Varicocele is a common correctable cause of male infertility and may be associated with abnormal semen parameters, impaired testicular function, and scrotal discomfort. Microsurgical subinguinal varicocelectomy is a commonly used surgical approach because it allows careful preservation of the testicular artery, lymphatic channels, vas deferens, and vasal vessels under magnification. However, persistent or recurrent varicocele may still occur after surgery, possibly because of missed or persistent venous channels.

This randomized controlled trial will compare two surgical techniques in infertile men with clinically palpable varicocele and abnormal semen parameters. Participants will be randomly assigned to either microsurgical subinguinal varicocelectomy with selective extended venous stripping or standard microsurgical subinguinal varicocelectomy with conventional vein ligation and division.

The main purpose of the study is to determine whether selective extended venous stripping reduces the rate of clinically and Doppler-confirmed persistent or recurrent varicocele at 12 months after surgery compared with the standard microsurgical technique. The study will also compare semen parameter improvement, pain improvement in participants with baseline pain, pregnancy outcomes, operative time, postoperative complications, and the need for additional treatment during 12 months of follow-up.

Inclusion Criteria:

• Male patients aged 18 to 50 years.
• Couple infertility for at least 12 months.
• Clinically palpable grade I to III varicocele confirmed by physical examination.
• Abnormal semen parameters documented on at least two semen analyses performed 2 to 4 weeks apart according to World Health Organization laboratory standards.
• Female partner evaluation completed or planned, with no untreated severe female factor that would make natural conception impossible.
• Willingness to comply with postoperative follow-up at 3, 6, and 12 months.
• Written informed consent.

Exclusion Criteria:

• Azoospermia or cryptozoospermia, defined as absence of sperm in the native ejaculate on at least two baseline semen analyses, including cases in which sperm are detected only after centrifugation.
• Known clinically significant chromosomal or genetic abnormality that independently explains severe male infertility, when identified before enrollment.
• Previous varicocelectomy of the index side.
• Previous inguinal, scrotal, or retroperitoneal surgery that may alter spermatic cord anatomy.
• Subclinical varicocele only.
• Isolated scrotal pain with normal semen parameters.
• Hypogonadotropic hypogonadism requiring hormonal induction therapy.
• Testosterone therapy within the previous 6 months.
• Use of anti-estrogens, gonadotropins, or aromatase inhibitors within the previous 3 months.
• Active genitourinary infection.
• Testicular tumor or history of testicular cancer.
• Severe systemic disease contraindicating surgery or anesthesia.
• Inability to provide informed consent.
• Inability or unwillingness to complete follow-up.

Deidentified individual participant data supporting the main study results may be shared upon reasonable request. Shared data may include baseline demographic and clinical characteristics, treatment allocation, operative variables, semen analysis parameters, pain scores, Doppler ultrasound findings, pregnancy outcomes, recurrence outcomes, and postoperative complications. No directly identifying participant information will be shared.

Data will be available beginning 6 months after publication of the main study results and will remain available for 3 years.

Data will be shared with qualified researchers who submit a scientifically sound research proposal. Requests will be reviewed by the principal investigator and study investigators. Data will be provided only after approval of the request and, when required, completion of a data sharing agreement.

Operating surgeons cannot be blinded because of the nature of the surgical procedures. Participants, semen laboratory personnel, Doppler ultrasound assessors, clinicians assessing postoperative recurrence, and the data analyst will remain blinded to treatment allocation whenever feasible until database lock. Operative details that may reveal allocation will not be disclosed to outcome assessors.