Ultrasound characteristics of subdermally implanted Implanon contraceptive rods

In Situ Imaging of Subcutaneous Drug Delivery Systems Using Microspatially Offset Low-Frequency Raman Spectroscopy

The noninvasive in situ monitoring of the status of drug retention and implant integrity of subcutaneous implants would allow optimization of therapy and avoid periods of subtherapeutic delivery kinetics. A proof-of principle study was conducted to determine the use of microspatially offset low-frequency Raman spectroscopy (micro-SOLFRS) for nonintrusive in situ analysis of subcutaneous drug delivery systems. Caffeine was used as the model drug, and it was embedded in a circular-shape Soluplus matrix via vacuum compression molding. For the exploratory analysis, prototype implants were positioned underneath skin tissue samples, and various caffeine concentrations (1-50% w/w) and micro-SOLFRS displacement settings (Δz = 0-8 mm) were tested from the pseudo three-dimensional (3D)-imaging perspective. This format allowed the optimization of real-time micro-SOLFRS analysis of implants through skin tissue that was embedded in an agarose hydrogel. Notably, this analytical approach allowed the temporal and spatial erosion of the implant and solid-state transformations of caffeine to be distinguished. The spectrometric results correlated with complementary high-performance liquid chromatography (HPLC) determination of changes in drug concentration, illustrating drug dissipation/diffusion characteristics. The discovered capability of micro-SOLFRS for in situ measurements of drugs and implants makes it attractive for biomedical diagnostics that, ultimately, could result in development of a new point-of-care technology.

Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance is effective, quick, and safe

Objectives

The aim of this study was to assess the feasibility, performance, and complications of a non-surgical, minimally-invasive procedure of deep contraceptive implant removal under continuous ultrasound guidance.

Methods

The ultrasound-guided procedure consisted of local anesthesia using lidocaine chlorhydrate 1% (10 mg/mL) with a 21-G needle, followed by hydrodissection using NaCl 0.9% (9 mg/mL) and implant extraction using a Hartmann grasping microforceps. The parameters studied were the implant localization, success and complication rates, pain throughout the intervention, volumes of lidocaïne and NaCl used, duration of the procedure, and size of the incision. Between November 2019 and January 2021, 45 patients were referred to the musculoskeletal radiology department for ultrasound-guided removal of a deep contraceptive implant and were all retrospectively included.

Results

All implants were successfully removed en bloc (100%). The mean incision size was 2.7 ± 0.5 mm. The mean duration of the extraction procedure was 7.7 ± 6.3 min. There were no major complications (infection, nerve, or vessel damage). As a minor complication, 21 patients (46.7%) reported a benign superficial skin ecchymosis at the puncture site, spontaneously regressing in less than 1 week. The procedure was very well-tolerated, with low pain rating throughout (1.0 ± 1.5/10 during implant extraction).

Conclusions

Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance alone is feasible, effective, and safe. In the present cohort, all implants were successfully removed, whatever the location, with short procedural time, small incision size, low pain levels, and no significant complications. This procedure could become a gold standard in this indication.

Key Points

• Minimally invasive removal of deep contraceptive implants under continuous ultrasound guidance alone is feasible, which led to a success rate of 100% whatever the location (even close to neurovascular structures), with only a small skin incision (2.7 ± 0.5 mm).

• The procedure was safe, quick, without any major complications, and very well tolerated in terms of pain.

• This minimally invasive ultrasound-guided procedure could become the future gold standard for the removal of deep contraceptive implants, as an alternative to surgical extraction, even for implants in difficult locations such as subfascial ones or those close to neurovascular structures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08263-4.

Referral Center Experience With Nonpalpable Contraceptive Implant Removals

OBJECTIVE

To describe our experience with office removal of nonpalpable contraceptive implants at our referral center.

METHODS

We performed a retrospective cohort study by reviewing the charts of patients referred to our family planning specialty center for nonpalpable or complex contraceptive implant removal from January 2015 through December 2018. We localized nonpalpable implants using high-frequency ultrasonography and skin mapping in radiology, followed by attempted removal in the office using local anesthesia and a modified vasectomy clamp. We abstracted information on demographics, implant location, and outcomes.

