Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
A major and increasing problem in liver transplantation is the shortage of donor livers, which forces the use of lower quality organs for transplantation (e.g. donor´s age over 65). New techniques are therefore needed to preserve donor livers before implantation. Treating the organs with oxygen gas (oxygenation) not only maintains the cell structures of the treated organ but also enables the repair of damaged structures. The aim of this study is to assess the effectiveness of short-term oxygenation (performed for 2 hours immediately before transplantation) in liver preservation to improve organ function especially during the critical first three days after transplantation.

Who can participate?
Patients over 18 years of age scheduled for their first liver transplantation

What does the study involve?
Participants are randomly allocated to one of two groups. For one group the donor liver is oxygenated for two hours before implantation. The other group receive standard care (cold storage of the donor liver without further treatment before implantation). Blood samples are taken daily for the first six days following surgery, at the day of discharge from the hospital and at each follow-up visit (every three months for up to three years). Complications reported by the participant are recorded at the day of discharge and at each follow-up visit. To assess the effectiveness of the treatment we measure blood values reflecting the quality of liver function, the duration of intensive care needed after surgery, and the rate of further transplants and deaths during the three months following transplantation.

What are the possible benefits and risks of participating?
Not provided at time of registration

Where is the study run from?
University Hospital of Essen (Germany)

When is the study starting and how long is it expected to run for?
August 2011 to September 2013

Who is funding the study?
Deutsche Forschungsgemeinschaft (German Research Community) (Germany)

Who is the main contact?
Prof. Dr. med. Andreas Paul

Trial website

Contact information



Primary contact

Prof Andreas Paul


Contact details

University of Duisburg-Essen
Hufelandstrasse 55

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Randomized controlled clinical trial to investigate oxygen persufflation as adjunct in liver preservation



Study hypothesis

Vascular oxygen persufflation of liver grafts in hypothermic condition performed for 2 hours prior to implantation maintains cell and organ integrity and function and also enables to some extend the repair of damaged structures and restoration of cellular ion and signal homeostasis. Thus the rate and severity of early graft dysfunction events can be lowered and the viability of marginal quality grafts increased. The aforementioned effects have been shown in a large animal model. The safety of the procedure and its applicability to the human situation has already been demonstrated as well. This trial is designed as a final proof-of-concept study aiming to establish oxygen persufflation as valuable adjunct in clinical liver preservation.

Ethics approval

Ethics Committee, Medical Faculty, University of Duisburg-Essen (Ethik-Kommission der Medizinischen Fakultät der Universität Duisburg-Essen), 10/01/2011, ref: 09-4281

Study design

Single-center randomized controlled single-blind clinical proof-of-concept study with two parallel arms

Primary study design


Secondary study design

Randomised parallel trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Preservation and implantation of liver grafts


In the treatment group donor livers will be subjected to 2 hours of venous systemic oxygen persufflation prior to implantation, while still being stored in ice cold preservation solution.

In the control group the standard preservation method will be applied (hypothermic storage without oxygen persufflation)

Intervention type



Not Applicable

Drug names

Primary outcome measure

Serum peak value of systemic aspartate aminotransferase during the first three days after transplantation

Secondary outcome measures

1. Death
2. Retransplantation within 3 months after implantation
3. Time of stay in intensive-care-unit
4. Hepatic tissue perfusion one hour after revascularization
5. Early onset of graft dysfunction (based on Quick´s value as well as the use of a refined scoring-system for initial graft function based on a multi-parameter [aspartate transaminase (AST), alanine aminotransferase (ALT), Quick and bilirubin] score according to Heise and co-workers

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Men and women beyond 18 years of age
2. Resident in Germany
3. Scheduled for first liver transplantation and graft already available
4. Patient is willing and able to attend regular follow up examinations
5. Written informed consent

Donor organs:
1. Donor grafts that are offered to the local transplant clinic for implantation, i.e. ‘organ rescue offers’
2. Donor age above 65

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Listed as high urgency (HU)
2. Participation in this study at an earlier time
3. Simultaneous participation in other clinical trial
4. Present alcohol or drug abuse
5. Positive test for human immunodeficiency virus (HIV)
6. Pregnant or nursing

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

University of Duisburg-Essen

Sponsor information


University Hospital Duisburg-Essen (Germany)

Sponsor details

Hufelandstrasse 55

Sponsor type

Hospital/treatment centre



Funder type

Research organisation

Funder name

Deutsche Forschungsgemeinschaft (MI 470/14-2)

Alternative name(s)

German Research Foundation, German Research Association, DFG

Funding Body Type

private sector organisation

Funding Body Subtype

Trusts, charities, foundations (both publically funded and privately funded)



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

2011 protocol in:

Publication citations

  1. Protocol

    Minor T, Pütter C, Gallinat A, Ose C, Kaiser G, Scherag A, Treckmann J, Paul A, Oxygen persufflation as adjunct in liver preservation (OPAL): study protocol for a randomized controlled trial., Trials, 2011, 12, 234, doi: 10.1186/1745-6215-12-234.

Additional files

Editorial Notes

05/08/2016: Plain English summary added.