Laser in ENT

LASER IN ENT

1. Lasers in ENT Dr Disha sharma ENT-HNS IGMC Shimla

2. introduction light amplification by stimulated emission of radiation

3. Albert einstein theodore Maiman C.Kumar N.Patel

4. Strong and jako

5. Principles of Laser Electrons in the atoms of the laser medium are first pumped to excited state by external energy source. Electrons are stimulated by external photon to emit their stored energy in form of photons – STIMULATED EMISSION

6. Photons now strike other excited atoms to release even more photons . Photons move back and forth between two parallel mirrors LIGHT AMPLIFICATION.

7. Properties of laser light Monochromatic .A single pure color emitted by a single wavelength Collimated .A beam in which all photons travel in same parallel direction coherent .All waves or photons travel in steps, or in phase with one another.

8. Types of Lasers Solid : Nd : YAG laser Liquid : Organic dye laser.( rhodamin 6G , disodium fluorescein) Gas : Helium Neon ( HeNe ) laser, CO2,Argon and Krypton Gas laser. Semiconductors : Gallium-Arsenide -Diode laser Excited dimer ( Eximer Laser) : Argon fluoride and Krypton fluoride

9. Patterns of laser output Continuous : continuously pumped ,emits light continuously • Pulse : laser energy delivered with each peak over an extremely short period of a few nanoseconds with rest period (allows time for tissues to cool down ) • Q-switched : Allows a high build-up of energy within the tube which is then released over a very short duration of a few nanoseconds

10. Cavity dumped Lasers- produces slightly shorter pulse of light Mode locked lasers- produces pulses of light as short as few pico seconds.

11. Control of the surgical laser Power Spot size Exposure time

12. Tissue effects Absorption Scattering Reflection transmision

13. Basic laser tissue interaction Photothermal Photomechanical Photochemical Photoablative

14. • When laser radiation strikes a tissue, the temperature begins to rise • 10 0 C – 45 0 C : Conformation change of proteins • 50 0 C : Reduction of enzyme activity • 60 0 - 99°C : Coagulation begins • 100°C and above : Vaporization starts • 400 0 -500°C : Char starts to burn

15. Argon Lasers 488 - 514 nm wavelength (Blue green spectrum ) in visible spectrum. Oxyhemoglobin is target chromophore . Small spot size (0 . 1 – 1 mm) , variable in size and intensity . Flexible delivery system Mainly used in ophthalmological procedures.

16. Selective absorption of light from Laser to photocoagulate pigmented lesion such as port wine stains, haemangiomas and telangiectasias . Stapedotomy in otosclerosis

17. Argon tunable Dye Laser High intensity beam that is focused on dye that continously circulates in a second layer optically coupled with the argon laser. Photodynamic therapy injection of photosensitizer hematoporphyrin derivative. Therapy for malignant tumors .

18. Limitations – Also absorbed by epidermal and dermal tissues due to melanin Continuous mode of operation Higher fibrosis prevalence of postoperative pigmentary alteration

19. CO2 Laser 10,600 nm wavelength Built –in coaxial helium neon Laser is necessary. Highest power continuous wave laser used for cutting or ablating tool using water as target chromophore Focus to <500 mm and seals blood vessels less than 0.5 mm Pulsed to accommodate thermal relaxation time (less pain and less edema ) Used in majority of procedures except those requiring coagulation of larger vessel

20. Comparatively a poor hemostat (not being effective in controlling bleeding from vessels greater than 0.5 mm in diameter ) Not transmissible through the common optical fibre Its use on the cords has the advantage of producing minimal scarring therefore glottic competency is rarely jeopardized

21. Uses of Co2 Laser Laser stapedotomy Recurrent respiratory papillomatosis In paediatric patients surgery for web , subglottic stenosis, capillary hemangiomas . Laser cordotomy , arytenoidectomy . Malignant & benign laryngeal tumours. Transoral robotic surgery.

