Congenital bilateral inguinal hernia, complete on one side, with postoperative hydrocele formation

Clinical History

The patient was admitted to the outpatient department of Paediatric Surgery clinic with bilateral inguino-scrotal swelling which was more prominent on the right. On the right, the swelling was permanent. On the left, the swelling was reducible, intermittent and induced by increase of intra-abdominal pressure (i.e. coughing or crying).

Imaging Findings

The patient underwent ultrasonography of groins and scrotum which revealed congenital bilateral bowel-containing inguinal hernias, with the right being complete (inguino-scrotal). There was bilateral hydrocele and both testes and their epididymides were normal in size, shape, location and echogenicity. (Fig. 1-3)
As reduction by manipulation was not possible on the right side, surgical treatment was performed with conventional open approach.
Two months post-operatively, follow-up ultrasonography revealed bilateral hydrocele. However, the inguinal canals on both sides were normal in width. Both testes were intrascrotal with normal blood flow signals on power Doppler. (Fig. 4-7)

Discussion

Hernias and hydroceles consist commonly encountered problems of routine paediatric practice. Embryologically, these disorders stem from the inability of the processus vaginalis to fully obliterate during the descent of testes. Inguinal hernias (IH) are usually indirect in neonates. [1, 2] The incidence of IH is 4.4% but higher in premature infants and when intraabdominal pressure is increased. [2] IH is located on the right in 60% of patients due to the fact that the right processus vaginalis obliterates after the left. 10% of IH are bilateral while a reported 5-20% of patients with clinically detected unilateral IH have a contralateral patent processus vaginalis, visible on ultrasonography. Bilateral IHs affect more frequently high risk prematures and low birth-weight neonates. [2]
While most IH are easily diagnosed clinically, ultrasonography is useful in evaluation of scrotal enlargement of unknown cause as it can differentiate IH from other diseases. [3]
An IH may contain fluid, peristalting small bowel loops and colon. When IHs contain omentum, they present as a complex hyperechoic mass on ultrasound. [2]
When diagnosing inguino-scrotal hernias, ultrasonography is 94.9% accurate, 85.7% specific and 95.4% sensitive while physical examination alone is 87.7% accurate. Even occult IHs can be diagnosed if 4 mm is used as the upper limit of the diameter of the internal inguinal ring. [4, 5]
Surgery is necessary to avert incarceration or strangulation of the contained bowel and to protect testicular blood flow and function from the pressure of the IH on the spermatic vessels. It is reported that an ischaemic testis in infants younger than 6 months of age, is statistically significantly larger compared to the contralateral on ultrasonography. [2, 6]
The urgency of the operation depends on the type of hernia and the likelihood of incarceration as an incarcerated inguinal hernia in infancy may cause testicular infarction. [1, 7]
Surgical manipulations during the conventional open hernia repair technique may cause temporal but not significant changes in PSV and RI on colour Doppler. [8]
Post-operative complications include testicular atrophy and necrosis (due to ischaemia), recurrence, iatrogenic ascent of the testis, hydrocele and ugly scars. Testicular atrophy criteria include RI>0.7 and 75% reduction of the testicular volume. Postoperative hydrocele occurs commonly and originates from continuing secretion of fluids. The quantity of fluid is usually small and resolves spontaneously after a few weeks. The frequency of postoperative hydrocele depends on the type of surgery, being 2.4% for laparoscopic and 5.4% for open technique. [9, 10]

Differential Diagnosis List

Final Diagnosis

Congenital bilateral inguino-scrotal hernia with postoperative hydrocele formation.

URL:	https://www.eurorad.org/case/11559
DOI:	10.1594/EURORAD/CASE.11559
ISSN:	1563-4086