RESULTS

Of 61 referrals, 55 patients attended their scheduled appointments. Seven patients had palpable implants; six elected removal. The other 48 patients had ultrasound localization, which identified 47 (98%) of the implants; the remaining patient had successful localization with computed tomography imaging. Nonpalpable implants were suprafascial (n=22), subfascial (n=25) and intrafascial (n=1); four of these patients opted to delay removal. Of 50 attempted office removals, all palpable (n=6), all nonpalpable suprafascial (n=21 [100%, 95% CI 83-100%]), and 19 out of 23 (83%, 95% CI 67-98%) subfascial implants were successful. Three of the four patients with failed subfascial implant office removal had successful operating room removal with a collaborative orthopedic surgeon; the other patient sought removal elsewhere. Transient postprocedure neuropathic complaints were noted in 7 out of 23 (30%, 95% CI 12-49%) subfascial and 1 out of 21 (5%, 95% CI 0-13%) suprafascial removals (P=.048). Nonpalpable implants were more likely to be subfascial in nonobese patients (24/34, 71%) as compared with obese (1/13, 8%) patients (P<.001). Seven (28%) of the 25 subfascially located implants had been inserted during a removal-reinsertion procedure through the same incision.

CONCLUSION

Most nonpalpable contraceptive implants can be removed in the office by an experienced subspecialty health care provider after ultrasound localization. Some patients may experience transient postprocedure neuropathic pain. Nonpalpable implants in thinner women are more likely to be in a subfascial location.

Contraceptive Implant Migration and Removal by Interventional Radiology

As the reversible contraceptive arm implants grow more popular, there is an increasing need to recognize the complications resulting from implant migration and removal. This review summarizes the findings of imaging and removal methods. When an implant is lost, the axillary region should be investigated first. If the implant still cannot be found, visualization though different methods have been employed for non-radiopaque implants. Real-time fluoroscopic-guided localization and removal can be accomplished for radiopaque Nexplanon. Once the implant has been located, standard removal method and other modified techniques can be used to safely remove the implant depending on the implant's location.

Contraceptive procedures

Although most women desire to control the size and spacing of their family, the rate of unintended pregnancy in the United States remains high, with approximately half of all pregnancies being unintended. Reducing unintended pregnancy is a national public health goal, and the increased use of long-acting reversible contraceptives (LARCs) (intrauterine devices and implants) can help meet this goal. LARCs are among the most effective forms of contraception available. There are few contraindications to their use, and insertion and removal are straightforward procedures that are well tolerated in the outpatient office setting.

Examining the efficacy, safety, and patient acceptability of the etonogestrel implantable contraceptive

Contraceptive implants provide long-acting, highly effective reversible contraception. The etonogestrel implant (ENG implant) is a single rod implant that offers three years of efficacy. The ENG implant was designed to provide contraceptive efficacy by inhibiting ovulation and Pearl Index scores reported for this method are similar to other long-acting reversible contraception as well as similar to sterilization. The implant has been shown to be safe during breast feeding and may improve symptoms of dysmenorrhea and endometriosis. Irregular bleeding patterns can be expected with the device's use and should be addressed in order to decrease rates of discontinuation.

Assessment of Implanon insertion and removal

OBJECTIVE

This report describes the proper technique and the time required for insertion and removal of Implanon.

METHODS

Implanon was inserted into 330 female volunteers for an assessment of efficacy, safety and tolerability over a 2-year period. Implanon was inserted subdermally using a unique, specially designed, preloaded, disposable applicator, and removal was accomplished either by the "pop-out" method or by grasping the implant with a small hemostat and removing it through a small incision.

RESULTS

The average length of time required for insertion was 0.5 min. The average length of time required for removal was 3.6 min. There were no reported pregnancies when Implanon was in situ.

CONCLUSION

Implanon is a single-rod subdermal contraceptive that is usually easily inserted and removed. Insertion and removal represent brief office procedures associated with a low rate of complications. Following proper insertion and removal procedures will minimize the possibility of complications.

Ultrasound-guided removal of Implanon devices

Our study has shown that ultrasound-guided localisation and removal of Implanon rods is safe, practical and highly successful. Over a 4-year period, 119 patients had successful, uncomplicated removal of their subdermal devices.The technique is particularly useful for removal of the device when it is not palpable or when an attempt at removal of a palpable device has not been successful.

