Simulation-based assessment of morcellation learning curves and safety: a comparative study of Hawk and Storz devices

Mechanical morcellation during prostate enucleation has a steep learning curve and risks bladder injury. This study evaluated the learning curve with an ex vivo model and compared the Hawk and Storz morcellators' efficiency and safety among urology residents.

A prospective, simulation-based study with three urology residents used an ex vivo model (chicken egg white for adenoma and yolk for bladder mucosa). Participants performed 30 trials (15 per device). Outcomes included morcellation time, irrigation volume, and yolk preservation. Data were analyzed with linear mixed-effects models for repeated measures.

A significant learning effect was observed, with morcellation time decreasing by an estimated 39.65 s with each subsequent trial (p < 0.001). The Hawk morcellator showed greater efficiency, being significantly faster than the Storz device (mean difference = -33.5s, p = 0.004) and using significantly less irrigation fluid (mean difference = 276.7 mL, p = 0.025). However, the rate of skill acquisition was the same for both devices (p = 0.57). Safety outcomes were similar, with yolk preservation rates of 80.0% for Hawk and 73.3% for Storz. Importantly, 83% of tissue injuries occurred during the first trial, with none observed from the third trial onward.

This ex vivo study demonstrated a steep learning curve for morcellation, with significant early proficiency gains. The Hawk morcellator showed superior operative efficiency with reduced procedure time and improved fluid management compared to the Storz system. Early error clustering emphasizes the value of simulation training in minimizing patient risk.