2017-18 HSC Section 4 Green Book

Plastic and Reconstructive Surgery • June 2015

of using porcine-derived matrix (Permacol; Covi- dien, Mansfield, Mass.) for chest wall reconstruc- tion in the pediatric population and found no evidence of clinically significant scoliosis after 2 years of follow-up. 22 Sodha et al. published a litera- ture review of acellular dermal matrix use in chest wall reconstruction in 2012 and found only a few case reports and one small case series. 61 Acellular dermal matrix in chest wall recon- struction is used primarily for its supposed anti- microbial properties and the relative frequency of contaminated thoracic surgical fields encoun- tered after extensive resections for malignancy. 61 Miller et al. performed a review at their institution and found no patients with infected resection sites requiring removal of their biomaterial. 24 In one case report, Rocco et al. describe a case of Perma- col exposure after rectus abdominis flap necrosis that was able to be managed conservatively with open wound management principles followed by rotational flap coverage. 23 Again, in this situation, one must consider these reports of successful bio- logical material reconstruction in the context of multiple reports of successful autogenous muscle flap reconstructions that have traditionally been used by plastic surgeons over the years. CRANIOFACIAL REPAIR Autologous bone transplantation, character- ized by maximal osteogenic, osteoconductive, and osteoinductive properties, is still the crite- rion standard for the repair of bony craniofacial defects compared with other modalities 62 ; how- ever, its use is limited by donor-site availability, donor-site morbidity, a time-consuming second harvest procedure that often requires remodel- ing before grafting, and an unpredictable degree of graft bone resorption. 2,62,63 Autologous bone grafting was demonstrated to result in the highest percentage of total bone volume formation in the setting of sinus floor reconstruction, an important measure of bone graft performance. However, calcium-based biomaterials, such as hydroxyapa- tite and β -tricalcium phosphate, are thought to be highly osteoconductive by facilitating attachment, proliferation, and migration of the cells critical to new bone formation compared with non–calcium- based synthetics. 62 When used alone, hydroxyap- atite may fail to become integrated with native tissue and β -tricalcium phosphate is brittle and has low fracture resistance 2 ; however, promising results have been observed when used in combi- nation with and/or augmented by the addition of growth factors and cultured cells. 63 In 2009,

Mesimaki et al. demonstrated the successful repair after hemimaxillectomy using an ectopic bone flap that originated as a titanium cage seeded with adipose-derived stem cells that were exposed to β -tricalcium phosphate and bone morphogenetic protein 2. 36 This method was then duplicated by Sandor et al. for reconstruction of a patient after the removal of a mandibular ameloblastoma. 42 Synthetic absorbable polymers have been used for years in the form of resorbable sutures, plates, and screws. Reconstruction of craniofacial defects has provided a platform for the develop- ment of new and inventive uses of these materials. The most commonly used materials include poly- l -lactic acid or one of its derivatives. Most notably, these materials have shown promise in the repair and recalibration of the oral and maxillofacial bones. Gunarajah and Samman performed a sys- tematic review of orbital floor blowout repair and determined that the use of biomaterials resulted in comparable if not improved outcomes com- pared with nonresorbable materials. 41 Yoshioka et al. compared poly- l -lactic acid to titanium for fixation after bilateral sagittal split mandibular setback surgery and observed no significant differ- ence in complications, but recommended using poly- l -lactic acid only in minimal load situations because of material breakage. 40 In 2012, a new and successful technique for fixation of Le Fort I osteotomies with poly- l -lactic acid ultrasonic weld- ing was described. 38 Acellular dermal matrix has also been used in repair of craniofacial defects with some success. Shridharani and Tufaro found diverse applica- tions for its use, including repair of the perforated septum or tympanic membrane; placement in the posterior lamella; as an adjunct in duraplasty; and for use in intraoral resurfacing and repair of defects such as the tongue, maxillary oral vestibule, floor of mouth, palate, tonsils, and parotid bed. 64 Bone replacement together with composite tissue prefabrication is likely to be a very exciting new area for biomaterial use. We are only beginning to appreciate what can be achieved by incorporating newer technologies, such as three-dimensional printing, with cellular regenerative components. These technological advances are in their infancy, as demonstrated by the number of studies that are either case reports or case series (Table 2), but is a field that carries extremely exciting potential. Rhinoplasty Rhinoplasty is one of the most complex and often requested procedures in plastic surgery and usually requires autologous graft materials

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