Author + information
- Received June 26, 2017
- Revision received July 5, 2017
- Accepted July 13, 2017
- Published online November 1, 2017.
- Matthew J. Kolek, MD, MSCI∗ (, )
- George H. Crossley, MD and
- Christopher R. Ellis, MD
- ↵∗Address for correspondence:
Dr. Matthew J. Kolek, Vanderbilt University Medical Center, Department of Medicine, 383 PRB, 2220 Pierce Avenue, Nashville, Tennessee 37232.
The MICRA leadless pacing system (Medtronic, Inc, Minneapolis, Minnesota) delivers VVI pacing implanted through a 23-F sheath via a femoral approach. We present feasibility of MICRA implantation via a right internal jugular (RIJ) vein approach in a patient with an inferior vena cava (IVC) filter, which is a contraindication for a femoral approach due to the concerns of the manufacturer about strong lateral forces distorting the IVC filter.
A 72-year-old man with protein S deficiency, extensive deep vein thrombosis, and a previous IVC filter, and who was recently diagnosed with a brain mass, presented for elective admission for open brain biopsy. Sinus arrest was noted on telemetry- and neurosurgery-requested pacing support. Leadless pacing was believed to be the best option due to protein S deficiency, although extensive clot burden in the IVC and the presence of the IVC filter precluded a femoral approach (Figure 1A). Therefore, we planned for MICRA implantation via the RIJ vein.
Ultrasound-guided access confirmed a patent RIJ with diameter of 1.1 cm. Superior vena cava (SVC) contrast venography through a 9-F sheath showed a patent course from the SVC to right atrium with no visible thrombus (Figure 1B). A stiff 0.035-inch guidewire was advanced to the level of the IVC filter, and the 23-F MICRA outer sheath and dilator were carefully advanced to the lower right atrium (Figure 1C, Online Video 1). The MICRA delivery system was placed through the outer sheath, and used to cross the tricuspid valve and deploy the device in the distal intraventricular septum (Figure 1D, Online Videos 2, 3, 4, 5, and 6), with no complications. Total procedural time, fluoroscopy time, and estimated blood loss were 37 min, 5.6 min, and 10 ml, respectively. The patient underwent open biopsy of his brain mass the following morning.
The presence of an IVC filter is an explicit contraindication for the placement of a MICRA pacemaker according to the Food and Drug Administration approved labeling. Although many devices have been safely advanced through IVC filters, the rationale for this prohibition is that when the MICRA is deployed into the ventricle, there are considerable right lateral forces that are exerted in the IVC, and therefore, on the filter. These forces would not be experienced during other cardiac procedures, and there is concern for compromising the integrity of the filter. MICRA can be safely implanted via a superior approach from the RIJ vein, thus avoiding potential complications of IVC filter dislodgement. Due to increased axial forces with the RIJ approach, and concerns about advancing a large sheath through the relatively small RIJ, the femoral approach should remain standard for most MICRA implantations.
Dr. Crossley is a consultant and speaker for Medtronic. Dr. Ellis has received research funding from Vanderbilt University and is a consultant for Medtronic. Dr. Kolek has reported that he has no relationships relevant to this paper to disclose.
- Received June 26, 2017.
- Revision received July 5, 2017.
- Accepted July 13, 2017.
- 2017 American College of Cardiology Foundation