Holmium Laser Enucleation Versus Bipolar Resection of the Prostate: A Prospective Randomized Study. Which to Choose?

Abstract

Background and Purpose:

Holmium enucleation of the prostate (HoLEP) has been established as an effective therapy for patients with benign prostatic hyperplasia (BPH), with less bleeding, shorter catheterization time, and shorter hospital stay. The evolution of the bipolar transurethral resection of the prostate (TURP) raised a question: Would it be able to provide all the advantages of HoLEP and compensate for all its drawbacks, including the higher costs and the steep learning curve?

Patients and Methods:

A randomized study was performed that compared HoLEP with bipolar TURP. The study included 60 patients with BPH who were randomized in two groups (1:1 fashion). The mean age, International Prostate Symptom Score, serum prostate-specific antigen value, maximum urinary flow rate, residual urine, prostate size, operative time, blood loss, resected volume, catheterization time, hospital stay, and intraoperative and postoperative complications were compared in both groups, with a follow-up period of 6 months postoperatively.

Results:

Both techniques were comparable to each other. They shared the same advantages of decreased perioperative morbidity. The longer operative time in the HoLEP group, however, was still statistically significant. In addition, the expense of performing HoLEP was nearly double that of bipolar TURP.

Conclusion:

HoLEP and bipolar TURP are effective in treating patients with lower urinary tract symptoms due to BPH, however; the long operative time, the steep learning curve, as well as the higher expenses of HoLEP are in favor of bipolar TURP.

Introduction

B enign prostatic hyperplasia (BPH) is a common urologic disorder that affects 33.5% of men aged 60 to 70 years.¹ For a long time, transurethral resection of the prostate (TURP) has been the standard surgical treatment of patients with small to medium-sized prostates. Because of the considerable complications that are associated with TURP—for example, the need for blood transfusions (2.0%–4.8%) and transurethral resection (TUR) syndrome (0%–1.1%),² especially for glands larger than 45 g—and resection time greater than 45 minutes, numerous alternatives have been tested to study their efficacy and safety compared with conventional TURP.

One of the most extensively studied alternative techniques for the management of BPH is holmium laser enucleation of the prostate (HoLEP) that uses the holmium laser to enucleate the prostatic adenoma from the surgical capsule in a way similar to open prostatectomy.³ This technique has the advantage of the possibility of enucleating larger adenomas with less risk of bleeding and almost no risk of TUR syndrome because physiologic saline is used as the irrigating fluid. In all studies that compare HoLEP with conventional TURP, HoLEP has been established as an effective therapy to relieve bladder outlet obstruction from BPH, regardless of the size of the prostate with less bleeding, shorter catheterization time, and shorter hospital stay. The longer operative time, the higher costs, and the steep learning curve of HoLEP were always in favor of conventional TURP and were considered by most expert urologists in this field as a limiting factor for the spreading of the technique.³

One of the other alternatives that has been studied recently is bipolar transurethral resection of the prostate in saline (TURis). In this technique, electricity runs between an active and a passive electrode, converting the irrigation solution (ie, physiologic saline) into a plasma layer that disintegrates tissue on contact.⁴ Intraoperative blood loss was found in several studies to be less with the bipolar resection compared with the monopolar resection.⁵ The evolution of the bipolar TURP raised a question: Would it be able to provide all advantages of HoLEP and compensate for its drawback? In addition, TURP is a technique with which most urologists are acquainted.

Patients and Methods

This study is a randomized study. It was performed in two centers between May 2008 and February 2010. All patients who met the inclusion criterion of presenting with lower urinary tract symptoms (LUTS) due to BPH and in whom surgery was indicated were included in the study. The study included 60 patients. The patients were randomized in a 1:1 fashion—the first patient placed in group A while the second patient was placed in group B at the center at which they presented. In both centers, all HoLEP were performed by one surgeon who had performed more than 150 cases of HoLEP before starting this study.

