A 4-year follow-up of a randomized prospective study comparing transurethral electrovaporization of the prostate with neodymium: YAG laser therapy for treating benign prostatic hyperplasia

Authors


Abstract

The Department of Urology and Nephrology in Mansoura, Egypt has turned their attention to many facets of urological practice in a thorough and interesting way. They have been involved in several technological treatments for LUTS in recent years, and here they describe a 4-year follow-up study where patients were randomized to Nd:YAG laser treatment or TUVP. They confirmed the view that TUVP is associated with effective and durable results, whereas the laser treatment was not.

Authors from Sheffield describe a pilot study wherein they evaluate the acute effect of magnetic stimulation of the pelvic floor on involuntary detrusor activity during natural filling. They found a decrease in the amplitude of involuntary detrusor contractions and an increase in bladder capacity assessed by cystometry. They found a variable effect on overactive bladder symptoms, and felt that magnetic stimulation may not produce a lasting effect on these symptoms.

OBJECTIVE

To compare the safety, efficacy and durability of neodymium (Nd):YAG laser prostatectomy with transurethral electrovaporization of the prostate (TUVP) for treating benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

From March 1995 to March 1997, 180 patients with bladder outlet obstruction secondary to BPH were randomized equally either to Nd:YAG laser therapy or TUVP. Laser therapy combined two different techniques, side-fire coagulation of the lateral lobes and contact vaporization of the median lobe. Before treatment the two groups had a comparable International Prostate Symptom Score (IPSS), quality-of-life score (QoL), maximum urinary flow rate (Qmax), postvoid residual urine volume (PVR), and prostate and adenoma volume. In all, 62 and 78 patients completed the 1, 2, 3 and 4-year follow-up from the laser and TUVP groups, respectively.

RESULTS

At each follow-up, the IPSS, QoL, Qmax and PVR were significantly better and more durable in the TUVP than in the laser group. In the TUVP and laser groups respectively, at the 4-year follow-up the mean value of the IPSS was 3.7 vs 11.9, the QoL 1.3 vs 3.1, the Qmax 21.4 vs 13.6 mL/s and the PVR 25.1 vs 64.6 mL (all P < 0.001). The mean prostate and adenoma volume were significantly lower after TUVP than after laser therapy (P < 0.001) at the 1- and 4-year follow-up, with final values of 27.9 vs 35.9 and 11.7 vs 20 mL (both P < 0.001) for the TUVP and laser groups, respectively. Retrograde ejaculation was significantly more common after TUVP (63%) than after laser therapy (18%; P < 0.001). Impotence was reported in 8% of men after TUVP and in none after laser therapy (P = 0.040). The re-operation rate was 12% after TUVP and 38% after laser treatment (P < 0.001).

CONCLUSION

These 4-year follow-up results confirm that TUVP is significantly more effective and durable than the Nd:YAG laser for treating BPH. Residual obstructing adenoma was the main cause of failure in the laser group, which reflects the inadequacy of laser therapy for removing the adenoma.

INTRODUCTION

In the last decade Nd:YAG laser therapy was one of the most intensely investigated techniques for treating men with BPH. Two large, multicentre prospective randomized trials (PRTs) comparing visual laser ablation of the prostate (VLAP) with TURP were published from the USA and UK, respectively [1,2]. Although these two studies revealed encouraging early results, late outcomes have not been reported. More recently, Kaplan and Te [3] reported on transurethral electrovaporization of the prostate (TUVP) in 25 patients, and found this technique to be effective. Perlmutter et al.[4] studied the effect of TUVP on living canine models, and showed that the procedure was safe. It caused tissue vaporization and desiccation with no dangerous heating of the prostatic capsule or neurovascular bundle. In the last few years, several PRTs comparing TUVP and TURP supported the use of TUVP, with the advantages of decreased blood loss, reduced catheter time and shorter hospital stay [5–8].

Herein we report a PRT to compare the efficacy, safety and durability of Nd:YAG laser prostatectomy with TUVP, reporting the results of a 4-year follow-up which, to our knowledge, is the longest so far reported.

