Conventional testicular sperm extraction (TESE) and non-obstructive azoospermia: is there still a chance in the era of microdissection TESE? Results from a single non-academic community hospital

A detection model of testis-derived circular RNAs in serum for predicting testicular sperm retrieval rate in non-obstructive azoospermia patients

BACKGROUND

Microdissection testicular sperm extraction is an effective method to retrieve sperm from non-obstructive azoospermia patients. However, its successful rate is less than 50%.

OBJECTIVES

To identify the predictive value of circular RNAs in serum for sperm retrieval rate in non-obstructive azoospermia patients.

MATERIALS AND METHODS

180 non-obstructive azoospermia patients were recruited in this study, including 84 individuals with successful sperm retrieval and 96 individuals with failed sperm retrieval. Our study contained two phases. First, 20 patients, selected from the 180 patients, were included in screening cohort. In this cohort, the top 20 circular RNAs from our previous testicular circRNA profiles were verified between successful and failed sperm retrieval groups using real-time polymerase chain reaction. Six circular RNAs with the most significantly different expressions were selected for further verification. Second, the 180 patients were included as discovery cohort to verify the six circular RNAs. Circular RNAs were extracted from serum in each participant. Logistic regression analysis was further performed to identify the predictive value and the area under the curve analysis was used to evaluate diagnostic efficiency, sensitivity, and specificity.

RESULTS

Six circular RNAs including hsa_circ_0058058, hsa_circ_0008045, hsa_circ_0084789, hsa_circ_0000550, hsa_circ_0007422, and hsa_circ_0004099 showed aberrant expressions between the successful and failed sperm retrieval group. In addition, both single-circular RNA panels and multi-circular RNA panels were finally verified to be significant in predicting sperm retrieval rate. Notably, multi-circular RNAs panels demonstrated better predictive abilities compared with single-circRNA panels, and the combined panel of six-circular RNAs (risk score = 1.094×hsa_circ_0058058+0.697×hsa_circ_0008045+0.718×hsa_circ_0084789-0.591×hsa_circ_0000550-0.435×hsa_circ_0007422-1.017×hsa_circ_0004099-1.561) exhibited the best predictive ability in the present study with an AUC of 0.977, a sensitivity of 91.7% and a specificity of 86.5%. A higher risk score indicated a higher risk of failure in sperm retrieval.

DISCUSSION AND CONCLUSION

Our study was the first to report that testis-derived circular RNAs in serum have the ability to predict sperm retrieval rate in non-obstructive azoospermia patients, whether it is a single-circular RNA or a combination of multi-circular RNAs.

Micromapping testicular sperm extraction: A new technique for microscopic testicular sperm extraction in nonobstructive azoospermia

Purpose

In microscopic testicular sperm extraction (mTESE) for nonobstructive azoospermia (NOA), sperm can be recovered relatively easily in some cases, and mTESE may be retrospectively considered excessive. However, mTESE is routinely performed in the majority of NOA patients because of the difficulty in predicting tissue status. A minimally invasive and comprehensive sperm retrieval method that allows on-the-spot tissue assessment is needed. We have developed and evaluated a novel sperm retrieval technique for NOA called micromapping testicular sperm extraction (MMTSE).

Methods

MMTSE involves dividing the testis into four sections and making multiple small needle holes in the tunica albuginea to extract seminiferous tubules and retrieve sperm. The sperm-positive group by MMTSE (Group I) underwent additional tissue collection (ATC) via a small incision, whereas the sperm-negative group by MMTSE (Group 0) underwent mTESE.

Results

In total, 40 NOA participants underwent MMTSE. Group I included 15 patients and Group 0 included 25 patients. In Group 1, sperm were recovered from all patients by ATC. In Group 0, sperm were recovered in 4 of 25 cases using mTESE.

Conclusions

MMTSE shows promise as a simple method that comprehensively searches testicular tissue and retrieves sperm using an appropriate method while minimizing patient burden.

Outcomes and affecting factors for ICSI and microTESE treatments in nonobstructive azoospermia patients with different etiologies: A retrospective analysis

INTRODUCTION

Nonobstructive azoospermia (NOA) is a common and severe form of male infertility. Microdissection testicular sperm extraction (microTESE) combined with intracytoplasmic sperm injection (ICSI) is an optimal treatment for men with NOA. However, the outcomes and affecting factors of ICSI for NOA patients with different etiologies receiving microTESE treatment are still unclear.

