Testicular Biopsy

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Testicular Biopsy

Testicular Biopsy

If sperm cells are not identified in a ejaculated semen sample, this condition is called azoospermia. In the general population, 1% of males are azoospermic. In infertile males, 1-5% of them are azoospermic.

There are two major types of azoospermia, Obstructive Azoospermia (OA) and Non-Obstructive Azoospermia (NOA). Obstruction along the ejaculatory duct leads to Obstructive Azoospermia. On the other hand, Non-Obstructive Azoospermia has several etiologies, such as Sertoli cell only syndrome, maturation arrest, Klinefelter syndrome, testicular atrophy or hypospermatogenesis. Both types of azoospermia need surgery to retrieve sperm cells. OA and NOA can be differentiated based on history, testicular exam, FSH levels, and testicular biopsy findings. Males with normal testicular volume, normal FSH and normal testicular biopsies are suggestive of OA. Males with reduced testicular volume, elevated FSH, and testicular biopsy showing compromised spermatogenesis are suggestive of NOA.

Several surgical methods have be employed to retrieve sperm and they are

  1. PESA, Percutaneous Epididymal Sperm Aspiration.
  2. MESA, Microsurgical Epididymal Sperm Aspiration.
  3. TESA, Percutaneous Testicular Sperm Aspiration.
  4. TESE, Testicular Sperm Extraction
  5. Micro-TESE (mTESE)
  1. For OA males, Percutaneous Epididymal Sperm Aspiration (PESA) is used. A needle is injected into the epididymis via the scrotal skin and sperm aspiration is performed.
  2. For MESA procedure, urologist opens up the epididymal tube under micro-surgery technique. A 24 gauge Angiocath is used for fluid aspiration. Fluid is then examined for sperm cells using a phase contrast microscope (x400). Urologist typically starts at cauda epididymis and moves to the other end of epididymis. The procedure continues until motile sperm is identified. This is also for OA males.
  3. For Percutaneous Testicular Sperm aspiration (TESA) procedure, several techniques have been used. One technique is fine needle aspiration, and patient is under anesthesia and urologist uses 19 to 23 gauge needles for sperm aspiration and each testis is aspirated multiple times. Fine needle aspiration can help us get sperm. But it does not provide enough testicular tissue for testicular tubular histology study. If a 14-gauge Tru-Cut needle is used, this is large needle cutting biopsy (LNCB). One other technique is LNAB and this is also a percutaneous procedure, and 18 or 20 gauge needle is used for sperm aspiration from testis.
  4. For TESE procedure, patient is under anesthesia and scrotal skin is opened up first. Dartos fascia, tunica vaginalis and tunica albuginea are then opened and testis is extruded. Testicular tissues are then collected.
  5. Micro-TESE is different from TESE in that tunica albuginea is opened in a special way such that testicular parenchyma can be observed while avoiding damage to subtunical vasculature. Then microscope is used and larger and more opaque tubules are identified and collected. Larger and opaque tubules tend to have sperm inside. mTESE has better sperm recovery rate than TESE and has less testicular damage.
  6. One other procedure that has also been used is transrectal ultrasound guided seminal vesicle sperm aspiration for OA males.

For OA males, the chance of sperm recovery after surgery is excellent. For NOA males, the likelihood of sperm recovery is reduced when he has elevated FSH level, small testicular volume, AZFa or AZFb microdeletion. On average only 50% of NOA males will yield sperm cells after surgical procedures.