Un-LINQed: Spontaneous extrusion of newer generation implantable loop recorders

BACKGROUND: Insertable cardiac monitors (ICMs) are often used for long-term monitoring of cardiac rhythm. The Medtronic's LINQ Reveal ™ is a new generation wireless, automated, and patient responsive subcutaneous ECG monitoring device. Despite several advantages to its small size we have noted an unusually high incidence of extrusion at our center. METHODS: & Results: We conducted a retrospective case analysis to review Reveal LINQs implanted at our center. All devices were inserted using the provided insertion tools. Patients with extruded devices were identified and details regarding the site and technique of insertion, incision closure, use of peri-operative antibiotics, and follow-up details were collected. 81 patients underwent 85 Reveal LINQ implants at a tertiary care University Hospital referral center. The most common reason for implant was suspected arrhythmia with or without structural heart disease or unexplained syncope. There were 4 spontaneous extrusions occurring within 7-24 days after insertion with an incidence rate of 4.7%. One extruded device was anchored to subcutaneous tissue, and no pocket/device infections or hematomas were noted. CONCLUSIONS: Device migration and erosion through skin are important potential adverse events for the Reveal LINQ implantable loop recorder. This study reports an unexpectedly high rate of extrusion without infection. The authors suggest that the depth of the incision is the main factor impacting extrusions. Larger studies are recommended, however, and a proposed measure to avoid spontaneous extrusion is the design of a longer manufacturer's blade in order to increase the depth of the incision and insertion.