Acute Limb Ischemia: An Update on Diagnosis and Management

Acute Limb Ischemia Management and Complications: From Catheter-Directed Thrombolysis to Long-Term Follow-up

Acute limb ischemia (ALI) is a vascular emergency that needs to be diagnosed and treated quickly to prevent permanent tissue damage and amputation. Catheter-directed thrombolysis is a possible treatment option for mild to moderate ALI, with improved results from endovascular procedures and thrombolytic drugs. However, patients receiving thrombolysis may experience higher rates of distal embolization, serious bleeding events, and stroke than those undergoing surgery. The review article emphasizes the need for postoperative and extended management of ALI patients, including monitoring for compartment syndrome, managing reperfusion damage, and reducing changeable cardiovascular risk factors such as lipid-lowering therapy, diabetes management, and smoking cessation. Complications that can arise from thrombolytic therapy are also discussed, including hemorrhagic complications, minor bleeding, and reperfusion damage, with recommendations to monitor patients closely during treatment and discontinue therapy immediately if any abnormalities are detected. Follow-up evaluations for patients, including Doppler ultrasound, ankle brachial index, pulse volume recordings, and laboratory tests, are recommended to ensure the best possible outcome for patients with ALI.

Tomographic 3D ultrasound for grading stenosis of superficial femoral artery

INTRODUCTION

Treatment decision of lower extremity peripheral arterial disease (PAD) is governed by the severity of stenosis. Tomographic 3D ultrasound (t3DUS) is a reliable imaging technique for measuring vessel stenosis. In this study we attempted to provide a precise measurement of superficial femoral artery (SFA) stenosis using t3DUS in patients with PAD.

METHODS

t3DUS was used to measure maximum stenosis percentage in SFA from 50 patients with lower extremity PAD. The maximum stenosed segment in SFA was defined using Duplex 2DUS aliasing was noted. The peak systolic velocity (PSV) was measured at the maximum stenotic site and proximal to aliasing for calculating the velocity ratio. The association between blood flow velocity ratio and the degree of stenosis measured using Duplex 2DUS and t3DUS, respectively, was assessed using Spearman rank correlation.

RESULTS

There was a strong positive correlation between velocity ratio and degree of stenosis in SFA measured using t3DUS (correlation value (r) = 0.99, p < 0.001). The correlation between Stenosis percentage and velocity ratio in SFA are as followed: <50:<2; 50-54:2-2.4; 55-59:2.5-2.9; 60-64:3-3.4; 65-69:3.5-3.9; 70-74:4-4.4; 75-79:4.5-4.9; >80:>5.

t3DUS can be used to provide precise measurement of the severity of SFA stenosis in patients with lower extremities arterial disease. The established criteria for grading SFA stenosis in this study can be applied to the current practice alongside Duplex 2DUS as it showed a strong positive correlation with velocity ratio. Further studies investigating the sensitivity and specificity of t3DUS in the assessment of stenosis in lower limbs arteries are required.

Patients with Acute Lower Limb Ischemia Continue to Have Significant Morbidity and Mortality

BACKGROUND

The treatment of acute lower limb ischemia (ALLI) has evolved over the last several decades with the availability of several new treatment modalities. This study was undertaken to evaluate the contemporary presentation and outcomes of ALLI patients.

METHODS

We retrospectively analyzed data from a prospectively collected database of all patients who presented to our tertiary referral hospital with acute ischemia of the lower extremity between May 2016 and October 2020. The cause of death was obtained from the Michigan State Death Registry.

RESULTS

During the study period, 233 patients (251 lower limbs) were evaluated for ALLI. Seventy-three percent had thrombotic occlusion, 24% had embolic occlusion, and 3% due to a low flow state. Rutherford classification of ischemia severity was 7%, 49%, 40%, and 4% for Rutherford grade I, IIA, IIB, and III, respectively. Five percent underwent primary amputations, and 6% received medical therapy only. The mean length of stay was 11 ± 9 days. Nineteen percent of patients were readmitted within 30 days of discharge. At 30 days postoperatively, mortality was 9% and limb loss was 19%. On multivariate analysis, 1 or no vessel runoff to the foot postoperatively was associated with higher 30-day limb loss. Patients with no run-off vessels postoperatively had significantly higher 30-day mortality. Cardiovascular complications accounted for most deaths (48%). At 1-year postoperatively, mortality and limb loss reached 17% and 34%, respectively.

CONCLUSIONS

Despite advances in treatment modalities and cardiovascular care, patients presenting with ALLI continue to have high mortality, limb loss, and readmission rates at 30 days.

Predictors of poor outcomes after lower extremity revascularization for acute limb ischemia

OBJECTIVES

Acute lower extremity ischemia is one of the most common emergencies in vascular surgery and is a cause of considerable morbidity and mortality. The goal of this study was to evaluate outcomes of revascularization for acute lower extremity ischemia and to determine factors associated with perioperative morbidity and mortality.

METHODS

A total of 354 patients underwent urgent revascularization for acute lower extremity ischemia at an academic medical center between 2014 and 2019. A retrospective review of patients' demographics, comorbidities, etiology and severity of limb ischemia, and procedural characteristics was recorded. Outcomes, including postoperative complications, perioperative limb loss, and mortality, were analyzed.

RESULTS

The mean patient age was 69 ± 17 years, and 52% were females. 50% of patients presented with Rutherford Class IIb ischemia. Arterial embolization was the most common cause of limb ischemia, seen in 33% of cases. Open surgical revascularization was performed in 241 (68%) patients, while endovascular and hybrid approaches were utilized in 53 (15%) and 60 (17%) cases, respectively. Postoperative adverse events occurred in 44% of patients, including wound complications (11%), cardiac (5%) and pulmonary (16%) complications, strokes (4%), UTIs (10%), renal failure (14%), bleeding (5%), and compartment syndrome (3%). The rate of unplanned return to the operating room was 21%. Major adverse cardiovascular events were seen in 103 (29%) patients and major adverse limb events were seen in 57 (16%) patients. The median length of stay was 10 days (IQR = 4); 49% patients were discharged to skilled nursing facility and 19% were readmitted within 30 days.The rate of amputation during index admission was 10%, and perioperative mortality was 20%. Gender, tibial runoff, and etiology of limb ischemia were independent predictors of limb loss. Women had lower risk of limb loss than men (OR, 0.11; 95% CI, 0.023, 0.38). Poor tibial runoff (one-vessel or absence of flow below the knee) was a significant predictor of limb loss as compared to three-vessel runoff (OR, 14.92; 95% CI, 1.92, 115.88). Aneurysmal disease (OR, 38.35; 95% CI, 3.54, 42.45) and traumatic injuries (OR, 108.08; 95% CI, 8.21, 159.06) were the strongest predictors of amputation as compared to other etiologies of limb ischemia. Multivariate model identified ESRD (OR, 9.2; 95% CI, 1.8-46.3), degree of ischemia (class IIb or higher vs class IIa; OR, 3.5; 95% CI, 1.2-10.6), and age (OR, 1.5; 95% CI 1.1-2.0 for every 10 years) as independent predictors of perioperative mortality.

