Stesura Seveso Archivio Italiano di Urologia e Andrologia 2025; 97(2):13867 1 ORIGINAL PAPER INTRODUCTION Urolithiasis represents a significant public health concern, affecting millions globally, with an estimated prevalence of 2-3%, and a recurrence rate of 50% (1). The existing liter- ature delineates various treatment modalities for renal and ureteral stones, including conservative management, endourological procedures, and open surgery (2). Extracorporeal shock wave lithotripsy has evolved consid- erably since its inception, establishing itself as a pivotal treatment option for renal and ureteral stones (3). The Dornier Compact Delta® III Pro optimizes the latest advancements in ESWL technology, featuring enhanced shock wave generation, improved imaging capabilities, and refined patient positioning systems (4). These innovations contribute to increased treatment efficacy, reduced proce- dural pain, and minimized recovery time, thereby solidify- ing ESWL's role in contemporary urological practice (3, 4). Numerous studies have identified various predictive factors influencing complications and the stone-free rate (SFR) fol- lowing ESWL for renal and ureteral stones. Among these, stone characteristics, such as size, density, location, shape, and degree of impaction, are critical determinants for treat- ment efficacy (5, 6). For instance, larger, denser stones, par- ticularly those located in anatomically challenging areas like the lower pole of the kidney with steep infundibulo- pelviceal angle, are associated with lower SFRs and higher treatment failures. Moreover, patient-related factors, includ- ing age, comorbidities, congenital anomalies, the degree of obstruction, infection status, body mass index (BMI), skin to stone distance can further alter treatment outcomes (5-7). Despite these advancements, there is a notable lack of studies about the latest, new generation lithotripters (8). Understanding the factors influencing SFRs is essential for optimizing patient selection and treatment strategies. In this context, the present study aims to assess SFRs and identify major negative predictive factors, influencing the success of ESWL utilizing the Dornier Compact Delta® III Pro, based on a retrospective analysis of our first 1000 patients treated at a secondary hospital. Background: The Dornier Compact Delta® III Pro is a next-generation extracorporeal shock wave lithotripter featuring flat-panel detector technology for enhanced imaging and a compact modular design. This study evaluates treatment outcomes and predictors of failure for this system, representing the first published clinical experience. Methods: We retrospectively analyzed the first 1,000 consecu- tive patients treated with the Dornier Compact Delta® III Pro for renal or ureteric stones between May 2022 and November 2023 at a secondary hospital. Stone-free status was assessed via radiography, ultrasonography, or computed tomography (CT) within three months post-treatment. Predictive factors for treat- ment failure were identified through univariate and multivari- ate logistic regression analyses. Results: The cohort had a median age of 37 years (IQR: 32- 44.2) and a body mass index (BMI) of 26 kg/m² (IQR: 24-29). Key characteristics included: prior urologic interventions in 36.6% of patients, single stones in 79.8% (median size 9 mm, IQR: 7-10), a median stone density of 1000 Hounsfield Units (HU) (IQR: 760-1200), and hydronephrosis observed in 55.3% of cases. Initial ESWL success was achieved in 80.5% of cases, increasing to 87.5% following repeat sessions (mean treatments: 1.2). Multivariate analysis identified four independent predic- tors of treatment failure: prior urologic intervention (adjusted odds ratio [aOR] 2.64, 95% CI 1.75-4.00, p < 0.001), multiple stones (aOR 0.45, 95% CI 0.24-0.77, p = 0.011), increased skin-to-stone distance (per cm: aOR 1.18, 95% CI 1.06-1.30, p < 0.001), and higher stone density (per 100 HU: aOR 1.12, 95% CI 1.06-1.18, p < 0.001). Conclusions: The Dornier Compact Delta® III Pro achieved an 87.3% stone-free rate with failure predictors consistent with established lithotripsy literature. These findings support the adoption of this device as an effective ESWL system, particular- ly for institutions prioritizing advanced imaging and a space- efficient design. KEY WORDS: Urolithiasis; ESWL; Dornier; Predictive factors; Stone-free rate. Submitted 2 April 2025; Accepted 25 April 2025 Predictors of treatment failure and outcome assessment of extracorporeal shock wave lithotripsy with the Dornier Compact Delta®III Pro: Experience from the first 1000 treatments Morshed