Greenlight laser photoselective vaporisation of the prostate (PVP)
Greenlight laser photoselective vaporisation of the prostate (PVP) is a relatively novel treatment for benign prostatic hyperplasia (BPH) that is now available in Singapore at the Gleneagle Hospital. It has long-term (7+ years) follow-up in the United States.
The green colour of the laser is rapidly absorbed by the red pigment found in blood (haemoglobin) and the prostate has an excellent blood supply. The rapid absorption of this greenlight causes the prostate tissue to vaporise and so it is possible to remove obstructing tissue to allow easier passage of urine.
The removal of tissue in this manner causes very little bleeding as veins and arteries are sealed at the time of vaporisation. Occasionally quite large blood vessels can be encountered during a prostatectomy but even these can readily be controlled and sealed closed with the greenlight laser.
The result is that there is very little blood loss during the procedure and therefore a very reduced in-patient stay in hospital and rapid return to normal activities. There is also no upper limit to the size of prostate that can be treated although obviously very large prostates require a longer operation.
As the blood vessels are instantly sealed there is very little absorption of any irrigation fluid (the fluid used to aid vision and carry the bubbles away during the procedure) and so PVP is very safe.
What is the Prostate and where the Prostate Located?
The prostate is a gland located at the outlet of the bladder and surrounds the urethra (the pipe the carries the urine out through the penis). At the lower end of the prostate is the sphincter muscle that controls continence and close to this is the verumontanum which is a small “hill” through which the ejaculatory ducts empty semen on ejaculation.What symptoms can the enlarged prostate cause?
An obstructing prostate may cause the urinary flow to become weak and in extreme cases to cease altogether leading to retention of urine requiring a catheter (a tube through the penis to drain urine into a bag). Other symptoms may be having to wait at a urinal before being able to start to pass water and finding at the end of urination the the stream may stop and start. Other associated problems may be getting up at night frequently to pass urine and passing frequently during the day sometimes without much warning.What are the alternative treatments?
Many men with symptoms can be treated with medication and gain a satisfactory response. The two commonly used families of drugs are the alpha –blockers (which cause the muscle in the prostate to relax) and the 5 alpha reductase inhibitors which stop testosterone being converted into a more active form and hence slowly shrink the prostate.Most men seeking surgery will have tried 1 or both of these families of drugs.
Men seeking surgery often fall into one of several groups:
1) Failure or only partial response to medication.
2) Those unwilling to take lifelong drugs.
3) Men with urinary retention and on catheters.
4) Men wanting relief from their symptoms by a single operative intervention.
What are the alternative operations?
The commonest operation for urinary symptoms due to an obstructing prostate is Trans – Urethral Resection of the Prostate (TURP). This is an effective procedure and has been considered the “gold-standard” operation for many years. It is a major procedure, however, and results in bleeding from the prostate gland, which may be severe. In order to stop this bleeding from clotting in the bladder, a catheter is placed (a tube through the penis into the bladder) and fluid is run through this to wash the bladder out until the bleeding stops. This results in an average in-patient stay of about 5 days. After a TURP return to normal activities is usually delayed for about 4 weeks. Due to this and other complications there has been much interest in less invasive procedures that cause less blood loss, shorter in-patient stay and faster return to normal life.
Any patient who has been offered a TURP is suitable for PVP. Due to the minimal bleeding PVP may also be suitable for patients who have been declined TURP due to prostate size.
What happen before the surgery?
atients referred for consideration of PVP will have a full medical history and prostate examination. They will be asked to fill out a specifically designed questionnaire to assess their symptoms (IPSS) and will have a urinary flow rate and ultrasound to assess how well, or badly, they can empty their bladder.
They will also have a PSA blood test taken (Prostate Specific Antigen) to further assess the prostate. Depending on the result of the PSA blood test, your urologist may advise you to have a prostate biopsy prior to performing the PVP surgery.
Patients suitable for surgery shall have routine pre-operative work-up including further blood tests, heart monitoring (ECG) and assessment by an anaesthetist. Other investigations may be needed to ensure fitness for anaesthetic and will be decided by the anaesthetist. The type of anaesthetic will be discussed with the anaesthetist. Patients are usually admitted to hospital on the arranged day of surgery and can discuss any last minute issues then.
Photoselective Vaporisation of the Prostate (PVP) uses a powerful, green laser to vaporise the prostate and hence produce a reduction in prostate size like the TURP. The green light is selectively absorbed by the red prostate tissue hence “photoselective”. The laser is delivered through a fibre passed down a telescope (cystoscope) through which the prostate can be viewed. There is minimal bleeding associated with this technique and with small prostates it is possible to leave the patient without a catheter after the operation.
What occur during the operation?
The operation can be conducted under general anaesthetic with the patient asleep or under a spinal block with the patient awake. The type of anaesthetic will be decided with the anaesthetist based on preference and safety.
Once anaesthetised a telescope is passed down the penis and into the bladder. The bladder and prostate are thoroughly inspected.
Using the laser under direct vision the obstructing prostatic tissue is vaporised creating a cavity to allow passage of urine.
A catheter may be placed if necessary at the end of the procedure.
If a catheter is placed then the patient will need to stay overnight for removal of the catheter the following morning.
What are the possible side-effects and complications?
1) Bleeding.It is very common for there to be some minimal blood in the urine after the procedure but this normally settles down within 1-2 weeks and usually occurs just as urination starts. A very tiny amount of blood in the urine is sufficient to cause it to be look blood stained. Significant bleeding is very uncommon.
2) Burning in the urine (dysuria).
Many patients experience little or no discomfort at all.
Early laser treatments resulted in really quite severe burning when passing water. The PVP has considerably less problems with burning but most patients experience some mild discomfort on urination for a week or so after the operation often in the tip of the penis. For larger prostates this may continue for slightly longer although many patients with large prostates report very minimal discomfort.
3) Impotence.
There have been no reported problems with erections after this procedure.
4) Incontinence.
Some urgency may be experienced after the procedure as the bladder will be used to having to generate high pressure to overcome the obstructing prostate. As the obstruction has been removed a few patients have found that they need to rush to the toilet at first. This settles down quickly after the operation for most people but some patients may benefit from a medicine to calm the bladder down. This is uncommon however.
For people with normal continence before the procedure there have been no reported problems with incontinence after this procedure and this would have to be considered an extremely unlikely outcome.
5) Prolonged catheterisation.
Unfortunately we find that some patients with long-term catheters before the operation have significant damage to the bladder muscle. This may result in the bladder not being able to empty even if the prostate has been removed. Occasionally these patients need to be discharged with their catheter and have it removed the following week. The same may occur with very massive prostates but this is usually not the case.
6) Retrograde ejaculation.
There is a circular muscle at the base of the bladder in the male. The only purpose of this muscle is to contract during ejaculation so that the semen is expelled from the penis rather than taking the shorter route into the bladder (retrograde ejaculation).
Sometimes it is necessary to cut this muscle in order to achieve a good outcome from the surgery as it lies under the prostate at the bladder neck. This is much less common than with the TURP where 80% of patients have retrograde ejaculation. Under half of PVP patients have this side-effect. This is completely harmless but obviously decreases the chance of fathering children without assistance. If children are contemplated please discuss this with the urologist prior to surgery.
Is it safe?
Yes.Due to the lack of bleeding and the lack of fluid absorption during the procedure it is safe. The fitness for anaesthetic will be assessed prior to surgery and any problems will be fully discussed.