- THIS MATERIAL IS PUBLISHED AND PROTECTED BY U.S. COPYRIGHT LAW - REPRODUCTION PROHIBITED UNLESS FOR PERSONAL USE, EXCEPTING AUTHOR PERMISSION - Peter F. Kelly, D.P.M., F.A.C.F.A.S. Diplomate, American Board of Podiatric Surgery Fellow, American College of Foot and Ankle Surgeons CHAPTER 37 LASER APPLICATIONS IN PODIATRIC SURGERY TABLE OF CONTENTS LASERS AND LASER PHYSICS HISTORY UNITS OF MEASUREMENT FUNDAMENTALS UNIQUE CHARACTERISTICS OF LASER LIGHT COMPONENTS OF A LASER LASER V. CONVENTIONAL PHOTONIC RADIATION THEORY of LASER OPERATION REALATION OF LASER LIGHT V. CONVENTIONAL LIGHT DELIVERY MECHANISMS TRANSMISSION MODES TISSUE INTERACTION TRANSMISSION CHARACTERISTICS THROUGH TISSUE CLINICAL TISSUE INTERACTION PHENOMENA POWER DENSITY WATTS PER CM2 Chart TIME LASERS APPLICABLE TO PODIATRIC SURGERY ----------------------------------------------------------------------------------- LASER SAFETY EYE PROTECTION HAZARDS OF THE LASER SMOKE PLUME ----------------------------------------------------------------------------------- CLINICAL LASER APPLICATIONS IN PODIATRIC SURGERY STANDARD OF CARE THE CO2 LASER PROPERTIES OF THE CO2 LASER ADVANTAGES OF USING THE CO2 LASER SELECTION OF LASER PARAMETERS DISADVANTAGES PROCEDURES PERFORMED USING THE CO2 LASER ASSIST THEORY OF CO2 LASER TISSUE INTERACTION CO2 LASER PROCEDURES TECHNIQUE OF CO2 LASER ABLATION TECHNIQUE OF CO2 LASER FOR INCISION/EXCISION HEMOSTASIS FOCUSED, FREE BEAM LASER APPLICATIONS OVERLASING CAVERNOUS HEMANGIOMA KELOID AND HYPERTROPHIC SCAR LASER ASSISTED OSSEOUS PROCEDURES BONE AND CARTILAGE LASER TREATMENT OF VERRUCA LASER NAIL MATRIXECTOMY POSTOPERATIVE CARE COMPLICATIONS PREVENTION OF COMPLICATIONS FROST AND WINOGRAD TECHNIQUE LASER TREATMENT OF ONYCHOMYCOSIS SUBTOTAL MATRIXECTOMY SUBUNGUAL HEMATOMA LASER TREATMENT OF GRANULOMAS CAUTION IN REVISIONAL PROCEDURES ----------------------------------------------------------------------------------- THE Nd:YAG LASER GENERAL DESCRIPTION MODES OF OPERATION THE CONTACT TIP SURGICAL APPLICATIONS ADVANTAGES OF Nd:YAG OVER SCALPEL Nd:YAG MEDICAL INDICATIONS PODIATRIC MEDICAL INDICATIONS FOR Nd:YAG SCALPEL CONTRAINDICATIONS INDICATIONS FOR FROSTED AND NONFROSTED CONTACT TIPS INAPPROPRIATE Nd:YAG PROCEDURES GENERAL CONSIDERATIONS IN APPLICATION OF THE Nd:YAG LASER REALISTIC EXPECTATIONS ----------------------------------------------------------------------------------- THE ARGON LASER GENERAL DESCRIPTION MECHANISM OF ACTION EYE PROTECTION SURGICAL APPLICATIONS INDICATIONS FOR THE ARGON LASER ADVANTAGES ARGON LASER DESTRUCTION OF VERRUCA POSTOPERATIVE CARE ----------------------------------------------------------------------------------- THE KTP LASER GENERAL CHARACTERISTICS FIBER PREPARATION SURGICAL APPLICATIONS KTP TREATMENT OF VERRUCA KTP APPLICATIONS TO PLANTAR FASCIOTOMY MECHANISM OF ACTION THERMAL LASER PROBLEMS INDICATING KTP LASER DISADVANTAGES OF KTP LASER ----------------------------------------------------------------------------------- OTHER SURGICAL LASERS Ho:YAG LASER COPPER VAPOR LASER Q-SWITCHED LASERS EXCIMER LASER Er:YAG LASER ----------------------------------------------------------------------------------- PHOTODYNAMIC THERAPY "PDT" MECHANISM OF OPERATION ----------------------------------------------------------------------------------- BIOSTIMULATION "BIOSTIM" ----------------------------------------------------------------------------------- BIBLIOGRAPHY SPEED-READING BIBLIOGRAPHY FURTHER READING LASER APPLICATIONS IN PODIATRIC SURGERY Applications of lasers to medicine and surgery have increased exponentially over the past decade. This technology has become established in the medical community and has become the standard of care for many procedures. Lasers have justified their utilization by the improved clinical outcome in the delivery of comparably more traumatic and 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 having indications unique to the desired tissue response. Fundamental to the surgeon in selecting the wavelength, power and control to produce the intended effect, with safe handling of the instrument, is a knowledge of laser physics for this tissue interaction. CLINICAL LASER APPLICATIONS IN PODIATRIC SURGERY STANDARD OF CARE 1. OPERATIVE REPORT - Include laser type power density calculation. i.e.: "Procedure: Austin Bunionectomy, left foot (Soft tissue with CO2 laser): With the CO2 laser set at 33,000 W/cm2 power density, a linear incision was ..." 