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Unlabelled: Gastroesophageal variceal bleeding in patients with cirrhosis is associated with significant morbidity and mortality, as well as a high rebleeding risk. Limited data are available on the role of transjugular intrahepatic portosystemic shunt (TIPS) with covered stents in patients receiving standard endoscopic, vasoactive, and antibiotic treatment. In this multicenter randomized trial, long-term endoscopic variceal ligation (EVL) or glue injection + β-blocker treatment was compared with TIPS placement in 72 patients with a first or second episode of gastric and/or esophageal variceal bleeding, after hemodynamic stabilization upon endoscopic, vasoactive, and antibiotic treatment. Randomization was stratified according to Child-Pugh score. Kaplan-Meier (event-free) survival estimates were used for the endpoints rebleeding, death, treatment failure, and hepatic encephalopathy. During a median follow-up of 23 months, 10 (29%) of 35 patients in the endoscopy + β-blocker group, as compared to 0 of 37 (0%) patients in the TIPS group, developed variceal rebleeding (P = 0.001). Mortality (TIPS 32% vs. endoscopy 26%; P = 0.418) and treatment failure (TIPS 38% vs. endoscopy 34%; P = 0.685) did not differ between groups. Early hepatic encephalopathy (within 1 year) was significantly more frequent in the TIPS group (35% vs. 14%; P = 0.035), but during long-term follow-up this difference diminished (38% vs. 23%; P = 0.121)., Conclusions: In unselected patients with cirrhosis, who underwent successful endoscopic hemostasis for variceal bleeding, covered TIPS was superior to EVL + β-blocker for reduction of variceal rebleeding, but did not improve survival. TIPS was associated with higher rates of early hepatic encephalopathy., (© 2015 by the American Association for the Study of Liver Diseases.)

Purpose: To assess the differences in radial force of carotid stents and whether the length of the lesion influences the measurements., Materials and Methods: Different models of tapered stents of similar size (length, 30 mm) were used. The tapered nitinol Acculink, Protégé, and Cristallo Ideale carotid artery stents and the straight, braided Elgiloy carotid Wallstent were compared. A measurement device consisting of three film loops along the stent body connected to aluminium rods with copper strain gauges was developed. Five stents of each type were deployed within 3-mm stenoses in simulated long (26 mm) and short (8 mm) stenoses., Results: In the short stenosis simulation, the greatest radial force was seen in the Protégé stent, at 3.14 N ± 0.45, followed by the Cristallo Ideale stent (1.73 N ± 0.51), Acculink (1.16 N ± 0.21), and Wallstent (0.84 N ± 0.10; P < .001). In the long stenosis simulation, peak radial force again was highest in the Protégé stent (1.67 N ± 0.37), but the Acculink stent was second (0.95 N ± 0.12) and the Wallstent third (0.80 N ± 0.06). The Cristallo Ideale stent, in contrast to the short stenosis simulation, produced the least radial force (0.44 N ± 0.13) in the long stenosis simulation (P = .001)., Conclusions: Radial forces exerted by carotid stents vary significantly among stent designs. Differences between stent types are dependent on the length of the stenosis. An understanding of radial force is necessary for a well-considered choice of stent type in each individual patient., (Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.)

Background: Little is known about the efficacy and safety of renal artery stenting in patients with atherosclerotic renal artery stenosis (ARAS) and impaired renal function., Objective: To determine the efficacy and safety of stent placement in patients with ARAS and impaired renal function., Design: Randomized clinical trial. Randomization was centralized and computer generated, and allocation was assigned by e-mail. Patients, providers, and persons who assessed outcomes were not blinded to treatment assignment., Setting: 10 European medical centers., Participants: 140 patients with creatinine clearance less than 80 mL/min per 1.73 m(2) and ARAS of 50% or greater., Intervention: Stent placement and medical treatment (64 patients) or medical treatment only (76 patients). Medical treatment consisted of antihypertensive treatment, a statin, and aspirin., Measurements: The primary end point was a 20% or greater decrease in creatinine clearance. Secondary end points included safety and cardiovascular morbidity and mortality., Results: Forty-six of 64 patients assigned to stent placement had the procedure. Ten of the 64 patients (16%) in the stent placement group and 16 patients (22%) in the medication group reached the primary end point (hazard ratio, 0.73 [95% CI, 0.33 to 1.61]). Serious complications occurred in the stent group, including 2 procedure-related deaths (3%), 1 late death secondary to an infected hematoma, and 1 patient who required dialysis secondary to cholesterol embolism. The groups did not differ for other secondary end points., Limitation: Many patients were falsely identified as having renal artery stenosis greater than 50% by noninvasive imaging and did not ultimately require stenting., Conclusion: Stent placement with medical treatment had no clear effect on progression of impaired renal function but led to a small number of significant procedure-related complications. The study findings favor a conservative approach to patients with ARAS, focused on cardiovascular risk factor management and avoiding stenting.