Group A included 30 patients who underwent HoLEP, while group B included 30 patients who underwent bipolar resection of the prostate. All of the patients were evaluated preoperatively by careful history taking; the International Prostate Symptom Score (IPSS) was calculated for every patient, who had a general examination and digital rectal examination. Laboratory investigations included serum creatinine, urine analysis, urine culture and sensitivity, serum prostate-specific antigen (PSA), complete blood picture, liver function tests as well as coagulation profile. Plain radiography of the abdomen (kidneys, ureters, and bladder), together with ultrasonographic assessment of the upper urinary tract and urinary bladder, and postvoid residual urine were performed, reserving intravenous urography for patients who presented with hematuria, stones, or an obstructed upper urinary tract. All patients underwent transrectal ultrasonography (TRUS) to detect the size of the prostate while those with either abnormal digital rectal examination and/or elevated serum PSA level underwent TRUS- guided biopsy to exclude prostate cancer. Uroflowmetry was performed for all patients who did not present with urinary retention.

Exclusion criteria

• Patients with mild symptomatology: IPSS score <8, maximum urinary flow rate (Q max) >15mL/sec and minimal postvoid residual urine.

• Patients with small prostates (<20 g as measured by TRUS).

• Patients with urethral stricture.

• Patients with neurogenic bladder.

• Patients with vesicoureteral reflux.

• Patients with a huge retentive bladder diverticulum in whom open surgery to remove the diverticulum was preferred.

• Patients with a history of urethral or prostatic surgeries.

• Patients with prostate cancer.

• Patients receiving anticoagulant therapy. (One of the main advantages of laser is the ability to be used safely in patients receiving anticoagulants. Bipolar TURP, however, could not be used for patients receiving anticoagulants, so we had to exclude those patients for the sake of proper randomization.)

Technique of HoLEP

To perform HoLEP, the following instruments were used: A continuous flow Iglesias resectoscope (Storz, Tuttlingen, Germany) consisting of 26F continuous flow outer sheath, rotatory middle part adaptor, laser working element, and Hopkins II 12 telescope. The laser power source was a high-powered 100W holmium:yttrium-aluminum-garnet laser device (Lumenis Medical Systems, Santa Clara, CA). A 550 μ cylindrical end firing laser fiber was used. A tissue morcellator was also used through the nephroscope. The irrigating fluid used was physiologic saline (0.9% NaCl).

The enucleation technique was similar to that previously described by Gilling and associates in 1996.⁶ We used 2 J/pulse, a frequency of 50 Hz, and a total power of 100W.

All patients received epidural anesthesia. The patients were placed in the lithotomy position and under video control. HoLEP started with bilateral bladder neck incisions at 5 and 7 o'clock down to the fibrous capsule to the level of the verumontanum, where both incisions were connected. The median lobe was then peeled off the surgical capsule in a retrograde fashion toward the internal urethral meatus, taking care to avoid subtrigonal dissection. Enucleation of the right lateral lobe started with a semicircular incision of the apical tissue between 7 and 9 o'clock and 11 and 9 o'clock. By connecting these two incisions at 9 o'clock, the apical dissection was clearly defined, and the lateral lobe was again dissected away from the surgical capsule in a retrograde fashion. This was repeated in a similar fashion for resection of the left lateral lobe.

Then we used the mechanical tissue morcellator through the nephroscope to morcellate the floating prostate lobes, taking care to close the outflow of the irrigation fluid through the continuous flow sheath to avoid suction and subsequent injury to the bladder walls. At the end of the procedure, careful hemostasis was performed, after which we inserted a 20F dual-way catheter in the bladder. Postoperative bladder irrigation was usually used for the next 2 hours postoperatively to ensure clear urine during the patient's transport and recovery from anesthesia.

Technique of bipolar resection of the prostate

Bipolar resection was performed using the bipolar system (Surgmaster TURis, Olympus, Tokyo, Japan). To perform bipolar TURis, the following instruments were used: A continuous flow resectoscope consisting of 26F continuous flow outer sheath, rotatory middle part adaptor, HF-resection electrodes; both the 30-degree small loop and 30-degree medium loop, Hopkins II 30-degree telescope, light-guide cable (3 mm plug type), active working element, and SurgMaster Electro-Surgical Unit consisting of HF bipolar cable for UES-40, 4 m length, and UES-40 HF unit. The irrigating fluid used was physiologic saline (0.9% NaCl). The height of the irrigation fluid was 60 cm in all cases. To prevent thermal damage to the urethra, we used copious amounts of jelly around the sheath in the urethra. We always carefully monitored any early exchange of worn loops and discarded loops with distortion or insulation faults.

