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European Urology
Volume 58, issue 2, pages e19-e28, August 2010Benign Prostatic Hyperplasia
Influence of Photoselective Vaporization of the Prostate on Sexual Function: Results of a Prospective Analysis of 149 Patients with Long-Term Follow-Up
Franck Bruyère 
, Alexis Puichaud, Helder Pereira, Benjamin Faivre d’Arcier, Antoine Rouanet, Aurélie Paule Floc’h, Thomas Bodin, Nicolas Brichart.
Accepted 26 April 2010, Published online 6 May 2010, pages 207 - 211
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Abstract
Background
Even though transurethral resection of the prostate remains the gold standard treatment for lower urinary tract symptoms (LUTS) refractory to medical therapy, photoselective vaporization of the prostate (PVP) has become a popular alternative. Early PVP studies seem encouraging, but few data exist regarding the effect of PVP on sexual function at long-term follow-up.
Objective
Our aim was to evaluate the impact of PVP on erectile function (EF) at long-term follow-up in men with LUTS due to benign prostatic hyperplasia (BPH).
Design, setting, and participants
One hundred forty-nine consecutive patients who underwent a prostate vaporization with the GreenLight laser performed by a single surgeon (FB) were prospectively enrolled in this study.
Intervention
All patients underwent PVP with the GreenLight laser performed by one experienced surgeon.
Measurements
All patients were evaluated by International Index of Erectile Function (IIEF-5) preoperatively and at 1, 3, 6, and 12 mo and then once a year. At each visit, the questionnaires were collected, and each patient's maximum flow rate and postvoid residual volume were measured with ultrasound. Biologic data were also collected at each visit, including prostate-specific antigen, creatinine, and bacterial urine culture.
Results and limitations
One hundred forty-nine patients were enrolled in the study. Median patient age was 74 yr. Urinary function was significantly improved over baseline in both men with normal or abnormal preoperative erectile function. Energy used was 255 ± 129 kJ. Hospitalization stay was 2.2 ± 3.1 d. Other than a temporary difference at 1 yr, IIEF-5 scores were comparable preoperatively and postoperatively if we consider all the population. However, considering patients with preoperative IIEF-5 >19, the postoperative IIEF-5 scores were significantly decreased at 6, 12, and 24 mo.
Conclusions
Sexual function appears to be maintained after PVP; however, in patients with normal preoperative EF, we showed a significant decrease in EF after PVP.
Keywords: Erectile function, Photoselective vaporization of the prostate, GreenLight, Benign prostatic hyperplasia.
Article Outline
1. Introduction
The GreenLight laser (American Medical Systems, Minnetonka, MN, USA) is a useful tool for surgically treating benign prostatic hyperplasia (BPH). Although transurethral resection of the prostate (TURP) remains the gold standard treatment for lower urinary tract symptoms (LUTS) refractory to medical therapy, photosensitive vaporization of the prostate (PVP) has become a popular alternative. Several reports show that PVP is efficient and bloodless and may have a shorter learning curve than TURP, making PVP an attractive alternative to TURP [1], [2], [3], and [4]. Early PVP studies seem encouraging, but few data exist regarding the effect of PVP on sexual function at long-term follow-up. Our study aims to evaluate the impact of PVP on erectile function (EF) at long-term follow-up in men with LUTS due to BPH.
2. Materials and methods
This study evaluated the impact of treating LUTS with PVP on EF. This study was conducted prospectively on all patients who underwent a prostate vaporization with the GreenLight laser performed by a single surgeon (FB). Indications for PVP were all LUTS refractory to medical treatments in patients who visited this surgeon (FB). All patients who elected to have PVP answered questionnaires preoperatively and at 1, 3, 6, and 12 mo and then once a year after PVP. At each visit, the questionnaires were collected, and each patient's maximum flow rate and postvoid residual volume were measured with ultrasound. Biologic data were also collected at each visit, including prostate-specific antigen, creatinine, and bacterial urine culture.
The International Index of Erectile Function (IIEF-5) and the International Prostate Symptom Score were completed by the patients themselves or with the assistance of the registrar in the case of patients who were unable to understand or to write.
Pre- and postoperative data were collected, including energy used, operative time, length of hospital stay, and time with catheter. Prostate volumes were measured preoperatively and postoperatively at 6 and 12 mo with ultrasound. All of FB's patients undergoing PVP were included in the study. Patients with oral anticoagulation continued their treatment, except those patients using clopidogrel, which was stopped for 2–5 d prior to the procedure.
