Tissue perfusion essential for spermatogenesis and outcome of testicular sperm extraction (TESE) for assisted reproduction

Contrast-enhanced ultrasound (CEUS) for the characterization of intra-scrotal lesions

Contrast-enhanced ultrasound (CEUS) has emerged as a promising imaging modality for the characterization of hepatic and renal lesions. However, there is a paucity of data describing the use of CEUS for the evaluation of intra-scrotal pathology. In the following review, we describe the clinical utility of CEUS for the characterization and differentiation of common and uncommon intra-scrotal conditions, including testicular torsion, infection, trauma, and benign and malignant intratesticular and extratesticular neoplasms. In addition, we outline key principles of CEUS and provide case examples from our institution.

Association between body condition score, testicular haemodynamics and echogenicity, nitric oxide levels, and total antioxidant capacity in rams

Higher body fatness adversely affects metabolic and hormonal homeostasis. The present work aimed to evaluate the association between body condition score (BCS) and haemodynamic pattern and echogenic appearence of the testes as well as nitric oxide (NO) levels and total antioxidant capacity (TAC). For that, fifteen Ossimi rams were blocked according to their BCS into a lower BCS group (L-BCS:2-2.5; n = 5), medium BCS group (M-BCS:3-3.5; n = 5), and higher BCS group (H-BCS:4-4.5; n = 5). Rams were examined for testicular haemodynamics (TH; Doppler ultrasonography), testicular echotexture (TE; B-mode image software analysis), and serum levels of NO and TAC (colorimetric). Results are presented as means ± standard error of the mean. There was a significant (P < 0.05) difference in the resistive index and pulsatility index means among the groups under experimentation, being the least in the L-BCS group (0.43 ± 0.02 and 0.57 ± 0.04, respectively) compared to the M-BCS (0.53 ± 0.03 and 0.77 ± 0.03, respectively) and H-BCS rams (0.57 ± 0.01 and 0.86 ± 0.03, respectively). Among blood flow velocity measurements [peak systolic, end-diastolic (EDV), and time-average maximum], only EDV showed significant (P < 0.05) higher values in the L-BCS group (17.06 ± 1.03 cm/s) compared to M-BCS (12.58 ± 0.67 cm/s) and H-BCS (12.51 ± 0.61 cm/s) groups. Regarding the TE results, there were no significant differences among the examined groups. There were significant differences (P < 0.01) in the concentrations of TAC and NO among the groups under experimentation, in which the L-BCS rams had the highest levels of TAC and NO in their sera (0.90 ± 0.05 mM/L and 62.06 ± 2.72 μM/L, respectively) than the M-BCS (0.058 ± 0.05 mM/L and 47.89 ± 1.49 μM/L, respectively) and H-BCS rams (0.45 ± 0.03 mM/L and 49.93 ± 3.63 μM/L, respectively). In conclusion, body condition score is associated with both testicular hemodynamic and the antioxidant capacity in rams.

Testicular haemodynamics, plasma testosterone and oestradiol concentrations, and serum nitric oxide levels in the Egyptian buffalo bull after a single administration of human chorionic gonadotropin

This current study aimed for the first time to evaluate the effect of a single intravenous administration of human chorionic gonadotropin hormone (hCG) on the testicular artery haemodynamics measurements (resistance [RI], and pulsatility indices [PI]), plasma steroids (estradiol-17β and testosterone) and nitric oxide (NO) levels in buffalo bulls. Twelve Egyptian buffalo bulls weighted 450 ± 20 kg were randomly divided into the hCG group (n = 6) and injected a single dose with Ovogest (EPIFASI; 5,000 IU, iv), whereas the others (n = 6) were injected with normal saline and served as controls. Doppler evaluation and blood sampling were performed just before the administration (hour 0) and at 1, 2, 4, 6, 8, 10, 24 and 28 hr after administration. Bulls in the control group did not show any alterations in hormonal levels and blood flow parameters (p > .05). In the hCG group, RI was declined (p < .05) in 6 hr post-administration (0.31 ± 0.01 versus 0.45 ± 0.01), while PI was declined (p < .05) later in 10 hr (0.74 ± 0.01 versus 1.23 ± 0.02). Additionally, testicular blood flow was increased (p < .05) 8 hr (42.02 ± 1.02 ml/min/100 g versus 31.34 ± 0.88 ml/min/100 g) after administration. Testosterone and NO levels were (p < .05) increased at 4 and 6 hr post-administration (3.55 ± 0.03 ng/ml versus 2.84 ± 0.01 ng/ml, and 55.32 ± 4.25 µmol/L versus 32.21 ± 1.55 µmol/L), whereas oestradiol levels were elevated (p < .05) in 6 hr (31.25 ± 0.08 pg/ml) only post-administration then declined. In conclusion, the single intravenous administration of hCG triggered many alterations in the supratesticular artery vascularization and hormonal profile that could affect positively on steroidogenesis and testicular function in buffalo bull.

