Navigating the evolution of catheter and tubing materials
Sruthi Chirra, consultant specialty chemicals, ChemBizR, discusses plastics usage in catheters and medical tubing from PVC to high-performance polymers and the rise of microcatheters in healthcare.
Plastic materials have monopolised the market for catheters and medical tubing since the 1940s, when they were first introduced and commercialised. PVC was the first synthetic plastic to be used successfully for medical tubing, and it quickly gained popularity. Various other polymers, such as PE, PP, silicone, and PU, were introduced for the segment and adapted for specific use cases over the following decades.
The industry is gradually shifting towards better processible and biocompatible materials while overcoming the industry's current challenges. The chemical leaching of PVC-based tubes is a well-discussed limitation of the material. It is caused by the high requirement of the plasticiser dosages to render desired flexibility to the material, which in turn permits high chemical leaching, raising concerns about patient exposure to potentially harmful substances.
Many suppliers are launching plasticiser-free PVC alternatives to tackle the issue. For example, Arkema markets its PEBAX MED, a plasticiser-free Block PEBA (polyether block amide) for the catheter market, claiming exceptional flexibility aided with toughness.
Suppliers have also launched several new products involving materials such as PEI (Polyetherimide), PI (Polyimide), Polysulfones and PEEK to address issues such as yellowing/oxidation to repeated sterilisation, better dimensional tolerances to precision extrusion, chemical resistance, and so on.
The types of classification and emerging market trends
The catheter and tubing market can be classified based on the technicalities of usage and is then further divided into distinct anatomical application areas, each with its own set of property criteria. In general, medical tubing is used in fluid transfer locations such as IV drips, ventilators, and so on that does not come in contact with the patient's body or internal fluids. Catheters, on the other hand, are typically implanted into bodily cavities or convey internal fluids, necessitating great biocompatibility when compared to regular medical tubing.
With the growing healthcare industry, including all aspects of diagnosis, monitoring, and therapy, polymer material demand is expected to grow at a compounded pace of 4-5% over the next five years. Microcatheters, a subclass of therapeutic catheters, are gaining popularity and growing at twice the rate of the overall market.
There are two major reasons for this soaring market penetration of microcatheters:
The rapid rise in minimally invasive cardio-vascular surgery, including procedures for infants that necessitate smaller and specifically designed microtubes that can be inserted into small, delicate blood vessels with minimal trauma to the surrounding tissue.
The microtubes are being used in areas other than cardiovascular procedures, such as neurovascular, interventional radiology, oncology, and more.
This increase in demand presents a great opportunity for high performance polymers in the microcatheters market, as they provide the tight tolerances required to extrude thin-walled structures, as well as the right mix of desired flexibility and compression resistance, all with no use of harmful plasticisers, which is a major source of impurity concern.
Although PVC, Silicone, PU, etc., currently have high volumetric consumption, the market is expected to shift toward higher use of Polysulfone, which has low concerns about chemical leaching and is also highly suitable for multiple sterilisation cycles.
High performance PEEK is also becoming more popular, particularly in applications such as ablation devices, where high heat resistance and strength are required but cost is not a major factor. The market for microcatheters is expected to grow at an 8-10% CAGR over the next five years, with a growing shift toward Polysulfone, PEEK, and a few others such as Polyamide and PEI.
The trend on Fluoropolymers (FPs)
Fluoropolymers have been used in the medical tubing and catheter markets for decades in a variety of anatomical areas. They currently account for a sizable demand of the catheter and tubing market and are used in interventional cardiology, urology, gastroenterology, and other medical fields.
However, the primary application of Fluoropolymers is in catheters designed for minimally invasive procedures and microcatheters. FPs are also sometimes regarded as the workhorse material of minimally invasive medical devices. The application of FPs in the segment is aided by lubricity/non-stick, chemical resistance, and coefficient of friction.
The future of material use for catheters
Undoubtedly, the market is expected to shift toward high performance polymers in specific and emerging application areas. However, PVC, the most often used material in the industry, is expected to maintain its demand with no significant decline in consumption. Although, the discussion over its limitations has raged on for the past two decades, demand has remained strong in the majority of general application areas.
The actual impact of chemical leaching on the patient or to the outcome of the medical procedure is more speculative and less concrete. As a result, in most circumstances, the preference leans towards its advantages such as low cost and ease of processing.