Removal of etonogestrel contraceptive implants in the operating theater: report on 28 cases

OBJECTIVES

We describe removal procedures for etonogestrel contraceptive implants in the operating theater. In addition, we discuss the management of removal of contraceptive implants that are difficult to palpate or are impalpable.

DESIGN

We conducted a retrospective single-center case series analysis of Implanon removals conducted at a university hospital between January 2002 and April 2005.

MATERIALS AND METHODS

We analyzed case notes for 28 patients who had their contraceptive implant removed in the operating theater.

RESULTS

Intermenstrual bleeding was the principal reason for removal (52.4%). Ten patients already had one attempted removal of their implant. Preoperative ultrasound localized the implant in all cases. Half of the removals were done under local anesthetic, with three cases progressing to general anesthesia (11%). Thirty percent of the implants had migrated from their initial implantation, 37% were in intramuscular tissue and 11% were in the humeral neurovascular sheath. The only postoperative complications were one small seroma and transient paresthesia in the territory of the ulnar nerve. The implant was not found in one case.

CONCLUSIONS

The removal of an implant that is not palpable or difficult to palpate should take place in the operating theater following localization by ultrasound. Patients must be fully informed about the procedure, including its complications and the risk for failure.

Location and removal of non-palpable Implanon® implants with the aid of ultrasound guidance

BACKGROUND

Implanon insertion appears to be an easy procedure, but in a small minority of cases difficulties have been encountered with removal if the rod is impalpable.

METHODS

Patients were referred to the contraceptive and sexual health service with non-palpable Implanon. Following a clinical assessment and examination of the arm where the implant had been inserted, an ultrasound examination was carried out to identify and locate the implant. These implants were subsequently removed, some under general anaesthesia and others under local anaesthesia.

RESULTS

Twenty-seven patients were referred to the unit with impalpable Implanon rods. In four cases the rods were palpable and were removed in the clinic setting without the need for further intervention. Positive identification of the implants was achieved in 21 of the remaining 23 cases using ultrasound. No implant was detected in two cases and etonogestrel was not demonstrated serologically in either woman, suggesting non-insertion. All 21 Implanon rods identified by ultrasound were successfully removed. In just over 52% of women a previous attempt at removal had been undertaken prior to referral.

CONCLUSIONS

It is possible to identify and locate impalpable Implanon rods with the aid of ultrasound, facilitating their subsequent safe removal. Although previous reports have identified the position of 'lost' implants using ultrasound, this is the first case series to discuss measuring the skin/implant depth. This parameter, together with the precise position of the implant (in muscle or fat), aids removal. All health professionals inserting and removing contraceptive implants should have been appropriately trained.

Ultrasound localisation and removal of non-palpable Implanon implants

BACKGROUND

Implanon is the trade name for a contraceptive implant that releases etonogestrel over a 3-year period. The rod is inserted into the subdermis of the upper arm. The implant should be palpable and easily removed through a small incision.

AIMS

To determine whether ultrasound is an accurate means of localising and guiding removal of non-palpable Implanon implants.

METHODS

All patients referred to The Northern Hospital, between March 2002 and October 2005, for localisation and/or removal of their non-palpable Implanon implants were included in this study. Ultrasound was used to locate the implants, the implant was considered localised when a linear echogenic rod with posterior acoustic shadowing was identified. When removal of the implant was requested and the implant was clear of neurovascular structures, blunt dissection was performed under ultrasound control and the implant was extracted. If the implant was considered too close to major neurovascular structures, the position of the implant was marked and the patient was referred for surgical removal.

RESULTS

Thirty-four women were included in the study. In 33 patients the implant was identified. In one patient no implant was found and its absence was confirmed by serum assay. Twenty-four patients were referred for implant removal. In 20 patients the implant was successfully removed under ultrasound guidance. In the other four patients the implant was close to neurovascular structures. The position of the implants was marked and surgical removal was successfully performed.

CONCLUSION

Ultrasound is highly accurate at localising and guiding removal of non-palpable Implanon implants.