CONCLUSIONS

Urgent revascularization for management of acute limb ischemia is associated with high morbidity and mortality. Elderly patients with ESRD presenting with severely threatened limbs have especially high risk of perioperative mortality and may not be ideal candidates for limb salvage.

The Impact of COVID-19 on Amputation and Mortality Rates in Patients with Acute Limb Ischemia: A Systematic Review and Meta-Analysis

Since the inception of the SARS-CoV-2 pandemic, healthcare systems around the world observed an increased rate of Acute Limb Ischemia (ALI) in patients with a COVID-19 infection. Despite several pieces of evidence suggesting that COVID-19 infection may also worsen the prognosis associated with ALI, only a small number of published studies include a direct comparison regarding the outcomes of both COVID-19 and non-COVID-19 ALI patients. Based on the above, a systematic review and a meta-analysis of the literature were conducted, evaluating differences in the incidence of two major outcomes (amputation and mortality rate) between patients concurrently affected by COVID-19 and negative ALI subjects. PubMed (MEDLINE), Web of Science, and Embase (OVID) databases were scrutinized from January 2020 up to 31 December 2023, and 7906 total articles were recovered. In total, 11 studies (n: 15,803 subjects) were included in the systematic review, and 10 of them (15,305 patients) were also included in the meta-analysis. Across all the studies, COVID-19-positive ALI patients experienced worse outcomes (mortality rates ranging from 6.7% to 47.2%; amputation rates ranging from 7.0% to 39.1%) compared to non-infected ALI patients (mortality rates ranging from 3.1% to 16.7%; amputation rates ranging from 2.7% to 18%). Similarly, our meta-analysis shows that both the amputation rate (OR: 2.31; 95% CI: 1.68-3.17; p < 0.00001) and mortality (OR: 3.64; 95% CI: 3.02-4.39; p < 0.00001) is significantly higher in COVID-19 ALI patients compared to ALI patients.

Ayurveda management for acute upper limb ischemia - a case report

Acute upper limb ischemia (AULI) is a medical and surgical emergency involving sudden decrease in limb perfusion resulting in threat for limb viability. A 52 years old male patient was suffered from AULI. He had the complaints of numbness and pain in left upper limb, headache and pale discoloration of left-hand fingers and acute onset left upper extremity weakness.The Ayurveda diagnosis was considered as Vatarakta. He was advised oral medications - Kaishor guggulu in the dose of 750 mg twice a day with Jwarhar kashaya 40 ml twice a day, Ashwagandha Churna 3 g, Guduchi churna1g, Shatavari churna 2 g, Chopchini churna 1 g with milk twice a day, Shilajatwadi loha 500 mg and Mahavatvidhvansana rasa 250 mg twice a day with honey. All these medications were continued for 12 months. Two courses of Mustadi yapana basti (medicated enema enriched with milk) and Shalishastika pinda swedana (a specific type of sudation with a poultice of rice bolus) and Nasya (nasal therapy) with Shadabindu oil were given. Initial computed tomography (CT) angiogram revealed the abrupt cutoff of the left brachial artery in distal part due to hypodense lesion (thrombus) in the lumen while after 12 months of treatment CT angiogram revealed 70-80 % luminal narrowing in proximal part of left ulnar artery. It suggests the revascularization of left ulnar artery. All the symptoms of AULI were also resolved. We report a unique case of AULI managed with Ayurvedic interventions.

Neuromuscular complications of the lower extremity after thrombectomy in a patient with superficial femoral artery occlusion: Case series

BACKGROUND

Ischemia reperfusion (IR) injury may result in rhabdomyolysis and compartment syndrome when blood supply returns after thrombectomy for patients with acute limb ischemia.

OBJECTIVE

We highlight the value of early diagnosis and treatment in post-thrombectomy patients with IR injuries in their lower legs.

CASE DESCRIPTION

Two patients received thrombectomy due to left superficial femoral artery occlusion. Both patients complained of left calf pain during ambulation at the 1- and 3-day follow up post-thrombectomy, as well as a heating sensation, swelling, weakness, and sensory changes in the affected leg. For early diagnosis musculoskeletal ultrasounds were performed and in both cases revealed swelling and change of echogenicity in the left calf. To further diagnosis, magnetic resonance imaging of the left leg revealed limb IR-induced muscular injury and rhabdomyolysis, respectively. In both cases, an electrodiagnostic study revealed peripheral nerve injury in the left leg. Medications were provided for neuropathic pain control and early rehabilitation was performed to improve function. In both cases, patients reported during their follow-up that their pain and muscle weakness had improved.

CONCLUSION

When post-thrombectomy calf pain occurs early evaluation and treatment should be performed to identify any potential IR injury.

Adipose-Derived Mesenchymal Stem Cells Protect Endothelial Cells from Hypoxic Injury by Suppressing Terminal UPR In Vivo and In Vitro

Adipose-derived stem cells (ASCs) have been used as a therapeutic intervention for peripheral artery disease (PAD) in clinical trials. To further explore the therapeutic mechanism of these mesenchymal multipotent stromal/stem cells in PAD, this study was designed to test the effect of xenogeneic ASCs extracted from human adipose tissue on hypoxic endothelial cells (ECs) and terminal unfolded protein response (UPR) in vitro and in an atherosclerosis-prone apolipoprotein E-deficient mice (ApoE-/- mice) hindlimb ischemia model in vivo. ASCs were added to Cobalt (II) chloride-treated ECs; then, metabolic activity, cell migration, and tube formation were evaluated. Fluorescence-based sensors were used to assess dynamic changes in Ca2+ levels in the cytosolic- and endoplasmic reticulum (ER) as well as changes in reactive oxygen species. Western blotting was used to observe the UPR pathway. To simulate an acute-on-chronic model of PAD, ApoE-/- mice were subjected to a double ligation of the femoral artery (DLFA). An assessment of functional recovery after DFLA was conducted, as well as histology of gastrocnemius. Hypoxia caused ER stress in ECs, but ASCs reduced it, thereby promoting cell survival. Treatment with ASCs ameliorated the effects of ischemia on muscle tissue in the ApoE-/- mice hindlimb ischemia model. Animals showed less muscle necrosis, less inflammation, and lower levels of muscle enzymes after ASC injection. In vitro and in vivo results revealed that all ER stress sensors (BIP, ATF6, CHOP, and XBP1) were activated. We also observed that the expression of these proteins was reduced in the ASCs treatment group. ASCs effectively alleviated endothelial dysfunction under hypoxic conditions by strengthening ATF6 and initiating a transcriptional program to restore ER homeostasis. In general, our data suggest that ASCs may be a meaningful treatment option for patients with PAD who do not have traditional revascularization options.

