BERKELEY, CA (UroToday.com) - During the last 15 years, laser treatment of benign prostatic hyperplasia (BPH) has challenged transurethral resection of the prostate (TURP) due to advances in laser technology, better understanding of the tissue-laser interactions, and growing clinical experience.
Various lasers have been introduced including neodymium:yttrium aluminium garnet (Nd:YAG), holmium:yttrium aluminium garnet (Ho:YAG), potassium titanyl phosphate:yttrium aluminium garnet (KTP:YAG), thulium and diode laser. All these different laser treatment modalities are included under the umbrella of the generic term “laser prostatectomy.” This term, however, may be misleading since the currently available lasers and laser techniques differ significantly in terms of handling, and different wave-length dependent laser - prostatic tissue interactions.
The idea behind the present review was to provide all the necessary information to help urologists distinguish one laser from another, highlight the evolution from coagulation to vaporization, resection and enucleation, and to critically evaluate the role of different laser modalities in the treatment by using an evidence-based approach.
An electronic search (MEDLINE) over the last 15 years was carried out to identify publications in the English language on laser treatment in men with BPH using the keywords: laser, prostate, BPH, holmium, photoselective vaporization of the prostate (PVP), Greenlight KTP, lithium triborate (LBO), thulium and diode. The proceedings of recent conferences (last 5 years) of the European Association of Urology, AUA and Endourological Society were also searched. Using an evidence-based approach, our search focused on the highest quality studies for each of the treatment options moving from available meta-analyses to randomised clinical trials (RCTs), and to larger case studies and was also based on systematic review articles that have already been published. The available type of study also indicates how extensively each of these different laser prostatectomies has been studied.
The evolution of laser therapy from coagulation to vaporization, resection, and enucleation has been impressive. Coagulation-based techniques (i.e. visual laser ablation of the prostate and interstitial laser coagulation) have been abandoned completely due to the early, high postoperative morbidity (mainly postoperative dysuria and the need for prolonged catheterization), the high re-operation rate and the emergence of more efficient and technically improved laser systems. Into the frame of the improved technical advantages and increased power outputs, the “ablation” is transferred more and more to “vaporisation” nowadays, because with vaporization an immediate tissue removal is visible during surgery. Holmium Laser Ablation of the Prostate (HoLAP), PVP and diode laser vaporization of the prostate is representative of the ablation/vaporization group. Laser resection represents the laser version of TURP and can be performed by both the Holmium and Thulium lasers. Laser enucleation represents the endoscopic equivalent of the established open pros¬tatectomy and is the most technically advanced form of laser pros-tate surgery. The holmium laser was the initial energy source utilised for the procedure, while recent studies have also reported the use of the Thulium laser for prostate enucleation.
More than ever, TURP is being challenged by HoLEP and Greenlight PV which both represent valid clinical alternatives. HoLEP is the most rigorously analyzed laser technique and current evidence supports the conclusion that HoLEP offers favourable outcomes for any prostate size with low early and late morbidity (Level of evidence 1a) while in addition, clinical efficacy remains durable up to 6 years (Level of evidence 4). HoLAP and HoLRP were the forerunners of many of the applications used today (such as PVP, diode applications and thulium vaporesection) but they have been largely superseded by the enucleation technique (HoLEP).
Few RCTs (Level of evidence 1b) and several large case studies (Level of evidence 4) demonstrated the short-term efficacy and low morbidity of Greenlight PV. However, PVP has grown in acceptance and popularity but long-term results from high quality studies are still awaited. The short-term efficacy of the emerging laser treatments (including diode and thulium prostatectomy) has been suggested by low quality studies (Level of evidence 3-4).
However, it should be emphasized that one of the main inherent limitations of the present review was the difficulty in making comparisons between different lasers. Reasons include the lack of direct, head-to-head comparative studies and the fact that the available lasers are at different points in their clinical maturation. In addition, although some studies addressed the cost of laser treatments it is difficult to draw solid conclusions applicable to every country since the cost effectiveness of all techniques depends on the existence of long-term data, costs of complications, and the different reimbursement systems in different countries.
The present review has also documented the need for better quality data to increase the level of evidence for each laser treatment.
Stavros A. Gravas, MD, PhD, FEBU as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.