Hersheychapter 37

8/9/2019 Hersheychapter 37

1/34

Chapter 37: Laser Applications in Podiatric Surgery

Lasers and Laser PhysicsFundamentals

Tissue InterractionLaser Safety

Clinical Applications in Podiatric SurgeryThe CO2 LaserThe Nd: YAG LaserThe ARGON LaserThe KTP Laser

Other Surgical Lasers


2/34

LASER APPLICATIONS IN PODIATRIC SURGERYApplications of lasers to medicine and surgery have increased exponentially over

the past decade. This technology has become established in the medical communityand has become the standard of care for many procedures. Lasers have justified theirutilization by the improved clinical outcome in the delivery of comparably more traumaticand invasive procedures. Some procedures are not possible without the precision or

uniqueness of this modality.There are a great variety of laser types and delivery systems, each havingindications unique to the desired tissue response. Fundamental to the surgeon inselecting the wavelength, power and control to produce the intended effect, with safehandling of the instrument, is a knowledge of laser physics for this tissue interaction.

LASERS AND LASER PHYSICS

HISTORY1. The Quantum Theory:Max Planck

1910Light is quantified in Photon unitsthe basic unit of light (6.625 x 10-27 erg sec (cm2/sec))2. Stimulated Emission Theory:Albert Einstein1917Basis of laser light3. First laser developed, demonstrated and patentedTheodore MaimanRuby Laser1960

UNITS OF MEASUREMENT1. Frequency Expressed in Cycles per Second (CPS)

Hertz (Hz)2. Wavelength The measurement of one crest to another of a particular frequency

3. Length Meter = the basic measurement unitPrefixcenti (cm) = 1 x 10-2 meters = .01 metersmili (mm) = 1 x 10-3 meters = .001 metersmicro (um) "micron" = 1 x 10-6 meters = .000001 metersnano (nm) = 1 x 10-9 meters = .000000001 meters

4. Time Second = the basic measurement unitPrefixmili (ms) = 1 x 10-3 seconds = .001 secondsmicro (us) = 1 x 10-6 seconds = .000001 secondsnano (ns) = 1 x 10-9 seconds = .000000001 secpico (ps)= 1 x 10

-12 seconds = .000000000001 sec5. Power Watts (W) = The basic measurement unit

Power density = Watts per centimeter squared (W/cm2)Joules (J) = Watts x Seconds of power on tissue


3/34

FUNDAMENTALS1. The wavelength is the key to tissue absorption, laser delivery systems and to lasersafety.2. Comparison with other modalities:Scalpel --> Mechanical pressure. Local effect. Controlled crushing.Electrocautery --> Electrons. Conduction through isotherms. Global effect.Radiosurgery --> Radio Frequency transmission. Local effect.Laser --> Photon absorption. Specific to tissue content. Thermal precision.3. The mnemonic "LASER":L ightA mplification byS timulatedE mission ofR adiation4. Laser frequencies most commonly used are in the infrared and visible spectra.5. These are non-ionizing photonic radiation.6. No lead shielding is required.

7. Exception: Excimer (UV) lasers are ionizing.8. Laser light is NOT a natural phenomena.

UNIQUE CHARACTERISTICS OF LASER LIGHTCoherentMonochromaticCollimated

Coherent = All crests of wavelengths line up. Crests and troughs are equidistant intime and space. This eliminates wavelengths canceling each other out and producinginterference patterns which would decrease its intensity. This enables very efficient

power production. Coherent light, (compared with incoherent, conventional light) can befocused to an exact single point. ie: 200 W of incoherent conventional light will illuminatea room. 200 W of coherent laser light will rapidly carve through the cement wall of theroom.

Monochromatic = Pure, single color. Responsible for the interaction of tissuechromophores producing a specific effect. ie: CO2 laser to incise and ablate amelanotictissue, Nd:YAG for deep tissue penetration, Argon penetrates epidermis.

Collimated = Emitted stream of photons is linear, and does not diverge. This alsoeliminates wavelengths producing interference patterns reducing power.

COMPONENTS OF A LASER1. Partially reflecting mirror 97%2. Fully reflecting mirror 100%3. Lasing media4. Xenon flash lamp5. high frequency Switching system6. High voltage power supply7. Delivery system - Articulating Arm, Fiberoptic, waveguide 8. Lense


4/34

9. Aiming Laser (HeNe), if required, depends on laser type

Conventional light radiation Laser lightradiation

+ Multiwavelength - polychromatic + Pure -monochromatic+ Divergent + Collimated+ Coherent + In phase+ Spontaneous Emission + StimulatedEmission

THEORY of LASER OPERATION1. Spontaneous Emission (conventional)2. Stimulated Emission (laser) CREATION OF LASER LIGHT V. CONVENTIONAL LIGHT1. Lasers are classified by the type of active media used in the laser tube.

ie: CO2 laser tube filled with CO2 (excitable media), N2, and He gasses.Nd:YAG is a Yttrium, Aluminum and Garnet crystaldoped with Neodymium as the excitable media.

2. Atoms are stimulated to rise from a lower energy shell to a higher shell,3. Then fall back to emit a specific monochromatic wavelength of light.4. These waves reflect in the laser media randomly at first, then become coherenttogether by being amplified by reflecting between the mirrors.5. Once their energy exceeds the threshold of transmission through the partiallyreflecting mirror, laser radiation is emitted in a linear, collimated, array.

6. Frequency doubling media is also used to change laser wavelength.ie: Tunable dye or KTP (Potassium, Titanium, Phosphate) laser.The KTP crystal pumps a KTP crystal. Efficiency drops to about 30% of input.

Nd:YAG Laser -----------> KTP Crystal------------> output1060 nm 532 nm

DELIVERY MECHANISMS1. Low frequencies = longer wavelengths = far- and mid-infrared.Articulating arms, or internally reflecting waveguides are used.2. At near-infrared, 2100 nm and above (Ho:YAG laser) fiberoptics contain these

frequencies having a higher index of refraction.3. Fiberoptics are constructed of quartz (Aluminum dioxide), silicon dioxide or silverhalides, coated with a plastic sheath.4. Lenses, or contact light scalpels of selective focal lengths, can be integrated into theterminal end of the fiberoptic system.5. The bare fiber is also used for free beam ablation work.TRANSMISSION MODES1. Desirable laser energy distribution energy follows a Gaussian curve.


5/34

2. Energy decay falls exponentially on either side of the curve.

TEM00 has a narrow spot size TEM01 small spot 0.3 mm at besttrue Gaussiancurve.

called "nearGaussian"0.2 mm diameterspots

not desirableappropriate forcutting

can be usedfor ablation.

TISSUE

INTERACTION1. This is THE most important aspect of lasers in medical science.2. Tissue interaction with the specific laser wavelength is the KEY to laser selection.

TRANSMISSION CHARACTERISTICS THROUGH TISSUE1. reflection2. transmission3. scattering4. adsorption

** Absorption of specific wave-length by specific chromophores is key.

CLINICAL TISSUE INTERACTION PHENOMENA

The effect on tissue by thermal lasers commonly used in Podiatry is both:1. power and2. time dependent:

POWER DENSITY1. Is the standard of expression in documenting laser power to tissue.2. Expressed in W/cm2.3. P.D. maybe constant while tissue spot size and power varies.


6/34

This allows physicians to communicate standard terminology, allows for preference. It is

the STANDARD OF CARE: in operative reports describing laser useIt is necessary for communicating standard measurement in the scientific community.

