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Nerve injury caused by removal of an implantable hormonal contraceptive
American Journal of Obstetrics and Gynecology (2006) 195, 323–6
www.ajog.org
Nerve injury caused by removal of an implantable hormonal contraceptive Gottfried Wechselberger, MD,a,* Dolores Wolfram, MD,a Petra Pu¨lzl, MD,a Elisabeth Soelder, MD,b Thomas Schoeller, MDa Departments of Plastic and Reconstructive Surgerya and Obstetrics and Gynecology,b Innsbruck Medical University, Innsbruck, Austria Received for publication June 8, 2005; revised August 21, 2005; accepted September 29, 2005
KEY WORDS Hormonal contraceptive Implanon Nerve injury Medial antebrachial cutaneous nerve
Implanon insertion and removal are relatively uncomplicated procedures in the hands of medical professionals familiar with the technique. However, injury to branches of the medial antebrachial cutaneous nerve during Implanon insertion and removal can result in impaired sensibility, severe localized pain, or the formation of painful neuroma that can be quite devastating to the patient. The best way to avoid injury to the medial antebrachial cutaneous nerve is to better understand its position relative to the standard area of Implanon insertion. In the event that an injury to the nerve is recognized, immediate plastic surgical measures should be undertaken to avoid displeasing sequels of nerve injuries. Therefore, the benefit of this generally well-tolerated, highly effective, and relatively cost-efficient contraception is guaranteed only in the hands of medical professionals familiar with the technique. Ó 2006 Mosby, Inc. All rights reserved.
Implanon (Organon International INC, Roseland, NJ), a single-rod contraceptive implant containing the progestin etonogestrel, is placed subcutaneously into the nondominant upper arm and provides highly effective, well-tolerated contraception for up to 3 years.1-6 Complications with insertion and removal, such as nonpalpable, subcutaneously implanted contraceptives, are reported in literature,7 but there are no reports about nerve injuries. However, traumatic peripheral neuropathy and other neurovascular injuries are reported as potential complication of both Norplant insertion and removal.8,9 The Norplant contraceptive (Wyeth * Reprint requests: Gottfried Wechselberger, MD, Department of Plastic and Reconstructive Surgery, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria. E-mail: [email protected] 0002-9378/$ - see front matter Ó 2006 Mosby, Inc. All rights reserved. doi:10.1016/j.ajog.2005.09.016
Pharmaceuticals, Collegeville, PA) consists of 6 subdermal capsules, and therefore, the risk for nerve injuries during insertion and removal is increased. We present a woman suffering an injury of the medial antebrachial cutaneous nerve after an unsuccessful attempt of Implanon removal. Additionally, the anatomy of the upper inner arm in consideration of vulnerable nerves and vessels is shown, and sequels of injuries are discussed.
Case report A 24-year-old woman was referred to our unit for removal of a previously implanted hormonal contraceptive after her gynecologist had attempted removal without success. The patient presented with paresthesia of the proximal ulnar forearm with a dimension of 10 to
324
Wechselberger et al
Figure 2 nerve.
Figure 1
Paresthetic area of the proximal ulnar forearm.
7 cm (Figure 1) and an impalpable implant. Paresthesia was noticed by the patient immediately after the operative intervention. Ultrasound examination revealed the exact location of the nonpalpable Implanon and no evidence of nerve injury. Operative exploration under general anesthesia showed a partially divided medial antebrachial cutaneous nerve (Figure 2) and the contraceptive implant in direct contact to the ulnar nerve. We removed the implant and performed a microsurgical epineural nerve coaptation with 10-0 Ethilon. The postoperative course was uneventful. Occupational therapy was started with sensory re-education, and 12 months postoperatively, sensation was normalized.
Anatomy The compact, dense brachial fascia encloses the muscles of the upper arm and superficial location of this fascia the subcutaneous vessels, nerves, and the lymphatic vessels are situated. The basilic vein breaks through the brachial fascia at the basilic hiatus in accompaniment of the medial antebrachial cutaneous nerve. The basilic hiatus and so the medial antebrachial cutaneous nerve are located in the distal part of the well-palpable medial bicipital
Partially divided medial antebrachial cutaneous
groove, which is confined by the biceps, the medial brachial intermuscular septum, and the triceps brachii. The medial antebrachial cutaneous nerve, also called the medial cutaneous nerve of the forearm, arises directly from the medial cord of the brachial plexus. The medial antebrachial cutaneous nerve divides into an anterior branch and an ulnar branch (Figure 3), which are located on the medial aspect of the forearm. It innervates the skin of the anterior and medial surfaces of forearm as far as the wrist. Clinically, nerve injuries may lead to specific nerve lesions, identified by specific loss of cutaneous innervation.