All patients received epidural anesthesia. The patients were placed in the lithotomy position and under video control. TURis started with resection at the 11 o'clock position, then was extended down to the 7 o'clock position; this was repeated on the other side starting from the 1 o'clock position down to the 5 o'clock position. The middle lobe was then resected, leaving the resection of the apical tissue as the final step of the procedure. At the end of the procedure, careful hemostasis was performed, after which we inserted a 20F dual-way catheter in the bladder. Postoperative bladder irrigation was usually used for the first 2 hours postoperatively to ensure clear urine during the patient's transport and recovery from anesthesia.

Total operative time, resection time, weight of the resected gland, blood loss, catheterization time, and hospital stay as well as intraoperative and postoperative complications were compared in both groups, with a follow-up period of 6 months postoperatively.

Statistical analysis

Statistical analysis was performed using the SPSS computer program (version 15 Windows). Quantitative data were expressed as means±standard deviation. Comparison between the mean values of the two groups was performed using the Student t test, while comparison between paired samples was performed using paired t test. P values ≤0.05 were considered statistically significant.

The sample size was of medium power (0.5), which suggests that the results would be adequate enough to evaluate and compare both techniques.

Results

In this study, 60 male patients with BPH were treated surgically. Patients were randomized in a 1:1 fashion. Group A included 30 patients who underwent HoLEP, while group B included 30 patients who underwent bipolar resection of the prostate.

In HoLEP group A (n=30), the mean age, mean preoperative IPSS for the 27 patients who could void, mean preoperative Qmax (n=27), mean preoperative total PSA, mean preoperative prostatic volume as measured by TRUS, mean preoperative hemoglobin level, and the mean preoperative serum sodium level are shown in Table 1 and compared with those data in the bipolar group.

Table 1.

Preoperative Patient Characteristics

	Group	N	Mean	SD	Minimum	Maximum	P value
Age (years)	HoLEP	30	60.0667	4.51001	53	68	0.319
	Bipolar	30	61.2000	4.21328	53	67
Pre Qmax (mL/sec)	HoLEP	27	7.3926	0.85121	5.6	9	0.117
	Bipolar	29	6.9897	1.02586	4.5	8.7
Pre IPSS	HoLEP	27	22.5556	2.45472	18	27	0.553
	Bipolar	29	22.1724	2.34626	19	28
PSA (ng/mL)	HoLEP	30	4.1633	1.27941	2.3	7.2	0.491
	Bipolar	30	4.3900	1.25130	2.6	7.6
Prostate vol (cc)	HoLEP	30	76.5000	17.22218	45	110	0.368
	Bipolar	30	80.6000	17.78725	55	120
Hb (g/dL)	HoLEP	30	13.3500	0.80889	11.9	15	0.611
	Bipolar	30	13.2500	0.70012	12.3	15.2
Preop Na (mmol/L)	HoLEP	30	133.8667	3.14844	128	141	0.307
	Bipolar	30	133.0667	2.85190	129	140

The t test was considered to be of statistical significance when the P value was ≤0.05. None of the preoperative patients' characteristics was found to be statistically significant between both groups.

SD=standard deviation; HoLEP=holmium laser enucleation of the prostate; pre=preoperative; Qmax=maximum urinary flow rate; IPSS=International Prostate Symptom Score; PSA=prostate-specific antigen; Hb=hemoglobin; Na=sodium.

In terms of the the perioperative outcome, in the HoLEP group A (n=30), the mean total operative time (lasing time+morcellation time), together with the mean morcellation time, mean postoperative hemoglobin, mean postoperative serum sodium, and the mean resected prostatic weight were compared with similar data in the bipolar group, group B (Table 2).

Table 2.

