Laser treatment for BPH is also called laser prostatectomy. The permanent effects of laser treatment on prostate tissue are vaporization and coagulation, which occur when laser energy heats prostatic tissue to 100°C. At this temperature, proteins denature and necrosis ensues, resulting in debulking of the prostate over time. This process can initially cause edema, which may increase prostate volume and make short-term catheterization necessary.
The procedure usually is performed in a hospital or surgical center. General, spinal, or local anesthesia with pudendal block and IV sedation may be used. Prior to treatment, patients undergo a preoperative evaluation that may include the following:
- Complete blood count
- Flow rate
- Residual volume
- PSA levels
- Serum creatinine
- Ultrasound of the prostate
Laser treatment may cause fewer side effects and less damage to surrounding tissue than surgery or microwave thermotherapy and usually eliminates the need for medication. It can be used in patients with metal implants in the hip or pelvic area, and cardiac pacemakers and defibrillators, who may not be candidates for microwave thermotherapy. Two laser treatment systems are described here: Indigo® and GreenLight PV.
Indigo® laser treatment, also called interstitial laser coagulation, is designed to permanently reduce BPH symptoms in one treatment session. The Indigo® laser system is a compact, transportable, low-power, semiconductor diode laser that uses a 15- to 20-watt variable power source to produce a wavelength of 830 nm. Low-power settings can be used to minimize tissue damage.
Indigo® laser treatment may be indicated for patients whose prostate is between 20 and 85 g. and for those with these BPH complications:
- Bladder calculi
- Diminished renal function
- Gross hematuria
- Overflow urinary incontinence
- Progressive deterioration of bladder function, which is demonstrated by increased residual urine or decreased bladder muscle tone and pressure on cystometrogram (CMG) or pressure-flow studies
- Recurrent urinary tract infections
- Urinary retention
- Upper urinary tract obstruction
Interstitial laser coagulation usually is performed on an outpatient basis under local or regional anesthesia, depending on the size of the prostate. It can be used to treat most any size prostate and, in many cases, treatment can be completed in 30 minutes or less.
During the Indigo® laser system procedure, laser energy is transmitted for about 3 minutes through a sterile probe that is enclosed in a temperature-resistant tip and inserted into the prostate through a cystoscope. This treatment coagulates obstructive prostatic tissue and seals blood vessels. The process can be used to treat another area of the prostate, if necessary.
After treatment, the body gradually resorbs the destroyed tissue, the prostate shrinks, and BPH symptoms typically decrease. Most patients require catheterization for several days to 1 week following the procedure due to edema. Antibiotics also may be prescribed. Symptoms continue to improve over the course of 612 weeks.
The Indigo® laser does not usually disrupt the urothelium and results in few side effects. Hematuria and dysuria are usually mild and commonly resolve within a week. Postoperative complications such as impotence, incontinence, and retrograde ejaculation are rare.
Photoselective vaporization of the prostate (PVP) is a minimally invasive laser treatment that permanently reduces BPH symptoms in one session using GreenLight PV (formerly called Niagara PV). This system vaporizes obstructive prostatic tissue and seals blood vessels using a high power 80-watt KTP laser (i.e., a potassium-titanyl phosphate crystal laser) and a fiberoptic delivery system inserted through a standard cystoscope. The procedure is performed on an outpatient basis in a hospital or surgical center and may be performed under local, spinal, or general anesthesia.
The KTP laser vaporizes obstructive prostatic tissue quickly and seals blood vessels, virtually eliminating complications and bleeding. The procedure takes 20 minutes to 1 hour to perform and produces results that are comparable to transurethral resection of the prostate (TURP), but with fewer complications. Unlike TURP, most patients taking anticoagulants can continue their medication prior to PVP.
Postoperative side effects are usually mild and transient and include dysuria and delayed hematuria (usually the result of strenuous activity). In most cases, catheterization is required for less than 24 hours.
Patients on warfarin may require catheterization for 1 or 2 days following the procedure until the urine is clear. Antibiotics may be prescribed for a week to 10 days and most patients are able to resume normal activities 13 days after the procedure. Strenuous activity should be avoided for 46 weeks.