Table of Contents  
INVITED REVIEW
Year : 2016  |  Volume : 18  |  Issue : 2  |  Page : 179-181

Epidemiology of varicocele


1 Division of Urology, Department of Surgery, McGill University, Montreal, Québec, Canada
2 Department of Urology, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia
3 Department of Radiology, Research Centre of the University of Montreal Hospital Centre, Québec, Canada

Date of Submission23-Nov-2015
Date of Decision06-Dec-2015
Date of Acceptance11-Dec-2015
Date of Web Publication08-Jan-2016

Correspondence Address:
Armand Zini
Division of Urology, Department of Surgery, McGill University, Montreal, Québec
Canada
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1008-682X.172640

Rights and Permissions
  Abstract 

Varicocele is a common problem in reproductive medicine practice. A varicocele is identified in 15% of healthy men and up to 35% of men with primary infertility. The exact pathophysiology of varicoceles is not very well understood, especially regarding its effect on male infertility. We have conducted a systematic review of studies evaluating the epidemiology of varicocele in the general population and in men presenting with infertility. In this article, we have identified some of the factors that can influence the epidemiological aspects of varicoceles. We also recognize that varicocele epidemiology remains incompletely understood, and there is a need for well-designed, large-scale studies to fully define the epidemiological aspects of this condition.

Keywords: epidemiology; infertility; varicocele


How to cite this article:
Alsaikhan B, Alrabeeah K, Delouya G, Zini A. Epidemiology of varicocele. Asian J Androl 2016;18:179-81

How to cite this URL:
Alsaikhan B, Alrabeeah K, Delouya G, Zini A. Epidemiology of varicocele. Asian J Androl [serial online] 2016 [cited 2017 Oct 20];18:179-81. Available from: http://www.ajandrology.com/text.asp?2016/18/2/179/172640 - DOI: 10.4103/1008-682X.172640


  Introduction Top


A varicocele is defined as an abnormal venous dilatation and/or tortuosity of the pampiniform plexus in the scrotum. Although varicoceles are almost always larger and more common on the left side, up to 50% of the men with varicocele, have bilateral varicoceles. [1] The rare, isolated right sided varicocele generally suggests that the right internal spermatic vein enters the right renal vein, but it should prompt further investigation as this finding may be associated with situs inversus or retroperitoneal tumors. It is generally reported that varicoceles are present in 15% of the general male population, in 35% of men with primary infertility, and in up to 80% of men with secondary infertility. [2],[3],[4]

The etiology of varicocele is though to be multi-factorial. The anatomic differences in venous drainage between the left and right internal spermatic vein (accounting for the predominance of left sided varicocele), and, the incompetence of venous valves resulting in reflux of venous blood and increased hydrostatic pressure are the most quoted theories for varicocele development. [5],[6] Physical exertion during puberty may lead to the development of varicocele whereas physical exertion at a later age can aggravate the condition but does not modify the prevalence of varicocele. [7],[8]

Investigators have proposed several mechanisms to explain the pathophysiology of varicocele. Scrotal hyperthermia likely represents the primary mechanism by which a varicocele affects endocrine function and spermatogenesis, both sensitive to temperature elevation. [9],[10],[11],[12] The reflux of adrenal and renal metabolite (supported by early anatomic radiographic studies) is another potential mechanism. [13],[14],[15],[16] Increased hydrostatic pressure in the internal spermatic vein from renal vein reflux may also be responsible for varicocele-induced pathology. [17]

The exact pathophysiology of varicocele, specifically, the influence of varicoceles on male fertility potential has not been established conclusively. To date, several studies have demonstrated an association between varicocele and reduced male fertility potential (e.g., poor semen parameters, infertility). However, most varicocele studies involve highly selected populations (e.g., infertile men) and rarely examine unselected men, representing an important reason for the difficulty in relating varicoceles with male fertility. [18]

Clinical (palpable) varicoceles are detected and graded based on physical examination: a grade 1 clinical varicocele is one that is only palpable during the Valsalva maneuver, a grade 2 varicocele is easily palpable with or without Valsalva but is not visible, while grade 3 refers to a large varicocele that is easily palpable and detected by visual inspection of the scrotum. [19] Despite having a varicocele grading system [19] it is important to recognize that epidemiological studies may report variable results due to variations in the detection of varicocele.

