Abdominal Aortic Aneurysm
Conditions
Keywords
Abdominal Aortic Aneurysm
Brief summary
The purpose of this trial is to assess whether a strategy of endovascular repair (if aortic morphology is suitable, open repair if not) versus open repair reduces early mortality for patients with suspected ruptured abdominal aortic aneurysm (AAA).
Detailed description
Rupture of the main blood vessel of the body in the abdomen (ruptured abdominal aortic aneurysm) is fatal in over three-quarters of cases. In the past, those that survive have reached hospital alive and undergone emergency open surgery to repair the aneurysm and stop the bleeding: however, after this major emergency surgery only half the patients leave hospital alive. A newer, less-invasive method of aneurysm repair, endovascular repair, is based on repairing the aneurysm by inserting the repair graft up through one of the arteries in the groin. Endovascular repair has been tested in the elective situation and is associated with a 3-fold reduction in operative mortality versus the standard open surgery. Early work with selected patients has suggested that endovascular repair may be associated with up to a 2-fold reduction in operative mortality and more rapid recovery for ruptured abdominal aortic aneurysms. However, only 55-70% patients are anatomically suitable for endovascular repair. Therefore, this research aims to determine whether a strategy of preferential emergency endovascular repair reduces both the mortality and cost of ruptured abdominal aortic aneurysm. Critically ill patients with a clinical diagnosis of ruptured aneurysm will be randomised, in the emergency room, to a strategy of endovascular repair if possible (endovascular first) or to current standard care (immediate transfer to the operating theatre for emergency open surgery). Patients randomised to endovascular first will require a specialist radiological examination (computed tomography, CT scan) to assess anatomical suitability and plan for endovascular repair. This will cause a short delay before definitive repair can be commenced. Those patients not suitable for endovascular repair, after CT scan, will be taken for standard open surgery. Patients will be randomised at 16-20 specialist centres in the United Kingdom (UK), who have already attained sufficient experience in using endovascular repair for ruptured aneurysms and can offer a routine service. The primary outcome measure is 30-day operative mortality, which we hope will improve by 14% with the endovascular first strategy (from 47% to 33%). Secondary outcome measures include 24h, in-hospital and 1-year and 3-year mortality, re-interventions associated with the two treatment strategies as well as quality of life, costs and cost-effectiveness. The research team includes specialists in clinical trials, health economics, statistics, pre-hospital & emergency care, interventional radiology, vascular & endovascular surgery, critical care, aneurysm research and a service user.
Interventions
PROCEDUREOpen repair
Standard treatment of emergency open surgery
PROCEDUREEVAR
Emergency endovascular aneurysm repair
Sponsors
London School of Hygiene and Tropical Medicine
University of Cambridge
The Leeds Teaching Hospitals NHS Trust
St George's, University of London
Imperial College London
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Clinical suspicion of ruptured abdominal aortic aneurysm after review in Accident and Emergency (or other hospital unit). * Men and women over the age of 50 years will be recruited.
Exclusion criteria
* Patients with known connective tissue disorders (eg Marfan syndrome) where endovascular repair may not be beneficial. * Patients with known previous repair of an abdominal aortic aneurysm, because procedures either open or endovascular are likely to be very complex and there are no guidelines for anatomical restriction to repair. * Deeply unconscious and moribund patients since the chances of recovery are minimal.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mortality | 30 days, 1-year and 3-years from randomisation | Mortality, at 3 pre-specified time points |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Quality-adjusted Life Years (QALYs) to Enable Cost-effectiveness Evaluation | 3-years from randomisation | QALYs are a product of length of life and quality of life, since both of these are important to patients. Therefore, it is a measure of the state of health of a person or group in which the benefits, in terms of length of life, are adjusted to reflect the quality of life. One QALY is equal to 1 year of life in perfect health. QALYs are calculated by estimating the years of life remaining for a patient following a particular treatment or intervention and weighting each year with a quality-of-life score (on a 0 to 1 scale). It is often measured in terms of the person's ability to carry out the activities of daily life, and freedom from pain and mental disturbance. |
| Hospital Costs to Enable Cost-effectiveness Evaluation | 3 years | Hospital costs to enable cost-effectiveness evaluation in Pounds (£) |
Countries
Canada, United Kingdom
Participant flow
Recruitment details
Recruitment from 1st September 2009 to 31st July 2013. After 600 recruitment target 13 more patients were randomised before sites could be closed down.
