Stesura Seveso


399Archivio Italiano di Urologia e Andrologia 2021; 93, 4

ORIGINAL PAPER

No conflict of interest declared.

techniques were reported to improve continence (4-6).
Recently, a new method is the Retzius-sparing (Rs) RARP
applied with the posterior approach, defined by Galfano
et al. (7). The basic principle of this approach is to pre-
vent interference with anatomical structures that provide
continence in the anterior region. In this context, many
surgeons may consider revising their method. 
Additionally, it is controversial for a surgeon who has
completed the learning curve with the standard approach
to change their technique using the Rs-RARP approach
with regard to functional and oncological results. 
In this study aimed to appraise the functional and onco-
logical outcomes during the Rs-RARP learning curve for a
surgeon with previous experience of the S-RARP proce-
dure.

MATERIALS AND METHODS

Patient selection and study design
After the local institutional review board approval, the  Rs-
RARP and S-RARP surgeries applied by a single surgeon
with experience in robotic surgery between 01.01.2017
and 01.01.2019 were retrospectively evaluated from a
prospectively-collected database. The first 50 cases dur-
ing the Rs-RARP learning curve and 50 cases after the sec-
ond 100 cases with the standard approach were enrolled
in the study. Surgeon participated in live surgeries before
performing Rs-RARP. In addition, in the first 10 cases,
patients with low-to-moderate volume prostates (≤ 60cc)
without a median lobe were preferred. Patients with pre-
vious prostate and abdominal surgery, incontinence, and
presence of lymph node metastasis were excluded from
the study. Fifty patients who met the inclusion criteria
and underwent Rs-RARP were considered group 1, and
50 patients who underwent S-RARP were group 2.

Evaluated variables
Preoperative evaluation included age, Charlson Comorbidity
Index score (CCI), prostate-specific antigen (PSA), International
Index of Erectile Function-5 (IIEF-5) score, Gleason score at
biopsy, clinical T stage, prostate volume, and D’Amico risk
group. Furthermore, perioperative variables and pathologi-

Objective: To appraise the outcomes on the
Retzius-sparing robot-assisted radical prosta-

tectomy (Rs-RARP) learning curve of a surgeon with previous
experience of anterior (standard) RARP.
Materials and methods: The first 50 cases during the Rs-RARP
learning curve (group 1) and 50 cases after the second 100
cases with the standard approach (group 2) were comprised in
the study. Patients who used zero or one safety pads were con-
sidered continent. Erectile function recuperation was character-
ized as the competence to achieve penetrative intercourse with-
out receiving any medication. All patients were reevaluated at
two weeks, first, third, sixth, and 12th months after surgery
using IIEF-5, PSA level, and continence status.
Results: Immediate continence rates following catheter removal
were 32/50 (64%) in Rs-RARP group and 26/50 (52%) in 
S-RARP group (p = 0.224). The continence recovery rate was
48/50 (96%) in Rs-RARP group and 46/50 (92%) in the S-RARP
group at 12 months follow-up (p = 0.400). Total nerve-sparing
surgery was enforced in 36/50 (72%) patients for group 1 and
35/50 (70%) patients for group 2. Potency recovery was 27/43
(62.8%) in Rs-RARP and 30/44 (68.2%) for S-RARP at 12
months follow up (p = 0.597). Surgical margin positivity was
detected in 6/50 (12%) cases in the Rs-RARP group and in 4/50
(8%) cases in the S-RARP (p = 0.444).
Conclusions: Functional and oncological results are not nega-
tively affected in the first 50 cases for a surgeon who is experi-
enced in S-RARP before transition to the Rs-RARP method. 

KEY WORDS: Learning curve; Radical prostatectomy; Retzius-
sparing;  Robotic surgery; Trifecta.

