Acute aortic occlusion: A narrative review for emergency clinicians.

INTRODUCTION: Acute aortic occlusion (AAO) is a rare but serious condition associated with significant morbidity and mortality. OBJECTIVE: This review provides an emergency medicine focused evaluation of AAO, including presentation, assessment, and emergency department (ED) management based on current evidence. DISCUSSION: AAO refers to obstruction of blood flow through the aorta due to either thrombosis or embolism. This condition primarily affects older adults ages 60-70 with cardiovascular comorbidities and most commonly presents with signs and symptoms of acute limb ischemia, though the gastrointestinal tract, kidneys, and spinal cord may be affected. The first line imaging modality includes computed tomography angiography of the chest, abdomen, and pelvis. ED resuscitative management consists of avoiding extremes of blood pressure or heart rate, maintaining normal oxygen saturation and euvolemic status, anticoagulation with heparin, and pain control. Emergent consultation with the vascular surgery specialist is recommended to establish a plan for restoration of perfusion to ischemic tissues via endovascular or open techniques. High rates of baseline comorbidities present in the affected population as well as ischemic and reperfusion injuries place AAO patients at high risk for complications in an immediate and delayed fashion after surgical management. CONCLUSIONS: An understanding of AAO can assist emergency clinicians in diagnosing and managing this rare but devastating disease.

Detection of femoropopliteal arterial steno-occlusion at MR angiography: initial experience with artificial intelligence.

BACKGROUND: This study evaluated a deep learning (DL) algorithm for detecting vessel steno-occlusions in patients with peripheral arterial disease (PAD). It utilised a private dataset, which was acquired and annotated by the authors through their institution and subsequently validated by two blinded readers. METHODS: A single-centre retrospective study analysed 105 magnetic resonance angiography (MRA) images using an EfficientNet B0 DL model. Initially, inter-reader variability was assessed using the complete dataset. For a subset of these images (29 from the left side and 35 from the right side) where digital subtraction angiography (DSA) data was available as the ground truth, the model's accuracy and the area under the curve at receiver operating characteristics analysis (ROC-AUC) were evaluated. RESULTS: A total of 105 patient examinations (mean age, 75 years ±12 [mean ± standard deviation], 61 men) were evaluated. Radiologist-DL model agreement had a quadratic weighted Cohen κ ≥ 0.72 (left side) and ≥ 0.66 (right side). Radiologist inter-reader agreement was ≥ 0.90 (left side) and ≥ 0.87 (right side). The DL model achieved a 0.897 accuracy and a 0.913 ROC-AUC (left side) and 0.743 and 0.830 (right side). Radiologists achieved 0.931 and 0.862 accuracies, with 0.930 and 0.861 ROC-AUCs (left side), and 0.800 and 0.799 accuracies, with 0.771 ROC-AUCs (right side). CONCLUSION: The DL model provided valid results in identifying arterial steno-occlusion in the superficial femoral and popliteal arteries on MRA among PAD patients. However, it did not reach the inter-reader agreement of two radiologists. RELEVANCE STATEMENT: The tested DL model is a promising tool for assisting in the detection of arterial steno-occlusion in patients with PAD, but further optimisation is necessary to provide radiologists with useful support in their daily routine diagnostics. KEY POINTS: • This study focused on the application of DL for arterial steno-occlusion detection in lower extremities on MRA. • A previously developed DL model was tested for accuracy and inter-reader agreement. • While the model showed promising results, it does not yet replace human expertise in detecting arterial steno-occlusion on MRA.

Sex Differences in Prehospital Identification of Large Vessel Occlusion in Patients With Suspected Stroke.

