










































This is an open access article under the terms of a license that permits non-commercial use, provided the original work is properly cited.  
© 2021 The Authors. Société Internationale d'Urologie Journal, published by the Société Internationale d'Urologie, Canada.

Key Words Competing Interests Article Information

Benign prostatic obstruction, endoscopic 
enucleation of the prostate, perioperative 
outcomes, robotic-assisted simple 
prostatectomy

None declared. Received on January 31, 2021 
Accepted on March 27, 2021

Soc Int Urol J.2021;2(4):196–209

DOI: 10.48083/LKVV8843

Perioperative Outcomes of Anatomic  
Endoscopic Enucleation of the Prostate,  
Robotic and Open Simple Prostatectomy  
From a Multi-Institutional Database
Muhieddine Labban,1 Nassib Abou Heidar,1 Vincent Misrai,2 Jad Najdi,1 Hani Tamim,3 Albert El-Hajj1

1 American University of Beirut Medical Center, Department of Surgery, Division of Urology, Beirut, Lebanon 2 Department of Urology, Clinique Pasteur, Toulouse, France  
3 American University of Beirut Medical Center, Clinical Research Institute, Beirut, Lebanon 
ML & NAH contributed equally to the manuscript. 

Abstract

Objective To compare the perioperative morbidity of robotic-assisted simple prostatectomy (RASP), anatomical 
endoscopic enucleation of the prostate (AEEP) and open simple prostatectomy (OSP) for the treatment of benign 
prostatic obstruction (BPO).

Methods The national surgical quality improvement program database was queried for AEEP, RASP, and OSP 
procedures. Clavien-Dindo-graded complications, length of hospital stay (LOS), and operative time were compared 
among the procedures. To control for the potentially confounding variables, we first conducted a multivariate 
backward conditional logistic regression, and then resorted to propensity score matching. 

Results We identified 2867 AEEP, 234 RASP, and 1492 OSP procedures. After matching, the risk of pulmonary, 
renal, infectious, and thromboembolic adverse events was lower after AEEP but not RASP in comparison with OSP  
(P < 0.05). In comparison with RASP, AEEP had lower cardiac and thromboembolic events (P < 0.05). When compared 
with OSP, AEEP had reduced odds of Clavien-Dindo grade I (OR = 0.12; 95% CI 0.10 to 0.16) and II (OR = 0.38; 95% 
CI 0.24 to 9.58) complications. Also, AEEP had lower odds for grade I and II as well as grade IV complications (OR = 
0.30; 95% CI 0.19 to 0.48, and OR = 0.05; 95% CI 0.01 to 0.24, respectively) compared with RASP. 

Conclusion AEEP and RASP were associated with fewer perioperative adverse events, a shorter LOS and a reduced 
risk of transfusion compared with OSP. AEEP was associated with overall lower complication rates than RASP  
and OSP. 

Introduction

Benign prostatic obstruction (BPO) is a common cause of lower urinary tract symptoms with a 75% prevalence 
in men older than 50 years[1]. BPO significantly impacts quality of life, often necessitating medical or 
surgical treatment[2]. The current standard of care advocates for anatomical endoscopic enucleation of the 
prostate (AEEP) of smaller prostates (< 80 grams) and recommends AEEP or simple prostatectomy for the 
treatment of larger prostates (> 80 grams)[3]. Nevertheless, open simple prostatectomy (OSP) remains the gold-
standard treatment for large glands[4]. Recently, robotic-assisted simple prostatectomy (RASP) has gained 
popularity among robotic surgeons as a minimally invasive method to enucleate large prostatic adenomas.  

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It has similar functional outcome to OSP, while 
potentially limiting postoperative morbidity, especially 
bleeding and length of hospital stay[5–7]. 

The AEEP imitates the traditional Millins procedure 
by endoscopically enucleating the prostatic adenoma. 
Holium laser enucleation of the prostate (HoLEP) 
was first described by Gilling in 1998. In comparison 
to OSP, AEEP has demonstrated similar functional 
outcomes and efficacy in larger prostates, but reduced 
rate of overa ll complications and postoperative 
transfusion[8–10]. Currently, AEEP, RASP, and OSP 
are part of the surgical armamentarium when dealing 
with large prostates, and proponents of each technique 
defend its superiority over the others; however, there 
are no large studies comparing the 3 procedures, and 
certainly no randomized clinical trials. Umari et al. 
showed that RASP has comparable functional outcomes 
to AEEP, while Zhang et al. showed that AEEP conferred 
a shorter hospital stay, reduced catheter time, and 
had lower transfusion rates than RASP[11–13]. Both 
studies showed similar complication rates between 
RASP and AEEP. Nevertheless, both studies are small 
retrospective series. Sorokin et al. and Mourmouris et al. 
retrospectively compared RASP and OSP and found that 
despite having comparable functional outcomes, RASP 
had reduced blood loss and catheterization time at the 
expense of a longer operative time[7,14]. The systematic 
review of RASP by Kordan et al. incorporated several 
single-center retrospective studies, which included a 
limited number of RASP procedures[15]. Therefore, 
using a large multi-institutional real-world dataset, 
we sought to compare head-to-head the perioperative 
surgical outcomes of AEEP, RASP, and OSP using diffe rent 
statistical methods to cross-validate our findings.

Materials and Methods
The American College of Surgeons National Surgical 
Quality Improvement Program is a prospectively 
filled, risk-adjusted, and validated 30-day outcome 
registry with contributions from 703 different hospitals, 
most of which are in the United States[16]. Since our 

institution is a participating hospital, access to the de-
identified database is granted and formal consent is not 
required. The database includes information on patients’ 
demographics, comorbidities, and 30-day postoperative 
outcomes that are entered by American College of 
Surgeons (ACS) trained surgical clinical reviewers. The 
database was queried for AEEP, RASP, and OSP without 
any concurrent procedures performed between 2008 
and 2017. Since there is no dedicated current procedural 
terminology (CPT) code for RASP, the CPT code for 

Abbreviations 
AEEP anatomical endoscopic enucleation of the prostate
BPO benign prostatic obstruction
COPD chronic obstructive pulmonary disease
CPT current procedural terminology
HoLEP Holium laser enucleation of the prostate
LOS length of stay
MACE major adverse cardiac event
OSP open simple prostatectomy
RASP robotic-assisted simple prostatectomy FIGURE 1. 