Submitted 28 August 2021; Accepted 19 September 2021   

INTRODUCTION
Prostate cancer is the most frequently diagnosed type of
cancer among men and is the second most common cause
of cancer-related death in men (1). Radical prostatectomy
is the most commonly offered treatment modality in eli-
gible patient groups (2). Robot-assisted radical prostatecto-
my (RARP) has become popular in the last two decades.
The method most widely adopted by urologists is stan-
dard-RARP with an anterior approach (3). 
The main issue after RARP is preserving continence and
erectile function, in addition to oncologic safety. Many

Does transition from standard to Retzius-sparing
technique in robot-assisted radical prostatectomy 
affect the functional and oncological outcomes?

Hakan Anıl 1, Kaan Karamık 2, Ali Yıldız 3, Murat Savaş 4

1 Department of Urology, Adana Seyhan State Hospital, Adana, Turkey;
2 Department of Urology, Antalya Korkuteli State Hospital, Antalya, Turkey;
3 Department of Urology, Okan University Hospital, Faculty of Medicine, Istanbul, Turkey;
4 Department of Urology, Antalya Memorial Hospital, Antalya, Turkey.

DOI: 10.4081/aiua.2021.4.399

Summary



Archivio Italiano di Urologia e Andrologia 2021; 93, 4

H. Anıl, K. Karamık, A. Yıldız, M. Savaş

400

cal features were noted: operative time, anastomosis dura-
tion, nerve-sparing status, intraoperative complications,
estimated blood loss, presence of lymph node dissection,
length of hospital stay, Foley catheter removal time, lymph
node positiveness, surgical margin status, and pathological
stage. Patients were followed for at 12 months for conti-
nence and potency recovery. 
Immediate continence evaluation was performed within 1
week after catheter removal. Patients who used zero or one
safety pads were considered continent. Erectile function
recovery was evaluated in the first month, initially. Erectile
function recuperation was characterized as the competence
to achieve penetrative intercourse without the use of any
medication. All patients were reevaluated at two weeks,
first, third, sixth, and 12th month after surgery using IIEF-
5, PSA level, and continence status.

Surgical technique
All robot-assisted radical prostatectomies were imple-
mented by a single surgeon (M.S) who routinely performed
over 100 RARPs per year. Our surgical principles were
close to that defined by Galfano et al. (7). After the place-
ment of 4 robot trocars and 1 assistant trocar, a 4 arms Da
Vinci robot system (Intuitive surgical, LA, USA) was
docked. The parietal peritoneum was incised horizontally
at the anterior layer of the Douglas pouch. Seminal vesicle
pedicles were identified and ligated by using Hem-o-Lok
clips. Also, vas deferens were identified and incised. 
The avascular zone was found by entering among the
Denonvillier’s fascia and the posterior prostatic fascia. 
The intrafascial plan was maintained and the prostate apex
was reached with dissection. The bladder neck was iden-
tified and incised. At this step, we don't use cardinal
stitches to identify the bladder neck, unlike Galfano and
colleagues (7). The anterior surface of the prostate was sep-
arated from the Santorini plexus. Apex separation was
achieved and the urethra identified and cutted. 
The prostate was placed in the endobag. The urethra-
bladder anastomosis was performed continuously with
3.0 v-lock sutures from the 12-o’clock position.

Statistical analysis
Variables were presented as mean±standard deviation,
median and interquartile range (25th-75th, IQR), frequency,
and percentage. Evaluation of categorical data was done
with the chi-square or Fisher’s exact test. The conformity of
the data to the normal distribution was checked with the
Shapiro-wilk test. Student’s t-test or Mann-Whitney U test
was used for continuous variables according to the distri-
bution. The Kaplan Meier analysis was applied to deter-
mine erectile and continence recovery. A two-way repeat-
ed-measures ANOVA was used to compare preoperative
and postoperative IIEF scores between surgical approaches.
Statistical analysis was conducted with IBM SPSS Statistics
for Windows, version 22.0 (IBM Corp., Armonk, NY). 
A p-value < 0.05 was considered as statistically significant.

RESULTS
Group 1 and group 2 comprised 50 patients with a medi-
an age of 63.5 (IQR 58-68.5) years, and 50 patients with
a median age of 66 (IQR, 62-68.5) years, respectively.

