Stesura Seveso


195Archivio Italiano di Urologia e Andrologia 2022; 94, 2

ORIGINAL PAPER

No conflict of interest declared.

SA also has advantages: it avoids some GA related com-
plications, allows an early mobilization, and is cost effec-
tive. Few studies compared different anesthesia modality
during RIRS for renal stones and the only randomized
controlled trial (9) compared RIRS performed under
combined spinal-epidural anesthesia with GA (10).
The aim of this study was to compare surgical results,
intraoperative and postoperative complications, and anal-
gesia demand of RIRS performed under SA versus GA.

MATERIALS AND METHODS
The data of the patient who underwent RIRS due to kid-
ney stones between January 2013 and January 2022 were
reviewed retrospectively.
Those with missing data, bilateral RIRS, additional proce-
dure with RIRS (percutaneous nephrolithotomy, rigid
ureterorenoscopy, etc.), urinary system anomaly (double
collecting system, horseshoe kidney, pelvic kidney, uri-
nary diversion, etc.), previous stone surgery, extracorpo-
real shock wave lithotripsy (ESWL) history, patients with
nephrostomy or double J stent were excluded from the
study.
A total of 502 patients were evaluated after exclusion cri-
teria. The ethics committee of the study was obtained
from the local Tepecik training and research hospital
local ethics committee. Informed consent was obtained
from all patients.
Stones and urinary systems of all patients were evaluated
with computed tomography (CT) in the preoperative low-
dose stone protocol, urinalysis and urine culture, and
biochemistry including urea, creatinine, and hemogram.
All patients underwent the procedure with a clean urine
culture or under antibiotic. All patients received pre-
operative antibiotic prophylaxis. Stone protocol CT was
performed for stone-free rate assessment at 4 week post
operative in all patients, and patients with residual stone
less than 4 mm were considered as stone-free.
We divided the patients in 2 groups, according to the
anesthesia regimen chosen by the anesthesiologist: SA
and GA.
Patients in both groups were compared in terms of demo-
graphic data such as age and gender, stone size, stone side,
stone localization, number of stones, and stone density as
Hounsfield Unit. The complications that developed within
both groups were grouped according to the modified
Clavien-Dindo classification and compared one by one.

Aim: The indications for retrograde intra-
renal surgery (RIRS) have greatly increased,

however, there is still no consensus on the use of spinal anesthe-
sia (SA) during this procedure. The aim of this study was to
evaluate the comparability of surgical outcomes of RIRS per-
formed under SA versus general GA for renal stones.
Materials and methods: This was a retrospective, observational
study in patients scheduled for RIRS in a single teaching hospital
in Turkey. Inclusion criteria were age > 18 years and the pres-
ence of single or multiple renal stones. We recorded information
concerning the site of lithiasis, the number of calculi, total stone
burden, and the presence of concomitant ureteral stones or
hydronephrosis. Results were evaluated in terms of surgical out-
come, intraoperative and postoperative complications. Patients
were followed-up until day 90 from discharge.
Results: The data of 502 patients, 252 in GA group and 250 in
SA group, were evaluated. The stone-free rate was 81% in the
GA group and 85% in the SA group (p = 0.12). No cases of con-
version from SA to GA were recorded. Complication rates were
similar in the 2 groups (19% vs 14.5%, p = 0.15).
Conclusions: In our cohort, RIRS performed under SA and GA
was equivalent in terms of surgical results and complications.

KEY WORDS: Spinal Anesthesia; Retrograde intra-renal surgery;
Urolithiasis.

