Hydrocele

Definition

Epidemiology

• Affects roughly 1% of adult men.
• More than 80% of newborn boys have a patent processus vaginalis at birth, but it closes spontaneously in most by 18 months of age (Bailey and Love's Short Practice of Surgery, 28th ed.).

Pathophysiology and embryology

Classification (Bailey and Love)

1. Communicating (congenital) hydrocele - a patent processus vaginalis allows peritoneal fluid to flow into the scrotum; associated with indirect inguinal hernias.
2. Non-communicating (vaginal) hydrocele - the processus vaginalis is closed; fluid accumulates due to excess production or impaired lymphatic absorption by the tunica vaginalis. If no cause is found, these are termed "primary" hydroceles - the most common type worldwide.
3. Encysted hydroceles of the processus vaginalis - the distal end closes normally but a mid-portion remains patent:
   • If the proximal end stays open and communicates with the tunica vaginalis -> "infantile hydrocele"
   • If the proximal end is closed -> "hydrocele of the cord"

Clinical features

• Painless, smooth, cystic scrotal swelling that transilluminates (a hallmark diagnostic sign).
• The testis is usually not separately palpable because it is surrounded by fluid.
• Can be unilateral or bilateral; congenital forms may fluctuate in size with position/activity (communicating with the peritoneal cavity).

Diagnosis

• Clinical exam plus transillumination is often sufficient.
• Scrotal ultrasound is used to confirm the diagnosis, exclude underlying testicular pathology (tumor, torsion, epididymo-orchitis), and characterize communicating hydroceles.

Management

• Congenital/infantile hydroceles: usually observed, since most resolve spontaneously as the processus vaginalis closes (often by 12-18 months); if persistent beyond ~1-2 years or associated with a hernia, surgical repair (herniotomy/ligation of the processus vaginalis) is indicated.
• Adult primary hydroceles:
  • Small, asymptomatic hydroceles can be observed.
  • Symptomatic or large hydroceles are treated with hydrocelectomy (surgical excision/eversion of the sac), which has lower recurrence rates than other options.
  • Aspiration and sclerotherapy is a less invasive alternative, particularly for patients who are poor surgical candidates.
• Secondary hydroceles: treat the underlying cause (infection, tumor, torsion); avoid needle aspiration if malignancy is suspected.
• Postoperative hydrocele is also a recognized complication after varicocelectomy (average incidence ~7%, range 3-33%), caused by lymphatic obstruction; use of microsurgical/magnified technique to preserve lymphatics greatly reduces this risk (Campbell-Walsh-Wein Urology).

Recent evidence (for awareness)