Assessment of Pulmonary Perfusion and Hemodynamic Measurements by Electrical Impedance Tomography in Patients Undergoing Pulmonary Thromboendarterectomy.

May 4, 2026 updated by: University of Sao Paulo General Hospital

Chronic thromboembolic pulmonary hypertension (CTEPH) is a condition in which old blood clots block the blood vessels in the lungs, making it harder for the heart to pump blood through the lungs. Surgery called pulmonary thromboendarterectomy can remove these clots and improve blood flow, but doctors need reliable ways to evaluate lung blood flow before and after surgery.

This study will evaluate a bedside imaging method called electrical impedance tomography (EIT), which can measure how blood flows through different regions of the lungs without radiation or invasive procedures. Patients undergoing surgery for CTEPH will be monitored with EIT before and after surgery, and the results will be compared with standard lung perfusion imaging.

The goal of this study is to determine whether EIT can provide useful information about lung blood flow and changes after surgery, and whether it could serve as a complementary bedside tool to help monitor patients with CTEPH.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Chronic thromboembolic pulmonary hypertension (CTEPH) results from persistent obstruction of the pulmonary arteries by organized thromboembolic material and is a potentially curable cause of pulmonary hypertension. Pulmonary thromboendarterectomy is the treatment of choice for eligible patients and leads to significant improvement in pulmonary perfusion and hemodynamics.

Assessment of regional pulmonary perfusion is essential in the management of CTEPH. While perfusion SPECT/CT is commonly used for this purpose, it cannot be performed at the bedside and involves exposure to ionizing radiation. Electrical impedance tomography (EIT) is a non-invasive, radiation-free imaging technique that allows bedside assessment of lung ventilation and pulmonary perfusion through analysis of pulsatility-related impedance changes.

In this prospective diagnostic study, pulmonary perfusion assessed by EIT will be evaluated in patients undergoing pulmonary thromboendarterectomy and compared with perfusion SPECT/CT. EIT measurements will be obtained in the perioperative period, and perfusion changes will be analyzed using quantitative indices derived from impedance signals. The study focuses on the feasibility and performance of EIT as a bedside method for assessing pulmonary perfusion changes associated with surgical treatment of CTEPH.

Study Type

Interventional

Enrollment (Estimated)

36

Phase

  • Not Applicable

Contacts and Locations

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

Study Contact

Study Contact Backup

  • Name: Jaomar JC Salazar, MD
  • Phone Number: +5511966477244
  • Email: jaomar@usp.br

Study Locations

  • Brazil
    • São Paulo
      • São Paulo, São Paulo, Brazil, 05403-900
        • Recruiting
        • Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da USP
        • Contact:
        • Contact:
          • Jaomar JC Salazar, MD
          • Phone Number: +5511966477244
          • Email: jaomar@usp.br

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

- Patients diagnosed with chronic thromboembolic pulmonary hypertension (CTEPH) followed at the Pulmonology Service of InCor-HCFMUSP and scheduled for pulmonary thromboendarterectomy at InCor-FMUSP.

Exclusion Criteria:

  • Age under 18 years
  • Pregnancy
  • Structural heart disease (atrial septal defect, ventricular septal defect, or valvular heart disease)
  • Cardiac arrhythmias
  • Use of a cardiac pacemaker or other implantable electronic device
  • Skin lesions on the thoracic region at the site of EIT electrode belt placement
  • Absence of central venous access on the day of the preoperative protocol evaluation
  • Difficulty understanding the procedures to be performed
  • Refusal to participate in the study (non-signing of the Informed Consent Form)
  • Refusal by the attending medical team

