Does Greenlight HPS ™ Laser Photoselective Vaporization Prostatectomy Affect Sexual Function?

Abstract

Purpose:

We evaluate the impact of GreenLight High-Performance System (HPS™) laser photoselective vaporization prostatectomy (PVP) on sexual function after treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH).

Patients and Methods:

We prospectively evaluated our initial single surgeon experience with GreenLight HPS™ laser PVP. All patients had American Urological Association Symptom Score (AUASS), Sexual Health Inventory for Men (SHIM), maximum flow rate (Qmax), and postvoid residual (PVR) determinations. Transurethral PVP was performed using a 120W GreenLight HPS™ side-firing laser system. AUASS, SHIM, Qmax, and PVR were evaluated 1, 4, 12, 24, and 52 weeks postsurgery. Wilcoxon signed rank test and the Student t-test were used to assess the changes from baseline.

Results:

Seventy-two patients completed 52 weeks of follow-up, having a median age of 69 (45–89) years. The median prostate volume was 62 (21–263) mL. Median AUASS improved significantly from 23 to 8, 6, 5, 5, and 4 (P < 0.05) at 1, 4, 12, 24, and 52 weeks, respectively. Median SHIM changed from 15 to 12, 16, 19, 16, and 17 during the follow-up period (P = 0.032, 0.427, 0.074, 0.081, and 0.259). Minimum change (0 ± 5) in SHIM occurred in 85.5%, 90.5%, 78.8%, 77.5%, and 73.7% of patients; 11.3%, 6.3%, 6.0%, 4.8%, and 7.0% of patients had deterioration of erectile function (SHIM reduction >5); and 3.2%, 3.2%, 15.2%, 17.7%, and 19.3% of patients had improvement of erectile function (SHIM increase >5). Incidence of new-onset retrograde ejaculation was 30%.

Conclusion:

GreenLight HPS™ laser PVP appears to not have a detrimental effect on erectile function.

Introduction

G reenLight High-Performance System (HPS™) laser (American Medical Systems, Minnetonka, MN) photoselective vaporiation prostatectomy (PVP) has become the surgical treatment of choice for patients with benign prostatic hyperplasia (BPH) at our institution, replacing transurethral resection of the prostate (TURP). The potassium-titanyl-phosphate (KTP) laser was used until June of 2006,¹ when the lithium triborate (LBO) laser, also known as the GreenLight HPS™ laser, was introduced.² In this laser, a diode pumped neodymium:yttrium-aluminum-garnet (Nd:YAG) laser light is emitted through an LBO crystal, resulting in a 532 nm wavelength high power “greenlight” laser. It has a more collimated laser beam that allows for more efficient tissue vaporization in comparison with its KTP predecessor.

The effects of TURP and KTP laser PVP on erectile function have been previously described by other groups.^3,4 In a multicenter American Urological Association (AUA) cooperative study, the rate of postoperative erectile dysfunction (ED) after TURP approximated 13%.⁵ A recent study showed maintained sexual function in patients who underwent KTP laser PVP for obstructive BPH.³ The effect of GreenLight HPS™ laser PVP on sexual function, however, if any, has yet to be assessed. The 120W LBO laser is a technologically enhanced higher power unit consisting of a higher power diode pumped Nd:YAG laser light emitted through an LBO crystal (“greenlight” laser).

Because of theoretical concerns regarding the potential for increased morbidity from its higher power (120W vs 80W delivered by the KTP laser system), we reviewed our initial results of postoperative erectile function after the treatment of lower urinary tract symptoms (LUTS) secondary to BPH with GreenLight HPS™ laser PVP to assess whether this system had a different impact on sexual function from published data regarding the KTP laser.

Patients and Methods

After obtaining approval from the Institutional Review Board, we prospectively evaluated our initial experience with the GreenLight HPS™ laser PVP from July 2006 through September 2009. All patients who were surgical candidates and in whom medical or surgical therapies had failed (TURP, transurethral microwave therapy [TUMT], KTP laser PVP, or holmium laser ablation of the prostate) underwent GreenLight HPS™ laser PVP by a single surgeon (CW).

