Lymphedemas of the lower limbs: a lymphoscintigraphic study

Patients with lymphoedema of the lower limbs (LLL) are usually affected by recurrent erysipelas. This bacterial infection is usually admitted as an aetiological factor, but it can be a consequence of some previous lymphatic abnormality. Classically, the commonest causative factors of LLL are bacterial infection, venous ulcers, trauma (leading to secondary lymphoedema) and congenital disorders of the lymphatic system (primary lymphoedema--praecox or tarda). PURPOSE: To identify previous lymphatics abnormalities in patients with LLL, admitted as having secondary lymphatic lymphoedema--as consequences of infection, trauma or other factors--, by using lymphoscintigraphic method. To observe advantages of this approach in practical assistance and evaluation of LLL cases. METHODS: Twelve patients with LLL, supposed to have primary (congenital) or secondary disorder affecting one or both lower extremities were submitted to lymphoscintigraphy at the Escola Paulista de Medicina of Sao Paulo, Brazil. Each patient received an intradermal injection of labelled Dextran (Dx-99mTc) at the first interdigital space of each foot and, after one to three hours, images of lower extremities, pelvic and abdominal areas were obtained with Gammatome CGR. RESULTS: Examination of all 24 lower extremities disclosed clinical diagnosis of lymphoedema in 17 (70.8%), being five (41.6%) with clinical signs of lymphoedema of both lower limbs and seven (58.3%) of a single one. The lymphoscintigraphic images revealed lymphatic disorders in 22 of the 24 extremities (91.7%). Lymphoscintigraphic abnormalities in clinically normal lower extremities were observed in five cases (41.3%). CONCLUSION: Lymphoscintigraphy is a non-invasive useful method to study LLL, with involvement of one or both limbs. It does not differentiate between primary and secondary lymphoedema, but makes possible to detect cases of normal appearance of the limbs with previous lymphatic defect(s), changing aetiological diagnosis. Some cases that appear to be secondary lymphoedema could be, in fact, associated with congenital abnormality(ies) of lymphatics, triggered by factors like trauma or venous ulcers.