The focus of this chapter is to examine and report on the epidemiology of varicoceles in the general male population and in infertile men.


  Methods Top


Initially, a MEDLINE search was performed including articles from 1992 to 2015. The MEDLINE search terms included: "varicocele," "epidemiology," and "infertility." To widen the search scope, EMBASE and Google Scholar search engines were used, as well as, major references of reviewed articles. Abstracts of more than 140 articles were identified, and a total of 82 articles were reviewed. The main focus was on articles discussing the epidemiological aspect of clinical varicoceles and their relationship to male infertility/subfertility.


  Epidemiology Of Varicocele - Clinical Factors Top


Prevalence of varicocele in the general male population

Most of the early epidemiological studies on varicocele evaluated the prevalence of this condition in young men (military recruits, adolescent school boys, prevasectomy). These early studies reported that the prevalence of varicocele in the general male population is about 15%. [2],[20],[21],[22],[23],[24] These early observations did not suggest that age was an important determinant of varicocele prevalence.

Subsequent epidemiological studies have demonstrated that varicoceles develop at puberty. Oster observed that no varicoceles were detected in 188 boys 6-9 years of age, but were detected with increasing frequency in boys 10-14 years of age, strongly suggesting that varicoceles develop at puberty. [25] More recently, Akbay et al. [26] evaluated the prevalence of varicoceles in 4052 boys aged 2-19. They reported that the prevalence of varicoceles was <1% in boys aged 2-10, 7.8% in boys aged 11-14 years and 14.1% in boys aged 15-19 years. These epidemiological observations suggest that the venous incompetence that is characteristic of varicocele primarily occurs during testicular development.

More recent studies suggest that the prevalence of varicoceles in adult men is age-related. Levinger et al. evaluated the age-related prevalence of varicoceles in men above the age of 30. [27] Out of 504 healthy men, 34.7% were found to have a varicocele on physical examination (with all examinations performed by the same investigator). On further analysis, they observed that the prevalence of varicocele increases by approximately 10% for each decade of life. Varicocele prevalence was 18% at age 30-39, 24% at age 40-49, 33% at age 50-59, 42% at age 60-69, 53% at age 70-79 and 75% at age 80-89. [27] Canales et al. reported a relatively high prevalence (42% prevalence) of varicocele in older men presenting to a prostate cancer screening program (mean age 60.7 years). [28] However, unlike the study of Levinger et al. the report of Canales et al. did not demonstrate an age-related increase in varicocele prevalence in their cohort likely because most men in their study were elderly. These epidemiological observations suggest that testicular venous incompetence increases with age, likely a result of the aging of venous valves. These data are in keeping with the age-related increase in the prevalence of lower limb varicose veins. [29]

Prevalence of varicocele in a population of infertile men

The prevalence of varicocele in men presenting for infertility is in the range of 25%-35%, and in that subset of men with secondary infertility it is 50%-80%. [3],[30] In 1992, the World Health Organization (WHO) conducted a large study in 34 centers over a 12-month period. [30] Men consulting for infertility evaluation were screened using a standardized protocol common to all participating centers. The WHO investigators evaluated 9034 men and reported that 25.4% of the men with an abnormal semen analysis had a varicocele. In contrast, in the same study, the prevalence of varicocele in men with a normal semen analysis was 11.7%. [30]

Gorelick and Goldstein evaluated 1001 infertile men and reported that the prevalence of varicocele is 35% in men with primary infertility and 81% in men with secondary infertility. [3] Similarly, Witt and Lipshultz evaluated 2989 infertile men and reported that a varicocele is identified in 69% of men with secondary infertility. [4] These two groups of investigators concluded that in some men, a varicocele is a progressive and not a static lesion resulting in the loss of previously established fertility. However, given the subsequent observations of Levinger et al. [27] it is also possible that the increased prevalence of varicocele in some men with secondary infertility is a result of the age-related increase in the prevalence of a varicocele as these men tend to be older than men with primary infertility. [3],[31]

Venous insufficiency

An association between varicose veins of lower extremities and varicoceles has been suggested. Yasim et al. reported on 100 patients undergoing surgical repair of varicose veins, of which 72% had varicoceles with multiple degrees of severity, suggesting a common origin, likely incompetent venous valves. [32] As suggested by Levinger et al. [27] in their study on the age-related increase in varicocele prevalence, systemic venous insufficiency may be at the root of both lower venous incompetence and testicular venous incompetence.