BACKGROUND: Differences in clinical presentation of acute ischemic stroke between men and women may affect prehospital identification of anterior circulation large vessel occlusion (aLVO). We assessed sex differences in diagnostic performance of 8 prehospital scales to detect aLVO. METHODS: We analyzed pooled individual patient data from 2 prospective cohort studies (LPSS [Leiden Prehospital Stroke Study] and PRESTO [Prehospital Triage of Patients With Suspected Stroke Study]) conducted in the Netherlands between 2018 and 2019, including consecutive patients ≥18 years suspected of acute stroke who presented within 6 hours after symptom onset. Ambulance paramedics assessed clinical items from 8 prehospital aLVO detection scales: Los Angeles Motor Scale, Rapid Arterial Occlusion Evaluation, Cincinnati Stroke Triage Assessment Tool, Cincinnati Prehospital Stroke Scale, Prehospital Acute Stroke Severity, gaze-face-arm-speech-time, Conveniently Grasped Field Assessment Stroke Triage, and Face-Arm-Speech-Time Plus Severe Arm or Leg Motor Deficit. We assessed the diagnostic performance of these scales for identifying aLVO at prespecified cut points for men and women. RESULTS: Of 2358 patients with suspected stroke (median age, 73 years; 47% women), 231 (10%) had aLVO (100/1114 [9%] women and 131/1244 [11%] men). The area under the curve of the scales ranged from 0.70 (95% CI, 0.65-0.75) to 0.77 (95% CI, 0.73-0.82) in women versus 0.69 (95% CI, 0.64-0.73) to 0.75 (95% CI, 0.71-0.79) in men. Positive predictive values ranged from 0.23 (95% CI, 0.20-0.27) to 0.29 (95% CI, 0.26-0.31) in women versus 0.29 (95% CI, 0.24-0.33) to 0.37 (95% CI, 0.32-0.43) in men. Negative predictive values were similar (0.95 [95% CI, 0.94-0.96] to 0.98 [95% CI, 0.97-0.98] in women versus 0.94 [95% CI, 0.93-0.95] to 0.96 [95% CI, 0.94-0.97] in men). Sensitivity of the scales was slightly higher in women than in men (0.53 [95% CI, 0.43-0.63] to 0.76 [95% CI, 0.68-0.84] versus 0.49 [95% CI, 0.40-0.57] to 0.63 [95% CI, 0.55-0.73]), whereas specificity was lower (0.79 [95% CI, 0.76-0.81] to 0.87 [95% CI, 0.84-0.89] versus 0.82 [95% CI, 0.79-0.84] to 0.90 [95% CI, 0.88-0.91]). Rapid arterial occlusion evaluation showed the highest positive predictive values in both sexes (0.29 in women and 0.37 in men), reflecting the different event rates. CONCLUSIONS: aLVO scales show similar diagnostic performance in both sexes. The rapid arterial occlusion evaluation scale may help optimize prehospital transport decision-making in men as well as in women with suspected stroke.

Intraoperative assessment of blood flow using transabdominal ultrasound during laparoscopic surgery of celiac artery compression syndrome.

Surgical treatment of celiac artery (CA) compression syndrome (CACS) is to release the median arcuate ligament (MAL) by removing the abdominal nerve plexus surrounding CA. In laparoscopic surgery of CACS, objective intraoperative assessment of blood flow in CA is highly desirable. We herein demonstrate a case of laparoscopic surgery of CACS with use of intraoperative transabdominal ultrasound. A 52-year-old woman was presented with epigastric pain and vomiting after eating. Contrast-enhanced computed tomography demonstrated significant stenosis at the origin of CA. Doppler study of CA was also performed, and she was diagnosed as CACS. Laparoscopic surgery was performed, and the MAL was divided. And then, Doppler study using intraoperative transabdominal ultrasound confirmed the successful decompression of CA. This patient was discharged on postoperative day 11, and her symptoms was improved. Intraoperative assessment of blood flow in CA using transabdominal ultrasound was a simple and useful method for laparoscopic surgery of CACS.

Arterial occlusion duration affects the cuff-induced hyperemic response in skeletal muscle BOLD perfusion imaging as shown in young healthy subjects.

