Vascular Anatomy of the Pelvis

Chapter 75


Vascular Anatomy of the Pelvis


Elizabeth A. Ignacio, Naomi N. Silva, Nadia J. Khati, Andres Krauthamer, Venkatesh Krishnasamy, Emily J. Timmreck, Emily M. Tanksi and Jordan Ruby


The rich vascular supply of the pelvis not only supports the structures contained within it, including the bladder, rectum, and reproductive organs, but also extends to the lower extremities. For a complete understanding of vascular anatomy as it pertains into the endovascular procedures of interventional radiology, it is useful to discuss the vascular structures in sections, from the bifurcation of the aorta and the inferior vena cava to the level of the common femoral arteries and veins. We will also review the anatomy of the iliac vessels, including their branches, common variants, and various collateral pathways (Fig. 75-1).


image
FIGURE 75-1 Blood supply of the pelvis. (From Townsend CM, Beauchamp RW, Evers BM, Mattox KL. Sabiston textbook of surgery. 17th ed. Philadelphia: Saunders; 2004. p. 2238.)


Arteries


Abdominal Aorta


The abdominal aorta terminates at the bifurcation into a right and left common iliac artery. This bifurcation is usually at the lower border of the L4 vertebral body (Fig. 75-2). On physical examination, this site corresponds to a point approximately 2.5 cm below the umbilicus, or at the level of a line drawn between the highest points of the iliac crests. Although the false pelvis (greater pelvis) has its superior border at the S1 level (first sacral vertebral body), it is important to consider the aortic bifurcation in any arterial evaluation of the pelvis (Fig. 75-3).


image
FIGURE 75-2 Lateral and anterior location of abdominal aortic bifurcation with reference to L3 and visualization of umbilical arteries and common iliac arteries. (From Roberts J, Hedges J. Clinical procedures in emergency medicine. 4th ed. Philadelphia: Saunders; 2004. p. 379.)

image
FIGURE 75-3 Digital subtraction angiogram in anteroposterior projection shows distal abdominal aorta (Ao) with small lumbar branches, common iliac artery (CIA), internal and external iliac arteries (Ext IA, Int IA), and common femoral artery (CFA). (From Mettler F, Guiberteau M. Essentials of radiology. 2nd ed. Philadelphia: Saunders; 2005. p. 379.)


Aortoiliac Bifurcation


As mentioned, the aorta bifurcates into a right and left common iliac artery. These two arteries pass anterior and slightly to the left of the L5 vertebra and superior sacrum before branching into the right and left external iliac and internal iliac (hypogastric) arteries (Figs. 75-4 and 75-5; also see Fig. 75-3). The external/internal iliac bifurcation occurs above the pelvic inlet of the true pelvis (lesser pelvis).


image
FIGURE 75-4 Abdominal aorta with major branches, bifurcation into common iliac arteries, and their split into external and internal iliac arteries. Middle sacral artery is included. (From Wein AJ, Kavoussi LR, Novick AC, et al., editors. Campbell’s urology. 9th ed. Philadelphia: Saunders; 2007. p. 6.)

image
FIGURE 75-5 Magnetic resonance angiogram of abdominal aorta, oblique view. Aorta bifurcates into common iliac arteries. These two arteries pass anterior to L5 vertebral body and superior sacrum.

An important pathologic process that can occur at the aortic bifurcation is an associated common iliac vein compression disorder called May-Thurner syndrome or iliac compression syndrome (Fig. 75-6). In brief, this syndrome involves compression of the right common iliac artery on the left common iliac vein against the spine and pelvic brim. This compression may clinically manifest as left lower extremity edema, pain, and/or iliofemoral deep vein thrombosis.


image
FIGURE 75-6 Anatomic visualization of abdominal aorta lying over inferior vena cava. (From Townsend CM, Beauchamp RW, Evers BM, Mattox KL. Sabiston textbook of surgery. 17th ed. Philadelphia: Saunders; 2004. p. 2043.)