Exogenous gonadotropin-releasing hormone counteracts the adverse effect of scrotal insulation on testicular functions in bucks

This study determined the effects of scrotal insulation on testicular functions in bucks and evaluated the impact of exogenous gonadotropin-releasing hormone (GnRH) administration before scrotal insulation on sperm production and testicular vascular dynamics. Twelve bucks were randomly divided into three groups: scrotal-insulated animals without GnRH treatment (INS), scrotal-insulated animals treated previously with GnRH (GnRH + INS), and animals without insulation as controls (CON). Doppler ultrasonography was used to evaluate testicular vascular changes, and semen samples were collected to assess seminal parameters. Testicular samples were collected from slaughtered bucks at the end of the experiment for histological investigations and immunohistochemical analysis for caspase 3 (apoptotic marker), and a vascular endothelial growth factor (VEGF; hypoxic marker) evaluation. Sperm motility drastically decreased (33%) in the INS group on day 8 compared with those in the GnRH + INS and CON groups (58% and 85%, respectively). Testicular blood flow significantly decreased for 3 and 2 weeks in the INS and GnRH + INS groups, respectively. The pulsatility index (PI) reached pretreatment values at 5 and 4 weeks after insulation in the INS and GnRH + INS groups, respectively. The resistance index (RI) values increased in both insulated groups for the first 2 weeks and decreased to control values 4 weeks after insulation. However, the maximum velocity (VP) started to increase reaching pretreatment values by the 5th and 3rd weeks after insulation in the INS and GnRH + INS groups, respectively. Histological investigations showed a marked reduction in lipid inclusions in Sertoli cells in the GnRH + INS group compared with those in the INS group. The distributions of both caspase 3 and VEGF decreased in the GnRH + INS group compared with those in the INS group. This study showed that the administration of a single dose of GnRH delayed the negative effects of scrotal insulation on different seminal traits and revealed the pivotal role of GnRH in compensating testicular insulation in bucks.

Exogenous L-carnitine Administration Ameliorates the Adverse Effects of Heat Stress on Testicular Hemodynamics, Echotexture, and Total Antioxidant Capacity in Rams

Heat stress (HS) diminishes the testicular antioxidant defense systems, which adversely affect the testicular blood perfusion. Improving the testicular hemodynamics during HS conditions is of a great impact on the whole reproductive performance in rams. This study aimed to evaluate the ameliorative effects of L-carnitine (LC) on the testicular blood flow and echotextures and also on the total antioxidants (TAC) and nitric oxide (NO) concentrations in the serum during HS conditions in rams. Testicular blood flow was evaluated through scanning of the supra-testicular artery (STA) spectral patterns through pulsed Doppler ultrasonography [peak systolic velocity (PSV), end-diastolic velocity (EDV), time average maximum velocity (TAMAX), resistive index (RI), and pulsatility index (PI)], while the echotexture assessment of testicular parenchyma was performed by a computerized software program. Moreover, TAC and NO concentrations were assayed colorimetrically using the spectrophotometer. There were significant decreases (P &lt; 0.05) in values of PSV at 48 and 168 h (23.45 ± 0.39 and 23.37 ± 1.41 cm/s, respectively), and TAMAX at 1, 48, and 168 h (17.65 ± 0.95, 17.5 ± 0.13, and 16.9 ± 1.05 cm/s, respectively) after LC administration compared to just before administration (31.92 ± 1.13 and 21.58 ± 0.92 cm/s, respectively). Values of RI and PI of the examined STA significantly decreased, especially at 1 h for RI (0.45 ± 0.02) and 1 and 48 h for PI (0.66 ± 0.06 and 0.65 ± 0.05, respectively) after LC treatment to 0 h (0.55 ± 0.03 and 0.84 ± 0.06, respectively). The EDV values did not show any significant (P &lt; 0.05) changes in all the experimental time points. There were significant (P &lt; 0.05) increases in the values of pixel intensity of the testicular parenchyma, especially at 1 and 168 h (78.71 ± 2.50 and 88.56 ± 4.10, respectively) after LC administration, compared to just before administration (69.40 ± 4.75). Serum NO levels tend to increase after LC administration (P = 0.07) concerning just before administration. While TAC values showed significant gradual increase and reached the highest values at 168 h (2.75 ± 0.58 mM/l) after LC administration, compared to 0 h (1.12 ± 0.05 mM/l). In conclusion, exogenous LC administration ameliorates testicular hemodynamic disruptions, as measured by spectral Doppler ultrasonography, via augmentation of the rams' total antioxidant capacity under HS conditions.

Effects of buserelin administration on testicular blood flow and plasma concentrations of testosterone and estradiol-17β in rams

This research aimed to examine for the first time the impact of single dose administration of gonadotropin-releasing hormone (GnRH) analog buserelin acetate on the testicular blood flow measurements (peak systolic velocity [PSV], end-diastolic systolic velocity [EDV], resistive index [RI], and pulsatility index [PI]) and the plasma steroids (testosterone and estradiol-17β) concentrations in rams. For this purpose, twelve adult Ossimi rams were randomly assigned into the buserelin group (n = 8) and were injected intravenously (iv) with buserelin acetate (0.008 mg/ram), whereas the remaining rams (n = 4) were injected with normal saline iv and served as a control group. Blood sampling and testicular pulsed-wave Doppler scanning were conducted immediately before (0) and 1, 3, 6, 24, 48, 72, 120, and 168 h after treatment. The control group did not reveal any substantial changes (P > 0.05) in the examined parameters, except for the EDV (P < 0.05). In the buserelin-treated group, a marked reduction in RI and PI values (P < 0.05) occurred 1 to 3 h after administration of buserelin. Besides, there was a significant increase in testosterone plasma concentrations following buserelin treatment. In conclusion, the administration of buserelin triggered a series of substantial changes in the testicular blood perfusion and steroidogenesis that could have a positive effect on testicular function in rams.