PATIENTS AND METHODS

From March 1995 to March 1997, 180 men with BOO secondary to BPH were randomized in equal groups either to Nd:YAG laser prostatectomy or TUVP. The inclusion criteria were a prostate volume of 20–80 mL, a serum PSA level of < 4 ng/mL, an IPSS of ≥ 15 and a maximum urinary flow rate (Qmax) of ≤ 10 mL/s. Patients were excluded if they had a urethral stricture, contracted bladder, large vesical diverticulum or a neuropathic bladder.

The evaluation before surgery included a full clinical examination, IPSS, quality-of-life score (QoL), Qmax and an estimate of the postvoid residual urine volume (PVR). Erectile function was assessed by a subjective patient questionnaire before and during the follow-up; before treatment 41 and 37 men were impotent in the laser and TUVP groups, respectively. The two groups were comparable in mean age, IPSS, QoL score, Qmax, PVR, prostate and adenoma volume (Table 1).

Table 1. Preoperative characteristics, the univariate analysis during the follow-up, and complications in the two groups
CharacteristicLaserTUVPP
  • *

    Impotent after/potent before;

  • patients re-operated/total number who completed the follow-up.

Before treatment
Mean (sd):
age, years  63.3 (6.5)  62.9 (5.9)0.173
IPSS  27.9 (5.3)  26.0 (5.8)0.251
QoL score    5 (0.8)    4.8 (0.9)0.762
Qmax, mL/s    6.9 (2.8)    6.4 (2.5)0.256
PVR, mL120 (97.5)125 (97.5)0.938
Prostate volume, mL  43.8 (13.4)  47.4 (16.1)0.153
Adenoma volume, mL  22.2 (9.5)  24 (10.7)0.161
serum PSA, ng/mL    1.1 (0.4)    1.3 (0.6)0.534
Univariate analysis for each follow-up (years)
IPSS
1  13.3 (6)    5.6 (3.5)0.003
2  12.2 (5.6)    5.2 (3.3)0.006
3  13.1 (5.7)    4.8 (2.6)0.002
4   11.9 (6.1)    3.7 (1.3)< 0.001
QoL score
1    3.4 (0.4)    1.4 (0.5)0.008
2    3.2 (0.5)    1.4 (0.4)0.009
3    3.3 (0.6)    1.4 (0.5)0.009
4    3.1 (1.0)    1.3 (0.5)< 0.001
Qmax, mL/s
1  15.1 (6.0)  20.8 (7.4)0.029
2  14.2 (6.3)  20.2 (4.4)0.007
3  13.9 (5.3)  20.5 (6.2)0.002
4  13.6 (3.6)  21.4 (4.1)< 0.001
PVR, mL
1  61.3 (49.2)  22.1 (22)< 0.001
2  73.2 (56.2)  33.4 (29)< 0.001
3  56.8 (47.0)  21.4 (18.0)< 0.001
4  64.6 (29.8)  25.1 (12.8)< 0.001
Prostate and adenoma volumes at 1 and 4 years, mL
Prostate, 1  33 (12.8)  25.8 (8.7)0.001
4  35.9 (11.0)  27.9 (8.6)< 0.001
Adenoma, 1  13.4 (7.6)    7.9 (4.7)< 0.001
4  20 (6.9)   11.7 (4.0)< 0.001
Univariate analysis
Op. duration, min  37.5 (15)  36.6 (16.4)0.786
Hospital stay, days    1.1 (0.5)    2.2 (0.8)0.107
Catheter period, days    6.8 (0.9)    2.3 (0.5)< 0.001
Follow-up, months  50.2 (6.4)  55.3 (7.2)0.831
Early and late complications in the first year, n
Bleeding at surgery    0    1
Postoperative:
haematuria    0    2
urinary retention    9    2
Late:
urethral stricture    2
bladder neck stenosis    2    2
retrograde ejaculation  16  57< 0.001
impotence    0/49*    4/53*0.04
Re-operation rates during the follow-up, n (%)
1  10/89 (11)    3/89 (3.3)0.0437
2    8/84 (10)    2/86 (2.3)0.0461
3    9/73 (12)    3/82 (3.7)0.0438
4    8/62 (13)    3/78 (3.9)0.0479
Total  35/90 (38)   11/90 (12)< 0.001

