Venous · IR Playbook

Varicocele Embolisation

Varicocele embolisation is percutaneous transvenous occlusion of the refluxing internal spermatic (gonadal) vein and its collaterals to abolish retrograde venous flow into the pampiniform plexus. The mechanism is purely haemodynamic: an incompetent or absent valve at the internal spermatic vein origin allows a standing column of renal or caval venous blood to reflux into the scrotum, raising testicular temperature and venous pressure, so occluding the refluxing channel — and every parallel channel — is the entire therapeutic act, and every failure mode is a missed parallel channel. Reported technical success is approximately 90-96% with recurrence around 6-13%. Because the procedure is entirely intravenous and spares lymphatics, the surgical complication of hydrocele is essentially avoided; the characteristic risks instead are coil migration and post-embolisation thrombophlebitis of the pampiniform plexus.

Learning objectives

Select patients in whom varicocele embolisation is indicated and exclude secondary varicocele due to renal vein compression or retroperitoneal mass
Identify the anatomical variants of the internal spermatic vein and collateral pathways that cause recurrence, and state the manoeuvre that detects each
Choose access route, catheter and embolic agent appropriate to the side treated and the venous anatomy encountered
Recognise the completion venographic endpoint that defines technical success
Manage coil migration, gonadal vein perforation and post-embolisation thrombophlebitis

Indications

Palpable varicocele with abnormal semen parameters in a couple with documented infertility
Adolescent varicocele with ipsilateral testicular growth arrest or progressive volume loss on serial ultrasound
Symptomatic varicocele with chronic scrotal pain refractory to conservative measures
Recurrent or persistent varicocele after surgical ligation, where venography defines the residual channel
Patient preference for a minimally invasive alternative to surgical varicocelectomy after counselling

Absolute contraindications

Secondary varicocele from renal vein or caval obstruction by tumour or extrinsic compression, until the underlying cause is addressed
Uncorrectable severe contrast hypersensitivity

Relative contraindications

Uncorrected coagulopathy or thrombocytopenia
Renal impairment limiting contrast volume
Subclinical varicocele with no clinical indication
Anatomically inaccessible or absent gonadal venous outflow on prior imaging

Equipment

5-6 F short vascular sheath
0.035 inch hydrophilic guidewire, 150-180 cm
5 F Cobra 2, Simmons 1 or multipurpose selective catheter, 65-100 cm depending on access
2.4-2.8 F microcatheter with 0.014-0.018 inch microwire for tortuous or small-calibre segments
Pushable fibred coils and detachable coils, sized to allow 20-30% oversizing of the target vein
Vascular plug for a wide single-channel internal spermatic vein
3% sodium tetradecyl sulphate or polidocanol with two syringes and a three-way tap for foam preparation
Non-ionic iodinated contrast, diluted for gentle venography
Tilting angiographic table or facility for reverse Trendelenburg positioning to augment the Valsalva venogram

