This pilot clinical study aims to assess the feasibility and clinical relevance of bedside monitoring of microenvironmental conditions within infected walled-off pancreatic necrosis (WOPN).

WOPN is a serious complication of acute pancreatitis, often associated with infection, organ failure, and the need for drainage or surgical intervention. Although infection is a key factor in prognosis, little is known about the local chemical environment inside the infected collections.

In this study, a sterile, miniaturized probe will be temporarily introduced into the necrotic cavity during standard percutaneous drainage. The goal is to record local microenvironmental parameters (such as acidity or related values) and monitor their changes over time.

By comparing these values with clinical data (e.g., inflammatory markers, microbiology, need for surgery), the study aims to determine whether such measurements can provide additional information about infection severity and treatment response.

The study does not involve any experimental treatment. All patients will receive standard medical care, including antibiotics, imaging, and drainage according to international guidelines.

Participation is voluntary. Only patients who provide informed consent will be enrolled.

Background:

Infected walled-off pancreatic necrosis (WOPN) represents a critical complication of acute necrotizing pancreatitis. Management typically includes antibiotics and step-up interventional drainage. However, decision-making is often based on indirect systemic markers, and very little is known about the actual in situ microenvironmental conditions (e.g., pH, oxygenation, redox status) inside the necrotic cavity.

Rationale and Innovation:

The metabolic and microbiological activity within infected WOPN likely alters the local chemical environment, particularly in terms of acidity and anaerobic conditions. These changes may influence pathogen virulence, host immune response, and - importantly - the stability and efficacy of administered antibiotics. There is currently no standard method for directly monitoring these local parameters at the bedside. This pilot study explores the feasibility and potential clinical value of such monitoring.

Objective:

To determine whether bedside microenvironmental monitoring inside infected WOPN is feasible, safe, and potentially useful for clinical decision-making.

Methods:

This is a single-arm, prospective, interventional feasibility study. Patients with clinically confirmed infected WOPN undergoing standard percutaneous drainage will be offered participation. A sterile, biocompatible mini-probe (≤1.5 mm diameter) will be introduced into the collection during drainage and used to monitor selected parameters (e.g., pH) intermittently or continuously for up to 24-72 hours. The sensor will be removed safely without compromising drainage.

Data will be collected on insertion feasibility, measurement quality, patient tolerance, and any complications. Clinical parameters (CRP, PCT, SOFA score), microbiology, and clinical outcomes (resolution of infection, need for surgery, mortality) will be tracked and compared with measured values.

Outcomes:

Primary outcomes include the feasibility of safe insertion and measurement, and preliminary correlation with infection severity and clinical course. Secondary outcomes include association of monitored values with microbiology, organ dysfunction, and treatment response.

Future Direction:

If successful, this study will lay the groundwork for larger observational trials and possibly interventional studies using pH- or microenvironment-guided therapy (e.g., antibiotic selection or early intervention).

Inclusion Criteria:

• Age ≥ 18 years
• Diagnosis of walled-off pancreatic necrosis (WOPN) confirmed by imaging (CT, MRI, or EUS)
• Clinical suspicion or confirmation of infection in WOPN (e.g., fever, elevated inflammatory markers, positive culture)
• Planned percutaneous drainage as part of standard care
• Ability to provide informed consent (or surrogate consent where applicable)

Exclusion Criteria:

• Coagulopathy not correctable prior to intervention (e.g., INR > 2.0 or platelets < 50×10⁹/L)
• Known allergy or hypersensitivity to materials used in the monitoring probe
• technical limitations precluding safe probe insertion

This is a single-center pilot study with a limited sample size and exploratory objectives. The decision to share individual participant data (IPD) will depend on the quality, completeness, and generalizability of the collected data, as well as institutional and ethical considerations regarding data anonymization and reuse. A data sharing plan may be developed in future phases of research if the findings support broader dissemination.