Comment Implanon, a progestin-only contraceptive implant with a Pearl index of 0, is an extremely effective, economical, and convenient alternative to oral or intrauterine contraceptives.1 Usually insertion and removal are relatively uncomplicated procedures1,2 in the hands of medical professionals who are familiar with the techniques, and the main adverse event causing discontinuation of implants is a change in bleeding pattern.3 Further reported adverse effects of Implanon are weight gain, acne, headache, and local pain at the implant site.4,5 The Implanon rod is inserted subcutaneously into the nondominant upper arm via a disposable sterile applicator, and after a maximum of 3 years, the removal or change of Implanon is performed by using the pop-out technique,6 which involves a 2-mm incision. With regard to the spectrum and incidence of complications with insertion and removal of Implanon (eg, swelling, redness, pain, hematoma, and significant fibrosis at the insertion site), Implanon is associated with very low insertion (0.3%) and removal (0.2%)
Wechselberger et al
325
Figure 3 Anatomy consists of: basilic hiatus (a); basilic vein (b); anterior and ulnar branch of the medial antebrachial cutaneous nerve (c); medial brachial cutaneous nerves (d); and intercostobrachial nerve (e).
complications.2 Another mentioned complication is the nonpalpable Implanon caused by an incorrect positioning, which requires a sonographic clarification or a localization via magnetic resonance imaging.7 However, in the literature we could not find any report about nerve injury caused by Implanon as presented in our case study. Injury to branches of the medial antebrachial cutaneous nerve during Implanon insertion and removal can result in a variety of clinical symptoms or manifestations that can be quite devastating to the patient. A transection of 1 or more branches of the medial antebrachial cutaneous nerve can produce impaired sensibility that is tolerable and noticed only when the area makes contact. When the proximal end of a transected medial antebrachial cutaneous nerve becomes entrapped in scar tissue, a discrete area of well-localized pain may occur. Palpation of or contact with the scar area can elicit severe localized pain over the distribution of the medial antebrachial cutaneous nerve that often radiates into to the posterior forearm and elbow. The best way to avoid injury to the medial antebrachial cutaneous nerve is to better understand its position relative to the standard area of Implanon insertion. In the event that an inadvertent injury to the medial antebrachial cutaneous nerve is recognized during insertion or removal, immediate measures should be undertaken to avoid the formation of painful neuroma. If the nerve is cut, a microsurgical epineural nerve coaptation with 10-0 Ethilon should be performed. If a primary nerve coaptation is not possible, its proximal end should be cauterized, transposed proximally, and buried into the deep muscle of the arm. In case of persistent painful neuromas, the neuroma is resected and the proximal nerve is buried into muscle.10
Although the subcutaneous insertion site in the upper arm seems to be ideal with regard to the low frequency of local complications and the short insertion and removal times, we should reconsider the area of implantation with regard to vulnerable nerves and vessels. The median supraumbilical region with Implanon insertion through the umbilicus could be ideal. The scar would be unsuspicious and vulnerable nerves are nonexistent.
Conclusion The simple handling of the insertion instruments, the minimal incision size, and the absence of sized anatomical structures on the medial part of the upper arm should not entice unversed surgeons to perform this operation unwarily. The benefit of this generally welltolerated, highly effective, and relatively cost-efficient contraception is guaranteed only in the hands of medical professionals familiar with the technique and anatomy of this region. The implantation area should be reconsidered.
References 1. Darney PD. Implantable contraception. Eur J Contracept Reprod Health Care 2000;5(Suppl 2):2-11. 2. Mascarenhas L. Insertion and removal of Implanon. Eur J Contracept Reprod Health Care 2000;5(Suppl 2):29-34. 3. Kovalevsky G, Barnhart K. Norplant and other implantable contraceptives. Clin Obstet Gynecol 2001;44:92-100. 4. Le J, Tsourounis C. Implanon: a critical review. Ann Pharmacother 2001;35:329-36. 5. Forinash AB, Evans SL. New hormonal contraceptives: a comprehensive review of the literature. Pharmacotherapy 2003;23: 1573-91.
326 6. Darney PD, Klaisle C, Walker DM. The ‘‘pop-out’’ method of Norplant removal. Adv Contracept 1992;8:188. 7. Boxheimer L, Marincek B, Jungius KP. Sonographic demonstration of a non-palpable Implanon implant using tissue harmonic imaging-three case reports. Rofo 2004;176:1177-9. 8. Smith JM, Conwit RA, Blumenthal PD. Ulnar nerve injury associated with removal of Norplant implants. Contraception 1998;57:99-101.
