Login to Access Video or Poster Abstract: MP62-05
Sources of Funding: None

Introduction

Extracorporeal Shock Wave Lithotripsy (SWL) is performed in only few centres across Australia including Monash Health. Currently patients fast for 2 hours prior to the procedure. On the day of procedure, bowel gas can obscure visualisation of the calculus resulting in 8% of cases being cancelled. This study aims to review whether bowel preparation or fasting for six hours prior to SWL will improve stone visualisation on the day of treatment, reduce cancellations and improve calculi clearance rates.

Methods

This is a single centre, randomised controlled trial, with ethics approval granted from Monash Health Human Research and Ethics Committee (approval number: 16324A). Patients who were selected for SWL were then consented for participation in the trial. Patients were randomly allocated to one of the three arms of the trial; 1. Two sachets of Sodium Picosulphate, 2. Six hours of fasting or 3. Fasting for two hours. Sodium Picosulphate sachets were provided by Fresenius-Kabi. Patients were included into the study if they had intra-renal calculi measuring between 8-12mm. Patients were excluded from the study, if they were over 75 years of age, had more than three medical co-morbidities or had any cardiac/renal conditions. At six weeks post SWL, all patients had a CT KUB to assess stone clearance and completed a survey on their subjective experience of the trial. Statistical analysis was performed using SPSS, t-test.

Results

Sixty patients were recruited in total, twenty into each of the three arms. In the bowel preparation group, there were no cancellations on the day of SWL treatment. All stones were fragmented, with one patient needing a repeat treatment for a 5mm intra-renal fragment. Of the patients who were fasting for either the six hours or the two hours, each group had two cancellations on the day of the procedure for poor visualisation of the calculus. This was a statistically significant difference of p = 0.03 between the bowel preparation and fasting groups. There were no complications related to the bowel preparation or fasting. There was no loss to follow-up. Patient satisfaction was high across all three groups, including those who received bowel preparation.

Conclusions

Giving bowel preparation within twelve hours of SWL appears to be an effective method of reducing bowel gas interference and improving the calculi visualisation at the time of SWL, resulting in fewer cancellations. Fasting for extended periods of time does not seem to make a significant difference. We are in the process of recruiting more patients to the study.

Funding

None