Role of Minimally Invasive (Micro and Ultra-mini) PCNL for Adult Urinary Stone Disease in the Modern Era: Evidence from a Systematic Review

Abstract

Purpose of ReviewThe role of PCNL and the expertise surrounding it has expanded in recent decades. Miniaturisation of equipment and instrument size has formed a part of this innovation. Although an increasing number of studies have been performed on miniaturised PCNL (Mi-PCNL) recently, a critical appraisal on these is lacking. We therefore conducted a systematic review of the literature to evaluate the efficacy, safety and feasibility of Mi-PCNL techniques (< 15 Fr).Recent FindingsA systematic review was conducted from 1990 to March 2017 on outcomes of Mi-PCNL [micro PCNL (m-PCNL) and ultra-mini PCNL (UMP)] in adult patients. Ten studies (three on m-PCNL and seven on UMP) were included in our study. Across the three studies, 118 patients (mean age 42.2 years, male to female ratio 1.3:1) underwent m-PCNL (4.8 Fr). For a mean stone size of 13.9 mm, a mean stone-free rate (SFR) was 89% and an overall complication rate was 15.2% [Clavien classification I (44%), II (28%), III (28%)], with no Clavien IV or V complications. Across the seven studies, 262 patients (mean age 49.4 years, male to female ratio 1.5:1) underwent UMP (13–14 Fr). For a mean stone size of 18.6 mm, a mean SFR was 88.3% and an overall complication rate was 6.2% [Clavien classification I (57%), II (36%), III (7%)], with no Clavien IV or V complications. While the transfusion rates for m-PCNL was 0.85%, only one case each in m-PCNL and UMP needed conversion to mini PCNL.SummaryOur review shows that for small- to medium-sized renal stones, Mi-PCNL can yield good stone-free rates whilst maintaining a low morbidity associated with it. There were no Clavien > III complications and no mortality with only one transfusion reported from this minimally invasive technique.

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

“…Jones et al published a systematic review study investigating the role of MicroPNL and UMP. Across seven studies a total of 262 patients were undergone UMP with a mean of stone size 18.6mm, SFR of 88.3% and complication rate of 6.2% (19). In our study, we calculated the SFR on 3 rd month control.…”

Role of pelvicalyceal anatomy in the outcomes of retrograde intrarenal surgery (RIRS) for lower pole stones: outcomes with a systematic review of literature

“…Although our review shows a good SFR for LPS, information on pelvicalyceal anatomy might prove to be useful when treating stones with unfavourable anatomy especially when they are large and have a hard composition. While IW and IL may not be as important, IPA seems to be important (< 30°) and in these cases an alternate treatment option such as minimally invasive PCNL procedure could be considered [28,29]. This is especially important for informed decision making with the patients, when counselling them for the treatment success for LPS and discussing alternate treatment options.…”

Updates in endourological management of urolithiasis

“…In general, the tract sizes were <15‐Fr (UMP <15‐Fr, micro‐PCNL <10‐Fr) . A recent systematic review concluded that UMP and micro‐PCNL can yield good stone‐free rates with low morbidity, and should be considered when ESWL or RIRS are prone to fail or have failed . In contrast, when mini‐PCNL was shown to have higher stone‐free rate than RIRS, UMP and micro‐PCNL had similar stone‐free rates with RIRS, and therefore mini‐PCNL was recommended for renal stones, as the current evidence has shown …”