Contraceptive implant migration

Last revised by Arlene Campos on 24 Jul 2023

Citation, DOI, disclosures and article data

Citation:

Baird-Fraser P, Campos A, Ranchod A, et al. Contraceptive implant migration. Reference article, Radiopaedia.org (Accessed on 16 Apr 2024) https://doi.org/10.53347/rID-97012

DOI:

https://doi.org/10.53347/rID-97012

Permalink:

https://radiopaedia.org/articles/97012

rID:

97012

Article created:

30 Jan 2022, Patrick Baird-Fraser

Disclosures:

At the time the article was created Patrick Baird-Fraser had no recorded disclosures.

View Patrick Baird-Fraser's current disclosures

Last revised:

24 Jul 2023, Arlene Campos ◉

Disclosures:

At the time the article was last revised Arlene Campos had no financial relationships to ineligible companies to disclose.

View Arlene Campos's current disclosures

Revisions:

10 times, by 7 contributors - see full revision history and disclosures

Systems:

Vascular, Chest, Interventional

Sections:

Interventional Radiology

Tags:

cases, case1

Contraceptive implant migration is a rare complication of etonogestrel implant insertion.

Contraceptive implants are most commonly inserted into the medial soft tissues of the upper non-dominant arm. They are 4 cm rod-shaped radio-opaque devices with the most commonly used being Nexplanon (Merck & Co., Inc., USA) and Implanon (Merck & Co., Inc., USA). They inhibit ovulation and are routinely replaced after 3 years. Complications are uncommon with most being local and minor.

However, implant migration is a reported rare complication with approximately 40 recorded (~10 with pulmonary migration) by the USA's Food and Drug administration and 12 published cases (c. 2020) ^ref.

The exact mechanism of migration is unclear but it is theorized that an inadvertent placement of the implant into the venous system may occur during the initial procedure with the implant embolizing via the right heart into the pulmonary arterial system¹.

Radiographic features

Ultrasound

Ultrasound is the first-line modality for locating contraceptive implants. Implants are linear echogenic structures with posterior acoustic shadowing measuring approximately 4 cm in length.

Plain radiograph

If unable to locate the device by palpation or ultrasound then a plain film of the shoulder/upper arm is performed. All contraceptive implants are radio-opaque ^ref. They appear as 4 cm thin rod-shaped structures. If no device is seen then the patient should proceed to a frontal +/- lateral chest radiograph.

Treatment and prognosis

Removal by endovascular procedures has been reported with varying success. The implants tend to endothelialise and become fixed so if left for a long period of time the risk of unsuccessful endovascular removal increases ^2-3.

The alternative method of removal reported is by thoracotomy and segmentectomy.

In multiple case reports the device was left in situ with follow up plan including patient review and monitoring of etonogestrel levels. This conservative approach was typically used in the asymptomatic patient who has no desire to conceive with the rationale being that etonogestrel levels may gradually diminish and the device eventually become inactive ⁴^-5.