Mini-PCNL versus standard-PCNL for the management of 20-40 mm size kidney stones: The initial result of a multi-center randomized controlled trial

Does Miniaturization Actually Decrease Bleeding After Percutaneous Nephrolithotomy? A Single-Center Randomized Trial

Introduction: Miniaturization of percutaneous nephrolithotomy (mPCNL) was proposed to decrease postoperative bleeding, as there is decreased parenchymal injury compared with standard percutaneous nephrolithotomy (SPCNL). Published randomized controlled trials (RCTs) evaluating bleeding after mPCNL have shown conflicting results. Hence, the evidence to say that mPCNL offers less postoperative bleeding is not robust. Materials and Methods: Prospective RCT was done by comparing mPCNL and SPCNL for treatment of renal stones of size 1 to 3 cm. Patients with active urinary tract infection, renal malformation, uncorrected coagulopathy, and raised serum creatinine (>1.5 mg/dL) were excluded. Blood loss was evaluated by measuring fall in hemoglobin and hematocrit on postoperative day 1. Postoperative pain was evaluated by visual analogue scale (VAS) score at 6, 24, and 48 hours. Results: A total of 60 patients (30 in each arm) were enrolled during the study period. All the baseline preoperative variables were comparable in both the groups. The SPCNL group had a significantly higher drop in hematocrit level as compared with mPCNL (4.6 ± 3.1% vs 3.1 ± 2.1%, p = 0.02). The mean fall in hemoglobin was higher in SPCNL as compared with mPCNL (1.61 ± 0.9 gm% vs 1.21 ± 0.7 gm%, p = 0.07), but it was not significant. Blood transfusion (BT) rate was comparable in both the groups (one patient in each group). The mPCNL group had significantly less VAS scores at 6 hours (3.27 ± 1.20 vs 4.40 ± 1.52, p = 0.002) and 24 hours (2.10 ± 0.54 vs 2.83 ± 1.05, p = 0.001) after surgery. Postoperative complications and hospital stay were comparable in both the arms. Conclusion: mPCNL is associated with less postoperative bleeding and pain than SPCNL. However, the small tract size does not prevent against the clinically significant bleeding requiring BT.

Tract sizes in percutaneous nephrolithotomy: does miniaturization improve outcome?

PURPOSE OF REVIEW

To provide a summary of surgical outcomes in percutaneous nephrolithotomy (PCNL) according to various techniques and tract sizes.

RECENT FINDINGS

Recent literature in this field concluded that standard PCNL (sPCNL) remains the optimal treatment for stones between 1 and 2.5 cm and can be managed with tracts 14-20 F, whereas small stones less than 1.5 cm can be treated with tracts under 14 F. According to new datasets, smaller tracts can be equally effective in the treatment and might offer the possibility to reduce bleeding, length of hospital stay, postoperative pain as well as overall complication rates when compared with sPCNL. On the other hand, longer operative time as well as lower stone-free rates, which have been the main drawbacks of the miniaturized approach, have recently shown to be comparable with sPCNL.

SUMMARY

At present, tract size is a highly debatable topic in percutaneous stone therapy. New systems for miniaturized PCNL have been developed to achieve comparable stone-free rates while reducing the incidence of common complications. The adoption of these techniques demands skilled surgeons and institutional investment for the acquisition of new equipment.