Role of graft oversizing in the fixation strength of barbed endovascular grafts

PurposeThe role of endovascular graft oversizing on risk of distal graft migration following endovascular aneurysm repair for abdominal aortic aneurysm is poorly understood. A controlled in vitro investigation of the role of oversizing in graft-aorta attachment strength for endovascular grafts (EVGs) with barbs was performed.MethodsBarbed stent grafts (N = 20) with controlled graft oversizing varying from 4-45% were fabricated while maintaining other design variables unchanged. A flow loop with physiological flow characteristics and a biosynthetic aortic aneurysm phantom (synthetic aneurysm model with a bovine aortic neck) were developed. The stent grafts were deployed into the aortic neck of the bio-synthetic aortic aneurysm phantom under realistic flow conditions. Computed tomography imaging of the graft-aorta complex was used to document attachment characteristics such as graft apposition, number of barbs penetrated, and penetration depth and angle. The strength of graft attachment to the aortic neck was assessed using mechanical pullout testing. Stent grafts were categorized into four groups based on oversizing: 4-10%; 11-20%; 21-30%; and greater than 30% oversizing.ResultsPullout force, a measure of post-deployment fixation strength was not different between 4-10% (6.23 ± 1.90 N), 11-20% (6.25 ± 1.84 N) and 20-30% (5.85 ± 1.89 N) groups, but significantly lower for the group with greater than 30% oversizing (3.67 ± 1.41 N). Increasing oversizing caused a proportional decrease in the number of barbs penetrating the aortic wall (correlation = −0.83). Of the 14 barbs available in the stent graft, 89% of the barbs (12.5 of 14 on average) penetrated the aortic wall in the 4-10% oversizing group while only 38% (5.25 of 14) did for the greater than 30% group (P < .001). Also, the stent grafts with greater than 30% oversizing showed significantly poorer apposition characteristics such as eccentric compression or folding of the graft perimeter. The number and depth of barb penetration were found to be positively correlated to pullout force.ConclusionGreater than 30% graft oversizing affects both barb penetration and graft apposition adversely resulting in a low pullout force in this in vitro model. Barbed stent grafts with excessive oversizing are likely to result in poor fixation and increased risk of migration.Clinical RelevanceMigration of the endovascular grafts in abdominal aortic aneurysm (AAA) patients continues to be a cause of long-term complication in patients. This study is an assessment of the role of graft oversizing, a key variable chosen by the physician, on the fixation strength of these implants to the parent aorta. The findings suggest caution when choosing stent grafts that are excessively oversized

Minimally invasive treatments for lower urinary tract symptoms in men with benign prostatic hyperplasia : a network metaanalysis (Protocol)

A C K N O W L E D G E M E N T S We are very grateful to Cochrane Urology, especially the Managing Editor Robert Lane, as well as Cochrane Urology Korea for supporting this review. Furthermore, we are grateful to Gretchen Kuntz for revising and providing feedback on the search strategies. We also thank Marco Blanker, Sevann Helo, and Murad Mohammad for their peer-review input of the protocol. S O U R C E S O F S U P P O R T Internal sources • Instituto Universitario Hospital Italiano, Argentina Salary support for Juan Franco, Luis Garegnani, Camila Micalea Escobar Liquitay • Department of Urology, Yonsei University Wonju College of Medicine, Korea, South Salary support for Jae Hung Jung • Minneapolis VA Health Care System, USA Salary support for Philipp Dahm • Department of Urology, University of Minnesota, USA Support in kind for Philipp DahmPeer reviewedPublisher PD

Minimally invasive treatments for benign prostatic hyperplasia : a Cochrane network meta-analysis

Acknowledgements This project was funded by the National Institute for Health Research (NIHR) [Cochrane Incentive Award (NIHR130819)]. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. We are very grateful to Cochrane Urology, especially Managing Editor Robert Lane, as well as Cochrane Urology Korea, for supporting this review. We are also grateful for the constructive feedback from the Cancer Network and the Methods Support Unit. We also thank Gretchen Kuntz for revising and providing feedback on the search strategies; Marco Blanker, Sevann Helo, and Murad Mohammad for their peer review input of the protocol; Dominik Abt, Bilal Chughtai, and Ahmed Higazy for providing details on the outcomes of their trials, for them to be incorporated accurately in our review; Marc Sapoval, Deepak Agarwal, Cameron Alexander, Harris Foster, and Mitchell Humphreys for their peer review input of the review. Juan Víctor Ariel Franco is a PhD candidate in the Programme of Methodology of Biomedical Research and Public Health, Universitat Autònoma de Barcelona (Spain)Peer reviewedPostprin