OBJECTIVE: Dynamic BOLD MRI with cuff compression, inducing ischemia and post-occlusive hyperemia in skeletal muscle, has been pointed out as a potential diagnostic tool to assess peripheral limb perfusion. The objective was to explore the robustness of this technique and its sensitivity to the occlusion duration. MATERIALS AND METHODS: BOLD images were acquired at 3 T in 14 healthy volunteers. [Formula: see text]-imaging with 5- and 1.5-min occlusions were acquired and several semi-quantitative BOLD parameters were derived from ROI-based [Formula: see text]-time curves. Differences in parameters from the two different occlusion durations were evaluated in the gastrocnemius and soleus muscles using non-parametrical tests. Intra- and inter-scan repeatability were evaluated with coefficient of variation. RESULTS: Longer occlusion duration resulted in an increased hyperemic signal effect yielding significantly different values (p < 0.05) in gastrocnemius for all parameters describing the hyperemic response, and in soleus for two of these parameters. Specifically, 5-min occlusion yielded steeper hyperemic upslope in gastrocnemius (41.0%; p < 0.05) and soleus (59.7%; p = 0.03), shorter time to half peak in gastrocnemius (46.9%; p = 0.00008) and soleus (33.5%; p = 0.0003), and shorter time to peak in gastrocnemius (13.5%; p = 0.02). Coefficients of variation were lower than percentage differences that were found significant. DISCUSSION: Findings show that the occlusion duration indeed influences the hyperemic response and thus should play a part in future methodological developments.

The Rapid Arterial oCclusion Evaluation (RACE) scale accuracy for diagnosis of acute ischemic stroke in emergency department - A multicenter study.

OBJECTIVE: It seems that the available data on performance of the Rapid Arterial oCclusion Evaluation (RACE) as a prehospital stroke scale for differentiating all AIS cases, not only large vessel occlusion (LVO), from the stroke mimics is lacking. As a result, we intend to evaluate the accuracy of the RACE criteria in diagnosing of AIS in patients transferred to the emergency department (ED). METHOD: The present study was a diagnostic accuracy cross-sectional study during 2021 in Iran. The study population consist of all suspected acute ischemic stroke (AIS) patients who transferred to the ED by emergency medical services (EMS). A 3-part checklist consisting of the basic and demographic information of the patients, items related to the RACE scale, and the final diagnosis of the patients based on interpretation of patients' brain MRI was used for data collection. All data were entered in Stata 14 software. We used the ROC analysis to evaluate the diagnostic power of the test. RESULT: In this study, data from 805 patients with the mean age of 66.9 ± 13.9 years were studied of whom 57.5% were males. Of all the patients suspected of stroke who transferred to the ED, 562 (69.8%) had a definite final diagnosis of AIS. The sensitivity and specificity of the RACE scale for the recommended cut-off point (score ≥ 5) were 50.18% and 92.18%, respectively. According to the Youden J index, the best cut-off point for this tool for differentiating AIS cases was a score > 2, at which sensitivity and specificity were 74.73% and 87.65%, respectively. CONCLUSION: It seems that, the RACE scale is an accurate diagnostic tool to detect and screen AIS patients in ED, Of course, not at the previously suggested cut-off point (score ≥ 5), but at the score > 2.

Prognostic factors for acute vertebrobasilar artery occlusion-reperfusion: a multicenter retrospective cohort study.