Body mass index (BMI)

Most studies on the subject of BMI have reported an inverse relationship between the prevalence of varicocele and BMI. Although some studies have found no significant differences in BMI between men with and without varicocele, [33],[34] other studies have reported that men with varicocele have lower BMI than men without varicocele, [35],[36] or that the prevalence of varicocoele decreases as BMI increases. [37],[38],[39],[40],[41],[42],[43]

The inverse relationship between the prevalence of varicocele and BMI may be due to detection bias. It is possible that the proper detection of a varicocele may be more difficult in obese patients (due to a thicker spermatic cord) and this may lead under-detection of varicocele in these men. However, investigators have also suggested that the "nutcracker" phenomenon (thought to be responsible for compression of the spermatic vein) may be dampened in obese men due to increased intra-abdominal adiposity. [37],[38]

Hereditary factors

Raman et al. reported on the hereditary patterns of varicoceles. [44] They concluded that 56% of first-degree relatives of patients with varicoceles had a palpable varicocele, which was 8-fold higher than their control group (men presenting for vasectomy reversal). [44] Mokhtari et al. also showed a 45% prevalence of varicoceles among first-degree relatives, compared to 11% in their control group (population of healthy men serving as kidney donors). [45] More recently in 2010, Gökçe et al. reported a prevalence of 34% among first-degree relatives and this was significantly different than their control group (population of healthy men). [46] These studies strongly suggest that the prevalence of varicocele can be influenced by hereditary factors. The specific genetic factors associated with the increased prevalence of varicocele among family members remains to be elucidated.

Limitations of existing studies

The published studies on varicocele prevalence in fertile and infertile men have provided us with a good insight into the epidemiological aspects of this condition. However, there are several limitations that need to be recognized regarding the available studies on varicocele epidemiology. One of the main limitations of these epidemiological studies is that comparison of the general male population and the infertile male population is mostly indirect because few studies examine varicocele prevalence in both of these groups. This is important because the diagnosis of varicocele greatly depends on the expertise of the clinician performing the physical exam and establishing the diagnosis may vary from center to center. Failure to carefully define the study populations (e.g., age, semen parameters, hereditary factors, co-existing venous insufficiency, BMI) is another important limitation of the available studies. These limitations would best be addressed by performing studies that carefully define the study population(s), physical examination findings (with inter-observer variability) and control for important clinical parameters (e.g., age, semen parameters, hereditary factors, co-existing venous insufficiency, BMI).


  Conclusion Top


Varicocele epidemiology remains incompletely understood. We need well-designed, large-scale studies that include evaluation of important clinical factors to comprehend fully the epidemiological aspects of this condition. Future studies must carefully define the study population(s), physical examination findings (with inter-observer variability) and all pertinent clinical parameters (age, semen parameters, hereditary factors, co-existing venous insufficiency, BMI) to further advance our knowledge in this field.


  Competing Interest Top


All authors declare no competing interests.

 
  References Top

1.
Abdulmaaboud MR, Shokeir AA, Farage Y, Abd El-Rahman A, El-Rakhawy MM, et al. Treatment of varicocele: a comparative study of conventional open surgery, percutaneous retrograde sclerotherapy, and laparoscopy. Urology 1998; 52: 294-300.  Back to cited text no. 1
    
2.
Clarke BG. Incidence of varicocele in normal men and among men of different ages. JAMA 1966; 198: 1121-2.  Back to cited text no. 2
    
3.
Gorelick JI, Goldstein M. Loss of fertility in men with varicocele. Fertil Steril 1993; 59: 613-6.  Back to cited text no. 3
    
4.
Witt MA, Lipshultz LI. Varicocele: a progressive or static lesion? Urology 1993; 42: 541-3.  Back to cited text no. 4
    
5.
Buschi AJ, Harrison RB, Norman A, Brenbridge AG, Williamson BR, et al. Distended left renal vein: CT/sonographic normal variant. AJR Am J Roentgenol 1980; 135: 339-42.  Back to cited text no. 5
    
6.
Braedel HU, Steffens J, Ziegler M, Polsky MS, Platt ML. A possible ontogenic etiology for idiopathic left varicocele. J Uro 1994; 151: 62-6.  Back to cited text no. 6
    
