP2 group ( P>0.05). According to high-resolution flat detector CT scan, the ISA incidence in EP2 group (10.5%) was significantly lower than that in EP1 group (25.0%, P<0.05); compared with the complete stent apposition group, the ISA group had significantly higher post-implanted residual stenosis rate, higher proportions of patients with calcification at the stenosis, larger angles of stent, higher diameter ratio of anterior and posterior vessels of the stenosis lesions, and lower proportion of patients with Enterprise 2 stent implantation ( P<0.05). Multivariate Logistic regression analysis showed that the angle of stents, diameter ratio of anterior and posterior vessels of the stenosis lesions and Enterprise 2 stent implantation were independent influencing factors for stent apposition; and Enterprise 2 stent implantation was an proactive factor for complete stent apposition. Perioperative complication rate showed significant difference between EP1 group and EP2 group (1.3% vs. 7.7%, P<0.05). Short-term in-stent restenosis between EP2 group and EP1 group was significantly different (26.1% vs. 7.0%, P<0.05). Conclusion:Compared with Enterprise 1 stent, Enterprise 2 stent has better apposition, higher safety, and lower incidence of short-term in-stent restenosis, enjoying clinical application value in treating symptomatic ICAS.

Objective:To establish the common carotid artery aneurysm models of Wallstent double stent overlapping implantation in miniature pigs, and evaluate the safety and effectiveness of this procedure by observing the imaging and pathological changes.Methods:Sidewall aneurysm and fusiform aneurysm models in Bama miniature pigs were established surgically and 2 Wallstent stents were overlapped and implanted in situ. Aneurysm healing immediately after surgery and during 8 weeks of follow-up were evaluated according to 2D-DSA by O'Kelly-Marotta (OKM) grading scale and Kamran scale; degrees of stent adhesion immediately after surgery and status of stent endothelialization and aneurysm healing at 2, 4, and 8 weeks after surgery were observed by high resolution C-arm CT(HR-CBCT) and optical coherence tomography (OCT); and the changes of stent endothelialization were evaluated by comparing the HR-CBCT and OCT results with histopathology at 8 weeks after surgery. Perioperative adverse events were recorded.Results:After successful establishment of common carotid artery aneurysm models (including 4 sidewall aneurysms and 4 fusiform aneurysms with average diameter of [11.0±2.8] mm) in 8 miniature pigs, a total of 16 Wallstent stents (2 in each aneurysm) were implanted across the aneurysmal neck, with a technical success rate of 100%. No serious complications such as acute stent thrombosis, or aneurysm rupture and bleeding were observed in the perioperative period. The 2D-DSA immediately after surgery showed obvious intracranial contrast agent retention in 6 patients (1 patient in grading 1, 3 in grading 2, and 2 in grading 3) and aneurysm occlusion in 2 patients (grading 4). Eight weeks after follow-up, all 8 aneurysms had complete occlusions (grading 4); and 2 experimental pigs had in-stent restenosis, with stenosis rates of 52% and 67%, respectively. HR-CBCT and OCT immediately after surgery and during follow-up indicated that the stent metal braid was gradually covered by proliferating intima, with disappeared aneurysm. The cause of in-stent restenosis in 2 experimental pigs was local intima hyperplasia resulted from poor stent adhesion, and pathological findings indicated that the intima hyperplasia was mainly composed of smooth muscle cells and fibrous connective tissues.Conclusion:In animal models, Wallstent stent overlapping implantation is safe and effective in common carotid aneurysms, but intraoperative adverse adhesion of overlapping stent should be avoided.