Search

Background: Endovascular repair of aortic aneurysmal disease is established due to perceived advantages in patient survival, reduced postoperative complications, and shorter hospital lengths of stay. High spatial and contrast resolution 3D CT angiography images are used to plan the procedures and inform device selection and manufacture, but in standard care, the surgery is performed using image-guidance from 2D X-ray fluoroscopy with injection of nephrotoxic contrast material to visualise the blood vessels. This study aims to assess the benefit to patients, practitioners, and the health service of a novel image fusion medical device (Cydar EV), which allows this high-resolution 3D information to be available to operators at the time of surgery. Methods: The trial is a multi-centre, open label, two-armed randomised controlled clinical trial of 340 patient, randomised 1:1 to either standard treatment in endovascular aneurysm repair or treatment using Cydar EV, a CE-marked medical device comprising of cloud computing, augmented intelligence, and computer vision. The primary outcome is procedural time, with secondary outcomes of procedural efficiency, technical effectiveness, patient outcomes, and cost-effectiveness. Patients with a clinical diagnosis of AAA or TAAA suitable for endovascular repair and able to provide written informed consent will be invited to participate. Discussion: This trial is the first randomised controlled trial evaluating advanced image fusion technology in endovascular aortic surgery and is well placed to evaluate the effect of this technology on patient outcomes and cost to the NHS. Trial registration: ISRCTN13832085. Dec. 3, 2021 [ABSTRACT FROM AUTHOR]

Purpose: Fenestrated endovascular aneurysm repair (fEVAR) is established for the treatment of juxtarenal, pararenal, and thoracoabdominal aortic aneurysms (TAAAs). Bridging stents are used to connect the main body of the stent graft to the aortic branch vessels. Complications related to the bridging stents compromise the durability of the repair and require urgent re-intervention. Here we present the midterm results of the BeGraft stent graft system used for fEVAR. Materials and method: All consecutive patients treated with fEVAR and the current BeGraft Peripheral Stent Graft between November 2015 and September 2016 were included. Results: Thirty-nine consecutive patients (38 men) were enrolled and 101 BeGraft second-generation stent grafts were implanted. The median aneurysm diameter was 60 mm (54.5–67.0 mm). Aneurysms were juxtarenal and pararenal (19/39, 48.1%), type 4 TAAA (3/39, 7.7%), type 1, 2, and 3 TAAA (7/39, 17.8%), type 5 TAAA (4/39, 10.2%), and 15.4% (6/39) had a type I endoleak following a previous EVAR. Fifty-five BeGrafts were implanted in mesenteric arteries (22 in coeliac trunks, 31 in the superior mesenteric artery, and 2 in a hepatic or splenic artery) and 46 into renal arteries (24 right and 22 left). The renal artery diameters were 5, 6, 7, and 8 mm in 9, 7, 26, and 4 patients, respectively. Mesenteric arteries were exclusively stented with 9 and 10 mm diameter devices. The median follow-up was 33 months (IQ25 17–IQ75 36). During follow-up, 11 patients died (28%) from non–aneurysm-related causes. The overall patency rates for bridging stents were 98% and 97% at 1 and 2 years, respectively, with a freedom from secondary procedure rate on BeGraft stent grafts of 96% (97/101). All events occurred on stents implanted in renal arteries. Conclusion: Early favorable outcomes are confirmed during longer term follow-up. Vigilant surveillance is required. [ABSTRACT FROM AUTHOR]

