How to do it: Varicocele Embolisation

INTRODUCTION Varicocele occurs when the pampiniform venous plexus in the spermatic cord becomes abnormally dilated. It has a general reported prevalence of 15% in males and occurs more on the left side.[1,2] It causes long-standing testicular pain with discomfort and issues with fertility. Scrotal ultrasonography shows an abnormally dilated plexus, with normal flow at rest and flow reversal on valsalva manoeuvre depending on grades of severity. Cross-sectional imaging helps to rule any out abdominal/testicular masses causing venous compression, especially when a patient presents with varicocele just on the right side [Figure 1].Figure 1: (a and b) Axial contrast-enhanced computed tomography sections at upper abdomen and pelvis shows dilated left gonadal vein (LGV) formed by pampiniform plexus near femoral head (yellow arrow) (c and d) Reformatted coronal and sagittal sections show LGV draining into left renal vein (yellow arrow)The primary therapeutic options are either surgical ligation and/or endovenous embolisation of the internal spermatic vein (ISV)/gonadal vein.[1] Embolisation is a cost-effective and minimally invasive method which requires only local anaesthesia. Considerable indications for endovascular management of varicocele are chronic pain, fertility problems and recurrence after surgical management. Failure of surgical management is usually attributed to collateral veins, which may not be visible at the time of surgical intervention but can be mapped and ascertained on venography.[1] VARICOCELE EMBOLISATION TECHNIQUE AND METHODOLOGY Pertinent anatomy The pampiniform plexus forms the gonadal vein near the femoral head. Subsequently, the right gonadal vein drains directly into the inferior vena cava (IVC) and one on the left side gonadal vein drains into the left renal vein [Figure 1]. The left gonadal vein drains into the left renal vein at an angle which builds up a higher hydrostatic pressure resulting in a higher incidence of varicocele on the left side.[3] There are anatomical variations which include duplication of gonadal or renal vein, single gonadal vein with multiple collateral communications with paravertebral, retroperitoneal and renal vein on the left side.[4] Sedation It is a daycare procedure done under local anaesthesia for access site with the cover of systemic pain medications as patient interaction and co-operation are required intraprocedurally to execute valsalva while performing venography. Site of approach Percutaneous access using a sterile aseptic technique is commonly obtained from the femoral or internal jugular vein (IJV) route, the right common femoral vein (CFV) being the most preferred site. Access from right-sided veins gives an easier and favourable angulation to cannulate the left-sided renal and gonadal veins. The right gonadal vein can be difficult to cannulate from the right CFV and thus one can go for the right IJV. Technique The right CFV is punctured using an 18G needle attached to a 10 cc syringe under ultrasound guidance. Blood is aspirated to confirm venous access. Flexible tip stiff wire is passed through the needle, followed by removal of the needle and insertion of 5Fr sheath over a dilator 5Fr hydrophilic catheter {C1 or C2 angiography catheter (Cook Medical, Bloomington, IN)} along with 0.035" hydrophilic J wire is introduced and negotiated into the IVC A digital subtraction venogram is then obtained to look for renal vein ostia, any anatomic variations and the presence or absence of filling thrombus. The renal vein ostia are identified as filling defect, as unopacified blood enters the contrast-filled IVC at the ostia with the patient's spine used as a reference The renal vein is then engaged using hydrophilic catheter and hydrophilic guidewire (Terumo Medical Corporation, Tokyo, Japan) [Figure 2] Fluoroscopic contrast injection/subtraction venogram of renal vein is done to determine the ostium of the gonadal vein. A microwire and a microcatheter (Progreat, Terumo Medical Corporation, Tokyo, Japan) are then used to supraselectively cannulate the gonadal vein [Figure 2] Following selective catheterisation of the target gonadal vein, digital subtraction venography is done at multiple levels from ostium to pubic symphysis with the patient performing Valsalva to provide an assessment of anatomy, diagnostic confirmation and to identify collaterals, which can cause treatment failure in the future if they are not selectively embolised. More commonly the collaterals such as duplicated gonadal vein, lumbar, renal capsular, iliac and circumarctic renal veins need to be looked out for[1] Thereafter, the microcatheter and microwire are placed distally within the gonadal vein Varicocele embolisation can be undertaken through multiple embolic agents at hand which such as coils, vascular plugs (e.g. Amplatzer; Abbott Laboratories, Chicago, IL), sodium tetradecyl sulphate (STS) foam, gel