Spatial aspects of blood coagulation: Two decades of research on the self-sustained traveling wave of thrombin

•Experimental results on self-sustained spatial propagation of clotting are analyzed.•Concept of thrombin traveling wave is discussed.•Special attention is paid to open questions and yet unsolved issues.•Some contradictions in the results of latest works are discussed.

In a number of experimental studies, it has been demonstrated that the forefront of blood coagulation can propagate in the manner of a signal relay. These data strongly support the concept that the formation of a blood clot is governed by a self-sustained traveling wave of thrombin. The present review critically appraises the experimental data obtained in recent decades concerning the self-sustained spatial propagation of thrombin. Open questions regarding the experimental detection of the self-sustained propagation of thrombin are discussed.