Preoperative assessment of each patient included AUA Symptom Score (AUASS), Quality of Life (QoL) score, Sexual Health Inventory for Men (SHIM),⁶ American Society of Anesthesiologists (ASA) risk score, serum prostate-specific antigen (PSA), serum hemoglobin and sodium levels, maximum flow rate (Qmax), and postvoid residual (PVR) measurements and determination of the prostate volume with transrectal ultrasonography (TRUS).

GreenLight HPS™ laser PVP was performed using a systematic approach described previously.⁷ In brief, after induction of general or spinal anesthesia, a side-firing GreenLight HPS™ laser, through a 23F continuous-flow cystoscope with physiologic saline irrigant, was used to perform transurethral PVP. Laser settings for vaporization and coagulation were 120W and 30W, respectively. PVP of the lateral lobes was completed first, with vaporization of the median lobe to follow if necessary. A 20F urethral catheter was inserted at the end of the procedure and removed two hours postsurgery. If the voiding trial was unsuccessful, the urethral catheter was replaced, and a repeated voiding trial was performed the morning after surgery.

Clinical outcomes, including AUASS, SHIM, Qmax, and PVR, were evaluated at 1 and 4 weeks, 3 and 6 months, and every 6 months thereafter. Serum PSA levels and prostate volume (measured with TRUS by a single operator [CW] blinded to the preoperative TRUS volume) were obtained at the 3-month visit. The PSA level was then measured yearly, unless otherwise indicated. Only patients who were sexually active with completed 1-year follow-up were included in the present study.

Continuous variables were presented as mean (standard deviation) or median (25th, 75th), and categoric variables were presented as frequency and percentage. The Wilcoxon signed rank test and the Student t test were used to assess the changes from baseline.

Results

To date, GreenLight HPS™ laser PVP was performed in 180 patients at our institution. Our short-term outcomes of GreenLight HPS™ laser PVP, need for postoperative urethral catheterization, and incidence, management, and prevention of perioperative complications in naïve patients with BPH have been reported previously.^2,8,9

In the current study, 72 sexually active patients were included among the 80 patients who completed a follow-up of 52 weeks. The median age was 69 (45–89) years, and the median ASA score was 2 (1–4).

Preoperatively, median AUASS was 23 (10–35), QoL score was 4 (2–6), Qmax was 9.4 (1.9–21.5) mL/s, PVR was 25 (0–415) mL, prostate volume was 62 (21–263) cc, and PSA was 1.5 (0.2–11.7) ng/mL. The PSA level was ≥4.0 ng/mL in 22 patients. Two eightfold TRUS-guided prostate core biopsy cycles were performed in 20 patients and confirmed the absence of malignancy. Adequately educated regarding the natural history of prostate cancer, one 81-year-old patient with previous negative prostate biopsies and a stable PSA level of 10.1 ng/mL for 15 years refused prostate biopsy. One patient had an elevated PSA level (8.26 ng/mL) because of urinary retention, which was treated with an indwelling urethral catheter until PVP was performed.

Thirty-one patients were preoperatively treated with α-blockers, 17 with combination α-blocker and 5α-reductase inhibitor, and 7 with 5α-reductase inhibitors (Table 1). Of the patients treated with α-blockers (48), 24 had normal ejaculatory function, 17 had retrograde ejaculation (absence of visible semen when achieving orgasm) secondary to α-blockade, and 7 had retrograde ejaculation secondary to previous surgical treatment of BPH (four TURP, two TUMT, and one KTP laser PVP). Of the 24 patients not receiving α-blockers preoperatively, 21 had normal ejaculatory function and 3 had retrograde ejaculation secondary to previous surgical treatment of BPH (two TURP and one TUMT). The median preoperative SHIM was 15 (1–25). Overall, the preoperative rate of ED (SHIM ≤21) was 82% (Table 2).

Table 1.