Embolism from a left ventricular myxoma presenting with acute limb ischaemia

Acute limb ischaemia (ALI) secondary to cardiac myxoma is uncommon. Embolic myxoma should be considered a differential diagnosis in young patients with ALI who do not have apparent cardiovascular risk factors. A multidisciplinary approach and comprehensive care can improve outcomes and optimise the collaborative treatment of ALI. Early referral to a hospital that can provide specialised treatment for ALI helps prevent significant tissue loss and surgical complications, such as amputation.A man in his 20s presented with bilateral ALI of both lower extremities, and an arterial duplex scan revealed a thrombus occluding all arterial segments of the bilateral lower extremities. An intracardiac mass adherent to the apical and anterior interventricular septum on two-dimensional echocardiography suggested a complex myxoma. The patient was diagnosed with ALI Rutherford category III, and bilateral hip disarticulation was performed. The patient was discharged with an anticoagulant.

Incidence and Predictors of Acute Limb Ischemia in Patients With Acute Myocardial Infarction-Insight from National Readmission Database

Acute limb ischemia (ALI) has been a rare complication of acute myocardial infarction (AMI), however, with the increasing use of mechanical circulatory devices it is seen more frequently. The incidence and predictors of ALI in patients with AMI in contemporary clinical practice are unknown. A retrospective review of patients with index hospitalization for AMI in the Nationwide Readmission Database from 2016 to 2019 was done. We evaluated the annual incidence of ALI and its impact on outcomes. We used multivariate logistic regression analysis to determine predictors of ALI. In 1,283,586 patients with AMI, 3,971 patients (0.31%) had ALI and 365 (0.03%) had limb amputation. The 3 major predictors of ALI were peripheral artery disease (odds ratio [OR] 11.91, 95% confidence interval [CI]: 10.78 to 13.51), intravascular microaxial left ventricular assist device (OR 4.39, 95% CI 3.86 to 5.00), and veno-arterial extracorporeal membrane oxygenation (OR 4.37, 95% CI 3.19 to 6.01). Intra-aortic balloon pump had a substantially lower predictive ability (OR 1.81, 95% CI 1.63 to 2.0, p <0.0001) than other forms of mechanical circulatory support. The mortality rate in patients with ALI was significantly higher than those without ALI (19.49% vs 4.85%, p <0.0001). Patients who developed ALI had higher rates of amputation (1.59% vs 0.02%, p <0.0001). This observational nationwide study showed that ALI is an important complication in patients with AMI and is more frequently seen in patients who have peripheral artery disease, and require a left ventricular assist device or venoarterial extracorporeal membrane oxygenation. This complication was also associated with significantly higher in-hospital mortality.

Predictors of Recurrent Venous Thromboembolism or Arterial Thrombotic Events during and after Anticoagulation for a First Venous Thromboembolism

After first episodes of venous thromboembolism (VTE), patients are at increased risk of recurrent VTE and arterial thrombotic events (ATE) compared with the general population, two disorders that are influenced by anticoagulation. However, risk factors of these conditions occurring during and after anticoagulation are little described. Using cause-specific hazard regression models, we aimed to determine risk factors of the composite outcome recurrent VTE/ATE, and separately recurrent VTE or ATE, during and after anticoagulation in patients with first episodes of VTE from a prospective cohort. Hazard ratios (HRs) are given with 95% confidence intervals (CIs). A total of 2,011 patients treated for at least 3 months were included. A total of 647 patients had recurrent VTE/ATE (incidence: 4.69% per patient-years) during overall follow-up (median: 92 months). Of these events, 173 occurred during anticoagulation (incidence: 3.67% per patient-years). Among patients free of events at the end of anticoagulation, 801 had a post-anticoagulation follow-up ≥3 months; and 95 had recurrent VTE/ATE (incidence: 1.27% per patient-years). After adjustment for confounders, cancer-associated VTE (HR: 2.64, 95% CI: 1.70-4.11) and unprovoked VTE (HR: 1.95, 95% CI: 1.35-2.81) were the identified risk factors of recurrent VTE/ATE during anticoagulation (vs. transient risk factor-related VTE). Risk factors of recurrent VTE/ATE after anticoagulation included 50 to 65 years of age (vs. < 50, HR: 1.99, 95% CI: 1.04-3.81), older than 65 years (vs. < 50, HR: 5.28, 95% CI: 3.03-9.21), and unprovoked VTE (vs. transient risk factor-related VTE, HR: 2.06, 95% CI: 1.27-3.34). Cancer-associated VTE and unprovoked VTE are the main risk factors of recurrent VTE/ATE during anticoagulation, while older age and unprovoked VTE mainly predict the risk of these events after anticoagulation.

Acute lower limb ischaemia secondary to aortic compression from uterine fibroid

A woman in her early 50s with uncontrolled diabetes mellitus and a huge uterine fibroid presented to the emergency department with diabetic ketoacidosis and bilateral acute lower limb ischaemia. Vascular and advanced imaging studies confirmed distal aortic compression by a huge uterine fibroid, resulting in extensive lower limb arterial thrombosis. After resuscitation, the patient underwent emergency hysterectomy, thromboembolectomy and amputation of the right leg. She remained critically ill and died of fulminant sepsis and multiorgan failure 10 days later. This case reports the effects of external vascular compression by a large pelvic mass.

