Post-Implantation Syndrome and Laboratory Markers Following EVAR and TEVAR (PIS and EVAR)

June 3, 2025 updated by: ümit arslan, Ataturk University

Biomarkers Predicting Postimplantation Syndrome After Endovascular Aortic Repair (EVAR) and Thoracic Endovascular Aortic Repair (TEVAR)

The aim of this observational study is to investigate the relationship between postimplantation syndrome (PIS) and laboratory inflammatory parameters following endovascular aortic repair (EVAR/TEVAR). PIS is a systemic inflammatory response that may occur after EVAR or TEVAR and lacks a standardized clinical definition. This study seeks to determine whether specific laboratory biomarkers-particularly white blood cell count, C-reactive protein (CRP), interleukin levels, and neutrophil-to-lymphocyte ratio (NLR)-can serve as reliable indicators for the diagnosis and assessment of PIS.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Endovascular repair of thoracic and abdominal aortic aneurysms (EVAR/TEVAR) has become a preferred alternative to open surgical repair due to its association with reduced perioperative morbidity and mortality. However, a notable proportion of patients undergoing these procedures may develop postimplantation syndrome (PIS), a systemic inflammatory response first described in 1999. Despite its clinical relevance, PIS remains poorly defined, with varying diagnostic criteria across the literature.

PIS is typically characterized by postoperative fever, fatigue, and an increase in inflammatory markers such as white blood cell (WBC) count, C-reactive protein (CRP), and interleukin-6 (IL-6). The neutrophil-to-lymphocyte ratio (NLR), a readily obtainable marker from complete blood count tests, has also gained attention as a reliable indicator of systemic inflammation. In contrast, procalcitonin levels in PIS patients often remain within normal limits, helping differentiate PIS from bacterial infections.

In this prospective observational study, 200 patients undergoing elective EVAR or TEVAR procedures under general anesthesia were included. All procedures were performed via bilateral femoral artery access using open femoral incisions. Patients were followed postoperatively and assessed for the development of PIS based on clinical and laboratory parameters.

Body temperature was measured at regular intervals, and inflammatory markers-including CRP, WBC count, IL-6, NLR, and procalcitonin-were recorded preoperatively and at 24, 48, and 72 hours postoperatively. PIS was defined as the presence of fever (>38°C) in association with elevated CRP and/or leukocytosis, in the absence of any clinical or microbiological evidence of infection.

Preliminary results showed that patients who developed PIS had significantly higher postoperative levels of WBC, CRP, IL-6, and NLR, while procalcitonin levels remained normal, supporting a non-infectious inflammatory etiology. Imaging and laboratory evaluations ruled out alternative sources of infection. No significant differences were observed in operative time or graft type between patients with and without PIS.

All data were collected prospectively and analyzed using the SPSS statistical software. The study aims to clarify the diagnostic criteria of PIS by identifying specific laboratory biomarkers that can reliably differentiate PIS from other postoperative complications, particularly infection. Furthermore, by better understanding the inflammatory response following EVAR/TEVAR, the study may contribute to improved postoperative management strategies.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
300

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Turkey
      • Erzurum, Turkey, 25240
        • Ataturk University
      • Erzurum, Turkey, 25100
        • Ataturk University
      • Erzurum, Turkey, 25025
        • Ataturk University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

The study population consists of adult patients (≥18 years) who underwent elective endovascular aneurysm repair (EVAR) or thoracic endovascular aortic repair (TEVAR) for abdominal or thoracic aortic aneurysms at a single tertiary care center. All participants had available pre- and postoperative laboratory data necessary for the evaluation of post-implantation syndrome and inflammatory biomarkers.

Description

Inclusion Criteria

  • Patients aged ≥18 years
  • Undergoing elective EVAR or TEVAR for abdominal or thoracic aortic aneurysm
  • Ability to provide informed consent
  • Availability of baseline and follow-up laboratory data (including IL-6, NLR, CRP, leukocyte count, procalcitonin, etc.)

