Imaging and angiography in male factor infertility

Future prospects for the advancement of treatment of men with NOA: focus on gene editing, artificial sperm, stem cells, and use of imaging

ABSTRACT

Nonobstructive azoospermia (NOA) affects about 60% of men with azoospermia, representing a severe form of male infertility. The current approach to manage NOA primarily involves testicular sperm retrieval methods such as conventional testicular sperm extraction (c-TESE) and microdissection testicular sperm extraction (micro-TESE). While combining testicular sperm retrieval with intracytoplasmic sperm injection (ICSI) offers hope for patients, the overall sperm retrieval rate (SRR) stands at around 50%. In cases where micro-TESE fails to retrieve sperm, limited options, like donor sperm or adoption, can be problematic in certain cultural contexts. This paper delves into prospective treatments for NOA management. Gene editing technologies, particularly clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) protein 9 (CRISPR/Cas9), hold potential for correcting genetic mutations underlying testicular dysfunction. However, these technologies face challenges due to their complexity, potential off-target effects, ethical concerns, and affordability. This calls for research to address key challenges associated with NOA management within the clinical settings. This also necessitate ongoing research essential for developing more sensitive diagnostic tests, validating novel treatments, and customizing current treatment strategies for individual patients. This review concluded that the future of NOA management may entail a combination of these treatment options, tailored to each patient's unique circumstances, providing a comprehensive approach to address NOA challenges.

Sonography in male infertility: a useful yet underutilized diagnostic tool

PURPOSE

To assess the utility of comprehensive sonographic examination including scrotal sonography, Testicular Doppler and Transrectal Ultrasound (TRUS) to evaluate the male reproductive system and differentiate between obstructive (OG) and non-obstructive (NOG) causes of azoospermia.

METHODS

30 infertile men with azoospermia and 30 control subjects with normospermia underwent sonographic evaluation. FNAC/biopsy findings were used for assigning a final diagnosis of obstructive or non-obstructive azoospermia. Qualitative and quantitative imaging parameters were retrospectively compared between the groups using Chi-square/Fisher's exact test and unpaired t-test, respectively. P < 0.05 was considered significant.

RESULTS

Ectasia of rete testis/epididymal tubules, altered epididymal echogenicity, dilated terminal vas deferens were significantly more common in OG while inhomogeneous testicular echo-texture and reduced testicular vascularity were more common in NOG (P < 0.05). Testicular volume and epididymal head size were significantly higher in OG than in NOG and controls (18.2 ml/10 mm Vs 8.2 ml/7.2 mm and 13.4 ml/8.8 mm respectively; P < 0.05); while Resistive Index (RI) of intra-testicular vessels was higher in NOG as compared to OG and controls (0.65 vs 0.54 and 0.52 respectively; P < 0.05). On ROC curve analysis, cut-off values of testicular volume (AUC: 0.939; P < 0.001), epididymal head size (AUC: 0.772; P = 0.001) and testicular RI (AUC: 0.761; P = 0.001) to differentiate between the groups were 12.1 ml (sensitivity-94.4%; specificity-83.3%), 9 mm (sensitivity-66.7%; specificity-71%) and 0.62 (sensitivity-62%; specificity-100%) respectively.

CONCLUSION

Comprehensive sonographic evaluation can be used to differentiate obstructive from non-obstructive infertility and should be routinely incorporated in the diagnostic workup of infertile men with azoospermia.

Future of Male Infertility Evaluation and Treatment: Brief Review of Emerging Technology

Over the past few decades, there have been significant advances in male infertility, particularly in the development of novel diagnostic tools. Unfortunately, there remains a substantial number of patients that remain infertile despite these improvements. In this review, we take heed of the emerging technologies that will shape the future of male infertility diagnosis, evaluation and treatment. Improvement in computer-assisted semen analyses and portability allow males to obtain basic semen parameters from the comfort of their home. Additionally, breakthrough ultrasound technology allows for preoperative prediction of potential areas of spermatogenesis within the testes, high-resolution optics permits better visualization during microdissection testicular sperm extraction (mTESE), and artificial intelligence improves sperm selection and identification.