Wechselberger et al 9. Dunson TR, Amatya RN, Krueger SL. Complications and risk factors associated with the removal of Norplant implants. Obstet Gynecol 1995;85:543-8. 10. Lowe JB, Maggi SP, Mackinnon SE. The position of crossing branches of the medial antebrachial cutaneous nerve during cubital tunnel surgery in humans. Plast Reconstr Surg 2004;114: 692-6.
www.ajog.org
Nerve injury caused by removal of an implantable hormonal contraceptive Gottfried Wechselberger, MD,a,* Dolores Wolfram, MD,a Petra Pu¨lzl, MD,a Elisabeth Soelder, MD,b Thomas Schoeller, MDa Departments of Plastic and Reconstructive Surgerya and Obstetrics and Gynecology,b Innsbruck Medical University, Innsbruck, Austria Received for publication June 8, 2005; revised August 21, 2005; accepted September 29, 2005
KEY WORDS Hormonal contraceptive Implanon Nerve injury Medial antebrachial cutaneous nerve
Implanon insertion and removal are relatively uncomplicated procedures in the hands of medical professionals familiar with the technique. However, injury to branches of the medial antebrachial cutaneous nerve during Implanon insertion and removal can result in impaired sensibility, severe localized pain, or the formation of painful neuroma that can be quite devastating to the patient. The best way to avoid injury to the medial antebrachial cutaneous nerve is to better understand its position relative to the standard area of Implanon insertion. In the event that an injury to the nerve is recognized, immediate plastic surgical measures should be undertaken to avoid displeasing sequels of nerve injuries. Therefore, the benefit of this generally well-tolerated, highly effective, and relatively cost-efficient contraception is guaranteed only in the hands of medical professionals familiar with the technique. Ó 2006 Mosby, Inc. All rights reserved.
Implanon (Organon International INC, Roseland, NJ), a single-rod contraceptive implant containing the progestin etonogestrel, is placed subcutaneously into the nondominant upper arm and provides highly effective, well-tolerated contraception for up to 3 years.1-6 Complications with insertion and removal, such as nonpalpable, subcutaneously implanted contraceptives, are reported in literature,7 but there are no reports about nerve injuries. However, traumatic peripheral neuropathy and other neurovascular injuries are reported as potential complication of both Norplant insertion and removal.8,9 The Norplant contraceptive (Wyeth * Reprint requests: Gottfried Wechselberger, MD, Department of Plastic and Reconstructive Surgery, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria. E-mail: [email protected] 0002-9378/$ - see front matter Ó 2006 Mosby, Inc. All rights reserved. doi:10.1016/j.ajog.2005.09.016
Pharmaceuticals, Collegeville, PA) consists of 6 subdermal capsules, and therefore, the risk for nerve injuries during insertion and removal is increased. We present a woman suffering an injury of the medial antebrachial cutaneous nerve after an unsuccessful attempt of Implanon removal. Additionally, the anatomy of the upper inner arm in consideration of vulnerable nerves and vessels is shown, and sequels of injuries are discussed.
Case report A 24-year-old woman was referred to our unit for removal of a previously implanted hormonal contraceptive after her gynecologist had attempted removal without success. The patient presented with paresthesia of the proximal ulnar forearm with a dimension of 10 to
324
Wechselberger et al
Figure 2 nerve.
Figure 1
Paresthetic area of the proximal ulnar forearm.
7 cm (Figure 1) and an impalpable implant. Paresthesia was noticed by the patient immediately after the operative intervention. Ultrasound examination revealed the exact location of the nonpalpable Implanon and no evidence of nerve injury. Operative exploration under general anesthesia showed a partially divided medial antebrachial cutaneous nerve (Figure 2) and the contraceptive implant in direct contact to the ulnar nerve. We removed the implant and performed a microsurgical epineural nerve coaptation with 10-0 Ethilon. The postoperative course was uneventful. Occupational therapy was started with sensory re-education, and 12 months postoperatively, sensation was normalized.
Anatomy The compact, dense brachial fascia encloses the muscles of the upper arm and superficial location of this fascia the subcutaneous vessels, nerves, and the lymphatic vessels are situated. The basilic vein breaks through the brachial fascia at the basilic hiatus in accompaniment of the medial antebrachial cutaneous nerve. The basilic hiatus and so the medial antebrachial cutaneous nerve are located in the distal part of the well-palpable medial bicipital
Partially divided medial antebrachial cutaneous
groove, which is confined by the biceps, the medial brachial intermuscular septum, and the triceps brachii. The medial antebrachial cutaneous nerve, also called the medial cutaneous nerve of the forearm, arises directly from the medial cord of the brachial plexus. The medial antebrachial cutaneous nerve divides into an anterior branch and an ulnar branch (Figure 3), which are located on the medial aspect of the forearm. It innervates the skin of the anterior and medial surfaces of forearm as far as the wrist. Clinically, nerve injuries may lead to specific nerve lesions, identified by specific loss of cutaneous innervation.
