WTP1.6 Unmask Latent Lymphoedema through bipedal Lymphoscintigraphy

Abstract Aim Lymphoscintigraphy (LSG) is the gold standard investigation in Lymphoedema. The study aimed to determine the presence of Latent Lymphoedema (LL) in the unaffected limb when a patient presents with unilateral lymphoedema. Methods All new and follow up patients seen in the Lymphoedema clinic between the January and May 2023 by either a vascular consultant or a lymphoedema nurse were included in the study. Their electronic patient records were retrospectively reviewed. Clinical presentation and findings were compiled from clinic letters and if the signs and symptoms were suggestive of lymphoedema they were then offered an LSG scan. Protocol involved determining the uptake of nano colloid tracer at the ilio-inguinal lymph nodes 2 hours post subcutaneous injection in the 1st web space of each foot. Quantitative uptake of < 8% at 2 hours was considered abnormal. Results 114 patients with a median age of 63.2 (Range 24-83) were seen in the Lymphoedema clinic. Of those, 62 patients had LSG scans. About 37% (n = 23) patients presented with unilateral swelling of lower limb. On LSG scan they had average uptake of 1.6 1.6% in the clinically affected limb. However 57% (n = 13) of these patients had an average of 2.7 2 % uptake in the unaffected Ilio-inguinal lymph nodes, unmasking latent Lymphoedema on that side. Conclusion Presence of lymphatic dysfunction on the unaffected limb should be considered as unmasking of LL. This will allow initiation of preventative measures to prevent development of gross disease in future.