A varicocele is a group of enlarged, varicose veins in the scrotum. Approximately 15 percent of the general male population has a varicocele, and as many as 35 to 40 percent of men who are being evaluated for infertility have one. Varicocele is the most surgically correctable cause of male factor infertility. It also causes persistent scrotal discomfort in a significant number of affected men, often under-recognised as a specific, treatable cause rather than just an unexplained ache.
Many men with varicocele have mild or no symptoms, and may have the condition indefinitely without it causing meaningful problems. Varicocele is a condition where timely surgical correction can reverse testicular damage, improve semen quality, restore hormonal function and alleviate discomfort, for a significant subset, especially those with testicular shrinkage, difficulty conceiving or persistent scrotal pain that is worse with standing or exercise.
A varicocele is an abnormal dilation and tortuosity of the pampiniform venous plexus, the network of small veins that drain blood from the testis and travel upward through the spermatic cord. Usually these veins drain well against gravity, with the help of one-way valves that prevent blood from pooling backwards. Valvular incompetence permits reflux of blood from the internal spermatic vein. Blood flows downward under hydrostatic pressure and engorges the veins around the testis and over time progressively dilates them until the typical cluster of enlarged tortuous scrotal veins is formed.
The principal inconvenience of varicocele is the heat which it occasions in the scrotum. This is why the testes are positioned outside the body cavity . Normal sperm production requires a temperature in the testes that is about two to three degrees Celsius lower than the temperature in the core of the body . The testis is cooled by the normal countercurrent heat exchange mechanism in the spermatic cord. Varicocele hinders this process by bringing the testis in close proximity to a large volume of warm venous blood which chronically elevates the temperature of the scrotum and inhibits sperm production and testosterone synthesis. Grading of varicocele reflects clinical severity:
| Grade | Clinical Finding | Doppler Finding | Significance |
| Subclinical | Not palpable or visible even with Valsalva | Reflux detected on Doppler ultrasound only | Controversial whether to treat; monitored |
| Grade 1 | Palpable only during Valsalva manoeuvre (bearing down) | Reflux on Doppler; small veins | Mild; treat if symptomatic or causing infertility |
| Grade 2 | Palpable at rest without Valsalva | Reflux confirmed on Doppler | Moderate; treat if symptomatic or causing infertility |
| Grade 3 | Visible through scrotal skin without palpation or Valsalva | Clear reflux; dilated veins > 3 mm | Significant; associated with greater testicular damage risk |
Primary varicocele is varicocele without any identifiable underlying cause, due to intrinsic valvular incompetence of the internal spermatic vein. This is the most common type by far and accounts for the vast majority of cases of varicocele. It is usually seen during or after puberty when the increased blood flow to the developing testis produces greater hydrostatic pressure than can be accommodated by borderline valvular competence. Primary varicocele is almost always left-sided or bilateral for anatomic reasons discussed below.
Secondary varicocele is caused by an external factor that increases the pressure in the veins draining the spermatic vein system. This is most commonly due to compression or blockage of the left renal vein by an abdominal or retroperitoneal mass, most severely a left renal cell carcinoma. Features that should prompt work-up for a secondary cause include a right-sided or bilateral varicocele in an older adult, a rapidly developing varicocele, and a varicocele that does not decompress in the supine patient. The first line of treatment for secondary varicocele should be directed at the underlying cause either with or prior to varicocele specific management.
Approximately 90 percent of clinically diagnosed varicoceles are left-sided. The left testicular vein enters the left renal vein at a right angle, resulting in a higher resistance to hydrostatic pressure than the right testicular vein, which enters the inferior vena cava directly at a more favourable angle. Anatomical asymmetry makes the left-sided valves much more liable to incompetence under physiological venous pressure, which accounts for the strong left-side predominance. An isolated right-sided varicocele is uncommon and should be investigated as above to rule out a secondary cause.
Approximately 20 to 30 percent of men with clinical varicocele will have bilateral varicocele . Bilateral varicoceles tend to be of a dominant left-sided grade with a smaller right-sided varicocele. Bilateral varicocele has been found to have a greater impact on sperm production than unilateral disease, as both testis are subjected to chronic heat stress. In men presenting for evaluation of infertility, scrotal Doppler ultrasound should be performed with specific attention to both sides, as right-sided varicoceles may be clinically subtle and only detectable with ultrasound examination.
Subclinical varicocele is not palpable or visible on clinical examination but is diagnosed by colour Doppler ultrasound showing venous reflux in the spermatic veins on Valsalva manoeuvre. The question of whether subclinical varicocele affects testicular function and whether treatment of the varicocele improves semen parameters or fertility outcomes is still a matter of debate in the urological literature. The treatment decision is based on the clinical context, including the findings of semen analysis, testicular volume assessment and fertility status and most recent guidelines do not recommend the treatment of the subclinical varicocele in isolation.
Most varicoceles are asymptomatic and are found incidentally on fertility evaluation or routine examination. However, the following signs require specific assessment of varicocele and should not be attributed to non-specific causes without investigation.
Dull Aching Pain or Heaviness in Scrotum
Varicoceles are caused by anatomical predispositions combined with a functional valvular incompetence of the testicular venous drainage system.
No , not every varicocele requires surgical correction . Asymptomatic varicocele in a man with normal semen analysis and not actively trying to conceive does not require treatment, but periodic monitoring is reasonable. Treatment indications are: clinical varicocele with abnormal semen analysis in a man trying to conceive or planning future fertility; clinical varicocele with progressive testicular atrophy; clinical varicocele causing persistent pain significantly affecting quality of life; or clinical varicocele with hypogonadism in which other causes have been excluded. The decision is individualised to the specific clinical situation of the patient, the fertility goals and symptom burden.
