Endoscopic retrieval devices are utilized for the removal of foreign bodies, polyps and oesophageal food impactions. Different types of snares, baskets, forceps, nets and graspers are available in the market, but choice depends mainly on the shape and size of object being retrieved.
Some devices are designed only for retrieval, while some are used for additional interventions. The success of the retrieval process may be a function of the experience of the endoscopist. It also depends on proper selection of retrieval device and skilful manipulation of the device.
Endoscopic retrieval devices like stone retrieval basket products aredesigned to pass through the channel of an endoscope. Some of the devices are:
Any standard polypectomy snare can be used for the objective of endoscopic retrieval. They come in various sizes like a jumbo snare with a 36 cm open loop. Some snares are rotatable which helps orient the loop around the target. Special snares (hexagonal, barbed, and crescent) are applicable in tissue removal.
They have a variety of jaw configurations such that the endoscopist can customize choice based on the features of the object being retrieved. Because of limited capacity of jaws, standard biopsy forceps are not useful for endoscopicretrieval.
A distal tooth or shark tooth forceps offers a more secure grip on the object being retrieved. Forceps with long jaws (alligator jaws) are useful for retrieving flat, hard objects like coins. Rubber-tipped forceps have been designed for small and hard objects like blades, pins and needles.
They are made of flexible, soft mesh material attached to the noose of a snare. When the snare loop is opened, the mesh forms a concave compartment which can capture a targeted object. Such nets come in a variety of configurations and sizes.
They have 5, 4, 3 or 2 prongs, which in open position, extend in a radial configuration and distal to the device tip, forming a space between the prongs. A handle permits retraction of prongs, trapping the object between them. They are used mostly to trap soft objects like food boluses.
Such baskets are ideal for retrieval of natural as well as foreign bodies like stone retrieval basket used for removing biliary (kidney) stones. They feature multiple wires which make it easy to capture certain objects, compared to a snare. Round objects which cannot be captured by snares or forceps can be retrieved by baskets. Four wire baskets are the standard but 6 wire ones can be used for tiny objects. The baskets are made in soft (braided wire) and hard (solid wire) configurations.
They consist of long, flexible wires connected to a strong magnet and are used mainly to retrieve ferro-magnetic foreign bodies. Prior to flexible endoscopy, these were used for gastric and oesophageal foreign body removal, making use of fluoroscopy. But currently such devices have been replaced by modern versions.
Biliary Stent Retrieval Devices
At certain times, it is better to remove a biliary or pancreatic stent over a wire to maintain duct access. The device is a hollow, wire-guided spring coil catheter with a threaded metal tip. By rotating the device, the stent is captured and pulled out.
These are the major types of endoscopic retrieval devices.