Sleep is required to consolidate odor memory and remodel olfactory synapses.

Animals with complex nervous systems demand sleep for memory consolidation and synaptic remodeling. Here, we show that, although the Caenorhabditis elegans nervous system has a limited number of neurons, sleep is necessary for both processes. In addition, it is unclear if, in any system, sleep collaborates with experience to alter synapses between specific neurons and whether this ultimately affects behavior. C. elegans neurons have defined connections and well-described contributions to behavior. We show that spaced odor-training and post-training sleep induce long-term memory. Memory consolidation, but not acquisition, requires a pair of interneurons, the AIYs, which play a role in odor-seeking behavior. In worms that consolidate memory, both sleep and odor conditioning are required to diminish inhibitory synaptic connections between the AWC chemosensory neurons and the AIYs. Thus, we demonstrate in a living organism that sleep is required for events immediately after training that drive memory consolidation and alter synaptic structures.

Wireless Pressure Ulcer Sensor: Validation in an Animal Model.

Pressure ulcers are increasingly prevalent in an aging population. The most commonly used method of pressure ulcer prevention is pressure off-loading achieved by physically turning bedbound patients or by using expensive, single application devices such as wheelchair cushions. Our aim is to approach the problem of pressure ulcer prevention in a new way: a wireless sensor worn by the patient at locations susceptible to pressure injury. The sensor will monitor local pressure over time and transmits the data wirelessly to a base station (in a hospital setting) or smartphone (for home care). When a condition that would be harmful to tissue is reached, an alert would enable immediate direct intervention to prevent development of a pressure ulcer. The goal of this study was to validate the sensor's use in a live animal model and to lay the foundation for building time-pressure curves to predict the probability of pressure injury. Sprague-Dawley rats underwent surgical implantation of bilateral steel discs deep to the latissimus dorsi muscles. After the animals recovered from the surgical procedure, pressure was applied to the overlying tissue using magnets of varying strengths (30-150 mm Hg) for between 1 and 8 hours. Our sensor was placed on the skin prior to magnet application to wirelessly collect data regarding pressure and time. Three days after pressure application, animals were killed, injuries were graded clinically, and biopsies were collected for histological analysis. Results reveal that all animals with magnet application for more than 2 hours had clinical evidence of ulceration. Similarly, histological findings of hemorrhage were associated with increased time of pressure application. However, at high pressures (120-150 mm Hg), there were ischemic changes within the muscular layer without corresponding skin ulceration. We have developed a wireless sensor that can be placed on any at-risk area of the body and has the potential to alert caregivers when patients are at risk of developing a pressure injury. Our sensor successfully transmitted pressure readings wirelessly in a live, mobile animal. Future studies will focus on safety and efficacy with human use and development of algorithms to predict the probability of pressure ulcer formation.

Kappa opioid receptors regulate hippocampal synaptic homeostasis and epileptogenesis.

OBJECTIVE: Homeostatic synaptic plasticity (HSP) serves as a gain control mechanism at central nervous system (CNS) synapses, including those between the dentate gyrus (DG) and CA3. Improper circuit control of DG-CA3 synapses is hypothesized to underlie epileptogenesis. Here, we sought to (1) identify compounds that preferentially modulate DG-CA3 synapses in primary neuronal culture and (2) determine if these compounds would delay or prevent epileptogenesis in vivo. METHODS: We previously developed and validated an in vitro assay to visualize the behavior of DG-CA3 synapses and predict functional changes. We used this "synapse-on-chip" assay (quantification of synapse size, number, and type using immunocytochemical markers) to dissect the mechanisms of HSP at DG-CA3 synapses. Using chemogenetic constructs and pharmacological agents we determined the signaling cascades necessary for gain control at DG-CA3 synapses. Finally, we tested the implicated cascades (using kappa opioid receptor (OR) agonists and antagonists) in two models of epileptogenesis: electrical amygdala kindling in the mouse and chemical (pentylenetetrazole) kindling in the rat. RESULTS: In vitro, synapses between DG mossy fibers (MFs) and CA3 neurons are the primary homeostatic responders during sustained periods of activity change. Kappa OR signaling is both necessary and sufficient for the homeostatic elaboration of DG-CA3 synapses, induced by presynaptic DG activity levels. Blocking kappa OR signaling in vivo attenuates the development of seizures in both mouse and rat models of epilepsy. SIGNIFICANCE: This study elucidates mechanisms by which synapses between DG granule cells and CA3 pyramidal neurons undergo activity-dependent homeostatic compensation, via OR signaling in vitro. Modulation of kappa OR signaling in vivo alters seizure progression, suggesting that breakdown of homeostatic closed-loop control at DG-CA3 synapses contributes to seizures, and that targeting endogenous homeostatic mechanisms at DG-CA3 synapses may prove useful in combating epileptogenesis.

