bluuebunny/crossref_metadata_2025_split huggingface dataset:
Duplex Sonography versus Angiography for Assessment of Femoropopliteal Arterial Disease in a “Real-World” Setting
Authors: Schlager Oliver , Francesconi Marcel , Haumer Markus , Dick Petra , Sabeti Schila , Amighi Jasmin , Mlekusch Wolfgang , Koppensteiner Renate , Minar Erich , Schillinger Martin 
Published: March 2015

Purpose: To evaluate the agreement of duplex ultrasound (DUS) versus digital subtraction angiography (DSA) for assessment of femoropopliteal arterial disease in a real-world clinical setting. Methods: Consecutive patients with peripheral artery disease who were scheduled for a percutaneous intervention were included in this retrospective study. During an 18-month period, 491 patients (276 men; median age 73 years, interquartile range 64–81) were enrolled. A peak systolic velocity ratio (PSVR) >2.4 was the optimal cutoff for detecting a >50% stenosis by DSA. Findings of preprocedural DUS in the proximal, middle, and distal ipsilateral superficial femoral artery and in the popliteal segment were analyzed for agreement with preprocedural femoropopliteal DSA using kappa statistics. Only the target limb in each patient was analyzed, for a total of 1964 vascular segments. Results: Agreement for the degree of stenosis in 10% increments was only moderate (weighted kappa 0.67, 95% CI 0.65 to 0.69). Using the PSVR >2.4 cutoff, agreement between DUS and DSA for a >50% stenosis was good (kappa 0.79, 95% CI 0.77 to 0.81). Sensitivity, specificity, positive predictive value, and negative predictive value for correctly detecting a >50% stenosis by DUS were 0.81 (0.78 to 0.84), 0.93 (0.91 to 0.94), 0.84 (0.81 to 0.87), and 0.91 (0.87 to 0.95), respectively. Comparable findings were observed within different patient subgroups. Conclusion: Agreement between DUS and DSA in the femoropopliteal segment is only moderate with respect to the absolute degree of stenosis. However, detection of a >50% stenosis can be done with acceptable precision in routine clinical practice using PSVR >2.4 as a threshold.
Angiographic Analysis of Intravascular Thrombus Volume in Patients with Acute Ischemic Stroke
Authors: Qureshi Adnan I. , Alkawi Ammar , Hussein Haitham M. , Divani Afshin A. 
Published: March 2015

Purpose: To investigate the role that intravascular thrombus volume plays in mechanical thrombectomy and dose-titrated algorithms using pharmaceutical thrombolytic therapies. Methods: The angiographic studies of 33 consecutive patients (19 women; mean age 66±11 years) who underwent endovascular treatment for acute ischemic stroke were reviewed. A double-injection technique was utilized that involved 2 catheters for simultaneous injection of contrast proximal and distal to the thrombus to delineate its boundaries. The thrombus volume was calculated using the formula for cylindrical objects after measuring its length and diameter. Results: The volume of the 36 thrombi measured in the study group was 46±59 mm3. The mean length and diameter were 10±6 and 2±1 mm, respectively. The time between symptom onset and acquisition of angiographic images ranged from 167 to 589 minutes (mean 336±109). In a multivariate analysis, thrombus volume was not associated with any recanalization (odds ratio 2.4, 95% CI 0.02–191) after adjusting for initial occlusion grade, time between symptom onset and angiography, and previous intravenous use of thrombolytic agents. Volume capacities for retrieval devices to retain 50% and 75% of the thrombi were estimated as 29.2 mm3 and 55.3 mm3, respectively. Conclusion: The large variation in thrombi volume must be considered in designing retrieval devices to optimize their performance.
CT Angiography of Stented Carotid Arteries: Comparison with Doppler Ultrasonography
Authors: Kwon Bae Ju , Jung Cheolkyu , Sheen Seung Hun , Cho Jae Hoon , Han Moon Hee 
Published: March 2015

