Active clinical trials for "Endoleak"

After endovascular treatment of an abdominal aortic aneurysm, lifelong imaging follow-up is needed to monitor the effectiveness of the treatment. One parameter in this follow-up is endoleak, which is leakage of blood into the aneurysm sac. The aim of this study is to investigate the value of magnetic resonance imaging using Vasovist as a contrast agent for the detection of endoleaks.

Endovascular procedures already brought enormous revolution in the process of treatment of patient with abdominal aortic aneurysm (AAA). It is well defined that early mortality and morbidity is significantly reduced comparing to open repair. The persistent concern is long term durability of devices and their success of aneurysm exclusion in order to prevent rupture. At the moment the best armament to prevent rupture after endovascular exclusion is the watchful waiting and timely reintervention. The main complication that follows this procedure and causing catastrophic long term complications is endoleak. The ideal algorithm to follow up patients after aneurysm exclusion has not been found. In order to reveal endoleak ultrasound is used more than before, however frequent computerized tomography is wasting a lot of costs and exposing patients to irradiation and nephrotoxic contrast. Matrix metalloproteinase activity has been demonstrated in the process of aneurysm development. Imbalance between MMP and its inhibitors TIMP provokes collagenolytic and elastolytic activity that is inducing aneurysmatic degeneration of aortic wall. Due to the previously described connection between aneurysm and MMP activity, it was proved that serum level of MMP-9 is significantly higher in patients with abdominal aortic aneurysm (AAA). Also, higher levels of MMP-9 were discovered in patients with inadequate aneurysm exclusion after endovascular procedure suggesting that degradation of the aortic wall is still ongoing process, not being the case with successfully excluded aneurysm. There might be a potential role of MMP-9 serum level as a biomarker of present endoleak after endovascular aneurysm exclusion. All published trials have shown correlation between MMP 9 activity and presence of endoleak, however, no correlation was made between specific types of endoleak and necessity to reoperation (clinical significance). Additionally there were only four trials presented in the literature investigating low number of patients. Since there is possible value of MMP-9 serum level as biomarker of present endoleak, further studies are necessary. This why we are organizing multicentre trial, that will cover significant number of patients in order to define Value of MMP-9 as a biomarker of successful initial exclusion Value of MMP-9 level as predictor of aneurysm shrinkage Value of MMP-9 level in patients with increased aneurysm diameter and no visible endoleak Correlation of the MMP -9 serum level with different type of enoleak Value of MMP-9 as biomarker of successful treatment of endoelak Material and methods Patient with AAA greater then 55 mm in diameter that are candidates for endovascular repair will be selected. Demographic, anatomical and data regarding the procedure will be gathered prospectively. Also serum levels of MMP-9 will be measured before procedure, during the first week before discharge, and after 1,6,12,18,24,36,48 months. On the same day of measuring MMP-9 level control MSCT and ultrasonography exam will be performed in order to collect data regarding the success of exclusion and presence of any endoleak with the accurate measurement of aneurysm diameter changes. Ultrasonography and MSCT exam will be performed by experienced physicians, also preoperative evaluation of anatomical data. In case of reintervention additional questionnaire will be filled regarding anatomical and procedure related data using pre and postoperative ultrasound and MSCT examination, while MMP-9 levels will be measured before procedure and after the procedure using the same protocol as for primary procedure. Statistical analysys Levels of MMP-9 in serum with presence of different types of endoleak will be correlated one week and 1,6,12,18,24,36 48 months after the procedure Anatomical data will be correlated with the decrease in MMP-9 level before and after procedure Levels of MMP-9 in serum after one week and one month will be correlated with further aneurysm shrinkage Level of MMP-9 in serum with type of endoleak will be correlated Level of MMP-9 before and after reoperation will be compared Level of MMp-9 in serum of patients with disappearing endoleaks will be followed Level of MMP-9 in serum of patients with new endoleaks will be followed

Ten percent of the population above 60 years develops an aortic abdominal aneurysm. In case of rupture, this pathology leads to death in more than 70% of the cases. Over the past ten years, Endovascular Aortic Aneurysm Repair (EVAR) has been the most used technique for elective treatment for abdominal aortic aneurysms (AAA) in patients with a favorable anatomy. But despite excellent postoperative results with a significant reduction of mortality , a close follow-up of these patients is mandatory to detect any potential endoleaks particularly in patients with a long-life expectancy. Failed Endovascular Infrarenal Aortic Aneurysm Repair (EVAR) with development of a proximal endoleak exposes the patient to the risk of rupture and must be treated. This type of endoleaks are often related to dilatation of the proximal neck of the AAA, and of the suprarenal aorta, making the use of any aortic fixation system, or uncovered stent ineffective. In these cases, open surgical conversion with stent graft removal is possible but at the price of a significant morbidity and mortality. The alternative is the use of a fenestrated or branched stent graft (F/BEVAR) extending the proximal sealing zone to a non-diseased aorta. The goal of this study was to evaluate the technical feasibility, early and midterm outcomes of (F/BEVAR) in patients with a proximal endoleak following a standard EVAR. The investigators performed a multicentre study between January 2010 and December 2019 in 8 French University Centres which included 85 patients with 3 years of post operative follow-up.