Patient Demographics and Preoperative Data

	Median	p25	p75	Min	Max
Age	69	63 Number	73 (%)	45	89
ASA Score
ASA 1		7	(10)
ASA 2		36	(50)
ASA 3		26	(36)
ASA 4		3	(4)
PSA ≥4 ng/mL		22	(31)
Biopsy for PSA >4 ng/mL		20^a	(91)
Negative biopsy for PSA >4 ng/mL		20	(100)
Medications
α-Blocker		31	(43)
5α-Reductase inhibitor		7	(10)
α-Blocker + 5α-reductase inhibitor		17	(24)
Macroscopic hematuria		1^b	(1)

One patient (81 years old with previous negative prostate biopsies and a stable prostate-specific antigen [level of 10.1 ng/mL for 15 years]) refused prostate biopsy. One patient with an elevated PSA level (8.26 ng/mL) because of urinary retention was treated with an indwelling urethral catheter.

Normal hematuria evaluation (CT urography and cystoscopy).

Min = minimum; max = maximum; ASA = American Society of Anesthesiologists; PSA = prostate-specific antigen.

Table 2.

Perioperative Erectile Function and Ejaculatory Function (Qualitative) Data

	No. preoperative (%)	No. postoperative (%)
SHIM Score
22–25 No ED	13 (18)	20 (27)
17–21 Mild ED	17 (23)	17 (23)
12–16 Mild to Moderate ED	12 (17)	7 (10)
8–11 Moderate ED	9 (12)	7 (10)
<7 Severe ED	21 (30)	21 (30)
Ejaculatory function
Normal	45 (63)	33 (46)
Retrograde^a with α-blocker	17 (23)	11 (14)
Retrograde^a from previous surgery:
- TURP	6 (9)	6 (9)
- TUMT	3 (4)	3 (4)
- KTP-Laser PVP	1 (1)	0
New-onset retrograde^a after GreenLight HPS™ laser PVP	–	21 (30)

Retrograde ejaculation defined as absence of visible semen when achieving orgasm.

SHIM = Sexual Health Inventory for Men; ED = erectile dysfunction; TURP = transurethral resection of the prostate; TUMT = transurethral microwave therapy; KTP = potassium-titanyl-phosphate; PVP = photoselective vaporization prostatectomy.

GreenLight HPS™ laser PVP median laser time and energy usage were 11 ± 12 (3–80) minutes and 73 ± 78 (11–547) kJ, respectively. Preoperative and postoperative serum hemoglobin and sodium levels were comparable. Median perioperative intravenous fluid infusion was 1000 ± 440 (400–3,000) mL of physiologic saline or Ringer's lactated solution (Table 3).

Table 3.

Perioperative Events

	Median ± SD	Range
Intraoperative
Energy usage (kJ)	73 ± 78	(11–547)
Total operative time (minutes)	30 ± 25	(6–165)
Total laser time (minutes)	11 ± 12	(3–80)
Intravenous fluid infusion	1000 ± 440	(400–3000)
Nonsignificant hematuria after urethral catheter insertion	1^a
	No. Patients (%)
Duration of urethral catheter placement
Catheter free	36 (50)
Catheter < 23 hours	29 (40)
Catheter 7 days	7 (10)
Postoperative (<30 days)
Nonsignificant hematuria
<1 week	46 (64)
≥1 week	9 (13)
Hematuria necessitating clot evacuation	1 (1)
Urinary tract infection	5 (7)
Delayed (>30 days)
Delayed hematuria	2 (3)^b
Prostate cancer	2 (3)
Prostatitis	1 (1)
Bladder neck contracture	0
Urethral stricture	0
Incontinence	0

Resolved with physiologic saline manual irrigation and light urethral catheter traction before leaving operative suite.

Normal hematuria evaluation (computed tomography urography and cystoscopy).

SD = standard deviation.

