Cleaning the tip with povidone-iodine solution significantly reduces power output from a radial emission endovenous laser catheter using 1470 nm

Background Endovenous laser ablation (EVLA) is a first line recommended treatment for incompetent truncal veins in the legs. The current “industry standard” is a single ring radially firing catheter, using a 1470 nm diode laser. It is common for doctors to treat more than one vein, and they often clean the catheter tip before re-introduction. We have observed some doctors using normal saline for this, but others using povidone-iodine. The aim of this in vitro study was to determine whether povidone-iodine reduces the power being emitted from the catheter tip. Methods Five radial catheters were tested, each connected in turn to a 1470 nm diode laser set at 10 W. Power emission was measured by a laser power detector connected to a power meter. The power meter recorded an average (mode) of the readings once the laser had reached a steady state. Each catheter was tested firing in air, after dipping in normal saline, then povidone-iodine and finally after wiping the povidone-iodine off the tip with a surgical gauze. Results The emitted power recorded for air (9.05 W) was significantly ( p < .05) more than for normal saline (8.90 W), povidone-iodine (8.69 W) and post-wiping off povidone-iodine (8.87 W). The power emitted with povidone-iodine on the tip was significantly less than with normal saline, which mimics the situation of the catheter in a vein surrounded by tumescence anaesthesia. Conclusion In a laboratory setting, povidone-iodine on the tip of a radially firing catheter transmitting laser energy at 1470 nm, significantly reduces the power being emitted. As this was a laboratory-based study, clinical studies are required to see if this translates into a significant problem during EVLA treatment.