METHODS

A total of 335 NOA patients undergoing microTESE from January 2017 to December 2021 were included in this retrospective analysis. The patients were divided into five groups (idiopathic, Klinefelter syndrome (KS), Y chromosome microdeletions (YCMDs), cryptorchidism and mumps orchitis) according to the etiologies. The clinical characteristics and outcomes of microTESE and ICSI were collected and comparisons were performed between clinical characteristics of patients who had successful sperm retrieval (SSR) and sperm retrieval failure (SRF). In addition, relationships between clinical characteristics and rates of SSR were explored by Kendall correlation analysis.

RESULTS

The overall SSR rate was 40.90%. SSR rate of the idiopathic group (31.22%) was the lowest and was much lower than that of other groups (KS: 48.65%, 28/58; YCMDs: 60.87%; cryptorchidism: 80.95%; mumps orchitis: 75.00%). The overall fertilization rate was 72.26%. No group differences were found among five groups (idiopathic: 73.91%; KS: 71.43%; YCMDs: 64.29%; cryptorchidism: 70.59%; mumps orchitis: 77.78%). The overall clinical pregnancy rate was 66.67%. No group differences were found among five groups (idiopathic: 68.63%; KS: 65.00%; YCMDs: 44.44%; cryptorchidism: 66.67%; mumps orchitis: 85.71%). The overall live birth rate was 66.67%. No group differences were found among five groups (idiopathic: 71.43%; KS: 53.85%; YCMDs: 50.00%; cryptorchidism: 75.00%; mumps orchitis: 66.67%). For SSR patients, the average age was significantly lower in the idiopathic group, while the average testicular volume was significantly greater in the cryptorchidism and mumps orchitis groups. However, no significant differences were found in the level of follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T) between patients who had SSR and SRF. In addition, negative relationships were found between age and rates of SSR in idiopathic NOA patients while positive relationships were found between testis volume and rates of SSR in patients with cryptorchidism and mumps orchitis.

CONCLUSION

Patients with idiopathic NOA had lowest SSR. In addition, the age in idiopathic NOA patients was a predictor for SSR while testicular volume in NOA patients with cryptorchidism and mumps orchitis was a predictor for SSR. However, the relationships between clinical characteristics and clinical outcomes in NOA patients were preliminary, and further validation needed to be carried out in a larger sample to increase statistical capacity before a definitive conclusion could be drawn.

A magnetic resonance imaging study in etiology of nonobstructive azoospermia

BACKGROUND

Testicular magnetic resonance imaging parameters, including apparent diffusion coefficient, fractional anisotropy, magnetization transfer ratio, and normalized metabolite concentrations represent useful noninvasive fingerprints of nonobstructive azoospermia. Nonobstructive azoospermia etiology might correlate with the spermatogenesis status.

OBJECTIVES

To assess the possible association between apparent diffusion coefficient, fractional anisotropy, magnetization transfer ratio, and normalised metabolite concentrations with nonobstructive azoospermia etiology.

MATERIALS AND METHODS

This retrospective study included 48 consecutive men with nonobstructive azoospermia and 18 age-matched controls. All participants underwent scrotal magnetic resonance imaging. The testicular apparent diffusion coefficient, fractional anisotropy, magnetization transfer ratio, and normalized metabolite concentrations were calculated. nonobstructive azoospermia men were classified into three groups, based on etiology: group 1, idiopathic; group 2, genetic causes; and group 3, non-genetic causes. Parametric and nonparametric statistical tests were used to evaluate differences in magnetic resonance imaging parameters between nonobstructive azoospermia groups and normal testes (group 4). Regression analysis was performed to assess the most predictive magnetic resonance imaging factor of nonobstructive azoospermia etiology.

RESULTS

Differences in mean apparent diffusion coefficient (p < .001), fractional anisotropy (p < .001), magnetization transfer ratio (p < .001), and normalized concentrations of total choline (p = .005), glucose (p = .012), myo-inositol (p = .024), and lipids (p = .010) were observed among groups. Regression analysis failed to identify the most discriminating magnetic resonance imaging feature for nonobstructive azoospermia etiology.

DISCUSSION AND CONCLUSION

Apparent diffusion coefficient, fractional anisotropy, magnetization transfer ratio, and normalized concentrations of total choline, glucose, myo-inositol, and lipids are helpful in discriminating nonobstructive azoospermia etiology. Magnetic resonance imaging may provide useful, noninvasive information on the microstructural and biochemical milieu of nonobstructive azoospermia testes.

