A Prospective, Randomized Controlled Study Comparing the Integrated Posterior-Anterior-Lateral (PAL) Approach and the Posterior Approach in Robot-Assisted Radical Prostatectomy: Evaluation of Perioperative Outcomes, Postoperative Functional Recovery, and Oncologic Control
Phase: NA
Conditions: Urologic Cancer, Prostate, Robot Assisted Laparoscopic Radical Prostatectomy
Sponsor: The First Affiliated Hospital of Zhengzhou University

Research Protocol Version: V1.0, Date: 2024/05/15 
A Prospective, Randomized Controlled Study 
Comparing the Integrated Posterior–Anterior–
Lateral (PAL) Approach and the Posterior 
Approach in Robot-Assisted Radical 
Prostatectomy 
Research Protocol 
 
 
Research Unit：The First Affiliated Hospital of 
Zhengzhou University 
Principal Investigator：Xuepei Zhang 
Contact Number：13837110911 
NCT ID：Not yet assigned 
 
 
 
 
 
 
May 15, 2024 
 
 

Research Protocol Version: V1.0, Date: 2024/05/15 
I. Research Background 
Radical prostatectomy is the standard treatment for localized prostate 
cancer. Rassweiler et al. first reported robot-assisted radical prostatectomy 
(RARP) in 2001. Given the Da Vinci robot's high-definition three-
dimensional imaging technology and flexible yet stable robotic arms, it is 
particularly suited for performing more precise dissection, anatomy, and 
suturing within confined spaces. Consequently, RARP has rapidly gained 
popularity worldwide and has even replaced traditional laparoscopic and 
open surgery in some hospitals. Patel et al. proposed the "pentafecta" for 
radical prostatectomy: long-term cancer control, urinary continence 
preservation, erectile function preservation, absence of surgical 
complications, and negative surgical margins. This remains the goal 
pursued by urologists. To achieve better treatment outcomes for patients, 
surgeons domestically and internationally have conducted in-depth 
research on various RARP approaches, such as the anterior approach, 
posterior approach lateral approach, and transvesical approach. However, 
each RARP approach has its own advantages and disadvantages. To 
maximize the benefits of each approach, based on our center's experience 
with over 1000 radical prostatectomies, we were the first in China to 
propose the PAL combined approach RARP in 2022. This approach 
involves initially using the posterior approach to separate the vas deferens, 
seminal vesicles, and Denonvilliers' fascia, followed by the anterior 

Research Protocol Version: V1.0, Date: 2024/05/15 
approach to separate the retropubic space, and then the lateral approach to 
separate the bladder neck and preserve the neurovascular bundles (NVB) 
as much as possible. 
II. Study Objectives 
(1) Study Objective 
    This study aims to compare the perioperative outcomes, pathological 
results, and early functional outcomes of the PAL combined approach 
RARP and the posterior approach (Retzius-sparing) RARP in the 
treatment of prostate cancer. 
(2) Study Significance 
1. To provide a new, safe, and effective surgical approach (not a non-
surgical method) for robotic radical prostatectomy in clinical 
practice. 
2. To provide a better foundation for the application of the PAL 
combined approach RARP. 
III. Research Trial Management 
The center will appoint one Principal Investigator overall, one Co-
Investigator, and one Lead Statistician. Standardized statistical analysis 
methods will be applied. The trial will be conducted strictly in accordance 
with the protocol, ensuring the timely, accurate, and truthful completion 

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of case report forms. Researchers will receive training prior to the trial's 
initiation to familiarize themselves with the study protocol and unify 
assessment criteria. 
Laboratory test reports must contain all essential items, including the 
date, test items, test results, and their normal reference ranges. A strict 
serious adverse event reporting system will be established. 
If you have any questions regarding this study, you may contact the 
Principal Investigator. 
Name 
Role in Study 
Phone Number  
Xuepei Zhang 
Principal Investigator 
13837110911 
Jinshan Cui 
Investigator 
13243131252 
Jin Tao 
Investigator 
- 
Yunlong Liu 
Investigator 
- 
Zhenhao LI 
Investigator 
- 
IV. Rationale for the Trial 
1. Surgeons domestically and internationally have conducted in-depth 
research on various RARP approaches, such as the anterior, posterior, 
lateral, and transvesical approaches. However, each RARP approach 
has its own advantages and disadvantages. 
2. Our center was the first in China to propose the PAL combined 
approach RARP in 2022. This approach involves initially using the 
posterior approach to separate the vas deferens, seminal vesicles, and 
Denonvilliers' fascia, followed by the anterior approach to separate the 
retropubic space, and then the lateral approach to separate the bladder 
neck and preserve the neurovascular bundles (NVB) as much as 

