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Liver CirrhosisNCT07658794

Intraoperative Assessment of Microcirculatory Function Using Vascular Occlusion Test During Liver Transplantation

An observational study of Liver Cirrhosis and Early Allograft Dysfunction, run by Ippokrateio General Hospital of Thessaloniki at 1 site in Greece.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

Early allograft dysfunction (EAD) remains one of the most important complications following orthotopic liver transplantation (OLT). Currently, there is no established intraoperative biomarker that reliably predicts graft dysfunction at an early stage. Read more about this study

Who is it for?
Any age
Conditions the study is for
Liver Cirrhosis, Early Allograft Dysfunction
How many people
50 participants
Where
1 siteGreece
Study dates
Jun 2026to Jun 2027
How long will I take part?
30 Days
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages Any age
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Study population: The study population will consist of adult patients undergoing orthotopic liver transplantation at the participating center. Eligible patients will be enrolled before surgery and monitored intraoperatively using Near-Infrared Spectroscopy during standardized Vascular Occlusion Tests. The cohort will include liver transplant recipients managed according to standard institutional anesthetic, surgical and postoperative care protocols

Who may be able to join

  • Adult patients aged 18 years or older
  • Patients scheduled to undergo orthotopic liver transplantation
  • Ability to obtain intraoperative Near-Infrared Spectroscopy measurements
  • Written informed consent obtained before enrollment

Who cannot join

  • Age younger than 18 years
  • Refusal or inability to provide informed consent
  • Emergency liver transplantation without sufficient time for enrollment
  • Inability to perform the Vascular Occlusion Test or obtain reliable NIRS measurements
  • Severe peripheral vascular disease or local upper-limb conditions interfering with monitoring

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Dimitrios Zafeiriadis, MD contact

+306980422306 ext. +30

imdzaf@gmail.com

Greece1 site
  • Ippokrateio General Hospital of Thessaloniki

    Thessaloniki, Thessaloniki, 54642

    Dimitrios Zafeiriadis, MD, +306980422306 ext. +30, imdzaf@gmail.com

Other trials in Greece

About this study

Official title: The Predictive Value of the Vascular Occlusion Test During Orthotopic Liver Transplantation for the Development of Early Allograft Dysfunction

Early allograft dysfunction (EAD) remains one of the most important complications following orthotopic liver transplantation (OLT). Currently, there is no established intraoperative biomarker that reliably predicts graft dysfunction at an early stage. Near-infrared spectroscopy (NIRS) combined with the vascular occlusion test (VOT) is a non-invasive method for assessing tissue oxygenation and microcirculatory reserve. This prospective observational study aims to investigate whether VOT-derived parameters, including desaturation slope, recovery slope and post-ischemic hyperemic area under the curve (AUC-H), can predict EAD in liver transplant recipients. Measurements will be performed at four predefined intraoperative timepoints: after induction of anesthesia, during the anhepatic phase, during the neohepatic phase and at the end of surgery. The primary outcome is the occurrence of EAD according to Olthoff criteria.

Read the detailed description

Orthotopic liver transplantation (OLT) is the treatment of choice for patients with end-stage liver disease and acute liver failure. Despite advances in surgical technique and perioperative management, early allograft dysfunction (EAD) remains a common postoperative complication associated with increased morbidity, prolonged intensive care unit stay and reduced graft survival.

Increasing evidence suggests that microcirculatory dysfunction may play a pivotal role in the pathophysiology of ischemia-reperfusion injury and graft dysfunction after OLT. In contrast to conventional macrocirculatory monitoring, microcirculatory assessment provides direct information regarding tissue oxygenation, endothelial function and the adequacy of oxygen delivery at the cellular level.

Near-infrared spectroscopy (NIRS) combined with the vascular occlusion test (VOT) is a non-invasive and well-established technique for evaluating microvascular reactivity. During VOT, transient arterial occlusion is induced using a pneumatic cuff, while tissue oxygen saturation (StO₂) is continuously recorded. Parameters derived from the test include the desaturation slope (downslope), the recovery slope (upslope) and the area under the post-ischemic hyperemic curve (AUC-H), reflecting tissue oxygen consumption, endothelial function and microvascular reserve, respectively.

The present study is a prospective, single-center observational cohort study aiming to investigate the prognostic value of VOT-derived parameters in liver transplant recipients. VOT measurements will be performed at four predefined intraoperative timepoints: following induction of anesthesia (baseline), during the anhepatic phase, during the neohepatic phase after graft reperfusion, and at the end of surgery.

The primary endpoint is the occurrence of early allograft dysfunction according to the Olthoff criteria. Secondary outcomes include intensive care unit length of stay, hospital length of stay, duration of mechanical ventilation and established liver transplant outcome scores including L-GrAFT, EASE and EASIX.

In addition, exploratory analyses will investigate the relationship between VOT-derived parameters normalized to oxygen delivery (DO₂ and DO₂I) and postoperative outcomes, aiming to determine whether microcirculatory reserve adjusted for systemic oxygen transport provides superior prognostic information.

Keywords
Vascular Occlusion Test, Near-Infrared Spectroscopy, Early Allograft Dysfunction, Liver Transplantation, Microcirculation
Medical subject headings
Liver Cirrhosis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT07658794
Study groupRoleWhat they receive
Adult Liver Transplant Recipients Undergoing Intraoperative VOT/NIRS MonitoringAdult patients undergoing orthotopic liver transplantation will be enrolled in this observational cohort. During surgery, they will undergo standardized Vascular Occlusion Tests using Near-Infrared Spectroscopy to assess peripheral tissue oxygen saturation and microcirculatory reactivity. Measurements will be performed at predefined intraoperative timepoints, including baseline, anhepatic, neohepatic and final phases. Reoxygenation slope, hyperemic area under the curve and related parameters will be analyzed for their association with early allograft dysfunction and postoperative outcomes.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incidence of Early Allograft Dysfunction Within 7 Days After Liver Transplantation

    Development of early allograft dysfunction after liver transplantation, defined according to established postoperative biochemical criteria, including elevated transaminases within the first 7 postoperative days, impaired coagulation, or hyperbilirubinemia.

    Measured: Within 7 days after liver transplantation

  2. Early Allograft Dysfunction

    Development of early allograft dysfunction after liver transplantation, defined according to established postoperative biochemical criteria, including elevated transaminases within the first 7 postoperative days, impaired coagulation, or hyperbilirubinemia.

    Measured: Within 7 days after liver transplantation

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Jun 2026
  2. Study startJun 2026 (estimated)
  3. Primary completionMar 2027 (estimated)
  4. Study completionJun 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
50 participants (estimated)
Target duration
30 Days
IDs, dates and publications
ClinicalTrials.gov ID
NCT07658794
Sponsor's protocol ID
ΕΣ:87/18-3-2026
Status last verified
Jun 2026
First submitted
15 Jun 2026
Last updated
1 Jul 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

An observational study of Liver Cirrhosis and Early Allograft Dysfunction, run by Ippokrateio General Hospital of Thessaloniki at 1 site in Greece.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 1 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Greece. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Dimitrios Zafeiriadis, MD (+306980422306 ext. +30, imdzaf@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incidence of Early Allograft Dysfunction Within 7 Days After Liver Transplantation (time frame: Within 7 days after liver transplantation). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Jul 2026.

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