Spigelian hernia: CT findings and clinical relevance.

OBJECTIVE: The purpose of our study was to evaluate the clinical relevance of preoperative CT in distinguishing between the two subtypes of spigelian hernia (SH).

MATERIALS AND METHODS: We reviewed retrospectively the CT images of 35 patients. The patients were divided into two groups on the basis of the SH subtype: interstitial SH group (n = 15) and subcutaneous SH group (n = 20). Clinical characteristics of patients and CT findings were analyzed. Bowel ischemia on surgery was also noted.

RESULTS: Sixteen right hernias and 19 left hernias were observed. Fifteen interstitial SH (43%) and 20 subcutaneous SH (57%) were found. No type of content showed a statistically significant association with one or other subtype of SH. Nine of the 26 patients presenting with SH with SB content showed signs of SBO on CT. Closed-loop SBO on CT was present in 5 of the 26 patients with SB content. An interstitial SH was observed in all of these 5 patients (p = 0.039). Surgery was performed on 10 patients. Bowel ischemia was found on surgery in 4 patients and showed no statistically significant association with a particular subtype of SH (p = 0.6).

CONCLUSION: Our study shows the importance of performing CT in SH. CT provides the diagnosis of SH, shows SH content, and demonstrates the presence of SBO or closed-loop SBO. Moreover, the distinction between the two subtypes of SH on CT appears to be of clinical relevance since closed-loop SBO is statistically associated with interstitial SH and the optimal surgical approach may differ.