No patient needed blood transfusion or hospital admission. Thirty-six (50%) of the 72 patients were catheter free at discharge, and 29 (40%) patients had the urethral catheter removed the following morning. Seven patients had a longer catheterization interval because of intraoperative dilation of a urethral stricture (four), meatal dilation (one), concomitant cystolitholapaxy (one), and persistent hematuria (one) (Table 3). Urinary tract infection developed in five (7%) patients. One (1%) patient presented with blood clot retention and needed cystoscopic clot evacuation. No bladder neck contractures, urethral strictures, or urinary incontinence was noted. Two patients with delayed (>30 postoperative days) hematuria underwent hematuria evaluation (CT urography and cystoscopy) that had negative findings for malignancy. During the follow-up interval, one patient with a preoperative PSA level of 1.4 ng/mL and one patient with a preoperative PSA level of 11.7 ng/mL, both with negative preoperative TRUS-guided prostate biopsy, manifested prostate cancer, which was diagnosed with repeated TRUS-guided prostate biopsy performed for a rising PSA level (Table 3).

Preoperative prostate medications were discontinued in all patients after surgery. Median AUASS improved from 23 to 8, 6, 5, 5, and 4 (P < 0.05) at 1, 4, 12, 24, and 52 weeks, respectively, while Qmax increased from 9.4 to 18.9, 19.5, 19.8, 20.7, and 18.9 mL/s (P < 0.05) during the follow-up interval. A statistically significant median prostate volume reduction of −53% (−20 to −76%) was measured 3 months postsurgery, with less marked changes (−31% and −24% at 3 and 12 months, respectively) in serum PSA levels (Table 4).

Table 4.

Clinical Outcomes

Clinical Outcomes
		Postoperative (weeks)
Parameter	Baseline	1	4	12	24	52
Number of Patients	72	62	63	66	62	72
AUASS
Median	23	8^a	6^a	5^a	5^a	4^a
p25, p75	18, 26	5, 10	4, 8	3, 7	3, 6	3, 5
Range	10–35	1–23	1–17	1–14	0–8	0 – 8
QoL score
Median	4	1^a	1^a	0^a	1^a	0^a
p25, p75	4, 5	1, 2	0, 1	0, 1	0, 1	0, 1
Range	2–6	0 – 6	0 – 3	0–2	0–6	0 – 6
Qmax (mL/s)
Median	9.4	18.9^a	19.5^a	19.8^a	20.7^a	18.9^a
p25, p75	6.6, 12.2	16.5, 23.7	16.8, 25.6	17.2, 24.7	17.8, 24.4	18.0, 24.4
Range	1.9–21.5	8.9–41.7	7.0–43.5	9.9–46.0	5.1–51.0	14.0 – 44.4
PVR (mL)
Median	25	34	39	15^b	10^b	11^b
p25, p75	0, 92	2–69	12, 75	0, 57	0, 54	0, 52
Range	0, 415	0–740	0–457	0–543	0–160	0 – 141
SHIM
Median	15	12	16	19	16	17
p25, p75	6, 20	5, 18	7, 22	10, 22	7, 22	6, 22
Range	1–25	1 – 25	1 – 25	1 – 25	1 – 25	1 – 25
TRUS prostate volume (cc)
Median	62	–	–	27^a	–	–
p25, p75	41, 103	–	–	18, 57	–	–
Range	21–263	–	–	8–170	–	–
Median % change	–	–	–	-53	–	–
PSA (ng/mL)
Median	1.5	–	–	1.1^a	–	1.1^a
p25, p75	0.8, 5.0	–	–	0.5, 2.7	–	0.5, 3.3
Range	0.2–11.7	–	–	0.2– 4.4	–	0.1–13.8
Median % change		–	–	-31	–	-24

P < 0.001.

P < 0.05.

AUASS = American Urological Association Symptom Score; QoL = quality of life; Qmax = maximum flow rate; PVR = postvoid residual; SHIM = Sexual Health Inventory for Men; TRUS = transrectal ultrasonography; PSA = prostate-specific antigen.

