Faculty Bibliography

BACKGROUND: Patients undergoing implant-based reconstruction in the setting of postmastectomy radiation therapy suffer from increased complications and inferior outcomes compared with those not irradiated, but advances in radiation delivery have allowed for more nuanced therapy. The authors investigated whether these advances impact patient outcomes in implant-based breast reconstruction. METHODS: Retrospective chart review identified all implant-based reconstructions performed at a single institution from November of 2010 to November of 2013. These data were cross-referenced with a registry of patients undergoing breast irradiation. Patient demographics, treatment characteristics, and outcomes were analyzed. RESULTS: Three hundred twenty-six patients (533 reconstructions) were not irradiated, whereas 83 patients (125 reconstructions) received radiation therapy; mean follow-up was 24.7 months versus 26.0 months (p = 0.49). Overall complication rates were higher in the irradiated group (35.2 percent versus 14.4 percent; p < 0.01). Increased maximum radiation doses to the skin were associated with complications (maximum dose to skin, p = 0.05; maximum dose to 1 cc of skin, p = 0.01). Different treatment modalities (e.g., three-dimensional conformal, intensity-modulated, field-in-field, and hybrid techniques) did not impact complication rates. Prone versus supine positioning significantly decreased the maximum skin dose (58.5 Gy versus 61.7 Gy; p = 0.05), although this did not translate to significantly decreased complication rates in analysis of prone versus supine positioning. CONCLUSIONS: As radiation techniques evolve, the maximum dose to skin should be given consideration similar to that for heart and lung dosing, to optimize reconstructive outcomes. Prone positioning significantly decreases the maximum skin dose and trends toward significance in reducing reconstructive complications. With continued study, this may become clinically important. Interdepartmental studies such as this one ensure quality of care. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

OBJECTIVE: To evaluate the effect of light-curing wavelengths on composite filler particle displacement, and thus to visualize localized polymerization shrinkage in a resin-based composite (RBC) containing camphorquinone (CQ) and Lucirin TPO (TPO). METHODS: Three light-curing units (LCUs) were used to light-cure a RBC containing CQ and TPO: a violet-only, a blue-only, and a dual-wavelength, conventional (Polywave(R), emitting violet and blue wavelengths simultaneously). Zirconia fillers were added to the RBC to act as filler particle displacement tracers. LCUs were characterized for total emitted power (mW) and spectral irradiant output (mW/cm2/nm). 2-mm high, 7-mm diameter silanized glass cylindrical specimens were filled in a single increment with the RBC, and micro-computed tomography (mu-CT) scans were obtained before and after light-curing, according to each LCU (n=6). Filler particle movement identified polymerization shrinkage vectors, traced using software, at five depths (from 0 up to 2mm): top, top-middle, middle, middle-bottom and bottom. RESULTS: Considering different RBC depths within the same LCU, use of violet-only and conventional LCUs showed filler particle movement decreased with increased depth. Blue-only LCU showed homogeneous filler particle movement along the depths. Considering the effect of different LCUs within the same depth, filler particle movement within LCUs was not statistically different until the middle of the samples (P>.05). However, at the middle-bottom and bottom depths (1.5 and 2mm, respectively), blue-only LCU compared to violet-only LCU showed higher magnitude of displacement vector values (P<.05). Use of the conventional LCU showed filler displacement magnitudes that were not significantly different than blue-only and violet-only LCUs at any depth (P>.05). With respect to the direction of particle movement vectors, use of violet-only LCU showed a greater displacement when close to the incident violet LED; blue-only LCU showed equally distributed particle displacement values within entire depth among the samples; and the conventional LCU showed greater filler displacement closer to the blue LED locations. SIGNIFICANCE: Filler particle displacement in a RBC as a result of light-curing is related to localized application of light wavelength and total emitted power of the light emitted on the top surface of the RBC. When the violet LED is present (violet-only and conventional LCUs), filler particle displacement magnitude decreased with increased depth, while results using the blue-only LED show a more consistent pattern of displacement. Clinically, these results correlate to production of different characteristics of curing within a RBC restoration mass, depending on localized wavelengths applied to the irradiated surface.

A global outbreak of invasive Mycobacterium chimaera infections after cardiac surgery has recently been linked to bioaerosols from contaminated heater-cooler units. The majority of cases have occurred after valvular surgery or aortic graft surgery and nearly half have resulted in death. To date, infections in patients with left ventricular assist devices (LVADs) have not been characterized in the literature. We report two cases of device-associated M. chimaera infection in patients with continuous-flow LVADs and describe challenges related to diagnosis and management in this population.

GENERAL PURPOSE: To provide information on risk factors for surgical site infections (SSIs) and actions to mitigate that risk. TARGET AUDIENCE: This continuing education activity is intended for surgeons, surgical teams, physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After participating in this educational activity, the participant should be better able to:1. Identify modifiable risk factors associated with the development of SSIs.2. Select steps to mitigate the risks for and morbidity from SSIs. ABSTRACT: Given the current reimbursement structure, the avoidance of a surgical site infection (SSI) is crucial. Although many risk factors are associated with the formation of an SSI, a proactive and interprofessional approach can help modify some factors. Postoperative strategies also can be applied to help prevent an SSI. If an SSI becomes a chronic wound, there are recommended guidelines and strategies that can foster healing.

