Laser?:

2. Laser?:

3. Role of laser and cryo surgery in ent Dr.nayana v g Senior resident

5. What is Laser ? Light Amplification by Stimulated Emission of Radiation • Stimulated radiation amplified with mirrors • Electromagnetic radiation • Specific wave length depending on lasing medium argon, CO2, nd:yag ,helium

6. Effects of laser on tissues Scattered and absorbed radiation causes tissue effects 60 Deg – protein denaturation 80 Deg – collagen degradation 100 Deg – tissue ablation

7. Properties and effects of lasers 1.photo thermal Cut, coagulate and vaporize tissue 2.photoacoustic lithotripsy Destroy cancer cells 3.photochemical 4.photodissociation Divide collagen - LASIK Visible lasers – Argon, KTP Invisible lasers – CO2

8. Clinical application depends on wave length and special absorptive power of tissues. 1.To vaporise. 2.To cut. 3.To coagulate the tissue.

9. TYPES OF LASERS • Argon • KTP-532 (Potassium titanyl phosphate) • Nd:YAG (Neodymium-yittrium aluminium garnet) • CO2

10. Clinical application of individual lasers Argon laser: (visible) wave length – 488-514 –blue • Easily transmitted through fluids • Absorbed by pigmented tissue and hemoglobin –used to treat hemangioma and telangiectasia • Focused on a small point • Stapedotomy

11. KTP LASER (visible) 532mm, blue- green Absorbed by hemoglobin Stapes surgery Endoscopic sinus surgery- to remove polyp inverted papilloma and vascular lesion Micro laryngeal surgery – polyp, cyst, papilloma, contact ulcer laryngocele and early malignant lesion Remove tracheobronchial lesion through bronchoscope

12. Nd:YAG laser (Invisible - separate aiming beam is required)wave length 1060mm • Pass through clear fluid and absorbed by pigmented tissue • Necrosis and thermal coagulation depth and laterally • Coagulation of blood vessels and control of bleeding-Hereditary hemorrhagic telangiectasia • Debulking of tracheobronchial lesions, esophageal lesions for palliation • Turbinectomy

13. CO2 laser -10400nm, invisible • Requires aiming beam of helium-neon laser • Cannot pass through flexible fibre scope. • Effective in vaporise tissues and give a blood less field. • Most commonly used laser in ENT surgery.

14. Nose – papilloma's, rhinophyma, telangiectasias, nasal polyp, choanal atresia, turbinectomy. Beneficial in bleeding dyscrasias and coagulopathies. • Oral cavity – leucoplakia, erythroplakia, superficial cancers, debulking of large inoperable tumours. – Advantages – transoral approach, precision surgery, haemostasis, less post-operative oedema and pain.

15. Oropharynx – tumours, laser tonsillectomy in coagulopathies. • Larynx – papilloma's, laryngeal web, subglottic stenosis, capillary haemangioma, vocal nodule, arytenoidectomy, malignant T1 lesions of VC.

16. Trachea & bronchi – papillomatosis, tracheal stenosis, granulation tissue, bronchial adenoma, debulking of obstructive malignant lesions. Plastic surgery – benign & malignant tumours of skin, vaporization of naevi and tattoos. Neuro-otology – acoustic neuroma.

17. Safety precautions 1.Display a sign board outside 2.Close the OT door. 3.Education of OT staff – surgeon, anaesthesiologist, nursing & theatre personnel – safety measures. 4.Protection of eye – protective glasses specific for the wave length – prevent accidental burns to cornea / retina. – Patients – double layer of saline moistened eye pads.

18. Safety precautions 5.Protection of other exposed areas – of skin and mucosa of patient not in surgical field – protected by saline soaked towels/ pads. 6.Evacuation of smoke - 2 separate suctions - for blood & smoke and steam from vaporization.

19. Safety precautions 7.Anaesthetic gas & equipment – non inflammable gases – halothane / enflurane used. -Wavelength specific endotracheal tube – CO2 laser – red rubber / silicone tube – wrapped by reflective metallic foil – Cuff inflated with methylene-blue coloured saline and protected with saline soaked cottonoids.

20. Advantages of laser 1.Precise incision 2.Easy and rapid ablation of tissue 3.Excellent hemostasis 4.Minimal post operative pain and edema of tissues 5.Ablate tissues in difficult locations in the tracheobronchial tree or crevices or cleft

21. disadvantages 1.High cost and maintenances of the instrument. 2. Special instruments 3. Airway fire

22. Cryosurgery in ent • Rapid freezing of tissues to -30deg followed by slow thawing causes destruction of benign and malignant lesions • Delivered either by closed or open system • Open system –liquid nitrogen spray or carbon di oxide snow • Closed system – cryoprobe-N2O,CO2 or liquid nitrogen

23. Cryo probe – Joule Thomson effect • Rapid expansion of compressed gas through a small hole produces cooling • Probes – different sizes and designs to suit area of cryo application • Probes – thermocouples to monitor temperature

24. Mechanism of tissue destruction 1.Dehydration – pure water inside and outside crystallizes ->rise in concentration of electrolytes, urea and dissolved gases, pH of medium changes-> cell death 2. Denaturation -> Denaturation of lipoproteins of cell membrane -> permeable to cations-> thawing-> cell lysis

25. Mechanism of tissue destruction 3.Thermal shock – arrest respiratory functions of the cell 4.Vascular stasis –arterial and venous occlusion -> infarct; micro thrombosis of capillaries Used in vascular tumours 5.Cryo immunization : specific auto antibodies to frozen tissues

26. technique • Applied under LA/GA • Area to be frozen is insulated • Cryoprobe is applied on the upon the tissue ->frozen for 3-8 min -> thaw slowly • Include a margin of normal tissues

27. technique • Necrotic tissue sloughs of in 3 to 6 weeks • Area heals by secondary intention • Repeated once or twice

28. Uses of cryo surgery in ENT 1. Benign vascular tumors : hemangioma involving skin, oral cavity and oropharynx, glomus tumors and angiofibroma 2. Premalignant lesions: leukoplakia oral cavity( less scarring, better quality of regenerated epithelium and no recurrence ), solar keratosis 3.Skin cancers like Bowen’s disease, basal cell carcinoma

29. 4.Debulking of malignant tumours to facilitate respiration, food intake, to relieve bleeding. 5.Hypertrophied IT 6.Cryo destruction of tonsils

30. Advantages Poor risk patients – without anaesthesia / LA. Bleeding disorders/coagulopathies. Minimal post treatment discomfort / pain.Minimal scarring. Can be used in multiple cancers or recurrence where 2nd course of Radiotherapy is contraindicated Out-patient procedure.

31. Disadvantages No tissue for biopsy in small lesions. Not possible to assess margins of tumour. No control of depth of freezing. Depigmentation & loss of hair on skin.

32. summary • CO2 Lasers have revolutionized the way otolaryngologists approach surgery, enabling highly precise and, often, less invasive treatment of a wide range of ENT applications. • Co2 laser are mostly used in ENT because of high precision in cutting along with coagulation. • Other laser used in ENT are diode laser, KTP, Nd:YAG • Cryosurgery helps to eradicate many benign and pre malignant • Inherent anesthetic and haemostatic properties make it suitable for outpatient service

33. Reference.. 1.Disease of Ear, Nose, Throat &Head and Neck surgery – PL Dhingra, Shruthi Dhingra Acknowledgement Images from google images and text book(Disease of Ear, Nose, Throat &Head and Neck surgery – PL Dhingra, Shruthi Dhingra)