2. CONSENT FORM - Include the laser type or wavelength used and the intended application of the laser if there is conventional instrumentation used. i.e.: "(Usual description of surgery), soft tissue with CO2 laser" 3. ETHICS IN ADVERTISING - Differentiate the application of the laser i.e.: "Laser assisted" bunionectomy, or "Laser for soft tissue" Advertise straightforward what laser procedures (warts, nails) are done if also advertising conventional procedures (bunionectomy) that are not performed with laser assistance. Public misconceptions: No incision, laser cuts bone. You will never lose a patient because of an honest disclosure of a procedure. THE Nd:YAG LASER GENERAL DESCRIPTION 1. 1060 nm, near-infrared, separate HeNe aiming beam 2. Most frequently used laser besides the CO2 laser 3. This is a general surgical instrument used most of the time by general, thoracic, plastic, and urology surgeons 4. See absorption chart - Nd:YAG is centered between other common medical lasers 5. Unique characteristic - the "window" of low absorption and high transmissibility YAG is poorly absorbed by hemoglobin, chromophores, protein, or water. 6. 99% of Podiatric use is with contact laser scalpels 7. Able to coagulate vessels < 0.2 mm diameter 8. User friendly, but tip selection, type and size must be understood 9. Power settings are very important 10. Endoscopically/arthroscopically compatible MODES OF OPERATION 1. Non-contact mode - used for debulking and treating deep tumors. higher power levels required i.e.: 40 W 2. Contact-tip mode - highly localized scalpel form similar to CO2 laser lower power i.e.: 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 for deep tumors Contact is used for incision and excisional work. THE INSTRUMENT 1. Instrument is portable, conventional nondedicated power OK2. C.W. mode only3. Flashlamp excites Neodymium-doped crystal of Yttrium, Aluminum, Garnet 4. Fiberoptic delivery system, air or water cooled within the sheath 5. Large variety of handpieces, general surgical one is used 6. Large variety of contact tips, fiber and handpiece combinations THE CONTACT TIP 1. Developed for 3-dimensional feedback, feels similar to a conventional scalpel Better control of dissection 2. Converts light energy from a laser into heat energy. 3. Very precise hot knives, tissue effect 50-200 microns 4. Types of conical tips: Frosted, clear, ceramic, titanium coated There are many combinations of tips: 1. Sapphire scalpels interchangeable - screw onto handpiece 2. Integrated quartz tips with fiber and handpiece also used 3. Scalpel must be in contact with tissue when power on or flare out of expensive tip will occur 4. Flare-out threshold temperature: Sapphire scalpel - 2000 degrees F Quartz scalpel - 1000 degrees F 5. Tip shapes - Chisel, flat, round, cylindrical, hook a. Long or short conical used in Podiatry b. Tapered conical tip concentrates energy c. Polished lense at distal end d. Available radii are 0.2-1.2 mm diameter i. when calculating P.D. don't forget diameter -> radius ii.and mm to cm conversions 6. Frosted and nonfrosted available a. Frosted - distal end roughened to allow lateral radiation except at lense and allows coagulation during dissection b. Nonfrosted - tip is clear i. radiation only at distal lense ii. appropriate for very fine dissection at low power levels c. Procedures are scalpel specific SURGICAL APPLICATIONS LASER SCALPEL STEEL SCALPEL Rapid dessication Controlled crushing Seals small nerves Smears small nerve endings Seals small vessels No microcoagulation Cell necrosis is small Cell necrosis is moderate Cuts with Light Energy Cuts with physical pressure High precision Normal tactile feedback ADVANTAGES OF Nd:YAG OVER SCALPEL 1. Less postoperative pain 2. Less bleeding of smaller vessels/lymphatics - less swelling 3. Sterilizes surgical site reducing chance of infection 4. Less cell necroses 5. Less fibroblastic stimulation - faster tissue remodeling Nd:YAG MEDICAL INDICATIONS 1. Situations contraindicating tourniquet particularly where a dry field is essential 2. Dissection of delicate tissue planes in all axis requiring contact 3. Patients where surgical trauma may stimulate adverse reactions Collagen-vascular disease (i.e.: SLE), gout, R.A., etc. 3. Patients with platelet, hematogenous and vessel disease, sickle cell, phlebitis 4. Elderly patient exhibiting capillary fragility PODIATRIC MEDICAL INDICATIONS FOR Nd:YAG SCALPEL 1. The Nd:YAG laser scalpel decreases the surgical pathophysiology of a. edema in a dependent extremity b. leakage