Melatonin improves testicular haemodynamics, echotexture and testosterone production in Ossimi rams during the breeding season

The objective was to determine effects of a single parenteral dose of melatonin on testicular blood flow indices, testicular echogenicity and plasma testosterone concentrations in rams during the physiological breeding season. We hypothesized that melatonin enhances testicular blood flow, echogenicity and plasma testosterone concentrations during the breeding season in rams. During the breeding season, 12 sexually mature Ossimi rams were randomly allocated to either a melatonin group (n = 8) that received 18 mg of melatonin in 1 ml of corn oil (injected SC) or a control group (n = 4) that received 1 ml corn oil only. Blood collection and ultrasonographic assessment of the testes and supratesticular arteries were conducted immediately before treatment (W0) and once weekly for 6 weeks after melatonin injection (W1-W6). Mean plasma testosterone concentrations were greater (p < .05; at least 1 ng/ml) in the melatonin-treated group compared to the control group from W4 to W6 after treatment. A decrease (p < .05) in both resistive index (RI) and pulsatility index (PI) began 1 week after melatonin injection (W1) and persisted until the end of the experiment, with mean RI and PI values in the melatonin group lower (p < .05) than those in the control group on W3 and W4. Furthermore, plasma testosterone concentrations in melatonin-treated rams were inversely correlated to both RI and PI (r = -.7 and -.6, respectively, p < .01). Testicular echogenicity decreased (p < .05) 1 week after melatonin injection (W1) and remained lower (p < .05) in the melatonin-treated group compared to the control group until the end of the study (W6). In conclusion, melatonin administration significantly altered testicular blood flow and echogenicity and increased plasma testosterone concentrations in Ossimi rams during the breeding season.

Exogenous oxytocin administration improves the testicular blood flow in rams

The current research aimed to examine the effects of single-dose oxytocin administration on testicular blood flow measurements peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) and plasma steroid (testosterone and oestradiol-17β) concentrations in rams. In the treated group, eight mature Ossimi rams during the breeding season were injected intravenously (iv) with 20 IU oxytocin, while the other eight male rams were administered normal saline (2 ml) iv as a control group. Venous blood samples and testicular blood flow in the left and right testes were examined immediately before (0) and 5, 30, 60 and 120 min after injections. The control group did not show significant changes in the variables examined (p > .05), except for the EDV (p < .05). In the treated group, the administration of oxytocin led to a significant decrease in RI and PI values starting 5 min after oxytocin administration until 60 min after its application (p < .05). The plasma concentrations of testosterone and oestradiol-17β raised from 5 to 30 min after oxytocin injection (p > .05) and then declined significantly until 120 min (p < .05). In conclusion, oxytocin is a potent testicular vasodilator affecting the testicular vascular tone and steroid concentrations in rams.

Intrasurgical parameters associated with successful sperm retrieval in patients with non-obstructive azoospermia undergoing salvage microdissection testicular sperm extraction

BACKGROUND

Patients with non-obstructive azoospermia with a previously failed conventional testicular sperm extraction may undergo a salvage microdissection testicular sperm extraction with the probability of successful sperm retrieval being almost dependent upon the number of previous surgical attempts and to different histopathologic categories.

OBJECTIVES

To determine whether the seminiferous tubules pattern and the histological categories could affect the sperm retrieval rate in patients with non-obstructive azoospermia undergoing salvage microdissection testicular sperm extraction after failed conventional testicular sperm extraction.

MATERIALS AND METHODS

Seventy-nine patients undergoing unilateral or bilateral salvage microdissection testicular sperm extraction were evaluated. During microdissection testicular sperm extraction, if present, dilated tubules were retrieved, otherwise, tubules with slightly larger caliber than that of the surroundings were removed. When no dilated tubule or tubule with slightly larger caliber was found, not dilated tubules were excised. A prediction model was built with seminiferous tubules pattern and testis histology as covariates.

RESULTS

Sperm retrieval was successful in 30 out of 79 patients. The prediction model correctly classified 88.3% of cases, explained the 29.7% variability of the outcome, and significantly predicted the microdissection testicular sperm extraction outcome with a sensitivity of 67.7% and a specificity of 90.2%, Both tubules with slightly larger caliber and not dilated tubules were negatively associated with the chance of retrieving spermatozoa. Among the histological categories, only early maturation arrest was significant to the model (log(SSR) = 0.57 - 1.9SDT - 3.3NDT - 1.76EMA) (where SSR is sperm retrieval rate, SDT is tubule with slightly larger caliber, NDT is not dilated tubule, and EMA is early maturation arrest). The model had a clearly useful discrimination (area under the curve = 0.814), the estimated performance was 0.8105, and internal calibration was acceptable (p > 0.05).

DISCUSSION

Seminiferous tubules pattern and testis histology may reliably explain the salvage microdissection testicular sperm extraction outcome in all patients with non-obstructive azoospermia apart from those with early maturation arrest, where the homogeneous apparent seminiferous tubules pattern may be misleading.

CONCLUSION

The outcome of salvage microdissection testicular sperm extraction can be predicted by the same intrasurgical parameters that have been demonstrated to predict the outcome of microdissection testicular sperm extraction in naïve patients with non-obstructive azoospermia.