BACKGROUND: This study aimed to analyze the long-term prognostic factors in acute vertebrobasilar artery occlusion (VBAO) patients treated with endovascular treatment (EVT). METHODS: This study was performed using the acute posterior circulation ischemic stroke registry database from 21 stroke centers in 18 cities in China and retrospectively included consecutive patients aged 18 years or older with an acute, symptomatic, radiologically confirmed VBAO who were treated with EVT between December 2015 and December 2018. Favorable clinical outcomes were evaluated by machine-learning methods. A clinical signature was constructed in the training cohort using the least absolute shrinkage and selection operator regression and was validated in the validation cohort. RESULTS: From 28 potential factors, 7 variables were independent prognostic factors and were included in the model: Modified Thrombolysis in Cerebral Infarction (M) [odds ratio (OR): 2.900; 95% confidence interval [CI]: 1.566-5.370], age (A) (OR, 0.977; 95% CI: 0.961-0.993), National Institutes of Health Stroke Scale (N) (13-27 vs. ≤12: OR, 0.491; 95% CI: 0.275-0.876; ≥28 vs. ≤12: OR, 0.148; 95% CI: 0.076-0.289), atrial fibrillation (A) (OR, 2.383; 95% CI: 1.444-3.933), Glasgow Coma Scale (G) (OR, 2.339; 95% CI: 1.383-3.957), endovascular stent-retriever thrombectomy (E) (stent-retriever vs. aspiration: OR, 0.375; 95% CI: 0.156-0.902), and estimated time of onset of the occlusion to groin puncture (Time) (OR, 0.950; 95% CI: 0.909-0.993) (abbreviated as MANAGE Time). In the internal validation set, this model was well calibrated with good discrimination [C-index (95% CI)=0.790 (0.755-0.826)]. A calculator based on the model can be found online ( http://ody-wong.shinyapps.io/1yearFCO/ ). CONCLUSION: Our results indicate that optimizing for EVT, along with specific risk stratification, may improve long-term prognosis. However, a larger prospective study is needed to confirm the findings.

Acute Occlusion of the Abdominal Aorta Associated with Left Ventricular Thrombus: A Case Report.

BACKGROUND Acute aortic occlusion (AAO) is a rare emergency with high mortality. The typical clinical presentation is the sudden appearance of pain, paralysis, sensory disturbances, and mottling of the lower extremities. The etiology of AAO can be broadly classified into 3 categories: in situ thrombosis, arterial embolism, and occlusion of grafts. AAO is a rare consequence of myocardial infarction in the era of anticoagulation therapy, as part of the management of acute coronary syndrome (ACS). CASE REPORT We report the case of a 65-year-old woman who presented with acute lower extremity pain and weakness after a myocardial infarction 2 weeks earlier. She was on standardized antiplatelet therapy, a high blood D-dimer level was found during a visit to the Emergency Department, a left ventricular mural thrombus was detected using bedside ultrasound, and computed tomography angiography revealed thrombotic occlusion of the abdominal aorta. AAO disease was diagnosed, but the patient refused further treatment and died after 7 days of follow-up. CONCLUSIONS In recent years, anticoagulation has become part of the standard of care for patients with myocardial infarction or atrial fibrillation, which has led to a lower incidence of arterial embolism leading to AAO than in situ thrombosis. Depending on the type of occlusion, there are also differences in the surgical approach. A computed tomography angiography of the abdomen should be performed on all patients in whom AAO cannot be ruled out. Timely diagnosis and prompt surgical intervention are essential to preventing mortality.

Two cases of vascular complications after urologic robotic surgery.

Peripheral arterial disease (PAD) of the lower extremity is common and includes aortoiliac occlusive disease (AIOD). Moreover, prostate cancer is the most common cancer in men and is now treated with surgical robotic-assisted procedures. This paper overviews two cases of limb ischemia after robotic-assisted radical prostatectomy (RARP) and their resolution. During both RARP, limb ischemia occurred due to the robotic instrument compressing the modified vascular structure. Indeed, in the surgical history of the concerned patients, one was treated by an endovascular procedure and the other one was treated by a surgical bypass for AIOD. Expectantly, these cases will alert the urologic surgeons to pay attention to the vascular surgery history of a patient before RARP.

Incidence and predictors of radial artery occlusion following transradial coronary angiography: the proRadial trial.