PVP was performed using a GreenLight laser via a 23-F continuous-flow dedicated endoscope. An 80-W potassium-titanyl-phosphate (KTP) generator was used for glands <40 cm3, and a 120-W lithium triborate (LBO) generator was used for glands >40 cm3. All patients received either general or epidural anesthesia and 1 g of cefuroxime preoperatively. Sodium chloride solution (0.9%) served as the irrigation fluid. At the end of the procedure, a two-way Foley catheter was inserted without irrigation. The catheter was removed after the urine cleared. Follow-up visits were scheduled at 1, 3, 6, and 12 mo and then once a year.
We compared all of the patients to patients with preoperative IIEF-5 score ≥19. Statistical analyses were performed using JMP v.8.0 software (SAS Institute Inc, Cary, NC, USA). For all evaluations, significance was set at p < 0.05. Nominal variables were compared using the Fisher exact test or χ2 analysis. The 95% confidence interval of the differences observed in the two groups was calculated.
3. Results
Table 1 summarizes patient characteristics. More than a third of the patients had an indwelling catheter before the procedure secondary to acute urinary retention. The median time with the catheter was 60 d (range: 3–365 d). Most of the patients who underwent PVP had cardiovascular disease, as demonstrated by high American Society of Anesthesiology (ASA) scores (>55% were ASA 3 or 4), and 59% of patients were on ongoing anticoagulant treatment.
Table 1
Patient characteristics
| Measurement or units | All men (n = 149) |
Patients with IIEF-5 ≥19 (n = 39) |
Patients with IIEF <19 (n = 110) |
p value | |
|---|---|---|---|---|---|
| Age, yr | Median (range) | 74 (49–98) | 65 (49–88) | 77 (51–98) | p < 10−3 |
| ASA score (%) | I II III IV |
19 (13.0) 46 (31.5) 79 (54.1) 2 (1.3) |
15 (38.5) 15 (38.5) 7 (17.9) 2 (5.1) |
4 (3.6) 31 (28.2) 72 (65.4) 0 (0.0) |
p < 10−3 NS p < 10−3 p = 0.017 |
| Previous surgical treatment for BPH (%) | None Open prostatectomy TURP Urethrotomy |
133 (89.8) 1 (0.7) 12 (8.0) 2 (1.3) |
35 (89.7) 0 (0.0) 2 (5.2) 2 (5.2) |
99 (90.0) 1 (0.9) 10 (9.1) 0 (0.0) |
NS |
| PSA | Median (range) | 3.4 (0.2–20.7) | 3.1 (0.2–20.7) | 3.5 (0.3–37.4) | NS |
| Indwelling catheter, n (%) | None | 96 (64.4) | 31 (79.4) | 45 (40.9) | p = 0.022 |
| Ongoing anticoagulant treatment, n (%) | Salicylic acid or clopidogrel | 48 (32.2) | 23 (58.9) | 25 (22.7) | p < 10−3 |
| Prostate volume | Median (range), ml | 60 (17–215) | 52 (17–145) | 60 (20–215) | NS |
| IPSS | Mean ± SD | 20.2 ± 6.9 | 20.5 ± 6.9 | 20.2 ± 7.3 | NS |
| QoL | Mean ± SD | 4.7 ± 1.1 | 4.8 ± 1.0 | 4.7 ± 1.2 | NS |
| Maximum flow rate | Mean ± SD, ml/min | 8.5 ± 5.2 | 7.3 ± 3.4 | 9.1 ± 5.5 | p = 0.057 |
| PVR volume | Mean ± SD, ml | 106 ± 125 | 93 ± 78 | 97 ± 136 | NS |
ASA = American Society of Anesthesiologists; BPH = benign prostatic hyperplasia; IIEF = International Index of Erectile Function; IPSS = International Prostate Symptom Score; NS = not significant; PSA = prostate-specific antigen; PVR = postvoid residual; QoL = quality of life; SD = standard deviation; TURP = transurethral resection of the prostate.
Table 2 displays the preoperative and immediate postoperative data. The power-to-prostate volume ratio was calculated and found to be 4250 J/cm3. On average, about 1 min was necessary to vaporize 1 cm3 of prostate.
Table 2
Pre- and postoperative data
| Measurement or units | All men | |
|---|---|---|
| Operative time | Mean ± SD, min | 58.3 ± 30.0 |
| Energy used | Mean ± SD, kJ | 255 ± 129 |
| Clot retention | 3 (2.0%) | |
| Indwelling catheter | Mean ± SD, d | 1.6 ± 3.0 |
| Hospitalization stay | Mean ± SD, d | 2.2 ± 3.1 |
SD = standard deviation.
In 86 cases, the LBO laser generator was used; the KTP generator was used in 63 cases. The median follow-up was 21 mo (range: 1 to 52 mo). Patients with normal preoperative EF had urinary function similar to that of the general population (Table 3), and all were improved over baseline.
