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KTP Photoselective Laser
Vaporization of the Prostate:
Indications, Procedure, and
Nursing Implications
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Nancy McFadin Mueller
Edward J. Mueller
L
aser technology has
evolved rapidly in the
field of urology. Over the
past decade, there has
been a concerted effort to surgically relieve bladder outlet
obstructive symptoms in men
with benign prostatic hypertrophy (BPH) by using a laser. The
challenge has been to find laser
technology with the same effectiveness and long-term results of
the surgical “gold standard,”
transurethral resection of the
prostate (TURP), without the
associated patient morbidities of
bleeding, prolonged catheterization, and extended convalescence.
Early surgical lasers were
often derivatives of industrial
lasers. Over time, they were
developed specifically for surgical applications. A better understanding of the interaction
between various laser wavelengths and tissue led to more
Nancy McFadin Mueller, MSN, RN,
CURN, is Nurse Clinician and Office
Manager, San Antonio, TX.
Edward J. Mueller, MD, is a Private
Practice Urologist, San Antonio, TX,
and Director, Incontinence and Pelvic
Floor Disorder Center, Methodist
Specialty and Transplant Hospital,
San Antonio, TX.
Note: CE Objectives and Evaluation
Form appear on page 379.
Over the past decade, there has been a concerted effort to surgically
relieve the bladder outlet obstructive symptoms in men with benign prostatic hypertrophy (BPH) by using a laser. Recent improvements in laser
technology have led to the development of promising new treatment
modalities.The potassium-titanyl-phosphate photoselective laser vaporization of the prostate procedure effectively vaporizes the obstructing
prostatic adenoma in a 1-day surgery procedure. Current results show
that this procedure provides a feasible option for men seeking long-term
relief of bladder outlet obstructive symptoms due to BPH.
effective laser procedures. The
neodymium YAG and holmium
lasers were found to decrease
morbidity of the procedure but
were unable to relieve the bladder outlet obstructive symptoms
compared to the traditional
TURP. By the end of the 20th century, the SLT neodymium:YAG
contact laser vaporization procedure showed promising results
(Mueller, 1996). Now, the potassium-titanyl-phosphate (KTP)
laser has been successful in effectively vaporizing the obstructing
adenoma and creating a wideopen prostatic fossa. The KTP
photoselective vaporization of
the prostate (PVP) is accomplished in day surgery under
general or spinal anesthesia.
There is minimal to no blood
loss, and the patient is usually
discharged home catheter-free on
the same day. The purpose of this
article is to provide an overview
of the procedure, laser physics
and safety, and nursing implications for patients undergoing this
surgery.
UROLOGIC NURSING / October 2004 / Volume 24 Number 5
Laser Physics
The acronym LASER stands
for Light Amplification by
Stimulated Emission of Radiation. In this process, light energy
is converted into thermal energy.
The light is emitted as a photon
that travels in waves. Laser light
differs from ordinary light by
three distinguishing characteristics: it is monochromatic, collimated, and coherent. Laser light
comprises photons that are all the
same wavelength, thus it is monochromatic. Collimated means that
the waves are all parallel to each
other and do not diverge significantly as they travel outward.
This property minimizes the loss
of power as the laser light travels.
Finally, the laser light is coherent, meaning the waves travel in
phases and in the same direction.
This property is extremely
important in generating power.
The degree of thermal damage
to tissue from laser light depends
on the temperature to which the
laser energy heats the tissue. There
is warming of tissue from 0 to 60
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degrees Centigrade. From 60 to
100 degrees Centigrade a process
called coagulation occurs. This
refers to a process of protein
denaturation and structural alteration of the blood, resulting in a
change of consistency and slowing
or stoppage of flow. Tissue dehydration and shrinkage then follow.
Above 100 degrees Centigrade
vaporization of tissue occurs. This
results in the conversion of liquid
or solid components of tissue to
vapor. The vaporized tissue is
immediately removed, creating a
cavity (Mueller, 2000).
