Ovarian artery

The ovarian artery is a vital blood vessel that supplies blood to the ovaries in females. It is one of two arteries responsible for the vascularization of the ovaries, along with the ovarian branches of the uterine artery. The ovarian artery is the female equivalent of the testicular artery in males.

Location

The ovarian artery arises from the abdominal aorta, typically at the level of the first or second lumbar vertebra (L1-L2), just below the origin of the renal arteries. After branching from the aorta, it descends along the psoas major muscle in the retroperitoneal space.^[7] It travels toward the pelvis, crossing over the external iliac artery before reaching the ovary through the suspensory ligament of the ovary. The ovarian artery also gives off branches to the fallopian tubes and anastomoses with the uterine artery to ensure a robust blood supply to the reproductive organs.

Anatomy

The ovarian artery is an essential vessel that supplies oxygenated blood to the ovaries, fallopian tubes, and parts of the uterus in females. It is a paired artery, with one ovarian artery supplying each ovary. Below is a detailed description of the anatomy of the ovarian artery, including its origin, course, branches, and relations with other structures.

Origin

The ovarian artery originates from the abdominal aorta, usually at the level of the first or second lumbar vertebra (L1-L2), just below the renal arteries.^[5] The ovarian arteries arise bilaterally from the lateral aspect of the aorta and represent the female counterpart of the testicular arteries in males.

Course

• Abdominal Course: After branching from the abdominal aorta, the ovarian artery descends into the pelvis, traveling along the psoas major muscle in the retroperitoneal space. The artery follows an oblique path as it moves inferiorly and laterally, parallel to the ureter.
• Pelvic Course:
  • As the ovarian artery approaches the pelvis, it crosses over the external iliac artery near the pelvic brim. After crossing the external iliac artery, it moves medially toward the ovary.
  • The ovarian artery then enters the suspensory ligament of the ovary (also known as the infundibulopelvic ligament), which attaches the ovary to the lateral pelvic wall. Within this ligament, the artery continues its descent toward the ovary.
• Termination at the Ovary: Upon reaching the ovary, the ovarian artery divides into smaller branches that supply the ovary and surrounding structures. It penetrates the mesovarium, the portion of the broad ligament that connects the ovary to the broad ligament, providing the ovarian tissue with a rich blood supply.

Branches

The ovarian artery gives off several important branches as it descends into the pelvis:

• Branches to the Ovary: The primary branches of the ovarian artery supply the ovary itself. These small branches enter the ovary via the hilum and penetrate the ovarian tissue, ensuring that the ovary receives sufficient oxygen and nutrients to support its function.
• Branches to the Fallopian Tubes: The ovarian artery also gives rise to small branches that supply the fallopian tubes (uterine tubes), which are responsible for transporting ova from the ovaries to the uterus.^[3] These branches run along the length of the fallopian tube, providing vascularization to its muscular and mucosal layers.
• Anastomoses with the Uterine Artery: The ovarian artery forms important anastomoses with the uterine artery, a branch of the internal iliac artery. The uterine and ovarian arteries connect at the tubal-ovarian anastomosis, ensuring a robust blood supply to the reproductive organs. This connection helps provide collateral blood flow to the ovary, fallopian tubes, and uterus.
• Peritoneal Branches: Along its course, the ovarian artery may give off small branches to the surrounding peritoneum, which lines the pelvic cavity. These branches help supply the surrounding tissues with blood.

Relations to Other Structures

The ovarian artery is closely related to several key anatomical structures as it descends through the abdomen and pelvis:

