Implant Insertion

Subdermal implant insertion places one or two progestogen-releasing rods just under the skin of the inner upper arm to give long-acting contraception. It is a minor procedure under local anaesthesia done by a trained provider in about 5 minutes. Placement at the correct depth decides whether later removal is easy.

Implant systems.

• Etonogestrel 68 mg single rod in a preloaded disposable applicator: 3 years.

• Levonorgestrel 75 mg each, two rods, inserted with a trocar: one system lasts 5 years and another 3 years.

Indications. Patient choice of a highly effective, long-acting, oestrogen-free method, including adolescents, nulliparous patients, breastfeeding patients and patients with a contraindication to oestrogen.

Timing.

• Within 7 days of the start of menses: no backup. At any other time when reasonably certain the patient is not pregnant: backup for 7 days.

• Postpartum: immediately after delivery, and at any time while amenorrhoeic. If not breastfeeding, immediately or within 21 days; after 21 days, once pregnancy is excluded and menses have not returned.

• Postabortion: immediately.

• Switching from a hormonal method used correctly: immediately. From an injectable: when the next injection is due. From an IUD: within 7 days of menses with removal at the same time, or later with the IUD kept until the next menses.

Equipment. Implant package with the seal and expiry checked; sterile gloves; antiseptic (chlorhexidine 2% in alcohol or povidone-iodine 10%); sterile drape; lidocaine 1% 2 to 3 mL with syringe and fine needle; scalpel (two-rod system only); adhesive strip, gauze and pressure bandage; marking pen.

Positioning and site.

• Patient supine, non-dominant arm flexed at the elbow and rotated outward, with the hand near the head.

• Site: inner upper arm, 8 to 10 cm above the medial epicondyle, in or just behind the groove between biceps and triceps, away from the neurovascular bundle. Mark the site and the path of the rod.

• Clean the skin with antiseptic, let it dry and apply a sterile drape.

Anaesthesia. Inject 1 to 2 mL of lidocaine 1% just under the skin along the planned track and wait about 1 minute. Do not inject deeper than the subdermal plane.

Single-rod technique.

• Remove the sterile cap and check that the rod is visible in the needle; do not touch the needle.

• Stretch the skin, pierce at a shallow angle of about 30 degrees, then lower the applicator to horizontal while lifting the skin with the needle tip, and advance the needle full length just under the skin.

• Unlock the obturator, keep it fixed in position and slide the applicator back to the hub so the rod stays in the arm, then withdraw the needle.

• Never push the rod in, and keep the applicator parallel to the skin.

Two-rod technique.

• Make a 2 mm incision with the scalpel at the planned site.

• Insert the trocar, bevel up, at a shallow angle under the skin and advance to the first mark near the hub, lifting the skin.

• Load the first rod into the trocar, hold the plunger fixed and withdraw the trocar over the rod; stop withdrawing before the trocar tip leaves the incision.

• Redirect the trocar beside the first rod to form a V of about 15 degrees and place the second rod the same way, keeping the tip of the first rod at the incision as a marker.

• Remove the trocar.

Confirmation. Palpate the whole length of each rod through the skin; the patient should feel them as well. If a rod cannot be felt, do not assume correct placement: give backup contraception and arrange imaging.

Closure. Close the incision with an adhesive strip, with no suture, then apply gauze and a pressure bandage.

Immediate problems.

• Difficulty advancing the rod: withdraw and reposition; never force.

• Rod ejected or contaminated during insertion: discard it and use a new sterile device.

• Bleeding or haematoma: apply pressure for 5 to 10 minutes and keep the bandage on for 24 to 48 hours.

• Vasovagal reaction: stop, lay the patient flat with legs raised and monitor. Allergy to anaesthetic or antiseptic: adrenaline 0.5 mg intramuscularly into the anterolateral thigh.

Delayed problems.

• Infection at the site (pain, heat, redness, pus): flucloxacillin 500 mg orally four times daily for 5 to 7 days, or cefalexin 500 mg orally four times daily for 5 to 7 days; remove the implant if there is no improvement in 48 to 72 hours or an abscess forms.

• Expulsion: usually early and linked to infection or poor placement; place a new implant through a new site after the problem has settled, and use backup contraception meanwhile.

• Deep insertion with nerve or vessel injury (numbness, tingling, weakness or pain in the arm): do not attempt removal; arrange imaging and specialist referral.

• Pregnancy with a non-palpable implant: exclude ectopic pregnancy and arrange imaging.

Instructions.

• Keep the site dry for 5 days.

• Remove the gauze and pressure bandage after 1 day and leave the adhesive strip for 5 more days.

• Expect mild soreness or bruising for a few days.

• Return for pain, heat, pus or redness at the site, or if a rod comes out.

Backup. None when inserted in the first 7 days of menses; otherwise 7 days.

Card. Give a card with the implant type, date of insertion, planned removal date and the provider's name.

Follow up. No routine visit is needed; offer a review at 3 months. Explain that irregular, infrequent or absent bleeding is expected and not harmful.

Special groups. Enzyme-inducing medicines (rifampicin, rifabutin, efavirenz, carbamazepine, phenytoin, phenobarbital, primidone) lower the effectiveness of implants; give condoms, or choose DMPA or an IUD.

Referral and escalation. Refer deep or non-palpable implants, neurological symptoms after insertion, failed insertion and infection that does not respond to treatment.