Central role of ultrasound in the evaluation of testicular function and genital tract obstruction in infertile males.

BACKGROUND: Scrotal color Doppler ultrasonography and transrectal ultrasonography provide crucial information about the clinical status of testes and male accessory glands. OBJECTIVE: To analyze the impact of ultrasound in the evaluation of infertile males. MATERIALS AND METHODS: A total of 1120 records from infertile men were retrospectively evaluated (from January 2016 up to June 2020). Data on physical examination, semen analysis, sperm culture, scrotal color Doppler ultrasonography and transrectal ultrasonography, as well as sex hormones were analyzed. Among them, 238 reports from oligozoospermic/azoospermic infertile patients (P) fulfilling the inclusion criteria were considered for data analysis. Patients were subdivided into two groups according to follicle-stimulating hormone (FSH) values (Pa with FSH < 8 U/L and Pb with FSH ≥ 8 U/L). Sixty-three fertile volunteers (mean ± SD years) were enrolled as controls (C). RESULTS: A higher prevalence of ultrasound abnormalities was recorded in P compared to C. Pb group had significantly lower bitesticular volume compared to Pa and C. Pa had a higher prevalence of transrectal ultrasonography abnormalities than Pb (69.9% vs. 38.4%), whereas Pb had a higher prevalence of abnormalities at scrotal color Doppler ultrasonography (60.0% vs. 28.3%, both p < 0.01). Bitesticular volume was inversely proportional to the number of altered seminal parameters and able to predict gonadotropin levels. A bitesticular volume <17 cc was associated with a higher risk of azoospermia (odds ratio = 1.799). Intratesticular vascularization was inversely correlated with gonadotropin levels and directly correlated with sperm count. A higher prevalence of prostate and seminal vesicle alterations was detected in patients and in Pa group, when compared with Pb group. DISCUSSION AND CONCLUSION: Ultrasound abnormalities are correlated with seminal parameters and may guide the clinician in the diagnostic workflow of male infertility, suggesting spermatogenesis impairment or genital tract obstructions.

Assessment of the accuracy of testicular dysfunction detection in male donkey (Equus asinus) with the aid of colour-spectral Doppler in relation to plasma testosterone and serum nitric oxide levels.

This study aimed to determine the usefulness of colour and pulsed Doppler modes for the accurate diagnosis of donkeys suffering from subfertility to determine whether testicular vascularity assessment could be an indicator for sperm functionality. The study sample was composed of 10 male donkeys with normospermia (control group) and 10 donkeys with hypospermia. Animals underwent scrotal circumference measurement, testicular Doppler examination, seminal evaluation, blood sampling and hormonal assay. Semen volume and concentration were significantly (p ≤ .05) lower in the subfertile group (30.25 ± 1.22 ml and 89.44 ± 2.55 × 106 /ml) as compared with the control group (82.76 ± 1.65 ml and 452.78 ± 1.25 × 106 /ml), and total sperm/ejaculation was significantly (p ≤ .05) higher in the normal donkeys (28.30 ± 2.32 × 109 /total ejaculated) as compared with the subfertile group. Intratesticular coloured area showed a marked decline in the hypospermic males. There was no significant difference between the two groups in testosterone level, although the normal group showed an increase in nitric oxide metabolites. Both Doppler indices of the three branches of the testicular artery were elevated significantly (p ≤ .05) in abnormal donkeys, whereas Doppler peak systolic and end-diastolic velocities were increased in the normal group. Male donkeys with subfertility demonstrated lower arterial vascularity parameters in the form of intratesticular coloured area and blood flow rate; therefore, the most optimal parameters for differentiating subfertile hypospermic from normospermic donkeys were found to be the two Doppler indices, velocities parameters, testicular blood flow rate and nitric oxide levels.

Extreme spermatogenesis failure: andrological phenotype and intracytoplasmic sperm injection outcomes.