There were statistically insignificant differences among
the groups regarding preoperative demographics and
clinical characteristics (Table 1). The median operative
time was 162.5 (IQR 137.5-210) mins and 150 (IQR
125-220) mins for groups 1 and 2, respectively (p =
0.865). Bilateral nerve-sparing surgery was performed in
36/50 (72%) and 35/50 (70%) patients for group 1 and
group 2, respectively. Intraoperatively, one patient had

Table 1. 
Demoghraphics and preoperative features.

Variable Rs-RARP S-RARP P value

Median (IQR) age, years 63.5 (58-68.5) 66 (62-68.5) 0.151 ͳ

Median (IQR) CCI score 2 (1-3) 2 (1-3) 0.531 ͳ

Median (IQR) BMI, kg/m2 27.2 (24.3-28.7) 28 (25-29.7) 0.223 ͳ

Median (IQR) PSA, ng/ml 9.7 (7.8-11.2) 8.0 (5-13.4) 0.183 ͳ

Gleason score at biopsy n (%) 0.797 ӿ

≤ 6 31 (62) 32 (64)
7 13 (26) 14 (28)
8-10 6 (12) 4 (8)

Clinical T stage n (%) 0.695 ӿ

T1a-c 33 (66) 29 (58)
T2a-b 15 (30) 19 (38)
T2c 2 (4) 2 (4)

Mean (± SD) prostate volume, mL 60.1 ± 24.2 58.8 ± 22.6 0.782 ¥

D’Amico risk classification n (%) 0.516 ӿ

Low 23 (46) 28 (56)
Intermediate 15 (30) 14 (28)
High 12 (24) 8 (16)

SD: standart deviation; IQR: interquartile range; CCI: Charlson Comorbidity Index; BMI: body mass index; 
PSA: prostate-specific antigen. ͳ: Mann- Whitney U test. ¥: Student’s t-test. ӿ: Chi-sqaure test
Data are presented as mean (± SD) or median (IQR) and frequency (percantage).

Table 2. 
Peroperative and postoperative results.

Variable Rs-RARP S-RARP P value

Median (IQR) operative time, mins 162.5 (137.5-210) 150 (125-220) 0.865 ͳ

Nerve sparing, n (%) 0.843ӿ
Bilateral 36 (72) 35 (70)
Unilateral 7 (14) 9 (18)
None 7 (14) 6 (12)

Lymph node dissection, n (%) 21 (42) 19 (38) 0.683 ӿ

Median (IQR) anastomosis time, mins 20 (15-20) 20 (15-20) 0.952 ͳ

Median (IQR) blood loss, mL 150 (100-200) 100 (65-150) 0.120 ͳ

Median (IQR) hematocrit decrease 4.2 (0.7-1.7) 3.9 (0.7-1.6) 0.668 ͳ

Median (IQR) discharged time, day 3 (2.7-3) 3 (2-3.5) 0.588 ͳ

Median (IQR) catheter removal time, day 8 (7-9) 8 (7-9) 0.431 ͳ

pT, n  (%)
T0 0 1 (2)
T2 38 (76) 36 (72)
T3a 7 (14) 8 (16)
T3b-4 5 (10) 5 (10)

pN, n  (%)
N0 20(40) 18 (36)
N+ 1(2) 1 (2)

Positive surgical margin, n (%) 0.444 ӿ

Yes 6 (12) 4 (8)
No 44 (88) 46 (92)

ͳ: Mann- Whitney U test. ¥: Student’s t-test. ӿ: Chi-sqaure test.
Data are presented as median (IQR) and frequency (percantage).



