The origin variability of the iliolumbar artery and iatrogenic sciatica.

The iliolumbar artery (ILA) is a standard branch from the posterior trunk of the internal iliac artery. It is the only pelvic artery ascending from pelvic cavity. Current study comprises 171 cadavers dissection to assess the origin variability of ILA. The present study identified the incidence of the ILA origin variability in Caucasian population which also clarified the iliolumbar variability in males and females. The current study shows that the ILA arises from the common iliac artery in 2%, from the external iliac artery in 0.3% and from the internal iliac artery in 13.8% either from its dorsal or dorsomedial aspects in 1 and 12.8%, respectively. The common, external and internal iliac arteries are defined as a high (early) origin and occurred in 16.1%. The posterior trunk of the internal iliac artery is the most common origin of the ILA found to be in 77.9%. Occasionally, it also arose from the superior gluteal artery (0.7%) and the sciatic artery (0.3%). Furthermore, the ILA arises from the anterior trunk indirectly as from the inferior gluteal artery in 0.3%. The ILA arising from the superior or inferior gluteal artery or from the sciatic artery is defined as a low (delayed) origin and occurred in 1.3%. In contrast, the ILA was 4.7%. Consequently, variability of the ILA leads to vascular variability of the lumbosacral trunk of the sciatic nerve. Clinicians have to be aware of these variations to avoid unnecessary ligation to prevent sciatic neuropathy.