The evolution of testicular sperm extraction and preservation techniques

Along with the advent of intracytoplasmic sperm injection in 1992, sperm retrieval procedures now allow the possibility of conception from male sterility. In cases of sterility due to blockages in the reproductive tract, sperm retrieval procedures are relatively straightforward and reliable. In nonobstructive azoospermia or testis failure, sperm often can be difficult to retrieve. For this reason, the field of testicular sperm retrieval has witnessed tremendous change and innovation to achieve higher sperm yields, increasing efficiency and safety, along with fewer complications. We review the history and evolution of testicular sperm retrieval since its inception. Using the findings from randomized controlled trials, basic science studies, meta-analyses, case-controlled or cohort studies, best-practice policies, and literature reviews, we outline the concepts, facts, and principles that have been elucidated over several decades of experience with sperm retrieval. We also appraise the merits and issues of the most popular sperm retrieval techniques and strategies. Finally, we define areas of future clinical and laboratory development that will further refine the field of testicular sperm retrieval.

Over-expression of hsa_circ_0000116 in patients with non-obstructive azoospermia and its predictive value in testicular sperm retrieval

BACKGROUND

Non-obstructive azoospermia (NOA), identified in approximately 10% of infertile males, is a multifactorial disease whose molecular mechanisms remain unknown.

OBJECTIVES

The aim of this study was to identify the role of hsa_circ_0000116 in NOA and illustrate its predictive value in testicular sperm retrieval.

MATERIALS AND METHODS

The study included 78 individuals, 58 with NOA and 20 with obstructive azoospermia (OA). Serum hormones including testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), and estradiol II (E2) were measured. Testicular histopathology was analyzed by at least two pathologists. The expression of hsa_circ_0000116 in testicular tissue samples was detected using real-time PCR, and the circRNA-miRNA-mRNA networks were predicted using bioinformatics analysis.

RESULTS

Our study illustrated that the expression of hsa_circ_0000116 was significantly higher in testicular tissue samples of NOA patients than in that of OA patients. Moreover, hsa_circ_0000116 was aberrantly expressed in three different pathological types of NOA: It was significantly up-regulated in patients with Sertoli cell-only syndrome (SCOS) when compared to patients with hypospermatogenesis (HS). In addition, the expression of hsa_circ_0000116 was negatively correlated with Johnsen score, while it was positively correlated with serum FSH level. A multivariate logistic regression model demonstrated that a high level of hsa_circ_0000116 was associated with a low rate of successful testicular sperm retrieval. Bioinformatics analysis and verification experiments showed that one of the most probable potential target miRNA for hsa_circ_0000116 was hsa-miR-449a. Further analysis indicated that hsa_circ_0000116 may be affecting the fertility function through a hsa_circ_0000116-miR-449-autophagy-related competing endogenous RNA (ceRNA) network.

DISCUSSION AND CONCLUSION

We report for the first time that hsa_circ_0000116 may play pivotal roles in regulating spermatogenesis and may also be a potential biomarker for the diagnosis and treatment of NOA, while acting as a predictive tool for the rate of successful testicular sperm retrieval in NOA patients.

Predictors of surgical sperm retrieval in non-obstructive azoospermia: summary of current literature

Intracytoplasmic sperm injection (ICSI), combined with surgical sperm retrieval (SR) techniques, is the sole option for patients with non-obstructive azoospermia to achieve fertility; however, with suboptimal results. Given the variability in clinical presentation, the potential role of factors that can predict the likelihood of successful testicular SR needs to be clarified. This article summarizes the current evidence concerning the variables predicting SR success in non-obstructive azoospermic patients with spermatogenic failure. For this, we used 60 articles, including 46 original papers and six meta-analyses. Clinical and laboratory factors, as well as adjuvant therapies and surgical retrieval methods, were the factors most commonly investigated. We found that Klinefelter syndrome, Y chromosome microdeletions in regions AZFa/b, and Sertoli cell-only histopathology were associated with reduced SR success. By contrast, testis volume > 12.5 ml, history of cryptorchidism, use of micro-TESE as the sperm retrieval method, and adjuvant therapy were associated with improved SR success. None of the predictors, alone or combined, provide definitive information about the chances of harvesting sperm in men with non-obstructive azoospermia, except for Y chromosome microdeletions in regions AZFa/b. In the latter, SR success is virtually nil. We conclude that SR outcomes in men with non-obstructive azoospermia are difficult to predict based on the existing variables. Although several predictors can be used for patient counseling, their clinical value is limited to either ensure SR success or discourage reproductive urologists from recommending SR to men with non-obstructive azoospermia seeking fertility. A notable exception includes the deletions involving the regions AZFa and/or AZFb of the Y chromosome; the affected patients should be counseled against undergoing SR.

