Testicular Sperm Extraction in Non-Obstructive Azoospermic Patients with Sertoli Cell-Only Syndrome Testicular Histology

Introduction

Non-obstructive azoospermia (NOA) means the absence of spermatozoa in semen analysis.1 Testicular failure is observed as a result of NOA in approximately 1% of all men and 10% of infertile men.2 The primary treatment for NOA is testicular sperm extraction (TESE) followed by intracytoplasmic sperm injection (ICSI).1 The testicular histopathology of NOA patients may include hypospermatogenesis, complete or incomplete maturation arrest, and Sertoli cell-only syndrome (SCOS). SCOS is a significant clinical condition where azoospermia and germ cells are not observed, and the success rate of TESE is low.3

Corresponding Author: Mehmet Vehbi Kayra, vehbikayra@hotmail.com, Received: 07.03.2023, Accepted: 30.06.2024, Available Online Date: 30.06.2024 Cite this article as: Kayra MV, Özer C. Testicular Sperm Extraction in Non-Obstructive Azoospermic Patients with Sertoli Cell-Only Syndrome Testicular Histology. J Cukurova Anesth Surg. 2024; 7(2): 78-80. https://doi.org/10.36516/jocass.1448280 Copyright © 2024 This is an open access article distributed under the terms of the Creative Commons Attribution-Non-Commercial-No Derivatives License 4.0 (CC-BY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

In studies, SCOS has been reported in 10.8-44% of infertile men with NOA.3

We aimed to investigate the sperm retrieval rate (SRR) in patients with SCOS testicular histology undergoing microdissection TESE (mTESE) and identify potential influencing factors.

Materials and methods

This study has been approved by the Başkent University Medical and Health Sciences Research Council (Project No: KA24/70) and conducted in accordance with the principles of the Helsinki Declaration. In our clinic, patients who underwent mTESE due to NOA were retrospectively evaluated. Only patients with a histopathological diagnosis of SCOS were included in the study. Individuals with other histopathological diagnoses, those who underwent conventional TESE (cTESE), and those with incomplete data were excluded from the study. SRRafter mTESE was calculated for patients with a pathology result of SCOS. The age, testicular volume, and Follicle-Stimulating Hormone (FSH) level of the groups with and without sperm were compared.

2.1. Surgical Technique

With sedoanalgesia and/or local anesthesia combination, mTESE procedures were performed by applying approximately 2 cm vertical incision to the scrotum. The tunica albuginea of the unilateral testis was opened with a vertical incision. Subtunical vessels were identified and avoided under the surgical microscope. Direct examination of the testicular parenchyma was performed at magnifications of x20 to x40 using an operating microscope. Small samples were taken from large, opaque seminiferous tubules. The procedure was terminated when a sufficient volume of sperm was obtained for ICSI. In the instance no sperm was found in one testis, the same procedure was repeated on the contralateral testis. A small tissue sample obtained surgically during the same session was placed in Bouin's solution and sent to the histopathology laboratory.

2.2. Statistical Analysis

Statistical analysis was performed using the SPSS V 22.0 statistical package. Normality of each continuous variable was checked using Kolmogorov-Smirnov and Shapiro-Wilk tests, along with histograms. Between-group comparisons were conducted using the Mann-Whitney U test for non-normally distributed data. P-values less than 0.05 were considered statistically significant.

Results

In our study, 186 patients with testicular histopathology diagnosed as SCOS were included. SRR after mTESE in these patients was 28%. In patients with retrieved sperm, the mean age was 33.8 ± 5.4 years, the mean testicular volume was 11.1 ± 6.3 ml, and the mean FSH level was 22.5 ± 12.7 mIU/ml. In patients without retrieved sperm, the mean age was 33.8 ± 6.1 years, the mean testicular volume was 10.3 ± 6.1 ml, and the mean FSH level was 21.0 ± 9.8 mIU/ml. There was no significant difference observed in mean age, testicular volume, and FSH level between the group with retrieved sperm and the group without retrieved sperm (p=0.97, p=0.24, p=0.38, respectively). The parameters evaluated in the study are shown in Table 1.

