A Guide to Contrast-Enhanced Computed Tomography in Adult Patients Supported With Extracorporeal Membrane Oxygenation.

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) fundamentally alters patient physiology and blood flow relevant to contrast delivery for computed tomography (CT) imaging. Here, we present a comprehensive guide to contrast-enhanced CT scanning in adult ECMO patients, addressing common questions related to contrast delivery via the ECMO circuit, and modifications to ECMO settings and scanning techniques, to avoid non-diagnostic CT scans. The approach is described in detail for patients supported on VA ECMO, with the return cannula sited in the femoral artery. Lesser modifications required for veno-venous ECMO (VV ECMO) are included in the supplemental material. Establishing a common understanding between the intensive care clinician, the CT radiographer, and the radiologist, concerning the patient's blood-flow-physiology, is the overarching goal. Our stepwise approach facilitates clear communication around modifications to the ECMO pump settings, contrast route and rate, as well as the scanning technique, for each individual scenario.

Robotically performed diagnostic coronary angiography.

OBJECTIVE: This study was performed to investigate the efficacy and safety of robotic diagnostic coronary angiography. BACKGROUND: Robotic percutaneous coronary intervention is associated with marked reductions in physician radiation exposure. Development of robotic diagnostic coronary angiography might similarly impact occupational safety. METHODS: Stable patients referred for coronary angiography were prospectively enrolled. After obtaining vascular access, diagnostic catheters were manually advanced over a wire to the ascending aorta. All subsequent catheter movements were performed robotically. The primary endpoint was procedural success, defined as robotic completion of coronary angiography without conversion to a manual procedure and the absence of procedural major adverse cardiovascular events (MACE-cardiac death, cardiac arrest, or stroke) and major angiographic complications (coronary/aortic dissection or embolization). The primary hypothesis was that the observed rate of the primary endpoint, evaluated at the completion of coronary angiography, would meet a pre-specified performance goal of 74.5%. RESULTS: Among 46 consecutive patients (age 67 ± 12 years; 69.6% male), diagnostic coronary angiography was completed robotically in all cases without the need for manual conversion and without any MACE or major angiographic complications. Thus, procedural success was 100%, which was significantly higher than the pre-specified performance goal (p < 0.001). Robotic coronary angiography was completed using 2 [2, 3] catheters per case with a median procedural time of 15 [11, 20] minutes. CONCLUSIONS: Robotic diagnostic coronary angiography was performed with 100% procedural success and no observed complications. These results support the performance of future studies to further explore robotic coronary angiography.

Immune Function After Splenic Artery Embolization for Blunt Trauma: Long-Term Assessment of CD27+ IgM B-Cell Levels.

Splenic artery embolization (SAE) plays a critical role in the treatment of high-grade splenic injury not requiring emergent laparotomy. SAE preserves splenic tissue, and growing evidence demonstrates preserved short-term splenic immune function after SAE. However, long-term function is less studied. Patients who underwent SAE for blunt abdominal trauma over a 10-year period were contacted for long-term follow-up. Sixteen participants (sex: women, 10, and men, 6; age: median, 34 years, and range, 18-67 years) were followed up at a median of 7.7 years (range, 4.7-12.8 years) after embolization. Splenic lacerations were of American Association for the Surgery of Trauma grades III to V, and 14 procedures involved proximal embolization. All individuals had measurable levels of IgM memory B cells (median, 14.30 as %B cells), splenic tissue present on ultrasound (median, 122 mL), and no history of severe infection since SAE. In conclusion, this study quantitatively demonstrated that long-term immune function remains after SAE for blunt abdominal trauma based on the IgM memory B cell levels.

Non-radiologist perception of the use of artificial intelligence (AI) in diagnostic medical imaging reports.

