Effect of Age on Sperm Recovery of Microdissection Testicular Sperm Extraction in Nonobstructive Azoospermia Patients
Condition: Non-obstructive Azoospermia
MeSH terms: Azoospermia
Study type: Observational

Summary: 
      Males with non-obstructive azoospermia (NOA) have an opportunity to obtain sperm by treatment
      with microdissection testicular sperm extraction (mTESE), gold-standard surgical technique
      for them. The overall sperm retrieval rate (SRR) of mTESE in NOA patients is about 50%, but
      the predictive factors of SRR remain were understudied, especially the effect of age. The
      purpose of this study was to explore the factors influencing the SRR of mTESE in NOA patients
      with different etiologies.

      Methods: This observational study recruit NOA patients treated with their first mTESE. The
      stratified research was used to investigate SRR by dividing patients into seven groups based
      on etiology. The primary outcome was SRR. Multivariable logistic regression was used to
      analyze the factors influencing SRR.
    

Detailed description: 
      As the most severe form of infertility, azoospermia is observed in approximately 10% to 15%
      of infertile males and can be classified as obstructive azoospermia (OA) and non-obstructive
      azoospermia (NOA), the latter of which cause spermatogenic dysfunction. Approximately 60% of
      NOA males are diagnosed with congenital, acquired, or idiopathic NOA (iNOA). The most common
      congenital causes of NOA are Klinefelter syndrome (KS) and Y chromosome azoospermia factor
      (AZF) deletions, whereas the acquired causes of NOA are mumps orchitis, cryptorchidism,
      cryptozoospermia, and iatrogenic causes (chemotherapy, radiotherapy, hypogonadotropic
      hypogonadism). For iNOA, the most common form of NOA, there is no clear cause in
      approximately 50-80% of cases.

      As a prevalent chromosomal abnormality, KS with two or more X chromosomes is the most common
      form of congenital NOA that affects approximately 3-4% of infertile males and more than 10%
      of azoospermic males. The incidence of Y-chromosome AZF microdeletions in fertile males is
      0.025%, but it increases to 2%-10% in infertile males. Mumps orchitis is the most common and
      serious complication of mumps virus infection in adolescents and young adults, with an
      incidence of 40% in males with postpubertal mumps, and approximately 30% of males suffer from
      infertility or subfertility. As an extremely severe form of oligozoospermia, cryptozoospermia
      is characterized by the absence of sperm in semen by microscopic examination but the presence
      of sperm in centrifuge sediment, with an incidence of approximately 8.73% in infertile males.
      Cryptorchidism represents one of the most common urogenital abnormalities in childhood,
      affecting 1.1%-45% of preterm and 1%-4.6% of full-term infants, and approximately 10% of
      infertile males have a history of cryptorchidism.

      Obtaining sperm by microdissection testicular sperm extraction (mTESE) is the primary
      treatment approach for males with NOA. The average sperm retrieval rate (SRR) in NOA males is
      approximately 50%, however, NOA patients with different etiologies have different SSRs
      ranging from 30% to 75%, with the highest and lowest SRRs corresponding to those with a
      history of mumps orchitis and iNOA, respectively. The predictive factors of SRR in males with
      NOA treated with mTESE include age; testis volume; serum follicle stimulating hormone (FSH),
      testosterone (T), inhibin B, and anti-Müllerian hormone (AMH) levels and testicular
      histopathology. However, the relationship between SSR and age in NOA patients undergoing
      mTESE is unclear, with several studies reporting no association between SSR and age or a
      negative correlation between SSR and age. Other studies have reported that older age was
      predictive of successful sperm retrieval.

      The goal of this study was to analyze the factors influencing the SRR in NOA patients with
      different etiologies treated with mTESE based on age, body mass index (BMI), testis volume
      hormone levels and infertility duration in a large cohort. Our findings provide valuable
      information on the likelihood of successful mTESE. Therefore, preoperative evaluations based
      on the information provided in this study will help patients and surgeons in selecting the
      best approach by shared decision-making.
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Non-obstructive azoospermia patients
      
Keywords: non-obstructive azoospermia; microdissection testicular sperm extraction; sperm retrieval rate; age