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Benign prostatic hyperplasia due to venous drainage malfunction in the male reproductive system: a price of erect posture in humans
Author(s) -
Schill W.B.,
BenShlomo I.
Publication year - 2008
Publication title -
andrologia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.633
H-Index - 59
eISSN - 1439-0272
pISSN - 0303-4569
DOI - 10.1111/j.1439-0272.2008.00887.x
Subject(s) - male reproductive system , hyperplasia , medicine , prostate , physiology , pathology , andrology , sperm , cancer
Ever since the discovery of hormones and their target organs, benign prostatic hyperplasia (BPH) has posed a paradox. In the face of age-related deterioration of circulating testosterone levels, the prostate undergoes a process of enlargement. The seminal observations by Gat et al., appearing in the current issue, revolutionise our view of BPH and its pathophysiology. They found that in ageing men, the drainage apparatus of the reproductive system is impaired due to physical wear and destruction of the one way valves in the internal spermatic veins. This results in crucial changes in intravascular and interstitial pressure and blood flow in the entire reproductive system, creating elevated venous back-pressure associated with back-flow of venous blood, affecting the prostate. It also exposes the gland to extremely high concentrations of biologically active, free testosterone from a new, additional, previously unrecognised source, directly from the testes. So, in addition to the physiological androgen arriving via the arterial blood, the gland is flooded with high concentrations of biologically active androgen some two orders of magnitude above normal, reaching it via the testicular and prostate drainage systems – the ‘back door’. Thus, in light of their previous work, which showed that the prevalence of varicocele increases with age, BPH is no longer to be considered paradoxical in ageing men. Rather, it is to be expected. Furthermore, by occluding the internal spermatic veins bilaterally including the associated network of venous bypasses, which are vertically oriented, they achieved a dramatic reversal of BPH, further supporting the direct role of the reversed venous flow from the testes to the prostate. They explain the overall diminished production of testosterone in older men as the result of relative testicular hypoxia caused by the impairment of the testicular venous drainage system. This has been demonstrated by histological findings and their previous observations on improvement in testosterone production in men with infertility and low testosterone levels. Epidemiological and evolutionary perspective