Submitted 21 April 2022; Accepted 20 May 2022 

INTRODUCTION
With the evolution of instruments and techniques, retro-
grade intrarenal surgery (RIRS) gained an established role as
a minimally invasive procedure with fast recovery, short
hospitalization, and low rates of complications (1-3). 
However, high-grade complications are still possible (4-5),
and linked to the use of general anesthesia (GA). 
In this scenario, the use of spinal anesthesia (SA) could
move toward the reduction of invasiveness, costs, and
hospitalization (6-7).
Endoscopic procedure of renal stones has increased in the
last decade in accordance with minimally invasive princi-
ples. Ureteral stone treatment has been described and
widely accepted under SA (8-9), however, GA is usually
offered during RIRS because it has some advantages: in
case of a large stone burden the lithotripsy is easier with
reduced renal movement caused by respiration, the com-
fort for the patient is expected to be better, and there is
no risk for the anesthesia duration to be exceeded. 

Spinal versus general anesthesia 
in retrograde intrarenal surgery

Mehmet Yoldas 1, Tuba Kuvvet Yoldas 2

1 Tepecik Training and Research Hospital Urology Clinic, Izmir, Turkey;
2 Ege University Faculty of Medicine Anesthesiology and Reanimation Department, Izmir, Turkey.

DOI: 10.4081/aiua.2022.2.195

Summary



Archivio Italiano di Urologia e Andrologia 2022; 94, 2

M. Yoldas, T. Kuvvet Yoldas

196

RIRS procedure
Under spinal or general anesthesia, ureter and renal pelvis
were evaluated under direct vision with a 7 F semi rigid
ureteroscope. The distance between the ureteropelvic
junction and the external meatus was marked on the rigid
scope and a 0.038 inch guide wire was placed in the col-
lecting system, 9.5 F ureteral access sheet was placed in
the collecting system on the guide as long as the measured
distance. After the guide was taken out, a 7-8 F flexible
scope was entered. The stone was broken with a 272 or
360 micron laser probe. At the end of the procedure, the
ureter was evaluated with a semi-rigid scope. When nec-
essary, a double J stent stent was placed in the ureter.

Anesthesia
In all patients, a peripheral vein was cannulated and a sin-
gle dose of antibiotic prophylaxis was administered and
normothermia maintained with warm air devices.
Perioperative heart rate, peripheral oxygen saturation,
and blood pressure values were monitored until transfer
to the urological ward, when the Aldrete score was ≥ 8. 
In the SA group, anesthesia was administered using a 25
gauge atraumatic Sprotte type needle with 10-20 mg
hyperbaric 1% or 0.05% bupivacaine at L2-3 level to pro-
vide a sensitive block up to T8-10. We administered an
intranasal oxygen supply only if SpO2 was below 92%.
Additional sedation was based on 2 mg midazolam bolus-
es or low-dose propofol infusion according to the
Schneider model effect-site target-controlled infusion 1
mg/mL, plus additional low-dose remifentanil (Minto
model effectsite target-controlled infusion 0.5-2 ng/mL) if
analgesia was inadequate. Target controlled infusion was
titrated based on the clinical response in the SA group. 
In the GA group, anesthesia was induced with propofol 2
mg/kg and fentanyl 1 mg/kg and maintained with either
propofol Schneider model effect-site target-controlled
infusion, sevoflurane or desflurane plus remifentanil with
the Minto model effect-site target-controlled infusion
according to the anesthesiologist’s choice. 
In all cases in the GA group, anesthesia depth was moni-
tored with the entropy index, targeting values between 40
and 60. After induction, a laryngeal mask was placed
avoiding the use of neuromuscular blockade when clinical-
ly feasible. We administered ranitidine plus ondansetron
intraoperatively as prevention of postoperative nausea and
vomiting. An opioid-free postoperative analgesia regimen
was preferred, based on acetaminophen 1000 mg plus
ketorolac 30 mg. Rescue doses were administered if the
pain numeric rating scale was above 4.

Statistical analysis
Continuous variables are reported as a mean ± SD and
compared with the Student’s t-test. Categorical variables
are presented as the absolute frequency (percentage) and
compared with the chisquare or Fisher’s test, as appro-
priate. All the statistical analyses were performed using
SPSS v.23 (IBM Corp., Armonk, NY), and significance con-
sidered for two-tailed p < 0.05.