Bolus characteristics based on Magnetic Resonance Angiography

BACKGROUND: A detailed contrast bolus propagation model is essential for optimizing bolus-chasing Computed Tomography Angiography (CTA). Bolus characteristics were studied using bolus-timing datasets from Magnetic Resonance Angiography (MRA) for adaptive controller design and validation. METHODS: MRA bolus-timing datasets of the aorta in thirty patients were analyzed by a program developed with MATLAB. Bolus characteristics, such as peak position, dispersion and bolus velocity, were studied. The bolus profile was fit to a convolution function, which would serve as a mathematical model of bolus propagation in future controller design. RESULTS: The maximum speed of the bolus in the aorta ranged from 5–13 cm/s and the dwell time ranged from 7–13 seconds. Bolus characteristics were well described by the proposed propagation model, which included the exact functional relationships between the parameters and aortic location. CONCLUSION: The convolution function describes bolus dynamics reasonably well and could be used to implement the adaptive controller design

Imaging after endovascular repair of abdominal aortic aneurysm

Endovascular repair of abdominal aortic aneurysm is a less invasive alternative to open surgery. With the recognition of this new treatment, however, many complications, some of them life-threatening, have been reported. Short-term and mid-term results have shown that this technology is advancing and needs close follow-up. Imaging plays a major role in the evaluation of the aorta after endolumenal repair. This article reviews the roles of different imaging techniques.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Imaging of complications after endoluminal treatment of abdominal aortic aneurysms

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Prostate embolization: patient selection, clinical management and results

Abstract Background Prostate artery embolization is an emerging technique, that with the continued publication of promising data, is slowly moving from the research to the everyday clinical setting. Main body This paper reviews the patient selection, clinical management and expected results of prostate artery embolization. Patient selection is paramount in delivering the desired results for any procedure. Likewise, the ability to clinically manage patients in the pre-operative and post-operative setting is an important skill to acquire when implementing new techniques. This paper introduces important urologic measurements/tests, patient selection paradigms, and clinical management concepts for interventional radiologists. It also reviews the outcomes patients can expect following prostate artery embolization as well as the complication profile. Conclusion Prostate artery embolization is a promising technique for the treatment of benign prostatic hyperplasia induced lower urinary tract symptoms

Embolisation des fibromyomes utérins

info:eu-repo/semantics/publishe

Embolisation des fibromyomes utérins Uterine fibroids embolization

Uterine artery embolization (UAE) for symptomatic leiomyomas is a new attractive treatment in patients who don't desire pregnancy and for which conventional therapy has failed. Uterine fibroid embolization can also be considered for patients who desire pregnancy when myomectomy is technically difficult or impossible and in case of recurrence after myomectomy. 90 % improvements are commonly reported in abnormal bleeding, pelvic pains, and in bulk-related symptoms. Although numerous pregnancies have been reported after UAE, the fertility rate after UAE remains to be compared to myomectomy. Absolute contra-indications are pregnancy, endometrial carcinoma, gynaecologic infections, adnexal masses, and rapid growth of uterine leiomyomas (considered as a significant sign of sarcoma). Besides procedure related risks of angiography some specific complications are reported :deep pelvic vein thrombosis with exceptional pulmonary embolus, vaginal discharges with sometime transcervical expulsion of fibroid (5 %), transient or permanent amenorrhea (4-5 %) and extensive necrosis (1-2 %) with possible perforation and infection. A hysterectomy is needed to manage this complication in 0,9 to 0,3 % of case. The mortality rate of embolisation is evaluated to 1/3.000 against 6/10.000 for the hysterectomy. UAE is proposed as a less invasive alternative to hysterectomy and myomectomy for the treatment of symptomatic leiomyomas. This technique allows reducing the hospital stay, the convalescence period, the morbidity and the mortality rate compared to conventional surgical treatment.SCOPUS: ar.jinfo:eu-repo/semantics/publishe