Prospective evaluation of poly-4-hydroxybutyrate mesh in CDC class I/high-risk ventral and incisional hernia repair: 18-month follow-up.

BACKGROUND: Long-term resorbable mesh represents a promising technology for complex ventral and incisional hernia repair (VIHR). Preclinical studies indicate that poly-4-hydroxybutyrate (P4HB) resorbable mesh supports strength restoration of the abdominal wall. This study evaluated outcomes of high-risk subjects undergoing VIHR with P4HB mesh. METHODS: This was a prospective, multi-institutional study of subjects undergoing retrorectus or onlay VIHR. Inclusion criteria were CDC Class I, defect 10-350 cm2, ≤ 3 prior repairs, and ≥ 1 high-risk criteria (obesity (BMI: 30-40 kg/m2), active smoker, COPD, diabetes, immunosuppression, coronary artery disease, chronic corticosteroid use, hypoalbuminemia, advanced age, and renal insufficiency). Physical exam and/or quality of life surveys were performed at regular intervals through 18 months (to date) with longer-term, 36-month follow-up ongoing. RESULTS: One hundred and twenty-one subjects (46M, 75F) with an age of 54.7 ± 12.0 years and BMI of 32.2 ± 4.5 kg/m2 (mean ± SD), underwent VIHR. Comorbidities included the following: obesity (n = 95, 78.5%), hypertension (n = 72, 59.5%), cardiovascular disease (n = 42, 34.7%), diabetes (n = 40, 33.1%), COPD (n = 34, 28.1%), malignancy (n = 30, 24.8%), active smoker (n = 28, 23.1%), immunosuppression (n = 10, 8.3%), chronic corticosteroid use (n = 6, 5.0%), advanced age (n = 6, 5.0%), hypoalbuminemia (n = 3, 2.5%), and renal insufficiency (n = 1, 0.8%). Hernia types included the following: primary ventral (n = 17, 14%), primary incisional (n = 54, 45%), recurrent ventral (n = 15, 12%), and recurrent incisional hernia (n = 35, 29%). Defect and mesh size were 115.7 ± 80.6 and 580.9 ± 216.1 cm2 (mean ± SD), respectively. Repair types included the following: retrorectus (n = 43, 36%), retrorectus with additional myofascial release (n = 45, 37%), onlay (n = 24, 20%), and onlay with additional myofascial release (n = 8, 7%). 95 (79%) subjects completed 18-month follow-up to date. Postoperative wound infection, seroma requiring intervention, and hernia recurrence occurred in 11 (9%), 7 (6%), and 11 (9%) subjects, respectively. CONCLUSIONS: High-risk VIHR with P4HB mesh demonstrated positive outcomes and low incidence of hernia recurrence at 18 months. Longer-term 36-month follow-up is ongoing.

Seroma Formation in Rat Latissimus Dorsi Resection in the Presence of Biologics: The Role of Quilting.