Purpose: To determine whether computed tomographic angiography (CTA) is a feasible modality for assessing stented carotid arteries and whether in-stent restenosis based on CTA concurs with ultrasonography (US). Methods: A retrospective review was conducted of 37 follow-up CTA and US images from 27 patients (23 men; median age 70 years, range 56–77) who received 34 nitinol carotid stents. CTA and US images were compared with respect to assessability and percent stenosis. Both visual estimation (≥50% or not) and the NASCET method were used to determine percent stenosis in CTA images. For US, a determination of ≥50% stenosis was based on peak systolic velocity (≥200 cm/s) and an internal carotid artery to common carotid artery ratio ≥2.5. Percent stenosis values by CTA were also compared to values (n=7, 21%) determined by catheter angiography. Results: CTA and US images were “totally assessable” in 27 (73%) and 15 (41%), “totally non-assessable” in 0 (0%) and 3 (8%), and “partially assessable” in 10 (27%) and 19 (51%), respectively. Assessability of CTA images was equal to or better than that of US images in 33 (89%). The percent stenoses by CTA and US were comparable in 20 cases. CTA found ≥50% stenosis using the NASCET method in 4 of 20 stents; none of these showed ≥50% stenosis by visual estimation of CTA or by spectral Doppler US. Compared with catheter angiography, CTA overestimated percent stenosis from 34% to 66% (mean 53%). US confirmed 2 angiographically proven restenoses, but CTA identified only 1. Conclusion: CTA provides better image quality for stented carotid arteries than US, but it might be inferior to US in determining restenosis in assessable cases. Therefore, CTA is likely to be an alternative to US in cases of non-assessability. A large-scale study including more restenosis cases is warranted to reveal which modality is more reliable for diagnosis of restenosis.
Rapid Pacing for Better Placing: Comparison of Techniques for Precise Deployment of Endografts in the Thoracic Aorta
Authors: Nienaber Christoph A. , Kische Stephan , Rehders Tim C. , Schneider Henrik , Chatterjee Tushar , Bünger Carsten Michael , Höppner Regina , Ince Hüseyin 
Published: March 2015

Purpose: To investigate the safety, efficacy, impact on positioning, and neurocognitive outcomes of 3 conceptually different methods of avoiding the “windsock” effect during thoracic stent-graft placement. Methods: A retrospective review was conducted of 70 patients (48 men; mean age 63 years) who underwent elective or emergency stent-graft placement in the thoracic aorta for various pathologies. Twenty-seven patients (18 men; mean age 64±12 years) had stent-graft positioning during rapid right ventricular (RV) pacing at 180 to 200 beats per minute. Another 27 patients (18 men; mean age 62±12 years) had stent-graft placement under controlled hypotension (≤45 mmHg) achieved with sodium nitroprusside (3 µg/kg/min). Sixteen patients (12 men; mean age 63±14 years) had intermittent cardiac arrest induced by a 0.5-mg/kg adenosine bolus prior to launching the stent-graft. Termination of the endovascular procedure, weaning, and recovery were conducted according to the same routines in all patients. Hemodynamics, landing precision (deviation from planned placement site), cerebral blood flow, and neurocognitive function were compared. Results: Rapid RV pacing (median 12 seconds) was conducted without technical difficulty or delayed recovery in any of the 27 patients. Once rapid pacing ceased, blood pressure recovered within 8 seconds from 22±8 mmHg to normal prepacing levels. The level of hypotension was most pronounced in the rapid RV pacing group (20±4 mmHg, p<0.001), and the duration of hypotension was also the shortest (20±10 seconds, p<0.001) at a pacing rate of 190±10 beats per minute. The instantaneous mean flow velocity was lowest (10±4 cm/s, p<0.001) and recovery to normal pressure was quickest (within 1 minute) with rapid pacing. Instrumentation for rapid pacing did not prolong the procedure, but shortened it ∼25 minutes. Moreover, precise positioning at a mean 2±2 mm from the predetermined launch site was observed with rapid pacing (p<0.05). There were no differences in postprocedural neurological assessment among groups. Conclusion: Rapid RV pacing is safe in selected patients and in experienced hands. It abbreviates hemodynamic compromise, shortens the endovascular procedure, and may eventually emerge as the preferred method to avoid the windsock effect during stent-grafting. The maneuver, however, requires knowledge of right cardiac anatomy and expertise in selecting patients.
Fenestrated and Branched Grafts for Para-Anastomotic Aortic Aneurysm Repair
Authors: Ziegler Peter , Perdikides Theodossios P. , Avgerinos Efthimios D. , Umscheid Thomas , Stelter Wolf J. 
Published: March 2015