External Iliac Artery


The external iliac arteries (right and left) course inferiorly and laterally but remain above the pelvic inlet. The inguinal ligament, found between the two points of the anterior-superior iliac spine (Fig. 75-7) and the pubic tubercle, marks the anatomic boundary of the trunk and lower limb. At this level there are two terminal branches of the external iliac arteries: the inferior epigastric artery and the deep circumflex artery (see Fig. 75-7). These branches provide arterial supply to the inferior abdominal wall. Beyond this point, the external iliac arteries become the common femoral arteries (Fig. 75-8).


image
FIGURE 75-7 Visualization of inferior epigastric artery, deep circumflex artery, femoral artery, and superior iliac spine. (From Townsend CM, Beauchamp RW, Evers BM, Mattox KL. Sabiston textbook of surgery. 17th ed. Philadelphia: Saunders; 2004. p. 1176.)

image
FIGURE 75-8 Visualization of external iliac artery becoming common femoral artery. (From Marx J. Rosen’s emergency medicine: concepts and clinical practice. 6th ed. St Louis: Mosby; 2006. p. 540.)


Internal Iliac Artery


The internal iliac artery and its branches constitutes the major arterial supply to the pelvic viscera, the wall, and the perineum, including the erectile tissues of the clitoris and penis as well as nerves extending into the gluteal region of the lower limb (Figs. 75-9 to 75-11). The main trunk of the internal iliac artery runs anteromedial to the sacroiliac joint before it divides into the anterior and posterior trunks just above the greater sciatic foramen (Fig 75-12; also see Fig. 75-9).


image
FIGURE 75-9 Anterior view of abdominal aorta splitting into common iliac arteries, and common iliac arteries splitting into internal and external iliac arteries. (From Gabbe SG, Niebyl JR, Simpson JL. Obstetrics—normal and problem pregnancies. 4th ed. Edinburgh: Churchill Livingstone; 2002. p. 1372.)

image
FIGURE 75-10 Lateral view of common iliac artery splitting into external and internal iliac arteries and major vessels of anterior and posterior trunk of internal iliac artery. (From Gabbe SG, Niebyl JR, Simpson JL. Obstetrics—normal and problem pregnancies. 4th ed. Edinburgh: Churchill Livingstone; 2002. p. 1373.)

image
FIGURE 75-11 Aortogram. Internal iliac arteries provide major arterial supply to pelvic walls and viscera.

image
FIGURE 75-12 Three-dimensional rendering of aortic bifurcation. Internal iliac artery runs anterior to sacroiliac joint and then divides into anterior and posterior branches.


Anterior Division


The anterior trunk of the internal iliac artery usually has six major branches, three parietal and three visceral. At this level the branching pattern is subject to many anatomic variations. By the most common order of their origin, these include the umbilical artery, obturator artery (see Fig. 75-10), inferior vesical artery, middle rectal artery (see Fig. 75-10), internal pudendal artery, and inferior gluteal artery (Figs. 75-13 and 75-14). These arterial branches supply the pelvic viscera, perineum, gluteal region, adductor region of the thigh, and in the fetus, the placenta. The uterine artery (see Fig. 75-10) also generally arises from the anterior division of the internal iliac artery, but several variations in its origin have been described in the literature.


image
FIGURE 75-13 Anterior view of obturator artery, middle rectal artery, internal pudendal artery, inferior gluteal artery, and median sacral artery. (From Townsend CM, Beauchamp RW, Evers BM, Mattox KL. Sabiston textbook of surgery. 17th ed. Philadelphia: Saunders; 2004. p. 1407.)

You may also need an Radiology appGet it now

Tags:
Dec 23, 2015 | Posted by in INTERVENTIONAL RADIOLOGY | Comments Off on Vascular Anatomy of the Pelvis
Premium Wordpress Themes by UFO Themes