Purpose: To report emergent transcatheter aortic valve implantation (TAVI) to treat acute severe aortic regurgitation caused by valve cusp dysfunction following proximal migration of an endograft implanted in the ascending aorta during endovascular arch repair.Case Report: A 65-year-old man had been previously treated with thoracic and fenestrated endografts in a 2-stage procedure for a chronic type B dissection. At 2-year follow-up, aneurysmal evolution of the distal arch led to development of a proximal type Ia endoleak. The patient was deemed unfit for open repair because of severe nonrevascularizable coronary artery disease. A custom-made endograft was designed consisting of a double inner branch arch endograft with a proximal component to reline the ascending aorta to avoid iatrogenic type A dissection. The first component was successfully deployed. However, this device migrated toward the aortic valve when the delivery system of the branch device was advanced through the aortic valve. Aortography and transesophageal echography showed acute aortic regurgitation due to obstruction of the left coronary valve cusp. An emergency bailout TAVI procedure was performed to successfully treat the aortic regurgitation.Conclusion: TAVI can be used as a bailout procedure for acute aortic valve dysfunction during endovascular arch or ascending aorta repair. [ABSTRACT FROM AUTHOR]

Purpose: To describe a case of percutaneous retrograde left renal artery cannulation and restenting for severe distortion of a bridging stent diagnosed at the time of fenestrated endovascular aneurysm repair (FEVAR). Case Report: A 79-year-old man underwent 4-vessel FEVAR, during which completion angiography showed a good postoperative result, but cone beam computed tomography (CBCT) demonstrated severe distortion of the proximal part of the left renal stent. An antegrade or hybrid approach to recannulate the vessel was not possible due to the stent architecture and patient comorbidities. Contrast-enhanced CBCT was used to define the needle trajectory for a percutaneous translumbar approach. Fusion imaging software registered the planned needle track to the live fluoroscopy image. Respiratory motion compensation was used. Retrograde cannulation of the left renal artery was achieved; via a through-and-through wire with the left femoral artery, the left renal artery stent was relined using a covered stent. No deterioration of renal function was observed following the procedure. Contrast-enhanced duplex ultrasound demonstrated good flow in all target vessels without endoleak. Conclusion: Translumbar puncture and retrograde catheterization of a severely distorted left renal artery stent is possible during FEVAR using advanced imaging applications and can prevent target vessel loss. [ABSTRACT FROM AUTHOR]

The management of type B aortic dissection is undergoing profound changes with timely TEVAR accepted as first-line strategy in the setting of complicated dissection; with recent technological advances and in experienced hands this intervention is considered safe and life-saving. With the ability to remodel the dissected aorta as a result of scaffolding even pre-emptive endovascular treatment is being considered and supported by long-term stability and often prevention of aneurysmal expansion. This insight and a growing number of silent risk conditions (resistant hypertension, partial false lumen thrombosis) may lower the threshold for TEVAR in asymptomatic patients in the subacute phase. In the chronic phase of a type B dissection patients are usually free of symptoms, however, with the expanding false lumen at risk of rupture. Advanced TEVAR options (including branches and fenestrations) are likely to be used more often than open surgical replacement of such aneurysmatic segment of the dissected aorta in that chronic phase. All dissection patients should be offered lifelong surveillance. [ABSTRACT FROM AUTHOR]

Accurate measurement of blood pressure is important because it is a biomarker for cardiovascular disease. Diagnostic catheterization is routinely used for pressure acquisition in vessels despite being subject to significant measurement errors. To investigate these errors, this study compares pressure measurement using two different techniques in vitro and numerical simulations. Pressure was acquired in a pulsatile flow phantom using a 6F fluid-filled catheter and a 0.014′′ pressure wire, which is considered the current gold standard. Numerical simulations of the experimental set-up with and without a catheter were also performed. Despite the low catheter-to-vessel radius ratio, the catheter traces showed a 24% peak systolic pressure overestimation compared to the wire. The numerical models replicated this difference and indicated the cause for overestimation was the increased flow resistance due to the presence of the catheter. Further, the higher frequency pressure oscillations observed in the wire and numerical data were absent in the catheter, resulting in an overestimation of the pulse wave velocity with the latter modality. These results show that catheter geometry produces significant measurement bias in both the peak pressure and the waveform shape even with radius ratios considered acceptable in clinical practice. The wire allows for more accurate pressure quantification, in agreement with the numerical model without a catheter. [ABSTRACT FROM PUBLISHER]

