Active clinical trials for "Aortic Aneurysm, Abdominal"

A major determinant of perioperative mortality is the inability of the heart to increase its output in response to surgical stress. This is termed perioperative cardiac failure (PCF), and may only be apparent postoperatively when oxygen demand is increased. The risk of perioperative cardiac complications is the summation of the individual patient's risk and cardiac stress related to the surgical procedure1. The functional capacity of the patient determines their ability to support the postoperative demand of increased oxygen consumption, and therefore of cardiac output. Exercise capacity is one of the most powerful predictors of cardiovascular and all cause mortality2. Cardiopulmonary exercise test (CPET) is an established investigation used, among other applications, in the preoperative assessment of patient fitness for surgery3. CPET involves monitoring the electrocardiographic trace and the exhaled gas mixture (particularly CO2, whose production depends on aerobic metabolism), during incremental exercise (usually on an exercise bike), on room air. Several parameters can be measured during CPET, including maximal systemic oxygen delivery, the anaerobic threshold (the oxygen delivery value at which anaerobic metabolism begins), maximum workload, and ST segment depression/elevation (as in a standard exercise tolerance test). The cardiopulmonary "performance" during CPET has been correlated with postoperative outcome3. Pulmonary function tests will be performed in order to assess lung function. It is well known that therapy with beta-blockers in patients with ischaemic heart disease and cardiac failure reduces perioperative morbidity and mortality4-7. However, beta blockers reduce myocardial contractility and the heart rate response to adrenergic stimulation, thus blunting the physiological response to stress/surgery/exercise. Whilst this mechanism may protect the heart perioperatively, it may decrease the ability of some patients to withstand other complications. This potential decrease in "performance" has never been quantified. There is no agreement on whether preoperative CPET should be performed on or off beta-blockers and, at Aintree in particular, it is standard procedure to take patients off beta-blockers prior to their CPET. Some argue that, as beta-blockade should be maintained in the perioperative period, CPET should be performed on medications, even if these could mask the presence significant ischaemic heart disease (a significant, modifiable, risk factor for surgery by beta blockade), and even if it is not always possible to maintain beta-blockade throughout the whole postoperative period. For these reasons, other clinicians prefer to perform CPET off beta-blockers, thus, potentially, overestimating the perioperative cardiorespiratory "performance", which may be diminished once the medications are resumed. Patients on long-term beta blockade may develop some tolerance to the medications, so the effect of acute and chronic beta blockade on cardiorespiratory performance may also be different. Aim To compare cardiopulmonary performances on and off beta blockers as objectively assessed by cardiopulmonary exercise testing.

Late endovascular abdominal aneurysm repair (EVAR) complications not amenable to endovascular correction can undergo either late open conversion (LOC) or semi-conversion (SC). LOC is defined as a total or partial endograft explantation >30 days after the initial EVAR. SC is defined as open or laparoscopic surgery for endoleak (EL) correction with complete endograft preservation. The aim of this study is to collect in a prospective database the technical aspects of a multicenter experience of LOC and SC, and to analyse early and long-term outcomes of these two treatments.

The purpose of this research study is to look at whether an investigational imaging agent, 64Cu-DOTA-ECL1i, used during Positron Emission Tomography (PET)/ Computed Tomography (CT) scanning, can help to identify conditions that place patients at an increased risk for AAA rupture. The study is also looking more closely at cellular, molecular and inflammatory properties of the aortic wall. Having the ability to identify markers that predict AAA progression/expansion and risk for rupture could allow the physician to manage patients in a more individualized, personal way.

The strength of movement which are applied on the EVAR are not only cranio-caudal but also lateral. The movement of the EVAR's body within the aneurysm could be an instability's criteria of the EVAR. The investigators would like to show that this lateral movement is a risk factor of reintervention they should follow and suggest a reinforced medical follow-up to avoid complications.

