Faculty Bibliography

BACKGROUND: The free fibula flap is the standard of care in mandibular reconstruction; however, procedural nuances continue to optimize results. More accurate and efficient osteotomies for graft insetting can be envisioned, which address the difficulty in obtaining a perfect match between the cut ends of the fibula and the mandible and the subsequent giving up of maximal bone contact. We propose a method of complementary offset osteotomies. The angled cuts were virtually planned using three-dimensional computed tomographic images. Optimal offset cuts maximized surface area contact and facilitated intraoperative repositioning in the setting of additional native bone margin requirement. METHODS: Using previously described protocols, three-dimensional virtual reconstructions of the facial skeleton and the fibula (average, series of five) were used to simulate osteotomies at 25, 30, 45, 60, 75, and 90 degrees to the long axis of the fibula. Complementary osteotomies were then simulated at the mandibular body just distal to the first molar in simulated free fibula reconstructions. Total area of apposing surfaces was calculated using computer-aided design. The results from the 25-, 30-, 45-, 60-, and 75-degree cuts were compared with the conventional 90-degree cut. Resin-based mandibular osteotomy guides and a complementary fibula jig were manufactured using computer-aided design. Two representative clinical cases were presented to illustrate proof of principle and benefits. RESULTS: The total surface area of apposing fibula and mandible surfaces in a conventional 90-degree cut was 103.8 +/- 2.05 mm. Decreasing this angle to 75, 60, 45, 30, and 25 degrees yielded increased surface areas of 0.86%, 10.3%, 35.3%, 136.7%, and 194.3%, respectively. Cuts of 25 degrees also allowed for adequate bony contact in the setting of additional margin requirements up to 2.77 cm. Complementary 45-degree cuts provided excellent bone-to-bone contact in a free fibula reconstruction using resin guides and a jig. This angle also facilitated access of the saw to the distal mandible. CONCLUSIONS: Virtual surgical planning is an increasingly recognized technology for optimizing surgical outcomes and minimizing operative time. We present a technique that takes advantage of the precision complementary osteotomies that this technology affords. By creating offset cuts, we can maximize bony contact and ensure adequate contact should additional margins or intraoperative adjustments be required. This flexibility maximizes the precision of premanufactured cutting guides, mitigates the constraints of sometimes unpredictable intraoperative environments, and maximizes bony contact.

BACKGROUND: Moderate to severe soft tissue deficits can exist with craniofacial microsomia or progressive hemifacial atrophy. The authors reviewed the surgical correction of these defects, including serial autologous fat grafting and parascapular free tissue transfer. METHODS: Recently treated patients at the Institute of Reconstructive Plastic Surgery at NYU Medical Center were identified. Patients with microvascular free flap underwent reconstruction with parascapular flaps. These flaps have been modified from previously reported inframammary extended circumflex scapular flaps. Demographic information, operative interventions, complications, and outcomes were reviewed and analyzed. The clinical outcomes of these patients were compared with previously reported patients who underwent serial autologous fat grafting. RESULTS: Five patients were recently treated with 7 parascapular flaps. The mean age of the patients at the time of parascapular flap reconstruction was 13.1 years. These were compared to those previously reported who have undergone serial autologous fat grafting. The mean number of procedures was less for the free tissue transfer cohort. There were no microvascular complications because all free flaps survived. One patient had wound dehiscence of the donor site managed with local wound care and healing by secondary intention. CONCLUSIONS: For patients undergoing multiple-stage reconstruction of craniofacial microsomia, serial fat grafting is a useful tool for soft tissue reconstruction. Alternatively, in those patients with isolated soft tissue hypoplasia, such as progressive hemifacial atrophy, microvascular free tissue transfer is a safe and efficient option.

