Diagnosis of inguinal hernia by prone- vs. supine-position computed tomography.

PURPOSE: The aim of this study was to investigate the efficacy of prone-position computed tomography (CT) for detecting and classifying inguinal hernia relative to supine-position CT before laparoscopic inguinal hernia repair.

METHODS: Seventy-nine patients who underwent laparoscopic transabdominal preperitoneal repair of inguinal hernia were enrolled in this prospective study. Patients diagnosed with inguinal hernia by physical examination underwent abdominal CT in the supine and prone positions for preoperative assessment. The anatomy of the right and left inguinal regions was confirmed during the surgery and compared with the preoperative CT findings.

RESULTS: The 79 cases included 87 operated lesions and 71 non-operated contralateral inguinal sites. Of the 84 clinical hernias, inguinal hernia was detected significantly more frequently on prone-position CT images (84, 100%) than on supine-position CT images (55, 65.5%). In addition, the inguinal hernia type was determined with significantly greater accuracy on prone-position CT images (96.4%) than on supine-position CT images (58.3%). Twenty-two occult hernias were detected by laparoscopy. The detection rate and accuracy for determining the type of occult hernia were significantly greater when using prone-position CT images [19 of 22 lesions (86.4%) and 77.3%, respectively] than when using supine-position CT images [8 of 22 lesions (36.4%) and 27.3%, respectively].

CONCLUSIONS: Prone-position CT is adequate for detecting and classifying inguinal hernia and for evaluating occult hernia.