Association between tissue loss type and amputation risk among Medicare patients with concomitant diabetes and peripheral arterial disease.

OBJECTIVE: Prior studies have described risk factors associated with amputation in patients with concomitant diabetes and peripheral arterial disease(DM/PAD). However, the association between the severity and extent of tissue loss type and amputation risk remains less well-described. We aimed to quantify the role of different tissue loss types in amputation risk among patients with DM/PAD, in the context of demographic, preventive, and socioeconomic factors. METHODS: Applying ICD-9 and ICD-10 codes to Medicare claims data(2007-2019), we identified all patients with continuous fee-for-service Medicare coverage diagnosed with DM/PAD. Eight tissue loss categories were established using ICD-9 and ICD-10 diagnosis codes, ranging from lymphadenitis(least severe) to gangrene(most severe). We created a Cox proportional hazards model to quantify associations between tissue loss type and one- and five-year amputation risk, adjusting for age, race/ethnicity, sex, rurality, income, comorbidities, and preventive factors. Regional variation in DM/PAD rates and risk-adjusted amputation rates was examined at the hospital referral region(HRR) level. RESULTS: We identified 12,257,174 patients with DM/PAD(48% male, 76% White, 10% prior myocardial infarction, 30% chronic kidney disease). While 2.2 million patients(18%) had some form of tissue loss, 10.0 million patients(82%) did not. The one-year crude amputation rate(major and minor) was 6.4% in patients with tissue loss, and 0.4% in patients without tissue loss. Among patients with tissue loss, one-year any amputation rate varied from 0.89% for patients with lymphadenitis to 26% for patients with gangrene. One-year amputation risk varied from two-fold for patients with lymphadenitis(aHR 1.96, 95%CI 1.43-2.69) to 29-fold for patients with gangrene(aHR 28.7, 95%CI 28.1-29.3), compared to patients without tissue loss. No other demographic variable including age, sex, race, or region incurred a hazard ratio for one- or five-year amputation risk higher than the least severe tissue loss category. Results were similar across minor and major amputation, and one- and five-year amputation outcomes. At a regional level, higher DM/PAD rates were inversely correlated with risk-adjusted five-year amputation rates(R2=0.43). CONCLUSION: Among 12 million patients with DM/PAD, the most significant predictor of amputation was presence and extent of tissue loss, with an association greater in effect size than any other factor studied. Tissue loss could be used in awareness campaigns as a simple marker of high-risk patients. Patients with any type of tissue loss require expedited wound care, revascularization as appropriate, and infection management to avoid amputation. Establishing systems of care to provide these interventions in regions with high amputation rates may prove beneficial for these populations.

Fluoroscopic Imaging for the Interventional Echocardiographer.

Procedural guidance during structural heart disease (SHD) interventions is achieved with both two-dimensional and three-dimensional transesophageal echocardiography as well as real-time fluoroscopic imaging. Although both image the cardiac anatomy, they are based on different principles of image acquisition. In the era of multimodality imaging with coregistration of anatomic landmarks and simultaneous real-time display, it is essential to have cross-disciplinary imaging knowledge. Besides improving communication, it also enhances patient care and, possibly, outcomes. In this study, the authors used a novel fluoroscopic phantom cardiac model with enhanced structural markers to display the basic fluoroscopic images used during SHD interventions. The projected images enhance the understanding of the orientation and relationship among intracardiac structures as seen on fluoroscopy. In this study, the authors present the basic fluoroscopic views for SHD interventions and the anatomic relationship for intracardiac structures using a custom-made phantom fluoroscopic heart model.

Three-Dimensional Printing of Patient-Specific Heart Valves: Separating Facts From Fiction and Myth From Reality.