22. Nd : YAG Laser (Neodymium-doped Yttrium Aluminum Garnet) 1064 nm wavelength with Helium-Neon (He-Ne) beam Solid state laser with fiberoptic carrier Deeper penetration (up to 4 mm) Radiant energy transmitted through clear fluid used in eye and water filled cavity urinary bladder. Ideal laser for ablation, coagulation and hemostasis in vascular malformations

23. Use in ENT Ablation palliation of obstructing tracheo bronchial lesion, oesophageal lesions. Removal of malignant tumors in oral cavity. Obstruction of tracheobronchial tree – complication hemorrhage - ND-YAG laser deep penetration

24. Limitations Greater scatter than CO2 Deep thermal injury Risk for transmural injury

25. KTP Laser ( Potassium - Titanyl -Phosphate) 532 nm wavelength with Oxyhemoglobin as primary chromophore • Continuous wave (CW) mode to cut tissue • Pulsed mode for vascular lesions. • Q-Switched mode for red/orange tattoo pigment • Delivery • Insulated fiber , fiber handpiece , scanner, or microscope for CW/pulsed mode • Articulating arm for Q-Switched mode

26. Use Tosillectomy Pigment dermal lesion Revision stapedotomy Limitation – unintended thermal injury

27. 585-NM pulsed dye laser Used in larynx absorption peak 577nm Targeted chromophore is oxyhemoglobin Papilloma ,vascular polyps, varices and vocal fold polyps Unlike CO2 laser ablation effects pulsed dye laser causes involution of lesion through disruption of vascular supply . Reduced risk of collateral thermal injury

28. Delivery system Articulated arm Mirror lens system Hollow wave guides Micromanipulator Fibreoptic fibre Fibre tip Robotic scanner

29. Articulated arm use system of hollow Tubes & mirrors to direct Laser beam to tissue. Micromanipulator F ocussing device connected To microscope create an Accurate &reproducible spot On target tissue

30. Fibre optic cable Inserted through biopsy channel of a fibreoptic endoscope. End of laser fibre must protrude beyond the end of endoscope. Preliminary check of the length of fibre required to achieve a satisfactory distal position.

31. Hollow wave guide fibre tip

32. Class 1 lasers pose no safety hazard (e.g., a CD player ). Class 2 lasers emit only wavelengths in the visible range of the spectrum and are not hazardous even when shined directly into the eye(helium-neon laser pointers). Class 3a lasers are hazardous to the eye . class 3b and 4 laser, looking directly into the beam close to its emergence from the applicator can injure the eye regardless of the lens systems used . . Medical lasers are in classes 3b and4

33. Safety considerations Education- 1 appropriate credential certifying mechanism required for physician, nurses to become involved with each. 2 Develop education policies for surgeon anaesthesiologist and nurses 3 periodic review of all laser related complications

34. Eye protection & skin protection Lasers absorbed by water (e.g., CO2) damage the anterior portions of the eye (cornea, lens ) wavelengths in the visible and NIR range (e.g., argon and Nd:YAG lasers) pass through the optical media of the eye and damage the retina. Wavelenght specific protected eye glass with side protectors Double layer of saline moistened eye pad . Saline saturated surgical towel completely drape

35. Smoke evacuation Seperated suction set up in aerodigestive tract One for Smoke and steam evacuation from operative field Constant suctioning prevent inhalation by patient surgeon or personnel.

36. Anaesthetic consideration and risk of intraoperative fire. ET tube ignition & injury to larngotracheal mucosa . Tubes are made laser safe in two ways by using: noncombustible or fire-resistant materials such as a metal spiral tube compressed foam ( Merocel Laser-Guard), which is made laser resistant by moistening . Methylene blue colored saline to inflate cuff

37. An endotracheal tube should be kept out of the operating field if at all possible If this cannot be done, a laser-resistant tube should be used . If a laser-resistant tube cannot be used, the surgeon should be able to identify the tube in the operative field at any time . In this case the part of the tube closest to the surgical site can be protected by covering it with wet neurosurgical cotton. Wrapping the tube with aluminum foil can give a false sense of security and is not advised.