A typical example using 14 Watts with a 0.2 mm diameter contact tip or spot size (whichis 0.1 mm radius)Traditional Algebraic:WATTS 14 4.46 446----------- = --------------------- = ----------------- = --------------------- = 44,600pi x r2 0.12 0.01 0.01

3.14 x ----- -----102 100

where: 0.1 is the radius10 is the conversion factor of 10 mm/cm

a shortcut algebraic:WATTS 14

127 x ----------- = 127 x --------- = 44,450d2 0.22


7/34

WATTS PER CM2Chart

WATTS TIP DIAMETER (mm) or CO2 Spot Size (mm)

0.1 0.2 0.4 0.6 0.8 1.0 2.0 3.0-----------------------------------------------------------------------------------------------------------------------

4 50,955 12,739 3,185 1,415 796 510 127 575 63,694 15,924 3,981 1,769 995 637 159 716 76,433 19,108 4,777 2,123 1,194 764 191 857 89,172 22,293 5,573 2,477 1,393 892 223 998 101,911 25,478 6,369 2,831 1,592 1,019 255 1139 114,650 28,662 7,166 3,185 1,791 1,146 287 127

10 127,389 31,847 7,962 3,539 1,990 1,274 318 14211 140,127 35,032 8,758 3,892 2,189 1,401 350 15612 152,866 38,217 9,554 4,246 2,389 1,529 382 17013 165,605 41,401 10,350 4,600 2,588 1,656 414 18414 178,344 44,586 11,146 4,954 2,787 1,783 446 19815 191,083 47,771 11,943 5,308 2,986 1,911 478 21216 203,822 50,955 12,739 5,662 3,185 2,038 510 22617 216,561 54,140 13,535 6,016 3,384 2,166 541 24118 229,299 57,325 14,331 6,369 3,583 2,293 573 25519 242,038 60,510 15,127 6,723 3,782 2,420 605 26920 254,777 63,694 15,924 7,077 3,981 2,548 637 28321 267,516 66,879 16,720 7,431 4,180 2,675 669 29722 280,255 70,064 17,516 7,785 4,379 2,803 701 31123 292,994 73,248 18,312 8,139 4,578 2,930 732 326

TIME

The gating of the flash lamp may be:1. C.W. Continuous Wave - Continuously on2. Single Pulsed - Continuous on for a preset period3. Superpulsed - Rapid pulsing at peak power at 250 - 1000 Hz.

Average power is determined by1. pulse width and2. repetition rate

This allows tissue to undergo "thermal relaxation"4. Ultrapulsed - Much higher RF (Radio Frequency) switching

nanosecond pulse width.More thermal precision.

5. Q-switched - Very high peak power with picosecond pulse width

THERMAL RELAXATION = Interval between pulses to allow dissipation of energy.Minimum interval is 1:10 ratio on-off.


8/34

ie: CO2 is strongly absorbed by water, therefore superficial penetration.Holmium is absorbed by water but not as much as C02, so deeper tissue penetration.Argon and KTP are absorbed by Hb and chromophores.Nd:YAG (bare fiber) is not absorbed by anything, so it penetrates.

LASERS APPLICABLE TO PODIATRIC SURGERY

WAVELENGTH USE IN PODIATRY DEPTH OF PENETRATION FUNCTION

10,600 umFar IR

CO2 Noncontact:DissectionDerm.Pathologies

Nail Pathologies

0.1 mm CuttingAblationCoagulation

1,060 umNear IR

Nd:YAG Bare Fiber Deep tumor destr.

6-8 mm AblationCoagulation

Nd:YAG Contact-tip:Dissection

50-200 u Cutting

2,100 umMid IR

Ho:YAG Near-contact:Cartilage and bone

0.4-0.6 mm Ablation

4881514 um Argon NoncontactVerruca

Dermal vessels Photoablation

532 um KTP Noncontact:Cutaneous vascularVerrucaContact:Dissection

Dermal vessels

1-2 mm

PhotoablationCutting

478 urn Copper-Vapor

Noncontact:Cutaneous vasc.lesions

Dermal vessels Photoablation


9/34

LASER SAFETY1. Reference: "ANSI 136.3 Publication" on laser safety2. Four Classes of Lasers:Class I - No ocular damage with direct viewingClass II - Ocular damage with prolonged exposureClass III - Ocular damage to the eye before the eye can blinkClass IV - Medical lasers. Great potential and hazard to the eyeand skin. Ignites combustible materials. Beam = fire hazard.3. Dedicated laser nurse in O.R. controlling use and monitoring laser safety4. Key operated, controlled access.5. Room shields to outside personnel.6. Eye protection for patient and all OR personnel.7. Wavelength specific eye protection hung outside the doorso that people can enter the room safely.8. Adequate smoke evacuation appropriate to tissue atomization.9. Dual stage filtration, carbon and 0.2 um filter.10 Coaxial visible aiming beam for use with invisible light lasers.

11 Proper filtering mask.

EYE PROTECTION1. Impact is direct or reflective.2. Minimal hazard zone is determined to be 6 feet away from the reflected zone.3. O. D. = Optical Density, expressed as an exponent of power of 10.ie: O. D. of 5 is 100 x as absorbent as O. D. of 34. Always expressed as an O.D. at a specific wavelength5. Recommended to surgeon (direct viewing field) - minimum O.D. of 5 @ wavelength.6. Recommended to OR personnel (indirect) - minimum O.D. of 3 @ wavelength.7. Conventional glass or plastic glasses will stop CO2

8. Recommend UV coating to stop the ultraviolet fluorescence off carbonization.9. Eye protection still necessary for endoscopic procedures, fibers could break.10. High density filters on endoscopes, arthroscopes, waveguides.11. The reflected light transmits directly back to the surgeon.

CO2 - corneal burn.Surgeon's cornea replaceable. Argon, KTP - retinal damage,Irreversible.

Nd:YAG absorbed in the vitreous humor causing posterior cataract formation.Reversible? Doubtful.

DRAPING FOR LASER SURGERY


10/34

1. Surgical site draping for CO2 laser use should be wet towels.2. Drapes should be dry for the Nd:YAG procedures.(Water is a transmitter at the YAG frequency and absorbed at CO2 frequency.)3. Laser nurse - laser on standby when not immediately using the instrument avoidsaccidental discharge.4. Multiple foot switches - Bovey, power saws, table, can be confused with the laser.5. A defocused beam has more of a tendency to start fires.6. A focused beam will have a tendency to drill.7. A prefocused beam will have a tendency to accelerate the hole it is drilling.The power density increases approaching the focal point.8. Always have water on hand, to extinguish a potential flame.9. Anodized instruments (blackened or roughened) are helpful to diffuse the beam,minimizes reflections but does not eliminate.10. Endotracheal tubes should be coated with Mirasil (noncombustible material).

HAZARDS OF THE LASER SMOKE PLUME1. Epidermis with the CO2 laser creates a great deal of smoke.2. The shock waves backscatter verrucoid particles which can be inhaled.

3. Vaporized tissue and debris is liberated by tissue atomization4. Studies show live intact DNA recovered from the laser plume.5. Hazard in AIDS and hepatitis patientsHazard in patients with infectious lesions, i.e. warts.6. Lesions have been reported by Dermatologists, Podiatrists, and Gynecologists.7. Formaldehyde also produced, large number of other carcinogens.

High power plume evacuators are required with dual stage filters.1. Charcoal filter for carcinogens, smell.2. Filtering down to 0.2 microns to filter out virusa. The key is good technique in smoke evacuation.

b. Keep the smoke evacuator close to the area of surgery.c. A laser mask will filter down to 0.3 microns.d. These measures reduce nearly all of the hazards of the viral particles

II - CLINICAL LASER APPLICATIONS IN PODIATRIC SURGERY

STANDARD OF CARE1. OPERATIVE REPORT - Include laser type power density calculation.ie: "Procedure: Austin Bunionectomy, left foot (Soft tissue with CO2 laser): With the CO2laser set at 33,000 W/cm2 power density, a linear incision was ..."

