Lumenis_techUS

a report by

Ph i l l i p P a lme r , P h . D .

R&D Program Manager for Urology, Lumenis

I n t r o d u c t i o n

Benign prostatic hyperplasia (BPH) is the non-cancerous enlargement of the prostate gland thatoccurs with age. Common symptoms for BPHinclude incomplete emptying of the bladder,urinary urgency and frequency and feelings ofincomplete voiding. While not usually life-threatening, BPH can cause considerablediscomfort and complete obstruction can lead toemergency surgery for resolution. BPH occurs inhalf of men 50 years old and increases to nearly90% for men over 80.1 Due to the aging of thepopulation, the number of patients with BPH isexpected to increase in the foreseeable future. Thegoals for any surgical BPH procedure are to be safeand effective, rapidly alleviate patient symptoms,minimize complications, shorten the length of stayand provide adequate durability.

L a s e r s a n d T i s s u e

A key characteristic of the laser is delivery ofmonochromatic energy, or light. An incandescentbulb emits a spectrum of colors, while a laser emitsa single color, or wavelength, of light. This enablesthe accurate targeting of specific types of tissues –different color lasers often generate dramaticallydifferent tissue interactions. In addition to beingmonochromatic, lasers can be separated into twocategories – continuous wave (CW) and pulsed. ACW laser emits light in a steady beam as long as thelaser is activated. Pulsed laser systems emit shortflashes of light, or pulses. These pulses are extremely

short in duration, resulting in vastly higher powerdensities than can be achieved by CW lasers.

The three basic laser-tissue interactions are ablation,coagulation and charring.2 Ablation, which isvolume removal of tissue by vapourisation, occurswhen an extremely high power density is generatedwithin the target tissue. The water within the tissueinstantaneously vapourizes, resulting in theimmediate removal of the tissue in a plume ofvapour. The majority of the heat created is carriedoff with the plume.

Coagulation is tissue destruction by heat withoutphysically removing it, occurring when the powerdensity is insufficient to create immediatevapourisation. This heating coagulates blood, but alsothermally damages the tissue. Localised hemostasis ispreferable to coagulation below the visible surface tominimize risk of damaging surrounding tissue andavoid unwanted tissue necrosis. Charring occurswhen tissue is carbonised from overheating.

Proper selection of the laser wavelength, pulse modeand power capabilities can maximise procedureefficacy, while minimising unwanted side effects.

Ho lm i um BPH T r e a tmen t s

The surgical techniques for using the holmium laserfor BPH treatment have evolved over the past 10years, due in large part to the work of Gilling andassociates.3–7 Holmium laser ablation of the prostate(HoLAP), resection of the prostate (HoLRP) and

The Super ior i ty o f Ho lmium Laser for Pros ta te Ab la t ion

B U S I N E S S B R I E F I N G : G L O B A L S U R G E R Y 2 0 0 4

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Technology & Services

1. Diagnosis of BPH – www.UrologyHealth.org2. Trost D, Zacherl A and Smith M F W, Surgical Laser Properties and Their Tissue Interactions (1992), pp.

131–162.3. Gilling P J, Cass C B and Fraundorfer M R, “Combination endoscopic laser ablation of the prostate (CELAP): The next

generation laser prostatectomy”, (abstract) J. Endourol. (1994), 8 (supp l), pp. 16–386.4. Gilling P J and Le Duc A, “Holmium laser resection of the prostate”, Eur. Urol. (1999), 35: pp. 155–160.5. Gilling P J, Kennett K M and Fraundorfer M R, “Holmium Laser Enucleation of the Prostate for Glands Larger than

100g: An Endouroligic Alternative to Open Prostatecomy”, J. Endourol (1998), 14: pp. 529–530.6. Gilling P J, Cass C B, Cresswell M D, Malcolm A R and Fraundorfer M R, “The Use of Holmium Laser in the

Treatment of Benign Prostatic Hyperplasia”, J. Endourol. (1996), 10: pp. 459–461.7. Moody J A and Lingeman J E, “Holmium Laser Enucleation of the Prostate with Tissue Morcelation: Initial United States

Experience”, J. Undourol. (2000), 14: pp. 219–223.

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enucleation of the prostate (HoLEP) techniques havebeen shown to provide equivalent or superioroutcomes as the transurethral resection of the prostate(TURP) procedure.8,9 In addition to fewer patientcomplications, the surgical advantages of usingholmium versus TURP include less bleeding,reduced transfusion rates, catheter time, length of stayand elimination of transurethral resection (TUR)syndrome since saline is used as the irrigant. Otheradvantages include a virtually bloodless field of viewduring the procedure and the ability for patients tomaintain their anti-coagulative medications.

Though HoLEP represents a state-of-the-artprocedure, the learning curve has preventedwidespread adoption. Recently, there has been asignificant resurgence in adoption of effective buteasier-to-learn high-power laser procedures includingHoLAP and photoselective vapourisation (KTP PVP).

