BACKGROUND AND OBJECTIVE: In a recent clinical trial, the 12-F laser sheath showed 95% success in completely explanting chronically implanted pacing leads smaller than 7.5-F diameter. For larger leads, two new sizes of laser sheath have been implemented, the 14-F and 16-F (outer diameter) devices, which accommodate leads up to 9.5- and 11.5-F, respectively. The object of this study was to determine the cutting ability of the larger devices compared to the 12-F design. MATERIALS AND METHODS: The rate of device advancement through fresh porcine aorta was measured for three sizes of laser sheath as pulsed ultraviolet light from a 308-nm XeCl excimer laser was applied. Dependent variables were fluence (mJ/mm2), laser pulse repetition rate, and pressure applied between the device and the tissue. RESULTS: At 60 mJ/mm2, 40 Hz repetition rate and 1.4 kg/cm2 pressure, all devices produced cutting rates in the range of 9-13 microns/pulse. Improvement in advancement per laser shot can be attained by increasing any independent variable studied. CONCLUSIONS: Physicians must apply only slightly greater force to the larger laser sheaths, and maximum available repetition rate and fluence implies maximum cutting speed.
BACKGROUND AND OBJECTIVE: In a recent clinical trial, the 12-F laser sheath showed 95% success in completely explanting chronically implanted pacing leads smaller than 7.5-F diameter. For larger leads, two new sizes of laser sheath have been implemented, the 14-F and 16-F (outer diameter) devices, which accommodate leads up to 9.5- and 11.5-F, respectively. The object of this study was to determine the cutting ability of the larger devices compared to the 12-F design. MATERIALS AND METHODS: The rate of device advancement through fresh porcine aorta was measured for three sizes of laser sheath as pulsed ultraviolet light from a 308-nm XeCl excimer laser was applied. Dependent variables were fluence (mJ/mm2), laser pulse repetition rate, and pressure applied between the device and the tissue. RESULTS: At 60 mJ/mm2, 40 Hz repetition rate and 1.4 kg/cm2 pressure, all devices produced cutting rates in the range of 9-13 microns/pulse. Improvement in advancement per laser shot can be attained by increasing any independent variable studied. CONCLUSIONS: Physicians must apply only slightly greater force to the larger laser sheaths, and maximum available repetition rate and fluence implies maximum cutting speed.