Some men may have a blockage of the ejaculatory ducts where the sperm from the vas deferens and the fructose rich fluid from the seminal vesicle enter into the prostatic urethra. The cause of such a blockage is often a cyst that the patient was born with. It could also be a cyst that occurred later in life, or a stone or a narrowing due to a stricture.
The clue to this condition is a very low volume of ejaculate (less than 1.5cc) with no sperm and a low semen PH and no fructose upon testing. The most common test to evaluate for ejaculatory duct obstruction is a transrectal ultrasound. An ultrasound probe placed in the rectum is maneuvered to visualize the prostate and seminal vesicles. If there is a blockage, then the seminal vesicles will appear dilated and backed up. The treatment for this condition is a telescopic procedure through the penis to cut away the obstructing tissue from the prostate. There is about a 50 percent success rate and about a 20 to 30 percent side effect rate. Side effects include chronic testicle or epididymal inflammation, retrograde ejaculation, or urinating difficulty.
An alternative treatment is sperm retrieval surgery with in vitro fertility.