Varicocele refers to the obstruction of venous return in the spermatic cord, valve failure, and blood reflux, leading to blood stasis, resulting in the expansion, elongation, and curvature of the varicose veins. Most people believe that varicocele can affect sperm production and semen quality, leading to infertility. Some individuals can recover their fertility after surgical treatment.
One, common triggering factors of varicocele
1. Physiological factors
The sexual function of young people is generally strong, and the blood supply to the contents of the scrotum is very abundant. In addition, long-term standing increases abdominal pressure, which is also one of the risk factors for the disease.
2. Anatomical factors
The veins inside the left spermatic cord near the left renal vein generally have no valves, so blood can easily reflux. The internal veins of the left spermatic cord are too long and enter the renal vein at a right angle, causing certain resistance to blood flow.
3. Other factors
Renal tumors, retroperitoneal tumors, renal hydrops, and other factors can compress the veins inside the spermatic cord, causing symptomatic or secondary varicocele of the spermatic cord.
Two, the pathological etiology of varicocele
1. Primary varicocele
The main cause of varicocele is the stasis of spermatic vein blood flow. Due to the influence of human upright posture, the venous return of the spermatic veins is affected. The venous wall and its surrounding connective tissue are weak or the cremaster muscle is underdeveloped, the venous valve is defective or incomplete, so varicocele is prone to occur. Recently, it has been reported that varicocele is closely related to masturbation. Pathological changes in the internal spermatic veins and blood flow disorders are intercausal and mutually influential, forming a vicious cycle. Both left and right spermatic veins can occur separately or simultaneously, but the incidence of left varicocele is higher, the reason being: the left spermatic vein is about 8-10 cm longer than the right, and it enters the renal vein at a right angle, resulting in high venous pressure. The left spermatic vein may be compressed by the colon, and the left renal vein may be compressed between the aorta and mesenteric artery, affecting the venous return of the spermatic veins, forming the so-called proximal 'clamp' phenomenon. The right common iliac artery may compress the left common iliac vein, causing the left spermatic vein to be blocked, forming the so-called distal 'clamp' phenomenon.
2. Symptomatic varicocele
Renal tumors with renal vein, inferior vena cava thrombus formation, retroperitoneal tumor compression, renal hydrops, or ectopic blood vessels can all cause symptomatic varicocele of the spermatic cord.
Three, why varicocele can cause male infertility
There are many cases of varicocele combined with male infertility. Varicocele causes pathological changes in the testicles, affecting spermatogenesis, causing a decrease in sperm motility, an increase in the number of immature sperm cells, and an increase in the number of acrosome heads. To date, there is no reliable evidence to clarify the mechanism of infertility, but it is believed to be related to the following factors:
1. The retention of blood in varicose veins causes the local temperature of the testicles to increase, affecting spermatogenesis.
2. The retention of blood affects the blood circulation of the testicles, leading to a lack of necessary nutritional supply and oxygenation, which affects spermatogenesis.
3. The reflux of blood in the internal spermatic veins on the left side brings metabolic products secreted by the adrenal glands and kidneys, such as steroids, catecholamines, serotonin, and others, to the testicles. Steroids can inhibit spermatogenesis, catecholamines can cause chronic intoxication of the testicles, serotonin can cause vasoconstriction, leading to premature shedding of immature sperm, and can cause male infertility.
4. The above factors can also affect the endocrine function of the testicular interstitium, interfere with spermatogenesis.
5. Left-sided varicocele can also affect the function of the right testicle, as there are abundant anastomoses between the venous vessels of the two testicles. The toxins in the left venous blood can reach the right side and affect the spermatogenesis of the right testicle.