Condition category
Circulatory System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Narrowing or blockages in the major arteries (aorto-iliac occlusive disease) can cause reduced blood flow to areas of the body leading to symptoms of pain (especially on movement) and tissue death (gangrene).

This is currently treated in Europe primarily using keyhole surgery techniques. These techniques are referred to as endovascular surgery. This may involve inserting a stent to keep the artery open for sufficient blood flow. The patient outcomes of these new techniques in treating blocked major arteries in the body are not well known.

Covered Endovascular Reconstruction of Aortic Bifurcation (CERAB) is a technique described to treat extensive aorto-iliac occlusive disease, especially in high risk patients. Despite promising outcomes from three years of research in cohorts from single hospitals, there is a lack of published results from other centres being able to reproduce these outcomes of this technique. Additionally, there are not currently results comparing the use of stent grafts (covered stents) and Bare Metal Stenting (BMS) for the endovascular treatment of aorto-iliac disease.

This study will look at the fate of patients who had this kind of treatment in many centres across Europe. The study aims to provide an understanding of what problems patients face following the surgeries and how optimal treatment can be provided.

Who can participate?
Information will be collected from patients who received treatment for aorto-iliac occlusive disease using endovascular surgery.

What does the study involve?
This is an observational trial. Patients will receive standard clinical care as per local policies and physicians' preference, and will not be required to attend any additional follow-up beyond standard care.

What are the possible benefits and risks of participating?
Only patients who have already had their surgery will be reported as part of this study. This project will have absolutely no impact on the clinical care of patients. No identifiable information will be collected and reported. There are no risks of participating as essentially the clinical care remains exactly the same.

Where is the study run from?
1. Guy's and St Thomas' NHS Foundation Trust (UK)
2. Leicester Vascular Institute (UK)
3. St Franziskus Hospital Münster (German)

When is the study starting and how long is it expected to run for?
Information for patients who had their surgery from May 2016 to April 2020 will be collected and reported

Who is funding the study?
This study is investigator-initiated and funded

Who is the main contact?
Dr Hany Zayed

Trial website

Contact information



Primary contact

Mr Hany Zayed


Contact details

Vascular Surgery Department
St Thomas' Hospital
Westminster Road
1st floor
United Kingdom
+44 02071887188

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number


Study information

Scientific title

Covered Stents vs Bare Metal Stent Endovascular Reconstruction for Aortic Occlusive Disease (COBRA registry)


COBRA Registry

Study hypothesis

To describe the short and medium-term outcomes following Covered Endovascular Reconstruction of Aortic Bifurcation (CERAB) and compare these with the performance of Bare Metal Stenting (BMS) reconstructions in a multicentre registry.

Ethics approval

1. NHS ethics approval not required as per HRA opinion March 2020, this registry does not impact on the pathway of clinical care and no identifiable data are collected. This is an observational study. Each centre outside the United Kingdom should seek all relevant approvals as per their local/national policies before commencing data collection of any description.
2. Ethical approval will be sought locally in Germany (St. Franziskus Hospital in Muenster) but this had been delayed due to the current public health emergency.

Study design

International multicentre cohort study

Primary study design


Secondary study design

Cohort study

Trial setting


Trial type


Patient information sheet

No participant information sheet available


Aortoiliac steno-occlusive arterial disease with ischaemic pain at rest or when walking (claudication) or tissue loss (gangrene)


This is an observational trial using retrospective data. Patients will receive standard clinical care as per best available evidence, local/regional/national care pathways, and physicians' preference using CERAB/endovascular treatment of aorto-iliac disease using a combination of covered stents and BMS in the aorta. Patients will not have any additional follow up, assessment or reporting to the investigators beyond standard clinical care. The surgical techniques and stents used, as well as patient outcome data, will be collected from clinician notes. No patient identifiable data will be collected or communicated.

Intervention type



Not Applicable

Drug names

A variety of BMSs and covered stents may be used as per local policies and physicians' preferences.

Primary outcome measure

Re-intervention-free-survival, defined as the composite endpoint of target lesion revascularization (TLR) and/or death, whichever occurred first, obtained from clinician notes collected at day of discharge from hospital, 30 days after the procedure, and latest available follow-up.

Secondary outcome measures

The following outcome measures will be obtained from clinician notes, collected at day of discharge from hospital, 30 days after the procedure, and latest available follow-up
1. Acute technical success
2. 30-days morbidity
3. 30-days mortality
4. Overall mortality
5. Conversion-to-surgery free time
6. Re-intervention free time

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Infrarenal chronic aorto-iliac occlusive/stenotic symptomatic disease for >14 Days
2. Treatment by an aortic stent graft or bare metal stent with or without iliac stenting

Participant type


Age group




Target number of participants

Observational study - no actual target.

Participant exclusion criteria

1. Acute aortic occlusive disease
2. Aneurysm related interventions
3. Previous aorto-iliac stenting or In-Stent-Restenosis
4. Aortic coarctation
5. Isolated Kissing-Stent-Reconstruction without aortic stents
6. Aortic injury/trauma related interventions
7. Suprarenal/visceral segment reconstructions

Recruitment start date


Recruitment end date



Countries of recruitment

Belgium, France, Germany, Greece, Italy, Netherlands, Spain, United Kingdom

Trial participating centre

Guy's and St Thomas' NHS Foundation Trust
Vascular Surgery Department St Thomas' Hospital Westminster Road, 1st floor
United Kingdom

Trial participating centre

St Franziskus Hospital Münster
Department of Vascular Surgery Hohenzollernring 70

Trial participating centre

Leicester Vascular Institute
Glenfield Hospital Groby Road
United Kingdom

Sponsor information


Guy's and St Thomas' NHS Foundation Trust

Sponsor details

St Thomas' Hospital
Vascular Surgery Department North Wing
Westminster Bridge Road
United Kingdom
+44 02071887188

Sponsor type

Hospital/treatment centre



St. Franziskus Hospital

Sponsor details

Hohenzollernring 70
+49 0251 9350

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Investigator initiated and funded

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Publication and dissemination intended in peer-reviewed journal, conferences, and online media.

IPD sharing statement:
The data sharing plans for the current study are unknown and will be made available at a later date

Intention to publish date


Participant level data

Not expected to be available

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

01/05/2020: Trial’s existence confirmed by University Hospitals of Leicester Department of Audit and Service Provision.