Green Light Laser Effective for Lower Urinary Tract Symptons
Shane Roberts
March 20, 2009
Laser vaporization of prostate tissue using a 120-watt GreenLight laser significantly reduces lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH), according to a study conducted at nine centers in seven countries.
The GreenLight laser is not yet widely used in North America or Europe, but this improved version of the potassium-titanyl-phosphate laser is gaining a foothold on both continents. The nine centers included hospitals in New York City and Boston.
Among 629 subjects with BPH-related LUTS, prostate volume fell by 55% over an average of 7.7 months' follow-up and PSA levels dropped by 43%, according to findings presented here at the World Congress of Endourology. Symptoms decreased significantly and urine flow rose significantly. The mean American Urological Association Symptom Score decreased from 21.6 at baseline to 8.4 after six months. The mean maximum flow rate rose from 8.1 to 20.2 mL/sec.
Investigators observed a 12.1% rate of intraoperative bleeding that mainly led to impaired intraoperative visibility, a 2.5% rate of capsular perforation, and an 8.3% rate of recatheterization because of urine retention in the immediate postoperative period. In addition, for 3.1% of patients, surgeons had to switch to transurethral prostatectomy because of bleeding or technical problems.
Investigators applied between 4.1 and 5.0 kJ for each milliliter of prostate tissue ablated. Prostates ranged volume from 24 to 165 mL. The average was 65.4 mL. The mean operating time was 64.5 minutes, including 44.9 minutes of laser application.
Lead investigator Alexander Bachmann, MD, provisional head of the department of urology at University Hospital Basel, in Switzerland, noted that patients who were receiving anticoagulation medication or have prostates too large to be eligible for transurethral prostatectomy were initially thought likely to benefit most from this approach.
"But we now use the GreenLight laser approach nearly routinely in all our patients with lower urinary tract symptoms due to prostate enlargement," Dr. Bachmann said.
Carson Wong, MD, associate professor and chief of the Section of Endourology, Laparoscopy and Minimally Invasive Surgery at the University of Oklahoma Health Sciences Center in Oklahoma City, reviewed the results and said "the clinical efficacy achieved in the study is impressive."
Still, he questioned why such large amounts of energy were applied during the laser treatments. The average energy used per patient was 274.8 kJ, compared with 85 kJ used in a study he and colleagues published recently on the use of Greenlight laser as a treatment for BPH-related LUTS (J Endourol. 2008;22:2341-2347).
Dr. Bachmann responded that based on his experience, vaporization is more intense at higher energy levels and more tissue can be ablated. "Although this can lead to an insignificantly higher rate of bleeding and capsular perforations, our aim is to maximize tissue ablation, especially in order to prevent a high rate of recurrent adenoma during follow-up," he said.
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The GreenLight laser is not yet widely used in North America or Europe, but this improved version of the potassium-titanyl-phosphate laser is gaining a foothold on both continents. The nine centers included hospitals in New York City and Boston.
Among 629 subjects with BPH-related LUTS, prostate volume fell by 55% over an average of 7.7 months' follow-up and PSA levels dropped by 43%, according to findings presented here at the World Congress of Endourology. Symptoms decreased significantly and urine flow rose significantly. The mean American Urological Association Symptom Score decreased from 21.6 at baseline to 8.4 after six months. The mean maximum flow rate rose from 8.1 to 20.2 mL/sec.
Investigators observed a 12.1% rate of intraoperative bleeding that mainly led to impaired intraoperative visibility, a 2.5% rate of capsular perforation, and an 8.3% rate of recatheterization because of urine retention in the immediate postoperative period. In addition, for 3.1% of patients, surgeons had to switch to transurethral prostatectomy because of bleeding or technical problems.
Investigators applied between 4.1 and 5.0 kJ for each milliliter of prostate tissue ablated. Prostates ranged volume from 24 to 165 mL. The average was 65.4 mL. The mean operating time was 64.5 minutes, including 44.9 minutes of laser application.
Lead investigator Alexander Bachmann, MD, provisional head of the department of urology at University Hospital Basel, in Switzerland, noted that patients who were receiving anticoagulation medication or have prostates too large to be eligible for transurethral prostatectomy were initially thought likely to benefit most from this approach.
"But we now use the GreenLight laser approach nearly routinely in all our patients with lower urinary tract symptoms due to prostate enlargement," Dr. Bachmann said.
Carson Wong, MD, associate professor and chief of the Section of Endourology, Laparoscopy and Minimally Invasive Surgery at the University of Oklahoma Health Sciences Center in Oklahoma City, reviewed the results and said "the clinical efficacy achieved in the study is impressive."
Still, he questioned why such large amounts of energy were applied during the laser treatments. The average energy used per patient was 274.8 kJ, compared with 85 kJ used in a study he and colleagues published recently on the use of Greenlight laser as a treatment for BPH-related LUTS (J Endourol. 2008;22:2341-2347).
Dr. Bachmann responded that based on his experience, vaporization is more intense at higher energy levels and more tissue can be ablated. "Although this can lead to an insignificantly higher rate of bleeding and capsular perforations, our aim is to maximize tissue ablation, especially in order to prevent a high rate of recurrent adenoma during follow-up," he said.
Dragonlasers - No 1 online store for green laser pointers & high power lasers
Click here for Laser Module
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