A 41-year-old man with a background of hereditary spastic paraplegia was not tolerating the side effects of oral baclofen and underwent ITB pump placement subcutaneously in the right lower quadrant of the abdomen. He regularly competes as an international power canoeist, and has a muscular build.
Ten months following ITB placement, he attended clinic with a history of pump site discomfort. On examination, the implanted pump had eroded a substantial amount of subcutaneous adipose tissue and the overlying skin was erythematous and tender. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were both within normal range. Whilst the overlying skin was intact on presentation, computed tomography demonstrated a fluid collection posterior to the pump. The fluid was aspirated with a needle, and was confirmed sterile on Gram stain microscopy and culture; this fluid was sampled for microbiological analysis and determined to be sterile. Twelve weeks later, the pump was re-sited to the right medial thigh. Intraoperatively, the pump was disconnected and removed from the original site. There was no evidence of infection in the pump cavity. A medial mid-thigh transverse incision was made and a subcutaneous pouch was created, into which the original pump was inserted. A new catheter was connected to the pump. It was first tunnelled out through an intermediate proximal thigh incision, in which the tubing was anchored to the muscle fascia (Fig. 1). Subsequently, the same catheter was tunnelled to the original abdominal pouch, where it was connected to the original distal spinal catheter with a straight connector. The pouch was irrigated with gentamicin solution and closed in layers.
Eight months later, the patient presented to his general practitioner complaining of swelling around the revised placement site. For the next 6 months he described intermittent episodes of warmth and erythema at the pump site that worsened during his physical training regime. Towards the end of this period we reviewed the patient in clinic and concluded that this swelling was likely precipitated by exercise. Ten days subsequent to this clinic visit, he was admitted due to increased swelling, pain and ulceration at the pump site. CRP, ESR and white blood cell count (WBC) were all normal. He underwent further surgery: the lateral part of the wound was reopened and thin, inflamed skin edges excised. The wound was washed and closed. Microbiological assessment of the excised skin edges revealed no evidence of infection.
At 1-month post-operative follow-up, evidence of dehiscence was still present along with underlying haematoma formation. Thinning of skin and small discharging vesicles were noted lateral to the scar. The patient underwent further surgery under the plastic surgery and neurosurgery team. The wound was debrided and washed out. A new proximal pocket was developed superficial to the deep fascia anterior to the thigh and the pump was re-sited for a second time. At post-operative follow-up, the patient was well and the wound was well healed. Six months later, there was no collection surrounding the pump, the patient was receiving regular ITB pump refills and is able to train without difficulty.