Excretory system and causes of obstruction
The exocrine system of the male genitalia includes the seminal vesicles, ejaculatory ducts, ampullae of the vas deferens, and prostate gland. Transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) are used in clinical practice to visualize them. Any developmental anomalies or obstruction throughout this tract inevitably lead to subfertility.
One of the frequent problems is obstruction of the epididymis (epididymis). If a cyst is detected during examination and the epididymis is enlarged proximal to it, this serves as a reliable indirect sign that the cystic lesion itself caused the obstruction.
Special attention should be given to congenital absence of the vas deferens:
- Bilateral agenesis is encountered in almost all patients suffering from cystic fibrosis.
- Unilateral absence is observed less frequently—in approximately 0.5% of men, and in most cases it is associated with unilateral renal agenesis.
Varicocele: etiology and impact on fertility
Varicocele represents a pathological dilatation and tortuosity of the veins of the pampiniformis plexus (plexus pampiniformis). Anatomically, these changes are localized superior and posterior to the testis. The condition may be idiopathic or secondary, arising against the background of venous valve incompetence.
Idiopathic varicocele almost always develops on the left side. This is explained by anatomical features: blood outflow from the left testis into the left renal vein has a longer and less direct pathway. If an isolated venous dilatation is detected on the right, especially in older patients, this traditionally raises suspicion for an intra-abdominal space-occupying lesion (although modern clinical data call this classical rule into question).
Varicocele is closely associated with male infertility, but a therapeutic dilemma lies here. Subclinical forms are found in 20–80% of completely healthy and fertile men. At the same time, even minimally expressed venous dilatation, visible only on ultrasound, is capable of provoking severe spermatogenesis impairment. It is important to remember: the size of a varicocele does not correlate with the degree of suppression of sperm production.
Ultrasound diagnostics
The main method for identifying scrotal vein pathologies is ultrasound examination. On sonograms, a varicocele appears as a cluster of multiple dilated, tortuous tubular structures located strictly posterior to the testis and frequently descending to its lower pole.
The universally accepted threshold value separating norm from pathology is considered to be a venous diameter greater than 2 mm. A number of studies use refined criteria: 2.7 mm for the subclinical stage and 3.6 mm for the clinically manifested disease.
To increase the accuracy of ultrasound, the patient must be placed in a standing position—this increases blood filling of the vessels. Since spontaneous blood flow may not be detected even with high sensitivity of Doppler modes, provocative maneuvers are mandatory: coughing, a sharp deep inspiration, or the Valsalva maneuver.
Venography and embolotherapy
Internal spermatic venography is rarely used today as an independent primary diagnostic method. Its main task is venous mapping prior to interventional radiological treatment (embolotherapy).
Indications for surgical intervention are subfertility and the presence of large symptomatic nodes. If a patient is diagnosed with a clinically evident left-sided varicocele and simultaneously a subclinical right-sided one, correction of both sides significantly increases the chances of restoring fertility.
The procedure consists of selective catheterization of the gonadal vein via a jugular or femoral approach with the administration of an iodine-based contrast agent. Coils, special occluders, hemostatic sponges, or sclerosing agents are used for vascular occlusion. The efficacy of coil embolization reaches 90–97%, although the presence of anatomical variations (e.g., anastomoses with retroperitoneal veins) may reduce the success of the intervention.
To remember the association of right-sided varicocele with pathologies: "On the left — physiology (long outflow pathway), on the right — oncology (suspicion of a space-occupying lesion)."
Class and exam questions
Does the degree of spermatogenesis impairment depend on varicocele size?
No, the size of the dilated veins does not correlate in any way with the severity of sperm production impairments.
What maneuvers are used on ultrasound to detect blood flow in varicocele?
Provocative tests are used: the Valsalva maneuver, coughing, and a sharp inspiration. They help visualize blood flow if it is not detected spontaneously.
What does an isolated right-sided varicocele in an elderly patient indicate?
Classically, this raises suspicion of an intra-abdominal space-occupying lesion compressing the vessels, although modern studies call this postulate into question.
Where exactly are dilated veins localized in varicocele according to ultrasound data?
They are visualized as tubular structures posterior to the testis and can extend all the way down to its lower pole.
What else to study on this topic
- Anatomy and hemodynamics of the pampiniformis plexus.
- Technique of the Valsalva maneuver during scrotal ultrasound.
- Genetic connection between cystic fibrosis and bilateral agenesis of the vas deferens.
- Interventional radiological methods: technique of gonadal vein coil embolization.
- Criteria for differential diagnosis of subclinical and clinical varicocele.
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