Bipolar transurethral resection in saline vs traditional monopolar resection of the prostate: results of a randomized trial with a 2-year follow-up

Authors

  • Qi Chen,

    1. Department of Urology, Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, and *Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
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  • Li Zhang,

    1. Department of Urology, Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, and *Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
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  • Qi-Liang Fan,

    1. Department of Urology, Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, and *Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
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  • Juan Zhou,

    1. Department of Urology, Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, and *Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
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  • Yu-Bing Peng,

    1. Department of Urology, Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, and *Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
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  • Zhong Wang

    1. Department of Urology, Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, and *Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
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Zhong Wang, Department of Urology, Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 639 Zhi Zaoju Road, Shanghai, China.
e-mail: zhongwang2001@yahoo.com

Abstract

Study Type – Therapy (RCT)
Level of Evidence 1b

OBJECTIVE

To present 2-year follow-up data of a randomized clinical trial comparing bipolar transurethral resection in saline (TURIS) with monopolar transurethral resection of the prostate (TURP).

PATIENTS AND METHODS

In all, 100 consecutive patients with benign prostatic hyperplasia (BPH) were randomized to TURIS or TURP. The breath ethanol test was used before and every 10 min during surgery to assess fluid absorption. Complications and treatment efficacy were evaluated after surgery.

RESULTS

The operative duration and resected tissue weight were similar between the groups. The mean decreases in serum sodium and haemoglobin after surgery were significantly less in the TURIS group. The mean (standard deviation) irrigant absorbed was significantly less in TURIS than in the TURP group, at 208 (344)mL vs 512 (706) mL respectively (P < 0.001). In both the TURIS and TURP groups there were significant improvements in International Prostate Symptoms Scores and maximum urinary flow rates. The acute and late complications in the groups were statistically similar.

CONCLUSION

Bipolar TURIS seems to be a safe and effective procedure, which is associated with significantly less fluid absorption and similar efficacy as traditional monopolar TURP.

Abbreviations
TUR(IS)

transurethral resection (in saline)

IIEF-5

five-item version of the International Index of Erectile Function

Qmax

maximum urinary flow rate

HoLEP

holmium laser enucleation of prostate ()

INTRODUCTION

TURP has been considered the gold standard for surgical treatment of BPH for many years [1]. However, the morbidity after TURP is significant [1,2]. In the past decade, several technologies have been developed to treat BPH with minimal risks and acceptable efficacy. Recently, the use of bipolar electrosurgical technology, transurethral resection of prostate in saline (TURIS), has shown less complications and comparable results to the standard TURP in early and short-term follow-ups [3]. Additionally, the use of 0.9% saline as the irrigation fluid has greatly reduced the risk of TUR syndrome owing to less fluid absorption [4]. In 1986, a simple method of measuring end-tidal breath alcohol levels for calculating the volume of the fluid absorption was introduced by Hulten et al. [5]. And this ethanol method has been proved accurate and reliable [6,7]. In the present study, we used the same technique to detect fluid absorption during TURP with the bipolar (TURIS) and monopolar (traditional TURP) systems, reporting 2-year follow-up data of TURIS vs TURP.

PATIENTS AND METHODS

Patients undergoing TURP from April 2005 to August 2007 at our institution were included in the study. The ethical committees of the hospital approved the study protocol, and all patients provided written-informed consent. Additionally, they all had failed medical therapy with α-blockers or 5α-reductase inhibitors. The inclusion criteria were indications for the surgical treatment of BPH. The exclusion criteria were patients with severe pulmonary disease, allergic response to alcohol, prostate cancer, bladder calculus, neurogenic bladder dysfunction, previous prostate surgery, urethral stricture and coagulopathy.

Fluid absorption was a primary aspect of the present study. In the study design, we expected that the absorption during TURIS would be 40% less than that during TURP. To detect a difference of that magnitude with a power of 90% and a significance level of 5%, and also considering research expenses and study period, 50 patients were set in each arm. Thus, 100 consecutive patients were randomized to either TURIS or TURP. The stratified permuted randomization algorithm (stratification factors including: age, TUR volume, IPSS and maximum urinary flow rate, Qmax) was performed to implement the randomization. Medications such as 5α-reductase inhibitors, α-blockers, anticholinergics and anticoagulant were stopped 1 week before surgery. All the patients were in lithotomy position, and epidural anaesthesia was used. All the procedures were performed by an experienced surgeon. Bladder washouts were stopped when macrohematuria ceased and then the catheter was be removed within 24 h.