The optical penetration
depth of laser light depends
strongly on the wavelength of the
laser light (O’Boyle & Carter,
2001). And certain tissue chromophores (a chemical group that
gives rise to color in a molecule)
have different absorptive characteristics of light. Thus, laser light
can be targeted to certain tissue
chromophores like oxyhemoglobin, melanin, and water. The
KTP laser emits visible green
light at a 532 nm wavelength that
targets the chromophore hemoglobin and penetrates tissue to a
depth of only 0.8 mm. Because of
its high absorption in blood and
its shallow penetration depth,
the thermal energy is confined in
a shallow tissue depth. The
superficial tissue is rapidly
vaporized, and only a 1 to 2 mm
rim of coagulated tissue remains
(Laserscope, 2003). This leads to
minimal bleeding during the procedure and fewer irritative symptoms postoperatively. And due to
the fact that the KTP laser beam
targets hemoglobin, the patient
can remain on ASA and/or other
anticoagulants such as clopidogrel (Plavix®) and warfarin
(Coumadin®) during the procedure. This is an extremely valuable attribute of the KTP laser
since some patients needing a
prostatectomy are unable to discontinue these medications for
even a short period of time without risking serious complications.
374
Laser Safety
Knowledge of laser safety is
essential for the surgeon and operating room staff. Appropriate
training is critical and should
include general laser principles
and also cover the particular laser
system that is being used. Lasers
have inherent hazards. These
include electrical shock, fire, and
eye injury (Childs, 1993). The
most common injuries from the
use of lasers are usually electrical,
thus only trained personnel
should open, adjust, or work on
the laser at any time. The laser
should always be unplugged
when work is being done on the
laser, and power cables and the
laser fiber should be handled with
dry hands to avoid a shock.
Two types of fire are associated with lasers. The first type is an
electrical fire that occurs when
the electrical components of the
laser catch fire. If this should
occur, the nurse should immediately disconnect the power cable
from the receptacle to extinguish
the fire. The second type of fire
that is possible with lasers is igniting the surgical drapes. Towels,
sponges, and other draping materials should remain moist during
the entire procedure.
The eyes are especially susceptible to laser injury because
even minor trauma to the optical
surfaces can lead to significant
morbidity. The laser energy can
severely damage the cornea
and/or retina. Therefore, when
the laser is in operation, protective eyewear must be worn by all
personnel. However, protective
eyewear for lasers is not interchangeable. It is specific for the
laser wavelength being used. Eye
injury with laser exposure is
related to the type of wavelength
used. Because of their high
absorption in water, CO2 lasers
will create a corneal abrasive
type of injury. KTP light is not
absorbed by water, and therefore
it can penetrate the vitreous
humor affecting the retina
(Laserscope, 2003). Eyewear is
labeled accordingly. The wavelength being used must be listed
on the eyewear. The nurse must
ensure that the patient also has
appropriate eye protection when
the laser is in operation. This
may include moist sponges,
moist towels, or eyewear specific
for the wavelength used. Figure 1
highlights practical hints for
laser safety in the operating
room.
Surgical Considerations
The PVP procedure vaporizes the obstructing adenoma
with minimal to no bleeding.
There is essentially no fluid
absorption and therefore, no risk
of TUR syndrome. This eliminates the two serious potential
complications of electrocautery
TURP in large prostates. Thus, all
patients, regardless of prostate
size, are potential candidates for
the KTP photoselective vaporization of the prostate. Nurses must
remember that the larger the
prostate, the longer the OR/anesthesia time.
The operating time is dependent on several factors. First, and
probably most important, is the
experience of the operating surgeon. It takes approximately 10
normal-size prostate cases to
become proficient with the
surgery. A mean operative time
of 36 minutes was reported for
treating a mean gland size of 55
cc (Malek & Nahen, 2004). For
the most efficient vaporization,
the laser should be 0.5 mm from
the tissue. As the tissue vaporizes, it moves away from the laser
fiber, and the distance between
the fiber and tissue increases.
