Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia: Effectiveness, Safety, and Overcoming of the Learning Curve

Transurethral resection of the prostate (TURP) has been considered as the standard for the surgical treatment for bladder outlet obstruction induced by benign prostatic hyperplasia (BPH). However, ever since Gilling and Fraundorfer reported the concept of holmium laser enucleation of the prostate (HoLEP) in 1998 [1], HoLEP has been increasingly used. HoLEP is considered to be at least equivalent to or better than TURP, has been reported to have the same long-term record as open prostatectomy, and also has been suggested as an endourological surgery that could replace open prostatectomy [2, 3]. Recently, HoLEP has been adopted by several hospitals in South Korea. However, no domestic study has been conducted on HoLEP as yet. Thus, we decided to describe our early experiences regarding the effectiveness and safety of HoLEP and to estimate the learning curve, which has been reported to be the largest disadvantage of HoLEP [4-6].

Recently, HoLEP has emerged as an attractive surgical alternative to the treatment of bladder outlet obstruction due to BPH [9]. The HoLEP technique is a method of removing all prostatic adenoma endourologically and might be as effective as open prostatectomy and theoretically reduce complications [3, 10, 11]. Kuntz et al reported in a study involving 120 patients with a 5-year follow-up study that HoLEP and open prostatectomy showed the same level of clinical improvement and that BPH did not recur; thus, it was concluded that HoLEP is an endourological alternative for open prostatectomy [3]. In addition, other studies reported that open prostatectomy was better in the indices of operation time and removed tissue weight, but that HoLEP was better in the indices of catheterization time, hospital stay, and bleeding or transfusion. The reason for HoLEP having less removed weight was thought to be due to tissue evaporation by laser during HoLEP [3, 6, 9, 12].

Previous studies have compared HoLEP and TURP and found that TURP was better in terms of operation time, whereas HoLEP was better in terms of resected tissue weight, catheterization time, hospital stay, and bleeding or transfusion [6, 13-15]. Furthermore, there was no difference in the uroflowmetry or change of symptom scores between both groups after 2 years of follow-up observations [14, 15]. Kuntz et al reported in a randomized study of 200 patients with a 1-year follow-up that HoLEP was better than TURP in terms of hospital stays, hemoglobin decrease, clinical improvement, and residual urine [2]. Furthermore, HoLEP was shown to be effective and safe for treating concurrent BPH in patients administered anticoagulants, in patients with a hemorrhagic disorder, and in patients with stones in the upper urinary tract or bladder [16-20].

However, the major disadvantage of HoLEP concerns overcoming the learning curve, which requires experience and time. Many surgeons have mentioned that although the HoLEP method was more difficult than TURP, one could overcome the difficulty with self-learning [5, 21-23]. Seki et al reported an enucleation efficiency study involving 70 patients who underwent HoLEP and were divided into 7 groups of 10 patients each. In the first group, enucleation efficiency was 0.3 g/min but in the last group it had increased to 0.75 g/min, showing that the accumulation of experience improved the learning curve [24]. Placer et al studied the learning curve of HoLEP in 125 patients who were divided into 5 groups in time-sequence order; they compared the first and last groups [4]. Enucleation efficiency was found to markedly increase from 0.3 g/min to 1 g/min, and mean operation times and the amount of energy used showed decreases of 47% and 45%, respectively, between these groups. Furthermore, regarding transient incontinence, which is representative of the complications of HoLEP, the prevalence in the first group of 50 patients was 28%, but that in the last group of 50 patients was markedly reduced by 6%. Thus, they mentioned that improvement of the learning curve had a direct effect of decreasing complications [4].

Recently, Shah et al reported the results of a study involving 162 patients who were divided into 3 groups by sequence of HoLEP (first group: 1-50, second group: 51-100, and third group: 101-162). Eight patients (5%) out of 162 showed a failure of lateral lobe enucleation, and thereby were switched to TURP. All 8 were among the first 25 treated, and enucleation efficiency was improved approaching a high point plateau after 50 cases. Experience with about 50 cases would be necessary to reach the expert level in this surgical technique, HoLEP. Also, instruction by more experienced urologists would bring about better results and shorten the learning curve [21]. In our study, HoLEP learning was self-taught and accomplished alone after attending as an observer and watching the self-learning video, because the opportunity to be supervised by an experienced urologist was not available in Korea. In the case of our study, enucleation failure for the first 20 cases led to switching to TURP in 6 patients (4%). This asserts the necessity of a systemized mentoring program.

The most significant complication that can develop in HoLEP is bladder injury during morcellation. Generally, its frequency is less than 10%, and most degrees of the injury are not severe [22]. However, introduction of morcellation by the inverse (downward) technique was effective at reducing bladder injury. The inverse (downward) technique could prevent blocking of the view of the posterior wall of the bladder by the tissues during morcellation and helped to maintain a sufficient distance of the morcellator from the bladder wall. A bladder wall injury by the blade during HoLEP would grasp the bladder trigon area, which is relatively safer, thus preventing the worst scenario or sequelae. In the case of our study, the morcellation time was significantly reduced and bladder injury and urethral catheterization time were also distinctively reduced (Table 6).

The frequency of urethral stricture and bladder neck contracture by HoLEP was also within the 5% range, which was similar to that of TURP [2, 25]. In our study, the short follow-up observation period did not allow assessment of this issue.

Transient incontinence is a postoperative complication of HoLEP that distresses many surgeons. The surgical features of total prostatic adenoma removal by HoLEP tend to induce higher frequencies of incontinence than does TURP and the condition lasts longer [26, 27]. The incontinence frequency was reported to be 1% through 44%. However, 3-10% is most common [4, 5, 22, 28, 29]. Higher incontinence frequency is reported during the initial try with less experience and is thought to be associated with the learning curve [4, 5]. The duration of postoperative incontinence is usually 3 to 6 months. Some surgeons reported permanent incontinence. However, incontinence is mostly a transient occurrence [4, 22, 28, 29]. An antiinflammatory or anticholinergic drug could be used to regulate incontinence [22, 28]. We also realized that the frequency of transient incontinence was markedly reduced as the number of cases increased. The reasons for such a decrease in the frequency of incontinence were considered to be improvement of the learning curve, efforts to reduce thermal injuries on the apex level by a laser, and the process of saving some amount of anterior fibromuscular stroma tissues [13, 28, 30].

HoLEP has fewer complication and is effective. It is a method that may completely remove prostatic adenoma tissues. In particular, its clinical effectiveness is excellent regardless of prostate size, and it is effective even in cases with a prostate volume of 100 ml or more. However, for self- taught surgeons, about 50 cases are needed to reach the experienced level; thus, we suggest the establishment of a systematic educational program to shorten the learning period.