• Psoas Major Muscle: As the ovarian artery descends from the abdominal aorta, it runs along the psoas major muscle in the retroperitoneal space. The artery lies anterior to the muscle, a common anatomical relationship for many vessels descending into the pelvis.
• Ureter: The ovarian artery crosses the ureter as it approaches the pelvis. The ureter, which carries urine from the kidney to the bladder, lies posterior to the ovarian artery. This anatomical relationship is particularly important during pelvic surgeries, such as ovarian or uterine procedures, as injury to the ureter can lead to complications.
• External Iliac Artery and Vein: Before entering the pelvis, the ovarian artery crosses over the external iliac artery and external iliac vein near the pelvic brim. This crossing occurs as the ovarian artery moves medially toward the ovary. Care must be taken during surgeries in this area to avoid damaging these major blood vessels.
• Suspensory Ligament of the Ovary: The ovarian artery travels through the suspensory ligament of the ovary (infundibulopelvic ligament), which connects the ovary to the lateral pelvic wall.^[1] The artery runs alongside the ovarian vein and nerve fibers within this ligament, providing the ovary with a direct blood supply.
• Broad Ligament of the Uterus: As the ovarian artery approaches the ovary, it passes through the broad ligament, a peritoneal fold that supports the uterus, ovaries, and fallopian tubes. The artery runs through the mesovarium, the part of the broad ligament that connects the ovary to the rest of the reproductive tract.

Variations

While the ovarian artery generally follows a predictable course, there are some anatomical variations that can occur:

• Multiple Ovarian Arteries: In some cases, a woman may have accessory ovarian arteries, which are additional arteries that arise from the aorta or nearby vessels. These accessory arteries may provide extra blood supply to the ovaries or other structures within the pelvis.
• Variable Origin: The ovarian artery typically arises from the abdominal aorta, but in some rare cases, it may arise from a different vessel, such as the renal artery or the common iliac artery. Such variations are uncommon but can be encountered during surgeries or diagnostic imaging.
• Tortuous Course: The ovarian artery can sometimes have a tortuous (twisting) course as it descends into the pelvis. This tortuosity is normal and accommodates the movements of the ovary and surrounding structures. It also helps ensure the artery can stretch and accommodate changes in position during pregnancy or other physiological changes.

Blood Flow and Perfusion

The ovarian artery is responsible for delivering a consistent and significant amount of blood flow to the ovary, fallopian tubes, and surrounding reproductive structures:

• Ovary: The ovarian artery’s primary role is to supply the ovarian tissue with oxygenated blood. The rich blood supply ensures that the ovary can function properly, supporting the growth and maturation of ovarian follicles and the production of hormones.
• Fallopian Tubes: The branches of the ovarian artery that supply the fallopian tubes ensure that the tubes remain well-vascularized, allowing them to transport the ovum from the ovary to the uterus.
• Uterine Anastomosis: The anastomosis with the uterine artery ensures that there is a collateral blood supply to the reproductive organs, which is especially important during pregnancy and in cases of arterial occlusion.^[8]

Function

The ovarian artery plays a vital role in supplying oxygenated blood to the ovaries, fallopian tubes, and parts of the uterus. It is essential for maintaining the reproductive function and hormonal balance in females. Below is a detailed breakdown of its functions.

Blood Supply to the Ovary

The primary function of the ovarian artery is to provide oxygenated blood to the ovary, supporting its role in oogenesis (the production of eggs) and hormone production.

• Oxygen and Nutrient Delivery: The ovarian artery ensures that the ovarian tissues receive a steady supply of oxygen and nutrients, which are necessary for the development of ovarian follicles and the production of oocytes (eggs). This blood supply supports the ovary’s role in the menstrual cycle, particularly during the phases of follicular growth and ovulation.
• Support for Hormone Production: The ovarian artery delivers the necessary blood supply to support the production of sex hormones, including estrogen and progesterone, which are critical for regulating the menstrual cycle, promoting the growth of the uterine lining, and preparing the body for potential pregnancy.

Blood Supply to the Fallopian Tubes

The ovarian artery provides blood to the fallopian tubes, which are essential for transporting the ovulated egg from the ovary to the uterus. This blood supply ensures that the fallopian tubes can carry out their functions of fertilization and egg transport.

• Support for Ciliary and Muscular Function: The fallopian tubes are lined with cilia, which help move the egg toward the uterus. The blood supply from the ovarian artery provides the oxygen and nutrients needed for the cilia and the muscular layers of the tube to function properly, facilitating the propulsion of the egg through the fallopian tube.
• Maintenance of Tube Integrity: The branches of the ovarian artery that supply the fallopian tubes ensure that the tubal epithelium and muscular layers receive adequate blood flow, maintaining their structure and function. This is essential for successful fertilization, as the tubes must be able to support the transport of sperm, the egg, and the fertilized zygote.

