Robot‐Assisted Simple Prostatectomy for Two Cases of Benign Prostatic Hyperplasia: The First Report in Japan

Abstract

ABSTRACT

Introduction

Robot‐assisted simple prostatectomy is associated with better perioperative outcomes than those of open simple prostatectomy. We report the outcomes of two cases treated with robot‐assisted simple prostatectomy.

Case Presentation

The first patient was an 81‐year‐old man with a prostate volume of 139 mL. The second patient was a 77‐year‐old man with a prostate volume of 98 mL. Robot‐assisted simple prostatectomy was performed using Da Vinci Xi. The operative times and enucleated weights for the first and second patients were 210 min and 82 g, and 191 min and 53 g, respectively. Postoperative uroflowmetry of the first and second patients revealed maximum flow rates and postvoid residual volumes of 32.5 mL/s and 15 mL at 6 months postoperatively, and 22.1 mL/s and 6 mL at 1 month postoperatively, respectively.

Conclusion

Robot‐assisted simple prostatectomy is useful for large prostates.

Abbreviations

• AFR
• average flow rate
• BPH
• benign prostatic hyperplasia
• HoLEP
• holmium laser enucleation of the prostate
• LSP
• laparoscopic simple prostatectomy
• OSP
• open simple prostatectomy
• Q _max
• maximum flow rate
• RASP
• robot-assisted simple prostatectomy
• RV
• residual volume
• VV
• voided volume

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Summary

• Robot-assisted simple prostatectomy (RASP) results in favorable outcomes for benign prostatic hyperplasia (BPH) cases.
• In Japan, the first RASP was performed safely, and the postoperative results were excellent.
• Further accumulation of cases is necessary to clarify which types of BPH are suitable for RASP.

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Introduction

According to the Japanese guidelines, surgical treatments for benign prostatic hyperplasia (BPH) exceeding 80 mL include simple prostatectomy, transurethral resection of the prostate, holmium laser enucleation of the prostate (HoLEP), photoselective vaporization of the prostate, transurethral enucleation with bipolar, thulium laser resection of the prostate, and aquablation. However, according to the American Urological Association guidelines, the recommended treatments for large prostates exceeding 80 mL are open simple prostatectomy (OSP), laparoscopic simple prostatectomy (LSP), or robotic simple prostatectomy as well as HoLEP and thulium laser enucleation of the prostate. Although the Japanese guidelines offer numerous treatment options for large prostates, only open surgery for simple prostatectomy is covered by insurance. Recently, advancements in robotic surgery have highlighted the utility of robotic simple prostatectomy. Robot-assisted simple prostatectomy (RASP) was performed for two patients at Hiroshima University Hospital after obtaining approval from the Ethical Committee for Clinical Research and the Division of Evaluation for Unapproved Drugs and Medical Devices of Hiroshima University. This report describes the outcomes of those patients.

Case Reports

When surgery is necessary for BPH, we explain treatment options to patients according to the domestic guidelines and perform procedures that are covered by insurance. However, because our two patients opted for self-pay treatment with RASP, we also explained surgical methods and their differences according to the international guidelines.

Case 1

An 81-year-old man presented to a local clinic because of nocturia and received water vapor energy therapy. However, his urinary frequency worsened. Therefore, he was referred to the Department of Urology at Hiroshima University Hospital. Magnetic resonance imaging revealed a prostate volume of 139 mL and middle lobe enlargement. The preoperative prostate-specific antigen level was 2.07 ng/mL.

Urine flow measurements revealed a maximum flow rate (Q_max) of 7.3 mL/s, an average flow rate (AFR) of 4.3 mL/s, a voided volume (VV) of 66 mL, and a residual volume (RV) of 181 mL. After surgical treatments were explained in accordance with Japanese guidelines [1], the patient opted to undergo RASP. The surgical, pneumoperitoneum, and console times were 210, 167, and 139 min, respectively. Blood loss, including urine, was 233 mL. The resected mass weighed 82 g. The urethral catheter was removed on postoperative day 10. No complications occurred within 6 months postoperatively. Uroflowmetry performed at 6 months postoperatively revealed a Q_max of 32.5 mL/s, an AFR of 18.3 mL/s, a VV of 242 mL, and an RV of 15 mL.

Case 2

A 77-year-old man with urinary retention underwent urethral catheter placement at a local clinic. After initiating medication, the catheter was removed; however, the patient subsequently developed a febrile urinary tract infection and septic shock. Therefore, he was referred to the Department of Urology at Hiroshima University Hospital for surgical intervention.