BACKGROUND: Seroma formation is a well-recognized complication associated with many operative procedures. Despite its ubiquity, a lack of definitive scientific understanding of the etiology, natural history, and biochemistry of seromas remains. We endeavored to create and examine seromas in a rat model in the setting of commonly used biologic implants and to examine the role of quilting sutures/mechanical fixation in mitigating seroma development. METHODS: Female Sprague-Dawley rats were assigned to either Quilting or Nonquilting groups then subdivided into one of 3 porcine dermal implant groups (Permacol Surgical Implant, Strattice Reconstructive Tissue Matrix, or XCM Biologic Tissue Matrix) or control group. A 5-cm midline back incision was made, the skin reflected and the latissimus dorsi muscle resected bilaterally. Implants were sutured into the surgical bed using a running suture. The skin of nonquilted rats was closed with a running subcuticular suture. Quilted rats underwent placement of absorbable quilting sutures spaced 2 cm apart between the skin and underlying implant or muscle before skin closure. Postoperatively, rats were monitored for seroma formation with fluid aspirated as needed. At 28 or 90 days, rats were euthanized. Seroma and implants were examined grossly and under light microscopy. RESULTS: Of nonquilted rats, 42/54 (78%) developed seromas compared with 19/46 (41%) of quilted rats (P < 0.05), defined by bursa cavity present at necropsy. When a biologic implant was present, 28/35 (80%) of nonquilted rats developed seromas compared with 12/33 (36%) of quilted rats (P < 0.05). In the control group, 14/19 (74%) of nonquilted rats developed seromas compared with 7/13 (54%) of quilted rats. This difference was not statistically significant. Bursa presence was confirmed histologically in all cases, with no difference in bursa character seen between groups. CONCLUSIONS: This study confirms a reliable rat model of seroma formation, with most of the rats exhibiting at least subclinical seromas. There was no difference in seroma formation rate in the presence of biologic implants, and no differences in bursa character between implants. Mechanical fixation with quilting sutures decreased seroma rate significantly in all subgroups. All rats with seromas at necropsy had histological evidence of a bursa with no difference in appearance between groups.

Engraftment of human HSCs in nonirradiated newborn NOD-scid IL2rγ null mice is enhanced by transgenic expression of membrane-bound human SCF.

Immunodeficient mice engrafted with human HSCs support multidisciplinary translational experimentation, including the study of human hematopoiesis. Heightened levels of human HSC engraftment are observed in immunodeficient mice expressing mutations in the IL2-receptor common γ chain (IL2rg) gene, including NOD-scid IL2rγ(null) (NSG) mice. Engraftment of human HSC requires preconditioning of immunodeficient recipients, usually with irradiation. Such preconditioning increases the expression of stem cell factor (SCF), which is critical for HSC engraftment, proliferation, and survival. We hypothesized that transgenic expression of human membrane-bound stem cell factor Tg(hu-mSCF)] would increase levels of human HSC engraftment in nonirradiated NSG mice and eliminate complications associated with irradiation. Surprisingly, detectable levels of human CD45(+) cell chimerism were observed after transplantation of cord blood-derived human HSCs into nonirradiated adult as well as newborn NSG mice. However, transgenic expression of human mSCF enabled heightened levels of human hematopoietic cell chimerism in the absence of irradiation. Moreover, nonirradiated NSG-Tg(hu-mSCF) mice engrafted as newborns with human HSCs rejected human skin grafts from a histoincompatible donor, indicating the development of a functional human immune system. These data provide a new immunodeficient mouse model that does not require irradiation preconditioning for human HSC engraftment and immune system development.

A multicenter randomized controlled trial comparing absorbable barbed sutures versus conventional absorbable sutures for dermal closure in open surgical procedures.

BACKGROUND: Barbed sutures were developed to reduce operative time and improve security of wound closure. OBJECTIVE: The authors compare absorbable barbed sutures (V-Loc, Covidien, Mansfield, Massachusetts) with conventional (smooth) absorbable sutures for soft tissue approximation. METHOD: A prospective multicenter randomized study comparing barbed sutures with smooth sutures was undertaken between August 13, 2009, and January 31, 2010, in 241 patients undergoing abdominoplasty, mastopexy, and reduction mammaplasty. Each patient received barbed sutures on 1 side of the body, with deep dermal sutures eliminated or reduced. Smooth sutures with deep dermal and subcuticular closure were used on the other side as a control. The primary endpoint was dermal closure time. Safety was assessed through adverse event reporting through a 12-week follow-up. RESULTS: A total of 229 patients were ultimately treated (115 with slow-absorbing polymer and 114 with rapid-absorbing polymer). Mean dermal closure time was significantly quicker with the barbed suture compared with the smooth suture (12.0 vs 19.2 minutes; P<.001), primarily due to the need for fewer deep dermal sutures. The rapid-absorbing barbed suture showed a complication profile equivalent to the smooth suture, while the slow-absorbing barbed suture had a higher incidence of minor suture extrusion. CONCLUSIONS: Barbed sutures enabled faster dermal closure quicker than smooth sutures, with a comparable complication profile. LEVEL OF EVIDENCE: 1.

