------------------------------------------------------------------------------ TITLE: ALLOPLASTIC MATERIALS IN COSMETIC SURGERY SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: DECEMBER 13 1989 RESIDENT PHYSICIAN: TODD E. SAMUELSON MD FACULTY: KAREN H. CALHOUN MD DATABASE ADMINISTRATOR: Melinda McCracken, M.S. ------------------------------------------------------------------------------ "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." I. INTRODUCTION A. BACKGROUND 1. Federal Food, Drug, and Cosmetic Act passed in May 1976 provided the FDA with regulatory power over medical devices. 2. Before this time there was little regulation on implants. 3. Now it requires a five step process for introduction of a new implant onto the market. B. THE IDEAL IMPLANT 1. Mimics the tissue that it replaces. 2. Not prone to infection or healing response. 3. Takes on the characteristics of the tissue it replaces. * The ideal implant doesn't exist. Each has attributes that make it desirable in certain circumstances. This paper hopes to elucidate: 1) What is available? 2) How is it useful? and 3) What potential adverse side effects exist? II. SOLID TISSUE IMPLANTS (BONE REPLACEMENT) A. USE FOR THESE IMPLANTS 1. Facial Contouring (Requiring more than just soft tissue adjustment) 2. Malar and mandibular augmentation 3. Replacement of bone deficits B. IDEAL FOR FACIAL BONE CONTOURING 1. Strong 2. Inert 3. Moldable 4. Radiolucent 5. Low thermal conductivity * Today the trend is toward finding implants that are not inert but allow bone ingrowth and eventual self remolding, with eventual resorption of the implant. C. CONSIDERATIONS 1. Quality of tissue coverage a. If inadequate tissue coverage exists an alloplastic implant is undesirable. b. Autograft materials are much preferred 2. Amount of trauma or potential movement a. Fixation may be required b. Integrateable or Autogenous material preferred here. 3. Exposure to outside a. Vascular supply to graft usually required here. b. With exposure of silicone this doesn't necessarily mean the graft had failed. D. SILICONE: 1. First reported in the 1940's 2. Consist of a group of long chain polymers with organic groups known as polydimethylsiloxane attached. 3. Three forms a. Heat vulcanized silicone (1) Comes in block form (2) Carvable with a knife b. Room temperature vulcanized sialastic (1) weaker than the block form (2) able to be molded in place (3) mixable in water and blood (4) no heat of polymerization c. Liquid silicone (1) Useful in soft tissue replacement (2) Attributes discussed later 4. Attributes: a. Inert b. Doesn't deteriorate c. Heat sterilized d. Doesn't adhere to other substances e. Radiolucent f. Low thermal conductivity g. Easy to use 5. Problems: a. Essentially none in the hard form. b. Rarely causes usually transient foreign body reaction. c. May slip, so fixation is advisable. (1) Dacron felt (2) Suture (3) Screw fixation E. ACRYLIC POLYMERS 1. Polymerized esters of acrylic acid or methylacrylic acid. 2. E.g. "Bone Cement" - Liquid monomer and powdered polymer. a. Monomer polymerized in reaction. b. Monomer that remains may lead to host reactivity. c. Reaction aided by aeration and time. 3. Attributes: a. Hard b. Rigid c. Translucent d. Impervious to fluid,gases, bacteria 4. Problems: a. Heat of polymerization may harm tissue. b. Porous so may lead to bone ingrowth and change of implant and thus cosmetic result. c. Slightly higher chance of tissue response. d. Also should be fixated. F. POLYETHYLENE 1. Straight chain aliphatic hydrocarbons 2. Attributes: a. Little host resistance b. Very strong in high density form c. Chemically inert d. Nonconductor e. Flexible but holds shape f. Resembles more cartilage than bone in its characteristics. 3. Problems a. Less ease of fabrication (1) Supplied in granules that must be heated to 300 degrees before use (2) Thus not autoclavable b. Not available in many forms c. Must use moulage for accurate results G. CERAMICS 1. Oxides of natural element or composites thereof a. Alumina (Al2 O3) b. Hydroxyapatite (Ca5 (PO4)3 OH) c. Bioglass major components (SiO2, CaO, Na2O) 2. Three rough categories: a. Inert b. Resorbable c. Reactive or bonding 3. Attributes: a. Can be constructed to be any of the three types. b. Allow for natural remodelling c. In addition to use as inert material they can be used as: (1) Bone scaffold (Resorbable) (2) Osseous integrated implants (Reactive) (3) Ossicular prosthesis (Properties of all three categories) 4. Problems: a. Precise balance between ingrowth, remodelling, and resorption not yet