Can Quality Improvement Tools Overcome the Translational Roadblock—the Vital Influence of the Researcher

Proposed Definition of Experimental Secondary Ischemia for Mouse Subarachnoid Hemorrhage

Inconsistency in outcome parameters for delayed cerebral ischemia (DCI) makes it difficult to compare results between mouse studies, in the same way inconsistency in outcome parameters in human studies has for long obstructed adequate comparison. The absence of an established definition may in part be responsible for the failed translational results. The present article proposes a standardized definition for DCI in experimental mouse models, which can be used as outcome measure in future animal studies. We used a consensus-building approach to propose a definition for "experimental secondary ischemia" (ESI) in experimental mouse subarachnoid hemorrhage that can be used as an outcome measure in preclinical studies. We propose that the outcome measure should be as follows: occurrence of focal neurological impairment or a general neurological impairment compared with a control group and that neurological impairment should occur secondarily following subarachnoid hemorrhage (SAH) induction compared with an initial assessment following SAH induction. ESI should not be used if the condition can be explained by general anesthesia or if other means of assessments sufficiently explain function impairment. If neurological impairment cannot reliably be evaluated, due to scientific setup. Verification of a significant secondary impairment of the cerebral perfusion compared with a control group is mandatory. This requires longitudinal examination in the same animal. The primary aim is that ESI should be distinguished from intervention-related ischemia or neurological deficits, in order establish a uniform definition for experimental SAH in mice that is in alignment with outcome measures in human studies.

Systematic Review of In Vivo Animal Models of Subarachnoid Hemorrhage: Species, Standard Parameters, and Outcomes

In preclinical models, modification of experimental parameters associated with techniques of inducing subarachnoid hemorrhage (SAH) can greatly affect outcomes. To analyze how parameter choice affects the relevance and comparability of findings, we systematically reviewed 765 experimental studies of in vivo animal SAH models (2000-2014). During the last decade, we found marked increases in publications using smaller species and models for simulating acute events after SAH. Overall, the fewer types of species and models used did not correlate with an increased standardization in the experimental characteristics and procedures. However, by species, commonly applied, reliable parameters for each experimental SAH technique were identified in mouse, rat, rabbit, and dog models. Our findings can serve as a starting point for discussion toward a more uniform performance of SAH experiments, development of preclinical SAH common data elements, and establishment of standardized protocols for multicenter preclinical trials.