Unifying community-wide whole-brain imaging datasets enables robust automated neuron identification and reveals determinants of neuron positioning in C. elegans.

We develop a data harmonization approach for C. elegans volumetric microscopy data, still or video, consisting of a standardized format, data pre-processing techniques, and a set of human-in-the-loop machine learning based analysis software tools. We unify a diverse collection of 118 whole-brain neural activity imaging datasets from 5 labs, storing these and accompanying tools in an online repository called WormID (wormid.org). We use this repository to train three existing automated cell identification algorithms to, for the first time, enable accuracy in neural identification that generalizes across labs, approaching human performance in some cases. We mine this repository to identify factors that influence the developmental positioning of neurons. To facilitate communal use of this repository, we created open-source software, code, web-based tools, and tutorials to explore and curate datasets for contribution to the scientific community. This repository provides a growing resource for experimentalists, theorists, and toolmakers to (a) study neuroanatomical organization and neural activity across diverse experimental paradigms, (b) develop and benchmark algorithms for automated neuron detection, segmentation, cell identification, tracking, and activity extraction, and (c) inform models of neurobiological development and function.

Fleur-de-lis panniculectomy after bariatric surgery: our experience.

BACKGROUND: Plastic surgeons are faced with increasing numbers of patients presenting for insurance-covered skin excision procedures following bariatric surgery. Panniculectomy for symptomatic relief of rashes is commonly performed, but an isolated infraumbilical amputation-type panniculectomy is a highly unaesthetic procedure, leaving many patients deeply dissatisfied. It may be also fraught with complications due to large incisions and potential for dead-space. In these patients, many surgeons avoid the fleur-de-lis panniculectomy, despite the body contour aesthetic advantage, because of increased time, more scarring, and a perceived increase in complications. METHODS: This is a retrospective chart review of 130 consecutive postbariatric surgery patients who had panniculectomy over a 2-year period at our institution. RESULTS: A total of 30 patients underwent a traditional panniculectomy and 100 patients had a fleur-de-lis panniculectomy. Mean weight loss from bariatric surgery to panniculectomy was 58.2 kg, with an average body mass index (BMI) of 30. Fifty-seven patients had additional procedures performed at the time of panniculectomy. Twenty-two patients (17%) had complications, with 5 in the traditional group (17%) and 17 in the fleur-de-lis group (17%) (P = 1.0). Six males (40%) had more complications compared with 18 females (15.7%) (P = 0.034). Patients with BMI <30 had 10 complications compared with patients with BMI ≥30 had 15 complications. CONCLUSIONS: There are many benefits of fleur-de-lis over traditional panniculectomy, even for medical necessity cases. There is limited undermining of tissue which minimizes/eliminates skin necrosis. Our experience with primarily fleur-de-lis panniculectomies shows a complication rate lower than most published data. Fleur-de-lis potentially creates a better symptom correction and cosmetic outcome by resecting maximal skin in both vertical and horizontal directions. These findings must be balanced against a potentially longer operation.

Long-Term, Prospective, Multicenter Study of Poly-4-Hydroxybutyrate Mesh (Phasix Mesh) for Hernia Repair in Cohort at Risk for Complication: 60-Month Follow-Up.