In many countries the gold standard for treating abdominal aortic aneurysms is still open surgery with a long incision. In patients with suitable anatomy alternatively an endovascular approach can be chosen. Since open surgery is more durable in many countries a laparoscopic procedure using " key hole surgery " has gained wider acceptance. The current study wants to prove that laparoscopic aortic aneurysm procedures are less invasive than open surgery with reduced recovery times.

The purpose of the study is to compare two different types of imaging techniques to identify endoleaks. Following the endovascular procedure, subjects are seen at one month to have computed tomographic angiography (CTA) to confirm the graft is not leaking (endoleak). CTA is the standard imaging technique used to identify endoleaks. This study will investigate if the image technique color duplex ultrasound with contrast enhanced ultrasound (CEUS) is a good tool to identify endoleaks too.

A retrospective cohort study of computed tomography scans of AAA patients considered for repair, in order to identify sex specific differences in abdominal aortic aneurysm (AAA) metrics and the association between anatomical differences/features of complexity and adverse patient outcome.

The primary objective of this research project is development and validation of a new, non-contrast gated aortic (NCGA) computer tomography scan algorithm for screening of aortic aneurysm in the chest and abdomen in at risk patients. This study would initially be performed in patients with a known aneurysm and done in addition to their indicated surveillance CT scan.

An aneurysm is a permanent and localized dilatation of an artery usually more than 50% of its normal diameter. Abdominal Aortic Aneurysms (AAA) is an aneurysm of the main artery of abdomen and affects 5% of men aged 65-74 years. Rupture of an aneurysm is the 10th leading cause of death in white men over 65 years of age in industrial countries. Treatment of asymptomatic AAA is considered when the diameter of an AAA reaches 5.5 cm. There are two treatment options available: conventional open surgical repair or endovascular repair, which is a less invasive mode of treatment. After the operation heart and lung complications are significant in patients undergoing major abdominal surgery. The commonest causes of death are due to heart problems. There are various studies which have shown benefits of pre operative exercise training in patients undergoing orthopaedic, lung and heart bypass surgery. Currently, there is no data available with regards to the effect of pre-operative (before operation) supervised exercise in patients undergoing surgery for an AAA. The main aim of this study will be to determine whether a pre-operative supervised exercise programme improves post-operative (after operation) outcome, compared to standard treatment. Patients will be entered in the study once a decision to repair their AAA has been made by the consultant. They will undergo pre-operative assessment and will be divided randomly into two groups. One group will have exercise training for 4-6 weeks before surgery and the other will not. After the operation they will be followed during the post-operative period to determine the presence or absence of complications. It is anticipated that complications will be less in the group which has undertaken exercise training before operation.

The role of teleradiology has far reaching implications for the health of remote and underserved populations. The ability to coordinate radiographic evaluation and diagnosis from a distance has the potential to raise the standard of patient care throughout the world. Perhaps the safest and most cost effective mode of teleradiology today is telesonography. The current project attempts to determine the extent that telesonography improves the standard of care within a rural government-run primary clinic within the Dominican Republic. The work reported herein is intended to compare the use of telesonography to the current standard of sonographic examination (referral to government hospital 60km from target clinic). The study was conducted by randomly assigning 100 patients with clinical indications for sonographic examination into experimental and control groups. Following a 60-day implementation period, the following research questions will be addressed: 1) To what extent does the use of asynchronous telesonography increase the percentage of definitive diagnoses based on the total number of scans (definitive diagnoses / total number of scans)? 2) To what extent does the use of asynchronous telesonography increase the continuity of care for patients? 3) To what extent does the elapsed time between scanning and final radiological interpretation decrease with the use of asynchronous telesonography? This study will also look at the history of telemedicine / telesonography and its dissemination into the mainstream practice of medicine, explore training protocols that may be used to assist others to establish new telesonography programs in a developing nations, and discuss both advances and persistent barriers to the implementation of telesonography programs. Hypothesis: The use of a store-and-forward telesonography system in this setting will increase the speed and number of final diagnoses per scan received by the target clinic and will increase the continuity of care by increasing the number and speed of follow-up appointments to the target clinic.