PPG vs. ICG in Gastrointestinal Resections

Saint Petersburg State University, Russia

Status: Enrolling

Conditions: Postoperative Complications; Gastric Cancer (GC); Perfusion; Anastomosis; Gastrointestinal Neoplasms; Colorectal Cancer

Treatments: Device: Imaging Photoplethysmography System; Drug: ICG fluorescence imaging technology

Study type: Interventional

Funder types: Other; NETWORK

Identifiers

NCT06222645

spbuippg001

Details and patient eligibility

About

This randomized controlled trial compares a novel optical technique against the standard of care for assessing tissue perfusion in gastrointestinal surgery. Participants are randomized to receive either intraoperative imaging photoplethysmography (iPPG) or indocyanine green (ICG) fluorescence imaging. In the ICG group, the fluorescence data are comprehensively analyzed in two distinct ways: (1) Qualitative Assessment: real-time visual interpretation of the angiogram flow by the operating surgeon; and (2) Quantitative Assessment: software-based analysis of fluorescence kinetics (e.g., time-to-peak, maximum intensity) to generate objective perfusion parameters. The study aims to determine the agreement between the iPPG-based evaluations and both the qualitative and quantitative dimensions of the ICG standard.

Full description

This randomized, parallel-group clinical study aims to compare two intraoperative imaging strategies for assessing tissue perfusion in a spectrum of gastrointestinal anastomoses, including both gastro-intestinal and entero-enteric reconstructions. The primary objective is to evaluate the diagnostic performance and clinical utility of a novel, non-contact optical technique-imaging photoplethysmography (iPPG)-against the current clinical standard, indocyanine green (ICG) fluorescence imaging.

Eligible and consented patients will be randomly assigned to one of two arms. The iPPG Arm will undergo perfusion evaluation solely using the investigational iPPG system. This method leverages a conventional video camera to detect pulsatile blood volume changes in microvascular tissue, offering a non-invasive, contrast-agent-free approach to perfusion assessment. The ICG Arm will be assessed using the standard fluorescence imaging protocol. A key feature of the study design is the pre-specified, comprehensive analysis within the ICG arm, which will incorporate both a qualitative assessment (the surgeon's real-time visual interpretation of the angiogram) and a quantitative analysis (computer-based calculation of fluorescence kinetics parameters, such as time-to-peak and inflow slope).

The study is designed to provide a head-to-head comparison of the two guiding strategies. Outcomes from the iPPG-guided arm will be systematically benchmarked against those from the ICG-guided arm. Furthermore, the internal comparison between qualitative and quantitative assessments within the ICG arm will yield valuable insights into the optimal methodology for interpreting perfusion data in clinical practice. This design allows for the evaluation of iPPG not only as a potential alternative to ICG but also for the refinement of the standard itself.

Enrollment: 200 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adult patients (age ≥ 18 years).
• Scheduled to undergo an elective gastrointestinal resection requiring a primary gastro-intestinal or entero-enteric anastomosis.
• Able to understand and provide written informed consent.

Exclusion criteria

• Known hypersensitivity or allergy to indocyanine green (ICG), iodine, or any component of the ICG formulation.
• Severe hepatic impairment (e.g., Child-Pugh Class C).
• Pregnancy or lactation.
• Emergency surgery.
• Inability to comply with the study protocol or follow-up schedule in the investigator's judgment.

Trial design

Primary purpose: Diagnostic

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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200 participants in 2 patient groups

Indocyanine green (ICG) imaging system

Active Comparator group

Description:

Participants in this arm undergo intraoperative tissue perfusion assessment guided by the standard Indocyanine Green (ICG) fluorescence imaging. This involves intravenous ICG injection. Perfusion is evaluated comprehensively through both qualitative (surgeon's visual interpretation) and quantitative (computer-based analysis of fluorescence kinetics, e.g., time-to-peak) methods. This arm represents the current standard of care.

Treatment:

Drug: ICG fluorescence imaging technology

Device: Imaging Photoplethysmography System

imaging photoplethysmography (iPPG)

Experimental group

Description:

Participants in this arm undergo intraoperative tissue perfusion assessment guided by the investigational Imaging Photoplethysmography (iPPG) system. This non-contact, camera-based technique detects microvascular blood volume changes without requiring exogenous contrast agents. The surgical team uses the real-time iPPG perfusion maps to evaluate anastomotic viability and guide surgical decisions.

Treatment:

Drug: ICG fluorescence imaging technology

Device: Imaging Photoplethysmography System