Management and localization strategies for the nonpalpable Implanon rod

PURPOSE

The goal of this paper is to review the imaging methods required for localizing nonpalpable Implanontrade mark.

METHOD

Different localization methods for nonpalpable Implanon rods are summarized, and clinical guidance is provided as to how best to localize such implants.

RESULTS

In the great majority of cases, optimal visualization of the single-rod Implanon rod is obtained with ultrasound using a high-resolution linear array transducer (10-15 MHz). An implant located just under the skin, under the fascia muscularis or one located deep in the muscle can most often be localized with ultrasound. In rare cases where ultrasound does not definitively locate the implant, magnetic resonance imaging is usually the next best choice. Measurements of serum etonogestrel levels may be necessary to confirm the presence or absence of the implant when it cannot be visualized by either of the two imaging methods.

DISCUSSION

Close clinical coordination between women's health care providers and radiologists is required to minimize or prevent removal complications and to facilitate subsequent contraceptive management of the patient.

A simple technique for localization of deeply inserted, nonpalpable Norplant implant

Norplant removal may be complicated if deep insertion causes difficulty in localization with palpation. Various methods have been used to locate these deeply seated implants. Soft tissue X-ray films (standard anteroposterior and lateral views) with a paper clip placed as a marker by the clinician provide a simple method of locating deep implants.

Ultrasound localisation of non-palpable Implanon

BACKGROUND

Localisation of the non-palpable Implanon is useful to confirm its presence or to assist the surgeon with its removal. Previous studies have suggested that almost all non-palpable Implanon implants can be located with ultrasound in phantoms.

AIM

To determine whether diagnostic ultrasound is a reliable method for localising non-palpable Implanon implant in-vivo.

METHODS

Ultrasound was carried out to localise the non-palpable Implanon implant. To ascertain the accuracy of the ultrasound findings, all patients were followed-up until the implant was removed or until it was proven absent by serial progesterone levels confirming ovulation or by negative etonogestrel levels.

RESULTS

In 22 out of 23 patients the Implanon was correctly identified as present. The specificity is 95.7% (95%CI 79.0-99.2%), the positive predictive value is also 95.7%. In six out of seven patients the Implanon was correctly identified as absent. The sensitivity is 85.7% (95%CI 48.7-97.4%), the negative predictive value is also 85.7%. Four patients were excluded due to incomplete follow-up.

CONCLUSION

Ultrasound is a reliable first line method for localising non-palpable Implanon. When the Implanon is localised on ultrasound, it is very likely present. When the Implanon is not seen on ultrasound, etonogestrel determination should be carried out to confirm its absence.

Nonpalpable ultrasonographically not detectable Implanon rods can be localized by magnetic resonance imaging

Recently, the contraceptive implant Implanon has been introduced in several European countries. In comparison to the six-capsule preparation Norplant, the removal of this single-rod system should be associated with less complications. However, the removal of nonpalpable Implanon rods can be difficult because the implant is not always visible with ultrasound. The aim of this study was to find a radiologic method for the localization of Implanon implants that are nonpalpable and can not be detected by ultrasound. X-ray, ultrasound, computed tomography, and magnetic resonance imaging (MRI) were investigated as methods to localize Implanon in a pig chest preparation and in a woman with a nonpalpable implant. The implant in the woman could be localized unequivocally only by MRI. We conclude that MRI is the best method for the unequivocal localization of nonpalpable, ultrasonographically not detectable Implanon rods. To avoid unnecessary scar tissue formation, it may be appropriate to defer surgery for the removal until definitive localization.

Insertion and removal of Implanon

Implanon is a single-rod contraceptive implant containing the progestin etonogestrel. Implants require insertion and removal by medical professionals. Detailed and unbiased counseling before insertion is essential, and should include contraceptive efficacy, insertion and removal procedures, and possible adverse events. Insertion and removal times have been measured in six open studies and in seven comparative studies in which Norplant (the six-capsule levonorgestrel implant) was used as the reference product. In comparative studies, the mean time needed for insertion of Implanon was 1.1 min and removal took 2.6 min. Insertion as well as removal of Implanon was four times faster than with Norplant. Complications with insertion and removal are rare in the hands of medical professionals familiar with the techniques.