Primary lymphedema and lymphatica porosa.

Abstract

It is the purpose of this paper to discuss briefly the accepted causes of primary lymphedema and to record a possible further cause to which the term “lymphatica porosa” has been given. Secondary lymphedema will not be considered. Technic of Examination The technic used in these cases is that originally described by Kinmonth (5). Patent blue dye (0.5 ml) is injected between two toe webs to delineate the lymphatics. Under local anesthesia a transverse incision is made over a visible lymphatic which is dissected free from its surrounding tissue and then cannulated. Hypaque 45 per cent, a water-soluble contrast medium, is used for the investigation of primary lymphedema, and the injection is made slowly by hand. Care is also taken that excessive pressure is avoided when giving the injection. A film has already been placed beneath the limb and the radiological exposure is made in the ward at the bedside with a portable x-ray machine. No time should elapse between filling the lymphatics with contrast medium and taking the film. To avoid this the exposure is made while the contrast agent is being introduced. These aspects of the technic are particularly important, as will be seen later in the paper, in judging the presence or absence of leakage from the lymphatic vessel. Kinmonth et al. in 1957 (6) divided primary lymphedema into the following groups according to their radiological findings and the results of the preliminary patent blue dye injections. Lymphangiectasis 24 per cent Lymphatic hypoplasia 55 per cent Lymphatic aplasia 14 per cent Dermal backflow 6 per cent This concise classification has been accepted as the basis for the diagnosis and management of primary lymphedema. Other factors not implied in this list, however, such as infection, trauma, and lymphatic and venous collateral channels influence the onset and course of lymphedema and need consideration. These factors may explain why clinically congenital lymphedema may appear at varying ages, e.g., lymphedema congenita, praecox and tarda. An appreciation of the role of these additional factors will help to explain many of the anomalies of the edematous limb. Lymphangiectasis: In this group the lymphatics are dilated, tortuous, and have valvular incompetence. They are in many respects analogous to varicose veins. In the series reported by Kinmonth, this group comprised 24 per cent which appears a higher incidence than that found by other workers. Buonocore and Young (2) do not mention lymphangiectasis in their paper on primary lymphedema. An example of this condition is seen in Figure 1. This 14-year-old boy, first seen in 1961, complained of swelling of the legs for the past six to seven years. A cousin had a similar history. Lymphangiography demonstrated dilated, tortuous, and valveless vessels, characteristic of lymphangiectasis. Lymphatic Hypoplasia: There may be either a decrease in the size or number of the lymphatics. Figure 2 shows the lymphangiogram of a 17-year-old girl seen in 1965 with complaints of swelling of the thigh for the past six months. The lymph vessels in the thigh are greatly reduced in size and number and have an abnormal distribution. The lymph vessels in the calf, where there was no edema, appeared normal. Figure 3 is the lymphangiogram of a 38-year-old female seen in 1962 with complaints of swelling of the left foot and ankle for six years. There is only a single lymphatic vessel passing through the leg and thigh to the groin. This is a case of “single hypoplasia.” Lymphatic Aplasia: This composed 14 per cent of the 107 cases reported by Kinmonth, an incidence similar to the findings of most workers in this field. The diagnosis is usually based on the presence of edema, intracutaneous flow of patent blue dye after injection and a failure of lymphatic delineation. However, it is still necessary in these cases to make an incision and search for a lymphatic vessel. Buonocore and Young stated in 1965 that intracutaneous dye staining is accepted as a sign of severe primary lymphedema. This, however, may occur with either primary or secondary lymphedema. As skin flow may also develop with either lymphatic aplasia or hypoplasia, only an experienced worker's failure to find a lymphatic can be taken as indicative of lymphatic aplasia.