Flowchart describing the selection criteria for patients 
who underwent anatomic endoscopic enucleation 
of the prostate (AEEP) or robotic-assisted simple 
prostatectomy (RASP) or open simple prostatectomy 
(OSP) from the national surgical quality improvement 
program (NSQIP)

Patients registered in ACS NSQIP 
database 2008–2017  

N = 6 274 508

COMPARISION OF THE PERIOPERATIVE MORBIDITY

AEEP-Group RASP-Group OSP-Group

Address procedure selection bias
Propensity score matching based on age, ASA class, 

BMI, predisposition to bleeding, COPD, 
congestive heart failure, functional status, 

hypertension, and diabetes, and operative year 

4593 Patients underwent either EEP 
or RASP or OSP between 2008 and 2017

49 371 patients were 
excluded if procedure 
was not done for benign 
prostatic obstruction 
(ICD 9: 600.0-600.9) 
or because of concurrent 
procedures

CPT 52 649 (EEP = 2880) or CPT 55 866 (RASP = 49 299) 
or CPT 55 821 (OSP = 1140) or CPT 55 831 (OSP = 645 ) 

N = 53 964

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RARP (55866) is used by surgeons. To select procedures 
done for BPO, all cases were filtered by the International 
Classification of Diseases -9 (ICD-9) codes 600.00-
600.90 or ICD-10 N40.00-N40.90, corresponding to the 
postoperative diagnosis of BPO procured from either 
brief postoperative note, operative report, and/or the 
pathology reports (Figure 1). The CPT codes for AEEP 
(52649) and OSP (55821 & 55831) were also selected. 
Even though the energy source for AEEP cannot be 
extracted from the database, HoLEP is currently the 
most commonly used energy source for AEEP in the 
United States[17]. As a primary endpoint, this study 
aimed to compare 30-day perioperative surgical 
complications and early mortality between AEEP, RASP, 
and OSP.

Baseline patient demographics, comorbidities, 
and laboratory markers were collected and managed. 
C omorbid it ie s i ncluded A mer ic a n S oc iet y of 
Anesthesiologists (ASA) class ≥ 3, corresponding 
to patients with severe systemic disease, diabetes, 
hypertension, being partially or totally physically 
dependent, chronic obstructive pulmonary disease 
(COPD), history of heart failure, myocardial infarction, 
and disseminated cancer. Additionally, the variables 
bleeding diathesis and long-term pharmaceutical 
steroid or immunosuppressant use were added. The 
variable bleeding diathesis incorporated patients on 
chronic anticoagulation therapy that had not been 
discontinued prior to the procedure, and patients with 
genetic hematological diseases. The variable chronic 
steroid use included patients who had regular intake 
of oral or parenteral corticosteroid medications or 
immunosuppressants for a chronic medical condition. 
We investigated the rate of anemia (hematocrit < 35%), 
thrombocytopenia (< 150 × 103/µL), and elevated serum 
creatinine (creatinine > 1 mg/dL). 

We performed 3 comparisons: (1) OSP versus AEEP, 
(2) OSP versus RASP, and (3) RASP versus AEEP. 
First, using a backward conditional logistic regression, 
we compared the 30-day perioperative procedural 
outcomes fac tored by orga n system, prolonged 
operative time, a nd ex tended leng t h of hospita l 
stay (LOS > 1 day) of the 3 procedures (RASP, AEEP, 
and OSP). Second, to mitigate the effect of procedure 
selection bias and potential confounding variables, 
propensity score matching (PSM) with replacement 
(giving priority to exact matches) was used to assess 
procedure-specific outcomes. This method would 
further decrease bias especially when dealing with very 
different numbers between the 3 arms[18]. Baseline 
demographics before and after matching are found in 
Supplementary Table 1. We defined major adverse 
cardiac event (MACE) as the incidence of one or 
more of the following: myocardial infarction, stroke/
cardiovascular events, cardiac arrest necessitating 

cardiopulmonary resuscitation (CPR), and death[19]. 
The pulmonary complications captured pneumonia 
and unplanned intubation events. We also identified 
patients with acute or progressive postoperative renal 
insufficiency requiring dialysis. Then, we gathered 
the occurrences of urinary tract infections, sepsis, 
and septic shock under infectious outcomes, and 
pulmonary embolism and deep venous thrombosis 
under venous thromboembolism (VTE). We also 
explored the rate of intraoperative and postoperative 
bleeding within the first 72 hours of surgery starting 
time. Moreover, we designated composite morbidity 
as the combination of pulmonary, renal, infectious, 
M ACE , V T E , a nd t ra nsf u sion outcomes. We 
further categorized ACS-National Surgical Quality 
Improvement Program (NSQIP) surgical outcomes in 
Clavien-Dindo grades according to previously published 
studies[20,21]. Clavien-Dindo grade I and grade II 
represent occurrences of surgical site infection (SSI), 
deep incisional SSI, organ space SSI, fascial dehiscence, 
pneumonia, urinary tract infections, deep venous 
thrombosis, progressive renal insufficiency, bleeding 
requiring transfusion. Grade III represents reoperation. 
Grade IV encompasses sepsis, septic shock, pulmonary 
embolism, myocardia l infarction, cardiac arrest 
necessitating CPR, unplanned intubation, ventilator 
dependence > 48 hours, acute renal failure necessitating 
dialysis, stroke, and coma. Grade V represents death. 

Statistics
We compared patient demographics, comorbidities, 
and preoperative laboratory markers, and computed 
outcomes between the 3 procedures using Mann-
Whitney U test for continuous variables and chi-
square test or Fisher exact test for categorical variables. 
Furthermore, a multivariate conditional backward 
logistic regression was constructed for each of the 
designated outcomes and adjusted for demographics, 
comorbidities, surgical procedure and the year the 
procedure was performed in. 

Since observational studies are subject to treatment-
selection bias, PSM allows estimation of treatment 
effect based on treatment assignment conditional to the 
accounted covariates[18,22]. Propensity score matching 
was used to adjust for covariates that could influence the 
choice of treatment of BPO: age, ASA class, body mass 
index, COPD, congestive heart failure, functional status, 
diabetes, hypertension, predisposition for bleeding, 
and the year of surgery to account for possible effect of 
the learning curve and changes in technique across the 
years. Using the generated propensity scores, weighted 
logistic regression analysis was conducted for the same 
outcomes. All analyses were conducted using the SPSS 
Statistics for Windows, version 25 (IBM Corp., Armonk, 
NY, US).

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Results
This series included 2867 AEEP, 234 RASP, and 1492 
OSP procedures. Figure 2 depicts the annual trends for 
the different procedures. While RASP has a constant 
proportion over the years, OSP caseload decreased at 
the expense of more AEEP procedures. A total of 24.3%, 
25.2%, and 27.3% of patients undergoing AEEP, RASP, 
and OSP, respectively, had an average age > 75. Patient 
demographics and comorbidities were similar for all 
3 procedures, except a higher proportion of patients 
undergoing AEEP had disseminated cancer (0.7%), 
were on chronic steroid treatment (2.5%), or were on 
anticoagulation (3.1%); (P = 0.019, P = 0.015, P = 0.012, 
respectively) (Table 1). There was also no difference 
in the rates of diabetes, hypertension, and COPD 
(P = 0.967, P = 0.470, and P = 0.304, respectively). In our 
cohort, there was an equal proportion of patients (0.4%) 
on dialysis who underwent either of AEEP or OSP (P > 
0.05). Additionally, the AEEP group had the highest 
proportion of patients with hematocrit < 35% (22.9%) 
and platelet count < 150K (26.3%) while the OSP group 
had the highest proportion of patients with INR ≥ 1.1 
(19.1%) (P < 0.001 for all variables). 