BACKGROUND:Impaired wound healing remains a major clinical problem with many etiologies. Altering gene expression to enhance healing is an innovative therapeutic approach. In recent years, we have developed a means to topically silence genes at the post-transcriptional level to locally alter wounds and improve the healing process. THE PROBLEM/OBJECTIVE:Many types of chronic wounds have been associated with alterations in the expression of genes that mediate healing. Targeting the expression of these genes in a way that can improve healing while limiting systemic side effects has been very challenging. BASIC/CLINICAL SCIENCE ADVANCES/UNASSIGNED:Our laboratory's recent work has focused on the use of topically applied small interfering ribonucleic acid (siRNA) to inhibit messenger RNA expression of certain mediators involved in healing in two different types of cutaneous injury-radiation-induced cutaneous injury and the diabetic excisional wound. By successfully inhibiting specific gene mediators with topical siRNA, we reversed downstream signaling pathways, which led to expedited wound healing in diabetic wounds and restoration to a more normal phenotype in radiation-induced skin injuries. CLINICAL CARE RELEVANCE/UNASSIGNED:The signaling pathways and gene mediators that we targeted and inhibited in murine models are present in humans. Applying parallel treatment strategies in humans may provide novel means of treating these burdensome and costly conditions. CONCLUSION/CONCLUSIONS:Our novel method for local gene silencing is effective in treating various types of cutaneous murine wounds. Topical gene silencing with siRNA obviates the side effects of systemic medication and has the potential to be effective in healing or preventing a wide array of cutaneous human conditions.

OBJECTIVE: This study aims to use the evidenced-based approach to better understand the surgical management and treatment of pressure ulcers. SUMMARY OF BACKGROUND DATA: Pressure sores are a cause of significant morbidity in the medical community. Although there are a multitude of preventative and treatment options, there remains some degree of uncertainty in the literature in defining the best way to treat and manage pressure sores. METHODS: An exhaustive literature search was performed using several electronic databases. The search revealed several identified modalities for treatment of pressure ulcers. We then assessed each modality individually for the level of evidence that exists in the most current literature, with preference given to more recent studies (2005-present). RESULTS: Here, we reviewed the most relevant, high-level evidence that exists for the following modalities for managing pressure ulcers from a surgical perspective: wound cleansers, repositioning, negative pressure therapy, enteral and parenteral feeding, vitamin and mineral supplementation, specialized mattresses, ultrasound therapy, honey, cellular therapy, debridement, ostectomy, and musculocutaneous and fasciocutaneous flap closure. CONCLUSIONS: Although many of the previously mentioned modalities are used, we encourage clinicians and health care providers to consider the evidence-based data when deciding how to most appropriately manage their patient's pressure sores.

BACKGROUND: Larger thoracic defects require stable yet flexible reconstruction to prevent flail chest and debilitating respiratory impairment. We present the use of locking rib-spanning plates as a chest salvage procedure. METHODS: A 30-year-old male presented with a massive desmoid tumor in the posterolateral aspect of the chest wall. The mass measured 22 by 14 by 6 cm and involved the posterior third through seventh ribs. The patient underwent wide excision and reconstruction in layers with a porcine dermal substitute for the pleura, locking rib-spanning plates for structural support, and coverage with ipsilateral latissimus dorsi. RESULTS: The patient tolerated the procedure without complication. He was extubated on postoperative day zero and has had an uneventful course. CONCLUSION: Chest wall reconstruction with rib-spanning plates is an alternative method of reconstruction for large chest wall defects. This method limits the foreign body burden while providing rigid structural support. This technique also makes chest wall reconstruction possible in situations that might previously have been treated with pneumonectomy.

Since obesity impairs wound healing and bone marrow (BM)-derived vasculogenic progenitor cells (PCs) are important for tissue repair, we hypothesize that obesity-impaired wound healing is due, in part, to impaired PC mobilization, trafficking, and function. Peripheral blood was obtained from nondiabetic, obese (BMI > 30, n = 25), and nonobese (BMI < 30, n = 17) subjects. Peripheral blood human (h)PCs were isolated, quantified, and functionally assessed. To corroborate the human experiments, 6-mm stented wounds were created on nondiabetic obese mice (TALLYHO/JngJ, n = 15) and nonobese mice (SWR/J, n = 15). Peripheral blood mouse (m)PCs were quantified and wounds were analyzed. There was no difference in the number of baseline circulating hPCs in nondiabetic, obese (hPC-ob), and nonobese (hPC-nl) subjects, but hPC-ob had impaired adhesion (p < 0.05), migration (p < 0.01), and proliferation (p < 0.001). Nondiabetic obese mice had a significant decrease in the number of circulating PCs (mPC-ob) at 7 (p = 0.008) and 14 days (p = 0.003) after wounding. The impaired circulating mPC-ob response correlated with significantly impaired wound closure at days 14 (p < 0.001) and 21 (p < 0.001) as well as significantly fewer new blood vessels in the wounds (p < 0.001). Our results suggest that obesity impairs the BM-derived vasculogenic PC response to peripheral injury and this, in turn, impairs wound closure.

