Polypectomy snares are used for resection of polyps. The snareconsist of a wire loop contained within a flexible synthetic polymer sheath. There is plastic handle at the operator end to open and close the wire loop.
Snares employ monopolar current i.e. the current flows from the snare to a return electrode (grounding pad).
Polypectomy snares are available in a variety of shapes, sizes, and materials.
- Braided stainless steel wire is the most commonly used material for polypectomy snares.
- The standard shape of the snare loop is oval or elliptical. Other shapes include round, crescent, or hexagonal. There are no studies to compare the effectiveness of various snare shapes. Most endoscopists have their personal preferences, however the standard size and shape snare suffices for the majority of cases.
- The standard size snare loops are typically 2.-2.5 cm in diameter. Mini-snares have loop diameters of 1.0 –1.5 cm. Jumbo snares have loop dimensions of up to 3 ×6 cm.
Rotatable snares can be adjusted so that the snare loop opens in an orientation favourable to polyp entrapment.
A barbed snare has been marketed for removal of sessile polyps. However, there are no studies to indicate superiority of modified over standard snares for resection of sessile colon polyps.