Research Protocol Version: V1.0, Date: 2024/05/15 
possible. There are currently no prospective studies comparing this 
combined approach with other approaches. 
V. Subject Selection and Withdrawal 
(1) Inclusion Criteria: 
Age ≥ 40 years and ≤ 80 years; 
Patients diagnosed with prostate cancer by prostate biopsy; 
Clinical T stage ≤ T3a; 
Full understanding of the clinical trial protocol and provision of signed 
informed consent. 
Any outpatient or inpatient volunteer patient who meets all the above 
criteria can be enrolled as a subject. 
(2) Exclusion Criteria: 
Pre-existing urinary incontinence; 
Previous endoscopic prostate surgery; 
Presence of severe underlying diseases rendering the patient unable to 
tolerate surgery or with a life expectancy of < 5 years; 
Presence of metastatic disease or suspected lymph node involvement at 
diagnosis; 
Patients deemed by the investigator as unsuitable for participation in 
this clinical trial. 
  Any patient meeting any of the above criteria cannot be enrolled as a 
subject. 
(3) Discontinuation (Withdrawal) Criteria: 
This refers to all patients who have signed the informed consent form, 
passed screening, and entered the trial but subsequently withdraw from 
the clinical trial. 
Common reason: The patient requests to stop the trial. 

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When a patient discontinues, the investigator must record the reason 
for discontinuation in the case report form and complete all possible 
assessments and examinations, documenting the last condition, 
including the last trial-related procedures performed. For 
discontinuations due to adverse events, this must be recorded in the 
case report form, and the sponsor must be notified. Discontinued cases 
will be included in the analysis according to different scenarios. 
VI. Study Protocol 
Study Design 
This is a prospective, randomized controlled, single-center clinical study. 
It primarily aims to compare the perioperative outcomes, pathological 
results, and early functional outcomes of PAL combined approach RARP 
and posterior approach (Retzius-sparing) RARP in the treatment of 
prostate cancer. All patients meeting the inclusion/exclusion criteria will 
be randomly assigned to one of two groups: the PAL combined approach 
group or the posterior approach group. This study plans to enroll no fewer 
than 30 patients per group. 
Inclusion Criteria 
Detailed inclusion and exclusion criteria are listed above. The key 
inclusion criterion is patients diagnosed with prostate cancer by biopsy 
and scheduled to undergo robot-assisted radical prostatectomy. 
Randomization 
Eligible subjects will be randomized in a 1:1 ratio to either the PAL 
combined approach group or the posterior approach group. The 
randomization process will be performed by an independent, dedicated 
statistician. 
Surgical Methods 

Research Protocol Version: V1.0, Date: 2024/05/15 
All patients will undergo surgery according to the standard procedures for 
robot-assisted radical prostatectomy. 
Posterior Approach (Retzius-sparing) RARP: Adhesions of the 
sigmoid colon are first released to expose the pouch of Douglas. The 
peritoneum is incised at the rectovesical pouch, taking care not to damage 
the ureters. The bilateral vas deferens are carefully dissected. Following 
the bilateral vas deferens leads to the identification and dissection of the 
bilateral seminal vesicles. The small arteries of the seminal vesicles can 
be managed using Hem-O-lok clips before cold knife transection, or 
using bipolar coagulation before transection. The bilateral seminal 
vesicles are freed. Denonvilliers' fascia is incised, and blunt dissection is 
performed along the anterior rectal fat plane towards the prostate apex. 
The parietal peritoneum of the rectovesical reflection is incised. The 
seminal vesicles and vas deferens are dissected and transected. 
Denonvilliers' fascia is incised transversely. Blunt dissection is performed 
along the posterior plane of the prostate towards the apex. The bladder 
neck is dissected and incised. Blunt dissection is performed intrafascially 
towards the apex. The puboprostatic ligaments and posterior urethra are 
dissected and transected, and the prostate is completely removed. 
PAL Combined Approach RARP:   Posterior Access  The 
sigmoid colon was mobilized, and dissection proceeded along the 
posterior bladder wall to expose the pouch of Douglas. The rectovesical 
peritoneal reflection was incised to identify and preserve the bilateral 
ureters, vas deferens, and seminal vesicles. Dissection was performed 
dorsal to the seminal vesicles to identify and open Denonvilliers' fascia. 
The fascia was then dissected along the posterior plane of the prostate 
until reaching the prostatic apex, with careful attention to avoiding rectal 
injury. The vas deferens was subsequently transected, and the seminal 
vesicles were dissected. A triangular anatomical zone was developed 

