Comparing environmental impacts of deep-seabed and land-based mining: A defensible framework.

The crises of climate change and biodiversity loss are interlinked and must be addressed jointly. A proposed solution for reducing reliance on fossil fuels, and thus mitigating climate change, is the transition from conventional combustion-engine to electric vehicles. This transition currently requires additional mineral resources, such as nickel and cobalt used in car batteries, presently obtained from land-based mines. Most options to meet this demand are associated with some biodiversity loss. One proposal is to mine the deep seabed, a vast, relatively pristine and mostly unexplored region of our planet. Few comparisons of environmental impacts of solely expanding land-based mining versus extending mining to the deep seabed for the additional resources exist and for biodiversity only qualitative. Here, we present a framework that facilitates a holistic comparison of relative ecosystem impacts by mining, using empirical data from relevant environmental metrics. This framework (Environmental Impact Wheel) includes a suite of physicochemical and biological components, rather than a few selected metrics, surrogates, or proxies. It is modified from the "recovery wheel" presented in the International Standards for the Practice of Ecological Restoration to address impacts rather than recovery. The wheel includes six attributes (physical condition, community composition, structural diversity, ecosystem function, external exchanges and absence of threats). Each has 3-5 sub attributes, in turn measured with several indicators. The framework includes five steps: (1) identifying geographic scope; (2) identifying relevant spatiotemporal scales; (3) selecting relevant indicators for each sub-attribute; (4) aggregating changes in indicators to scores; and (5) generating Environmental Impact Wheels for targeted comparisons. To move forward comparisons of land-based with deep seabed mining, thresholds of the indicators that reflect the range in severity of environmental impacts are needed. Indicators should be based on clearly articulated environmental goals, with objectives and targets that are specific, measurable, achievable, relevant, and time bound.

Association between End-Stage Renal Disease and Major Adverse Limb Events after Peripheral Vascular Intervention.

PURPOSE: To examine the effect of end-stage renal disease (ESRD) on the likelihood of major adverse limb events (MALEs) in patients with Rutherford Category 4-6 critical limb ischemia (CLI) who underwent percutaneous vascular intervention (PVI). MATERIALS AND METHODS: Two contemporaneous cohorts of patients who underwent PVI for symptomatic CLI from 2012 to 2022, differing in ESRD status, were matched using propensity score methods. This database identified 628 patients who underwent 1,297 lower extremity revascularization procedures; propensity score matching yielded 147 patients (180 limbs, 90 limbs in each group). Kaplan-Meier and Cox proportional hazard analyses were used to assess the effect of ESRD status on MALEs, stratified into major amputation (further stratified into above-knee amputation and below-knee amputation [BKA]) and reintervention (PVI or bypass). RESULTS: After PVI, 31.3% of patients in the matched cohorts experienced a MALE (45.7% ESRD vs 18.2% non-ESRD), and 15.6% experienced a major amputation (27.1% ESRD vs 5.2% non-ESRD). Cox proportional hazards analysis revealed that ESRD was an independent predictor of MALE (hazard ratio [HR], 3.15; 95% CI, 1.58-6.29; P = .001), major amputation (HR, 7.00; 95% CI, 2.06-23.79; P = .002), and BKA (HR, 7.56; 95% CI, 1.71-33.50; P = .008). CONCLUSIONS: ESRD is strongly predictive of MALE and major amputation risk, specifically BKA, in patients undergoing PVI for Rutherford Category 4-6 CLI. These patients warrant closer follow-up, and new methods may become necessary to predict and further reduce their amputation risk.

Free flap reconstruction of elbow soft tissue defects: Lessons learned from 15 years of experience.

