Surgical tubing consists of specialized, flexible conduits used in medical procedures to transfer fluids, gases, or function as components within medical devices. It is a fundamental element in healthcare, facilitating processes like intravenous fluid administration, drainage, and respiratory support. Material selection is highly regulated and based on the tubing’s intended use within or near the human body.
Primary Categories of Tubing Materials
Surgical tubing materials are broadly categorized into elastomers and thermoplastics, each offering distinct chemical and physical properties. Elastomers, which mimic the flexibility of rubber, are represented primarily by Silicone and Natural Rubber Latex. Silicone is a synthetic polymer valued for its high degree of inertness and resistance to extreme temperatures, making it a stable choice for medical applications. Natural Rubber Latex offers exceptional elasticity and stretchability, but its use has declined due to the risk of allergic reactions in patients and healthcare workers.
The category of thermoplastics includes materials that become moldable when heated, such as Polyvinyl Chloride (PVC) and Polyurethane (PU). PVC is one of the most widely used plastics in medical tubing because it is cost-effective, easily sterilized, and can be made highly flexible by adding plasticizers. Polyurethane is a polymer prized for its superior abrasion resistance, durability, and high tensile strength, often merging the qualities of both plastic and rubber. Other specialized polymers, including Thermoplastic Elastomers (TPEs) and Polyethylene, are also used when specific characteristics like high purity or chemical resistance are required.
Essential Material Performance Requirements
Material selection for surgical tubing is governed by strict performance requirements centered on patient safety and device function. Foremost is biocompatibility, meaning the material must not cause adverse biological responses, such as inflammation or toxicity, when contacting bodily tissues or fluids. This is crucial for tubing used inside the body or for long-duration fluid transfer. Materials must also minimize the leaching of chemical components, such as plasticizers, into transferred fluids, maintaining purity.
Materials must also tolerate sterilization methods without degrading physical properties. They must withstand common processes like high-temperature steam autoclaving, gamma radiation, or ethylene oxide (EtO) gas to ensure sterility. Mechanical properties are critical for reliable function, including the appropriate durometer (hardness) to prevent kinking when bent. Tubing must also possess sufficient tensile strength to avoid rupture under pressure and maintain a consistent bore diameter for predictable fluid flow.
Material-Specific Medical Applications
The unique properties of each material dictate its suitability for specific roles within the medical field. Silicone tubing, known for its inertness and long flex life, is often the preferred choice for peristaltic pump segments, where the tubing must endure repeated compression without failure. Its stability and non-reactivity also make it ideal for long-term implantable devices and catheters that remain in the body for extended periods.
Polyvinyl Chloride (PVC) tubing is widely used in high-volume, disposable applications such as intravenous (IV) sets and blood bags due to its combination of clarity, flexibility, and affordability. While modern formulations often use non-phthalate plasticizers to address safety concerns, PVC remains the standard for safe blood storage. Polyurethane is frequently utilized for specific types of catheters and vascular access devices because its high strength allows for thinner walls, maximizing the internal diameter for flow while maintaining durability and flexibility.