JCU - January 2022 - 7

Irani et al.
7
Introduction
Percutaneous nephrolithotomy (PCNL) is the gold-standard
procedure for the extraction of large renal stones, as it
is associated with low morbidity and acceptable stone
clearance. A ureteric catheter is inserted retrogradely using
the conventional method to infuse the contrast media
needed for the visualization of the renal collecting system
under fluoroscopic guidance.1 Although the insertion of a
ureteral catheter is recommended in many studies, others
have suggested that using a ureteric catheter is not always
necessary, mainly in uncomplicated cases, as its use may
cause catheter-related complications and can have adverse
effects on quality of life.2
An antegrade percutaneous approach without retrograde
catheter insertion for the treatment of upper urinary
tract stones has been reported for many years. In 1978,
Arthur Smith described the first antegrade stent placement
when he introduced a Gibbons stent through a percutaneous
nephrostomy.3 To date, various antegrade techniques
for the removal of renal stones and retrieval of ureteral
stents using ultrasound (B-mode, Doppler) or C-armed
fluoroscopy without retrograde pyelography have been
reported.4-8 Armas-Phan et al. reported a successful PCNL
with an antegrade approach to the renal collecting system
under ultrasound guidance in their patients.9 It has also
been shown that surgical outcomes, postoperative complications
and radiation exposure are comparable between
catheterized and non-catheterized patients who have
undergone PCNL.10
This study was conducted to evaluate the efficacy of a
novel percutaneous access method using stone-directed
antegrade pyelography with the 'bull's eye' technique in
removing stones occupying the renal collecting system
without the need to insert a ureteral catheter.
Methods
This clinical trial was carried out from January 2017 to
June 2018, and 100 adult patients (57 men, 43 women) who
were referred to the stone clinic of Shahid Faghihi Hospital
of Shiraz University of Medical Sciences were enrolled
(Figure 1). To determine the minimum required sample
size, based on the study of Somani et al.,11 we estimated a
total required sample size of 80 (40 in each group). Given a
25% attrition rate, the final sample size was determined as
100 (50 in each group). Patients with a lower-pole renal
stone >15 mm, non-lower-pole renal stone >20 mm, calyceal
diverticular stone, staghorn or partial staghorn stone
and those who failed to respond to shock-wave lithotripsy
(SWL) who had radiopaque or semi-opaque renal stones on
plain abdominal radiography were included in the study.
Those with a solitary kidney or abnormal renal function
were excluded. The protocol was in accordance with the
Declaration of Helsinki and the local committee (ethical
code: IR.SUMS.REC.1396.167). The study was conducted
after obtaining Institutional Review Board approval and
was registered at the clinical trial registration centre (registration
code: IRCT20171126037628N2). After providing
the patients with adequate information, they were all asked
to sign an informed written consent. In order to allocation
the patients randomly into either the retrograde ureteral
catheter or the stone-directed group, we implemented block
randomization using 25 blocks (with a size of four) with
random allocation software.
All procedures were performed by a single surgeon
(D.I.) who had equal experience in both techniques.
Preoperative laboratory tests, including urine analysis,
urine culture, complete blood count, coagulation profiles
and renal function tests, were recorded. Patients with a urinary
tract infection (UTI) were treated with appropriate
antibiotics preoperatively.
All patients underwent an intravenous pyelogram or a
spiral computed tomography scan of the abdomen before
the operation. All procedures were performed in the prone
position after appropriate padding.
The stone size was considered as the sum of the longest
axis of the stone if patients had multiple calculi. The
patients were given 1 g ceftriaxone (Ceftrax®; Jaber Ebne
Hayyan, Tehran, Iran) preoperatively.
Surgical procedure
C-arm fluoroscopy was used to detect the location of the
target stone. A 17 cm 18-gauge Chiba needle using the
'bull's eye' technique under fluoroscopic guidance was
used to reach the targeted stone or a branch of the stone (in
staghorn or partial staghorn stones). The C-arm was rotated
30° toward the surgeon and 30° caudally to help the needle
advance appropriately towards the targeted stone or a
branch of the stone after creating a 'bull's eye' sign on the
fluoroscopy screen (Figure 2). The C-arm has then rotated
back to 30° away from the surgeon and 30° cranially to
monitor the depth of the puncture. With this approach, the
needle tip was moved forward until the stone was reached.
After that, the internal obturator of the needle was removed,
and antegrade injection of the diluted iodinated contrast
media was performed to enhance the renal collecting system
(Figure 3). In cases where the needle was inserted
through the appropriate calyx in the very first puncture, the
procedure was continued as described in the next section.
Otherwise, a second puncture was performed under fluoroscopic
guidance to insert the needle into the desired calyx.
For patients with a renal pelvis stone, first we approached
the stone using a 23-gauge Chiba needle, and after that, a
18-gauge Chiba needle was used for the second puncture.
In the retrograde pyelography access group, after performing
cystoscopy and insertion of a ureteral catheter (5
or 6 Fr), retrograde pyelography was done. Access to the
desired calyx was achieved using the 'bull's eye'

