Comparison of Hiraoka’s Transurethral Detachment Prostatectomy and Transurethral Resection of the Prostate Effects on Postoperative Erectile Function in Patients With Benign Prostatic Hyperplasia: A Prospective Randomized Controlled Study

Chunyu Pan, MD; Yunhong Zhan, PhD, MD; Yueyang Zhao, PhD, MD; Bin Wu, MD, PhD; Song Bai, PhD, MD

FIRST PUBLISHED: July 11, 2020 – The Journal of Sexual Medicine

DOI: https://doi.org/10.1016/j.jsxm.2020.06.001

Introduction

Men with benign prostatic hyperplasia (BPH) often cope with lower urinary tract symptoms (LUTS) and other symptoms that negatively affect their quality of life. Medications may help, but about 30% of patients have surgery.

Transurethral resection of the prostate (TURP) is considered the gold standard surgical procedure. In past studies, some men have developed erectile dysfunction (ED) after TURP, while others found that their erectile function improved.

Hiraoka et al. has developed a procedure called transurethral detachment prostatectomy (TUDP), described as “the first endoscopic enucleation of the prostate using a prostate-detaching blade.” TUDP uses a “cold knife blunt detachment approach through the urethra under direct endoscopic supervision” and has some advantages such as shorter surgery time, low amount of perioperative bleeding and high resection rate of hyperplastic tissue.

The current paper was a single-center randomized controlled study that compared postoperative erectile function after TURP and TUDP.

Materials and Methods 

Patients

The final study cohort included 104 men who were diagnosed with BPH between September 2018 and February 2019 and were randomly divided into the TUDP and TURP groups. Fifty-two men underwent TURP procedures, and the remaining 52 had TUDP surgery.

All of the men had moderate or severe LUTS, recurrent urinary retention, recurrent hematuria that could not be managed with conservative treatment, recurrent urinary tract infection, prostate volume between 30 mL and 100 mL, and a regular sex life before and after surgery.

Hiraoka’s TUDP Surgical Method

Hiraoka’s TUDP surgical method was described as follows:

“Surgical instruments included Hiraoka’s prostate-detaching blade (Olympus, Tokyo, Japan), needle-shaped cutting electrode and cutting loop, 26 Fr continuous-flow sheath and resectoscope (Olympus, Tokyo, Japan), 26 Fr Storz nephroscope, and Lumenis VersaCut Tissue Morcellator (Israel).

“Patients were placed in a lithotomy position after anesthesia. A resectoscope was inserted into the urethra. Circumferential marks were then made at the junction of distal adenoma and proximal external urethral sphincter with a loop electrode. Then, a circumferential incision with a depth of 3–4 mm was made in the urethral mucosa along the marks previously made with a needle-shaped cutting electrode. The incision was parallel to the anterior oblique position of the sphincter. Hiraoka’s prostate-detaching blade was then inserted at the incision lines previously made in the urethral mucosa at the 5 or 7 o’clock positions and exposed the smooth surface of the surgical capsule. Under direct vision, hyperplastic prostate tissues are white, fibrous, and dense. The surgical capsule is spongy and soft, with transversely running vessels. Once the detaching plane was exposed, it was expanded anteriorly and laterally. If the visual field is affected by bleeding, there is need to change loop electrodes to stop bleeding. Detachment was stopped at the bladder neck to avoid complications, such as more bleeding, moving astray from the detaching plane, and capsular perforation, especially at the 6 o’clock position, which should be treated last because of rich blood supply and closely linked hyperplastic tissues. Anterior muscle fibers were detached at the 12 o’clock position with a prostate-detaching blade before extending to the left and right sides and stopping at the 5 and 7 o’clock positions. Hyperplastic tissues were resected at the 5–7 o’clock positions from the bladder neck with a cutting electrode. The detached adenoma was then pushed into the bladder. Finally, the dissected adenoma was cut into smaller pieces with a morcellator.”

TURP Surgical Method 

The TURP surgical method was described in this way:

“Surgical instruments included 26 Fr continuous-flow sheath and resectoscope (Karl Storz) and monopolar cutting loops (diameter 0.8 mm, cutting power 120 W, coagulation power 80 W, irrigation fluid: mannitol). The surgical procedure was similar to that previously reported in the literature.”

Outcome Measures and Follow-Up

The 5-item International Index of Erectile Function (IIEF-5) and minimal clinically important difference (MCID) were the study’s primary endpoints. The Quality of Life Scale (QOLS) and independent prognostic factors for MCID were secondary endpoints.

Follow-up assessments were conducted 3, 6, and 12 months after surgery.

The International Prostate Symptom Score (IPSS) tool was also used.

Results 

The men’s average age was similar in both groups (65 years for TUDP, 64 for TURP). They also had comparable scores on the IPSS at baseline and 3 months following surgery.

Compared to the TURP group, the men in the TUDP had fewer complications, which included blood transfusion, prostate capsule perforation, and retrograde ejaculation.

Other findings included the following:

• IIEF-5 scores. Three months after surgery, differences in IIEF-5 scores in both groups were not statistically significant. However, scores improved in the TUDP group at the 6- and 12-month follow-up points compared to the TURP group (18.87 vs. 14.79 at 6 months and 18.08 vs. 15.73 at 12 months).
• MCID. At the 3-month follow-up point, 36.5% of men in the TUDP group and 26.9% of men in the TURP group had achieved an MCID. At the 6-month follow up point, 88.5% of the men in the TUDP group had done so, compared to 30.8% of the TURP group. At 12 months, the rates were 80.8% for the TUDP group and 46.2% for the TURP group.
• QOLS. After surgery, men in the TUDP group had lower QOLS scores compared to men in the TURP group.
• IPSS. After 12 months, improvement in IPSS scores aligned with improvement in IIEF-5 scores in both groups.

Discussion

Patients in both groups had improved erectile function 6 months after surgery, and these results were maintained to the 12-month mark. This result might be explained by improvement of LUTS after surgery.

However, improvements were more significant for patients who underwent Hiraoka’s TUDP procedure, perhaps because there was no thermal damage to the cavernous nerves and blood vessels. In addition, more excess prostate tissue is removed during TUDP than during TURP.

The surgical method was “the independent prognostic factor of erectile function improvement in patients after prostate surgery.”

Several limitations were identified:

• This was a single-center study.
• The sample size was small.
• Confounding variables, such as depression or anxiety, were not assessed.
• The definition of MCID was validated based on the IIEF-EF domain, not the IIEF-5.
• Other aspects of sexual function were not evaluated.
• TUDP is a complex technique, and there was a learning curve.

Multicenter and large-sample studies are recommended.