Faculty Bibliography

BACKGROUND: Although bone repair is often a relatively rapid and efficient process, many bone defects do not heal. Because an adequate blood supply is essential for new bone formation, we hypothesized that augmenting new blood vessel formation by increasing the number of circulating vasculogenic progenitor cells (PCs) with AMD3100 and enhancing their trafficking to the site of injury with recombinant human parathyroid hormone (rhPTH) will improve healing. METHODS: Critical-sized 3-mm cranial defects were trephined into the right parietal bone of C57BLKS/J 6 mice (N = 120). The mice were divided into 4 equal groups (n = 30 for each). The first group received daily subcutaneous injections of AMD3100 (5 mg/kg). The second group received daily subcutaneous injections of rhPTH (5 mg/kg). The third group received both AMD3100 and rhPTH. The fourth group received subcutaneous injections of saline. Circulating vasculogenic PC numbers, new blood vessel formation, and bony regeneration were assessed. Progenitor cell adhesion, migration, and tubule formation were assessed in the presence of rhPTH and AMD3100. RESULTS: Flow cytometry demonstrated that combination therapy significantly increased the number of circulating PCs compared with all other groups. In vitro, AMD3100-treated PCs had significantly increased adhesion migration, and tubule formation was assessed in the presence of rhPTH. Combination therapy significantly improved new blood vessel formation in those with cranial defect compared with all other groups. Finally, bony regeneration was significantly increased in the combination therapy group compared with all other groups. CONCLUSIONS: The combination of a PC-mobilizing and traffic-enhancing agent improved bony regeneration of calvarial defects in mice.

BACKGROUND: Fat necrosis is a well-known complication of free tissue transfer and fat grafting that is becoming increasingly reported in the literature. However, there is no clear consensus on how fat necrosis is defined and classified in the plastic surgery literature. METHODS: A systematic review of the literature was performed using the PubMed database of the National Library of Medicine and National Institutes of Health and Google Scholar from January 1, 2003, to November 1, 2013. The keywords used in the search included "fat necrosis" and "plastic surgery." RESULTS: Sixty-nine articles were chosen that met the authors' criteria and were included in this review. There was wide variation on the size requirements and postoperative timing when defining fat necrosis. In addition, the workup sought after clinical examination to confirm a diagnosis of fat necrosis varied, including radiographic studies, histopathologic examination, or a series of studies. CONCLUSIONS: Based on the articles reviewed in this article, a more uniform definition needs to exist that is clearly defined in all articles that report on fat necrosis. The authors suggest defining fat necrosis as a palpable, discrete, and persistent subcutaneous firmness found postoperatively that measures at least 1 cm during physical examination. Fat necrosis can be identified and confirmed by imaging and histopathology or through intraoperative findings. The authors provide a classification system for fat necrosis that can be used by clinicians to describe fat necrosis into varying grades of severity to ultimately help guide clinical decision-making.

BACKGROUND: The free fibula osteocutaneous flap has become the criterion standard for reconstruction of complex mandibular defects. The authors present their institutional experience with optimization of flap contouring and inset using virtual planning and prefabricated cutting jigs. METHODS: All free fibula-based mandible reconstructions performed at the authors' institution using virtual planning technology between 2009 and 2012 were retrospectively analyzed. The authors evaluated a variety of patient and procedural variables and outcomes. A series of cases performed before virtual planning was reviewed for comparison purposes. RESULTS: Fifty-four reconstructions were performed in 52 patients. Patients were divided evenly between a private university-affiliated medical center and a large county hospital. The most common indications were malignancy (43 percent), ameloblastoma (26 percent), and osteonecrosis/osteomyelitis (23 percent). Thirty percent of patients had irradiation of the recipient site and 38 percent had previous surgery. Sixty-three percent of patients received dental implants, with 47 percent achieving functional dentition. Twenty-five percent of patients had immediate dental implant placement, and 9 percent had immediate dental restoration. Postoperative imaging demonstrated excellent precision and accuracy of flap positioning. Comparison with cases performed before virtual planning demonstrated increased complexity of flap design along with reduced operative time in the virtually planned group. CONCLUSIONS: Preoperative virtual planning along with use of prefabricated cutting jigs allows for precise contouring and positioning of microvascular fibula free flaps in mandibular reconstruction. Using this technique, the authors have achieved unprecedented rates of dental rehabilitation along with reduced operative times. The authors believe that virtual planning technologies are an emerging criterion standard in mandible reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

BACKGROUND: Reconstruction in the setting of prior breast irradiation is conventionally considered a higher-risk procedure. Limited data exist regarding nipple-sparing mastectomy in irradiated breasts, a higher-risk procedure in higher-risk patients. METHODS: The authors identified and reviewed the records of 501 nipple-sparing mastectomy breasts at their institution from 2006 to 2013. RESULTS: Of 501 nipple-sparing mastectomy breasts, 26 were irradiated. The average time between radiation and mastectomy was 12 years. Reconstruction methods in the 26 breasts included tissue expander (n = 14), microvascular free flap (n = 8), direct implant (n = 2), latissimus dorsi flap with implant (n = 1), and rotational perforator flap (n = 1). Rate of return to the operating room for mastectomy flap necrosis was 11.5 percent (three of 26). Nipple-areola complex complications included one complete necrosis (3.8 percent) and one partial necrosis (3.8 percent). Complications were compared between this subset of previously irradiated patients and the larger nipple-sparing mastectomy cohort. There was no significant difference in body mass index, but the irradiated group was significantly older (51 years versus 47.2 years; p = 0.05). There was no statistically significant difference with regard to mastectomy flap necrosis (p = 0.46), partial nipple-areola complex necrosis (p = 1.00), complete nipple-areola complex necrosis (p = 0.47), implant explantation (p = 0.06), hematoma (p = 1.00), seroma (p = 1.00), or capsular contracture (p = 1.00). CONCLUSION: In the largest study to date of nipple-sparing mastectomy in irradiated breasts, the authors demonstrate that implant-based and autologous reconstruction can be performed with complications comparable to those of the rest of their nipple-sparing mastectomy patients.