Residency · Residency · Interventional Radiology

Varicocele Embolization

Overview

Varicocele is an abnormal dilation of the pampiniform venous plexus within the scrotum. Present in ~15% of the male population; found in 35-40% of men with primary infertility. Percutaneous varicocele embolization is a minimally invasive alternative to surgical varicocelectomy. Performed via venous access with catheterization of the gonadal (internal spermatic) vein.

Anatomy

Gonadal Vein Anatomy

Left gonadal vein: drains into the left renal vein at a near-perpendicular angle. This perpendicular insertion and lack of competent valves explain the 80-90% left-sided predominance. Nutcracker effect: compression of left renal vein between SMA and aorta increases venous pressure. Right gonadal vein: drains directly into the IVC at an oblique angle. Lower incidence of varicocele on the right. Isolated right varicocele should prompt evaluation for retroperitoneal pathology (renal mass, IVC thrombus). Pampiniform plexus: network of veins surrounding the spermatic cord, draining via the gonadal vein. Collateral pathways: cremasteric vein, deferential vein, external pudendal veins (can cause recurrence if not addressed).

Clinical Grading

Grade I: palpable only with Valsalva maneuver. Grade II: palpable without Valsalva but not visible. Grade III: visible through scrotal skin.

<image>Diagram showing the anatomy of the left gonadal vein draining into the left renal vein with the pampiniform plexus and common collateral venous pathways that can contribute to varicocele recurrence</image>

Indications for Treatment

Established Indications

Symptomatic varicocele (scrotal pain, heaviness, discomfort). Infertility with abnormal semen parameters and clinically palpable varicocele. Testicular atrophy (>20% volume difference) in adolescents. Recurrent varicocele after surgical repair.

Controversial Indications

Subclinical varicocele (detected only on ultrasound, not palpable). No strong evidence that treatment of subclinical varicoceles improves fertility. AUA/ASRM guidelines do not recommend treatment of subclinical varicoceles. Normal semen parameters with palpable varicocele. Azoospermia with varicocele (may improve sperm retrieval rates for IVF).

Embolization Technique

Access

Right common femoral vein or right internal jugular vein access. Femoral approach: 5-Fr sheath; catheter advanced to left renal vein → left gonadal vein. Jugular approach: may be preferred for right gonadal vein (direct IVC access). Left gonadal vein catheterization from the femoral approach: Cobra or reverse-curve catheter into left renal vein. Identify gonadal vein ostium (inferiorly directed). Advance catheter or microcatheter into the gonadal vein.

Venography

Inject contrast to map the gonadal vein and its branches. Identify collateral pathways (parallel channels, cremasteric connections). Confirm reflux into the pampiniform plexus (with Valsalva if needed). Identify the level of the inguinal canal (do not embolize below this level — risk of testicular ischemia).

Embolic Agents

Coils: most commonly used; metallic coils (fibered or detachable) placed from the inguinal ring to the mid-gonadal vein. Multiple coils deployed at various levels to prevent recanalization. Sandwich technique: coils at distal and proximal ends with sclerosant or additional coils between. Sclerosant (sodium tetradecyl sulfate, polidocanol, or absolute ethanol): Injected to ablate the vein wall and small collaterals. Often combined with coils for more complete occlusion. Balloon occlusion can be used to prevent reflux of sclerosant into renal vein. NBCA glue: liquid embolic providing permanent occlusion; used at select centers. Amplatzer vascular plug: single-device proximal occlusion (used in combination with distal coils).

Procedural Steps

Catheterize the gonadal vein; advance to the level of the inguinal canal. Perform venography to map anatomy and reflux. Embolize from distal to proximal: Place coils at the level of the inguinal ring (most distal safe level). Place additional coils at mid-gonadal vein and proximal levels. If using sclerosant: inject between coil clusters. Repeat venography to confirm occlusion and absence of residual reflux. Check for collateral pathways; embolize any significant parallel channels. For bilateral varicocele: catheterize and embolize right gonadal vein as well. Remove catheter and sheath; manual compression.

