Diagnosis & Evaluation


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Every structure in the body requires blood flow - inflow of fresh blood through arteries and outflow of blood through veins. The testes are no different - in fact, there are 5 recognized venous drainage systems from the testicles:


  1. Gonadal (testicular) vein: these are the longest and drain up near the kidneys
  2. Deferential (vasal) veins: travel with the vas deferens
  3. Cremasteric: these terminate in the inferior epigastric veins
  4. Gubernacular: drain to the superficial scrotal system
  5. Sub-inguinal collaterals: drain to the superficial system

The venous drainage system acts as a 'heat exchange system' which keeps the operating temperature of the testis below that of core body temperature. Sperm production works best when the temperature is a little lower. The blood returning in veins leaving the testis cools the incoming blood entering the testis from the arteries. This arterio-venous heat exchange system is called the the pampiniform plexus. The gonadal, deferential and cremasteric veins all contribute. The gonadal vein is the main contributor - it also happens to be the longest vein and most prone to cause a varicocele.


Everyone has veins in the scrotum - this is normal. However, when the veins forming the pampiniform plexus are larger then usual they are called varicoceles. These are similar to varicose veins that occur in the legs. Varicoceles are very common: they occur in about 1 in every 7 males, hence approximately 450 million men on earth have a varicocele. Obviously, not all men with varicoceles have difficulty conceiving and most men with varicoceles are able to father children.


Sometimes, however, the pooling of blood in the pampiniform plexus can result in impairment of sperm production by overheating the testis. In extreme cases, there may be no sperm at all in the ejaculate (azospermia).




Most varicoceles are idiopathic - meaning that a specific cause is not identified. This doesn't mean that we don't understand the ways in which venous drainage is compromised, just that we're not sure what 'sets them off'. For most men, a varicocele is simply a normal anatomical variation. Several different hypotheses have been proposed for why varicoceles are more common on the left than on the right including differences in the anatomy of the LEFT versus the RIGHT gonadal vein. The LEFT vein is longer, inserts into the LEFT renal vein which passes under the superior mesenteric artery. The finding of an isolated RIGHT gonadal vein is somewhat unusual and in certain men an ultrasound is recommended to exclude obstruction of the LEFT gonadal vein by a mass.


Diagnosis & Evaulation


Varicoceles can be classified based on physical examination  (the so called 'clinical varicocele') or based on ultrasound. When a varicocele can be identified on ultrasound but not on physical exam it is called a 'subclinical varicocele'. Physical examination is usually more sensitive and relevant than ultrasound for diagnosis and classification. There are several classifications for varicoceles, both clinical and sonographic. Here are 2 commonly used classifications.


Clinical Ultrasound

Grade I (small): palpable with valsalva only

Grade II (moderate): palpable standing w/o valsalva

Grade III (large): visible

Small: 2-3.4 mm

Medium: 3.5-4.9 mm

Large: ≥5 mm

Why to Treat Varicoceles


There are 3 basic reasons why men present for varicocele correction.

  1. They are having difficulty with having a child (infertility) or want to preserve future fertility
  2. They are having pain or discomfort (symptoms)
  3. They are having hormone dysfunction from the varicocele (hypogonadism) - this is rare


The most common reason for varicocele correction is infertility. It is worthwhile to examine the role of varicocele correction in infertility. There are multiple scenarios in which it may be of value. There are 3primary issues to consider:


  1. How likely is it that the varicocele is having a negative effect on fertility?
  2. How likely is correction of the varicocele to improve the fertility outcome of interest under the specific circumstances?
  3. How should the varicocele be treated if it warrants treatment?


Probably the biggest issue is deciding if the varicocele is contributing to a couple's difficulty with fertility because there are usually multiple issues at play, varicocele being just one issue. Furthermore, the data on varicocele correction is limited - there are few randomized controlled trials (the gold standard of evidence in medicine) and those that exist have many confouding elements such that with rare exception some clinical judgement is necessary to chart the best course of action.


When to Treat Varicoceles in Infertile Couples


Varicoceles are about 4x more common in men having difficulty conceiving than those without problems. Despite this, a varicocele may not be the major contributing factor to infertility nor does correction of the varicocele ever guarantee that the desired outcome will occur. What varicocele correction can do in select circumstances is increase the odds of a good outcome. What's a good outcome? Ultimately, having a healthy baby is the goal but there can be other goals that can be used as stepping stones to achieve that outcome. Things such as improving the sperm concentration (or facilitating the production of sperm where none can be identified) or even using a less intensive modalities to achieve a pregnancy (for example, intrauterine insemination rather than in vitro fertilization).


Several medical societies publish guidelines on varicocele correction (NICE, AUA, EUA). They are all very similar. In general, all of the following criteria should be met before considering varicocele correction:


  1. Infertility: Difficulty obtaining a pregnancy after 1 year of trying
  2. Low numbers of sperm: Oligospermia - sperm concentrations less than 20 million per ml
  3. Larger varicocele: generally defined as a Grade 2 or greater varicocele


One will appreciate that these indications cover virtually all the specific scenarios discussed below. Virtually all studies show that in the absence of these criteria, correction of a varicocele is unlikely to make any difference in the chances of obtaining a pregnancy. The guidelines do not recommend correction (or advise caution) if the varicocele is subclinical or there is a substantial female factor. This last element may make varicocele correction futile.