Perioperative Outcomes

	Group	N	Mean	SD	P value
Operative time (min)	HoLEP	30	110.5000	28.80822	0.000
	Bipolar	30	76.5000	19.87678
Morcellation time (min)	HoLEP	30	29.4333	5.67926	0.000
	Bipolar	30	.0000	.00000
Postop Na (mmol/L)	HoLEP	30	135.8000	3.35693	0.587
	Bipolar	30	135.3333	3.25188
Postop Hb (g/dL)	HoLEP	30	12.8100	.75537	0.508
	Bipolar	30	12.6833	.71539
Resected weight (g)	HoLEP	30	55.9667	14.74258	0.018
	Bipolar	30	65.6667	16.12095

The test was considered to be of statistical significance when the P value was ≤0.05.

SD=standard deviation; HoLEP=holmium laser enucleation of the prostate; postop=postoperative; Na=sodium; Hb=hemoglobin.

In the bipolar group (group B) (n=30), the mean total operative time (no morcellation was needed because we used the resection technique and not the enucleation technique) was 76.5±19.87 (45–120) minutes. The mean postoperative hemoglobin level was 12.68±0.715 (11.5–14.3) g/dL. The mean postoperative serum sodium level was 135.33±3.25 (131–142) mmol/L. The mean resected prostatic weight was 65.66±16.12 cc (Table 2).

The longer total operative time in the HoLEP group (group A) was found to be statistically significantly higher than group B with a P value of <0.05. Also, the resected prostatic tissue in group A was found to be less than that in the bipolar group (group B). This was also found to be statistically significant (P<0.05).

One patient in the HoLEP group had a stone bladder, and lithotripsy using the holmium laser was performed before enucleation of the prostate. On the other hand, two patients had stones in the bladder in the bipolar TURP group (group B). In both patients, mechanical stone bladder crushing was performed before proceeding to TURP. Although the visibility was more difficult because of slight mucosal bleeding, bipolar TURP was finished successfully in both patients without significant prolongation of the operative time, and the operative time was calculated after the stones were dealt with in both groups.

In the HoLEP group (group A), the mean preoperative hemoglobin level was 13.3±0.8 g/dL, while the mean postoperative hemoglobin value was 12.8±0.75 g/dL. The mean preoperative serum sodium was 133.86±3.14 mmol/L while the mean postoperative serum sodium was 135.8±3.3 mmol/L. In the bipolar group (group B), the mean preoperative hemoglobin level was 13.2±0.7 g/dL, while the mean postoperative hemoglobin level was 12.6±0.7 g/dL. The mean preoperative serum sodium level was 133.06±2.85 mmol/L while the mean postoperative serum sodium level was 135.33±3.25 mmol/L. This denoted that there was no significant blood loss or drop in serum sodium level with subsequent hyponatremia and risk of TUR syndrome in both groups. None of the patients in either groups needed blood transfusion or hypertonic saline administration.

In the HoLEP group (group A), the catheter was removed in 29 patients after 24 hours; they all voided successfully with a mean hospital stay 49.06±5.84 hours. Acute retention following the removal of the urethral catheter developed in one patient. Cystoscopy revealed obstructing apical prostatic tissue that was resected. This resulted in a longer postoperative hospital stay (80 h). In the bipolar group (group B) (n=30), the catheter was removed after 24 hours in all patients, who voided successfully with a hospital stay of 48 hours.

Although one patient in group A stayed in the hospital for a longer time, there was no statistically significant difference in the postoperative catheterization time or the hospital stay in both groups.

The follow-up visits were scheduled at 1 week, 2 weeks, 1 month, 3 months, and 6 months postoperatively for all patients included in the study. At each visit, the patients were followed up by IPSS score, Qmax, and ultrasonography for residual urine. In the HoLEP group, the mean IPSS 6 months postoperatively was 5.5±1.07479, the mean Qmax was 20.8267±1.21341 mL/sec, the mean postvoid residual urine was 20.3±1.4 mL, while in the bipolar group, the mean IPSS 6 months postoperatively was 5.3333±1.32179, the mean Qmax was 20.5633±0.92232 mL/sec, the mean postvoid residual urine was 25.6±1.89 mL (Tables 3 and 4).

