Vocal Fold Injection

This book provides step-by-step illustrated descriptions of diverse vocal fold injection techniques, including some not previously described. The aim is to provide laryngologists in general, and especially those who are less experienced, with the detailed understanding and guidance needed in order to achieve optimal outcomes. Highly experienced experts describe approaches via the transoral, transnasal, and transcutaneous routes and offer guidance on indications, injection materials, pre- and postoperative care, and the management of complications. Special considerations that must be borne in mind when employing different vocal fold injection techniques, in different settings, are also carefully explained. In offering comprehensive, up-to-date information on this minimally invasive and cost-effective procedure, __Vocal Fold Injection__ will be an essential aid for practitioners. Preface Contents Contributors Part I: General Considerations and Preoperative Preparations 1: History of Vocal Fold Injection 1.1 Historical Perspective of Vocal Fold Injection 1.2 Paraffin 1.3 Cartilage and Bone Paste 1.3.1 Cartilage 1.3.2 Bone Paste 1.3.3 Shortcomings of Cartilage and Bone Paste 1.4 Tantalum 1.5 Teflon 1.5.1 Introduction of Teflon 1.5.2 Clinical Efficacy and Technical Improvement of Teflon Injection 1.5.3 Tissue Response to Injected Teflon 1.5.4 Complications of Teflon 1.6 Silicone 1.6.1 Introduction of Silicone 1.6.2 Development of Improved Form of Silicone 1.6.3 Shortcoming of Silicone 1.7 Gelfoam 1.8 Collagen 1.8.1 Exogenous Collagen (Heterologous Bovine Collagen, Zyderm® or Zyplast®) 1.8.2 Human Collagen 1.8.2.1 Autologous Collagen (Purified Human Forms of Autologous Collagen) 1.8.2.2 Homologous Collagen (Purified Forms of Human Collagen from Homologous Cadaveric Skin, Micronized Acellular Derma Compound, Cymetra®) References 2: Surgical Anatomy for Vocal Fold Injection 2.1 Laryngeal Framework 2.1.1 Hyoid Bone 2.1.2 Thyroid Cartilage 2.1.3 Cricoid Cartilage 2.2 Laryngeal Membranes and Ligaments 2.2.1 Extrinsic 2.2.2 Intrinsic 2.3 Laryngeal Cavity 2.3.1 Preepiglottic Space 2.3.2 Paraglottic Space 2.4 Vocal Fold 2.4.1 Gross Anatomy 2.4.2 Microanatomy 2.5 Anatomical Consideration for VFI References 3: Indications for Vocal Fold Injection 3.1 Unilateral Vocal Fold Paralysis 3.1.1 Definition 3.1.2 Etiology 3.1.2.1 Iatrogenic 3.1.2.2 Neoplastic (Non Laryngeal) 3.1.2.3 Idiopathic 3.1.3 Evaluation 3.1.3.1 History Taking 3.1.3.2 Laryngoscopy and Stroboscopy 3.1.3.3 Imaging Studies 3.1.3.4 Voice Assessments 3.1.3.5 Laryngeal Electromyography 3.1.4 Treatment 3.1.4.1 Principle 3.1.4.2 Spontaneous Recovery 3.1.4.3 Voice Therapy 3.1.4.4 Surgical Management 3.2 Benign Vocal Fold Lesions 3.2.1 Definition 3.2.2 Etiology 3.2.3 Diagnosis 3.2.4 Treatment 3.3 Spasmodic Dysphonia 3.3.1 Definition 3.3.2 Etiology 3.3.3 Diagnosis 3.3.4 Treatment 3.4 Vocal Process Granuloma 3.4.1 Definition 3.4.2 Etiology 3.4.3 Diagnosis 3.4.4 Treatment References 4: Anesthesia for Vocal Fold Injection 4.1 Introduction 4.2 Anatomy 4.2.1 Nasal Cavity 4.2.2 