<image>Fluoroscopic venogram of the left gonadal vein showing reflux into the pampiniform plexus (left) and post-embolization image showing coils occluding the gonadal vein with no residual reflux (right)</image>

Outcomes

Technical Success

90-98% technical success rate for embolization. Failure to catheterize gonadal vein: 2-5% (anatomic variants, venous spasm).

Clinical Outcomes

Symptom improvement (pain/discomfort): 85-95%. Semen parameter improvement: 60-80% (increase in sperm count, motility, or morphology). Spontaneous pregnancy rate: 30-45% after treatment (comparable to surgery). Recurrence rate: 5-10% (usually from unrecognized collateral pathways).

Comparison with Surgical Varicocelectomy

Embolization: Same-day procedure, local anesthesia/sedation. Faster recovery (1-2 days vs. 1-2 weeks). Lower risk of hydrocele and testicular artery injury. Higher recurrence rate in some series (5-10% vs. 1-5% for microsurgical). Can treat bilateral disease in single session. Microsurgical varicocelectomy: Gold standard surgical approach; lowest recurrence rate (1-2%). Direct visualization of testicular artery and lymphatics (lower hydrocele rate). General or regional anesthesia; longer recovery. Meta-analyses show comparable fertility outcomes between embolization and surgery.

Fertility Improvement Debate

Multiple meta-analyses show improvement in semen parameters after varicocele treatment. Whether treatment improves pregnancy rates is debated. Cochrane review: weak evidence for improved live birth rates after varicocele treatment. Most reproductive medicine guidelines recommend treatment in the context of clinical varicocele + abnormal semen + otherwise unexplained infertility.

Complications

Common (Minor)

Groin/scrotal discomfort (usually self-limited, 24-48 hours). Access site hematoma.

Uncommon

Coil migration (into renal vein, IVC, or pulmonary arteries): rare with proper technique. Venous perforation. Thrombophlebitis of gonadal vein (rare). Recurrence from collateral reconstitution. Allergic reaction to contrast or sclerosant. Testicular atrophy (extremely rare — from inadvertent embolization below inguinal ring or testicular artery injury).

Clinical Pearls

An isolated right-sided varicocele should raise suspicion for retroperitoneal pathology (renal mass, retroperitoneal tumor, IVC thrombus) — always image the retroperitoneum. The key to preventing recurrence is identifying and embolizing parallel venous channels — venography with Valsalva and careful fluoroscopic evaluation is essential. Do not place embolic material below the level of the inguinal ring — this risks compromising drainage of the pampiniform plexus and testicular perfusion. Combining coils with sclerosant achieves a more complete occlusion than coils alone, reducing recurrence rates. The "sandwich technique" (distal coils → sclerosant → proximal coils) prevents sclerosant reflux into the renal vein while ensuring thorough ablation. Embolization is an excellent option for recurrent varicocele after surgery — it avoids re-operation in a scarred surgical field. For adolescent varicoceles with testicular atrophy, treatment is recommended regardless of fertility considerations — testicular growth typically catches up after successful treatment. Counsel infertile patients that varicocele treatment may improve semen parameters but is not guaranteed to result in pregnancy; it should be part of a comprehensive fertility evaluation.

<image>Post-embolization CT scout image showing metallic coils distributed along the left gonadal vein from the inguinal region to the retroperitoneum confirming complete embolization</image>

References

• Jarvis S, et al. Varicocele Embolization: Technique, Outcomes, and Complications. Semin Intervent Radiol. 2016;33(3):183-188.
• Bechara CF, et al. Percutaneous Varicocele Embolization. Tech Vasc Interv Radiol. 2009;12(3):173-180.
• Practice Committee of the ASRM. Report on Varicocele and Infertility. Fertil Steril. 2014;102(6):1556-1560.
• Kroese AC, et al. Varicocele Treatment in Men with Subfertility: Cochrane Systematic Review. Cochrane Database Syst Rev. 2012;(10):CD000479.
• Iaccarino V, Venetucci P. Interventional Radiology of Male Varicocele. Cardiovasc Intervent Radiol. 2012;35(6):1263-1278.
• Schauer I, et al. Varicocele Embolization vs. Microsurgical Subinguinal Varicocelectomy: Meta-Analysis. Urology. 2012;80(5):949-956.

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