Following male orgasm, sperm are ejaculated after traveling rapidly in sequence through the vas deferens duct, the prostate gland, and the urethra. The vas deferens must be patent to allow the passage of sperm in the ejaculate.
Causes of total obstruction of the vas deferens:
- Primary occlusion: Congenital Absence of the Vas Deferens (CAVD):
In some cases men are born with occlusion of the vas deferens, obstructing the free passage of sperm in the ejaculate.
- Acquired blockage of the vas deferens.
In this situation, the duct is open at birth but becomes blocked following an acquired insult such as vasectomy, failed vasectomy reversal, blunt trauma, and infection. The condition of total obstruction of these ducts is diagnosed when a man who has hormonally, functioning testes (normal blood FSH/LH levels) has absolutely no detectable sperm in his ejaculate (azoospermia). Physical or ultrasound or laboratory examination will help determine the cause.
About CAVD and its relationship to Cystic Fibrosis: It is important to be aware that there is a known association between the autosomally recessive inherited genetic condition of cystic fibrosis (CF) and CAVD. CF is a highly debilitating and life-endangering condition that predominantly affects the lungs and pancreas. Nearly all men with cystic fibrosis have CBAVD, while male carriers for CF, although otherwise seemingly healthy, also have an increased risk compared to those men who carry no abnormal genes.
Treatment: Fertility treatment of total obstruction of the vas deferens, involves egg retrieval with in vitro fertilization (by intracytoplasmic sperm injection-ICSI) using surgically harvested sperm. The sperm is most commonly obtained through two (2) possible procedural approaches;
- Microsurgical epidydimal sperm aspiration (MESA) where a small incision made in the scrotum to expose superficial sperm ducts (vasa eferentia) on the surface of one or both testicles. A needle is introduced into these ducts and sperm-containing fluid is aspirated. MESA can be done either under local anesthesia but general anesthesia is often preferred.
- Percutaneous Testicular Sperm Extraction (TESE). This is almost always done under local anesthesia. With TESE, a biopsy thin needle is introduced directly through the scrotal wall into the testicle(s\ without making a skin incision in the scrotum. Hair-thin biopsy specimens of testicular tissue are removed in the space of 5-10 minutes. Sperm are extracted from the biopsied testicular tissue and used to perform intracytoplasmic sperm injection (ICSI) on each egg to achieve fertilization in the Petri.
The use of MESA/TESE with ICSI renders IVF/ET just as successful when applied in cases of sperm duct obstruction as when conventional IVF/ET is done. The procedures are simple to perform, relatively low-cost, safe, and the risk of complications is small. Although not very incapacitating, MESA is a more painful and procedure than TESE which is virtually pain-free. In fact, most men can literally take off a few hours for the TESE procedure and thereupon return to normal activity. One of the advantages of MESA is that unlike percutaneous TESE which needs to be repeated each time IVF is performed, a single MESA allows for the collection, freezing and storage of sperm for subsequent use.