ABC of General Paediatric Surgery: INGUINAL HERNIA, HYDROCELE, AND THE UNDESCENDED TESTISBMJ 1996; 312 doi: https://doi.org/10.1136/bmj.312.7030.564 (Published 02 March 1996) Cite this as: BMJ 1996;312:564
- Mark Davenport
Clinical embryology and anatomy of the inguinal region
The testis is formed from coelomic epithelium and primordial germ cells in a longitudinal fold high on the posterior abdominal wall at a similar level to the developing kidneys. As gestation proceeds, the testis migrates down the posterior wall towards the deep inguinal ring, probably under the control of the hormone mullerian duct inhibitory factor. The gubernaculum, a condensation of mesenchyme, forms within the future inguinal canal and guides the testis through the layers of the body wall towards the scrotum. Two factors seem to be important in this second stage—the release of testosterone from the fetal testis itself and an intact genitofemoral nerve, which probably releases substances causing gubernacular contraction.
A tongue of the peritoneal cavity also precedes the migrating testis through the canal—the processus vaginalis. After birth this peritoneal communication should obliterate and disappear, but failure to do this may lead to two of the commonest problems of this region, hernias and hydroceles.
Anatomically these are virtually all indirect and often complete (that is, the sac comes all the way to the scrotum). Infantile hernias occur in about 1-2% of births and are much more common in premature babies than in full term infants. They appear as an intermittent, usually reducible, lump in the groin. The correct management is a surgical herniotomy when the child's condition allows. In most uncomplicated cases this should be within two or three weeks of diagnosis. Infant hernias should be referred to regional centres where appropriate anaesthetic and surgical support is available to allow early repair rather than waiting until an infant is old enough, perhaps over 1 year old, for it to be repaired locally.
Inguinal hernias in infants need early referral for surgery because of the high incidence of complications
Almost one third of …