HoLAP takes advantage of the exceptional ablativecapabilities of the holmium laser, enabling surgeons toprovide immediate symptom relief without

undergoing a significant learning curve. The procedureis easy to learn thanks to the superficial ‘what-you-see-is-what-you-get’ tissue interaction and the ‘paint-brush’ technique. Gilling confirmed that HoLAP wassimple to perform and demonstrated its durability for over seven years.10 Furthermore, Gilling and co-workers reported a mean surgical time of 30.8 minutesfor glands averaging 40.5cc. In another study byMottet, post-operative results for HoLAP were shownto be similar to TURP with respect to symptom relief,while reducing catheterisation time.11 Mottet foundthat the higher the laser power, the quicker theablation procedure. Consequently, the most efficientresults are achieved when using a high-powerholmium laser such as the Lumenis VersaPulse®

PowerSuite™ 100W Holmium Laser system.

The primary urology delivery devices used with theVersaPulse PowerSuite laser are the SlimLine™ andDuoTome SideLite™ fibres. SlimLine fibres aremulti-use, end-firing fibres available in four differentsizes. They offer the surgeon several options to meetthe flexibility and power requirements for a widerange of procedures, including HoLRP and HoLEP.

The DuoTome SideLite fibre is a 550µm disposable,side-firing fibre that directs the beam at a 70° from thefibre axis. Being disposable, the DuoTome offers theadded convenience of eliminating the need for post-surgical reprocessing and ensures peak performance foreach new case. The lateral energy delivery makes theDuoTome especially well suited for HoLAP.

The easy-to-see DuoTome fibre tip markings verifyenergy direction and help the surgeon correctlyposition the fibre within the endoscope. There are twodistinct orientation marks and a position index. Adotted black line is located 90° from the energy exitsite. A solid black line, along the fibre axis, is positioned180° from the output beam. To reduce the likelihoodof activating the laser within the endoscope, a solid linearound the circumference of the fibre tip indicates theminimum safe retraction distance into the endoscope.The DuoTome also has an adjustable locking knob thatenables the doctor to rotate and precisely position thefibre within the endoscope and on the tissue. TheDuoTome requires a fibre bridge with a >_ 7.5 F innerdiameter that is available from several differentendoscope companies.

Figure 1: The VersaPulse PowerSuite 100W Holmium

Laser and DuoTome SideLite 550 Fibres are Ideal

for Prostate Vapourisation

8. Tooher R, Sutherland P, Costello A, Gilling P, Rees G and Maddern G, “A Systematic Review of Holmium LaserProstatectomy For Benign Prostatic Hyperplasia”, J. Uro. (2004), 171, pp. 1,773–1,781.

9. Larner T R G, Agarwal D and Costello A J, “Day-case Holmium Laser Enucleation of the Prostate for Gland Volumesof <60 ml: early experience”, BJU (2003), 91: pp. 61–64.

10. Tan A H H, Gilling P J, Kenneth F H and Fraundorfer M R, “Long-term results of high-power holmium laservaporization (ablation) of the prostate”, BJU Int. (2003), 91 pp. 707–709.

11. Mottet N, Anidjar, A, Bourdon O, Louis J F, Teillac P, Costa P and Le Duc A, “Randomized Comparison orTransurethral Electroresection and HolmiumLYAG Laser Vaporization for Symptomatic Benign Prostatic Hyerplasia”, J.Endourol. (1999), 13: pp. 127–130.


The Super ior i ty o f Ho lmium Laser for Pros ta te Ab la t ion


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Ho lm i um V e r s u s K T P f o r P r o s t a t eV a p ou r i s a t i o n

The holmium wavelength is 2,140nm, which fallswithin the infrared portion of the spectrum and isinvisible to the naked eye. At this wavelength,water within the target tissue is the chromophore.Since prostate tissue is predominantly water, thedepth of penetration for the holmium laser islimited to <0.5mm.

Holmium energy is delivered in pulses throughtiny vapour bubbles. The vapour bubble(sometimes referred to as the ‘Moses Effect’) iscreated at the tip of the fibre when operating in afluid medium. It has been suggested that theirrigant absorbs most of the laser energy, makingablation with holmium energy inefficient.However, the opposite is true. The bubble absorbsonly a small fraction of the total laser energy in thepulse when the fibre is placed in direct or nearcontact with the target tissue. The remainingenergy instantly vapourizes tissue, removing itbefore it can conduct heat and cause deeperthermal damage. A fluid environment is one inwhich holmium is highly effective and deliversoptimal results.

KTP lasers like the Laserscope GreenLight PV™system target haemoglobin as the chromophore. Thedepth of penetration is four times deeper thanholmium, typically 2.0mm. The quasi-CWGreenLightPV laser has longer pulse periods withmuch lower peak power (~280W) compared withthe extremely short pulses delivered by the holmiumlaser that generate very high peak power (~5,000W).Both wavelengths ablate approximately one to twograms of tissue per minute. However, holmiumablates without generating the complicationsassociated with tissue necrosis often found with thedeeper penetration and lower peak powers of KTP.12

Consequently, the high-power holmium laser is anideal and versatile selection for BPH treatment sinceit precisely and cleanly ablates without charring ordeeply necrosing surrounding tissue.

