Читать книгу Saving Your Sex Life: A Guide for Men With Prostate Cancer - John P. Mulhall - Страница 10

Besides the penis, there are a number of other reproductive organs that should be considered, including the seminal vesicle and the prostate itself. The prostate is a small, walnut-shaped sized organ in the healthy male that sits beneath the bladder and surrounds the urethra. It is separated from the erectile bodies by a muscle layer (the urogenital diaphragm), which is about 1 cm in thickness. The prostate is composed of two major types of tissue: glands, which secrete fluid that is part of semen, and the tissue between the glands known as a stroma. Within the stroma is muscular tissue, and the tone of this tissue in some men dictates urinary function. The prostate produces an acidic fluid, which makes up about 20 to 25% of the seminal fluid (that is, the fluid that is ejaculated). Sitting behind the prostate are two sets of paired structures, the seminal vesicle on the outside and the vas deferens on the inside (Figure 4). The vas deferens travels from the testicle up through the scrotum and the inguinal hernia canal into the pelvis and enters the prostate. This, of course, is the delivery mechanism for sperm. Much to people’s surprise, sperm constitute only 5 to 10% of the volume of the semen that is ejaculated. By the way, normal men produce about 50 million sperm in each cc of semen!

The seminal vesicles are paired structures, which on x-ray look a little like rabbit ears. These structures are glands that produce the vast majority (approximately 70 to 85%) of the seminal fluid. The fluid produced by the seminal vesicle is alkaline in nature and, thus, semen is generally alkaline, as the seminal vesicle fluid amount is larger than the acidic prostate fluid. The seminal vesicles and the vas deferens on each side actually join to form the ejaculatory duct. A right- and left-side ejaculatory duct is present. The ejaculatory duct travels through the prostate and opens into the urethra. The urethra travels through the prostate much in the same way as if you core a whole apple so that there is a channel running through the apple.

Figure 4 • Rear view of the prostate. Sitting behind the prostate are the seminal vesicles (one on each side) and inside these the vas deferens (one on each side). The seminal vesicle and vas deferens join to form the ejaculatory duct, which passes through the prostate.

At the time of radical prostatectomy, not only is the prostate removed, but the seminal vesicles are also removed. Also during the procedure, the vas deferens is cut and ligated (closed off with suture or metal clips) behind the prostate. This is why patients who have had a radical prostatectomy do not ejaculate despite the fact that most of them achieve a normal orgasm. Furthermore, patients who have had a radical prostatectomy are sterile, although they do produce sperm which is made by the testicles and travels into the vas deferens within their scrotum. This sperm can be extracted at a later date, and this can be utilized with a woman’s eggs using in-vitro fertilization (IVF). For patients who want to continue to have children, it is recommended that, prior to radical prostatectomy or prostate radiation, semen be banked for purposes of future attempts of in-vitro fertilization. Saying that, if a man has not banked sperm and decides that he wants to increase the size of his family after radical prostatectomy, a simple procedure can be performed to extract tissue from his testicle which has a very high likelihood of providing enough sperm for the purposes of IVF. Following prostate radiation, the ejaculation ducts and prostate ducts often undergo scarring with time (nothing with radiation occurs immediately), and over the course of one to five years after the completion of radiation, there is a very high likelihood that the man will notice a significant reduction in the amount of fluid ejaculated and may eventually end up with a very similar situation to patients after prostate surgery where there is no ejaculation whatsoever. Again, most patients—post-radiation therapy for prostate cancer—are capable of achieving an orgasm even if they are not ejaculating.