The fate of clinically insignificant residual fragments following retrograde intrarenal surgery and factors affecting spontaneous passage

• Published in: Urolithiasis Vol. 52; no. 1; p. 39
• Main Authors: Senel, Samet, Ceviz, Kazim, Ozden, Cuneyt, Gultekin, Huseyin, Gokkaya, Cevdet Serkan, Koudonas, Antonios
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 28.02.2024; Springer Nature B.V
• Subjects: Body mass index; Follow-Up Studies; Hospitals; Humans; Kidney Calculi - surgery; Lithotripsy - methods; Medical Biochemistry; Medical imaging; Medicine; Medicine & Public Health; Nephrology; Patients; Retrospective Studies; Risk Factors; Surgery; Treatment Outcome; Urinary tract diseases; Urology; Stone related events; RIRS; Spontaneous passage; Clinical insignificant residual fragments
• DOI: 10.1007/s00240-024-01544-9
• ISSN: 2194-7236; 2194-7228

The remaining stone fragments after retrograde intrarenal surgery (RIRS) can lead to stone recurrence/regrowth, or stone-related events (SRE). We aimed to delineate the clinical circumstances that are decisive for spontaneous passage of clinical insignificant residual fragments (CIRF) (primary outcome) and define risk factors for stone recurrence/regrowth and their clinical manifestation (secondary outcome). A total of 115 patients who had CIRF following RIRS were included in this study. Demographic, clinical data, stone, and anatomic characteristics including infundibulopelvic angle (IPA), infundibular length (IL) and follow-up data of patients were analyzed. The mean follow-up time was 27.5 ± 6.9 months. 31 (26.9%) patients passed the CIRF spontaneously. Patients were divided into two groups as spontaneous fragment passage group and fragment remaining group and compared with respect to demographic, clinical, stone-related, and anatomic characteristics. 61.2% of patients had lower pole CIRF in fragment remaining group and 83.3% of patients in spontaneous fragment passage group ( p  = 0.031). In addition, IPA was wider in spontaneous fragment passage group (60.7° vs 51.4°, p  = 0.001). A subanalysis was performed for fragment remaining group. In 84 patients, 44 (52.4%) patients were stable for their CIRF at their follow-up and included in stable group. 40 (47.6%) patients experienced stone re-growth (27 patients) or SRE (13 patients) at their follow up. Patients in re-growth/SRE group were older (49.1 vs 39.4 years, p  = 0.047), had higher body mass index (28.2 vs 27 kg/m 2 , p  = 0.03) and larger CIRF (2.8 vs 2.1 mm). CIRFs may be not expelled spontaneously and they may lead to additional morbidity and lithotripsy interventions.