AEEP had the shortest median (interquartile range) 
operative time of the 3 procedures: 93 (59 to 131) 
minutes for AEEP versus 184 (149 to 234) minutes for 
RASP and 109 (82 to 152) minutes for OSP (P < 0.001; 
Table 2). At the univariate level, fewer complications 
were observed with AEEP and RASP compared to OSP, 
yet there was no significant difference in rates of return 
to the operating room and 30-day mortality among the 3 
procedures (P > 0.05). 

Af ter adjusting for other covariates, AEEP had 
decreased odds of postoperative pulmonary, renal, 
infectious, cardiac, and thromboembolic complications 
in comparison with OSP (P < 0.05) (Table 3). AEEP 
versus RASP conferred lower odds of MACE (OR = 0.18; 
95% CI 0.04 to 0.75) and VTE (OR = 0.22; 95% CI 0.06 
to 0.82). These findings were echoed in the PSM model. 
Furthermore, after matching, AEEP had lower odds 
of Clavien-Dindo grade I & II adverse events (AEEP 
versus OSP, OR = 0.14; 95% CI 0.10 to 0.20, and AEEP 
versus RASP, OR = 0.40; 95% CI 0.26 to 0.62) (Table 4). 
AEEP also had reduced odds of grade IV complications 
(AEEP versus RASP, OR = 0.20; 95% CI 0.09 to 0.45, 
and AEEP versus OSP, OR = 0.29; 95% CI 0.12 to 0.71) 
in comparison with OSP and R ASP, respectively. 
Nevertheless, the type of surgery did not predict early 
postoperative mortality (Clavien-Dindo grade V). 
Despite having the largest proportion of patients with 
bleeding diathesis (3.1%), AEEP was associated with 
a significantly lower risk for bleeding necessitating 
blood product transfusion than both OSP and AEEP; 
(AEEP versus OSP, OR = 0.06; 95% CI 0.04 to 0.11, and 

AEEP versus RASP, OR = 0.18; 95% CI 0.10 to 0.35). 
Additionally, AEEP was associated with a shorter LOS 
and decreased risk of overall morbidity than both OSP 
and RASP (P < 0.05). Similarly, the odds of operative 
time exceeding 90 minutes were lower for AEEP (AEEP 
versus OSP, OR = 0.56; 95% CI 0.45 to 0.70; AEEP versus 
RASP OR = 0.08; 95% CI 0.05 to 0.14). 

Discussion 
We used a real-world national database to provide 
objective operative outcome comparison between 
AEEP, RASP, and OSP: 3 procedures dedicated for the 
surgical management of symptomatic large prostates. 
When taking OSP as a reference, both AEEP and RASP 
had a shorter hospital stay and lower transfusion rates. 
Additionally, in comparison with OSP and RASP, 
AEEP had shorter operative time, shorter LOS, lower 
transfusion rates, and decreased odds of grade I and II as 
well as grade IV complications.

BPO resulting from large adenomas poses a more 
challenging decision-making process. The American 
Urologica l Association 2020 guidelines indicate 
that treatment options for large glands include 
open, laparoscopic, or robotically assisted simple 
prostatectomy, and that laser enucleation with RASP 
and AEEP have a lower risk profile because of their 
minimally invasive nature[4]. Meyer et al. documented 
the shift in numbers from OSP to RASP in the last 
decade, which they speculate occurred because the 
availability of robotics has made this the most cost-
effective approach and it requires no further training[23].  

2008

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%
2009 2010 2011 2012 2013 2014 2015

Pr
op

or
tio

n 
Pe

rc
en

t (
%

)
Operative Year

AEEP          OSP          RASP

FIGURE 2. 

Annual trends for endoscopic enucleation of 
the prostate (AEEP) or robotic-assisted simple 
prostatectomy (RASP) or open simple prostatectomy 
(OSP)

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TABLE 1. 

Baseline demographics, comorbidities, and laboratory markers among patients who have benign prostate 
obstruction who underwent anatomic endoscopic enucleation of the prostate (AEEP) or robotic assisted simple 
prostatectomy (RASP) or open simple prostatectomy (OSP)

Variable
AEEP (N = 2867)

n (%)
RASP (N = 234)

n (%)
OSP (N =1492)

n (%) P-value

Non-White 259 (9.7) 32 (14.2) 210 (15.4) < 0.0001

≤65 962 (33.9) 66 (28.2) 407 (27.4) < 0.0001

65 – ≤75 1187 (41.8) 109 (46.6) 674 (45.3)

>75 692 (24.3) 59 (25.2) 406 (27.3)

ASA ≥ 3 1331 (46.4) 101 (43.2) 706 (47.3) 0.485

BMI ≥ 30 986 (34.4) 72 (30.8) 546 (36.6) 0.137

Diabetes 522 (18.2) 44 (18.8) 270 (18.1) 0.967

Smoker 265 (9.2) 20 (8.5) 130 (8.7) 0.816

Dependenta 52 (1.8) 2 (0.9) 20 (1.3) 0.396

COPD 115 (4.0) 7 (3.0) 47 (3.2) 0.304

Heart failure 12 (0.4) 0 (0.0) 4 (0.3) 0.747

Hypertension 1,646 (57.4) 144 (61.5) 861 (57.7) 0.470

Dialysis 11 (0.4) 0 (0.0) 6 (0.4) 1.0000

Disseminated cancer 20 (0.7) 0 (0) 2 (0.1) 0.019

Chronic steroid 73 (2.5) 4 (1.7) 19 (1.3) 0.015

Myocardial infarction 2 (0.1) 0 (0.0) 0 (0.0) 0.603

Bleeding diathesisb 89 (3.1) 2 (0.9) 28 (1.9) 0.012

Creatinine >1 1,235 (43.1) 105 (44.9) 686 (46.0) 0.182

Albumin < 3.5 744 (26.0) 91 (38.9) 537 (36.0) < 0.0001

Leukocyte > 6.5K 1,314 (45.8) 125 (53.4) 858 (57.5) < 0.0001

Hematocrit < 35% 656 (22.9) 29 (12.4) 249 (16.7) < 0.0001

Platelet < 150K 753 (26.3) 44 (18.8) 196 (13.1) < 0.0001

INR ≥ 1.1 366 (12.8) 31 (13.2) 285 (19.1) < 0.0001

ASA: American Society of Anesthesiology; BMI: body mass index; COPD: chronic obstructive pulmonary disorder;  
INR: international normalized ratio.
aDependent patients require partial or total assistance from another person for daily activities.  
b Bleeding diathesis is defined as any chronic or persistent condition that places the patient at risk of excessive bleeding, including chronic 
anticoagulation that has not been discontinued prior to the procedure.

