Inguinal hernias

with thanks to Dr Jemma Say for putting the following information together:

Inguinal Hernias

An indirect inguinal hernia is a protrusion of abdominal contents into the inguinoscrotal or labial canal via an open deep inguinal ring due to the failure of obliteration of the processus vaginalis.

 In fetal life the descent of the testis into the inguinal canal and scrotum is preceded by a small pouch of peritoneum; the processus vaginalis. After birth this peritoneal communication is obliterated, failure to do so results in either a hydrocele or hernia, depending on the degree of fusion.  

 Indirect hernias are more commonly seen in a paediatric population, as opposed to direct inguinal hernias in adult patients, where the musculature is weak and abdominal contents protrude through the wall of the inguinal canal.


The incidence is 1-2%, occurring 9 times more commonly in males. The majority are found on the right (60%), 15% are bilateral, more commonly with a family history. Presentation is most frequently in infancy.

Increased Incidence

  • Preterm infants (10-30%)
  • Abdominal wall defects (e.g. prune belly syndrome)
  • Connective tissue disorders (e.g. Ehlers Danlos syndrome)
  • Chronic respiratory disease
  • Undescended testes
  • Increased intraabdominal pressure


The diagnosis is clinical, although USS can play a role in older children with indeterminate pain. Surgery is indicated for all paediatric patients with inguinal hernia.

The risks of not performing surgery include bowel incarceration or necrosis, and testicular or ovarian compromise and necrosis. This risk is greatest in early infancy; premature infants have an incarceration risk of up to 30%, and therefore often warrant treatment prior to discharge.  Some surgeons keep under close review for a few weeks post discharge so that these still very small babies put on a bit of weight before the operation.

If a patient presents with incarceration, an attempt at reduction should be made and urgent surgery is required, as the risk of reincarceration is as high as 15% if surgery is delayed more than 5 days.

Referral Pathway

All inguinal hernias should be referred, paediatric patients >1 year can be referred to Mr Brearley at Whipps Cross while those <1 should be referred to the Royal London Hospital. Surgery involves either open or laparoscopic techniques (tranperitoneal or preperitoneal approaches). The majority are performed as an outpatient with normal activity resuming within 48 hours.


IPEG guidelines for Inguinal Hernia and Hydrocele, Nov 2009.

Ashcraft’s Paediatric Surgery, Holcomb G W, Murphy. J P

ABC of General Paediatric Surgery: Inguinal hernia, hydrocele and the undescended testis: BMJ 1996 312:564

Patient Information Leaflets

Video information

Distinguishing indirect and direct inguinal hernia

Indirect inguinal hernia repair


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