A varicocele is an abnormal tortuosity and dilation of the testicular veins and the pampiniform venous plexus of the spermatic cord.


  • Rare in prepubertal boys, increases with age to approximately 15% in late adolescence and healthy adult population
    • 2 to 10 years old, <1%
    • 11 to 14 years old, 7.8%
    • 15 to 19 years old, 14.1%
  • Based on World Health Organization observational study (1992), 15–20% of adult varicocele patients have fertility problems.
    • Varicocele presents in 25% of men with abnormal semen analysis and 12% of men with normal semen parameters.
    • Present in 35–40% of males with primary infertility
  • Left-sided predominance, 90%
  • No racial predilection

Risk Factors

  • Exact mechanisms have not been fully elucidated.
  • May be related to physiologic changes in puberty, such as rapid testicular growth and increased testicular blood flow
  • Associated with increased height and low body mass index
  • Increased risk in 1st-degree relatives of patients with a varicocele


  • Association between varicocele and testicular dysfunction/fertility compromise
    • Impaired spermatogenesis: decreased motility, decreased density, and increased number of pathologic sperm forms; decreased total sperm count
  • Ipsilateral testicular hypotrophy
    • Recent data demonstrates correlation between varicocele grade and testicular hypotrophy although not observed in prior studies.
    • Testicular “catch-up growth” can be seen after varicocelectomy.
    • Catch-up growth can all be seen in 30–50% of patients managed conservatively.
  • Potentially caused by an embryonic field defect, affecting growth of bilateral testicles
  • Exact mechanisms not clearly elucidated—multiple theories:
    • Hyperthermia: Varicocele increases intratesticular temperature, likely by interfering with the pampiniform plexus’ ability to provide countercurrent cooling system.
    • Potential reflux of renal and adrenal metabolites, potentially causing testicular damage
    • Increased production of nitric oxide and reactive oxygen species correlate with severity of varicocele.
    • Endocrine abnormalities are found in subset of patients with varicocele, including low testosterone, abnormal response to gonadotropin-releasing hormone (GnRH), and impaired Leydig cell function.


Associated with anatomy of left testicular vein

  • Inserts into renal vein at right angle (right testicular vein drains into vena cava)
  • Incompetent or absent valves
  • Left testicular vein 8 to 10 cm longer than right, with increased pressure
  • Increased venous pressure from “nutcracker phenomenon”: compression of left renal vein as it passes between aorta and superior mesenteric artery

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