Table 1. Comparison of the two commonest ICH modeling techniques.

Autologous blood injection	Collagenase injection
Main purpose
Investigating mechanisms of hemorrhagic damage	Assessing long-term functional outcomes following ICH
Advantages
Produces consistent hemorrhage volume	Stimulates human disease more accurately
A clinically relevant comparison	Simple procedure
Simple procedure	Can be used in multiple species
Can be used in multiple species	Dose-dependent hemorrhage size
	May imitate bleeding–rebleeding phenomenon
	Mimics a spontaneous bleed
Disadvantages
Excessive inflammatory response?	Excessive inflammatory response?
Does not emulate small vessel rupture	Mechanism different to human condition
Not a spontaneous bleed	Neurotoxicity of collagenase
Not suitable for evaluating rebleeding
Cannot evaluate microvascular breakdown effects
Not suitable for studying long-term effects of ICH

ICH, intracerebral hemorrhage.