Lead externalization – a potential source of lead-related infective endocarditis?

A 32-year-old patient with a single chamber implantable cardioverter-defibrillator (ICD) was admitted to a cardiological ward due to recurrent episodes of fever since 1 month before. Blood tests showed a slightly elevated C-reactive protein (CRP) level without leukocytosis or procalcitonin increase. The transthoracic echocardiography (TTE) examination revealed a vegetation (29 mm × 6 mm) in the lower right atrium connected with the lead; the image was confirmed in transesophageal echocardiography (TEE). Negative blood culture was only probably negative due to the antibiotic therapy. The patient was diagnosed with lead-related infective endocarditis (LRIE), received modified antibiotic therapy and was initially qualified for the surgical extraction of the ICD system, but he did not agree to surgery. After consultation with the referential transvenous lead extraction (TLE) center the patient was qualified for TLE. Preoperative fluoroscopy revealed an interesting finding – ICD lead externalization was observed at the same location as the previously described vegetation. The TLE procedure was performed under general anesthesia in a hybrid operating room with intraoperative TEE monitoring and cardiac surgical standby. Due to the presence of a relatively large vegetation, a special nitinol basket was introduced into the main pulmonary artery for pulmonary circulation protection. The lead was removed using a Byrd dilator sheath (Cook, USA). Although during the procedure the vegetation was fragmented (only small parts were caught by the basket) there were no clinical signs of pulmonary embolism. There were no periprocedural complications. Postoperative examination of the extracted Riata (St. Jude Medical, USA) defibrillating lead showed significant cable externalization with remnants of the vegetation and relevant lead degeneration (Figure 1).
Lead externalization is relatively common among Riata leads. However, in the literature we may find cases of such a phenomenon in different leads produced by different manufacturers [1]. The mechanism of externalization of Riata leads is related to their specific construction. Inside there are several conductors which may move relative to the insulation, leading to its further damage – ‘inside-out abrasion’. In some research there was no evident correlation between lead externalization and electrical failure [2], but a large Canadian registry confirmed the impact of externalization on lead failure [3]; in our case...


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