Contents of the Female Inguinal Canal
The female inguinal canal primarily contains the round ligament of the uterus and a potential peritoneal pouch called the canal of Nuck. 1
Anatomical Components
Round ligament of the uterus: This is the primary structure traversing the female inguinal canal, analogous to the spermatic cord in males 1
Canal of Nuck: A pouch of peritoneum that accompanies the round ligament through the inguinal canal, analogous to the processus vaginalis in males 2
Lymphatic vessels: The inguinal canal contains lymphatic drainage that varies based on location - proximal drainage goes to perirectal nodes, while drainage from areas immediately above the dentate line goes to internal pudendal and internal iliac nodes 1
Origin and Insertion of the Round Ligament
Origin: The round ligament attaches to the uterine cornu (antero-superior part of the uterus) near the origin of the fallopian tube 2, 3
Path: It passes under the broad ligament and enters the inguinal canal 3
Termination: Contrary to traditional teaching that the round ligament terminates in the labia majora, recent anatomical studies show it typically terminates in one of three locations 3:
- After the external inguinal ring (52.6% of cases)
- Before the internal inguinal ring (26.3% of cases)
- Under the pubic bone (22.1% of cases)
- No round ligaments were found to terminate in the labia majora in adult anatomical studies 3
Embryological Development
In female embryological development, the craniosuspensory ligament is maintained, allowing the ovary to retain its dorsal retroperitoneal position 1
Unlike in males where the gubernaculum thickens, in females it persists as the ovarian round ligament 1
The canal of Nuck forms when the peritoneal pouch that accompanies the round ligament fails to completely obliterate 2
Clinical Significance
Inguinal hernias: Incomplete obliteration of the canal of Nuck can lead to indirect inguinal hernias in females 2
Hydrocele of the canal of Nuck: A rare condition in females caused by fluid accumulation in the persistent canal 2
Ovarian herniation: The ovary can herniate through the patent canal of Nuck, which may lead to complications such as strangulation, torsion, and potential infertility 4
Round ligament management during hernia repair: During inguinal hernia repair in females, surgeons must decide whether to divide or preserve the round ligament. Division of the round ligament is not associated with increased complications or recurrence and may result in decreased pain at 6 months post-surgery 5
Important Distinctions from Male Anatomy
The female inguinal canal lacks the testicular vessels and vas deferens found in males 1
The round ligament is thinner than the male spermatic cord 1
Inguinal hernias are much less common in females than males, with more than 90% of pediatric inguinal hernias diagnosed in boys 6
Understanding the contents and variations of the female inguinal canal is essential for proper diagnosis and management of inguinal pathologies in female patients.