Anatomical variations of the inguinal morphometric features in patients with inguinal hernia and its association with the type of inguinal hernia: a prospective clinical study

Background: Variations of inguinal canal and inguinal nerves are not uncommon. Knowledge about those variations is important to avoid inadvertent injury to the vital structures and to prevent recurrence.Methods: This prospective clinical study included all patients undergoing open inguinal hernia repair. Laparoscopic hernia repair, emergency surgery for complication and recurrent inguinal hernia were excluded. Parameters studied include interspinous distance, length and obliquity of inguinal ligament, attachment of conjoint tendon, condition of transversalis fascia and position and variations of ilioinguinal nerve.Results: The study included 192 patients. The mean interspinous distance (ISD) was 22±3.45 cm (CI: 30-32). ISD was not significant different among the two types of hernia. The mean length of internal oblique on inguinal ligament from anterior superior iliac spine was significantly longer in patients with indirect inguinal hernia (4±0.791 vs. 4.27±1.34; p=0.000). Significant patients in the direct hernia had weak transversalis fascia ((95% vs. 43%). 80% of the patients with direct hernia had defect in the transversalis fascia compared to only 8.8% in the indirect hernia. The difference is statistically significant. The nerve variation was present in only 1.3% in direct hernia group compared to 3.5% in the indirect hernia group.Conclusions: It was observed that the type of hernia did not significantly influenced by the length of inguinal ligament, the mean distance of midinguinal point, obliquity of the inguinal ligament. The nerve variation was present in only 1.3% in direct hernia group compared to 3.5% in the indirect hernia group.