Use of contrast enhanced ultrasound in testicular diseases: A comprehensive review

Background

Contrast‐enhanced ultrasound (CEUS) is a sonographic technique that increases the diagnostic accuracy of ultrasound and color Doppler ultrasound (CDUS) when studying testicular abnormalities. However, its role in clinical practice is still debatable because there are no accepted standards regarding how and when this technique should be used for patients with testicular disease.

Objectives

To perform a nonsystematic review of the current literature to highlight the strength and flaws of performing CEUS and to provide a critical overview of current research evidence on this topic.

Materials and methods

A thorough search of published peer‐reviewed studies in PubMed was performed using proper keywords.

Results

Strong enhancement of neoplastic lesions (both benign and malignant) during CEUS aids in differential diagnosis with non‐neoplastic lesions, which usually appears either nonenhanced or enhanced in a manner similar to that of the surrounding parenchyma. CEUS enhancement has a high predictive value in the identification of neoplastic lesions, whereas a similar or complete absence of enhancement may be interpreted as strong evidence of benignity, although there are exceptions. Literature on quantitative analysis is still scarce, though promising, particularly in distinguishing benign from malignant neoplasms. Furthermore, CEUS may be useful in many emergency situations, such as acute scrotum, blunt scrotal trauma, and focal infarction of the testis. Finally, CEUS can help increase the probability of sperm recovery in azoospermic males.

Discussion and conclusion

CEUS is a safe, easy‐to‐perform, and cost‐effective diagnostic tool that can provide a more accurate diagnosis in testicular lesions and acute scrotal disease. However, further studies with larger cohorts are required to refine the differential diagnosis between benign and malignant neoplasms. Finally, these preliminary results can instigate the development of innovative research on pre‐testicular sperm extraction to increase the chances of sperm recovery.

Novel methods to enhance surgical sperm retrieval: a systematic review

Objectives: To explore the use of novel technologies in sperm retrieval in men with azoospermia due to a production defect. Methods: We performed a Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA)-compliant systemic literature review for manuscripts focussed on novel sperm-retrieval methods. We identified 30 studies suitable for qualitative analysis. Results and Conclusions: We identified multiple new promising technologies, each with its own distinct set of benefits and limitations, to enhance chances of sperm retrieval; these include the use of multiphoton microscopy, Raman spectroscopy, and full-field optical coherence tomography during a microdissection-testicular sperm extraction procedure. ORBEYE and ultrasonography technologies can also serve to better visualise areas of sperm production. Finally, artificial intelligence technology can play a role in the identification of sperm and, perhaps, better-quality sperm for use with assisted reproduction. Abbreviations: AI: artificial intelligence; ANN: artificial neural network; ART: assisted reproductive technology; 3D: three-dimensional; DNN: deep neural networks; FFOCT: full-field optical coherence tomography; H&E: haematoxylin and eosin; ICSI: intracytoplasmic sperm injection; IVF: in vitro fertilisation; MESA: micro-epididymal sperm aspiration; MeSH: Medical Subject Heading; MPM: multiphoton microscopy; (N)OA: (non-)obstructive azoospermia; SCO: Sertoli cell-only syndrome; SRR: sperm retrieval rates; TESA: testicular sperm aspiration; (micro-)TESE: (microdissection-) testicular sperm extraction; (CE)US: (contrast-enhanced) ultrasonography.

Three-Dimensional Analysis of Busulfan-Induced Spermatogenesis Disorder in Mice

We examined if the distribution of impaired or normal spermatogenesis differs along the length of seminiferous tubules in disorders of spermatogenesis. For this purpose, three-dimensional (3D) reconstruction of seminiferous tubules was performed in mice with experimental spermatogenesis disorder induced by intraperitoneal injection of busulfan, and the areas of impaired and normal spermatogenesis were analyzed microscopically. The volume of the testis and length of seminiferous tubules decreased, and the proportion of tubule areas with impaired spermatogenesis increased depending on the dose of busulfan. With the highest dose of busulfan, although the proportion of impaired spermatogenesis was similar among individual seminiferous tubules, it was slightly but significantly higher in shorter tubules and in tubule areas near branching points. The tubule areas with impaired and normal spermatogenesis consisted of many segments of varying lengths. With increasing doses of busulfan, the markedly impaired segments increased in length without changing in number, whereas normal segments, although reduced in number and length, remained even with the highest dose of busulfan. Individual remaining normal segments consisted of several different stages, among which stage I and XII were found at higher frequencies, and stage VI at a lower frequency than expected in normal seminiferous tubules. We also examined if the distribution of impaired or normal spermatogenesis differs among different 3D positions in the testis without considering the course of seminiferous tubules. Although the proportions of impaired spermatogenesis with the minimum dose of busulfan and normal spermatogenesis with the highest dose of busulfan greatly varied by location within a single testis, there were no 3D positions with these specific proportions common to different testes, suggesting that the factors influencing the severity of busulfan-induced spermatogenesis disorder are not fixed in location among individual mice.