Salah 1, 2, Maged Al-Ghashmi 1, Bela Tallai 1, 2, Abu Baker 1, Mohammed Ibrahim 1, 2, Tawiz Gul 1, 2, Hatem Kamkoum 1, Salvan Alhabash 1, Hossameldin Alnawasra 1, Abdoulhafid Elmogassabi 1, Maged Alrayashi 1, Mohammed Ebrahim 1, Mohamed Abdelkareem 1, Faisal Ahmed 3 1 Urology Section, Hazm Mebaireek General Hospital, Hamad Medical Corporation, Doha, Qatar; ² College of Medicine, Qatar University, Doha, Qatar; ³ Department of Urology, School of Medicine, Ibb University, Ibb, Yemen. DOI: 10.4081/aiua.2025.13867 Summary Archivio Italiano di Urologia e Andrologia 2025; 97(2):13867 M. Salah, M. Al-Ghashmi, B. Tallai, et al. 2 PATIENTS AND METHODS Study design This retrospective study was conducted at Hazm Mebaireek General Hospital, Hamad Medical Corporation, Doha, Qatar, between May 2022 and November 2023. A total of 1,000 adult patients (≥ 16 years) with renal col- lecting system and ureteric stones (≤ 25 mm) underwent extracorporeal shock wave lithotripsy (ESWL) using the Dornier Compact Delta® III Pro lithotripter (Dornier MedTech GmbH, Germany). The study was performed in accordance with the ethical principles outlined in the Declaration of Helsinki and received approval from the Medical Research Center of the institution (ID MRC-01-25-167). Due to the retro- spective nature of the study, the ethics committee waived the requirement for patient consent while ensuring that patient confidentiality and data protection measures were strictly adhered to. Inclusion criteria Adult patients (≥ v16 years) with ureteral and/or renal stones with a maximum diameter less than 25 mm were included. Exclusion criteria – Active urinary tract infection (UTI) or urosepsis, – Active anticoagulation, – Pregnancy, – Untreated coagulopathies, – Poorly controlled hypertension, – Aortic aneurysms, – Bilateral ureteric stone, – Solitary kidney, and – Renal insufficiency. Pre-treatment assessment All patients underwent comprehensive assessment, including complete medical history, physical examina- tion, laboratory analyses (urine analysis, urine culture and/or sensitivity analysis, complete blood count, coagu- lation profile, blood urea nitrogen analysis, and serum creatinine levels), and radiological examinations (plain abdominal radiograph, ultrasonography, and computed tomography scan). ESWL procedure The extracorporeal shock wave lithotripsy procedure was conducted using the Dornier Compact Delta® III Pro lithotripter (Dornier MedTech GmbH, Germany) at a max- imal intensity of 15 kV. Patients were positioned in a supine position and received sedation and analgesia throughout the procedure. A low initial power setting of 8 kV was employed, with sequential voltage ramping to maximize patient comfort. For kidney stones ultrasound imaging was conducted to localize stone fragments and monitor fragmentation in real-time, while fluoroscopy was used for targeting ureteric stones. Post-treatment and outcome Patients were assessed for the first time 2 weeks following the initial session using a plain radiograph. Repeat treat- ment was instituted in 66 cases where fragmentation was deemed inadequate (defined as either no fragmentation or stone fragments exceeding 4 mm in size). Successful ESWL was defined as the absence of any visible stones on radiological images within a 3-month post-treatment period either on plain radiograph, US, or CT scan ordered based on the practitioner’s preference. Stones with no change or the presence of fragments larger than 4 mm beyond 3 months were considered as failure. Data collection A self-constructed questionnaire was developed for the purpose of data collection. Information was obtained from participants through structured interviews and examinations of their medical records. Independent, val- idated chart reviews facilitated the collection of data. Patient characteristics recorded included age, gender, body mass index (BMI), comorbidities, prior radiologic interventions, and the use of anticoagulants. Stone char- acteristics documented encompassed size, location, skin- to-stone distance (SSD), density measured in Hounsfield Units (HU), and the presence of hydronephrosis. Additionally, details regarding the ESWL treatment were captured, including the number of shock waves deliv- ered, required power, frequency, analgesia usage, pain tolerance, fluoroscopy time and dosage, treatment dura- tion, and the total number of sessions. Treatment out- comes measured included stone clearance, any postoper- ative emergencies, complications, and the necessity for further procedures. All data collected were assessed for accuracy, complete- ness, and consistency. Two independent