Comparison of Techniques for Transurethral Laser Prostatectomy: Standard Photoselective Vaporization of the Prostate Versus Transurethral Laser Enucleation of the Prostate

Abstract

Background and Purpose:

Transurethral laser enucleation of the prostate (TLEP) using the potassium-titanyl-phosphate (KTP) laser offers an alternative technique to traditional photovaporization. The study objective was to determine the comparative efficacy between transurethral photovaporization of the prostate (PVP) with a TLEP technique using the 80W 532 nm KTP laser.

Patients and Methods:

A series of 97 vs 170 patients who underwent PVP vs TLEP, respectively, with the KTP laser system at Weill Cornell Medical College from September 2001 to May 2009 was studied retrospectively. Outcome measures included laser time, prostate volume lased per unit time, International Prostate Symptom Score (IPSS), postvoid residual (PVR), and maximum flow rate (Qmax). Statistical analyses were performed using the Shapiro-Wilk, Mann-Whitney, Wilcoxon, and unpaired t tests.

Results:

Baseline parameters were similar between groups, although volume was greater in the TLEP group (83 vs 63 cc, P=0.04). Median laser time was longer in the TLEP group (90 vs 50 min, P<0.001) with a higher median energy used (308 vs 165 kJ, P<0.001). The volume lased per unit time was shorter, however, for TLEP (0.92 cc/min) than for PVP (1.26 cc/min). A greater median number of fibers were used in TLEP (2.5 vs 2.0, P=0.001). Improvements in median IPSS and PVR were seen in the TLEP group (5.0, P<0.001; 55.5, P=0.02, respectively) but not in the PVP group (P=0.40 and 0.30). Median Qmax and prostate-specific antigen (PSA) level improved similarly in both groups. Final IPSS was lower for the TLEP group (P<0.001), but other final parameters were statistically equivalent.

Conclusions:

In our series, both PVP and TLEP techniques were safe and effective. Although changes in Qmax and PSA were similar between the two techniques, improvement in urinary symptoms and PVR was superior with the TLEP technique. The TLEP technique was a more efficient method for laser prostatectomy.

Introduction

B enign prostatic hyperplasia (BPH) is a common and bothersome complaint of the aging male population. It is present in about half of men above the age of 60 years. Approximately one third of these patients have lower urinary tract symptoms (LUTS).¹ As bother from symptoms worsen, the likelihood of undergoing surgery increases threefold. The gold standard for treatment has been transurethral resection of the prostate (TURP). Although effective, TURP has been associated with a significant risk of surgical complications and side effects, particularly TUR syndrome or dilutional hyponatremia.^2,3 These risks are increased if the prostate gland is large (greater than 45 g) or, similarly, if the surgical time exceeds 90 minutes.⁴ Traditional TURP also carries a significant risk of intraoperative and postoperative bleeding.³

Photoselective vaporization of the prostate (PVP) with the 532 nm laser has shown promise in treating patients with LUTS with a significantly lower complication rate compared with traditional TURP.^5,6 Indeed, the use of PVP has increased significantly from 3% to 16%.⁷ Treating large prostate glands, however, has proven to be problematic. With larger glands, fiber integrity deteriorates over time, leading to decreased power output and longer operative times. Standard PVP also yields no tissue available for pathologic analysis. Holmium and thulium transurethral laser prostatectomies have addressed these issues by using a prostate enucleation technique.^8

–13 We describe our technique, the transurethral laser enucleation of the prostate (TLEP), with associated outcomes and compare them with standard PVP with the GreenLight™ system (American Medical Systems, Inc., Minnetonka, MN).

Patients and Methods

TLEP technique

The TLEP technique consists of first creating a midline groove though the median lobe at the 6 o'clock position to the level of the trigone (Fig. 1). Vaporization is not performed as traditionally defined with large sweeping motions. Instead, quick sweeping motions and proximal-distal movement of the fiber is used to create a groove. Efficient vaporization is confirmed by the appearance of bubbles.

FIG. 1.

Schematic of transurethral laser enucleation of the prostate procedure.