The development of prosthetic heart valves by Dr. Charles Hufnagel in 1952 was a major clinical innovation; however, it was not an ideal solution. Mechanical prosthetic heart valves are rigid, immunogenic, require anticoagulation, do not grow with the patient, and have a finite life.1 An ideal prosthetic valve should overcome all these limitations. Considering the prevalence of valvular heart disorders, there is considerable interest in the creation of patient-specific heart valves. Following the introduction of three-dimensional (3D) printing in 1986 by Chuck Hill, rapid advances in multimodality 3D imaging and modeling have led to a generation of tangible replicas of patient-specific anatomy. The science of organogenesis has gained importance for a multitude of valid reasons: as an alternate source of organs, for realistic drug testing, as an alternative to animal testing, and for transplants that grow with the patient. What scientists imagined to be seemingly impossible in the past now seems just a step away from becoming a reality. However, due to the disruptive nature of this technology, often there are commercially-motivated claims of originality and overstatement of the scope and applicability of 3D printing. It often is difficult to separate fact from fiction and myth from reality. In this manuscript, the authors have reviewed the historic perspective, status of the basic techniques of organogenesis with specific reference to heart valves, and their potential.

Motion-Tracking Machines and Sensors: Advancing Education Technology.

Graduate medical education is predominantly based on a time-based apprenticeship model, with implied acquisition of proficiency after a pre-set amount of clinical exposure. While motion metrics have been used previously to measure skill performance indicators, these assessments have largely been performed on a summative scale to describe the performance of complete tasks or procedures. By segmenting performances of interest and assessing the essential elements individually, a more comprehensive understanding of the aspects in need of improvement for a learner can be obtained. The purpose of this review is to discuss technologies applicable to motion tracking, their benefits and limitations, approaches to data processing, and potential applications based on recent improvements in this technology. Objective analysis of motion metrics may improve educational standards of learning and efficiency by both standardizing the feedback process for trainees and reducing the volume of instructors required to facilitate practice sessions. With rigorous validation and standardization, motion metric assessment may also prove useful to demonstrate competency in technical procedures as part of a comprehensive certification process.

Three-Dimensional Transesophageal Echocardiography Simulator: New Learning Tool for Advanced Imaging Techniques.

The use of intraoperative three-dimensional (3D) transesophageal echocardiography (TEE) has grown exponentially in recent years. Three-dimensional TEE technology has evolved to allow for real-time display of 3D images and, thus, has become the standard of care for the evaluation of cardiac anatomy and function. Its use has provided a new dimension of clinical insight when managing patients for cardiac surgery or structural heart interventions. While the intraoperative utility of 3D TEE has expanded, there has been a slower advancement in the area of training and, specifically, simulator-based training in 3D TEE. This training is essential, as the skill set involved in acquiring 3D data sets differs from that of two-dimensional (2D) TEE and requires users to be able to appreciate how 3D anatomic display differs from that of tomographic cross-sectional 2D imaging. This added skill set requires mental reconstruction and spatial reorientation to appreciate the added elevational dimension in frustum-based imaging and is best achieved in a simulation environment rather than the busy operating room. In this review article, the authors evaluate the functionality of a 3D TEE simulator and how simulators such as this can establish preclinical proficiency in novices in the expanding area of advanced 3D TEE imaging.

Assessing Skill Acquisition in Anesthesiology Interns Practicing Central Venous Catheter Placement Through Advancements in Motion Analysis.

OBJECTIVES: The study authors hypothesized that a combination of previously used (path length, translational motions, and time) and novel (rotational sum) motion metrics could be used to analyze learning curves of anesthesiology interns (postgraduate year 1) practicing central venous catheter placement in the simulation setting. They also explored the feasibility of using segmented motion recordings to inform deliberate practice. DESIGN: A prospective cohort study. SETTING: A single academic medical center. PARTICIPANTS: Anesthesiology interns (postgraduate year 1). INTERVENTIONS: Anesthesiology interns underwent a 2-day training course in which they performed 9 central venous catheter placements, while attached to motion sensors on the dorsum of their dominant hand and ultrasound probe. MEASUREMENTS AND MAIN RESULTS: Motion metrics were analyzed using generalized estimating equations for both the overall procedure and predefined segments. Five attending anesthesiologists performed 3 trials each for comparison. Overall, there was a negative trend in path length, translational motions, rotational sum, and time (p < 0.001), with the exception of translational motions of the ultrasound probe. Interns reached within 1 standard deviation of the attending anesthesiologists by trials 7-to-8 for most metrics. Segmentation identified specific components of the procedure that were either significantly improved upon or required deliberate practice. The novel metric of rotational sum exhibited a moderate-to-strong positive correlation with other metrics (p < 0.001). CONCLUSIONS: A comprehensive series of motion metrics was able to describe the learning curves of novices training to perform central venous catheter placement in the simulation setting. Furthermore, it was determined that segmentation may provide additional insight into skill acquisition and inform deliberate practice.

