Hydrocele

Hydroceles are fluid collections within the tunica vaginalis of the scrotum or along the spermatic cord. The tunica vaginalis is the serous space that surrounds the testis.

Hydroceles need to be fully investigated if there is any suspicion of an underlying cause. In children, most hydroceles are communicating type, in which patency of the processus vaginalis allows peritoneal fluid to flow into the scrotum. Non-communicating hydroceles are caused by excessive fluid production within the tunica vaginalis.¹

• Clinically apparent scrotal hydrocoeles are evident in 6% of term males beyond the newborn period
• Most paediatric hydroceles are congenital, but rarer causes include malignancy and infection
• Hydroceles presenting in adults may be secondary to orchitis, epididymitis, tuberculosis, torsion, testicular tumours, trauma, following renal transplantation and post-radiation therapy.²

• Scrotal enlargement with a non-tender, cystic swelling
• Pain is not a feature unless the hydrocoele is infected or if there is pain from an underlying cause
• The testis is usually palpable but may be difficult to palpate if the hydrocele is large
• A hydrocele lies anterior to and below the testis and will transilluminate.

Other causes of scrotal swelling:

• Hernia: bowel in the scrotum may transilluminate. Inguinal hernias may be associated with a hydrocele on the same side
• Tumours of the testis or spermatic cord: testicular teratomas may present with a cystic mass that may transilluminate. Adults with testicular tumors may present with new-onset scrotal swelling.
• Epididymo-orchitis: a reactive hydrocele may occur in association with testicular infection
• Epididymal cyst: will usually transilluminate but lies posterior to and above the testis, within the epididymis
• Varicocele
• Fournier's gangrene: necrotizing fasciitis of the scrotal skin and penis that is usually associated with an acute unilateral group A streptococcus infection of the tunica vaginalis. Ultrasound of scrotum may show gas in the wall of the scrotum. It is treated by intravenous antibiotics and excision of necrotic tissue.
• The hydatid of Morgagni: is a small cystic remnant at the upper pole of the testis.

Investigations are not required for simple hydroceles but are essential if there is any doubt in the diagnosis or any suggestion of an underlying cause. Failure to clearly delineate the testis, tenderness on palpation or internal shadows on transillumination are all indications for further investigation:

• Ultrasound can help to determine if any underlying pathology is present. Spermatoceles can be clearly distinguished
• Duplex sonography may provide information about testicular blood flow when a hydrocoele may be associated with chronic torsion of the testis.¹
• Diagnostic aspirations should be avoided as they may lead to the spread of malignant cells
• Serum alpha-fetoprotein and human choriogonadotropin levels help to exclude malignant teratomas or other germ cell tumours.

• Many newborn hydrocoeles resolve before the age of 1 year and so observation is usually appropriate for hydroceles in infants
• Once underlying pathology has been excluded, adults with non-communicating hydroceles can be managed conservatively, with reassurance and a scrotal support
• Therapeutic aspiration
• An exploratory operation is required if the diagnosis is uncertain or underlying pathology cannot be excluded. Other indications for operation are if the hydrocoele is large and uncomfortable, becomes infected or repeatedly reaccumulates after aspiration.
• Surgical removal of a hydrocele can be performed by either:¹
  • Inguinal approach with ligation of the processus vaginalis high within the internal inguinal ring. This is the procedure of choice for paediatric communicating hydroceles. An inguinal approach is essential if a testicular tumour has been identified pre-operatively, or is a possibility.
  • Scrotal approach with excision or eversion and suturing of the tunica vaginalis. Recommended for chronic non-communicating hydroceles.

• Infection is uncommon
• Complications of operation:
  • Infertility may occur with bilateral injury to the vas deferens
  • Testicular atrophy may occur due to injury to the testicular blood supply
  • Haematoma
  • Temporary or permanent ilioinguinal or genitofemoral nerve injury due to entrapment or division during inguinal approaches
  • Secondary cryptorchidism due to excessive scar formation
  • Recurrence of the hydrocele after inguinal approaches is usually reactive and resolves within several months.

• The prognosis is dependent on the presence of any underlying cause
• Most congenital hydroceles resolve by the end of the first year of life.