Oropharynx 4.2.3 Larynx 4.3 Medications 4.3.1 Anesthetics 4.3.1.1 Lidocaine 4.3.1.2 Tetracaine 4.3.2 Decongestants 4.3.3 Anti-Secretion Medications 4.4 Procedures 4.4.1 Patient Preparation 4.4.2 Nasal Anesthesia 4.4.3 Pharyngeal Anesthesia 4.4.4 Laryngeal Anesthesia 4.4.5 Skin Anesthesia 4.5 Medical Concerns References Part II: Approaches for Vocal Fold Injection 5: Trans-Oral Approach 5.1 Introduction 5.2 Indications for Trans-Oral Technique 5.3 Contraindications for Trans-Oral Technique 5.4 Anesthesia 5.5 Equipment and Injection Material 5.6 Procedure 5.6.1 Setup and Positioning 5.6.2 Trajectory Approximation and Arytenoid Palpation 5.6.3 Technique 5.6.4 Complications 5.6.5 Post-Injection References 6: Trans-Cricothyroid Approach 6.1 Introduction 6.2 Surgical Techniques 6.2.1 Basic Steps for Vocal Fold Injection with Trans-CT Approach 6.2.2 Techniques to Locate the Level of the True Vocal Fold 6.2.3 Techniques to Estimate Exact Location of the Needle Tip 6.3 Conclusion References 7: Trans-Thyrohyoid Approach 7.1 Technique 7.1.1 Procedure 7.1.2 Needle Preparations 7.1.3 Technical Tips 7.2 Advantages and Limitations References 8: Trans-Cartilaginous Approach 8.1 Injection Laryngoplasty Techniques in Korea 8.2 Transcartilaginous Approach Procedure 8.3 Other Uses of the Transcartilaginous Approach 8.4 Advantages and Disadvantages the Transcartilaginous Approach 8.5 Technical Pitfalls of the Transcartilaginous Approach References Part III: Considerations in Immobile Vocal Folds 9: Optimal Injection Timing for Vocal Fold Paralysis 9.1 Natural History of VF Paralysis 9.2 Optimal Injection Timing References 10: Ideal Material Selection for Vocal Fold Augmentation 10.1 Material Selection 10.2 Short-Term Vocal Fold Injection Augmentation Materials 10.2.1 Carboxymethylcellulose Products 10.2.2 Hyaluronic Acid Products 10.3 Durable Vocal Fold Injection Augmentation Materials 10.3.1 Calcium Hydroxylapatite Products 10.3.2 Polydimethylsiloxane 10.3.3 Silk-Hyaluronic Acid References 11: Autologous Materials for Vocal Fold Augmentation 11.1 Introduction 11.2 Autologous Fat Injection 11.2.1 Introduction 11.2.2 Surgical Techniques 11.2.2.1 Liposuction 11.2.2.2 Fat Purification 11.2.2.3 Fat Injection 11.2.3 Advantage and Disadvantage 11.3 Autologous Cartilage Injection 11.3.1 Introduction 11.3.2 Surgical Technique and Clinical Outcome (Fig. 11.7) 11.3.3 Advantage and Disadvantage References 12: EMG Guided Injection Laryngoplasty 12.1 Unilateral Vocal Fold Paralysis 12.2 Laryngeal EMG 12.2.1 Basic Neurophysiology of Larynx 12.2.2 The Electrodiagnostic Apparatus 12.2.3 Preparation and Insertion of Needle Electrode 12.2.3.1 Cricothyroid (CT) Muscle 12.2.3.2 Thyroarytenoid and Lateral Cricoarytenoid (TA/LCA) Muscle Complex 12.2.4 Basic Interpretation of EMG 12.2.4.1 In the Muscle at Rest (Keep Silent) 12.2.4.2 In the Muscle at Voluntary Contraction (Phonating Vowel/I/) 12.2.5 Laryngeal EMG and Prognosis of Unilateral Vocal Fold Paralysis 12.3 Laryngeal EMG Guided Injection Laryngoplasty for UVFP 12.3.1 Rationale of Laryngeal EMG Guided Injection