Advances in applications of color Doppler ultrasonography in the andrological assessment of domestic animals: A review

Compared to human cases, potential applications of Doppler imaging technology in farm animals' practice are still limited and are mostly concerned with females. Testicular blood perfusion (TBP) is the pathway through which all nutrients, oxygen, and regulatory agents pass through to the testis. TBP is crucial to the testis function because of the high metabolic rate and very low concentration of oxygen in the seminiferous tubules, which constitute about 70%-80% of the testicular mass. Color Doppler ultrasonography is one of the recent non-invasive technologies, which plays a vital role in the assessment of blood flow to the testis in various animal species. In the past 20 years, a significant number of studies have highlighted the importance of assessments of TBP using color Doppler ultrasonography to illustrate its potential uses for breeding soundness examination, diagnosis, and monitoring of infertility problems in farm animals. This review was aimed at providing, for the first time, updated knowledge on the potential clinical uses of color Doppler ultrasonography for the assessment of TBP in domestic animals. Additionally, a few essential details on the relationship between TBP and male fertility are discussed in this review. Furthermore, a number of caveats relating to the use of color Doppler ultrasonography are discussed, which collectively appear to constrain its routine, on-farm application for breeding soundness assessments, at least at the present. The new perspectives related to animal reproduction that researchers claim to do in further investigations are also discussed.

Analysis of factors affecting repeat microdissection testicular sperm extraction outcomes in infertile men

OBJECTIVE

There is no clear consensus on which patients and how many of microscopic testicular sperm extraction (mTESE) procedures will be successful. In this study, we aimed to evaluate the sperm retrieval rates and factors affecting these rates in men who underwent repeat mTESEs.

MATERIAL AND METHODS

A total of 346 patients who underwent mTESE for sperm retrieval were included in the study. Patients were divided into groups according to the number of mTESE operations. Patients' karyotype, follicle-stimulating hormone (FSH) and testosterone levels, varicocele presence, and testis volumes were recorded from patient files. The sperm retrieval rates were compared between groups, and predicting factors for successful sperm retrieval were evaluated.

RESULTS

Microscopic TESE was applied for the first time in 244 patients, 1-2 times in 73 patients, and 3-4 times in 29 patients. There was a significant difference between groups in preoperative FSH values and postoperative testicular histopathology (p=0.004 and p<0.001). The sperm retrieval rate in the group of patients who had not undergone previous TESE was higher than the group of patients that had undergone TESE for 1-2 times and 3-4 times (p=0.028). In addition, testicular volume, histology, karyotype, and Y-chromosome microdeletion were predicting factors for successful sperm retrieval (p=0.011, p=0.039, p=0.002, and p<0.001, respectively).

CONCLUSION

Our results confirm the necessity for repeat mTESE operations to be performed by experienced surgeons in reference centers to optimize the chance of reduced sperm retrieval rates with recurrent biopsies.

Assessment of the use of contrast enhanced ultrasound in guiding microdissection testicular sperm extraction in nonobstructive azoospermia

BACKGROUND

The aim of this study is to assess the value of contrast-enhanced ultrasound (CEUS) as a new non-invasive approach to locate the testicular area in which spermatogenesis is most likely to be found in non-obstructive azoospermic testes and to evaluate the accuracy of CEUS as a predictor of successful sperm retrieval.

METHODS

CEUS was performed in 120 nonobstructive azoospermia (NOA) patients. Microdissection testicular sperm extraction (M-TESE) was performed on the best and poorest perfusion areas selected by CEUS and on conventional areas.

RESULTS

In the 187 testicles that underwent M-TESE, the sperm retrieval rates (SRRs) in the best perfusion area and poorest perfusion area over the maximal longitudinal section and conventional area were 63.1, 34.7 and 47.1%. According to receiver operating characteristic (ROC) analysis, the arrival times (AT) ≤27 s, time-to-peak intensity (TTP) ≤45 s, and peak intensity (PI) ≥11 dB were the best predictors of positive sperm retrieval. The location of the best perfusion area was able to guide M-TESE to improve the success rates.

CONCLUSIONS

Testicle CEUS is suggested to be performed in all patients with NOA. If AT≤27 s, TTP ≤ 45 s or PI≥11 dB are found in the best perfusion area, M-TESE is strongly recommended.

Low testosterone in ApoE/LDL receptor double-knockout mice is associated with rarefied testicular capillaries together with fewer and smaller Leydig cells

The testis as a site for atherosclerotic changes has so far attracted little attention. We used the apolipoprotein E (ApoE)/low density lipoprotein (LDL) receptor deficient mouse model (KO) for atherosclerosis (20, 40, 60 and 87-week-old) to investigate whether Leydig cells or the capillary network are responsible for reduced serum testosterone levels previously observed in extreme ages of this model. In KO mice, overall testosterone levels were reduced whereas the adrenal gland-specific corticosterone was increased excluding a general defect of steroid hormone production. In addition to micro-CT investigations for bigger vessels, stereology revealed a reduction of capillary length, volume and surface area suggesting capillary rarefaction as a factor for diminished testosterone. Stereological analyses of interstitial cells demonstrated significantly reduced Leydig cell numbers and size. These structural changes in the testis occurred on an inflammatory background revealed by qPCR. Reduced litter size of the KO mice suggests hypo- or infertility as a consequence of the testicular defects. Our data suggest reduced testosterone levels in this atherosclerosis model might be explained by both, rarefication of the capillary network and reduced Leydig cell number and size. Thus, this study calls for specific treatment of male infertility induced by microvascular damage through hypercholesterolemia and atherosclerosis.

Prospective evaluation of scrotal ultrasound and intratesticular perfusion by color-coded duplex sonography (CCDS) in TESE patients with azoospermia

PURPOSE

The objective of this study was to assess whether CCDS might improve the outcome of testicular sperm retrieval in patients with azoospermia. Furthermore, we evaluated potential sonographic alterations of the testis before and after trifocal and Micro-TESE.

