PVP for the management of BPH
Please explain the importance of BPH in a urology practice.
Dr. Hai: BPH is one of the most common conditions afflicting males who present to the urologist. There are approximately 2 million people who are symptomatic from BPH and receiving treatment. According to Medicare figures, about 130,000 to 150,000 of these people undergo TURP; the rest either receive other forms of surgical treatment, such as transurethral needle ablation or microwave therapy, or take medical, herbal, or nonformulary products to relieve their symptoms. It is very important for a urologist to have an appropriate and effective treatment for BPH.
Dr. Nseyo: BPH, which oftentimes leads to bladder outlet obstruction, is a very important and expensive public health problem. It is a disease of the aging and the majority of the baby boomer generation are now reaching their 50s and 60s, so you are talking about a large number of patients.
Please describe the procedure of PVP.
Dr. Malek: PVP is the application of high-power KTP laser energy to vaporize benign obstructive prostatic tissue that develops with BPH. The PVP procedure was invented at the Mayo Clinic in 1997, but the KTP laser has been around since the 1980s.
When first introduced, the KTP laser was available in 20 watts of power, which subsequently was increased to 40 watts. At this time, Nd:YAG laser coagulation was being used for BPH; however, dysuria plagued about 30% of the patients and urinary retention lasted up to 11 days. We found that the KTP laser vaporized tissue very effectively and so we developed a hybrid technique using both the KTP and the Nd:YAG lasers. With this combination, we were able to create a channel in the previously YAG laser-treated tissue so that patients could urinate faster and would require only 3 days of catheterization rather than 5 to 11 days. In addition, dysuria was reduced to 12.5%, which is similar to the incidence after TURP.
With experience, we realized that the KTP laser alone, rather than the hybrid, produced more favorable results. At our behest, Laserscope developed a 60-watt machine, which proved safe and successful when introduced clinically in 1997. Using the 60-watt laser, the procedure could be used on an average prostate of 30 to 40 cc and up to 60 cc in volume. Patients were able to void after their catheter was removed in less than 24 hours; therefore, urinary retention was no longer a problem. Patients had excellent flow rates and made rapid recoveries with practically a meager number of complications compared with other procedures, especially TURP.
We now have a machine with 80 watts of KTP power-the Niagara PV System. The increased power has allowed us to perform the surgery 30% to 50% faster compared with the 60-watt laser. The 80-watt laser also appears to be more hemostatic-I've done a number of cases with this laser and haven't seen a single drop of blood loss!
Dr. Hai: PVP is a form of laser procedure that is most effective in vaporizing prostatic tissue. The KTP laser is photoselective and has an attractiveness towards hemoglobin, sealing off the blood vessels so there is no bleeding at all. The laser also has a very strong effect in vaporizing the prostatic tissue; in essence, the tissue turns into vapor without leaving any residue or charring effect. The depth of penetration with this laser is very controlled-it only affects tissue 1 to 2 mm in depth. There is no extensive damage beyond what is vaporized. These are the reasons why PVP is a very successful procedure.
I have been using lasers for more than 10 years and have been involved in perfecting the PVP technique. Recently, I began working with the 80-watt KTP laser and have done about 70 cases so far. The increased wattage has reduced bleeding and increased the efficacy of vaporization, allowing us to perform the procedure faster with less anesthesia time. I perform the procedure with a continuous flow cystoscope and use a video system with magnification, which allows everyone in the operating room to view the procedure. The video system also protects your eyes and is easier on your back. The KTP laser comes out at the tip of a disposable fiberoptic delivery system at a 70° angle towards the operator. There is no danger of it hitting beyond your visual field and causing any damage.
The PVP procedure takes anywhere from 20 to 50 minutes to perform, depending on the size of the prostate gland. A 30- to 50-g prostate can be completed in 20 minutes, but a 100- to 120-g prostate may take up to 50 minutes. A prostate larger than 120 g would probably be treated with open prostatectomy. We rarely see prostates larger than this size because people will seek treatment before it gets that large.
Dr. Nseyo: PVP is really a revolutionary procedure where a high-powered KTP laser is transmitted through a fiber to evaporate the prostate. It melts away tissue, with clouds of vapor right in front of you. We recently treated a 100-g prostate in 52 minutes, and the patient had an indwelling catheter only overnight. We could not have achieved that with TURP. If we had used TURP, the patient would have had significant blood loss, or would have remained in the hospital with a catheter for a long time. An open prostatectomy would have resulted in significant blood loss, requiring blood transfusion and a 2- to 3-day hospital stay. I've been a urologist for about 18 years, and I'm very impressed with PVP.
How does PVP compare with other procedures for treating BPH?
Dr. Malek: If you look at surgery as a form of controlled injury, then PVP is the most benign form of surgical injury that I've ever inflicted on the prostate to relieve obstruction.