Table 3
Urinary results for all patients and patients with International Index of Erectile Function-5 score of 19 or higher
| Total population (n = 149) | ||||||
|---|---|---|---|---|---|---|
| Initial | At discharge | 1 mo | 6 mo | 1 yr | 2 yr | |
| (n = 149) | (n = 137) | (n = 131) | (n = 112) | (n = 77) | (n = 28) | |
| IPSS, mean ± SD | 20.2 ± 6.9 | – | 13.6 ± 3.8 | 6.6 ± 5.9 | 5.5 ± 4.6 | 4.8 ± 3.2 |
| QoL, mean ± SD | 4.7 ± 1.1 | – | 3.6 ± 1.9 | 1.6 ± 1.9 | 1.4 ± 1.5 | 1.1 ± 1.0 |
| Qmax, ml/min, mean ± SD | 8 ± 5 | 13 ± 8 | 15 ± 25 | 19 ± 43 | 15 ± 8 | 14 ± 12 |
| PVR volume, ml, mean ± SD | 102 ± 125 | 52 ± 90 | 19 ± 30 | 29 ± 47 | 19 ± 32 | 20 ± 36 |
| Patients with initial IIEF-5 ≥19 (n = 39) | ||||||
|---|---|---|---|---|---|---|
| n = 39 | n = 39 | n = 38 | n = 32 | n = 26 | n = 17 | |
| IPSS, mean ± SD | 20.5 ± 6.9 | – | – | 4.5 ± 4.3 | 5.0 ± 3.7 | 5.5 ± 4.2 |
| QoL, mean ± SD | 4.8 ± 1.0 | – | – | 1.3 ± 1.5 | 1.3 ± 1.8 | 1.5 ± 1.3 |
| Qmax, ml/min, mean ± SD | 7.3 ± 3.4 | 17 ± 7.1 | 18.8 ± 5.7 | 19.9 ± 8.1 | 16.8 ± 7.2 | – |
| PVR volume, ml, mean ± SD | 93 ± 78 | 29 ± 33 | 17 ± 35 | 14 ± 18 | 7 ± 12 | 5 ± 9 |
IIEF = International Index of Erectile Function; IPSS = International Prostate Symptom Score; PVR = postvoid residual; Qmax = maximum flow rate; QoL = quality of life; SD = standard deviation.
Other than a temporary difference at 1 yr, IIEF-5 scores were comparable preoperatively and postoperatively, if we consider all the population (Table 4); however, if only the population with normal preoperative EF is analyzed, the postoperative IIEF-5 scores were significantly decreased. None of them used any treatment for their erectile dysfunction.
Table 4
Changes in International Index of Erectile Function (IIEF)-5 scores from baseline in the global population and those patients with a baseline IIEF score of 19 or higher
| Initial | 6 mo | 1 yr | 2 yr | ||
|---|---|---|---|---|---|
| All patients | IIEF-5 | 8.0 ± 9.1 | 6.3 ± 8.6 | 5.4 ± 8.2 | 7.8 ± 10.1 |
| p | – | NS | 0.049 | NS | |
| Patients with IIEF-5 ≥19 | IIEF-5 | 22.0 ± 2.1 | 19.6 ± 4.5 | 16.2 ± 8.3 | 16.7 ± 9.2 |
| p | – | 0.01 | 0.0003 | 0.0029 |
NS = not significant.
4. Discussion
We found a significant decrease in IIEF-5 scores in patients with normal preoperative EF following PVP. Only one previous study analyzed the outcome of EF after PVP [5]. In this study, the authors showed an improvement in all the IIEF domains over baseline, even at 6 mo [5]. In particular, the EF domain increased from a baseline of 11.3 ± 1.8 to 14.7 ± 1.7 (p = 0.015). Nevertheless, only 45 patients were included in that study, and the standard IIEF questionnaire was used. We decided to evaluate EF with the IIEF-5, which is easier to use and understand than the complete IIEF [6]. Furthermore, the IIEF-5 questionnaire offers the advantage of having been previously validated in the language used by this study population. The differences found between our study and the study by Paick et al. [5] are important. Both our study and the previous study showed similar improvements in urinary symptoms, but the patients in Paick et al's study received PVP at much lower energy levels. The EF may have decreased in our population because of the high energy used in our study; however, the two populations may have differed in terms of other characteristics (e.g., diabetes, vascular diseases, and medical treatments) that can influence EF.