METHODS

78 patients were enrolled prospectively: 24 with obstructive azoospermia (OA) and 54 with non-obstructive azoospermia (NOA). 31 of 54 patients in the NOA group had negative surgical sperm retrieval. Testicular volume, hormonal parameters and sonographical findings were compared before and after TESE. The spermatogenetic score was determined for all retrieval sites. CCDS was performed at the upper, middle and lower segment of the testis. Ultrasound parameters and peak systolic velocity (PSV) were measured pre- and post-operatively.

RESULTS

Testicular volume and epididymal head size were significantly increased in OA patients compared to NOA patients. Ultrasound parameters were comparable between NOA patients with and without successful sperm retrieval. A higher intratesticular PSV was significantly correlated with a better spermatogenic score in the corresponding sonographic position. However, after adjustment for other clinical confounders, PSV does not show a significant influence on the spermatogenic score. Testicular volume decreased significantly in all patients post-operatively after 6 weeks (p < 0.001). Finally, the PSV significantly increased in all patients 24 h after surgery and nearly returned to baseline levels after 6 weeks (p < 0.001).

CONCLUSIONS

A higher intratesticular PSV may be helpful as a pre-operative diagnostic parameter in mapping for better sperm retrieval, but CCDS does not help to predict successful testicular sperm retrieval after adjustment for other clinical confounders.

The development of surgical sperm extraction and new challenges to improve the outcome

Surgical sperm extraction with intracytoplasmic sperm injection has become widespread worldwide and is regarded as the sole option for patients with azoospermia. However, the sperm retrieval rate remains unsatisfactorily low, particularly for men with non-obstructive azoospermia (NOA). Therefore, the technical challenges associated with improving the sperm retrieval rate for men with NOA are being addressed. The most successful method developed to date is microdissection testicular sperm extraction (micro-TESE), which is rapidly becoming recognized as a useful technique due to its relatively high sperm retrieval rate and low complication rate. However, even with micro-TESE, the sperm retrieval rate for men with NOA remains at 30-60 %, with an even lower birth rate. The technical challenges associated with improving the outcomes of surgical sperm extraction are being approached through the use of ultrasound and optimal surgical devices such as narrow band imaging, multiphoton microscopy, and optical coherent tomography. In addition to the difficulties related to searching for sperm, medical treatments that induce spermatogenesis remain controversial. For example, varicocele repair prior to surgical sperm extraction and hormonal therapy before and after TESE have been extensively examined. We herein briefly summarized the development process in surgical sperm extraction up to the present and technical challenges to improve the outcomes of surgical sperm extraction.

Identification of Spermatogenically Active Regions in Rat Testes by Using Narrow-band Imaging System

OBJECTIVE

To evaluate the feasibility of narrow-band imaging (NBI) system in microdissection testicular sperm extraction (micro-TESE).

MATERIALS AND METHODS

Firstly, we investigated angiogenic potential in human testicular specimens obtained from 48 patients who underwent micro-TESE. We then created a testicular injury model in rats with a single topical injection of cisplatin into the testes, and the testes were observed with and without NBI. To assess the relation between pathological changes and visual images, an immunofluorescence study of blood vessels in rat testes was carried out. We finally conducted an experiment that assumed micro-TESE by using a nonobstructive azoospermia (NOA) rat model induced by busulfan.

RESULTS

The number of blood vessels in the specimens of hypospermatogenesis was significantly greater than that in the specimens of maturation arrest and Sertoli cell only. In rat testes, cisplatin caused atrophic changes, and significant differences in visual color between atrophic and normal lesions were noted using NBI. The number of seminiferous tubules with spermatozoa in atrophic regions was significantly lower than that in normal regions, and a significantly small number of blood vessels in atrophic regions was also noted compared with that in normal regions. NBI also identified patchy spermatogenesis in the busulfan-induced NOA rat model.

CONCLUSION

An NBI system can distinguish spermatogenically active regions through the visualization of blood vessels in rat testes. This system may have the potential to provide useful information during micro-TESE for men with NOA.

Effect of a single injection of gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) on testicular blood flow measured by color doppler ultrasonography in male Shiba goats

Although color Doppler ultrasonography has been used to evaluate testicular blood flow in many species, very little has been done in goat. Eight male Shiba goats were exposed to a single intramuscular injection of either gonadotropin-releasing hormone (GnRH group; 1 µg/kg BW) or human chorionic gonadotropin (hCG group; 25 IU/kg BW). Plasma testosterone (T), estradiol (E2) and inhibin (INH) were measured just before (0 hr) and at different intervals post injection by radioimmunoassay. Testis volume (TV) and Doppler indices, such as resistive index (RI) and pulsatility index (PI) of the supratesticular artery, were measured by B-mode and color Doppler ultrasonography, respectively. The results indicated an increase in testicular blood flow in both groups, as RI and PI decreased significantly (P<0.05), but this increase was significant higher and earlier in hCG group (1 hr) than in the GnRH group (2 hr). A high correlation was found for RI and PI with both T (RI, r= −0.862; PI, r= −0.707) and INH in the GnRH group (RI, r=0.661; PI, r=0.701). However, a significant (P<0.05) correlation was found between E2 and both RI (r= −0.610) and PI (r= −0.763) in hCG group. In addition, TV significantly increased and was highly correlated with RI in both groups (GnRH, r= −0.718; hCG, r= −0.779). In conclusion, hCG and GnRH may improve testicular blood flow and TV in Shiba goats.