BACKGROUND: The elbow is a complex joint that is vital for proper function of the upper extremity. Reconstruction of soft tissue defects over the joint space remains challenging, and outcomes following free tissue transfer remain underreported in the literature. The purpose of this analysis was to evaluate the rate of limb salvage, joint function, and clinical complications following microvascular free flap coverage of the elbow. METHODS: This retrospective case series utilized surgical logs of the senior authors (Stephen J Kovach and L Scott Levin) to identify patients who underwent microvascular free flap elbow reconstruction between January 2007 and December 2021. Patient demographics and medical history were collected from the medical chart. Operative notes were reviewed to determine the type of flap procedure performed. The achievement of definitive soft tissue coverage, joint function, and limb salvage status at 1 year was determined from postoperative visit notes. RESULTS: Twenty-one patients (14 male, 7 female, median age 43) underwent free tissue transfer for coverage of soft tissue defects of the elbow. The most common indication for free tissue transfer was traumatic elbow fracture with soft tissue loss (n = 12, [57%]). Among the 21 free flaps performed, 71% (n = 15) were anterolateral thigh flaps, 14% (n = 3) were latissimus dorsi flaps, and 5% (n = 1) were transverse rectus abdominis flaps. The mean flap size was 107.5 cm2. Flap success was 100% (n = 21). The following postoperative wound complications were reported: surgical site infection (n = 1, [5%]); partial dehiscence (n = 5, [24%]); seroma (n = 2, [10%]); donor-site hematoma (n = 1, [5%]); and delayed wound healing (n = 5, [24%]). At 1 year, all 21 patients achieved limb salvage and definitive soft tissue coverage. Of the 17 patients with functional data available, 47% (n = 8) had regained at least 120 degrees of elbow flexion/extension. All patients had greater than 1 year of follow-up. CONCLUSION: Microvascular free flap reconstruction is a safe and effective method of providing definitive soft tissue coverage of elbow defects, as evidenced by high rates of limb salvage and functional recovery following reconstruction.

Identifying Health-Related Quality of Life Domains After Upper Extremity Transplantation.

OBJECTIVE: To identify the most important health-related quality of life (HRQOL) domains and patient-reported outcomes after upper extremity transplantation (UET) in individuals with upper extremity amputation. DESIGN: Verbatim audio-recordings of individual interviews and focus groups were analyzed using qualitative, grounded theory-based methods to identify important domains of HRQOL and provide guidance for outcomes measurement after UET. SETTING: Individual interviews were conducted by phone. Focus groups were conducted at 5 upper extremity vascularized composite allotransplantation (VCA) centers in the US and at an international conference of VCA experts. PARTICIPANTS: Individual phone interviews were conducted with 5 individuals with lived experience of UET. Thirteen focus groups were conducted with a total of 59 clinical professionals involved in UET. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Not applicable. RESULTS: Twenty-eight key HRQOL domains were identified, including physical functioning and medical complications, positive and negative emotional functioning, and social participation, relations, and independence. We identified key constructs for use in evaluation of the potentially substantial physical, medical, social, and emotional effects of UET. CONCLUSIONS: This study provides an overview of the most important issues affecting HRQOL after UET, including several topics that are unique to individuals with UET. This information will be used to establish systematic, comprehensive, and longitudinal measurement of post-UET HRQOL outcomes.

A Multicenter Prospective Randomized Comparison of Conduits Versus Decellularized Nerve Allograft for Digital Nerve Repairs.

PURPOSE: While there are advantages and disadvantages to both processed nerve allografts (PNA) and conduits, a large, well-controlled prospective study is needed to compare the efficacy and to delineate how each of these repair tools can be best applied to digital nerve injuries. We hypothesized that PNA digital nerve repairs would achieve superior functional recovery for longer length gaps compared with conduit-based repairs. METHODS: Patients (aged 18-69 years) presenting with suspected acute or subacute (less than 24 weeks old) digital nerve injuries were recruited to prticipate at 20 medical centers across the United States. After stratification to short (5-14 mm) and long (15-25 mm) gap subgroups, the patients were randomized (1:1) to repair with either a commercially available PNA or collagen conduit. Baseline and outcomes assessments were obtained either before or immediately after surgery and planned at 3-, 6-, 9-, and 12-months after surgery. All assessors and patients were blinded to the treatment arm. RESULTS: In total, 220 patients were enrolled, and 183 patients completed an acceptable last evaluable visit (at least 6 months and not more than 15 months postrepair). At last follow-up, for the short gap repair groups, average static two-point discrimination was 7.3 ± 2.8 mm for PNA and 7.5 ± 3.1 mm for conduit repairs. For the long gap group, average static two-point discrimination was significantly lower at 6.1 ± 3.3 mm for PNA compared with 7.5 ± 2.4 mm for conduit repairs. Normal sensation (American Society for Surgery of the Hand scale) was achieved in 40% of PNA long gap repairs, which was significantly more than the 18% observed in long conduit patients. Long gap conduits had more clinical failures (lack of protective sensation) than short gap conduits. CONCLUSIONS: Although supporting similar levels of nerve regeneration for short gap length digital nerve repairs, PNA was clinically superior to conduits for long gap reconstructions. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I.

