Efficacy and Safety of Modified Prostatic Urethral Lift (mPUL-ZA) for Benign Prostatic Hyperplasia

Abstract

Background:

Transurethral prostatic suspension and expansion, internationally referred to as prostatic urethral lift (PUL), is a minimally invasive treatment for lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH). However, implant deployment at the prostatic apex may be technically difficult because of limited lateral operating space and obstruction by the pubic arch. A modified technique involving zero-angle firing and needle-guided puncture was developed to facilitate implant placement in this region.

Objective:

This study aims to evaluate the feasibility, preliminary efficacy, and safety of the modified transurethral prostatic suspension and expansion procedure using zero-angle firing and needle-guided puncture in men with BPH-related lower urinary tract symptoms.

Methods:

This is a prospective, single-center, single-arm, open-label exploratory interventional study involving 12 male participants. The principal eligibility criteria include an age of 50-80 years, a prostate volume of 30-80 mL, an International Prostate Symptom Score (IPSS) greater than 12, a maximum urinary flow rate (Qmax) of 15 mL/s or less with a voided volume of at least 125 mL, and a post-void residual urine volume (PVR) of less than 350 mL. Patients with previous prostate surgery, confirmed or suspected prostate cancer, neurogenic bladder, urethral stricture, severe coagulation disorders, or anticoagulant therapy that cannot be safely discontinued or adjusted will be excluded.

All participants will undergo the modified transurethral prostatic suspension and expansion procedure. Implants will be deployed in the proximal and middle portions of the prostate using the conventional technique. At the prostatic apex, particularly when lateral rotation is restricted or pubic arch interference is anticipated, the delivery device will be maintained at the urethral midline in a neutral, zero-angle orientation. The needle will be fired in this position, followed by incremental manual compression to facilitate adequate tissue capture and needle-guided penetration of the prostatic capsule. The implant will then be tensioned and deployed.

Participants will be evaluated at baseline and followed at 14 days, 30 days, 90 days, and 12 months after surgery. The primary outcome is the change in IPSS from baseline to 90 days after surgery. Secondary outcomes include changes in quality-of-life score, Qmax, PVR, and Sexual Health Inventory for Men score; technical success; operative time; number of implants; estimated blood loss; catheterization duration; and length of hospital stay. Safety outcomes include gross hematuria, urinary urgency, dysuria, urinary retention, re-catheterization, urinary tract infection, urethral stricture, readmission, device-related adverse events, secondary intervention, and reoperation.

Continuous outcomes will be summarized using appropriate descriptive statistics and compared between baseline and follow-up using a paired-samples t-test or Wilcoxon signed-rank test, depending on the distribution of paired differences. Categorical variables will be reported as frequencies and percentages. All statistical tests will be two-sided, with a significance level of 0.05. Given the exploratory nature and small sample size, effect estimates and confidence intervals will be emphasized alongside P values.

Expected significance:

This study is expected to provide preliminary evidence regarding whether zero-angle firing and needle-guided puncture can facilitate implant deployment at the prostatic apex while improving urinary symptoms, urinary flow, and quality of life without adversely affecting erectile function. The findings may support the design of subsequent multicenter, controlled studies with larger sample sizes.

Keywords:

benign prostatic hyperplasia; lower urinary tract symptoms; transurethral prostatic suspension and expansion; prostatic urethral lift; zero-angle firing; needle-guided puncture; minimally invasive treatment

Registration information:

Study period: June 1, 2023 to December 31, 2023; ethics approval date: August 31, 2023; ethics approval number: S2023-493-01; principal investigator: Qing Yuan; planned sample size: 20 participants; registration status: retrospectively registered.

Inclusion criteria

• Male patients aged 50 to 80 years old;
• Clinically diagnosed with benign prostatic hyperplasia accompanied by lower urinary tract symptoms;
• Prostate volume measured by transabdominal or transrectal ultrasonography ranges from 30 mL to 80 mL;
• International Prostate Symptom Score (IPSS) > 12 points;
• Maximum urinary flow rate (Qmax) ≤ 15 mL/s;
• Voided volume ≥ 125 mL during uroflowmetry examination;
• Post-void residual urine volume (PVR) measured by ultrasonography < 350 mL;
• Having sexual intercourse within 6 months prior to enrollment;
• Sexual Health Inventory for Men (SHIM) score > 6 points;
• Preoperative clinical assessment confirms preservation of antegrade ejaculation;
• Judged by the investigator to be eligible for prostatic urethral lift;
• Able to understand the study content and voluntarily sign the written informed consent form;
• Able to complete all scheduled follow-up visits in accordance with the study protocol.

Exclusion criteria

• Urethral conditions that preclude insertion of a 20F cystoscopic scope;
• History of TURP, laser surgery, pelvic surgery, or radiotherapy;
• Total prostate-specific antigen (tPSA) > 10 ng/mL, or history of prostate cancer or bladder cancer;
• Neurogenic bladder, urethral stricture, severe coagulopathy, or concurrent use of anticoagulants contraindicated for the procedure;
• Intra-prostatic protrusion (IPP) > 1 cm;
• Other medical conditions or comorbidities contraindicating HoLEP or PUL;
• Refusal to disclose sexual function status.