Extracorporeal Shock Wave Lithotripsy (ESWL) Outcome Based on CT Scan and Patient Parameters Using ESWL Score.

OBJECTIVE: To prospectively evaluate ESWL (extracorporeal shock wave lithotripsy) outcomes and validate ESWL Score. STUDY DESIGN: An observational study. PLACE AND DURATION OF STUDY: The Aga Khan University Hospital, from January 2021 to December 2021. METHODOLOGY: Patients with symptomatic, solitary, radio-opaque renal stone measuring <15 mm with normal renal functions were included in this study. Stone size <11mm, BMI <27 Kg/m2, and stone density <900 Hounsfield units (HU) were all given 1 point each to give a total ESWL Score between 0-3 to each patient. Patients were evaluated after 4-weeks for the outcome i.e. stone clearance and complications. RESULTS: A total of 146 patients were included in the study. Median values for age, stone size, BMI and stone density were 40 years, 8 mm, 27 Kg/m2, and 774 HU respectively. Post ESWL, 99 (68%) patients were stone-free while 47 (32%) patients had residual stones. The stone clearance increased with the increasing score: 50% for ESWL score 0, 55.6% for ESWL score 1, 66.1% for ESWL score 2, and 85.7% for ESWL score 3 (p=0.01). The area under the curve (AUC) of ESWL score was 0.655 with 95 % CI (p=0.001). CONCLUSION: ESWL Score is a useful predictor of the success of ESWL. It can help decide the individualised and appropriate modality of treatment and assist with patient counselling. KEY WORDS: Stone, Lithotripsy, Extracorporeal, Score, Shock wave, Outcome.

A Prospective Evaluation of the Association of Ureteral Wall Thickness With Intraoperative Stone Impaction in Ureteroscopy.

Background and objective In this study, we aimed to analyze the association of ureteral wall thickness (UWT) measured on non-contrast CT (NCCT) with stone impaction as found in ureteroscopy (URS). Materials and methods We analyzed 43 patients who underwent URS and pneumatic/laser lithotripsy for ureteric stones from May to November 2022. The UWT was measured by an experienced radiologist on NCCT. Clinical predictors of the impacted stone were calculated by univariate and multivariate regression analysis. The receiver operating characteristic (ROC) curve was calculated for the UWT cutoff to apply it for impaction with different parameters. We also evaluated the association of intra- and postoperative parameters of the two groups with UWT. Results Out of the 43 patients with stones, 26 (60.46%) patients had impacted stones. Univariate analysis was used to analyze the site (left-sided stone impacted more commonly), stone size, stone density [Hounsfield unit (HU)], hydronephrosis, UWT, and duration between initial presentation and surgery, and multivariate analysis was utilized to assess stone density, as well as UWT's association with impacted stones. The ROC curve showed a cutoff of 3.5 mm for UWT with an accuracy of 0.83. High UWT (≥3.5 mm) was associated with a significantly lower stone-free rate, more complications, and mean operative time as compared to low UWT (<3.5 mm) (p<0.05). Conclusion Based on our findings, high UWT is associated with high rates of impacted stones and a lower stone-free rate when compared to low UWT.