This study evaluated the safety and efficacy of percutaneous nephrolithotomy (PCNL) guided solely by ultrasonography in over 700 cases over 5 years. Access to the pelvicalyceal system was successful in all cases using ultrasonography. The overall stone-free rate was 87.4% and complications were minor, with a low 16% rate. The study demonstrated that PCNL can be performed safely and effectively using only ultrasonography guidance, avoiding the risks of radiation exposure from fluoroscopy.

1. JOURNAL
CLUB

2. PERCUTANEOUS
NEPHROLITHOTOMY GUIDED
SOLELY BY
ULTRASONOGRAPHY

3. A 5-YEAR STUDY OF >700 CASES
Song Yan, Fei Xiang and Song Yongsheng
Division of Urology, Sheng Jing Hospital,
China Medical University, Shenyang, China

4. OBJECTIVE
To evaluate the safety and efficacy of
percutaneous nephrolithotomy (PCNL)
solely guided by ultrasonography (US).

5. INTRODUCTION
 Percutaneous nephrolithotomy (PCNL) has been
performed as a minimally invasive method of
removing kidney stones since 1976.
 Because of the improvements in technique and
equipment, PCNL is now considered to be a
generally safe management option, with a low
incidence of complications [1,2]
1. Wen CC, Nakada SY. Treatment selection and outcomes: renal
calculi. Urol Clin North Am 2007; 34: 409–19
2. Lingeman JE, Miller NL. Management of kidney stones. BMJ
2007; 334: 468–72

6.  Pelvicalyceal system (PCS) access is key to
successful PCNL and is generally performed under
fluoroscopic guidance.
 Although protective gowns can be used by patients
and physicians during these procedures, radiation
exposure can still affect the surgical team over the
long term, and the hazard is dose-independent [3].
3. Safak M, Olgar T, Bor D, Berkmen G, Gogus C. Radiation doses
of patients and urologists during percutaneous
nephrolithotomy. J Radiol Prot 2009; 29: 409–15

7.  The use of ultrasonography (US) can avoid
radiation exposure and provides a reliable method
for the localization of renal stones, especially non-
opaque stones that are not visible via fluoroscopy.
 Moreover, colour US can be used as a tool for the
localization of intrarenal arteries and helps to avoid
their puncture by a Chiba needle [4,5].
4. Lu M-H, Pu X-Y, Gao X, Zhou X-F, Qiu J-G, Tu S-T. Comparative study of
clinical value of single B-mode ultrasound guidance and B-mode combined
with color Doppler ultrasound guidance in mini-invasive percutaneous
nephrolithotomy to decrease hemorrhagic complications. Urology 2010; 76:
815–20
5. Tzeng B-C, Wang C-J, Huang S-W, Chang C-H. Doppler ultrasound-guided
percutaneous nephrolithotomy: a prospective randomized study. Urology
2011; 78: 535–9

8.  Osman et al. [6] suggested that PCNL punctures should be
carried out under US guidance; however, they completed
the rest of the procedure under fluoroscopic guidance.
 Some studies [7,8] have recommended the use of PCNL
guided solely by US for single stones in moderately to
markedly dilated PCSs by an experienced urologist
6. Osman M, Wendt-Nordahl G, Heger K, Michel MS, Alken P, Knoll T.
Percutaneous nephrolithotomy with ultrasonography- guided renal access:
experience from over 300 cases. BJU Int 2005; 96: 875–8
7. Hosseini M, Hassanpour A, Farzan R, Yousefi A, Afrasiabi MA.
Ultrasonography guided percutaneous nephrolithotomy. J Endourol 2009;
23: 603–7
8. Gamal WM, Hussein M, Aldahshoury M, Hammady A, Osman M, Moursy E,
Abuzeid A. Solo ultrasonography-guided percutanous nephrolithotomy for
single stone pelvis. J Endourol 2011; 25: 593–6