No relationship between biopsy sites near the main testicular vessels or rete testis and successful sperm retrieval using conventional or microdissection biopsies in 220 non-obstructive azoospermic men

In 220 consecutive patients with non-obstructive azoospermia, sperm retrieval was attempted by a combination of conventional and microdissection testicular sperm extraction (TESE). For sperm retrieval, 2-3 conventional biopsies were performed followed by a microdissection TESE in cases of negative conventional biopsies. During the surgery, the vasculature of the testis was assessed using the operative microscope, and the location of positive biopsies was registered in relation to the blood supply. The overall sperm retrieval rate was 58.2%. From the initial conventional biopsies, sperm could be retrieved in 46.8% of the patients. With microdissection TESE, sperm could be retrieved from an additional 11.4% of the patients. The further use of microdissection TESE improved the sperm retrieval rate significantly (P=0.017). No significant accumulation of positive biopsies was found towards the rete testis or the main testicular vessels.

Evaluation of testicular artery blood flow by Doppler ultrasonography as a predictor of spermatogenesis in the dog

The present study examines the relationship between reproductive and seminal characteristic with blood flow supply of the testis in male dogs by means of Doppler ultrasonography. Five male dogs were subject to a clinical examination, blood sampling, B-Mode and Doppler ultrasonography of the testis, semen evaluation at collections and after storage at 4°C for 24, 48 and 72 h in three replicates 30 days apart. Peak Systolic Velocity was positively correlated with testicular volume and negatively with live sperm at collections and after 24h. A negative correlation existed between Resistive Index and Pulsatility Index with total and progressive motility at collections and also after 24, 48 and 72 h. Resistive Index and Pulsatility Index were also negatively correlated with the percentage of membrane intact sperms with curled tails at collections while the latter was positively correlated with End Diastolic Velocity. Moreover, positive linear correlations of weight with bilateral testicular volume and total sperm concentration and also between age and abnormal sperm at collections and after 24h were established. The results suggest that the Resistive Index and Pulsatility Index seem to be potential markers of seminal quality in dogs.

Microdissection testicular sperm extraction: an update

Patients with non-obstructive azoospermia (NOA) were once considered to be infertile with few treatment options due to the absence of sperm in the ejaculate. In the last two decades, the advent of intracytoplasmic sperm injection (ICSI), and the application of various testicular sperm retrieval techniques, including fine needle aspiration (FNA), conventional testicular sperm extraction (TESE) and microdissection testicular sperm extraction (micro-TESE) have revolutionized treatment in this group of men. Because most men with NOA will have isolated regions of spermatogenesis within the testis, studies have illustrated that sperm can be retrieved in most men with NOA, including Klinefelter's syndrome (KS), prior history of chemotherapy and cryptorchidism. Micro-TESE, when compared with conventional TESE has a higher sperm retrieval rate (SRR) with fewer postoperative complications and negative effects on testicular function. In this article, we will compare the efficacy of the different procedures of sperm extraction, discuss the medical treatment and the role of testosterone optimization in men with NOA and describe the micro-TESE surgical technique. Furthermore, we will update our overall experience to allow counseling on the prognosis of sperm retrieval for the specific subsets of NOA.

Effect of pentoxifylline treatment on testicular perfusion and semen quality in Miniature horse stallions

The objective was to investigate the effects of pentoxifylline (PTX) on testicular perfusion and sperm production in stallions. In a preliminary study, six mature Miniature horse stallions were given 0, 8.5, or 17.0 mg/kg of PTX orally, twice daily, for 3 d. Total Arterial Blood Flow Rate (TABFR) was higher (P < 0.05) in all treated versus control stallions during and after treatment. Two months later (during the fall and winter), the same stallions received either 0 or 17 mg/kg of PTX orally, twice daily for 60 d. Resistance and pulsatility indices (RI and PI, respectively) decreased in PTX-treated stallions between Treatment 1 and Post-treatment periods. Arterial diameter, as well as Total Arterial Blood Flow (TABF), decreased in controls between Baseline and Treatment 1 (P < 0.05). A similar decrease in arterial diameter was delayed in Group TREATED, but reached significance during Post-treatment (P < 0.05), whereas TABF did not change in this group. Furthermore, TABFR had a transient tendency to increase during Treatment 1 (P < 0.1), whereas it steadily decreased in controls and reached significance in the Post-treatment period (P < 0.05). Both RI and PI were negatively correlated with end diastolic velocity (EDV) in both groups (P < 0.0001). There were positive correlations between RI and peak systolic velocity (PSV) in treated stallions during Treatment 1 (RI: r = 0.53, P = 0.021; PI: r = 0.59, P = 0.007). Also, there were negative correlations between Time Averaged Maximum Velocity (TAMAX) and Doppler indexes in treated stallions during Treatment 2 period (RI: r = -0.49, P = 0.006; PI: r = -0.47, P = 0.008), and during Post-treatment periods (RI: r = -0.40, P = 0.049; PI: r = -042, P = 0.039). Transient hydrocele occurred in all treated stallions (a potential complication of high-dose PTX). Semen end points were not significantly affected by PTX treatment. In conclusion, PTX delayed the seasonal decrease of testicular perfusion in stallions. Sperm quality and quantity were not significantly affected; perhaps they would have been enhanced by prolonged treatment.

