What are the causes of hydrocele and varicocele?

Causes of Hydrocele and Varicocele

Hydroceles are primarily caused by an imbalance in fluid production and reabsorption between the layers of the tunica vaginalis, while varicoceles result from incompetent valves in the spermatic veins leading to venous reflux and dilation.

Causes of Hydrocele

Primary Causes

• Congenital: Incomplete involution of the processus vaginalis during fetal development 1

  • The processus vaginalis normally obliterates between 25-35 weeks of gestation
  • Failure of this process results in a patent processus vaginalis (PPV)
  • Most common in infants, with prevalence as high as 80% in term male infants 1

• Idiopathic: Imbalance between fluid production and reabsorption in the tunica vaginalis 2

  • Most common type in adolescents
  • Results from disruption in the normal equilibrium of serous fluid in the potential space between parietal and visceral layers

Secondary Causes

• Reactive: Inflammation from nearby structures 1

  • Can develop secondary to epididymitis or epididymo-orchitis
  • As inflammation progresses, a reactive hydrocele may develop

• Post-procedural: Complication following varicocele repair 2, 3

  • Higher risk with non-artery-sparing procedures
  • Procedures performed without microsurgical aid
  • Any surgery requiring cord dissection
  • Caused by lymphatic obstruction (confirmed by protein concentration in hydrocele fluid) 3

• Trauma: Injury to scrotal structures 1

Causes of Varicocele

Primary Causes

• Venous valve incompetence: Failure of valves in the internal spermatic vein 4

  • Results in retrograde blood flow
  • Leads to dilation of pampiniform plexus veins (>4mm)
  • Most commonly affects left side due to anatomical differences

• Anatomical factors: 4, 5

  • Left internal spermatic vein enters renal vein at a right angle
  • Longer venous path on left side
  • Compression of left renal vein between superior mesenteric artery and aorta ("nutcracker phenomenon")

Secondary Causes

• Venous obstruction: External compression of venous drainage 4

  • Can be caused by retroperitoneal masses
  • Renal tumors
  • Retroperitoneal fibrosis

• Multiple venous channels: Presence of collateral veins 5

  • External spermatic veins
  • Gubernacular veins
  • These collaterals can cause recurrence after treatment

Relationship Between Hydrocele and Varicocele

• Post-varicocelectomy hydrocele: A common complication of varicocele repair 6, 2, 7

  • Occurs in up to 30% of cases after conventional varicocelectomy
  • Caused by disruption of lymphatic drainage during surgery
  • Can be prevented by lymphatic-sparing techniques:
    • Microsurgical approaches
    • Methylene blue mapping of lymphatic vessels
    • Percutaneous embolization (completely avoids lymphatic channels)

• Diagnostic considerations: Both conditions can present with scrotal swelling 1

  • Ultrasound with color Doppler is essential for differentiation
  • Hydrocele appears as anechoic fluid collection surrounding testis
  • Varicocele shows dilated, tortuous veins with reversed flow on Valsalva

Clinical Implications

• Hydrocele management: 2

  • Observation for congenital hydroceles (most resolve by 18-24 months)
  • Surgical repair (hydrocelectomy) for persistent or symptomatic cases
  • Post-varicocelectomy hydroceles may initially be managed with observation or aspiration

• Varicocele management: 4

  • Treatment indicated for pain, testicular size discrepancy, or infertility
  • Options include microsurgical varicocelectomy or endovascular embolization
  • Lymphatic-sparing techniques recommended to prevent hydrocele formation

Understanding these distinct but sometimes related pathologies is essential for proper diagnosis and management of scrotal swelling.