Pressure Resistance vs. Kink Resistance: Two Critical Mechanical Properties of DSA Contrast Injection Tubing

When performing an angiography, one of the unsung yet vital pieces of the puzzle is the DSA Contrast Injection Tubing. This component, along with the angiographer’s precision, safety, and reliability, must undergo extreme and complex internal dynamics in the anatomy of the patient while avoiding collapse, leaks, and loss of flow. Two of the most important mechanical properties of the tube that determine the tubing’s success or failure are pressure resistance and kink resistance. Knowing the extremes in which both exist is important for everyone involved in the angiography workflow, whether it be the physician, the purchasing agent, or the angiography department manager.

In this paper, we will discuss the importance of both properties, the engineering behind them, and the reason why Greetmed GT211 Series products are perfectly suited for today’s angiography needs.

What is Pressure Resistance in DSA Contrast Injection Tubing?

Pressure resistance is the ability of a tube to withhold high pressure fluids without rupturing, leaking, or deforming. In DSA procedures, contrast media is injected at a velocity of 10mL/s and a pressure of about 1200 PSI. The tubing must hold that force—procedure after procedure.

•High pressure ensures image quality: Adequate pressure overcomes resistance from small catheters, narrow vessels, and viscous contrast agents to achieve the flow rates required for diagnostic clarity.

•Pressure rating must match injector capability: Modern DSA injectors deliver adjustable pressures up to 1200 PSI. Elastic tubing that meets a specific rating is a weak point in the injection system.

The construction and materials used determine the type of fluid and pressure of the tubing; Braided reinforcements that contain polyester monofilaments and are immersed in polyurethane are what provide the tubing the adequate protection for the tubing to withstand high pressure.

Regarding compliance with standards, the greater the pressure rating, the more tubing withstands the test of  DIN EN ISO 1402 and ASTM D1599 with 1200 PSI as the minimum rating for high pressure early angiography tubing.

Withstand in a high pressure and tubing ruptures the procedure is meaningless and wastes the contrast media, interruptions imaging processes, requires repeat scans, and increases the patient exposure to additional radiation and contrast.

What is Kink Resistance and Why Does it Matter?

The kink resistance explain the bending and coiling of a tubing without undergoing deformation or collapsing tubing. Kinking of tubing narrows the cross-sectional area (in some instances up to 50%), totally or partially, limiting or totally obstructing the fluid flow. Kinking of tubing in the angiography suite means loss of contrast, failed injection and  compromising study of the anatomy.

•The anatomy is very bland: The tubing are required to navigate the entire patient area and to go through the bed rails and to be beside other equipment. Kink resistance ensures that the tubing keeps the entire area clear of obstructions.

•Low temperature conditions threaten the tubing flexibility: Kinking is a tubing failure event.

•An increased possibility of kinking is directly linked to the thickness of the wall: In the design, a compromise must be made between the wall thickness, the flexibility of the wall, and the wall's material strength.

•The ability to resist kinks has to be tested to industry standards: The industry has developed a standardized tape assessment procedure, which includes the assessment of bending, ensuring that the product behaves in a consistent manner over the complete production run.

The Engineering Challenge: Balancing Two Conflicting Demands

The requirements for pressure resistance and kink resistance can be contradictory. A tube made to hold 1200 PSI and not burst is likely to be so rigid that it will not be able to be bent without kinking. On the other hand, a tube made to be so flexible that it will not kink is likely to not have a wall thickness that will withstand the high-pressure injection. This challenge is what the manufacturers of DSA Contrast Injection Tubing have to deal with.

Flexibility and resistance to braiding can be achieved with a 100% polyester monofilament braid, which is encapsulated in a clear polyurethane.

These two elements can be adjusted to meet the specific requirements of the tubing and to optimize kink and pressure resistance.

•Coextrusion is also a possibility: where clear tubing is a necessity and extreme pressure is not a factor, a co-extrusion can be used. This design has a polyamide layer for pressure resistance, and a layer of polyurethane for flexibility, without the braid.