Procedure steps

Position the patient supine with the neck or groin prepared according to the chosen access. Set up for reverse Trendelenburg tilt, since a semi-upright position combined with Valsalva maximises reflux and makes a marginal varicocele demonstrable.
Under ultrasound guidance puncture the right internal jugular or right common femoral vein and place a 5-6 F sheath. Ultrasound guidance rather than landmark puncture is used because the target is a low-pressure vein adjacent to an artery and the procedure carries no other bleeding risk to justify a blind stick.
Advance a 5 F Cobra 2 or multipurpose catheter over the guidewire into the left renal vein and perform a gentle hand-injection renal venogram in the anteroposterior projection. Watch specifically for reflux into a gonadal vein origin at the inferior border of the renal vein and for a stenotic aortomesenteric segment; a tight renal vein waist with dense collateral filling changes the plan and the procedure is abandoned.Pearl: Ask the patient to perform a Valsalva during the renal venogram — the gonadal ostium that is invisible at rest often opacifies immediately.
Engage the gonadal ostium with the catheter tip and advance the hydrophilic wire caudally, following it with the catheter down the internal spermatic vein. The wire should pass freely; resistance, buckling or a catheter tip that will not follow indicates a valve or a tortuous segment and is the point at which a coaxial microcatheter is introduced rather than force applied. The step is complete when the catheter sits in the mid to lower internal spermatic vein.Pearl: Reshape a Simmons or use a jugular approach when the ostium is acutely angled cranially and a forward-facing catheter repeatedly prolapses.
With the catheter tip near the level of the inguinal ligament and the table tilted head-up, hand-inject dilute contrast during sustained Valsalva and record the full length of the vein to the renal vein. You are looking for reflux to the pampiniform plexus, for duplicated or plexiform limbs, for renal capsular and lumbar collaterals and for midline-crossing channels. This map determines the length to be embolised and every branch that must be separately occluded, and the step is not complete until the vein is opacified continuously from plexus to ostium.Pearl: Repeat the run in a shallow oblique if two limbs are superimposed in the anteroposterior projection — a duplication hidden by overlap is the classic origin of recurrence.
Position the catheter tip just above the level of the inguinal ligament and deploy fibred coils oversized 20-30% relative to the measured vein diameter, starting with a coil sized to anchor. Watch the coil form a stable nest without elongating along the vein; a coil that straightens and advances caudally is undersized and must be retrieved or supplemented before proceeding. The distal end of the embolised segment should sit above the pampiniform plexus so that the plexus itself is not thrombosed.Pearl: Deploy the first coil with the catheter tip advanced slightly beyond the intended nest and withdraw as the coil forms, so the pack builds against the catheter rather than being pushed downstream.
Standard textbook technique: with the distal coil pack acting as a barrier that prevents caudal escape toward the pampiniform plexus, withdraw the catheter a few centimetres and inject foamed sclerosant prepared by repeated exchange between two syringes through a three-way tap, while the patient performs Valsalva to slow renal venous washout. Observe the foam filling the vein under fluoroscopy and stop when it approaches the level intended for the proximal coils. Practice varies: published series have not shown a consistent advantage of adding sclerosant to coils, so coil-only treatment is a defensible strategy.Pearl: A head-up tilt with jugular access lets gravity hold the foam column in the target segment instead of letting it float proximally.
Selectively catheterise each duplicated limb, lumbar or capsular collateral and midline-crossing channel identified on the diagnostic run and occlude it with coils or microcoils. Confirm after each that contrast no longer passes into that channel on repeat Valsalva injection; a residual channel at this stage is the anatomical basis of recurrence and there is no later opportunity to address it.
Withdraw the catheter to the proximal internal spermatic vein and deploy coils to within 1-2 cm of the renal vein ostium, leaving no coil protruding into the renal vein. Watch that the last coil sits entirely within the gonadal vein on a magnified fluoroscopic view before detaching or releasing.Pearl: Use a detachable coil for the most proximal position so it can be repositioned if it prolapses toward the renal vein.
Inject contrast into the renal vein or the internal spermatic vein stump during Valsalva with the patient tilted head-up. The endpoint is stasis at the coil pack with no antegrade or retrograde contrast passage beyond it and no opacification of the pampiniform plexus by any route. Any residual filling means an unoccluded channel and requires return to step 8.
If a clinically significant right varicocele coexists, engage the right internal spermatic vein at the anterolateral inferior vena cava just below the right renal vein using a reverse-curve catheter, and repeat the venographic assessment and embolisation sequence. Check the right renal vein if the caval origin cannot be found, since a minority of right internal spermatic veins drain there.
Remove the sheath and obtain haemostasis with manual compression at the venous puncture site. Record fluoroscopy time and dose-area product, since the gonads are within or adjacent to the imaged field.