INTRODUCTION: Incorporating artificial intelligence (AI) in diagnostic medical imaging reports has the potential to improve efficiency. Although perception of radiologists, radiographers, medical students and patients on AI use in image reporting has been explored, there is limited literature on non-radiologist clinicians' opinion on this topic. METHOD: Single-centre online survey targeting non-radiologist medical staff conducted from May to August 2021 at a tertiary referral hospital in Melbourne, Australia. Survey questions revolved around clinicians' level of comfort acting on AI-generated reports with varying levels of radiologist involvement and scan complexity, opinion on medicolegal responsibility for erroneous AI-issued reports and perception of data privacy and security. RESULTS: Eighty-eight responses were collected, including 47.9% of consultants. Non-radiologist clinicians across all seniorities and specialties felt significantly less comfortable acting on AI-issued reports compared with radiologist-issued reports (mean comfort radiologist 6.44/7, mean comfort AI 3.35/7, P < 0.001) but felt equally comfortable with an AI-hybrid model of care (mean comfort hybrid 6.38/7, P = 0.676). Non-radiologist clinicians believed that medicolegal responsibility with errors in AI-issued reports mostly lay with hospitals or health service providers (65.9%) and radiologists (54.5%). Regarding data privacy and security, non-radiologist clinicians felt significantly less comfortable with AI issuing image reports instead of radiologists (P < 0.001). CONCLUSION: A hybrid AI-generated radiologist-confirmed method of image reporting may be the ideal way of integrating AI into clinical practice based on the perception of our referring non-radiologist medical colleagues. Formal guidelines on medicolegal responsibility and data privacy should be established prior to utilising AI in the clinical setting.

Utility of computed tomography angiography in traumatic lower limb injury: Review of clinical impact in level 1 trauma centre.

INTRODUCTION: CT angiography (CTA) is efficient and accurate in detecting lower limb vascular injury in the setting of trauma (1-6). Less clear is the in-practice correlation between appropriate indications for these examinations and subsequent clinical impacts. MATERIALS AND METHODS: All CT leg angiography acquired from January 2016 through April 2019 were reviewed via retrospective search. Studies not acquired for trauma were excluded. Imaging and reports were reviewed to assess for vascular injury. Electronic medical records were reviewed to assess the presence or absence of classical 'hard' or 'soft' signs of vascular injury and whether vascular intervention was undertaken. RESULTS: A total of 347 lower limb injuries were identified in 273 men and 74 women. Mean age was 41.5 years ranging from 15-95 years. 268 cases were fractures with 177 open injuries. 301 of injuries were secondary to blunt trauma, 31 penetrating injury occurred and 15 cases were ascribed to blast/gunshot injury. 74 (21.3%) studies were deemed to have a positive finding of vascular injury, 249 (71.8%) were reported as negative and 24 (6.9%) were indeterminate. Of the cases with positive findings, 26 underwent intervention (7.4% of all patients undergoing CTA). No patients with negative CTA required intervention, while three (3, 0.8% of total) with indeterminate findings required intervention. Where there were no clinical signs (absence of any hard or soft signs) 249 CTA's were performed and none required any form of intervention. CONCLUSION: In the absence of clinical signs of vessel injury, CT angiography is unlikely to demonstrate vascular injury requiring intervention in the setting of lower limb trauma.

Comparison of Reperfusion Strategies for ST-Segment-Elevation Myocardial Infarction: A Multivariate Network Meta-analysis.

Background We systematically reviewed trials comparing different reperfusion strategies for ST-segment-elevation myocardial infarction and used multivariate network meta-analysis to compare outcomes across these strategies. Methods and Results We identified 31 contemporary trials in which patients with ST-segment-elevation myocardial infarction were randomized to ≥2 of the following strategies: fibrinolytic therapy (n=4212), primary percutaneous coronary intervention (PCI) (n=6139), or fibrinolysis followed by routine early PCI (n=5006). We categorized the last approach as "facilitated PCI" when the median time interval between fibrinolysis to PCI was <2 hours (n=2259) and as a "pharmacoinvasive approach" when this interval was ≥2 hours (n=2747). We evaluated outcomes of death, nonfatal reinfarction, stroke, and major bleeding using a multivariate network meta-analysis and a Bayesian analysis. Among the strategies evaluated, primary PCI was associated with the lowest risk of mortality, nonfatal reinfarction, and stroke. For mortality, primary PCI had an odds ratio of 0.73 (95% CI, 0.61-0.89) when compared with fibrinolytic therapy. Of the remaining strategies, the pharmacoinvasive approach was the next most favorable with an odds ratio for death of 0.79 (95% CI, 0.59-1.08) compared with fibrinolytic therapy. The Bayesian model indicated that when the 2 strategies examining routine early invasive therapy following fibrinolysis were directly compared, the probability of adverse outcomes was lower for the pharmacoinvasive approach relative to facilitated PCI. Conclusions A pharmacoinvasive approach is safer and more effective than facilitated PCI and fibrinolytic therapy alone. This has significant implications for ST-segment-elevation myocardial infarction care in settings where timely access to primary PCI, the preferred treatment for ST-segment-elevation myocardial infarction, is not available.

Simultaneous intracoronary, intracardiac, and pulmonary venous thrombosis.

