**3.6 Spigelian hernia**

A Spigelian hernia is relatively rare, but more often diagnosed since the introduction of CTscan and laparoscopy. The Spigelian hernia occurs along the semilunar line at the level of the absence of the posterior rectus sheath (semicircular line, below the umbilicus). Almost all Spigelian hernias are interparietal due to the intact external oblique aponeurosis covering the hernia. A large Spigelian hernia is most often found laterally and inferior to its defect in the space directly posterior to the external oblique muscle.

The Spigelian hernia has different factors of etiology (Lange & Kleinrensink, Surgical Anatomy of the Abdomen, Elsevier gezondheidszorg, 2002):


Clinical diagnosis of a Spigelian hernia is challenging, but imaging with ultrasonography or CT-scan will confirm the presence of the hernia. Up to 20% of Spigelian hernias present incarcerated and therefore elective repair is indicated when diagnosed. The technique of laparoscopic repair is similar to other ventral hernia repairs. Compared to open repair, laparoscopic repair of Spigelian hernias is associated with a decreased morbidity, shorter hospital stay and low recurrence rate (Moreno-Egea et al., 2002).