Purpose: To compare clinical success, functional capacity, and quality of life during 12 months after revascularization or supervised exercise training in patients with intermittent claudication., Materials and Methods: This study had institutional review board approval, and all patients gave written informed consent. Between September 2002 and September 2005, 151 consecutive patients who presented with symptoms of intermittent claudication were randomly assigned to undergo either endovascular revascularization (angioplasty-first approach) (n = 76) or hospital-based supervised exercise (n = 75). The outcome measures were clinical success, functional capacity, and quality of life after 6 and 12 months. Clinical success was defined as improvement in at least one category in the Rutherford scale above the pretreatment level. Significance of differences between the groups was assessed with the unpaired t test, chi(2) test, or Mann-Whitney U test. To adjust outcomes for imbalances of baseline values, multivariable regression analysis was performed., Results: Immediately after the start of treatment, patients who underwent revascularization improved more than patients who performed exercise in terms of clinical success (adjusted odds ratio [OR], 39; 99% confidence interval [CI]: 11, 131; P < .001), but this advantage was lost after 6 (adjusted OR, 0.9; 99% CI: 0.3, 2.3; P = .70) and 12 (adjusted OR, 1.1; 99% CI: 0.5, 2.8; P = .73) months. After revascularization, fewer patients showed signs of ipsilateral symptoms at 6 months compared with patients in the exercise group (adjusted OR, 0.4; 99% CI: 0.2, 0.9; P < .001), but no significant differences were demonstrated at 12 months. After both treatments, functional capacity and quality of life scores increased after 6 and 12 months, but no significant differences between the groups were demonstrated., Conclusion: After 6 and 12 months, patients with intermittent claudication benefited equally from either endovascular revascularization or supervised exercise. Improvement was, however, more immediate after revascularization.

Background: The clinical outcome of a covered vs. uncovered transjugular intrahepatic portosystemic shunt (TIPS) for patients with Budd-Chiari syndrome (BCS) is as yet largely unknown., Objectives: To compare patency rates of bare and polytetrafluoroethylene (PTFE)-covered stents, and to investigate clinical outcome using four prognostic indices [Child-Pugh score, Rotterdam BCS index, modified Clichy score and Model for End-Stage Liver Disease (MELD)]., Methods: Consecutive patients with BCS who had undergone TIPS between January 1994 and March 2006 were evaluated in a retrospective review in a single centre., Results: Twenty-three TIPS procedures were performed on 16 patients. The primary patency rate at 2 years was 12% using bare and 56% using covered stents (P=0.09). We found marked clinical improvement at 3 months post-TIPS as determined by a drop in median Child-Pugh score (10-7, P=0.04), Rotterdam BCS index (1.90-0.83, P=0.02) and modified Clichy score (7.77-2.94, P=0.003), but not in MELD (18.91-17.42, P=0.9). Survival at 1 and 3 years post-TIPS was 80% (95% CI: 59-100%) and 72% (95% CI: 48-96%). Four patients (25%) died and one required liver transplantation., Conclusions: A transjugular intrahepatic portosystemic shunt using PTFE-covered stents shows better patency rates than bare stents in BCS. Moreover, TIPS leads to an improvement in important prognostic indicators for the survival of patients with BCS.