This leads to less-efficient vaporization and can even cause coagulation. As more skill is
acquired, the surgeon learns to
continually advance the tip of
the laser fiber toward the vaporizing tissue to maintain the 0.5
mm distance.
The second important factor
in operating time is the vascularity of the tissue. Because the
UROLOGIC NURSING / October 2004 / Volume 24 Number 5
Figure 1.
Practical Hints for Laser Safety
1.
Eye wear is a must! It is impossible to move out of the way or turn
the head quickly enough to avoid eye injury from a Class IV laser.
2.
Ensure that the patient has appropriate eye protection too. This may
include moist sponges, moist towels, or eye wear specific for the
laser being used.
3.
Use the aiming beam when operating the KTP laser. This avoids
patient injury to tissues not targeted for vaporization.
4.
Examine the laser fiber carefully for cracks before using. If it is
cracked, or accidentally dropped, immediately dispose of it.
5.
Handle power cables and laser fibers with dry hands to avoid shock.
6.
Give laser commands loudly and clearly, such as “Laser On,”
“Standby,” “Blue Line,” and “Laser Off.”
chromophore for the laser is
hemoglobin, a highly vascular
gland will vaporize quickly.
Prostates that are less vascular
will vaporize much slower and
consequently, the operating time
increases. This is the case in
transurethral microwave thermotherapy (TUMT) or transureteral needle ablation (TUNA)
failures, or in men who have had
external beam radiation for
prostate cancer.
Finally, the size of the
prostate, as previously mentioned, affects the length of the
operating time. The size of the
prostate correlates directly to the
operating time. As would be
expected in a study of men with
large prostates, the operating
time increased. In men with an
average preoperative prostate
volume of 161 cc, the mean OR
time was 121 minutes (Sandhu,
Casey, Gonzalez, Kaplan, & Te,
2004).
A concern with the PVP procedure is the lack of tissue for
pathologic evaluation and the
possibility of missing a prostate
cancer. Therefore, it is imperative
that each patient in whom
prostate cancer is a reasonable
concern should have a normal
digital rectal examination (DRE)
and serum prostate-specific antigen test (PSA) prior to the procedure. If there is any question, a
transrectal ultrasound and biopsy of the prostate should be performed. If the results are negative, the patient is a candidate for
the procedure.
Preoperative Preparation
Lasers still hold a certain
mystique to patients. Because the
laser procedure generates immediate results, patient expectations during the postoperative
period may be unrealistic. The
nurse should counsel the patient
regarding the procedure as well
as postoperative instructions (see
Figure 2). Addressing realistic
expectations and the patient’s
individual concern will ensure
fewer problems in the postoperative period (Carney et al., 1995).
The procedure is performed
under general or spinal anesthesia. Accordingly, the patient
should restrict activity for the
first 48 hours after surgery. Some
of the patient’s preoperative BPH
symptoms (such as frequency,
urgency, and nocturia) may continue or even increase for a short
time after surgery. Usually, these
symptoms respond well to anticholinergic medications and
nonsteroidal anti-inflammatory
medications, and will resolve
within the first 4 to 6 weeks after
surgery. Discussing this with the
patient prior to surgery helps
ensure a better understanding.
UROLOGIC NURSING / October 2004 / Volume 24 Number 5
Erectile dysfunction is an infrequent occurrence following
surgery. Conversely, retrograde
ejaculation occurs in most men
after a TURP. Patients need to
know that the absence of antegrade ejaculation will not lessen
the ability to achieve or maintain
erection or experience orgasm.
Possible surgical complications
must also be discussed with the
patient. Although rare, these
include ureteral obstruction,
bladder neck contracture, urethral stricture, and incontinence.