Cancer patients in pain require high doses of opioids and quickly become opioid-tolerant. Previous studies have shown that both chronic cancer pain and high dose opioid use lead to mu-opioid receptor down-regulation. In this study we explore down-regulation of OPRM1, the mu-opioid receptor gene, as a mechanism f,or opioid tolerance in the setting of opioid use for cancer pain. We demonstrate in a cohort of 84 cancer patients that high dose opioid use correlates with OPRM1 hypermethylation in peripheral leukocytes of these patients. We then reverse-translate our clinical findings by creating a mouse cancer pain model; we create opioid tolerance in the mouse cancer model to mimic opioid tolerance in the cancer patients. Using this model we determine the functional significance of OPRM1 methylation on cancer pain and opioid tolerance. We focus on two main cells within the cancer microenvironment: the cancer cell and the neuron. We show that targeted re-expression of mu-opioid receptor on cancer cells inhibits mechanical and thermal hypersensitivity, and prevents opioid tolerance, in the mouse model. The resultant analgesia and protection against opioid tolerance are likely due to preservation of mu-opioid receptor expression on the cancer-associated neurons.

PURPOSE: Currently, surgeons approach autogenous microtia repair by creating a two-dimensional (2D) tracing of the unaffected ear to approximate a three-dimensional (3D) construct, a difficult process. To address these shortcomings, this study introduces the fabrication of patient-specific, sterilizable 3D printed auricular model for autogenous auricular reconstruction. METHODS: A high-resolution 3D digital photograph was captured of the patient's unaffected ear and surrounding anatomic structures. The photographs were exported and uploaded into Amira, for transformation into a digital (.stl) model, which was imported into Blender, an open source software platform for digital modification of data. The unaffected auricle as digitally isolated and inverted to render a model for the contralateral side. The depths of the scapha, triangular fossa, and cymba were deepened to accentuate their contours. Extra relief was added to the helical root to further distinguish this structure. The ear was then digitally deconstructed and separated into its individual auricular components for reconstruction. The completed ear and its individual components were 3D printed using polylactic acid filament and sterilized following manufacturer specifications. RESULTS: The sterilized models were brought to the operating room to be utilized by the surgeon. The models allowed for more accurate anatomic measurements compared to 2D tracings, which reduced the degree of estimation required by surgeons. Approximately 20 g of the PLA filament were utilized for the construction of these models, yielding a total material cost of approximately $1. CONCLUSION: Using the methodology detailed in this report, as well as departmentally available resources (3D digital photography and 3D printing), a sterilizable, patient-specific, and inexpensive 3D auricular model was fabricated to be used intraoperatively. This technique of printing customized-to-patient models for surgeons to use as 'guides' shows great promise.

GENERAL PURPOSE: To provide information from a review of the literature about chronic ulcers associated with tophaceous gout. TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After participating in this educational activity, the participant should be better able to:1. Identify the pathophysiology of tophaceous gout, its presentation, phases, and common comorbidities.2. Evaluate the findings in this review regarding effectiveness of interventions for chronic tophaceous ulcers. ABSTRACT: OBJECTIVE: Treating chronic ulcers associated with tophaceous gout is an uncommon but important clinical challenge. However, treatments vary greatly from topical therapies, to debridements, to free flap wound coverage. To the authors' knowledge, this is the first study to assemble and compare these different approaches in order to guide effective treatment. DATA SOURCES: An electronic search of MEDLINE (PubMed) was conducted. Search terms included (gout and ulcer) not "peptic ulcer," and (gout, chronic wound) or (gout, nonhealing wound). STUDY SELECTION: Studies that discussed the presentation, characterization, or treatment of gout-associated wounds were included. The literature search yielded 9 case reports and case series; there were no randomized controlled studies or reviews. DATA EXTRACTION: Patient and wound characteristics, treatment approaches, and outcomes were noted. DATA SYNTHESIS: The 82% of 22 patients were male, aged 36 to 95 years. Three patients had not been previously diagnosed with gout, whereas others had received a diagnosis 2 to 35 years prior to presentation with an ulcer. Many patients had comorbidities including diabetes and peripheral vascular disease. Most of the 43 total ulcers occurred on the feet. Treatments included topical 3% citric acid in petroleum jelly, allogeneic culture dermal substitute, silver-containing dressing and heterologous lyophilized collagen, debridements, and free flap coverage. CONCLUSIONS: Chronic tophaceous wounds are a worldwide problem. Although physicians report some successes with different treatments, controlled studies are needed to determine the most effective approach and to identify risk factors and preventive strategies.

PURPOSE: This study evaluated whether simplified drilling protocols would provide comparable histologic and histomorphometric results to conventional drilling protocols at a low rotational speed. MATERIALS AND METHODS: A total of 48 alumina-blasted and acid-etched Ti-6Al-4V implants with two diameters (3.75 and 4.2 mm, n = 24 per group) were bilaterally placed in the tibiae of 12 dogs, under a low-speed protocol (400 rpm). Within the same diameter group, half of the implants were inserted after a simplified drilling procedure (pilot drill + final diameter drill), and the other half were placed using the conventional drilling procedure. After 3 and 5 weeks, the animals were euthanized, and the retrieved bone-implant samples were subjected to nondecalcified histologic sectioning. Histomorphology, bone-to-implant contact (BIC), and bone area fraction occupancy (BAFO) analysis were performed. RESULTS: Histology showed that new bone was formed around implants, and inflammation or bone resorption was not evident for both groups. Histomorphometrically, when all independent variables were collapsed over drilling technique, no differences were detected for BIC and BAFO; when drilling technique was analyzed as a function of time, the conventional groups reached statistically higher BIC and BAFO at 3 weeks, but comparable values between techniques were observed at 5 weeks; 4.2-mm implants obtained statistically higher BAFO relative to 3.75-mm implants. CONCLUSION: Based on the present methodology, the conventional technique improved bone formation at 3 weeks, and narrower implants were associated with less bone formation.