Comparison of clinical and laboratory data of patients in groups

FSH: Follicle-Stimulating Hormone *group with retrieved sperm **group without retrieved sperm

Discussion

The most common histological diagnosis in patients with NOA is SCOS1. It is expected that in patients diagnosed with SCOS, there would be a lower SRR compared to other histological diagnoses1. However, due to the heterogeneity of testicular histology, it has been reported that spermatozoa can still be found in these patients as well4. In two different studies examining the success rate of sperm retrieval in patients with testicular histopathology diagnosed as SCOS, the success rate was found to be 27.6% and 23.6%, respectively4,5. In our study, this rate was 28%, which is consistent with these studies. However, in another study, an SRR of 14.8% was found6. The reason for this discrepancy may be attributed to the multicenter nature of the study, resulting in heterogeneous patients and TESE being performed by different surgeons.

Due to the emergence of accompanying diseases that negatively affect testicular perfusion and germ cell loss with age, theoretically, lower success rates in terms of SRR are expected in elderly patients7. It is known that age is one of the important factors affecting the SRR after TESE8. In a study involving a limited number of patients (n=64), the patient age was found to be similar between the groups with no sperm retrieved during TESE (36.4 years) and the groups with sperm retrieved (37.2 years), with slightly higher age observed in the TESE-positive group7. Similarly, Guneri et al.9 also identified age as an important factor in their study (38 years versus 42 years). Okada et al.10 also demonstrated that patient age is a factor influencing TESE outcomes, determining that the median age was significantly different between the unsuccessful and successful TESE groups (38 (28-43) and 31 (25-40) years, respectively). However, studies evaluating only SCOS patients have reported that age does not have an effect on the SRR4,5. In our study, it was also determined that age did not have an effect on the SRR, and we believe this is due to the selection of patients being homogeneous in terms of age.

It is known clinically that testicular volume correlates with spermatogenesis. Turunc et al.11 found a positive correlation between testicular volume and SRR in patients with NOA, and determined that SRR was significantly lower in patients with testicular volume below 5 mL. However, in this study, distinction based on testicular histopathology was not made. In our study, it was found that testicular volume was not a determining factor for the presence or absence of sperm in the groups. This result differs from studies that only examined SCOS patients and reported lower SRR in men with smaller testicular volumes who underwent cTESE12,13. However, recent mTESE studies with large series of NOA patients have shown that testicular volume does not have any effect on SRR6,14,15. This suggests that performing mTESE or cTESE in SCOS patients may lead to different outcomes in terms of testicular volume.

There are studies suggesting that serum FSH levels can predict the presence of sperm retrievable by cTESE16. Conversely, it has also been reported that FSH has poor predictive value for sperm retrieval via TESE13,17. In addition to studies indicating that FSH levels are determinant for patients with testicular histopathology diagnosed as SCOS, there are also studies showing that it has no effect4-6. The discrepancy in the relationship between FSH levels and SRR success may stem from differing demographic characteristics across studies. A study by Silber et al.18 demonstrated that FSH concentration is inversely proportional to the number of germ cells in the testis, yet it lacks correlation with more advanced stages of spermatogenesis. Additionally, it has been noted that FSH can only reflect the global function of spermatogenesis and cannot evaluate the function of an isolated region within the testis18. By allowing for more detailed examination of each part of the testis, the mTESE method increases the chance of finding spermatogenic areas19. Therefore, mTESE can increase the SRR rate even when the overall spermatogenesis function of the testis is very low19. This may explain why FSH cannot accurately predict the SRR of mTESE.

4.1. Limitation

Our study has two main limitations. The first of these is that it is a retrospective study. The other is that parameters related to ICSI and its outcomes, such as fertilization rate, implantation rate, clinical pregnancy rate, and live birth rate, were not evaluated. The high number of patients in this special group is one of the strengths of our study.

Conclusion

The results of our study provide valuable insights for counseling men with NOA. Testicular sperm retrieval is feasible in cases of NOA with a SCOS histology. Consequently, patients undergoing testicular biopsy with TESE for histological assessment can concurrently consider preparation for ICSI if sperm is obtained.

Statement of ethics

This study has been approved by the Başkent University Medical and Health Sciences Research Council (Project No: KA24/70) and conducted in accordance with the principles of the Helsinki Declaration.

Conflict of interest statement

The authors declare that they have no financial conflict of interest with regard to the content of this report.

Funding source

The authors received no financial support for the research, authorship, and/or publication of this article.

Author Contributions

All authors read and approved the final version of the manuscript.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Originality Assertion

The authors have not submitted this article to another journal previously.