2. CONSENT FORM - Include the laser type or wavelength used and the intendedapplication of the laser if there is conventional instrumentation used. ie: "(Usualdescription of surgery), soft tissue with CO2 laser"

3. ETHICS IN ADVERTISING - Differentiate the application of the laser ie: "Laserassisted" bunionectomy, or "Laser for soft tissue"

Advertise straightforward what laser procedures (warts, nails) are done if alsoadvertising conventional procedures (bunionectomy) that are not performed with laser


11/34

assistance.

Public misconceptions: No incision, laser cuts bone.You will never lose a patient because of an honest disclosure of a procedure.

THE CO2 LASERPROPERTIES OF THE CO2 LASER1. Active media is C02, helium, nitrogenCarbon dioxide is the excited mediaHelium and neon are catalysts2. High absorption in water, Tissue mostly watertherefore superficial absorption"What-you-see-is-what-you-get"Low scattering in tissues3. Invisible beam at 10,600 nm far-infrared, helium-neon aiming beam necessary

ADVANTAGES OF USING THE CO2 LASER1. Thermal precisionMaximum impact on target and minimum damage to adjacent tissue2. Absolute hemostasis minimizing postoperative edema. Coagulates small bloodvessels, lymphatics (


12/34

SELECTION OF LASER PARAMETERS1. Appropriate power, spot size, power duration, and angle to tissue

2. Ablational work: spot size less than 2-3 mm in diameter3. Incisional work: spot size less than 0.3 mm in diameter

DISADVANTAGES1. Cost, power, alignment, control, additional informed consent2. Smoke evacuation system3. Combustible materials risk, extra drapes, higher protection4. Special training for physician/staff5. Learning curve6. Credentialling process/extension of privileges if hospital use

PROCEDURES PERFORMED USING THE CO2 LASER ASSIST1. Plantar Verruca Ablation2. Porokeratoma Ablation3. Nail Matrixectomy Ablation4. Fungal Nail Treatment - Drilling through nail plate5. Heel Fissure Debridement6. Ulcer Debridement/Sterilization7. Incisional Procedures for soft tissue component (of neuroma, bunion, etc.)

THEORY OF CO2 LASER TISSUE INTERACTION1. Controlled, highly localized vaporization.

2. Energy is absorbed by water.3. High conductivity minimal to adjacent tissue damage.4. Avoid tissue carbonization - increases and conducts thermal effects Immediatelyseen. Worse problem at low power densities. Global tissue temperature and thermalconductivity. Wipe this off with a damp gauze.CO2 LASER PROCEDURES

TECHNIQUE OF CO2 LASER ABLATION


13/34

1. Power Density over 1000 W/cm22. Larger spot size- 2-3 mm

The following diagrams, illustrate two methods: linear and circular overlap.The goal is an evenly ablated surface.

1. Circumscribe lesion by 2 mm peripherally2. Curette representative area and send biopsy for pathology.

3. Deep channels should be avoided.4. Do not penetrate dermis in verrucoid lesions.5. If you have a 0.2 mm spot size at focal point, defocus to 1.0 mm.For example, 20 watts with a 1 mm spot size equals 2540 watts/cm2 power density.Scarring results from dermal penetrationIPK's and porokeratosis are focally penetrated to the dermis.1. Need to lase to subdermal fat.2. 75% cure rate, somewhat higher than conventional applications.3. Little scarring.4. More focal treatment is required at higher power levels.5. Remove char by lavage or sponge

TECHNIQUE OF CO2 LASER FOR INCISION/EXCISION1. Power density greater than 6,000 watts/cm2 preferred2. Small spot size, maximum 0.3 mm diameter,3. TEM01 lasers are not able to produce less than 0.3 mm spot at focal point.Thus they are not appropriate for making incisions.4. TEM00 lasers are available to deliver 0.1 mm, but commonly 0.2 mm.

Example:a. 20 watts with 0.2 mm spot size equals 63,500 watts/cm2 power density.b. Technique: smooth rapid continuous motionc. In focusd. Traction and countertraction perpendicular to incision.

5. Traction/countertraction of the incised area will enable smooth tissue planedelineation.6. Retrace path to achieve desired depth.7. Important: Characteristics of individual lasers vary greatly.


14/34

8. Test on a tongue blade first.Depth should be a little over halfway through with minimal charring.

NOTES:1. A TEM00 laser produces a very different effect compared to a TEM01 machine2. A superpulsed laser has a variety of pulse settings to achieve the same P. D.3. The ultrapulsed lasers cut faster at lower power settings.4. These are characterized by very short duration RF pulsed power supplies

Power densities are a general rule of thumb and should be adjusted to1. each wavelength,2. the particularinstrument and3. the type oftissue undergoing surgery.

HEMOSTASIS1. By Coagulation:Defocus to a spot size greater than twice the vessel diameter

Use a Power density less than 1500 watts/cm2

Technique: defocus beam to increase spot size and direct beam at site2. By Dessication (thermal contraction):Spot size 1 mmPower density as with coagulationTechnique: direct beam to tissue immediately adjacent

FOCUSED, FREE BEAM LASER APPLICATIONS1. In Focus: Incision2. Defocus: Debulking3. Greatly defocused: Coagulating

4. Prefocused: Avoid altogether

OVERLASINGSignificant problem to inexperienced user is "Overlasing"Definition: delivery of an inappropriate amount of laser energy to target tissueor to the surrounding tissuesproducing unintended tissue destruction.(Immediately visualized with CO2 lasers.)

CAVERNOUS HEMANGIOMA1. Considered ablative surgery requiring high power densities.

2. This is a highly vascular tumor.3. Nd:YAG (bare fiber) is appropriate for deep penetration4. Causes deep thermal vascular stenosis.5. CO2 is not good for coagulation for these tumors, but it can be used.6. KTP and Argon are more appropriate for superficial vascular lesions.

KELOID AND HYPERTROPHIC SCAR1. Excellent indication for CO2 laser excision because of lack of fibroblast stimulation.2. Superficial epidermal incision with the CO2 laser, NOT with the steel scalpel.


15/34

3. Avoid charring, will delay healing.4. Refer to technique for incision/excision

LASER ASSISTED OSSEOUS PROCEDURES1. Advertise as laser assisted bunionectomy.2. Lasers used for soft tissue dissection only.3. Not FDA approved for osseous work.4. Used for incision, soft tissue dissection and capsular work.5. Result is less postoperative pain, edema, and earlier range of motion.6. Fascial layers - very little water contenttherefore is more transmissible at this wavelength7. Excellent for capsular incision. Earlier ROM.contraindicated for periosteal dissection hemostasis of ALL vessels.This seals the metaphyseal arteries and slows periosteal healing8. Remember the delayed skin healing effect9. Leave the sutures in a few days longer10. Fibroblast stimulation is minimal thus scar formation is minimal11. Better cosmetic result.

BONE AND CARTILAGE1. Accidentally hitting the bone cortex will take 16-20 weeks to heal. Solution: Debridedamaged cortex immediately. Damage is usually superficial.2. Carbonization in a joint will set up severe chronic inflammation. Solution: Lighten upon capsular dissection in this area Irrigate thoroughly postoperatively, as always3. Excellent application for subchondrodesis proceduresInstead of using K-wire to drill use CO2 at high P.D. for 0.5 seconds. Space closertogether with less mechanical disturbance to cartilage

LASER TREATMENT OF VERRUCA

1. CO2, Nd:YAG, Argon, KTP 532 can be used.2. Selection or combination treatments depend upon clinical presentation.

The technique is to ablate in a layering method1. Anesthesia, avoid epinephrine.Avoid directly sublesional.2. Drape area using moist towels or laser safe drapes.3. Power density CO2 laser: 6,000 to 21,000 watts/cm

2.Decrease for light skinned and thin skinned individualsAlso reduce power density for thin areas on dorsal areas of the foot4. Circumscribe lesion taking 2 mm min border of normal appearing tissue

at the periphery. Viable verruca in this tissue.5. Do this in focus.6. Submit representative biopsies.7. Plow multiple interspersing furrows and crosshatch these to an even base.8. Next wipe area with a sterile, moist gauze to remove char. Avoid relasing char.9. Repeat lasing and wiping until dermal/epidermal separation occurs. Epidermis willappear to peel away from the dermis.10. Several passes are required on the plantar surface of the foot. Desired depth ispapillary dermis.


