Bipolar Plasma Enucleation of the Prostate: 5 Years Outcomes

Abstract

Background:

Aim of our study is to assess outcomes and safety of button bipola transurethral enucleation of the prostate (B-TUEP) in patients with lower urinary tract symptoms (LUTS) caused by benign prostatic enlargement (BPE) in a single-center cohort study.

Materials and Methods:

All patients with LUTS caused by BPE undergoing button B-TUEP between May 2012 and December 2013 were prospectively enrolled in our study. Data on clinical history, physical examination, urinary symptoms, erectile function, uroflowmetry, and prostate volume were collected at 0, 1, 3, 6, 12, 24, 36, 48, and 60 months. Early and long-term complications were recorded.

Results:

Overall 50 patients were enrolled at baseline. Nine patients were excluded during the 5 years. All patients completed the procedure without severe complications. In terms of outcomes, improvement in International Prostate Symptom Score (IPSS) were sustained for all 5 years and mean difference from baseline at 5 years was 17 points. As well, improvements in Q_max (maximum urinary flow rate) were sustained for all 5 years and mean improvement at 5 years was 16 mL/second. Erectile function was slightly improved after surgery and maintained for the following 5 years.

Conclusions:

Our single-center study suggests that B-TUEP may have excellent outcomes at 5 years with no recurrence. Further multicentre studies should confirm our results.

Introduction

Lower urinary tract symptoms (LUTS) are considered a highly prevalent condition in men. LUTS can be classified in storage, voiding, and postmicturition symptoms and are mostly related to clinical benign prostatic hyperplasia (BPH).¹ According to the latest European Association of Urology Guidelines, in patients with prostates between 30 and 80 cc, transurethral resection of the prostate (TURP) may be considered the gold standard.

Classic TURP has several limitations, including complications and recurrence. If performed with monopolar devices heating of the deeper tissues, nerves, or sphincters, and TUR syndrome may be considered major limitations of the technique especially if performed by trainees. To overcome these limitations several bipolar devices have been introduced and proven equally effective in randomized clinical trials when compared with monopolar TURP.^1,2

Although the introduction of the bipolar technology has overcome monopolar limitations, recurrence is still an important limitation of TURP especially if compared with enucleation techniques claiming the need of technical innovation.^3,4 In the past years, some authors have introduced the bipolar enucleation of the prostate (B-TUEP) using several different technologies proving its safety and medium-term efficacy; however, long-term data are lacking.

Aim of this study was to assess safety, efficacy, and long-term durability of B-TUEP for the treatment of bladder outlet obstruction caused by benign prostatic enlargement (BPE).

Materials and Methods

After an internal review board approval, all patients undergoing B-TUEP between May 2010 and December 2011 were prospectively enrolled. All patients signed an informed consent and all the procedures were performed in accordance to the Declaration of Helsinki. Exclusion criteria included prior history of prostatic or urethral surgery, urethral stricture, neurovesical dysfunction, and/or prostate cancer.

All patients were preoperatively evaluated with clinical history and physical examination. Age, body mass index, prostate-specific antigen (PSA), and hemoglobin levels were recorded. Symptoms were evaluated with the International Prostate Symptom Score (IPSS), including quality of life (QoL) score. Erectile function was evaluated using the International Index of Erectile Function (IIEF-5) Questionnaire. Prostate volume was measured using transrectal 7.5 MHz ultrasonography probe (BK Medical) and calculated using the ellipsoid formula (π/6 × width × height × depth of prostate).

Indications for surgery included preoperative IPSS ≥12 points and/or QoL ≥4 and/or maximal urinary flow rate (Q_max) <15 mL/second and/or not responding to medical therapy and/or not willing to undergo medical therapy. All operations were performed by one single expert surgeon (R.G.).

Operative techniques

B-TUEP was performed using an Olympus SurgMaster UES-40 bipolar generator, OES-Pro bipolar resectoscope, continuous-flow saline irrigation, and “button” type vaporesection electrodes (Olympus Europe, Hamburg, Germany). The procedure starts with an apical incision with the button laterally to the verumontanum. Prostatic anatomy, such as the presence or absence of a medium lobe does not change the surgical approach. A laterolateral movement and a distoproximal compression of the button is then performed extending the 5 o’ clock and 7 o’ clock incisions. The adenoma is partly vaporized and the button creates a progressive pedunculation. The pedunculated adenoma, which is avascular, is then resected with the loop. The button is then used for final hemostasis.

Surgical outcomes

Operative time and weight of resected prostatic tissue were recorded intra-operatively. A dedicated uropathologist analyzed B-TUEP specimens. After surgery duration of bladder irrigation, time to catheter removal, hospital stay, and postoperative hemoglobin levels (on postoperative day 1) were recorded. Patients were evaluated at 1, 3, 6, 12, 18, 24, 36, 48, and 60 months with uroflowmetry, IPSS, IIEF-5 Questionnaire score, QoL score, PSA, and postvoid residual (PVR). At 6, 12, 24, 36, 48, and 60 months, prostatic volume (PV) was measured.

