EURURO Vol. 72 No. 2

236 320

Platinum Priority – Editorial
Referring to the article published on pp. 220–235 of this issue
Miniaturized Percutaneous Nephrolithotomy: A Decade of
Paradigm Shift in Percutaneous Renal Access
Mahesh[2_TD$DIFF] R. Desai, Arvind P. Ganpule
Muljibhai Patel Urological Hospital, Nadiad, India
The last decade has seen a paradigm shift from conventional
percutaneous nephrolithotomy (PCNL) to PCNL with a tract
size as small as 4.8 Fr. This validates the prophetic
statement [3_TD$DIFF]made more than a decade ago: ‘‘I would hope
that in the future, our therapies will heal absolutely and
harm not at all... and so let us continue to move, from knife
to cannula to needle to nothing’’
In the well-written systematic review by the European
Association of Urology Urolithiasis Guidelines Panel in this
issue of European Urology, the authors conclude that
miniaturized PCNL (miniperc, ultraminiperc, microperc) is
as efficacious and safe as conventional PCNL with accept-
able complications. They also note that the contemporary
indications for miniaturized PNL are medium stones of up to
20 mm, although there are no credible data to support an
upper limit for stone size. In addition, a few specific
indications mentioned for miniaturized PCNL include
stones in diverticula and stones in spidery collecting
systems. This review notes the indications for extracorpo-
real shockwave lithotripsy and flexible ureteroscopy versus
miniaturized PCNL. However, in this subset of patients it
would be a matter of debate to define the role of each of
these modalities .
As noted in the review, there is an inverse relationship
between tract size and operative time. In our opinion, there
also exists an inverse relationship between tract size
bleeding and intraoperative visibility during miniaturized
PCNL. Interestingly, this systematic review shows that
miniaturized PCNL has a significantly longer operating time
It needs to be emphasized that the smaller the tracts we
utilize, the better should be the optics and devices to break
and retrieve the fragments. Limitations in stone fragmen-
tation and retrieval are important factors that contribute to
longer operating times in miniaturized PCNL. The longer
operating time in miniaturized PCNL could be offset by the
use of a suction device compatible with small-diameter
energy sources.
It needs to be emphasized that regardless of how small
the tract size, the key to a successful procedure remains
perfect percutaneous renal access. The ideal percutaneous
tract should be a short, straight tract traversing the
subcutaneous tissue and entering the calyx through the
cup . This principle is of utmost importance in
miniaturized PCNL with smaller tracts, as an improper
access tract invariably leads to troublesome ooze, which in
turn obscures vision and can adversely affect the outcome.
As noted in the review, there have been anecdotal studies
that address concerns regarding increased intrarenal
pressure during miniaturized PCNL. It is worth remember-
ing that although higher intrapelvic pressures were
observed, these did not alter the outcome in terms of stone
clearance and complications. Further randomized multi-
center studies in the future would definitely address this
issue.
The limitations of this review, as admitted by the
authors, are the poor quality of the evidence drawn from
small single-arm studies; notably, only two randomized
control studies could be analyzed. In addition, we feel that
there is a possibility that the data analysis might be skewed
because of a lack of uniform terminology in articles
describing new miniPCNL, ultraminiPCNL, and microperc
techniques. For assessment of stone-free rates and imme-
diate stone-free rates described in various studies in the
review, either plain X-ray and/or ultrasound or computed
tomography imaging was used. The lack of uniformity in
various studies in both these regards hinders proper
available at
journal homepage:
DOI of original article: .
* Corresponding author. Department of Urology, Muljibhai Patel Urological Hospital, Nadiad 387001, India. Tel. +91 98 24188685.
E-mail address: (A.P. Ganpule).
0302-2838/# 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.