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Our results ref lect the findings of a meta-analysis 
compiling 37 observational studies that explored the role 
of minimally invasive technique in simple prostatectomy 
and revealed that this procedure offers decreased blood 
loss and shorter LOS with comparable functional 
outcomes to OSP[24]. The largest reported outcome 
series for laparoscopic simple prostatectomy and RASP 
(n = 1330) was from an American-European multicenter 
study[25]. The cohort had a median operative time of 100 
minutes, a median estimated blood loss of 200 mL, and a 
median LOS of 4 days[25]. Besides, 10.6% of the patients 
had a Clavien-Dindo grade l or grade ll complication[25]. 

Although the findings are consistent with our results, no 
large studies have compared RASP with AEEP. 

The patients in our cohort undergoing either 
procedure were similar in baseline characteristics with 
patient ≥ 75 representing around a quarter of patients 
undergoing any of the 3 procedures[26]. On the other 
hand, patients on chronic anticoagulation were more 
likely to undergo AEEP. Although the risk of bleeding 
was considerable for patients on anticoagulation, 
the rate of transfusion was significantly lower with 
AEEP than with either OSP or RASP. This could be 

TABLE 2. 

Univariate analysis for postoperative outcomes following anatomic endoscopic enucleation of the prostate (AEEP), 
robotic-assisted simple prostatectomy (RASP), and open simple prostatectomy (OSP) for benign prostatic obstruction 

Variable
AEEP 

(N = 2867)
n (%)

RASP 
(N = 234)

n (%)

OSP
(N =1492) 

n (%)
P-value

Pulmonarya 8 (0.3) 2 (0.9) 26 (1.7) < 0.0001

Renalb 6 (0.2) 0 (0.0) 14 (0.9) 0.003

Infectiousc 93 (3.2) 12 (5.1) 98 (6.6) < 0.0001

MACEd 8 (0.3) 3 (1.3) 15 (1.0) 0.002

VTEe 8 (0.3) 3 (1.3) 29 (1.9) < 0.0001

Transfusionf 38 (1.3) 16 (6.8) 275 (18.4) < 0.0001

LOS > 1 day 441 (15.4) 157 (67.1) 1 338 (89.7) < 0.0001

Operative time 93 (59 – 131) 184 (149 – 234) 109 (82 – 152) < 0.0001

Return to OR 54 (1.9) 6 (2.6) 45 (3.0) 0.057

mortality 3 (1.3) 1 (0.4) 3 (0.2) 0.227

Composite morbidityg 150 (5.2) 32 (13.7) 389 (26.1) < 0.0001

MACE: major adverse cardiac event; VTE: venous thromboembolism; LOS: length of hospital stay; OR: operating room. 
apneumonia and unplanned intubation; bacute and progressive renal failure; curinary infections, sepsis, and septic shock; dmyocardial infarction, stroke/
cardiovascular events, cardiac arrest necessitating cardiopulmonary resuscitation, and death; epulmonary embolism and deep venous thrombosis; 
fbleeding requiring transfusion; gpulmonary, renal, infectious, MACE, VTE, transfusion outcomes. 

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TABLE 3. 

Multivariate backward conditional logistic regression comparing the perioperative outcomes of endoscopic  
anatomic enucleation of the prostate (AEEP), robotic-assisted simple prostatectomy (RASP),and open simple 
prostatectomy (OSP) 

Postoperative 
Outcomes

OSP
AEEP

OR (95%CI)
RASP

OR (95%CI)
RASP

AEEP
OR (95%CI)

Pulmonarya Reference
0.19 (0.09 – 0.44) 

P < 0.001
0.62 (0.14 – 2.68) 

P = 0.52
Reference –

Renalb Reference
0.14 (0.04 – 0.47)  

P = 0.002 – Reference –

Infectiousc Reference
0.49 (0.36 – 0.66) 

P < 0.001
0.89 (0.48 – 1.66) 

P = 0.71
Reference

0.54 (0.29 – 1.01)  
P = 0.05

MACEd Reference
0.27 (0.11 – 0.67) 

P = 0.005
1.12 (0.30 – 4.19) 

P = 0.87
Reference

0.18 (0.04 – 0.75)  
P = 0.02

VTEe Reference
0.16 (0.07 – 0.35) 

P < 0.001
0.59 (0.17 – 2.03) 

P = 0.40
Reference

0.22 (0.06 – 0.82)  
P = 0.03

OT > 90 min Reference
0.48 (0.42 – 0.56) 

P < 0.001
7.36 (4.32 – 12.53) 

P < 0.001 Reference
0.09 (0.05 – 0.15) 

P < 0.001

Transfusionf Reference
0.04 (0.03 – 0.07) 

P < 0.001
0.30 (0.17 – 0.52) 

P < 0.001 Reference
0.14 (0.07 – 0.27)  

P < 0.001

LOS > 1 day Reference
0.02 (0.01 – 0.03)  

P < 0.001
0.18 (0.13 – 0.27) 

P < 0.001 Reference
0.08 (0.06 – 0.12) 

P < 0.001

Composite  
morbidityg

Reference
0.14 (0.11 – 0.18)  

P < 0.001
0.45 (0.30 – 0.68)  

P < 0.001 Reference
0.30 (0.20 – 0.46);  

P < 0.001

 Clavien-Dindo Grade Complications

Grade I & II CD Reference
0.12 (0.10 – 0.16) 

P < 0.001
0.38 (0.24 – 9.58)  

P < 0.001
Reference

0.30 (0.19 – 0.48)  
P < 0.001

Return to OR Reference – – Reference –

Grade IV CD Reference
0.26 (0.16 – 0.42);  

P < 0.001 – Reference
0.05 (0.01 – 0.24)  

P < 0.001

Mortality Reference – – Reference –

CD: Clavien-Dindo; CI: confidence interval MACE: major adverse cardiac event; VTE: venous thromboembolism; OR: odds ratio; OT: operative time
apneumonia and unplanned intubation; bacute and progressive renal failure; curinary infections, sepsis, and septic shock; dmyocardial infarction, stroke/
cardiovascular events, cardiac arrest necessitating cardiopulmonary resuscitation, and death; epulmonary embolism and deep venous thrombosis; 
fbleeding requiring transfusion; gpulmonary, renal, infectious, MACE, VTE, transfusion outcomes. Logistic regression model adjusted for race, age,  
American Society of Anesthesiology (ASA) class, functional dependence, body mass index (BMI), smoking, diabetes, hypertension, predisposition to 
bleeding (includes anticoagulation), chronic obstructive pulmonary disease (COPD), history of heart failure, dialysis dependence, chronic steroid use,  
history of disseminated cancer, laboratory markers (creatinine, leukocyte count, hematocrit, platelet count), and surgical procedure (AEEP versus RASP 
versus OSP), and year of operation.

