“Theatre acting is the operation with a scalpel, movie acting is an operation with a laser”. Michael Caine.Being the instrument in hands of urologist laser is much more than a single-application device. Its applicability is deeply dependent on physical properties, settings, and environment. With knowledge of how the device work, why it affects the tissue, and how this laser-tissue inter-action goes surgeon can shape further clinical work to choose the best devices or techniques of surgery. Tailor-ing the laser effects on the needs of the patient.In this paper, we tried to briefly describe what a laser device consists of, the most important laser-tissue interac-tions that are necessary for understanding the operation of the laser, and the main laser systems that are used in urology.

Greenlight laser prostate vaporization is considered a valid alternative to transurethral prostate resection (TURP) for patient with LUTS due to BPH. The current review highlights the current evidence on greenlight technique and current state of-the-art. We will review clinically relevant concerns such as size limitation, economic issues and same-day surgery options. We will also describe technological improvements over time and its relationship with current vaporization practices. CURRENT SITUATION: Based on clinical trial Goliath, Greenlight 180W vaporization showed non-inferiority to TURP and similar mid-term functional outcomes. A benefit towards length of hospital stay, similar complication rate (below 80% at 2 years). The current laser generators (higher potency) are able to provide an ablative effect on tissue that is associated to a shorter operative time. The major advantage of greenlight laser is the same day discharge, with a low readmission rates. Greenlight laser is more cost-effective than TURP. CONCLUSIONS: Green light laser remains as an alternative valid option despite the technological improvements in the field.

Thulium lasers operate at wavelengths be-tween 1940-2013 nm either in a continuous wave or in a pulsed mode, which enables smooth incisions with fast vaporization or effective laser lithotripsy for urolithiasis.Thulium laser enucleation is a minimally invasive and size-independent treatment for benign prostatic hyper-plasia (BPH) with excellent long-term results. Since its in-troduction, several modifications in the technology and surgical techniques have been proposed such as vapo-resection, vaporization and enucleation with regard to BPH treatment. Recent developments in the thulium laser technology in-clude the introduction of a super pulsed thulium fiber laser. This technique delivers the laser energy through an active fiber with an absorption maximum in water at a wavelength of 1940 µm. Preclinical studies showed a significantly higher stone fragmentation rate in different ex vivo models compared to the Ho:YAG laser. Another innovative thulium laser that works, as a hybrid laser has yet not been tested clinically, however, will soon be introduced. With the introduction of both new thulium lasers as novel devices, the armamentarium in the field of endourology for lithotripsy and enucleation increases. We here pre-sent different thulium lasers and surgical techniques that are possible to perform with each device including the reasons and advantages of each modification.

Endoscopic enucleation of the prostate was first described by Hiraoka in 1986, using a monopolar resectoscope. His contribution was largely ignored until Gilling and Fraundorfer published their three-lobe enucleation technique with the Holmium laser in 1998, that ended establishing itself as a reliable option for the treatment of HBP, backed by ample scientific evidence. Later on, enucleation performed with other lasers, as well as bipolar energy, have shown concordance in their clinical results. As a result, the term AEEP (anatomic endoscopic enucleation of the prostate) emerged to encompass all these techniques. During the last few years there have been significant advances in two areas: first, technology, with the development of pulse modulation for Holmium generators (MOSES) as well as high-speed morcellators. Second, the development of new surgical techniques that recog- nize the importance of the early release of the sphincter from the apex of the adenoma during the operation as well as the careful preservation of the external sphincter’s mucosa, to avoid early stress incontinence. In this paper, we review the recent evolution of both technology and surgical technique. AEEP has been risen to a new level, reducing operative time significantly, usually under one hour, and radically reducing the incidence of early temporary stress incontinence, and maybe also facilitating the learning curve of AEEP.

OBJECTIVE: Prostate enucleation is becoming more relevant within BPH treatment. Nowadays is probably the gold standard for enucleation. Several studies have shown holmium laser as the most frequently used safe and efficient energy source. The long learning curve remains as its major drawback. The current review aims to describe step to step technique at our institution and describing the rational for its use. METHODS: A detailed description on our step-to-step Holep technique is provided. We focused on the main differences with other techniques already described highlighting the largest experience reported. RESULTS: None of the published series has shown better results in terms of functional, safety and less complications outcomes on the short and long term. No differences are shown in terms of intraoperative/postoperative blood loss, reoperations, capsular perforations or urethral strictures. Our techniques provides shorter surgical length and improved efficiency than blocking and trilobular techniques. The rates of early continence are 4% vs 5-40%. Lastly, improvement in morcellator devices delivered no complications related to that part of the surgery. CONCLUSIONS: Holep is the gold standard technique for prostate enucleation. It provides improved functional and safety outcomes than with other techniques. A standardized and optimized technique is mandatory.