It is important to assure the
patient that someone will be
available to talk to him during
the postoperative period to
answer questions or concerns.
Case Presentation
Mr. Smith is a 67-year-old
real estate agent who has been
followed for progressive bladder
outlet obstructive symptoms for
the past 10 years. He has been on
various medical therapies and is
now on a combination of doxazosin and finasteride. Mr. Smith
states that while the medications
do help, he continues to have
symptoms of frequency and
urgency. He relates that this often
creates embarrassing situations
when he is with clients and does
not have ready access to a bathroom. He gets up three times during the night to urinate. His
International Prostate Symptom
Score (I-PPS) is 25/35. Mr. Smith
is frustrated spending money on
medications yet continuing to
experience irritative BPH symptoms. He wants relief. His past
medical history is significant in
that the patient has mitral valve
prolapse and a family history of
coronary artery disease. He is on
81 mg of ASA daily.
Uroflow has a volume of 303
ml with a peak flow rate of 11 cc
per second and an average flow
rate of 7 ml per second with a 150
cc post void residual urine (see
Figure 3). On DRE, there is a large,
smooth, nontender prostate.
Cystoscopy reveals trilobar hyper-
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Figure 2.
Postoperative Instructions for the KTP “Green Light”
Laser TURP
Medication
• Take the prescribed antibiotic for 3 days following your surgery.
• Take Tylenol® or a nonsteroidal anti-inflammatory medication (such as
Aleve® or Motrin®) as needed for pelvic discomfort.
• If you have bladder spasms, urgency, and/or frequency call our office
and talk to the nurse. A prescription can be given to help with this
problem.
Activity
• Take it easy for the first 48 hours (2 days) after hospital discharge.
Do not drive or operate dangerous equipment for 48 hours
following anesthesia.
• You may be able to resume nonstrenuous activities after 48 hours
unless otherwise directed.
• Avoid strenuous exercise, heavy lifting, bike riding, and yard work for
2 weeks, as the vibrations and movement may cause bleeding.
• No sexual activity for 2 weeks after surgery.
Diet and Fluids
• Avoid coffee, tea, carbonated beverages, alcoholic beverages, citrus
juices, and spicy foods for the first 3 days following surgery. These
are bladder irritants.
• Increase your intake of fluids, particularly WATER, for the first 30 days
(1 month) following surgery.
Bowels
• Do not strain when having a bowel movement. You can expect irregular bowel habits for the first few days after surgery. You may need a
stool softener or gentle laxative (such as milk of magnesia) during the
first 2 weeks of your recovery.
Expected Signs and Symptoms
• You may experience urinary urgency and/or frequency for the first
month following surgery. Please call our office to discuss medications
that may relieve this.
• You may have a small amount of bleeding with urination on occasion.
This may be accompanied with small blood clots. This is normal and
should be relieved by increasing your fluid intake.
When to Call Our Office
Please call our office immediately if any of the following symptoms
occur:
• Bright red bleeding in urine with a heavy blood clot.
• Fever over 101 degrees F.
• Inability to urinate for more than 4 hours.
• Feeling of bladder fullness that does not go away after urinating.
• Severe pain at any time.
Please call our office anytime if you have questions regarding your procedure.
You are to return to the office 1 month following your surgery.
Date ____________________
Time ____________________
376
plasia with a 3.5 cm prostatic
fossa and visual obstruction from
the verumontanum. Bladder
shows 2+ trabeculations but no
cellules. PSA is 0.9 ng/ml.
The PVP procedure is scheduled, and details of the surgery
are discussed with Mr. Smith.
Since the procedure is relatively
new, most patients do not know
what to expect. Mr. Smith watches a video of the procedure, is
given a brochure with a description of the laser procedure, and
the nurse reviews written postoperative instructions/expectations with him (see Figure 2).