Patients with very low sperm count through direct sperm examination can exhibit extreme oligozoospermia or cryptozoospermia (after centrifugation). The management of these patients is a real challenge for both clinicians and biologists. In this retrospective and comparative cohort study, we compared the andrological phenotype of patients with extreme alterations of spermatogenesis and assessed whether the origin of spermatozoa (testicular or ejaculate) had any influence on intracytoplasmic sperm injection (ICSI) outcomes. A total of 161 ICSI cycles were performed using ejaculated spermatozoa from 75 patients with extreme oligozoospermia (EOS) or cryptozoospermia (CS) and 150 ICSI cycles using extracted testicular spermatozoa from 74 patients with non-obstructive azoospermia (NOA). Physical, hormonal, ultrasound assessments, and ICSI outcomes were performed in each group. Cryptorchidism was significantly more frequent in the NOA group (60.8% vs. 22.6%, p = 0.001). FSH levels were significantly higher [18.9 IU/L (5.9-27.0) vs. 15.3 IU/L (9.0-46.5), p = 0.001] and the majority of inhibin B levels measured were found mostly undetectable in the NOA group as compared to EOS/CS group (31.1% vs. 10.7%, p = 0.0004). Moreover, we found no significant differences in the respect to the fertilization rates (48.9% and 43.3%, p = 0.43), implantation rates (17.4% and 15.9%, p = 0.77), and percentage of top quality embryo (22.4% and 20.4%, p = 0.73) between the two groups. The clinical pregnancy rates per embryo transferred were comparable in both groups (28.3% and 27.4%, p = 0.89). In this study, we showed for the first time a different andrological phenotype between EOS/CS and NOA groups. Indeed, cryptorchidism was significantly more frequent with more severe endocrine parameters found in the NOA group. These results reflect a more profound alteration in spermatogenesis in NOA patients. However, there was no difference in ICSI outcomes between NOA and EOS/CS groups.

Prednisone treatment in infertile patients with oligozoospermia and accessory gland inflammatory alterations.

The association between inflammation of the male reproductive system and oligozoospermia has been frequently reported in the clinical work-up of male infertility. To improve sperm parameters in infertile patients with genital inflammation, many phytochemical and nutraceutical drugs are currently being used. However, their use is still empirical and no conclusive data have been provided about their efficacy. The treatment with steroid anti-inflammatory drugs might be useful in reducing inflammation and improving sperm parameters, thus increasing the fertility outcome. The aim of this study was to evaluate if glucocorticoid treatment improves seminal parameters in infertile oligozoospermic patients presenting signs of accessory gland inflammation at genital ultrasound. A total of 90 infertile patients were enrolled in the study. They presented normal testicular volume, normal FSH plasma levels, the presence of various degrees of oligozoospermia, associated with scrotal and trans-rectal ultrasound signs indicative of accessory gland inflammation, but negative microbiological analysis on semen and/or prostatic secretions. Patients were randomly allocated into three groups of treatment, receiving, respectively, 5, 12.5, and 25 mg daily oral Prednisone for one month. Seminal parameters were evaluated at admission and after treatment. In patients undergoing Prednisone treatment at a daily dose of 5 mg we observed a significant increase in total sperm count. At a daily dose of 12.5 mg, Prednisone treatment improved sperm concentration, total sperm count, and the percentage of sperm motility. Twenty-five mg of Prednisone led to significant improvement in all the sperm parameters, except for semen volume. These results clearly demonstrate that Prednisone treatment can significantly improve sperm parameters in a selected population of oligozoospermic patients. These findings suggest that Prednisone treatment should be considered in idiopathic oligozoospermic patients with supposed normal spermatogenesis and accessory gland inflammatory alterations, in order to improve sperm parameters and fertility outcome.

Testicular contrast harmonic imaging to evaluate intratesticular perfusion alterations in patients with varicocele.

PURPOSE: To determine whether changes in intratesticular microcirculation perfusion affect spermatogenesis in patients with left varicocele we performed testicular contrast harmonic imaging. MATERIALS AND METHODS: A total of 90 patients with left varicocele (oligospermia in 50 and normozoospermia in 40) and 36 controls without varicocele (oligospermia in 16 and normozoospermia in 20) were enrolled in the study. Before contrast harmonic imaging all participants were evaluated by clinical examination, hormonal analysis, semen sample and scrotal ultrasound. We calculated contrast material arrival time in the arteriolar circulation (wash-in), time to peak in arterial circulation, arrival time in the venular circulation (washout) and mean transit time in each testis on contrast harmonic imaging. RESULTS: We found no difference in the distribution rate of varicocele grade in patients with vs without oligospermia. All contrast harmonic imaging parameters were significantly higher in patients with varicocele plus normozoospermia or oligospermia and controls. We found no significant differences in contrast harmonic imaging parameters in patients with lower varicocele grading with respect to the higher grades. In patients with varicocele we found a negative linear correlation between total sperm count and left mean transit time (r = -0.29). In a multivariate model left mean transit time was the only independent predicting parameter of oligospermia (p <0.05). Mean transit time greater than 36 seconds predicted oligospermia in patients with left varicocele with 78% sensitivity and 58% specificity. CONCLUSIONS: To our knowledge we report for the first time that testicular contrast harmonic imaging may be a new diagnostic tool able to improve our knowledge about the influence of varicocele on intratesticular microcirculation.

