The Science of Surgical Force: A New Field of Study in Urology

Precise and efficient application of force on tissue is a core competency of surgical practice, ingrained into surgeons' hands through years of training. To date, safe force thresholds have only begun to be evaluated for urologic tissues. We introduce The Science of Surgical Force, an emerging discipline within Urology, by conducting the first comprehensive synthesis of force-related data across urologic procedures. We aim to define force thresholds that inform safe practice, enhance surgical technique, and guide future innovation.

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses compliant scoping review was registered with International Prospective Register of Systematic Reviews and conducted using PubMed, Cochrane Library, and Scopus. Two independent reviewers screened studies evaluating surgical mechanical force applied to human GU. Data were categorized by organ, instrument, and procedure. Study quality and bias were assessed using the Newcastle-Ottawa Scale and Cochrane Risk-of-Bias tool.

Among 4988 studies identified (1974-2024), only 36 met our Urology-focused inclusion criterion; these studies involved 741 patients and 46 ex vivo tissue specimens. Force data were reported for the fascia (n = 2), kidney (n = 5), prostate (n = 10), ureter (n = 9), urethra (n = 5), and vagina (n = 5). Ureteral studies identified 6-8 Newtons (N) as a safety threshold. Prostate studies focused on brachytherapy and cancer localization, with needle insertion forces ranging from 2 to 9 N depending on tissue type and needle gauge. Other organs showed wide variability and limited data. Only seven studies were randomized controlled trials; the mean quality score was 6.3, indicating an overall low level of quality among the force studies.

This is the first comprehensive review defining surgical force thresholds across urologic tissues to support integration of force-aware technologies into practice and education. Future work should focus on standardizing force application to improve outcomes, especially as force-sensing tools are developed and artificial intelligence-guided platforms become more widely available.