Purpose: To investigate the use of fenestration and branch artery stenting during endovascular stent-graft repair of para-anastomotic aneurysms (PAA). Methods: A retrospective review was conducted of 9 patients (all men; mean age 71 years, range 60–80) who received custom-designed fenestrated endoprostheses for PAA repair. Eight tubular fenestrated devices and 1 composite device (fenestrated tube plus modular bifurcated body) with a total of 31 fenestrations were used. Results: The mean operating time was 318±93 minutes (range 220–485); the mean fluoroscopy time was 77±38 minutes (range 39–158), during which a mean 121±81 mL (range 33–300) of contrast was used. Technical success was achieved in all cases. Over a mean follow-up of 12±5.5 months (range 6–24), 1 secondary intervention was carried out due to a break in a side branch stent-graft; 2 transient renal impairments and 1 permanent renal insufficiency unrelated to renal artery patency were observed. So far, no vessel loss has emerged. Conclusion: Conventional repair of PAA has been a standard procedure for many years, though it carries high surgical risk as well as perioperative mortality. Fenestrated endografts may be a promising alternative in selected patients.
Influence of Wall Compliance on Hemodynamics in Models of Abdominal Aortic Aneurysm
Authors: Gaillard Emmanuel , Bergeron Patrice , Deplano Valérie 
Published: March 2015

Purpose: To determine complementary criteria to existing morphological criteria, which are not reliable but are used to justify surgical intervention to treat abdominal aortic aneurysm (AAA). Methods: An experimental study was conducted in which 2 models of AAA, 1 rigid and 1 soft, were used to study the influence of compliance on aneurysm dynamics. The heart rate was 70 beats per minute, and the mean flow rate was 1.02 L/min. Velocity measurements were made with particle image velocimetry in 2 planes parallel to flow (1 vertical and 1 horizontal). Results: The general flow patterns generated in the rigid AAA model were in agreement with the literature. In both models, a vortex occurred at the beginning of systolic deceleration in the proximal part of the AAA, near the anterior wall. The vortex remained confined to the proximal part during the entire cycle in the rigid model, whereas in the soft model, the vortex migrated to the distal segment during the cycle and impacted the AAA walls. This impact generated a local pressure increase on the wall. In the soft model, another vortex was created near the posterior wall. These vortices eroded and weakened the walls of the distal segment, which can cause rupture. Conclusion: Compliance of the aneurysm wall might become another criterion to justify surgical intervention.
Fenestrated Endografting for Aortic Aneurysm Repair: A 7-Year Experience
Authors: Ziegler Peter , Avgerinos Efthimios D. , Umscheid Thomas , Perdikides Theodosios , Stelter Wolf J. 
Published: March 2015

Purpose: To present a 7-year single-center clinical experience with fenestrated endografts and side branches. Methods: Between April 1999 and August 2006, 63 patients (57 men; mean age 70.5611.6 years, range 25–89) received custom-designed Zenith fenestrated endoprostheses for a variety of aneurysms (59 abdominal, 1 thoracoabdominal, and 3 thoracic). They were all unsuitable for standard EVAR owing to short aortic necks and high risk for open surgery. Results: Nineteen tube grafts and 44 composite bifurcated grafts with a total of 122 fenestrations and 58 side branches were used. Technical success was achieved in 55 (87.3%) patients and in 118 (96.7%) vessels. Treatment success was 93.7%. The mean follow-up was 23±18 months (median 14, range 6–77). Overall, 9 (7.4%) visceral branches were lost: 4 intraoperative, 2 perioperative, and 3 late. There were 12 (19.0%) endoleaks identified: 5 (7.9%: 4 type Ia and 1 fenestration-related type III) primary and 7 (11.1%: 4 type II, 1 type I, and 2 type III) secondary endoleaks; 4 resolved, 4 were treated, and 4 are under observation. At 77 months, 75.3% of patients were free of a reintervention. All reinterventions were performed within the first 14 months. Fourteen cases of renal impairment were seen [6 permanent (only 1 on dialysis) and 8 transient]. One (1.6%) conversion and 1 (1.6%) rupture were recorded; aneurysm-related mortality was 4.8% (3/63). Conclusion: The favorable outcomes in this study, which encompasses the team's learning curve with fenestrated endografts and side branches, support the use of these devices in selected patients.
“Paving and Cracking”: An Endovascular Technique to Facilitate the Introduction of Aortic Stent-Grafts through Stenosed Iliac Arteries
Authors: Hinchliffe Robert J. , Ivancev Krassi , Sonesson Björn , Malina Martin 
Published: March 2015