of intravascular fluid in the surgical site of the foot from hydrostatic pressure c. nerve microtrauma and axonal depolarization d. local surgical cell necroses (v blade) e. scar formation f. nosocomial infection 2. Extremity surgery a. Hydrostatic pressure of lower limb b. terminal perfusion, and c. weightbearing structure undergoing surgery are all indications 3. Hypertensive patient with peripheral edema 4. Plastic reconstruction 5. Wet cases 6. Cases where visualization must be optimized i.e.: Nerve decompression within ganglion complex 7. Any situation where cell necrosis must be minimized CONTRAINDICATIONS Defer these cases until the learning curve plateau is reached 1. Digital surgery - cannot justify utilization Instrument overkill for procedure 2. Revisional surgery - actually indicated but these surgeries carry a higher risk by default If successful laser gets the credit If not successful surgeon gets blamed Public expectations of lasers are high 3. Any bone work - not FDA approved This is not a wavelength for this 4. Medical-Legal cases - Same idea as revisional Surgery 5. Amputation - Same idea as revisional surgery 6. PVC cases - Same idea 7. Acute Trauma cases - no time to call in laser team INDICATIONS FOR FROSTED AND NONFROSTED CONTACT TIPS PROCEDURE CONTACT-TIP COMMENT Nerve releases and Neuroma Nonfrosted Thermal Radiation Neurectomy Nonfrosted Lateral Radiation Bunionectomy (soft tissue) Frosted Limit capsular dissection Ganglions Nonfrosted Particularly those adjacent to muscle Tendon transplants/lengthening Nonfrosted Long remodeling time Heel spur (soft tissue) Frosted Excellent visualization Plantar Fasciotomy Nonfrosted Around calcaneus only General Podiatric Surgery Frosted Coagulation during dissection INAPPROPRIATE Nd:YAG PROCEDURES 1. Wrong tip = wrong procedure i.e. Neuroma sx with frosted tip Induces thermal periostitis in adjacent metatarsals This can be done with frosted at short power applications 2. Nail matrixectomy = burns periosteum use CO2 3. Warts = can use, but it's more easily treated with CO2 4. See contraindications GENERAL CONSIDERATIONS IN APPLICATION OF THE Nd:YAG LASER 1. Drapes are dry. Water transmits this wavelength. 2. Separate mayo stand for fiberoptics with expensive tips and power equipment 3. Notch filter glasses are the best eyewear protection, best visibility 4. Select general surgery handpiece 5. Select tip size and frosting based on presurgical plan 6. Laser nurse will connect fiberoptics to launch pad on laser 7. Calibrate instrument and hand off calibration cone, now contaminated Select power level, C.W. mode 8. Incision is made with a steel blade only to the dermis When you see the whiteness of the dermis - stop Contact tip is held 45 degrees to tissue New frosted tips need 2 seconds at full power to "age" 9. Traction - countertraction throughout procedure 10. Room suction to be used for the minimal smoke plume much less than CO2 laser 11. Deeper dissection now before using forceps Use traction - countertraction 12. Dissect in linear strokes. Avoid burying the tip. This laser needs less pressure than a steel blade Tactile feel is like a hot knife through butter So let the laser do the work 13. Repeat dissection strokes until each plane of tissue is complete 14. Dissection may be adjacent to vessels, stay 3-4 mm from nerves at high power levels 14-16 W 15. Hemostasis of larger vessels can be with the laser alternate on either side, observe coagulation 16. Capsular dissection may be made right over cartilage with no damage to cartilage 17. Dissect only the periosteum/capsule you intend to discard Good hemostasis, but seals off periosteal vessels 18. Remainder of capsule/periosteum done with blade 19. Bone work with conventional power instrumentation 20. Watch on-time during intermetatarsal neuroma surgery Avoid thermal periostitis in adjacent metatarsals 21. Seal nerve endings in neuroma sx. with the contact tip Prevents stump neuroma formation 22. Minimal char formation seen Very dry and atraumatic surgical site seen 23. Closure is conventional, dressings conventional 24. Sutures remain in a few days longer Expect macroscopic bleeding due to tourniquet reflux hyperemia REALISTIC EXPECTATIONS 1. Learning curve is steeper than CO2 Laser 2. Postoperative bruising still seen 3. Swelling, and pain still seen - although diminished 4. Macroscopic bleeding present but diminished 5. Be ready for the unexpected - New technology presents new situations 6. Do simple cases first