The Value of Hounsfield Unit in Retrograde Intrarenal Surgery Versus Percutaneous Nephrolithotomy for the Treatment of Renal Stone of 2-3 cm: A Single-center Prospective Pilot Study

Background: To determine whether the Hounsfield Unit (HU) value of no-contrast computer computed tomography (NCCT) might offer better guidance in the selection of RIRS or PCNL in renal stones of 2-3 cm. Methods: A total of 158 patients with kidney stones (2-3 cm) who underwent PCNL/RIRS from March 2016 to January 2019 were enrolled in this study. Age, gender, stone sizes, locations, average HU value of stones, surgery time, hospital stay time, stone-free rate, and complications at the time of hospitalization and 3-month follow-up were measured to identify the surgery efficiency. Results: Upon consideration of the HU value, the mean surgery time was significantly decreased in RIRS comparing to the control RIRS (cRIRS) group (47.73 ± 15.52 vs. 72.41 ± 27.71 min, P < 0.05). Statistically, the surgery time was strongly influenced by the HU values both in RIRS (OR 93.8, P < 0.01) and PCNL (OR 8.21, P < 0.05). HU values proved to have a strong positive relation with surgery time in RIRS while a low positive relation in PCNL (P < 0.05). Conclusion: Overall, for renal stones of 2-3 cm, RIRS might be a safe and efficacious treatment option if the HU value and other parameters could be comprehensively accounted for. Individual precision surgery might provide ideal treatment and prognosis for patients requiring long-term continuous clinical procedures.