Nd:YAG laser prostatectomy was carried out as a combination of two techniques: (i) side-firing coagulation of two lateral lobes using fibres (SFB, Surgical Laser Technology, SLT, Oaks, PA) with a lateral beam angle of 90°, a beam divergence of 30°, at 40 W for 90 s at each coagulation spot; (ii) vaporization of the median lobe using contact (sapphire) tips (SLT, Model MTRL−10) at 60 W in a retrograde fashion. Side-firing coagulation was carried out at the following sites: (i) the 2 and 4 o’clock positions for the left lobe; (ii) the 8 and 10 o’clock positions for the right lobe; (iii) the 12 o’clock position for the anterior commissure. Coagulation spots were usually applied at three different levels, i.e. just below the bladder neck, the mid prostate and the apex. For larger prostates (> 50 mL) a row of coagulation spots was delivered for each 1 cm of the length of the prostatic urethra.

TUVP was delivered using a Vaportrode™ electrode (Circon ACMI, MA, USA) under 250–300 W of pure cutting current in an antegrade fashion, with an electrosurgical generator (Valleylab Force 40, Boulder, CO, USA) providing the power. The median lobe was vaporized first, followed by the two lateral lobes. Vaporization was continued down to the surgical capsule until a wide prostatic cavity was created, followed by careful coagulation.

In all, 62 and 78 patients completed 4 years of follow-up for the laser and TUVP groups, respectively. The serum PSA level was measured at the 2-, 3- and 4-year follow-up to exclude prostatic carcinoma. The mean (sd) follow-up was 50.2 (6.4) and 55.3 (7.2) months for laser and TUVP groups, respectively. The results were assessed by univariate analysis, which included the paired and unpaired Student's t-tests and the chi-square test.

RESULTS

At the 1-year follow-up, all efficacy variables (IPSS, QoL, Qmax and PVR) had improved more in the TUVP than in the laser group; the differences between the groups were statistically significant (Table 1). The operative duration, hospital stay, postoperative catheter period and follow-up for both groups are also shown in Table 1, with the early and late complications during the first year.

At subsequent follow-up the TUVP group maintained a better clinical outcome than the laser group for the IPSS, QoL, Qmax and PVR (Table 1). The mean prostate and adenoma volume were significantly lower in the TUVP group (P < 0.001) at 1 and 4-year follow-up (Table 1), and at the 4-year follow-up the percentage reduction in prostate volume was 18.2% and 41.2%, and of adenoma 10% and 52% in the laser and TUVP groups, respectively.

The number of patients completing each follow-up and the re-operation rates are also shown in Table 1, with revisional surgery over the whole follow-up summarized in Table 2. Patients having repeat laser and TUVP were included in the follow-up and only those undergoing TURP excluded. Patients who were re-operated were evaluated by pressure-flow studies before surgery and confirmed to be obstructed (maximum detrusor pressure> 70 cmH2O). A second laser prostatectomy was attempted in seven patients but failed to relieve the obstruction in four with a prostate volume of> 50 mL; these men had a later TURP. However, the six patients who had a repeat TUVP showed a marked improvement in pressure-flow criteria.

Table 2. Revisional surgery at the 1, 2, 3 and 4-year follow-up
Group/yearVIUBNIRe-laserTURP
  1. VIU, visual internal urethrotomy; BNI, bladder neck incision; *repeated procedure.

Laser, n
1027  3
2000  8
301*0  9
4000  8
Total03728
TUVP, n
1222  1
2001  1
3002  1
401*1  2
Total236  5

No new cases of urethral stricture or bladder neck stenosis were reported, but bladder neck incision was repeated for one patient in each arm. None of the four patients who reported impotence in the TUVP group improved over the 4-year follow-up.

The causes of withdrawal from the trial are listed in Table 3; during the 4-year follow-up, nine patients (four laser and five TUVP) underwent TRUS and prostate biopsy because they had high serum PSA levels (4.6–6.3 ng/mL). The needle biopsy showed well-differentiated prostatic carcinoma (Gleason score 2 + 2) in one TUVP patient in the fourth year, which was managed by radical prostatectomy.