7.
Rigano E, Santoro G, Impellizzeri P, Antonuccio P, Fugazzotto D, et al. Varicocele and sport in the adolescent age. Preliminary report on the effects of physical training. J Endocrinol Invest 2004; 27: 130-2.  Back to cited text no. 7
    
8.
Scaramuzza A, Tavana R, Marchi A. Varicoceles in young soccer players. Lancet 1996; 348: 1180-1.  Back to cited text no. 8
    
9.
Zorgniotti AW, Macleod J. Studies in temperature, human semen quality, and varicocele. Fertil Steril 1973; 24: 854-63.  Back to cited text no. 9
    
10.
Goldstein M, Eid JF. Elevation of intratesticular and scrotal skin surface temperature in men with varicocele. J Uro 1989; 142: 743-5.  Back to cited text no. 10
    
11.
Saypol DC, Howards SS, Turne TT, Miller ED. Influence of surgically induced varicocele on testicular blood flow, temperature, and histology in adult rats and dogs. J Clin Invest 1981; 68: 39-45.  Back to cited text no. 11
    
12.
Ali JI, Weaver DJ, Weinstein SH, Grimes EM. Scrotal temperature and semen quality in men with and without varicocele. Arch Androl 1990; 24: 215-9.  Back to cited text no. 12
    
13.
Comhaire F, Vermeulen A. Varicocele sterility: cortisol and catecholamines. Fertil Steril 1974; 25: 88-95.  Back to cited text no. 13
    
14.
Cohen MS, Plaine L, Brown JS. The role of internal spermatic vein plasma catecholamine determinations in subfertile men with varicoceles. Fertil Steril 1975; 26: 1243-9.  Back to cited text no. 14
    
15.
Ito H, Fuse H, Minagawa H, Kawamura K, Murakami M, et al. Internal spermatic vein prostaglandins in varicocele patients. Fertil Steril 1982; 37: 218-22.  Back to cited text no. 15
    
16.
Abbatiello ER, Kaminsky M, Weisbroth S. The effect of prostaglandins and prostaglandin inhibitors on spermatogenesis. Int J Fertil 1975; 20: 177-82.  Back to cited text no. 16
    
17.
Shafik A, Bedeir GA. Venous tension patterns in cord veins. I. In normal and varicocele individuals. J Uro 1980; 123: 383-5.  Back to cited text no. 17
    
18.
Zini A, Boman JM. Varicocele: red flag or red herring? Semin Reprod Med 2009; 27: 171-8.  Back to cited text no. 18
    
19.
Dubin L, Amelar RD. Varicocele size and results of varicocelectomy in selected subfertile men with varicocele. Fertil Steril 1970; 21: 606-9.  Back to cited text no. 19
    
20.
Vaughan EDJ, Perlmutter AP Lue TF, Goldstein M. (Eds). Impotence and Infertility. USA: Springer Science and Business Media; 2013.  Back to cited text no. 20
    
21.
Johnson DE, Pohl DR, Rivera-Correa H. Varicocele: an innocuous condition? South Med J 1970; 63: 34-6.  Back to cited text no. 21
    
22.
Steeno O, Knops J, Declerck L, Adimoelja A, van de Voorde H. Prevention of fertility disorders by detection and treatment of varicocele at school and college age. Andrologia 1976; 8: 47-53.  Back to cited text no. 22
    
23.
Alcalay J, Sayfan J. Prevalence of varicocele in young Israeli men. Isr J Med Sci 1984; 20: 1099-100.  Back to cited text no. 23
    
24.
Kursh ED. What is the incidence of varicocele in a fertile population? Fertil Steril 1987; 48: 510-1.  Back to cited text no. 24
    
25.
Oster J. Varicocele in children and adolescents. An investigation of the incidence among Danish school children. Scand J Urol Nephrol 1971; 5: 27-32.  Back to cited text no. 25
    
26.
Akbay E, Cayan S, Doruk E, Duce MN, Bozlu M. The prevalence of varicocele and varicocele-related testicular atrophy in Turkish children and adolescents. BJU Int 2000; 86: 490-3.  Back to cited text no. 26
    
27.
Levinger U, Gornish M, Gat Y, Bachar GN. Is varicocele prevalence increasing with age? Andrologia 2007; 39: 77-80.  Back to cited text no. 27
    
28.
Canales BK, Zapzalka DM, Ercole CJ, Carey P, Haus E, et al. Prevalence and effect of varicoceles in an elderly population. Urology 2005; 66: 627-31.  Back to cited text no. 28
    
