INCREASED LYMPHOSCINTIGRAPHIC FLOW PATTERN IN THE LOWER-EXTREMITY UNDER EVALUATION FOR LYMPHEDEMA

Objective: To analyze the clinical and scintigraphic features in four postoperative patients with lower limb edema, Design: Four case report s are presented, and causes of increased lymphatic flow are discussed, Material and Methods: Filtered Tc-99m-sulfur colloid (0.1 mL 20 MBq) was administered by subcutaneous injection into the second web space o f each foot, Sequential local (inguinal) and whole-body imaging was pe rformed periodically up to 24 hours after the injections, The patients were three women who were 40, 51, and 86 years of age and an 81-year- old man, Results: Each patient had unilateral lower extremity swelling and had recently undergone an ipsilateral lower limb operation. One f emale patient had previously undergone proximal femoral vein ligation, and another female patient had venous insufficiency demonstrated by D oppler ultrasonography, The male patient had a history of severe arter ial insufficiency, and the remaining female patient had no venous or a rterial abnormalities, On lymphoscintigraphy, all patients showed incr eased lymphatic flow in the edematous lower limb, Only the male patien t also demonstrated abnormal dermal backflow pattern, Conclusion: Incr eased lymphatic flow most likely is a normal response to lower limb ed ema in the presence of normal peripheral lymphatic structures, In the four described cases, a recent lower limb surgical procedure may have resulted in disturbance of normal proximal lymphatic channels, The rol e of sympathetic innervation of the peripheral lymphatic system is a p otential factor determining lymphatic response to trauma or surgical i ntervention, Increased flow on lymphoscintigraphy may not necessarily represent normal flow, especially if other scintigraphic features of a bnormal lymphatic function-such as dermal backflow pattern-are present .