Safety and efficacy of transurethral vaporization of the prostate using plasma kinetic energy: Long-term outcome.

OBJECTIVE: The objective of this study was to assess the long-term efficacy and safety of plasma kinetic vaporization (PKVP) of the prostate for symptomatic benign prostatic hyperplasia. PATIENTS AND METHODS: Twenty-one patients had been enrolled in this study at Al-Azhar University Hospitals to evaluate their long-term follow-up after PKVP. The outcome was evaluated using the International Prostate Symptom Score (IPSS), quality of life (QOL), peak urinary flow rate (Qmax), postvoiding residual (PVR) of urine, prostate volume, prostate-specific antigen (PSA) level, and long-term complications of the surgery.
RESULTS: Preoperatively, IPSS was 22.14 ± 2.22, QOL score was 4.90 ± 0.54, Qmax was 8.97 ± 2.49 ml/s, PVR was 138.5 ± 56.5 ml, prostate volume was 64.32 ± 11.16 ml, and PSA level was 4.18 ± 1.95 ng/ml. Two years' post-PKVP, IPSS decreased to 8.57 ± 5.55, QOL score decreased to 1.90 ± 1.22, Qmax increased to 17.17 ± 7.91 ml/s, PVR decreased to 38.81 ± 59.54 ml, prostate volume decreased to 22.45 ± 7.22 ml, and PSA level decreased to 1.59 ± 0.74 ng/ml. One patient (4.8%) developed bulbar urethral stricture, 1 (4.8%) developed bladder neck contracture, and 1 (4.8%) developed meatal stenosis. Erectile dysfunction was reported by two out of 12 patients who were sexually potent before surgery, and retrograde ejaculation was reported by 10 patients (83%).
CONCLUSION: The present study has demonstrated satisfactory good efficacy and safety of PKVP on the long term.

INTRODUCTION

Benign prostatic hyperplasia (BPH) is a common health problem among the aged males. It may lead to an array of urinary voiding difficulties that negatively affect the quality of life (QOL) among older men.[1]

The conventional monopolar transurethral resection of the prostate (TURP) is still recommended as the gold standard surgical procedure for lower urinary tract symptoms (LUTSs) caused by BPH.[2]

Although many new endoscopic options developed for the treatment of BPH, there is a continuous effort to develop minimally invasive, efficacious, safer, and cost-effective treatment options. Bipolar plasma kinetic vaporization (PKVP) of the prostate possesses some of these properties.[3]

In 2009, the European Association of Urology (EAU) recommended transurethral PKVP as an alternative to the conventional monopolar TURP with promising initial reports of lower morbidity and similar efficacy and durability.[4]

Several randomized studies showed that PKVP can achieve similar results to TURP in improving peak urinary flow rate (Qmax) and symptom scores in the short-term follow-up period.[5]

Elhelali et al., 2014[6] had studied the short-term outcome of PKVP in a randomized controlled study comprised 60 patients at Al-Azhar University and concluded that the procedure is safe and effective after 6-month follow-up.

However, the assessment of long-term outcomes of PKVP is spare in the medical literature. Hence, the aim of this study was to assess the long-term efficacy and safety of PKVP of prostate for symptomatic BPH.

PATIENTS AND METHODS

This was a prospective study conducted to evaluate the long-term follow-up of 30 patients who had undergone transurethral PKVP at Al-Azhar University Hospitals from November 2011 to 2013 and had achieved satisfactory short-term outcome. A local ethical committee approved the study, and all patients provided written informed consent before inclusion. Patients were called by phone and invited for follow-up up to 24 months. Only 21 patients had returned and completed their 24 months of follow-up.

Nine patients were lost to follow-up at 2 years’ visit. Seven patients were missed due to loss of all contact methods and change of their phone numbers, one patient died but the cause of death was unrelated to myocardial infarction, and another patient refused to follow-up.

Exclusion criteria were patients with known newly diagnosed neurogenic bladder disorders, confirmed prostate cancer, and associated severe comorbidities.

The International Prostate Symptom Score (IPSS) and QOL questionnaires were completed by the patients, prostate volumes and postvoiding residual (PVR) were measured using transrectal ultrasonography, and uroflowmetric assessments were performed.