[Akute arterielle Embolie nach einer Knie-Totalendoprothese: Ein Bericht über zwei Fälle und Literaturübersicht]

Die akute arterielle Embolie ist eine seltene, aber schwerwiegende Komplikation nach einer Knie-Totalendoprothese (Knie-TEP). Es besteht ein allgemeiner Konsens darüber, dass in dieser Situation sofort eine Revaskularisation durchgeführt werden muss, aber die spezifische Behandlung ist immer noch umstritten. Wir berichten über zwei Fälle von Embolien der Kniekehlenarterie, die durch eine akute arterielle Thrombose nach Knie-TEP verursacht wurden. Bei beiden Patienten kam es nach der Operation zu einem Gefühls- und Bewegungsverlust der rechten unteren Extremität und einer Pulsationsschwächung der Arteria dorsalis pedis; eine Angiografie zeigte eine Embolie der Arteria poplitea. Einer der Patienten erhielt eine Thrombolysetherapie, entwickelte jedoch eine großflächige Infektion und Nekrose des rechten Wadenmuskels und benötigte nach erfolgreicher Thrombolyse ein mehrfaches Debridement und Hauttransplantationen. Bei dem anderen Patienten wurde eine Thrombektomie, eine Gefäßrekonstruktion und eine prophylaktische Fasziotomie durchgeführt; nach der Operation blieben ein Taubheitsgefühl im Fuß und eine leichte Streckschwäche zurück. Die Autoren empfehlen Chirurgen, Hochrisikopatienten mit Knie-TEP eine angemessene Aufmerksamkeit zu widmen. Vor der Operation sind eine sorgfältige Anamnese und körperliche Untersuchung erforderlich. Der chirurgische Eingriff sollte präzise und schonend durchgeführt werden, nach der Operation sind das Gefühl der Gliedmaßen und die Blutzirkulation aufmerksam zu beobachten. Bei abnormalem Fußgefühl und schwacher arterieller Pulsation sollten umgehend erforderliche Untersuchungen (Doppler-Ultraschall und Arteriografie) durchgeführt werden. Wenn eine arterielle Thrombose diagnostiziert wurde, muss die Blutversorgung sofort wiederhergestellt werden. Verzögert sich die Diagnose um mehr als 6 Stunden, kann eine prophylaktische Fasziotomie erforderlich sein, um nachteilige Folgen zu vermeiden.

Novel Application of Large Bore Aspiration in the Treatment of COVID-19 Associated Acute Limb Ischemia Using the Penumbra CAT 12 Lightning Aspiration System

COVID-19 associated cardiovascular complications have been well documented throughout the pandemic and are associated with higher rates of morbidity and mortality. Hypercoagulable states resulting from systemic inflammation have been associated with increasing incidences of acute myocardial infarctions (AMI) and acute limb ischemia (ALI). Herein, we present a case of AMI complicated by ALI in a patient with COVID-19 in which aspiration thrombectomy using the Penumbra CAT 12 thrombectomy catheter was used in the management of acute popliteal artery occlusion.

Anticoagulation With Platelet Transfusions for Acute Limb Ischemia With Severe Thrombocytopenia

Acute limb ischemia (ALI) is a medical and surgical emergency, and the mainstays of treatment are therapeutic anticoagulation and surgery. These interventions require adequate platelet count and functionality. Anticoagulation and surgery can be complicated in thrombocytopenic patients and require interdisciplinary management for optimal outcomes, as literature is limited in this population. We present a case of a patient with severe thrombocytopenia who developed limb ischemia from cancer-associated thrombosis (CAT). We propose a management strategy for anticoagulation and perioperative platelet transfusion, with successful revascularization without adverse bleeding events. While successful, more data is required to investigate long-term outcomes.

Vascular Diseases: Etiologic, Diagnostic, Prognostic, and Therapeutic Research

The impacts of vascular diseases (VD) include increased morbidity and mortality, which are related to factors such as population aging, socio-economics, or an increasing prevalence of risk factors, e [...].

Necessity, Role, and Outcomes of Fasciotomy in Patients with Acute Limb Ischemia

BACKGROUND

The incidence of compartment syndrome in patients with acute lower limb ischemia (ALLI) and the effects of fasciotomy on outcomes are largely undefined. This study aimed to define the incidence of compartment syndrome in patients with ALLI and to examine whether different fasciotomy strategies are associated with specific patient outcomes.

METHODS

A single center retrospective study of patients who had ALLI between April 2016 and October 2020 at a tertiary care center. Patients were categorized into groups as having received early and late therapeutic fasciotomy (TF), early prophylactic fasciotomy (PF), early exploratory fasciotomy, and no fasciotomy. Primary outcome was 30-day amputation rate. Secondary outcomes were 30-day and 1-year mortality, 1-year amputation rate, and length of stay. Groups were compared using descriptive statistics to assess the association of fasciotomy approach with outcomes.

RESULTS

During the study period, 266 patients were treated for ALLI, and 62 patients (23%) underwent 66 fasciotomies. A total of 41 TF, 23 PF, and 2 exploratory fasciotomies were done. There were 58 early fasciotomies performed (88% of 66 limbs): 33 (57%) early TF, 23 (40%) PF, and 2 (3%) exploratory. There were 8 patients who developed compartment syndrome after their revascularization operation and received delayed TF (12% of 66 limbs). The total number of TF was 41, which was 15% of all ALLI patients. The mean ± SD time to fasciotomy closure was 6.7 ± 5.7 days, which did not differ between PF and TF groups. Significantly more patients in the TF had an amputation at 30 days (11 [29%] vs 1 [5%]; P = 0.03) and at 1 year (6 [18%] vs 2 [9%]; P = 0.02) than those in the PF group. Length of stay was increased in both TF (16 days) and PF (19 days) patients compared to non-fasciotomy patients (10 days; P < 0.01) but did not differ between the 2 fasciotomy groups (P = 0.4). Thirty-day limb loss was highest in patients who underwent early TF (10/33, 33%), intermediate in those with delayed TF (1/8, 13%), and lowest in PF (1/23, 5%; P = 0.03).

CONCLUSIONS

Approximately 15% of patients with ALLI in our cohort required a TF for compartment syndrome. Close postoperative monitoring of ALLI patients who did not undergo early fasciotomy did detect delayed CS; however, this approach did not prevent limb loss. To optimize limb salvage, physicians treating patients with ALLI should be experienced in how to recognize and treat compartment syndrome.

Mönckeberg's Disease With Calcified Lower Limb Ischemia in Saudi Arabia: A Rare Case Report and Literature Review

Mönckeberg's disease, a rare medial calcific arteriosclerosis, predominantly affects lower extremity arteries with an unclear etiology. If untreated, severe complications like ischemic necrosis and gangrene may arise. We present a case of a 28-year-old male with spontaneous lower limb swelling, abscess, and itching. Despite a history of deep vein thrombosis and warfarin therapy, Mönckeberg's disease was suspected. Imaging revealed diffuse vascular calcification of the media of the arterial wall bilaterally in the right and left femoral vessels with heterogenous irregular soft tissue collection in the right with suspected infection. Following treatment, the patient's symptoms improved, and follow-up imaging showed resolution of fluid collections and improved calcification appearance. This report highlights the importance of considering Mönckeberg's disease in the differential diagnosis of lower extremity swelling and the need for timely management to prevent serious complications.