BACKGROUND: Long-term resorbable mesh represents a promising technology for ventral and incisional hernia repair (VIHR). This study evaluates poly-4-hydroxybutyrate mesh (P4HB; Phasix Mesh) among comorbid patients with CDC class I wounds. STUDY DESIGN: This prospective, multi-institutional study evaluated P4HB VIHR in comorbid patients with CDC class I wounds. Primary outcomes included hernia recurrence and surgical site infection. Secondary outcomes included pain, device-related adverse events, quality of life, reoperation, procedure time, and length of stay. Evaluations were scheduled at 1, 3, 6, 12, 18, 24, 30, 36, and 60 months. A time-to-event analysis (Kaplan-Meier) was performed for primary outcomes; secondary outcomes were reported as descriptive statistics. RESULTS: A total of 121 patients (46 male, 75 female) 54.7 ± 12.0 years old with a BMI of 32.2 ± 4.5 kg/m 2 underwent VIHR with P4HB Mesh (mean ± SD). Fifty-four patients (44.6%) completed the 60-month follow-up. Primary outcomes (Kaplan-Meier estimates at 60 months) included recurrence (22.0 ± 4.5%; 95% CI 11.7% to 29.4%) and surgical site infection (10.1 ± 2.8%; 95% CI 3.3 to 14.0). Secondary outcomes included seroma requiring intervention (n = 9), procedure time (167.9 ± 82.5 minutes), length of stay (5.3 ± 5.3 days), reoperation (18 of 121, 14.9%), visual analogue scale-pain (change from baseline -3.16 ± 3.35 cm at 60 months; n = 52), and Carolinas Comfort Total Score (change from baseline -24.3 ± 21.4 at 60 months; n = 52). CONCLUSIONS: Five-year outcomes after VIHR with P4HB mesh were associated with infrequent complications and durable hernia repair outcomes. This study provides a framework for anticipated long-term hernia repair outcomes when using P4HB mesh.

Frontal sinus repair through a frontalis rhytid approach.

Frontal sinus fractures have traditionally been repaired through a bicoronal approach. This incision provides a wide exposure, but is not without complications, particularly in the patient with or at risk for hairline recession. We present a series of 15 patients who underwent open reduction and internal fixation of anterior table frontal sinus fractures through a frontalis rhytid forehead incision and their results based on the scar appearance, forehead contour, frontalis function, sensation and fracture reduction. Paresthesias cranial to the incision in the supraorbital or supratrochlear distribution were noted in 12 of the 15 patients with resolution in all except 1 patient who did not regain sensation at 4 months follow-up. In all patients, satisfactory forehead contour and fracture reduction were achieved, as were scar appearance and frontalis function at 4 months follow-up. We thus recommend this approach in the treatment of anterior table frontal sinus fractures, with special consideration for the patient with or at risk for anterior hairline recession.

Adductor magnus perforator flap revisited: an anatomical review and clinical applications.

BACKGROUND: The adductor magnus musculocutaneous perforator flap is a medial thigh flap whose utility is often overshadowed by that of its anatomic neighbor, the gracilis flap. It has a large, reliable pedicle and associated skin paddle. Few reports have been published describing the use of this flap as a local or free tissue transfer. The purpose of this study is to revisit and further characterize the anatomy of this extremely versatile yet underutilized flap. MATERIALS/METHODS: A total of 13 cadavers (n = 26 thighs) were dissected to identify the musculocutaneous perforators that supply the skin of the posteriomedial thigh. The vascular anatomy was studied using multiple modalities. Based on the anatomic data, a local V-Y advancement flap was designed. A total of 8 patients (n = 10 flaps) underwent reconstruction of locoregional defects. RESULTS: Our anatomic studies confirmed the presence of multiple parallel musculocutaneous perforators that travel through the adductor magnus muscle and course obliquely in a posterior-inferior direction. We found that the primary perforator is reliably found approximately 8 cm distal to the groin crease and 2 cm posterior to the posterior border of the gracilis muscle. We discovered that it is consistently accompanied by a separate perforator located 2 cm distally. Minimal dissection into the muscle revealed a Y-configuration of these 2 perforators. This configuration was present in 100% of the cadaveric dissections and is supplied by the first medial branch of the profunda femoris artery. Computed tomography angiograms depicted vascular arborization of the perforators supplying the flap. Clinical experience showed that complete flap survival was achieved in all of the cases. CONCLUSION: The adductor magnus perforator flap is a reliable flap that offers robust blood supply, through a consistent vascular pedicle, to an extensive skin territory. Our anatomic studies revealed the consistent presence of 2 proximal perforators in the medial thigh that are linked by an intramuscular Y-configuration that provides enhanced blood supply to a local V-Y advancement flap design. The location of the skin paddle on the proximal medial thigh allows for minimal donor-site morbidity as it can be closed primarily with a V-Y advancement flap design, obviating the need for skin grafting.