Comment Implanon, a progestin-only contraceptive implant with a Pearl index of 0, is an extremely effective, economical, and convenient alternative to oral or intrauterine contraceptives.1 Usually insertion and removal are relatively uncomplicated procedures1,2 in the hands of medical professionals who are familiar with the techniques, and the main adverse event causing discontinuation of implants is a change in bleeding pattern.3 Further reported adverse effects of Implanon are weight gain, acne, headache, and local pain at the implant site.4,5 The Implanon rod is inserted subcutaneously into the nondominant upper arm via a disposable sterile applicator, and after a maximum of 3 years, the removal or change of Implanon is performed by using the pop-out technique,6 which involves a 2-mm incision. With regard to the spectrum and incidence of complications with insertion and removal of Implanon (eg, swelling, redness, pain, hematoma, and significant fibrosis at the insertion site), Implanon is associated with very low insertion (0.3%) and removal (0.2%)
Wechselberger et al
325
Figure 3 Anatomy consists of: basilic hiatus (a); basilic vein (b); anterior and ulnar branch of the medial antebrachial cutaneous nerve (c); medial brachial cutaneous nerves (d); and intercostobrachial nerve (e).
complications.2 Another mentioned complication is the nonpalpable Implanon caused by an incorrect positioning, which requires a sonographic clarification or a localization via magnetic resonance imaging.7 However, in the literature we could not find any report about nerve injury caused by Implanon as presented in our case study. Injury to branches of the medial antebrachial cutaneous nerve during Implanon insertion and removal can result in a variety of clinical symptoms or manifestations that can be quite devastating to the patient. A transection of 1 or more branches of the medial antebrachial cutaneous nerve can produce impaired sensibility that is tolerable and noticed only when the area makes contact. When the proximal end of a transected medial antebrachial cutaneous nerve becomes entrapped in scar tissue, a discrete area of well-localized pain may occur. Palpation of or contact with the scar area can elicit severe localized pain over the distribution of the medial antebrachial cutaneous nerve that often radiates into to the posterior forearm and elbow. The best way to avoid injury to the medial antebrachial cutaneous nerve is to better understand its position relative to the standard area of Implanon insertion. In the event that an inadvertent injury to the medial antebrachial cutaneous nerve is recognized during insertion or removal, immediate measures should be undertaken to avoid the formation of painful neuroma. If the nerve is cut, a microsurgical epineural nerve coaptation with 10-0 Ethilon should be performed. If a primary nerve coaptation is not possible, its proximal end should be cauterized, transposed proximally, and buried into the deep muscle of the arm. In case of persistent painful neuromas, the neuroma is resected and the proximal nerve is buried into muscle.10
Although the subcutaneous insertion site in the upper arm seems to be ideal with regard to the low frequency of local complications and the short insertion and removal times, we should reconsider the area of implantation with regard to vulnerable nerves and vessels. The median supraumbilical region with Implanon insertion through the umbilicus could be ideal. The scar would be unsuspicious and vulnerable nerves are nonexistent.
Conclusion The simple handling of the insertion instruments, the minimal incision size, and the absence of sized anatomical structures on the medial part of the upper arm should not entice unversed surgeons to perform this operation unwarily. The benefit of this generally welltolerated, highly effective, and relatively cost-efficient contraception is guaranteed only in the hands of medical professionals familiar with the technique and anatomy of this region. The implantation area should be reconsidered.
References 1. Darney PD. Implantable contraception. Eur J Contracept Reprod Health Care 2000;5(Suppl 2):2-11. 2. Mascarenhas L. Insertion and removal of Implanon. Eur J Contracept Reprod Health Care 2000;5(Suppl 2):29-34. 3. Kovalevsky G, Barnhart K. Norplant and other implantable contraceptives. Clin Obstet Gynecol 2001;44:92-100. 4. Le J, Tsourounis C. Implanon: a critical review. Ann Pharmacother 2001;35:329-36. 5. Forinash AB, Evans SL. New hormonal contraceptives: a comprehensive review of the literature. Pharmacotherapy 2003;23: 1573-91.
326 6. Darney PD, Klaisle C, Walker DM. The ‘‘pop-out’’ method of Norplant removal. Adv Contracept 1992;8:188. 7. Boxheimer L, Marincek B, Jungius KP. Sonographic demonstration of a non-palpable Implanon implant using tissue harmonic imaging-three case reports. Rofo 2004;176:1177-9. 8. Smith JM, Conwit RA, Blumenthal PD. Ulnar nerve injury associated with removal of Norplant implants. Contraception 1998;57:99-101.
Wechselberger et al 9. Dunson TR, Amatya RN, Krueger SL. Complications and risk factors associated with the removal of Norplant implants. Obstet Gynecol 1995;85:543-8. 10. Lowe JB, Maggi SP, Mackinnon SE. The position of crossing branches of the medial antebrachial cutaneous nerve during cubital tunnel surgery in humans. Plast Reconstr Surg 2004;114: 692-6.