Mini vs standard percutaneous nephrolithotomy for renal stones: a comparative study

Abstract

To compare the outcome of mini-percutaneous nephrolithotomy (Mini-PNL) versus standard-PNL for renal stones. Retrospective study was performed between March 2010 and May 2013 for patients treated by Mini-PNL or standard-PNL through 18 and 30 Fr tracts, respectively, using pneumatic lithotripsy. Semirigid ureteroscope (8.5/11.5 Fr) was used for Mini-PNL and 24 Fr nephroscope for standard-PNL. Both groups were compared in stone free rate(SFR), complications and operative time using Student-t, Mann-Whitney, Chi square or Fisher's exact tests as appropriate in addition to logistic regression analysis. P < 0.05 was considered statistically significant. Mini-PNL (378) and standard-PNL (151) were nearly comparable in patients and stones criteria including stone burden (3.77 ± 2.21 vs 3.77 ± 2.43 cm; respectively). There was no significant difference in number of tracts or supracostal puncture. Mini-PNL had longer operative time (68.6 ± 29.09 vs 60.49 ± 11.38 min; p = 0.434), significantly shorter hospital stay (2.43 ± 1.46 vs 4.29 ± 1.28 days) and significantly higher rate of tubeless PNL (75.1 vs 4.6%). Complications were significantly higher in standard-PNL (7.9 vs 20.5%; p < 0.001). SFR was significantly lower in Mini-PNL (89.9 vs 96%; p = 0.022). This significant difference was found with multiple stones and large stone burden (> 2 cm), but the SFR was comparable between both groups with single stone or stone burden ≤ 2 cm. Logistic regression analysis confirmed significantly higher complications and SFR with standard-PNL but with significantly shorter operative time. Mini-PNL has significantly lower SFR when compared to standard-PNL (but clinically comparable) with markedly reduced complications and hospital stay. Most of cases can be performed tubeless. The significant difference in SFR was found with multiple stones or large stone burden (> 2 cm), but not with single stones or stone burden ≤ 2 cm.

The Safety and Efficacy of Mini Percutaneous Nephrolithotomy During Learning Curve

“…Even a complex stone burden can be safely and efficiently managed with Mini PCNL . 12,13 In our series the stone free rate was significantly associated with number of stones (p = 0.004) and weakly associated with size (p = 0.3) and hardness (p = 0.2). Stone free rate was significantly lower with multiple calyceal stones in case of Mini PCNL.…”

“…Mini PCNL had significant advantage over standard PCNL in terms of reduced bleeding (mean haemoglobin drop of 0.8 mg%) leading to higher chance of tubeless procedure (75-80%) and reduced hospital stay (2.43-4.5 days). [11][12][13][14] The operative time for Mini PCNL was found to be 45-69 minutes which was higher than standard PCNL but statistically insignificant (p >0.3). 11,12 Kukreja et al 15 demonstrated similar safety and efficacy in his prospective randomised study in management of adult nephrolithiasis of size 15 to 30 mm with no difference in operative time between standard and Mini PCNL.…”

“…[11][12][13][14] The operative time for Mini PCNL was found to be 45-69 minutes which was higher than standard PCNL but statistically insignificant (p >0.3). 11,12 Kukreja et al 15 demonstrated similar safety and efficacy in his prospective randomised study in management of adult nephrolithiasis of size 15 to 30 mm with no difference in operative time between standard and Mini PCNL. A review of more than 10,000 cases revealed a stone-free rate of 86.7% and 86.1% for simple and complicated stones respectively following Mini PCNL.…”

A comparison among PCNL, Miniperc and Ultraminiperc for lower calyceal stones between 1 and 2 cm : A prospective, comparative, multicenter and randomised study.

“…The MP studies have showed comparable and equal SFR and reduced comorbidities compared to conventional PCNL (8,14,15). ElSheemy et al compared MP and standard PCNL through 18 and 30 Fr tracts respectively (16). According to their results there was significant difference on SFR in between patients who had larger stone burden (>2cm 2 ).…”

“…Conventionally the miniaturization of PCNL has defined by diameter less than 20 Fr(7). The Minipercutaneous (MP) (16)(17)(18), Ultraminiperc (UMP) (11)(12)(13)(14) and Micropercutaneous (MicroPNL) (<10Fr) are currently feasible and modern alternatives with minimal invasiveness (2). The MP is accepted as suitable for renal stones <2 cm in size while UMP is for renal stones <1.5cm (7,8).…”