Blood Supply to the Uterus

Although the uterine artery is the primary blood supplier to the uterus, the ovarian artery plays a significant supporting role by forming anastomoses with the uterine artery, ensuring that the upper part of the uterus and the fallopian tubes receive a reliable blood supply.

• Anastomosis with Uterine Artery: The ovarian artery connects with the uterine artery at the level of the fallopian tubes and upper uterus. This connection forms a collateral blood supply to these structures, which is critical in situations where the primary blood supply from the uterine artery may be compromised.
• Support for Pregnancy: During pregnancy, the increased blood supply provided by the ovarian artery supports the developing fetus.^[6] The anastomoses between the ovarian and uterine arteries help increase blood flow to the uterus as it expands and requires more oxygen and nutrients.

Maintenance of Reproductive Organ Health

The ovarian artery plays an essential role in maintaining the overall health of the reproductive organs by providing a continuous blood supply to the ovaries, fallopian tubes, and adjacent tissues.

• Prevention of Ischemia: By delivering oxygenated blood to these tissues, the ovarian artery helps prevent ischemia (lack of blood supply), which could lead to tissue damage or dysfunction in the reproductive organs. This blood flow is particularly important for ensuring that the ovaries can continue to function normally throughout a woman’s reproductive years.
• Tissue Repair and Regeneration: The ovarian artery also supports the regenerative processes in the ovaries and fallopian tubes by providing the necessary oxygen and nutrients to repair tissues after ovulation or minor injuries. The blood supply ensures that the ovarian tissue can recover after each ovulation cycle, maintaining its ability to produce eggs.

Hormonal Support and Regulation

The ovarian artery supports the production and secretion of key sex hormones, including estrogen, progesterone, and androgens, which are necessary for menstrual cycle regulation and reproductive health.

• Estrogen Production: During the follicular phase of the menstrual cycle, the ovarian follicles produce estrogen, which is essential for the development of the uterine lining and preparing the body for potential fertilization. The ovarian artery provides the blood supply that sustains this hormone production.
• Progesterone Production: After ovulation, the corpus luteum forms from the ruptured follicle and produces progesterone, a hormone that helps maintain the uterine lining for a potential pregnancy. The ovarian artery delivers the blood needed for the corpus luteum to function and secrete progesterone.

Role in Reproductive Cycle

The ovarian artery plays a critical role in the overall menstrual and reproductive cycles by supporting the physiological processes within the ovaries and fallopian tubes.

• Follicular Growth and Ovulation: By supplying blood to the ovary, the ovarian artery enables the development of ovarian follicles, which grow and mature during the early phase of the menstrual cycle.^[4] At mid-cycle, the ovarian artery supports ovulation, the process where a mature egg is released from the follicle.
• Corpus Luteum Support: After ovulation, the corpus luteum is formed and remains functional due to the blood supply from the ovarian artery. The corpus luteum produces progesterone, which helps maintain the uterine lining, creating favorable conditions for implantation if fertilization occurs.

Collateral Circulation in Pathological Conditions

The ovarian artery plays a role in collateral circulation, particularly in cases where the primary uterine artery or surrounding vessels may be compromised.

• Backup Blood Supply: The anastomoses between the ovarian and uterine arteries provide a redundant blood supply to the reproductive organs, helping to prevent ischemia in the event of arterial occlusion or during surgical procedures that may compromise the blood flow from the uterine artery.
• Tumor Vascularization: In cases of ovarian or uterine tumors, the ovarian artery may provide additional blood flow to the abnormal growths, contributing to the vascularization of these tumors.

Clinical Significance

The ovarian artery is clinically significant because it provides a crucial blood supply to the ovaries, fallopian tubes, and parts of the uterus.^[2] Disruption of blood flow through the ovarian artery, such as from vascular occlusion, trauma, or surgical ligation, can lead to ovarian ischemia, which may result in reduced ovarian function, infertility, or tissue damage.

In surgical procedures like hysterectomy or ovarian cystectomy, careful management of the ovarian artery is essential to avoid excessive bleeding or compromising blood flow to the ovaries and fallopian tubes. The ovarian artery is also involved in collateral circulation with the uterine artery, providing an alternative blood supply to the uterus and reproductive organs in cases of uterine artery occlusion.