[Does trunk varicosity precede insufficiency of the perforating veins?]

The author discusses the theoretical question of precedence of trunk, or perforator, incompetency. Whatever the case, the treatment is always the same. Drawing attention to the laws published in 1970 determining the opening and closing of small vessels, the author mainly discusses the so-called "balloon effect": of which the "physiological valvule" is a derivation, concluding that trunk varicosity precedes perforating vein incompetence. When the deep system is intact, the author prefers to use the term "blow down", reserving the term "blow out" for secondary varices, the deep system being damaged.