Regional Anaesthesia for Lower Extremity Amputation is Associated with Reduced Post-operative Complications Compared with General Anaesthesia.

OBJECTIVE: Primary and secondary lower extremity amputation, performed for patients with lower extremity arterial disease, is associated with increased post-operative morbidity. The aim of the study was to assess the impact of regional anaesthesia vs. general anaesthesia on post-operative pulmonary complications. METHODS: A retrospective analysis of 45 492 patients undergoing lower extremity amputation between 2005 and 2018 was conducted using data from the American College of Surgeons National Safety Quality Improvement Program database. Multivariable logistic regression was carried out to assess differences in primary outcome of post-operative pulmonary complications (pneumonia or respiratory failure requiring re-intubation) within 48 hours and 30 days after surgery between patients receiving regional (RA) or general anaesthesia (GA). Secondary outcomes included post-operative blood transfusion, septic shock, re-operation, and post-operative death within 30 days. RESULTS: Of 45 492 patients, 40 026 (88.0%) received GA and 5 466 (12.0%) RA. Patients who received GA had higher odds of developing pulmonary complications at 48 hours (2.1% vs. 1.4%; adjusted odds ratio [aOR] 1.39, 95% confidence interval [CI] 1.09 - 1.78; p = .007) and within 30 days (6.3% vs. 5.9%; aOR 1.15, 95% CI 1.09 - 1.78; p = .039). The odds of blood transfusions (aOR 1.11, 95% CI 1.02 - 1.21; p = .017), septic shock (aOR 1.29, 95% CI 1.03 - 1.60; p = .025) and re-operation (OR 1.26, 95% CI 1.03 - 1.53; p = .023) were also higher for patients who received GA vs. patients who received RA. No difference in mortality rate was observed between patients who received GA and those who received RA (5.7% vs. 7.1%; odds ratio 0.95, 95% CI 0.84 - 1.07). CONCLUSION: A statistically significant reduction in pulmonary complications was observed in patients who received RA for lower extremity amputation compared with GA.

Enhanced Post-Operative Recovery with Continuous Peripheral Nerve Block After Lower Extremity Amputation.

BACKGROUND: Despite progress in perioperative care standards, there has not been a significant risk reduction in morbidity and mortality rates of lower extremity amputations, an intermediate risk surgery performed on high risk patients. The single-shot peripheral nerve block has shown equivocal impact on postoperative course following lower extremity amputation. Hence, we assessed the potential of preemptive use of continuous catheter-based peripheral nerve block in lower extremity amputations for reduction in pulmonary complications, acute post-operative pain scores, and opioid use in post-operative period. METHODS: A retrospective review of a quality improvement project initiated in 2018 was conducted to compare outcomes amongst general anesthesia in combination with a catheter-based peripheral nerve block (catheter group) and general anesthesia alone in patients receiving lower extremity amputation. The rate of postoperative pulmonary complications was identified as a primary endpoint. The secondary outcomes assessed were acute post-operative pain scores and opioid consumption up to 48 hours. Our analysis was adjusted for potential confounding variables inclusive of demographics, medical comorbidities, type of surgical procedure and smoking status. RESULTS: Ninety-six patients were included in the study (61 in the general anesthesia group, 35 in the catheter group). After adjusting for baseline demographics, comorbidities, surgical technique and smoking status, the odds of postoperative pulmonary complications were significantly lower with catheter-based peripheral nerve block in comparison to general anesthesia alone, OR 0.11 [95% CI, 0.01- 0.88] (P = 0.048). The decrease in acute pain scores was also observed in the catheter group when compared to general anesthesia alone, OR 0.72 [95% CI, 0.56 - 0.93] (P = 0.012). Similarly, the opioid consumption was also lower in the catheter group in comparison to general anesthesia alone, OR 0.97 [95% CI, 0.95 - 0.99] (P = 0.025). CONCLUSION: Preemptive use of continuous peripheral nerve block in patients undergoing lower extremity amputation reduces the incidence of pulmonary complications, acute postoperative pain scores and narcotic use in post-operative period.