16/34

11. Healing will occur from basal cells in the dermal papillae.12. Relase superficial areas until an homogeneous depth is encounteredto rete ridges.13. Photocoagulate in a defocused mode.Coagulate the surface to a very light haze.This also sterilizes the surgical bed of viral particles.14. Work is complete. Do not revaporize. Inspect with magnification.15. Silvadene cream and sterile dressing for 24 hours.Avoid occlusive dressings.Extra strength Tylenol for small lesionsHydrocodone 2.5 mg i-ii Q 4 h prn for large masses16. Expect moderate drainage for 3 days to 1 week.Wound closes completely in 1 month entirely healed.In 2 months no signs of treatment are usually visible.

* Treat lesions less than 1 cm from each other as one lesion* Do not leave a bridge of healthy skin between.

Handling large lesions:i.e. large, mosaic verruca.1. Keep depth of penetration even.2. Circumscribe and divide the lesion into quadrants.3. Lase each quadrant individually.4. If the patient is supine, work from posterior to the anteriorIf bleeding is encountered be sure it does not drain over the surgical site.5. Be prepared with extra smoke evacuation filters.

To accomplish hemostasis, if needed::1. reduce the power density and "brush" hemorrhagic area.

2. Power density can be reduced by backing off to a defocused mode.3. Suction blood away first - laser does not coagulate free blood

Postoperative Care:1. Patient seen 3 days to 1 week2. Patient allowed to clean twice daily with H202 and bandaidexception: large lesions require redressing until drainage decreases.3. Normal bathing after first redressing.Accommodative pad if needed.4. Stop dressing when drainage ceases, no dressing at night.5. Monitor patient for at least 6 months due to the nature of HPV.

6. Success rate easily 90% after learning curve reached.

Complications:1. Infection--rare, laser sterilizes the bed.2. Overlasing

NOTES:3. Increased pain--result of overlasing.4. Increased bleeding--result of overlasing


17/34

5. Increased scarring--result of overlasing6. Scarring--Penetration of dermis

LASER NAIL MATRIXECTOMY1. No epinephrine2. No tourniquet - will have good hemostasis3. Avulse the nail, do not ablate with laser4. Power settings: 0.2 mm spot size, 125 mm focal length lense, 10 watts CW5. Aim at 45 degrees, under proximal nail fold for acisional technique6. Outline matrix and circumscribe to periphery of distal phalanx condyle avoid lasingbone.7. Lase the matrix in layers achieving a uniform layer of desiccated tissue. Debride witha dermal curette to the next layer of matrix. Stop when coming close to bone. Severalpasses are necessary8. Keep site very dry and free from blood.9. Dilute phenol may be used as an adjunct, but the laser replaces the blade.1. Techniques for missing part of the matrix are just a probable with laser or blade

2. Characterized as a blind procedure.3. Burning bone may result in periostitis, very rare.4. Recurrence after learning curve partial permanent procedure, hallux, 0.5%.5. These rate of results after learning curve reached.6. Usually recurrence is keloid, hypertrophic scar formers, and psoriatic patients7. Patients with high epidermal growth turnover8. Total permanent if recurrent in these patients

POSTOPERATIVE CARE1. Leave sterile dressing on 24 hPatient to change at home

Patient to clean twice daily with H202. No soaks.2. Some tissue necrosis 1 week3. Patient to keep dry for 3 days4. Patients seen 24 hours - 3days postop5. Bandaid dressing6. Normal healing7. Discontinue dressing and soakswhen drainage ceases, generally 2 weeks8. Allow it to drain 1-3 weeks until it stops draining spontaneously.9. Total permanent drain more on the 3 week margin, lesser digit partials for a week or

so.COMPLICATIONS1. Increased pain2. Increased drainage3. Delayed healing4. Soft tissue infection5. Thermal osteitis6. Osteomyelitis7. Overlasing is generally the culprit of all those complications.


18/34

PREVENTION OF COMPLICATIONS1. Use appropriate power density2. Keep the hand piece moving or apply power with periodicity3. Keep exposure time on a given spot to a minimum4. Don't relase over char5. Always know where the beam is going, especially these blind procedures

FROST AND WINOGRAD TECHNIQUE1. Do not use lasers to cut the nail- excessive heat.Use incisional power densities as described for incisional procedures2. Laser is 90 degrees to the skin, P.D.= 40,000 W/cm2

Then decrease when performing matrixectomy3. Incision would be the same otherwise as the Winogradplease refer to that section within this review book4. Laser incision is made straight back past the eponychiumSecond curvlinear incision around soft tissue pathologyRemove hypertrophied nail lip and granuloma tissue.

5. Closure with 4-0 Nylon suture.6. Tourniquet is not necessary.

LASER TREATMENT OF ONYCHOMYCOSIS1. No anesthesia required2. Laser "mottling" techniques3. Object is to punching holes in the top nail plate4. This allows topical medications to penetratea. Laser settings to just barely fire through a tongue depressor.b. These settings should be just subthreshold for patient feeling any heatc. Laser must be in a pulsed mode

d. holes drilled 4-5 mm aparte. Three separate treatments 6 weeks apart.f. Topical antifungal applied BID

SUBTOTAL MATRIXECTOMY1. Anesthesia as before2. The plate is always removed conventionally3. Lasing is performed on the total matrix4. however only scanned to 50% of the depth5. The idea is to remove only part of the nail matrix to result in a thinner nail

SUBUNGUAL HEMATOMA1. No anesthesia2. Same procedure as mottling technique3. Slightly higher power Density may be used4. Lase a couple of holes until the nail plate is penetrated.5. Hematoma will isolate thermal effects.

LASER TREATMENT OF GRANULOMAS


19/34

These respond very well to laser treatment1. Ablate the granuloma in a crisscross pattern, the same as verruca2. Alternate with a moist gauze until normal tissue is encountered3. Good hemostasis should be encountered throughout the procedure4. No chemocautery, bovey, or hemostatic solutions are necessary5. Once the granuloma is gone the minimal bleeding encountered stops6. Defocus, relase, apply sterile dressing.7. Home treatment and followup as with verruca.

CAUTION IN REVISIONAL PROCEDURESScar tissue, if encountered, has less water content.Therefore reduce power density when you relase this type of tissues. Otherwise excessvaporization penetrating tissue planes may occur.

THE Nd:YAG LASER

GENERAL DESCRIPTION1. 1060 nm, near-infrared, separate HeNe aiming beam2. Most frequently used laser besides the CO2 laser3. This is a general surgical instrument used most of the time by general, thoracic,plastic, and urologic surgeons4. See absorption chart - Nd:YAG is centered between other common medical lasers5. Unique characteristic - the "window" of low absorptionand high transmissibilityYAG is poorly absorbed by hemoglobin, chromophores, protein, or water.6. 99% of Podiatric use is with contact laser scalpels7. Able to coagulate vessels < 0.2 mm diameter8. User friendly, but tip selection, type and size must be understood9. Power settings are very important

10. Endoscopically/arthroscopically compatible

MODES OF OPERATION1. Non-contact mode - used for debulking and treating deep tumors.higher power levels required ie: 40 W2. Contact-tip mode - highly localized scalpel form similar to CO2 laserlower power ie: 12-16 W (frosted tip)

4-6 W (nonfrosted)3. Contact-tip is very superficial absorption, cutting only at the tip."What-you-see-is-what-you-get"

Noncontact is indicated fordeepContact is used forincision and tumors.excisional work.

