Post-traumatic lipoma in chronic irritated device pocket

Introduction: ICD-implantation is well-established therapy for ventricular arrhythmias with low complication rate. Besides technical failure forcing lead/device replacement, swelling of device pocket represents the most common reason for surgical re-intervention. The local pocket embossment could originate from bleeding, acute or chronic pocket infection, mechanical irritation and may finally lead to device or lead perforation or may cause recidivating fistula or seroma. Affected patients often suffer from painful motoric constraints and are consequently scheduled for pocket revisions.

Fig.1: pre- and inter-operative view

Aims: A 46-year-old male (176cm/77kg), with history of open chest closure of atrial septum defect and correction of pulmonary atresia in 1994, catheter ablation of atrial tachycardia in 1996 and 2001, underwent implantation of single-chamber ICD after episode of ventricular fibrillation in 2003. Because of swollen painful ICD-pocket caused by mechanical irritation a pocket revision with caudal ICD-relocation was performed in 2009. After symptom-free period the patient was re-admitted to our hospital in May 2011 with severe, but only moderate painful, device-pocket swelling (Fig.1). Fever, increase of systemic inflammatory parameters and local inflammation signs were missing. A pocket revision was planed due to suspicion of chronic seroma. After incision a large mass of lipoid like tissue was exposed. This structure originated in the subpectoral ICD-pocket and extended in the subcutaneous fat below the left mammilla (Fig.2). We were able to remove this large tissue mass completely (12×6x3cm). The histopathology analysis diagnosed a large benign lipoma. Microbiology excluded bacterial colonization. The old ICD-pocket was closed and a new one created further cranial. The further postoperative course was event free.

Discussion: Besides the common pocket complications some rare tumors like post-traumatic lipoma may occur in chronic irritated device pockets. In general benign lipoma with an incidence of 1% is typically manifested in the middle age (40–60 years). Discomfort, chronic pain and restriction of important structures require therapeutic consequences. Tumor removal should be performed in toto in order to prevent its recurrence. A malignant transformation into liposarcomas is very rare. Taken together, a possibility of post-traumatic lipoma should be implicated into differenzial diagnosis when swelling of chronic irritated device pocket occur.