Purpose: To evaluate the patency of sirolimus-eluting stents (SES) compared to bare-metal stents (BMS) in the treatment of atherosclerotic renal artery stenosis (RAS)., Methods: Between November 2001 to June 2003, 105 consecutive symptomatic patients (53 men; mean age 65.7 years) with RAS were treated with either a bare-metal (n=52) or a drug-eluting (n=53) low-profile Palmaz-Genesis peripheral stent at 11 centers in a prospective nonrandomized trial. The primary endpoint was the angiographic result at 6 months measured with quantitative vessel analysis by an independent core laboratory. Secondary endpoints were technical and procedural success, clinical patency [no target lesion revascularization (TLR)], blood pressure and antihypertensive drug use, worsening of renal function, and no major adverse events at 1, 6, 12, and 24 months., Results: At 6 months, the overall in-stent diameter stenosis for BMS was 23.9%+/-22.9% versus 18.7%+/-15.6% for SES (p=0.39). The binary restenosis rate was 6.7% for SES versus 14.6% for the BMS (p=0.30). After 6 months and 1 year, TLR rate was 7.7% and 11.5%, respectively, in the BMS group versus 1.9% at both time points in the SES group (p=0.21). This rate remained stable up to the 2-year follow-up but did not reach significance due to the small sample. Even as early as 6 months, both types of stents significantly improved blood pressure and reduced antihypertensive medication compared to baseline (p<0.01). After 6 months, renal function worsened in 4.6% of the BMS patients and in 6.9% of the SES group. The rate of major adverse events was 23.7% for the BMS group and 26.8% for the SES at 2 years (p=0.80)., Conclusion: The angiographic outcome at 6 months did not show a significant difference between BMS and SES. Renal artery stenting with both stents significantly improved blood pressure. Future studies with a larger patient population and longer angiographic follow-up are warranted to determine if there is a significant benefit of drug-eluting stents in treating ostial renal artery stenosis.

Purpose: To investigate the pressure gradient and degree of flow reduction associated with embolus protection filters for carotid stenting in an in vitro experiment., Methods: Three filter devices with a perforated membrane design and one wire mesh type filter were tested. At a pressure of 70 mmHg, the flow reduction and pressure gradient were measured in a 5-mm tube using blood-mimicking fluid., Results: The pressure gradient in the wire mesh filter was 1.65+/-0.49 mmHg (95% CI 1.32 to 1.86). The mean pressure gradient in the perforated membrane filters was 6.88+/-2.62 mmHg (95% CI 6.22 to 7.55, p<0.0001). There was also a significant correlation between pressure gradient and flow reduction (r=-0.77, p<0.01)., Conclusion: Embolic protection filters cause a pressure gradient and obstruct blood flow. This effect is marked in perforated membrane filters and almost absent in the wire mesh filter.

Background: The patency of arteriovenous (AV) expanded polytetrafluoroethylene (ePTFE) hemodialysis grafts is severely compromised by intimal hyperplasia (IH) at the venous anastomosis and in the venous outflow tract. We addressed the potential of primary placement of a sirolimus-eluting stent (SES) in a validated porcine model., Methods and Results: In 25 pigs, ePTFE AV grafts were created bilaterally between the carotid artery and the jugular vein, whereupon a self-expandable nitinol stent (14 SESs and 11 bare-metal stents) was implanted over the venous anastomosis in 1 of the 2 grafts. After exclusion of technical failures and 1 unilateral occlusion, 16 pigs (9 SESs and 7 bare-metal stents) were included for further analysis. After 28 days, we measured graft flow and performed quantitative angiography. The pigs were then euthanized, and grafts with adjacent vessels were excised for histological analysis. Minimal luminal diameter was substantially larger in the SES group compared with unstented controls (5.9+/-0.2 versus 3.8+/-0.4 mm, respectively, P=0.01), which was accompanied by more prominent graft flow (SES, 1360+/-89 mL/min versus unstented, 861+/-83 mL/min, P=0.05). IH at the venous anastomosis was 77% less in the SES group compared with unstented controls (0.44+/-0.05 versus 1.92+/-0.5 mm2, respectively, P=0.01), whereas IH increased markedly when bare-metal stents were used (5.7+/-1.4 mm2, P=0.05)., Conclusions: SESs in the venous outflow of AV grafts significantly reduce IH and increase vessel diameter and graft flow compared with unstented grafts. These findings suggest that SESs have the potential to improve primary patency of AV grafts in hemodialysis patients.

