Abstract
Objective: To determine mean skin to stone distance
(SSD) for successful disintegration of renal stones in
patients undergoing shock wave lithotripsy (SWL) for
the treatment of renal stone.
Methodology: This descriptive cross-sectional study
was conducted at the department of Urology, Sindh
Institute of Urology and Transplantation, Karachi. A
total number of 91 patients having stone size > 4 mm
was included in the study. Mean SSD was measured
using NCCT before treatment with SWL. Data
analysis was carried out using SPSS version 20.0.
Results: Out of 91 patients, there were 59 (64.8%)
male and 32 (35.2%) females. The mean age of
patients was 45.75 ± 10.03 years. Mean duration of
kidney stone disease was 8.28 ± 4.21 months. Mean
size of kidney stone was 12.95 ± 3.24 mm. Mean SSD
was 70.72 ± 6.01 mm. Complete stone disintegration
occurred in 84 (92.3%) patients while it was
unsuccessful in seven (7.7%) patients. Mean SSD in
patients with complete stone disintegration was 69.52
± 4.45 mm and was 94.71 ± 2.28 in patients with
unsuccessful stone disintegration (p < 0.001).
Conclusion: Mean SSD was 69.52 ± 4.45 mm in
patients with successful stone clearance. SSD was
higher in overweight to obese patients as compared to
the normal weight patients.
Keywords: Shock wave lithotripsy, non-contrast
computed tomography, skin to stone distance, renal
stone.
