USE OF PERFUSION FIXATION FOR IMPROVED NEUROPATHOLOGIC EXAMINATION

Objective.-To assess the efficacy of 10% formalin perfusion fixation a s a method of rapid fixation to examine the human brain immediately fo llowing autopsy.Design.-Compare the histology and immunohistochemistry from human brains in which one hemisphere undergoes perfusion fixatio n using 10% buffered formalin, and the contralateral nonperfused hemis phere undergoes standard 14-day immersion fixation in 8 L of 10% buffe red formalin. Setting.-Autopsy material in a general medical-surgical university hospital. Participants.-Pathologists, neuropathologists, re sident pathologists, and pathology assistants. Intervention.-Immediate ly following brain removal, a single hemisphere was perfused with 1 L 10% buffered formalin over a 15- to 20-minute period. The contralatera l nonperfused hemisphere served as a control, undergoing standard imme rsion fixation for 2 weeks in 10% formalin. The perfusion-fixation hem isphere 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 auto psy neuropathology report within 3 to 5 days in concert with the syste mic section of the report. Main Outcome Measure.-Perfusion-fixation br ain sections were compared with immersion-fixation brain sections from the same brain. The effects on hematoxylin-eosin, Bielschowsky's silv er, 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 i mmersion fixation in terms of (1) technical preparation of section, (2 ) quality and intensity of staining with both hematoxylin-eosin and si lver, and (3) immunoreactivity localization with a variety of immunohi stochemical reactions. Conclusions.-Immediate perfusion of the brain i s an easily performed fixation technique that yields comparable or sup erior fixation to prolonged immersion fixation and allows an immediate complete neuropathologic examination and report within 3 to 5 days of performance of the autopsy.