Transcatheter mitral valve-in-valve-in-valve replacement with transseptal puncture in the presence of an atrial septal occluder device.

Quite often the iatrogenic atrial septal defect created after percutaneous transcatheter mitral valve replacement procedures is closed with an atrial septal occluder device thus precluding further transseptal interventions if required. In this case report, we describe a patient who previously underwent a valve-in-valve transcatheter mitral valve replacement and iatrogenic atrial septal defect closure with an Amplatzer device, who developed severe prosthetic mitral valve stenosis. This patient required a second percutaneous valve-in-valve in-valve procedure with a transseptal puncture in the presence of an atrial septal occluder device.

Unusual bilateral variation of the flexor digitorum accessorius longus muscle and its relation on tarsal tunnel syndrome.

PURPOSE: During standard anatomical dissection for a medical anatomy course, we encountered an unusual bilateral variant of a unipennate flexor digitorum accessorius longus (FDAL) muscle, a supernumery muscle of the deep posterior leg and medial ankle. METHODS: We documented the muscles course and measured the diameter and length of the FDAL muscle belly, as well as the full length of its tendinous attachments. RESULTS: On both right and left legs, the FDAL originated from the proximal posterior fibula and distal one-third of the flexor hallucis longus muscle. The tendon had a distal attachment on the flexor digitorum longus (FDL) tendon and traveled with the FDL tendon as it inserted on the third distal phalanx. The left FDAL full length was 42.54 cm; the length of the muscle belly was 16.26 cm; and the circumference of the muscle belly was 4.44 cm. The right FDAL full length was 44.20 cm; the length of muscle belly was 12.06; and the circumference (belly) was 4.44 cm. Surrounding musculature and neurovasculature follow standard anatomical courses. CONCLUSION: This anatomical documentation provides opportunities for clinicians to consider mechanical influences of the FDAL on plantar foot function and further consider the accessory ankle muscles that have the potential to cause compressive neuropathies such as tarsal tunnel syndrome.

Three-Dimensional Printing and Transesophageal Echocardiographic Imaging of Patient-Specific Mitral Valve Models in a Pulsatile Phantom Model.

Three-dimensional printing is increasingly used in the health care industry. Making patient-specific anatomic task trainers has been one of the more commonly described uses of this technique specifically, allowing surgeons to perform complex procedures on patient-specific models in a nonoperative setting. With regard to transesophageal echocardiography (TEE) training, commercially available simulators have been increasingly used. Even though these simulators are haptic in nature and anatomically near realistic, they lack patient specificity and the training of the dynamic workflow and imaging protocol used in the operative setting. Herein a customized pulsatile left-sided heart model that uses patient-specific 3-dimensional printed valves under physiological intracardiac pressures as a TEE task trainer is described. With this model, dynamic patient-specific valvular anatomy can be visualized with actual TEE machines by trainees to familiarize themselves with the surgery equipment and the imaging protocol.

Inter-Rater Reliability for the Amputation Endpoint in the National Vascular Quality Initiative.