achieved. b. As a result probably not as useful as static bone replacement (ie Facial or mandibular augmentation. III. FIRM TISSUE IMPLANTS (PTFE-TEFLON,PTFE/GRAPHITE-PROPLAST) A. Proplast 1. Use (Both hard and soft tissue replacement) a. TMJ lining b. Middle ear implants c. Facial Contouring (Often used to mimic muscle) d. Tracheal Prosthesis e. Mandibular augmentation 2. Advantages a. Porous allowing for tissue ingrowth and stability b. Consistency between hard and soft 3. Problems a. Dark color (ProlastII is white) b. Surface fragmentation => darkening of the skin with phagocytosis by surrounding cells c. Difficult to sculpt d. Compressable (May be utilized as an attribute) e. Only come in 10 mm thick size f. Use of Proplast with a Teflon lining can overcome some of the fragmentation problems. B. Teflon 1. Use a. Lining of TMJ prosthesis b. Teflon and Glycerine - vocal cord injection c. Middle ear lining d. Tubing of various kinds 2. Attributes a. Inert b. Nonadherent 3. Problem a. Electronegative leads to easy soilage if not handled in a sterile fashion b. Even surgical gloves can leave a lot of debris IV. SOFT TISSUE IMPLANTATION A. USE 1. Usually injected in the subcutaneous tissues for augmentation and contouring. 2. May be placed directly especially in nasal surgery to add fullness. 3. Wrinkle camouflage. B. LIQUID SILICONE 1. Protocol: a. Preparation of the patient (1) Expected results and benefits (2) Pain of administration (3) Adverse reactions (4) Normal reactions (a) Transient ecchymosis (b) Transient foreign body reaction (5) Discussion of reported experience (6) Patient motivation b. Test site to be injected c. Small volume of injection with numerous repeat visits as necessary. d. Small Neddle - 27 or 30 gage e. Technique: (1) Fanning technique (2) Serial puncture (a) Preferred because of less chance for embolism. (b) Less volume deposited per injection. 2. Adverse Reaction a. Pain b. Edema (1) Usually transient (2) May be relieved by injection of triamcinilone c. Ecchymosis d. Erythema (1) Persistence implies superficial injection (2) Treated corticosteroid preparation e. Pigmentation (1) Implies superficial injection (2) Bluish or brown in color f. Texture (1) In minute droplet therapy there should be natural feel (2) Rubbery feel may occur with too much and too superficial an injection g. Embolism (1) Pain at injection (2) Pain in ipsilateral eye (3) Dilation of the pupil (4) Extra occular muscle changes (5) N/V , back pain h. Granulomatous reaction (1) Usually with non medical grade silicone (2) Tx: Steroids topical or injectable, antibiotics. 3. Contraindications a. Breasts b. Eyelids (To thin, distensible, tendency for discoloration) c. Vascular abnormalities (embolism) d. Bound Down scar (Doughnut deformity) e. Fibrocytic lesions f. Expectation of perfection C. Injectable Collagen 1. Much less side effects 2. More likely to resorb 3. Similar contraindications * Both Silicone and collagen can be considered safe if used properly. Collagen is only slightly more safe. But collagen may resorb and repeat deposition is often necessary as early as 1 year. D. Avatine (Bovine Collagen) 1. Low reactivity 2. Useful for nasal augmentation to 1cm 3. Most desireable for smoothing effect E. Supramid (related to Nylon and Dacron) 1. Resistant to infection 2. Causes soft tissue reaction which anchors the graft 3. Used for small nasal grafts 4. Degradation may be problematic V. FUTURE WORK 1. Biodegradeable scaffolds and implants 2. Osseous integrated implants 3. Glues -------------------------------------------------------------------------------- BIBLIOGRAPHY 1. Williams DF: Biocompatibility of Clinical Implant Materials Vols. I and II. CRC Press Inc. 1981 2. Rubin LR: Biomaterials in Reconstructive Surgery. C.V. Mosby Co. 1983. 3. Adams JS: "Grafts and Implants in Nasal and Chin Augmentation: A Rational Approach to Material Selection." Otol Clin N Am Nov 1987. 4. Bluestone CD et al: "Teflon Injection Pharyngoplasty." Laryngoscope 78: 558-564. 5. Berghaus A: " Porous Polyethelyne in Reconstructive Head and Neck Surgery." Arch Otol 1985(3) 154-164. 6. Webster RC et al: "Injectable Silicone for Facial Soft-Tissue Augmentation." Arch Otol H&N Surg 1986(112) 290-296. 7. Knapp TR et al: "The Augmentation of Soft Tissue With Injectable Collagen." Clin Plas Surg 1985(12) 221-225. 8. Braley S: "The Silicones in Maxillofacial Surgery." Laryngoscope 1978: 549-557. 9. Cipric JA: "Silcone Implant Correction of Facial Deformities." Laryngoscope 1978 565-585. -------------------------------END---------------------------------------