Laryngoplasty 12.3.2 Procedure of Laryngeal EMG Guided Injection Laryngoplasty 12.3.3 Injection Material, Volume, and Effect Duration 12.3.4 Algorithm of EMG Guided Injection Laryngoplasty for UVFP 12.4 Consultation Cautions and Limitations References 13: Ancillary Techniques for Vocal Fold Injection 13.1 Trans-Nasal Injection 13.2 Light-Guided Injection 13.3 Ultrasound Guided Injection 13.4 Others References Part IV: Postoperative Considerations 14: Post-Injection Care and Complication Management 14.1 Complication Management 14.1.1 Introduction 14.1.2 Calcium Hydroxlyapatite (CaHA) 14.1.3 Collagen; Cymetra, Zyplast 14.1.4 Hyaluronic Acid (Restylane) 14.1.5 Special Consideration 14.2 Post-Injection Care References 15: Perioperative Voice Therapy 15.1 Introduction 15.2 Prior to Speech-Language Pathology Involvement 15.3 Indirect and Direct Voice Therapy 15.4 Outcome Metrics in Voice Therapy 15.5 Benign Vocal Fold Lesions 15.6 Vocal Fold Paralysis 15.7 Presbyphonia 15.8 Laryngeal Dystonia 15.9 Timing 15.9.1 Preoperative Therapy 15.9.2 Postoperative Voice Rest 15.9.3 Other Postoperative Therapy 15.10 Frequency and Duration 15.11 Factors Predictive of Successful Voice Therapy References Part V: Special Considerations in Various Vocal Fold Injections 16: Botulinum Toxin Injection for Laryngeal Disorders 16.1 Treatment of Adductor Spasmodic Dysphonia 16.1.1 General Principles of BoNTA Injection for Adductor SD 16.1.2 Treatment Protocols of BoNTA Injection for Adductor SD 16.1.3 BoNTA Injection Techniques for Adductor SD 16.2 Treatment of Abductor SD 16.2.1 General Principles of BoNTA Injection for Abductor SD 16.2.2 BoNTA Injection Techniques for Abductor SD 16.3 Treatment of Other Laryngeal Disorders References 17: Vocal Fold Steroid Injection 17.1 Evolving History of Vocal Fold Steroid Injection (VFSI) 17.2 Mechanisms of Steroid Injection for Benign Vocal Lesions 17.3 Techniques and Injection Routes of VFSI 17.4 Indications for VFSI 17.5 Adverse Events after VFSI 17.6 Recurrence of Vocal Lesions after VFSI References 18: Vocal Fold Growth Factor Injection 18.1 Basic Fibroblast Growth Factor 18.1.1 Biological Activity on Wound Healing 18.1.2 Preclinical Data of bFGF on the Vocal Fold 18.1.3 Clinical Application of bFGF Injection for Vocal Fold Scar, Sulcus, and Atrophy 18.2 Hepatocyte Growth Factor 18.2.1 Anti-Fibrotic Activity 18.2.2 Preclinical Data of HGF on Vocal Fold Scar 18.2.3 Clinical Trial References 19: Other Therapeutic Vocal Fold Injections 19.1 Cidofovir and Bevacizumab 19.1.1 Clinical Application of Cidofovir or Bevacizumab on Recurrent Respiratory Papillomatosis 19.1.2 Potential Risk of Adjuvant Therapy for RRP 19.1.3 Outcomes of Adjuvant Therapy for RRP 19.2 Tissue-Engineered Materials 19.2.1 Hyaluronic Acid-Based Materials 19.2.2 Hyaluronic Acid-Based Microgels 19.2.3 Synthetic Polymer Materials 19.3 Stem Cell Therapy 19.3.1 Regeneration Therapy for the Vocal Folds 19.3.2 Preclinical Study of Stem Cell Therapy 19.3.3 Clinical Trial of Stem Cell for VF Regeneration 19.4 Platelet-Rich Plasma 19.5 Gene Therapy References