LASER (Light Amplification by Stimulated Emission of Radiation) technology consists of the emission of a high-energy light beam. In medicine, it is used to cut, coagulate, fragment and evaporate biological or synthetic tissues. In the field of Functional Urology and Urogynecology its use has been widely explored. This article tries to give an overview of its applications in this subspecialty. MATERIAL AND METHOD: A non-systematic free search was performed in Pubmed, Embase and Google Scholar, combining the terms “laser”, “laser technology”, “interstitial cystitis”, “trigonitis”, “urinary tract infections”, “mesh”, “mesh complications”, “microbiome”, “menopause genitourinary syndrome”, “vulvovaginal atrophy”, “urinary incontinence”, “pelvic organ prolapse”, “lichen sclerosus”, “complications” and “vaginal laxity”. All relevant studies were retrieved in full text, in order to prepare a summary of each of the pathologies in which laser therapy has been used in Functional Urology and Urogynecology over time. RESULTS: There are different types of lasers and different application modalities to treat a wide variety of functional pathologies, including interstitial cystitis, trigonitis, mesh complications, urinary incontinence or pelvic organ prolapse. In some of them its use has been abandoned, despite the fact that, theoretically, they offer advantages over other therapies, such as in the case of interstitial cystitis. In others there is still not enough evidence in terms of safety and efficacy to be an alternative to other conventional treatments. CONCLUSIONS: Although laser therapy offers certain advantages over other treatments, its use has not been generalized in the subspecialty of Functional Urology and Urogynecology. More evidence is needed to demonstrate its efficacy and safety.

OBJECTIVES: In recent years, there has been a rise concerning the research and development of focal prostate cancer therapies as a consequence of the high percentage of low-risk and localized prostate cancers. These focal therapies aim at preserving the gland in selected patients to avoid overtreatment. The application of lasers for focal ablation and photodynamic therapy has shown promising results in exchange for a minimal rate of adverse events compared to radical treatments. MATERIAL AND METHODS: An extensive review of the available literature on focal laser treatments for localized prostate cancer was conducted. A search in PubMed and Embase was carried out by the following keywords: “Localised prostate cancer”, “Low-risk prostate cancer”, “Focal therapy”, “Magnetic Resonance in localized prostate cancer”, “Focal laser ablation” , “Photodynamic therapy” and “TOOKAD”. RESULTS: Photodynamic therapy with TOOKAD is the only focal therapy evaluated in a phase III clinical trial, showing a lower rate of progression and a longer time to progression compared to active surveillance. Other studies carried out have revealed a percentage up to 80% of negative biopsies 6 months after TOOKAD. Likewise, the quality of life of patients treated using focal laser ablation techniques and photodynamic therapy has been minimally altered, as most adverse effects have been shown to be mild and transient, with dysuria and hematuria being the most frequent. CONCLUSIONS: Despite the fact that focal therapies are still not recommended outside the context of clinical trials and the lack of comparative studies between the different techniques, laser focal therapies seem to have a future within the new approaches for localized prostate cancer.