9.  Mayank et al. [9] suggested US as an adjunct to
fluoroscopy for renal access in PCNL; however, a
large series is still needed to prove the safety and
efficiency of PCNL guided solely by US in various
stone cases. In the present study, we reported our
experience and evaluated the feasibility and
efficacy of PCNL performed solely under US
guidance.
9. Agarwal M, Agrawal MS, Jaiswal A, Kumar D, Yadav H, Lavania P. Safety
and efficacy of ultrasonography as an adjunct to fluoroscopy for renal
access in percutaneous nephrolithotomy (PCNL). BJU Int 2011; 108:
1346–9

10. PATIENTS AND METHODS
 From May 2007 to July 2012, 705 24-F-tract PCNL
procedures were performed (679 patients, of whom
26 had bilateral stones).
 Calyceal puncture and dilatation were performed
under US guidance in all cases.
 The procedure was evaluated for access success,
length of postoperative hospital stay, complications
(modified Clavien system) [10], stone clearance
and the need for auxiliary treatments.
10. de la Rosette JJ, Opondo D, Daels FP et al. Categorisation of
complications and validation of the Clavien score for
percutaneous nephrolithotomy. Eur Urol 2012; 62: 246–55

11.  The inclusion criteria permitted the inclusion of
patients with single pelvic or calyceal stones >2.0
cm in diameter or with multiple or staghorn stones.
 Stones refractory to ESWL and proximal ureteric
stones >1.5 cm in diameter were also included.
 Patients were not excluded if they had a history of
open renal stone surgery or if they had impaired
renal function.
 Patients with an ectopic kidney or urosepsis were
excluded from the study.

12. Characteristic:
 Mean (SD) age 49 (7)
 Gender, n (%)
 M 409 (60.2)
 F 270 (39.8)
 Laterality, n (%)
 Left 365 (51.8)
 Right 314 (44.5)
 Bilateral 26 (3.7)
 Stone type, n (%)
 Pelvic or upper ureter 114 (16.2)
 Calyxeal 211 (29.9)
 Multiple or Staghorn 380 (53.9)
 Mean (SD) stone burden, mm2 453.86 (131.63)
 Grade of hydronephrosis, n (%)
 None 69 (9.8)
 Mild 191 (27.1)
 Moderate 267 (37.9)
 Severe 178 (25.2)
 Histories of open renal stone surgeries, n (%) 26 (3.7)
 Abnormality, n (%)
 Solitary kidney 8 (1.1)
 Horse shoe kidney 13 (1.8)
 Medullary sponge kidney 5 (0.7)
 Vertebral deformity 4 (0.6)
Demographic and clinical characteristics of the 679 patients in the study.

13. PATIENT ASSESSMENT
 Medical history
 Physical examination
 Urine analysis & urine culture
 Renal function test
 Coagulation test.
 All patients underwent unenhanced CT or
i.v.urography to clarify the size and location of the
calculi and the grade of hydronephrosis, before
undergoing surgery.

14.  During their hospital stay, all patients were
prescribed parenteral antibiotics, according to their
urine culture results, to minimize the incidence of
UTIs.
 Under general or epidural anaesthesia. Epidural
anaesthesia was usually preferred because
patients were able to cooperate with the surgical
team when the position was changed. General
anaesthesia was used only when epidural
anesthesia was not suitable for a patient.
 One surgical team performed all the operations.

15.  Initially, US was performed to detect the presence of organs in
the path of the puncture to avoid organ injury.
 For a single stone involved one calyx or staghorn stones
involved one calyx and the pelvic, the calyx harbouring the
stone was chosen.
 For a single pelvic stone, a posterior middle calyx puncture,
via the 12th subcostal space between the posterior axillary
line and scapula line, was preferred. This allowed access to
the renal pelvis and more convenient observation of the
collecting system.
 For staghorn stones, to use the one-tract approach, the
middle calyx was chosen in most of the cases, as this
provides more convenient access for a nephroscope to the
other calyces.
 To use a multiple-tract approach, the upper pole puncture was
usually preferred as the first puncture site.