OBJECTIVES: This study investigated the contemporary incidence and predictors of radial artery occlusion as well as the effectiveness of antithrombotic treatment for radial artery occlusion following transradial coronary angiography. BACKGROUND: The radial artery is the standard access for coronary angiography and even complex interventions. Postprocedural radial artery occlusion is still a common and significant complication. METHODS: This prospective study enrolled 2004 patients following transradial coronary angiography. After sheath removal, hemostasis was obtained in a standardized fashion. Radial artery patency was evaluated by duplex ultrasonography in all patients. In case of occlusion, oral anticoagulation was recommended and patients were scheduled for a 30-day follow-up including Doppler ultrasonography. RESULTS: A new-diagnosed radial occlusion was found in 4.6% of patients. The strongest independent predictors of radial occlusion were female sex and active smoking status. In the subgroup of patients with percutaneous coronary interventions, female sex followed by sheath size > 6 French were the strongest predictors of radial occlusion. 76 of 93 patients with radial occlusion received an oral anticoagulation for 30 days. However, reperfusion at 30 days was found in 32% of patients on oral anticoagulation. CONCLUSION: The incidence of radial artery occlusion following coronary angiography in contemporary practice appears with 4.6% to be lower as compared to previous cohorts. Female sex and smoking status are the strongest independent predictors of radial occlusion followed by procedural variables. The limited effectiveness of oral anticoagulation for treatment of radial artery occlusion suggests a primarily traumatic than thrombotic mechanism of this complication.

Risk factors and frequency of acute and permanent femoral arterial occlusion in neonates with CHD who undergo ultrasound-guided femoral arterial access.

OBJECTIVE: We investigated frequency and risk factors of acute loss of the arterial pulse and permanent femoral arterial occlusion in neonates with CHD who underwent ultrasound-guided femoral arterial access. METHODS: We divided the patients into groups according to the presence of acute loss of the arterial pulse and permanent femoral arterial occlusion. We obtained data related to patient characteristics and access variables of ultrasound-guided femoral arterial access from our database of cardiac catheterisation between August, 2017 and May, 2021. We used an echocardiography-S6, 12-MHz linear probe, 21-gauge needle, 0.018"guidewire, and a 4F sheath for arterial access. RESULTS: Ultrasound-guided femoral arterial access was obtained in 323 (98.8%) of the 327 neonates. We identified acute loss of the arterial pulse in 130 (40.2%) patients and permanent femoral arterial occlusion in 19 (5.9%) patients. Median weight was 3.05 (Interquartile range (IQR): 2.80-3.40) kg, first attempt success rate was 88.2%, and median access time was 46 sec (IQR: 23-94). Logistic regression analysis identified coarctation of the aorta (odds ratio: 2.46; 95% CI: 1.30-4.66; p = 0.006) as independent risk factor for acute loss of the arterial pulse, but did not identify any independent risk factors for permanent femoral arterial occlusion. CONCLUSIONS: This study showed coarctation of the aorta as an independent risk factor for acute loss of the arterial pulse, but did not identify any independent factors for permanent femoral arterial occlusion in neonates with CHD. Although most cases of acute loss of the arterial pulse resolve in the early period, the frequency of permanent femoral arterial occlusion remains high despite effective treatment.

Success rate of endovascular recanalization for femoropopliteal artery total occlusion using the wingman catheter system.

Chronic total occlusion (CTO) in the femoropopliteal artery is challenging to treat. The Wingman catheter system is a novel device for CTO penetration with a nitinol/stainless steel beveled tip. There is a lack of real-world clinical data indicating the success rate. We evaluated the efficacy of the Wingman system. This was a single-center retrospective study. We enrolled 27 consecutives patients who underwent treatment for femoropopliteal CTO using the Wingman system in 2021. The primary outcome was success of CTO-crossing and secondary outcomes were success of the procedure, Wingman-related complications, and predictors for success of Wingman crossing. The mean age of the study population was 76 years and the mean CTO length was 122 mm. The success rate of Wingman crossing was 40.7% and the overall procedure success rate was 100%. Only one case of embolism and one of perforation associated with the Wingman procedure were seen; both were successfully recovered. Univariate analysis revealed in-stent occlusion and non-severe calcification to be factors associated with success (16.7% vs 0%, p = 0.012 and 12.5% vs 50.0%, p = 0.036, respectively). These real-world data of the Wingman system demonstrate it to be a safe and one of option for treating femoropopliteal CTO.

Impact of radial compression protocols on radial artery occlusion and hemostasis time in coronary angiography.

