Lymphatic cannulation without dye.

Abstract

Since Kinmonth (2) first described lymphangiography after lymphatic cannulation, this useful procedure has been applied extensively. The ease of its accomplishment has been improved by modification of injection apparatus, needles (1, 6, 7), and plastic cannulae (4, 5). Any radiologist, with only minimal additional training, is now able to perform lymphangiography well. The one factor that has not changed is the technic of identifying the lymphatic to be cannulated. Small intradermal or subcutaneous injections of a blue dye are usually absorbed by the lymphatics after a delay of fifteen to thirty minutes. Often the color is so intense that it can be seen through the intact skin, but this is not always the case. In the United States the choice of dye is limited. Evans blue, the one most widely used, has been approved by the Food and Drug Administration for parenteral use (3). Others, such as brilliant blue (FD & C blue No. 1) and patent blue (Alphazurine) have not been approved (8, 9). Ordinarily, Evans blue does not stain lymphatics intensely. The resultant color is so similar to that of the surrounding vein that the effectiveness of the dye is limited. It was this factor, plus the color blindness of the author, that prompted an attempt at lymphatic cannulation without the use of dye. Method Because a lymphatic of suitable size is situated in the first interosseous space of the foot, this site is employed (Fig. 1). After local anesthesia, a longitudinal incision of 2 cm is made and the tissues are gently dissected. Usually a lymphatic of good size is located within 5 mm of either side of the incision. The nerves, veins, and lymphatics of the foot are distinguished easily (Fig. 2). The nerves are solid structures without a lumen, shiny but not translucent. When compressed, the veins have a small central channel that contains blood. This channel may not be seen, but the wall of the vein is opalescent and relatively thick. The walls of the lymphatics are thin and translucent. When the lymphatics are distended, their beaded nature may be appreciated. After identification of a lymphatic, cannulation is accomplished with a 27-gauge or a 30-gauge needle. Results The method of lymphangiography described has been employed by the author and his colleagues for one year. Unsatisfactory completion of lymphangiography in two instances was the result of cannulation failure and not because the lymphatic was not identified. Success was obtained in 25 of 27 patients. Discussion The exclusion of a dye in lymphangiography has numerous advantages. Esthetically, it is more acceptable to the patient, particularly to the young woman with Hodgkin's disease. The delay after injection of dye is eliminated, thus shortening the period of examination. Evans blue, the only approved dye for this use, is of poor efficacy. The complications that result from the injection of dye are avoided.