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

To prospectively evaluate ESWL (extracorporeal shock wave lithotripsy) outcomes and validate ESWL Score.

An observational study.

The Aga Khan University Hospital, from January 2021 to December 2021.

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.

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).

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.

Stone, Lithotripsy, Extracorporeal, Score, Shock wave, Outcome.