Microvascular free tissue transfer for reconstruction of complex lower extremity trauma: Predictors of complications and flap failure.

BACKGROUND: Despite advanced wound care techniques, open fractures in the setting of lower extremity trauma remain a challenging pathology, particularly when free tissue transfer is required for coverage. We aimed to evaluate factors associated with flap failure in this setting using a large, heterogeneous patient population. METHODS: Retrospective review of patients who underwent traumatic lower extremity free flap reconstruction (2002-2019). Demographics wound/vessel injury characteristics, pre and perioperative factors, and flap outcomes were analyzed. RESULTS: One hundred eighty-eight free flaps met inclusion criteria, with 23 partial (12.2%) and 13 total (6.9%) flap failures. Angiography was performed in 87 patients, with arterial injury suffered in 43.1% of those evaluated. Time to flap coverage varied within 3 days (4.5%), 10 days (17.3%), or 30 days of injury (42.7%). In all, 41 (21.8%) subjects suffered from major flap complications, including failure and takebacks. Multivariate regression demonstrated the presence of posterior tibial (PT) artery injury predictive of both flap-failure (Odds ratio [OR] = 11.4, p < .015) and major flap complications (OR = 12.1, p < .012). Immunocompromised status was also predictive of flap failure (OR = 12.6, p < .004) and major complications (OR = 11.6, p < .007), while achieving flap coverage within 30 days was protective against flap complications (OR = 0.413, p < .049). Defect size, infection, and injury location were not associated with failure. CONCLUSIONS: When examining a large, heterogeneous patient cohort, free flap outcomes in the setting of lower extremity open fractures can be influenced by multiple factors. This presence of PT artery injury, flap coverage beyond 30 days of injury, and immunocompromised status appear predictive of flap complications in this context.

What is needed to ensure long-term sustainability for the field of vascularized composite allotransplantation?

The field of vascularized composite allotransplantation (VCA) has demonstrated remarkable advances since its inception with some excellent long-term results in a variety of graft types. However, unlike solid organ transplantation, it has yet to become mainstream. We therefore discuss strategies on ensuring long-term sustainability by addressing continued clinical developments of VCA to improve the risk-to-benefit balance, importance of public support, improved policy and financial support, and need for a bridge to the future of transplant surgery. There has been headway on all fronts and collaboration among the VCA centers for centralization of data and incorporation of patient voices will be essential for continued progress.

Replantation versus transplantation: Where do we stand?

PURPOSE: Despite advances in extremity trauma care and reconstructive microsurgery, management of the traumatic amputations remains a challenge. The majority of patients will forever experience some level of disability even with replantation or advanced prosthetics. The goal of this article is to familiarize hand and reconstructive surgeons with the current state of upper extremity transplantation, so they better can educate their amputee patients regarding this as an option following limb loss. METHODS: Current literature, in addition to the international registry on hand and composite tissue transplantation, was reviewed to assemble a summary of outcomes in upper extremity replantation and transplantation. RESULTS: Sensory and functional outcomes of replantation and transplantation are comparable. Reported complications of immunosuppression are similar to those of other solid organ transplants. The financial cost of hand transplantation is high, but comparable to the lifetime cost of prosthesis use. CONCLUSION: While the risk of immunosuppression is a serious consideration for patients pursuing hand transplantation, in the well-selected and informed patient, hand transplantation can dramatically improve patient reported to outcomes and quality of life.

Effects of neurodevelopmental risk factors on brainstem maturation in premature infants.

BACKGROUND: Interpeak latencies (IPL), as measured by the auditory brainstem-evoked responses (ABR) test, represent the conduction time, and therefore the maturation of the brainstem auditory pathway. We aimed to study the effect of various risk factors for the neurodevelopmental delay on the conduction time in the auditory pathway among normal hearing premature infants, at term postmenstrual age (PMA). METHODS: Retrospective analysis of 239 premature infants (gestational age 32.5 ± 2.1 weeks, birth weight 1827 ± 483 g). Interpeak latencies, demographic data, and risk factors were recorded. RESULTS: Sex, PMA at ABR test, being small for gestational age (SGA), intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL), and days of invasive ventilation were found to significantly affect the IPL's in the auditory pathway in a univariate analysis. Multivariable regression analysis revealed that male sex and less advanced PMA at the examination were independent factors associated with prolonged IPL's, while bronchopulmonary dysplasia, IVH or PVL and being SGA shortened the IPL's. Non-invasive mechanical ventilation, did not affect the caudal part of the auditory pathway, despite its high noise level. CONCLUSIONS: Among various risk factors for the neurodevelopmental delay, male sex was associated with delayed, while IVH or PVL, BPD and SGA could be associated with accelerated auditory brainstem maturation. IMPACT: Auditory brainstem-evoked response (ABR) test, among normal hearing infants, can serve as a clinical tool to assess brainstem auditory maturation. Different neurodevelopmental risk factors could have different effects on the maturity of the auditory pathway. Male sex is significantly associated with prolonged interpeak latencies (IPL) among preterm and term infants, while intraventricular hemorrhage or periventricular leukomalacia, bronchopulmonary dysplasia, and being small for gestation age may be associated with shortened IPL The corrected age at ABR testing is of significance, among preterm and term infants.

