Perfusion fixation in brain banking: a systematic review.

Area of Science:

• Neuroscience
• Histology
• Biomolecular Profiling

Background:

• Perfusion fixation is standard in animals for brain studies, but immersion fixation is common for human autopsy tissue.
• Immersion fixation limits tissue architecture preservation, hindering advanced analyses like connectomics.
• Challenges and benefits of human brain perfusion fixation are not well-defined.

Purpose of the Study:

• To systematically review and synthesize existing literature on perfusion fixation of human brain tissue.
• To define the methods used in human brain perfusion fixation and compare outcomes with immersion fixation.
• To assess the impact of perfusion fixation on histology quality for postmortem human brain samples.

Main Methods:

• Conducted a systematic literature search across four databases.
• Screened abstracts and full-text publications for studies on human brain perfusion fixation.
• Extracted data on perfusion fixation methods and comparative outcomes with immersion fixation.

Main Results:

• Identified 35 studies involving 558 human brains and diverse perfusion fixation techniques.
• Found moderate evidence that perfusion fixation yields equal or superior histology quality compared to immersion fixation.
• Perfusion fixation can preserve large tissue volumes in equal or less time than immersion fixation.

Conclusions:

• Perfusion fixation is a viable and effective method for preserving human brain tissue for advanced research.
• This review provides a resource for researchers implementing perfusion fixation in human or large animal brains.
• Further research is needed to compare in situ vs. ex situ perfusion and optimize fixation protocols for different donor types.