PO-693-05 REMOVAL OF A CHRONICALLY-IMPLANTED LEADLESS VENTRICULAR PACEMAKER AFTER 9-YEARS USING A HIGHLY TORQUE RETRIEVAL CATHETER A CASE REPORT

Abstract

Leadless cardiac pacemakers (LPs) are an effective and safe alternative to transvenous pacemakers for single-chamber ventricular pacing. However, the feasibility of retrieving and replacing chronically implanted LPs is not well understood. We report a case of LP retrieval and replacement of a 9-year chronically implanted Nanostim LP. N/A An 84 year old woman had a Nanostim LP (St Jude Medical Inc) implanted in December 2012, with good pacing parameters: threshold 0.5 V at 0.4 ms, impedance 500 Ohm, R-wave amplitude 7.5 mV. The parameters remained stable over time until the most recent clinic visit (early November 2021), when interrogation failed - indicating battery end-of-life. One month later, she underwent LP retrieval. Fluoroscopy revealed significant swinging movement of the LP docking button - suggestive that success of retrieval was likely. After femoral venous access, with fluoroscopy + ICE guidance, we used a tri-loop snare LP retrieval catheter (Abbott Inc) designed to be engage the LP in a highly torque-responsive manner. After confirming coaxial alignment between the snare and the docking button, the snare was closed, and locked around the docking button on the proximal end of the LP. After closing the snare, the retrieval catheter was docked with the LP. The protective sleeve was then advanced over the LP to assist with the coaxial alignment between the retrieval catheter docking cap and the LP. Thereafter, the retrieval catheter was rotated counterclockwise to allow the LP to unscrew from the myocardium. After less than 2 minutes, the tri-Loop retrieval catheter snared the docking cap, and the soft protective sleeve was easily advanced over the LP. After two full rotations, and in less then 2 minutes, the LP was released from the RV wall. The explanted LP device had limited adherent tissue ingrowth. During the same procedure, a new LP (Aveir VR; Abbott Inc.) was implanted: acute threshold 1 V/0.4, Impedance 630 ohm and R wave amplitude 9 mV. This case report demonstrates the feasibility of retrieval of even long-term chronically-implanted LPs after 9 years duration. Successful retrieval seems to be related to the combination of i) identifying swinging motion of the LP with fluoroscopy, plus ii) the high torque-responsiveness of the retrieval catheter.