Distal Segment Of Stent Research Articles

Pathological migrating intramural hematoma in stenting for carotid artery dissection: A ten-year consecutive cohort study

ObjectiveTo study the phenomenon, incidence and management of pathological migrating intramural hematoma in stenting for carotid artery dissection. MethodsWe consecutively enrolled CAD patients with stenting treatment over 10-year period, and retrospectively analyzed the pathological migrating intramural hematoma (PMIH) incidence of these CAD patients. Besides, we also explored the related factors with PMIH and provided an appropriate management strategy. ResultsA total of 67 CAD underwent stenting. PMIH occurred in 7 cases (10.4%). The median time from onset of symptoms to stenting was 5 days (3 to 11 days). There were 4 cases of PMIH in the proximal segment of stent and 3 cases of PMIH in the distal segment of stent. All the patients presented with new stenosis and no patient presented with dissecting aneurysm. Through proper management, none of the patients had occurred clinical complications. ConclusionPathological migrating intramural hematoma phenomenon exists in the stenting for carotid artery dissection, rescue angioplasty or stenting is needed for early treatment of moderate and severe stenosis due to migrating intramural hematoma on preventing further ischemic events.

Assessment of coronary bio-degradable stent by using coronary computed tomography angiography

Objective To investigate the possibility of showing coronary bio-degradable stent(BDS) and luminal stenosis by using coronary computed tomography angiography(CCTA). Methods A total of 27 consecutive patients who had undergone CCTA follow-up for BDS implantation were enrolled from January to June of 2015. The duration between CCTA and coronary BDS implantation was 1 year. The patients' age were (54±7) years in average. There were 18 male and 9 female patients. Of those patients, 18 BDS were implanted in left anterior descending coronary artery, and 9 in right coronary artery. Quantitative measurement of luminal stenosis, average areas of noncalcified and calcified plaque in proximal segment of stent (5 mm proximal to the stent), intra-stent, and distal segment of stent (5 mm distal to the stent) were performed and compared, using Kruskal Wallis as well as Mann-Whitney U tests. Results The mean length of BDS was (16.1±4.4) mm. Coronary diameter stenosis (%) of the proximal segment, intra-stent and distal segment to BDS were 14.4%(11.5%, 23.1%), 23.4%(17.4%, 27.4%), and 16.4%(12.7%, 24.1%), respectively(H=10.17,P 0.05). Conclusion CCTA could be used to assess coronary bio-degradable stent and luminal stenosis without affection of mental artifact. Intra-stent restenosis was more frequently observed than proximal and distal segments of the BDS. Key words: Coronary artery; Tomography, X-ray computed; Stent

Temporal Correlation between Wall Shear Stress and In-Stent Stenosis after Wingspan Stent in Swine Model

A recent randomized clinical trial on intracranial atherosclerosis was discontinued because of the higher frequency of stroke and death in the angioplasty and stent placement group than in the medical treatment group. An in-depth understanding of the relationship between biologic responses and flow dynamics is still required to identify the current limitations of intracranial stent placement. Five Wingspan stents were deployed in tapered swine ascending pharyngeal arteries. Temporal wall shear stress distributions and in-stent stenosis were evaluated at days 0, 7, 14, and 28 after stent placement. The physiologic role of wall shear stress was analyzed regarding its correlation with in-stent stenosis. In-stent stenosis reached a peak of nearly 40% at day 14 and decreased mainly at the distal stent segment until day 28. The wall shear stress demonstrated a characteristic pattern with time on the basis of the in-stent stenosis change. The wall shear stress gradient increased from the proximal to distal segment until day 14. At day 28, the trend was reversed dramatically, decreasing from the proximal to the distal segment. A significant correlation between the in-stent stenosis growth until day 14 and low wall shear stress values just after stent placement was detected. In-stent stenosis regression between days 14 and 28 was also associated with the high wall shear stress values at day 14. These data suggest that the physiologic wall shear stress can control the biphasic in-stent stenosis change in tapered arteries.

P-024 Stress distribution after intracranial stent by realistic model

There is no effective treatment for symptomatic intracranial atherosclerotic stenosis, which has an association with a high rate of recurrent stroke. Percutaneous transluminal angioplasty and stenting (PTAS) has been applied...