THE INSTRUMENT1. Instrument is portable, conventional nondedicated power OK2. C.W. mode only


20/34

3. Flashlamp excites Neodymium-doped crystal of Yttrium, Aluminum, Garnet4. Fiberoptic delivery system, air or water cooled within the sheath5. Large variety of handpieces, general surgical one is used6. Large variety of contact tips, fiber and handpiece combinations

THE CONTACT TIP1. Developed for 3-dimensional feedback, feels similar to a conventional scalpel Bettercontrol of dissection2. Converts light energy from a laser into heat energy.3. Very precise hot knives, tissue effect 50-200 microns4. Types of conical tips: Frosted, clear, ceramic, titanium coated

There are many combinations of tips:1. Sapphire scalpels interchangeable - screw onto handpiece2. Integrated quartz tips with fiber and handpiece also used3. Scalpel must be in contact with tissue when power onor flare out of expensive tip will occur4. Flare-out threshold temperature:

Sapphire scalpel - 2000 degrees FQuartz scalpel - 1000 degrees F5. Tip shapes - Chisel, flat, round, cylindrical, hooka. Long or short conical used in Podiatryb. Tapered conical tip concentrates energyc. Polished lense at distal endd. Available radii are 0.2-1.2 mm diameteri. when calculating P.D. don't forget diameter -> radiusii. and mm to cm conversions6. Frosted and nonfrosted availablea. Frosted - distal end roughened to allow lateral radiation except at lense and allows

coagulation during dissectionb. Nonfrosted - tip is cleari. radiation only at distal lenseii. appropriate for very fine dissection at low power levelsc. Procedures are scalpel specific

SURGICAL APPLICATIONS

LASER SCALPEL STEEL SCALPELRapid dessication Controlled crushingSeals small nerves Smears small nerve endings

Seals small vessels No microcoagulationCell necrosis is small Cell necrosis is moderateCuts with Light Energy Cuts with physical pressureHigh precision Normal tactile feedback

ADVANTAGES OF Nd:YAG OVER SCALPEL1. Less postoperative pain2. Less bleeding of smaller vessels/lymphatics - less swelling3. Sterilizes surgical site reducing chance of infection


21/34

4. Less cell necroses5. Less fibroblastic stimulation - faster tissue remodeling

Nd:YAG MEDICAL INDICATIONS1. Situations contraindicating tourniquetparticularly where a dry field is essential2. Dissection of delicate tissue planes in all axis requiring contact3. Patients where surgical trauma may stimulate adverse reactionsCollagen-vascular disease (ie: SLE), gout, R.A., etc.3. Patients with platelet, hematogenous and vessel disease,sickle cell, phlebitis4. Elderly patient exhibiting capillary fragility

PODIATRIC MEDICAL INDICATIONS FOR Nd:YAG SCALPEL1. The Nd:YAG laser scalpel decreases the surgical pathophysiology ofa. edema in a dependent extremityb. leakage of intravascular fluid in the surgical siteof the foot from hydrostatic pressure

c. nerve microtrauma and axonal depolarizationd. local surgical cell necroses (v blade)e. scar formationf. nosocomial infection2. Extremity surgerya. Hydrostatic pressure, terminal perfusion. weightbearingb. structure undergoing reconstructive surgery are allc. factors complicating foot and ankle surgery3. Hypertensive patient with peripheral edema4. Plastic reconstruction5. Wet cases

6. Cases where visualization must be optimizedie: Nerve decompression within ganglion complex7. Any situation where cell necrosis must be minimized

CONTRAINDICATIONSDefer these cases until the learning curve plateau is reached1. Digital surgery - cannot justify utilizationInstrument overkill for procedure2. Revisional surgery - actually indicatedbut these surgeries carry a higher risk by defaultIf successful laser gets the credit

If not successful surgeon gets blammedPublic expectations of lasers are high3. Any bone work - not FDA approvedThis is not a wavelength for this4. Medical-Legal cases - Same idea as revisional Surgery5. Amputation - Same idea as revisional surgery6. PVC cases - Same idea7. Acute Trauma cases - no time to call in laser team


22/34

INDICATIONS FOR FROSTED AND NONFROSTED CONTACT TIPS

PROCEDURE CONTACT-TIP COMMENTNerve releases and Neuroma Nonfrosted Thermal RadiationNeurectomy Nonfrosted Lateral RadiationBunionectomy (soft tissue) Frosted Limit capsular dissectionGanglions Nonfrosted Particularly those

adjacent to muscleTendon transplants/lengthening Nonfrosted Long remodeling timeHeel spur (soft tissue) Frosted Excellent visualizationPlantar Fasciotomy Nonfrosted Around calcaneus onlyGeneral Podiatric Surgery Frosted Coagulation duringdissection

INAPPROPRIATE Nd:YAG PROCEDURES1. Wrong tip = wrong procedureie Neuroma sx with frosted tipInduces thermal periostitis in adjacent metatarsals

This can be done with frosted at short power applications2. Nail matrixectomy = burns periosteumuse CO23. Warts = can use, but it's more easily treated with CO24. See contraindications

GENERAL CONSIDERATIONS IN APPLICATION OF THE Nd:YAG LASER1. Drapes are dry. Water transmits this wavelength.2. Separate mayo stand for fiberoptics with expensive tips and power equip3. Notch filter glasses are the best eyewear protection, best visibility

4. Select general surgery handpiece5. Select tip size and frosting based on presurgical plan6. Laser nurse will connect fiberoptics to launch pad on laser7. Calibrate instrument and hand off calibration cone, now contaminatedSelect power level, C.W. mode8. Incision is made with a steel blade only to the dermisWhen you see the whiteness of the dermis - stopContact tip is held 45 degrees to tissueNew frosted tips need 2 seconds at full power to "age"9. Traction - countertraction throughout procedure10. Room suction be used for the minimal smoke plume

much less than CO2 laser11. Deeper dissection now before using forceps Use traction - countertraction12. Dissect in linear strokes. Avoid burying the tip.This laser needs less pressure than a steel blade Tactile feel is like a hot knife throughbutter So let the laser do the work13. Repeat dissection strokes until each plane of tissue complete14. Dissection may be adjacent to vessels, stay 3-4 mm from nerves at high powerlevels 14-16 W15. Hemostasis of larger vessels can be with the laser


23/34

alternate on either side, observe coagulation16. Capsular dissection may be made right over cartilagewith no damage to cartilage17. Dissect only the periosteum/capsule you intend to discardGood hemostasis, but seals off periosteal vessels18. Remainder of capsule/periosteum done with blade19. Bone work with conventional power instrumentation20. Watch on-time during intermetatarsal neuroma surgeryAvoid thermal periostitis in adjacent metatarsals21. Seal nerve endings in neuroma sx. with the contact tipPrevents stump neuroma formation22. Minimal char formation seenVery dry and atraumatic surgical site seen23. Closure is conventional, dressings conventional24. Sutures remain in a few days longerExpect macroscopic bleeding due to tourniquet reflux hyperemia

REALISTIC EXPECTATIONS

1. Learning curve is steeper than CO2 Laser2. Postoperative bruising still seen3. Swelling, and pain still seen - although diminished4. Macroscopic bleeding present but diminished5. Be ready for the unexpected -New technology presents new situations6. Do simple cases first

THE ARGON LASER

GENERAL DESCRIPTION1. Dual wavelength output:

Blue 488 nmGreen 514 nm very close to KTP 532 nm (pure green)

2. 1 to 2 mm depth of penetration.3. Operates as a coagulation device, not used for cutting4. Argon and KTP pass epidermis to absorb in the dermal hemoglobin selectivelyNd:YAG and CO2 do not absorb in the region of the Hb curve5. Fiberoptic delivery system6. collimated handpiece, freebeam fiber, contact7. Aiming beam is a low power argon beam, hard to see through OD 3 or 5 glasses8. 30 degree divergence on the KTP fiber, 2 degree divergence on the Argon fiber.9. 488 nm filter is used to filter out green component

10. Hemoglobin Absorption is a bimodal curve11. Ideally the wavelength should fall on the peak absorption of this curve and bemaximally transmissible through other tissues

MECHANISM OF ACTION1. Chromophores on the bottom of the foot are minimal2. They pose little problem because the epidermis, dermisbasal layer is transparent to this wavelength3. Absorption at this wavelength is low


24/34

first absorbed in the hemoglobin within the vessels of the reticular dermis4. vessels are stenosed via selective photoablation.a. Able to coagulate vessels less than 1 mm in diameter.b. Indicated for tissue coagulation and necrosis procedures (acisional)c. KTP laser, 532 nm can be used also for vascular stenosis.d. Deeper dermal structures, such as capillary hemangioma, other lasers are indicatedfor this such as the free beam Nd:YAG.