Purpose: To describe a technique that facilitates the safe introduction of aortic stent-grafts through diseased iliac arteries. Technique: The technique involves relining and dilating (“paving and cracking”) stenosed iliac arteries with covered stents prior to the introduction of the main aortic stent-graft. It has been successfully used to introduce aortic stent-grafts in patients where other transfemoral endovascular measures have failed. Conclusion: This technique increases the applicability of transfemoral EVAR and prevents serious complications as a result of access-related damage to the iliac arteries.
Effect of Suprarenal Fixation of Aortic Stent-Grafts on the Renal Artery Ostia: Assessment of Morphological Changes by Virtual Intravascular Endoscopy
Authors: Sun Zhonghua , O'Donnell Mark E. , Winder R. John , Ellis Peter K. , Blair Paul H. 
Published: March 2015

Purpose: To investigate the morphological effects of suprarenal fixation of aortic stent-grafts on the renal artery ostia (RaO) by analysis of suprarenal stent wire distribution and vascular calcification across the RaO using virtual intravascular endoscopy (VIE). Methods: Fourteen consecutive patients (11 men; mean age 75 years) from a single institution were studied following endovascular aortic aneurysm repair (EVAR) using the Zenith endograft system from September 1999 to March 2002. Imaging assessment included computed tomographic (CT) measurement of renal artery intraluminal ostial diameter and quantification and analysis of uncovered stent struts across the RaO and radiological determination of RaO calcification. Morphological changes following EVAR at 3 time points (before and within 1 week after stent-grafting, and at the most recent follow-up) were compared for each patient to determine whether suprarenal stent struts or RaO calcification affected intraluminal ostial diameter. Renal function was assessed by temporal measurements of serum creatinine concentration and creatinine clearance. Results: The renal ostium was distorted to variable degrees in all cases at a mean follow-up of 41±6.6 months. An increase in ostial diameter was identified in most patients if the right RaO was calcified when comparing the 1-week postoperative and most recent follow-up CT images (p<0.05). There was no direct relationship between the number of stent struts crossing the RaO and the morphological/dimensional changes (p>0.05). Renal function was not significantly affected. Conclusion: Patients undergoing suprarenal fixation of aortic stent-grafts experienced morphological changes of the RaO to a variable extent at midterm follow-up. Although the presence of stent struts did not significantly affect dimensional changes, we observed that calcification at the renal artery ostium may influence the development of atherosclerotic effects as a direct relationship between the calcification and ostial diameter. Future studies utilizing VIE to determine the long-term safety of this technique in these particular patients requires investigation.
Angioplasty and Stenting versus Carotid-Subclavian Bypass for the Treatment of Isolated Subclavian Artery Disease
Authors: AbuRahma Ali F. , Bates Mark C. , Stone Patrick A. , Dyer Benjamin , Armistead Lauren , Dean L. Scott , Lavigne P. Scott 
Published: March 2015

Purpose: To compare the results of a large series of percutaneous transluminal angioplasty (PTA)/stenting procedures in the subclavian artery with the results of a series of carotid-subclavian by pass grafts (CSBG) performed at the same institution for subclavian artery disease. Methods: Between 1993 and 2006, 121 patients (43 men; mean age 63 years, range 38–85) underwent subclavian artery PTA/stenting and were compared to a group of 51 patients (29 men; mean age 62 years, range 46–75) with isolated subclavian artery occlusive disease treated with CSBG using polytetrafluoroethylene grafts. Graft or PTA/stenting patency was determined clinically and confirmed by Doppler pressures and/or duplex ultrasound/angiography. The cumulative patency and overall survival rates were calculated using the life-table method. Results: The mean follow-up for the PTA/stent group was 3.4 years versus 7.7 years for the CSBG group. The technical success rate for the CSBG group was 100% versus 98% (119/121) for the PTA/stent group. The overall perioperative complication rate in the stent group was 15.1% (18/119: 11 minor and 7 major complications) versus 5.9% (3/51: 2 phrenic nerve palsy and 1 myocardial infarction) in the bypass group (p=0.093). There was no perioperative stroke or mortality in the CSBG group. The major perioperative complications in the stent group included 4 thromboembolic events, 1 congestive heart failure, 1 reperfusion arm edema, and 1 pseudoaneurysm. There was 1 perioperative death in the stent group. The 30-day patency rate was 100% for the bypass group and 97% (118/121) for the PTA/stent group. The primary patency rates at 1, 3, and 5 years were 100%, 98%, and 96% for the CSBG group versus 93%, 78%, and 70% for the stent group, respectively (p<0.0001). Freedom from symptom recurrence was also statistically superior in the bypass group versus the stent group (p<0.0001). There were no significant differences in the survival rates between both groups at any time point (p=0.322). Conclusion: Both CSBGs using PTFE grafts and subclavian PTA/stenting are safe, effective, and durable; however, CSBG is more durable in the long term. PTA/stenting of the subclavian artery should be the procedure of choice for high-risk patients; however, CSBG should be offered to good-risk surgical candidates who may be seeking a more durable procedure.
The Role of Carotid Stenting
Authors: Loftus Ian M. , Thompson Matthew M. 
Published: March 2015