Exosomes from adipose-derived stem cells promote angiogenesis and reduce necrotic grade in hindlimb ischemia mouse models

Objectives

Acute hindlimb ischemia is a peripheral arterial disease that severely affects the patient's health. Injection of stem cells-derived exosomes that promote angiogenesis is a promising therapeutic strategy to increase perfusion and repair ischemic tissues. This study aimed to evaluate the efficacy of adipose stem cell-derived exosomes injection (ADSC-Exos) in treating acute mouse hindlimb ischemia.

Materials and Methods

ADSC-Exos were collected via ultracentrifugation. Exosome-specific markers were analyzed via flow cytometry. The morphology of exosomes was detected by TEM. A dose of 100 ug exosomes/100 ul PBS was locally injected into acute mice ischemic hindlimb. The treatment efficacy was evaluated based on the oxygen saturation level, limb function, new blood vessel formation, muscle structure recovery, and limb necrosis grade.

Results

ADSC-exosomes expressed high positivity for markers CD9 (76.0%), CD63 (91.2%), and CD81 (99.6%), and have a cup shape. After being injected into the muscle, in the treatment group, many small and short blood vessels formed around the first ligation and grew down toward the second ligation. The SpO2 level, reperfusion, and recovery of the limb function are more positively improved in the treatment group. On day 28, the muscle's histological structure in the treatment group is similar to normal tissue. Approximately 33.33% of the mice had grade I and II lesions and there were no grade III and IV observed in the treatment group. Meanwhile, in the placebo group, 60% had grade I to IV lesions.

Conclusion

ADSC-Exos showed the ability to stimulate angiogenesis and significantly reduce the rate of limb necrosis.

Mechanical Thrombectomy for Acute and Subacute Blocked Arteries and Veins in the Lower Limbs: A Health Technology Assessment

Background

A blockage to the blood vessels in the lower extremities may cause pain and discomfort. If left unmanaged, it may lead to amputation or chronic disability, such as in the form of post-thrombotic syndrome. We conducted a health technology assessment of mechanical thrombectomy (MT) devices, which are proposed to remove a blood clot, which may form in the arteries or veins of the lower legs. This evaluation considered blockages in the veins and arteries separately, and included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding MT for lower limb blockages, patient preferences and values, and clinical and health system stakeholders' perspectives.

Method

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Cochrane tool for randomized controlled trials or the risk of bias among non-randomized studies (RoBANS) tool for nonrandomized studies, and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search. We did not conduct a primary economic evaluation since the clinical evidence is highly uncertain. We also analyzed the budget impact of publicly funding MT treatment for inpatients with arterial acute limb ischemia and acute deep vein thrombosis (DVT) in the lower limb in Ontario. To contextualize the potential value of MT, we spoke with people with acute DVT. To understand the barriers and facilitators of accessing MT, we surveyed clinical and health system stakeholders to gain their perspectives.

Results

We included 40 studies (3 randomized controlled trials and 37 observational studies) in the clinical evidence review. For patients who experience arterial acute limb ischemia, compared with catheter-directed thrombolysis (CDT) alone, MT has greater technical success and patency and reduced hospital length of stay, but the evidence for these outcomes is uncertain (GRADE: Very low). Mechanical thrombectomy may reduce the volume of thrombolytic medication required and CDT infusion time (a determinant for intensive care unit [ICU] need) in patients experiencing acute DVT, but it is uncertain if this is to a meaningful degree (GRADE: Moderate to Very low). It may also reduce the proportion of people who experience post-thrombotic syndrome and overall hospital length of stay, but it is uncertain (GRADE: Very low).We estimated that publicly funding MT for people with arterial acute limb ischemia in Ontario would lead to an annual cost savings of $0.17 million in year 1 to $0.14 million in year 5, for a total savings of $0.83 million over 5 years. This cost savings was mainly attributed to reduced ICU stays among people who received MT, but the results had considerable uncertainty. For the population with acute DVT, publicly funding MT would lead to an additional cost of $0.77 million in year 1 to $1.44 million in year 5, for a total additional cost of $5.5 million over 5 years.The people with acute DVT with whom we spoke reported that MT was generally seen as a positive option, and those who had undergone the procedure reported positively on its value as a treatment to quickly remove a clot. Accessing treatment for DVT could be a barrier, especially in more remote areas of Ontario.Clinicians using the technology advised that facilitators to accessing the technology included perceived improvements in patient outcomes, resourcing requirements, addressing unmet needs, and avoidance of ICU stay. The main barrier identified was cost. Clinicians who were not using the technology advised that barriers were low case-use volume, along with costs for the equipment and for health human resources.

Conclusions

Mechanical thrombectomy may have greater technical success and patency and reduce hospital length of stay for patients experiencing an arterial acute limb ischemia and, for patients with an acute DVT, it may reduce CDT volume and infusion time, the proportion of people who experience post-thrombotic syndrome, and hospital length of stay. Mechanical thrombectomy may reduce the associated ICU costs, but it has higher equipment costs compared with usual care. Publicly funding MT in Ontario for populations with arterial acute limb ischemia may not lead to a substantial budget increase to the province. Publicly funding MT for acute DVT would lead to an additional cost of $5.5 million over 5 years. For people with acute DVT, MT was seen as a potential positive treatment option to remove the clot quickly. Overall, the majority of clinical stakeholders we engaged with (including both those with and without experience with MT) were supportive of the use of the technology.

Unilateral Limb Ischemia in a COVID-19 Patient: A Case Report

Coronavirus disease 2019 (COVID-19) has been primarily linked to respiratory complications, including acute respiratory distress syndrome (ARDS). However, several systemic manifestations of the disease may also occur. One of the emerging complications that is being increasingly reported in the literature is the hypercoagulable and intense inflammatory state in COVID-19 patients, which leads to venous and/or arterial thrombosis, vasospasm, and ischemia. Despite the recent advances in diagnostic and treatment modalities, the diagnosis and management of vascular ischemia in this patient population remain a challenge, resulting in increased morbidity and mortality. In this case report, we highlight the etiology and potential treatment of limb ischemia in COVID-19 patients.

Ultrasound Elastography to Differentiate the Thrombus and Plaque in Peripheral Arterial Diseases

Purpose

Arterial stiffness and steno-occlusion of the lower-extremity can result from many vascular lesions, including acute thromboembolisms, soft plaques, calcified plaques, or inflammatory disease. Ultrasound (US) elastography measures the tissue deformation response to compression and displays tissue stiffness. This study aimed to evaluate the characteristics of arterial lesions in the lower extremities using US elastography.