16.  In the absence of hydronephrosis, saline was
infused through the ureteric catheter to ensure the
ballooning of the PCS. Mild hydronephrosis was
sufficient to access the targeted calyx.
 A colour-Doppler US system with a 3.5-MHz
transducer (Hitachi Aloka, Tokyo, Japan) was used
in this study.

17.  An 18-gauge co-axial needle was introduced into the most
convex point of the targeted calyx under US guidance, either
freehand or using a needle-guiding system fixed to the US
probe.
 A US-guided puncture through the cup of the desired calyx to
traverse a minimum of cortical tissue and establish the shortest
straight tract between the skin and calyx, avoiding visceral
injury.
18- gauge needle
Target calyx
(A)Percutaneous puncture of a selected calyx was performed under real-
time US guidance.
(B) An 18-gauge needle entering the target calyx is shown on US.
A B

18.  At the end of the procedure, the patient’s stone-free
status was double-checked using US and a flexible
nephroscope.
 For large staghorn stones occupying several
calyces, which were difficult to remove using a
single tract, a second or third tract was created
using the same technique to help remove the
stones.
 The operating time was defined as the time from
introduction of the 18-gauge co-axial needle into
the patient’s skin until the placement of the
nephrostomy tube.

19. POST-OPERATIVE PERIOD
 A blood count test was performed on the first
postoperative day to assess the change in the
patient’s haematocrit level.
 In addition, on this day, the Foley catheters were
removed if haematuria was not evident.
 The ureteric catheter was routinely replaced by a JJ
stent at the end of the primary operation, and this
stent was maintained in place for 3 weeks
postoperatively to facilitate the passage of residual
fragments and drainage of blood clots.

20.  Stone-free status was defined as the absence of visible
fragments on CT.
 Clinically insignificant residual fragments (CIRFs) were
defined as those that were <4 mm in diameter, non-
obstructive, and asymptomatic.
 CT was routinely performed for residual stones 48 h and
4 weeks after surgery; re-PCNL, ureteroscopy, and
ESWL were considered as auxiliary treatments, when
indicated.
 In patients who were considered stone-free or with
CIRFs, the nephrostomy tubes were removed 72 h after
operation; however, the nephrostomy tube was left in
place if a second PCNL session was planned owing to
the presence of residual stones.

21. RESULTS
 Access to the PCS was successful in all cases.
 The mean (SD) operating time was 66 (25) min, with
618 (91.0%) patients receiving epidural and 61 (9.0%)
receiving general anaesthesia.
 Of the total patient population, 626 (91.5%) patients
were treated in the prone supine and 53 (8.5%), in the
lateral flank position.
 Although most of the cases, e.g. 594 (84.3%) cases,
were managed successfully by a single tract, a second
tract was used in 85 (12.1%) cases, and 26 (3.7%)
patients required a third tract.

22.  The mean (SD) postoperative hospital stay was 3.98
(1.34) days, with the patients showing a mean (SD)
decline in haemoglobin levels of 2.24 (2.02) g/L.
 Complete clearance was confirmed by CT, conducted 48
h after surgery in 63.5% of the patients.
 The stone-free rate was 70.5% among patients with a
single calculus (229 of 325 cases) and 57.1% in cases
involving staghorn or multiple calculi (217 of 380 cases).
 CIRFs were confirmed by CT performed 48 h after
surgery in 77 (20.6%) cases involving a single calculus
(77 of 325 cases) and in 80 (21.1%) cases involving
staghorn or multiple calculi (80 of 380 cases).