reviewers achieved an inter-rater agreement of 98.2% on key vari- ables, with any discrepancies addressed by a senior con- sultant urologist. Statistical analysis Statistical analyses were performed using SPSS v22 (SPSS Inc., Chicago, Illinois, USA). Descriptive statistics were utilized to characterize the study population, with con- tinuous variables reported as means ± standard deviation (SD) for normally distributed data or as medians interquartile range (IQR) for non-normally distributed data. Categorical variables were presented as frequencies (%). Bivariable analyses involved chi-square or Fisher's exact tests for categorical variables, and t-tests or Mann- Whitney U tests for continuous variables. Multivariable logistic regression models were employed to identify independent predictors of ESWL treatment failure, incorporating variables with p-values < 0.2 from the bivariable analysis or those deemed clinically rele- vant. Model fit was assessed using the Hosmer- Lemeshow test, with p-values > 0.05 indicating adequate fit. Discrimination was evaluated using the area under the receiver operating characteristic (ROC) curve. Variables exhibiting multicollinearity (variance inflation factor [VIF] ≥ 5), sparse data (cell counts < 5), or exces- sive missingness (> 15%) were excluded from the final models. The final analysis considered variables with p-values < 0.05 and adjusted odds ratios (aOR) with corresponding 95% confidence intervals (CIs) as statistically significant. Archivio Italiano di Urologia e Andrologia 2025; 97(2):13867 3 Predictors of treatment failure and outcome assessment of extracorporeal shock wave lithotripsy... RESULTS Patient and stone characteristics Table 1 presents the demographic and clinical characteris- tics of 1,000 patients undergoing extracorporeal shock wave lithotripsy (ESWL). The median age was 37.0 years (IQR: 32.0-44.2), with a male predominance (99.7%). Left-sided stones were more common (54.7%) than right-sided stones (45.3%). The median BMI was 26.0 kg/m² (IQR: 24.0- 29.0), and the majority of patients (79.0%) had no comor- bidities; 7.5% had diabetes mellitus (DM), 9.6% had hyper- tension (HTN), and 0.3% had coronary artery disease (CAD). Prior urologic interventions (e.g., percutaneous nephrolithoto- my [PCNL], ureteroscopy [URS], or previous ESWL) were reported in 36.6% of patients, while 10.8% had undergone previous double-J (DJ) stenting (28 patients [2.8%] for ureteric stones and 80 patients [8.0%] for renal stones). Single stones predominated (79.8%), with a median size of 9.0 mm (IQR: 7.0-10.0) and density of 1,000.0 Hounsfield Units (HU) (IQR: 760.0-1,200.0). Hydronephrosis was present in 55.3% of cases. Laboratory results included median creatinine levels of 86.0 µmol/L (IQR: 77.0-97.0), blood urea nitrogen (BUN) of 4.2 mmol/L (IQR: 3.4-5.1), and hemoglobin of 14.8 g/dL (IQR: 14.0-15.5). Preoperative urine cultures were negative in 97.4% of cases. Stones were primarily renal (59.1%) or ureteral (40.7%), with a median stone-to-skin distance of 9.0 cm (IQR: 8.0-11.0). ESWL procedure details The mean power delivered was 6.6 ± 1.2 kV (range: 2.0- 10.0), with an average of 3,314.1 ± 517.2 shocks per ses- sion (range: 900.0-4,200.0). Procedures lasted an average of 44.0 ± 5.1 minutes (range: 15-57), with 96.0% utiliz- ing a frequency of 80 shocks per minute. Guidance was provided via ultrasound (50.3%) or fluoroscopy (49.7%). Analgesia included midazolam/morphine (61.2%) or fen- tanyl (37.2%). Most patients (89.6%) tolerated the proce- dure well; 8.0% reported mild pain, while 2.4% had low tolerance for the procedure. Treatment outcomes Initial ESWL success was achieved in 80.5% of cases, Table 1. Patient and stone characteristics of individuals who underwent extracorporeal shock wave lithotripsy. Characteristic Subgroup Total (n = 1000) Stone Clearance P-value Yes (n = 875) No (n = 125) Age (years) Median (IQR) 37.0 (32.0–44.2) 37.0 (32.0–44.0) 38.0 (30.0–45.0) 0.951 Gender Male 997 (99.7%) 870 (99.7%) 127 (100%) 1.000 Female 3 (0.3%) 3 (0.3%) 0 (0%) Laterality Left 547 (54.7%) 484 (55.4%) 63 (49.6%) 0.255 Right 453 (45.3%) 389 (44.6%) 64 (50.4%) Body mass index (kg/m2) Median (IQR) 26.0 (24.0–29.0) 26.0 (24.0–29.0) 27.0 (24.0–30.0) 0.099 Comorbidities None 790 (79.0%) 685 (78.5%) 105 (82.7%) 0.571 Diabetes Mellitus 75 (7.5%) 68 (7.8%) 7 (5.5%) Hypertension 96 (9.6%) 85 (9.7%) 11 (8.7%) CAD 3 (0.3%) 2 (0.2%) 1 (0.8%) Others* 36 (3.6%) 33 (3.8%) 3 (2.4%) Previous DJ stenting No 892 (89.2%) 781 (89.5%) 111 (87.4%) 0.585 Yes 108 (10.8%) 92 (10.5%) 16 (12.6%) Previous urologic intervention No 634 (63.4%) 570 (65.3%) 64 (50.4%) 0.002 Yes 366 (36.6%) 303 (34.7%) 63 (49.6%) Stone number Single 798 (79.8%) 687 (78.7%) 111 (87.4%) 0.030 Multiple 202 (20.2%) 186 (21.3%) 16 (12.6%) Stone size (mm) Median (IQR) 9.0 (7.0–10.0) 9.0 (7.0–10.0) 9.0 (7.0–11.0) 0.052 Stone density (HU) Median (IQR) 1000.0 (760.0–1200.0) 980.0 (750.0–1200.0) 1100.0 (911.5–1250.0) < 0.001 Hydronephrosis No 447 (44.7%) 387 (44.3%) 60 (47.2%) 0.602 Yes 553 (55.3%) 486 (55.7%) 67 (52.8%) Creatinine (µmol/L) Median (IQR) 86.0 (77.0–97.0) 86.0 (77.0–97.0) 86.0 (78.5–94.5) 0.787 Blood urea nitrogen (mmol/L) Median (IQR) 4.2 (3.4–5.1) 4.3 (3.4–5.2) 4.0 (3.2–5.1) 0.122 White blood cells (mcL) Median (IQR) 7.7 (6.6–9.2) 7.8 (6.6–9.2) 7.5 (6.8–9.1) 0.525 Hemoglobin (g/dL) Median (IQR) 14.8 (14.0–15.5) 14.8 (14.0–15.5) 14.8 (14.0–15.5) 0.734 Preoperative urine culture Negative 974 (97.4%) 847 (97.0%) 127 (100%) 0.094 Positive 26 (2.6%) 26 (3.0%) 0 (0%) Stone-to-skin distance (cm) Median (IQR) 9.0 (8.0–11.0) 9.0 (8.0–11.0) 10.0 (9.0–12.0) < 0.001 Stone location Kidney 591 (59.1%) 523 (59.7%) 68 (54.4%) 0.034 Ureter 407 (40.7%) 350 (40.1%) 57 (45.6%) Bladder 2 (0.2%) 2 (0.2%) 0 (0%) IQR: Interquartile range; CAD: Coronary artery disease; HU: Hounsfield units. * Others: Includes chronic kidney disease, asthma, etc. Bold p-values: Statistically significant (p < 0.05). Archivio Italiano di Urologia e Andrologia 2025; 97(2):13867 M. Salah, M. Al-Ghashmi, B. Tallai, et al. 4 increasing to 87.5% following repeat sessions (mean treat- ments: 1.2). Success rates varied by stone location: – Renal stones: 78.2% (lower calyx: 76.0%, mid calyx: 80.6%, upper calyx: 81.3%, renal pelvis: 82.4%). – Ureteral stones: 83.1% (proximal ureter: 82.0%, distal ureter: 83.7%). Treatment failure occurred in 12.5% (n = 125), necessitat- ing additional interventions: semirigid URS (5.4%), flexible URS (0.7%), or PCNL (0.4%). Postoperative complications arose in 4.6% (n = 46), primarily renal colic (4.2%). Rare complications included bowel perforation (0.1%, n = 1), urosepsis (0.1%), and pyelonephritis (0.1%). Bowel perfo- ration details (n = 1): A 36-year-old male with a history of recurrent renal stones and prior ESWL treatments devel- oped acute abdominal pain 4 hours after ESWL for an 8- mm right upper ureteral stone. Preoperative evaluation revealed leukocytosis (WBC 13×10³/μL) with 80% neu- trophils. CT imaging demonstrated pneumoperitoneum and mesenteric stranding. During emergent laparoscopy, purulent intraperitoneal fluid was noted along with a 6-mm small bowel perforation 120 cm distal to the duodenojeju- nal flexure with adhesions. Due to limited space and adhe- sions the procedure was converted to open. The patient underwent primary repair with peritoneal lavage and con- current Double-J stent placement for persistent ureteral obstruction. The presence of purulent fluid during explo- ration suggested early localized peritonitis. The patient made a full recovery postoperatively, highlighting the importance of prompt surgical intervention in such rare complications. Predictors of ESWL failure Univariate analysis identified significant predictors of ESWL failure, including prior urologic intervention (17.2% vs. 10.1%; p = 0.002), multiple stones (7.9% vs. 13.9%; p = 0.030), higher stone density (1100.0 vs. 980.0 HU; p < 0.001), and increased stone-to-skin distance (10.4 vs. 9.6 cm; p < 0.001). However, multivariate analysis confirmed significant predictors of ESWL failure, including prior inter- vention (aOR 2.64; 95% CI: 1.75-3.99; p < 0.001), multiple stones, which were associated with reduced odds of clear- ance (OR 0.45; 95% CI: 0.24-0.77; p = 0.003), increased stone density, where each 100-HU increase raised the risk of failure (OR 1.00; 95% CI: 1.00-1.00; p < 0.001), and stone- to-skin distance, where each 1-cm increase elevated failure odds by 18% (OR 1.18; 95% CI: 1.06-1.30; p = 0.002). Stone location (kidney vs. ureter) was found to be non-sig- nificant (p = 0.547) (Table 2). DISCUSSION The present study aimed to provide significant insights into the efficacy and predictive factors associated with extracorporeal shock wave lithotripsy utilizing the Dornier Compact Delta® III Pro for the management of renal and ureteric stones. The results indicate an overall stone-free rate that increased from 80.7% following the initial ESWL procedure to 87.3% after repeat treatments. This progressive improvement underscores the potential of the Dornier Compact Delta® III Pro to enhance treat- ment efficacy, marking a noteworthy presence in the con- temporary stone management practice. The demographic characteristics of our cohort provide valuable