Laser Surgery
Procedures. Laser technology is used for removal of prostate tissue. Laser procedures can usually be done as an outpatient procedure, and there is little risk for bleeding. Different procedures are used to provide different degrees of thermal cell destruction that range from coagulation to complete vaporization:
- Interstitial laser coagulation (ILC) involves insertion of a scope through the prostate. A fiberoptic tip is threaded through the scope to direct a diode laser emission to targeted areas of the prostate. The coagulated tissue is naturally absorbed back into the body. Approved in 1998, this procedure is being performed less frequently as urologists turn to newer laser technologies (HoLEP, PVP).
- Holmium laser enucleation of the prostate (HoLEP) is a newer technique that can actually cut and vaporize the tissue. Vaporization is effective immediately and also may pose lower risks for prolonged urinary retention and reoperation rates than coagulation. The Holmium laser is showing very good results with low complication rates in small studies, and trials have reported benefits lasting more than four years. (HoLEP is actually proving to be better than TURP or even open prostatectomy for removing very large prostate glands.)
- Photoselective vaporization of the prostate (PVP) uses a potassium-titanyl-phosphate (KTP) laser ("green-light" laser) to vaporize prostate tissue. The procedure is virtually bloodless and may be a better option for men taking anticoagulant medication. Results from several recent clinical trials report sustained improvement up to 1 year after the procedure. More studies are needed to confirm long-term efficacy.
Complications. The laser procedure carries a lower risk for incontinence than TURP or TUVP, another minimally invasive procedure. Studies have been mixed on whether laser surgery poses any risk for sexual dysfunction. In one study, TURP had a lower risk for sexual dysfunction, although the risk from either procedure was very low and it wasn't clear that lasers had even been responsible for this complication. After laser procedures, and especially after coagulation, the prostate often temporarily enlarged and caused obstruction and irritation. Sometimes these symptoms were severe. Most men require a temporary catheter to drain urine after laser procedures. Newer laser procedures may significantly reduce these adverse effects.
Thermotherapy and Other Less Invasive Procedures
The National Institutes of Health (NIH) formed a consortium of research centers to evaluate minimally invasive surgical therapies (MIST) for treatment of BPH. The first clinical trial, launched in August 2004, is comparing the benefits and risks of minimally invasive surgery to a combination drug regimen. Patients are randomly assigned to one of three treatment arms: transurethral microwave thermotherapy (TUMT), transurethral needle ablation (TUNA), or finasteride/alfuzosin drug therapy.
Transurethral Microwave Thermotherapy (TUMT). Transurethral microwave thermotherapy (TUMT) delivers heat using microwave pulses to destroy prostate tissue. Studies have found that between 60 - 80% of men respond favorably to the treatment and the benefits seem to last. A 2001 study reported that it remained effective for at least 18 months and was superior over the long-term to the alpha-blocker drug terazosin. Improvement is not as complete as with TURP, but TUMT has fewer complications.
- Candidates. TUMT may be beneficial for men with larger prostates and moderate to severe bladder obstruction, including those who require indwelling catheters. A 2000 study, for example, concluded that is was a safe and effective therapy for treatment of urinary retention. In general, the procedure should not be performed on men who have pacemakers, defibrillators, or any metal implants. One possible exception, the Targis System, was approved for use for patients with hip or penile implants that are located at least 1.5 inches from the urethra. Men who have had previous radiation therapy to the pelvic area are at higher risk for injuries from this procedure.
- Procedure. A microwave antenna is inserted through the urethra with ultrasound used to position it accurately. The antenna is enclosed in a cooling tube to protect the lining of the urethra. Computer-generated microwaves pulse through the antenna to heat and destroy prostate tissue. When the temperature becomes too high, the computer shuts down the heat and resumes treatment when a safe level has been reached. The procedure takes 30 minutes to 2 hours, and the patient can go home immediately afterward. About 30% of patients experience some pain during the procedure. The patient should report any pain that appears to be unusually severe, however, since this could indicate improper application.
- Complications. Swelling in the urinary tract often occurs later, which prevents urination and requires the use of a temporary catheter for about 3 days until the swelling subsides. There have also been reports of serious injuries to the penis and urethra from overheating due to improper application. It is important to note that TUMT does not significantly affect sexuality or cause incontinence or retrograde ejaculation, which are risks with some other prostate procedures.
Transurethral Needle Ablation. Transurethral needle ablation (TUNA) is a simple, safe, and relatively inexpensive procedure using needles to deliver high-frequency radio waves that heat and destroy prostate tissue. The procedure usually requires only a local anesthetic. One study reported that improvement was maintained in most patients after 2 years, although older men (over 70) had slightly worse symptoms and quality-of-life scores. Although small clinical studies have reported that TUNA is as effective as TURP, some experts believe that in actual medical practice TURP is still more effective.
Some studies have reported urinary retention, blood in the urine, retrograde ejaculation, and painful urination after the procedure, although in general TUNA has few or none of TURP's severe side effects. TUNA poses a very low to no risk for incontinence and impotence, and may be a good option for younger men.
Transurethral Electrovaporization. Transurethral electrovaporization (TUVP) uses high voltage electrical current delivered through a resectoscope to combine vaporization of prostate tissue and coagulation that seals the blood and lymph vessels around the area. Deprived of blood, the excess tissue dies and is sloughed off over time. Patients who have TUVP may be able to have their catheter removed within hours after the procedure compared to normal removal time of 3 - 5 days after TURP. A 5-year study reported that it was as effective as TURP over the long-term and had a similar complication rate.
Ultrasound. High-intensity focus ultrasound (HIFU) is a heat procedure under investigation that uses ultrasound to destroy specific prostate tissue. The principles are similar to transurethral microwave thermotherapy, but ultrasound techniques may destroy excess tissue without damaging other parts of the urethra.
Water-Induced Thermotherapy. A device called Thermoflex, which circulates heated water through a catheter to destroy prostatic tissue, has been approved for treating BPH. Another technique uses a balloon filled with hot water to destroy tissue around the urethra. Water-induced thermotherapy (WIT) does not require anesthesia and can be completed during a single outpatient visit.
Prostatic Stents
Prostatic stents used for BPH are flexible mesh tubes that are inserted into the urethra. They are made of special alloys that do not cause reactions in the body. Typically, the insertion procedure takes only 15 minutes and requires only regional anesthetic and mild sedation. It usually requires minimal recuperation and no overnight hospital stay. Unfortunately, long-term studies are reporting high rates of dissatisfaction. Between 8 - 37% of the stents need to be removed later because of poor placement or complications, including irritation when urinating, urinary tract infections, and treatment failure. At this point stents seem to be best suited for high-risk surgical patients and those with a limited life expectancy. Stents composed of new materials and properties may increase their role.
Previous Section
