Effects of surgical repair of experimental left varicocele on testicular temperature, spermatogenesis, sperm maturation, endocrine function, and fertility in rabbits

Varicocele, Functional Foods and Nutraceuticals: From Mechanisms of Action in Animal Models to Therapeutic Application

Varicocele is one of the main causes of infertility in men, thus representing an important clinical problem worldwide. Inflammation contributes mainly to its pathogenesis, even if the exact pathophysiological mechanisms that correlate varicocele and infertility are still unknown. In addition, oxidative stress, apoptosis, hypoxia, and scrotal hyperthermia seem to play important roles. So far, the treatment of varicocele and the care of the fertility-associated problems still represent an area of interest for researchers, although many advances have occurred over the past few years. Recent experimental animal studies, as well as the current epidemiological evidence in humans, demonstrated that many functional foods of natural origin and nutraceuticals that are particularly abundant in the Mediterranean diet showed anti-inflammatory effects in varicocele. The aim of the present narrative review is to mainly evaluate recent experimental animal studies regarding the molecular mechanisms of varicocele and the state of the art about possible therapeutic approaches. As the current literature demonstrates convincing associations between diet, food components and fertility, the rational intake of nutraceuticals, which are particularly abundant in foods typical of plant-based eating patterns, may be a reliable therapeutic supportive care against varicocele and, consequently, could be very useful in the cure of fertility-associated problems in patients.

The Management of Clinical Varicocele: Robotic Surgery Approach

Varicocele is a pathologic dilation of the testicular veins within the spermatic cord. Varicocele is considered the most common problem in reproductive medicine practice. It 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, and several theories have been proposed to explain it. Varicocele can impair sperm quality and fertility via various mechanisms: reflux of adrenal metabolites, increased testicular hypoxia, oxidative stress, and increased testicular temperature have been proposed. Several studies have reported the significant benefits on semen parameters with the surgical treatment of varicocele: reducing oxidatively induced sperm DNA damage and potentially improving fertility. Varicocele repair should be offered as a part of treatment option for male partners of infertile couples presenting with palpable varicoceles. Nowadays, there are several surgical approaches available for the treatment of varicocele, such as the retroperitoneal approach, inguinal approach, and the subinguinal approach. The subinguinal microscopic approach offers the best outcomes, such as shorter hospital stays, preservation of the testicular arteries and lymphatics, least number of postoperative complications, recurrence, and a higher number of pregnancies. Currently robotic-assisted laparoscopic surgery is widely adopted in urology and surgeons began to explore the potential applications of the robotic platform to male infertility microsurgical operations. Robotic approach offers many advantages: elimination of tremor, retraction with third arm, high quality, 3-dimensional visualization and surgeon ergonomics, all contributing to the precision of surgery.

Conventional semen analysis and advanced sperm function tests in diagnosis and management of varicocele

Clinical varicoceles are a common cause of male infertility and affect sperm parameters as measured in a conventional semen analysis. Varicocelectomy has been shown in prospective studies to improve semen parameters in men with a clinical varicocele. Clinical varicoceles are also a well-known source of oxidative stress which may affect the quality of spermatozoa. Spermatozoa are particularly susceptible to oxidative stress due to a limited capacity for DNA repair. The susceptibility of spermatozoa to oxidative stress is modulated by a balance between ROS and antioxidants, which can be quantified by various laboratory assays. Varicocelectomy has been consistently shown to reduce both ROS and sperm DNA fragmentation, and various assays should be utilised in the diagnosis and treatment of infertile men with a clinical varicocele.

The duration of infertility affects semen parameters in primary infertile men: results of a single-centre, cross-sectional study

OBJECTIVE

To assess the relationship between the duration of infertility (DI) and the seminal parameters of a cohort of White-European primary infertile men.

PATIENTS AND METHODS

Data from 1644 infertile men were analysed. Patients were grouped according to the self-reported DI into 12-month time frames. Semen analysis values were assessed based on 2010 World Health Organisation reference criteria. Descriptive statistics tested the difference in clinical, hormonal and seminal parameters between groups. Logistic regression models assessed the impact of DI on semen parameters.