Evaluation of blood-testis barrier integrity in terms of adhesion molecules in nonobstructive azoospermia

Blood-testis barrier (BTB) is critical for maintaining fertility. The integrity of tight junctions (TJs) provides restricted permeability of BTB. The aim of this study was to evaluate the relationship between BTB and Sertoli cells. Testicular sperm extraction (TESE) obtained from nonobstructive azoospermia (NOA) patients was examined: Group I (spermatozoa+) and Group II (spermatozoa-). The tissues were stained with haematoxylin eosin, periodic acid-Schiff and Masson's trichrome for Johnsen's score evaluation. Apoptosis and adhesion molecules such as claudin-11, occludin and ZO-1 were assessed. In Group I, the integrity of the seminiferous tubules was intact. In Group II, some seminiferous tubule walls were lined only with Sertoli cells, had a thickening of the basement membrane, and oedema in interstitial spaces. In Group I, the seminiferous tubule consisted of a stratified columnar epithelium, claudin-11 expressions were observed as linear staining in the basal zone of the tubule, while seminiferous tubules, with low epithelium, displayed a punctate type of staining. Immunohistochemical observations were consistent with the ultrastructural findings. In Group II, high apoptosis and unstained/irregular TJ formation in claudin-11, occludin and ZO-1 were observed. In conclusion, disruption of relation between BTB and TJs may reveal inadequate spermatogenesis, which is one of the mechanisms behind azoospermia.

Sperm recovery and ICSI outcomes in men with non-obstructive azoospermia: a systematic review and meta-analysis

BACKGROUND

Factor affecting sperm retrieval rate (SRR) or pregnancy rates (PR) after testicular sperm extraction (TESE) in patients with non-obstructive azoospermia (NOA) have not been systematically evaluated. In addition, although micro-TESE (mTESE) has been advocated as the gold standard for sperm retrieval in men with NOA, its superiority over conventional TESE (cTESE) remains conflicting.

OBJECTIVE AND RATIONALE

The objective was to perform a meta-analysis of the currently available studies comparing the techniques of sperm retrieval and to identify clinical and biochemical factors predicting SRR in men with NOA. In addition, PRs and live birth rates (LBRs), as derived from subjects with NOA post-ICSI, were also analysed as secondary outcomes.

SEARCH METHODS

An extensive Medline, Embase and Cochrane search was performed. All trials reporting SRR derived from cTESE or mTESE in patients with NOA and their specific determinants were included. Data derived from genetic causes of NOA or testicular sperm aspiration were excluded.

OUTCOMES

Out of 1236 studies, 117 studies met the inclusion criteria for this study, enrolling 21 404 patients with a mean age (± SD) of 35.0 ± 2.7 years. cTESE and mTESE were used in 56 and 43 studies, respectively. In addition, 10 studies used a mixed approach and 8 studies compared cTESE with mTESE approach. Overall, a SRR per TESE procedure of 47[45;49]% (mean percentage [95% CI]) was found. No differences were observed when mTESE was compared to cTESE (46[43;49]% for cTESE versus 46[42;49]% for mTESE). Meta-regression analysis demonstrated that SRR per cycle was independent of age and hormonal parameters at enrolment. However, the SRR increased as a function of testis volume. In particular, by applying ROC curve analysis, a mean testis volume higher than 12.5 ml predicted SRR >60% with an accuracy of 86.2% ± 0.01. In addition, SRR decreased as a function of the number of Klinefelter's syndrome cases included (S = -0.02[-0.04;-0.01]; P < 0.01. I = 0.12[-0.05;0.29]; P = 0.16). Information on fertility outcomes after ICSI was available in 42 studies. Overall, a total of 1096 biochemical pregnancies were reported (cumulative PR = 29[25;32]% per ICSI cycle). A similar rate was observed when LBR was analysed (569 live births with a cumulative LBR = 24[20;28]% per ICSI cycle). No influence of male and female age, mean testis volume or hormonal parameters on both PR and LBR per ICSI cycle was observed. Finally, a higher PR per ICSI cycle was observed when the use of fresh sperm was compared to cryopreserved sperm (PR = 35[30;40]%, versus 20[13;29]% respectively): however, this result was not confirmed when cumulative LBR per ICSI cycle was analysed (LBR = 30[20;41]% for fresh versus 20[12;31]% for cryopreserved sperm).