Purpose: To investigate the pattern of catecholamine response in patients undergoing carotid endarterectomy (CEA) or carotid artery stenting (CAS)., Methods: Adrenaline, noradrenaline, and renin levels were measured at 5 time points in 12 patients undergoing 13 CEAs (1 bilateral) and 13 patients undergoing unilateral CAS. Arterial blood samples were taken at the following time points: (1) after induction in CEA patients or 5 minutes following first contrast injection in CAS patients, (2) 5 minutes following ICA clamp release in surgical patients or deflation of the balloon in the CAS cohort, (3) 60 minutes following ICA clamp release in surgical patients or deflation of the balloon in the CAS cohort, and (4) 24 hours following the procedure. Intraoperative blood pressure and heart rate were recorded using radial arterial monitoring. Changes in adrenaline, noradrenaline, and renin levels are expressed as ratios versus baseline., Results: Patterns of adrenaline and noradrenaline release were significantly different in patients undergoing CAS and CEA, with much higher and more variable surges of adrenaline and noradrenaline occurring in CEA patients. Adrenaline and noradrenaline levels increased significantly over baseline following carotid artery clamping in patients undergoing CEA (noradrenaline ratio before clamping: 1.54+/-1.25, 24 hours after unclamping: 8.38+/-16.35 [p<0.001]; adrenaline ratio before clamping: 1.12+/-0.49, 60 minutes after unclamping: 17.59+/-19.14 [p<0.001]). Conversely, in patients undergoing CAS, catecholamine levels remained unchanged (noradrenaline ratio before dilation: 0.96+/-0.23, 24 hours after the procedure: 0.92+/-0.32 [p=NS]; adrenaline ratio before dilation: 0.83+/-0.33, 60 minutes after balloon deflation: 0.56+/-0.32 [p=NS])., Conclusions: CAS is associated with a significantly less marked catecholamine response than CEA, which may reflect down-regulation of the sympathetic nervous system in response to carotid sinus stimulation during carotid angioplasty.

Intraluminal stent signal characterization by MRI is generally hampered by signal loss from the metallic stent material. This signal loss is related to magnetic susceptibility and RF shielding. Even when stent materials with low magnetic susceptibility are used, RF shielding can still be problematic. In this article we have shown that high flip angle imaging enables morphology assessment and tissue characterization in stents made of stainless steel 316L, NiTinol, and ABI-alloy., (Copyright 2003 Wiley-Liss, Inc.)

Introduction: Peak systolic velocity (PSV) measurements of blood flow inside vascular stents allow reliable detection of in-stent re-stenosis. The purpose of this in vitro study was to evaluate the feasibility of obtaining PSV measurements inside vascular stents made of Stainless Steel and Nitinol, using a velocity encoded MR technique., Materials/methods: In a flow phantom, stents of Stainless Steel and Nitinol were studied. The phantom was integrated into a closed-tubing circuit driven by a MR dedicated pulsatile flow pump. MR imaging was performed on a 1.5 T system. The PSV in the tube without stent was used as the gold standard to determine the accuracy and the variability (paired t-test and Pittman's test) of the PSV measurements inside the stents., Results: PSV values inside the stents showed percentual difference in mean of -15 to 21% (P < 0.05) at a pump setting of 10 and 20 ml/s., Conclusion: PSV measurements can be accurately obtained inside stents made of Stainless Steel and Nitinol. MR-velocity measurements may be used in patients to non-invasively evaluate stent patency and in-stent re-stenosis., (Copyright 2002 Elsevier Science B.V.)

Purpose: To determine pretreatment variables that may predict 1-year clinical outcome of stent placement for renal artery stenosis., Methods: In a prospective study, 40 consecutive patients (29 men; mean age 60 +/- 9.1 years) with angiographically proven atherosclerotic renal artery stenosis were treated with stent placement because of drug resistant hypertension (n=14), renal function impairment (n=14), or both (n=12). Clinical success at 1 year was defined as a decrease of diastolic blood pressure > or = 10 mmHg or a decrease in serum creatinine > or = 20%, depending on the indication for treatment. Regression analysis was performed using anatomical parameters from angiography and intravascular ultrasound, estimates of renal blood flow from renal scintigraphy, and single-kidney renal function measurements., Results: Patients treated for hypertension had better outcome than those treated for renal function impairment, with clinical success rates of 85% and 35%, respectively. Preserved renal function, with low serum creatinine and high 2-kidney glomerular filtration rate at baseline, was associated with clinical success in the entire patient group at follow-up (p=0.02 and p=0.03, respectively). An elevated vein-to-artery renin ratio on the affected side was borderline predictive (p=0.06). In patients treated for renal impairment, lateralization to the affected kidney (affected kidney-to-2-kidney count ratio < or = 0.45) on the scintigram emerged as a significant predictor for clinical success, with an odds ratio of 15 (p=0.048)., Conclusions: Clinical success of renal artery stent placement is better for the treatment of hypertension than for preserving renal function. In patients with renal function impairment, lateralization to the affected kidney on the scintigram appears to be a predictor of clinical success.