OBJECTIVE: To review recent and rele-vant information regarding the use of high-power (HPL) and low-power (LPL) Holmium:YAG lasers (Ho:YAG) in retrograde intrarenal surgery (RIRS) for lithotripsy.METHODS: A PubMed/Embase search was conducted and recent and relevant papers on Ho:YAG for RIRS were reviewed.RESULTS: Settings for Ho:YAG are pulse energy (PE), pulse frequency (PF), and pulse width. Currently, the ma-jority of LPL can also adjust pulse-width but cannot reach PF as high as HPL, however, the higher energy outputs reached by HPL are rarely useful in lithotripsy. Higher PE might enhance ablation but generates larger fragments and higher retropulsion. Pulse width does not affect en-ergy output but delivers energy for a longer time-length. Dusting and basketing are complementary techniques. Dusting seeks to pulverize stones into particles ≤250 µm avoiding the use of instruments for stone retrieval, where-as in fragmenting, the stones are break into smaller piec-es which are then retrieved. Dusting can prevent the use of supplies such as access sheaths and baskets and also prevent the complications related to their use. However, is not always feasible in clinical practice to fully ablate a stone into dust, then the use of this supplies and pop-corn technique are helpful for rendering a patient stone-free. The energy gap between HPL and LPL is wide and leaves room for a mid-power laser classification, which can overcome the main drawback of LPL, the expenses of HPL, and still holding its versatility for other procedures beyond stones. CONCLUSIONS: HPL and LPL have similar effective-ness, but long-term cost-effectiveness comparisons are underexplored. Newer HPL would need to be com-pared to emerging technologies as the thulium fiber, and prove superiority to mid-power laser to determine how powerful is enough for Ho:YAG in the years to come.

Holmium laser has been established as the gold-standard for the ureteroscopic management of urinary stone disease. However the role of laser in percutaneous nephrolithotomy (PCNL) varies, as multiple energy sources and lithotripters are available. Currently, lasers are becoming more relevant with the development of several miniaturized PCNL techniques. The purpose of this article is to review the role of laser in percutaneous renal surgery, and whether or not it is the best option for this approach. Discussion points include: the history and background of lasers in urologic surgery, PCNL and its outcomes in the literature, the positives and negatives of lasers versus other lithotripters in several different PCNL techniques, emerging laser technology such as thulium fiber laser, the use of lasers in establishing percutaneous renal access, and laser’s role in non-stone percutaneous renal surgery.

The SuperPulsed Thulium fiber laser has recently become available to the urologist. It can be safely and efficiently applied to humans for the purposes of laser lithotripsy. Particularly, this innovative technology overcomes the main limitations of Holmium:YAG lasers, which had been the principal source of energy for litho-tripsy over the past decades.The SuperPulsed Thulium fiber laser allows a broader range of pulse energy (0.025 to 6.0 J), pulse frequency (up to 2000 Hz) and pulse duration (0.05 to 12 ms), as well as smaller operating laser fibers (50-150 µm core), compared to Holmium:YAG lasers. The laser emission at 1940 nm leads to a four-fold higher energy absorption in water, which ensures precise lithotripsy and a high degree of safety. Multiple comparative in vitro studies suggest a 1.5 to 4 times faster stone ablation rate in favor of the SuperPulsed Thulium fiber laser, when compared to Holmium:YAG la-sers. It has also been shown to generate particularly fine stone dust, and electronic pulse modulation allows su-perior stone stabilization. The SuperPulsed Thulium fiber laser, like the Holmium:YAG laser, has been repeatedly reported thermodynamically safe, provided that a min-imal irrigation flow (10-15 ml/min) and relatively low average power (≤ 25 W) is maintaining throughout the lithotripsy process.These new standards are particularly advantageous for fine and rapid ureteroscopic stone dusting, and open paths that were not been amenable to the Holmium:YAG laser.

OBJECTIVE: To assess current efficacy and safety of low power HoLEP (Holmium Laser Enu-cleation of the Prostate) for the treatment of obstructing and symptomatic prostatic adenomas and to identify the mechanisms supporting the related clinical advantages.METHODS: A systematic review was conducted using relevant databases (Ovid Medline, PubMed, Scopus and Web of Sciences), employing (“low power” OR “high power”) AND (“HoLEP” OR “holmium laser enucle-ation of the prostate”) as search terms. Inherent publica-tions were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRIS-MA) guidelines. Additionally, the reference lists of the selected papers were checked manually. RESULTS: We included any kind of study (n=15) dealing with low power HoLEP because of the scarcity of the re-sults obtained with the bibliographic search. Low power HoLEP seems to be fully comparable to the traditional high power HoLEP in terms of feasibility, efficacy and safety. An additional clinical advantage of the low pow-er approach might be the reduced incidence of postop-erative dysuria, with limited intensity and duration, possi-bly due to the decreased amount of energy delivered to the capsular plane with a less aggressive modality, con-jugated with appropriate technical enucleative choices. The physical rationale of low power HoLEP is discussed.CONCLUSIONS: Low power HoLEP is feasible, safe and effective, and might play a not exclusive role in the reduction of incidence, intensity and duration of postop-erative dysuria.