Critical lower limb ischaemia following excision of the rectum.

Critical lower limb ischaemia can occur following rectal surgery by a number of mechanisms. Patients with aorto-iliac stenosis or occlusion may be dependent on collateral circulation to the lower limbs from the visceral arteries supplying the descending colon, sigmoid colon and the rectum. Division of these collaterals can precipitate critical ischaemia of the leg. This is an uncommon scenario but one that should be considered in arteriopaths undergoing rectal surgery. Two cases of this complication are reported and the mechanisms discussed.