Contact information
Type
Scientific
Primary contact
Dr Vilas Navapurkar
ORCID ID
Contact details
Box 17
Addenbrooke's Hospital
Cambridge
CB2 2QQ
United Kingdom
+44
vilas.navapurkar@addenbrookes.nhs.uk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
N0544174260
Study information
Scientific title
Acronym
Study hypothesis
To measure the effect of a non-invasive technique called ischaemic preconditioning (IPC) on cardiac function during surgery to repair aortic aneurysms (an abnormal dilatation of the major artery in the body).
Ethics approval
Not provided at time of registration
Study design
Randomised controlled trial
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Not specified
Trial type
Treatment
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Condition
Surgery: Open abdominal aortic aneurysm repair
Intervention
The technique of IPC temporarily reduces the blood flow to the patients legs in sequence for five minutes at a time. This causes the muscle in the patients legs to release various chemicals that can protect tissue against damage due to periods of reduced blood and oxygen supply. Once blood flow to the leg is fully restored, these substances enter the general circulation and can protect distant organs such as the heart, brain or kidneys from damage due to reduced blood flow. The Vascular Research Unit at Addenbrookes Hospital has shown that IPC reduces the levels of a protein in the blood called troponin I which is a marker of heart muscle damage.
We would like to investigate the effect of IPC on heart function by using established perioperative cardiovascular monitoring techniques.
IPC is not standard practice in major vascular surgery at present.
The Vascular Research Unit is undertaking a randomised controlled trial to look at the effect of IPC on renal function during AAA repair. We would like to use the monitoring techniques outlined below in the patients assigned to IPC in the randomised controlled trial to collect prospective data on how IPC effects heart function.
The patients assigned to the IPC group will have the blood flow to their legs reduced for two five minute periods by clamping the main artery to each leg in turn during the early stages of their operation. Cardiac output and allied haemodynamic data will be measured with a LiDCO monitor. This is a minimally invasive, continuous method of measuring cardiac output and deriving cardiac index, systemic vascular resistance and stroke volume variance. These are routine measures of cardiac function. This monitor uses clinically insignificant doses of intravenous lithium that are non toxic and do not harm or affect the patient in any way. The monitor is used routinely on patients in the Intensive Care Unit and HDU in Addenbrooke's hospital. The LiDCO is attached to an arterial drip. A central venous drip is also required as a port of injection for the lithium. Both of these drips are sited as routine monitors during such surgery and maintained in the post operative period. A 12 lead ECG monitor will be used to measure any cardiac ischaemia and serum troponin I levels to measure any cardiac injury.
No adverse events have been reported during IPC in previous trials by the Vascular Research Unit. The additional monitoring will not be in any way harmful to the patient and is routinely employed in many UK hospitals. Patients will be given an information sheet about the study when they attend outpatients about eight weeks before surgery. Contact details will be provided should they wish to discuss the study further. There will be opportunity to discuss any issues at the pre-admission clinic. All these patients are admitted the day before surgery. They will then be asked if they wish to participate in the study. Written informed consent will be obtained.
Intervention type
Procedure/Surgery
Phase
Not Specified
Drug names
Primary outcome measure
Cardiac output measurement.
Secondary outcome measures
Not provided at time of registration
Overall trial start date
31/03/2006
Overall trial end date
31/03/2009
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
Any patient scheduled to undergo elective infra-renal aneurysm repair will be eligible for inclusion. The following entry criteria with respect to renal function shall apply:
1. No history of acute renal failure
2. No history of renal replacement therapy (haemodialysis, haemofiltration, peritoneal dialysis)
3. No previous renal transplant
4. No previous renal disease
5. Serum creatinine less than 150 micromols/L at pre-operative assessment
6. Serum urea less than 20 mmols/L at pre operative assessment
Participant type
Patient
Age group
Adult
Gender
Not Specified
Target number of participants
40 - 9 patients as of July 2008
Participant exclusion criteria
1. Patients with aneurysms above the level of the renal arteries have a very high risk of renal damage during surgery. These aneurysms are relatively uncommon. Their inclusion could bias the trial.
2. Patients with lower limb amputations will be excluded as they have less muscle in their lower limbs. Thus, the IPC stimulus could be inadequate and bias the trial results.
3. Patients with ankle-brachial pressure index < 0.7 will be excluded as the IPC technique could trigger acute lower limb ischaemia.
4. Patients who have undergone previous endovascular repair of the aneurysm will be excluded.
Recruitment start date
31/03/2006
Recruitment end date
31/03/2009
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Box 17
Cambridge
CB2 2QQ
United Kingdom
Sponsor information
Organisation
Record Provided by the NHSTCT Register - 2006 Update - Department of Health
Sponsor details
The Department of Health
Richmond House
79 Whitehall
London
SW1A 2NL
United Kingdom
+44 (0)20 7307 2622
dhmail@doh.gsi.org.uk
Sponsor type
Government
Website
Funders
Funder type
Government
Funder name
Cambridge Consortium - Addenbrooke's (UK) - Own Account
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list
1. 2009 results in Haemodynamic effects of ischaemic preconditioning during open abdominal surgery; S Yarham, S Bass, A Beane, S Walsh, ME Gaunt, VU Navapurkar; Abstracts of the Proceedings of the Anaesthetic Research Society; BJA 2009, 102 (4) 575 576P