Table 3. Causes of withdrawal from the trial during the follow-up
CauseLaserTUVP
  • *

    Eight patients of 62 in the laser and two of 78 in the TUVP group underwent TURP immediately after completing the 4-year follow-up; therefore they were not considered as withdrawals at the 4-year follow-up.

Died from cardiopulmonary diseases  1  2
Unable to attend follow-up (declining mobility)  2  1
Could not be traced despite efforts  5  5
Diagnosis of prostate cancer  0  1
TURP*20  3
Total2812

DISCUSSION

Many clinical trials have been reported comparing Nd:YAG laser prostatectomy with TURP, and TUVP with TURP, but very few have compared laser therapy with TUVP. In the present study TUVP resulted in a more durable and better outcome than laser treatment, as assessed by the IPSS, QoL, Qmax and PVR at 1, 2, 3 and 4 years of follow-up. Notably, the QoL score for the laser group still showed dissatisfaction at 4 years of follow-up.

Reek et al.[9] reported on 59 patients treated by VLAP with a mean follow-up of 33 months; the re-operation rate was 15%. In the remaining patients, the Qmax and PVR were stable but the QoL score increased during the long-term follow-up, and no longer differed from the baseline value. They concluded that VLAP does not seem to be a sufficient therapeutic alternative to TURP. Sengor et al.[10] reported on 230 patients treated by VLAP and with a long-term follow-up. The IPSS, Qmax and PVR improved at 1 year and continued to 5 years; the re-operation rate was only 5.5%, and the authors claimed that VLAP had a durable therapeutic effect.

Gujral et al.[11] reported a PRT comparing VLAP and TURP in 82 patients with BPH and chronic urinary retention. TURP was significantly better than laser therapy as assessed by the IPSS and Qmax (P = 0.035 and 0.029, respectively) but there were no differences in PVR and QoL score between the groups. They noted significantly more treatment failures with laser therapy than TURP (P = 0.0014). The time to catheter removal was nine times longer in the laser group (P < 0.001) but complication rates were significantly higher after TURP. Donovan et al.[12] in another PRT reported that laser therapy and TURP effectively improved the IPSS, QoL, Qmax and PVR in the short-term, but TURP was more effective than laser therapy.

TUVP was compared with high-density laser vaporization in a PRT [13], with each group including 29 patients. Both procedures were equally safe and effective at 1 year of follow-up. Prolonged catheterization and postoperative irritative voiding symptoms were reported as significant disadvantages of laser therapy compared with TUVP. Shingleton et al.[14] reported a similar PRT, including 31 patients; both groups had comparable improvements at 1, 3 and 6 months of follow-up. In these two studies there were relatively few patients and the follow-up was short.

In the Oxford laser prostate trial, contact laser vaporization was compared with TURP in double-blind PRT. There was no statistically significant difference between the arms in AUA-7 symptom score and Qmax at the 1-year follow-up [15]. At the 5-year follow-up the reoperation rate was 14.5% for TURP and 18% for laser therapy [16]. In the present laser group, 35 men required re-operation; there was residual obstructing adenoma at the lateral lobes which had been treated by side-fire laser, and none at the site of the median lobe, treated by contact laser. This finding reflects the efficacy of contact vaporization compared with side-firing coagulation.

In another study [17] 50, 45 and 46 patients with BPH were randomized to TURP, contact laser prostatectomy and TUVP, respectively. The mean Qmax increased 2.4 times after TURP, 2.5 times after laser prostatectomy and 2.4 times after TUVP. The Schafer grade decreased by 0.3 times in all groups. There was no obstruction (Schafer grade> 2) after TURP or TUVP, but it was evident in two patients after laser therapy. The authors concluded that the degree of improvement in urodynamic and uroflowmetry variables was comparable among the three groups at the 6-month follow-up.