Before surgery, the baseline characteristics were collated, which included urological history, presence of concurrent diseases, previous drug therapy, prostate volume (TRUS measurement), postvoid residual urine volume, IPSS, Qmax and the five-item version of the International Index of Erectile Function (IIEF-5). Blood investigations included measurement of PSA level, serum sodium and haemoglobin. Serum sodium and haemoglobin were also measured immediately after surgery. The breath ethanol test was carried out during the operation. After surgery, resected prostatic weight, operative duration, serum sodium decrease, haemoglobin decrease and early complications were recorded. IPSS, Qmax, IIEF-5 and late complications were followed-up at 6, 12 and 24 months. The present study was a single ‘blinded’ trial where only the patients were ‘blinded’ to the different treatments while the surgeons and supervisors were not.

The procedures ware similar for TURIS/TURP. The generator for TURIS (Olympus, SurgMasterSystem, Japan) was set at 180 W for cutting and 100 W for coagulation. The irrigation fluid used was 3 L normal saline (0.9%) tagged with 1% ethanol. TURP (Olympus, Japan) needs a diathermy pad for the return current and the TURP generator was set at 120 W and 70 W for cutting and coagulation, respectively. For TURP a 4% mannitol solution with 1% ethanol was used for irrigation. All the irrigation bags were hung 60 cm above the operating table.

For the breath ethanol tests, a breathalyser (Lion Alcolmeter® 500, Barry, UK) was used. During the procedure, an assistant instructed patients to inhale and exhale forcefully into the mouthpiece of the alcolmeter, and then the result would show on the display. The data was collected before surgery and at 10-min intervals throughout the operation. The total amount of fluid absorbed was calculated using the Widmark formula [8]. According to the breathalyser and the formula, absorption of <40 mL was difficult to detect and was considered as no absorption in the present study.

All measurement data were statistically analysed with the two-tailed Student t-test and presented as the mean (sd). The results were analysed with the use of descriptive statistics with the paired t-test and chi-square test used to calculate continuous variables and categorical data. Differences were considered statistically significant at P < 0.05.

RESULTS

As shown in Table 1, there were no statistically significant differences in baseline characteristics between the groups. The perioperative data are also shown in Table 1. While the operative duration and resected prostate weight were similar between the groups, serum sodium and haemoglobin were significantly lower in the TURP group. In all, 45 patients in TURIS group and 38 in TURP group were able to use the breathalyser during the operation. The mean volume of fluid absorbed was significantly less in TURIS group.

Table 1.  Baseline characteristics and perioperative data
VariableTURISTURPP
  1. PVR, postvoid residual urine volume.

No. of patients5050 
Baseline   
 Mean (sd; range):   
  Age, years69.7 (7.6; 55–87)71.2 (6.3; 57–88)0.83
  PSA level, ng/mL1.8 (1.2; 0.01–3.72)2.0 (1.4; 0.03–3.94)0.52
  TRUS volume, mL60.2 (18.7; 34–102)59.1 (17.3; 30–98)0.38
  IPSS22.8 (5.7; 14–32)21.8 (6.2; 12–33)0.41
  Qmax, mL/s7.1 (3.7; 3.4–13)7.9 (3.5: 2–14)0.61
  PVR, mL73.1 (33.6; 23–146)80 (36.2; 30–175)0.28
Perioperative   
 Mean (sd; range):   
  Operative duration, min59 (19; 22–119)60 (18; 25–110)0.82
  Resected weight, g40 (16; 29–89)38.9 (14.5; 19–85)0.31
 N (%) patients with absorption17/45 (37.8)25/38 (65.8)0.015
 Mean (sd; range):   
  Fluid absorption, mL208 (344; 0–1450)512 (706; 0–3250)<0.001
  Serum sodium decrease, mmol/L3.4 (1.4; 0–6.9)6.3 (2.9; 2–15)<0.001
  Haemoglobin decrease, g/dL1.1 (0.6; 0.2–2.4)1.6 (0.7; 0.4–3.2)0.008

Nine of 45 patients in the TURIS group and 15 of 38 in the TURP group had capsular perforation during the TUR. Figure 1A shows a strong relationship between fluid volume absorption and operative duration in the TURIS group (Spearman’s rank correlation coefficient 0.73). There were two cases of capsular perforation with no discernible fluid absorption but in these cases the operative durations were <30 min. While, in all the other cases of capsular perforation with identifiable fluid absorption the operative durations were >50 min. Fig. 1B, shows that there was a strong correlation between fluid volume absorption and operative duration in the TURP group (Spearman’s rank correlation coefficient 0.75). All the cases with capsular perforation appeared to have identifiable fluid absorption.