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TABLE 4. 

Propensity score matching comparing the perioperative outcomes of anatomic endoscopic enucleation of the 
prostate (AEEP), robotic-assisted simple prostatectomy (RASP), and open simple prostatectomy (OSP) 

Postoperative  
Outcomes

OSP
AEEP

OR (95%CI)
RASP

OR (95%CI)
RASP

AEEP
OR (95%CI)

Pulmonarya Reference
0.15 (0.04 – 0.60) 

P = 0.007
0.45 (0.09 – 2.28) 

P = 0.336
Reference

0.36 (0.07 – 1.92) 
P = 0.228

Renalb Reference
0.12 (0.02 – 0.90) 

P = 0.04 - Reference -

Infectiousc Reference
0.47 (0.28 – 0.77) 

P = 0.003
0.79 (0.41 – 1.54) 

P = 0.493
Reference

0.61 (0.32 – 1.17) 
P = 0.608

MACEd Reference
0.26 (0.06 – 1.15) 

P = 0.08
1.32 (0.35 – 5.00) 

P = 0.681
Reference

0.22 (0.05 – 0.87) 
P = 0.03

VTEe Reference
0.13 (0.03 – 0.50) 

P = 0.003
0.67 (0.18 – 2.44) 

P = 0.544
Reference

0.26 (0.09 – 0.92) 
P = 0.03

OT > 90 min Reference
0.56 (0.45 – 0.70) 

P < 0.001
6.01 (3.45 – 10.45) 

P < 0.001 Reference
0.08 (0.05 – 0.14) 

P < 0.001

Transfusionf Reference
0.06 (0.04 – 0.11) 

P < 0.001
0.33 (0.19 – 0.59) 

P < 0.001 Reference
0.18 (0.10 – 0.35) 

P < 0.001

LOS > 1 day Reference
0.02 (0.01 – 0.03) 

P < 0.001
0.24 (0.17 – 0.35) 

P < 0.001 Reference
0.09 (0.06 – 0.12) 

P < 0.001

Composite  
morbidityg

Reference
0.15 (0.11 – 0.22) 

P < 0.001
0.46 (0.30 – 0.71) 

P < 0.001 Reference
0.35 (0.22 – 0.53) 

P < 0.001

 Clavien-Dindo Grade Complications

Grade I & II Reference
0.14 (0.10 – 0.20) 

P < 0.001
0.40 (0.26 – 0.62) 

P < 0.001 Reference
0.36 (0.23 – 0.56) 

P < 0.001

Return to OR Reference – – Reference –

Grade IV Reference
0.20 (0.09 – 0.45) 

P < 0.001
0.76 (0.32 -1.79) 

P = 0.527
Reference

0.29 (0.12 – 0.71) 
P = 0.007

Mortality Reference
0.56 (0.03 – 9.86) 

P = 0.693
2.19 (0.20 – 23.36) 

P = 0.518
Reference

0.23 (0.02 – 2.39) 
P = 0.220

CD: Clavien-Dindo; CI: confidence interval; MACE: major adverse cardiac event; VTE: venous thromboembolism; OR: odds ratio; OT: 
operative time. Covariates included in the PSM model were age category, ASA class, BMI, COPD, congestive heart failure, hypertension, 
diabetes, functional status, predisposition to bleeding, and year of operation.

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attributed to the use of lasers, with the ability to heat  
wel l-vascu la r i z ed t issue t hereby cou nterac t i ng 
bleeding[27]. Further, a high power (80 to 100 W) 
energ y source can achieve simultaneous cutting 
and coagulation[27]. Consequently, AEEP is a safer 
modality than RASP for the treatment of patients 
on anticoagulation[28,29]. Furthermore, our results 
echo the findings of other studies that show AEEP 
is associated with the least blood loss among the 3 
modalities[8,30]. 

In our study, AEEP is also associated with a 
shorter operative time and shorter hospital stay. These 
findings are in concordance with the literature where 
a prolonged operative time is attributable to technical 
factors of robotic surgery, such as applying the ports 
and docking the robot[11–13]. In our study, the median 
operative time for RASP is slightly longer (184 [149 to 
234] minutes) than reported in the literature (150 to 
160 minutes). A systematic review by Kordan et al. also 
revealed a shorter average operative time for OSP (79 to 
93 minutes) depending on the surgical series[15]. This is 
probably because the ACS NSQIP database reflects real-
world outcomes of different levels of surgical expertise 
[23,25]. No information is available on catheterization 
time, but if we assume that the LOS is a surrogate for 
catheterization time, AEEP should have a shorter 
catheterization time[12,13,25]. An increased need for 
continuous bladder irrigation because of bleeding 
may also lengthen hospital stay after RASP and OSP 
compared with AEEP.

RASP is estimated to be more costly than its open 
counterpart and costs twice as much as AEEP[31]. The 
case has been made that the procurement of AEEP to 
hospitals is costly and necessitates a steeper learning 
curve[23]. However, diverse endonucleation techniques 
have an acceptable learning curve of 25 to 50 cases with 
similar perioperative and functional outcomes[32,33]. 
Therefore, the availability of the modality and the 
surgeon’s level of comfort would dictate the type of 
surgery offered to patients. Hence, AEEP and RASP 
have both mitigated the risks associated with OSP 
while conserving equivalent functional outcomes; 
however, AEEP offers the advantage of a shorter 
operative time, reduced LOS, and safer profile than 
RASP[34]. In comparison to transurethral resection of 
the prostate, AEEP has also demonstrated superiority 
as it reduces the risk of postoperative urinary tract 
infections and decreases the LOS[35]. Therefore, 
AEEP could be preferable for large adenomas except 
in the presence of co-existing conditions such as large 
bladder calculi that would require a long operative time 
to eradicate endoscopically, or diverticula where the 

robotic technique would more efficiently manage both 
conditions concomitantly[23,36]. 

Treatment cost encompasses surgical instruments, 
complications, and hospita l stay among ot hers.  
In comparison to OSP, RASP has higher operating 
expenses (USD 2797), but its safer profile (decreased 
transfusion rate and shorter LOS) might render it 
more cost-effective than its open counterpart[15,37].  
On the other hand, AEEP (HoLEP) was found to be  
9.6% (EUR 2356) cheaper than OSP[38]. The surgeons’ 
expertise and the institution caseload directly impact the 
perioperative and functional outcomes, which in turn 
influence costs. Costs also vary according to country, 
type of institution (public versus private, military versus 
civil), and type of cost analysis conducted. Further 
studies with more precise comparisons are needed to 
assess the costs of the 3 procedures[15].

