230 320
3.5.
Case series
Ten case series were included, five of which were full-text
articles
[8,18,20,23,25]and five congress abstracts
[29– 33]. The smallest tract size studied was 4.8 Fr (
m
PNL) in a
case series of 68 patients (70 renal units)
[31]. SFR was high
(98.5%), while blood loss, complication rates, procedure
duration, and hospital stay were low (
Table 2 ). Three
studies
[8,20,30]involved case series in which patients
(
n
= 74, 62, and 26, respectively) were treated using tract
sizes of 11–13 Fr. SFRs were high (92.4%, 86.7%, and 97.2%,
respectively), while blood loss, complication rates, proce-
dure duration, and hospital stay were low
( Table 2 ).
Conversion to mPNL occurred in approximately 3% of the
procedures. One study of 72 patients treated with 14 Fr
mPNL
[25]had SFR of 87.5% and an extended hospital stay
of 7.7 3.2 d (range 4–22). Two studies reported on a tract
size of 18 Fr. Lu et al
[23]compared procedures with and
without placement of a final nephrostomy tube (both
n
= 16)
[23] ,and Abdelhafez et al
[18]compared stones measuring in
<
20 mm (
n
= 98) to stones measuring 20 mm (
n
= 93) in
maximal diameter. Lu et al
[23]found that ISFRs were
comparable, but that tubeless procedures were associated
with fewer patients reporting back pain (p = 0.003) and
shorter hospital stay (3 vs 4 d;
p
= 0.032;
Table 2). Abdelhafez
et al
[18]found that the ISFR was higher for patients with
smaller stones (90.8% vs 76.7%;
p
= 0.007), while the SFRs at
1 mo after auxiliary procedures were comparable (98.9% vs
94.6%;
p
= 0.1). Complication rates were comparable (
p
= 0.2),
while blood loss was lower (
p
= 0.015) and the procedure
duration (
p
<
0.001) and hospital stay were shorter
(
p
= 0.002) in patients with smaller stones. One abstract
reported on 301 procedures utilizing tracts sized 20 Fr (the
smallest tract size usedwas not stated)
[29] .The SFRwas high
at 99%, while blood loss, analgesic requirements, and
complication rates were low, and procedure duration and
hospital stay short. Two abstracts reporting on mPNL did not
explicitly state the size of the sheaths used
[32,33] ,so this
information was obtained via e-mail correspondence with
the authors: Miller et al
[32]used 16.5 Fr and Zimmermanns
et al
[33]used 18 Fr. Using data from the CROES PNL Global
Study, Miller et al
[32]reported a comparatively low ISFR
(46.5%) with a fair rate for immediate clinically insignificant
residual fragments (79.4%). Complication rates were com-
paratively high (eg, urosepsis in 12.9% of patients) and the
procedure duration was 174 min (
Table 2 ). Zimmermanns
et al
[33]presented results for two groups: the complete
cohort of 652 patients (all stone sizes) and a subgroup of
183 patients with stones measuring 500 mm
2
in area. No
p
values were reported, although the ISFR was comparable in
both groups (93.6% vs 91.8%).
3.6.
RoB and confounding assessment
Figure 2summarizes the key RoB and confounding
assessments. Only two studies were RCTs; the remaining
16 were either NRCSs or case series resulting in high RoB
associated with no randomization, incomplete outcome
data (attrition bias), and selective outcome data reporting.
Table 2 (
Continued
)
Study ID, design,
country, recruitment period
Subgroups
(of mPNL group)
Intervention
Comparator
Outcomes
measured
n
at baseline
Outcomes
Reported
p
v
alues
Notes
Summary
Int Com
Int
Com
Lu 2012, case series,
China, 2009–2010
[23]
NA
mPNL 18 Fr
(with 16 Fr
nephrostomy tube)
NA
Benefits: ISFR
Harms: CG, BL
Secondary outcomes:
DHS, DP, pain
16 NA Tubed mPNL
ISFR: 13 (81.3%)
CG: 1: 2 (12.5%)
BL: 2.14 0.51
TL mPNL
ISFR: 14 (87.5%)
CG: 1: 3 (18.8%)
BL: 1.91 0.62
[2_TD$DIFF]
1
1
0.26
0.43
0.003
0.032
TL mPNL has the advantages
of shorter hospital stay and
less back pain compared to
tubed mPNL
Tubeless mPNL 18 Fr
16
[6_TD$DIFF]
DP: 65.19 21.5
Pain: 14 (87.5%)
DHS: 4 (3–12) d
Other: urinary extravasation: 0
DP: 59.69 17.95
Pain: 5 (31.3%)
DHS: 3 (2–7) d
Other: urinary extravasation: 1
Sung 2006, case series,
Korea, 1999–2002
[25]
NA
mPNL 14 Fr
NA
Benefits: ISFR, SFR
Harms: fever, BL
Secondary outcomes:
SP, DHS
72 NA ISFR: 58/72 (80.6%)
SFR: 63/72 (87.5%)
CG 1 [fever]: 7 (9.7%), CG 3 [embolized
hemorrhage]: 1 (1.4%)
BL: 1/72 (1.4%)
SP: 11/72 (15.3%)
DHS: 7.68 3.21 [4–22] d
NA
NR
FU: 7 mo
High ISFR influenced by stone
diameter and burden. Low
complication rate and short
hospital stay
AP = adjunctive procedure; AR = analgesic requirement; BL = blood loss; BT = blood transfusion; CG = Clavien grade; CIRFR = clinically insignificant residual fragment rate; CROES = Clinical Research Office of the
Endourological Society; DB = database; DHS = duration of hospital stay; DP = duration of procedure; EDV = emergency department visit; FU = follow-up (here meaning time point for delayed assessment of stone status, if
applicable); HR = hospital readmission; IPP = intrarenal pelvic pressure; ISFR = immediate SFR; ICIRFR = immediate CIRFR; LC = lower calyces; MC = middle calyces; mPNL = mini-PNL; NR = not reported; P = pelvis;
PNL = percutaneous nephrolithectomy; QOL = quality of life; RCT = randomized controlled trial; SFR = stone-free rate; SP = secondary procedure; sPNL = standard PNL; TL = tubeless; TRNA = time to return to normal
activities; UC = upper calyces; umPNL = ultra-mini-PNL; UPJ = ureteropelvic junction; US = urosepsis; VI = visceral injury.
E U R O P E A N U R O L O G Y 7 2 ( 2 0 1 7 ) 2 2 0 – 2 3 5
230