23.  Auxiliary treatments, including ESWL in 52 patients,
re-PCNL in 41 patients and ureteroscopy in 18
patients, were performed 1 week after the primary
procedure in 111 (15.7%) cases for residual stones
>4 mm in size.
 The overall stone-free rate at 4 weeks after the
ancillary procedures was 87.4%, with stone-free
rates of 92.6% associated with cases of simple
stones and 82.9% for those involving complex
stones

24.  CT was used to confirm the initial stone-free status
determination made in 447 of 469 cases and
confirm the CIRF determination made in 147 of 165
cases; the initial determinations were made intra-
operatively by US and flexible nephroscopy.
 The sensitivities of intra-operative US-guidance and
flexible nephroscopy for detecting significant
residual stones and clinically insignificant residual
fragments were 95.3 and 89.1%, respectively.
 Some of the larger, US-detected, residual stones
were not extracted because of the increased risk of
haemorrhage.

25. Variable ( RESULT OF US-GUIDED PCNL)
Number of access attempts required, n (%)
1 594 (84.3)
2 85 (12.1)
≥3 26 (3.7)
Anaesthesia, n (%)
Epidural 618 (91.0)
General 61 (9.0)
Position, n (%)
Flank 53 (8.5)
Prone 626 (91.5)
Mean (SD) operating time, min 66 (25)
Mean (SD) decline in haemoglobin level, g/L 2.24 (2.02)
Mean (SD) postoperative hospital stay, days 3.98 (1.34)
Mean cost (operation, medicine and peri-operative examinations),$ 4611.15
Stone-free rate confirmed by CT 48 h after one stage operation,n/No. of cases (%) 447/705 (63.4)
Single 243/325 (74.8)
Multiple or Staghorn 204/380 (53.7)
CIRF after one stage operation, n/No. of cases (%) 147/705 (20.9)
Single 67/325 (20.6)
Multiple or Staghorn 80/380 (21.1)
Fragments >4 mm after one-stage operation, n/No. of cases (%) 111/705
Single 15/325 (4.6)
Multiple or Staghorn 96/380 (25.3)
Ancillary procedures for stone residues >4 mm after operation, n/No. of cases (%) 111/705 (15.7)
Second- or third-stage PCNL 41/111 (36.9)
ESWL 52/111 (46.8)
Ureterscopy 18/111 (16.2)
Overall stone-free rate at 4 weeks after operationconfirmed by CT, n/No. of cases (%) 616/705 (87.4)
Single 301/325 (92.6)
Multiple or Staghorn 315/380 (82.9)

26. Complication n (%)
Total no. of complications 113 (16.0)
Grade 1 94 (13.3)
Nephrostomy tube displacement 7 (1.0)
Transient fever <38 °C 87 (12.3)
Grade 2 17 (2.4)
Haemorrhage requiring transfusion (3-single & 9-multiple tract) 12 (1.7)
Non-septic infections requiring additional antibiotics(instead of prophylactics)
UTI 3 (0.4)
Pneumonia 2 (0.3)
Grade 3 2 (0.3)
Grade 3a: perirenal haematoma needing intervention 1(0.15)
Grade 3b: haemorrhage requiring embolism 1 (0.15)
Grade 4 0
Grade 5 0

27. DISCUSSION
 Percutaneous nephrolithotomy is the primary procedure
for the management of patients with renal stones who
are not candidates for ESWL.
 Fluoroscopic guidance has been used to guide the
percutaneous renal access, establish the working tract
and perform the stone manipulation.
 The use of US guidance has other advantages in
addition to being free of ionizing radiation; for example,
it results in fewer punctures, has shorter operating times
and avoids contrast-related complications [12].
12. Basiri A, Ziaee SA, Nasseh H et al. Totally ultrasonography guided
percutaneous nephrolithotomy in the flank position. J Endourol 2008;
22: 1453–7

28.  This form of guidance allows imaging of the intervening
structures with the benefit of minimizing the risk of injury
to nearby organs.
 Moreover, the use of US at the end of the procedure
helps the urologist to look for non-opaque and semi-
opaque residual stones that are not visualized by
radiography [13].
 The European Association of Urology recommends
initial puncture under US guidance because it reduces
radiation hazards [14].
13. Basiri A, Ziaee A, Kianian H, Mehrabi S, Karami H, Moghaddam S.
Ultrasonographic versus Fluoroscopic Access for Percutaneous
Nephrolithotomy: a Randomized Clinical Trial. J Endourol 2008; 22: 281-
4
14. European Association of Urology. Guidelines on urolithiasis. 2012
http://www.uroweb.org/gls/pdf/21_Urolithiasis_LR.pdf

29.  This technique was safe and reliable, and no faulty
dilatation was found in this study.
 During the study, there was just one case in which
the operator failed to establish the working channel
in the first attempt because of the accidental
dislodging of the guidewire; however, a second
attempt was made and the operation was
completed successfully without any complications.