RESULTS
The data of 502 patients, 252 in GA group and 250 in SA
group, were evaluated retrospectively.

The mean age of GA group was 47.31(16-83) years and
the mean age of SA group was 46.16 (20-75) years; GA
group included 156 (62%) men and 96 (38%) women,
SA group 176 (71%) males and 74 (29%) females.
The mean stone size was 13.57(+-2,6) mm2 in GA group
and 12.43(+-2,8) mm2 in SA group. There was no statis-
tically significant difference between the two groups for
stone size (p = 0.21).
In GA group, 124 patients had a stone in the right side
and 128 in the left side, in SA group 128 patients had a
stone in the right side and 122 patients in the left side
(p = 0.25).
In GA group the stone was in the lower calyx, which was
the most difficult to reach, in 71 (28.4%) patients, where-
as in SA it was in the lower calyx in 71 (28.7%) patients
(p = 0.13).
The demographic and stone data of the patients are shown
in Table 1 and intraoperative and post-operative data of
the patients in Table 2.
The operation time of the patients in GA group was 57.65
(+-11.56) min, in SA group 54.3 (+-12.1) min. The dura-
tion of scopy in the GA group was 24.29 (+-2.3) sec, in
the SA group. 26.32 (+-3.2) sec. Operation time and
duration of scopy was equal between the two groups (p =
0.29 and p = 0.35, respectively).
Mean hospital stay was 1.06 (+-0.25) days in GA group,
and 1.37 (+-0.22) days in SA group. Although in SA
group hospital stay was longer, there was no statistically
significant difference between groups (p = 0.12).
Complications developed in 48 (19%) patients in the GA
group and in 36 (14.5%) patients in SA group. No differ-
ence was observed for grade 1 (p = 0.18) and grade 2 (p =
0.11) complication rate between the two groups.
None of our patients needed blood transfusion. 
Due to stenosis in the distal ureter in 3 of our patients in
GA group, access to the renal pelvis was achieved by
using baloon dilatation. 
High post-operative fever was detected in 20 patients of
GA group: two of them received parenteral antibiotic in
hospital, 2 of them were treated with oral antibiotic as
outpatients, 16 patients were treated with antipiretic as
outpatients; 16 patients in SA group developed fever and
were treated with antipiretic as outpatients; 5 were treat-
ed with oral antibiotic as outpatients.

Table 1. 
The demographic and stone data of the patients.

GA group (252) SA group (250) P-value

Age 47.31+-3.5 46.16+-3.8 0.39

Stono size cm2 13.57(+-2.6)  12.43(+-2.8)  0.25

Gender F 96(38%) 74 (29%)  0.22
M 156 (62%) 176 (71%)

Laterality Right 124 128 0.52
Left 128 122

Localization 0.19
Lower calix 71 (28.4%) 71 (28.3%) 0.16
Middle calix 11    (4.4%) 21  (8.3%) 0.08
Upper calix 9   (3.7%) 5   (2%) 0.08

Pelvis 118  (46.4%) 117 (46.2%) 0.15
More than one calix 43    (16.9%) 36   (14.5%) 0.15



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Spinal versus general anesthesia in retrograde intrarenal surgery

Subcapsular hematoma and then urinoma developed in
GA group in 2 patients who were treated with double J
stent and percutaneous drainage.
Low-grade ureteral injury occurred in 8 patients in GA
group and 1 patient in SA group, and they were followed
up with double J stent. No avulsion occurred in any of
our patients.
Nephrostomy or double J stents were placed in 8 patients
in GA group and 1 patient in SA group due to renal colic
and hydronephrosis. Stents were removed 2 weeks later
due to regression of hydronephrosis and colic.
Re-URS was performed in 8 of our patients in GA group
because of the steinstrasse; this complication was not
observed in any of our patients in SA group.
In GA group, the laser probe tip or the hydrophilic tip of
the Sensor guide remained in the renal pelvis in 3 patients
as a result of a fracture of the device.
Six patients in GA group and one patient in SA group were
followed up in the post-operative intensive care unit.
In GA group, one patient died due to post-operative
multi-organ failure and sepsis.

