Intratesticular Artery Resistive Index Changes After Varicocelectomy

This study aims to evaluate how blood flow inside the testicles changes after surgery to correct a varicocele, and whether these changes correlate with improvements in semen quality and testosterone levels.

Varicocele is a common, treatable cause of male infertility that can negatively affect testicular function by altering blood flow and temperature. While surgery (varicocelectomy) often improves fertility, doctors are continually looking for ways to predict which patients will benefit the most from the procedure. This study uses scrotal color Doppler ultrasound to measure the Intratesticular Artery Resistive Index (RI), which is an indicator of blood flow resistance and microvascular health, before and after surgery.

Researchers will recruit 40 infertile men with clinically palpable varicoceles. Participants will undergo a baseline evaluation that includes a physical exam, semen analysis, a blood test for total testosterone, and a specialized ultrasound to measure the RI under different physical conditions (lying down, standing, and during a Valsalva maneuver/bearing down).

All participants will then undergo a microscopic sub-inguinal varicocelectomy, which is the standard microsurgical treatment. Three months after the surgery, participants will return for follow-up testing to repeat the semen analysis, testosterone blood test, and ultrasound.

The main goal of the study is to determine if pre-operative RI measurements can serve as an early, reliable predictor of surgical success, specifically looking at the recovery of testicular function, sperm parameters, and hormonal levels.

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Key information

Conditions

Varicocele Cardiovascular Diseases Endocrine System Diseases Genital Diseases Genital Diseases, Male Gonadal Disorders Hypogonadism Infertility Infertility, Male Male Infertility Male Urogenital Diseases Secondary Hypogonadism Urogenital Diseases Vascular Diseases

Age range

18 year–65 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

About this study

Varicocele is a highly prevalent cause of male infertility, estimated to affect up to 40% of men presenting with infertility. It disrupts the thermoregulatory and hemodynamic environment of the testis, leading to mechanisms such as hyperthermia, hypoxia, impaired blood flow, and the backflow of adrenal metabolites. These factors collectively cause dysfunction in both Sertoli and Leydig cells. Consequently, varicocele is recognized as a significant cause of secondary hypogonadism, resulting in reduced serum testosterone levels alongside impaired spermatogenesis and reduced sperm morphological integrity.

Scrotal color Doppler ultrasonography (CDUS) is a critical tool for assessing testicular vascular perfusion. The Resistive Index (RI), calculated from the peak systolic and end-diastolic velocities of the intratesticular and capsular arteries, serves as a reliable indicator of parenchymal microperfusion and microvascular integrity. Elevated RI values in varicocele patients reflect impaired microvascularization and significantly reduced testicular perfusion.

To evaluate the predictive value of RI on surgical outcomes, this study utilizes a highly standardized assessment protocol at baseline and at a 3-month post-operative follow-up:

Semen Analysis: Evaluations are conducted in strict accordance with the WHO Laboratory Manual for the Examination and Processing of Human Semen, 6th edition (2021). Samples are collected after an abstinence period of 2-7 days and analyzed within 60 minutes of collection.
Hormonal Assessment: Serum Total Testosterone is measured using a standardized immunoassay technique. To ensure reproducibility and minimize the influence of diurnal hormonal variation, all blood samples are collected via venipuncture following an overnight fast, strictly between 8:00 AM and 10:00 AM.
Specialized CDUS Protocol: To eliminate inter-observer variability, all ultrasound examinations are performed by a single experienced radiologist utilizing the LOGIQ P7 system (GE Healthcare) equipped with a high-frequency linear transducer. The core of the investigation involves measuring the intratesticular artery RI using pulsed-wave Doppler under four distinct, standardized physiological conditions: supine at rest, supine during a Valsalva maneuver, standing at rest (after a 3-minute pooling period), and standing during a Valsalva maneuver. Testicular volume is also calculated using the ellipsoid formula.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Infertile male patients with clinically palpable varicocele (Grade I to III).

Exclusion criteria

Extremes of age (pediatric or geriatric populations).
History of previous scrotal surgery or trauma.
Active urogenital infection (e.g., epididymo-orchitis).
History of testicular torsion.
Any comorbidity that may independently affect testicular vascularity or hemodynamics.

Treatment and study plan

Microscopic Sub-inguinal Varicocelectomy

Procedure

The procedure involves making a sub-inguinal incision just below the external inguinal ring. Using an operating microscope, the spermatic cord is carefully isolated and systematically dissected. All internal spermatic veins are identified and ligated. Meticulous care is taken to preserve the testicular artery and its branches, the cremasteric artery, the vasal artery, the vas deferens, and lymphatic vessels to minimize the risk of post-operative complications such as hydrocele formation.

Primary outcomes

Change in Intratesticular Artery Resistive Index (RI)

Time frame: Baseline (pre-operative) and 3 months post-operatively.

The Intratesticular Artery Resistive Index (RI) is assessed using scrotal color Doppler ultrasonography. It is calculated from the peak systolic and end-diastolic velocities of the intratesticular and capsular arteries to evaluate testicular parenchymal microperfusion and vascular impedance. Measurements are taken under standardized physiological conditions.

Sponsors and collaborators

Lead sponsor

Assiut University

Other

Registry information

Official study title

Evaluation of Changes in Intratesticular Artery Resistive Index Following Varicocelectomy and Their Correlation With Semen Parameters and Testosterone Levels

Important dates

Study start: 2026
Primary completion: 2027
Study completion: 2027
First posted: Apr 8, 2026
Registry last updated: Apr 8, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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