Once the midline groove is created, a lateral groove on the 5 o'clock side of the median lobe is created. This groove is aimed lateral to the ipsilateral ureteral orifice and again deepened to the level of the trigone. The tissue in between the two grooves is next vaporized using larger sweeps, starting from the apex, or the most distal aspect, of the tissue. Care is taken to ensure the ureteral orifices are identified, and the laser is targeted away from them when treating the bladder neck area. Small fragments of prostate tissue are often detached and swept into the bladder by irrigation. These fragments are removed by an Ellik evacuator at the end of the case. A similar procedure is then performed on the contralateral 7 o'clock side.

Attention is next turned to the lateral lobes. A groove is created as previously described at the 11 o'clock position, and the right lateral lobe is subsequently vaporized until the groove at the floor of the prostate is encountered. Care is taken to limit lateral torque on the cystoscope to prevent prostatic perforation. The same technique is then performed on the opposite side with the starting groove at 1 o'clock. Once both lateral lobes have been vaporized, the anterior prostate is vaporized, and attention is turned toward the apex. With the cystoscope positioned at the verumontanum, apical tissue is vaporized. Care is taken not to position the fiber with the backside facing the verumontanum, because the small amount of back-scatter that occurs during PVP can injure the ejaculatory ducts when they are in close proximity.

Hemostasis is confirmed at the end of the case, and any remaining tissue in the bladder is removed. In most cases, a 22F or 24F three-way catheter is inserted. Continuous bladder irrigation is not usually needed, and often the catheter can be removed in the recovery room.

After obtaining approval from the Institutional Review Board (IRB), a retrospective review was performed. A series of 97 vs 170 patients who underwent PVP vs TLEP, respectively, with the GreenLight™ laser system (American Medical Systems, Inc., Minnetonka, MN) at Weill Cornell Medical College from September 2001 to May 2009 was studied. Data were collected on patient demographics, International Prostate Symptom Score (IPSS), prostate-specific antigen (PSA), and perioperative parameters. Maximum flow rate (Qmax), postvoid residual (PVR), and prostate volume as determined by transrectal ultrasonography were recorded.

Patients included in the study included men age 50 years or greater with moderate or severe LUTS, defined by an IPSS greater than 8 with significant bother, Qmax of <10 mL/sec, obstruction found on urodynamics (UDS) as defined by a Bladder Outlet Obstruction Index of >40.

Intraoperative parameters collected included number of laser fibers used, total amount of laser energy used, total procedural time, American Society of Anesthesiologists score, complications, as well as serum electrolytes and hemoglobin levels immediately after the operation.

Patients were evaluated for follow-up at 1, 3, 6, 12, 18, 24, and 36 months. At each of these visits, patients were evaluated for IPSS score, Qmax, and PVR. At 12, 24, and 36 months, serum PSA was measured. Statistical analyses were performed using the Shapiro-Wilk, Mann-Whitney, Wilcoxon, and unpaired t tests (SPSS 15.0, SPSS Inc., Chicago, IL).

Results

Baseline parameters were similar between the PVP and TLEP groups, although prostate volume was greater in the TLEP group (83 vs 63 cc, P=0.04) (Table 1). Median laser time was commensurately longer in the TLEP group (90 vs 50 min, P<0.001) with a higher median energy used (308 vs 165 kJ, P<0.001). The volume lased per unit time was shorter, however, for TLEP (0.92 cc/min) than for PVP (1.26 cc/min). A greater median number of fibers was used in the TLEP group (2.5 vs 2.0, P=0.001). Median duration of follow-up was slightly longer in the PVP group (26.3 vs 24.7 mos, P<0.001). Data were available at 12 months and beyond for 59 and 103 patients, respectively (Table 2). Improvements in median IPSS and PVR were seen in the TLEP group (5.0, P<0.001; 55.5, P=0.02, respectively) but not in the PVP group (P=0.40 and 0.30). Median Qmax and PSA, however, improved similarly in both groups. Final IPSS was lower for the TLEP group (P<0.001), but other final parameters were statistically equivalent between the two groups. Complications were graded according to the modified Clavien classification and assessed at interval follow-ups (Table 3).¹⁴ In the PVP group, the most common complications were Clavien grade I, such as urinary tract infection (UTI), hematuria, urgency/dysuria (n=3, 4, 3), respectively). In the TLEP, the most common complications were Clavien grade I, such as UTI, hematuria, urgency/dysuria (n=1, 3, 4, respectively). No difference in the rates of complications were seen between the two groups (P=0.36). No blood transfusions were needed in either group. There were no grade IV or V complications seen in either group.

