Varicocele (VC) is a common genitourinary disorder in men and a major cause of male infertility. It is mostly seen in young adults, with an incidence of 10% to 15% of the normal male population and 19% to 41% of male infertility. Varicocele is a vascular spermatogenic disorder caused by the expansion of the spermatic veins and trapezius plexus that surrounds the spermatic cord. It is more common on the left side, but can also occur bilaterally or solely on the right side. Traditionally, an inguinal incision is made and the internal spermatic vein is ligated at a high level and part of the dilated vein is removed from the scrotum. Etiology The disease is a vascular disease characterized by varying degrees of dilatation and tortuosity of the trapezius plexus in the spermatic cord. It can be divided into primary and secondary VCs according to the etiology. Primary VC may be caused by increased intravascular pressure, the left spermatic vein travels long and converges at right angles to the left renal vein, superior mesenteric artery and aorta to compress the left renal vein, affecting the left internal spermatic vein reflux, which is known as “Nutcracker” phenomenon (NCS), weak connective tissue around the internal spermatic vein and venous valve dysfunction and incomplete closure. It is caused by anatomical factors such as weak connective tissue around the internal spermatic vein and venous valve dysfunction, incomplete closure, abnormal tissue structure of the spermatic vein wall, anatomical variation of the spermatic vein, and underdevelopment of the levator muscle. Secondary causes of VC may include intra-abdominal or retroperitoneal tumors, hydronephrosis, and ectopic vascular compression of the superior spermatic veins. Clinical manifestations Patients often do not receive timely diagnosis and treatment due to the lack of self-perceived symptoms, which eventually leads to impaired spermatogenesis in some patients. A small number of patients may have scrotal swelling and localized painful swelling when standing, which may radiate to the lower abdomen, groin area or posterior lumbar region, with symptoms worsening after exertion or prolonged standing, and alleviating or disappearing after lying down and resting. Examination The use of staining methods and morphological analysis of sperm in strict accordance with WHO standards can help evaluate the degree of fertility impairment in infertile patients, and also facilitate the standardization of operation and unification of analysis standards. Therefore, color Doppler flow imaging (CDFI) is recommended for patients with low sperm density, low viability, low vitality and high malformation rate in the routine semen examination. CDFI can visually and accurately observe the degree of dilatation of varicocele and the state of blood flow, which is a non-invasive and accurate diagnostic pathway. Infrared scrotal thermometry or spermatic venography are also available. The clinical diagnostic criteria of CDFI are: 1, clinical type VC at least 3 or more spermatic veins are detected in the spermatic plexus under calm breathing, one of them has an inner diameter >2.0mm or the inner diameter of the vein increases significantly when the abdominal pressure is increased, or the venous blood reflux is obvious after the Valsalva test; 2, subclinical type VC the spermatic vein is ≥1.8mm, the blood reflux does not appear under calm breathing, and the reflux appears in the Valsalva test. Valsalva test appears reflux, reflux time phase ≥ 800ms. Diagnosis A more accurate diagnostic method that is currently applied is color Doppler flow phenomenon. Treatment Surgical treatment is the main treatment method, which can achieve the desired therapeutic effect. Some of them are also treated with (or combined with) drugs. Secondary factors such as renal tumor, hydronephrosis, retroperitoneal tumor, and ectopic vessels should be excluded first. Primary VC with infertility or semen abnormality is an indication for treatment regardless of the severity of the symptoms. At present, surgical treatment includes high ligation of the internal spermatic vein through the inguinal canal, laparoscopic surgery, high ligation of the internal spermatic vein through the retroperitoneum, and interventional embolization of the spermatic vein. Compared with inguinal canal surgery and laparoscopic surgery, retroperitoneal high ligation of spermatic veins has the advantages of less surgical trauma, not easy to damage other blood vessels, not easy to miss ligation of spermatic veins, short operation time, low operation cost and postoperative complications, low recurrence rate, etc. It is the preferred treatment for unilateral varicocele. The degree of improvement of semen parameters and pregnancy rate of those who have surgery combined with medication are significantly better than the treatment of surgery alone.