Testicular histopathology as a predictor of a positive sperm retrieval in men with non-obstructive azoospermia
Correspondence: David Ralph, The Institute of Urology, University College London Hospital, 235 Euston Road, London NW1 2BU, UK.
What's known on the subject? and What does the study add?
- The management of patients with non-obstructive azoospermia (NOA) involves testicular sperm extraction (TESE or microdissection TESE) combined with intracytoplasmic sperm injection (ICSI). Sperm retrieval is successful in up to 50% of men with NOA; however, there is no single clinical finding or investigation that can accurately predict a positive outcome. Several studies have concluded that testicular biopsy is the best predictor of a successful TESE.
- The present study shows that the strongest predictor of the success of TESE is when tubules with mature spermatozoa (Johnsen score ≥8) are found in the histopathology specimen, irrespective of the overall state of spermatogenesis. The findings suggest that a lower limit threshold value of 2% of tubules with spermatogenesis in the histopathology specimen will result in a positive sperm retrieval.
- However, it is not practical to perform a diagnostic biopsy before TESE because this would mean that patients undergo two surgeries, which adds to the cost and increases the complications.
- The diagnostic biopsy is best coupled with an initial TESE before starting the ICSI cycle. Based on the findings of the histopathology specimen, patients may be then offered a repeat TESE if more sperm is needed on the day of ovum pick-up and ICSI. Also, if the initial TESE was negative, the biopsy result will help in the decision to offer a repeat TESE. This regimen is more cost-effective because the ICSI cycle will be started only if adequate sperm is retrieved.
- To assess whether testicular histopathology can predict the outcome of testicular sperm extraction (TESE) in men with non-obstructive azoospermia (NOA) and therefore the role of preoperative diagnostic testis biopsy.
Patients and Methods
- The study comprised a retrospective analysis of 388 patients with azoospermia who were referred from 2005 to 2010.
- Information collected included a clinical history and an examination including age and testicular size, serum follicle-stimulating hormone, two semen analyses and testicular histology collected at the time of surgical sperm retrieval (TESE or microdissection TESE).
- In total, 388 patients with a mean (range) age of 37 (18–66) years were included in the present study.
- Based on the history, clinical and laboratory findings, 112 patients had obstructive azoospermia and 276 patients had NOA.
- All patients in the obstructed group had a positive sperm retrieval. The sperm retrieval rate for the NOA group was 50%.
- An analysis of the results showed that the best predictor of a positive sperm retrieval was when tubules with mature spermatozoa were seen at biopsy, irrespective of the overall state of spermatogenesis (P < 0.001).
- The presence of tubules with spermatazoa on biospy is the best predictor of a positive surgical sperm retrieval in patients with NOA.
- The diagnostic biopsy is best coupled with an initial TESE before starting the intracytoplasmic sperm injection (ICSI) cycle.
- Based on the findings of the histopathology specimen, patients may be offered a repeat TESE if more sperm is needed on the day of ovum pick-up and ICSI, or a redo TESE if the initial TESE was negative.