RESULTS

A DI of <12, 13-24, 25-36, 37-48, 49-60 and >60 months was found in 207 (12.6%), 651 (39.6%), 387 (23.5%), 168 (10.2%), 92 (5.6%) and 139 (8.4%) men, respectively. Patient's age (P < 0.001) and body mass index (P < 0.001) significantly increased along with DI. Hormonal values were similar across groups. Sperm concentration significantly decreased with DI (P = 0.01). Similarly, a higher rate of non-obstructive azoospermia (NOA) was more frequently found in men with a longer DI (P = 0.03). There were no differences in semen volume, sperm progressive motility, total motile sperm count (TMSC), and normal morphology across groups. Multivariable logistic regression analysis showed that DI was significantly associated with the risk of oligozoospermia (P < 0.001), TMSC <5 × 10⁶ (P < 0.001), and NOA (P < 0.001).

CONCLUSIONS

This cross-sectional study showed that DI had a negative impact on semen parameters in primary infertile men. Sperm concentration was negatively associated with DI and patients with a longer DI reported higher rates of azoospermia. Furthermore, DI was significantly associated with a higher risk of oligozoospermia, low TMSC, and NOA.

The value of ultrasonography in the diagnosis of varicocele

A varicocele is described as pathologically enlarged, tortuous veins of the pampiniform plexus, leading to an increased testicular temperature and adrenal metabolite reflux into the testes. Varicocele can impair spermatogenesis and is considered to be the most common cause of male infertility. Patients may palpate a thickening in the scrotum or complain of dull scrotal or inguinal pain, which increases when standing or during erection. In the case of a sudden onset of varicocele in elderly men, it is necessary to exclude renal tumor and extend diagnostic ultrasound with the assessment of the abdominal cavity. The diagnosis of varicocele is based on medical history and physical examination, which involves palpation and observation of the scrotum at rest and during the Valsalva maneuver. Ultrasound is the imaging method of choice. The width and the number of vessels in the pampiniform plexus as well as the evaluation and measurement of regurgitation during the Valsalva maneuver are typical parameters analyzed during ultrasound assessment. However, diagnostic ultrasound is still a controversial method due to numerous and often divergent classification systems for varicocele assessment as well as its poor correlation with clinical manifestations. As a result of introduction of clear ultrasound criteria as well as the development of elastography and nuclear magnetic resonance, diagnostic imaging can play an important role in assessing the risk of damage to the testicular parenchyma, qualifying patients for surgical treatment and predicting the effects of therapy.

Varicocele: A Review

Varicoceles are relatively common clinical problem that are associated with pain, testicular atrophy, and reduced fertility rates. After a brief historical perspective is presented, this article reviews the anatomy, indications, treatment options, and potential complications related to varicoceles.

Novel insights into the pathophysiology of varicocele and its association with reactive oxygen species and sperm DNA fragmentation

Varicocele has been associated with reduced male reproductive potential. With the advances in biomolecular techniques, it has been possible to better understand the mechanisms involved in testicular damage provoked by varicocele. Current evidence suggests the central role of reactive oxygen species (ROS) and the resultant oxidative stress (OS) in the pathogenesis of varicocele-associated male subfertility although the mechanisms have not yet been fully described and it is likely to be multifactorial. Excessive ROS is associated with sperm DNA fragmentation, which may mediate the clinical manifestation of poor sperm function and fertilization outcome related to varicocele. Testing of ROS/OS and DNA fragmentation has the potential to provide additional diagnostic and prognostic information compared to conventional semen analysis and may guide therapeutic management strategies in individual patient.

Reassessing the role of subclinical varicocele in infertile men with impaired semen quality: a prospective study

OBJECTIVE

To evaluate the seminal, hormonal, and spontaneous pregnancy outcome after percutaneous embolization of the internal spermatic vein in infertile men with left-sided subclinical varicocele and one or more abnormal semen parameters.