When the above criteria are applied, varicocele correction improves the odds of a pregnancy by 2-4 times. (Ficarra et al Current Urology Opinion 2010)



Scenario 1: Infertile Men with a Clinical Varicocele PLUS Azospermia or Oligospermia PLUS Undergoing Assisted Reproduction (IUI/IVF)


Men who have no sperm (azospermia) or few sperm (oligospermia = less than 20 million per mL) can benefit from correction of their varicocele. A review of all the published studies on the subject showed a clinically relevant improvement in multiple scenarios with different outcomes (Kirby et al. Fertility and Sterility November 2016).


The improved odds of having success following varicocele correction compared to leaving the varicocele untreated in specific groups was as follows:


  1. 1.7x improved odds of live birth in oligospermic men using IUI/IVF
  2. 2.3x improved odds of live birth in azospermic men using IUI/IVF
  3. 1.8x improved odds for pregnancy in oligospermic/azospermic men as a whole using IUI/IVF
  4. 2.3x improved odds for prgenancy in azsopermic men
  5. 8.4x improved odds of a live birth in oligospermic/azospermic men as a whole using IUI
  6. 2.5x increased odds of retrieving sperm in azospermic men using testicular sperm extraction (TESE)


Groups in which varicocele correction demonstrated questionable, limited or no benefit:


  1. Varicocele correction in in azospermia prior to testicular sperm extraction (TESE) before planned IVF/ICSI. The pooled analysis showed an 2.2 times improved odds ratio for live birth rate and a 2.3 times improved odds ratio for pregnancy but this was not statistically significant. One of the 2 studies did show a substantial increase in the sperm retrieval rate with TESE (53% vs. 30%, odds ratio 2.63) but there was no statistically significant difference in the fertilization rate (64% vs. 54%) or the pregnancy rate (31% vs. 22%). (Inci et al J Urology October 2009) 
  2. When the ICSI variant of IVF is being used, pregnancy rates, implantation and miscarriage rates do not seem to be improved by varicocele correction. (Pasqualotto et al Journal of Andology 2012)


Scenario 2: Fertile Men PLUS Clinical Varicocele PLUS Recurrent Miscarriage


By definition, couples who have conceived are considered fertile even if the pregnancy did not result in a live birth. First trimester loss (miscarriage) is a devastating event for couples. There are a myriad of causes which can be challenging to identify and treat. The question of whether treatment of a varicocele might be beneficial, even in the absence of abnormalities in the semen analysis based on WHO criteria, was addressed in this study. (Ghanaie et al Urology Journal Spring 2012) The short answer is that varicocele correction should be considered under these circumstances, even if the sperm concentration is well within normal range to start. 


There was a 2 fold difference in the pregnancy rate - from about 20% to 40% in the year following treatment favoring those couples in which the men had their varicocele corrected. Furthermore, the probability of miscarriage was about 70% vs. 15% in the couples where the man had undergone varicocele correction. There are several issues with this study including the small number of patients in the study and these results have not been reproduced elsewhere.


Scenario 3: Infertile Males PLUS Clinical Varicocele PLUS High DNA Fragmentation


DNA fragmentation and its measurement is a controversial subject in male infertility to say the least. Overlooking those controversies, the question of whether men with varicoceles and an increased DNA fragmentation index (DFI) might see some measureable benefit in fertility by correction of the varicocele has been asked.


In many ways, the current data does not advance clinical management. The data for improvement in DFI and other parameters such as sperm concentration following varicocele correction is reasonably strong. (Roque et al Int Urol Nephrol 2018) The issue is that the men who underwent varicocele correction could have been selected for varicocele repair based on the 3 criteria above (infertility + large varicocele + oligospermia) without ever having done the DNA fragmentation testing in the first place. Ultimately, one would like to know if the DFI independently predicts benefit from varicocele correction even when the sperm counts are high (since we already know that doing varicocele correction with low sperm counts is beneficial). What these studies show is that one of the basic mechanisms by which varicoceles cause infertility is by injuring the DNA.




After your varicocele is treated, follow-up is required. In general:


  1. Physical examination and follow-up ultrasound to ensure satisfactory treatment
  2. Semen analysis to check for improvement in parameters. Usually done every 3 months or so following treatment until a pregnancy is achieved


A sperm takes roughly 3 months to make from scratch. As a consequence, the earliest that any beneficial effect of varicocele correction would be seen is 3 months. This is when the first semen analysis should be done. There is little improvement in results after 6 months. Therefore, if a change in strategy is being contemplated following varicocele correction (e.g. moving from IUI to IVF), this can be safely made at 6 months without concern that the semen analysis might improve further. On average, a 10 million/mL improvement in sperm concentration is expected - but results are highly variable with about 1/5 of men seeing less than 5 million/mL of improvement (this includes no improvement) and another 1/5 seeing greater than 15 million/mL improvement.