Oxidative stress and epididymal sperm transport, motility and morphological defects

OBJECTIVES

Radical oxidative species (ROS) have an important effect on sperm quality and quantity. Oxidative stress (OS) occurs when production of potentially destructive reactive oxygen species (ROS) exceeds the body's own natural antioxidant defenses, resulting in cellular damage. OS is a common pathology seen in approximately half of all infertile men. Increased ROS generation and reduced antioxidant capacity is negatively correlated with sperm concentration and motility in infertile men. For the first time, we used a more stable and reliable sensitive carbonyl protein (CP) detection method to determine ROS in seminal plasma than measuring ROS directly to clarify the effect of OS on spermatozoa in terms of protein dysfunction. This is the first report to measure CP in seminal plasma as an indicator of OS. Furthermore, for the first time we correlated the results of CP measurement with light microscopy in combination with ultrastructural analysis by electron microscopy.

MATERIAL AND METHODS

20 patients with idiopathic oligoasthenoteratozoospermia (iOAT) and 10 fertile controls were enrolled in this study. CP values were measured by enzyme-linked immuno sorbent assay (ELISA) to detect the level of OS. Transmission electron microscope (TEM) was used to detect axonemal anomalies.

RESULTS

Compared to fertile controls, statistically highly significant higher degrees of abnormal sperm parameters (P<0.001) could be found in iOAT patients. CP values were highly significantly elevated in iOAT patients than in normal controls (P<0.001). A statistically highly significant difference in different axonemal anomalies were found between iOAT patients and normal controls (P<0.001). CP values have been found to be positively correlated with different axonemal anomalies (absence of axoneme (r(2)=0.841), missing of central singlet tubules (r(2)=0.702) and missing of outer doublet tubules (r(2)=0.869). A statistically negative correlation were found between different axonemal anomalies (absent axoneme (r(2)=-0.780), missing of central singlet tubules (r(2)=-0.611), and missing of outer doublet tubules (r(2)=-0.738) and forward progressive sperm motility.

CONCLUSION

High levels of CP can be measured in iOAT patients, indicating that OS could underlie the aetipopathogenesis of the syndrome. OS negatively affects flagellar axonemal structure with subsequent impairment of forward progressive sperm motility. This can put an attention for antioxidants as a therapy for iOAT syndrome and further research to find how to decrease ROS production.

Which is the best sperm retrieval technique for non-obstructive azoospermia? A systematic review

Our objective was to establish which is the best sperm retrieval technique in non-obstructive azoospermia based on the available evidence. To date, no randomized controlled trial has compared the efficiency of these strategies and thus current recommendations are based on cumulative evidence provided by descriptive, observational and controlled studies. Three outcome measures were assessed for the sperm retrieval techniques: sperm retrieval rate (SRR), complications and live birth rate. Twenty-four descriptive studies reporting on the results of testicular sperm extraction (TESE) were encountered. Seven controlled studies that compared microdissection (MD) TESE with conventional TESE and seven controlled studies comparing fine needle testicular aspiration (FNA) with TESE were identified. The mean SRR for TESE was 49.5% (95% CI 49.0-49.9). TESE with multiple biopsies results in a higher SRR than FNA especially in cases of Sertoli-cell-only (SCO) syndrome and maturation arrest. Current evidence suggests that MD performs better than conventional TESE only in cases of SCO where tubules containing active focus of spermatogenesis can be identified. MD appears to be the safest technique regarding post-operative complications followed by FNA. Only three studies could be identified concerning the influence of the sperm retrieval technique on clinical pregnancy and live birth rate, hence no definitive conclusions can be made. However, so far there appears to be no impact of the technique itself on success rates.

Microdissection testicular sperm extraction: effect of prior biopsy on success of sperm retrieval

PURPOSE

We determined the effect of prior biopsies with no sperm seen on the chance of sperm retrieval with microdissection testicular sperm extraction in men with nonobstructive azoospermia.

MATERIALS AND METHODS

A total of 311 men with NOA underwent microdissection testicular sperm extraction. Of these patients 135 underwent no prior biopsies, 159 underwent 1 or 2 diagnostic testicular biopsies per testis and 17 underwent 3 or 4. The outcome measure studied was the success of sperm retrieval with microdissection testicular sperm extraction. Serum follicle-stimulating hormone and histopathological diagnosis were examined as predictive factors for sperm recovery.

RESULTS

Spermatozoa were retrieved in 150 men by microdissection testicular sperm extraction (48%). The success of sperm retrieval in patients who underwent 3 to 4 biopsies (23%) was lower than the retrieval rate in patients who underwent no prior biopsies (56%) and 1 to 2 biopsies per testis (51%) (p = 0.04). When histopathology was considered, patients with Sertoli-cell-only diagnosis on prior diagnostic biopsy had lower retrieval rates compared to the group with no biopsies (p = 0.02). Men with maturation arrest and hypospermatogenesis had similar microdissection testicular sperm extraction sperm retrieval rates regardless of the number of prior biopsies. Spermatozoa recovery was independent of serum follicle-stimulating hormone.

CONCLUSIONS

There is no threshold of prior negative biopsies that precludes the success of sperm retrieval using microdissection testicular sperm extraction. A limited number of testicular biopsies provide limited or no prognostic value for sperm retrieval with microdissection testicular sperm extraction.