401Archivio Italiano di Urologia e Andrologia 2021; 93, 4

Transition from standard to Retzius-sparing

complete ureteral injury in the Rs-RARP group. One
patient in the S-RARP group had external iliac vein injury
during lymph node dissection. Both complications were
managed intracorporeally. As a result of the histopatho-
logical examination of radical specimens, surgical margin
positivity was detected in 6/50 (12%) cases in the Rs-
RARP group and in 4/50 (8%) cases in the S-RARP (p =
0.444). Intra-postoperative clinical and pathological out-
comes are summarized in Table 2.
The median catheter discharge time was 8 days (IQR 7-9)
in group 1 and 8 (IQR 7-9) days for group 2, respective-
ly (p = 0.431). Immediate continence rates following
catheter removal were 32/50 (64%) in the Rs-RARP group
and 26/50 (52%) in the S-RARP group (p = 0.224). 
The continence recovery rate was 48/50 (96%) in the Rs-
RARP group and 46/50 (92%) in the S-RARP group at 12-
month follow-up (p = 0.400). Comparison of both
groups according to continence recovery using Kaplan-
Meier methods is shown in Figure 1A. Eighty-seven
patients, 43 in group 1 and 44 in group 2, who achieved
preoperative sexual intercourse were included in the
erectile function evaluation. The mean baseline IIEF-5
score was 21.6 ± 2.5 and 20.7 ± 2.6 in group 1 and 2,

respectively (p = 0.143). No statistically significant differ-
ence was found between the surgical approach in terms of
IIEF score reductions at 12-month follow-up (p = 0.260)
(Figure 1B). Potency recovery of patients who underwent
bilateral or unilateral nerve-sparing surgery was 27/43
(62.8%) in group 1 and 30/44 (68.2%) in group 2 at 12
months follow up. This difference was not statistically
significant (p = 0.597). Figure 1C shows the Kaplan-
Meier curve for potency recovery at 12-months follow-up
(p = 0.719). Biochemical recurrence was observed in 7/50
(14%) patients in group 1, and 6/50 (12%) patients in
group 2 at median 33 (IQR 28-40) months follow-up (p =
0.766). Biochemical recurrence-free survival analysis
according to surgical approaches is shown in Figure 1D.

DISCUSSION
One-third of men with localized prostate cancer undergo
radical prostatectomy (8). Incontinence is an adverse effect
faced by patients after radical prostatectomy. Rs-RARP
recently gained popularity with early continence results. In
this article, we questioned the effect of the Rs-RARP learn-
ing curve on functional and oncological results for a sur-

Figure 1. 
Comparison of functional and oncological outcomes between groups.



Archivio Italiano di Urologia e Andrologia 2021; 93, 4

H. Anıl, K. Karamık, A. Yıldız, M. Savaş

402

geon who was experienced in S-RARP before. This study
provided that the Rs-RARP learning curve period is not
adversely affected by either functional or oncologic results.
The number of cases required to achieve competence in
radical prostatectomy is uncertain. Also, there is no
objective parameter to be used in defining the learning
curve. A study based on complications showed that the
complications were significantly reduced after 150 cases
(9). In another study examining the learning curve for
robotic radical prostatectomy by an experienced surgeon
with the open approach, they reported that self-confi-
dence and comfort similar to open surgery were achieved
after performing 250 robotic surgeries (10). In a recent
study, Islamoglu et al. reported that the surgeon experi-
enced in laparoscopy and open radical prostatectomy
should have experience of at least 50 cases to achieve the
optimal surgical time. However, they found that the
learning curve did not affect positive surgical margin
(11). Another study reported the requirement of 90 cases
after intensive structured modular training to achieve
optimal perioperative and functional outcomes (12). 
In this context, we think that the learning curve for Rs-
RARP is person-based and will vary depending on the
surgeon's previous skills in laparoscopy and S-RARP.
In 2010, Galfano et al. defined Rs-RARP for the first time
in their study, which they defined as the Bocciardi
approach (7). The theory of this approach is that it has a
positive effect on continence and erectile function by pro-
tecting structures such as the Santorini plexus, pudendal
artery, and pubourethral ligament. Recent studies show
that Rs-RARP is advantageous especially in terms of imme-
diate continence (13). In their series of 200 cases, Galfano
et al. reported a continence rate of 90% at 1 week and 96%
at the end of 1 year (14). In a randomized controlled study
comparing Rs-RARP with S-RARP, continence rates at 1
week were 71% versus 48% in favor of Rs-RARP (p = 0.01)
(2). In a series of 256 cases involving surgeons on the
learning curve, the immediate continence rate was report-
ed as 82% and 90% at the end of 12 months (15). On the
other hand, it was emphasized that the high continence
rate seen in the early period with the Rs-RARP approach is
similar to S-RARP after 12 months (12). In our study,
although the continence rates in the first week were high-
er in the Rs-RARP group compared to the S-RARP group,
no statistical difference was found. At the end of the first
year, results were excellent in both groups.
Sexual potency evaluation was performed in patients with
preoperative penetrative sexual intercourse and patients
undergoing bilateral or unilateral nerve-sparing surgery.
At the end of 12 months, we found a potency rate of
62.8% in the Rs-RARP group and 68.2% in the S-RARP
group. Olivero and colleagues reported a sexual potency
rate of 80.4% in their study with surgeons on the Rs-
RARP learning curve. However, they included young
patients with full-nerve-sparing procedures in the analy-
sis in this study (15). In a randomized prospective study
including 3rd-month penetrative intercourse rates for 30
anterior and 30 posterior approaches by Mennon et al.,
rates were reported as 36.7% in the anterior group and
43.7% in the posterior group. They emphasized that at
the end of the 12th month erection sufficient for penetra-
tive intercourse increased to 69.2% in the anterior group