Pre-assignment details
Exclusions: persons younger than 50 years, prior AAA repair
Participants by arm
| Arm | Count |
|---|---|
| Open Repair Immediate Open Surgery
Open repair: Standard treatment of emergency open surgery | 297 |
| Endovascular Strategy Endovascular strategy involves immediate computed tomography (CT) and emergency EVAR, with open repair for patients anatomically unsuitable for EVAR
EVAR: Emergency endovascular aneurysm repair | 316 |
| Total | 613 |
Baseline characteristics
| Characteristic | Open Repair | Endovascular Strategy | Total |
|---|---|---|---|
| Age, Continuous | 76.7 years STANDARD_DEVIATION 7.8 | 76.7 years STANDARD_DEVIATION 7.4 | 76.7 years STANDARD_DEVIATION 7.6 |
| Race and Ethnicity Not Collected | — | — | 0 Participants |
| Region of Enrollment Canada | 6 participants | 7 participants | 13 participants |
| Region of Enrollment United Kingdom | 291 participants | 309 participants | 600 participants |
| Sex: Female, Male Female | 63 Participants | 70 Participants | 133 Participants |
| Sex: Female, Male Male | 234 Participants | 246 Participants | 480 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 297 / 297 | 316 / 316 |
| other Total, other adverse events | 3 / 243 | 5 / 259 |
| serious Total, serious adverse events | 125 / 297 | 117 / 316 |
Outcome results
Primary
Mortality
Mortality, at 3 pre-specified time points
Time frame: 30 days, 1-year and 3-years from randomisation
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Open Repair | Mortality | 1-year mortality | 133 Participants |
| Open Repair | Mortality | 3-year mortality | 165 Participants |
| Open Repair | Mortality | 30-day mortality | 111 Participants |
| Endovascular Strategy | Mortality | 30-day mortality | 112 Participants |
| Endovascular Strategy | Mortality | 1-year mortality | 130 Participants |
| Endovascular Strategy | Mortality | 3-year mortality | 151 Participants |
Secondary
Hospital Costs to Enable Cost-effectiveness Evaluation
Hospital costs to enable cost-effectiveness evaluation in Pounds (£)
Time frame: 3 years
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Open Repair | Hospital Costs to Enable Cost-effectiveness Evaluation | 19483 GBP (£) | Standard Deviation 22412 |
| Endovascular Strategy | Hospital Costs to Enable Cost-effectiveness Evaluation | 16878 GBP (£) | Standard Deviation 19624 |
Secondary
Quality-adjusted Life Years (QALYs) to Enable Cost-effectiveness Evaluation
QALYs are a product of length of life and quality of life, since both of these are important to patients. Therefore, it is a measure of the state of health of a person or group in which the benefits, in terms of length of life, are adjusted to reflect the quality of life. One QALY is equal to 1 year of life in perfect health. QALYs are calculated by estimating the years of life remaining for a patient following a particular treatment or intervention and weighting each year with a quality-of-life score (on a 0 to 1 scale). It is often measured in terms of the person's ability to carry out the activities of daily life, and freedom from pain and mental disturbance.
Time frame: 3-years from randomisation
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Open Repair | Quality-adjusted Life Years (QALYs) to Enable Cost-effectiveness Evaluation | 0.97 life-years | Standard Deviation 1.02 |
| Endovascular Strategy | Quality-adjusted Life Years (QALYs) to Enable Cost-effectiveness Evaluation | 1.14 life-years | Standard Deviation 1.03 |