An accurate conception of the anatomic relations of the inguinal region in its normal condition and again when a hernia is present is essential to the surgeon. The inguinal canal as we find it during the course of an operation differs somewhat from that as we know it from our dissections.
Normally there is no inguinal canal after the test is has descended into the scrotum. Even prior to the migration of the testis from its position just below the kidney to the inguinal canal, the latter contains a pouch or diverticulum of peritoneum which is the vaginal process.
If the testis remains in the inguinal canal or even in ihe upper part of the scrotum (just outside the external abdominal ring) this pouch remains open and a hernia results in the majority (50 per cent.) of cases of undeseended testis.
EISENDRATH DN. THE ANATOMY AND RADICAL CURE OF INGUINAL HERNIA.. JAMA. 1904;XLIII(11):721-726. doi:10.1001/jama.1904.92500110001c