In a study I published with Randall Kuntzman and David Barrett in the Journal of Urology in 2000, complications with PVP were relatively scarce in the 55 patients that we followed over 24 months.4 There were no intraoperative or immediate postoperative problems, except for nonurological febrile reactions in 2 patients. Hematuria was negligible or nonexistent, despite the use of antiplatelet medications. Sterile dysuria occurred in only 7% of patients compared with 10.2% reported for TURP.5 Retrograde ejaculation was present in 9% of patients after 2 years compared with 96% of patients treated with holmium:YAG laser prostatectomy. The incidence of retrograde ejaculation was less than expected given our deliberate attempt to resect the bladder neck widely, as in TURP.
Compared with our procedure using the KTP laser, holmium:YAG laser prostatectomy takes longer to perform versus TURP, is accompanied by hematuria requiring bladder irrigation in 1.6% of patients, re-catheterization in 8%, and urinary symptoms requiring analgesia in 46%.6
After PVP, patients become very comfortable very quickly. With other procedures, including minimally invasive procedures such as transurethral needle ablation, microwave therapy, and interstitial laser, it takes weeks for people to be comfortable.
Dr. Hai: PVP is a marked improvement over all the other procedures. Minimally invasive procedures such as transurethral needle ablation and microwave therapy decrease symptoms by damaging the nerves. For this reason, improvement is temporary and in due course-3, 6, 12 months later-the patient presents with the same symptoms. In addition, these procedures do not remove much tissue to open up the prostatic channel. Flow rates may improve temporarily, but in time, they return to the baseline rates. Many patients undergoing these procedures go into urinary retention and require catheters for weeks or even months. Even though these procedures are minimally invasive in the sense that they are performed in the office, some patients need more than 1 session or repeat treatments to obtain relief, and many return to medication or seek other forms of treatment.
For years, TURP has been the gold standard for surgical treatment of BPH. Although we considered this procedure very benign, 25% to 30% of patients have some form of complication from it-excessive bleeding, TUR syndrome, urinary retention, urinary incontinence, and impotence. Since TURP is performed under general or spinal anesthesia, most patients are hospitalized and catheterized for 1 to 5 days. A few patients may also need constant irrigation after the procedure because of bleeding. In addition, there are certain risks and complications specific to the elderly population.
Dr. Nseyo: PVP compares fairly well with the gold standard-TURP. The data show an advantage of PVP over TURP. Treating a 100-g prostate in under an hour can't be done with TURP. PVP reduces hospitalization stay, anesthesia time, and the amount of irrigation required compared with TURP. These translate into lower costs.
There is also a positive impact on quality of life. The patient is out of the hospital the next day and is able to resume nonvigorous activities within a week. Compared with other minimally invasive procedures, PVP requires 1 session of therapy. You couldn't treat a 100-g prostate with transurethral needle ablation or microwave in a single session. Interstitial laser prostatectomy coagulates the prostate, allowing it to scar over time and open up the urinary tract. This means that the patient has acute inflammation, must wear a catheter, or be subjected to significant irritable voiding symptoms. These issues are not seen with PVP.
The problem I see with current minimally invasive therapies is the delayed effect of the treatment and the need for catheterization for prolonged periods of time. None of the new minimally invasive procedures have been able to withstand the test of time. Within 2 to 5 years, the effects seem to wane, requiring retreatment.
PVP may become an outpatient procedure, which is a big selling point. It should be pointed out, however, that the drive for outpatient procedures may be more in the interest of the practitioner, not the patient. The patient wears the catheter and not the physician. Putting the patient first makes me think twice before offering the treatment modality that I do.
Are there any disadvantages to PVP?
Dr. Malek: In my experience, there are no disadvantages to this procedure. The only ones I can see are if PVP is performed by an inexperienced physician in a large prostate and by someone who is not familiar with lasers and the damage that they can inflict.
Urologists need to have a clear understanding as to what lasers are all about and what they do. If the laser is not delivered (ie, aimed and fired) properly, one could damage the trigone, the orifices of the ureters that are located on the trigone, and even the urinary sphincter. The KTP laser is capable of damage just like any other surgical device.
Dr. Hai: I have not found any significant disadvantages. Contraindications to this procedure include patients with acute prostatitis, diagnosis of acute urinary tract infection at the time of treatment, or a confirmed or suspected malignancy of the prostate.
Dr. Nseyo: I think the disadvantage is not seeing a clean prostate when the procedure is completed because of the vaporization. I've seen photos from the Mayo Clinic by Dr. Malek, and in about a month, the entire prostate is very well healed. It looks smooth and clean. The cloudy appearance of the prostate immediately after PVP shouldn't be a concern because it doesn't affect the patient's outcome.