Table 3.

Preoperative and Postoperative Comparisons

	Group	N	Mean	SD	P value
Pre IPSS	HoLEP	27	22.55	2.45	0.553
	Bipolar	29	22.17	2.34
Pre Qmax (mL/sec)	HoLEP	27	7.39	0.85	0.117
	Bipolar	29	6.98	1.02
Postop IPSS (6 months)	HoLEP	30	5.5	1.07	0.594
	Bipolar	30	5.33	1.32
Postop Qmax (6 months) mL/sec	HoLEP	30	20.82	1.21	0.348
	Bipolar	30	20.56	0.92
Residual urine (mL) (6 months)	HoLEP	30	20.3	1.4	0.344
	Bipolar	30	25.6	1.89

The t test was considered to be of statistical significance when the P value was ≤0.05.

SD=standard deviation; pre=preoperative; IPSS=International Prostate Symptom Score; Qmax – maximum urinary flow rate; postop=postoperative.

Table 4.

Mean Postoperative Values

	Mean IPSS		Mean Qmax mL/sec		Mean residual urine mL
	HoLEP	Bipolar	HoLEP	Bipolar	HoLEP	Bipolar
Preoperative	22.55	22.17	7.39	6.98	–	–
1 week	6.9	6.5	17.7	19.2	37.4	26.9
2 weeks	6.2	6.3	19.2	18.7	28.2	27.8
1 month	5.7	5.5	20.6	20.5	29.1	32.1
3 months	5.5	5.4	20.77	20.4	22.7	24.9
6 months	5.5	5.33	20.82	20.56	20.3	25.6

IPSS=International Prostate Symptom Score; Qmax=maximum urinary flow rate; HoLEP=holmium laser enucleation of the prostate.

None of the follow-up data was found to be statistically significant between either group.

Discussion

BPH is a common problem that necessitates treatment in 25% to 40% of men between 50 and 80 years.⁷ The conventional, monopolar TURP has proven to be an effective and relatively safe treatment for men with BPH. Despite the low mortality (0.25%) associated with this technique, it still carries the risk of hemorrhage necessitating blood transfusion (2.0%–4.8%) and TUR syndrome (0%–1.1%).² This incidence increases with gland size >45 g and resection time longer than 90 minutes.⁸ Various minimally invasive therapies have been investigated to reduce these morbidities.

Currently, there are sufficient data to suggest that HoLEP is a safe substitute for conventional monopolar TURP and is associated with lower morbidity rates with comparable long-term results irrespective of prostate size.⁹ The main advantage of HoLEP over the conventional monopolar TURP is being more hemostatic with less blood loss. The reason is that resection in HoLEP occurs at the level of the capsule so that the vessels are opened only once, unlike monopolar TURP, in which the same vessels are reopened while the resection is carried down to the capsule. Furthermore, laser produces deeper coagulation necrosis than the high frequency electric current. These two factors lead to less bleeding and subsequent better visibility and easy identification of important landmarks.¹⁰

On the other hand, HoLEP is associated with several difficulties; resection using a straight laser fiber represents a problem at the apical region. Also, most surgeons are accustomed to the antegrade resection of monopolar TURP, while the resection in HoLEP occurs in retrograde fashion, and resection of the lateral lobes starts at the apical region, which might endanger the sphincter safety. Therefore, it is clear that HoLEP has its own learning curve. In a prospective study, Shah and associates¹¹ reported that an endourologist who is not familiar with the procedure can achieve outcomes comparable to that of experts with experience of at least 50 cases.