Overall, the postoperative rate of ED (SHIM ≤21) 1 year after GreenLight HPS™ laser PVP was 72%. The median SHIM changed from 15 to 12 (P = 0.032), 16 (P = 0.427), 19 (P = 0.074), 16 (P = 0.081), and 17 (P = 0.259) during the follow-up interval (Table 4). The incidence of new-onset retrograde ejaculation was 21/72 (30%). Minimum change (0 ± 5) in SHIM occurred in 85.5%, 90.5%, 78.8%, 77.5%, and 73.7 % of patients at 1, 4, 12, 24, and 52 weeks, respectively. Deterioration of erectile function (SHIM reduction >5) occurred in 11.3%, 6.3%, 6.0%, 4.8%, and 7.0% of patients, while improvement of erectile function (SHIM increase >5) was noted in 3.2%, 3.2%, 15.2%, 17.7%, and 19.3% of patients during the follow-up interval.

Qualitative perioperative erectile function data stratified by amount of energy (<100,000 vs. ≥100,000 Joules) delivered during GreenLight HPS™ laser PVP are shown in Table 5.

Table 5.

Perioperative Erectile Function (Qualitative) Data

	Preoperative SHIM Score	Postoperative SHIM Score	p-value
Group I (Energy < 100,000 Joules)	No. of patients (%)	No. of patients (%)
22-25 No ED	5 (10.9)	12 (26.1)	> 0.05
17-21 Mild ED	14 (30.4)	11 (23.9)
12-16 Mild to Moderate ED	8 (17.4)	3 (6.5)
8-11 Moderate ED	6 (13.0)	4 (8.7)
< 7 Severe ED	13 (28.3)	16 (34.8)
Total	46 (100)	46 (100)
Group II (Energy ≥ 100,000 Joules)	No. of patients (%)	No. of patients (%)
22-25 No ED	7 (29.2)	8 (33.4)	> 0.05
17-21 Mild ED	3 (12.5)	5 (20.9)
12-16 Mild to Moderate ED	4 (16.6)	4 (16.6)
8-11 Moderate ED	3 (12.5)	3 (12.5)
< 7 Severe ED	7 (29.2)	4 (16.6)
Total	24 (100)	24 (100)

Discussion

LUTS and ED are highly prevalent conditions that affect the aging male. According to the Massachusetts Male Aging Study, some degree of ED (moderate to severe in two-thirds of cases) is present in 52% of men between 40 and 70 years old.¹⁰ Sexual drive, erectile function, ejaculatory function, problem assessment, and overall sexual satisfaction have been shown by cross-sectional studies to negatively correlate with increasing age and LUTS.^11,12 In fact, the relative risk of ED may increase from 1.8 to 7.5 depending on the degree of urinary symptoms.¹³ Furthermore, a strong association between AUASS, Qmax, total prostate volume, and transition zone volume and domains of sexual function—i.e. libido, erectile capability, ejaculation, problem assessment, and overall sexual satisfaction—was detected in the National Institutes of Health-sponsored Medical Therapy of Prostatic Symptoms trial, which studied the effect of finasteride and/or doxazosin on BPH progression.¹⁴ On multivariate analysis, as in other sentinel studies,¹⁵ the association between LUTS and ED proved to be independent of the usual comorbidities.

BPH is a primary cause of LUTS and has been shown to be exceeded only by aging and diabetes as a risk factor for ED.¹⁶ Several medical and surgical options are available for the treatment of symptomatic BPH. Benefits and adverse events of each treatment include their effects on sexual function. α-blockers might favor the proerectile mechanism altering the balance of vasoconstrictive and vasorelaxant penile forces, thus ultimately improving ED. Penile filling pressure, however, might be reduced by hypotensive effects mediated by α₁-blockers.¹⁷ A longitudinal multicenter Dutch study analyzed the effects of different treatments for BPH on sexual function in patients aged 50 years and older who were treated with surgery (207), α-blockers (43), finasteride (47), or watchful waiting (234). Questionnaires about symptomatology, including four items regarding sexual function, were administered at baseline and at 9-month follow-up. Data were complete and suitable for evaluation in 426 patients and showed no changes in 66% of patients, improvement in 20% of patients, and deterioration in 11% of patients. These proportions remained approximately equal in each treatment group.¹⁸