DISCUSSION
The first treatment choice for intrarenal stones < 2 cm in
size and hard stones is RIRS (11). 
In this study, we report similar SFR, intraoperative and
postoperative outcomes and complications in patients
treated with RIRS under GA versus SA. Our results concord
with the previous published studies and added value to the
use of SA for RIRS, particularly when a fast recovery and a
short hospitalization are intended to be achieved. Kidney
stone surgeries are developing towards to non-invasive
methods. Endoscope miniaturization, improved deflection
mechanism, improved optical quality, and advancement in

laser technology have led to the increased use of URS for
kidney and ureteral stones (12). 
The 2022 EAU Urolithiasis Guidelines states that for retro-
grade stone removal both local and SA is feasible, howev-
er, the majority of patient still undergo GA (13). SA
reduces anesthesiologic costs and hospital stay when com-
pared with GA. Generally, the anesthesiologist for rapid
endoscopic procedures proposes SA because it has lower
risks of anaphylaxis, vascular, pulmonary, and neurologi-
cal complications and compared with GA it does not pres-
ent the risk of intubation-related problems (14).
The overall complication rate was found to be 3.5% in a
series of 11.885 prospectively studied RIRS published by
CROES. According to the modified Clavien classification,
2.8% of these complications are grade 1 and 2 (15). 
In our study, general complications were 48 (19%) in GA
group, 36 (14.5%) in SA group; grade 1-2 complications
20 (7.9%) in GA group and 20 (8%) in SA group. 
This may have been caused by the high density of diffi-
cult cases (lower pole, more than 1 stone and large stone
size) because we are a third-level hospital.
For grade 1-2 complications, no significant difference was
found between the two groups.
Urinoma and hematoma have been reported in the litera-
ture to be more likely in patients over 70 years of age,
using anticoagulants and having chronic kidney disease;
the probability of this complication is less than 1%. 
In our study, 2 (0.4%) patients in GA group had supcap-
sular hematoma cured with nephrostomy and double J
stent insertion. Bleeding is seen at a rate of 0.3-2.1% after
URS, due to the introduction of the scope, stone breakage
procedure or damage caused by the guide wire in the
calyceal structures. Bleeding often stops spontaneously,
but the hematoma caused by it may cause colic pain and
hydronephrosis in the postoperative period. Six patients
in GA group, and one patient in SA group had nephros-
tomy due to clot hydronephrosis and renal colic. Two
patients in GA group had double J stent for the same rea-
sons and the catheters were removed 2 weeks later in
their follow-up.
Stone tract (Clavien 3b), which is an important complica-
tion, was seen in 9 (0.6%) patients in a study conducted
with 1571 patients (16). This complication is the only that
was found associated to stone size. In fact, SFR after RIRS
was found significantly correlated with the stone size (17). 
In our study, Steinstrasse was observed in 8 (1.7%)
patients in GA group who had stones larger than 3 cm
according with the literature. The fragments were endo-
scopically extracted and the stones cured. This complica-
tion was not observed in any patient in SA group.
Loss of the integrity of the stents is also an important
problem. Zisman et al. (18) evaluated ureteral stents with
spontaneous multiple fragmentations observing that the
fracture resistance was decreased dramatically. Fractured
stents were removed after 4 weeks. Due to cost problems,
some materials were used longer than the recommended
time. We may have encountered this complication due to
the high stone load in our cases and the long duration of
the cases.
In the prospective study of CROES, it was reported death
in 5 cases due to sepsis, pulmonary embolism, multiple
organ dysfunction, and cardiac causes (15). 

Table 2. 
Intraoperative and post-operative data of the patients.