Magnetic resonance imaging revealed a prostate volume of 98 mL. The preoperative prostate-specific antigen level was 1.25 ng/mL. Urine flow measurements revealed a Q_max of 6.7 mL/s, AFR of 4.8 mL/s, VV of 216 mL, and RV of 84 mL. The surgical, pneumoperitoneum, and console times were 191, 170, and 131, respectively. Blood loss, including urine, was 170 mL. The resected mass weighed 53 g. The urethral catheter was removed on postoperative day 6. No complications occurred within 1 month postoperatively. Uroflowmetry at 1 month postoperatively revealed a Q_max of 22.1 mL/s, AFR of 15.8 mL/s, VV of 200 mL, and RV of 6 mL.

Surgical Procedures

Patients were placed in the Trendelenburg position at 25°. Using the four-arm Da Vinci Xi Surgical System, a five-port transperitoneal approach with a port configuration was performed. The distance between the robot ports was set to 8 cm. A 12-mm trocar and a 5-mm trocar (AIR SEAL system) were used for case 1 and case 2, respectively (Figure 1). A vertical incision was made in the posterior bladder wall using the transperitoneal approach (Figure 2a), and the bladder wall was suspended from the abdominal wall (Figure 2b). The bladder mucosa was incised circumferentially from the 6 o'clock position of the internal urethral orifice (Figure 2c), and the prostatic adenoma was dissected free of the prostatic capsule using electrocautery and blunt dissection (Figure 2d). Any perforated blood vessels were coagulated using bipolar forceps. Injury to the external sphincter was avoided by careful handling at the apex of the prostate at the point of its transection from the urethra. Careful separation of the prostatic apex from the prostatic capsule was ensured to prevent damage to the external urethral sphincter. The prostatic urethra was carefully identified, and the urethra was transected at a position that preserved the verumontanum (Figure 3a). The proximal prostatic urethra was everted circumferentially using 3-0 Vicryl sutures (Figure 3b), and the incised edge of the bladder neck mucosa was secured to the prostatic fossa floor with approximated sutures (Figure 3c). Thereafter, a 20-Fr Foley catheter with a 30-mL cuff was inserted.

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Discussion

This is the first report of RASP for BPH in Japan. RASP is not covered by insurance in Japan; however, the American Urological Association guidelines [2] recommend RASP, OSP, and LSP for BPH with a prostate volume ≥ 80 mL. Outcomes of minimally invasive simple prostatectomy and HoLEP for BPH with a prostate volume ≥ 120 mL have been reported. Although significant differences in surgical outcomes were not observed, the urethral catheterization duration and hospital stay tended to be longer with minimally invasive simple prostatectomy [3]. A comparison of treatment outcomes achieved with thulium laser enucleation of the prostate and RASP for BPH with a prostate volume ≥ 80 mL revealed that RASP was associated with longer operative times and hospital stays. However, with RASP, the enucleated prostate weight was significantly greater, and the incidence of urinary tract infections within the first month postoperatively was significantly lower [4]. Because HoLEP and thulium laser enucleation of the prostate are transurethral procedures, the incidence of postoperative urethral strictures is higher (3.85%) than that associated with LSP/RASP (1.76%) [5]. Additionally, the stress incontinence rate immediately postoperatively until 2 months postoperatively with HoLEP is 15.4%, whereas the stress incontinence rate gradually decreases with RASP and reaches 0% by 2 months postoperatively [6]. Compared with OSP, RASP is associated with less blood loss and fewer intraoperative complications, including transfusions. Additionally, the urethral catheterization duration and hospital stay are shorter; therefore, it is a safe surgical approach [7]. Additionally, the postoperative Q_max of RASP is better than that of LSP; therefore, RASP ensures not only safety but also favorable functional outcomes [8]. RASP was first reported in 2008 [9]. Since then, it has been performed using the Millin, Frayer, Madigan, and posterior approaches [10].

The Millin technique is unsuitable for cases involving median lobe hypertrophy and is associated with postoperative sexual dysfunction. The Frayer technique is associated with postoperative bladder irritation caused by the bladder incision. The Madigan technique is associated with minimal postoperative urinary incontinence and a lower risk of urethral stricture, and it preserves ejaculatory function [11]. When selecting a surgical procedure, the advantages of each technique should be considered [12]. We selected the posterior approach because it minimizes the anatomical impact of mobilizing the bladder and provides ample working space for robotic instruments. This approach resulted in a favorable postoperative course. Additional cases in Japan should be accumulated to demonstrate the superiority of RASP.

Acknowledgments

We thank Editage () for English language editing.

Ethics Statement

The Ethical Committee for Clinical Research: patient 1, no. 14; patient 2, no. 15. The Division of Evaluation for Unapproved Drugs and Medical Devices of Hiroshima University: patient 1, no. 2024002; patient 2, no. 2024025.

Consent

Informed consent was obtained from both patients for the publication of this case report.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author (H.K.) upon reasonable request.

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