Another technique that has been introduced is the bipolar resection of the prostate. One main advantage of the bipolar instrument is that it is possible to use physiologic saline (NaCl 0.9%) as irrigating fluid. Ho and colleagues,¹² in a randomized study, compared both the bipolar and monopolar resection of the prostate; they showed a significant advantage of the bipolar approach regarding the occurrence of TUR absorption syndrome (0 of 48 bipolar vs 2 of 52 monopolar patients undergoing resection). There was no significant difference, however, between the two groups regarding the postoperative complications, Qmax, or IPSS. Similarly, other studies have reached the same conclusion that both techniques are similar regarding the duration of surgery, improvement in Qmax, residual urine volume, and IPSS. The bipolar resection, however, has the advantages of being more hemostatic with less risk of hemorrhage that necessitate blood transfusion and low risk of TUR syndrome using physiologic saline as irrigant fluid.¹³ Consequently, bipolar TURP needs less duration of postoperative catheterization and shorter hospitalization.^14,15

In our study, we compared both HoLEP and bipolar resection of the prostate, trying to find out the advantages of each technique over the other. By comparing the statistical data of both groups, they were similar regarding the preoperative characteristics, denoting proper randomization. It was found that the mean total operative time in the HoLEP group was longer than in the bipolar group (110.5 vs 76.5 min). This was found statistically significant (P≤0.05). The longer operative time with HoLEP may be attributed to several factors. First, the technique of retrograde resection of the apical tissue consumes more time for cautious resection of tissues at the region of the sphincter. The second is the time needed for morcellation of the enucleated adenoma.¹⁶ A third technical factor that prolongs the procedure is that we used the laser power to separate the adenoma sharply from the prostatic capsule and not the technique of mechanical peeling of the adenoma off the capsule using the sheath of the resectoscope and the irrigant fluid.

The mean resected prostatic weight in the HoLEP group was less than in the bipolar group (55.9667 vs 65.6667 cc). This was statistically significant (P≤0.05). The less retrieved prostatic tissue in the HoLEP group may be attributed to the fact that an extra 10% of the retrieved tissue should be added in the HoLEP group representing the estimated vaporized tissue during the enucleation technique.¹⁷ We were using the enucleation technique as described in the text. Sometimes, particularly in large prostates, we started the enucleation away from the sphincter, leaving some apical tissue to be resected separately at the end of the procedure. We were using the laser energy to separate the adenoma from the capsule, however.

Some other laser experts (such as Prof. Mostafa EL Hilaly at McGill University, Montreal, Canada) use the tip of the resectoscope to peel the adenoma mechanically off the capsule under pressure of the irrigation fluid. His technique is very impressive—it saves much time and uses less laser energy—however, we find it difficult particularly if the patient had previous infection or biopsy, which leads to adherence of the adenoma at particular planes. We were very cautious at the apex, so we might have left some apical tissue to avoid stress urinary incontinence that might occur not only from injury to the external sphincter, but also from using high laser energy close to it. This might explain the less retrieved tissue; however, only one patient had obstructing tissue at the apex that necessitated secondary resection.

In both groups, there was no significant drop in the hemoglobin level, and none of the patients in either group needed blood transfusion. Also, the serum sodium level did not drop in either group, despite the fact that bipolar resection of the prostate does not prevent fluid absorption¹⁸ the use of physiologic saline as the irrigant protects the patients from the risk of TUR syndrome.

Although one patient in the HoLEP group needed recystoscopy and laser resection of the residual apical obstructing tissues with longer catheterization and hospitalization, this was not found to be statistically significant in the overall postoperative catheterization and hospitalization time in both groups (P=0.326).

Both techniques were successful in relieving the bladder outlet obstruction due to BPH and improving the patients' symptomatology. This was evidenced by the drop of mean IPSS from 22.5556 (preoperatively) to 5.5 (6 months postoperatively in the HoLEP group) and from 22.17 (preoperatively) to 5.33 (6 months postoperatively in the bipolar group) and the increase of the mean Q max from 7.39 (preoperatively) to 20.82 mL/sec (6 months postoperatively in the HoLEP group) and from 6.9897 (preoperatively) to 20.56 mL/sec (6months postoperatively in the bipolar group). Both subjective and objective improvement of the patients were maintained during the follow-up period of 6 months, and none of them complained of recurrence of symptoms; urethral stricture or bladder neck fibrosis did not develop in any patient during the follow-up period.