Data were analyzed statistically using univariate analysis. All findings were compared to the patient's preoperative data using the changes in IPSS, QOL score, Qmax, PVR of urine (PVRU), prostate-specific antigen (PSA), prostate volumes, and safety variables for the technique. Student's t-test was used to compare continuous variables and the Chi-square test and Fisher's exact test for categorical variables. In all tests, P < 0.05 was considered to indicate statistically significant differences. Data were analyzed using Statistical Program for the Social Sciences (SPSS Inc, Chicago, IL, USA) version 20.0. Quantitative data were expressed as mean ± standard deviation. Qualitative data were expressed as frequency and percentage

RESULTS

Follow-up of the 21 patients continued postoperatively for >2 years with a mean of 2.24 ± 0.55 years. Results were compared to the preoperative data.

The mean age of the studied patients was 62.81 ± 5.55 and 65.05 ± 5.40 years at preoperative and long-term follow-up period, respectively.

Table 1 shows a statistically highly significant difference between preoperative and long-term follow-up according to the IPSS, QOL, Qmax, PVR, prostate volume, and PSA (P < 0.001) [Figure 1]. It also showed statistically nonsignificant changes in Qmax and QOL score at short- and long-term follow-up.

Table 1

Pre- and post-operative (6 months and 2 years) data of the patients

Mean±SD	Preoperative	Short-term results (6 months)	Long-term results (2 years)	P1	P2
IPSS	22.14±2.22	5.29±3.73	8.57±5.55	<0.001	0.013
QOL score	4.90±0.54	1.38±1.24	1.90±1.22	<0.001	0.086
Qmax (ml/s)	8.97±2.49	19.94±4.12	17.17±7.91	<0.001	0.163
PVR (ml)	138.5±56.5	3.57±14.24	38.81±59.54	<0.001	0.013
Prostate volume (g)	64.32±11.16	-	22.45±7.22	<0.001
PSA (ng/ml)	4.18±1.95	-	1.59±0.74	<0.001

IPSS: International Prostate Symptom Score, QOL: Quality of life, PVR: Postvoiding residual, PSA: Prostate-specific antigen, SD: Standard deviation, Qmax: Peak urinary flow rate

Figure 1

A statistically highly significant difference between preoperative and long-term follow-up according to the International Prostate Symptom Score, quality of life, peak urinary flow rate, postvoiding residual, prostate volume, and prostate-specific antigen. It also showed statistically nonsignificant changes in peak urinary flow rate and quality of life score at short- and long-term follow-up. IPSS: International Prostate Symptom Score, QOL: Quality of life, PVR: Postvoiding residual, Qmax: Peak urinary flow rate

Long-term follow-up showed that one patient (4.8%) developed bulbar urethral stricture; the patient underwent internal optical urethrotomy with improvement of IPSS (from 19 to 9), Qmax (from 2.8 to 15 ml/s), and PVR (from 159 ml to 40 ml).

One patient (4.8%) developed bladder neck contracture, but we lost contact with him and missed further follow-up.

One patient (4.8%) developed meatal stenosis; the patient underwent meatoplasty with improvement of IPSS (from 19 to 7) and Qmax (from 7.3 to 16 ml/s).

Retention occurred once for one patient who was catheterized for 5 days. Later, the patient improved on medical treatment. None of the 21 patients underwent reoperations. Urinary tract infection reported by 3 (14.3%) patients which was mild infection resolved with oral antibiotics. Erectile dysfunction was reported by two patients (16%) of 12 patients who were sexually potent before PKVP, and retrograde ejaculation was reported by 10 patients (83%).

DISCUSSION

BPH is the most common cause of LUTS in aged males. Many new treatment options are available today to manage these BPH-related symptoms. Based on symptoms severity and BPH-related complications, an individualized decision between watchful waiting, medical therapy, minimally invasive therapy, TURP, and open prostatectomy can be made.[7]

According to the EAU Guidelines, the classical monopolar TURP still represents the gold standard therapeutic approach in cases of average size BPH (between 30 and 80 mL) with the indication for surgery.[8]

The development of bipolar vaporization and resection systems in the last decade has become more important because they allow removal of tissue using an iso-osmotic saline solution and may provide improved surface coagulation during resection without requiring a return electrode applied to the skin.[9]

Many studies reported experience and satisfactory results with PKVP comparable with TURP early after treatment. Our study showed satisfactory results on the long term.

