From the Guidelines
In an inguinal hernia, the hernia sac is typically located anterior and lateral to the cord structures. The spermatic cord structures (including the vas deferens, testicular artery, and pampiniform plexus) pass through the inguinal canal. When an inguinal hernia develops, the peritoneal sac containing abdominal contents protrudes through a weakness in the abdominal wall. This hernia sac usually emerges anterior and to the outside (lateral) of the cord structures, as described in the embryology and natural history of the patent processus vaginalis 1. This anatomical relationship is important for surgeons to understand when repairing inguinal hernias. During surgery, careful dissection is required to separate the hernia sac from the cord structures to avoid damaging vital components of the spermatic cord. In indirect inguinal hernias, which are more common, the hernia sac follows the path of descent of the testicle and enters the inguinal canal through the internal inguinal ring. In direct inguinal hernias, the sac protrudes directly through a weakness in the posterior wall of the inguinal canal (Hesselbach's triangle), but still typically remains anterior to the cord structures. Understanding this anatomical relationship is crucial for proper diagnosis, surgical planning, and successful hernia repair while preserving the integrity of the spermatic cord structures, as highlighted in the assessment and management of inguinal hernia in infants 1. Some key points to consider include:
- The incidence of inguinal hernias is approximately 3% to 5% in term infants and 13% in infants born at less than 33 weeks of gestational age 1.
- The timing of inguinal hernia repair in preterm and term infants represents a balance of the risks of inguinal hernia incarceration and of postoperative respiratory complications 1.
- Laparoscopic repair has been used effectively in preterm infants, with reported hernia recurrence rates comparable to those associated with open repair 1. However, the most important consideration is the anatomical relationship between the hernia sac and the cord structures, which is critical for successful hernia repair.
From the Research
Anatomical Relationship of Hernia Sac to Cord Structures
The anatomical relationship of the hernia sac to the cord structures in an inguinal hernia is complex and varies depending on the type of hernia.
- In indirect inguinal hernias, the sac emerges through a weakness in the deep inguinal ring, lateral to the inferior epigastric vessels, and passes into the inguinal canal beside and in contact with the cord but outside of its covering fasciae 2.
- The hernia sac can contain spermatic cord structures such as the vas deferens, epididymis, and embryonal rests, although this is rare, occurring in less than 1% of cases 3.
- Spermatic cord lipomas, which are found in 20-70% of all inguinal hernia repairs, can originate from preperitoneal fatty tissue within the internal spermatic fascia and are in topographical proximity to the arteries, veins, lymphatics, nerves, and deferent duct within the spermatic cord 4.
- In some cases, the hernia sac can be intimately fused to the spermatic cord structures, making dissection and division of the sac challenging 5.
Types of Inguinal Hernias
There are different types of inguinal hernias, including:
- Indirect inguinal hernias, which are usually congenital and form a sac in the core of the spermatic cord covered by the internal spermatic, cremasteric, and external spermatic fasciae 2.
- Direct inguinal hernias, which are acquired and have a sac that lies beside or behind the cord 2.
- Juxtacordal indirect inguinal hernias, which are a rare type of hernia where the sac emerges through a weakness in the deep inguinal ring and passes into the inguinal canal beside and in contact with the cord but outside of its covering fasciae 2.
Clinical Significance
Understanding the anatomical relationship of the hernia sac to the cord structures is important for preoperative counseling and surgical planning, as it can help reduce the risk of injury to the spermatic cord structures and improve outcomes 3, 5. Additionally, recognizing the presence of spermatic cord lipomas can help prevent misdiagnosis and ensure proper treatment 4, 6.