BACKGROUND: Fat grafting has been shown clinically to improve the quality of burn scars. To date, no study has explored the mechanism of this effect. We aimed to do so by combining our murine model of fat grafting with a previously described murine model of thermal injury. METHODS: Wild-type FVB mice (n=20) were anaesthetised, shaved and depilitated. Brass rods were heated to 100 degrees C in a hot water bath before being applied to the dorsum of the mice for 10s, yielding a full-thickness injury. Following a 2-week recovery period, the mice underwent Doppler scanning before being fat/sham grafted with 1.5cc of human fat/saline. Half were sacrificed 4 weeks following grafting, and half were sacrificed 8 weeks following grafting. Both groups underwent repeat Doppler scanning immediately prior to sacrifice. Burn scar samples were taken following sacrifice at both time points for protein quantification, CD31 staining and Picrosirius red staining. RESULTS: Doppler scanning demonstrated significantly greater flux in fat-grafted animals than saline-grafted animals at 4 weeks (fat=305+/-15.77mV, saline=242+/-15.83mV; p=0.026). Enzyme-linked immunosorbent assay (ELISA) analysis in fat-grafted animals demonstrated significant increase in vasculogenic proteins at 4 weeks (vascular endothelial growth factor (VEGF): fat=74.3+/-4.39ngml(-1), saline=34.3+/-5.23ngml(-1); p=0.004) (stromal cell-derived factor-1 (SDF-1): fat=51.8+/-1.23ngml(-1), saline grafted=10.2+/-3.22ngml(-1); p<0.001) and significant decreases in fibrotic markers at 8 weeks (transforming growth factor-ss1(TGF-ss): saline=9.30+/-0.93, fat=4.63+/-0.38ngml(-1); p=0.002) (matrix metallopeptidase 9 (MMP9): saline=13.05+/-1.21ngml(-1), fat=6.83+/-1.39ngml(-1); p=0.010). CD31 staining demonstrated significantly up-regulated vascularity at 4 weeks in fat-grafted animals (fat=30.8+/-3.39 vessels per high power field (hpf), saline=20.0+/-0.91 vessels per high power field (hpf); p=0.029). Sirius red staining demonstrated significantly reduced scar index in fat-grafted animals at 8 weeks (fat=0.69+/-0.10, saline=2.03+/-0.53; p=0.046). CONCLUSIONS: Fat grafting resulted in more rapid revascularisation at the burn site as measured by laser Doppler flow, CD31 staining and chemical markers of angiogenesis. In turn, this resulted in decreased fibrosis as measured by Sirius red staining and chemical markers

ABSTRACT: The goal of this article was to illustrate the ease in which virtual surgery and computer-aided design and manufacturing can be used by the craniomaxillofacial surgeon to create tremendously accurate postoperative results and provide confidence with even the most complex three-dimensional bony reconstructions. With advancements in software technology and three-dimensional printing, our ability to plan and execute precise bony reconstruction has become a reality. With this technology, guides can be made to ensure exact bony repositioning or replacement. These guides can help guide cutting of the bone and can act as splints to precisely reposition the bone and direct plate placement. With use of these computer-aided design and manufacturing guides and the addition of guidance technology, the position of the bone can be guaranteed intraoperatively. We review our unique and advanced method in approaching some of these problems and illustrate the application of these techniques in mandibular reconstruction, orthognathic surgery, maxillofacial trauma, and temporomandibular joint reconstruction. This technology continues to evolve, and our indications for its application continue to grow. This article represents only a small portion of the types of cases in which these techniques have already been applied.