Prospective, multicenter study of P4HB (Phasix™) mesh for hernia repair in cohort at risk for complications: 3-Year follow-up.

BACKGROUND: This study represents a prospective, multicenter, open-label study to assess the safety, performance, and outcomes of poly-4-hydroxybutyrate (P4HB, Phasix™) mesh for primary ventral, primary incisional, or multiply-recurrent hernia in subjects at risk for complications. This study reports 3-year clinical outcomes. MATERIALS AND METHODS: P4HB mesh was implanted in 121 patients via retrorectus or onlay technique. Physical exam and/or quality of life surveys were completed at 1, 3, 6,12, 18, 24, and 36 months, with 5-year (60-month) follow-up ongoing. RESULTS: A total of n = 121 patients were implanted with P4HB mesh (n = 75 (62%) female) with a mean age of 54.7 ± 12.0 years and mean BMI of 32.2 ± 4.5 kg/m2 (±standard deviation). Comorbidities included: obesity (78.5%), active smokers (23.1%), COPD (28.1%), diabetes mellitus (33.1%), immunosuppression (8.3%), coronary artery disease (21.5%), chronic corticosteroid use (5.0%), hypo-albuminemia (2.5%), advanced age (5.0%), and renal insufficiency (0.8%). Hernias were repaired via retrorectus (n = 45, 37.2% with myofascial release (MR) or n = 43, 35.5% without MR), onlay (n = 8, 6.6% with MR or n = 24, 19.8% without MR), or not reported (n = 1, 0.8%). 82 patients (67.8%) completed 36-month follow-up. 17 patients (17.9% ± 0.4%) experienced hernia recurrence at 3 years, with n = 9 in the retrorectus group and n = 8 in the onlay group. SSI (n = 11) occurred in 9.3% ± 0.03% of patients. CONCLUSIONS: Long-term outcomes following ventral hernia repair with P4HB mesh demonstrate low recurrence rates at 3-year (36-month) postoperative time frame with no patients developing late mesh complications or requiring mesh removal. 5-year (60-month) follow-up is ongoing.

Femur flap for tibial reconstruction: percent circumference required to convey a mechanical advantage over the fibula.

The fibula flap is commonly used to reconstruct the tibia. This has risk of postoperative fracture despite long-term non-weight bearing. A flap using noncircumferential distal femur is proposed. This study is to determine the circumference of femur required to produce greater strength than the fibular flap. Femurs and fibulas were harvested from eight cadavers. The structural strength of fibula and femur flaps was assessed using three-point bend. Compression testing was performed on osteotomized and whole femurs to assess donor site morbidity. The 35% flap (mean maximum force at fracture 869 N) was not significantly stronger than the fibula flap (626 N; P > 0.05). The 40% flap (1225 N) was significantly stronger than the fibula flap ( P < 0.01). There was no significant difference between forces at fracture for whole femurs (3978 N), femurs with 35% osteotomies (3604 N), and femurs with 40% osteotomies (3493 N; P = 0.87). Change occurred in the fracture pattern of femurs following osteotomies. Whole femurs consistently fractured at the femoral neck, and osteotomized femurs consistently fractured obliquely from the osteotomy. A flap consisting of 40% of the circumference of the distal femur exceeds the structural strength of the fibular flap. Taking such a flap changes the femur's structural integrity; fixation may be prudent following harvest.

Do Novice and Expert Users of Clinical Decision Support Tools Need Different Explanations?