Assessment of the intratesticular resistive index by colour Doppler ultrasonography measurements as a predictor of spermatogenesis.

OBJECTIVE: To investigate the value of the resistive index (RI) of intratesticular arteries, and to establish diagnostic criteria for normal and pathological sperm counts on the basis of quantitative colour Doppler ultrasonography (CDUS), as the assessment of the testicular RI is widely used to measure intratesticular blood flow. PATIENTS AND METHODS: In all, 160 men (aged 22-43 years, 320 testicles) were prospectively investigated; 80 had a normal and 80 a pathological sperm count, the latter having mild oligoasthenozoospermia. The RI was measured using a high-frequency Doppler ultrasound probe (14 MHz), three times on each testicle at an intratesticular artery in the upper, middle and lower testicular pole. The testicular volume was also measured by US. The RI values were compared between patients with normal and pathological sperm counts, and were compared statistically with testicular volumes. In addition, blood samples were obtained for DNA extraction, chromosome analysis and hormonal evaluations. RESULTS: Patients with normal sperm counts had a mean (sd) RI of 0.54 (0.05) and a mean testicular volume of 18.7 (5.2) mL, the respective values in those with pathological sperm counts were 0.68 (0.06) and 16.8 (6.0) mL, with a significantly greater RI in the latter (P < 0.001), but with no statistically significant difference in testicular volume between the groups (P > 0.05). CONCLUSION: These preliminary data suggest that an RI of >0.6 might be suggestive of a pathological sperm count in andrological patients. The intratesticular RI as measured by CDUS seems to be a reliable indicator for routine clinical use to identify subfertile men.

Increased total antioxidant capacity in seminal plasma of varicocele patients: a multivariate analysis.

To investigate seminal antioxidant systems and their correlation with hormonal pattern in varicocele patients, we studied 33 varicocele (VAR) patients (12 oligozoospermic, 21 normozoospermic) and 34 non-VARs (10 idiopathic oligozoospermic, 24 normozoospermic). Non-enzymatic total antioxidant capacity (TAC) was measured using H(2)O(2)-metamyoglobin, which generates the radical form, spectroscopically detectable, of the chromogen 2,2',-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS): time till appearance (Lag) of ABTS*(-) signifies antioxidant concentration. Lag was significantly longer in VARs than controls suggesting ineffective utilization of antioxidants. A significant direct correlation (r = 0.65, p < 0.01) of Lag with sperm count was observed in non-VARs, while in VARs it was inverted, as well as with hematic FSH levels. A multivariate analysis including FSH, Lag, progressive spermatozoa, oligozoospermia and varicocele indicated a strong inverse correlation between FSH and motility (r(2) = 0.31, p > F = 0.0007), not modified by Lag (r(2) = 0.31, p > F = 0.002). Their inverse correlation with Lag may suggest that higher FSH levels, improving sperm antioxidant efficiency, counterbalance varicocele-induced dyspermia.

Large-needle percutaneous aspiration biopsy of the testicle in men with nonobstructive azoospermia.

Two hundred thirteen testicular specimens of men with nonobstructive azoospermia were obtained by large-needle percutaneous aspiration biopsy. The mean values of the number of seminiferous tubules per histologic section, dimension, weight, and the fraction of biopsies with spermatogenetic cells (53, 0.2 x 0.3 x 0.62 cm, 385 mg, and 63%, respectively) were similar to those obtained by open or other surgical biopsy techniques that were used for assisted fertilization in the same type of patients.

Sperm recovery prediction in azoospermic patients using Doppler ultrasonography.

