Inferior gluteal veins
Inferior gluteal veins start at the top part of the back side of the thigh and help drain oxygen-depleted blood from the pelvic region.
This vein is also referred to as the vena comitans or the sciatica veins of the inferior gluteal artery. The vena comitans is the Latin expression that means the “accompanying vein” and describes veins that have a close relationship with an artery, so that the pulsing of the artery also helps move blood through the vein.
The inferior gluteal veins are usually paired with other veins and located on the sides of an artery. They are usually found with smaller arteries, as larger arteries typically do not have venae comitantes.
The inferior gluteal veins enter into the pelvis by coming through the lower portion of the greater sciatic foramen, which is the pelvis' major opening. After entering into the pelvis, they form a single stem that opens up into the hypogastric vein's lower portion. The hypogastric vein is another term used for the internal iliac vein.