Paediatric inguinal hernias are caused by the persistence of the peritoneal lining as it descends down the inguinal canal, leaving a patent processes vaginalis (PPV), which usually closes by 12 months of age. If the PPV is wide enough, it may allow intra-abdominal contents such as bowel, omentum or ovary, to descend into the inguinal canal or below, resulting in a hernia.
The child will present with an inguinal lump that feels soft and squelchy. To elicit the hernia, asking the child to strain or jump may help demonstrate the bulge if it is not initially present.
To reduce a hernia, wait until the child is relaxed and use gentle, concentric pressure with both hands and all 10 fingers. This can sometimes require a minute or so of gentle pressure. The hernia may pop out again quickly, but if it remains easily reducible it can be dealt with electively.
In boys it is important to ensure that the testis is palpable below the hernia (an undescended testis in the inguinal canal can sometimes be mistaken as an irreducible hernia). While an ultrasound can be diagnostic, its surgical use is limited to cases where there is clinical uncertainty.
Irreducible hernias require emergent review, as incarceration and strangulation can compromise both bowel and gonads. Beware overlying skin erythema, abdominal distension with bilious (green) vomiting or an unwell child.
The requirement to perform contralateral repair for the approximately 5% chance of a contralateral hernia developing should be considered against the risks. Laparoscopy or hernioscopy can assess the contralateral ring to guide this decision, and occasionally laparoscopic repair may be preferable to open repair.
Hydrocoeles
The presence of a PPV in a male with only a small opening allows intraperitoneal fluid to drain down into the scrotum surrounding the testes and occurs in 98% of boys at birth. More than 95% of cases will spontaneously resolve by one year of age and so repair should not be considered until well after then. The hydrocoele is often soft and easy to drain. Both testes should be palpated to ensure they are symmetrical.
Occasionally, a hydrocoele is tense and not drainable, or they can appear as a cystic lesion above the testes but within the cord structures (encysted hydrocoele). In these cases, or if the diagnosis is unclear, imaging with ultrasound may be appropriate. If there is any concern about underlying torsion (especially pain, tenderness or overlying erythema) then the family should be referred urgently with the child fasting to an emergency department with paediatric surgical services. A simple hydrocoele should otherwise be given the chance to resolve spontaneously with consideration for repair if it persists or reappears beyond two years of age.
Undescended testes
While 3% of boys will be born with undescended testes (UDT), a testis may continue to descend towards the base of the scrotum until three months of age, and only one percent of all boys will go on to require repair. It is ideal to repair an UDT soon after six months of age to aid in germ cell maturation and decrease the risks of trauma, torsion and malignancy.
The most common misdiagnosis is retractile testes. All boys have a cremasteric reflex that retracts the testes superiorly when they are cold or threatened (including an examining doctor or ultrasound probe!). In most cases, the testes can be milked down into the scrotum where they should stay without any tension (they shouldn’t spring back up like they are attached to an elastic band).
The examination involves using two hands and the pulps of all fingertips to gently sweep down over the inguinal region, one hand at a time repeatedly, from superior-laterally towards the scrotum until the testis is felt or delivered into the scrotum (using soap or lubricant can help this technique). If a testis is quite retractile annual review is recommended as there is a 5% chance that it may ‘ascend’ and become maldescended needing repair.
An impalpable testis may be intrabdominal, or may have undergone a perinatal torsion event, and elective surgical review and intervention will likely be required.
Key messages
- The diagnosis for common inguino-scrotal pathologies in children is usually made clinically
- The timing and age for referral and surgical correction depends on the indication, with some conditions able to be initially observed for resolution
- Beware the tender testes (either scrotal or inguinal), especially with erythema, that may be a torsion event and need urgent review and management by a surgeon.
Author competing interests – nil