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between the bladder neck, prostate base, and right neurovascular bundle 
to facilitate subsequent dissection steps. Anterior Access  The 
preperitoneal space was developed by dividing the medial umbilical 
ligaments and the urachus, gaining access to the retropubic space (Fig. 
1D). At this stage, the dorsal vascular complex was left intact. The 
endopelvic fascia, puboprostatic ligaments, and other anterior supporting 
structures were preserved to maintain anatomical integrity. Lateral 
Access  The dissection plane along the bladder neck was defined. 
Building on the previously developed posterior plane, the triangular space 
bordered by the bladder, prostate base, and neurovascular bundle was 
further expanded. The mobilized seminal vesicles were retracted through 
this corridor to provide controlled traction. The bladder neck was then 
sharply divided close to the prostate, releasing any residual attachments 
and preserving surrounding muscle and connective tissue. The prostatic 
pedicles were subsequently clipped and dissected under direct vision to 
maintain hemostasis and anatomical precision. Neurovascular Bundle 
Dissection  With the right seminal vesicle retracted toward the midline, a 
working plane was developed between the prostatic capsule and 
surrounding fascia. Dissection proceeded in an antegrade manner to 
release the neurovascular bundle without the use of thermal energy. The 
same approach was applied to the contralateral side to ensure bilateral 
nerve preservation. Apical Dissection and Urethral Division  The 
prostate was elevated cephalad to expose the apex and adjacent posterior 
structures. Dissection at the apical region was performed with careful 
attention to preserving the maximal length of the urethral stump. Blunt 
and sharp dissection was carried out beneath the dorsal venous complex 
to avoid injury to anterior vascular structures. The pelvic fascia and 
puboprostatic ligaments were preserved. The urethra was then incised 
posteriorly under direct vision, completing the apical dissection and 

Research Protocol Version: V1.0, Date: 2024/05/15 
allowing for en bloc removal of the prostate. After prostate dissection, 
continuous urethrovesical anastomosis was performed using a 3-0 suture. 
VII. Observation Indicators 
Primary Observation Indicator: 
The primary observation indicator is the urinary continence rate after 
catheter removal. The urinary continence rate is defined as the number of 
patients with recovered continence per group divided by the total number 
of patients in that group. Urinary continence rates will be assessed at 1 day, 
1 week, 3 months, 6 months, and 1 year after catheter removal. Recovery 
of urinary continence is defined as not using any pads or using only 1 safety 
pad per day with no leakage. Urinary incontinence is defined as using more 
than 1 pad per day. Immediate continence and early continence are defined 
as recovery of continence within 7 days and within 3 months after catheter 
removal, respectively. 
Secondary Observation Indicators: 
(1) Perioperative indicators, such as: operative time, estimated blood loss, 
intraoperative and postoperative complications, time to drain removal, 
postoperative hospital stay; 
(2) Positive surgical margin status in the pathology report. 
VIII. Ethical Requirements and Patient Informed Consent 
This clinical trial will be conducted in accordance with the Declaration of 

Research Protocol Version: V1.0, Date: 2024/05/15 
Helsinki (1996 version) and relevant Chinese regulations and guidelines 
for clinical trial research. The trial protocol must be approved by the Ethics 
Committee of each participating institution before the trial commences. 
Before each patient is enrolled in this trial, the investigating physician is 
responsible for providing a complete and comprehensive explanation, in 
written form, to the patient or their designated representative, regarding the 
trial's purpose, procedures, and potential risks. Patients should be informed 
that they have the right to withdraw from the trial at any time. Each patient 
must be given a copy of the informed consent form before enrollment. The 
investigating physician is responsible for ensuring that each patient signs 
the informed consent form before entering the trial and for retaining the 
form in the study files. 
IX. Statistical Analysis 
Statistical tests will employ parametric methods or models wherever 
possible. All statistical tests for indicators will be two-sided, and a P-value 
≤ 0.05 will be considered statistically significant. 
Descriptive statistics for quantitative indicators will include the mean, 
standard deviation, median, and interquartile range. Descriptive statistics 
for categorical indicators will include counts and percentages. Statistical 
analysis will be performed using professional software such as SPSS, SAS, 
and R. 

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X. Data Retention 
The investigator shall retain all study documents, including identification 
of all participating subjects (enabling effective cross-referencing of 
different records, such as hospital source records), all original signed 
informed consent forms, and all case report forms, etc. The investigator 
shall retain the clinical trial data for 5 years after the completion of the 
clinical trial. 
XI. Expected Timeline for the Clinical Trial 
(1) Trial preparation period: Month 1. 
(2) Clinical trial observation period: Months 2 – 8. 
(3) Data collection, statistical analysis, and summarization period: Months 
8 -18.