foam and glue. One can choose either of them based on personal/institutional preference and experience[1] Coils, both detachable and pushable (Boston Scientific), can be used for varicocele embolisation. It is crucial that coil nest should be compact and stable for completely occluding the flow of the gonadal vein[1] [Figure 3] To promote adequate embolisation, the sandwich technique is employed using embolisation agent between the nests of coils. One can either use glue, STS or thick slurry of gel foam [Figure 3] STS is a sclerosant that is mixed with air and contrast media in specific volumes. The solution is then stirred and agitated in syringes connected to a three-way stop cock resulting in the production of a smooth foam which can then be delivered through the catheter. Glue (n-butyl-2-cyanoacrylate, n-BCA) is a liquid embolic that is infused with ethiodised oil usually in a 1:1 ratio with 1 mL of each constituent. Before instilling the glue embolic agent, it is imperative to flush the delivery catheter with 5% dextrose solution to stop letting the glue polymerise in the lumen of the catheter[1] The embolic agent delivery is initiated near the deep inguinal ring usually at the landmark of the superior aspect of the femoral head/acetabulum. The first coil nest is deployed either at the level of the pubic symphysis or below the most inferior collateral branch of gonadal vein. The secondary embolisation agent such as gel foam slurry, sterol or glue is injected proximally to this coil pack to prevent any distal reflux of embolisation agent into the pampiniform plexus. The secondary embolisation agent embolises the small collaterals which are too narrow to catheterise. The second coil nest is then placed proximal to the secondary embolisation agent site thus, forming a 'sandwich', which prevents wash off and reflux of embolisation agent into the ipsilateral renal vein and further into systemic venous circulation [Figure 3]. Repeat venogram is then undertaken to see for any residual predominant collateral which can then be cannulated and selectively occluded[1] [Figure 4] Technical success depends on ensuring occlusion of contrast flow within all visible collaterals with no reflux or migration of embolisation agent [Figure 4] Final completion venography is undertaken to authenticate that the treatment was adequate. Figure 2: (a and b) Digital subtraction venogram with catheter in left renal vein shows reflux of contrast into the left gonadal vein (yellow arrow) with the catheter jerking into inferior vena cava (blue arrow) (c) Fluoroscopic image shows reflux of contrast into dilated pampiniform plexus (red arrow)Figure 3: The left gonadal vein was supra selectively catheterised and embolised using sandwich technique (coil-gel foam-coil) (a and b) Fluoroscopic image shows distal coil nest (yellow chevron) with contrast gel foam slurry in between (green arrow), followed by proximal coil nest (red chevron)Figure 4: (a) Digital subtraction venogram shows no reflux distally to proximal coil nest (red chevron) (b) Fluoroscopic image shows contrast stasis (yellow arrow) proximal to coil nest with no collaterals or reflux. Note made of opacified left renal pelvis (blue arrow)POST-PROCEDURE CARE Patients are to be kept under observation for 1–2 h until they start oral intake and walking without support. Regular day-to-day activities can be undertaken the next day, however, with the instruction to abstain from any straining activity such as heavy lifting for at least 2 weeks. Conventional post-procedural complaints can be nausea, testicular and/or backache and low-grade fevers which can be managed using non-steroidal anti-inflammatory drugs. Follow-up ultrasound is usually done at a month and 6 monthly intervals[5] [Figure 5].Figure 5: Post-procedure follow-up duplex ultrasonography of scrotum in supine position pre-Valsalva (a) and post-Valsalva (b) do not show any increased caliber and vascularity of pampiniform plexus after exacerbation with ValsalvaCOMPLICATIONS Complications include vessel injury/contrast extravasation, which is normally self-limiting. However, persistent contrast extravasation should be looked at following which the procedure may be postponed to be done at the next sitting. Difficulty to catheterise the gonadal vein has been seen often on the right side due to a technically adverse origin from the IVC. This can be tackled by adapting and tailoring the primary catheter and/or use of selective microcatheters.[5] Thrombophlebitis of pampiniform plexus can be seen in 1%–4% of patients following the procedure who can present with swelling and pain in the scrotum.[5,6] This can be normally managed by anti-inflammatory medications. It is imperative to embolise distal ISV through coils to prevent this complication. Recurrence has been seen more commonly on the right (18.9%) side as compared to the left (3.2%).[5,7] Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.