Arterial and venous thromboses are very prevalent diseases and it has been discovered that they share some common pathways, but their presentation in young patients is rare and should raise concern for thrombophilia. Therefore, the case is presented of a 34 year-old female with no prior pertinent history and with no predisposing factors. She was diagnosed with a pulmonary embolism, with an incidental finding of a left ventricular thrombus. A coronary artery thrombosis was also found. The patient met the criteria for a thrombophilia work-up, but the authors would like to express their concern on whether these tests are truly necessary, as they would not have change the patient management.

Fractional flow reserve use during elective coronary angiography among elderly patients in the US.

Fractional flow reserve (FFR) is a physiologic measurement of coronary artery perfusion. Studies have demonstrated its benefit in lowering cost and improving outcomes in patients undergoing elective coronary angiography, though follow-up surveys have demonstrated low usage nationwide. We sought to investigate the actual usage in elderly patients undergoing elective coronary angiography. Overall utilization of FFR for elective coronary angiography was 6.3%. Age, sex, race, prior stress testing and region of the country were all statistically significant predictors for FFR use. There still exist many barriers to widespread adoption of this modality, which require further exploration.

Hemodynamic and clinical response to transseptal mitral valve-in-valve and valve-in-ring.

OBJECTIVE: To understand the clinical and hemodynamic response of patients with stenotic versus regurgitant prosthetic mitral valve degeneration to transseptal transcatheter mitral valve-in-ring/-valve replacement (TMVR). BACKGROUND: Patients with prosthetic mitral valve repair/replacement failure frequently present high-risk surgical challenges. TMVR has been employed as an alternative to surgery. METHODS: Forty-four patients with stenotic/regurgitant degeneration of prior prosthetic mitral annuloplasty and replacement (38) underwent mitral TMVR. Clinical, echocardiographic, and invasive hemodynamic monitoring was conducted at baseline and follow-up. RESULTS: Relative to patients with regurgitant degeneration (28), patients with stenotic degeneration had baseline higher mitral valve gradients (12 ± 4 vs. 7 ± 3 mmHg, p < 0.01) and smaller areas (1.0 ± 0.4 vs. 1.5 ± 0.4 cm2 , p = 0.01). TMVR yielded significant reduction in left atrial v-wave pressures in stenotic and regurgitant cohorts (-7 ± 11, p = 0.03, and -11 ± 12 mmHg, p < 0.01, respectively) and significant, sustained symptomatic improvement. Intracardiac pressures overall, including left ventricular end diastolic pressures, remained elevated. CONCLUSION: Despite baseline differences in valvular disease, TMVR leads to significant hemodynamic and clinical improvement in both stenotic and regurgitant prosthetic mitral valve disease. In both cohorts, TMVR reduced intracardiac pressures to similar postprocedural levels, but pressures remained supranormal. This outcome suggests a multifactorial process defines the pathophysiology of patients undergoing TMVR, including contributions from prosthetic degeneration, changes in left atrial compliance, and diastolic dysfunction, and highlights the need to consider such factors in patient evaluation and treatment.

Pesticide Exposure Assessment Paradigm for Solitary Bees.

Current pesticide risk assessment for bees relies on a single (social) species, the western honey bee, Apis mellifera L. (Hymenoptera: Apidae). However, most of the >20,000 bee species worldwide are solitary. Differences in life history traits between solitary bees (SB) and honey bees (HB) are likely to determine differences in routes and levels of pesticide exposure. The objectives of this review are to: 1) compare SB and HB life history traits relevant for risk assessment; 2) summarize current knowledge about levels of pesticide exposure for SB and HB; 3) identify knowledge gaps and research needs; 4) evaluate whether current HB risk assessment schemes cover routes and levels of exposure of SB; and 5) identify potential SB model species for risk assessment. Most SB exposure routes seem well covered by current HB risk assessment schemes. Exceptions to this are exposure routes related to nesting substrates and nesting materials used by SB. Exposure via soil is of particular concern because most SB species nest underground. Six SB species (Hymenoptera: Megachilidae - Osmia bicornis L., O. cornifrons Radoszkowski, O. cornuta Latreille, O. lignaria Say, Megachile rotundata F., and Halictidae - Nomia melanderi Cockerell) are commercially available and could be used in risk assessment. Of these, only N. melanderi nests underground, and the rest are cavity-nesters. However, the three Osmia species collect soil to build their nests. Life history traits of cavity-nesting species make them particularly suitable for semifield and, to a lesser extent, field tests. Future studies should address basic biology, rearing methods and levels of exposure of ground-nesting SB species.