Other Indications for Varicocele Correction


There are other reasons to repair varicoceles but these are less common than the reasons stated above. Other reasons for varicocele correction include:




Varicocele-related pain is not a common presentation. The mechanism is poorly understood that may be related to back pressure, hypoxia or compression of surrounding neural fibers by the dilated veins.


Varicocele-related pain is uncommon and therefore pain in the scrotum should not routinely be attributed to a varicocele if one is present. The vast majority of men who have varicoceles did not have any symptoms and it is thought that in a substantial number of man who had discomfort in the presence of varicoceles that the discomfort is completely unrelated to the varicocele. In short, when should not assume the varicoceles causing pain. Scrotal pain include testis tumors, fluid collections, pain following vasectomy or hernia repair, nerve entrapment syndromes, infection, referred pain from hernia or even ureteral stones. In a large number of cases the scrotal pain may not have an identifiable cause.


Approach and almost always include a period of observation of at least a few months following onset of symptoms to determine if the discomfort will spontaneously resolve.


Conservative methods to address the pain can include limiting physical activities, scrotal elevation and nonsteroidal anti-inflammatory drugs. There is no known medication that can specifically help with varicocele-related pain.


Most studies demonstrate that varicocele-related pain only occurs in men with large varicoceles (grade 3) and that repair is unlikely to help unless the pain is worse with prolonged standing and is a 'dull ache'.  There are no head-to-head studies which can guide one in determining if surgery or embolization is more effective in addressing varicocele related pain. The success rates for resolution of pain following surgery averages approximately 90% for improvement in pain and 50% for complete resolution in pain (Paick et al. Review The World Journal of Men's Health 2019 January 37(1): 4-11).


There is less data on the use of varicocele embolization to treat varicocele-related pain. Sonographic resolution of the varicocele has been estimated at about 70% with improvement in pain described in roughly 90% of patients. Approximately 5% of patients could not have the procedure completed because of technical issues (Puche-Sanz et al. Andrology 014;2:716-20.)

Preservation of future fertility.

Adolescents may present with varicoceles. While they may not actively be attempting to achieve a pregnancy, preservation of fertility is important. Consideration to repair should be given to teenages with varicoceles grade 2 or larger associated with a significant discrepancy in testicular volume or consistency. The fact that there may be a normal discrepancy in testicular volume and consistency as a male progresses through puberty can make a decision difficult. In such cases, repeated examination every 6-12 months is warranted.

Endocrine dysfunction.

This is only seen in the most severe cases of large varicoceles with severe testicular atropy. Low testosterone, often accompanied by high FSH and LH, are observed.


How to Treat Varicoceles: Mangement Options


If you have a varicocele and are not having any problems, they can usually just be left alone. If you meet criteria for correction, there are 2 primary options for repair:


  1. Surgery: subinguinal microscopic varicocelectomy
  2. Embolization: a procedure performed by a radiologist to block the gonadal vein


There are pros and cons to each. In general, subinguinal microscopic varicocelectomy is the most effective way to repair a varicocele because not only can it correct the veins that are the major contributors to the varicocele (the gonadal and cremasteric veins) but also can address the collateral veins to the superficial system (the gubernacular and subinguinal veins). Note that the deferential vein is left intact so that venous drainage from the testis is preserved. It is recommended that the same approach be used both children and adults since this has the highest efficacy and best preservation of testicular function. Approaches that are generally inadvisable include a scrotal approach as the risk of injury to the testicular blood supply is higher. High ligation approaches are associated with an increased failure rate and are much more invasive in the subinguinal approach. The inguinal approach is also associated with more pain than the subinguinal approach.


Embolization only addresses the gondal vein so the success rates are usually a little lower. Having said that, since the gonadal veins are the main contributing factor to a varicocele, embolization will correct a majority of varicoceles. The trade off for a higher success rate for surgery is a longer recovery time (weeks rather than days). In some circumstances, surgery will provide a much higher success rate - especially if you have a very, very large varicocele - and can also be used if an embolization fails. 


While complications are rare, both procedures can be associated with the development of fluid collections (hydroceles or lymphoceles), bleeding and pain. Embolization requires the use of intravenous contrast which can cause a reaction; the venipuncture in the neck may cause problems and the coils/'superglue' used to block off the veins may migrate and are permanent. Surgery can be associated with infection in rare cases.


Surgery is associated with a roughly 5% risk of hydrocele formation and a risk of recurrence of less than 5%.


Both of these approaches require subspecialized training for optimal results - either in male infertility or interventional radiology. Fortunately, there are a couple of urologists in the Greater Vancouver area with subspecialty training as well as certain radiologists who have a incredible amount of experience in varicocele embolization.


On the Web

General Urology Web Sites

AUA patient information brochure on varicoceles


Author(s): K Poon  Major Revision/Review: June 2016