Flexible ureterorenoscopy and Ho: YAG laser fragmentation for stones with a mean density greater than 900HU: An alternative to extracorporeal shockwave lithotripsy

Stylianos Kontos, Athanasios Papatsoris, Sarath K. Nalagatla


Background: A number of patient and stone characteristics predict SWL failure. When one or more of these factors are present, therapies such as flexible ureterorenoscopy and holmium: YAG lasertripsy (FURSL) have been promoted, with improved stone free rates (SFRs). There has been no study of FURSL efficacy in the treatments of stones with a density greater than 900 Hounsfield units (HU), another predictor of treatment failure with SWL. We aimed to assess the efficacy of FURSL in such cases.

Patients and methods: Patients undergoing FURSL from April 2012 - April 2014, under the care of a single surgeon were identified, and cases with at least one stone with a mean stone density greater than 900HU were assessed retrospectively. Patient and stone characteristics were recorded. Treatment outcomes and complications were detailed. Analysis of the differences in patient and stone qualities related to SFR after the first procedure were made.

Results: Sixty - six patients were included. The mean age was 58 (35 - 78) years. The mean stone density was 1216 (902 - 1768) HU. The mean maximal stone diameter was 13.2 (6.3 - 33) mm.  Most stones were either renal pelvic or lower calyceal in position, accounting for 18 (27.3%) patients each. SFR after the first FURSL treatment was 74.2%. Only 7 (10.6%) patients had procedure associated morbidity. When comparing patients who were stone free with one treatment of FURSL to those who were not, there was no significant difference in gender, mean age or mean stone density. There was however, a significant difference in maximal stone diameter (9.1mm and 15.1mm respectively, p< 0.001) and position of the stones (p< 0.001).

Conclusion: This study confirms FURSL is safe and effective for calculi with a mean density greater than 900HU. Improved SFR, and possibly favourable complication rate, compared with SWL has been shown and FURSL could be considered as the treatment of choice in such cases.



Η πυκνότητα (density) των πυελοκαλυκικών λίθων αποτελεί έναν από τους κύριους παράγοντες που πρέπει να λαμβάνει υπόψιν του ο ουρολόγος πριν καταλήξει στη μέθοδο αντιμετώπισής τους. Λίθοι με πυκνότητα πάνω από 900 HU είναι δύσκολο να αντιμετωπιστούν με τη χρήση υπερήχων, ακόμα και με πολλαπλές συνεδρίες, ενώ αντιθέτως η εύκαμπτη ουρητηροσκόπηση και η χρήση Laser Holmium είναι ασφαλής και οικονομική μέθοδος, που ίσως θα έπρεπε να θεωρηθεί θεραπεία εκλογής για «σκληρούς» λίθους.



flexible ureterorenoscopy; Ho: YAG laser fragmentation; stone density; εύκαμπτη ουρητηροσκόπηση, Ho: YAG laser λιθοτριψία, πυκνότητα λίθου

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DOI: http://dx.doi.org/10.19264/hj.v27i4.101