Materials and Methods

We retrospectively analyzed the data of 20 patients who visited our institute for arterial disease treatment between May 2016 and November 2017. An US examination with B-mode and strain elastography (SE) was performed of four different lesion types at 45 sites: acute and subacute thromboembolisms, soft plaques, calcified plaques, and thromboangiitis obliterans lesions (TAOs). During SE, stress was externally applied by the operator using the transducer. Strain ratio (SR) was calculated as the fraction of the average strain in the reference area divided by the average strain in the lesion. The SR was compared among different lesion types, with the accompanying vein as the reference region of interest.

Results

The strain was highest in the soft plaques (0.63%±0.23%), followed by the TAOs (0.45%±0.11%), calcified plaques (0.44%±0.13%), and acute thromboembolisms (0.34%±0.23%), which were statistically significant (P=0.026). However, the mean SR was highest for the calcified plaques (2.33%±0.80%), followed by the TAOs (1.63%±0.40%), acute thromboembolisms (1.60%±0.48%), and soft plaques (1.51±0.39), and which were statistically significant (P=0.013).

Conclusion

Despite several limitations, vascular elastography may be useful for differentiating between lesion types in peripheral arterial disease.

A Rare Combination of Arterial and Venous Thrombosis as a Sequalae of COVID-19

Coronavirus disease 2019 (COVID-19) has been a devastating condition claiming millions of lives, crippling countless people, and causing economic turmoil all over the world since the outbreak started in Wuhan Province of China in December 2019. Numerous papers have been published in the literature about COVID-19-related complications affecting almost all systems in the human body. One of the severe complications of this disease is thromboembolism, which affects both the arterial and venous systems and is well documented. There are few reports about both arterial and venous system involvement in the same patient. Herein, we report the case of COVID-19, who presented with critical limb ischemia caused by both arterial and venous thrombosis.

Prophylactic and Therapeutic Fasciotomy for Acute Compartment Syndrome after Revascularization for Acute Lower Limb Ischemia - Renal and Wound Outcomes

OBJECTIVES

Acute Compartment Syndrome (ACS) is a significant complication after revascularization for Acute Lower Limb Ischemia (ALI). High risk patients sometimes undergo prophylactic fasciotomy (PF) to prevent ACS. Patients that develop ACS undergo therapeutic fasciotomy (TF). The optimal timing of fasciotomy has been debated. The aim of this study was to describe and compare renal and wound outcomes in patients undergoing PF and TF.

METHODS

A retrospective cohort study including 76 patients undergoing PF (n=40) or TF (n=36) after revascularization for ALI between 2006 and 2018. Estimated Glomerular Filtration Rate (e-GFR) was used to evaluate renal function and compare within (paired-samples t-test) and between (ANOVA) groups. Wound complications and healing time were compiled from the complete wound healing period and compared between groups with Pearson's chi²- and log-rank test, respectively.

RESULTS

E-GFR improved over the in-hospital period with 8.2ml/min/1.73m² (95% CI 2.4-14.1, p=0.007) in the PF group and 4.4ml/min/1.73m² (95% CI 1.2-7.7, p=0.010) in the TF group, with no significant difference between the two groups (0.3ml/min/1.73m², 95% CI -6.7-7.4, p=0.93). The rate of wound infections was higher after TF (PF=60.6 % and TF=82.4 %, p=0.048), whereas rate of other wound complications (PF=61.3 % and TF=35.3%, p=0.036) was higher after PF.

CONCLUSION

Overall wound complications were high, whereas renal function improved during in-hospital stay. A more conservative approach to fasciotomy could avoid unnecessary fasciotomies and reduce wound complications, while have the potential to sufficiently preserve renal function if fasciotomy is needed for ACS. This would be possible and safe if an early diagnosis and treatment of ACS can be ensured.

Tetrahydropalmatine induces the polarization of M1 macrophages to M2 to relieve limb ischemia-reperfusion-induced lung injury via inhibiting the TLR4/NF-κB/NLRP3 signaling pathway

Tetrahydropalmatine (THP) is the main component of the Chinese medicine Corydalis yanhusuo, which has been reported to alleviate limb ischemia-reperfusion-induced acute lung injury (LIR-ALI). This study aimed to investigate the mechanism underlying the effect of THP on relieving LIR-ALI. LIR-ALI model was established in rats with the presence or absence of THP pretreatment. Then, BEAS-2B cells and THP-1 macrophages were cocultured with rat serum from the Sham group and the Model group in the presence or absence of THP pretreatment. Subsequently, lung/body weight and lung wet/dry ratio of rats were calculated. Histological changes of lung tissues were observed by hematoxylin-eosin staining. Expression of CD86 and CD163 in lung tissues of rats was assessed by quantitative reverse transcription polymerase chain reaction, immunohistochemistry staining, and flow cytometry analysis. Levels of inflammatory cytokines were measured by enzyme linked immunosorbent assay. The expression of proteins related to toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB)/NLRP3 signaling was detected by western blot analysis. Results revealed that THP significantly relieved LIR-ALI in rats. Moreover, THP also reduced CD86 expression but elevated CD163 expression in lung tissues of rats with LIR-ALI. Furthermore, THP inhibited inflammation in serum and bronchoalveolar lavage fluid of rats with LIR-ALI and inactivated the TLR4/NF-κB/NLRP3 signaling in vivo. Additionally, coculture of serum from rats in the Model group also reduced viability, promoted inflammation, inactivated TLR4/NF-κB/NLRP3 expression in BEAS-2B cells and inhibited macrophage polarization, while these effects were all reversed by THP treatment. Collectively, THP could induce the polarization of M1 macrophage to M2 to suppress inflammation via inhibiting TLR4/NF-κB/NLRP3 signaling, thereby attenuating LIR-ALI.

Approaches to Peripheral Artery Disease in Diabetes: Are There Any Differences?

Peripheral artery disease (PAD) increases the risk of diabetes, while diabetes increases the risk of PAD, and certain symptoms in each disease increase the risk of contracting the other. This review aims to shed light on this harmful interplay between the two disorders, with an emphasis on the phenotype of a patient with both diabetes and PAD, and whether treatment should be individualized in this high-risk population. In addition, current guideline recommendations for the treatment of PAD were analyzed, in an attempt to establish the differences and evidence gaps across a population suffering from these two interconnected disorders.

