A comparative study of guidewire electrical resistance

Authors


Dr F. Desgrandchamps Department of Urology, Saint-Louis Hospital, 1 avenue Claude Vellefaux, 75010, Paris, France.

Abstract

Objective

 To evaluate the electrical resistance to current conduction of different guidewires used routinely in endourology and thus determine the risk of short circuits between the active electrode and the guide.

Materials and methods

 Using a standard resistance meter, the electrical resistance of four different types of guidewires was measured. Pure stainless-steel, polytetrafluoroethylene (PTFE)-painted, PTFE-sheathed and hydrogel-sheathed guidewires were tested, both when new and after mechanical abrasion of the external layer to reproduce their condition after use.

Results

 The pure stainless-steel guidewire had no resistance to electrical current. The electrical insulation of the PTFE-painted guidewires was poor and was eliminated by mechanical abrasion of the paint. New PTFE-sheathed and hydrogel-sheathed guidewires had a safe electrical resistance (>10 kΩ) but this insulation was easily eliminated by mechanical abrasion of the external layer.

Conclusions

 To minimize the risk of electrosurgical adverse effects during a guidewire-assisted endoscopic procedure, the operator should preferably use a new guidewire for each procedure, use sheathed guidewires and ensure that the guidewire is in good condition, or cover it with a ureteric catheter, before applying current.

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