Intermittent Catheter Types

Currently, intermittent catheters on the market are mainly classified into three categories: uncoated catheters, coated catheters, and closed catheter systems.

1. Uncoated Catheters

Also known as standard catheters, uncoated catheters are frequently utilized in clean intermittent catheterization (CIC). It is recommended to apply lubricant during insertion. These catheters are available in both latex-containing and latex-free materials.

Latex-free uncoated catheters are currently the most prevalent option. They are made from medical-grade plastics like polyvinyl chloride (PVC) , offering varying levels of flexibility and a broad range of diameters to suit different needs.

Red rubber catheters contain latex and are not suitable for individuals with latex allergies. These catheters are relatively soft, which can make insertion somewhat challenging.

Most uncoated catheters are for single use, though reusable models are also available. Reusable catheters are typically constructed from materials such as silicone, latex, fiberglass, or stainless steel. However, using reusable catheters comes with inherent drawbacks: maintaining proper cleanliness and storage conditions over the long term is difficult.

2. Coated Catheters

Hydrophilic-coated catheters are produced by covering the entire surface of catheter with a hydrophilic polymer, mainly polyvinylpyrrolidone (PVP). PVP is a safe and non-allergenic substance that has been widely used in the medical device and cosmetics industries.

When the catheter comes into contact with water, the PVP coating absorbs water molecules and forms a biocompatible saline layer on the catheter surface, creating a water-based outer coating. This thick, smooth surface ensures that the catheter remains lubricated during both insertion and removal, reducing friction between the catheter and the urethral mucosa to a minimum—for this reason, these catheters are also called ultra-smooth catheters.

Hydrophilic-coated catheters are generally categorized into two types:

• Dry hydrophilic-coated catheters: These catheters are stored in a dry condition. Before catheterization, the catheter body must be soaked in water to activate the hydrophilic coating.
• Pre-lubricated hydrophilic-coated catheters: Each catheter is packaged in a water-based environment, which keeps the hydrophilic coating fully activated. The catheter can be taken out and used right away after opening the package.

3. Closed Catheter Systems

Catheters in closed systems are integrated directly with a collection bag, and are available in four variants: uncoated, dry hydrophilic-coated with water sachet, pre-lubricated hydrophilic-coated, and pre-lubricated gel catheters.

Most closed catheter systems are designed with an introducer tip  to prevent catheter contamination and the subsequent entry of bacteria into the bladder. During the catheterization process, operators are not allowed to touch the catheter directly with their hands, which requires a certain degree of manual coordination.