Functional histology of human scrotal wall layers and their overlooked relation with infertility: a narrative review

Male infertility currently contributes to nearly half of the reported infertility cases. Scrotal wall layers play a cardinal role in regulating testicular physiology. However, few studies have focused on the functional histology of these layers and their relations with infertility in humans. The objective of the present narrative review is to collate novel insights into the functional histology of the human scrotal wall layers and their relation with infertility. The data was extracted from articles published between 1946 and 2021. The study was performed between January and December 2021. 71 original studies have been included in this review. Despite the fact that few studies have presented detailed functional histology of the human scrotal wall layers, this narrative review elucidates the possible influence of scrotal histology on infertility. Scrotal wall layers-associated pathologies may induce infertility by various mechanisms. They can impose mechanical forces that may affect the testicular histology and stimulate testicular inflammation. Moreover, they may induce testicular hyperthermia. Various unanswered clinical questions have been identified in this narrative review. More clinical studies are needed to assess the effect of alterations in the components of the scrotal wall layers on fertility (e.g., due to the exposure to metabolic and/or psychological stressors). In addition, testing the effectiveness of various pharmacological/surgical interventions to treat scrotal wall layers-associated pathologies will provide more insights into infertility treatment.

Male infertility

It is estimated that infertility affects 8-12% of couples globally, with a male factor being a primary or contributing cause in approximately 50% of couples. Causes of male subfertility vary highly, but can be related to congenital, acquired, or idiopathic factors that impair spermatogenesis. Many health conditions can affect male fertility, which underscores the need for a thorough evaluation of patients to identify treatable or reversible lifestyle factors or medical conditions. Although semen analysis remains the cornerstone for evaluating male infertility, advanced diagnostic tests to investigate sperm quality and function have been developed to improve diagnosis and management. The use of assisted reproductive techniques has also substantially improved the ability of couples with infertility to have biological children. This Seminar aims to provide a comprehensive overview of the assessment and management of men with infertility, along with current controversies and future endeavours.

Experience of using shear wave elastography in evaluation of testicular stiffness in cases of male infertility

PURPOSE

The purpose of this study was to determine quantitative testicular tissue stiffness values in normal and infertile men using shear wave elastography (SWE), and to evaluate the relationship between infertility and testicular stiffness value.

METHODS

In total, 100 testes of 50 infertile patients with abnormal semen parameters were classified as group A, and 100 testes of 50 control subjects were classified as group B. These two groups were compared in terms of age, testicular volume, and SWE values. The group B testes were randomly chosen from patients who had applied for ultrasonography for any reason, and who had no testis disease and no history of infertility.

RESULTS

The mean age of the patients was 27.83 years, and no significant difference in age was found between the groups (P = 0.133). No significant difference in testicular volume was found between the groups (P = 0.672). The SWE values were significantly higher in group A than in group B (P = 0.000 for both m/s and kPa values). SWE values had a negative correlation with mean testicular volume in group A (for m/s values: P = 0.043; for kPa values: P = 0.024).

CONCLUSION

SWE can be a useful technique for assessing testicular stiffness in infertile patients to predict parenchymal damage in testicular tissue that leads to an abnormality in sperm quantity. In addition, decreased testicular volume, together with increased SWE values, can reflect the degree of parenchymal damage.

Noninvasive evaluation of testicular function by measuring oxygen saturation of scrotal-testicular tissue

We conducted a single-center cross-sectional study to determine whether scrotal-testicular tissue oxygen saturation (S-T StO₂) measured by finger-mounted near-infrared spectroscopy is useful for the evaluation of testicular function. S-T StO₂ was significantly higher in patients with nonobstructive azoospermia (NOA, p< 0.05), and showed a positive correlation with luteinizing hormone levels (LH) even in participants without NOA (r = 0.34, p< 0.05), suggesting that elevated S-T StO₂ is associated with a reduction in testicular function.

Microdeletions at DYS448 and DYS387S1 associate with increased risk of male infertility

Male infertility affects many people of reproductive age. Diagnosis and therapies based on descriptive semen parameters have helped some of the infertility patients; however, further progress in reproductive therapy demands a better understanding of the molecular and genetic causes for male infertility. Although Y chromosome microdeletions have been a hot subject of genetic studies on male infertility, the relationship between male infertility and microdeletions at Y chromosome loci DYS448, DYS387, and DYS627 remains unclear. Here we analyzed the microdeletions at these three loci in 200 infertility male patients and 200 healthy subjects and showed that microdeletions at DYS448 and DYS387 correlate with male infertility. Our results suggest that genetic analyses of Y chromosome loci DYS448 and DYS387 can be genetic markers for reproductive diagnosis and therapy.