Our study is limited by its retrospective nature. 
While national databases like NSQIP allow outcome 
comparison among a large sample population, they 
might not include surgery-specific clinical data such 
as prostate size, average gram resected per minute, 
and functional outcomes such as post-void residual, 
International Prostate Symptom Score, quality of life 
scores, and incontinence rates. Additionally, large  
databases do not consider surgeon experience and  
learning curve on the outcome. Another limitation 
inherent to the database is the inability to capture 
events occurring more than 30 days after the procedure. 
Moreover, we were not able to assess continence, lower 
urinary tract symptoms, and sexual function because 
they are not captured in NSQIP. Furthermore, we were 
unable to control for the selection bias that results from 
the choice of procedure being highly dependent on 
the expertise available in each institution. However, 
we conducted 2 forms of analysis to cross-check our 
results. Our methodology might not have captured 
all RASP procedures performed in the study period. 
Nonetheless, this study provides an accurate assessment 
of the feasibility of the use of AEEP and RASP by a large 
number of surgeons with a wide range of expertise and 
experience.

Conclusion 
We report the outcomes of OSP, AEEP, and RASP 
in a large real-world cohort of patients. AEEP was 
found to have a safer profile than OSP and RASP as it 
conferred a shorter operative time, shorter hospital stay, 
and lower incidence of postoperative complications. 
Thus, AEEP could be advantageous for frail patients 
with large prostates or for those dependent on chronic 
anticoagulation.

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Author Contributions 
Muhieddine Labban: Methodology, formal analysis, 
writing—original draft 
Nassib Abou Heidar: Conceptualization, methodology, 
writing—original draft 
Vincent Misrai: Validation, writing—review and editing 
Jad Najdi: Writing-original draft 
Hani Tamim: Data curation, project administration 
Albert El-Hajj: Conceptualization, methodolog y, 
writing—review and editing, supervision

All authors read and approved the final version of the 
manuscript. 

Acknowledgements 
The ACS NSQIP and the hospitals participating in the 
ACS NSQIP are the source of the data used herein; 
they have not verified and are not responsible for the 
statistical validity of the data analysis or the conclusions 
derived by the authors.

References

1. Egan KB. The Epidemiology of benign prostatic hyperplasia associated 
with lower urinary tract symptoms: prevalence and incident rates. Urol 
Clin North Am.2016;43(3):289-97. Epub 2016/08/01. doi: 10.1016/j.
ucl.2016.04.001. PubMed PMID: 27476122.

2. Wei JT, Calhoun E, Jacobsen SJ. Urologic diseases in America project: 
benign prostatic hyperplasia. J Urol.2008;179(5 Suppl):S75-80. 
Epub 2008/04/25. doi: 10.1016/j.juro.2008.03.141. PubMed PMID: 
18405761.

3. Gratzke C, Bachmann A, Descazeaud A, Drake MJ, Madersbacher 
S, Mamoulakis C, et al. E AU guidelines on the assessment of 
non-neurogenic male lower urinary tract symptoms including benign 
prostatic obstruction. Eur Urol.2015;67(6):1099-109. Epub 2015/01/24. 
doi: 10.1016/j.eururo.2014.12.038. PubMed PMID: 25613154.

4. AUA Announces Updates to Clinical Guidance for Surgical 
Management of LUTS Attributed to BPH. 2020. Epub June 25.2020.

5. Stolzenburg JU, Kallidonis P, Qazi H, Ho Thi P, Dietel A, Liatsikos 
EN, et al. Extraperitoneal approach for robotic-assisted simple 
prostatectomy. Urology.2014;84(5):1099-105. Epub 2014/12/03. doi: 
10.1016/j.urology.2014.06.045. PubMed PMID: 25443912.

6. Shah AA, Gahan JC, Sorokin I. Comparison of robot-assisted versus 
open simple prostatectomy for benign prostatic hyperplasia. Curr 
Urol Rep.2018;19(9):71-. doi: 10.1007/s11934-018-0820-1. PubMed 
PMID: 29998354.

7. Mourmouris P, Keskin SM, Skolarikos A, Argun OB, Karagiannis AA, 
Tufek I, et al. A prospective comparative analysis of robot-assisted 
vs open simple prostatectomy for benign prostatic hyperplasia. BJU 
Int.2019;123(2):313-7. Epub 10/15. doi: 10.1111/bju.14531. PubMed 
PMID: 30198196.

8. Lin Y, Wu X, Xu A, Ren R, Zhou X, Wen Y, et al. Transurethral 
enucleation of the prostate versus transvesical open prostatectomy 
for large benign prostatic hyperplasia: a systematic review and meta-
analysis of randomized controlled trials. World J Urol.2016;34(9):1207-
19. Epub 2015/12/25. doi: 10.1007/s00345-015-1735-9. PubMed PMID: 
26699627.

9. Gilling PJ, Cass CB, Cresswell MD, Fraundorfer MR. Holmium laser 
resection of the prostate: preliminary results of a new method for the 
treatment of benign prostatic hyperplasia. Urology.1996;47(1):48-51. 
Epub 1996/01/01. doi: 10.1016/s0090-4295(99)80381-1. PubMed 
PMID: 8560662.

10. Gilling PJ, Wilson LC, King CJ, Westenberg AM, Frampton CM, 
Fraundorfer MR. Long-term results of a randomized trial comparing 
holmium laser enucleation of the prostate and transurethral resection 
of the prostate: results at 7 years. BJU Int.2012;109(3):408-11. Epub 
2011/09/03. doi: 10.1111/j.1464-410X.2011.10359.x. PubMed PMID: 
21883820.

11. Zhang MW, El Tayeb MM, Borofsky MS, Dauw CA, Wagner KR, 
Lowry PS, et al. Comparison of perioperative outcomes between 
holmium laser enucleation of the prostate and robot-assisted simple 
prostatectomy. J Endourol.2017;31(9):847-50. Epub 2017/06/24. doi: 
10.1089/end.2017.0095. PubMed PMID: 28637364.

12. Umari P, Fossati N, Gandaglia G, Pokorny M, De Groote R, Geurts 
N, et al. Robotic assisted simple prostatectomy versus holmium 
laser enucleation of the prostate for lower urinary tract symptoms 
in patients with large volume prostate: a comparative analysis from a 
high volume center. J Urol.2017;197(4):1108-14. Epub 2016/09/13. doi: 
10.1016/j.juro.2016.08.114. PubMed PMID: 27615435.

13. Baldini A, Fassi-Fehri H, Duarte RC, Crouzet S, Ecochard R, Abid N, 
et al. Holmium laser enucleation of the prostate versus laparoscopic 
transcapsular prostatectomy: perioperative results and three-
month follow-up. Curr Urol.2017;10(2):81-6. Epub 05/30. doi: 
10.1159/000447156. PubMed PMID: 28785192.