JCU - January 2022

Table of Contents for the Digital Edition of JCU - January 2022

Contents
JCU - January 2022 - Cover1
JCU - January 2022 - Contents
JCU - January 2022 - 2
JCU - January 2022 - 3
JCU - January 2022 - 4
JCU - January 2022 - 5
JCU - January 2022 - 6
JCU - January 2022 - 7
JCU - January 2022 - 8
JCU - January 2022 - 9
JCU - January 2022 - 10
JCU - January 2022 - 11
JCU - January 2022 - 12
JCU - January 2022 - 13
JCU - January 2022 - 14
JCU - January 2022 - 15
JCU - January 2022 - 16
JCU - January 2022 - 17
JCU - January 2022 - 18
JCU - January 2022 - 19
JCU - January 2022 - 20
JCU - January 2022 - 21
JCU - January 2022 - 22
JCU - January 2022 - 23
JCU - January 2022 - 24
JCU - January 2022 - 25
JCU - January 2022 - 26
JCU - January 2022 - 27
JCU - January 2022 - 28
JCU - January 2022 - 29
JCU - January 2022 - 30
JCU - January 2022 - 31
JCU - January 2022 - 32
JCU - January 2022 - 33
JCU - January 2022 - 34
JCU - January 2022 - 35
JCU - January 2022 - 36
JCU - January 2022 - 37
JCU - January 2022 - 38
JCU - January 2022 - 39
JCU - January 2022 - 40
JCU - January 2022 - 41
JCU - January 2022 - 42
JCU - January 2022 - 43
JCU - January 2022 - 44
JCU - January 2022 - 45
JCU - January 2022 - 46
JCU - January 2022 - 47
JCU - January 2022 - 48
JCU - January 2022 - 49
JCU - January 2022 - 50
JCU - January 2022 - 51
JCU - January 2022 - 52
JCU - January 2022 - 53
JCU - January 2022 - 54
JCU - January 2022 - 55
JCU - January 2022 - 56
JCU - January 2022 - 57
JCU - January 2022 - 58
JCU - January 2022 - 59
JCU - January 2022 - 60
JCU - January 2022 - 61
JCU - January 2022 - 62
JCU - January 2022 - 63
JCU - January 2022 - 64
JCU - January 2022 - 65
JCU - January 2022 - 66
JCU - January 2022 - 67
JCU - January 2022 - 68
JCU - January 2022 - 69
JCU - January 2022 - 70
JCU - January 2022 - 71
JCU - January 2022 - 72
JCU - January 2022 - 73
JCU - January 2022 - 74
JCU - January 2022 - 75
JCU - January 2022 - 76
JCU - January 2022 - 77
JCU - January 2022 - 78
JCU - January 2022 - Cover3
JCU - January 2022 - Cover4
https://www.nxtbookmedia.com