Evaluation of ideal irrigation fluid in ‘Greenlight’ photoselective vapourization of the prostate

120 W lithium triborate laser for photoselective vaporization of the prostate: comparison with 80 W potassium-titanyl-phosphate laser in an ex-vivo model

PURPOSE

To evaluate the ablative and hemostatic properties of the recently introduced 120 W lithium triborate (LBO) 532 nm laser and compare the results against the conventional 80 W potassium-titanyl-phosphate (KTP) laser.

MATERIALS AND METHODS

The ex-vivo model of the isolated blood-perfused porcine kidney was used to determine the ablation capacity, hemostatic properties, and coagulation depth of the GreenLight HPS laser system (American Medical System, Minnetonka, MN) that used an output power of 120 W. The results were compared with the KTP laser that used output power levels of 30 W, 50 W, and 80 W. Unperfused kidneys were weighed before and after 10 minutes of laser ablation in an area of 3 x 3 cm; the weight difference marked the amount of removed tissue. Bleeding was determined by the weight difference of a swab before and after it was placed on the bleeding surface for 60 seconds after ablating a surface area of 9 cm(2) on blood-perfused kidneys.

RESULTS

With a tissue removal of 7.01 +/- 1.83 g after 10 minutes of laser ablation at 120 W, the LBO laser offered a significantly higher ablation capacity compared with 3.99 +/- 0.48 g reached with the conventional KTP laser at 80 W in the same time interval (P < 0.05). The bleeding rate was also significantly increased using the LBO at 120 W compared with the conventional device at 80 W (0.65 +/- 0.26 g/min vs 0.21 +/- 0.07 g/min; P < 0.05). The corresponding depths of the coagulation zones were 835 +/- 73 microm and 667 +/- 64 microm (P < 0.05), respectively.

CONCLUSION

The 120 W LBO laser offers a significantly higher tissue ablation capacity compared with the conventional 80 W KTP laser. Because the increased efficacy of the device is accompanied by a higher bleeding rate and a slightly deeper coagulation zone, the user has to select the appropriate output power levels carefully for a safe and efficient treatment. Nevertheless, the bleeding rate compared with previous studies of transurethral resection of the prostate is significantly reduced.

[Photoselective vaporization of the prostate with Laser Greenlight HPS: current role, technical aspects and review of the literature]

Photoselective vaporization of the prostate with 120W HPS Greenlight laser is one of the most attractive modalities of surgical treatment for benign prostatic hyperplasia at present. The specific physical characteristics of this laser provides an excellent safety and effectiveness profile, making it the ideal technique for high-risk patients or patients ongoing oral anticoagulation. Moreover, the undeniable reduction of urethral catheterization time and hospital stay compared to transurethral resection of prostate (TURP) involves a much more comfortable postoperative period for patients. We have conducted a Medline/Pubmed search, presenting in this review the outcomes and current surgical techniques described in recent studies. We have also reviewed the controversial aspects and limitations attributed to this technique.

The evolution of KTP laser vaporization of the prostate

The search for a minimally invasive approach to the treatment of Lower Urinary Tract Symptoms (LUTS) suggestive of Benign Prostatic Hyperplasia (BPH) is probably as old as Transurethral Resection of the Prostate (TURP). In an effort to overcome the limitations and morbidities of TURP, and in light of evidence suggesting that medical treatment for BPH has a limited life-span, laser-based treatments have emerged during the last decade. Photoselective Vaporization of the Prostate (PVP) by the "GreenLight" KTP laser is considered one of the most promising options, one that is constantly evolving new technologies in prostate surgery. In this overview of KTP laser usage in BPH treatment, we will briefly discuss the evolution of this modality since it was first introduced and focus on the available evidence regarding safety, efficacy and cost parameters of its application.

Update on photoselective vaporization of the prostate

Photoselective vaporization of the prostate (PVP) with a potassium titanyl phosphate (KTP) laser may be the most promising new technology applied to the treatment of benign prostatic hyperplasia (BPH). The specific laser light characteristics and the ideal interactions between KTP lasers and prostatic tissue result in an even and efficient vaporization of the prostate and the formation of a clearly deobstructed prostate cavity. PVP can be a day-care procedure, with few hours of catheterization and minimal postoperative discomfort, offering outcomes at least equivalent to the reference standard transurethral resection of the prostate. Although larger studies are necessary to further define where PVP stands in the management of BPH, this review focuses on contemporary treatment techniques and their limitations, and comments on the outcomes of its current use.

Greenlight laser in benign prostatic hyperplasia: turning green into gold

PURPOSE OF REVIEW

The purpose of this review is to present recent clinical data published upon the photoselective vaporization of the prostate procedure and introduce new ideas about the future influence of this new technology upon the treatment of benign prostatic hyperplasia.

RECENT FINDINGS

Published studies have provided significant evidence that the photoselective vaporization of the prostate laser procedure is efficient, safe, easy to learn and early results show that it can compete with transurethral resection of the prostate. The major advantages of this technique are that it is a bloodless procedure, the patient goes home after a few hours and it can be applied to all patient categories. The cost of the photoselective vaporization of the prostate procedure is being investigated and a few studies addressing this issue seem to conclude that this surgical option is a cost effective decision. Lately, thoughts about early surgical intervention with the photoselective vaporization of the prostate laser are being expressed but properly designed studies are needed.

SUMMARY

The photoselective vaporization of the prostate laser procedure is getting worldwide fast recognition and it is the first time that transurethral resection of the prostate and open prostatectomy are being threatened. The cost of this procedure is being examined but it is difficult to draw solid conclusions since reimbursement strategies differ between various countries.

Photoselective vaporization of the prostate (GreenLight PV): lessons learnt after 3500 procedures

The technical recommendations of an international group of experts on photoselective vaporization of the prostate (PVP; GreenLight PV) for benign prostatic hyperplasia are described. Their experience stems from the treatment of over 3500 patients at five centres in Europe and the United States. The objectives of this physician-based initiative are to optimize the results achieved with PVP by standardizing the procedure, as well as to recommend training requirements.