38. 50ml bulb syringe and basin of saline should be available Stop ventilation immediately Withdraw tube and flush saline Re establish airway immediately Bronchoscopy to assess degree of injury I/V steroids Remain intubated Repeat bronchoscopy

39. Keep lasers in standby mode when not in operation Bystanders should remain at a safe distance. Warning sign & locked doors Wear protective glasses (the right kind) in the laser environment Never use the laser as a pointer ( coworkers are not a target) Do not aim the beam at other instruments (reflections) Do not aim the beam at flammable materials (especially the endotracheal tube ) Check your system (be informed)

40. Laser in otology Stapes surgery chronic hyperplastic mucosal suppuration Cholesteatoma tympanosclerosis malleus fixation adhesive processes external auditory canal exostoses vascular lesions of the middle ear . tympanic membrane -middle ear ventilation problems, transtympanic endoscopy, and the treatment of perforations inner ear- peripheral vestibular disorders , tinnitus and sensorineural hearing loss .

41. Three types of continuous-wave (CW) thermal laser are currently used in otologic surgery : the argon laser the KTP laser CO2 laser The Er:YAG laser is a pulsed laser that produces an oligothermal tissue effect.

42. Laser Use in the External Auditory Canal Vascular Lesion - hemangiomas and telangiectasias of the external auditory canal with argon laser light . Polyps and Granulations Exostoses : Er:YAG laser Stenoses : co2 laser Debulking Inoperable Tumors

43. Laser Use on the Tympanic Membrane laser myringotomy : CO2 and Er:YAG lasers opening of at least 2 mm should be created with the CO2 laser Secretory Otitis Media Acute Eustachian Tube Dysfunction Barotrauma Acute Otitis Media With Vestibulocochlear Complications Transtympanic Endoscopy

44. Laser myringotomy

45. Tympanic Membrane Perforations and Atrophic Scars Graft Fixation for Tympanic Membrane Defects epidermoid Cysts of the Tympanic Membrane

46. Laser Use in the Middle Ear Medialization of the Malleus co2 laser for dividing scar tissue and exposing the malleus . Resecting the distal third of the malleus handle Malleus Fixation vaporization of the malleus neck or sclerotic foci around the malleus head with the laser can mobilize the chain Tympanosclerosis : on the tympanic membrane and on the ossicular chain and its surroundings causing fixation and obliteration of the window niches can be removed

47. Chronic Otitis Media Cholesteatoma Vascular Lesions (glomus tumour)

48. Otosclerosis Using a drill to perforate a thick footplate obliterating the oval window niche (as in obliterative otosclerosis ) can cause harmful vibrations to be transmitted to the inner ear. goal of laser stapedotomy is to create a precise opening while protecting the inner ear and avoiding damage to the remaining middle ear structures CO2 laser CW mode . A power of 1–22 W pulse duration of 0.03–0.05 s power density ranges from 4000 W/cm2 to 80,000 W/cm2. A single laser applicationpoduces precise footplate opening 0.5–0.7 mm in diameter .

49. Obliterative Otosclerosis - The CO2 laser can vaporize a fenestra in the stapes footplate, regardless of its thickness or degree of fixation, without mechanical trauma to the inner ear . Overhanging Facial Nerve CO2 laser beam can be carefully applied tangentially at low power (1–2 W), using short pulse lengths of 0.05 s, to remove the bone. a conventional stapedotomy with a curved perforator . redirect the CO2 laser beam with a mirror .

50. Overhanging Promontory: covering the footplate with saline solution or moist gelatin sponge), the bony overhang can be ablated. Inaccessible Footplate due to an abnormal course of the facial nerve or a vascular anomaly fenestration of the promontory Floating Footplate : Laser enables to create a fenestra of the desired diameter even in a floating footplate

51. CO2 Laser Revision Stapedotomy Adhesions are frequently present and are vaporized with the CO2 laser using the safe and effective laser parameters prosthesis is exposed by noncontact vaporization of the fibrous attachments the soft tissue covering the oval window niche is uniformly vaporized Once the distal end of the prosthesis has been cleared of all fibrous attachments, it is detached from the incus and extracted with a 90° hook 2 mm long . tissue at the center of the oval window is then uniformly vaporized incus is badly eroded, a malleovestibulopexy done

