Ejaculatory Duct Obstruction (EDO) is a surgically correctable cause of male infertility occurring in 1% to 5% of subfertile men. Complete bilateral obstruction results in low-volume, acidic, fructose-negative azoospermia, while partial obstruction causes severe oligoasthenozoospermia.
How to Read Your Semen Analysis & TRUS Imaging Reports
| Diagnostic Marker | Normal Reference Limit | Complete EDO Finding | Diagnostic & Clinical Implication |
|---|---|---|---|
| Semen Volume | ≥ 1.5 mL | Low (<1.0 mL, often 0.2–0.5 mL) | Seminal vesicle fluid is physically blocked and cannot pass. |
| Seminal pH | ≥ 7.2 | Acidic (< 7.0–7.2) | Seminal fluid becomes pure acidic prostatic fluid (pH 5.0–6.5). |
| Seminal Fructose | Positive / Present | Negative / Undetectable | Confirms the complete absence of seminal vesicle secretions. |
| TRUS Imaging | Ducts < 2 mm; vesicles < 1.5 cm | Dilated vesicles (>1.5 cm) & midline cysts | Identifies the exact anatomical site of the ejaculatory duct obstruction. |
Diagnostic Workup Logic
- Semen Biochemistry: The clinical triad of low volume, acidic pH, and absent fructose with azoospermia/severe oligospermia points directly to EDO or CBAVD.
- Transrectal Ultrasonography (TRUS): High-resolution imaging detects midline intraprostatic cysts, ejaculatory duct dilation (>2.3 mm), and seminal vesicle enlargement.
- Seminal Vesicle Aspiration (SVA) & Chromotubation: SVA revealing abundant motile spermatozoa confirms distal ductal blockage.
Etiology & Classifications
- Congenital Cysts: Midline prostatic utricle cysts, Müllerian duct cysts, or Wolffian duct developmental cysts compressing the ductal lumina.
- Acquired Obstructions: Post-infectious scarring from chronic prostatitis or urethritis, ejaculatory duct calculi (stones), or iatrogenic surgical trauma.
Clinical Management & Solutions
- Transurethral Resection of the Ejaculatory Ducts (TURED): Endoscopic unroofing of the cysts and resection of the ejaculatory duct orifices, restoring semen flow patency in 50% to 75% of cases.
- Post-Operative Monitoring: Serial semen analyses every 3 months to monitor patency and screen for re-stricturing or retrograde ejaculation post-surgery.