A systematic review performed in 1994 by the United States Department of Health and Human Services on diagnosis and treatment of BPH showed retrograde ejaculation in 75% and impotence in 13% of patients who had undergone TURP. In a multicenter AUA cooperative study performed on 1,000 men, the rate of postoperative ED after TURP was 13%.⁵ In another study, the incidence and risk factors of ED after TURP was evaluated using the International Index of Erectile Function (IIEF-5)⁶ and measuring nocturnal penile tumescence (NPT) by Rigiscan in 63 patients who underwent TURP for BPH. After a postoperative follow-up of at least 3 months to allow resolution of temporary postoperative sexual dysfunction, the incidence of ED was 14%. Patients with lower preoperative NPT parameters—ie, number of erectile episodes, duration of erection, base rigidity, and tip rigidity—had greater chances of postoperative ED development. There was no significant difference in these objective parameters, however, before and after TURP.

IIEF-5 <20 (mild ED, relative risk 3.1) and diabetes mellitus (ED developed in 40% of BPH patients with diabetes, relative risk 3.9) were found to be significant independent risk factors for ED.⁴ Poulakis and associates¹⁹ evaluated the incidence of ED using the IIEF-5 after TURP in a large prospective study of 629 patients with BPH. Six months after surgery, there was a 12% increase in ED from 65% preoperatively to 77% postoperatively. Important factors associated with new-onset ED after TURP were diabetes mellitus (P = 0.003, relative risk 3.67) and intraoperative capsular perforation (P = 0.02, relative risk 1.12).

The impact on sexual function of holmium laser enucleation of the prostate was compared with that after TURP in a two-center randomized trial.²⁰ Of 120 patients with symptomatic BPH, 60 were randomized to undergo HoLEP (group 1) and 60 to undergo TURP (group 2). Sexual function was assessed with IIEF-5 and nonvalidated general assessment questions. At 12- and 24-month follow-up, nonsignificant improvements of erectile function occurred in both groups, because the rate of ED decreased by 1.7% and 3.3% in groups 1 and 2, respectively. At each follow-up evaluation, retrograde ejaculation increased significantly (P < 0.001) in both groups when compared with baseline. All of the above resulted in a significant (P < 0.001) deterioration in the mean IIEF-5 orgasmic function domain score in both groups when compared with baseline, but with no differences between the two surgical procedures. Postoperative intercourse satisfaction, sexual desire, and overall satisfaction were similar to preoperative baseline despite the increased rate of ejaculatory dysfunction induced by TURP and HoLEP.

The advent of the KTP laser renewed the interest in laser PVP for the treatment of patients with symptomatic BPH. Recent multicenter prospective studies reported that KTP laser PVP had no adverse impact on sexual activity or function in 75 of 139 sexually active men. Retrograde ejaculation was 36% at 12 month follow-up.^21,22 Paick and colleagues²³ evaluated the impact of KTP laser PVP on erectile function in 45 patients with BPH and LUTS using the IIEF-5. Average energy usage was 110 (12–306) kJ. Six (13.3%) patients reported retrograde ejaculation. Their data showed significant improvement of most IIEF-5 item scores except for “intercourse frequency” and “desire frequency,” which remained unchanged after the procedure. The authors ascribed such promising results to fast, efficient tissue heating and vaporization, resulting in less scar tissue formation during the healing process compared with other techniques.

In a randomized study, the outcomes of KTP laser PVP for prostate glands >80 cc were compared with those of transvesical open enucleation of prostatic adenomas, the traditional alternative to TURP for large-volume BPH. Perioperative erectile function was assessed using IIEF-5 questionnaires. All patients were followed for 18 months. IIEF-5 scores remained unchanged within each group throughout the entire follow-up, and there was no statistically significant difference in IIEF-5 scores between the groups.²⁴

Kavoussi and Hermans³ prospectively showed maintenance of erectile function 12 months after KTP laser PVP using the SHIM in 105 consecutive patients. The mean SHIM was 10.7 preoperatively and 10.4 postoperatively (P = 0.83). The mean SHIM of eight patients who needed an indwelling catheter preoperatively was 10.5 preoperatively and 23.0 postoperatively (P = 0.0007). Perioperatively, the SHIM remained unchanged in patients who were performing preoperative clean intermittent catheterization and in the subgroup of patients with no or mild ED (SHIM ≥17).³