Kavoussi et al previously used the IIEF-5 score to evaluate EF following PVP [7]. In their study, 105 patients who did not require a catheter before the operation maintained equivalent EF postoperatively, and patients with indwelling catheters prior to surgery had improved EF following PVP. In Kavoussi et al's study, only eight patients identified concern about decreased EF following surgery. Unfortunately, the study was not powered to draw conclusions from such a small group. When considering their complete study population, Kavoussi and colleagues found a nonsignificant decrease in the mean Sexual Health Inventory for Men score (from 10.7 to 10.4). Hamann et al suggested that erectile function remained unaffected by the procedure according to the IIEF [8]. With a median power of 3177 J/cm3 of prostate, the IIEF was 12.8. It was 12.1 and 13.8 preoperatively, at 3 mo and 12 mo, respectively (p was not significant). Unfortunately, they used the overall population to form this conclusion. As suggested in our study, they should have analyzed patients who were preoperatively potent. Furthermore, the number of patients evaluated at each visit is unknown, and thus it is impossible to use their conclusion about EF.
The effect of TURP on EF is still controversial. One potential mechanism of EF post TURP could be thermal injury to the erectile nerves. We postulate that PVP acts through the same mechanism to affect EF. The thermal effect of lasers depends on both the wavelength and light source. Given the unique nature of PVP, the impact of this procedure on EF should not be deduced from data regarding other laser treatments, such as holmium:yttrium aluminum garnet laser enucleation of the prostate, which did not influence EF in one previous study [9]. Improvements or maintenance of EF after TURP has been published in many studies [10], [11], and [12]. The significant risk factors associated with erectile dysfunction following TURP were capsular perforation and cardiovascular diseases [12]. Because the distance between the urethra to the capsule, indicative of prostate volume, generally remains larger at the end of each PVP procedure than after TURP, the impact of the laser on EF may be lower.
Furthermore, we used the 120-W GreenLight laser, about which very few studies have been published [1], [13], [14], and [15]. We did not find any differences in EF between patients who underwent an 80-W procedure and patients treated with 120 W. This finding argues against the general theory that the amount of power used could have injured the nerves. We theorize that the impact of PVP on EF is due to the diffusion of the power around the prostate, perhaps more at the apex than the base; as such, we plan to decrease the power at the apex in future studies.
The power used in this study is significantly different from prior published studies. Ruszat and colleagues used an average of 2700 J/cm3 of prostate [15], and Nomura et al required 4700 J/cm3 (4,500 J/cm3–6190 J/cm3 depending on the prostate size) [16]. In our study, we used about 4200 J/cm3 of prostate. Unfortunately, Ruszat et al. [15] did not analyze the impact of PVP on EF in their 62 patients who underwent a high-performance-system procedure.
4.1. Limitations of the study
Our study evaluated EF after PVP in a large population with very little missing data. Unfortunately, subgroups were not large enough to allow for multivariate analysis (eg, patients with diabetes, age). Moreover, although ejaculation status was queried at every visit, the IIEF-5 does not assess this area; therefore, we do not know the impact of PVP on ejaculation. In our study, 70% of patients with normal EF exhibited retrograde ejaculation, but very few reported annoyance with this problem.
To our knowledge, this study is the first to show a negative effect of PVP on EF. Such results can be used to counsel patients regarding expected results after PVP. Longer follow-up and larger studies are needed to predict risk factors for developing erectile dysfunction after PVP.
5. Conclusions
Sexual function appears to be maintained after PVP; however, in patients with normal preoperative EF, we showed a significant decrease in EF after PVP. Our study corroborated the encouraging urinary results published previously and confirmed the maintenance of such positive results at 2 yr. These data are important to take into account when counseling patients before PVP and when selecting patients to undergo this technique. Further studies are needed to confirm our results regarding EF and to confirm continued urinary improvement after a longer follow-up period.
Author contributions: Franck Bruyère had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Bruyère, Faivre d’Arcier
Acquisition of data: Bodin, Floc’h, Rouanet, Puichaud, Pereira.
Analysis and interpretation of data: Bruyère.
Drafting of the manuscript: Bruyère, Brichart
Critical revision of the manuscript for important intellectual content: Brichart.
Statistical analysis: Bruyère.
Obtaining funding: None.
Administrative, technical, or material support: None.
Supervision: Bruyère
Other (specify): None.
Financial disclosures: I certify that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg, employment/affiliation, grants or funding, consultancies, honoraria, stock ownership or options, expert testimony, royalties, or patents filed, received, or pending), are the following: None.
Funding/Support and role of the sponsor: None.
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Footnotes
Urology Department, University Hospital of Tours, Loire Valley, France
Corresponding author. Urology Department, 2 bd Tonnellé, 37044 Tours, France. Tel. +33 2 34389542; Fax: +33 2 47476991.
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