Intravascular Lithotripsy as a Novel Treatment Method for Calcified Unprotected Left Main Diseases-Comparison to Rotational Atherectomy-Short-Term Outcomes

Background: The unprotected calcified Left Main disease represents a high-risk subset for percutaneous coronary intervention (PCI), and it is associated with a higher number of periprocedural complications and an increased rate of in-stent thrombosis and restenosis. Adequate lesion preparation plays a crucial role in achieving a favorable PCI outcome. Rotational Atherectomy (RA) is a well-established plaque-modifying method; nevertheless, the data regarding the effectiveness of RA in LM diseases is scarce. Recently, the novel ShockWave-Intravascular-Lithotripsy(S-IVL) device has been introduced to the PCI armamentarium in order to modify the calcified plaque. Methods: We performed a retrospective evaluation of 44 consecutive subjects who underwent the LM-PCI, and who were supported by either the RA or S-IVL. Results: The Rota group consisted of 29 patients with a mean syntax score of 28.0 ± 7.5. The S-IVL group was composed of 15 subjects with a syntax score of 23.3 ± 13.0 There were no statistical differences regarding MACE between the RA and Shockwave arms of the in-hospital group (10.3% vs. 6.7%), or in the six month (17.2% vs. 13.3%) follow-up group. Conclusions: RA and S-IVL could be safe and effective therapeutic strategies for calcified LM disease. Further studies with a higher number of participants and longer follow-up times are warranted to establish the potential benefits of RA and S-IVL for the management of LM stenosis.

Risk Factors for Major Adverse Cardiovascular Events and Major Adverse Limb Events after Venous Thromboembolism: A Large Prospective Cohort Study

BACKGROUND

 There is an increased risk of arterial events including major adverse cardiovascular events (MACE) and major adverse limb events (MALE) after venous thromboembolism (VTE). However, their risk factors remain little explored.

METHODS

 We aimed to determine the risk factors for MACE (acute coronary syndrome/stroke/cardiovascular death) and MALE (limb ischemia/critical limb ischemia/non-traumatic amputation/any limb revascularization) after VTE. Competing risk models (Fine-Gray) were used in a multicenter prospective cohort of 4,940 patients (mean age: 64.6 years and median follow-up: 64 months).

RESULTS

 MACE occurred in 17.3% of participants (2.35% per patient-years) and MALE in 1.7% (0.27% per patient-years). In multivariable analysis, the identified risk factors for MACE were the age of 50 to 65 years (vs. <50 years, hazard ratio [HR]: 2.00, 95% confidence interval [CI]: 1.38-2.91), age >65 years (vs. <50 years, HR 4.85, 95% CI: 3.35-7.02), pulmonary embolism + deep vein thrombosis (DVT) (vs. isolated-DVT, HR: 1.25, 95% CI: 1.02-1.55), unprovoked-VTE (vs. transient risk factor associated-VTE, HR: 1.29, 95% CI: 1.04-1.59), current tobacco use (vs. never, HR: 1.45, 95% CI: 1.07-1.98), hypertension (HR: 1.61, 95% CI: 1.30-1.98), past history of symptomatic atherosclerosis (HR: 1.52, 95% CI: 1.17-1.98), heart failure (HR: 1.71, 95% CI: 1.21-2.42), atrial fibrillation (HR: 1.55, 95% CI: 1.15-2.08), and vena cava filter insertion (HR: 1.46, 95% CI: 1.03-2.08). The identified risk factors for MALE were the age of 50-65 years (vs. <50 years, HR: 3.49, 95% CI: 1.26-9.65) and atrial fibrillation (HR: 2.37, 95% CI: 1.15-4.89).

CONCLUSIONS

 Risk factors for MACE and MALE after VTE included some traditional cardiovascular risk factors, patient's comorbidities, and some characteristics of VTE.

Medial Arterial Calcification: A Significant and Independent Contributor of Peripheral Artery Disease

Over 200 million individuals worldwide are estimated to have peripheral artery disease (PAD). Although the term peripheral can refer to any outer branch of the vasculature, the focus of this review is on lower-extremity arteries. The initial sequelae of PAD often include movement-induced cramping pain in the hips and legs or loss of hair and thinning of the skin on the lower limbs. PAD progresses, sometimes rapidly, to cause nonhealing ulcers and critical limb ischemia which adversely affects mobility and muscle tone; acute limb ischemia is a medical emergency. PAD causes great pain and a high risk of amputation and ultimately puts patients at significant risk for major adverse cardiovascular events. The negative impact on patients' quality of life, as well as the medical costs incurred, are huge. Atherosclerotic plaques are one cause of PAD; however, emerging clinical data now shows that nonatherosclerotic medial arterial calcification (MAC) is an equal and distinct contributor. This ATVB In Focus article will present the recent clinical findings on the prevalence and impact of MAC in PAD, discuss the known pathways that contribute specifically to MAC in the lower extremity, and highlight gaps in knowledge and tools that limit our understanding of MAC pathogenesis.

Histological and immunohistochemical study of the effect of ozone versus erythropoietin on induced skeletal muscle ischemia-reperfusion injury in adult male rats

Ischemia reperfusion (IR) injury of skeletal muscles is a serious problem because of its local and systemic complications. Previous studies reported that ozone and erythropoietin could alleviate IR effect on several organs. The current research is established to evaluate the possible protective role of ozone versus erythropoietin following IR injury of the gastrocnemius muscle. Fifty rats were equally divided into five groups: I control, II ischemia reperfusion (IR), III post-reperfusion ozone treated, IV post-reperfusion erythropoietin-treated, and V recovering post-reperfusion without treatment groups. The right femoral arteries of all rats were clamped for three hours to induce ischemia then clamps were released to allow reperfusion for two hours. Rats of group II were scarified immediately after reperfusion period. Rats of group III were injected with ozone just after reperfusion for 14 days. Animals of group IV were injected with erythropoietin just after reperfusion for 14 days. Rats of group V rats were kept for 2 weeks following reperfusion without treatment. Blood samples were obtained to estimate lactate dehydrogenase (LDH) and creatine kinase (CK) enzymes. Gastrocnemius muscle was processed for measurement of tissue malondialdehyde (MDA), as well as examination by light and electron microscopes. iNOS and PCNA immunohistochemistry and statistical analysis were applied. The current results indicated that both ozone and erythropoietin could be used as protective agents reducing the muscular damage induced by IR injury.

