Left-sided leg edema of the elderly: a common variant of the iliac compression syndrome.

BACKGROUND Anatomically, the right common iliac artery crosses the left iliac vein and its accompanying lymphatics. We hypothesized that this situation could lead to a predominance of edema, telangiectasis, and venous varicosities on the left lower extremities of older persons. METHODS To test this hypothesis, a research assistant who was blinded to the study goals examined 215 predominantly elderly residents of North Carolina homes for the aged and disabled. RESULTS Among these subjects, 17.7 percent had predominantly left-sided edema, and 5.7 percent had predominantly right-sided edema (P < 0.001). When the 88 subjects with pitting edema greater than 3 mm were studied, 34.5 percent showed a left-sided predominance, and 6.9 percent showed a right-sided predominance (P < 0.001). In contrast, no significant difference was found in the lateralization of venous varicosities or of telangiectasis. CONCLUSIONS Asymmetric edema is common and is usually left-sided in older persons. Compression of the left common iliac vein and its accompanying lymphatics by the right iliac artery, rather than overt clinical disease, might explain the majority of asymmetric edema seen in clinical practice.