BACKGROUND: National quality reporting efforts after revascularization for peripheral artery disease (PAD) are ongoing. Validation of endpoints are necessary in national quality registries. OBJECTIVES: This study sought to examine the interrater reliability for the endpoint of major amputation at 1 year in the Vascular Quality Initiative (VQI) registry and the Medicare-linked Vascular Quality Initiative registry (VQI-VISION) against electronic health record (EHR) review. METHODS: Surgical or endovascular revascularization procedures between January 1, 2010, and December 31, 2017, in the VQI registry and VQI-VISION for 2 academic health systems were queried. Major amputation data were abstracted by trained data collectors for the VQI and derived from Current Procedural Terminology codes for VQI-VISION. Cases underwent protocolized adjudication for the endpoint of major amputation by EHR review. Paired tests were used to evaluate the sensitivity and specificity. Spearman's ρ and Cohen's κ were used to evaluate interrater reliability. RESULTS: Amputation endpoints for 1,936 revascularizations were examined. Compared with major amputation data in EHR review, the sensitivity for the VQI registry was 35.9% and the specificity was 99.4% (ρ = 0.53; κ = 0.48). For VQI-VISION, sensitivity was 67.7% and specificity was 98.9% (ρ = 0.75; κ = 0.74). For any amputation in VQI data, sensitivity was 35.3% and specificity was 99.3% (ρ = 0.53; κ = 0.46), and for VQI-VISION, they were 71.6% and 97.7%, respectively (ρ = 0.75; κ = 0.74). CONCLUSIONS: Almost two-thirds of the amputations in the VQI registry and one-third of amputations in VQI-VISION were missing at 1 year compared against adjudicated EHR review. In preparing for national reporting systems for major amputation tracking, data collection system reform is needed.

Rapid Weight Gain and Weight Differential Predict Competitive Success in 2100 Professional Combat-Sport Athletes.

PURPOSE: Combat-sport athletes commonly undergo rapid weight loss prior to prebout weigh-in and subsequently rapid weight gain (RWG) prior to competition. This investigation aimed to evaluate the effect of RWG and weight differential (WD) between opponents on competitive success. METHODS: A retrospective cohort study was performed using data from professional mixed martial arts (MMA) and boxing events held between 2015 and 2019. The primary outcome was RWG (relative and absolute) between weigh-in and competition stratified by bout winners and losers. Binary logistic regression was used to explore the relationships among bout outcome, RWG, and WD between competitors on the day of their bout. RESULTS: Among 708 MMA athletes included, winners regained more relative body mass (8.7% [3.7%] vs 7.9% [3.8%], P < .01) than losers. In 1392 included male boxers, winners regained significantly more relative body mass (8.0% [3.0%] vs 6.9% [3.2%], P < .01) than losers. Each percentage body mass increase resulted in a 7% increased likelihood of victory in MMA and a 13% increase in boxing. The relationship between RWG and competitive success remained significant in regional and male international MMA athletes, as well as boxers. WD predicted victory in international mixed martial artists and boxers. WD predicted victory by knockout or technical knockout in international MMA athletes and regional boxers. CONCLUSION: This analysis of combat-sport athletes indicates that RWG and WD influence competitive success. These findings raise fair-play and safety concerns in these popular sports and may help guide risk-mitigating regulation strategies.

Motion Analysis: An Objective Assessment of Special Operations Forces and Tactical Medics Performing Point-of-Care Ultrasound.

BACKGROUND: Point-of-care ultrasound (POCUS) is commonly employed to image the heart, lungs, and abdomen. Rapid ultrasound for shock and hypotension (RUSH) exams are a critical component of POCUS employed in austere environments by Special Operations Forces (SOF) and tactical medics for triage and diagnosis. Despite its utility, training for POCUS remains largely unstandardized with respect to feedback and markers of proficiency. We hypothesized that motion analysis could objectively identify improvement in medics' performance of RUSH exams. Furthermore, we predicted that motion metrics would correlate with qualitative ratings administered by attending anesthesiologists. METHODS: A team of civilian and military attending anesthesiologists trained 24 medics in POCUS during a 5-day course. Each medic performed eight RUSH exams using an ultrasound probe equipped with an electromagnetic motion sensor to track total distance travelled (path length), movements performed (translational motions), degrees rotated (rotational sum), and time. Instructors (experts) observed and rated the exams on the following items: image finding, image fine-tuning, speed, final image accuracy, and global assessment. Motion metrics were used to provide feedback to medics throughout the course. Generalized estimating equations were used to analyze the trends of motion metrics across all trials. Correlations amongst motion metrics and expert ratings were assessed with Pearson correlation coefficients. RESULTS: Participants exhibited a negative trend in all motion metrics (p < 0.001). Pearson correlation coefficients revealed moderate inverse correlations amongst motion metrics and expert ratings. CONCLUSION: Motion analysis was able to quantify and describe the performance of medics training in POCUS and correlated with expert ratings.

