Being told your semen analysis shows zero sperm — azoospermia — is one of the most shocking diagnoses a man can receive. The immediate fear is that fatherhood is impossible. In the majority of cases, that fear is unfounded. Modern surgical sperm retrieval techniques — PESA, TESA, and Micro-TESE — can recover sperm directly from the reproductive tract, even when none appear in the ejaculate, and this sperm can be used with ICSI (intracytoplasmic sperm injection) to fertilise eggs and create embryos.
At Mother Hospitals & IVF Center, Boduppal, Hyderabad, Dr. E. Prashanthi Reddy's team works with experienced urologists and andrologists to evaluate and treat male factor infertility, including azoospermia. This guide explains the types of azoospermia, the different surgical retrieval techniques, what each involves, and what the outcomes look like.
Two Types of Azoospermia — and Why the Distinction Matters
Before discussing TESA or PESA, it is essential to understand that azoospermia is not a single condition. There are two fundamentally different types, and the treatment approach depends entirely on which type a man has.
Obstructive Azoospermia (OA)
In obstructive azoospermia, the testes are producing sperm normally — but a blockage somewhere along the reproductive tract prevents sperm from reaching the ejaculate. The blockage may be in the vas deferens (the tube that carries sperm from the epididymis to the urethra), the epididymis, or the ejaculatory ducts. Common causes include:
- Previous vasectomy (the most common cause of OA)
- Congenital bilateral absence of the vas deferens (CBAVD) — often associated with CFTR gene mutations
- Infection-related scarring (epididymitis, STIs)
- Previous hernia repair or scrotal surgery damaging the vas
- Ejaculatory duct obstruction
In OA, sperm retrieval is almost always successful because the testes are functioning normally. PESA or TESA will typically yield good quantities of motile sperm.
Non-Obstructive Azoospermia (NOA)
In non-obstructive azoospermia, the problem is with sperm production itself — the testes are not producing sperm in adequate quantities, or sperm production has failed completely. Causes include:
- Klinefelter syndrome (XXY chromosomes)
- Y chromosome microdeletions (AZF region deletions)
- Testicular failure following mumps orchitis, radiation, or chemotherapy
- Hormonal disorders (hypogonadism)
- Cryptorchidism (undescended testes)
- Genetic conditions affecting spermatogenesis
In NOA, sperm retrieval is more challenging — not all areas of the testis fail equally, and small pockets of active sperm production ("focal spermatogenesis") may exist. Micro-TESE is the preferred technique in NOA because it allows these focal areas to be identified under magnification. Sperm retrieval rates in NOA range from 30–70% depending on the underlying cause.
PESA — Percutaneous Epididymal Sperm Aspiration
PESA is the simplest and least invasive surgical sperm retrieval technique. It is primarily used for obstructive azoospermia where the epididymis (the coiled tube behind the testis where sperm mature and are stored) contains sperm.
How PESA is performed: Under local anaesthesia or light sedation, a fine needle is passed directly through the scrotal skin into the epididymis. Fluid is aspirated and immediately examined under the microscope by an embryologist. If sperm are found, the sample is processed and used for ICSI. The procedure takes 15–20 minutes and is done as a day procedure — no incision, no stitches, and most men return to normal activity within 1–2 days.
When PESA is appropriate:
- Obstructive azoospermia (vasectomy reversal failure, CBAVD, post-infection blockage)
- When initial testing suggests the epididymis is the site of blockage
Limitation: PESA retrieves mature sperm from the epididymis but does not access testicular sperm directly. If the epididymis is damaged or sperm are not found on aspiration, TESA may follow in the same session.
TESA — Testicular Sperm Aspiration
TESA involves aspirating sperm directly from the testicular tissue itself using a needle. It is used when PESA fails to yield sperm, or when the blockage is at or proximal to the epididymis, or in selected cases of non-obstructive azoospermia where initial assessment suggests some sperm production.
How TESA is performed: Under local anaesthesia, a fine needle is inserted into the testis and gentle suction applied to aspirate seminiferous tubule tissue and fluid. The aspirate is examined by the embryologist immediately for the presence of sperm. Multiple passes at different areas of the testis may be made to maximise yield. The procedure is slightly more uncomfortable than PESA and may produce more bruising, but most men recover within 3–5 days.
