The incidence and analysis of ipsilateral occult hernia in patients undergoing hernia repair: a single institution retrospective study of 1066 patients

BACKGROUND: Misdiagnosis or failure to intraoperatively detect occult hernia in the inguinal region can lead to the recurrence of postoperative hernia and the appearance of local pain symptoms, which affect the patient’s quality of life and make it difficult to reperform hernia repair. METHODS: This study included 1066 inguinal hernia patients who underwent surgical treatment at Shanghai Tongren Hospital between January 2016 and October 2018 to investigate ipsilateral occult hernia epidemiology, to analyze the characteristics of ipsilateral occult hernias with regards to patient age, gender, classification and anatomical site, and to explore the superiority and inferiority of the expert hernia surgeons/ non-expert hernia surgeons group and of operation methods in finding occult inguinal hernias. RESULTS: The incidence of ipsilateral occult hernia in the surgical population was 8.26%. Ipsilateral occult hernia included indirect inguinal hernia, direct inguinal hernia, femoral hernia, obturator hernia, and spigelian hernia, among which the highest incidence was direct inguinal hernia (4.11%), followed by indirect inguinal hernia (2.45%). There was no difference in the incidence of ipsilateral occult hernia between males and females, but there were significant differences in the incidence of ipsilateral occult hernia, which decreased gradually with increasing age in patients younger than 70 years-old; there was no difference in incidence in patients over 70 years-old. There were significant differences in the incidence of ipsilateral occult hernia in the bilateral inguinal region between direct and femoral hernia, with the higher incidence found on the right side; in contrast, there was no difference in the incidence of indirect inguinal hernia in the bilateral inguinal region. There was no difference in the ability of experienced physicians to detect ipsilateral occult inguinal hernias, either professionally or by surgery. CONCLUSIONS: Ipsilateral occult inguinal hernia has a higher incidence in patients with inguinal hernia, especially older patients; therefore, it is necessary for experienced surgeons to carefully detect for possible occult hernia during the operation and in elderly patients.