Protocols for hemostasis after trans-radial approach (TRA) vary depending on the institute as there is no established evidence-based protocol. This study aimed to investigate the clinical implications of radial compression protocols. Consecutive patients who underwent outpatient invasive catheter angiography before and after April 2018 were treated with traditional and new protocols, respectively. Using the same hemostasis band, in the conventional protocol, fixed amount of air was removed soon after the procedure, 2 h later, and 3 h later, whereas the air was removed as much as possible every 30 min in the new protocol. A total of 1842 patients (71 ± 10 years old, 77% male) were included. Compared with the traditional protocol group (n = 1001), the new protocol group (n = 841) had a significantly lower rate of dual antiplatelet therapy (35% and 24% in the traditional and new groups, respectively, p < 0.001). The time required for complete hemostasis was approximately one-third with the new protocol (190 ± 16 and 66 ± 32 min, p < 0.001) with no clinically relevant bleeding. The incidence of radial artery occlusion (RAO) was 9.8% and 0.9% in the traditional and new protocol groups, respectively (p < 0.001). After adjusting for covariates, the new protocol was associated with a reduced risk of RAO (odds ratio 0.10, p < 0.001) and a shorter hemostasis time (odds ratio 0.01, p < 0.001). The new protocol for hemostasis after TRA was strongly associated with a shorter hemostasis time and a lower rate of RAO.

Change in somatosensory evoked potentials detect an acute arterial stent occlusion in lower extremity during spinal surgery: Case report.

The authors report a case in which an acute thrombosis of a pre-existing arterial stent occurs in a patient's lower extremity during a lumbar spinal fusion surgery. The event was detected by acute changes in somatosensory evoked potentials (SSEPs) which were being monitored during the procedure. The neurophysiology technologist reported a 10 % increased latency and 50 % loss of amplitude in the left posterior tibial nerve recordings. While still in the operating room, further investigation, including doppler and arteriogram, demonstrated a complete occlusion of one of the two contiguous stents within the superficial femoral artery (SFA). A vascular surgeon was then able to emergently perform trans-arterial thrombectomy and restore flow through the extremity while still in the operating room. The observed events demonstrate the ability of SSEP monitoring to potentially detect arterial occlusion early, allowing for a rapid diagnosis and expedient treatment, in this case immediate, thus avoiding significant limb threatening morbidity.

Evaluation of the distal radial approach in percutaneous coronary interventions. A controlled, randomized non-inferiority trial.

INTRODUCTION: The conventional radial approach (CRA), the gold standard approach for percutaneous coronary interventions (PCI), is associated with the risk of radial artery occlusion (RAO). The distal radial approach (DRA) is an effective alternative with fewer complications. AIM: To evaluate the efficacy in terms of puncture success and safety by RAO rate of the DRA in elective PCI in Tunisian patients. METHODS: It was a randomized controlled non-inferiority trial including patients hospitalized for elective PCI. The protocol was previously published (Tunis Med 2022; 100(3): 192-202). The primary endpoints were puncture success and RAO rate at 30 days. RESULTS: Overall, 250 patients were included and the groups were comparable. The preprocedural examination of the radial pulse and the Barbeau test were similar. The majority of PCIs were coronary angiography (82%). In ITT, respectively in CRA versus DRA, puncture success rates were similar (97.6% versus 96.8%; p≤0.500). RAO rates were similar (2.4% versus 3.2%; p≤0.500). Crossovers were similar. PCI through DRA lasted longer but was not more irradiating, however it required more contrast. Overall bleeding and vascular complications were similar. CONCLUSION: This study demonstrated the non-inferiority of DRA compared to CRA for elective PCIs in a Tunisian population regarding puncture success and RAO rate at 30 days. Multicenter trials including urgent PCI with systematic ultrasound screening for RAO are needed.

The efficacy of nitroglycerin to prevent radial artery spasm and occlusion during and after transradial catheterization: A systematic review and meta-analysis of randomized controlled trials.