PURPOSE: To evaluate power Doppler ultrasonography to predict sperm recovery in azoospermic patients. METHODS: Color Doppler and power Doppler ultrasonography of testis were performed in 38 patients before testicular sperm extraction. Analysis of blood flow included the pulsatility and resistance index of intratesticular vessels and testicular artery, and power Doppler of testis. The results of power Doppler of testis were classified into three categories: 0, no vessels found; 1, one to three vessels; 2, more than three vessels found. RESULTS: Power Doppler of both testis showed a significant difference between obstructive azoospermia and non-obstructive azoospermia (Fisher's exact test - P = 0.02), and between the groups with and without sperm recovery (Fisher's exact test - P = 0.001). Doppler indices of intratesticular vessels and testicular artery were similar between the groups. CONCLUSIONS: Testicular Power Doppler assessment showed that patients with obstructive azoospermia have better blood flow than patients with non-obstructive azoospermia, and power Doppler is able to predict sperm recovery in azoospermic patients.

Power Doppler ultrasound mapping in nonobstructive azoospermic patients prior to testicular sperm extraction.

This study was conducted to localize the testicular regions, which have better blood circulation by power Doppler ultrasonography in patients with nonobstructive azoospermia before testicular sperm extraction (TESE), and to investigate whether these vascularized areas have a high sperm retrieval rate or not. We evaluated 110 testes of 55 cases that were diagnosed as nonobstructive azoospermia. The mean age of the study group was 33 years (range 26 to 42). Patients with Y chromosome microdeletions, karyotype and hormonal abnormalities (except elevated FSH levels) were excluded from the study. In all cases, testes were evaluated by power Doppler ultrasonography before testicular sperm extraction. Testis was divided vertically into five equal parts and the area with maximum vascularity was determined subjectively. During testicular sperm extraction, starting from best-perfused areas, biopsies were done. If no motile or sufficient amount of sperm was found, TESE procedure was tried on the contralateral testis. TESE were performed from 82 testes and for the regions that show good and poor vascularity. The sperm finding rate was 38% and 14%, respectively (OR = 3.55)(p = 0.001). Power Doppler ultrasound mapping of the testis in nonobstructive azoospermic cases is a reliable and informative method to assess spermatogenic foci. It is a noninvasive technique that minimizes the unnecessary removal of hormone producing tissue and gives chance to end the TESE earlier than currently practiced procedures.

Fine-needle and large-needle percutaneous aspiration biopsy of testicles in men with nonobstructive azoospermia: safety and diagnostic performance.

OBJECTIVE: To assess by ultrasonography the safety of the association fine-needle aspiration (FNA) plus a new percutaneous large-needle aspiration biopsy technique (LNAB), and to compare the results obtained with the two techniques in the same testicle and with FNA in the two testicles of the same patient. DESIGN: Retrospective analysis of clinical, ultrasonographic, and pathologic data. SETTING: Clinical and academic research environment. PATIENT(S): Three hundred and eighty-seven testicles of 233 patients (ages 19 to 57 years) with nonobstructive azoospermia were consecutively examined with FNA (154) or FNA + LNAB (233); 54 patients (89 testicles) examined with FNA + LNAB underwent a second ultrasonography up to 63 days after. INTERVENTION(S): Ultrasonography, FNA, LNAB. MAIN OUTCOME MEASURE(S): Hypoechoic area at ultrasonography; cytologic picture at FNA or LNAB of only Sertoli cells (category 1), spermatogenetic cells different from elongated spermatids or spermatozoa (category 2), and elongated spermatids and/or spermatozoa (category 3). RESULT(S): Among the 54 patients monitored by ultrasonography 48 (88.9%) showed no difference and 6 (11.1%) showed an hypoechoic area < or =1 cm in the second image. Category 1 occurred at FNA or LNAB in a very similar number of testicles (36% vs. 36.9%). Categories 2 and 3 were more frequent at LNAB (29.9% vs. 9.8%) and at FNA (54.2% vs. 33.2%), respectively. One hundred and sixty-six patients had both testicles examined by FNA; 147 pair of testicles were concordant for the presence or the absence of spermatozoa or elongated spermatids. In the remaining 19 patients (11.4%), these spermatogenetic cells were shown only in the specimen from one of the two testicles. These 19 patients accounted for 20.0% of 93 patients with spermatogenetic cells in at least one of the two testicles. CONCLUSION(S): The combination of FNA and LNAB did not produce clinically or subclinically relevant complications. No important differences in the identification of category 1 with FNA or LNAB were found. Fine-needle aspiration was more adequate in identifying category 3, which was particularly relevant in 20% of the men who had these cells in at least one of the two testicles.