Table 1.

Preoperative Variables

	PVP		TLEP
	Preoperative (n=97)	Postoperative (n=59)	Preoperative (n=170)	Postoperative (n=103)
Age	69.1		70.0
IPSS	16.7	9	16.7	5^{a b}
QoL	5	2^a	4	2^a
Qmax	9.8	12.7^a	9.9	12.2^a
Voided volume	148	143	140	135
PVR	75	43.5	116	55.5^a
Prostate volume	63^a	N/A	83^a	N/A
PSA	2.01	1.50^a	2.20	1.30^a

Denotes P<0.05 between preoperative and postoperative values.

Denotes P<0.05 between photoselective vaporization of the prostate and transurethral laser enucleation of the prostate groups for the same preoperative or postoperative parameter.

PVP=photoselective vaporization of the prostate; TLEP=transurethral laser enucleation of the prostate; IPSS=International Prostate Symptom Score; QoL=quality of life; PVR=postvoid residual; PSA=prostate-specific antigen.

Table 2.

Postoperative Variables

	PVP		TLEP
	Preoperative	Postoperative	Preoperative	Postoperative
Mean IPSS	13.8	6.0^a	17.0	5.0^a
QoL	3.0	1.0	3.0	1.0^a
Qmax	12.7	14.3	11.0	16.5
Voided Volume	240	252	226	246^a
PVR	30	3	52.0	43

Denotes P<0.05 between preoperative and postoperative values.

PVP=photoselective vaporization of the prostate; TLEP=transurethral laser enucleation of the prostate; IPSS=International Prostate Symptom Score; QoL=quality of life; Qmax=maximum flow rate; PVR=postvoid residual.

Table 3.

Complications

	PVP	TLEP
UTI	3	1
BNC	2	3
Urethral stricture	4	2
Hematuria	4	3
Transient incontinence <4 weeks	1	1
Urinary urgency	3	4
Re-treatment	1	0

PVP=photoselective vaporization of the prostate; TLEP=transurethral laser enucleation of the prostate; UTI=urinary tract infection; BNC=bladder neck contracture.

Discussion

The gold standard for the surgical management of BPH has been TURP. While this surgery has proven effective for decades, it has also, unfortunately, been prone to complications. TURP-related complications include bleeding, infection, prostatic capsule perforation, clot retention, incontinence, sexual dysfunction, retrograde ejaculation, urethral stricture, and TUR syndrome resulting from absorption of irrigation fluid.^15,16 Technology correspondingly evolved, using other forms of energy to resect, ablate, or vaporize prostatic tissue while improving on the side-effect profile of traditional TURP. Laser technology specifically has been used to treat patients with BPH for more than a decade.¹⁷ Various types of laser energies including, neodymium:yttrium-aluminum-garnet (YAG), holmium:YAG, potassium titanyl phosphate:YAG, thulium, and diode, have been studied.^18
–20

PVP has been studied in multiple randomized controlled trials (RCTs) and other settings, with outcomes comparable to those of TURP. In fact, PVP has demonstrated an improved side-effect profile compared with TURP while maintaining comparable clinical outcomes.^21

–27 An RCT conducted by Bouchier-Hayes and associates,²² for example, compared PVP GreenLight with TURP. The authors reported on 76 patients with 44 evaluable at 12 months. Both groups demonstrated an increase in mean flow rate and decreased IPSS. There was equivalent improvement in PVR volume, QoL scores, and bother scores. The mean duration of catheterization was shorter in the PVP group (12.2 vs 44.5 h). Also, the PVP group reflected a shorter length of hospital stay (1.08 vs 3.4 days). Indeed, while PVP technique has evolved over time, the mainstay of treatment has always involved vaporization of prostate tissue.²⁸ While PVP offers comparable outcomes to TURP with several advantages, there are some limitations to standard vaporization technique, however. In larger glands, multiple laser fibers are often needed, while resection times are significantly prolonged. In addition, many urologists emphasize the importance of retrieving prostate tissue for pathologic diagnosis. To facilitate removal of large amounts of tissue using less energy per tissue vaporized, vaporization-enucleation or vaporization-resection techniques with the GreenLight laser have been described.^29,30 The technique is similar to both the holmium and thulium laser enucleation techniques described in other series.^8

–13

The PVP technique initially offered advantages for use in systemically anticoagulated patients. The evolution of the technique to enucleation now makes the GreenLight more comparable to holmium laser enucleation of the prostate (HoLEP) and thulium laser enucleation of the prostate (TmLEP).

