Neonatal and Pediatric Endovascular Simulation: What Changes Beyond Vessel Size?

2026-09-29

"How patient scale changes vascular access, device interaction, system response, and procedural workflow"

A neonatal endovascular training simulator should not be treated as an adult platform reproduced at a smaller scale. In neonatal and pediatric cardiovascular surgery and interventional or endovascular practice, patient scale changes access geometry, device-to-anatomy relationships, imaging requirements, physiological response, and the margin for error.

Simulator requirements should begin with the intended learning outcome. They must define how access is obtained, where the training task ends, what feedback learners need, and which risks or complications matter. This prevents a procedure list from being mistaken for a complete training specification.

Pediatric Is a Range Not a Scale Factor

The 2025 American Society of Echocardiography guidelines for ultrasound guided vascular cannulation identify small vessel size, anatomical variation, and prior cannulation as important sources of difficulty in pediatric vascular access. Vessel cross-sectional area and subcutaneous depth also affect the access task in young children. These factors change target selection, probe and needle handling, entry angle, and the margin for error.

The term pediatric is consequently too broad to function as a complete simulator specification. A newborn, an infant, a small child, and an adolescent do not present the same vessel dimensions, device options, or procedural constraints. A program may need more than one anatomical configuration, or at least a clearly defined patient band, instead of one generic pediatric scale.

Organizing Training by the Primary Learning Objective

Vascular access should not be confused with the complete endovascular procedure. The 2023 AEPC recommendations for training in interventional catheterisation for congenital heart disease describe a progression from vascular access and catheter guidance to interpretation of hemodynamic and angiographic data, procedural planning, intervention, and post-procedural care. A useful classification should therefore reflect the main purpose of the training rather than the specialty, access route, or guidance method alone.

Table 1 uses three primary objectives: establishing vascular access, performing diagnostic or interventional catheterization, and establishing or managing extracorporeal circulation and organ support. The procedures are representative examples rather than an exhaustive list.

Table 1 Representative training domains and simulation considerations

Primary training objective	Representative procedures and applications	Key simulation considerations
Vascular access and catheter or cannula placement	Puncture, guidewire advancement, dilation, and catheter or cannula placement to establish venous, arterial, umbilical, or large-bore access; performed by landmark, ultrasound-guided percutaneous, or surgical cut-down techniques	Target-site anatomy, selected access method, tissue and vessel response, device fit, final position and function, and access-related complications
Diagnostic and interventional catheterization	Diagnostic cardiac catheterization, angiography, pressure and oximetry measurement, balloon dilation, stenting, embolization, and structural defect closure	Access-to-target pathway, wire and catheter behavior, imaging, data interpretation, device delivery and deployment, and management of procedural complications
Extracorporeal circulation and organ support	ECMO and ECPR, cardiopulmonary bypass, and continuous renal replacement therapy	Therapy-appropriate access or cannulation, equipment and circuit preparation, initiation of support, pressure-flow response, patient-system interaction, troubleshooting, and coordinated team action

These domains often form a sequence. A vascular access course may end after functional catheter or cannula placement is confirmed. A catheterization course continues into navigation, measurement, or intervention. Extracorporeal training continues into equipment, circuit behavior, physiological response, and team workflow. The intended end point determines the required scope.

Imaging should be specified within each objective. Ultrasound may support vessel assessment and real-time access, while landmark-based or surgical approaches rely on different anatomical cues and tissue interaction. Fluoroscopy, angiography, or echocardiography may become important during navigation and intervention. Compatibility should be verified for the modality and equipment used in the course.

What Changes Beyond Vessel Diameter

Access Method and Guidance

The simulator should reproduce the features that influence the selected access method. For ultrasound-guided access, these include vessel depth, orientation, compressibility, neighboring structures, and the relationship between the image and needle trajectory. Landmark-based access depends more on surface anatomy and expected vessel location, while surgical cut-down requires exposure, vessel handling, and direct placement.

Device Behavior Along the Pathway

As anatomy becomes smaller, device compatibility means more than whether an instrument physically fits. The relevant questions include how much of the vessel the device occupies, whether a wire or catheter can follow the intended curve or branch, and whether the delivery system approaches the target with plausible support and orientation. The available imaging should provide the information needed to make those decisions.

From Placement to System Response

The required feedback depends on what follows placement. Access training may require confirmation of catheter or cannula function. Diagnostic and interventional training may continue into pressure measurement, device deployment, or assessment of the procedural result. Extracorporeal support adds circuit connection, flow establishment, and interpretation of the patient’s response.

Designing for Complications and Disrupted Workflows

A course that reproduces only the expected sequence cannot assess how learners respond when the procedure deviates from plan. Selected scenarios may involve failed access, loss of wire or catheter position, malposition, bleeding, inadequate flow, obstruction, or clinical deterioration. The relevant problem should be recognizable, produce interpretable consequences, and permit an appropriate response.

This is especially important in extracorporeal circulation and organ support. ECMO, ECPR, and cardiopulmonary bypass connect cannulation with circuit initiation and pressure-flow management. CRRT connects vascular access with the machine, filter, circuit, alarms, and treatment response. Pediatric CRRT studies have linked treatment delivery to access function, circuit pressures, machine alarms, and clotting, while simulation-based education has improved filter life and reduced unplanned changes.

Fit for Purpose Fidelity and Platform Selection

The appropriate level of fidelity follows the learning objective. A focused ultrasound-guided access station may require accurate anatomy, imaging behavior, replaceable vessels, and realistic needle interaction. Catheter-based intervention places greater demands on the vascular pathway, device behavior, target orientation, and imaging. Surgical cannulation or extracorporeal support may require an operative field, functional connection to a circuit, monitored parameters, and team roles.

The training environment may combine a patient model with clinical or modified equipment, imaging systems, circuits, monitors, software, instructor-controlled cues, and structured debriefing. Selection should consider the patient band, task end point, devices, required feedback, complications, assessment needs, and operating conditions. The goal is the most appropriate platform or combination of tools for the intended program.

Applying the Framework to DORA

One example is SurgMate’s NeoPeds Endovascular Procedures Training Platform (DORA). DORA supports selected neonatal and pediatric objectives in vascular access, cannulation, and catheter-based or endovascular training. Its modular anatomy, ultrasound-compatible access sites, replaceable vessels, and adjustable circulatory parameters can connect procedural practice with observable system response.

The platform should be evaluated against the objectives of each course, including the required anatomy, devices, imaging, equipment integration, feedback, and scenarios. Other tools can then be added where the curriculum extends beyond DORA’s role.

Patient Scale Changes Training Requirements

Neonatal and pediatric simulation must account for more than vessel diameter. The required design depends on the patient group, access method, procedural pathway, functional end point, and consequences learners must recognize. Defining these requirements first allows programs to select a fit-for-purpose training environment. Explore DORA to see how one neonatal and pediatric platform can support selected vascular and endovascular training objectives.