WIDER IMPLICATIONS

This analysis shows that cTESE/mTESE in subjects with NOA results in SRRs of up to 50%, with no differences when cTESE was compared to mTESE. Retrieved sperms resulted in a LBR of up to 28% ICSI cycle. Although no difference between techniques was found, to conclusively clarify if one technique is superior to the other, there is a need for a sufficiently powered and well-designed randomized controlled trial to compare mTESE to cTESE in men with NOA.

Sperm fine-needle aspiration (FNA) mapping after failed microdissection testicular sperm extraction (TESE): location and patterns of found sperm

We sought to evaluate the ability of fine-needle aspiration (FNA) mapping to find sperm and to guide sperm retrieval after failed microdissection testicular sperm extraction (micro-TESE) in nonobstructive azoospermic men. In this study of consecutive male infertility cases, interventions included testicular FNA mapping and subsequent sperm retrieval. Outcomes included the frequency and location of found sperm on FNA maps after failed micro-TESE and the salvage sperm retrieval success. Among 548 patients undergoing FNA mapping from 2010 to 2016, 82 men with previous micro-TESE procedures were identified. The mean time between micro-TESE and FNA mapping was 2.2 years. A total of 2825 (1424 on right and 1401 on left) sites were mapped. At least one site revealed mature sperm in 24 (29.3%) of 82 men with prior failed micro-TESE procedures. There was an equal likelihood of detecting sperm in either testis (6.1% right; 5.7% left; P = 0.58). Digital "heat maps" revealed differences in sperm findings within the testis with mature sperm more likely found in the testis periphery rather than centrally. Fifteen (62.5%) patients subsequently underwent sperm retrieval procedures guided by FNA maps. Sufficient sperm were retrieved in all cases, and in 10 (66.7%) of 15 cases, extra sperm were frozen for future use. In a significant proportion of failed micro-TESE procedures representing the largest study to date, sperm were detected by FNA mapping and could be reliably retrieved through FNA map-guided surgical sperm retrieval. When present, sperm were more likely to be found in the testis periphery rather than centrally with FNA mapping.

New insights into the morphological and hormonal characteristics of spermatogenic arrest

The reported sperm retrieval rate (SRR) in patients with nonobstructive azoospermia (NOA) due to spermatogenic arrest (SA) is highly variable in the literature. This discrepancy could be explained by the heterogeneity of testicular tissues. Surprisingly, even though inhibin B levels reflect directly Sertoli cell function; no studies have evaluated this parameter in SA. We aimed to clarify the morphological and biological profile in 158 men with SA. From the total population, patients whose seminiferous tubules diameter was below 165 µm have higher SRR (46.9% vs. 27.4%, p < 0.05), lower inhibin levels and a higher frequency of nonuniform SA (71.9% vs. 38.7%, p < 0.001). On multivariate analysis, patients with late SA and a history of cryptorchidism were positively associated with successful sperm extraction. Patients with successful SRR and uniform SA exhibited inhibin levels twofold lower than those with failed TESE (45 pg/ml vs. 95 pg/ml, p < 0.05), whereas FSH levels were similar in the two groups. In this study, we showed for the first time that the mean diameter of the seminiferous tubules may be of value in the diagnosis of SA. Our results suggest that inhibin levels could be useful in the management of NOA with SA, along with FSH levels and testicular volume.