A key requirement for the successful adoption of clinical decision support systems (CDSS) is their ability to provide users with reliable explanations for any given recommendation which can be challenging for some tasks such as wound management decisions. Despite the abundance of decision guidelines, wound non-expert (novice hereafter) clinicians who usually provide most of the treatments still have decision uncertainties. Our goal is to evaluate the use of a Wound CDSS smartphone App that provides explanations for recommendations it produces. The App utilizes wound images taken by the novice clinician using smartphone camera. This study experiments with two proposed variations of rule-tracing explanations called verbose-based and gist-based. Deriving upon theories of decision making, and unlike prior literature that says rule-tracing explanations are only preferred by novices, we hypothesize that, rule-tracing explanations are preferred by both clinicians but in different forms: novices prefer verbose-based rule-tracing and experts prefer gist-based rule-tracing.

Machine learning models for synthesizing actionable care decisions on lower extremity wounds.

Lower extremity chronic wounds affect 4.5 million Americans annually. Due to inadequate access to wound experts in underserved areas, many patients receive non-uniform, non-standard wound care, resulting in increased costs and lower quality of life. We explored machine learning classifiers to generate actionable wound care decisions about four chronic wound types (diabetic foot, pressure, venous, and arterial ulcers). These decisions (target classes) were: (1) Continue current treatment, (2) Request non-urgent change in treatment from a wound specialist, (3) Refer patient to a wound specialist. We compare classification methods (single classifiers, bagged & boosted ensembles, and a deep learning network) to investigate (1) whether visual wound features are sufficient for generating a decision and (2) whether adding unstructured text from wound experts increases classifier accuracy. Using 205 wound images, the Gradient Boosted Machine (XGBoost) outperformed other methods when using both visual and textual wound features, achieving 81% accuracy. Using only visual features decreased the accuracy to 76%, achieved by a Support Vector Machine classifier. We conclude that machine learning classifiers can generate accurate wound care decisions on lower extremity chronic wounds, an important step toward objective, standardized wound care. Higher decision-making accuracy was achieved by leveraging clinical comments from wound experts.

Salvage of a lower extremity by microsurgical transfer of tibial bone from the contralateral extremity traumatically amputated at the ankle level.

The authors present a case of free vascularized transfer of the tibial bone as an osteomyocutaneous flap based on the posterior tibial vessels. A 42-year-old man presented with severe crush injury to bilateral legs. The left tibial bone and soft tissue defect required reconstruction with an osteomyocutaneous free flap. Since the contralateral leg was traumatically amputated at the level of the ankle, a decision was made to harvest a free tibial osteomyocutaneous flap with below-knee-amputation completed. The transfer was achieved successfully with complete survival of the flap and bony union. This report describes the technical and healing aspects of such a unique transfer which may rarely be indicated.

Correlation of bioimpedance changes after compressive loading of murine tissues in vivo.

OBJECTIVE: Rises in the incidence of pressure ulcers are increasingly prevalent in an aging population. Pressure ulcers are painful, are associated with increased morbidity and mortality, increase the risk for secondary infections and inpatient stay, and adds $26.8 billion annually to the healthcare costs of the USA. Evidence suggests that a change in the bioimpedance of living tissue in response to continuous local contact pressure can be a useful indicator for the onset of pressure injuries. APPROACH: Thirty-five Sprague Dawley rats were subjected to various skin pressures for differing periods of time via a surgically inserted steel disk and an externally applied magnet. Contact pressure and bioimpedance were measured and correlated with tissue loading intensity and compared to clinical ulcer grading. MAIN RESULTS: Moderate relationships between bioimpedance changes and tissue loading intensity were found. Stronger correlations were found by utilizing a combination of bioimpedance and phase angle. Thresholds were applied to the bioimpedance parameters and the usefulness of bioimpedance in classifying different ulcer stages is demonstrated. SIGNIFICANCE: These results indicate that bioimpedance may be useful as an early indicator of pressure ulcer formation and has practical significance in the development of early pressure injury detection devices.

A New Vision for Preventing Pressure Ulcers: Wearable Wireless Devices Could Help Solve a Common-and Serious-Problem.

With an aging population, the incidence and prevalence of wound problems is on the rise. Bedsores (also known as pressure ulcers or decubitus ulcers) are painful, take months to heal, and, for many patients, never do, leading to other health problems. The condition has become so acute that treating bedsores is now a significant burden on the healthcare system. An estimated 2.5 million pressure ulcers are treated in U.S. hospitals each year, adding US$11 billion annually to health care costs.