GA group SA group P-value

Operation time (min) 57.65 54.3 0.29
(+/-11.56) (+/-12.1)

Scopy time (sc) 24.29 26.32 0.35
(+/-2.3) (+/-3.2)

Postoperative hospitalization (days) 1.06 1.37 0.12
(+-0.25) (+/- 0.22)

Complications 48 (19%) 36 (14.5%) 0.15
Degree 1 Use of antiemetics, antipyretics,

analgesics etc. 16 (6.2%) 11 (4.4%) 0.18
Degree 1 Headache (cerebrospinal fluid leak

after spinal anesthesia) 4 (1.6%)
Degree 2 Fever requiring antibiotics 4 (1.7%) 5 (2%) 0.11
Degree 3a Hematoma, urinoma 1 (0.4%) 1 (0.4%) 0.25
Degree 3a Low grade ureteral injury 4 (1.7%) 5 (2%) 0.09
Degree 3a Nephrostomy insertion 3 (1.3%) 5 (2%) 0.08
Degree 3a Installing post op djs 2 (0.1%) 0 1.00
Degree 3b Urs again (due to ureteral stone) 8 (1.7%) 0 1.00
Degree 3b Foreign body in the ureter (djs guide

wire basket ureteral sheed etc.) 3 (1.3%) 0 1.00
Degree 4 Intensive care follow-up due to sepsis 6 (1.2%) 5 (2%) 0.19
Degree 5 Ex 1 (0.2%) 0 1.00

Stone free rate (SFR) 202 (81%) 214 (85%) 0.12



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M. Yoldas, T. Kuvvet Yoldas

198

In our series, 6 patients were followed up with post-oper-
ative sepsis: 2 with hydronephrosis due to ureteral stone,
1 with hemorrhage and clot-related hydronephrosis with-
out stones, and 3 patients with sepsis without any stone
or hydronephrosis. All the patients had pre-operative
hydronephrosis. These results are comparable to most
previous report of the literature.
One of our patients died due to post-operative sepsis and
multiorgan failure in GA group. This 76-year-old patient
had a stone size of 0.9 cm2 and 2 stones in the lower calyx
and pelvis. The urine culture was clean preoperatively
but preoperative hydronephrosis was present. The stone
size was small but the stone was difficult to reach and the
operation time was long (108 min). Furthermore, ureter-
al access sheath (UAS) could not be used due to ureteral
stenosis. In the literature, it is emphasized that sepsis is
generally related with high intrapelvic pressure (15, 17).
Consequently, UAS should be used during RIRS and high
pressure should be avoided.
In the literature the success rate of RIRS is reported to be
between 73.6% and 94.1%. 
In the study of 207 patients conducted by Reşorlu et al.
(19) in 2012, it was described a new scoring system
(Reşorlu-Ünsal Taş score) that can help us predict postop-
erative stone-free rates (18). 
In the study, the factors affecting success were examined
and parameters such as age, gender, body mass index, stone
size, stone side, location, composition, number of stones,
lower pole infundibulopelvic angle, use of anticoagulant
therapy, skeletal and renal anomalies were evaluated. 
They reported that stone size, number, location, compo-
sition, renal malformations, and lower pole infundibu-
lopelvic angle significantly affected success. In our cases,
the success rate of 81% in GA group and 85% in SA
group were lower than in the literature, because of high
frequency of lower pole stones and multiple stones. 
According to the literature, in our study we did not find
any statistically significant differences in terms of intra-
operative and postoperative complications, analgesia
demand, and SFR in patients with single or multiple renal
stones with a stone burden up to 30 mm treated with
flexible ureteroscopy in GA versus SA (SFR rate p = 0.12).

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Correspondence
Mehmet Yoldas, MD (Corresponding Author)
yoldas_2297@hotmail.com
Tepecik Training and Research Hospital Urology Clinic, Izmir (Turkey)

Tuba Kuvvet Yoldas, MD
drtuba2004@hotmail.com
Ege University Faculty of Medicine, Anesthesiology and Reanimation
Department, Izmir (Turkey)