Rapid weight gain following weight cutting in male professional boxers.

OBJECTIVES: Weight classifications are used in boxing and other combat sports to match opponents of similar size. Professional boxers commonly engage in a potentially harmful practice known as rapid weight loss or 'weight cutting' to make weight the day prior to competition before rehydrating and refueling. This investigation describes the prevalence and magnitude of rapid weight gain in boxers following weigh-in as well as differences in practice with respect to weight class and promotion. METHODS: This analysis describes official weight data from male professional boxers collected by the California State Athletic Commission between 2015 and 2018. A total of 399 athletes were included in the study. RESULTS: Among included athletes, 389 (97.5%) athletes gained weight between official weigh-in and competition. Total absolute body mass gained was 4.4 ± 2.2 kg corresponding to a total relative body mass gain of 7.2 ± 3.5%. Boxers competing in international promotions gained significantly more body mass than regional competitors (8.0 ± 3.0% vs. 6.6 ± 3.7%; p < 0.001). In total, 82 (20.6%) athletes gained 10% body mass or more before competition. More international competitors reached this 10% threshold than regional competitors (25.3% vs. 17.4%; p = 0.03). CONCLUSIONS: These findings indicate high prevalence and magnitude of RWG in professional boxing, particularly in boxers competing in elite international promotions.

Closed Bronchoscopy System: An Innovative Approach to Minimize Aerosolization During Bronchoscopy.

Health care workers performing aerosolizing procedures on patients with transmissible infections such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are at high-risk for disease acquisition. Current guidelines designed to protect health care workers during aerosolizing procedures prioritize personal protective equipment and enhanced infection control techniques, in particular during procedures such as intubation. To date, little emphasis has been placed on risk mitigation in the setting of bronchoscopy, a procedure that has significant aerosolization potential. Herein, we present an innovative closed bronchoscopy system designed to reduce aerosolization during bronchoscopy.

Comprehensive Ultrasound Course for Special Operations Combat and Tactical Medics.

BACKGROUND: Advances in ultrasound technology with enhanced portability and high-quality imaging has led to a surge in its use on the battlefield by nonphysician providers. However, there is a consistent need for comprehensive and standardized ultrasound training to improve ultrasound knowledge, manual skills, and workflow understanding of nonphysician providers. MATERIALS AND METHODS: Our team designed a multimodal ultrasound course to improve ultrasound knowledge, manual skills, and workflow understanding of nine Special Operations combat medics and Special Operations tactical medics. The course was based on a flipped classroom model with a total time of 43 hours, consisting of an online component followed by live lectures and hands-on workshops. The effectiveness of the course was determined using a knowledge exam, expert ratings of manual skills using a global rating scale, and an objective structured clinical skills examination (OSCE). RESULTS: The average knowledge exam score of the medics increased from pre-course (56% ± 6.8%) to post-course (80% ± 5.0%, p < .001). Based on expert ratings, their manual skills improved from baseline to day 4 of the course for image finding (p = .007), image optimization (p = .008), image acquisition speed (p = .008), final image quality (p = .008), and global assessment (p = .008). Their average score at every OSCE station was > 91%. CONCLUSION: A comprehensive multimodal training program can be used to improve military medics' ultrasound knowledge, manual skills, and workflow understanding for various applications of ultrasound. Further research is required to develop a reliable, sustainable course.