Abstract 15809: Ascending Late Onset Bacteremia Causing ICD Pocket Infection via a Lead-Associated Veno-Pocket Fistulous Tract

Abstract

Case Presentation: A 51-year-old man with a history of non-ischemic cardiomyopathy, resolved line-associated Staph aureus bacteremia (SAB), and subsequent defibrillator (ICD) implant presented with sepsis. He was covered empirically with antibiotics and 4/4 blood cultures from admission grew MSSA. On exam, the patient’s pocket was non-tender, non-erythematous, and non-fluctuant, with a well-healed incision. A chest CT revealed multiple septic pulmonary emboli. ICD extraction was performed, exactly 580 days after last pocket entry. In the OR, the pocket drained copious pus and a distinct fistulous tract was noted along the lead, tracking to the pocket from the axillary vein ( Figure ). Full pocket debridement was performed, the entire system was extracted, and a drain was placed. The ICD lead tip culture grew MSSA; however, the pocket culture was negative. A source for the SAB was not determined. After completion of antibiotics and confirmatory negative blood cultures, a contralateral ICD was implanted. Discussion: A significant subset of CIED pocket infections present late (≥1 year from last pocket entry) and presume either indolent pocket infection descending to the bloodstream or, more likely, in the case of virulent bacteria like Staph aureus, ascending hematogenous spread to the device pocket. However, macroscopic evidence of this mechanism has not yet been demonstrated. The Figure grossly illustrates a presumed phenomenon - bacteria from the bloodstream forming a lead-associated fistulous tract to a previously sterile pocket, demonstrating proof-of-concept of a continuous environment between the pocket and bloodstream. This pathophysiology is central to established CIED guidelines on bacteremia, which emphasize the importance of early extraction and alternate-site re-implantation.