[Lumbar epidurography with iohexol: the effect of aging on the leakage of contrast media from the intervertebral foramina].

The lateral and longitudinal spread of contrast media was investigated by lumbar epidurography with 8 ml of iohexol in 47 patients aged 25 yr to 86 yr. Iohexol was injected through the epidural catheter epidurally advanced by 5 cm cephalad from the L 1-4 interspace. A significant correlation was found between the longitudinal spread of iohexol and aging. No correlation was found between the leakage of iohexol from the intervertebral foramina and aging. This finding may deny the hypothesis that in elderly patients, the more extensive longitudinal spread of local anesthetics in the epidural space may be caused by its smaller leakage from the intervertebral foramina.