Impact of fixed-dose combination Cal/BD foam on the work productivity of patients with psoriasis: results from the 52-week randomized, double-blind, PSO-LONG trial.

BACKGROUND: Psoriasis contributes to unemployment, work impairment, missed workdays and substantial indirect costs due to lost productivity. Combination Cal/BD foam is the only topical that is approved for long-term maintenance treatment of plaque psoriasis for 52 weeks. This is the first known investigation of the effect of topical psoriasis therapy on productivity. OBJECTIVE: To examine the change in work productivity and activity impairment after 4 weeks of treatment with fixed-dose combination calcipotriol 50 µg/g/betamethasone dipropionate 0.5 mg/g (Cal/BD) foam and observe long-term changes after 52 weeks of long-term management (proactive or reactive treatment). METHODS: This is a post-hoc analysis of the PSO-LONG trial - a phase 3, randomized, double-blind, vehicle-controlled, parallel group, international multi-centre trial of treatment with combination Cal/BD foam. Work and activity impairment due to psoriasis were assessed by the Dermatology Life Quality Index (DLQI) and the Work Productivity and Activity Impairment Psoriasis (WPAI:PSO) questionnaire at baseline, week 4, week 28 and week 56. The improvement in hours of work productivity was translated into monthly and annual indirect cost savings estimates for patients in Italy, Sweden, United Kingdom, Canada and Germany. RESULTS: Using fixed-dose combination Cal/BD foam for four weeks significantly reduced psoriasis-related work presenteeism, total work productivity impairment (TWPI) and total activity impairment (TAI) over 56 weeks, with significant improvements observed as early as 4 weeks after the baseline visit. The proportion of patients reporting impact on work productivity (as measured by presenteeism and TWPI) and activity impairment (as measured by both DLQI-Q7b and TAI) also decreased. CONCLUSION: Fixed-dose combination Cal/BD foam used for long-term management of psoriasis significantly reduces psoriasis-related work productivity and activity impairment which may result in substantial indirect cost savings. Clinical Trial Registration NCT02899962, EudraCT number: 2016-000556-95.

5-Year Activity and Participation Outcomes of the First Successful Pediatric Bilateral Hand Transplantation: A Case Report.

AIMS: Describe the 5-year outcomes of the first successful pediatric bilateral hand transplantation. METHODS: The child underwent quadrimembral amputation at age two and received bilateral hand allografts at age eight. Rehabilitation included biomechanical, neurorehabilitation, and occupational approaches in acute and outpatient settings. Therapist observed outcomes, patient-reported measures, and parent-reported measures were repeated over a 5-year period. RESULTS: Observation assessments revealed functional dexterity skills and modified independence to full independence with self-care activities. The parent reported the child had moderate difficulty with upper extremity functioning 25-, 41-, and 48-months post-transplantation, and mild difficulty at 60-months; the child reported no difficulties in this domain at 41 months. Five years post-transplantation the child reported enjoying many age-appropriate activities, and high-quality peer relations were endorsed by both parent and child. CONCLUSION: The child developed hand movements for daily activities and was completing daily activities with improved efficiency. Health-related quality of life outcomes were favorable.

ACCURACY OF CLINICAL AND RADIOGRAPHIC MEASUREMENTS OF PERIODONTAL INFRABONY DEFECTS OF DIAGNOSTIC TEST ACCURACY (DTA) STUDIES: A SYSTEMATIC REVIEW AND META-ANALYSIS.

