THE MECHANISM OF THROMBOPHLEBITIC EDEMA

PREVIOUS LITERATURE  The mechanism of the edema that follows thrombophlebitis of the extremities has provoked considerable discussion for many years. Repeated experimental investigations have tended to support first the theory of venous obstruction, then that of lymphatic origin, without having served to bring the problem to definite decision. Many years ago, Cohnheim¹ showed that ligation or extirpation of all of the lymphatics from an extremity fails to produce edema of that limb. These experiments have been repeated many times since then, with numerous variations, and usually with the same results. Clinical observations, however, of edemas following mechanical extirpations of lymph nodes or the compression of the lymphatics by tumor growth have given constant support to the belief that lymphatic obstruction will sufficiently interfere with the return of fluid to result in edema of the extremity. The clinical improvement noted after surgical procedures intended to provide new lymphatic pathways from