Beyond Endarterectomy: Addressing Device-Associated Thrombus in CTEPH Surgery

1/3Pulmonary endarterectomy (PEA) is the definitive curative therapy for operable chronic thromboembolic pulmonary hypertension (CTEPH). 1 The operation requires meticulous removal of organized fibrotic obstruction together with the diseased intima from the pulmonary arteries.This highly technical procedure offers the possibility of restoring near-normal pulmonary hemodynamics.However, even with successful removal of obstructive material, long-term outcomes depend not only on what is taken out but also on what remains.Among residual contributors to thromboembolic risk, transvenous cardiac implantable electronic device (CIED) leads have emerged as a clinically important but often under-recognized factor.In this issue of the Right Heart Journal, Nemoto et al. 2 report a concise and valuable case series involving 9 CTEPH patients with transvenous CIED systems who underwent simultaneous lead extraction and epicardial lead implantation during PEA.Although these 9 cases represent only about 1 percent of the center's 880 operated patients, the clinical implications extend well beyond the size of the cohort.Their findings prompt a renewed examination of how intravascular pacing hardware contributes to disease progression and how its management should be integrated into surgical planning.Growing evidence indicates that intravascular pacing leads are associated with a substantial thrombotic burden.Autopsy and imaging studies reveal thrombi near pacemaker or implantable cardioverter-defibrillator leads in up to one-third of patients. 3Mobile lead thrombi have been associated with higher pulmonary artery systolic pressures, suggesting a direct impact on right ventricular load and pulmonary vascular resistance. 4Specific to CTEPH, Nayak et al. 5 identified a greater burden of distal disease among CIED carriers, despite fewer documented venous thromboembolic events.This observation supports the concept that transvenous leads may act as a chronic nidus for small, recurrent emboli that accumulate in the distal pulmonary circulation.Nemoto et al. 2 add essential clinical evidence by showing organized thrombus adherent to extracted leads in 5 of 9 patients.Notably, in one case, preoperative imaging failed to detect the thrombus, and it was identified only during surgery.This reinforces an important clinical reality.Lead-associated thrombosis may be completely silent and radiographically occult, and cannot be reliably excluded by routine preoperative imaging in CTEPH candidates.