Several studies have shown HoLEP to be a reasonable alternative.^31
–33 HoLEP was shown to result in significantly shorter hospital stays (27.6±2.7 vs 49.9±5.6 h), catheterization times (17.7±0.7 vs 44.9±10 h), and greater prostate tissue removed (40.4±5.7 vs 24.7±3.4 g) compared with TURP with equivalent improvements in voiding parameters and symptom score. The procedure, however, has been criticized as being technically challenging with the requirement of a morcellator, which can cause significant morbidity, higher rates of (usually transient) urinary incontinence, long operative times, and a long learning curve.^34,35

Results of TmLEP were first presented by Bach and colleagues.¹² in 2007. The one RCT that compared TmLEP with TURP reports 100 patients randomized to either group and followed for 12 months.³⁶ TmLEP was significantly superior to TURP in catheterization time (45.7±25.8 h vs 87.4±33.8 h, P<0.0001), hospital stay (115.1±25.5 h vs 161.1±33.8 h, P<0.0001), and drop in hemoglobin (0.92±0.82 g/dL vs 1.46±0.65 g/dL, P<0.001); it needed equivalent time, however, to perform (46.3±16.2 vs 50.4±20.7 min, P>0.05). Improvements in Qmax (23.7±6.0 vs 24.1±6.4, P=0.77), IPSS (3.5±2.9 vs 3.9±2.7, P=0.46), UDS (PdetQmax) (38.1±17.5 vs 38.9±17.3, P=0.80) parameters were comparable between groups. The authors concluded that TmLEP was equally efficacious to TURP with no difference in complications. Subsequent studies have shown TmLEP to provide immediate improvement in flow comparable to that of TURP, although postoperative rates of dysuria are higher with TmLEP. The reoperation rate is 4.8% after 12 months, which is higher than TURP but comparable to PVP.^13,37

Son and coworkers²⁹ reported on the use of the 120W Greenlight High Performance System laser in the Seoul technique, in which the median lobe is first vaporized-resected after the bladder neck is demarcated at the 5 and 7 o'clock positions. Lateral lobes are then vaporized-resected after two semi-circular lines are made back to the level of the verumontanum. These authors reported on 104 men with prostate volumes greater than 40 mL who were grouped between standard vaporization alone (n=40) vs the Seoul technique (n=64). IPSS, QoL, Qmax, and PVR were all significantly improved compared with baseline in both groups at 1, 3, 6, and 12 months (P<0.05). The Seoul technique group, however, had greater volume reduction per unit operative time (mL/min) (0.44±0.15 vs 0.36±0.21, P=0.31), per lasing time (mL/min) (0.97±0.48 vs 0.68±0.38, P=0.001), and per laser energy (mL/kJ) (0.25±0.15 vs 0.19±0.14, P=0.27). In addition, two prostate cancers were detected in this group using the prostatic tissue obtained from the resection.

The results of TLEP demonstrate that although overall laser time was longer, the volume lased per unit time was shorter compared with the PVP group. There was the added benefit of tissue available for pathology with no requirement for an intravesical morcellator as is typically required in HoLEP/TmLEP. In addition, the data demonstrated statistically significant improvements in IPSS and PVR in the TLEP group. The other surgical options for patients with such larger glands include open simple prostatectomy, HoLEP/holmium laser ablation of the prostate, TmLEP, or a limited or staged TURP. Simple prostatectomy constitutes a more significant operation from the patient's standpoint regarding catheterization times, length of stay, and recovery time. Staged TURP is an option but may have higher reoperative rates because of incomplete removal of the obstructing adenoma.

The TLEP technique may also be particularly useful for managing large glands, especially for the less experienced surgeon. With the traditional PVP technique, the anatomic landmarks can be lost early in the case with large glands. Bleeding combined with inadequate irrigant flow can also degrade visualization and efficient laser vaporization. Use of the TLEP technique first creates a resection landmark through use of deep grooves to the surgical capsule. This ensures complete vaporization of the transition zone without risking capsular perforation. Large intravesical or middle lobes are also treated more safely by creation of the lateral grooves, which allow the median lobe to be treated by aiming the laser from laterally to medially away from the ureteral orifice without having to aim toward the trigone. This decreases the forward scatter of the laser, thereby lessening the risk of injury to the ureteral orifices as well as trigone. Finally, the enucleation component of TLEP has decreased operative times, resulting in more efficient tissue removal than through vaporization alone.