Testicular sperm vs epididymal sperm: Sperm retrieved from the testis are less mature than epididymal sperm — they have not completed the maturation process that normally happens during epididymal transit. However, ICSI bypasses the need for normal sperm function: a single sperm is injected directly into the egg, and the injection itself delivers the sperm past the barriers it would normally need to penetrate independently. Testicular sperm retrieved via TESA are entirely suitable for ICSI.
Micro-TESE — Microsurgical Testicular Sperm Extraction
Micro-TESE is the gold-standard procedure for non-obstructive azoospermia. It requires an operating microscope and is performed by a specialist urologist trained in microsurgery. Rather than blindly aspirating from the testis, Micro-TESE allows the surgeon to directly visualise individual seminiferous tubules — the microscopic tubes within the testis where sperm are produced. Tubules that look "fuller" or "more opaque" under the microscope are more likely to contain active sperm production and are selectively extracted.
Why Micro-TESE is superior to conventional TESA in NOA:
- It samples far more of the testis than a needle biopsy, increasing the chance of finding focal areas of spermatogenesis.
- It removes less testicular tissue overall, reducing damage to the remaining tissue and preserving testosterone-producing Leydig cells.
- Sperm retrieval rates with Micro-TESE in NOA are 30–70% vs 10–25% with conventional TESA.
What to expect: Micro-TESE is performed under general anaesthesia and takes 1–3 hours. It is a day-surgery procedure. Scrotal discomfort and swelling for 1–2 weeks is expected. The embryologist processes the retrieved tissue in the laboratory immediately after surgery, freezing any sperm found for use in a subsequent IVF/ICSI cycle.
| Technique | Best For | Anaesthesia | Sperm Retrieval Rate | Recovery |
|---|---|---|---|---|
| PESA | Obstructive azoospermia | Local / sedation | >90% in OA | 1–2 days |
| TESA | OA (PESA failed) / mild NOA | Local / sedation | 40–60% in OA; 10–25% in NOA | 3–5 days |
| Micro-TESE | Non-obstructive azoospermia | General | 30–70% in NOA | 1–2 weeks |
What Happens to Retrieved Sperm?
Once sperm are successfully retrieved, the embryologist's role begins. Retrieved sperm — whether from PESA, TESA, or Micro-TESE — are used exclusively with ICSI (intracytoplasmic sperm injection). In ICSI, a single sperm is selected under high magnification and injected directly into each mature egg. This bypasses all the natural barriers that motility-impaired or immature sperm would struggle with.
If sperm retrieval is scheduled on the same day as egg collection (synchronised), fresh sperm are used immediately. More commonly, especially with Micro-TESE (which is a larger procedure), sperm are retrieved and cryopreserved (frozen) in advance. The female partner then undergoes her IVF stimulation cycle, and at egg collection, frozen sperm are thawed and used for ICSI. This approach allows planning and avoids the risk of a failed retrieval on egg collection day.
For more details on TESA and PESA at Mother Hospitals, see TESA / PESA / Micro-TESE in Hyderabad. For a complete overview of male infertility treatment, visit our Male Infertility Treatment page.
Investigations Before Surgical Sperm Retrieval
Before recommending a retrieval procedure, Dr. Prashanthi's team conducts a thorough work-up:
- Repeat semen analysis × 2 (to confirm azoospermia)
- Post-centrifugation analysis — checking the spun-down pellet for any sperm missed on standard analysis
- Hormonal panel — FSH, LH, testosterone, prolactin. Elevated FSH strongly suggests NOA; normal FSH with low volume ejaculate suggests obstructive cause.
- Scrotal ultrasound — to assess testicular volume, epididymal dilation (suggesting obstruction), and varicocele.
- Genetic testing — karyotype (to detect Klinefelter syndrome), Y chromosome microdeletion analysis (AZFa, AZFb, AZFc). AZFa and AZFb deletions are associated with very low retrieval success; AZFc deletion still allows meaningful retrieval in many cases.
- CFTR gene mutation analysis — if CBAVD is suspected (men with absent vas deferens)
Azoospermia Is Not the End of the Road
Dr. Prashanthi says: "When a couple comes to us with a report showing zero sperm, the husband often feels devastated and believes all hope is gone. We sit with them, explain what the diagnosis means, and walk them through the options. For many men — particularly those with obstructive azoospermia — a simple procedure in the morning gives us the sperm we need. For non-obstructive cases, Micro-TESE finds sperm in a significant proportion of men. With ICSI, even a handful of sperm is enough to create embryos and achieve a pregnancy. Azoospermia is a diagnosis — not a verdict."