REVIEW   

Acta Phlebologica 2016 August;17(2):37-51

Copyright © 2016 EDIZIONI MINERVA MEDICA

lingua: Inglese

Basic science in venous hemodynamics

Fausto PASSARIELLO ¹, Kirk W. BEACH ², Claude FRANCESCHI ³, Claudio ALLEGRA ⁴, Nicos LABROPOULOS ⁵

¹ Vasculab Foundation ONLUS, Naples, Italy; ² Division of Vascular Surgery, Department of Bioengineering, University of Washington, Seattle, WA, USA; ³ Hopital Saint Joseph and CHU Pitié Salpetriere, Paris, France; ⁴ S. Giovanni Hospital, Rome, Italy; ⁵ Vascular Laboratory, Department of Surgery, Stony Brook University Medical Center, Stony Brook, NY, USA

This paper tries to fill the gap in phlebology between our knowledge of the biological phenomena and the physical and chemical laws of the inanimate world. Instead of being divided into the classical chapters of physics and physiology, the paper chooses an overall point of view, based on the concept of energy in its multiple forms. Regarding pressure and volumes in veins and in the venous walls, energy plays its role as a volume term, as well as a surface term. Special attention is given to the behaviour of the collapsible tubes and to the often forgotten waterfall phenomenon. Discovered long ago, this topic periodically comes to the consideration of new researchers and it is very far from the trivial interpretation of the reflux as a waterfall. Indeed, a well-known case of ascending upward waterfall will be described. The appendices cover some difficult theoretical topics, which have instead a great practical and educational meaning. For instance, forgetting the simple rules for the treatment of significant digits populates our scientific magazines of very interesting but unreliable numbers, which miss their role in the communication of the experimental results.