BACKGROUND: The aim of this study was to determine the accuracy of clinical and radiographic measurements of infrabony periodontal defects. METHODS: The MEDLINE-Pubmed and Cochrane-CENTRAL electronic databases were searched from initiation to May 2020. The inclusion criteria were clinical trials, human subjects with at least one infrabony defect, measurements of clinical attachment level (CAL), radiographic bone level (rBL), and intraoperative bone level (iBL) used as the reference standard. RESULTS: In total, 11 studies including 17 comparisons were included in this meta-analysis. All 17 comparisons showed that the values of the CAL and rBL measurements underestimated the iBL values. For CAL, the analysis showed a significant difference of means of -1.22 (P < .00001; 95%CI: [-1.49; -0.95]) and for rBL -1.10 (P < .00001; 95%CI: [-1.34; -0.85]). No significant DiffM were observed between the CAL and rBL measurements (DiffM -0.05; P = .76; 95%CI: [-0.39; 0.28]). CONCLUSION: The results of this systematic review and meta-analysis show that both clinical and radiographic measurements substantially underestimate the bone level when compared to intraoperative level measurements. However, there was no significant difference in the results between the clinical attachment level measurements and the radiographic observation.

Retrospective evaluation of endodontic case reports published in the International Endodontic Journal and the Journal of Endodontics for their compliance with the PRICE 2020 guidelines.

AIM: To evaluate, retrospectively, the quality of previously published case reports in Endodontics according to the PRICE 2020 guidelines. METHODOLOGY: An electronic literature search was conducted in PubMed database on 12 March 2020, to identify case reports published during the last five years in the International Endodontic Journal and the Journal of Endodontics. For each of the included case reports, information regarding fulfilment of each of the items of the PRICE 2020 guidelines was extracted as '0' (not present in the manuscript), '1' (present in the manuscript) and 'NA' (not applicable) and translated into a score (percentage of items fulfilled). Additionally, the percentage of papers fulfilling each item was calculated. RESULTS: Overall, 70 endodontic case reports were identified. The scores of the papers ranged between 56.41% and 79.55%, with a mean score of 70.26 ± 4.36% (SD). The percentage of papers fulfilling each item of the applicable PRICE 2020 items ranged widely, between 0% and 100%. The median of the percentage of all the items (n = 47) was 97.01% and mean 73.33 ± 36.28% (SD). The lowest scores were recorded for specific items in the following domains: 'Case Report Information'-Items 6c, 6g-i, 'Patient Perspective'-Item 8a and 'Quality of Images'-Items 12c-d. CONCLUSIONS: Several areas with low reporting rates were identified in case reports published over the last 5 years in Endodontics. Authors should be encouraged to follow the PRICE 2020 guidelines in order to increase the quality and improve reproducibility of their case reports.

Hand Trauma Network in the United States: ASSH Member Perspective Over the Last Decade.

PURPOSE: Upper extremity trauma is common, however the provision of emergency call for hand trauma can be challenging for hospital systems and hand surgeons. Over the past decade, the American Society for Surgery of the Hand (ASSH) has developed the Hand Trauma Network and an Emergency Hand Care Committee to refine care for hand trauma patients. METHODS: The ASSH administered surveys to members about the provision of emergency hand call in 2010 and 2019. Demographic information was collected including surgeon age, years in practice, board certification, practice setting, and ACS trauma level. Other survey questions included willingness and obligation to take call, as well as barriers to providing emergency call. Financial aspects of call were also queried. RESULTS: Survey responses were obtained from 672 surgeons in 2010 and 1005 surgeons in 2019. There was a decrease in surgeons with obligatory hand call from 2010 to 2019 (70% vs 50%, P < .05) and an increase in the number of surgeons not taking hand call in 2019 (34%) compared to 2010 (18%, P < .05). In both surveys, the main barrier for providing hand call was "lifestyle considerations," 39% (2010) and 47% (2019). There was no change in the percentage of surgeons working at facilities that provide 24/7 emergency hand call services or the percentage of hand surgeons paid to take call. CONCLUSIONS: Certain aspects of providing emergency hand surgery care have not changed substantially in the past decade, including the number of centers that provide emergency hand coverage. A greater number of surgeons are not taking any hand call. Further efforts are required to promulgate advances in hand trauma call by the ASSH. CLINICAL RELEVANCE: The development of the ASSH Hand Trauma Network has not yet resulted in substantive improvement in the number of facilities that provide emergency hand coverage or the number of hand surgeons providing emergency hand care.

