99mTc-HSA lymphoscintigraphy and leg edema following arterial reconstruction

Twelve patients with peripheral arterial occlusive disease were evaluated prospectively in an effort to further investigate the etiology of pedal and lower leg edema that occurs following revascularization (e.g., aorto-iliac or femoropopliteal bypass). Serum total protein, albumin, blood urea nitrogen, and creatinine levels were measured (in addition to peripheral venous pressure), and lymphoscintigraphy of the lower leg was performed. These parameters were assessed just prior to surgery, four weeks postoperatively, and again at follow-up. The serum levels obtained four weeks after surgery and on subsequent follow-ups were significantly higher than the preoperative values. Preoperative peripheral venous pressure was not significantly different from that obtained after surgery. There was no correlation between these pressure measurements and the degree of edema (Grades I to IV correspond to increasing degrees of severity). For both the supine and upright positions, lymphoscintigraphic counts in the inguinal region were significantly higher after surgery. However, the relative increase was dependent upon the severity of edema. The postoperative lymphoscintigraphic count in the upright position was 77 +/- 33 CPS in patients with Grades I and II edema (n = 6) and 20.6 +/- 16.2 CPS in patients with Grades III and IV edema (n = 10) (p less than 0.01). Thus, a lesser degree of postoperative pedal and lower leg edema was associated with higher lymphoscintigraphic counts. We conclude that major contributors to the development of lower extremity edema following arterial reconstruction are failed capillary hydrostatic pressure and interrupted lymphatic drainage.