Varicocele Ultrasound: Grading, the Valsalva Maneuver, and Reporting Standards

Varicocele is one of the most common scrotal findings and one of the most common correctable causes of male infertility — which makes getting the technique right, particularly the Valsalva component, genuinely consequential for the patient downstream.

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What It Is

A varicocele is dilation and tortuosity of the pampiniform plexus, the network of veins draining the testicle. Reflux of blood through incompetent valves — most often in the internal spermatic (gonadal) vein — allows retrograde flow and progressive venous dilation.

Why the left side so dominates: The left gonadal vein drains into the left renal vein at a right angle, a less favorable hemodynamic path than the right gonadal vein's oblique drainage directly into the IVC. The left vein is also longer, giving gravity more length to work against valve competence. Roughly 85–90% of varicoceles are left-sided or bilateral; a purely right-sided varicocele is uncommon and, in an older patient, worth a specific look for a retroperitoneal or renal mass compressing venous drainage — a real if infrequent cause worth keeping in mind.

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Technique

Probe: High-frequency linear, 7–15 MHz.

Position: Supine initially, then standing or in reverse Trendelenburg for confirmation — gravity-dependent venous distension is often far more apparent upright, and a varicocele missed supine is a genuinely common false negative.

Approach: Scan the scrotum in both grayscale and color Doppler, focusing on the superior and posterior aspect of the testicle, where the pampiniform plexus is most prominent.

The Valsalva Maneuver

This is the technique detail that most affects diagnostic accuracy, and it is frequently rushed.

1. Locate the pampiniform plexus in a longitudinal or transverse plane with color Doppler active.
2. Ask the patient to bear down as if having a bowel movement — a true Valsalva, not just holding their breath.
3. Watch for retrograde flow augmentation — venous flow reversing direction or markedly increasing during the strain.
4. Hold color and, ideally, spectral Doppler through the entire maneuver — the reflux is often transient and easy to miss if you're not actively watching when it happens.

A varicocele that looks borderline at rest can become unmistakable with a well-performed Valsalva. Conversely, a poorly performed one — a shallow breath-hold instead of real abdominal straining — under-detects reflux and can produce a false negative. Coach the patient explicitly; most people's instinctive "Valsalva" on request is too weak to be diagnostic.

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Diagnostic Criteria

Vein Diameter

The most widely used threshold: pampiniform plexus veins measuring ≥ 2.5–3.0 mm in diameter, at rest, in a resting supine patient, support the diagnosis. Some protocols use 2.0 mm as a lower threshold for a "mild" finding. Measure the largest vein, perpendicular to its long axis, at its widest point.

Reflux Duration

Retrograde flow lasting greater than 1–2 seconds during Valsalva is considered a positive study by most protocols. Briefer flow reversal can be a normal variant.

Combining Both

The most reliable studies use diameter plus a positive Valsalva together — diameter alone, without reflux confirmation, is a weaker criterion, since a dilated-looking vein without demonstrable reflux is a less specific finding.

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Grading Systems

Clinical (Dubin) grading, based on physical exam, is what most referring providers will already have documented:

Grade	Clinical finding
Subclinical	Not palpable, detected only on imaging
I	Palpable only with Valsalva
II	Palpable without Valsalva
III	Visible through the scrotal skin without palpation

Sonographic grading varies by institution, but a commonly used version:

Grade	Vein diameter	Reflux
Mild	2.5–3.0 mm	Brief reflux with Valsalva
Moderate	3.0–4.0 mm	Sustained reflux with Valsalva
Severe	> 4.0 mm	Reflux at rest or with minimal provocation

Report both diameter and reflux behavior explicitly rather than only a grade label — the referring urologist needs the underlying numbers, not just a category, particularly when tracking a patient over time or planning intervention.

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Bilateral Assessment and Testicular Volume

Always scan both sides, even with an obviously symptomatic side — bilateral varicoceles are common and change management.

Measure testicular volume on both sides. Varicocele is associated with ipsilateral testicular volume loss, and a significant volume discrepancy (commonly cited around 10–20% or greater difference) is a recognized indication for surgical correction, particularly in adolescents where growth impact is a specific concern.

Testicular volume (mL) = Length × Width × Height × 0.71

Use the same ellipsoid-based approach and coefficient consistently for both testes so the comparison is meaningful.

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Mimics and Differentials

Hydrocele: Anechoic, non-compressible, no Doppler flow — straightforward to distinguish, but a large hydrocele can obscure adjacent plexus veins and complicate the exam.

Epididymal cyst / spermatocele: Discrete anechoic structure, no flow, no change with Valsalva.

Inguinal hernia containing bowel or omentum: Can extend into the scrotum and show peristalsis or echogenic fat — recognizably different in real-time scanning, and won't demonstrate venous reflux physiology.

Post-varicocelectomy recurrence or hydrocele: In a patient with prior surgery, know the surgical history — recurrent or persistent dilated veins after ligation have a different clinical implication than a new, untreated varicocele.

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Reporting for Infertility Workup

When the clinical context is infertility, be specific and complete:

• Diameter of the largest vein, each side
• Presence, duration, and character of Valsalva-induced reflux, each side
• Testicular volume, each side, with the calculated percentage difference
• Grade, using your institution's system, explicitly stated alongside the raw measurements

This level of detail is what actually drives the referring provider's decision about whether correction is likely to help — a bare "varicocele present" without these specifics is of limited use for that purpose.

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Key Images to Capture

1. Right hemiscrotum — grayscale, longitudinal and transverse
2. Right pampiniform plexus — color Doppler at rest
3. Right pampiniform plexus — color and spectral Doppler during Valsalva
4. Left hemiscrotum — same sequence
5. Right and left testicular volume measurements (three dimensions each)
6. Standing or reverse Trendelenburg confirmation view if the supine study was equivocal

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Reporting Language

"Left pampiniform plexus veins measure up to 3.8 mm at rest, with sustained retrograde flow lasting approximately 3 seconds during Valsalva maneuver, augmented further in the standing position. Right pampiniform plexus veins measure up to 1.8 mm with no significant reflux. Left testicular volume 12.1 mL, right testicular volume 16.4 mL — an approximately 26% volume discrepancy. Findings consistent with a moderate left varicocele with associated ipsilateral testicular volume loss."

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SonoBuddy is a reference tool for sonographers — grading and management decisions belong with the referring urologist.