The Axillary Fossa: An Uncovered Hidden Site as a New Alternative for Cardiac Pacemaker and Defibrillator Implantation.

Inadequate thickness of subcutaneous tissue, pectoralis muscle wasting, and/or a lack of availability of subpectoral space can become significant issues in patients with or requiring cardiovascular implantable electronic devices (CIEDs). This is particularly concerning but not exclusive in the elderly population, who may experience discomfort and hypersensitivity of the site as well as the potential for erosion and an increased risk of infection. Thus, the use of an alternative location, the axillary fossa, offers several advantages that make it a suitable option. Specifically, it usually has a preserved fat pad (even in thin patients); is unperturbed by arm movement; is not directly exposed to contact; is easily accessed with no significant compromise of neurovascular structures; and is near the conventional subclavicular sites, with enough lead length to reach in case of the need for generator replacement. Here, we present a series of five patients, including details of their anatomy and the implant techniques used. Two underwent device replacements, with one of them presenting with significant ongoing site discomfort and the other with extreme tissue thinning, respectively. Two patients with no significant fat layer or pectoral muscle wasting had new pacemakers implanted. Lastly, a biventricular implantable cardioverter-defibrillator generator was reimplanted in a younger patient who had issues with protrusion and discomfort in the setting of thin subcutaneous tissue and the subpectoral space being occupied by a large breast implant. In conclusion, the use of the axillary fossa as a new alternative CIED implantation site, using the proposed implant technique, appears feasible and safe and demonstrated excellent results related to patient comfort and adequate device cover in five cases.