30.  100% access to the kidney as well as 87.4% complete
stone clearance, were achieved. The stone-free rate in
this series was comparable with the rates gained from
PCNL results reported in other series under either US or
fluoroscopic guidance [15,16].
 Osman et al. [17] reported that the sensitivity of plain
abdominal film of kidney, ureter and bladder (KUB) for
detecting stone-free rates was 40.3% and that of US
was 37.1%.
15. Shoma AM, Eraky I, El-Kenawy M, El-Kappany HA. Percutaneous
nephrolithotomy in the supine position: technical aspects and
functional outcome compared with the prone technique. Urology 2002;
60: 388–92
16. Basiri A, Mohammadi Sichani M, Hosseini SR et al. X-ray-free
percutaneous nephrolithotomy in supine position with ultrasound
guidance.World J Urol 2010; 28: 239–44
17. Osman Y, El-Tabey N, Refai H et al. Detection of residual stones
after percutaneous nephrolithotomy: role of non-enhanced spiral
computerized tomography. J Urol 2008; 179: 198–200

31.  The sensitivities of KUB and US for detecting significant
residual stones were reported to be 58.3 and 41.6%,
respectively; for detecting CIRFs, the reported
sensitivities were 15.3 and 30.7%, respectively;
however, Alan et al. [18] reported that the sensitivities of
US for detecting significant residual stones and CIRFs
were 83.3 and 87.5%, respectively, based on KUB
detection.
 In their study, the stone-free status was double-checked
during the operation using a flexible nephroscope and
US, but CT was also routinely performed to confirm the
residual stone status on the second postoperative day.
18. Alan C, Kocoğlu H, Ates F, Ersay AR. Ultrasound-guided X-ray free
percutaneous nephrolithotomy for treatment of simple stones in the
flank position. Urol Res 2011; 39: 205–12

32.  Percutaneous nephrolithotomy is usually performed with the
patient in a prone position, but this prone position has several
disadvantages. For example, PCNL with the patient in this
position is difficult when the patient is obese or has spinal
anomalies or cardiovascular disease [19].
 Karami et al. [20] reported performing PCNL under US guidance
in 40 patients in the lateral position with an access rate of 100%
and a complete stone-removal rate of 85%.
 In the present study, PCNL was performed in the lateral position
for the 53 patients who had insufficient cardiac output or
pulmonary disease and US guidance was proven to be a safe
and convenient procedure in both positions.
19. Manohar T, Jain P, Desai M. Supine percutaneous nephrolithotomy: effective approach
to high-risk and morbidly obese patients. J Endourol 2007; 21: 44–9
20. Karami H, Arbab AH, Rezaei A, Mohammadhoseini M, Rezaei I. Percutaneous
nephrolithotomy with ultrasonography-guided renal access in the lateral decubitus
flank position. J Endourol 2009; 23: 33–5

33. CONCLUSION
 Total US-guided PCNL is safe and convenient, and
may be performed without any major complications
and with the advantage of preventing radiation
hazards and damage to adjacent organs.

34. CONFLICT OF INTEREST
 None declared.

35. CRITICAL ANALYSIS
PROS
 Good number
 Performed by single surgical unit at one health centre
 No mortality with optimum complications (16%)
CONS
 Cross sectional study
 No comaparision with standard fluroscopy guided
puncture
 16% required auxillary procecures
 Usage of DJ stents in all cases requiring intervention to
remove them.