Despite a number of randomized trials, debate continues about the role of carotid angioplasty and stenting (CAS) for both symptomatic and asymptomatic disease. None of the trials has shown superiority of one treatment modality over the other, but protagonists of stenting have encouraged a shift away from conventional surgery. The minimally invasive nature of CAS is appealing, but concerns have been raised about the periprocedural stroke rate in the randomized trials. To counter this evidence, there are increasing numbers of registries and series, many partly or wholly sponsored by the endovascular industry, some of which demonstrate reasonable results. These need to be studied with caution, as patients deemed high risk of carotid endarterectomy may actually be at very low risk of stroke. Furthermore, strict inclusion and exclusion criteria mean that results may not be a true reflection of everyday clinical practice. The aim of this review is to document the evidence to date, predominantly from the randomized trials, for both symptomatic and asymptomatic carotid disease and establish the current role of carotid stenting.
In Vitro Performance Assessment of Distal Protection Devices for Carotid Artery Stenting: Effect of Physiological Anatomy on Vascular Resistance
Authors: Siewiorek Gail M. , Wholey Mark H. , Finol Ender A. 
Published: March 2015

Purpose: To assess in vitro the performance of 5 distal protection devices (DPDs) by evaluating the capture efficiency, pressure gradient, volume flow rate, and vascular resistance in the internal carotid artery (ICA). Methods: The time-averaged mean peak velocity in the common carotid artery and a blood-mimicking solution were used to simulate physiological conditions in a silicone carotid phantom representing average human carotid artery geometry with a 70% symmetrical ICA stenosis. Five milligrams of dyed 200-μm nominal diameter polymer microspheres (larger than the pore size of the devices, except Spider RX, which was tested with 300-μm-diameter particles) were injected into the ICA. The percentages of particles missed after injection and lost during device retrieval were measured for the 5 devices (Spider RX, FilterWire EZ, RX Accunet, Angioguard XP, and Emboshield). The normalized pressure gradient, fraction of the volume flow rate, and vascular resistance in the ICA were calculated. Results: Spider RX captured the most particles (missing 0.06%, p<0.05) and yielded the smallest normalized pressure gradient increase (4.2%), the largest volume flow rate fraction (0.40), and the smallest vascular resistance in the ICA (272 mmHg/L·min−1, a 5.4% increase with respect to initial conditions). Angioguard XP captured the fewest particles (missing 36.3%, p<0.05 except Emboshield) and resulted in the largest normalized pressure gradient increase (37%) in the ICA. RX Accunet produced the smallest volume flow rate fraction in the ICA (0.30) and the largest vascular resistance in the ICA (470 mmHg/L·min−1, an 82.2% increase). Emboshield migrated ∼6 cm distal to the original position after particle injection. FilterWire EZ lost the fewest particles during retrieval (0.45%, p<0.05 except Accunet RX and Spider RX) and had the best overall performance with 200-μm emboli (p<0.05 except Accunet RX). Conclusion: None of the devices tested completely prevented embolization. Overall, Spider RX had the best performance and is conjectured to have the best wall apposition of the devices tested. Vascular resistance should be considered a key filter design parameter for performance testing since it represents a quantitative estimation of the “slow-flow phenomenon.” Our findings should be extrapolated cautiously to help interventionists choose the best device.