The use of small cannulas, inserted into the feet or legs by means of trocars, in cases of massive edema, for the purpose of draining off the edema fluid was introduced by Southey in 1877. In recent years attention has been redirected to these tubes by Paul D. White and others.
Drainage of fluid by means of these in cases of obstinate edema, not relieved in other ways, is often very satisfactory. Frequently, however, the tubes drain well for only a comparatively short period, soon becoming plugged. There seems to be two reasons for this: first, the small diameters of the tube and its openings and, second, its smooth, cylindric contour, which permits the tissues to adhere closely to it, thereby tending to plug the openings and prevent drainage.
There seems to be no objection to using tubes with twice the diameter of the ordinary Southey cannula, with openings correspondingly