Background: This study examined the effects of stent placement for renal artery stenosis on the function of treated and contralateral kidneys., Methods: Eighteen patients who underwent stent placement for unilateral renal artery stenosis presenting with hypertension and/or renal failure were studied before angiography and stent placement and at their one-year follow-up. Renal vein blood samples were taken at both sides, at each side simultaneously with a sample from the aorta, to measure the plasma renin concentration and the concentrations of 131I-hippuran and 125I-thalamate during constant systemic infusion of these radiochemicals. This allowed an assessment of the single-kidney contributions to the total renin secretion, effective renal plasma flow (131I-hippuran clearance) and glomerular filtration rate (125I-thalamate clearance)., Results: At the one-year follow-up, the vein-to-artery renin ratio at the treated side had decreased to normal, from 1.65 +/- 0.131 to 1.23 +/- 0.076 (mean +/- SEM; P = 0.011), indicating an improved renal blood flow. Contralaterally it rose from 1.09 +/- 0.042 to 1.17 +/- 0.029 (P = 0.055) at follow-up. The extraction ratio of 131I-hippuran improved at the treated side (0.48 +/- 0.049 to 0.62 +/- 0.034; P = 0.003) and contralaterally (0.67 +/- 0.033 to 0.73 +/- 0.026; P = 0.043). The extraction ratio of 125I-thalamate, which equals filtration fraction, improved at both sides (0.12 +/- 0.014 to 0.17 +/- 0.012 at the treated side, P = 0.001; 0.18 +/- 0.013 to 0.22 +/- 0.011 contralaterally, P = 0.002). Two-kidney effective renal blood flow and glomerular filtration rate remained unchanged., Conclusion: Renal artery stenting was capable of causing improvement of glomerular filtration rate of the treated kidney, although the overall glomerular filtration rate did not change.

Background: The clinical outcome of a covered vs. uncovered transjugular intrahepatic portosystemic shunt (TIPS) for patients with Budd–Chiari syndrome (BCS) is as yet largely unknown. Objectives: To compare patency rates of bare and polytetrafluoroethylene (PTFE)-covered stents, and to investigate clinical outcome using four prognostic indices [Child–Pugh score, Rotterdam BCS index, modified Clichy score and Model for End-Stage Liver Disease (MELD)]. Methods: Consecutive patients with BCS who had undergone TIPS between January 1994 and March 2006 were evaluated in a retrospective review in a single centre. Results: Twenty-three TIPS procedures were performed on 16 patients. The primary patency rate at 2 years was 12% using bare and 56% using covered stents ( P=0.09). We found marked clinical improvement at 3 months post-TIPS as determined by a drop in median Child–Pugh score (10–7, P=0.04), Rotterdam BCS index (1.90–0.83, P=0.02) and modified Clichy score (7.77–2.94, P=0.003), but not in MELD (18.91–17.42, P=0.9). Survival at 1 and 3 years post-TIPS was 80% (95% CI: 59–100%) and 72% (95% CI: 48–96%). Four patients (25%) died and one required liver transplantation. Conclusions: A transjugular intrahepatic portosystemic shunt using PTFE-covered stents shows better patency rates than bare stents in BCS. Moreover, TIPS leads to an improvement in important prognostic indicators for the survival of patients with BCS. [ABSTRACT FROM AUTHOR]

: PurposeHigh-precision external beam radiotherapy (EBRT) has been suggested as a potential alternative to endovascular brachytherapy for the treatment of coronary artery in-stent restenosis. The purpose of our study was to investigate and compare different options to define a smallest feasible target volume.: Methods and materialsThe cardiac motion of 17 coronary artery stents in 17 patients was studied by use of biplane conventional angiography, recorded during breath-hold. Each stent was reconstructed in three dimensions by use of biplane sets of frames covering an entire cardiac cycle. The volume traversed by the stent during the entire or part of the cardiac cycle was determined. Four options to define the stent-traversed volume (STV) as a target for high-precision EBRT were investigated.: ResultsThe mean STV during the entire cardiac cycle was 3.5 cm3; the STV represented less than 1% of the heart volume in all patients. The STV during the diastolic and systolic phase resulted in a mean reduction of 26.6% and 29.1%, respectively, compared with the STV during the entire cardiac cycle. The smallest STV, measured during a 160-ms interval within the cardiac cycle, resulted in a mean maximal reduction of 75.9% compared with the STV during the entire cardiac cycle.: ConclusionsThe STV during the entire cardiac cycle represents a small potential target volume for high-precision EBRT. A significant reduction of this target volume is possible in case of definition during a selected interval within the cardiac cycle. [Copyright &y& Elsevier]