The lateral umbilical fold is an anatomical feature of the inner surface of the anterior abdominal wall. It is one of the peritoneal folds that are evident on the internal surface of the abdominal wall when viewed, for instance, during laparoscopic surgery.
Structure
The lateral umbilical fold is created by the underlying inferior epigastric vessels (artery and vein). These vessels branch from the external iliac vessels and ascend to supply blood to the lower part of the anterior abdominal wall. The fold is essentially a ridge of peritoneum (the membrane lining the internal surface of the abdomen) that has been lifted or pushed forward by the underlying vessels.
In detail, the structure of the lateral umbilical fold includes:
- Inferior Epigastric Vessels: These are the core components that cause the peritoneum to elevate and form the fold. They include the inferior epigastric artery and its accompanying veins.
- Peritoneal Covering: A layer of peritoneum covers these vessels, adhering closely to them and forming the visible fold on the inner surface of the abdominal wall.
- Position: Each lateral umbilical fold is located laterally to the medial umbilical fold (which contains the obliterated umbilical artery) and medial to the deep inguinal ring, an opening in the transversalis fascia through which structures such as the spermatic cord in males or the round ligament in females pass.
Location
The lateral umbilical folds are located on the inner surface of the anterior abdominal wall, on either side of the midline. Each fold is lateral (to the side) to the medial umbilical fold, which is created by the remnant of the obliterated umbilical artery. Specifically, these folds are positioned over the inferior epigastric vessels as they course from the pelvis upward toward the umbilicus.
Function
The lateral umbilical folds themselves do not have physiological functions in the way organs do, but they play important roles in clinical and surgical contexts:
- Surgical Landmarks: They serve as crucial landmarks during abdominal surgeries, especially in laparoscopic procedures. The folds help surgeons identify key anatomical structures, such as the inferior epigastric vessels, and navigate the abdominal cavity safely to avoid unintentional damage.
- Hernia Identification and Repair: The lateral umbilical folds are significant in the context of hernia diagnosis and treatment. The area lateral to these folds is a common site for indirect inguinal hernias, as it marks the location of the deep inguinal ring. Understanding the exact location of these folds assists surgeons in distinguishing between direct and indirect inguinal hernias and in planning the appropriate surgical approach for repair.
- Vascular Reference: While the folds themselves do not perform vascular functions, the inferior epigastric vessels that cause the formation of these folds are important for the blood supply to the lower anterior abdominal wall. In surgical planning, especially for procedures that require tissue flaps or grafts, the preservation of these vessels can be crucial.
Clinical Significance
While the lateral umbilical folds themselves do not perform any active physiological functions, they are significant in clinical practice for several reasons:
- Hernia Relations: The area lateral to the fold is a common site for indirect inguinal hernias, as this is where the deep inguinal ring is located. Conversely, the area medial to the fold can be a site for direct inguinal hernias. Understanding the relationship between these folds and hernias is crucial for diagnosis and surgical repair.
- Blood Supply: The inferior epigastric vessels are important for the blood supply to the lower anterior abdominal wall. In certain surgical procedures, such as the creation of a urinary bladder from a segment of intestine (orthotopic neobladder), these vessels may need to be preserved or manipulated.