and 89% in the posterior group (16). In our study, the
rate of erectile function was found to be lower in the Rs-
RARP group compared to the literature. This may be
because we included patients from all age groups and
patients who underwent unilateral nerve-sparing surgery.
Positive surgical margin is a valuable data for evaluating
oncological outcomes after radical prostatectomy. Galfano
et al. found a PSM rate of 22% in the first 100 cases in
their learning curve and 9% in the second 100 patients
(14). Sayyid and colleagues reported that PSM after Rs-
RARP and S-RARP were similar in accordance to pT stage
subgroups (for pT2 stage: 16.7% PSM in Rs-RARP vs
13.7% PSM in S-RARP, p = 0.54; for pT3 stage: 47.1% and
47.8%, respectively, p = 0.95) (17). In another study com-
paring Rs-RARP and S-RARP, the rate of PSM was 10% in
the S-RARP group and 28.2% in the Rs-RARP group, and
this difference was statistically significant (p = 0.05).
However, when pT stage subgroups were compared, no
statistical significance was found (18). Also, many studies
comparing Rs-RARP and S-RARP reported similar PSM
rate and biochemical recurrence-free survival (8). In our
study, in accordance with the literature, there was no sig-
nificant difference in PSM rate between the groups. 
Our study has some limitations. First bias may be due to
the retrospective design. Second, the study has a relative-
ly small sample size. On the other hand, our data were
collected prospectively and all surgical procedures were
performed by a single surgeon. 

CONCLUSIONS
This study reported the outcomes for cases on the Rs-RARP
learning curve of a surgeon with previous experience of 
S-RARP. According to the data in our study, when a sur-
geon who is experienced in S-RARP switches to the Rs-
RARP method, functional and oncological results are not
negatively affected in the first 50 cases. Although immedi-
ate continence was found to be lower than the literature in
our study, the results are excellent at the end of 12 months.
Surgeons previously experienced in the S-RARP approach
can safely move to the Rs-RARP approach.

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Correspondence
Hakan Anıl, MD (Corresponding Author)
dr.hakananil@gmail.com
Department of Urology, Adana Seyhan State Hospital, Adana (Turkey)

Kaan Karamık, MD
Department of Urology, Antalya Korkuteli State Hospital, Antalya (Turkey) 

Ali Yıldız, Asst. Prof., MD
Department of Urology, Okan University Hospital, Faculty of Medicine,
Istanbul (Turkey)

Murat Savaş, Prof. Dr., MD 
Department of Urology, Antalya Memorial Hospital, Antalya (Turkey)