Figure 1.

Volume of irrigant absorbed during TURIS (A) and TURP (B).

Table 2 lists the complications. None of the present patients developed TUR syndrome. In the TURP group, two patients needed re-catheterization due to urine retention after catheter removal, whereas none in the TURIS group required re-catheterization. During the short-term follow-up, 18 patients (eight in the TURIS and 10 in the TURP group) complained of some degree of incontinence, but this resolved within 6 months. During the 2-year follow-up, re-operations for urethral stricture and bladder-neck contracture were needed in 6% of patients in the TURIS group and in 10% of the TURP group (P= 0.71). In patients who were sexual active, retrograde ejaculation was reported by eight of 22 patients in the TURIS group and nine of 18 patients in the TURP group.

Table 2.  Complications
VariablesTURIS, n (%)TURP, n (%)P
Acute complications   
 TUR syndrome00
 Blood transfusion1 (2)3 (6)0.62
 Re-catheterization02 (4)0.49
 Transitory urge incontinence8 (16)10 (20)0.79
Late complications (6–24 months)   
 Urethral stricture2 (4)3 (6)1.0
 Bladder-neck contracture1 (2)2 (4)1.0
 Stress incontinence02 (4)0.49
 Retrograde ejaculation, n/N (%)8/22 (36)9/18(50)0.52

The follow-up data are presented in Table 3. All 100 patients completed the 2-year follow-up. Compared with baseline, there were significant improvements in IPSS and Qmax in both groups after surgery. At the 6-, 12- and 24-month follow-ups, there were no statistical differences between the groups in IPSS and Qmax. The IIEF-5 was completed by 52 patients (24 in TURIS and 28 in TURP group) during follow-up, which showed that there was no significant reduction in erectile function after TUR in either group.

Table 3.  Follow-up data
VariableBaselineFollow-up, months
61224
IPSS    
 Mean (sd; range):    
  TURIS22.8 (5.7; 14–32)5.5 (3.6; 0–16)4.2 (2.6; 0–10)3.7 (2.7; 0–10)
  TURP21.8 (6.2; 12–33)5.8 (3.9; 0–15)4.1 (2.3; 0–11)3.8 (2.6; 0–9)
 P0.410.790.680.59
Qmax    
 Mean (sd; range):    
  TURIS7.1 (3.7; 3.4–13)22.5 (7.8; 7–40)23.2 (8.1; 9–45)25.5 (9.0; 9–44)
  TURP7.9 (3.5; 2–14)21.9 (9.2; 8–42)22.2 (8.8; 8–43)24.8 (8.3; 9–43)
 P 0.610.390.72
IIEF-5    
 Mean (sd; range):    
  TURIS18.9 (5.9; 8–24)19.1 (6.0; 8–24)19.5 (6.1; 8–25)20.4 (6.0; 8–25)
  TURP19.5 (5.4; 7–25)19.6 (5.7; 9–25)19.3 (4.0; 8–25)19.6 (5.9; 8–26)
 P0.610.390.720.65

DISCUSSION

In recent years, several techniques have shown promise in replacing TURP as the standard procedure for treating BPH. Foremost being holmium laser enucleation of prostate (HoLEP) and bipolar TUR. HoLEP has been proved size independent, efficient and safe for long-term outcomes [9,10], but the long learning curve and significant initial cost that are inevitable have prevented its widespread use especially in developing countries. With the bipolar device, there are no new skills that need to be learnt to perform the operation when the operator is proficient in standard TURP.

Like other bipolar systems, the TURIS system allows coagulation of most small venous vessels during the resection. If opening large veins and venous sinuses of the prostate, the 100 W coagulation can immediately seal them. Due to the excellent visualization and a smaller resection loop, an experienced operator should have less capsular perforation. Therefore, irrigation fluid absorption can be greatly reduced thus avoiding TUR syndrome. To date, mid- or long-term results of using this device are lacking. Thus, we report the outcome of a prospective randomized trial comparing traditional TURP and bipolar TURIS with a 2-year follow-up.

