ERCP Accessories-Stone Extraction Basket

ERCP Accessories-Stone Extraction Basket

The stone retrieval basket is a commonly used stone retrieval helper in ERCP accessories. For most doctors who are new to ERCP, the stone basket may still be limited to the concept of "tools for picking up stones", and it is not enough to deal with the complicated ERCP situation. Today, I will summarize and study the relevant knowledge of ERCP stone baskets based on the relevant information I have consulted.

General classification

The stone retrieval basket is divided into a guide wire-guided basket, a non-guide wire-guided basket, and an integrated stone-retrieval basket. Among them, the integrated retrieval-crush baskets are the ordinary retrieval-crush baskets represented by Micro-Tech and the Rapid Exchange (RX) retrieval-crush baskets represented by Boston Scientifi. Because the integrated retrieval-crush basket and quick-change basket are more expensive than ordinary baskets, some units and operating doctors may reduce their use due to cost issues. However, regardless of the cost of simply abandoning it, most operating doctors are more willing to use basket (with a guide wire) for fragmentation, especially for slightly larger bile duct stones.

According to the shape of the basket, it can be divided into "hexagonal", "diamond" and "spiral", namely diamond, Dormia and spiral, among which Dormia baskets are more commonly used. The above baskets have their own advantages and disadvantages, and need to be flexibly selected according to the actual situation and personal usage habits.

Because the diamond-shaped basket and Dormia basket is a flexible basket structure with "expanded front end and reduced end", it can make it easier for the basket to retrieve stones. If the stone cannot be taken out after being trapped because the stone is too large, the basket can be released smoothly, so as to avoid embarrassing accidents.

Ordinary "diamond" basket
Regular "hexagon-rhombus" baskets are used relatively rarely, or only in stone crusher baskets. Due to the larger space of the "diamond" basket, it is easy for smaller stones to escape from the basket. The spiral-shaped basket has the characteristics of "easy to put on but not easy to untie". The use of the spiral-shaped basket requires a full understanding of the stone and the estimated operation to avoid the stone getting stuck as much as possible.

Spiral basket
The quick-exchange basket integrated with crushing and crushing is used during the extraction of larger stones, which can shorten the operation time and improve the success rate of crushing. In addition, if the basket needs to be used for imaging, the contrast agent can be pre-flushed and exhausted before the basket enters the bile duct.

Second, the production process

The main structure of the stone basket is composed of a basket core, an outer sheath and a handle. The basket core is composed of basket wire (titanium-nickel alloy) and pulling wire (304 medical stainless steel). The basket wire is an alloy braided structure, similar to the braided structure of a snare, which helps to capture the target, prevent slippage, and maintain a high tension and is not easy to break. The pulling wire is a special medical wire with strong tensile force and toughness, so I will not go into details here.

The key point to talk about is the welding structure between the pulling wire and the basket wire, the basket wire and the metal head of the basket. In particular, the welding point between the pulling wire and the basket wire is more important. Based on such a design, the requirements for the welding process are very high. A basket with a slightly poor quality may not only fail to crush the stone but also cause the welding point between the pulling wire and the mesh basket wire to break during the process of stone crushing after the stone is removed, resulting in the basket and the stone remaining in the bile duct, and subsequent removal. Difficulty (usually can be retrieved with a second basket) and may even require surgery.

The poor welding process of the wire and the metal head of many ordinary baskets can easily cause the basket to break. However, Boston Scientific's baskets have made more efforts in this regard and designed a safety protection mechanism. That is to say, if the stones still cannot be broken with high pressure crushing stones, the basket that tightens the stones can protect the metal head at the front end of the basket to ensure the integration of the basket wire and the pulling wire. Integrity, thus avoiding baskets and stones left in the bile duct.

I will not go into details about the outer sheath tube and handle. In addition, various stone crusher manufacturers will have different stone crushers, and I will have the opportunity to learn more later.

How to use

Incarcerated stone removal is a more troublesome thing. This may be the operator's underestimation of the patient's condition and accessories, or it may be a feature of the bile duct stones themselves. In any case, we should first know how to avoid incarceration, and then we must know what to do if incarceration occurs.

To avoid basket incarceration, a columnar balloon should be used to dilate the nipple opening before stone extraction. Other methods that can be used to remove the incarcerated basket include: use of a second basket (basket-to-basket) and surgical removal, and a recent article has also reported that half (2 or 3) of the wires can be burned using APC. break, and release the incarcerated basket.

Fourth, the treatment of stone basket incarceration

The use of the basket mainly includes: the choice of the basket and the two contents of the basket to take the stone. In terms of basket selection, it mainly depends on the shape of the basket, the diameter of the basket, and whether to use or spare an emergency lithotripsy (generally, the endoscopy center is routinely prepared).

At present, the "diamond" basket is routinely used, that is, the Dormia basket. In the ERCP guideline, this kind of basket is clearly mentioned in the section of stone extraction for common bile duct stones. It has a high success rate of stone extraction and is easy to remove. It is the first-line choice for most stone extraction. For the diameter of the basket, the corresponding basket should be selected according to the size of the stone. It is inconvenient to say more about the choice of basket brands, please choose according to your personal habits.

Stone removal skills: The basket is placed above the stone, and the stone is tested under angiographic observation. Of course, EST or EPBD should be performed according to the size of the stone before taking the stone. When the bile duct is injured or narrowed, there may not be enough space to open the basket. It should be retrieved according to the specific situation. It is even an option to find a way to send the stone to a relatively spacious bile duct for retrieval. For hilar bile duct stones, it should be noted that the stones will be pushed into the liver and cannot be retrieved when the basket is taken out of the basket or the test is performed.

There are two conditions for taking stones out of the stone basket: one is that there is enough space above the stone or beside the stone to allow the basket to open; the other is to avoid taking too large stones, even if the basket is completely opened, it cannot be taken out. We have also encountered 3 cm stones that were removed after endoscopic lithotripsy, all of which must be lithotripsy. However, this situation is still relatively risky and requires an experienced doctor to operate.

Post time: May-13-2022