Multiplane/3D transesophageal echocardiography monitoring to improve the safety and outcome of complex transvenous lead extractions

Both transesophageal echocardiography (TEE) and intracardiac echocardiography have been used to assist transvenous lead extractions. The clinical utility of continuous echocardiographic monitoring during the procedure is still debated, with different reports supporting opposite findings. In cases where the procedure is expected to be difficult, we propose adding a continuous TEE monitoring using a static 3D/multiplane probe in mid‐esophageal position, with digital remote manipulation of the field of view. This approach may improve the chances of a successful extraction, increase safety, or even guide the entire intervention. We present here a short case series where continuous monitoring by TEE played an important role.

Both transesophageal echocardiography (TEE) and intracardiac echocardiography have been used to assist transvenous lead extractions. The clinical utility of continuous echocardiographic monitoring during the procedure is still debated, with different reports supporting opposite findings. In cases where the procedure is expected to be difficult, we propose adding a continuous TEE monitoring using a static 3D/ multiplane probe in mid-esophageal position, with digital remote manipulation of the field of view. This approach may improve the chances of a successful extraction, increase safety, or even guide the entire intervention. We present here a short case series where continuous monitoring by TEE played an important role.

K E Y W O R D S
continuous echocardiography monitoring, intraprocedural echocardiography, multiplane echocardiography, transesophageal echocardiography, transvenous lead extraction the femoral approach using a snare tool (Needle's-Eye Snare, Cook Medical). A new shock lead was successfully implanted.

| PATIENT 2
A 69-year-old man with sick sinus syndrome had a dual-chamber pacemaker implanted in 2010. Shortly after implantation, both leads became dysfunctional. During the first extraction, both leads were replaced but only the atrial lead could be removed. The old RV lead was abandoned. In 2017, the new leads also became dysfunctional. The chest X-ray and left arm phlebography showed signs of subclavian crush syndrome ( Figure 3). The presence of three relatively old leads was considered to complicate the extraction procedure, which was then performed under continuous TEE monitoring ( Figure 4). The locking stylet could not be inserted in the leads (probably due to the subclavian crush); thus, a femoral approach with a snare tool (Needle's-Eye Snare, Cook Medical) was chosen. The atrial lead was extracted with ease as well as the most recent implanted RV lead. During careful but progressive pulling of the abandoned RV lead, we saw near inversion of the RV cavity with TEE ( Figure 4). In this short period, the blood pressure dropped but quickly recovered after the lead detached and the RV re-expanded (Movie S2). The patient was re-implanted with a new dual-chamber pacemaker ( Figure 5). No complication was noted, and the patient was quickly discharged.

| PATIENT 3
A 51-year-old woman presented to the emergency department with palpitations. One week before, she had undergone a full-system dual-chamber pacemaker extraction. No pacemaker was re-implanted due to the absence of pacing in the previous 5 years. Her ECG at presentation showed sinus rhythm with frequent multifocal premature ventricular complexes and short runs of ventricular tachycardia. Her chest X-ray was normal and did not demonstrate a complication of the recent lead extraction. On transthoracic echocardiography, a very weak linear echo was visible (Movie S3) in the right atrium (RA). A thoracic CT scan was performed, and a linear structure could be noticed coursing from the proximal SVC to the RV apex ( Figure 6). The most probable diagnosis was a retained fragment of the silicone insulation of the previous extracted RV lead. After discussing the case in a heart team, it was decided to try a TEE-guided percutaneous removal. Surgical removal remained as an escape option. The retained silicone sheath could not be visualized with high-intensity fluoroscopy; thus, the extraction was guided by TEE. By 3D and multiplane imaging, the  Hemodynamic stability is acquired by releasing pulling pressure or successful extraction.
Macroscopic inspection of the extracted lead is mandatory to identify missing parts of the leads suggesting retention of lead fragments. Partial lead extraction is relatively rare, with an incidence ranging around 2%-3%. 11 Usually, distal lead fragments fracture due to mechanical stress during extraction and become obvious on fluoroscopy checkup. Cases have been described of remaining fragments of the silicone protective tube around the lead. These can easily be missed by fluoroscopy if no metallic fragment is retained. 12,13 Echocardiography however is an ideal imaging tool in this clinical scenario, given the relatively high contrast between intracavitary blood and any type of solid foreign body. This is illustrated by our Patient 3 in whom, although a multimodality approach was needed for the diagnosis, TEE was the only intraprocedural imaging tool allowing successful guidance of the TLE procedure.  There are of course disadvantages to this approach. Working space in the intervention room is already limited, and continuous monitoring implies longer radiation exposure for the sonographer.
We tried to overcome this limitation by using a static probe with an imaging plane that could be remotely rotated toward the target structures. Also, the probe shadow may obstruct the fluoroscopic image, but this was not a real issue in the cases described here.

| CON CLUS ION
In selected cases where the complexity of the lead extraction is anticipated to be high, continuous TEE monitoring can be used to increase the success rate of the procedure, prevent or rapidly diagnose complications, or even guide the entire intervention. The use of static 3D/multiplane probes that allow remote manipulation of the field of view can help reduce radiation and improve management of the working space.

CO N FLI C T O F I NTE R E S T
All authors declare that they have no competing interests.

E TH I C A L A PPROVA L A N D CO N S E NT TO PA RTI CI PATE
Written informed consent was obtained from the patients for publication of this case series and all accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

AVA I L A B I LIT Y O F DATA A N D M ATE R I A L
The datasets generated and analyzed in the current report are not publicly available due to patient privacy but are available from the corresponding author on reasonable request.