Objective To discuss the effects of applying electric heating pattern instrument in experimental teaching of fixed partial denture technology.Methods Totally 98 prosthodontic undergraduates of 2008 and 2009 grades were selected in this study； 46 students of 2008 grade were taken as control group and 52 students of 2009 grade were taken as experimental group.Students in experimental group made wax patterns with electric heating pattern instruments to melt inlay wax while those in control group made wax patterns with instruments heated by alcohol lamps.Teaching effects were evaluated by experimental test scores and questionnaires.Results Test scores of experimental group were (22.6± 1.8),obviously higher than those of (22.6-± 1.8) in control group (P ＜ 0.05).Satisfaction degree of experimental group were increased significantly compared with that of control group based on the resuits of questionnaire.Conclusions Applying electric heating pattern instrument in making wax patterns in experimental teaching of fixed partial denture technology is easy to operate and can improve the quality of wax pattern and working efficiency as well as enhance students' confidence,therefore it is worthy further spreading.

Objective:To explore the degradation property of novel magnesium alloy stents in Bama mini-pig models of carotid artery stenosis, and evaluate the feasibility of observing their dynamic and continuous process by high-resolution C-arm CT.Methods:Twelve Bama mini-pigs were selected; carotid artery stenosis models were established by large balloon over-dilation and high-fat and high-salt diet in Bama pigs; 24 weeks after that, self-made braided degradable magnesium alloy stents were inserted into the carotid artery stenosis models (confirmed by DSA) by balloon dilation. Degrees of stent patency and in-stent restenosis were examined by DSA immediately after procedure and on the 30 th, 60 th and 90 th d of procedure. Four experimental pigs were sacrificed on the 30 th, 60 th and 90 th d of procedure, respectively; the degradation property of the novel magnesium alloy stents was observed according to results of high-resolution C-arm CT in the inserted-stent areas and staining results of specimens in the stenosis areas, and stent imaging features during degradation were summarized. Results:Twelve Bama mini-pig models of carotid artery stenosis were established and 12 magnesium alloy stents were successfully inserted with a technical success rate of 100%. Both immediate postoperative and follow-up angiography showed patency of the vascular lumens without obvious in-stent restenosis. High-resolution C-arm CT and pathological examination showed homogeneous stent lumens and clear delineation of the stent meshes, with slightly degraded stent on the 30 th d of procedure; the stent lumen was blurred and some magnesium alloy wires were fractured with developed degradation of the stent on the 60 th d of procedure; and the stent meshes and stent strut could not be visualized due to severe degradation of the stent on the 90 th d of procedure. Conclusion:Magnesium alloy degradable stent is almost completely degraded within 90 th d of procedure in Bama mini-pig models of carotid artery stenosis, and high-resolution C-arm CT can be used to dynamically monitor the degradation of the stent in vivo.

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 establish the carotid artery in-stent restenosis (ISR) models in Bama pigs after Neuroform EZ stent implantation, and observe and summarize their imaging and pathological characteristics.Methods:Thirteen healthy Bama pigs from Guangxi Province were chosen; carotid artery intima was injuried by balloon over-dilation; Neuroform EZ stents were implanted at the vascular injury sites to establish ISR models. Blood flow at areas accepted carotid artery stent implantation in Bama pigs was monitored by bedside color ultrasound every 2 weeks after surgery; once hemodynamic changes (acceleration or deceleration of the blood flow) in stents were detected, DSA, intravascular ultrasound (IVUS), optical coherence tomography (OCT) and high-resolution MRI (HR-MRI) were performed immediately. Bama pigs were then sacrificed and tissues at the stents were taken; HE staining was used to observe the pathological changes.Results:Thirteen Neuroform EZ stents were implanted into 13 Bama pigs after balloon over-dilation of the unilateral carotid arteries with a technical success rate of 100%. Hemodynamic changes in stents were detected in these 13 pigs (10 with acceleration and 3 with deceleration) at (12.46±3.57) weeks after stenting (ranged from 6-18 weeks); ISR of different degrees was found in all these 13 pigs by DSA with an average stenosis rate of (44.23±9.39)%. IVUS and OCT found that the main body of stents was covered by hyperplastic intima, and thickened intima resulted in local lumen stenosis; and obvious vascular wall enhancement in these lumens was shown on HR-MRI. HE staining showed rupture of intravascular internal elastic lamina and severely arterial intimal hyperplasia;and the hyperplastic intima was mainly composed of smooth muscle cells.Conclusion:Carotid artery ISR models in Bama pigs can be accurately and reliably established at approximately 12 weeks by tearing endovascular intima with balloon over-dilation and implanting Neuroform EZ stents, and multiple imaging and pathology methods confirm that ISR is caused by hyperplastic intima.

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.

Objective:To investigate the application value of optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in evaluating flow diverter (FD) apposition and endothelialization in aneurysm animal models, and analyze the effect of incomplete stent apposition (ISA) on aneurysm lumen healing and stent endothelialization.Methods:Lateral common carotid artery aneurysm models in swines were established by surgical method and then FD was implanted. Immediately after surgery, OCT and IVUS were used to evaluate the locations and degrees of ISA, and difference between these 2 methods in evaluating FD apposition was compared. DSA was performed at 12 weeks after surgery to evaluate the aneurysm occlusion (Kamran grading) and stent patency. OCT and IVUS were used again to observe the stent endothelial situation; by comparing with histopathologic results, effect of ISA on aneurysm healing and stent endothelialization was analyzed.Results:Lateral common carotid artery aneurysm models in 6 swines were established, and 6 Tubridge FDs were successfully implanted. Compared with IVUS (3 stents, 4 locus), OCT could detect more ISA (6 stents, 14 locus); and the vascular diameter change area (7 locus), aneurysm neck area (4 locus) and the head and tail of FD (3 locus) were the main sites of FD malapposition; average distance between stent wire and vessel wall was (560.14±101.48) μm. At 12 weeks after surgery, DSA showed that 1 patient had a little residual contrast agent at the aneurysm neck (Kamran grading 3), and the remaining 5 had complete aneurysm occlusion (Kamran grading 4). One FD had moderate lumen stenosis, and the other 5 FDs had lumen patency. OCT indicated mostly disappeared acute ISA; ISA proportion decreased to 21.4 % (3/14), including 2 in the aneurysm neck and 1 in the partial stent. Histopathological results showed bare stent woven silk, without obvious endothelial coverage; in one FD with luminal stenosis, intimal hyperplasia was mainly composed of vascular smooth muscle cells.Conclusion:In carotid artery aneurysm model with FD implantation, OCT can detect more ISA than IVUS; most acute ISA have good outcome at 12 th week of follow-up, while severe ISA can cause delayed FD endothelialization and delayed aneurysm occlusion.

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.