|
?:definition
|
-
Endoscopic urinary tract snares designed to position and tighten fine-gauge, flexible or semirigid, adjustable, wire loops around a region of tissue for mechanical or electrosurgical resection and hemostasis. These devices typically consist of a hollow tubular structure (e.g., a cannula), with one or more adjustable wire loops that protrude at the working end. The snare is introduced into the urinary tract through the working channel of a cystoscope or ureteroscope; a mechanism at the proximal end (handle) controls how much wire extends out of the channel and the movement of the sliding cutting loop as the loop is withdrawn into the cannula. The snare loops are made of monofilament or braided wires and may be attached at the proximal end to an electrosurgical (usually monopolar) unit that provides circulation of radio-frequency electric current between the isolated metal loop (i.e., acting as an active electrode) and an external neutral electrode to heat the tissues, facilitating coagulation. Endoscopic urinary tract snares may be single-use (i.e., disposable) or reusable; they are used mainly for electrosurgical removal of polyps, tumors, and other abnormal tissue from the urinary tract, but mechanical (cold) resection may be used for small polyps.
|
![[This page as RDF]](https://research.tib.eu/covid-19/static/rdf-icon.gif){kind=icon}