Purpose To investigate the feasibility of high-resolution late gadolinium enhancement (LGE) imaging using a three-dimensional (3D) stack of spirals k-space trajectory for the detection of left atrial (LA) ablation lesions. LGE imaging inherently suffers from low SNR, so that improvements in spatial resolution and imaging time are challenging. The spiral trajectory offers greater acquisition efficiency, and this is used for increased spatial resolution. Materials and Methods Nine healthy subjects and 10 pre/post pulmonary vein isolation patients underwent an MRI examination. A Cartesian 3D inversion-recovery gradient-echo sequence was performed followed by a 3D inversion-recovery gradient-echo with a spiral trajectory. Image quality, fat suppression and sharpness were graded by expert cardiologists. Results No statistical significance was determined for SNR or image quality between the Cartesian and spiral images; however, fat suppression was significantly improved with the spiral approach ( P = 0.002). The enhancement in the Cartesian scan was found to have significantly higher CNR ( P = 0.02). Conclusion The feasibility of spiral LGE in the left atrium has been demonstrated. Similar image quality and sharpness were observed with both acquisitions. This spiral sequence has sub-millimeter spatial resolution improved fat suppression and maintains a comparable level of SNR compared with the Cartesian scan. J. Magn. Reson. Imaging 2014;39:211-216. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Purpose: [ABSTRACT FROM AUTHOR]

The objective of this study was to identify factors predicting the need for reintervention after endovascular repair of isolated iliac artery aneurysm (IIAA). We reviewed prospectively collected database records of all patients who underwent endovascular repair of IIAA between 1999 and 2008. Detailed assessment of the aneurysms was performed using computed tomography angiography (CTA). Follow-up protocol included CTA at 3 months. If this showed no complication, then annual duplex scan was arranged. Multivariate analysis and analysis of patient survival and freedom from reintervention were performed using Kaplan-Meier life tables. Forty IIAAs (median diameter 44 mm) in 38 patients were treated (all men; median age 75 years), and median follow-up was 27 months. Endovascular repair of IIAA was required in 14 of 40 aneurysms (35%). The rate of type I endoleak was significantly higher with proximal landing zone (PLZ) diameter >30 mm in the aorta or >24 mm in the common iliac artery or distal landing zone (DLZ) diameter >24 mm (P = 0.03, 0.03, and 0.0014, respectively). Reintervention rate (RR) increased significantly with increased diameter or decreased length of PLZ; increased DLZ diameter; and endovascular IIAA repair (P = 0.005, 0.005, 0.02, and 0.02 respectively); however, RR was not significantly affected by length of PLZ or DLZ. Freedom-from-reintervention was 97, 93, and 86% at 12, 24, and 108 months. There was no in-hospital or aneurysm-related mortality. Endovascular IIAA repair is a safe treatment option. Proper patient selection is essential to decrease the RR. [ABSTRACT FROM AUTHOR]