29.
Callam MJ. Epidemiology of varicose veins. Br J Surg 1994; 81: 167-73.  Back to cited text no. 29
    
30.
The influence of varicocele on parameters of fertility in a large group of men presenting to infertility clinics. World Health Organization. Fertil Steril 1992; 57: 1289-93.  Back to cited text no. 30
    
31.
Walsh TJ, Wu AK, Croughan MS, Turek PJ. Differences in the clinical characteristics of primarily and secondarily infertile men with varicocele. Fertil Steril 2009; 91: 826-30.  Back to cited text no. 31
    
32.
Yasim A, Resim S, Sahinkanat T, Eroglu E, Ari M, et al. Clinical and subclinical varicocele incidence in patients with primary varicose veins requiring surgery. Ann Vasc Surg 2013; 27: 758-61.  Back to cited text no. 32
    
33.
Delaney DP, Carr MC, Kolon TF, Snyder HM, Zderic SA. The physical characteristics of young males with varicocele. BJU Int 2004; 94: 624-6.  Back to cited text no. 33
    
34.
Kiliç S, Aksoy Y, Sincer I, Oðuz F, Erdil N, et al. Cardiovascular evaluation of young patients with varicocele. Fertil Steril 2007; 88: 369-73.  Back to cited text no. 34
    
35.
May M, Taymoorian K, Beutner S, Helke C, Braun KP, et al. Body size and weight as predisposing factors in varicocele. Scand J Urol Nephrol 2006; 40: 45-8.  Back to cited text no. 35
    
36.
Baek M, Park SW, Moon KH, Chang YS, Jeong HJ, et al. Nationwide survey to evaluate the prevalence of varicoceles in South Korean middle school boys: a population based study. Int J Urol 2011; 18: 55-60.  Back to cited text no. 36
    
37.
Handel LN, Shetty R, Sigman M. The relationship between varicoceles and obesity. J Uro 2006; 176: 2138-40.  Back to cited text no. 37
    
38.
Nielsen ME, Zderic S, Freedland SJ, Jarow JP. Insight on pathogenesis of varicoceles: relationship of varicocele and body mass index. Urology 2006; 68: 392-6.  Back to cited text no. 38
    
39.
Prabakaran S, Kumanov P, Tomova A, Hubaveshki S, Agarwal A. Adolescent varicocele: association with somatometric parameters. Urol Int 2006; 7: 114-7.  Back to cited text no. 39
    
40.
Tsao CW, Hsu CY, Chou YC, Wu ST, Sun GH, et al. The relationship between varicoceles and obesity in a young adult population. Int J Androl 2009; 32: 385-90.  Back to cited text no. 40
    
41.
Al-Ali BM, Marszalek M, Shamloul R, Pummer K, Trummer H. Clinical parameters and semen analysis in 716 Austrian patients with varicocele. Urology 2010; 75: 1069-73.  Back to cited text no. 41
    
42.
Soylemez H, Atar M, Ali Sancaktutar A, Bozkurt Y, Penbegul N. Varicocele among healthy young men in Turkey; prevalence and relationship with body mass index. Int Braz J Urol 2012; 38: 116-21.  Back to cited text no. 42
    
43.
Gokce A, Demirtas A, Ozturk A, Sahin N, Ekmekcioglu O. Association of left varicocoele with height, body mass index and sperm counts in infertile men. Andrology 2013; 1: 116-9.  Back to cited text no. 43
    
44.
Raman JD, Walmsley K, Goldstein M. Inheritance of varicoceles. Urology 2005; 65: 1186-9.  Back to cited text no. 44
    
45.
Mokhtari G, Pourreza F, Falahatkar S, Kamran AN, Jamali M. Comparison of prevalence of varicocele in first-degree relatives of patients with varicocele and male kidney donors. Urology 2008; 71: 666-8.  Back to cited text no. 45
    
46.
Gökçe A, Davarci M, Yalçinkaya FR, Güven EO, Kaya YS, et al. Hereditary behavior of varicocele. J Androl 2010; 31: 288-90.  Back to cited text no. 46
    



