Use of perfusion fixation for improved neuropathologic examination.

Objective: To assess the efficacy of 10% formalin perfusion fixation as a method of rapid fixation to examine the human brain immediately following autopsy.
Design: Compare the histology and immunohistochemistry from human brains in which one hemisphere undergoes perfusion fixation using 10% buffered formalin, and the contralateral nonperfused hemisphere undergoes standard 14-day immersion fixation in 8 L of 10% buffered formalin.
Setting: Autopsy material in a general medical-surgical university hospital.
Participants: Pathologists, neuropathologists, resident pathologists, and pathology assistants.
Intervention: Immediately following brain removal, a single hemisphere was perfused with 1 L 10% buffered formalin over a 15- to 20-minute period. The contralateral nonperfused hemisphere served as a control, undergoing standard immersion fixation for 2 weeks in 10% formalin. The perfusion-fixation hemisphere was immediately available for neuropathologic examination, and histologic sections of the brain were processed immediately with the other necropsy tissue sections. This allows completion of a final autopsy neuropathology report within 3 to 5 days in concert with the systemic section of the report.
Main Outcome Measure: Perfusion-fixation brain sections were compared with immersion-fixation brain sections from the same brain. The effects on hematoxylin-eosin, Bielschowsky's silver, and immunohistochemical staining were evaluated by an experienced neuropathologist and a general pathologist with no prior knowledge of the fixation technique.
Results: Perfusion fixation revealed equal and occasionally superior histologic sections compared with traditional immersion fixation in terms of (1) technical preparation of section, (2) quality and intensity of staining with both hematoxylin-eosin and silver, and (3) immunoreactivity localization with a variety of immunohistochemical reactions.
Conclusions: Immediate perfusion of the brain is an easily performed fixation technique that yields comparable or superior fixation to prolonged immersion fixation and allows an immediate complete neuropathologic examination and report within 3 to 5 days of performance of the autopsy.