details into the patient population underwent ESWL. The median age of participants was 37 years, with a substantial predominance of males (99.7%) and a high prevalence of single stones (79.8%). Although these find- ings corroborate results from previous studies that under- score the male predominance in urolithiasis (9-11), our situation is different, as the area covered by our facility, is mainly occupied by male labor population. A pivotal finding of our multivariate analysis was the iden- tification of specific predictors for treatment failure follow- ing ESWL, with a history of previous urologic intervention emerging as the most significant factor, reflected by an odds ratio of 2.64 (95% CI: 1.75-4.00). This underscores the challenges posed by altered renal anatomy or scarring from prior procedures, aligning with findings from Gültekin et al., which demonstrated that overall stone-free rates after ESWL treatment were significantly lower in patients with a history of prior ureteroscopy or stone surgery, particularly for stones in the lower calix (12). Additionally, repeated ESWL may contribute to long-term fibrotic degeneration of the collecting system, thereby complicating subsequent ESWL treatment efforts (13). The impact of patient characteristics on the success rate Table 2. Predictive factors for extracorporeal shock wave lithotripsy failure in multivariate analysis. Characteristic Stone clearance Multivariate logistic regression Subgroup Yes (n = 873) No (n = 127) Crude OR (95% CI) p-value Adjusted OR (95% CI) p-value Previous urologic intervention No 570 (89.9%) 64 (10.1%) Ref - Ref < 0.001 Yes 303 (82.8%) 63 (17.2%) 1.87 (1.30–2.69) < 0.001 2.64 (1.75–3.99) < 0.001 Stone number Single 687 (86.1%) 111 (13.9%) Ref - Ref 0.006 Multiple 186 (92.1%) 16 (7.9%) 0.53 (0.31–0.91) 0.021 0.45 (0.24–0.77) 0.003 Hounsfield unit (HU) (Per 100-unit increase) - - 1.12 (1.06–1.18) < 0.001 1.00 (1.00–1.00) * < 0.001 Stone-to-skin distance (cm) (Per 1 cm increase) - - 1.15 (1.05–1.26) 0.002 1.18 (1.06–1.30) 0.002 Stone location Kidney 523 (88.5%) 68 (11.5%) Ref - Ref 0.241 Ureter 350 (86.0%) 57 (14.0%) 1.25 (0.86–1.81) 0.241 1.17 (0.70–1.97) 0.548 Bladder 2 (100%) 0 (0%) - - - - IOR = Odds ratio; CI = Confidence interval; Ref = Reference category. Statistically significant values (p < 0.05) are in bold. *HU was modeled as a continuous variable; OR represents per 100-unit increase for clinical interpretability. Multivariate logistic regression: Adjusted for all significant variables from univariate analysis. Hosmer-Lemeshow goodness-of-fit test: p = 0.42 (indicating good fit); Area under the ROC curve (AUC): 0.72 (95% CI: 0.67–0.77), suggesting moderate discrimination. Archivio Italiano di Urologia e Andrologia 2025; 97(2):13867 5 Predictors of treatment failure and outcome assessment of extracorporeal shock wave lithotripsy... of ESWL remains a subject of debate in literature. Previous studies, such as those by Shinde et al., have indi- cated that female gender may be a significant negative predictor for stone clearance due to lower pain thresholds in women, which can impact their tolerance to higher energy shock waves, potentially leading to complications (7). Other studies, such as those by El-Nahas et al. (14), have identified BMI as a significant factor influencing stone clearance, while Alharbi et al. noted that stone loca- tion and laterality significantly affected ESWL efficacy (15). They also found that stones in patients with diabetes mellitus and hypertension exhibited lower fragmentation rates (15). In our study, the median age across gender groups was relatively consistent at 37.0 years (IQR: 32.0 to 44.2), suggesting that age-related effects on ESWL out- comes may be negligible within this range. Furthermore, the gender distribution was predominantly male (99.7%), limiting the applicability of gender as a predictive factor. The distribution of comorbidities, particularly diabetes mellitus and hypertension, did not exhibit significant dis- crepancies, indicating minimal influence on stone clear- ance. Although our median BMI was 26.0 kg/m² (IQR: 24.0 to 29.0), which is within typical ranges, we acknowl- edge that previous reports suggest a relationship between BMI and successful stone fragmentation (16). The discrep- ancies between our findings and past literature highlight the need for future investigations with larger, more diverse cohorts to explore the impact of a broader range of patient characteristics on ESWL success rates. Comprehensive methodologies, including multi-center studies, may better delineate these relationships, ultimately enabling