Iatrogenic embolization following cardiac intervention: postmortem analysis of 110 cases

Abstract

Introduction: Iatrogenic embolization following cardiac investigative procedures may result from hydrophilic polymer emboli (HPE) from catheter valve and vessel wall calcifications, and air embolism from open heart surgery. This retrospective clinical pathologic analysis was undertaken to ascertain the frequency and extent of these potentially fatal complications.

Methods: This retrospective clinical pathologic autopsy analysis with premortem diagnostic imaging correlation identified 110 individuals who had undergone endovascular procedures between 2010 and 2016 within 90 days of death and followed by hospital autopsy. Clinical outcomes, radiologic studies, and autopsy materials were reviewed.

Results: Iatrogenic emboli were assessed as causing death in 9/110 autopsy cases (8.2%) and 9/34 (26.5%) cases with proven iatrogenic emboli. Iatrogenic emboli caused strokes in 10/110 (9.1%) autopsy cases including calcified emboli (CE, n=6), HPE (n=2), cardiac valvular tissue (n=1), and air embolism (n=1). Seven cases of calcified emboli complicating endovascular procedures were identified: four of the CE were thought to be the cause of death due to fatal strokes (n=2) and fatal myocardial (n=1) and colonic infarction (n=1). The CE likely originated from calcified aortic valves and atherosclerotic aortic plaques. Histologic evidence of HPE was found in 23% (25/110) of cases; 54% (26/48) showed evidence of infarction in postprocedural imaging, with radiologic evidence of infarction in 32% (8/25) of cases with HPE histology. Endovascular aortic repair was associated with the greatest density/distribution of HPE. HPE material showed degradation with time and was often associated with an inflammatory response. HPE directly contributed to death in three cases. One fatal air embolism followed open heart surgery, and one cardiac tissue embolus resulted in a major stroke.

Conclusions: We advocate for greater awareness of these underrecognized and occasionally fatal complications of endovascular procedures. Targeted postprocedural imaging has a role in the identification of iatrogenic embolic infarcts.

Keywords: Calcified emboli; Complications; Hydrophilic polymer emboli; Iatrogenic embolization; Postprocedural imaging.