Safety

Complications were recorded and classified into perioperative, early, and long-term complications. Perioperative complications have been described in our previous article.⁴ Postoperatively early complications such as urethral stricture, residual adenoma, acute urinary retention, transient urinary incontinence, and readmission rate were recorded. In the long-term reintervention rate and urethral strictures were recorded.

Statistical analysis

Statistical analyses were performed using Statistical Package for the Social Sciences (SPSS, Inc., Chicago, IL). Continuous variables are presented as mean ± standard deviation and were compared using the Mann–Whitney test. Categorical data (percentages) were compared using the chi-square test or Fisher's exact probability test. Differences from baseline were evaluated using the Wilcoxon test. p-Values <0.05 were considered statistically significant.

Results

Overall 50 patients were enrolled at baseline. During the 5 years of follow-up, nine patients were excluded from the analysis (Table 1). Baseline characteristics are listed in Table 2.

Table 1.

Patients Excluded from the Analysis

First year	Two bladder neck stenosis, two prostate cancer
Second year	One prostate cancer
Third year	One prostate cancer
Fourth year	One prostate cancer, one muscle invasive bladder cancer
Fifth year	One muscle invasive bladder cancer

Table 2.

Baseline Characteristics of the Cohort Population

Age, years	64.3 ± 5.4
PV, mL	49.7 ± 14.24
PSA, ng/mL	2.63 ± 1.34
Operation time, minutes	48.1 ± 8.0
Enucleation time, minutes	44.1 ± 3.9
Enucleation weight, g	35.2 ± 8.1
Decrease in sodium, mmol/L	0.69 ± 0.42
Catheterization	2.2 ± 0.3
Hospital stay	2.6 ± 0.6

PSA = prostate-specific antigen; PV = prostatic volume.

All patients completed the procedure without severe complications. No patient required transfusion, two patients had temporary retention, and transient urge incontinence in two patients. Retrograde ejaculation was present in all cases. Regarding long-term complications, only two patients had bladder neck stenosis after surgery in the first 6 months, whereas no other patient presented stenosis after 1 year.

In terms of outcomes, improvement in IPSS were sustained for all 5 years and mean difference from baseline at 5 years was 17 points. As well, improvements in Q_max were sustained for all 5 years and mean improvement at 5 years was 16 mL/second. Mean prostate volume was <20 cc for all 5 years. Lastly, mean QoL after surgery was maintained and mean PSA levels remained <1 ng/mL (see Table 3).

Table 3.

Preoperative Data and Follow-Up of the Cohort Population

	Baseline	12 Months	24 Months	36 Months	48 Months	60 Months
Patients	50	46	46	43	41	41
Q_max (mL/second)	8.73 ± 3.20	22.3 ± 4.74	23.2 ± 0.30	25 ± 3.4	25 ± 3.3	25 ± 3.4
QoL	2.16 ± 1.12	1.25 ± 0.33	1.04 ± 0.20	1.04 ± 0.20	1.12 ± 0.30	1.05 ± 0.15
IPSS	21.72 ± 5.15	4.78 ± 2.36	5.48 ± 3.05	5.0 ± 2.2	4.6 ± 0.9	5.3 ± 0.9
IIEF-5	19.6 ± 3.55	20.95 ± 2.45	21.13 ± 2.68	21.9 ± 2.3	21.8 ± 5.4	21.8 ± 6.1
PVR (mL)	90.1 ± 36.70	16.3 ± 9.9	16.5 ± 6.66	16 ± 6.9	16 ± 6.7	17 ± 6
TRUS (cc)	49.7 ± 14.24	17.54 ± 5.55	17.54 ± 5.55	17 ± 17.0	16 ± 5.0	17 ± 5
PSA (ng/mL)	2.63 ± 1.34	0.76 ± 0.61	0.7 ± 0.51	0.6 ± 0.18	0.6 ± 0.26	0.6 ± 0.43

IIEF-5 = International Index of Erectile Function; IPSS = International Prostate Symptom Score; PVR = postvoid residual; Q_max = maximum urinary flow rate; QoL = quality of life; TRUS = transrectal ultrasound.

Erectile function was slightly improved after surgery and maintained for the following 5 years.

Discussion

This study confirms that B-TUEP is a lasting technique in patients with LUTS/BPE. As already shown in a previous study, the technique is safe and effective with similar outcomes in the short term when compared with the available data on TURP. Although the numbers are low, our study confirms that efficacy is sustained for 5 years and more importantly no patient presented recurrence. Moreover, only two patients presented bladder neck stenosis in the first year, whereas no patients after. To our knowledge, this is the first available long-term data on the efficacy of B-TUEP technique in patients with LUST/BPE.