EYE PROTECTION1. Optical Density (O.D.) minimum of 5 at 488 nm.2. Unfortunately, these glasses block out the aiming beamThe aiming beam is a low level intensity treatment beam.3. Visible light eye protection radically alters the colors of the surgical field

SURGICAL APPLICATIONSINDICATIONS FOR THE ARGON LASER1. This treatment is very useful for incisionless surgeryIt is highly favored by the patient,

particularly in the large verrucae on the plantar aspect of the foot and the posterioraspect of the heel normally a CO2 laser would leave an ulcerative defect Immediateshoe gear2. Multiple disseminating lesions or mosaic warts on the plantar foot3. Vascular lesions of a superficial nature 4. Patients having communicable diseases when a bloodless field is desired5. It is not indicated for highly fibrotic and scarred verrucoid lesions. Scar tissuetransmits this frequency giving a painful result

ADVANTAGES

1. Minimal exposure to blood--this is an incisionless procedure.2. Decreased laser plume about 5% of that with CO2 laser A smoke evacuator is stillrequired3. Good treatment for immunocompromised patients4. Faster than CO2 laser, i.e. a 45 minute procedure for the CO2 laser forverruca plantaris would take 5 minutes with the Argon laser5. It is repeatable6. Sterile preparation unnecessary.Surgeon still should be gloved for isolation from lesion contaminants.

ARGON LASER DESTRUCTION OF VERRUCA

1. Object = delivery of energy to the superficial dermis - papillary plexus These are thevessels feeding the wart.The wart is an epidermal structure, not a dermal structure. It is however fed by vesselsfrom the dermis.2. Anesthesia peripheral to lesions and without epinephrine3. Thick sections of epidermis should be debrided previous to treatment This minimizesepidermal carbonization.4. Inject peripherally - do not blanch skin from the injection pressure5. Collimated handpiece is used with 600 nm to 1 mm diameter fiber


25/34

6. 5 degree to 30 degree divergence. Focusing handpieces are available.7. Bare fiber is held 1-2 cm from tissue8.2-4 mm spot, 5.5 watts, 0.5 seconds for the plantar foot.May be used continuous mode and brushed when a good technique is adapted.9. Selection of appropriate power density is very important.3 watts for thin skin, 6.5 watts for thick skin10. Include 2 - 3 mm border peripheral to the wart,11. Carefully check this tissue for a "blanching effect".12. Allow for a 3 to 5 second delay in this blanching13. This is a result of the coagulationof the superficial dermal vessels. No vaporization occurs

NOTES:1. Some carbonization is normal in thick epidermisAvoid charring this by continuous circular motions.2. When blanching occurs, this is the proper setting.Also the proper rate of hand piece movement.3. This is a time dependent phenomena.

4. After the vasculature is coagulated the chromophores have absorbed the wavelength.5. If blanching is not encountered, do not increase power,do not slow down handpiece movement.6. Repeat the same movement of the handpiece over the area.7. When proper parameters are determined, continue treatment beyond the test area.8. The result is not only power and spot size, giving P.D., but time dependent.

POSTOPERATIVE CARE1. Accommodative pad prnNo dressing necessary.Patient can put his shoe and sock on and walk out of the operating room.

2. Hydrocodone 2.5 mg i-ii Q 4-6 h prn pain3. Blistering likely to occur in 3 to 5 days.Patient may incise and drain this at home.After I&D, patient is to leave the skin on, for a protective barrier.4. At one week a black necrotic skin component will formThis lasts 3 weeks and spontaneously sheds.5. Check patient in 3-4. Recheck in 10 weeks.6. Should fully heal within 4 to 5 weeks.No scarring should be seen.A slight hypopigmentation may be observed.7. Ulceration is not possible with this laser as the chromophores, hemoglobin

and oxyhemoglobin stops the absorption in the superficial papillary plexus.

THE KTP LASERGENERAL CHARACTERISTICS1. Very similar to Argon laser. Single wavelength 532 nm (v. 514 nm Argon).2. Difference: KTP can cut tissue, contact mode3. Very useful in selected tissue (below)4. A frequency doubled Nd:YAG laser5. Blanching of the skin also seen similar to the Argon laser


26/34

6. Note indications for vascular tumors:Argon superficialKTP moderateNd:YAG (bare fiber) deep

7. Absorption coefficient is slightly increased over the ArgonA.C. - The distance it takes for the radiation to diminish 90% in tissue.8. Contraindicated in surgery in close proximity (0.5 cm) to thin cortical boneVessels of the bone will absorb this wavelength, necrose vascular supply9. Contact mode and free beam mode

FIBER PREPARATIONFiber preparation is done previous to each case1. Fiber must be cleaved:a. Optical fibers have a crystalline natureb. A cleaver is used to penetrate the sheath and score the fiber cortex this sets up astress riser so the fiber can be snappedc. the end of the fiber is inspected for a flat, even surfaceemitted laser light should be circular and symmetrical

d. The sheath must be stripped.e. 4 mm recommended by manufacturer, but emits too much lateral lightf. so strip 2-3 mm instead, but enough so the sheath doesn't meltg. So leave it to Cleaver to strip off the sheath for fiber preparation

SURGICAL APPLICATIONSKTP TREATMENT OF VERRUCA1. Same as for Argon2. Treatment is slightly deeper3. Blanching is similar but has more significance of penetration depth

KTP APPLICATIONS TO PLANTAR FASCIOTOMY1. MECHANISM OF ACTIONa. KTP is a nonthermal laserb. Selective wavelength absorptionc. Operates in contact mode by specific photoablation of protein and hemoglobin.d. Pericalcaneal tissue = adipose, muscle, and plantar fasciaAdvantage - transmission through clear adipose.Advantage - plantar muscle contact - very little bleedinge. Muscle is highly vascular and plantar fascia is separated offUsually muscular bleeding is considerableAbsorption in muscle is superficial - stopped by Hb

f. Lower power levels required

2.. THERMAL LASER PROBLEMS INDICATING KTP LASERa. Thermal lasers, C02, Nd:YAG --> adipose photohydrolysis and liquefactionb. This water and fat liquefaction interferes with laser cuttingc. Disadvantage CO2 laser - strongly absorbed by water and no cutting occursd. Disadvantage Nd:YAG laser - water transmits and energy is disseminated.e. Surgical site in heel spur work is deep and visibility must be optimizedParticularly with endoscopic size incisions


27/34

3. DISADVANTAGES OF KTP LASERa. Retinal hazardb. Fiber preparation before every casec. Cannot dissect in close proximity to boned. Inefficient laser - requires dedicated 220 V 50 A linee. Larger zone of necrotic damage and zone of coagulation than the CO2f. Takes a long time to dissect through vertical septa and plantar fasciag. Must take care not to deliver much energy into muscle (well absorbed)h. Learning curve


28/34

OTHER SURGICAL LASERSOther medical lasers available with properties, delivery systems unique to each Podiatryis already using these, but be familiar with basic lasers first