Applying the Delphi Method to Define a Focus for the National Outcomes Registry for Tracking the Hand (NORTH).

Surgical registries have provided reliable, generalizable, and applicable clinical data that have shaped many fields. Broad collection of defined data can answer clinical questions with greater numbers of patients and more ability to generalize to routine clinical care than randomized trials. National hand surgical registries exist outside the United States. Before the pursuit of a registry, the focus of such an effort must be defined to ensure that registry goals are feasible. This article presents the consensus process conducted by the American Society for Surgery of the Hand's Registry Task Force exploring potential diagnoses for a hand registry.

Principles of Orthoplastic Surgery for Lower Extremity Reconstruction: Why Is This Important?

BACKGROUND: Regardless of the antecedent etiology, lower extremity salvage and reconstruction attempts to avoid amputation, restore limb function, and improve quality of life outcomes. This goal requires a treatment team well versed in neurovascular pathology, skeletal and soft tissue reconstruction, and physical rehabilitation. METHODS: A review was performed of historical milestones that lead to the development of orthoplastic extremity reconstruction, principles of current management and the evidence that supports an orthoplastic approach. Based on available evidence and expert opinion, the authors further sought to provide insight into the future of the field centered around the importance of a multidisciplinary management protocol. RESULTS: Historically, orthopaedic and plastic surgeons worked separately when faced with challenging reconstructive cases involving lower extremity skeletal and soft tissue reconstruction. With time, many embraced that their seemingly separate skill-sets and knowledge could be unified in a collaborative orthoplastic approach in order to offer patients the best possible chance for success. First coined by the senior author (LSL) in the early 1990s, the collaborative orthoplastic approach between orthopaedic and plastic surgeons in limb salvage for the past several decades has resulted in a unique field of reconstructive surgery. Benefits of the orthoplastic approach include decreased time to definitive skeletal stabilization/soft tissue coverage, length of hospital stay, post-operative complications, need for revision procedures and improved functional outcomes. CONCLUSION: The orthoplastic approach to lower extremity reconstruction is a collaborative model of orthopaedic and plastic surgeons working together to expedite and optimize care of patients in need of lower extremity reconstruction. The implementation of protocols, systems, and centers that foster this approach leads to improve outcomes for these patients. We encourage centers to embrace the orthoplastic approach when considering limb salvage, as the decision to amputate is irreversible.

The Role of Cadaver-Based Flap Course in Microsurgical Education and Practice Patterns of Attendees: A Survey Study.

BACKGROUND: In 2017, our institution initiated a cadaver laboratory-based course dedicated to teaching reconstructive microsurgery indications, preoperative planning, and flap dissection. The goals of this study are to describe the demographics and experience of participants/instructors and to evaluate the learning objectives and effectiveness of the course. METHODS: Penn Flap Course (PFC) participants were sent an anonymous survey at the inaugural PFC 2017. Then, in 2019, both instructors and participants were sent a more comprehensive survey. Surveys included questions regarding demographics, training background, experiences in practice and/or training, and course evaluation. RESULTS: At PFC 2017, participant response rate was 25% (12/44), and the primary reason for attending the course was to observe and learn from instructor dissections (66.7%). At PFC 2019, the response rate was 77.3% (17/22) for faculty and 73.0% (35/48) for participants. Both in 2017 and 2019, the vast majority of participants reported perceived improvement in understanding of flap dissection principles across all anatomic domains (94.3%-100%). In 2019, when asked about their background experience, the majority of participants reported comfort performing arterial and venous anastomosis without supervision (71%-77%) and being least comfortable with head and neck (H&N) microsurgery (mean comfort level: 5.2/10). Half of the participants (e.g., residents) find the presence of a microsurgery fellow at their institution useful to their educational experience. Instructors with additional fellowship training in microsurgery reported performing a higher volume of free flaps per week (7 vs. 2.3) and per year (94.2 vs. 27.8; p < 0.05 for both) and trend toward performing more H&N reconstruction (p = 0.057). CONCLUSION: Participants feel least comfortable with H&N microsurgical reconstruction. Surgical faculty with microsurgical fellowship training performs greater volume of microsurgical cases with a trend toward more H&N reconstruction. A cadaver/lecture-based flap course is an effective way to improve participants' perceived confidence and understanding of complex flap and microsurgical reconstructive procedures.

Removal of dyes by immobilization of Trametes versicolor in a solid-state micro-fermentation system.