This article has been cited by
1 The Role of Varicocele in Male Factor Subfertility
Dillon Sedaghatpour,Boback M. Berookhim
Current Urology Reports. 2017; 18(9)
[Pubmed] | [DOI]
2 Prevalence of varicocoele and its association with body mass index among 39,559 rural men in eastern China: a population-based cross-sectional study
J. Liu,S. Zhang,M. Liu,Q. Wang,H. Shen,Y. Zhang,D. Yan
Andrology. 2017; 5(3): 562
[Pubmed] | [DOI]
3 The Dilemma of Adolescent Varicoceles: Do They Really Have to Be Repaired?
Bryan S. Sack,Mattias Schäfer,Michael P. Kurtz
Current Urology Reports. 2017; 18(5)
[Pubmed] | [DOI]
4 The impact of coexisting sperm DNA fragmentation and seminal oxidative stress on the outcome of varicocelectomy in infertile patients: A prospective controlled study
Shabieb A. Abdelbaki,Jehan H. Sabry,Ahmed M. Al-Adl,Hanan H. Sabry
Arab Journal of Urology. 2017; 15(2): 131
[Pubmed] | [DOI]
5 Indocyanine Green Angiography-assisted Laparoendoscopic Single-site Varicocelectomy
Keiji Tomita,Susumu Kageyama,Eiki Hanada,Tetsuya Yoshida,Yuki Okinaka,Shigehisa Kubota,Masayuki Nagasawa,Kazuyoshi Johnin,Mitsuhiro Narita,Akihiro Kawauchi
Urology. 2017;
[Pubmed] | [DOI]
6 Determination of spermatic vein reflux after varicocele repair helps to define the efficacy of treatment in improving sperm parameters of subfertile men
S. D’Andrea,A. Micillo,A. Barbonetti,A. V. Giordano,S. Carducci,A. Mancini,S. Necozione,F. Francavilla,S. Francavilla
Journal of Endocrinological Investigation. 2017;
[Pubmed] | [DOI]
7 Varicocele embolization with glue and coils: A single center experience
C. Bilreiro,P. Donato,J.F. Costa,A. Agostinho,V. Carvalheiro,F. Caseiro-Alves
Diagnostic and Interventional Imaging. 2017;
[Pubmed] | [DOI]
8 Adjuvant Treatment with Qilin Pill for Men with Oligoasthenospermia: A Meta-Analysis of Randomized Controlled Trials
Xin Jin,Changfeng Man,Dandan Gong,Yu Fan
Phytotherapy Research. 2017;
[Pubmed] | [DOI]
9 Unilateral right-sided varicocele associated with pancreatic cancer: A cadaveric case report
Kelly E. Davis,Charles T. Simpkin,Cindy K. Funk
Translational Research in Anatomy. 2017; 7: 1
[Pubmed] | [DOI]
10 Varicocele and male infertility: current concepts and future perspectives
Ashok Agarwal,SandroC Esteves
Asian Journal of Andrology. 2016; 18(2): 161
[Pubmed] | [DOI]
11 Afterword to varicocele and male infertility: current concepts and future perspectives
SandroC Esteves,Ashok Agarwal
Asian Journal of Andrology. 2016; 18(2): 319
[Pubmed] | [DOI]
12 Varicocele in a Young Man: Something We Should Be Worried About?
Raul I. Clavijo,Ranjith Ramasamy
European Urology. 2016;
[Pubmed] | [DOI]
13 Effect of Varicocelectomy on Serum FSH and LH Levels for Patients with Varicocele: a Systematic Review and Meta-analysis.
Daxue Tian,Wei Huang,Huilei Yan,Huantao Zong,Yong Zhang
Indian Journal of Surgery. 2016;
[Pubmed] | [DOI]
14 Risk of varicocele in patients with rheumatoid arthritis, ankylosing spondylitis, and psoriatic disease: a population-based case–control study
H-Y Chiu,I-T Wang,W-F Huang,Y-W Tsai,T-F Tsai
Scandinavian Journal of Rheumatology. 2016; : 1
[Pubmed] | [DOI]
15 Beneficial effects of microsurgical varicocoelectomy on sperm maturation, DNA fragmentation, and nuclear sulfhydryl groups: a prospective trial
N. Alhathal,M. San Gabriel,A. Zini
Andrology. 2016;
[Pubmed] | [DOI]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Methods
Epidemiology Of ...
Conclusion
Competing Interest
References

 Article Access Statistics
    Viewed1404    
    Printed83    
    Emailed0    
    PDF Downloaded574    
    Comments [Add]    
    Cited by others 15    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]