Table 1: Advantages and disadvantages of in vivo, in vitro, ex vivo, and in silico studies.

Advantages Disadvantages Ref.
In vivo More realistic data;
Good to validate new practices and techniques.
Difficult to control variables;
Difficult to visualize;
Long measuring times;
Insufficient resolution;
Low reproductively;
Ethical issues.
[17, 30, 68, 69]
In vitro Easy to control variables;
Easy to visualize;
Good to validate numerical studies;
Reduce the use of animals;
Do not have ethical issues.
Difficult to measure some variables (e.g., WSS);
Do not represent the complexity that happens in vivo;
Critical to reproduce exact geometry;
Difficult to reproduce real wall motion.
[42, 62, 70]
Ex vivo No post-surgical animal care;
Maintain the architecture of the tissues closer to the in vivo setting;
Moderate control of variables;
Better visualization compared to in vivo.
Short observation time;
Difficult to visualize;
The age of the models may represent a critical factor;
Isolation of the arteries is a critical process;
Ethical issues.
[42, 71]
In silico Construction of more realistic virtual models;
Reduction of lead times and costs of new designs and greater detail of the results;
Complement experimental and clinical approaches;
Ability to simulate biofluid flows
that are not reproducible in experiments.
Difficult to define mathematically some physiological and biological parameters;
Require experimental validation;
The results are dependent on the accuracy of the mesh performed;
Complex simulations can be very long.
[45, 70, 72, 73]