refine- ment of patient selection criteria for ESWL. In our report, the influence of stone characteristics on treatment outcomes in ESWL is pronounced, with multi- ple stones and increased stone density, measured in HU, identified as key predictors of treatment failure. Specifically, stones with higher HU values (mean 1074.2 ± 303.2 in non-clearance cases) correlate with diminished ESWL efficacy, indicating that denser stones are more resistant to shock wave fragmentation (17, 18). Furthermore, an increased SSD negatively affected clear- ance rates, with failed cases exhibiting a mean distance of 10.4 ± 2.3 cm compared to 9.6 ± 2.1 cm in successful cases. Conversely, our report found the presence of multi- ple stones to be a significant predictive factor for ESWL failure. In contrast, stone location and size did not achieve statistical significance in multivariate analysis, with kidney and ureter stone locations yielding similar outcomes (upper: 88.46% clearance; lower: 86% clearance, p = 0.241). Median stone sizes demonstrated marginal signifi- cance (median size: 9.0 mm, p = 0.052). Factors such as hydronephrosis also showed no significant influence on treatment outcomes (p = 0.602). These individual results may be attributed to the use and technical characteristics of the new Dornier Compact Delta®III Pro ESWL machine resulting in enhanced fragmentation efficacy. Comparative Performance of Modern ESWL Systems in different reports are mentioned in Table 3 (8, 19-24). Table 3. Comparative performance of modern Extracorporeal Shock Wave Lithotripsy (ESWL) systems. System Sample size Initial Final SFR Follow-up Auxiliary Major Key Additional (Study, year) (n) Stone-Free period procedures complications* technological significant findings Rate (SFR) features Storz Modulith SLX-F2 474 82.7% 77% 3 months 14.7% 0.8% Dual-focus • Lower pole stones had 12% (Elkoushy et al., 2011) (19) (subcapsular hematoma) electromagnetic lower success rate (p = 0.03) • Stented patients showed 14.5% reduced efficacy Storz Modulith SLX-F2 361 - EQ** = 0.646 - 22% 1.7% Adjustable • Standard focus (6 mm) improved (Suzuki et al., 2010) (20) (hematoma) focal zones (6-9 mm) ureteral stone outcomes by 17% • SMLI*** > 0.65 correlated with complications Siemens Lithoskop 183 - 91% 3 months 7.1% 0.5% Acoustic pressure • Pediatric SFR = 94% (n = 13) (Neisius et al., 2013) (8) (hematoma) monitoring • No difference by stone location (p = 0.41) Dornier Compact Delta II 336 - 78.2% (renal) 3 months 11.5-14% None reported Optical coupling control • OCC improved SFR by 15.4% (Lv et al., 2016) (21) (OCC) (p < 0.01) 81.7% (ureteral) • Reduced skin ecchymosis by 60% EDAP-Sonolith Praktis 703 - 95.3% 4 weeks 30.6% None major Ultrasound • Efficiency quotient (EQ) = 0.71 (Lee et al., 2005) (22) localization • Treatment time < 45 mins for 89% cases Dornier MFL 5000 347 - 82.4% 4 weeks 51.6% 4% (steinstrasse) Electrohydraulic source • 23% longer treatment time (Sheir et al., 2003) (23) vs electromagnetic • Higher re-treatment rate for > 10 mm stones Dornier Compact Delta 614 - 95.9% 6 weeks 18% 26.4% hematuria Electromagnetic • 37% faster than (Yang & Hyun, 2007) (24) with ultrasound electroconductive models • Better for obese patients (BMI > 30) * Major complications defined as: Steinstrasse requiring intervention, subcapsular hematoma > 2 cm, or sepsis; ** EQ (Efficiency Quotient) = [% Stone-Free/(100 + % Re-treatment + % Auxiliary Procedures)] × 100; *** SMLI (Storz Medical Lithotripsy Index) = Energy × Number of Shocks/1000. Archivio Italiano di Urologia e Andrologia 2025; 97(2):13867 M. Salah, M. Al-Ghashmi, B. Tallai, et al. 6 Technological advancements in shock wave technology have positioned ESWL as the primary treatment for most renal and ureteric stones (3). The Dornier Compact Delta® III Pro exemplifies these innovations, featuring enhanced shock wave generation and dual imaging systems that enable precise targeting while minimizing radiation expo- sure (4). With the capability to deliver up to 1000000 shock waves, this device surpasses the efficiency of ordi- nary lithotripters, facilitating outpatient procedures with reduced analgesia requirements and lower morbidity. Additionally, the Dornier Compact Delta® III Pro inte- grates advanced imaging, maximal energy delivery, and improved operational efficiency, supporting urologists to achieve effective stone management. Recent developments in lithotripters, such as the Modularis Vario, have further optimized key components, enhancing patient comfort and imaging quality (4). These technological advance- ments not only improve stone comminution but also