Etiology of azoospermia in 100 consecutive nonvasectomized men.

History was taken systematically for 100 azoospermic, nonvasectomized men referred consecutively to a Danish fertility clinic. The men were examined by ultrasound, and their blood samples were analyzed for karyotype, Y microdeletions, and cystic fibrosis transmembrane conductance regulator gene mutations. In 29% of patients, the condition could be explained by genetic abnormalities; in 22%, by diseases or external influence; and in 27%, by former cryptorchidism. The azoospermic condition remained unexplained in only 22%.

Sonographic evidence of minimal and short-term testicular damage after testicular sperm aspiration procedures.

OBJECTIVE: To evaluate ultrasonically the incidence and duration of tissue damage after testicular sperm aspiration (TESA) procedures. DESIGN: Prospective, nonrandomized study. SETTING: Assisted reproductive technology program. PATIENT(S): Thirty-two men with obstructive azoospermia. INTERVENTION(S): Physical and serial testicular ultrasound examinations 1.5, 3, and 6 months after the surgical procedure. MAIN OUTCOME MEASURE(S): Systematic evaluation of the testicular parenchyma and blood flow. RESULT(S): In 93.7% of the patients (30 of 32), no evidence of parenchymal or vascular injuries was found 6 weeks after the procedure. In the remaining 2 patients, transient evidence of tissue damage disappeared after 3 months. CONCLUSION(S): Testicular sperm aspiration is a safe surgical method for sperm retrieval for IVF. Repeated surgical attempts might be considered within 2 months, provided there is no evidence for tissue damage on sonography.

A new power Doppler ultrasound guiding technique for improved testicular sperm extraction.

OBJECTIVE: To develop a noninvasive procedure that employs image processing of power Doppler ultrasound (PDUS) images of several orthogonal cross-sections of the testis to construct a three-dimensional (3D) mapping of preferential testicular regions in which spermatozoa are most likely to be found in nonobstructive azoospermic testes. DESIGN: Clinical study. SETTING: Ultrasound and andrology units in a large university-affiliated municipal hospital. PATIENT(S): Twenty-four nonobstructive azoospermic men. INTERVENTION(S): Before testicular sperm extraction was performed, PDUS images were acquired at seven cross-sections to reconstruct a 3D testicular vascularity index (TVI) matrix for spatial mapping of testicular regions in which spermatozoa are most likely to be found. The predictions based on TVI values of 107 regions were compared with the biopsy results. MAIN OUTCOME MEASURE(S): Prediction of presence or absence of spermatozoa by TVI values. RESULT(S): The prediction rate of the TVI matrix for the presence or absence of spermatozoa was 74.8%. The positive predicted value was 72%, negative predicted value was 75.6%, and specificity was 89.8%, but sensitivity was 47.3%. CONCLUSION(S): Our technique may obviate the need for arbitrary multiple biopsies that inflict some degree of damage upon testicular tissue and may increase the success rate of identifying viable spermatozoa in testicular tissue.

A case report of CUAVD with azoospermia: a proposal of a rational diagnostic approach.

Since its introduction in 1992, intracytoplasmic sperm injection (ICSI) has made the treatment of severe male infertility possible, particularly that of azoospermia, both secretory and secretory. Some azoospermic subjects have a pathological development of the seminal pathways, and in particular of the vas deferens and/or ejaculatory ducts. A large part of these subjects show, like patients affected by cystic fibrosis, mutations in the cystic fibrosis transmembrane regulator (CFTR) gene. Some of these azoospermic subjects are indeed paucisymptomatic fibrosis cystic patients who bear the risk of transmitting cystic fibrosis, seminal pathways alterations and, possibly, renal malformations to their offspring. We describe a case of an infertile patient with right CUAVD and azoospermia previously treated by crossed epididimovasostomy in the absence of any genetic and an adequate anatomic evaluation. He was then found to be CFTR mutation positive and without demonstrable spermatozoa in the vesicular fluid despite ultrasound evidence of left ejaculatory duct obstruction. During the second TESA-ICSI cycle an ongoing pregnancy was obtained. An extensive genetic examination for CFTR mutations and a through anatomical study is, therefore, mandatory in these patients to select the most appropriate treatment in CFTR mutation positive and negative CUAVD patients.