Heterogenicity of testicular histopathology and tubules as a predictor of successful microdissection testicular sperm extraction in men with nonobstructive azoospermia

Only a few studies evaluate the presence of spermatozoa intraoperatively. The study aimed to assess whether the heterogenicity of testicular histopathology and seminiferous tubules can predict the outcome of microdissection testicular sperm extraction (micro-TESE) in men with nonobstructive azoospermia (NOA).The study comprised a retrospective analysis of 94 patients with azoospermia who were referred from 2016 to 2017. Under optical magnification, they were classified into 2 groups based on the diameter of tubules intraoperatively, namely homogeneous tubules and heterogeneous tubules. Postoperatively, patients were divided into 2 groups of heterogeneous histopathology and homogeneous histopathology according to the 8 histopathological classification subgroups. The sperm retrieval rate was the main outcome.Testicular spermatozoa were successfully retrieved in 27 men (28%). The sperm retrieval rate in those with heterogeneous histopathology was higher than men with homogeneous histopathology (47% vs 12%; P < .001). The sperm retrieval rate of each histopathological subgroup in men who had the heterogeneous histopathology was higher, compared with the homogeneous histopathology (Sertoli cell only [SCO]: 30% vs 6%; maturation arrest [MA]: 38% vs 0%; tubular hyalinization: 42% vs 20%, respectively). Under the optical magnification, the sperm retrieval rate was significantly higher in men with heterogeneous vs homogeneous tubules (65% vs 15%, P < .001). Moreover, the sperm retrieval rate of the contralateral testicular was higher in men who had heterogeneous tubules, compared with the homogeneous tubules (25% vs 3%; P = .036).Heterogenicity of histopathology is an effective predictor in men with histopathological information available from a previous diagnostic biopsy or conventional TESE attempt preoperatively for successful sperm retrieval. Homogeneous tubules seem beneficial for some patients to perform a limited (superficial) contralateral micro-TESE after no spermatozoa were identified initially.

Should azoospermic patients with varicocele disease undergo surgery to recover fertility?

Introduction:

Varicocele disease is well-known cause of infertility in men. The presence of spermatic varices veins create a hostile environment to spermatogenesis. It results in reduced quality of the sperm production and in some cases can determine a total absence of sperm. The varicocelectomy procedure in patients with non-obstructive azoospermia (NOA) can raise the rates of sperm in the semen analysis. A positive rate for sperm, even if very low, may be sufficient to enable the capture of sperm intended for in-vitro fertilization without the use of donor sperm.

Objetive:

To evaluate the raise of sperm in NOA patients with varicocele disease who were submitted to a bilateral procedure to recovery sperm production.

Method:

We analized the sperm results of 25 NOA patients who undergone to a bilateral varicocelectomy procedure.

Results:

From a total of 25 patients, three (12%) recovered sperm count four months after procedure. One year after the procedure, five (20%) patients recovered sperm production.

Conclusion:

Patients with varicocele disease and azoospermia, without genetic changes or obstruction of the spermatic tract, should undergo surgical procedure to recover sperm.

Testicular histology may predict the successful sperm retrieval in patients with non-obstructive azoospermia undergoing conventional TESE: a diagnostic accuracy study

PURPOSE

The present study sought to determine the diagnostic accuracy of FSH level, testicular volume, and testicular histology in predicting the successful sperm retrieval (SSR) in a large cohort of patients with non-obstructive azoospermia undergoing conventional testicular sperm extraction (TESE).

METHODS

We retrospectively evaluated 356 patients with non-obstructive azoospermia between June 2004 and July 2009. Binary logistic regression was used to evaluate the diagnostic accuracy of our predicting model, identifying sperm retrieval rate as binary dependent variable. The predictive accuracy of all variables individually evaluated was quantified with area under curve (AUC) estimates derived from receiver operating characteristic (ROC) curve.

RESULTS

The mean patients' age was 36.8 years. Testicular sperm were retrieved in 158 out of 356 patients (44.3 %). Histological diagnosis of Sertoli cell only syndrome (SCO) was obtained in 216 patients (60.6 %), while 55 patients (15.4 %) had maturation arrest (MA) and 85 (23.8 %) had hypospermatogenesis (HYPO). The binary logistic regression model was statistically significant (χ ² = 96.792, p < 0.0001) and correctly classified 72.8 % of cases with 46.8 % sensitivity and 93.4 % specificity, positive predictive value (PPV) 85.06 %, negative predictive value (NPV) 68.7 %, +likelihood ratio (LR) 7.13, and -LR 0.57. Only testicular histology was significant to the model, while FSH and testicular volume were not. Sperm retrieval rate (SRR) was significantly higher in patients with HYPO compared to patients with SCO or MA (88.2 vs 30.5 and 30.9 %, respectively, p < 0.0001) CONCLUSIONS: This study demonstrates that including testicular histology in a model for predicting sperm retrieval increases its diagnostic accuracy. As histology is not available prior to TESE, this model applies only to patients with previous testicular surgery.