In this well-conducted retrospective cohort study, Kuchakulla et al. 1 examine the role of preoperative total testicular volume as a predictor of clinically meaningful improvement in total motile sperm count (TMSC) following microsurgical varicocelectomy. By focusing on TMSC category upgrading rather than isolated semen parameter changes, the authors address an outcome that is directly relevant to patient counseling and downstream reproductive decision-making. In their study, just over half of men (51%) experienced an upgrade in the TMSC category after microsurgical varicocelectomy, with improvement strongly influenced by baseline spermatogenic reserve. Men who upgraded had higher preoperative TMSC and substantially larger total testicular volume (33.0 vs. 23.4 mL). Importantly, upgrading was not uniform across baseline categories: improvement occurred in 7% of azoospermic men, 60% of those in the in vitro fertilization (IVF) range, and 73% of men initially in the intrauterine insemination (IUI) range, with many transitioning to thresholds compatible with less invasive reproductive options. Using ROC analysis, the authors identified a total testicular volume threshold of ≥25.5 mL, which was associated with a nearly 12-fold increase in the odds of TMSC upgrading, and an upgrade rate approaching 70%, compared with only 20% below this threshold. These data illustrate how testicular volume and baseline TMSC together may help stratify expectations following varicocelectomy and guide counseling regarding the likelihood of shifting from IVF to IUI or natural conception pathways. The study also reinforces the biological plausibility of testicular volume as a surrogate marker of male pubertal development 2, spermatogenic reserve 3, and endocrine function 4, aligning with prior observations linking larger testicular size to preserved Sertoli cell mass 5. In this context, the Kuchakulla et al. findings support the continued integration of testicular volume into the routine preoperative assessment of infertile men with clinical varicocele. At the same time, an important methodological consideration deserves emphasis. In this study, testicular volume was estimated exclusively by physical examination (PE), without the use of a Prader orchidometer or scrotal ultrasound. In routine clinical practice, testicular volume is most commonly assessed using a Prader orchidometer or ultrasound. The Prader orchidometer provides a practical bedside estimate and correlates positively with ultrasound-derived testicular volume in both fertile and infertile men, making it a reasonable surrogate in everyday practice 3. While bedside Prader orchidometry offers some degree of standardization, it is known to systematically overestimate testicular volume by 2–3 mL compared with ultrasound, particularly in smaller testes 3. Scrotal ultrasound, when performed using standardized techniques and validated formulas, provides greater measurement accuracy and reproducibility, especially when numeric thresholds or predictive cut-offs are proposed, and is particularly indicated when physical examination is limited or unreliable, such as in the presence of large hydroceles, inguinal cryptorchidism, very small testes, or epididymal enlargement 3, 6. Ultrasound-based testicular volume can be calculated using different mathematical formulas derived from testicular length, width, and height measurements; among these, the ellipsoid formula (length × width × height × 0.52) is endorsed by both the European Academy of Andrology (EAA) and the European Society of Urogenital Radiology, as it correlates more closely with orchidometric estimates and is automatically generated by most modern ultrasound systems 3, 6. According to EAA reference data, mean testicular volume in healthy fertile men is approximately 17 ± 4 mL, with ultrasound-derived lower reference limits of 12 mL and 11 mL for the right and left testes, respectively, defining testicular hypotrophy 3. Current guidance supports testicular volume assessment as part of the male evaluation; the European Association of Urology (EAU) explicitly recommends measurement using a Prader orchidometer or ultrasound 7, whereas the American Association of Urology/American Association for Reproductive Medicine (AUA/ASRM) guideline emphasizes physical examination and advises that scrotal ultrasound should not be routine in the initial work-up 8, reserving it for selected scenarios where examination is limited. According to the EAA guidelines 4, assessment of testicular volume is an essential component of the andrological evaluation. It should be performed as part of a structured physical examination, complemented by scrotal ultrasound as part of the routine investigation. While testicular volume estimated by the Prader orchidometer correlates with ultrasound-derived measurements and with testicular function, the EAA guideline does not mandate a specific method for volume assessment, recognizing the complementary roles of clinical examination and imaging. Physical examination remains central to the andrological evaluation and is practical in routine clinical settings. Nevertheless, it is inherently operator dependent. In the context of varicocele diagnosis, for example, PE remains an essential component. Clinical diagnosis and grading of varicoceles are based on scrotal inspection and palpation in the standing and supine positions, with the Valsalva maneuver, and this hands-on assessment guides both initial management decisions and surgical planning 9, 10. However, physical examinations are operator-dependent, and the reliability of varicocele grading varies with examiner experience. In a study published in Andrology, Cocuzza et al. demonstrated that inter-observer agreement for varicocele detection and clinical grade is only moderate overall, although it improved significantly when urologists with andrology training performed the assessments compared with less experienced examiners 11. Specifically, concordance rates were markedly higher among senior urologists than residents, illustrating that variability in clinical skill can influence both diagnosis and grading. This observation reinforces that while PE is indispensable, it is subject to inter-observer variability and should be interpreted considering examiner expertise; in equivocal cases or when precise grading influences management, supplementary imaging, such as scrotal ultrasound, may help standardize assessment and support clinical decision-making. Such nuances are important when testicular volume or varicocele grade serve as key predictors in outcome models, as variability in physical assessment may inadvertently introduce measurement imprecision into both clinical practice and research settings. The limitations discussed above do not detract from the relevance of the present study but highlight the need for cautious interpretation of absolute volume thresholds and for future validation using standardized imaging-based measurements. Lastly, it is also important to place the clinical relevance of varicocele treatment within the framework of contemporary guideline recommendations. The recently released World Health Organization (WHO) guideline on the prevention, diagnosis, and treatment of infertility recognizes varicocele repair as one of the few male-factor interventions with a sufficiently robust evidence base to warrant explicit recommendation in couples with clinical varicocele and abnormal semen parameters 12. Specifically, the WHO guideline supports treatment of clinically palpable varicoceles in infertile men with abnormal semen parameters, while not recommending intervention for subclinical varicoceles detected only by imaging. Importantly, when surgical treatment is indicated, the guideline states that microsurgical varicocelectomy should be preferred over other techniques when feasible, reflecting its superior outcomes and lower complication and recurrence rates reported in comparative studies. This endorsement reflects a synthesis of cumulative evidence that clinical varicocele and associated testicular dysfunction are modifiable contributors to male infertility and that varicocelectomy remains the most consistently supported therapeutic option in this domain. 13 Placing the present study's findings against this guideline backdrop reinforces the practical importance of accurately characterizing both testicular volume and clinical varicocele status—not only as diagnostic constructs but also as elements that may influence treatment decisions and prognostication. Overall, the study of Kuchakulla and colleagues makes a valuable contribution to the field by reinforcing the prognostic relevance of testicular volume in the setting of varicocelectomy. Future studies incorporating standardized scrotal ultrasound protocols may further refine these observations and help determine whether imaging-based volume assessment improves predictive accuracy beyond clinical examination alone. Sandro C. Esteves: conceptualization and writing – original draft, review and editing. The author has nothing to report. The author has nothing to report. The author declares no conflicts of interest. Data sharing is not applicable as no new data were generated in this study.
Sandro C. Esteves (Mon,) studied this question.