Data to support "Failure mechanisms in off-label electrosurgery devices for BASILICA, LAMPOON, and SESAME"

Background Transcatheter electrosurgery to traverse or lacerate leaflets, using commercial off-the-shelf catheter devices off-label, may fail unexpectedly or cause unintended heating. Objectives To identify mechanisms of energy loss and non-target heating in off-label transcatheter electrosurgery systems. Methods We simulated electrosurgical traversal and Flying-V laceration in BASILICA and LAMPOON leaflet modification and SESAME transcatheter myotomy, using a 2-compartment testbed. We measured current distribution and regional heating in assemblies using metal-braided and non-metallic catheters. We tested short-duration, low-power and long-duration, high-power electrification. Results Higher-power and long-duration electrification caused substantial catheter shaft heating, compared with short-duration, lower-power energy application. The shaft heating reflected diversion of energy away from targets for tissue traversal or laceration. The heating was caused by electromagnetic coupling between the guidewire and metallic catheter braiding. Metallic braiding and damaged insulation were major contributors. Non-metallic catheters reduced these effects. In SESAME, the risk of dangerous intramyocardial heating was reduced by connecting the intracavitary limb of the Flying-V to the electrosurgery generator, rather than the intramyocardial limb. Conclusions Metallic braiding in commonly-used microcatheters and guiding catheters diverts energy from electrosurgical targets to catheter shafts. The diverted energy causes significant bystander heating, risking thermal injury. Energy applications ≤2s largely avoided these failure modes on the benchtop. Operators should favor non-metallic catheters when feasible, use the shortest effective energy application, and during SESAME selectively energize the intracavitary limb. Purpose-built electrosurgical devices may improve safety and reliability.