We present the early results of a policy of treating all anatomically suitable ruptured abdominal aortic aneurysms (rAAAs) by emergency endovascular aneurysm repair (eEVAR), regardless of hemodynamic instability. Data were retrospectively collected from prospectively maintained databases identifying patients with rAAA from 2006 to 2007. Forty-seven patients with true rAAA were identified (87% men; median age 76 years [range 63-97 years]), of whom 18 (38%) were treated with eEVAR, 19 (40%) received open aneurysm repair (OAR), and 10 (21%) were managed nonoperatively. Fifteen of 18 (83%) eEVAR patients received an aortouni-iliac device + femorofemoral crossover, 2 patients (11%) had bifurcated devices, and 1 patient (6%) had a new iliac limb. Thirty-day mortality was 11% (2 of 18) for eEVAR and 32% (6 of 19) for OAR (p = not significant). At the 6-month follow-up, mortality was 22% (4 of 18) for eEVAR and 37% (7 of 19) for OAR (p = not significant). A clinically significant early survival advantage is suggested for eEVAR in patients presenting with rAAA. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the early outcome of endovascular repair of abdominal aortic aneurysms (EVAR) with an unfavorable neck anatomy using extralarge stent-grafts. We carried out a retrospective review of all patients who underwent elective EVAR using large diameter stent-grafts between June 2006 and February 2008. All patients had computed tomography angiography (CTA) for procedure planning, and detailed assessment of the aneurysm neck was performed using a three-dimensional CTA workstation. All patients were followed up with CTA at 3 and 12 months and annual duplex thereafter when appropriate. This analysis included 25 patients (23 men, 2 woman; median age, 76 years; age range, 60-88 years). The median aneurysm diameter was 7 cm, and the median aneurysm neck diameter was 31 mm. Extralarge Cook-Zenith stent-grafts were used in all patients, with a top-end diameter of 36 mm (n=23) and 40 mm (n=2). The follow-up period ranged from 3 to 24 months, with a median of 6 months. Primary and assisted primary technical success rates were 80% and 96%, respectively. Reintervention was required to treat proximal type I endoleak (n=1), iliac limb kink (n=2), and occluded femorofemoral crossover graft (n=1). These early results show that EVAR using extralarge stent-grafts with suprarenal fixation can be a reliable modality to treat infrarenal aortic aneurysms with an unfavorable neck anatomy. [ABSTRACT FROM AUTHOR]

Better understanding of hemodynamics conceivably leads to improved diagnosis and prognosis of cardiovascular diseases. Therefore, an elaborate analysis of the blood-flow in heart and thoracic arteries is essential. Contemporary MRI techniques enable acquisition of quantitative time-resolved flow information, resulting in 4D velocity fields that capture the blood-flow behavior. Visual exploration of these fields provides comprehensive insight into the unsteady blood-flow behavior, and precedes a quantitative analysis of additional blood-flow parameters. The complete inspection requires accurate segmentation of anatomical structures, encompassing a time-consuming and hard-to-automate process, especially for malformed morphologies. We present a way to avoid the laborious segmentation process in case of qualitative inspection, by introducing an interactive virtual probe. This probe is positioned semi-automatically within the blood-flow field, and serves as a navigational object for visual exploration. The difficult task of determining position and orientation along the view-direction is automated by a fitting approach, aligning the probe with the orientations of the velocity field. The aligned probe provides an interactive seeding basis for various flow visualization approaches. We demonstrate illustration-inspired particles, integral lines and integral surfaces, conveying distinct characteristics of the unsteady blood-flow. Lastly, we present the results of an evaluation with domain experts, valuing the practical use of our probe and flow visualization techniques. [ABSTRACT FROM AUTHOR]

Insight into the dynamics of blood-flow considerably improves the understanding of the complex cardiovascular system and its pathologies. Advances in MRI technology enable acquisition of 4D blood-flow data, providing quantitative blood-flow velocities over time. The currently typical slice-by-slice analysis requires a full mental reconstruction of the unsteady blood-flow field, which is a tedious and highly challenging task, even for skilled physicians. We endeavor to alleviate this task by means of comprehensive visualization and interaction techniques. In this paper we present a framework for pre-clinical cardiovascular research, providing tools to both interactively explore the 4D blood-flow data and depict the essential blood-flow characteristics. The framework encompasses a variety of visualization styles, comprising illustrative techniques as well as improved methods from the established field of flow visualization. Each of the incorporated styles, including exploded planar reformats, flow-direction highlights, and arrow-trails, locally captures the blood-flow dynamics and may be initiated by an interactively probed vessel cross-section. Additionally, we present the results of an evaluation with domain experts, measuring the value of each of the visualization styles and related rendering parameters. [ABSTRACT FROM PUBLISHER]