Holmium also fragments all types of calculi, includingcystine and calcium oxalate monohydrate.13,14 Thewavelength and short pulse duration of the lasercoupled with the highly flexible delivery devicesenable the treatment of all stones, regardless of

composition, size and location within the urinarytract.15 KTP lasers lack stone fragmentation capabilities.

In addition to exceptional and versatile surgicalperformance, the VersaPulse PowerSuite 100Wholmium laser has several key features that set it apartfrom the GreenLight PV KTP laser system.

• The US Food and Drug Administration (FDA)clearance for more indications

The VersaPulse PowerSuite is FDA-cleared for awide range of indications spanning multiplespecialities.

Figure 2: The Line Around the Circumference of the

Fibre Indicates the Minimum Endoscopic Retraction

Distance

A) DuoTome side view shows dotted line oriented 90° from energy exit window;

B) Direct view of exit window. small dot is adhesive used during the manufacturing

process;

C) A solid line along the fibre axis is 180° from energy exit window

Figure 3: The Superficial Penetration of Holmium

Provides Efficient Vapourisation Without Risking

Necrosis of Surrounding Tissue that can Occur with

KTP

12. Reuter E, CEO, LaserScope. Patient Safety Guidelines for GreenLightPV™ ADDStat™ Fiber Optic Device,12/12/2003.

13. Das A, Michael J and Bagley D H, “Intrarenal use of the holmium laser”, Laser Surg. Med. (1997), 21: pp. 198–202.14. Teichman J M H, Rogenes V J, McIver B J and Harris J M, “Holmium:Yttrium-Aluminum-Garnet laser cystolithotrpsy

of large bladder calculi”, Urology (1997), 50: pp. 44–4815. Grasso M and Chalik Y, “Principles and Applications of Laser Lithotripsy: Experience with the Holmium Laser

Lithotrite”, J. Clin. Laser Med. Surg. (1998), 16 pp. 3–7.


• Plug and playThe VersaPulse PowerSuite can be plugged intoany standard 220VAC 30Amp outlet and has aself-contained cooling group. In contrast, theGreenLight laser requires a 50Amp line and anexternal water cooling system. Installation forthese electrical and plumbing requirements canoften amount to a substantial financial cost forthe hospital.

• Fibre performanceThe holmium laser and DuoTome fibre deliveroptimal ablative effects when in direct or nearcontact with the target tissue. In contrast,extended use of the KTP fibre can reduceoptical characteristics to such an extent thatablation will no longer occur and the KTP laserthen operates with a purely coagulative effect.Tissue necrosis is highly likely in this case. Thisincreases the occurrence of undesirable post-operative outcomes, specifically protractedcatheterisation times and continuation of thesymptoms associated with BPH after surgery astissue slowly sloughs off.12

• Clear field of viewSafety eye-wear used for holmium is clear andprovides a natural ‘full-color’ field of view. This isin direct contrast to the orange tinted glassesrequired when using a KTP laser. The orange huemodifies the field of view, which may make itdifficult to see and detect bleeding.

• State-of-the-art user interfaceThe VersaPulse PowerSuite offers over 200 lasersettings accessible through a color touch screen,permitting convenient and precise control of thetreatment. GreenLight PV offers a limitedinterface with only basic adjustability.

• Innovative backup designThe VersaPulse PowerSuite system is uniquewithin the market place for its CaseSaver™ feature.The 100W is actually four lasers in one, alloperating in unison. The CaseSaver feature enablesthe surgeon to continue a case at reduced power inthe event of a mechanical or optical malfunction.

Con c l u s i o n

Clinical studies have shown the holmium laser to bea safe treatment modality, similarly effective toTURP with equivalent or superior outcomes. TheLumenis VersaPulse PowerSuite 100W holmiumlaser and its accompanying fibres and accessories offerthe greatest treatment versatility of any laser systemon the market today, with the ability to rapidlyvapourise prostate tissue, incise strictures, ablatetumours and fragment stones. Furthermore, theVersaPulse PowerSuite is FDA-cleared for a widerange of surgical procedures in ear nose and throat(ENT), gynaecological, arthroscopy, pulmonary,gastroenterology and general surgery settings, makingit a veritable laser Swiss Army knife. The VersaPulsePowerSuite 100W in conjunction with theDuoTome and SlimLine delivery devices offerssuperior technological advantages for thoseconsidering a highly versatile and proven laser systemfor BPH and multiple surgical applications. ■


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Contact Information

Lumenis Inc, 2400 Condensa Street,

Santa Clara, CA 95051

Tel.: 408-764-3000, Fax: 408-764-3140

e-Mail: [email protected]

http://www.lumenis.com


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