Exclusion Criteria

  • Evidence of active infection at the time of procedure
  • Known autoimmune or inflammatory disease (e.g., rheumatoid arthritis, lupus)
  • Current use of immunosuppressive or anti-inflammatory therapy
  • Malignancy under active treatment
  • End-stage renal or hepatic failure
  • Emergency or ruptured aneurysm repair
  • Incomplete postoperative laboratory data

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Post-Implantation Syndrome: Lab Trends after EVAR/TEVAR
This cohort includes patients who underwent endovascular aneurysm repair (EVAR) or thoracic endovascular aortic repair (TEVAR). The study investigates the occurrence of post-implantation syndrome (PIS) and its association with early postoperative laboratory markers, including interleukin-6 (IL-6), neutrophil-to-lymphocyte ratio (NLR), leukocyte count, C-reactive protein (CRP), and procalcitonin levels. No additional pharmacologic or procedural interventions were applied beyond standard perioperative care.
Procedure: Endovascular Aortic Intervention
This intervention involves EVAR or TEVAR for the treatment of abdominal or thoracic aortic aneurysms, respectively. The procedures were performed using commercially available stent-grafts via a transfemoral approach under standard perioperative protocols. The study specifically focuses on the systemic inflammatory response following these interventions, with close monitoring of laboratory parameters including IL-6, neutrophil-to-lymphocyte ratio (NLR), CRP, leukocyte count, and procalcitonin during the early postoperative period. No adjunctive anti-inflammatory or immunomodulatory therapies were administered.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Evaluation of Postimplantation Syndrome (PIS) Incidence
Time Frame: 0-8 days

PIS is defined as the presence of fever (>38°C) without an identifiable source of infection, accompanied by leukocytosis (white blood cell count >12,000/mm³) and/or elevated C-reactive protein (CRP >7 mg/L). The incidence rate of PIS will be calculated based on the number of patients meeting these diagnostic criteria following EVAR or TEVAR procedures.

Unit of Measure:

Percentage of participants with PIS (%)
0-8 days

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
C-reactive Protein (CRP) Level
Time Frame: within first 72 hours postoperatively

Serum CRP levels will be measured preoperatively and within 72 hours postoperatively. CRP values >7 mg/L will be considered elevated and potentially supportive of PIS diagnosis.

Unit of Measure:

mg/L
within first 72 hours postoperatively
White Blood Cell (WBC) Count
Time Frame: within first 72 hours postoperatively

Total leukocyte count will be assessed preoperatively and within 72 hours postoperatively. Values >12,000/mm³ will be considered elevated.

Unit of Measure:

10³ cells/μL
within first 72 hours postoperatively
Interleukin-6 (IL-6) Level
Time Frame: within first 72 hours postoperatively

Plasma IL-6 concentration will be measured preoperatively and within 72 hours postoperatively. IL-6 levels >7 ng/mL will be considered indicative of systemic inflammation.

Unit of Measure:

ng/mL
within first 72 hours postoperatively
Neutrophil-to-Lymphocyte Ratio (NLR)
Time Frame: within first 72 hours postoperatively

Neutrophil-to-Lymphocyte Ratio (NLR)

Description:

NLR will be calculated from the differential leukocyte count. A value >4 will be used as a cut-off indicating systemic inflammatory response.

Unit of Measure:

Unitless (ratio)
within first 72 hours postoperatively
Procalcitonin (PCT) Level
Time Frame: within first 72 hours postoperatively

Serum procalcitonin levels will be evaluated preoperatively and within 72 hours postoperatively. PCT <1 ng/mL will be considered as non-specific for bacterial infection but still relevant in inflammatory profiling.

Unit of Measure:

ng/mL
within first 72 hours postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Ataturk University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: umit arslan, Ataturk University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2018

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2024

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 15, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 12, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 3, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 11, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 11, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 3, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • UA_ES_01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data (IPD) will not be made publicly available due to institutional policies and the potential for overlapping use of the same dataset by other researchers within the institution. However, data may be shared upon reasonable request, provided that appropriate ethical approvals and data-sharing agreements are in place

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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