52. Laser Use in the Inner Ear Cochleostomy Laser cochleostomy inserting the electrode of a cochlear implant. effective for an ossified cochlea Peripheral Vestibular Disorders:

53. Tinnitus and Sensorineural Hearing Loss Low-level laser therapy Acoustic Neuroma : availability of fiberoptic delivery; spot size focusable to 0.15 mm, free passage of argon laser light through media such as cerebrospinal fluid, and good hemostatic effect of the argon laser wavelength. pulsed holmium:YAG laser for the removal of cranial and spinal meningiomas and neuromas

54. Laser in rhinology Intranasal Laser Applications Turbinate Reduction enlarged inferior nasal turbinates secondary to allergic or vasomotor rhinitis Thermal damage due to laser energy causes scarring of the mucosal epithelium. in the submucosa, reduces the swelling capacity and secretory functions of the turbinate. Laser surgery of hypertrophic inferior turbinates is appropriate only if the obstruction is largely due to severe mucosal swelling

55. Nd:YAG induces marked fibrosis in the mucosa with atrophy of the mucous glands and shrinkage of the venous plexus . deep penetration . CO2 laser : reduce turbinate mucosa by excision or vaporization

56. septal surgery include the CO2 laser, Nd:YAG laser and diode laser . confined to removing a ridge or spur chiefly on the anterior portions of the septum . An S-shaped septal deformity with an ascending ridge should still be corrected using conventional techniques.

57. Paranasal sinus surgery: The removal of polyps in patients who refuse conventional surgery or are poor candidates for general anesthesia . treatment of circumscribed recurrent polyposis following prior intranasal surgery .

58. Lacrimal Duct Surgery : Laser-Assisted Transcanalicular Dacryocystorhinostomy Laser-Assisted Intranasal Dacryocystorhinostomy Laser-Assisted Dacryoplasty

59. Choanal atresia:

60. epistaxis

61. Hereditary Hemorrhagic Telangiectasia

62. Benign tumours Malignant tumours synechia

63. Extranasal Laser Applications Laser Treatment of Rhinophyma

64. intranasal Photodynamic Therapy

65. Laser Use in the Oral Cavity and Oropharynx The ( CO2), ( Nd:YAG ), ( KTP), and argon lasers are most commonly used for soft-tissue surgery in the oral cavity and oropharynx. occlusion of small transected vessels, providing hemostasis bloodless field; no-touch operating technique ; precise incisions no need for sutures .

66. Hyperplasia of the Lingual Tonsil Vascular Malformations Other Benign Tumors : papillomas , fibromas, cysts, and ranulas excision and vaporization. Premalignant Lesions : leukoplakia and erythroplakia . Labial and Lingual Frenoplasties

67. Lasers in the Treatment of Snoring and Sleep Apnea laser-assisted uvulopalatoplasty (LAUP ) appropriate for higher grades of OSA. contraindications for LAUP in primary snoring : AHI greater than 20–30/h BMI greater than 28 kg/m2 Midfacial deformities Posterior airway space at the mandibular level smaller than 10 mm Severe concomitant medical disease Severe neurologic or psychiatric comorbidity

68. Laser Tonsillectomy

69. Lasers in the Treatment of Salivary Gland Disease “optical breakdown.” When laser pulses of sufficiently high energy and short duration are applied to tissue, they form a plasma that causes the sudden volume expansion of fluids and generates a shockwave. The laser fiber is advanced to the stone through an endoscope . The particles of the fragmented stone are either passed spontaneously with the salivary flow or flushed out through the working channel of the endoscope.

70. 5 Lasers for Benign Diseases of the Larynx, Hypopharynx, and Trachea Laser Surgery of the Vocal Cords epithelial changes (vocal nodules, leukoplakia , hyperkeratosis, acanthosis, dysplasia, etc .), exudative changes in the Reinke space (vocal cord polyps, Reinke edema ). granulomas: (contact granuloma, intubation granuloma), scarring, and subepithelial lesions ( cysts)

71. Laser surgery can be done under general endotracheal anesthesia and using jet ventilation postoperative monitoring in an intensive care unit (ICU) following laser surgery for airway stenosis.

