Use of Integra dermal substitute to prevent implantable device extrusion in an Olympic athlete

Abstract

We present a challenging case of imminent metallic implant extrusion in a Paralympic athlete managed with a single-stage procedure using ‘Integra’ dermal substitute. The patient had hereditary spastic paraparesis, for which a baclofen pump delivering intrathecal medication was vital in the management of his condition. The device had been most recently implanted into the thigh after previous complications. Integra provided robust soft-tissue coverage over the implanted baclofen pump in the thigh. Different operative management strategies were considered but the use of Integra was felt to offer the least morbidity and a quick recovery. The patient was able to successfully compete in a Paralympic canoeing qualifying event the week following surgery and achieve medal success. To the authors’ knowledge, this is first case in which Integra has been used in such circumstances.

Background

Integra, a dermal regeneration template, is available in single and bilayer forms. It is composed of bovine tendon type 1 collagen and shark cartilage glycosaminoglycan (chondroitin 6-sulphate).¹ Integra provides a framework for the formation of a neodermis. Prerequisites for its use include a vascularised, non-infected wound bed.

Integra was developed in the 1970s¹ and later introduced into the UK for use in 1996. It is now a widely accepted tool for the management of burns and in reconstructive surgery and its clinical application continues to expand.²

Case presentation

A 43-year-old, wheelchair user, Paralympic canoeist with a background of progressive hereditary spastic paraparesis presented to the plastic surgery department. He had required subcutaneous insertion of a balofen pump to deliver the medication intrathecally for the management of his severe, intractable spasticity.

The patient had previously experienced C5 disc prolapse and undergone with C5, C6 discectomy and fusion in 2010 but was otherwise fit and well.

The baclofen pump was initially inserted into the abdomen by the neurosurgical team 3 years prior. Due to the lack of subcutaneous tissue, it was relocated to the anterolateral aspect of the right thigh and required multiple subsequent scar revisions.

The patient presented to the plastic surgery department with evidence of imminent implant extrusion (figure 1). He was due to compete in the qualifying trials of the Paralympic games the following week. Examination showed an area of skin 15 mm² with the implant immediately fixed underneath, lying proximal to the transverse access scar. The high risk of extrusion and total implant device loss was conveyed to the patient.

Figure 1.

Preoperative picture demonstrating imminent implant extrusion.

The surgical management involved making an elliptical incision around the involved skin, with de-epithelialisation the skin enclosed. An incision was made medially through the de-epithelialised tissue which was opened up under direct vision. The pump remained covered by scar tissue throughout. A medial thigh flap was undermined and stress relaxation of the skin allowed easy tension free closure. Single-stage Integra dermal regeneration template was inserted on top of the scar tissue that encased the device after making the lateral pocket. The skin was then closed with double breasting of the tissues over the Integra matrix. This was achieved by advancing the medial wound edge over the de-epithelialised skin. (figure 2) Double breasting the tissues aimed to offset the wound tension, prevent scar stretch and increase the durability of the soft-tissue layer at the previously vulnerable extrusion site.

Figure 2.

Cross-sectional diagram demonstrating operative technique.

18-month postoperatively, he has had no further acute complications at the site of reoperation.

Outcome and follow-up

The patient achieved medal success at the Olympic Games 2016 and remains well with durable wound coverage.

Discussion

Hereditary spastic paraparesis is a diverse group of inherited diseases which predominantly result in spasticity and weakness affecting the lower limbs. The condition results in the degeneration of the axons of upper motor neurons in the spinal cord. As the longest fibres supply the lower extremities, these are affected more severely. Multiple genes associated with the condition have been identified. Antispasmodic medication, for example, baclofen plays a crucial role in the management of the condition.

The exterior surface of the implantable baclofen device is titanium; the pumps are relatively large and difficult to conceal. They are implanted subcutaneously in adults to enable refilling.³ Skin breakdown and infection are the most common causes of complications with such devices. Wound breakdown occurred in 22% of patients in one study within 12 months of insertion.⁴

Such cases are challenging for plastic surgeons, with limited reconstructive options. The options in this case for salvaging the implant were the use of a dermal regeneration template, of which the most commonly used is ‘Integra’ as in this case, or a more complex reconstructive procedure to cover the implant with a pedicled muscle flap.⁵ Alternatively, the pump could have been relocated. The latter two options were not preferable in this patient.

Despite being wheelchair user, the patient was extremely physically active. Continuous uninterrupted use of the infusion pump was of great importance to him; it alleviated his spasticity significantly. Ongoing durable soft-tissue coverage over the pump was also important for his ongoing competitive involvement in sport. More invasive soft-tissue coverage using a local muscle flap would likely have left him with further physical limitations from donor site morbidity, which the patient was keen to avoid. It would have also left a bulky area on the thigh likely to interfere with his performance and would require a longer recovery. Options to relocate the pump in this patient were also limited due to previous surgery on the contralateral thigh. Using a local flap in the area was considered to have too high a risk of recurrent implant extrusion, so the option was discounted.

A single-stage procedure was possible with Integra dermal substitute, avoiding donor-site morbidity and the high cost associated with replacing an exposed implant. It also enabled robust implant coverage to be achieved, with reduced tension on overlying skin and reduced visibility of the implant profile. The capsule surrounding the implant provided an ideal vascularised bed for the Integra. By double breasting the overlying tissue, a further defence against wound breakdown and tissue erosion was provided.⁶ Soft-tissue reconstruction with the addition of Integra has been shown to achieve favourable functional outcomes and higher patient satisfaction when used for patients after burn injury, the main patient group in which it is used.⁷ To the authors’ knowledge, this is the first case in which Integra has been used in these circumstances.

This challenging case describes a novel use of single-stage Integra to provide durable implant coverage in a physically active patient. Metallic implant extrusion can be dilemma for which plastic surgeons are called on to manage when others have run out of options. The use of Integra in this case avoided the need to relocate and replace the pump, and avoided the need to perform more extensive reconstructive surgery. Wound breakdown and implant extrusion are recognised complications of implantable devices and Integra may provide an alternative surgical option for the future in such cases. To the authors’ knowledge, the use of Integra to cover a metallic implant in such circumstances has not been reported previously.

Ultimately in the future, the implant will expire and require replacing. At this point, we suggest the implant should be relocated and enveloped in a thicker matrix, for example, ‘Strattice’, with the access scar further away from the device to further reduce the risk of extrusion and skin breakdown.

Learning points.

• Metallic implant extrusion can be dilemma for which plastic surgeons are called on to manage when others have run out of options.

• Integra can provide durable implant coverage in a physically active patient.

• To the authors’ knowledge, this is the first case in which Integra has been used in this manner to cover an implant at risk of imminent extrusion.