The study has several limitations. It is retrospective in nature. The period of follow-up is limited. The learning curve during the early TLEP cases is also not taken into account because this represents a surgical series from a highly experienced PVP surgeon. Results of this study should be validated in a prospective, randomized study over a longer period.

Conclusions

Footnotes

Disclosure Statement

Dr. Te is a consultant for American Medical Systems. For the remaining authors, no competing financial interests exist.

Abbreviations Used

References

McVary

, Roehrborn

, Avins

et al. Update on AUA guideline on the management of benign prostatic hyperplasia. J Urol, 2011; 185:1793–1803.

Mebust

, Holtgrewe

, Cockett

, Peters

. Transurethral prostatectomy: immediate and postoperative complications. A cooperative study of 13 participating institutions evaluating 3,885 patients. 1989. J Urol, 2002; 167:999–1004.

Rassweiler

, Teber

, Kuntz

, Hofmann

. Complications of transurethral resection of the prostate (TURP)—incidence, management, and prevention. Eur Urol, 2006; 50:969–980.

Fitzpatrick

. Which BPH treatment is the most clinically efficacious and cost-effective? Nat Clin Pract Urol, 2007; 4:358–359.

Ahyai

, Gilling

, Kaplan

et al. Meta-analysis of functional outcomes and complications following transurethral procedures for lower urinary tract symptoms resulting from benign prostatic enlargement. Eur Urol, 2010; 58:384–397.

Burke

, Whelan

, Goeree

et al. Systematic review and meta-analysis of transurethral resection of the prostate versus minimally invasive procedures for the treatment of benign prostatic obstruction. Urology, 2010; 75:1015–1022.

, Elliott

, Wilt

, McBean

. Practice patterns in benign prostatic hyperplasia surgical therapy: The dramatic increase in minimally invasive technologies. J Urol, 2008; 180:241–245.

Kumar

. Rapid communication: Holmium laser ablation of large prostate glands: An endourologic alternative to open prostatectomy. J Endourol, 2007; 21:659–662.

Suardi

, Gallina

, Salonia

et al. Holmium laser enucleation of the prostate and holmium laser ablation of the prostate: Indications and outcome. Curr Opin Urol, 2009; 19:38–43.

10.

Naspro

, Bachmann

, Gilling

et al. A review of the recent evidence (2006–2008) for 532-nm photoselective laser vaporisation and holmium laser enucleation of the prostate. Eur Urol, 2009; 55:1345–1357.

11.

Tooher

, Sutherland

, Costello

et al. A systematic review of holmium laser prostatectomy for benign prostatic hyperplasia. J Urol, 2004; 171:1773–1781.

12.

Bach

, Herrmann

, Ganzer

et al. RevoLix vaporesection of the prostate: Initial results of 54 patients with a 1-year follow-up. World J Urol, 2007; 25:257–262.

13.

Szlauer

, Götschl

, Razmaria

et al. Endoscopic vaporesection of the prostate using the continuous-wave 2-microm thulium laser: Outcome and demonstration of the surgical technique. Eur Urol, 2009; 55:368–375.

14.

Clavien

, Strasberg

. Severity grading of surgical complications. Ann Surg, 2009; 250:197–198.

15.

Borboroglu

, Kane

, Ward

et al. Immediate and postoperative complications of transurethral prostatectomy in the 1990s. J Urol, 1999; 162:1307–1310.

16.

Mebust

, Holtgrewe

, Cockett

, Peters

. Transurethral prostatectomy: Immediate and postoperative complications. A cooperative study of 13 participating institutions evaluating 3,885 patients. J Urol, 1989; 141:243–247.

17.

Hoffman

, MacDonald

, Slaton

, Wilt

. Laser prostatectomy versus transurethral resection for treating benign prostatic obstruction: A systematic review. J Urol, 2003; 169:210–215.

18.

Teichmann

, Herrmann

, Bach

. Technical aspects of lasers in urology. World J Urol, 2007; 25:221–225.

19.