X-ray computed tomography imaging (CT) is routinely used in follow-up after endovascular aneurysm repair (EVAR). Contrast-enhanced ultrasound (CEUS) has been shown to give accurate information about endoleak after EVAR. Benefits of CEUS over CT include less radiation exposure, avoidance of renal function deterioration due to repeated X-ray contrast agent application and decrease in the cost of EVAR follow-up. This study is designed to investigate if results from literature are reproducible in St Olavs Hospital in Trondheim (Norway), to gain experience with the technique and to introduce CEUS as an alternative for detection of endoleak in this hospital.

Re-hospitalization or re-intervention is sometimes necessary to treat type I and type III endoleaks after EVAR for its persistent increasing of pressure in aneurysm lumen. Color-coded quantitative digital subtraction angiography (CQDSA) provides an easy and quick way to post-process the traditional digital subtraction angiography (DSA) which converts the peak time of the maximal contrast medium intensity into a single polychromatic image. With the help of CQDSA, a quantitative evaluation of the endoleak hemodynamics and a risk analysis of the type I or type III endoleak could be performed during the EVAR procedure. This approach may offer an objective assessment of the needs for immediate re-intervention, conservative therapy or treatment endpoint in the future.

This study will be a cross-sectional survey of interobserver variability associated with contrast enhanced ultrasound (CEUS) to detect endoleaks using computed tomographic angiography (CTA) as the practice standard. The investigators will enroll 40 consecutive patients undergoing endovascular abdominal aortic aneurysm repair (EVAR). At the first follow-up visit after the procedure, participants will undergo two abdominal ultrasound examinations with and without contrast, and one CTA. Analyses will be conducted to examine interobserver variability in the detection and characterization of endoleaks using contrast-enhanced ultrasound (CEUS). Other endpoints include examination of sensitivity and specificity of CEUS compared to CTA, and characterization of the number and types of endoleaks detected.

Abdominal Aortic Aneurysm (AAA) is a known vascular entity that may be life threatening condition .The most common treatment approach nowadays is the endovascular approach, a procedure known as endovascular aortic repair (EVAR). The most common procedure related complication is the expansion of the aneurysm from a "feeding vessel", usually a lumbar or intercostal artery. Another known complication is an endoleak from the stentgraft.Today, accepted EVAR follow up protocol consists of one multiple multiphasic CT angiography (CTA) scan, one month after the procedure and ultrasound exams there after . Ultrasonography is a useful method for detection and evaluation of AAA, has no ionizing radiation and is useful for the dynamic estimation of the aortic width in patients post EVAR. However, the sensitivity of ultrasonography solely for detection of endoleaks in post EVAR patients is not high.In recent years, the development of "fusion" applications allows the dual modality merge between ultrasound and CT scans that can be used as follow up examinations of known imaging findings on CT .Another application that had been developed for ultrasound machines is the ability to generate a 3 dimensional (3D) reconstruction which allows more precision. In the recent year the usage of intravenous contrast agent for ultrasonography based on microbubbles (BRACO SONOVIEW) has been approved by the Israeli ministry of health. This contrast agent is not nephrotoxic and the risk for allergic reaction is very low statistically similar to Gadolinium.A 3D contrast enhanced ultrasonography "fused" together with CTA may be a helpfull addition , which lacks radiation and odine contrast reactions and nephrotoxicity ,in the follow up in post EVAR patients , by means of identifing endoleaks at an earlier stage than by ultrasound alone. The purpose of our research is to evaluate the combined modality (fusion of CTA with CEUS) mentioned above in identifing early endoleaks in post EVAR patients and thus enabilng early intervention when needed

A single site cross-sectional comparison of paired diagnostic imaging modalities. This study will show the sensitivity and specificity of CEUS in detecting the various types of endoleaks, in comparison to tCTA, following EVAR. It will collect data to allow comparison of diagnostic accuracy across modalities including CDU, CEUS and tCTA. It will collect time taken to perform the various types of scan, to allow healthcare costs to be calculated for each imaging modality.