Presented by: Luigi Candela MD
Division of Experimental Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy. Università Vita-Salute San Raffaele, Milan, Italy

Introduction

Retrograde intrarenal surgery (RIRS) with laser lithotripsy is increasingly used as an alternative to shock wave lithotripsy for pediatric patients with upper urinary tract stones. Holmium:YAG (Ho:YAG) laser represents the gold standard for RIRS lithotripsy due to its proven efficacy and safety in pediatric patients. Recently, Thulium Fiber Laser (TFL) has been introduced in clinical practice for stone lithotripsy as a promising alternative to Ho:YAG laser. We sought to evaluate TFL safety and efficacy compared to High-power (HP) Ho:YAG laser in pediatric patients who have undergone RIRS for kidney stones. 

 

Materials

We retrospectively reviewed data from pediatric patients who underwent RIRS for kidney stones <2cm in greatest diameter between 2018 and 2020 in 4 Urology Departments. Outcomes of interest were: i) safety of the procedures, assessed through intra- and postoperative complications, and ii) efficacy of the technique assessed through surgical operative time (OT), stone-free rate and reintervention rate. Complete perioperative data were collected. Complications were assessed 4 to 6 weeks post-operatively. Stone-free (SF) was defined as the absence of visible fragments or as the presence of a single residual fragment ≤2 mm at 3 months post-operative imaging. Student's T-test for continuous variables, and Chi-square and Fisher's exact test for categorical variables were used to compare outcomes between patients treated with HP Ho:YAG (Group 1) and TFL (Group 2). Univariate (UVA) and multivariate (MVA) logistic regression analyses were performed to predict SF-associated factors.

Results

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: data from 126 pediatric patients were analyzed, 97 in group 1 and 29 in group 2. Mean (SD) age was 10 (4.7) and 7 (4.73) years in group 1 and 2 (p=0.004), respectively. Mean (SD) largest stone diameter was 9.7 (4.23) vs 10.97 (3.69) mm in group 1 and 2, respectively (p=0.325).  Rate of elevated serum creatinine, positive urine culture, ureteral pre-stenting, preoperative administration of tamsulosin and antibiotics, normal kidney anatomy, and number and location of stones were comparable between group 1 and 2 (all p>0.05). All the procedures were successfully performed and no intraoperative complications were reported in both groups. No major postoperative complication occurred. SF rate was 81.4% and 89.7% (p=0.45) and reintervention rate was 14.4% and 6.89% (p=0.046) in group 1 and 2, respectively. At UVA and MVA, the type of laser did not influence SF rate. However, pre-stenting and single stones were positively associated with SR rate. 

Conclusion

Both laser technologies are safe and effective and showed similar SF rates. TFL showed less OT and lower re-intervention rate. These results provide the opportunity to urologists to use either TFL or Ho:YAG laser during RIRS in pediatric patients since both technologies demonstrated satisfactory outcomes. Further prospective comparative studies are needed to corroborate our findings. 

Funding

none

Co-Authors

Daniele Castellani, MD
Urology Unit, Azienda ospedaliero-Universitaria delle Marche, Università Politecnica delle Marche, Ancona, Italy

Catalina Solano, MD
Urology Unit, Tenon Hospital, Paris, France

Mariela Corrales, MD
Urology Unit, Tenon Hospital, Paris, France

Marie Chicaud, MD
Urology Unit, Tenon Hospital, Paris, France

Stessy Kutchukian, MD
Urology Unit, Tenon Hospital, Paris, France

Frederic Panthier, MD
Urology Unit, Tenon Hospital, Paris, France

Steeve Doizi, MD
Urology Unit, Tenon Hospital, Paris, France

Jeremy Yuen-Chun Teoh, MD
S.H. Ho Urology Centre, The Chinese University of Hong Kong, Hong Kong, China

Yiloren Tanidir, MD
Marmara University Istanbul Pendik Education and Research Hospital, Urology, Istanbul, Turkey

Khi Yung Fong, MD
National University Hospital, Singapore

Chandramohan Vaddi, MD
Preeti Urology and Kidney Hospital, Telangana, India

Mriganka Mani Sinha, MD
University Hospital Southampton NHS Foundation Trust, Southampton, UK

Deepak Ragoori, MD
Asian Institute of NephroUrology; Hyderabad

Bhaskar Kumar Soman, MD
University Hospital Southampton NHS Foundation Trust, Southampton, UK

Francesco Montorsi, MD
Università Vita-Salute San Raffaele, Milan, Italy

Andrea Salonia, MD
Università Vita-Salute San Raffaele, Milan, Italy

Olivier Traxer, MD
Urology Unit, Tenon Hospital, Paris, France

Vineet Gauhar, MD
Division of Urology, Ng Teng Fong General Hospital, National University Health System, Singapore