Needle-perc-assisted endoscopic surgery versus retrograde intrarenal surgery for the treatment of 1- to 2-cm lower-pole renal stones in patients with unfavorable infundibulopelvic anatomy: a matched-pair analysis

Abstract

Purpose: To compare the safety and efficacy of needle-perc-assisted endoscopic surgery (NAES) and retrograde intrarenal surgery (RIRS) for the treatment of 1- to 2-cm lower-pole stones (LPS) in patients with complex infundibulopelvic anatomy.

Methods: Between June 2020 and July 2022, 32 patients with 1- to 2-cm LPS and unfavorable lower-pole anatomy for flexible ureteroscopy were treated with NAES. The outcomes of these patients were compared with patients who underwent RIRS using matched-pair analysis (1:1 scenario). The matching parameters such as age, gender, body mass index, stone size, hardness, and pelvicalyceal anatomy characteristics including infundibular pelvic angle, infundibular length, and width were recorded. Data were analyzed using the Student's t-test, Mann-Whitney U test, and Fisher's exact test.

Results: The two groups had similar baseline characteristics and lower-pole anatomy. The stone burden was comparable between both groups. NASE achieved a significantly better initial stone-free rate (SFR) than RIRS (87.5% vs 62.5%, p = 0.04). The auxiliary rates for the NAES and RIRS groups were 12.5% and 31.3%, respectively (p = 0.13). Finally, the SFR after 1 month follow-up period was still higher for the NAES group than RIRS group (93.8% versus 81.3%), but the difference was not statistically significant (p = 0.26). Concerning the operation duration, overall complication rates, and postoperative hospital stay, there were no differences between two groups.

Conclusion: Compared to RIRS for treating 1- to 2-cm LPS in patients with unfavorable infundibulopelvic anatomy for flexible ureteroscopy, NAES was safe and effective with higher SFR and similar complication rate.

Keywords: Lower-pole stone; Needle-perc; RIRS; Ultrasound guidance.