Varicocele




(1)
Pediatric Surgery, AlSadik Hospital, Qatif, Saudi Arabia

 




25.1 Introduction






  • The testes are supplied by blood vessels that originate in the abdomen and course down through the inguinal canal as part of the spermatic cord to the testis.


  • The testis is drained by a plexus of veins called the pampiniform venous plexus. These course upward and coalescence to form the testicular vein. The left testicular vein drains at right angle into the left renal vein while the right testicular vein drains directly into the inferior vena cava.


  • Upward flow of blood in the veins is ensured by small one-way valves that prevent backflow.


  • A varicocele is an abnormal enlargement and tortuosity of the pampiniform plexus of veins (Fig. 25.1).

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    Fig. 25.1
    Diagrammatic representation of a varicocele


  • Varicoceles result from defective valves, or compression of the vein by a nearby structure. This leads to dilatation of the testicular veins and the formation of a varicocele.


  • The true incidence of adolescent varicoceles is not known because most adolescent varicoceles are asymptomatic.


  • The initial presentation of varicoceles usually occurs during puberty, with an incidence in 13-year-old adolescent boys equal to that of adult men (15 %).


  • Rarely, varicoceles are noted in the prepubertal period.


  • Although varicoceles may be bilateral, they are usually unilateral and almost always on the left side.


  • It has been estimated that 90 % of all varicoceles occur on the left side. This is attributed to the fact that the right testicular vein drain directly into the inferior vena cava while the left testicular vein drains at a right angle into the left renal vein. This predisposes to slower drainage in the left testicular vein.


  • A unilateral right-side varicocele raises certain concerns and should prompt an investigation for an underlying obstructive cause such as:



    • A tumor


    • Retroperitoneal fibrosis


    • Thrombosis or occlusion of the inferior vena cava


  • These patients should be investigated radiographically including computed tomography (CT).


  • Situs inversus is another rare cause of a right-side varicocele which must be kept in mind.


25.2 Etiology






  • The exact etiology of varicoceles is unknown and various theories have been proposed to explain this taking in consideration the fact that 90 % of all varicoceles occur on the left side.


  • Varicoceles are divided into two types depending on the etiology.



    • Primary or idiopathic varicocele


    • Secondary varicocele


  • Primary or idiopathic varicocele:



    • This is the commonest type.


    • It occurs as a result of defective valves within the veins along the spermatic cord.


    • This results in backflow of blood into the pampiniform plexus and causes its dilatation, tortuosity and increased pressures.


    • The majority of idiopathic varicoceles occur on the left side.


    • This is because the left testicular vein drains into the left renal vein (at a 90-degree angle), while the right testicular vein drains directly into the inferior vena cava.


    • Isolated right sided varicoceles are rare.


    • Increased length of the left testicular vein:



      • The left vein is 8–10 cm longer than the right testicular vein. This may contribute to an increased pressure in the left testicular vein when compared to the right testicular vein.


  • Secondary varicocele:



    • This results from compression of the venous drainage of the testicle.


    • This can develop as a result of pelvic or abdominal tumors that causes compression of the veins draining the testes.


    • A unilateral right-sided varicocele that is newly diagnosed in a patient older than 40 years of age should raise the possibility of an underlying malignancy.


    • The most common cause is renal cell carcinoma (hypernephroma) followed by retroperitoneal fibrosis or adhesions.


    • In the pediatric age group, left-sided Wilms’ tumor with extension into the renal vein can cause obstruction of the testicular vein leading to left varicocele. In those with right-sided Wilms’ tumor, a varicocele can develop if the tumor extends into the inferior vena cava and leads to obstruction of the right renal vein.


    • “The Nutcracker syndrome”:



      • This is one non-malignant causes of a secondary varicocele.


      • In this condition, the superior mesenteric artery compresses the left renal vein between it and the aorta, causing increased pressures which is transmitted retrograde into the left pampiniform plexus of veins.


25.3 Pathophysiology






  • The pampiniform plexus of veins is the network of veins that normally drain the testicle.


  • Normally, the size of the veins that make up the pampiniform plexus range from 0.5 to 1.5 mm


  • This plexus of veins travels along the posterior portion of the testicle with the epididymis and vas deferens, and then into the spermatic cord and upwards where they coalesces to form the testicular vein.


  • Upward flow of blood in the veins is ensured by small one-way valves that prevent backflow.


  • The right testicular vein drains into the inferior vena cava, while the left testicular vein drains into the left renal vein at right angle to the renal vein, which then drains into the inferior vena cava.


  • The pampiniform plexus of veins not only drains the blood from the testes, vas and epididymis but also has an important function to lower the temperature of the testes.


  • A varicocele develops when there is dilatation and tortuosity of the veins of the pampiniform plexus.


  • It has been estimated that a varicocele develops when the size of these veins exceeds 2 mm.


  • The development of a varicocele with these dilated veins leads to an increase in the temperature around the testes resulting in testicular atrophy, reduction in the quality and the quantity of the sperms and infertility. This effect on sperm quantity and quality is progressive.


  • It has been shown also that blood from the testes that cannot drain via the pampiniform plexus may drain via communicating vessels through the prostate. The increased flow of blood to the prostate can lead to congestion and enlargement of the prostate gland secondary to cell proliferation resulting from the high concentration of free testosterone reaching directly from the testes to the prostate.


  • It has been shown that a varicocele that persists will lead to histopathological changes in the testis which include:



    • The affected testis is abnormally small as compared with the contralateral testis.


    • Seminiferous tubule sclerosis


    • Small vessel degenerative changes


    • Abnormalities of Leydig, Sertoli, and germ cells


    • The subsequent effects of a varicocele on semen include:



      • Decreased sperm motility


      • Lower total sperm counts


      • Increased number of abnormal sperm forms


  • These changes may be reversed with corrective surgery.


  • The reasons for altered sperm production, testicular size, and morphologic changes in the testis are not clearly understood. The proposed pathophysiologic mechanisms include the followings:

Jul 10, 2017 | Posted by in UROLOGY | Comments Off on Varicocele

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