Changes in Regional Ventilation-Perfusion Match Following Percutaneous Transluminal Angioplasty for Arteriovenous Graft Thrombosis

Changes in Regional Ventilation-Perfusion Match Following Percutaneous Transluminal Angioplasty for Arteriovenous Graft Thrombosis: A Prospective Observation Pilot Study

Patients with end-stage renal disease (ESRD) often require arteriovenous grafts (AVG) for hemodialysis. AVG thrombosis is a common complication, usually managed by percutaneous transluminal angioplasty (PTA) to restore blood flow. PTA achieves patency by balloon-mediated compression and fragmentation of thrombus. Small thrombus fragments may enter the venous circulation and cause transient pulmonary microembolism, leading to ventilation-perfusion (V/Q) mismatch. This study uses electrical impedance tomography (EIT) to noninvasively monitor short-term changes in regional ventilation and perfusion during and after PTA, exploring the immediate pulmonary physiological consequences of thrombus fragmentation and revascularization in dialysis patients.

Study Overview

• Status: Recruiting
• Conditions: End Stage Renal Disease on Dialysis; Arteriovenous Graft Thrombosis
• Intervention / Treatment: Diagnostic test: Electrical Impedance Tomography (EIT) Monitoring

Detailed Description

Arteriovenous graft (AVG) thrombosis is a major source of vascular access failure in ESRD. PTA restores patency through balloon dilation and mechanical thrombus compression. Minor embolic debris can reach the pulmonary bed, transiently disturbing perfusion distribution and V/Q matching. Because the pulmonary circulation is sensitive to sudden peripheral hemodynamic shifts, the PTA period provides a unique opportunity to observe lung perfusion response dynamically.

This single-center, prospective, observational pilot study will continuously record regional ventilation and perfusion by EIT at six time points: 10 min before PTA, at recanalization, and 10, 20, 30 min after, and at procedure completion. Measured variables include: V/Q matching index (primary), physiological dead space fraction (Vd/Vt), intrapulmonary shunt fraction, SPO₂/FiO₂ ratio, and hemodynamic data (balloon pressure, recanalization time, blood flow recovery). Results will be analyzed using repeated-measures ANOVA or mixed-effects modeling.

• Study Type: Observational
• Enrollment (Estimated): 20

Contacts and Locations

• Study Contact: Name: qiancheng xu, PhD; Phone Number: +86-18297529106; Email: qianchengxu@wnmc.edu.cn

Study Locations

• China
  • Wuhu, China
    • Recruiting
    • The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College)
    • Contact: Shengsheng xu; Phone Number: 86-18315329399; Email: taoshengsheng@yjsyy.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients with end-stage renal disease (ESRD) undergoing maintenance hemodialysis who present with thrombosed arteriovenous grafts (AVG) requiring clinically indicated percutaneous transluminal angioplasty (PTA) to restore patency. The study population will consist of adult patients (18-80 years) admitted to the interventional radiology or dialysis access unit of the First Affiliated Hospital of Wannan Medical College (Yijishan Hospital). All participants will receive routine PTA treatment as part of standard care. EIT monitoring will be applied non-invasively to collect ventilation and perfusion signals before and after PTA. No additional interventions beyond routine clinical management will be introduced.

Description

Inclusion Criteria

1. Age ≥ 18 years.
2. Diagnosis of end-stage renal disease receiving maintenance hemodialysis.
3. Documented AVG thrombosis requiring PTA.
4. Able to cooperate and tolerate EIT monitoring.
5. Provided written informed consent.

Exclusion Criteria

1. Severe respiratory failure incompatible with supine position.
2. Thoracic skin condition or deformity preventing EIT electrode placement.
3. Acute pulmonary embolism or acute pulmonary edema before procedure.
4. NYHA Class IV heart failure or hemodynamic instability.
5. Pregnancy or breastfeeding.
6. Any other circumstance judged unsuitable by investigator.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Observation Cohort; All enrolled patients will undergo clinically indicated PTA under standard care. EIT monitoring will be performed continuously before, during, and after recanalization to record regional ventilation and perfusion data. No experimental drug or device will be administered beyond routine care.	Diagnostic test: Electrical Impedance Tomography (EIT) Monitoring; Non-invasive 16-electrode EIT belt applied at the 4th intercostal level. Continuous data acquisition begins 10 min pre-PTA, continues throughout balloon angioplasty, and up to 30 min post-recanalization. No alteration to standard clinical care.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Ventilation-Perfusion Matching Index	Quantitative index derived from EIT ventilation and perfusion maps, indicating spatial regional correlation of air and blood flow distribution.	Baseline (10 min before PTA), immediate post-recanalization, 10, 20, 30 minutes, and procedure end.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Peripheral Oxygen Saturation		Baseline (10 min before PTA), immediate post-recanalization, 10, 20, 30 minutes, and procedure end.
Change in Physiological Dead Space Fraction	Ratio of physiologic dead space to tidal volume, calculated by EIT validated algorithm, reflecting inefficiency of ventilation.	Baseline (10 min before PTA), immediate post-recanalization, 10, 20, 30 minutes, and procedure end.
Change in Intrapulmonary Shunt Fraction	Percentage of the lung region showing perfusion without ventilation, estimated from EIT perfusion signals.	Baseline (10 min before PTA), immediate post-recanalization, 10, 20, 30 minutes, and procedure end.
Change in Regional Ventilation and Perfusion Distribution	Variation in spatial patterns of pulmonary ventilation and perfusion derived from pixel-based EIT data.	Baseline (10 min before PTA), immediate post-recanalization, 10, 20, 30 minutes, and procedure end.

Collaborators and Investigators

• Sponsor: First Affiliated Hospital of Wannan Medical College

Study record dates

Study Major Dates

• Study Start (Actual): October 24, 2024
• Primary Completion (Estimated): September 30, 2027
• Study Completion (Estimated): December 30, 2027

Study Registration Dates

• First Submitted: May 23, 2026
• First Submitted That Met QC Criteria: May 23, 2026
• First Posted (Actual): May 29, 2026

Study Record Updates

• Last Update Posted (Actual): May 29, 2026
• Last Update Submitted That Met QC Criteria: May 23, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Percutaneous Transluminal Angioplasty; Electrical Impedance Tomography; Pilot Study; Shunt; Dead Space; Ventilation-Perfusion Matching; Pulmonary Microembolism
• Other Study ID Numbers: 2026-ICU04

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No