The GreenLight HPS™ laser PVP was recently introduced, but its impact on sexual function has yet to be assessed. In our series, sexual function was assessed by administering the SHIM questionnaire preoperatively and at each office visit during the follow-up period. The median SHIM remained unchanged throughout the 12-month follow-up with the exception of a significant (P = 0.032) decrease 1 week postoperatively. Temporary ED immediately after TURP has been described,²⁵ and the findings in our study seem to match such data. Compared with baseline, 19% of patients had improvement of their erectile function (SHIM increase >5) and the postoperative rate of ED (SHIM ≤21) decreased from 82% to 72% at 1 year after GreenLight HPS™ laser PVP.

Our patient population was also stratified into two groups according to the amount of energy received during GreenLight HPS™ laser vaporization of the prostate (Group I: <100,000 Joules; Group II: ≥100,000 Joules). Perioperative SHIM scores were compared and data were analyzed using the chi-square analyses using a SHIM score equal to or less than 21 as indicative of erectile dysfunction. Results shown in Table 5 appear to confirm that Greenlight HPS™ laser PVP did not have a negative impact on sexual function. Interestingly, our data might suggest that the quality of life of patients who received less than 100,000 Joules (Group I) improved after laser treatment of symptomatic benign prostatic hyperplasia. The percentage of patients with a SHIM score equal to or greater than 22 increased from 11% to 26%. This could have been secondary to improvement of LUTS, discontinuation of α-blockers and 5α-reductase inhibitors, or both. However, such improvement was not noted in Group II. Although it would be interesting to correlate the perioperative SHIM scores with the preoperative prostate volume (determined with transrectal ultrasonography) and perioperative AUASS, and to assess voltage thresholds as they relate to SHIM score changes, our sample size is too small for such an evaluation at this time.

Although the small sample size may have affected the statistical power of our study, limiting the detection of certain differences among the variables studied at the considered follow-up intervals, it might be said that overall, erectile function in the current study did not worsen after GreenLight HPS™ laser PVP. This might be related to (1) the cessation of preoperative medications, such as α-blockers and finasteride; (2) the improvement of patients' LUTS (Table 3); (3) less scar tissue formation during the healing process compared with other techniques with faster tissue heating and vaporization achieved with the 120W GreenLight HPS™ laser PVP as previously hypothesized for the 80W KTP laser PVP²³; or (4) a combination of all these factors.

The higher power of the GreenLight HPS™ laser system prompted us to assess whether this system had an impact on sexual function that was different from published data regarding the KTP laser. The incidence of new-onset retrograde ejaculation after GreenLight HPS™ laser PVP (30%) was similar to that reported in large, multicenter prospective studies on KTP laser PVP (36%). The rates of adverse events were comparable as well.^9,21,2

Conclusion

Data on patient sexual function after GreenLight HPS™ laser PVP are scant. To our knowledge, this is the first report that evaluates the effect of this procedure on erectile function. Our initial results suggest that GreenLight HPS™ laser PVP is safe and effective for the management of LUTS secondary to BPH and is not associated with increased postoperative ED. At 1-year follow-up, improvement of sexual function as assessed by the SHIM questionnaire is noted. The incidence of retrograde ejaculation is comparable with that after KTP laser PVP.

Footnotes

Acknowledgments

We are grateful to Amy B. Wisniewski, Ph.D., for her assistance in the preparation of this manuscript. We are also thankful for the contributions from Beverly K. Shipman, Glenn M. Sulley, R.N., Colleen F. Davis, M.A., DeAnna J. Kuykendall, M.A., Raquel Carranco, M.A, and Maria Gonzalez, M.A.

Disclosure Statement

Dr. Wong is a consultant for American Medical Systems, Inc., Minnetonka, Minnesota.

Abbreviations Used

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