Complications

Coil migration
Gonadal vein perforation
Thrombophlebitis of the pampiniform plexus
Recurrent or persistent varicocele
Contrast-induced reaction or nephropathy
Access site haematoma
Gonadal radiation exposure

Exam pearls

Around 90% of varicoceles are left-sided because the left internal spermatic vein inserts perpendicularly into the left renal vein, giving a longer and less favourable venous column than the oblique right caval insertion; an isolated right varicocele demands abdominal imaging to exclude an obstructing lesion.
A varicocele arising in the setting of left renal vein compression between the aorta and superior mesenteric artery is secondary, and embolising the gonadal vein removes a decompressive collateral and can worsen renal venous congestion.
The commonest anatomical cause of recurrence after varicocele embolisation is a duplicated or plexiform internal spermatic vein or a renal capsular collateral left unoccluded, which is why the diagnostic Valsalva venogram must be obtained from the low internal spermatic vein before any coil is deployed.
Coils for varicocele embolisation are oversized by 20-30% relative to the measured vein diameter; undersizing is the mechanism of coil migration to the pulmonary circulation.
Hydrocele is a recognised complication of surgical varicocelectomy from lymphatic injury but essentially does not occur after embolisation, which is entirely intraluminal.
Post-embolisation thrombophlebitis of the pampiniform plexus is an expected self-limiting sequela managed with scrotal support and non-steroidal analgesia, and is distinguished from infection by the absence of fever and erythema.

Viva questions

A young man has a left varicocele and cross-sectional imaging shows the left renal vein compressed between the aorta and superior mesenteric artery with prominent lumbar collaterals. Why should you not embolise the internal spermatic vein?: The varicocele is secondary: the gonadal vein is functioning as a decompressive outflow channel for an obstructed left renal vein. Occluding it removes that outflow and can precipitate renal venous hypertension with haematuria and flank pain, so the renal vein obstruction, not the gonadal vein, is the target.
Your completion venogram looks satisfactory but the patient has a palpable varicocele at 3 months with reflux on Doppler. What is the most likely anatomical explanation and how would you have detected it at the index procedure?: A duplicated or plexiform internal spermatic vein, or a renal capsular or lumbar collateral reconstituting the vein below the proximal coils. It is detected by performing the diagnostic Valsalva venogram from the low internal spermatic vein in more than one projection before any coil is placed, so that overlapping parallel limbs are separated.
Why is the distal coil pack placed at the level of the inguinal ligament rather than lower, closer to the varicocele itself?: Embolising into the pampiniform plexus thromboses the plexus directly and produces severe thrombophlebitis rather than a controlled occlusion of the refluxing conduit. The therapeutic aim is to interrupt the refluxing column above the plexus and let the cremasteric and deferential veins provide drainage.
A coil elongates and disappears cranially during deployment. What do you do at the table, in order?: Stop deploying and locate the coil fluoroscopically first, since its position dictates the retrieval strategy. Snare it from the existing venous access while it remains in the renal vein or inferior vena cava, where retrieval is straightforward; if it has already reached the pulmonary circulation, image the chest and weigh retrieval against leaving a stable asymptomatic peripheral coil, then resume with a properly oversized or detachable coil.
Why does hydrocele occur after surgical varicocelectomy but essentially not after embolisation?: Hydrocele follows inadvertent division or ligation of the spermatic lymphatics running with the cord. Embolisation is entirely intraluminal and does not touch the lymphatics, so the mechanism is absent.
You cannot find the right internal spermatic vein at the inferior vena cava. What are your next steps and why?: Search the anterolateral caval wall just below the right renal vein with a reverse-curve catheter, since the right vein enters at an acute cranially directed angle that a forward-facing catheter cannot engage. If still unfound, catheterise the right renal vein, because in a minority the right internal spermatic vein drains into it rather than the cava.
What is the objective endpoint that lets you finish the case, and why is contrast stasis at the coil pack alone insufficient?: Stasis at the coil pack with no contrast beyond it and, critically, no opacification of the pampiniform plexus by any route on Valsalva venography. Stasis at the pack alone can coexist with a duplicated limb or capsular collateral that fills the plexus in parallel, which is exactly the finding that predicts recurrence.
Why is semen analysis deferred to 3-6 months rather than repeated at 6 weeks?: A full spermatogenic cycle with epididymal transit takes approximately three months, so a sample at 6 weeks reflects germ cells produced before treatment and will show no change, risking a false conclusion of clinical failure.