Improved detection of in-stent restenosis by blood pool agent-enhanced, high-resolution, steady-state magnetic resonance angiography

The aim of this study was to assess whether visualisation of in-stent changes can be improved with high-resolution, steady-state, blood pool contrast-enhanced MR angiography compared with first-pass MR angiography. Intra-arterial digital subtraction angiography (DSA) served as the reference standard. Twenty patients after stent placement in the superficial femoral artery (SFA) underwent MRA prior to reintervention. MRA of the SFA includes first-pass MRA as well as 3D high-resolution MRA in the steady state (SS-MRA) after injection of Gadofosveset trisodium. Sensitivity and specificity values for the detection of significant in-stent lesions by means of SS-MRA were calculated at the proximal, middle and distal stent segments in comparison to DSA. Kappa statistics were used to determine agreement between the two techniques. Sensitivity and specificity values for the detection of significant stenosis with SS-MRA reached 95% in the proximal, 100% in the middle and 100% in the distal stent segment. Kappa coefficients between SS-MRA and DSA were 0.789, 0.797 and 0.859 for the proximal, middle and distal segments, whereas the Kappa coefficients for FP-MRA were 0,211, 0,200 and 0,594 in these segments, respectively. Detection of in stent stenosis is significantly improved using SS MRA, in comparison to state-of-the-art FP-MRA.

Endothelium-dependent coronary vasomotor response and neointimal coverage of zotarolimus-eluting stents 3 months after implantation

BackgroundZotarolimus-eluting stents (ZES) have a higher rate of neointimal coverage than the first-generation drug-eluting stents on optical coherence tomography (OCT).ObjectiveTo determine whether neointimal coverage of stent struts detected by OCT...

Impaired Endothelial Vasomotor Function After Sirolimus-Eluting Stent Implantation

Sirolimus inhibits endothelial cell proliferation in vitro, but although the sirolimus-eluting stent (SES) is widely used because of the very low rates of in-stent restenosis, the influence of SES on coronary endothelial vasomotor function in humans is not well known. The present study included 21 patients treated with SES, and 12 patients treated with conventional bare metal stent (BMS). Endothelium-dependent vasomotor function was evaluated 6 months after stent implantation, using intracoronary acetylcholine infusion. Changes in diameter at the 5-mm proximal and distal edges of the stent, and at the control segment were assessed by quantitative coronary angiography. To evaluate native endothelial function, an intracoronary acetylcholine test was performed before stenting. In the 21 SES patients acetylcholine infusion at 10(-8) mol/L and 10(-7) mol/L produced significant vasoconstriction in the proximal stent segment (-11.3+/-10.3%, and -14.1+/-11.3%, respectively) and the distal stent segment (-13.7+/-9.3%, and -17.5+/-12.5%, respectively). In contrast, in the 12 BMS patients, acetylcholine infusion at the same concentrations did not produce a vasoconstrictive response in the proximal stent segment (5.0+/-8.2% and 4.9+/-9.1%, respectively) or the distal stent segment (4.2+/-7.6% and 5.1+/-7.7%, respectively). Intracoronary nitroglycerin induced a similar grade of vasodilation in the peri-stent area in both groups. Local endothelial function before SES implantation showed no vasoconstrictive response. In contrast to vasodilation in BMS patients, SES implantation in the peri-stent area resulted in a vasoconstrictive response to acetylcholine. SES implantation may impair endothelial function in humans.

Risk factors for lower urinary tract infection and bacterial stent colonization in patients with a double J ureteral stent

We investigated the potential risk factors for lower urinary tract infection and bacterial stent colonization in patients with double-J stents. A total of 195 double-J stents from 190 patients (95 men and 95 women, mean age 40.22 years) were examined. In all patients, prophylactic antimicrobial therapy was administered at the time of stenting. The stents and urine samples were removed aseptically and the proximal and distal tip segments of the stents were obtained. Three culture specimens were obtained from each stent segment and urine sample. Chi-square tests, odds ratio, and relative risk were used for the statistical analysis. Bacterial colonies were found in 24% (47 of 190) of the urine samples, 31% (61 of 195) of the proximal stent segments, and 34% (67 of 195) of the distal stent segments. Of the pathogens identified, Escherichia coli (34 of 47) was the most common. Diabetes mellitus (P < 0.01), chronic renal failure (P < 0.001), and pregnancy (P < 0.01) were found to be risk factors for lower urinary tract infection in patients with stents. An increased stent colonization rate was associated with implantation time, age, and female sex, but these were not statistically significant for lower urinary tract infection Diabetes mellitus, chronic renal failure, and pregnancy are associated with a higher risk of lower urinary tract infection. Therefore, patients in these categories should be monitored carefully for infectious complications.

Stent Implanation Into Tapering Coronary Arteries is Associated With Greater Intimal Proliferation in the Distal Stent Segment

Stent Implanation Into Tapering Coronary Arteries is Associated With Greater Intimal Proliferation in the Distal Stent Segment

Stent implantation into tapering coronary arteries is associated with greater intimal proliferation in the distal stent segment

Stent implantation into tapering coronary arteries is associated with greater intimal proliferation in the distal stent segment