14. Sorokin I, Sundaram V, Singla N, Walker J, Margulis V, Roehrborn 
C, et al. Robot-assisted versus open simple prostatectomy for 
benign prostatic hyperplasia in large glands: a propensity score-
matched comparison of perioperative and short-term outcomes. 
J Endourol.2017;31(11):1164-9. Epub 2017/09/01. doi: 10.1089/
end.2017.0489. PubMed PMID: 28854815.

15. Kordan Y, Canda AE, Köseoglu E, Balbay D, Laguna MP, de la Rosette 
J. Robotic-assisted simple prostatectomy: a systematic review. J Clin 
Med.2020;9(6). Epub 2020/06/13. doi: 10.3390/jcm9061798. PubMed 
PMID: 32527020; PubMed Central PMCID: PMCPMC7356910.

205SIUJ.ORG SIUJ  •  Volume 2, Number 4  •  July 2021

Perioperative Outcomes of Anatomic Endoscopic Enucleation of the Prostate

http://SIUJ.org


16. Surgeons ACo. ACS NSQIP Hospitals 2020 [cited 2020 July 20]. Available 
from: https://www.facs.org/search/nsqip-participants?allresults=.

17. Lerner LB, Rajender A. Laser prostate enucleation techniques. Can 
J Urol.2015;22(Suppl 1):53-9. Epub 2015/10/27. PubMed PMID: 
26497344.

18. Stuart EA. Matching methods for causal inference: a review and a look 
forward. Stat Sci.2010;25(1):1-21. doi: 10.1214/09-STS313. PubMed 
PMID: 20871802.

19. Berger A, Simpson A, Bhagnani T, Leeper NJ, Murphy B, Nordstrom B, 
et al. Incidence and cost of major adverse cardiovascular events and 
major adverse limb events in patients with chronic coronary artery 
disease or peripheral artery disease. Am J Cardiol.2019;123(12):1893-9. 
Epub 03/16. doi: 10.1016/j.amjcard.2019.03.022. PubMed PMID: 
31014542.

20. Dindo D, Demar tines N, Clavien PA. Classification of surgical 
complications: a new proposal with evaluation in a cohort of 6336 
patients and results of a survey. Ann Surg.2004;240(2):205-13. Epub 
2004/07/27. doi: 10.1097/01.sla.0000133083.54934.ae. PubMed 
PMID: 15273542; PubMed Central PMCID: PMCPMC1360123.

21. Shahait M, Labban M, Dobbs RW, Cheaib JG, Lee DI, Tamim H, 
et al. A 5-Item frailty index for predicting morbidity and mortality 
after radical prostatectomy: an analysis of the American College of 
Surgeons national surgical quality improvement program database. 
J Endourol.2021. Epub 2020/09/17. doi: 10.1089/end.2020.0597. 
PubMed PMID: 32935596.

22. Austin PC, Stuart EA. Moving towards best practice when using 
inverse probability of treatment weighting (IPTW) using the propensity 
score to estimate causal treatment effects in observational studies. 
Stat Med.2015;34(28):3661-79. Epub 2015/08/03. doi: 10.1002/
sim.6607. PubMed PMID: 26238958.

23. Meyer D, Weprin S, Zukovski EB, Porpiglia F, Hampton LJ, Autorino 
R. Rationale for robotic-assisted simple prostatectomy for benign 
prostatic obstruction. Eur Urol Focus.2018;4(5):643-7. doi: https://doi.
org/10.1016/j.euf.2018.07.007.

24. Lucca I, Shariat SF, Hofbauer SL, Klatte T. Outcomes of minimally 
invasive simple prostatectomy for benign prostatic hyperplasia: a 
systematic review and meta-analysis. World J Urol.2015;33(4):563-70. 
doi: 10.1007/s00345-014-1324-3.

25. Autorino R, Zargar H, Mariano MB, Sanchez-Salas R, Sotelo RJ, 
Chlosta PL, et al. Perioperative outcomes of robotic and laparoscopic 
simple prostatectomy: a European–American multi-institutional 
analysis. Eur Urol.2015;68(1):86-94. doi: https://doi.org/10.1016/j.
eururo.2014.11.044.

26. Elshal AM, Elmansy HM, Elhilali MM. Transurethral laser surgery 
for benign prostate hyperplasia in octogenarians: safet y and 
outcomes. Urology.2013;81(3):634-9. Epub 2013/01/22. doi: 10.1016/j.
urology.2012.11.042. PubMed PMID: 23332997.

27. Sivarajan G, Borofsky MS, Shah O, Lingeman JE, Lepor H. The role 
of minimally invasive surgical techniques in the management of 
large-gland benign prostatic hypertrophy. Rev Urol.2015;17(3):140-9. 
PubMed PMID: 26543428.

28. Rivera M, Krambeck A, Lingeman J. Holmium laser enucleation 
of the prostate in patients requiring anticoagulation. Curr Urol 
Rep.2017;18(10):77. Epub 2017/08/07. doi: 10.1007/s11934-017-0727-2. 
PubMed PMID: 28780634.

29. El Tayeb MM, Jacob JM, Bhojani N, Bammerlin E, Lingeman JE. 
holmium laser enucleation of the prostate in patients requiring 
anticoagulation. J Endourol.2016;30(7):805-9. Epub 05/03. doi: 
10.1089/end.2016.0070. PubMed PMID: 27065437.

30. Li J, Cao D, Peng L, Ren Z, Gou H, Li Y, et al. comparison between 
minimally invasive simple prostatectomy and open simple 
prostatectomy for large prostates: a systematic review and meta-
analysis of comparative trials. J Endourol.2019;33(9):767-76. Epub 
2019/06/28. doi: 10.1089/end.2019.0306. PubMed PMID: 31244334.

31. Juaneda R, Thanigasalam R, Rizk J, Perrot E, Theveniaud PE, Baumert H. 
Holmium laser enucleation versus laparoscopic simple prostatectomy 
for large adenomas. Actas Urol Esp.2016;40(1):43-8. Epub 07/29. doi: 
10.1016/j.acuro.2015.05.010. PubMed PMID: 26233479.

32. Kampantais S, Dimopoulos P, Tasleem A, Acher P, Gordon K, Young A. 
assessing the learning curve of holmium laser enucleation of prostate 
(HoLEP). A systematic review. Urology.2018;120:9-22. Epub 07/04. doi: 
10.1016/j.urology.2018.06.012. PubMed PMID: 30403609.

33. Peyronnet B, Robert G, Comat V, Rouprêt M, Gomez-Sancha F, 
Cornu J-N, et al. Learning curves and perioperative outcomes after 
endoscopic enucleation of the prostate: a comparison between 
GreenLight 532-nm and holmium lasers. World J Urol.2017;35(6):973-
83. Epub 10/20. doi: 10.1007/s00345-016-1957-5. PubMed PMID: 
27766387.