Ho:YAG LASER1. a near-contact laser being used for resecting calcaneal spurs2. good for endoscopic and arthroscopic work3. transmits through water4. also indicated for cartilage ablative procedures for joint restoration

COPPER VAPOR LASER1. Known largely for treating port wine stainand congenital cutaneous vascular pathologies2. Two wavelengths - yellow and green3. yellow for superficial vascular4. green for deeper vascular5. dermatological surgery6. very inefficient, large laser, long warmup period

Q-SWITCHED LASERS1. used to be used in ophthalmic procedures2. Q-switched Ruby and Q-switched Nd:YAG for tatoo removal3. no anesthesia necessary4. multiple treatments necessary5. little scarring results, mild hypopigmentation

EXCIMER LASER1. UV laser, 0.2 mm absorption2. Ionizing radiation

3. Cardiac catheterization, osteotomy, corneal sculpting4. High frequency, short wavelength means high precision

Er:YAG LASER1. Mid infrared, 0.1 mm absorption2. Bone surgery3. Difficulty in fiberoptic delivery - fragile and toxic


29/34

BIBLIOGRAPHY

1. Arndt, Kenneth A., "Argon Laser Therapy of Small Cutaneous Vascular Lesions",Journal of the American Academy of Dermatology, vol. 118, April 1982, pp. 220-224.

2. Borovoy, Mathew; Fuller, Terry A.; Elson, Lawrence M.; Laser Safety in Podiatry", TheJournal of Foot Surgery, 1985, vol. 24, no. 2, pp. 136-138.

3. Borovoy, Mathew; Klein, Jeffery T.; Fuller, Terry A.; "Carbon Dioxide LaserMethodology for Ablation of Plantar Verrucae", vol. 24, no. 6, 1985, pp. 431-437.

4. Cacciaglia, G.B.: Reigelhaupt, R.W.; "Effectiveness of Lasers on Plantar Papillomas:A Preliminary Study", Journal of Foot Surgery, vol. 24, no. 1, 1985, pp. 477-481.

5. Carlson, Bruce A., and Pyrcz, Robert A., "Lasers in Podiatry and Orthopaedics",Nursing Clinics of North America, v. 25, No. 3, September 1990, Pg. 719-723.

6. Carlson, Bruce A.; Pyrcz, Robert; "Human Papilloma Virus-Induced Lesions: TheirTreatment and the Evolution of an Alternative Laser Application", Current PodiatricMedicine, November 1989, pp.9-12.

7. Carlson, Bruce A., "Complications Associated with Laser Surgery", Clinics in PodiatricMedicine and Surgery, vol. 4, no. 4, October 1987, pp. 823-828.

8. Chromey, Paul A., "The Significance of Power Density in Applying the CO2 Laser",Current Podiatric Medicine, September 1986, pp. 20-22.

9. Chromey, Paul A., "The Application of CO2 Laser to Soft Tissue Tumors", CurrentPodiatric Medicine, May 1986, pp.24-27.

10. Collis, Sheldon; Rowland, Roberta N.; "Lasers For Podiatry Principles andLanguage", Current Podiatry, April 1984, pp. 33-34.

11. Kaplan, Isaac, "The CO2 Laser In Clinical Surgery: Past, Present, and Future",Journal of Clinical Laser Medicine and Surgery, pp. 341-343, vol. 9, no. 5, 1991.

12. Kelly, Peter F.; "Nd:YAG Contact-Tip Laser Reduces Pain from Foot Surgery",Clinical Laser Monthly, Volume 10, No. 1, January, 1992.

13. Kelly, Peter F., "Nd:YAG Contact Tip V. Cold Steel Applications in Podiatric Foot and

Ankle Surgery", American Society for Laser Medicine and Surgery, Supplement 4, 1992.

14. Kelly, Peter F.; "The Light Scalpel - Nd:YAG Laser Contact-Tip", Issue 24, 1992, TheLaser Letter, International Society of Podiatric Laser Surgery, Doylestown, PA.

15. Kelly, Peter F.; "The Nd:YAG Laser for the Podiatric Surgeon", The Laser Letter,Issue 25, 1992, International Society of Podiatric Laser Surgery, Doylestown, PA.


30/34

16. Kelly, Peter F.; "KTP Laser Application to Calcaneal Spur Surgery", Clinical LaserMonthly; Volume 11, No. 3, April, 1993.

17. Kelly, Peter F., "KTP Laser Application to Calcaneal Spur Resection and PlantarFasciectomy", American Society for Laser Medicine and Surgery, Supplement 5, 1993

18. Landsman, Mark J.; Mancuso, John E.; Abramow, Steven P.; "Laser's Use in Boneand Joint Surgery, Clinics in Podiatric Medicine and Surgery, vol. 9, no. 3, July 1992, pp.721-737

19. McDowell, Brian A., "Carbon Dioxide Laser Excision of Benign Pedal Lesions,Clinics in Podiatric Medicine and Surgery, vol. 9, no. 3, July 1992, pp. 617-632.

20. Mueller, Terrance J.; Carlson, Bruce A.; Lindy, Marc P.; "The Use of the CarbonDioxide Surgical Laser for the Treatment of Verrucae", Journal of the American PodiatryAssociation, vol. 70, no. 3, March 1980, pp. 136-141.

21. Nicholson, Ronald A., "Two Techniques Described using C02 Laser for

Matrixectomy", Laser Practice Report, vol. 7, no. 7, pp. 1 S-2S.

22. Pyrcz, Robert A.; Carlson, Bruce A.; "Lasers in Podiatry and Orthopedics", NursingClinics of North America, vol. 25, no. 3, September 1990, pp. 719-723.

23. Wasserman, Gerald, "Treatment of Morton's Neuroma with the Carbon DioxideLaser", Clinics in Podiatric Medicine and Surgery, vol. 9, no. 3, July 1992.

SPEED-READING BIBLIOGRAPHY

1. "Continued efforts to enhance the utilization of laser technology and the ability of laser

education at teaching hospitals are key for the future." Lanzafame, Raymond, J.;Hinshaw, Raymond, J.; "Laser Education, Laser Usage, and Surgical Attitudes: AChallenge for the Future", Pg. 279-81, Journal of Clinical Laser Medicine and Surgery,Volume 10, No. 4, 1992.

2. "It (the CO2 laser) routinely provides a bloodless surgical field as well as unusualsurgical precision." Fairhurst, Mark V.; Roenick, Randall K.; Brodland, David G.;Subspecialty Clinics: Dermatology, "Carbon Dioxide Laser Surgery for Skin Disease",Mayo Clinical Proceedings, Vol. 67, Pg. 49-58, 1992.

3. "Thermally induced tissue destruction is accurate with little damage to surrounding

normal tissue because the coherent, collimated, monochromatic beam of light can befocused to a very tiny point using an optical lens system. Histologically, the area oftissue necrosis adjacent to the laser incision is less than 0.1 mm, usually 50-70 microns.This facilitates healing with reduced scarring. The zone of cellular damage varies from0.3 to 0.5 mm." Chromey, Paul A., Current Podiatric Medicine, September 1986, Pg. 20-22.


31/34

4. "Carbon dioxide laser offers many advantages demonstrated in this study, includingminimal bleeding, improved healing, reduced edema, improved postoperativediscomfort, minimal scarring and minimal infection." Cacciaglia, G.B., Reigelhaupt, R.W.,"Effectiveness of Lasers on Plantar Papillomas: A Preliminary Study", Journal of FootSurgery, Vol. 24, No. 1, 1985, Pg. 477-481.

5. "Since the beam affects well defined areas of the skin, there is minimal necrosis ofadjacent tissue; consequently, postoperative pain, edema, and scarring are minimized."Mueller, Terrance J.; Carlson, Bruce A.; Lindy, Mark P.; "The Use of the Carbon DioxideSurgical Laser for the Treatment of Verrucae", Journal of the American PodiatryAssociation, Vol. 70, No. 3, March 1980, Pg. 136-141.