Meta-analyses published consistently show that microscopic varicocelectomy results in a statistically significant and clinically relevant improvement in sperm concentration, motility and morphology in men with clinical varicocele and preoperative semen abnormalities. The rate of pregnancy in men who have undergone a varicocelectomy is about 30 to 50 percent naturally over one to two years after surgery in appropriately selected couples, and compares favourably with the outcome of proceeding directly to assisted reproduction without treating the varicocele first. The degree of improvement is individual and depends on the pre-operative semen parameters, the testicular function reserve and if any female factor also contributes to the couple’s infertility. Not all men with varicocele and abnormal semen will show improvement after surgery. Careful patient selection and realistic outcome counselling before surgery are important.
Microsurgical varicocelectomy is the gold-standard surgical technique for varicocele repair. It is performed through a small subinguinal incision with the aid of an operating microscope that magnifies eight to fifteen times. The optical magnification enables the surgeon to accurately identify and ligate all dilated spermatic veins (usually ten to twenty or more on each side) and reliably preserve the critical structures that run within the spermatic cord: the testicular artery, lymphatics and vas deferens. Testicular atrophy due to damage to testicular artery, scrotal oedema due to failure in preservation of lymphatics, obstructive azoospermia due to injury of vas. The lowest recurrence rate (around one percent), lowest complication rate and highest post-operative improvement in semen parameters are seen with microscopic varicocelectomy when compared with open high ligation or laparoscopic varicocelectomy.
The time course of a complete spermatogenic cycle (about 72 to 74 days) is followed in the improvement of semen quality after microscopic varicocelectomy. 3 months after surgery typically show significant improvement in semen parameters on semen analysis with progressive further improvement over the next 3 to 6 months. Most studies evaluate outcomes at 6-12 months postoperatively, at which time the greatest benefit is usually seen. Therefore patients should have realistic expectations that semen analysis at six weeks post-operatively will not yet reflect the benefit of surgery and should plan the three month and six month post-operative semen analyses with their treating urologist.
Yes , varicocele affects spermatogenesis and Leydig cell function and a proportion of men with varicocele have low testosterone levels as a consequence . The Leydig cells responsible for testosterone synthesis are disrupted by the same heat stress and oxidative damage from venous reflux that impairs sperm production. A number of studies have shown that successful varicocelectomy increases testosterone levels in hypogonadal men with varicocele, sometimes significantly and comparable to the improvement from testosterone replacement therapy, but without its side effects, including suppression of spermatogenesis. Varicocele should be specifically screened for as a possible cause in any man with hypogonadism of unknown cause, especially when surgical correction has the potential of restoring testosterone and preserving fertility potential.
The primary varicocele itself is not associated with cancer and is a benign condition. However, it is important to recognise that secondary varicocele, especially a new-onset right-sided varicocele, a rapidly developing varicocele, or one that does not decompress on lying flat, can be the presenting sign of a left renal cell carcinoma or retroperitoneal mass compressing or invading the renal vein. Hence, suitable imaging is mandatory in all atypical presentations of varicocele to exclude secondary aetiology. A primary varicocele occurring in the typical pattern, left-sided, gradually progressive in a young or middle-aged man, which decompresses with recumbency, does not require imaging for cancer exclusion routinely, though clinical judgement is left to the treating specialist.
Recurrence after microscopic varicocelectomy is rare with published series reporting rates of approximately one to two percent . Recurrence rates after open high ligation ( Palomo ) techniques are ten to fifteen percent and after laparoscopic approaches are two to five percent . Recurrence is due to dilation of smaller veins not removed at surgery or of collateral venous pathways, again under the same mechanism of hydrostatic pressure. This is an important determinant in the gold-standard recommendation status of microscopic varicocelectomy with its recurrence rate being significantly less than the non-microscopic approaches. Colour Doppler ultrasound confirms recurrence if suspected after surgery and options are repeat microsurgical repair or radiological embolisation of residual or recurrent veins.
Current evidence and guidelines from major reproductive medicine societies, including the American Urological Association and European Association of Urology recommend that men with clinical varicocele and abnormal semen analysis should be offered varicocelectomy before proceeding to IVF or ICSI because: – surgical repair may achieve natural pregnancy or significantly improve semen quality to a point where less intensive assisted reproduction (IUI) becomes sufficient; – it improves semen quality for any subsequent assisted reproduction; – it may restore testicular function and testosterone levels beneficially; – the cost and patient burden of varicocelectomy is substantially lower than a cycle of IVF or ICSI. Therefore, referring directly to IVF or ICSI without correcting a clinically significant varicocele is a missed opportunity for a more efficient and less invasive route to pregnancy.
Current paediatric urology and andrology guidelines recommend surgical repair in adolescents with clinical varicocele and associated testicular atrophy (defined as a volume differential of two millilitres or more between the affected and unaffected testis) to prevent progressive testicular damage during the critical developmental period of adolescence. Adolescence varicocele left untreated with ipsilateral testicular atrophy may be associated with progressive loss of testicular volume and spermatogenic capacity into adult life. In adolescents without testicular atrophy and with normal contralateral testicular compensation, watchful waiting with regular monitoring is a reasonable alternative with the caveat that evidence of progression should prompt surgery. This decision needs a full discussion between the patient, their family and the specialist.
