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Ejaculatory Behavior and Seminal Vesicle Size During Radical Prostatectomy

Impact of Preoperative Ejaculation or Abstinence on Seminal Vesicle Size and Intraoperative Dissection Parameters During Radical Prostatectomy: A Randomized Controlled Trial

Status
Not yet recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07243795
Acronym
PreRP-EJAC
Enrollment
40
Registered
2025-11-24
Start date
2025-12-01
Completion date
2026-10-09
Last updated
2025-12-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Prostate Cancer Patients Undergoing Radical Prostatectomy

Keywords

Prostate Cancer, Radical Prostatectomy, Seminal Vesicle, Ejaculation, Abstinence, Surgical Dissection

Brief summary

The goal of this clinical trial is to learn if recent ejaculation or abstinence before surgery affects seminal vesicle size and dissection-related surgical factors in adult men with prostate cancer undergoing radical prostatectomy. The main questions it aims to answer are: Does ejaculation within 36 hours before surgery reduce seminal vesicle size compared to abstinence of 72 hours or more? Does seminal vesicle size affect the ease or difficulty of surgical dissection during radical prostatectomy? Researchers will compare an ejaculation group to an abstinence group to see if seminal vesicle volume and intraoperative surgical parameters differ between them. Participants will: Follow specific instructions to either ejaculate or abstain before surgery Undergo a transrectal ultrasound (TRUS) to measure seminal vesicle size after anesthesia but before surgery Have their surgical dissection time and difficulty rated by the operating surgeon

Detailed description

Radical prostatectomy (RP) remains a cornerstone treatment for localized prostate cancer. During RP, the anatomical dissection of seminal vesicles (SVs) can be challenging, and SV volume may influence intraoperative visibility, dissection ease, and the risk of complications. Recent imaging studies suggest that ejaculatory activity significantly affects SV size. In particular, abstinence has been associated with larger SV volumes on MRI and TRUS, while ejaculation may lead to temporary SV shrinkage. These physiological changes, though well-documented radiologically, have not been systematically studied in a surgical setting. This trial aims to explore whether ejaculatory behavior in the days before RP alters the surgical anatomy and impacts dissection-related metrics. Forty adult male patients with biopsy-confirmed prostate cancer, scheduled for RP, will be randomized in a 1:1 ratio into two groups: Ejaculation group: At least one ejaculation within 36 hours preoperatively. Abstinence group: No ejaculation for ≥72 hours before surgery. Under anesthesia and prior to surgery, transrectal ultrasound (TRUS) will be performed to measure bilateral SV dimensions. The average volume will serve as the primary endpoint. Intraoperative outcomes include dissection time, visual clarity, and perceived difficulty rated by the primary surgeon using a Likert scale. SV volume from final pathology reports will also be collected and compared. This is a low-risk, behavior-based interventional study involving no experimental drug or device. The main purpose is to assess whether preoperative sexual behavior can be optimized to improve surgical planning and efficiency. Alpha-blocker usage and other potential confounders will be documented and adjusted for in the analysis. If significant anatomical or procedural differences are observed, findings from this study may inform future multicenter research and guide preoperative patient counseling for RP.

Interventions

BEHAVIORALRecent Ejaculation

Participants are instructed to ejaculate at least once within 36 hours prior to radical prostatectomy. This behavioral intervention is used to evaluate its effect on seminal vesicle volume and intraoperative dissection parameters.

BEHAVIORALPreoperative Abstinence

Participants are instructed to abstain from ejaculation for at least 72 hours prior to radical prostatectomy. This behavioral intervention is used to assess whether prolonged seminal vesicle filling affects intraoperative anatomy and dissection.

Sponsors

National Taiwan University Hospital
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
SINGLE (Outcomes Assessor)

Masking description

The operating surgeon was masked to the participant's group assignment. Group allocation was concealed until after surgery. Neither the participant nor the research investigator performing TRUS was masked.

Intervention model description

Participants will be randomly assigned in a 1:1 ratio to either a recent ejaculation group or an abstinence group before radical prostatectomy.

Eligibility

Sex/Gender
MALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Male patients aged 18 years or older * Histologically confirmed prostate cancer * Scheduled for radical prostatectomy * Able and willing to comply with assigned ejaculation or abstinence protocol * Willing to complete preoperative questionnaire * Willing to undergo transrectal ultrasound (TRUS) 12-14 hours before surgery * Able to understand and sign informed consent

Exclusion criteria

* Prior bilateral seminal vesicle resection or congenital absence of seminal vesicles * Anatomical abnormalities preventing SV identification * Hormone therapy within 6 months before surgery * Inability to recall ejaculation history in the past 3 days * Inability to follow behavioral instructions or TRUS protocol * Severe anorectal disease or history of anorectal surgery preventing TRUS * Cognitive or psychiatric conditions impairing informed consent * Incomplete data or poor-quality imaging * Prior prostate cancer treatment * Belonging to a vulnerable population (e.g., minors, prisoners, pregnant individuals, cognitively impaired, etc.)

Design outcomes

Primary

MeasureTime frameDescription
Seminal vesicle volume measured by preoperative transrectal ultrasound (TRUS)12-14 hours before surgery (afternoon prior to operation)Seminal vesicle volume is measured by the research investigator using transrectal ultrasound (TRUS) in the outpatient ultrasound room approximately 12-14 hours before surgery. Both vesicles are measured in three dimensions (length × width × height), and the average volume is calculated using the ellipsoid formula (L × W × H × 0.52). The values will be compared between groups with recent ejaculation versus abstinence.

Secondary

MeasureTime frameDescription
Dissection time of seminal vesicles during radical prostatectomyDuring surgery (intraoperative)The time required for bilateral seminal vesicle dissection is recorded in minutes from surgical video or intraoperative notes.
Surgical difficulty score of seminal vesicle dissectionImmediately after SV dissection during surgeryThe primary surgeon rates the difficulty of SV dissection on a Likert scale from 1 (very easy) to 5 (very difficult), based on anatomical clarity and tissue handling.
Intraoperative visual clarity score of seminal vesiclesDuring SV dissection, intraoperativelyThe operating surgeon rates visual clarity of the surgical field (especially SV region) using a Likert scale from 1 (very poor) to 5 (excellent).
Seminal vesicle volume reported in postoperative pathologyWithin 7 days after surgery (postoperative pathology report)Pathology reports include three-dimensional measurements of both SVs. Final volume is calculated using the same ellipsoid formula and compared with TRUS findings.

Countries

Taiwan

Contacts

Primary ContactYen Ho, M.D.
yenho.md@gmail.com+886933092258

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026