METHODS

A total of 218 patients underwent percutaneous embolization, and 119 patients were included as the observation group. All patients were followed up prospectively for 39.4 ± 6.5 months. Semen parameters and hormonal levels were evaluated before any procedure and 6 months after.

RESULTS

Significant improvement in the mean sperm concentration, total motility, and lower follicle-stimulating hormone levels was noted in those who underwent varicocele embolization as compared with those not treated. After 39.4 ± 6.5 months, pregnancy rates were 46.3% for the treated group and 11.8% for the control group (P = .011).

CONCLUSION

In infertile men, small varicoceles, even subclinical ones, should be identified and treated.

Percentage change of FSH value: new variable to predict the seminal outcome after varicocelectomy

In the literature, there is no good agreement with variables to predict seminal outcome after varicocelectomy. The purpose of this study was to evaluate the FSH percentage change (Δ% FSH) as a predictor of the seminal outcome after varicocelectomy together with other known predictors. We evaluated 118 patients who underwent varicocelectomy. We assessed factors that could be predictors of the improvement of semen characteristics: LH, FSH, total and free testosterone before operation, testis volume, age, testicular pain, body mass index (BMI), Δ% FSH, varicocele Doppler ultrasound grade using regression analysis. Mean sperm concentration increased from 27 ± 12 to 52 ± 15 million per ml post-operatively (P < 0.003), mean sperm motility increased from 31 ± 12 to 40 ± 13 million per ml following the operation (P < 0.02), also mean FSH value changed from 10.2 ± 8.3 to 6.7 ± 7.2 UI/L (P < 0.01). In unvaried regression analysis, Δ% FSH, BMI and age were predictors of the improvement of semen characteristics. In multiple regression analysis, only Δ% FSH and age were predictors. Negative correlation with age and positive correlation with Δ% FSH were observed. Our findings suggest that Δ% FSH (before and after varicocelectomy) and age are significant factors predicting the improvement of semen characteristics.

Varicocele-induced infertility: Newer insights into its pathophysiology

The association between varicoceles and male infertility has been known since the 1950s; however, the pathophysiology of the process remains uncertain. The primary proposed hypotheses involve hyperthermia, venous pressure, testicular blood flow, hormonal imbalance, toxic substances, and reactive oxygen species. It is difficult to identify a single or dominant factor, and it is likely that many of these factors contribute to the infertile phenotype seen in clinical practice. Moreover, patient lifestyle and genetic factors likely affect patient susceptibilities to the varicocele insult. While the current studies have weaknesses, they provide building blocks for futures studies into the pathophysiology of the varicocele.

Is varicocelectomy indicated in subfertile men with clinical varicoceles who have asthenospermia or teratospermia and normal sperm density?

OBJECTIVE

Varicocele is the most common treatable cause of male infertility and is associated with progressive decline in testicular function. Varicocelectomy, a commonly performed operation, is indicated in infertile males with varicoceles who have oligospermia, asthenospermia, teratospermia or a combination of these factors. It is not clear if varicocelectomy is indicated if the patients have normal sperm density associated with asthenospermia or teratospermia.

METHODS

We reviewed 167 patients with varicocele-associated male infertility over a 7-year period (December 1999-November 2005). Pre- and post-varicocelectomy seminal fluid analyses, assessed using the World Health Organization criteria, were obtained at intervals of 4-6 months. Wilcoxon signed rank tests were used to evaluate for statistical significance and P < or = 0.05 was considered significant.

