UNIVERSITE DE GENEVE FACULTE DE MEDECINE Département des Neurosciences Cliniques Professeur P. Montandon et Dermatologie Clinique et Policlinique d'Oto-rhino- laryngologie et Chirurgie Cervico-Faciale Division de Chirurgie Cervico-Faciale Professeur W. Lehmann PAROTIDECTOMY COMPLICATIONS. NEW TECHNIQUES FOR THEIR OBJECTIVE EVALUATION, PREVENTION AND TREATMENT Travail présenté par le Docteur Pavel Dulguerov pour obtenir le titre de Privat Docent Genève 1999 TABLE OF CONTENTS Table of contents ....................................................................................................................................................... 1 Table of illustrations ................................................................................................................................................. 4 Acknowledgements ................................................................................................................................................... 7 SUMMARY ................................................................................................................................................................ 9 1. INTRODUCTION .......................................................................................................................................... 13 1.1. History of parotid surgery ................................................................................................................ 14 1.2. Anatomy ............................................................................................................................................. 19 1.2.1. Parotid fascia ............................................................................................................................ 24 1.2.2. Contents of the parotid space ............................................................................................... 29 1.2.3. Histology ................................................................................................................................... 30 1.2.4. Parotid lobes ............................................................................................................................ 32 1.2.5. Facial nerve anatomy .............................................................................................................. 34 1.2.5.1 Marginal mandibular branches. ................................................................................... 37 1.2.5.2. Cervical branches. ......................................................................................................... 38 1.2.5.3. Buccal branches............................................................................................................. 38 1.2.5.4. Zygomatic branches. .................................................................................................... 38 1.2.5.5. Temporal branches. ...................................................................................................... 38 1.3. Indications of parotidectomy .......................................................................................................... 41 1.3.1. Histopathology of parotid lesions ........................................................................................ 42 1.3.2. Preoperative work-up of parotid lesions ............................................................................ 44 1.4. Surgical techniques of parotidectomy ............................................................................................ 45 1.4.1. Parotid surgery mandates ...................................................................................................... 45 1.4.2. Nomenclature of parotid operations ................................................................................... 46 1.4.3. General techniques of parotidectomy ................................................................................. 48 1.4.3.1. Anesthesia ...................................................................................................................... 48 1.4.3.2. Patient positioning ........................................................................................................ 49 1.4.3.3. Infiltration ...................................................................................................................... 49 1.4.3.4. Patient preparation ....................................................................................................... 49 1.4.3.5. Draping ........................................................................................................................... 49 1.4.3.6. Incision ........................................................................................................................... 49 1.4.3.7. The superficial skin flap ............................................................................................... 50 1.4.3.8. Dissection of the posterior parotid ........................................................................... 51 1.4.4. Techniques for facial nerve identification .......................................................................... 52 1.4.5. The superficial parotidectomy .............................................................................................. 57 1.4.6. The total parotidectomy ........................................................................................................ 60 1.4.7. Wound closure ......................................................................................................................... 60 2. PAROTIDECTOMY COMPLICATIONS ................................................................................................. 61 2.1. Facial nerve ......................................................................................................................................... 62 2.1.1. Historical background ............................................................................................................ 62 2.1.2. Techniques of evaluation of facial nerve function ............................................................ 64 2.1.3. Topographic facial nerve function testing .......................................................................... 66 2.1.3.1. Burres' linear measurement studies ........................................................................... 66 2.1.3.2. Multi-camera linear measurement studies ................................................................ 71 2.1.3.3. Other linear measurement studies ............................................................................. 71 2.1.3.4. Image subtraction techniques ..................................................................................... 73 2.1.3.5. Miscellaneous techniques ............................................................................................ 76 2.1.3.6. Conclusions .................................................................................................................... 78 1 2.1.4. Facial nerve paralysis grading classifications ...................................................................... 79 2.1.5. Physiopathology of facial nerve paralysis ........................................................................... 86 2.1.5.1. Ischemia .......................................................................................................................... 86 2.1.5.2. Mechanical trauma – compression injuries .............................................................. 88 2.1.5.3. Mechanical trauma –crushing ..................................................................................... 89 2.1.5.4. Mechanical trauma –stretching .................................................................................. 90 2.1.5.5. Cold injury ...................................................................................................................... 91 2.1.5.6. Damage from electrocautery ...................................................................................... 92 2.1.5.7. Damage from repeated stimulations ......................................................................... 93 2.1.5.8. Nerve toxic substances ................................................................................................ 93 2.1.5.9. Parotidectomy data ....................................................................................................... 93 2.1.6. Incidence of postparotidectomy facial nerve paralysis .................................................... 94 2.1.7. Prevention of facial paralysis during parotidectomy ........................................................ 99 2.2. Frey syndrome ................................................................................................................................ 100 2.2.1. Historical background .......................................................................................................... 100 2.2.2. Etiology ................................................................................................................................... 105 2.2.3. Anatomy and physiology ..................................................................................................... 108 2.2.4. Pathogenesis of Frey syndrome ......................................................................................... 110 2.2.5. Investigation of Frey syndrome ......................................................................................... 113 2.2.6. Incidence of Frey syndrome ..............................................................................................