Can a left-sided scrotal varicocele with a 3.4 mm resting vein diameter and reflux be the cause of bilateral testicular atrophy?

A Left-Sided Varicocele with 3.4 mm Diameter is Unlikely to Cause Bilateral Testicular Atrophy

You should not attribute bilateral testicular atrophy to this small left-sided varicocele, as the vein diameter (3.4 mm) is below the threshold for clinical significance, and varicoceles—even when clinically significant—predominantly affect the ipsilateral (left) testis, not both testes. 1, 2

Why This Varicocele is Not the Cause

Vein Diameter Below Clinical Threshold

• Your patient's maximum resting vein diameter of 3.4 mm falls into the normal-to-borderline range, as varicose veins are defined as dilated veins ≥3 mm 3, and clinically significant varicoceles typically measure 5.0-6.6 mm depending on grade 2
• Grade I varicoceles average 5.0 mm, Grade II average 5.8 mm, and Grade III average 6.6 mm, compared to 2.5 mm in normal testicular units 2
• The presence of reflux on ultrasound alone does not determine clinical significance, as varicoceles affect 15% of normal males with most never requiring treatment 2

Bilateral Atrophy Pattern Inconsistent with Unilateral Varicocele

• Left varicoceles cause predominantly ipsilateral (left-sided) testicular damage, not bilateral atrophy 4
• In a study of 188 infertile patients with left varicocele, the left testis showed significant pathological changes compared to the right side, with only 7% showing more pronounced damage on the right 4
• After unilateral varicocelectomy in adolescents, the treated left testis grew an average of 50.1% while the contralateral testis grew only 23%, demonstrating that varicocele effects are predominantly unilateral 5

Non-Palpable Varicoceles Are Not Clinically Meaningful

• The American Urological Association and European Association of Urology recommend against routine ultrasonography to identify non-palpable varicoceles because these findings are not clinically meaningful 1
• Non-palpable (subclinical) varicoceles do not cause clinically significant testicular damage and should not be treated 1
• The American Urological Association warns against attributing testicular atrophy to a non-palpable varicocele and pursuing varicocelectomy, as this is a common error that will not reverse the atrophy 1

What You Should Investigate Instead

Hormonal Evaluation for Primary Testicular Dysfunction

• Obtain FSH, LH, total testosterone, and SHBG immediately to investigate primary hypogonadism, which commonly presents with bilateral testicular atrophy 1
• Elevated FSH and LH with low testosterone indicate primary testicular failure affecting both testes 1

Genetic Testing if Severe Oligospermia Present

• If sperm concentration is <5 million/ml, obtain karyotype testing and Y-chromosome microdeletion analysis (AZFa, AZFb, AZFc regions) 1
• Genetic abnormalities occur in approximately 4% of men with very low sperm counts 1

Comprehensive Scrotal Ultrasound Review

• Review the ultrasound for alternative pathology including masses, hematomas, infarcts, or inflammatory changes that could explain bilateral atrophy 1
• Assess testicular size, texture, and homogeneity bilaterally 1

Historical Factors

• Investigate prior testicular trauma or infection (epididymo-orchitis), which can cause permanent bilateral testicular damage and atrophy 1
• Evaluate for systemic conditions such as chronic liver disease, which can increase SHBG levels and affect testicular function bilaterally 1

Critical Pitfall to Avoid

Do not proceed with varicocelectomy for this patient. The small vein diameter (3.4 mm), bilateral pattern of atrophy (rather than left-sided predominance), and likely non-palpable nature of this varicocele all indicate that surgical intervention will not reverse the atrophy and represents a common clinical error 1, 2. The bilateral nature of the atrophy demands investigation for systemic, hormonal, or genetic causes rather than attributing it to a borderline left varicocele.