•Both designs now achieve 1200 PSI ratings: thanks to recent innovations, both types of tubing - braided and co-extruded - can be designed for high pressure applications.

•One-size-fits-all solutions simply do not exist: Different tubing characteristics must adapt to different angiography suites, injector models, and clinical protocols, hence differing options across the product line is critical.

Greetmed's GT211 Series Makes the Optimal Balance

Greetmed has kink and pressure resistance to GT211 Series DSA Contrast Injection Tubing so that it is designed to be used easily in the clinical environment. With three different lengths and two different pressure ratings, the GT211 line provides angiography departments with the appropriate options to customize tubing for varying procedural needs.

GT211 Series Specifications

Why the GT211 Series is Unique

The only series on the market with dual pressure ratings for injector compatibility, 600 PSI variants are used in standard angiography protocols while 1200 PSI variants are used in high-flow neurovascular and interventional procedures.

•Three clinically relevant levels: 60 cm, 90 cm, and 120 cm options eliminating slack and reducing kink risk as tubular length is matched to the room layout.

•Braided kink-resistant technology: the GT211 series has advanced construction to ensure unimpeded flow even at maximum bend conditions.

•Production is consistent and predictable as Greetmed has international standards for quality management systems.

•Ready and Complete Configuration: Each unit of GT211 tubing comes pre-assembled for immediate clinical use. After EO sterilization, it is supplied as a sterile sc. no extra assembly is needed to use it.

Making the Right Choice for Your Angiography Department

Each option available in the DSA Contrast Injection tubing line is unique, and therefore, the choice is not easy and requires careful thought. The need for tubing in a busy Multi-Interventional Cardiology Suite could drastically differ from what is needed in a simple unit. Understanding mechanical trade-offs involved in the Tubing Pressure and Kink resistance may help the buyers optimize choice for Workflow reliability and improve patient safety.

•Match the pressure rating to your injector’s maximum output: If your injector is rated at 1200 PSI and so is your tubing then you eliminate the risk of the tubing being the limiting factor.

•Choose based on room setup rather than personal preference: The least amount of tubing that can reach from injector to patient is the best.

•Suppliers that have conducted mechanical testing take precedence: Ask for pressure resistance testing data (per ASTM D1599) and for kink resistance (per EN 13868)

•Adopt a single product line across multiple suites: Using the same tubing series across multiple suites standardizes and simplifies everything from staff training to inventory management.

Contact Greetmed with your injector model, preferred tubing length, and pressure rating requirements. Our team will help you select the right GT211 configuration for your clinical environment and establish a reliable supply pathway for routine use.

Frequently Asked Questions (FAQ)

Q: For neurovascular procedures, what is the minimum pressure rating that I should consider for DSA Contrast Injection Tubing?

A: Tubing must have a pressure rating of 1200 PSI for neurovascular angiography, as it involves high-flow contrast delivery through microcatheters. Greetmed’s GT211-DSA-1200 series is made for this purpose.

Q: Is kink resistance a real term or just for marketing purposes?

A: There is a way to quantify kink resistance according to EN 13868, where a kink is defined as a bend that results in >50% reduction of flow. Established companies, Greetmed included, test and verify kink resistance according to these standards.

Q: Does longer tubing have higher kink risks?

A: Yes, because the excess greats more opportunity for kinking. This is the reason why GT211 has tubing lengths of 60 cm, 90 cm, and 120 cm; to help eliminate the excess based on the actual layout of the room.

Q: Is it possible to use 1200 PSI tubing with a 600 PSI injector?

A: Yes. Tubing that is pressure rated higher can be use at a lower pressure. This is not case with the 600 PSI tubing on a 1200 PSI injector, as it is unsafe and may result to a rupture.

Q: Why do braided DSA Contrast Injection Tubing have more kink resistance when compared to the non braided versions..

A: The integrated polyester braid helps to prevent of a bend in a specific area of the tube wall as it helps to even out the bending stress. An non braided tubing has to manage stiffness and kinking only with the wall thickness.