RESULTS

The mean age of the patients and their spouses were 35 and 28 years, respectively. The mean duration of infertility was 3.2 years (range, 1.5-7.5). Oligospermia, teratospermia, asthenospermia, oligospermia, asthenospermia and teratospermia (OAT) syndrome and azoospermia were found preoperatively in 106 (63.5%), 58 (34.7%), 154 (92%), 118 (71%) and 15 (9%) patients, respectively. Overall, significant improvements in semen volume (P < 0.001), sperm density (P < 0.001), sperm motility (P < 0.001) and sperm vitality (P < 0.001) were obtained after varicocelectomy. There was, however, no significant improvement in sperm morphology after varicocelectomy (P = 0.220). When patients with preoperative oligospermia (sperm density, <20 million/mL) were considered separately, varicocelectomy led to significant improvement in all the semen parameters except the sperm morphology (P = 0.183). Conversely, when varicocele patients with a sperm density of > or =20 million/mL (normospermia) associated with asthenospermia and/or teratospermia were considered separately, they did not show significant improvement in any of the semen parameters after varicocelectomy (P > 0.05). In addition, azoospermic patients did not show significant improvement in any of the semen parameters (P > 0.05)

CONCLUSION

No significant improvement in semen parameters may be obtained in patients with clinical varicocele and preoperative normospermia. It is possible that only patients with preoperative oligospermia may benefit from varicocelectomy. Larger multi-institutional studies are needed to determine more definitively if asthenospermia or teratospermia in normospermic subfertile males with clinical varicoceles are in fact indications for varicocelectomy.

Apoptotic Sertoli cell death in hypogonadic (hgn/hgn) rat testes during early postnatal development

AIM

To determine the involvement of apoptotic cell death in postnatal pathogenesis in mutant strain of hypogonadic (hgn/hgn) rats testes. We evaluated the numbers and types of cells undergoing apoptotic cell death.

METHODS

Tissue sections were stained by the TUNEL method for in situ detection of apoptotic cells, with specific antibodies used as markers of testicular somatic and germ cells.

RESULTS

We found that apoptosis in the hgn/hgn testes during the early postnatal period occurred primarily in Sertoli cells, which should actively proliferate during this stage of differentiation. These findings strongly suggest that the normal allele of hgn is involved in the direct or indirect control of differentiation and proliferation of Sertoli cells.

CONCLUSION

To our knowledge, this is the first report demonstrating early postnatal apoptosis of Sertoli cells, suggesting that the hgn/hgn rat is a unique model for the study of Sertoli cell deficiency.

Relationship between the number of veins ligated in a varicocelectomy with testicular volume, hormonal levels and semen parameters outcome

PURPOSE

Correlate semen analysis, hormones, and testicular volume with the number of veins ligated.

METHODS

Patients were divided into three groups: Group 1 (< or = 5 veins), Group 2 (6-10 veins), and Group 3 (> 10 veins). We evaluated testicular volume, hormonal levels, sperm concentration, and motility before and after the surgical procedure.

RESULTS

In Group 1, even though there was an improvement in both testicular volume and sperm concentration; testosterone levels and sperm motility did not improve with surgery. In Group 2, no changes were detected in the both testicular volumes, in sperm concentration, motility, and testosterone levels. In Group 3, an improvement was seen in the right testicle volume, testosterone levels, and sperm concentration. Follicle-stimulating hormone levels decreased following the surgical procedure in all groups.

CONCLUSION

Patients with more than 10 ligated veins have better chances to improve sperm concentration. FSH levels decreased in all groups of patients.

Testicular growth, sperm concentration, percent motility, and pregnancy outcome after varicocelectomy based on testicular histology

OBJECTIVE

To evaluate the outcome following surgery in two different patterns of testicular histology in patients with varicocele.

DESIGN

Prospective study.

SETTING

Academic medical center.

PATIENT(S)

Sixty patients underwent varicocelectomy and had a testicular histology diagnosis of germ-cell aplasia (group I, n = 28) or maturation arrest (group II, n = 32).

INTERVENTION(S)

Varicocelectomy.

MAIN OUTCOME MEASURE(S)

Preoperative hormone levels, testicular size, and sperm parameters. After varicocelectomy, variations in testicular size, semen parameters, and pregnancy rates were evaluated.

RESULT(S)

The mean volume of the right and left testicle was smaller in group I patients than in group II. In addition, the mean sperm concentration before treatment was lower in group I than in group II. The mean volume of the left and right testicle increased in group I after the intervention. The mean postoperative sperm concentration and motility in group II showed no increase, whereas the mean sperm concentration in group I did increase. The pregnancy rate was higher in group II (14/26, 53.8%) than in group I (4/16, 25%) (P=.02).