Although most patients are discharged the same day as the procedure, Mr. Smith is prepared to
spend 1 night (23 hours) at the
hospital if needed. Mr. Smith’s
cardiologist is notified of the
surgery and advises that the ASA
be continued to prevent deep
vein thrombosis.
The surgery. Mr. Smith is
admitted to the day surgery unit
of the hospital. After preparation
in the preoperative area, including a prophylactic long-acting IV
antibiotic, he proceeds to the
operating room. Following the
induction of general anesthesia
he is placed in the dorsal lithotomy position, and prepped and
draped in the usual sterile manner. The urethra is lubricated
with K-Y® jelly and the 22F laserscope inserted without difficulty
into the bladder. Panendoscopy
is performed and the ureteral orifices are identified well back
from the bladder neck. The verumontanum is identified and the
obstruction is visualized (see
Figure 4). The laser is set at 80
watts and the bladder neck tissue
is vaporized to capsular fibers as
far laterally as possible. The left
and right lateral lobes are vaporized from the bladder neck to the
verumontanum bilaterally by
sweeping the laser beam across
the prostatic adenoma. Each pass
vaporizes a 0.8 mm depth of tissue. By slowly sweeping the laser
beam over the tissue and slowly
UROLOGIC NURSING / October 2004 / Volume 24 Number 5
Figure 3.
Preoperative Uroflow
require no postoperative recuperation period. Even though the
patient has been counseled
before surgery, he may seem surprised when he experiences postoperative symptoms. Providing a
listening ear and reinforcing realistic expectations can positively
influence the patient’s perception of his surgical experience.
Results
moving the beam toward the
verumontanum, the lateral lobes
are slowly vaporized from the
bladder neck to the verumontanum. If any bleeding is encountered the laser is backed off the
bleeding vessel and activated,
thus coagulating the bleeding
vessel and stopping the bleeding.
At the end of the procedure the
prostatic fossa is wide open and
when viewed from the verumontanum no tissue can be seen (see
Figure 5). The urethra is once
again lubricated with K-Y jelly
and an 18F 3-way Foley catheter
is inserted into the bladder and
connected to normal saline irrigation. The patient is transported
to the recovery room, and then to
the ward. Mr. Smith is maintained
on catheter drainage for 3 hours to
allow the bladder to recover from
the anesthesia and to regain
enough tone to contract and
empty. After this period, the
catheter is plugged and the bladder filled with 300 cc of normal
saline irrigant through the continuous irrigation port. The Foley
catheter is then removed, and
after he urinates, Mr. Smith is
discharged to home the afternoon
of surgery.
Postoperative period. The
following afternoon, the nurse
calls Mr. Smith at home. He is
experiencing some mild urgency;
otherwise he is voiding without
difficulty. At the end of the first
month Mr. Smith returns for his
postoperative appointment. A
urinalysis is done and his postoperative uroflow reveals significant improvement (see Figure 6).
He is very happy with the procedure and all bladder outlet
obstructive symptoms are gone.
Nursing Implications
At present, a tremendous
amount of information about
BPH is available to the public.
The advice obtained from the
Internet, lay literature, and family and friends can be overwhelming to the patient. One of the
important roles of the nurse is
that of educator. The nurse can
help the patient sort through the
available information, providing
clarification and education
regarding the disease process as
well as the available therapies for
BPH. Even the many types of
lasers used to treat BPH can be
confusing to the patient when
trying to make a treatment decision. The PVP procedure is a relatively new treatment, and taking
the time to discuss the procedure
and the pre and postoperative
instructions is very important
(Laserscope, 2004).
A second and equally important role of the nurse is that of
providing
patient
support.
