Failure Mechanisms in Off-Label Electrosurgery Devices for BASILICA, LAMPOON, and SESAME.

BACKGROUND

Transcatheter electrosurgery using off-label guidewire-catheter systems to traverse or lacerate tissue may fail unexpectedly or cause nontarget heating.

OBJECTIVES

The aim of this study was to identify mechanisms of energy loss and nontarget heating in off-label transcatheter electrosurgery systems.

METHODS

The authors simulated electrosurgical traversal and flying-V laceration used in BASILICA (bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction), LAMPOON (laceration of the anterior mitral leaflet to prevent outflow obstruction), and SESAME (septal scoring along the midline endocardium) in a 2-compartment benchtop model. Current distribution and regional heating were measured in metallic-braided and nonmetallic catheter assemblies.

RESULTS

Longer, higher power energy applications caused substantial catheter shaft heating and diverted energy delivery away from traversal or laceration targets. This reflected coupling between the guidewire and metallic catheter components and was amplified by thermal damage to insulation. Shorter, lower power applications and nonmetallic catheters reduced these effects. In SESAME, the risk for dangerous intramyocardial heating was reduced by connecting the intracavitary limb of the flying-V to the electrosurgery generator, instead of the intramyocardial limb.

CONCLUSIONS

Metallic braiding in commonly used microcatheters can divert energy away from electrosurgical targets to catheter shafts and cause clinically important nontarget heating. In this benchtop model, energy applications of ≤2 seconds largely avoided these failure modes. Operators should favor nonmetallic catheters when feasible, use the shortest effective energy applications, and in SESAME energize the intracavitary limb. Purpose-built electrosurgical devices may improve safety and reliability.