Hydrophilic polymer embolism and associated vasculopathy of the lung: prevalence in a retrospective autopsy study

Abstract

Hydrophilic polymers are commonly applied as surface coatings on vascular devices and have been shown to dissociate during endovascular use, causing hydrophilic polymer embolism (HPE). Adverse effects related to this phenomenon have been recognized and reported. The prevalence of this complication is unknown. We conducted a retrospective study to determine the prevalence of HPE among hospital autopsies over a 29-month period. Postmortem tissue was histologically evaluated for the presence, location(s) and extent of HPE. HPE findings were correlated with documented clinical and laboratory data and patient outcome. Of 136 hospital autopsies examined, 18 (13%) showed evidence of HPE involving the lungs (n = 18), heart (n = 1) or central nervous system (n = 1). Localized pulmonary HPE was seen in 12 patients (9%). Multifocal pulmonary HPE was found in 6 patients (4%) and was associated with clinical vasculitis (33%; P < .0001), suspected pulmonary ischemia (50%; P = .008), coagulopathy (67%; P = .002), and constitutional disease (83%; P = .01). Within affected lung, associated histopathologic changes included occlusive intravascular or perivascular inflammation (89%), intravascular fibrous response (56%), microthrombus formation (44%), vasculitis (28%), and/or pulmonary microinfarction (28%). Statistically significant differences in hospital days (P = .008) and number of vascular interventions (P = .01) were noted between affected and unaffected patients. We conclude that HPE is an underdiagnosed phenomenon with primary involvement of the lungs, where secondary vascular changes are common. Additional studies may be needed to clarify risks and to identify preventative strategies for this iatrogenic complication of catheterizations and “minimally invasive” endovascular techniques.

Polymer-induced central nervous system complications following vascular procedures: spectrum of iatrogenic injuries and review of outcomes

“…3), acute ischemic infarcts in 5 patients (16%) [4,6,7,10,12] (Fig. 4), and other white matter ischemic lesions in 4 patients (13%) [6,7,14]. Involved vessels measured 13 to 600 µm in diameter and varied in number from 2 to more than 100 per case.…”

“…Early stages of polymer degradation included macrophagic > giant cell > granulomatous > lymphocytic responses. Later stages of degradation, identified in patients with prolonged reactions, included microabscess formation and/or neutrophilic response [5,7,14,17]. Heterogeneous reactions were often noted [14].…”

“…In 2009, we reported to the US Food and Drug Administration the first fatal case of polymer embolism, which involved the brain [6]. In spite of limited recognition and reporting of this complication, multiple cases over recent years provide additional evidence that morbidity and mortality associated with these iatrogenic phenomena are underrecognized [5–14]. Further characterization of polymer reactions, including organ-specific effects, and identification of etiologic factors are therefore warranted and have potential to improve the safety of new and emerging vascular technologies.…”

Hydrophilic Polymer Embolism in the Lung as an Adverse Event ― Autopsy Case of Thromboembolisms in Multiple Organs Associated With Heparin-Induced Thrombocytopenia ―

“…1 We suspect that hydrophilic polymer embolization in the lung is not typically a critical cause of death, unlike embolization in the coronary or cerebral arteries. Friction between devices and excess friction between devices and the vessel walls during cannulation may also play a role in the development of complications.…”

“…1 Due to the advantages of lubrication and biocompatibility, coating substances are widely used in medical devices for minimally invasive diagnostic and therapeutic cerebrovascular, cardiovascular and peripheral procedures. Polymer emboli involving the lung were first documented as an embolization of hydrophilic coating of a central venous catheter, which resulted in the development of cavitary lung nodules.…”