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

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Diagnostic Imaging Ar.
Patients with chronic thromboembolic pulmonary hypertension undergoing pulmonary thromboendarterectomy will be evaluated using electrical impedance tomography (EIT) for assessment of regional pulmonary perfusion in the preoperative and postoperative periods. EIT-derived perfusion indices will be analyzed and compared with imaging-based thrombus burden and pulmonary perfusion assessed by SPECT-CT.
Diagnostic test: Electrical Impedance Tomography (EIT).
Non-invasive, radiation-free bedside assessment of pulmonary perfusion using Electrical Impedance Tomography (EIT). EIT will be performed using the Enlight 2100 system (Timpel Medical®, Brazil) in the preoperative and postoperative periods of pulmonary thromboendarterectomy. Pulmonary perfusion will be assessed through analysis of pulsatility signals and first-pass kinetics following hypertonic saline bolus injection, generating regional perfusion maps and quantitative indices, including the wasted ventilatory index. Data will be analyzed offline.
Diagnostic test: Pulmonary Perfusion SPECT-CT.
Pulmonary perfusion assessment performed using single-photon emission computed tomography (SPECT) with technetium-99m-labeled macroaggregated albumin, fused with non-contrast chest computed tomography (CT) acquired during both inspiratory and expiratory phases. The fusion of functional perfusion images from SPECT with anatomical images from CT allows regional assessment of pulmonary perfusion and thromboembolic burden. This examination will be performed in the preoperative period and during postoperative follow-up and will serve as a reference imaging modality for comparison with Electrical Impedance Tomography-derived perfusion measures.
Procedure: Pulmonary Thromboendarterectomy.
Pulmonary thromboendarterectomy performed according to standard institutional clinical practice for the treatment of chronic thromboembolic pulmonary hypertension. This surgical procedure is conducted solely for clinical indication and is not investigational. Imaging and monitoring assessments included in this study do not alter the surgical technique or perioperative clinical management.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Evaluation of perfusion maps obtained by Electrical Impedance Tomography (EIT) in the pre- and postoperative period using the wasted ventilation index..
Time Frame: From the preoperative period to the immediate postoperative period during intensive care unit stay (on the day of surgery).
Change in pulmonary perfusion assessed by Electrical Impedance Tomography (EIT) using the Enlight 2100 system (Timpel Medical®, Brazil), quantified by the wasted ventilatory index derived from regional perfusion maps, comparing preoperative and postoperative measurements in patients undergoing pulmonary thromboendarterectomy.
From the preoperative period to the immediate postoperative period during intensive care unit stay (on the day of surgery).

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Comparison of pulmonary perfusion assessed by Electrical Impedance Tomography and SPECT-CT.
Time Frame: From the preoperative period to the postoperative follow-up (up to 6 months after surgery).
Comparison of changes in regional pulmonary perfusion assessed by Electrical Impedance Tomography (EIT) and by SPECT-CT imaging, expressed as percentage variation between preoperative and postoperative evaluations in patients undergoing pulmonary thromboendarterectomy.
From the preoperative period to the postoperative follow-up (up to 6 months after surgery).
Incidence of adverse events related to Electrical Impedance Tomography perfusion assessment.
Time Frame: From the preoperative period to hospital discharge, up to approximately 30 days
Incidence and type of adverse events related to pulmonary perfusion assessment using Electrical Impedance Tomography, including events associated with the use of hypertonic saline injection.
From the preoperative period to hospital discharge, up to approximately 30 days

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Quality of life assessed by SF-36 questionnaire after pulmonary thromboendarterectomy.
Time Frame: Up to 6 months after surgery.
Quality of life assessed using the Short Form-36 (SF-36) questionnaire during outpatient follow-up after pulmonary thromboendarterectomy. Scores range from 0 to 100, where higher scores indicate better quality of life.
Up to 6 months after surgery.
Correlation between EIT-derived pulsatility and hemodynamic parameter.
Time Frame: From the preoperative period to the immediate postoperative period (during intensive care unit stay).
Correlation between changes in pulsatility (ΔZsys) assessed by Electrical Impedance Tomography and hemodynamic parameters, including stroke volume, cardiac output, and mean pulmonary artery pressure, measured using thermodilution via pulmonary artery catheter.
From the preoperative period to the immediate postoperative period (during intensive care unit stay).
Change in plasma sodium concentration after hypertonic saline injection
Time Frame: From baseline (before saline injection) to up to 2 hours after injection during hospitalization.
Change in plasma sodium concentration measured before and after hypertonic saline injection used for Electrical Impedance Tomography perfusion assessment, expressed in mEq/L.
From baseline (before saline injection) to up to 2 hours after injection during hospitalization.

Collaborators and Investigators

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

Sponsor

University of Sao Paulo General Hospital

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)

February 25, 2025

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

February 10, 2026

First Submitted That Met QC Criteria

May 4, 2026

First Posted (Actual)

May 11, 2026

Study Record Updates

Last Update Posted (Actual)

May 11, 2026

Last Update Submitted That Met QC Criteria

May 4, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 78916224.4.0000.0068

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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