7° Congresso Nazionale

RESULTS
All patients are alive; for 57 nephrolithotripsy procedures
stone-free rate was 98.3%; in 1 pt (1,7%) the procedure
was unsuccessful (impossibility to perform
nephrostomic access); in 3 pts (5,2%) occured bleeding
with bladder plugging at drainage remove (3rd postoperative
day) that needed stenting (mono J catheter for
some days) and in two patients (2/3 pts) blood transfusion
(3 units of heterologous blood in 1 pt and 1 unit of
autologous blood in 1 pt); in 5 patients (8,7%) the postoperative
anaemia without evidence of significant bleeding
needed blood transfusion (2 units of autologous
blood each in 4 patients and 1 unit of heterologous
blood in 1 patient); totally, 7/63 pts were transfused
(11%); in 1 patient in 7th postoperative day
hydronephrosis without evidence of residual stones, that
needed stenting; for residual procedures (6 patients)
there were no complications; the mean extimated blood
loss was 0,65 + 1,05 g/dL HB (range 0,1- 3,9 g/dL HB);
the mean hospital stay was 4,2 + 2,8 days (range 2- 14
days).
DISCUSSION
The recent introduction on the market of miniaturized
instruments has given strong evidence to the possibilities
of being less invasive in the percutaneous procedures.
This was made possible by the small diameter probes
suitable to be used with L.A.SE.R., which proves very
useful in lithotripsy. Besides the presence of flexible
fibroscopes is highly suitable for the exploration of the
renal cavities.
All this has led to the construction of operative nephroscopes,
aimed to obtaining the same results with the least
possible parenchymal loss.
Until the last year the few experiences of “minipercutaneous
procedures” had to be effected with a technology
unfit for this purpose, but adapted to the specific case, as
in our experience, with obvious limitations in use and
indication.
In literature too very little has been said about mini percutaneous
but only about single or rare experiences,
often in the pediatric field, without the necessary directions
for the standardization of the technical and instrumental
characteristics required by any procedure for an
objective analysis of the result.
If all the Authors mentioned have agreed on the need of
being as least invasive as possible towards the kidney by
effecting nephrostomic approach of small diameter, there
is always the problem of using different instruments, so
in the pediatric experience.
Even if Traxers experimental reports do not show, after 6
weeks, different functional results in terms of parenchimal
damage, utilizing different sized nephrostomy tract
(11 or 30 Fr)(1).
Jackman et al (2). Helal et al (3) described initially the
technique in children with the use of 11 Fr to 15 Fr peelaway
and subsequently the use of a 13 Fr ureteroscopy
sheath for working access. Feng et.(4) al in a prospective
randomized trial to assess the efficacy and morbidity
through standard PCN involved tract dilation to 30 Fr
for passage of a 34 Fr working sheath and their 2 mini-
7° Congresso Nazionale Associazione Italiana di Endourologia
PCN involved tract dilation to 22 Fr for passage of a 26
Fr sheath with tubeless procedure, no overall advantage
was found for the mini-PCN versus the standard technique,
imputing however the disadvantages of the microprocedures
to the poorer visualization and optics and
difficulty with the use of the nephroscopic graspers.
Chan et al.(5) describes the use mini-PCN by means of
13 Fr ureteroscopy and stresses how the procedure
reduces morbidity compared with the standard procedure
in terms of efficiency and effectiveness for stone
removal.
In the abstract “role of Miniperc in the management of
urolithiasis”, Bhargava et al. (6) evaluate the effectiveness
of the procedure with 14 Fr (19 cm Length) access
ureteric sheath and the use of the ureteroscopy of 8 Fr
and pneumatic lithotripsy in 30 patients. They conclude
that ”Miniperc” is a safe and very useful procedure.
Also Monga et al.(7) describes the miniaturization of percutaneous
nephrolithotomy, a natural evolution of the
gold standard by using of 20 Fr compared with the traditional
30 Fr sheath. The Author points out that the
reduction of the approach allows less bleeding and postoperative
pain in 16 patients.
Desai et al. (8) refers to a paediatric surgery experience
with 45 renal Units in 40 cases using the paediatric
nephroscope 14 Fr with a 2,4 mm working channel with
dilatation of the approach from 18,5 to 24 Fr according
to the age of the children. The Authors describes this
procedure as safe ed appropriate option in the modern
management of paediatric urolithiasis.
Also Zattoni (9) in his personal experience (with the new
17 Fr nephroscope in renal stone and nephrostomic
channel of 20 Fr) of 9 cases including 6 children suggests
that paediatric nephroscope should be considered a standard
part of the endourologic equipment.
In our experience, the miniperc procedures allows significant
reduction in blood loss: in a previous study of
our group (10) we have compared three groups of
patients that’s undergoes percutaneous procedures with
various techniques of nephrostomy tract dilation to 34
Fr: 105 total patients, of which 59 progressive dilation
with Amplatz metallic dilators, 36 with One- Shot technique
and 15 with pneumatic dilation: in first group the
extimated blood loss was 2,08 + 1,43 g/dL HB (0,3- 8,7
g/dL), in second group 1,64 + 0,95 g/dL HB (0- 3,9
g/dL), in third group 1,90 + 1,12 g/dL (0,2- 3,7 g/dL); in
our actual series the extimated blood loss was 0,65 +
1,05 g/dL (0,1- 3,9 g/dL); the data are particularly significant
in comparison with first group (p < 0,001), but
remains also significant in comparison with second
group (p < 0,05) and third group (p < 0,02) (Table 3).
In our previous study we have also evaluated mean operating
times, that were respectively 38 minutes with
Alken metallic dilators, and 29 minutes with One-Shot
or pneumatic dilation. In actual series mean operating
times are more of 60 minutes: a demonstration (statistically
significant, but also intuitive) of major expensiveness
in operating time of miniperc procedures in comparison
with standard nephrostomy tract accesses, independently
of dilation technique. The mean hospital stay
in present study was 4,2 + 2,8 days (range 2- 14 days);
in previous study was 5,74 +3,54 days (range 2-20 days)
Archivio Italiano di Urologia e Andrologia 2007, 79, 3, Supplemento 1
45