Micali S. et al., 2021: Initial Experience and Evaluation of a Nomogram for Outcome Prediction in Management of Medium-sized (1-2 cm) Kidney Stones
Micali S, Sighinolfi MC, Iseppi A, Morini E, Calcagnile T, Benedetti M, Ticonosco M, Kaleci S, Bevilacqua L, Puliatti S, De Nunzio C, Arada R, Chiancone F, Campobasso D, Eissa A, Bonfante G, Simonetti E, Cotugno M, Galli R, Curti P, Schips L, Ditonno P, Villa L, Ferretti S, Bergamaschi F, Bozzini G, Zoeir A, Sherbiny AE, Frattini A, Fedelini P, Okhunov Z, Tubaro A, Landman J, Bianchi G, Rocco B.
Department of Urology, Azienda Ospedaliero-Universitaria, Urological Residency School Network, University of Modena & Reggio Emilia, Modena, Italy.
Department of Urology, Azienda Ospedaliero-Universitaria, Urological Residency School Network, University of Modena & Reggio Emilia, Modena, Italy. Electronic address:
Clinical and experimental medicine (CEM), Department of Surgical, Medical, Dental and Morphological Sciences with Interest in Transplant, Oncology and Regenerative Medicine, University of Modena & Reggio Emilia, Modena, Italy.
Department of Urology, Ospedale Sant'Andrea, "La Sapienza" University, Rome, Italy.
Department of Urology, University of California, Irvine, Orange, CA, USA.
Department of Urology, AORN Antonio Cardarelli, Naples, Italy.
Department of Urology, Ospedale Civile di Guastalla, Urological Residency School Network, University of Modena & Reggio Emilia, Guastalla, Italy.
Department of Urology, Tanta University, Tanta, Egypt.
Department of Urology, Ospedale Maggiore, Urological Residency School Network, University of Modena & Reggio Emilia, Parma, Italy.
Department of Urology, Ospedale di Vaio, Urological Residency School Network, University of Modena & Reggio Emilia, Fidenza, Italy.
Department of Urology, Policlinico San Pietro, Ponte San Pietro, Italy.
Department of Urology, Ospedale Mater Salutis, Legnago, Italy.
Department of Urology, Ospedale SS. Annunziata, Chieti, Italy.
Department of Urology, IRCCS Giovanni Paolo II, Bari, Italy.
Department of Urology, IRCCS Ospedale San Raffaele, Milan, Italy.
Department of Urology, Arcispedale S. Maria Nuova, Urological Residency School Network, University of Modena & Reggio Emilia, Reggio Emilia, Italy.
Department of Urology, ASST Valle Olona, Urological Residency School Network, University of Modena & Reggio Emilia, Busto Arsizio, Varese, Italy.
Abstract
Background: The gold standard treatment for solitary medium-sized (1-2 cm) renal stones is not defined by recent guidelines, since management modalities including shockwave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), and percutaneous nephrolithotomy (PNL) are recommended. Improved ability to predict patient outcomes would aid in patients' counseling and decision-making.
Objective: To develop a nomogram predicting treatment failure, based on preoperative clinical variables, to be used in the preplanning setting.
Design, setting, and participants: We recruited 2605 patients from 14 centers and carried out a multicenter retrospective analysis of 699 SWL, 1290 RIRS, and 616 PN L procedures performed as first-line treatment for 1-2-cm kidney stones. The variables evaluated included age, gender, previous renal surgery, body mass index, stone size, location, stone density, skin-to-stone distance, presence of urinary tract infections (UTIs), and hydronephrosis.
Outcome measurements and statistical analysis: Multivariate logistic regression was fitted to predict treatment failure, defined as the presence of residual fragments >4 mm. A nomogram was developed based on the coefficients of the logit function.
Results and limitations: A total of 2431 (93.3%) patients were stone free; 174 (6.7%) treatment failures were recorded and considered the event to be predicted. On univariate analysis, type of procedure, preoperative hydronephrosis, stone density, stone location, and laterality turned out to be statistically significant. Skin-to-stone distance, UTIs, and previous renal surgery were predictors of failure on multivariate analysis. Each variable was given a score based on statistical relevance. The main limitation of the current study is its retrospective nature.
Conclusions: This nomogram provides a prediction of treatment failure and need of reintervention for medium-sized kidney stones. External validation is needed to determine its reproducibility and validity.
Eur Urol Focus. 2021 Jan 5:S2405-4569(20)30314-X. doi: 10.1016/j.euf.2020.12.012. Online ahead of print. PMID: 33419709.
Comments 1
This is all mathematics and regional habits. The patient material was collected from 14 departments in 11 or 10 years. 699 ESWL cases devided by 14 departments are 50 cases per department; devided by 10 years would be 5 ESWL cases per year per department. The total 2600 cases devided by 14 departments and 10 years amounts to 19 cases per department per year. I know that these calculations are not correct and not fair but the questions arises what data like these and nomograms developed from them represent and how good they are for other users. E.g. inclusion of the data on ultra-slow frequency ESWL from Japan or Egypt (1, 2) would lead to a very different nomogram.
I miss some of the major Italian Endourologists among the authors. The reader who is interested in Italian Endourology is referred to (3) and the comment in this blog.
The nomogram lacks internal validation and, as suggested by the authors, needs external validation.
1 Al-Dessoukey AA, et al. Ultraslow full-power shock wave lithotripsy versus slow power-ramping shock wave lithotripsy in stones with high attenuation value: A randomized comparative study. Int J Urol. 2020 Feb;27(2):165-170. doi: 10.1111/iju.14158
2 Ito K, et al. Extremely-slow, half-number shockwave lithotripsy for asymptomatic renal stones