The role of ultrasonographically guided puncture of the human rete testis in the therapeutic management of nonobstructive azoospermia.

We attempted to characterize the cells collected from the rete testis via ultrasonographically guided puncture. Unilateral puncture of the rete testis was performed in nine men with obstructive azoospermia and 51 men with nonobstructive azoospermia. All the aspirated samples from the rete testis were observed via confocal scanning laser microscope and some of them after fluorescent in situ hybridization techniques. Then therapeutic testicular biopsy was performed in the punctured testis of each man. Spermatozoa were found in all rete testis samples and all biopsy samples from obstructed men. Twenty-two nonobstructed men demonstrated absence of spermatozoa in biopsy samples. Twenty-nine nonobstructed men showed spermatozoa in biopsy material and 24 of these men (82%) had demonstrated spermatozoa in rete testis samples. There were no significant differences in fertilization and cleavage rate between intracytoplasmic sperm injection trials using biopsy spermatozoa and rete testis spermatozoa both in obstructed and nonobstructed men. Considering that puncture of the rete testis does not reduce the volume of testicular parenchyma, is less invasive and apparently causes less detrimental effect on testicular vasculature than biopsy, puncture of rete testis is recommended as first line approach for the treatment of azoospermic men. If puncture is negative for spermatozoa in nonobstructed men, biopsy is indicated.

Clinical and endocrine follow-up of patients after testicular sperm extraction.

OBJECTIVE: To evaluate the risk of testicular damage from testicular biopsies that are carried out for testicular sperm extraction (TESE) in infertile men. DESIGN: Prospective controlled clinical study. SETTING: Academic hospital. PATIENT(S): Forty infertile males with azoospermia. Examination of the clinical, endocrine, biochemical, and sonographic data in average after 18 months after TESE was performed. MAIN OUTCOME MEASURE(S): Measurements before and after TESE: hormone values, testicular size, morphologic characteristics, and power Doppler after scrotal sonography. RESULT(S): Comparison of preoperative and postoperative values of basal testosterone, FSH, LH, and estradiol levels did not reveal any differences. Twelve of 26 patients had subnormal testosterone values before TESE; 14 of 39 patients had subnormal levels afterward. Postoperative sonographic measurements showed no significant difference of the testicular volume as compared with the preoperative values. Results of power Doppler sonography revealed pathological conditions (n = 5) in patients with former iliacal or testicular operations. CONCLUSION(S): Endocrine testicular function and testicular size were not impaired after testicular biopsy when compared with preoperative data. However, patients with nonobstructive azoospermia seem to be at risk for androgen deficiency due to primary testicular failure after repeated testicular biopsies.

Spermatogenesis and spectral echo-colour Doppler traces from the main testicular artery.

OBJECTIVE: To assess whether the peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive index (RI) of testicular arteries may be useful in distinguishing the various causes of dyspermia when compared with follicle-stimulating hormone (FSH) and testicular volume. PATIENTS, SUBJECTS AND METHODS: The study included nine men with obstructive and 20 with unobstruc-tive azoospermia, 17 with oligoasthenospermia and clinical varicoceles, with male accessory glans inflammation (MAGI), 38 with undetermined oligoasthenospermia, 19 with MAGI, 11 with clinical varicoceles, 32 subjects with normal sperm analysis and recent paternity (fertile controls), and 15 with normal sperm analysis and a varicocele with recent paternity (fertile + varicoceles). Testicular volume, FSH, PSV, EDV and RI were compared among the dyspermic and/or control groups using analysis of variance. RESULTS: The PSV and RI were useful for identifying the different groups of patients, while EDV, FSH and testicular volume were not. Men with varicoceles, varicoceles + MAGI or fertile with varicoceles had the highest PSV and RI; fertile controls, those with obstructive azoospermia and MAGI had similar PSVs and RIs, those with unexplained oligoasthenospermia had a significantly lower PSV and RI, and men with unobstructive azoospermia had the lowest PSV and RI. CONCLUSIONS: The RI and PSV are reliable indicators for routine clinical use to identify infertile/dyspermic men, while EDV, FSH and testicular volume are not. The RI and especially PSV clearly differentiated obstructive from unobstructive azoospermia.