34. Humphreys MR, Miller NL, Handa SE, Terry C, Munch LC, Lingeman JE. 
Holmium laser enucleation of the prostate--outcomes independent of 
prostate size? J Urol.2008;180(6):2431-5. Epub 10/19. doi: 10.1016/j.
juro.2008.08.019. PubMed PMID: 18930490.

35. Heidar NA, Labban M, Misrai V, Mailhac A, Tamim H, El-Hajj A. Laser 
enucleation of the prostate versus transurethral resection of the 
prostate: perioperative outcomes from the ACS NSQIP database. 
World J Urol.2020. doi: 10.1007/s00345-020-03100-7.

36. Nestler S, Bach T, Herrmann T, Jutzi S, Roos FC, Hampel C, et al. 
Surgical treatment of large volume prostates: a matched pair analysis 
comparing the open, endoscopic (ThuVEP) and robotic approach. World 
J Urol.2019;37(9):1927-31. Epub 12/04. doi: 10.1007/s00345-018-
2585-z. PubMed PMID: 30515596.

37. Sutherland DE, Perez DS, Weeks DC. Robot-assisted simple 
prostatectomy for severe benign prostatic hyperplasia. J Endourol. 
2011;25(4):641-4. Epub 2011/03/19. doi: 10.1089/end.2010.0528. 
PubMed PMID: 21413877.

38. Salonia A, Suardi N, Naspro R, Mazzoccoli B, Zanni G, Gallina 
A, et al. Holmium laser enucleation versus open prostatectomy 
for benign prostatic hyperplasia: an inpatient cost analysis. 
Urology.2006;68(2):302-6. Epub 2006/08/15. doi: 10.1016/j.urology. 
2006.02.007. PubMed PMID: 16904441.

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SUPPLEMENTARY TABLE 1A. 

Comparison of baseline demographics before and after propensity score matching for anatomic enucleation  
of the prostate (AEEP) and open simple prostatectomy (OSP) 
 

Variable

Before matching After matching

OSP AEEP
P -value

OSP AEEP
P -value

n (%) n (%) n (%) n (%)

Age ≥ 68* (median age) 861 (57.9) 1488 (52.4) 0.001 323 (61.5) 531 (55.7) 0.03

ASA ≥ 3 706 (47.3) 1331 (46.4) 0.587 252 (48.1) 443 (46.4) 0.549

Dependent functional status 52 (1.8) 20 (1.3) 0.262 6 (1.1) 14 (1.5) 0.649

BMI ≥ 30 546 (36.6) 986 (34.4) 0.151 200 (38.2) 345 (36.1) 0.464

Diabetes mellitus 270 (18.1) 522 (18.2) 0.934 96 (18.3) 174 (18.2) 0.962

COPD 47 (3.2) 115 (4.0) 0.177 14 (2.7) 32 (3.4) 0.533

Congestive heart failure 4 (0.3) 12 (0.4) 0.6 1 (0.2) 2 (0.2) 0.938

Hypertension 861 (57.7) 1646 (57.4) 0.872 303 (57.8) 549 (57.5) 0.912

Bleeding disorder 28 (1.9) 89 (3.1) 0.018 8 (1.5) 20 (2.1) 0.551

Year of operation ≥ 2014 988 (66.2) 2072 (72.3) < 0.001 315 (60.0) 642 (67.2) 0.006

ASA: American Society of Anesthesia; BMI: body mass index; COPD: chronic obstructive pulmonary disease 

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SUPPLEMENTARY TABLE 1B. 

Comparison of baseline demographics before and after propensity score matching for robotic-assisted simple 
prostatectomy (RASP) and open simple prostatectomy (OSP)

Variable

Before matching After matching

OSP RASP
P -value

OSP RASP
P -value

n (%) n (%) n (%) n (%)

Age ≥ 68 (median age) 861 (57.9) 133 (56.8) 0.759 741 (57.8) 113 (57.4) 0.938

ASA ≥ 3 706 (47.3) 101 (43.2) 0.260 610 (47.5) 85 (43.4) 0.283

Dependent functional status 20 (1.3) 2 (0.9) 0.758 18 (1.4) 2 (1.0) 0.761

BMI ≥ 30 546 (36.6) 72 (30.8) 0.092 483 (37.6) 62 (31.6) 0.112

Diabetes mellitus 270 (18.1) 44 (18.8) 0.855 234 (18.2) 36 (18.4) 1

COPD 47 (3.2) 7 (3.0) 1 40 (3.1) 6 (3.0) 1

Congestive heart failure 4 (0.3) 0 (0.0) 0.649 3 (0.2) 0 (0.0) 1

Hypertension 861 (57.7) 144 (61.5) 0.285 732 (57.1) 120 (60.9) 0.316

Bleeding disorder 28 (1.9) 2 (0.9) 0.305 26 (2.0) 2 (1.0) 0.416

Year of operation ≥ 2014 988 (66.2) 120 (51.3) < 0.001 883 (68.9) 105 (53.6) < 0.001

ASA: American Society of Anesthesia; BMI: body mass index; COPD: chronic obstructive pulmonary disease

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SUPPLEMENTARY TABLE 1C.  

Comparison of baseline demographics before and after propensity score matching for open  
simple prostatectomy (OSP) and robotic assisted simple prostatectomy (RASP)

Variable

Before matching After matching

RASP AEEP
P -value

OSP RASP
P -value

n (%) n (%) n (%) n (%)

Age ≥ 68 (median age) 133 (56.8) 1488 (52.4) 0.189 177 (56.5) 1357 (51.9) 0.219

ASA ≥ 3 101 (43.2) 1331 (46.4) 0.341 88 (42.7) 1211 (46.3) 0.345

Dependent functional status 2 (0.9) 52 (1.8) 0.321 2 (1.0) 44 (1.7) 0.578

BMI ≥ 30 72 (30.8) 986 (34.4) 0.282 64 (31.1) 915 (35.0) 0.287

Diabetes mellitus 101 (43.2) 1331 (46.4) 0.341 38 (18.4) 477 (18.2) 1

COPD 2 (0.9) 52 (1.8) 0.321 6 (2.9) 106 (4.1) 0.468

Congestive heart failure 72 (30.8) 986 (34.4) 0.282 0 (0.0) 12 (0.5) 0.619

Hypertension 101 (43.2) 1331 (46.4) 0.341 126 (60.9) 1492 (57.1) 0.307

Bleeding disorder 2 (0.9) 89 (3.1) 0.065 2 (1.0) 85 (3.3) 0.089

Year of operation ≥ 2014 120 (51.3) 2072 (72.3) < 0.001 112 (54.4) 1946 (74.4) < 0.001

ASA: American Society of Anesthesia; BMI: body mass index; COPD: chronic obstructive pulmonary disease

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