CONCLUSION(S)

Patients with germ-cell aplasia present a postoperative increase in testicular size but the pregnancy rate is higher in patients with maturation arrest following surgery.

Semen profile, testicular volume, and hormonal levels in infertile patients with varicoceles compared with fertile men with and without varicoceles

OBJECTIVE

To assess semen analysis, testicular volume, and hormone levels in fertile and infertile patients with varicoceles and fertile men without varicoceles.

DESIGN

Retrospective study.

SETTING

Academic medical center.

PATIENT(S)

Patients were divided into three groups: fertile men with varicoceles (n = 79), infertile men with varicoceles (n = 71), and fertile men without varicoceles (n = 217).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Levels of LH, FSH, and total T and testicular volume in fertile and infertile men with varicoceles and fertile controls without varicoceles.

RESULT(S)

LH (IU/L) and T (ng/dl) levels were not statistically different across the three groups. FSH levels were significantly higher in infertile men with varicoceles (7.8 +/- 7.6 IU/L) than in the fertile men with varicoceles (3.5 +/- 2.1 IU/L) or in fertile men without varicoceles (3.5 +/- 1.9 IU/L). The right testicle was smaller in infertile patients with varicoceles (18.7 +/- 8.3 cm(3)) than in fertile men with varicoceles (25.2 +/- 13 cm(3)) or in fertile men without varicoceles (24.9 +/- 10.7 cm(3)). In addition, the left testicle was smaller in infertile men with varioceles (17.6 +/- 8.9 cm(3)) than in fertile men with varicoceles (21.6 +/- 7.8 cm(3)) or in fertile men without varicoceles (23.4 +/- 8.3 cm(3)). Sperm concentration was lower in infertile men with varicoceles (33.7 +/- 23.3 x 10(6)/mL) than in fertile men with varicoceles (101.8 +/- 76.6 x 10(6)/mL) or in fertile men without varicoceles (111.8 +/- 74.2 x 10(6)/mL). In addition, sperm motility was lower in infertile men with varicoceles (37.2% +/- 23.9%) than in fertile men with varicoceles (53.9% +/- 17.4%) or fertile men without varicoceles (58.9% +/- 15.8%).

CONCLUSION(S)

Infertile patients with varicoceles have higher levels of FSH, smaller testes, and lower sperm concentration and motility compared with controls with or without varicoceles. No statistical differences were seen in the variables evaluated among the fertile men with incidental varicoceles detected at physical examination and those without varicoceles.

Pre-decondensed sperm head injections into female pronuclei result in chromosomal mingling, zygotic cleavage, and adequate embryonic and fetal development up to delivery of healthy offspring: a novel method of assisted syngamy

Investigation of the developmental potential post-injection of a pre-decondensed or non-pre-decondensed sperm head into the female pronucleus of a pre-activated oocyte. Rat pre-activated oocytes were treated with intrapronuclear pre-decondensed sperm head injections (IPSHI) (n = 133) or intrapronuclear non-pre-decondensed sperm head injections (INPSHI) (n = 138). All injected oocytes were transferred to pseudopregnant female recipients. Rat IPSHI techniques resulted in the delivery of five healthy offspring. Rat INPSHI techniques did not result in any pregnancies. Rat IPSHI techniques can result in delivery of healthy offspring. Successful performance of human IPSHI techniques might serve as a novel method to manage cases of intracytoplasmic sperm injection failure due to lack of development of male pronucleus or due to failure in pronuclei fusion.

Effect of surgically induced varicocele on testicular blood flow and Sertoli cell function

OBJECTIVES

To evaluate the effect of varicocele on testicular blood flow and expression by Sertoli cells of transferrin and androgen-binding protein (ABP), to determine whether varicoceles impair Sertoli cell function.