Hochreiter

, Thalmann

, Burkhard

, Studer

. Holmium laser enucleation of the prostate combined with electrocautery resection: The mushroom technique. J Urol, 2002; 168:1470–1474.

20.

Bach

, Huck

, Wezel

et al. 70 vs 120 W thulium:yttrium-aluminium-garnet 2 microm continuous-wave laser for the treatment of benign prostatic hyperplasia: A systematic ex-vivo evaluation. BJU Int, 2010; 106:368–372.

21.

, Malloy

, Stein

et al. Photoselective vaporization of the prostate for the treatment of benign prostatic hyperplasia: 12-month results from the first United States multicenter prospective trial. J Urol, 2004; 172:1404–1408.

22.

Bouchier-Hayes

, Anderson

, Van Appledorn

et al. KTP laser versus transurethral resection: early results of a randomized trial. J Endourol, 2006; 20:580–585.

23.

Horasanli

, Silay

, Altay

et al. Photoselective potassium titanyl phosphate (KTP) laser vaporization versus transurethral resection of the prostate for prostates larger than 70 mL: A short-term prospective randomized trial. Urology, 2008; 71:247–251.

24.

Al-Ansari

, Younes

, Sampige

et al. GreenLight HPS 120-W laser vaporization versus transurethral resection of the prostate for treatment of benign prostatic hyperplasia: A randomized clinical trial with midterm follow-up. Eur Urol, 2010; 58:349–355.

25.

Tugcu

, Tasci

, Sahin

, Zorluoglu

. Comparison of photoselective vaporization of the prostate and transurethral resection of the prostate: A prospective nonrandomized bicenter trial with 2-year follow-up. J Endourol, 2008; 22:1519–1525.

26.

Bachmann

, Schürch

, Ruszat

et al. Photoselective vaporization (PVP) versus transurethral resection of the prostate (TURP): A prospective bi-centre study of perioperative morbidity and early functional outcome. Eur Urol, 2005; 48:965–972.

27.

Spaliviero

, Araki

, Culkin

, Wong

. Incidence, management, and prevention of perioperative complications of GreenLight HPS laser photoselective vaporization prostatectomy: Experience in the first 70 patients. J Endourol, 2009; 23:495–502.

28.

Gomez Sancha

, Bachmann

, Choi

et al. Photoselective vaporization of the prostate (GreenLight PV): Lessons learnt after 3500 procedures. Prostate Cancer Prostatic Dis, 2007; 10:316–322.

29.

Son

, Ro

, Min

et al. Modified vaporization-resection for photoselective vaporization of the prostate using a GreenLight high-performance system 120-W Laser: The Seoul technique. Urology, 2011; 77:427–432.

30.

Zorn

, Liberman

. GreenLight 180W XPS photovaporization of the prostate: How I do it. Can J Urol, 2011; 18:5918–5926.

31.

Kuntz

, Lehrich

. Transurethral holmium laser enucleation versus transvesical open enucleation for prostate adenoma greater than 100 gm.: A randomized prospective trial of 120 patients. J Urol, 2002; 168:1465–1469.

32.

Kuo

, Kim

, Lingeman

et al. Holmium laser enucleation of prostate (HoLEP): The Methodist Hospital experience with greater than 75 gram enucleations. J Urol, 2003; 170:149–152.

33.

Tan

, Gilling

, Kennett

et al.

A randomized trial comparing holmium laser enucleation of the prostate with transurethral resection of the prostate for the treatment of bladder outlet obstruction secondary to benign prostatic hyperplasia in large glands (40 to 200 grams)

J Urol, 2003; 170:1270–1274.

34.

Hurle

, Vavassori

, Piccinelli

et al. Holmium laser enucleation of the prostate combined with mechanical morcellation in 155 patients with benign prostatic hyperplasia. Urology, 2002; 60:449–453.

35.

El-Hakim

, Elhilali

. Holmium laser enucleation of the prostate can be taught: The first learning experience. BJU Int, 2002; 90:863–869.

36.

Xia

, Zhuo

, Sun

et al. Thulium laser versus standard transurethral resection of the prostate: A randomized prospective trial. Eur Urol, 2008; 53:382–389.

37.

Bach

, Netsch

, Haecker

et al. Thulium:YAG laser enucleation (VapoEnucleation) of the prostate: Safety and durability during intermediate-term follow-up. World J Urol, 2010; 28:39–43.