ele- vate success rates in treating renal and ureteric stones, consequently decreasing the need for auxiliary interven- tions. Notably, the Dornier Compact Delta®III Pro's supe- rior capabilities contribute to increased SFRs and lower complication rates, as demonstrated by a low postopera- tive emergency rate of only 4.6%. Future research is war- ranted with this device and compare its efficacy and out- come measures across various clinical settings. Clinical implications The results of this study provide valuable insights into the efficacy of the newly introduced ESWL machine, the Dornier Compact Delta®III Pro, highlighting its significant role in the management of renal and ureteric stones, as evidenced by a commendable stone-free rate of 87.3%. The identification of critical predictors of treatment fail- ure, including prior urologic interventions, the presence of multiple stones, increased stone-to-skin distance (SSD), and stone density, enables clinicians to conduct more nuanced preoperative evaluations and implement tailored therapeutic strategies. However, it is important to note that these findings align with those already described in the existing literature and are well-established within the international medical community. Limitations of the study This study acknowledges several limitations that may impact the interpretation of the findings. Firstly, the mod- erate sample size, monocentric design, and retrospective nature of the investigation present inherent challenges, as reliance on secondary data may introduce variability due to inconsistencies in documentation and the potential for bias in the results. Additionally, technical limitations in the methodologies employed to define stone clearance could affect the accuracy and reliability of the findings. The sin- gle-center design further restricts the generalizability of the results to broader populations, and the three-month fol- low-up duration may not adequately capture delayed treat- ment failures that could occur over an extended period. Despite these challenges, this investigation represents the inaugural report correlating stone clearance with the newly launched ESWL machine, the Dornier Compact Delta® III Pro, at our institution. Consequently, our results underscore the critical need for further research involving larger sample sizes and, ideally, multicentric approaches that incorporate institutions utilizing and operating the same machine. Such studies would enhance the robustness of the findings and contribute to a more comprehensive understanding of the effectiveness of this ESWL system in diverse clinical settings. CONCLUSIONS The Dornier Compact Delta® III Pro has demonstrated considerable efficacy in the treatment of renal and ureteric stones, achieving a stone-free rate of 87.3%. This study identified several key predictors of treatment fail- ure, including prior urologic interventions, the presence of multiple stones, increased skin-to-stone distance, and higher stone density. These findings affirm the continued relevance of ESWL as a mainstay in the contemporary management of renal and ureteral stones. Future multi- center randomized controlled trials are warranted to val- idate these preliminary results and further evaluate the performance of the Dornier Compact Delta® III Pro lithotripter in diverse clinical settings. REFERENCES 1. Stamatelou K, Goldfarb DS. Epidemiology of Kidney Stones. Healthcare (Basel, Switzerland) 2023; 11(3). 2. Sarier M, Duman I, Callioglu M, et al. Outcomes of Conservative Management of Asymptomatic Live Donor Kidney Stones. Urology 2018; 118:43-46. 3. Mosquera Seoane L, Ortiz Salvador JB, Budia Alba A, Perez Fentes DA. Technological innovations in shock wave lithotripsy. Actas Urol Esp (Engl Ed) 2024; 48:105-10. 4. Dornier MedTech. Dornier Delta III. Secondary Dornier MedTech. Dornier Delta III 2023. https://www.dornier.com/prod- ucts-item/dornier-delta-iii/. 5. Lee SM, Collin N, Wiseman H, Philip J. Optimisation of shock wave lithotripsy: a systematic review of technical aspects to improve outcomes. Transl Androl Urol 2019; 8(Suppl 4):S389-s97. 6. Wagenius M, Oddason K, Utter M, et al. Factors influencing stone-free rate of Extracorporeal Shock Wave Lithotripsy (ESWL); a cohort study. Scandinavian journal of urology 2022; 56:237-43. DECLARATIONS Ethical approval: The study adhered to the principles of the Helsinki Declaration and was approved by the Ethics Committee of Hazm Mebaireek General Hospital, Hamad Medical Corporation, Doha, Qatar (ID MRC-01-25-167). Availability of data: Data is available upon request. Competing interests: The authors declare no conflicts of interest. Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Acknowledgments: None. Archivio Italiano di Urologia e Andrologia 2025; 97(2):13867 7 Predictors of treatment failure and outcome assessment of extracorporeal shock wave lithotripsy... 7. Shinde S, Al Balushi Y, Hossny M, et al. Factors Affecting the Outcome of Extracorporeal Shockwave Lithotripsy in Urinary Stone Treatment. Oman Medical Journal 2018; 33:209-17. 8. Neisius A, Wöllner J, Thomas C, et al. Treatment efficacy and out- comes using a third generation shockwave lithotripter. BJU Int 2013; 112:972-81. 9. Campbell MF, Walsh PC, Wein AJ, et al. Campbell-Walsh-Wein urology. 12th ed. / editor-in-chief, Alan W. Partin; editors, Roger R. Dmochowski, Louis R. Kavoussi, Craig A. Peters ed: Elsevier, 2021. 10. Al-Zubi M, Al Sleibi A, Elayan BM, et al. The effect of stone and patient characteristics in predicting extra-corporal shock wave lithotripsy success rate: A cross sectional study. Ann Med Surg 2021; 70:102829. 11. Fisang C, Anding R, Müller SC, et al. Urolithiasis--an interdisci- plinary diagnostic, therapeutic and secondary preventive challenge. Dtsch Arztebl Int. 2015; 112:83-91. 12. Gültekin MH, Türegün FA, Ozkan B, et al. Does Previous Open Renal Stone Surgery Affect the Outcome of Extracorporeal Shockwave Lithotripsy Treatment in Adults with Renal Stones? J Endourol 2017; 31:1295-300. 13. Abdel-Khalek M, Sheir KZ, Mokhtar AA, et al. Prediction of success rate after extracorporeal shock-wave lithotripsy of renal stones--a mul- tivariate analysis model. Scand J Urol Nephrol 2004; 38:161-7. 14. El-Nahas AR, El-Assmy AM, Mansour O, Sheir KZ. A prospec- tive multivariate analysis of factors predicting stone disintegration by extracorporeal shock wave lithotripsy: the value of high-resolution noncontrast computed tomography. Eur Urol 2007; 51:1688-93. 15. Alharbi AS, Gameraddin M, Gareeballah A, et al. Assessment of Hounsfield Units and Factors Associated with Fragmentation of Renal Stones by Extracorporeal Shock Wave Lithotripsy: A Computerized Tomography Study. Tomography 2024; 10:90-100. 16. Abou-Farha M, El-Abd A, Gameel T, et al. Efficacy of extracor- poreal shockwave lithotripsy, with modified position of the machine head in the treatment of lower calyceal stones in obese patients. Urol Ann 2022; 14:81-84. 17. Garg M, Johnson H, Lee SM, et al. Role of Hounsfield Unit in Predicting Outcomes of Shock Wave Lithotripsy for Renal Calculi: Outcomes of a Systematic Review. Curr Urol Rep 2023; 24:173-85. 18. Abdelaziz H, Elabiad Y, Aderrouj I, et al. The usefulness of stone density and patient stoutness in predicting extracorporeal shock wave efficiency: Results in a North African ethnic group. Can Urol Assoc J. 2014; 8:E567-9. 19. Elkoushy MA, Hassan JA, Morehouse DD, et al. Factors deter- mining stone-free rate in shock wave lithotripsy using standard focus of Storz Modulith SLX-F2 lithotripter. Urology 2011; 78:759-63. 20. Suzuki K, Yamashita Y, Yoshida M, Matuzaki J. A single center experience with a lithotripsy machine "Modulith SLX-F2" : evalua- tion of dual focus system and clinical results. Hinyokika Kiyo 2010; 56:81-6. 21. Lv JL. A new optical coupling control technique and application in SWL. Urolithiasis 2016; 44:539-44. 22. Lee CH, Koh SK, Kim HJ. Experience of extracorporeal shock wave lithotripsy with electroconductive lithotriptor (ECL, EDAP- Sonolith Praktis) in 703 patients with urinary calculi. Korean J Urol 2005; 46:375-81. 23. Sheir KZ, Madbouly K, Elsobky E. Prospective randomized com- parative study of the effectiveness and safety of electrohydraulic and electromagnetic extracorporeal shock wave lithotriptors. J Urol 2003; 170:389-92. 24. Kim YH, Kim HJ, Oh JS. Comparative Study of the Results of Electromagnetic (EML Dornier Compact Delta®) and Electroconductive (ECL, EDAP-Sonolith Praktis) Extracorporeal Shock Wave Lithotriptors. Korean J Urol 2007; 48:1027-34. Correspondence Morshed Salah (Corresponding Author) msalah1@hamad.qa; morshed.salah@gmail.com Urology Section, Hazm Mebaireek General Hospital, Hamad Medical Corporation, Doha, Qatar Maged Al-Ghashmi majidghashmi2013@gmail.com Bela Tallai belatallai@gmail.com Abu Baker abu_kmcite@yahoo.com Mohammed Ibrahim mibrahim26@hamad.qa Salvan Alhabash salwansaad@gmail.com Hatem Kamkoum hatemkamkoum@gmail.com Tawiz Gul tawizgul@yahoo.com; tgulistan@hamad.qa Hossameldin Alnawasra halnawasra@hamad.qa Abdoulhafid Elmogassabi AElmogssabi@hamad.qa Maged Alrayashi malrayashi@hamad.qa Mohammed Ebrahim mebrahim2@hamad.qa; mohammed.alezi@gmail.com Mohamed Abdelkareem M.a.alkareem@gmail.com Faisal Ahmed fmaaa2006@yahoo.com