Introduction/epidemiology

Testicular varicocele is a common condition of pampiniform plexus which is usually asymptomatic but may result in severe pain, discomfort, subfertility, and/or physical deformity. The incidence of testicular varicocele has been reported in as many as 23% of the normal healthy male population. Rates as high as 42% have been reported in the elderly population, suggesting a correlation with age [1]. A subset of patients (i.e. nutcracker syndrome, discussed later) may present with hematuria and links to subfertility have been reported as far back as the 1800s [2]. The etiology of the subfertility appears to be related to the quality of the semen, which is dependent on testosterone production [1, 2].

Varicoceles are predominantly unilateral, with the majority of cases occurring on the left side due to venous drainage anatomy (see later). Bilateral varicoceles are present in a subset of patients; however, the incidence is debated in the literature and has been reported to be as high as 80% when diagnosed with imaging [2]. Along with improvement in diagnostics, many treatment options have also emerged to treat these patients, with a trend toward less‐invasive procedures. Herein, we describe the clinical presentation, imaging manifestations, treatment indications, and treatment options, with a focus on gonadal vein embolization.

Etiology/anatomy/pathophysiology

The pampiniform plexus consists of three spermatic vein tributaries with interspersed anastomoses resulting in collateral circulation between the anterior, middle, and posterior pampiniform plexuses. Varicoceles result from a reversal of blood flow in the gonadal veins that drain the pampiniform plexus. Etiologies of primary or idiopathic varicocele appear to be multifactorial [1, 2]. Primary varicocele occur more commonly on the left as the left gonadal vein drains into the left renal vein (LRV) as opposed to directly into the inferior vena cava (IVC), as it does on the right. The left gonadal vein is thus longer than the right gonadal vein and makes an acute angle as it drains into the LRV. The increased LRV pressure, compared with the IVC, results in retrograde flow into the left gonadal vein. “Nutcracker phenomenon” or compression of the LRV as it traverses between the aorta and the superior mesenteric artery (SMA) is a common etiology of a primary varicocele [2]. Venous valves are present in 90% of patients; they are usually located at the junction of the gonadal vein and its draining vein (i.e. renal vein on the left and IVC on the right). Congenital absence of venous valves or valvular incompetence predispose patients to reflux and thus varicoceles [1].

Secondary varicoceles occur from extrinsic pathologic compression of the LRV or draining spermatic vein, most commonly abdominopelvic malignancies. Nonmalignant masses such as hydroureter and abdominal aortic aneurysms are also sources of compression. A rare cause of varicocele formation is a splenorenal shunt which may form in patients with portal hypertension. Accordingly, clinical examination and radiologic evaluation (detailed later) are crucial in the initial consultation of a patient presenting with varicocele to identify treatable secondary causes as treatment would be considerably different.

Patient evaluation and selection

Preprocedural evaluation is imperative in patients who present with symptoms consistent with varicocele. A focused but detailed history must be obtained to rule out other causes of testicular pain and subfertility [2]. For example, patients with abdominal malignancies may present with abdominal pain or symptoms of mass compression (i.e. urinary or bowel obstruction). Patients with anemia or hypercoagulable states may declare malignancy on blood tests. As mentioned earlier, patients with nutcracker syndrome may present with hematuria, either macroscopic or microscopic on urinalysis. Patients with splenorenal shunts may present with signs and symptoms of portal hypertension.

Semen analysis should be obtained not only to confirm etiology of patients presenting for subfertility but also to gauge results post treatment. Physical examination is also important as it may elucidate alternate diagnoses for patients with secondary varicoceles. Classic physical examination finding includes a “bag of worms” scrotum. Patients should be examined in both the supine and standing positions. The supine position may reveal alternate diagnoses such as intrascrotal neoplasm or infection. Furthermore, varicoceles that do not resolve while lying supine may be secondary to an underlying cause (i.e. neoplasm). Varicoceles declare themselves in the standing position due to the effects of gravity on venous flow and may be accentuated by Valsava (Figure 127.1). A grading system based on physical examination findings is detailed in Table 127.1 [1, 2].

Radiologic evaluation of presumed testicular varicocele should begin with ultrasound using a high‐frequency, high‐resolution 7–10 MHz linear transducer performed in the standing position. As with history and physical examination, testicular ultrasound can help identify alternate diagnoses, especially in cases where a varicocele is not seen or palpated. Diameters of dilated vessels in the pampiniform plexus and the main draining vein can be measured (normal: up to 2 mm) [1]. Grayscale ultrasound should be accompanied with duplex imaging (color and pulsed). These techniques allow for real‐time visualization of reflux into the pampiniform plexus, especially with Valsalva, which increases sensitivity and specificity (up to 95%). Multiple scoring systems have been developed to determine the presence of a varicocele on color Doppler ultrasound, the most commonly used being the Sarteschi’s classification (Table 127.2) [3, 4]. Testicular ultrasound volume must be measured in children because testicular growth (usually of the left testicle) is affected by varicocele. Return of normal testicular development following treatment is achieved in up to 80% of patients [4].

Patients in whom a primary varicocele is diagnosed and have pain or subfertility issues should be referred for treatment. Large (grade III) varicoceles that cause cosmetic issues may also be considered for treatment. Patients with isolated right‐sided varicoceles, bilateral varicoceles, or varicoceles that do not reduce with change in position (standing to supine) or do not demonstrate increase with Valsalva require further workup. A contrast‐enhanced computed tomography (CT) or magnetic resonance imaging (MRI) scan of the abdomen and pelvis should be obtained to exclude malignant and benign masses causing obstruction. Furthermore, cross‐sectional imaging may be of value in cases where there is atypical anatomy. For example, there are many congenital variations of the left and right spermatic veins, especially in cases of urogenital sinus and renal anomalies, which often occur together [2]. A wide range of pelvic anastomoses with pelvic veins must be identified to prevent persistence or recurrence of varicoceles (i.e. retroperitoneal, lumbar, iliac veins, etc. Figure 127.2a) [5]. These variations may present a dilemma to the interventional radiologist when attempting to treat the patient. Cross‐sectional imaging for the evaluation of the varicose veins is detailed in the next section in patients with pelvic congestion syndrome.

Surgical options to treat varicoceles include open varicocelectomy, laparoscopic varicocelectomy, and microsurgical subinguinal varicocelectomy. Open varicocelectomy requires general or intrathecal anesthesia in order to make one of three incisions. The Palomo technique involves an open retroperitoneal approach for proximal ligation spermatic vessels. Smaller incisions using a low inguinal or subinguinal approach have been developed. Laparoscopic varicocelectomy also requires general anesthesia and utilizes a transperitoneal approach. Microsurgical subinguinal varicocelectomy is a less‐invasive alternative to open and laparoscopic techniques that does not involve the abdominal fascia or musculature but still allows for identification of anatomy (including adjacent arteries) and can be performed under local anesthesia [2]. The first endovascular treatment of a varicocele dates back to 1978 [1]. Since then, advances in imaging and techniques have allowed for successful of gonadal vein embolization. Furthermore, radiation exposure is concerning for the pediatric population [6]. Gonad shielding and collimation is thus crucial. Accordingly, a multidisciplinary approach among interventional radiology, urology, and reproductive medicine should be undertaken to care for these patients.