A novel bioreactor system (low cost and easily scaled-up) is presented for dye decolorization applying filamentous fungi. In this two-phase bioreactor, dyes were decolorized at 28°C in a first phase by immobilized fungi in spherical cartridges prepared with a high-density plastic polyethylene mesh and filled with wheat bran as substrate for growth. In a second phase the capacity of the ligninolytic enzymes (laccase and Mn-peroxidase) present in the extracellular extracts from the solid residues was exploited for decolorization at 50°C. Each sphere behaved as a small-scale bioreactor for cell-culture. This system allowed the decoupling of growth (sterile condition) and decolorization (non-sterile condition) stages. The ability to decolorize the azo dye xylidine and the triphenylmethane Malachite Green by two Argentinean strains of Trametes versicolor was evaluated. The highest decolorization rates were displayed by T. versicolor BAFC 2234. When both dyes were applied together in the bioreactor, after a first phase (100min) 73.5% of Malachite Green and 40% of xylidine decolorization was attained, while at the end of the second phase (240min) a 97% and 52% decolorization was observed. Laccase activity was detected in the decolorized solution, but no Mn-peroxidase activity. The easy change of the cartridges allows the continuous use of the bioreactor in the non-sterile decolorization of dye-containing effluents.

Characterization of a mouse model to study the relationship between apical periodontitis and atherosclerosis.

AIM: First, to determine the feasibility of using the low-density lipoprotein receptor knockout (LDLR KO) mouse model to study apical periodontitis (AP). Secondly, to investigate the causal relationship between AP and atherosclerosis. It was hypothesized that it would be feasible to induce AP and atherosclerosis in LDLR KO mice and find a difference in atherosclerosis between AP and Sham groups. METHODOLOGY: Using a published methodology, AP was induced in LDLR KO mice by exposing the dental pulp of the four first molars (Tx). Shams received only anaesthesia. Mice were fed a high fat, Western-type diet (WTD), to induce atherosclerosis. At 16 weeks, mice were euthanized and aortas collected to measure atherosclerosis lesion burden (oil red O staining). Periapical lesions were validated using micro-CT and histology. Systemic inflammation was measured using a cytokine array. RESULTS: Both groups developed a similar degree of atherosclerosis (mean lesion area 7.46 ± 0.44% in the Tx group compared with 7.65 ± 0.46%, in the Sham group, P = 0.77), and a similar degree of inflammation. Periapical lesions (PALs) in all four molars were only identified in a small subset of Tx mice. CONCLUSIONS: A novel mouse model, which combines AP and CVD, was created. This model allows investigation of the relationship between the two diseases, whilst avoiding other potential common confounders. Although no difference in the degree of atherosclerosis was found between the groups, more studies in which the number of periapical lesions, changes in systemic inflammation and the degree of atherosclerosis are correlated are necessary to ultimately determine the impact of AP on CVD.

Reconstruction of Traumatic Defects of the Tibia With Free Fibula Flap and External Fixation.

INTRODUCTION: Traumatic intercalary defects of the tibia may be effectively managed with the free fibula flap. However, any alteration of limb alignment with residual bony angular deformity of the tibia must be also addressed. We describe the use of the free fibula flap in conjunction with external fixation to allow residual deformity correction and patient mobilization ambulation during healing of the free flap. METHODS: Retrospective medical record review was conducted of patients with segmental tibial defects greater than 7 cm who underwent reconstruction with fibula free flap and simple pin-bar external fixation, followed by conversion to 6-axis computer-assisted multiplanar circular ring external fixation to correct residual bony deformity. Outcomes analyses included free flap complications, return to the operating room, complications associated with the external fixation, bony union, correction of residual deformity, amputation rate, visual analog pain scales, and patient satisfaction. RESULTS: Eight patients (8 tibiae) underwent reconstruction. Mean tibial bone defect was 10.2 cm; all limbs had soft-tissue defects (mean size, 138 cm). Free fibula grafts were harvested as osteocutaneous or osteomyocutaneous flaps (average length, 12 cm). Complications included 1 delayed union and 3 (37.5%) patients readmitted for graft fracture. Ultimately, 100% of patients achieved graft union with satisfactory correction of residual limb deformity. Limb salvage rate was 100%. DISCUSSION: Management of segmental tibial bone loss utilizing initial simple external fixation and microsurgical reconstruction followed by application of computer-assisted circular external fixator may provide a reliable reconstructive protocol for posttraumatic tibial defects with residual bone malalignment.