A Study of the Clinical Manifestation of Subclinical Inguinal Hernias

抄録

Contralateral inguinal hernias that occur after inguinal hernia repair may include so-called subclinical inguinal hernias (SIH). These latent hernias are not accompanied by symptoms such as swelling. However, few studies have investigated the prevalence and incidence of SIH using imaging. This paper documents a study of SIH incidence detected on hernia studies and risk factors for the clinical manifestation of SIH. These hernia studies comprised computed tomography images obtained prior to inguinal hernia repair with the patient in a prone position to decompress the inguinal region. Our subjects were 77 patients diagnosed as having a contralateral asymptomatic SIH before inguinal hernia repair between January 2006 and December 2015. Clinical manifestation occurred in 27.3% (21 patients), and the 5-year incidence was 23.3%. We investigated risk factors and found that the size of the hernia that was surgically repaired first was a significant factor (mean value of 157.6 cm³ in the incidence group and 77.8 cm³ in the non-incidence group; p=0.029). We also found that the cut-off value for hernia size on the symptomatic side was 44.5 cm³; above this value, the 5-year incidence was 32.5% (13 patients), whereas below it, the incidence was 13.5% (5 patients) (p=0.0205). SIH incidence is relatively high, and patients with large symptomatic hernias tend to experience clinical manifestation of contralateral SIH. We therefore believe that careful follow-up should be performed, and single-stage or early surgery should be considered.