Our study showed highly significant improvement in the mean IPSS and the mean Qmax at 2 years of follow-up in comparison with the preoperative data. These results were comparable with many recent studies. In agreement with our study, Martis et al.[10] reported that the mean IPSS decreased from 18 preoperatively to 5 at 24 months of follow-up and the mean Qmax increased from 8.5 ml/s preoperatively to 22 ml/s at 24 months of follow-up.

The study of Geavlete et al.[8] reported that the mean IPSS decreased from 24.3 preoperatively to 5.0 at 18 months of follow-up and the mean Qmax increased from 6.6 ml/s preoperatively to 23.7 ml/s at 18 months of follow-up. Koca et al.[3] reported that the mean IPSS decreased from 21 preoperatively to 7.6 at 36 months of follow-up and the mean Qmax increased from 6 ml/s preoperatively to 14.4 ml/s at 36 months of follow-up.

Our study showed highly significant improvement in the mean QOL score and the mean PVR at 2 years of follow-up in comparison with the preoperative data. In agreement with our study, Geavlete et al.[8] reported that the mean QOL score decreased from 4.3 preoperatively to 1.0 at 18 months of follow-up, and the mean PVR decreased from 91 ml preoperatively to 29 ml at 18 months of follow-up. Kranzbühler et al.[11] reported that the mean QOL score decreased from 4.0 preoperatively to 1.0 at 1 year of follow-up and the mean PVR decreased from 87 ml preoperatively to 11 ml at 1 year of follow-up.

Our study showed highly significant improvement in the mean prostate volume and the mean PSA at 2 years of follow-up in comparison with the preoperative data. Geavlete et al., 2011[8] reported comparable results, the mean preoperative prostate volume was 54.1 g, and the mean preoperative PSA level was 1.95 ng/ml. After 2 years of follow-up, the mean prostate volume decreased to 16.4 g and the mean PSA level decreased to 0.87 ng/ml.

Long-term follow-up showed that one patient (4.8%) developed bulbar urethral stricture, one patient (4.8%) developed bladder neck contracture, and one patient (4.8%) developed meatal stenosis. Retention occurred once for one patient. None of the 21 patients underwent reoperations.

In agreement with our results, Geavlete et al.[8] demonstrated that 0.6% of the patients in the PKVP group developed bladder neck contracture and 4.7% of the patients developed urethral stricture at 18 months of follow-up. Kranzbühler et al., 2013[11] demonstrated that three patients (3.6%) out of 83 patients who have undergone PKVP procedure developed urethral stricture and 4 patients (4.8%) had developed bladder neck sclerosis after 12 months of follow-up.

In contrast to our study, Kaya et al.[5] showed that no bladder neck stricture, urinary incontinence, or meatal stenosis was reported by patients underwent PKVP at 2 years of follow-up.

Urinary tract infection was reported only in three patients (14.3%) at 2 years’ follow-up. In agreement with our study, Reich et al.[12] demonstrated that urinary infection with significant bacteriuria occurred in three men (10%) and none of them developed fever.

In this study, long-term follow-up showed that two of them (16%) developed erectile dysfunction. Retrograde ejaculation was reported by 10 of them (83%). In agreement with our results, Kaya et al.[5] reported that erectile dysfunction was found in three patients (12%) after PKVP and retrograde ejaculation was reported by 14 patients (56%) after 3 years of follow-up. Koca et al.[3] reported that five patients (22%) out of 22 patients underwent to PKVP procedure developed erectile dysfunction (22%) while retrograde ejaculation was reported by 13 patients (59%) at 3 years of follow-up.

This study is a prospective study with long-term follow-up. The small sample size is the limitation of this study, so longer period of follow-up and larger number of studied patients are recommended for better evaluation of the durability of the safety and efficacy of the PKVP.

CONCLUSION

Bipolar PKVP is a promising new technique for the treatment of BPH; it proved good efficacy and safety on long-term results.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.