(115) The Case of the Missing Nexplanon.

Background: The etonogestrel single-rod implant (Nexplanon®) is an effective contraceptive with an unintended pregnancy rate of 0.5% in the first year of use. FDA-approved for 3 years, the etonogestrel implant appears to be effective for up to 5 years. Inserted subdermally typically in the upper arm, a non-palpable implant is concerning for device migration.

Case: A 19 yo girl presented 4 years after Nexplanon® placement for implant removal. The implant was not palpable in the upper extremity and was not visualized on ultrasound. She was lost follow and 1 year later the implant was not visible on chest Xray. Blood etonorgestrel level returned as 0 pg/mL. The patient disclosed multiple episodes of alcohol use and gaps in her memory while she was intoxicated and when she may have removed the device.

Comments: Nearly 150 cases of etonogestrel implant migration have been reported. Migration has been reported primarily to the lung/pulmonary artery but also to the chest wall, axilla, clavicle/neckline/shoulder, and vasculature in sites other than lungs. Since 2015, prescribing information for the etonogestrel implant includes advice on localizing a non-palpable implant. Although a phone number is provided to request a blood etonogestrel level if imaging does not locate the implant, this process is not clearly outlined. We present an algorithm for the management of a non-palpable implant (Figure 1). If upper extremity and chest imaging fail to locate the implant, a blood sample from the patient is collected in a redtop tube then spun and frozen. The implant sponsor provides a Credo shipping cube, an environmentally friendly, reusable, temperature-controlled shipping container in which the frozen blood sample is sent to Columbia Irving School of Medicine. There may be a 1-month delay in obtaining results as samples are only processed once each month. A detectable etonogestrel level is an indication for full body imaging for implant location and removal. Our patient had an undetectable blood level of etonorgestrel. Although it was initially difficult for our team to imagine patient self-removal of the etonogestrel implant, an Amazon search for “numbing cream for injections” yielded a benzocaine 15% numbing wipe for under $10 and a search for “Nexplanon removal kit” yielded a suture removal kit for less than $5 and razor blades for less than $10 (Figure 2). All items were available for overnight delivery.