Background/purpose: History taking and physical examination alone no longer meet the surgeon's need in the diagnosis of inguinal hernia. Ultrasonography (US) provides a good and safe diagnostic tool for inguinal hernias in boys.
Methods: From 1995 to 1997, 244 boys with inguinal hernias (41 bilateral and 203 unilateral), received preoperative US on both groins to confirm the diagnosis. Those with positive US findings, such as viscera or fluid in inguinal canal or widening of the internal inguinal ring, underwent surgery.
Results: The accuracy of diagnosis with US and clinical assessment were 97.9% and 84%, respectively. More than 95% of widening of internal inguinal rings (>4 mm) proved to be hernias. There were two direct inguinal hernias and two femoral hernias, which were misdiagnosed by clinical examination, but proved to be diagnosed correctly by US.
Conclusions: US serves as a noninvasive and highly accurate diagnostic tool for inguinal hernias in boys. Using 4 mm as the upper limit of the normal diameter of the internal inguinal ring, an occult inguinal hernia can be easily detected before surgery.