The guiding wire referred to here is the guiding wire specially designed for ERCP. As the concept of "guiding wire" is quite extensive, it also has corresponding applications in cardiology, vascular surgery, gynecology, and gastroenterology. Among them, the guiding wires used in gastrointestinal endoscopy can be divided into general guiding wire, super hard guiding wire, and ERCP-specialized guiding wire. Other specialized guiding wires have their own characteristics and are different from ERCP-specialized guiding wires, so please pay attention to distinguishing their usage. The guiding wire is the most commonly used accessory in ERCP operation. It is used frequently and has a huge role. The operating doctor metaphorically refers to it as the "lifeline". If the guiding wire insertion is unsuccessful, the entire operation cannot proceed and be completed, and the ERCP operation will fail. Therefore, we still need to understand the content about the guiding wire.
A good ERCP guidewire should have the following characteristics: thin and flexible, super smooth, tough and not easy to break, easy to recognize, non-transparent to X-rays, and anti-tangling. With the continuous improvement of the design and production technology and experience of the guiding wire, the guiding wires on the market now have the above characteristics. However, besides these characteristics, guiding wires produced by different companies have relatively different "personalities". Generally speaking, the quality is still very good. For example, the disposable digestive tract guide wire exclusively produced by LOIC Medical. Many endoscopists have their own guiding wire selection habits and experience.
The core part of the ERCP guiding wire is the tip - the "eel head". Because the soft and resilient movement is similar to that of eels, the tip end of the guiding wire is called the eel head. The soft and elastic front end can conveniently and selectively enter the narrow segment, while also ensuring that the guiding wire can avoid stabbing or puncturing tissue to cause perforation. After the tip end touches the tissue, it will immediately bend and rebound, ensuring that the guiding wire can safely and effectively pass through the narrow lesions of the bile duct and pancreatic duct. Although the process of improving the "eel head" is obvious, guiding wire-induced perforation during ERCP endoscopy still occurs from time to time. To avoid guiding wire perforation, it is important to select the appropriate guiding wire and improve the experience and skills of insertion.
The toughness of the guiding wire mainly manifests itself after it passes through the narrow segment. It also fully reflects the importance of the "lifeline". The toughness of the guiding wire determines its supporting force and hardness. Therefore, guiding wires that are too hard or too soft may cause operation difficulties or increase operation difficulty in diagnosis and treatment of ERCP.
The outer surface of the ERCP guiding wire has a hydrophilic coating. After being immersed in water, the outer surface becomes very smooth, making it easy to pass through cutting knives, ballons, and mesh baskets. After the guiding wire is lubricated with the hydrophilic coating, it can be easily and sensitively exchanged for accessories and also makes it convenient to rotate the guiding wire and related accessories, such as shaking and rotating the guiding wire in a fine operation.
The visibility label of the guiding wire mainly facilitates the doctor's observation of the movement of the guiding wire under direct vision through the endoscope. The design of the labeling of guiding wires of different companies has slight differences, but it is based on facilitating doctors to observe the movement of guiding wires under endoscopy. Currently, most guiding wires have spiral stripes as their main label, so it is called the zebra guide wire .
The diameter of the guiding wire has various sizes, such as 0.018inch, 0.025inch, 0.035inch, and 0.038inch. However, currently in clinical practice, the 0.025inch and 0.035inch diameters are the most commonly used. The 0.035inch guiding wire is hard enough, but due to its relatively large diameter, its ability to pass through narrow segments is insufficient. The 0.025inch guiding wire has a thinner diameter, which brings advantages for passing through narrow lesions, but its hardness is not enough, which may cause insufficient support force when passing through narrow segments or placing stents, and often leads to the failure of guiding wire insertion.