Single vs Serial Dilatation of Access Tract in Percutaneous Nephrolithotomy: A Randomised Control Study on its Feasibility and Effects in Management of Renal Calculi

Abstract

Introduction: Percutaneous Nephrolithotomy (PCNL) is the recommended treatment for renal calculi. The tract dilatation method has a significant effect on the surgical outcome. One- Shot Dilatation (OSD) involves dilatation using the dilator and Amplatz of desired size, while Serial Dilatation (SD) involves increasing the dilator size progressively upto the desired size. Aim: To compare the success and complication rates of SD techniques and OSD technique using Amplatz dilators. Materials and Methods: This was a randomised control study, conducted in a tertiary care centre of Bharati Hospital, Pune, Maharashtra, India, from March 2020 to December 2021. A non probability sampling technique was followed and hundred consecutive patients of renal calculus were included in the study. The patients were then randomly allocated using random number table to undergo PCNL via a One shot Dilatation (OSD- group I) or Serial Dilatation (SD-group II) of access tract. After the initial work-up, the patients underwent PCNL, tract dilated as per the group enrolled. The two groups were then compared for patient demographics, stone characteristics (size, number, location), dilatation type, access time, tract size, access quality, bleeding at entry, operative time, radiation time, postoperative analgesic requirement, tube or tubeless procedure, time for removal of the nephrostomy tube and double ‘J’ stent placement. The statistical inference was obtained by Analysis of Variance (ANOVA), Kruskall-Wallis t-test, Fisher’s-exact test or Chi-square test. Significance was said when p-value <0.05. The analysis was performed on p-value. Results: In the patients from group I, there was lesser blood loss (Haemoglobin drop 0.89 vs 1.34 gm/dL), clot at entry (6% vs 28%), and radiation exposure (60.9 sec vs 94.1 sec) as compared to group II patients. This was also reflected in reduced mean operative time (46.2 min vs 57.1 min) and lesser duration of hospital stay (3 vs 4 days) among group I patients. Conclusion: The OSD was found to be superior to SD using Amplatz dilatation in PCNL in terms of having reduced blood loss and reduced exposure to radiation for the patient.

Keywords

• access tracts
• amplatz
• dilatation methods