72. Contact granuloma

73. Vocal cord polyp

74. Subepithelial Vocal cord cyst

75. Surgery to Improve Swallowing Zenker diverticulum deficient or delayed relaxation of the crico - pharyngeus muscle

76. Laser Treatment of Airway Stenosis Supraglottic Stenosis Glottic Airway Stenosis Bilateral Recurrent Nerve Paralysis Arytenoidectomy Cordectomy Posterior cordectomy Temporary lateral fixation Subglottic and Tracheal Stenoses Airway Stenosis Due to Malignant Disease

77. Posterior cordectomy on the left side for bilateral recurrent nerve paralysis. a Microlaryngoscopic view

78. Laser Surgery of Benign Tumors of the Larynx and Trachea (recurrent laryngeal papillomatosis)

79. SUBGLOTTIC AND TRACHEAL STENOSIS CO2 laser therapy is well accepted as the first approach to the problem of benign stenosis of the upper airway. use of a rigid bronchoscope is necessary for the CO2 laser bronchoscopy because the CO2 laser energy cannot be transmitted through a flexible fibre.

80. Complications of endoscopic laser surgery in the larynx, trachea, and hypopharynx combustion of ventilation tube materials and anesthetic gas mixtures during surgical laser use in the larynx . . Combustion of tube materials can be avoided by the use of laser-safe tubes . Ignition of anesthetic gas mixtures during procedures using jet ventilation can be prevented by ventilating the patient with room air (rather than pure oxygen) and by operating in intermittent apnea . On the whole, such incidents can be safely avoided by the selection of suitable materials, operating methods, and analgesic techniques.

81. Lasers for Malignant Lesions in the Upper Aerodigestive Tract diameter of the CO2 laser beam : adjusted to produce either of two effects: Tissue ablation with a spot size of 1–4 mm or Tissue cutting with a spot size of 0.2–1 mm . The limits of the resection are defined by the tumor extent visible under the operating microscope and can be adapted to individual circumstances. With cancers involving the anterior commissure, the perichondrium about the vocal cord attachment should be dissected from the cartilage with a round knife to

82. Carcinoma of the Oral Cavity Pharyngeal Carcinoma Laser Microsurgery of Glottic Carcinoma T1 and T2a Glottic Carcinoma Glottic Carcinoma with Involvement of the Anterior Commissure

83. Early glottic cancer

84. Carcinomas of the anterior commissure should always be resected en bloc under high magnification . The vocal cord insertion on the thyroid cartilage is completely removed along with the surrounding perichondrium . If subglottic tumor growth is visible below the anterior commissure, the resection should be extended to the inferior border of the thyroid cartilage to ensure that extralaryngeal tumor spread around the inferior edge of the thyroid cartilage is not missed

85. T2b and T3 Glottic Carcinoma The resection can be extended to the perichondrium of the thyroid cartilage and cricoid cartilage, to the thyroid and cricoid cartilages themselves to the arytenoid cartilage the cricothyroid ligament and the extralaryngeal soft tissues

86. Laser Microsurgery of Supraglottic Carcinoma SUPRAGLOTTIC T1 AND T2 carcinomas of the suprahyoid epiglottis or ventricular fold can usually be clearly exposed and excised Infrahyoidepiglottis incision in the glossoepiglottic vallecula and splitting the epiglottis in the midline , including the preepiglottic fat preserving the vocal cords and arytenoid cartilages

87. Laser Microsurgery of Hypopharyngeal Carcinoma poorest prognosis . High rate of local tumor recurrence H igh cervical lymph node metastases at the time of diagnosis metachronous distant metastases high incidence of metachronous second primary tumors . Laser surgery appears to be effective for T1 T2 hypopharyngeal cancer treatment as long as clear surgical margins can be achieved.

88. Disadvantage high cost of purchase & maintenance special training special precautions & safety measures special anaesthesia requirements