Stone clearance rate and postoperative recovery of mini percutaneous nephrolithotomy: A single-institute study

Abstract

Introduction: During the last two decades, the evaluation and management of renal and upper ureteric stones has vastly altered. The era of endoscopic surgery replaced open pyelolithotomy or nephrolithotomy which caused a significant morbidity. During this decade we saw evolution of endoscopic surgery where Mini PCNL (Mini Perc), Ultra Mini and Micro Perc have further achieved stone clearance with better outcomes pertaining to reduced morbidity because of reduction in caliber of tract dilatation, even avoiding a nephrostomy post rocedure in select cases. Aim of this study summarizes the outcome of patients undergoing Mini Perc. The primary objective of the study was to get post-Operative evaluation of complications associated with Mini Perc by Modified Clavien Dindo Grading and secondary objectives were to see Post-Operative pain assessment by Visual Analogue scale and to see Stone clearance rate of the surgical procedure. Materials and Methods: Research was carried out in the form of a Hospital-based prospective observational study as per the guidelines shared by the Prospective Observational Clinical Studies Good Research Practices Task Force (formed May 16, 2010). Hospital-based prospective observational study of 78 consecutive patients who underwent Mini Perc between Aug 2018 and May 2020 at tertiary care centre were vetted against the criteria for inclusion and exclusion. The management policy for pelvicalyceal calculi at the study centre has closely followed those of the American Urological Association (AUA) guidelines for managing renal stones. Results: The mean age of the group was 43.3 years (range 16-84) with 47 males and 38 females. Mean stone size was 20.11 mm (range 11-38 mm) and mean operative time was 44.5 min (range 29-98 min). Double J (DJ) stent was placed in all patients as a prophylaxis to prevent obstructive uropathy / post op urinary leak. Postoperatively, the most commonly noted complication was fever recorded in 12 (15.38%) patients followed by bleeding at the surgical site in 03 (3.84%) patients. Sepsis was noted in 02 (2.56%) patients, pleural injury in 01(1.28) patient. Haemorrhage requiring intervention was recorded in 01 (1.28%) of patients. Pain assessment done at specified interval showed progressive decreasing trend in intensity as evaluated by visual analogue scale. The stone clearance rate in our study was 96.15% at the end of one month following post op period. Conclusion: The study shows that Mini Perc remains standard of care for management of Renal and upper ureteric stone. The technique beyond doubt is safe, efficient, feasible and economical in achieving excellent stone clearance rates. The Modified Clavien-Dindo system of grading for perioperative complications is easy to use and reproducible. It can be used as an objective and reliable method for describing the complications of the surgical procedure.

Keywords

• kidney stone
• mini perc
• minimally invasive surgery
• percutaneous nephrolithotomy