Radial artery spasm (RAS) is the most common cause of transradial access site crossover and is a common intra-procedural complication. RAS incidence can lead to radial artery occlusion (RAO) postprocedure, preventing the radial artery as a future access site. We evaluated the efficacy of nitroglycerin preventing RAS and RAO during transradial catheterization discussing the different routes of administration, including topical, subcutaneous, and intra-arterial. A systematic review and meta-analysis included all relevant articles until April 23, 2022. We searched six databases Google Scholar, Web of Science, SCOPUS, EMBASE, PubMed (MEDLINE), and CENTRAL. We registered our review protocol in PROSPERO with ID: CRD42022330356. We included 11 trials with 5814 patients. Compared to placebo, the pooled analysis favored subcutaneous nitroglycerin in preventing RAS (risk ratio [RR]: 0.57 with 95% confidence interval [CI] [0.43-0.77], p = .0003) and RAO (RR: 0.39 with 95% CI [0.16-0.98], p = .05). In contrast to the intra-arterial nitroglycerin that showed nonstatistically significant results in preventing RAS and RAO (RR: 0.8 with 95% CI [0.63-1.02], p = .07)- (RR: 0.78 with 95% CI [0.6-1.01], p = .06)), respectively. Also, topical nitroglycerin did not prevent RAS (RR: 0.73 with 95% CI [0.42-1.24], p = .24). Compared with placebo, subcutaneous nitroglycerin during transradial catheterization reduced the incidence of RAS and RAO. Meanwhile, Intra-arterial and topical nitroglycerin did not show statistically significant outcomes. Subcutaneous nitroglycerin may be a practical and cost-effective technique to facilitate transradial catheterization; however, more RCTs are needed to evaluate the subcutaneous versus intra-arterial nitroglycerin administration.

Repetitive application of remote ischemic conditioning (RIC) in patients with peripheral arterial occlusive disease (PAOD) as a non-invasive treatment option: study protocol for a randomised controlled clinical trial.

BACKGROUND: The best medical treatment (BMT) for most patients with early stage of peripheral arterial occlusive disease (PAOD) is often limited to gait training and pharmacological therapy besides endovascular surgery. The application of remote ischemic conditioning (RIC) has been described as a promising experimental strategy for the improvement of therapeutic outcome in cardiovascular disease but has not proven beneficial effects in clinical practice and treatment of PAOD yet. METHODS: Here we describe a prospective, randomized trial for the evaluation of possible effects of repeated application of RIC in patients with PAOD. This monocentric study will enrol 200 participants distributed to an intervention group receiving RIC + BMT and a control group only receiving BMT for four weeks. Patients are at least 18 years of age and have diagnosed PAOD Fontaine stage II b. Pain-free and total walking distance will be measured via treadmill test (primary endpoints). In addition, ankle-brachial index (ABI) and quality of life (QoL) will be assessed using the SF-36 and VascuQoL-6 questionnaire. Moreover, evaluation of markers for atherosclerosis, angiogenic profiling and mononuclear cell characterization will be performed using biochemical assays, proteome profiling arrays and flow cytometry (secondary endpoints). DISCUSSION: Our prospective, randomized monocentric trial is the first of its kind to analyse the effects of chronic and repetitive treatment with RIC in patients with PAOD and might provide important novel information on the molecular mechanisms associated with RIC in PAOD patients. TRIAL REGISTRATION: Prospectively registered in the German Clinical Trials Register (Deutsche Register Klinischer Studien) Registration number: DRKS00025735; Date of registration: 01.07.2021.

Differentiation of Lower Extremity Skin Changes in the Intensive Care Setting.

Digital and lower extremity skin changes often signify critical underlying disorders. Patients in the intensive care unit also frequently have hemodynamic instability requiring the use of vasoactive medications, which may lead to various presentations of limb ischemia; preexisting conditions increase these patients' risk for arterial embolization. Most arterial emboli are clots that originate in the heart and travel to distant vascular beds, where they cause arterial occlusion, ischemia, and, potentially, infarction; the 2 most common sequelae are stroke and lower limb ischemia. Emboli also arise from atherosclerotic plaques. Other conditions can also cause skin color changes in this vulnerable population. Prompt recognition and differentiation of lower extremity skin changes can result in improved patient outcomes. A thorough literature search was conducted to differentiate the primary causes of lower extremity and digital skin changes in the critically ill patient and outline diagnostic and management techniques.