The inguinal canal (IC) is a slanted, tube-like structure within the lower anterior abdominal wall, extending above and parallel to the inguinal ligament. It originates superolaterally from the lower part of the external oblique muscle’s aponeurosis and extends medially and inferiorly across the abdominal wall. This canal is approximately 3-5 cm in length.
The canal commences at the internal inguinal orifice, known as the deep inguinal ring, which is positioned lateral to the inferior epigastric vessels on the posterior wall of the abdominal cavity. This orifice considered as a defect in the transversalis fascia. The canal then travels medially and slightly downward, through the layers of the abdominal wall. It ends at the external inguinal orifice/ superficial inguinal ring, situated about 1 cm superolateral to the pubic tubercle.
- Anterior wall, in addition to the superficial inguinal ring that plays a key role in shaping the medial third of the anterior wall, there is also the external oblique muscle’s aponeurosis, with additional support from the internal oblique muscle, particularly on the lateral side.
- Posterior wall/ the floor, formed by the conjoint tendon ( the insertion point of the external and internal obliques muscles) most medial and transvesalis fascia lateral to it.
- Roof/ superior wall, formed by the arching fibers of internal obliques (IO) and transversalis fascia and transversus abdominis as an additional support. As IO begins from the lateral two-thirds of the inguinal ligament and the iliac crest, These fibers move upwards and then curve down and inwards across the canal.
- Inferior wall, formed mainly by the inguinal ligament, which extends from the hip bone’s front edge to the groin. Another additional support that include the lacunar ligament, branching off from the inguinal ligament, also contributes to the medial aspect of the floor. Additionally, the iliopectineal arch, part of the iliopsoas fascia, may provide lateral support.
- Deep/ lateral inguinal ring
Located above the midpoint of the inguinal ligament, lateral to the epigastric vessels, it considered as a defect in the transversalis fascia developed at embryology and terminates superolateral to the pubic tubercle by the superficial ring. When there are an increase in the intra-abdominal pressure the Internal Obliquis Muscle contracts making the canal taut.
- Superficial inguinal ring
The end of the inguinal canal found 1 cm superolateral to the pubic tubercle, it is a defect in the aponeurosis of the external obliques, this ring surrounded medially by rectus abdominis it’s (inferolateral border), laterally by inferior epigastric vessel, and medial inguinal ligament inferiorly forming a triangle called inguinal triangle that is a landmark of the superficial ring.
- Ilioinguinal nerve, lymph, and blood vessels in both sex.
- Spermatic cord and its coverings in the male
- Round ligament of the uterus in the female
- Direct hernia, protrusion of abdominal viscera through the posterior wall, it is acquired during adulthood.
- Indirect hernia, protrusion of abdominal viscera through the deep inguinal ring, the common type and represents about 50% and more liable to be congenital most common on the right side.
Inguinal endometriosis, in cases with inguinal canal stroma and ectopic endometrial glands.
Neoplasms, may develop from any structures of the canal.
Varicosities of round Ligament in females, and varicoceles in males.
Inguinal neuralgia, a common source of discomfort in the lower abdomen and upper thigh, arises primarily due to damage or injury of specific nerves these include; the ilioinguinal, iliohypogastric, and the genital branch of the genitofemoral nerve.
The treatment will depend on the problem or deficit to this area for more treatment interventions you can find:
- Tuma F, Lopez RA, Varacallo M. Anatomy, abdomen and pelvis, inguinal region (inguinal canal). 2023 July. StatPearls [Internet]
- Caserta NM, Penachim TJ, Contardi EB, Barbosa RC, Gomes TL, Martins DL. Contents of the inguinal canal: identification by different imaging methods. Radiologia Brasileira. 2021 Feb 3;54:56-61.
- About Medicine. 3D Tour of the Inguinal Canal.Available from: http://www.youtube.com/watch?v=XrUGnE_qf3w[last accessed 3/8/2021]
- Revzin MV, Ersahin D, Israel GM, Kirsch JD, Mathur M, Bokhari J, Scoutt LM. US of the inguinal canal: comprehensive review of pathologic processes with CT and MR imaging correlation. Radiographics. 2016 Nov;36(7):2028-48.
- Shadhu K, Ramlagun D, Chen S, Liu L. Neuralgia due to iliohypogastric nerve injury after inguinal hernioplasty: a case report. BMC surgery. 2018 Dec;18:1-3.