Long-term outcomes of melody valve-in-valve implantation for bioprosthetic mitral valve dysfunction.

OBJECTIVES: This study reports long-term outcomes percutaneous Melody valve (Medtronic, Minneapolis, Minnesota) valve-in-valve therapy in patients with prosthetic valve dysfunction. BACKGROUND: Repeat valve surgery is associated with high morbidity and mortality. Transcatheter mitral valve-in-valve is a promising alternative in patients at high-risk for cardiac surgery. METHODS: We conducted a retrospective cohort analysis of 13 patients who underwent Melody valve-in-valve for bioprosthetic dysfunction from July 2011 to October 2013. RESULTS: Mean age was 74.4 years, 46% male, and STS score 13.5 ± 6.8%. All patients had NYHA class 3 or 4 symptoms with improvement to class 1 or 2 in 82% post procedure. Median follow-up was 4.5 years with longest follow-up of 5.5 years. Thirty-day mortality was 15.4% with 1-year mortality of 25% and no other reported deaths until 4.5 years. 76.9% of patients had mitral gradient of 5 mmHg or less immediately postprocedure. One patient required repeat valve procedure for structural deterioration at 4.4 years. At 1, 3, and 5 year follow-ups 75% of patients were NYHA class 1 or 2, mean gradients were 4.5 ± 0.6, 6.8 ± 0.5, and 7.5 ± 0.7, respectively. Using 4-point scale, mitral regurgitation postprocedure was 0.8 ± 0.6. At 1, 3, and 5 years this increased to 1.0 ± 1.1, 1.3 ± 1.3, and 2.5 ± 2.1, respectively. CONCLUSIONS: Melody valve-in-valve therapy was effective with 1-year symptomatic improvement. Prosthesis deterioration requiring repeat intervention was observed in one patient. Larger cohorts with multicenter registries are needed to determine the role of this percutaneous valve-in-valve therapy as valve technology and procedural techniques improve.

Catheter-based closure of aortic and mitral paravalvular leaks: existing techniques and new frontiers.

INTRODUCTION: Significant paravalvular leak (PVL) complicates between 6% and 15% of valve replacements and can result in heart failure and hemolysis. Paravalvular leak can be effectively treated with repeat surgery; however, these procedures are associated with significant operative morbidity. Percutaneous PVL closure is increasingly being utilized as the first line therapy for symptomatic patients, but efficacy may be limited by the lack of dedicated closure devices. AREAS COVERED: This article will review the etiology and prevalence of PVL, discuss outcomes with surgical closure, describe the mounting data supporting percutaneous interventions, and highlight areas for future research emphasizing the need for new dedicated closure devices. EXPERT COMMENTARY: Percutaneous PVL closure can be safely accomplished in the majority of patients with PVL thereby avoiding the risks associated with repeat surgical intervention. However, percutaneous interventions are associated with higher rates of persistent leakage in part due to off-label use of devices intended for other applications. Efforts to develop devices specifically intended for PVL closure are needed to further improve outcomes for percutaneous PVL closure.

Case of Segmental Arterial Mediolysis.

Segmental arterial mediolysis (SAM) is a rare, non-inflammatory, vascular condition that predominantly affects medium-sized to large-sized abdominal arteries and can present with haemorrhage into the abdominal cavity. We report the case of a patient with SAM of the coeliac, splenic, renal and gastroduodenal arteries in whom endovascular coil embolisation was successfully used to treat a bleeding gastroduodenal artery pseudoaneurysm.

An Artificial Turf-Based Surrogate Surface Collector for the Direct Measurement of Atmospheric Mercury Dry Deposition.

This paper describes the development of a new artificial turf surrogate surface (ATSS) sampler for use in the measurement of mercury (Hg) dry deposition. In contrast to many existing surrogate surface designs, the ATSS utilizes a three-dimensional deposition surface that may more closely mimic the physical structure of many natural surfaces than traditional flat surrogate surface designs (water, filter, greased Mylar film). The ATSS has been designed to overcome several complicating factors that can impact the integrity of samples with other direct measurement approaches by providing a passive system which can be deployed for both short and extended periods of time (days to weeks), and is not contaminated by precipitation and/or invalidated by strong winds. Performance characteristics including collocated precision, in-field procedural and laboratory blanks were evaluated. The results of these performance evaluations included a mean collocated precision of 9%, low blanks (0.8 ng), high extraction efficiency (97%-103%), and a quantitative matrix spike recovery (100%).