TURP is considered the standard surgical therapy in patients with LUTS caused by BPE. Despite improvements in equipment and techniques over the years, TURP remains associated with significant morbidity and retreatment rates.⁵ The major late complications are urethral strictures (2.2%–9.8%) and bladder neck stenosis (0.3%–9.2%) and a retreatment rate range is 3% to 14.5% after 5 years. In our experience, bladder neck stenosis rate was 4%, which is comparable with TURP; however, none of the patients were retreated, which is an excellent result.

Surgical enucleation for the treatment of LUTS caused by BPE remains the most complete method to remove adenomas of any size; the history of surgical enucleation is >100 years old.⁶ The concept of surgical enucleation was revisited with the advent of endoscopic alternatives to open enucleation. Endoscopic enucleation allows for maximal removal of the adenoma and results in a potentially equivalent efficacy when compared with its open counterpart, with significantly lower morbidity. Holmium laser enucleation of the prostate (HoLEP) was the first endoscopic enucleative technique described.⁷ Bipolar plasmakinetic technology was introduced in several centers showing better coagulation and identification of the prostatic capsule. The use of saline as irrigation fluid lowered the incidence of surgical complications. In our experience, the rate of transfusion was extremely low; 1 in 50 patients and no patient presented TUR syndrome confirming the available data on bipolar technology.

The use of transurethral plasmakinetic enucleation of prostate (PKEP) was first introduced by Chinese urologists who developed the technique and proved its short-term efficacy and safety.^8,9 Our group, first introduced the use the Olympus button in the enucleation of the prostate and compared it with open surgery proving safety and short-term efficacy of the technique.^3,4 TURP is often not extended up to the capsule fibers to avoid capsular perforation and bleeding. As a result, some adenoma may remain and a high recurrence rate may be seen in patients undergoing conventional transurethral resection of the prostate. In our experience, none of the patients presented recurrences. Our prospective study carefully recorded PSA levels and performed transrectal ultrasonography every year. According to our results, PSA remained stable <1 ng/mL and PV <20 cc suggesting long durability of B-TUEP in the removal of prostatic adenoma.

Elmansy and colleagues reported the long-term durability at 10 years of subjective and objective outcomes and complication rates after HoLEP.¹⁰ Postoperatively all variables showed significant improvement starting at month 1 of follow-up and remained stable for the entire follow-up period. Netsch and colleagues evaluate thulium vapoenucleation of the prostate (ThuVEP) for patients with symptomatic benign prostatic obstruction with long-term follow-up. At the 48-month follow-up mark, Q_max, PVR, IPSS, and QoL still differed significantly from baseline (p < 0.001). None of the patients were retreated during follow-up for recurrent prostatic tissue.¹¹ All these data are in line with our results and suggest that B-TUEP is a valid alternative to HoLEP and thulium laser enucleation of the prostate (ThuLEP). Overall, we strongly believe that enucleation of the prostate should be the gold standard for all prostate sizes. Although limited by some technical difficulties, enucleation for the prostate seems to be a definitive solution in patients with LUTS/BPE. An important aspect to underline is that B-TUEP can be performed without the need of further equipment when compared with ThuLEP or HoLEP. This enables every surgeon in every situation to approach the technique. Studies should assess the learning curve of a B-TUEP.

Sexual function is rarely affected when performing BPH surgery independently of the surgical technique used. According to our results, B-TUEP slightly improved EF and was maintained for the 5 years of follow-up. We registered some deterioration in older patients because of aging (data not shown); however, our study is not powered enough to record these differences. Standing to the available literature neither HoLEP nor thulium enucleations adversely affect sexual functioning.^12,13 Klett and colleagues found that HoLEP did not adversely affect sexual function in the long term. Jeong and colleagues reported a slight decrease in sexual functioning after operation, but this had improved after 12 months. In terms of ejaculation disorders, the probability of retrograde ejaculation is 75% after operation.¹⁴

We have to acknowledge some limitations to our study. Our study is a small single-center cohort, which is a major limitation of our study. However, long-term data are lacking in the literature and our patients were all followed meticulously every year with uroflowmetry, PSA, and transrectal ultrasound volume. Another important limitation is the lack of a TURP control group, which may limit our conclusions. Lastly, surgeries were all performed by an expert endoscopic surgeon; therefore, our results may not apply to all populations and series.

Notwithstanding all these limitations, this study is the only available long-term data on B-TUEP. If our results should be confirmed in larger multicentre cohorts, our technique could be an optimal alternative to TURP.

Conclusions

According to our results, B-TUEP seems to be a safe and long-lasting technique for the treatment of patients with LUTS/BPE. Randomized clinical trials with longer follow-up are needed to make definitive conclusions.

Footnotes

Author Disclosure Statement

No competing financial interest exist.

Abbreviations Used

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