6. "Podiatry started using the laser for the excision of Morton's neuroma and forincisional approaches to bunionectomy and other podiatric procedures." "The sameadvantages were found to be present for incisional procedures: less bleeding, pain, andpostoperative edema." Peyrcz, Robert A., Carlson, Bruce A., "Lasers In Podiatry andOrthopedics", Nursing Clinics of North America, Vol. 25, No. 3, September 1990, Pg.719-723.

7. "Utilizing the CO2 laser in neuroma surgery for making incisions and sealing the nervestump decreases postoperative pain and healing, allowing patients to resume normalambulation faster than with conventional scalpel surgery." Wasserman, Gerald, Clinicsin Podiatric Medicine and Surgery, "Treatment of Morton's Neuroma With the CarbonDioxide Laser", Vol. 9, No. 3, July 1992, Pg. 671-686.

8. "The contact method of performing endoscopic and open surgery with the Nd:YAGlaser opens a new era in laser surgery ... with cutting capabilities previously only seenwith the CO2 laser." "The CO2 laser operating at a wavelength of 10,600 nm with energyoutputs of 100 watts is effective at cutting and coagulation of SUPERFICIAL blood

vessels." Joffe, Stephen N.; Schroder, Tom; Lasers in General Surgery, Year BookMedical Publishers, Inc., Laser Center of America, Cincinnati, OH, Pg. 125-130, 1987.

9. "We concluded that CO2 laser surgery for hemophiliacs has a confirmed place formodern laser technology." Santo-Dias, A.; "CO2 Laser Surgery in HemophiliaTreatment", Journal of Clinical Laser Medicine and Surgery, Pg. 297-301, Volume 10,No. 4, 1992.

10. "Because of the large amount of water in body tissue, this laser (CO2) will cause avaporization of the tissue at the focal point and seal the small blood vessels andlymphatics. The laser creates an incision that leaves residual tissue undamaged."

Kaplan, Isaac; "Twenty Years of CO2 Laser Surgery: A Review and Update", Journal ofClinical Laser Medicine and Surgery, Pg. 57-60, Volume 11, No. 2, 1993.

11. "Certain advantages of the use of the CO2 laser stand out: absence of hemorrhageand cellular vaporization which permit, due to a perfect visibility, appreciation at everymoment of the quantity of tissue that needs to be removed." Dourov, Nicolas; Nammour,Samir; "Removal of Benign Tumors Using the CO2 Laser", Journal of Clinical LaserMedicine and Surgery, Pg. 109-113, Volume 10, No. 2, 1992.


32/34

12. "This action results in a fine hemostatic incision leaving the residual tissue relativelyundamaged." "The treated areas heal rapidly because the skin appendages escapepermanent damage." Kaplan, Isaac; "The CO2 Laser In Clinical Surgery: Past, Present,and Future", Journal of Clinical Laser Medicine and Surgery, Pg. 341-343, Volume 9,No. 5, 1991.

13. "Surgical laser technology has been available for nearly 30 years and is being usedincreasingly in many surgical disciplines including orthopedic surgery." Cahill, Sandy;Kopta, Joseph A.; Kosanke, Stanley D.; Rayan, Ghazi M.; Stanfield, Denver T.; "Effectsof Rapid Pulsed CO2 Laser Beam on Cortical Bone In Vivo", Lasers in Surgery andMedicine, Pg. 615-620, Volume 12, No. 6, 1992.

14. "The lack of wound contraction, scarring, and good reepithelialization combined withprecise tissue destruction makes CO2 laser surgery ideal for this procedure whencompared with conventional techniques." Keng, S. B.; Loh, H. S.; "The Treatment ofEpulis Fissuratum of the Oral Cavity by CO2 Laser Surgery", Journal of Clinical LaserMedicine and Surgery, Pg. 303-306, Volume 10, No. 4, 1992.

15. "The advantage of the CO2 laser technique was that it produced minimal thermaldamage to the surrounding tissues." Fallouh, Hayel; Sultan, Raymond A.; "CombinedCO2-Nd:YAG Radiation in Liver and Anorectal Diseases", Journal of Clinical LaserMedicine and Surgery, Pg. 255-263, Volume 10, No. 4, 1992.

FURTHER READING

1. Sherk, Henry H., Editor, Lasers in Orthopaedics, J.B. Lippincott Company,Philadelphia, PA, 1990.

2. Ballow, Edward B., D.P.M., Editor, Laser Surgery of the Foot, First Edition,

International Society of Podiatric Laser Surgery, Doylestown, PA, 1988.

3. Joffe, Stephen N.; Schroder, Tom; Lasers in General Surgery, Year Book MedicalPublishers, Inc., Laser Center of America, Cincinnati, OH, 1987.

4. "Lasers In Podiatry and Orthopedics", Nursing Clinics of North America, Vol. 25, No.3, September 1990.


33/34

PHOTODYNAMIC THERAPY "PDT"

MECHANISM OF OPERATION1. Requires an injection, dissemination and systemic absorption of protoporphyrins2. Malignant cells take up the protoporphyrinThese can be visualized under UV lightPatient must remain away from all light during this treatment session and have aphotosensitivity up to six weeks post treatment3. Laser radiation is applied at a specified frequency, usually red light area. and for aspecified time - result is Joules to tissue4. Wavelength depends on protoporphyrin5. Results is a single oxygen produced which destroys malignant tissue selectively

BIOSTIMULATION "BIOSTIM"1. A few milliwatts hitting mitochondria stimulating thermal mechanism.2. No heat is produced.3. Mitochondrial chromophores.4. This is FDA investigational.

5. Applied to wound healing, to nerve regeneration, and chronic pain--analgesic.6. Elicits a systemic effects7. 0 milliwatts, tunable dye, helium-neon, 12 joules per week for 30 weeks8. Applied to rheumatoid arthritis, trigeminal neuralgia, osteoarthritis, sciatica, diabeticneuropathy.9. Has 60 to 85% of pain relief10. 5-hydroxyindolacetic acid, 5-HIAA producedUrinary HIAA output increase correlated with pain relief11. Systemic effects:stimulation of human lymphocytesDecreased pain and inflammation of distant ion irradiated sites Increased urinary 5-

HIAA, product of serotonin metabolism12. Dose:50 milliwatts, tuneable dye or helium-neon laser, 12 joules per week for 30 weeks.13. Proposed mechanism:absorption of light by photoreceptor or chromophore in the mitochondria activates therespiratory chain, resulting in a cellular response.14. Primary process:a. Electron train excitationb. acceleration of electron transfer in redox pairs (activates and stimulates).c. Transfer of excitation energy from oxygento single oxygen (oxidative effect inhibiting healing).

d. Respiratory chain components are probably the primary photoacceptors.e. Flavins, cytochromes, cytochrome oxidase.f. Respiratory chain in a unitary dynamic system can be acted uponat various points causing change in the whole state of response.Summary:1. Effects are dose dependent. Higher energies seem to be damaging.2. Coherent light is preferred versus non-coherent.3. Narrowed band monochromatic light preferred, i.e. helium-neon coherent andmonochromatic light


34/34

4. Competing wavelengths cancel the effects, therefore coherent light is preferred.5. Transcutaneous irradiation penetrates deeply enough toproduce generalized effect in many cases.6. 4 joules/cm2 penetrates approximately 1 cm.7. Local radiation with systemic effects.i.e., 5-HIAA production from serotonin metabolism.8. Depends upon the physiological status of cell before radiation.9. The biostimulation effect is not always possible.

Date post:	30-May-2018
Category:	Documents
Upload:	poddata
View:	216 times
Download:	0 times

Hersheychapter 37

Documents