The present re-operation rates were 11%, 10%, 12% and 13% after laser therapy at 1, 2, 3 and 4 years, respectively. Gottfried et al.[18] and te Slaa et al.[19] reported outcomes in 188 and 233 men treated by laser prostatectomy; the re-operation rates were 8% and 6.4%, respectively, at 1 year. Puri et al.[20] reported on the ‘ugly truth’ of laser prostatectomy in a PRT; in that series, 10% of patients treated by VLAP were re-treated within 1 year and it failed to relieve BOO in half the patients. Jung et al.[21] compared VLAP with TURP in a prospective unrandomized trial with a follow-up of 1 year; 80% of patients with prostates of> 50 mL remained obstructed after treatment and 29% required re-treatment within 3 months after initial VLAP. Schatzl et al.[22] reported that up to 25% of the patients treated by VLAP, TUVP and other less invasive techniques needed re-operation by TURP within the first 2 years.

In the present laser group, bladder neck stenosis occurred in 2.2% and retrograde ejaculation in 17.7%; there was no impotence or incontinence. Kabalin et al.[23] and Costello et al.[24], in their combined results including 428 patients, reported no incontinence or impotence after laser prostatectomy, and the most serious complications were bladder neck stenosis in 2.8% and prostatitis or epididymitis in 2.1%. Anson et al.[2] reported no impotence after VLAP but there was a surprisingly high incidence of retrograde ejaculation (33% vs 63% after TURP).

Shokeir et al.[5] reported a PRT comparing TUVP with TURP, in men with a prostate size limit of < 60 mL. The clinical improvement in IPSS, Qmax and PVR was equivalent at 1 year, but the number of patients reaching this assessment was not stated. Saad et al.[25] reported that the symptom score and Qmax were similar after TURP and TUVP, but the re-operation rate after TUVP was higher than after TURP, suggesting that TUVP should probably be limited to smaller prostates. Ekengren et al.[26] reported that TUVP and TURP were both effective in relieving BOO, but the outcome appeared to be slightly better after TURP. Kupeli et al.[27] in a PRT including 100 patients, reported that the Vapor-cut™ electrode seemed to give results comparable to those of TURP for the IPSS, Qmax and operative duration; both the catheterization time and hospital stay were significantly shorter for the Vapor-cut group.

Hammadeh et al.[8] reported that at 3 years after TUVP and TURP there were significant and maintained improvements in IPSS, QoL, Qmax and PVR, with a re-operation rate in each group of 4% during the first year, 4% in the second and 5% in the third.

De Sautel et al.[28] reported the pressure-flow outcome after TUVP in 40 patients (29 with LUTS and 11 with urinary retention). With subjective and objective improvement, the maximum detrusor pressure decreased from 95 to 44.7 cmH2O in 24 of the patients with LUTS, and from 89.3 to 67.7 cmH2O in six of those with retention. These results confirmed the equivalence of TUVP and TURP in relieving obstruction. Others also noted similar improvements in pressure-flow criteria after TUVP [6,29]. In the present TUVP group, the percentage reduction in prostate and adenoma volumes was 45% and 68%, respectively (at 1 year). Gallucci et al.[6] reported an average reduction of 84% in adenoma volume after TUVP.

In the present series, urethral stricture and bladder neck stenosis occurred in 2.2% after TUVP; others reported stricture after TUVP in 3–5%[28,30]. Impotence occurred in 7.5% and retrograde ejaculation in 63% of the present patients treated by TUVP; Hammadeh et al.[7] reported impotence in 17% after TUVP and 11% after TURP (P = 0.49), and retrograde ejaculation in 72% and 89%, respectively (P = 0.47). Urethral stricture developed in 4% in each group and bladder neck stenosis in 3% and 4%, respectively.

In conclusion, TUVP is significantly more efficient and durable than Nd:YAG laser therapy for treating BPH. Obstructing residual adenoma was the main cause of failure of laser prostatectomy, which reflects the inadequacy of the laser to remove prostatic adenoma. This explains the higher re-operation rate after laser therapy than after TUVP over the 4-year follow-up. TUVP appears to be an attractive and effective alternative to TURP, using available technology and a technique familiar to all urologists. The risk of impotence after TUVP is no greater than that reported after TURP.

Abbreviations
PRT

prospective randomized trial

VLAP

visual laser ablation of the prostate

TUVP

transurethral electrovaporization of the prostate

Qmax

maximum urinary flow rate

QoL

quality-of-life (score)

PVR

postvoid residual urine volume;

Ancillary