Sometimes a patient thinks that
because the results of the laser
treatment are immediate, he will
UROLOGIC NURSING / October 2004 / Volume 24 Number 5
PVP laser prostatectomy produces rapid, safe, and effective
relief of the bladder outlet obstructive symptoms of benign prostatic
hypertrophy (Malek, Kuntzman, &
Barrett, 2000; Malek, Barrett, &
Kuntzman 1998). In a long-term
study by Dr. Reza Malek from the
Mayo Clinic in Rochester,
Minnesota, pre and postoperative
I-PPS symptom scores, mean peak
flow rate and post-void residual
urines were evaluated out to 3
years postoperatively. The I-PPS
score decreased from an average of
22.0 preoperatively to 5.4 at 3
months and remained stable at 3
years. The mean peak flow rate
increased from a preoperative
average of 7.8 cc/sec to an average
of 27.8 cc/sec at 3 months postoperatively and remained stable at
3 years. The post-void residual
urine averaged 154 cc preoperatively and decreased to an average
of 44 cc at 3 months postoperatively and also remained stable at
3 years (Malek, Kuntzman, &
Barrett, 2003).
Conclusion
Recent improvements in laser
technology have led to the development of promising new treatment modalities. The PVP procedure effectively vaporizes the
obstructing prostatic adenoma in
a 1-day surgery procedure. The
patient experiences almost no
bleeding and most men are able to
return to normal activity within
48 hours. Further studies are
needed to address the issue of irritative symptoms some men experience in the first 4 to 6 weeks following surgery. Current results
377
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Figure 4.
The Prostate Preoperatively
show that this procedure provides a feasible option
for men seeking long-term relief of the bladder outlet obstructive symptoms due to BPH. Longer term
followup studies are now in progress. •
References
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Figure 5.
The Prostate Postoperatively
Carney, S., Karlowicz, K., Meredith, C., Pear, S., Reilly, N.,
Swibold, L., et al. (1995). Urinary tract obstructions. In K.
Karlowicz (Ed.), Urologic nursing: Principles and practice
(pp. 107-141). Philadelphia: W.B. Saunders.
Childs, S.J. (1993). Laser-assisted transurethral resection of the
prostate. Baltimore: Williams and Williams.
Laserscope. (2003). Laserscope patient information guide for the
GreenLight PVP laser procedure. San Jose, CA: Author.
Laserscope (2004). Laserscope physician training manual, revision D. San Jose, CA: Author.
Malek, R.S., Barrett, D.M., & Kuntzman R.S. (1998). High-power
potassium-titanyl-phosphate (KTP/532) laser vaporization
prostatectomy: 24 hours later. Adult Urology, 51(2), 254254.
Malek, R.S., Kuntzman, R.S., & Barrett, D.M. (2000). High power
potassium-titanyl-phosphate laser vaporization prostatectomy. Journal of Urology, 163, 1730-1733.
Malek, R.S., Kutzman, R.S., & Barrett, D.M. (2003). KTP Laser
prostatectomy: Long term experience. Presented at the
American Urological Association Annual Meeting, April
2003.
Malek, R., & Nahen, K. (2004). Laser treatment of obstructive
BPH: Problems and progress. Contemporary Urology, 16(5),
37-43.
Mueller, E.J. (2000). Options for treatment: Contact. In M.I.
Resnick & I.M. Thompson (Eds.), Advanced therapy of
prostate disease (pp 562-568). London: B.C. Decker, Inc.
Mueller, E.J. (1996). Contact laser vaporization of the prostate:
One surgeon’s experience with 50 consecutive cases.
Techniques in Urology, 2(3), 136-141.
O’Boyle, P.J., & Carter, A. (2001). KTP lasers. In P.D. Miller, E.
Eardley, & S.A. Kaplan (Eds.), Benign prostatic hyperplasia
(pp 69-77). London: Martin Dunitz, Ltd.
Sandhu, J., Casey, K., Gonzalez, R., Kaplan, S., & Te, A. (2004).
High power KTP photoselective laser vaporization prostatectomy in men with large prostates: The New York
Presbyterian series of 64 patients. Journal of Urology,
179(4), 400-401.
Figure 6.
Postoperative Uroflow
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