New white fibrous clots publication

Self-Reported Observations of Unusual White Fibrous

Structures in Embalmed Corpses: Multi-Year Survey

Results from Embalmers in Five Countries, 2022–

2025

% of embalmers reporting structures

2022 66%

2023 73%

2024 83%

2025 71%

% average number of corpses

2022 24%

2023 20%

2024 27%

2025 19%

Beginning in 2020–2021,

embalmers in multiple countries reported observing large, tough, rubbery white or off-white fibrous structures,

in the veins and arteries of embalmed corpses.

Described as distinct from classic postmortem clots.

Postmortem blood clots are well described

“chicken-fat” clots (yellowish, friable plasma)

“currant-jelly” clots (dark red, RBC-rich)

Typically non-adherent to vessel walls

Differ from antemortem thrombi in consistency and appearance

Beginning in late 2021 and into 2022

Embalmers in multiple countries began reporting observations of large, tough, rubbery, white or off-white fibrous structures in the veins and arteries of embalmed corpses.

Experienced practitioners; unlike any postmortem clots encountered in decades of practice

Larger, more extensive, tougher, and different in color and handling from traditional chicken-fat or currant-jelly clots.

The structures are typically large (often several inches to over a foot in length, occasionally approaching the length of a limb)

tough and rubbery in texture (elastic, resistant to tearing or fragmentation,

and sometimes compared to calamari or earthworms),

predominantly white or off-white, and extensively fill or conform to the vascular lumen.

Impede normal drainage of blood and hinder uniform distribution of embalming fluid

Photographic documentation provided by multiple practitioners

Methods

Four annual cross-sectional surveys (2022–2025)

Active embalmers in the United States, Canada, United Kingdom, Australia, and New Zealand

(professional associations and direct emails to funeral homes)

Core questions assessed observation of unusual white fibrous structures and estimated percentage of corpses affected.

Results

808 total responses

Some embalmers reported 0% of corpses effected

Proportion of embalmers reporting observation of these structures ranged from 66% to 83%.

Average prevalence in corpses ranged from 19% to 27%.

The 2022 survey showed a marked increase in first observations beginning in 2020 and accelerating in 2021.

Among those who had observed them, 14–17% reported seeing them in 2018 or 2019

Discussion and Limitations

Participation was voluntary

Relied on non-probability sampling

Embalmers who had noticed unusual findings may have been more likely to respond, introducing (selection and response bias)

No standardized definitions or photographic, histological or biochemical confirmation

These findings constitute a potential safety signal that warrants independent investigation by forensic pathologists and biomedical researchers to characterize the structures and determine their etiology.