The expenses of HoLEP are higher than those of bipolar because of the initial cost difference of both devices. It is much more expensive to buy a 100 W holmium laser device and a morcellator than to buy a bipolar diathermy device. Also, the expenses of the repair of the holmium laser device are high if any serious problem happens; for example, we had a problem in the laser cavity of a former 80 W holmium laser device that necessitated a 10,000 euro repair. The holmium laser, however, is used not only for the prostate, but it can also be used for stones, tumors, or strictures. The laser fibers are used for many patients, which partially offsets the initial high costs of buying the device and its maintenance.

Conclusion

Both techniques, HoLEP and TURis, are safe and effective for treating patients with symptomatic BPH, with less risk of bleeding, less risk of TUR syndrome, short postoperative catheterization time (24 h), and short hospital stay (48 h). HoLEP is associated with longer operative time and has a steep learning curve; in addition, the expense of performing HoLEP is nearly double that of bipolar TUR, which are points in favor of TURis and qualifies the technique to spread widely in most hospitals.

Footnotes

Disclosure Statement

No competing financial interests exist.

Abbreviations Used

References

Meigs

, Mohr

, Barry

et al. Risk factors for clinical benign prostatic hyperplasia in a community-based population of healthy aging men. J Clin Epidemiol, 2001; 54:935–944.

Rassweiler

, Teber

, Kuntz

, Hofmann

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

Gilling

, Kennett

, Das

et al. Holmium laser enucleation of the prostate (HoLEP) combined with transurethral tissue morcellation: An update on the early clinical experience. J Endourol, 1998; 12:457–459.

Wendt-Nordahl

, auml;cker

, Reich

et al. The Vista system: A new bipolar resection device for endourological procedures: Comparison with conventional resectoscope. Eur Urol, 2004; 46:586–590.

Patankar

, Jamkar

, Dobhada

, Gorde

. Plasma Kinetic Superpulse transurethral resection versus conventional transurethral resection of prostate. J Endourol, 2006; 20:215–219.

Gilling

, Cass

, Cresswell

, Fraundorfer

. Holmium laser resection of the prostate. Preliminary results of a new method for BPH. Urology, 1996; 47–48.

Oesterling

. Benign prostatic hyperplasia: A review of its histogenesis and natural history. Prostate Suppl, 1996; 6:67–73.

Mebust

, Holtgrewe

, Cockett

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

Elzayat

, Habib

, Elhilali

. Holmium laser enucleation of the prostate: a size-independent new “gold standard.” Urology, 2005; 66,suppl 5:108–113.

10.

El-Hakim

, Elhilali

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

11.

Shah

, Mahajan

, Sodha

al. Prospective evaluation of the learning curve for holmium laser enucleation of the prostate. J Urol, 2007; 177:1468–1474.

12.

, Yip

, Lim

et al. A prospective randomized study comparing monopolar and bipolar transurethral resection of prostate using transurethral resection in saline (TURIS) system. Eur Urol, 2007; 52:517–522.

13.

Bishop

. Bipolar transurethral resection of the prostate—a new approach. AORN J, 2003; 77:979–983.

14.

Starkman

, Santucci

. Comparison of bipolar transurethral resection of the prostate with standard transurethral prostatectomy: Shorter stay, earlier catheter removal and fewer complications. BJU Int, 2005; 95:69–71.

15.

Yoon

, Kim

, Moon

et al. Transurethral resection of the prostate with a bipolar tissue management system compared to conventional monopolar resectoscope: One-year outcome. Yonsei Med J, 2006; 47:715–720.

16.

Mottet

, Anidjar

, Costa

et al. A randomized study comparing the holmium: YAG vaporization and the transurethral resection of symptomatic BPH. J Endourol, 1997; 11,suppl1:160.

17.

Gilling

, Mackey

, Cresswell

et al. Holmium laser versus transurethral resection of the prostate. A randomized prospective trial with 1 year followup. J Urol, 1999; 162:1640–1644.

18.

Rassweiler

, Schulze

, Stock

et al. Bipolar transurethral resection of the prostate—technical modifications and early clinical experience. Minim Invasive Ther Allied Technol, 2007; 16:11–21.