METHODS

Experimental varicocele was established in male Sprague-Dawley rats by partial ligation of the left renal vein. The control group received a sham operation. At 30 minutes after surgery, rats underwent a xenon-133 washout study, and at 30 days after surgery, transferrin, ABP, and testicular blood flow were evaluated. Expression of transferrin and ABP were evaluated using immunohistochemical techniques. Testicular blood flow was measured using xenon-133 clearance techniques. Statistical analyses were done with an independent t test.

RESULTS

The testicular blood flow was 16.7 +/- 1.25 mL/100 g/min in varicocele-bearing rats and 21.01 +/- 0.46 mL/100 g/min in sham-operated rats 30 minutes after surgery. Testicular blood flow remained decreased at 30 days in varicocele-bearing rats (15.12 +/- 1.08 mL/100 g/min) and remained stable in the control group (19.45 +/- 0.55 mL/100 g/min). The expression of transferrin and ABP was significantly reduced in varicocele-bearing rats compared with the control group.

CONCLUSIONS

Our study suggests that a decrease in testicular blood flow may lead to impaired Sertoli cell function in varicocele-bearing rats.

Beneficial effects of electrical stimulation before round spermatid nuclei injections into rabbit oocytes on fertilization and subsequent embryonic development

OBJECTIVE

To evaluate the effects of electrical stimulation of rabbit oocytes before round spermatid nuclear injection procedure on oocyte activation and fertilization.

DESIGN

The ratio of activated oocytes to the number of successfully injected oocytes and the proportion of offspring to the number of activated oocytes after round spermatid nuclear injections into oocytes stimulated via mechanical stimulation (group A) or a combination of electrical and mechanical stimulation (group B) was compared.

INTERVENTIONS

Round spermatid nuclei were isolated from mature male rabbits and microinjected into the oocytes of groups A and B. Injected oocytes were cultured for 24 hours. The embryos developed from groups A and B were transferred to synchronized recipient does.

RESULTS

Embryos that developed normally through implantation in groups A and B were carried successfully through complete gestation in the recipient does. The ratio of the activated oocytes to the number of successfully injected oocytes and the proportion of offspring to the number of activated oocytes were significantly higher in group B.

CONCLUSION

Electrical stimulation of oocytes before ooplasmic spermatid nuclear injections and ET procedures has beneficial effects on oocytes activation, fertilization, and subsequent embryonic development.

Reproductive capacity of the nucleus of the male gamete after completion of meiosis

PURPOSE

Our purpose was to investigate the possibility of achieving fertilization and subsequent normal embryonic development by injecting round spermatid nuclei into rabbit oocytes.

RESULTS

Two-to four-cell-stage embryos developed after round spermatid nuclear injections into rabbit ooplasma could further develop in vitro up to the expanding blastocyst stage or in vivo up to complete gestation.

CONCLUSION

The current findings show that the haploid set of chromosomes of round spermatid can pair with the chromosomes of the ootid to participate in complete fertilization and subsequent embryonic and fetal development. In addition, we suggest that postmeiotic modifications of the round spermatid are not required for the pairing of male gamete chromosomes with those of the ootid.

Anatomical characteristics of the left testicular venous system in man

Autopsy was performed on 49 male cadavers and the entire course of the left testicular vein (LTV) was studied. The testicular venous pathway was divided into four levels: scrotal, inguinal, pelvic, and lumbar. At the scrotal level, many small testicular veins constituting the pampiniform plexus showed various anastomoses with the cremasteric and vasal veins. At the inguinal and pelvic level, 4-12 and 2-8 LTVs were recognized, respectively. At the pelvic level, absence of valves was seen in 33% of the cases. At the lumbar level, 1-5 LTVs were observed and were mainly anastomosed with the retroperitoneal, ureteral, and kidney capsular veins. Absence of valves at the lumbar level was seen in 37% of the cases. In 11 cases, the valves that were present were incompetent. The presence of more than one LTV at the lumbar level indicates the necessity for attentive identification of all of the testicular veins during surgical treatment of varicocele.