The most significant feature of the bipolar TURIS system is its reduced effect on serum sodium levels due to less fluid absorption. In a report by Ho et al. [3] the declines in mean postoperative serum sodium levels for TURIS and monopolar TURP groups were 3.2 and 10.7 mmol/L, respectively (P < 0.01). The mean resection time and mean weight of resected prostate tissue were similar. Also in the present study, the decrease in serum sodium was greater and more irrigant was absorbed in the TURP cohort, while the resection time was similar between the groups. These data suggest that the key advantage of the bipolar TURIS system is less fluid absorption during surgery. From our experience, this results not only from the use of saline as the irrigant, but also because of less capsular perforation owing to a precise resection from the clear visual field obtained using TURIS.

Fluid absorption during standard TURP has been extensively studied, and its impact recognised. A prolonged resection time (>90 min) [11], excessive pressure in the prostatic fossa (fluid bags should not exceed a height of 60 cm) [12], an extended resection with bleeding, capsular perforation [13], as well as the surgeon’s experience and skill are considered the main factors that contribute to fluid absorption and the subsequent complications. However, there is little published data on TUR using the bipolar system. Thus, in the present study of TURIS, we specifically looked at operative duration and capsular perforation while controlling for the other factors. There was a significant relationship between operative duration and irrigant absorbed especially when the operative duration was >50 min (Fig. 1A). The two cases of capsular perforation with no identifiable absorption were short operations, while the other seven cases with fluid absorption were all >50 min. This suggests that a shorter operation can balance out the trend of absorption caused by capsular perforation when performing the TURIS operation. Nevertheless, in prolonged procedures, the impact of capsular perforation on fluid absorption could be significant. But, in the TURP group (Fig. 1B) capsular perforation resulted in greater fluid absorption.

Acute and late complications were less frequent in the TURIS group. The rates of blood transfusion and re-catheterization were lower in the TURIS than in the TURP group. In the present study, eight patients (16%) in the TURIS and 10 (20%) in the TURP group had self-limiting transitory urge incontinence after surgery, which probably resulted from the high energy applied to the capsule. In the long-term follow-up, two patients (4%) in the TURP group had stress incontinence whereas there were none with stress incontinence in the TURIS group. The complications such as urethral stricture and bladder-neck contracture were not significantly different between the groups. This result appears to be similar to the study by Autorino et al. [14], where at a 4-year follow-up, urethral stricture developed in 3% and bladder-neck sclerosis in 3% in the bipolar plasmakinetic-TURP group, with no significant difference from the monopolar TURP group.

Sexual dysfunction is a common complication and indicates that TURP should be carefully performed especially in younger patients. Retrograde ejaculation (occurs in 53–75% of patients [1]) and erectile dysfunction are the main complications, which can have a significant impact on quality of life in sexual active men. In the Veterans Affairs Cooperative Study, at a mean follow-up of 2.8 years, 19% of men after TURP had deterioration in their sexual performance [15]. In the present study, erectile dysfunction was assessed using the IIEF-5 and there was no significant effect on sexual activity in either group; although, the TURIS group had a lower rate of retrograde ejaculation than TURP group. We concluded this might occur for the following reasons: firstly, with the bipolar device, electric current did not pass through the body and did no harm to the surrounding nerves; secondly, the precise resection due to the clear visual field made it possible to preserve the tissue around the verumontanum. However, this issue still awaits confirmation in long-term follow-up.

In randomized controlled trail studies comparing monopolar and bipolar resection with at least 1-year follow-up, the improvements in IPSS and Qmax were significant in the groups. But there were no statistical differences in any of the variables measured between the groups [3,16–18]. Similarly, in the present report, the mean IPSS improved six-fold and the mean Qmax increased three-fold in both groups at the 2-year follow-up. We are still monitoring the long-term consequences for these patients.

In conclusion, the present study shows that the clinical efficacy of bipolar TURIS is durable and comparable with that of traditional TURP at 2 years follow-up. The mean fluid absorption was much less during the TURIS procedure (assessed using the breath ethanol test). The present study shows that the bipolar system is a promising technique to challenge the ‘gold standard’ surgical therapy for BPH.

ACKNOWLEDGEMENTS

This study was supported by Shanghai Shenkang Hospital Development Center (SHDCI2007313) and Science and Technology Fund of Shanghai JiaoTong University School of Medicine (09XJ21002).

CONFLICT OF INTEREST

There were no competing financial interests.

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