The buttocks contain a significant network of arteries that provide a rich blood supply to the region’s large muscles and overlying tissues. This anatomical area, known as the gluteal region, is composed of the powerful gluteal muscles—the maximus, medius, and minimus. These muscles require a dense vascular network to support their function in movement and stability. The arteries nourish the muscle fibers, connective tissue, and skin.
The Major Arterial Supply
The gluteal region receives its primary blood flow from two major vessels: the Superior Gluteal Artery (SGA) and the Inferior Gluteal Artery (IGA). The SGA is the largest of the two and is the main contributor to the vascular supply of the upper gluteal muscles. It enters the gluteal area and splits into superficial and deep branches to distribute oxygenated blood. The superficial branch travels between the gluteus medius and gluteus maximus muscles, primarily supplying the gluteus maximus and the overlying skin.
The deep branch of the SGA runs deeper, supplying the gluteus medius, gluteus minimus, and the tensor fasciae latae muscle. This branch further divides into superior and inferior divisions. The IGA is a smaller vessel but plays a substantial role, particularly in the lower portion of the gluteus maximus muscle. It also contributes to the blood supply of structures in the posterior thigh.
These two main arteries form connections, or anastomoses, with neighboring vessels, such as the medial circumflex femoral artery. This interconnected network ensures the gluteal region maintains a reliable blood supply even if one vessel is partially compromised. The SGA provides approximately 45% of the small perforating blood vessels to the gluteal region, while the IGA contributes about 30%.
Understanding the Source of Blood Flow
The Superior and Inferior Gluteal Arteries do not originate within the buttocks themselves but are branches of the Internal Iliac Artery, a major vessel located deep within the pelvic cavity near the sacrum. The Internal Iliac Artery itself is a major branch of the Common Iliac Artery.
The Superior Gluteal Artery branches off the posterior division of the Internal Iliac Artery, making it the largest terminal branch of that division. The Inferior Gluteal Artery usually arises from the anterior division of the Internal Iliac Artery. This difference in origin reflects their separate pathways.
To reach the gluteal region, both arteries must exit the pelvis through the greater sciatic foramen. The Superior Gluteal Artery passes above the piriformis muscle. Conversely, the Inferior Gluteal Artery exits below the piriformis muscle. This anatomical arrangement relative to the piriformis is a defining landmark for the vessels’ path into the buttock.
Clinical Importance and Safety
The presence and specific pathways of the gluteal arteries have significant implications for medical procedures, especially intramuscular (IM) injections. Healthcare providers must carefully select an injection site to avoid puncturing these major blood vessels or the adjacent sciatic nerve. An inadvertent injection into an artery can lead to severe complications, including a hematoma or the drug entering the bloodstream too quickly.
The traditional injection area, known as the dorsogluteal site (the upper-outer quadrant of the buttock), carries a higher risk because of its proximity to both the Superior Gluteal Artery and the sciatic nerve. Studies have shown that blood aspiration, which indicates proximity to a blood vessel, occurs in a notable percentage of injections in this area. This risk has led to a growing preference for the ventrogluteal site, which is located on the side of the hip.
The ventrogluteal site is considered safer because it targets the gluteus medius and minimus muscles, located away from the primary pathway of the sciatic nerve and the major gluteal arteries. To locate this safer area, a technique is used to create a “V” shape between the index finger on the anterior superior iliac spine and the middle finger extended toward the iliac crest. The dense vascularity of the gluteal muscles is beneficial for drug absorption, but the risk of injury necessitates precise technique for all injections.