Inflammation as a mechanism and therapeutic target in peripheral artery disease

Peripheral artery disease is one of three major clinical manifestations of atherosclerosis, the other two being coronary artery and cerebrovascular disease. Despite progress in surgery, antithrombotic therapy and therapies that modify conventional risk factors (lipid-, blood pressure-, and glucose-lowering interventions), patients with peripheral artery disease have unacceptably high risk of vascular complications. Additional strategies to reduce this residual risk are needed. The accumulated evidence that inflammation plays an important role in the pathogenesis of atherosclerosis has spurred recent efforts to evaluate anti-inflammatory agents as an additional therapeutic approach for atherothrombosis prevention and treatment. In this review, we examine the evidence supporting the role of inflammation in atherosclerosis, review recent trials evaluating anti-inflammatory approaches to reduce cardiovascular complications, and offer insights into the opportunities for novel anti-inflammatory strategies to reduce the burden of cardiovascular and limb complications in patients with peripheral artery disease.

Acute on Chronic Limb Ischemia Treatment: Case Series

ABSTRACT   BACKGROUND: Acute on chronic limb ischemia is a condition caused by acute disruption in chronic vessel disease. The major cause is peripheral arterial disease or embolism. Treating the acute phase while considering the origin of disease is important to treat acute on chronic limb ischemia. CASE DESCRIPTION: 3 cases were described on this serial case report. The first and second case represent acute on chronic limb ischemia conditions with history of intermittent claudication (IC) and signs of acute limb ischemia (ALI) upon arrival. They were both treated with surgical intervention for ALI. Despite of adequate surgical intervention, both cases showed suboptimal limb recovery. Both patients were referred for further evaluation of chronic vessel disease with angiography. Third case represent chronic limb ischemia as end point of treatment from the first and second case. Patient with worsening IC despite adequate medical and exercise treatment underwent angiography examination. Angiography result found two sites of total occlusion of right common iliac artery and superficial femoral artery. Angioplasty and primary stenting were done on common iliac artery. Drug coated balloon and stenting was also performed on superficial femoral artery. CONCLUSION: Patients with acute on chronic limb ischemia need to be treated during acute phase and the remaining chronic vessel disease. Consideration and care should be taken when managing similar cases for optimal treatment.   KEYWORDS: Acute on chronic limb ischemia, Thrombectomy, Angioplasty, Drug-coated Balloon.

Pharmacomechanical Thrombectomy for Acute Limb Threatening Lower Extremity Arterial Thrombosis Secondary to COVID-19

Purpose The aim of this study was to report the clinical effectiveness and safety of pharmacomechanical thrombectomy (PMT) for acute limb threatening lower extremity arterial thrombosis secondary to coronavirus disease 2019 (COVID-19).

Methods In this retrospective study, the clinical and imaging records of six patients (6 men, mean age 56 years) with COVID-19-related lower extremity arterial thrombosis and treated with PMT using the Angio-Jet device were reviewed. Patients presented with symptoms of acute pain in the affected limb, pallor, pulselessness, paresthesia, or paralysis. Thrombosis involved below knee arteries in all patients, and above knee arteries in three patients. Reteplase 18 mg was infused into the thrombus using the power pulse mode on the Angio-Jet device. This was followed by rheolytic thrombectomy and then, intra-arterial infusion of urokinase 100,000 IU/hour for 5 hours. All patients received systemic intravenous heparin. Technical success, clinical success, and complications of PMT were analyzed.

Results The mean thrombectomy duration was 190.83 ± 99.18 seconds. Adjuvant balloon angioplasty was performed in two patients. The mean hospital stay was 7.67 ± 4.50 days. PMT was technically successful in all (100%) patients. Five patients had excellent clinical outcome with at least one palpable pulse and no tissue loss. One patient required minor amputation. One patient developed self-limiting retroperitoneal hematoma.

Conclusion In our series, PMT with supplemental intra-arterial urokinase infusion was highly successful in treating acute peripheral arterial thrombosis secondary to COVID-19.

Atypical presentation of fistula dysfunction due to brachial arterial embolization mimicking stroke

Vascular access thrombosis is an important complication with great impact on access patency and, consequently, on a patient's quality of life and survival. We report the case of a 73-year-old woman with chronic kidney disease on hemodialysis with a radiocephalic arteriovenous fistula on the right arm that was brought to the emergency department with decreased strength in her right arm, ipsilateral hypoesthesia and facial hemi-hypoesthesia. The patient was given a brain computed tomographic scan that did not confirm suspicion of stroke. On re-examination, the patient had new-onset pain at arteriovenous fistula level, and her right arm was cold and pale. The nephrology department was called for arteriovenous fistula evaluation. On physical examination, her forearm fistula had a decreased thrill and arm elevation exacerbated its paleness. A bedside ultrasound was performed for arteriovenous fistula assessment. Doppler ultrasound revealed: partial thrombosis at brachial bifurcation, a flow of 80-105 mL/min at brachial artery level and a radial artery with a damped waveform. Anastomosis and draining vein were permeable. In this case, the diagnosis of acute embolic brachial artery occlusion was made by a fast bedside ultrasound evaluation. The patient underwent thromboembolectomy with Fogarty technique, recovering fistula thrill, radial and cubital pulses. Thromboembolism of the fistula feeding artery is a rare cause of vascular access thrombosis and it is rarely mentioned in the literature. In this report, failure to recognize the upper limb ischemia would have led to delayed treatment, potentially resulting in the fistula's complete thrombosis and further limb ischemia. We highlight the importance of a diagnosis method like Doppler ultrasound, which allows for rapid evaluation at the patient's bedside.

Traumatic proximal brachial artery injury selectively managed non-operatively: A case report and review of the literature

A right hand dominant 18-year-old female with a body mass index greater than forty presented to the trauma bay after sustaining two gunshot wounds to her right upper extremity. On physical exam, she had doppler signals and she reported neuropathy in the right median nerve distribution. She had no active signs of bleeding and she was subsequently taken to computed tomography which revealed an abrupt proximal brachial artery opacification with distal reconstitution in addition to having air tracking into the axillary and subclavian arteries. She underwent further resuscitation with normalization of perfusion as her radial and ulnar arteries became palpable. Traditionally, proximal brachial artery injuries are managed by an open surgical approach, which has a morbidity associated with the surgical dissection. Additionally in this case, there was concern for a blast injury near the potential graft inflow site. This case report highlights a patient who sustained a proximal brachial artery occlusion that was managed medically with antithrombotic agents and serial exams.

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The brachial artery lies alongside the median nerve.

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Anatomical nerve deficits may hint at the presence of vascular injuries.

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Elbow collaterals keep the distal arm perfused during brachial artery occlusion.

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Hard signs without bleeding/absence of perfusion can have a deliberate assessment.

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Injuries proximal vs. distal to the profunda branch typically have different injury patterns.

Experimental Evaluation of the Effectiveness of Aspiration-Based Techniques to Treat Different Types of Acute Thromboembolic Occlusions in the Femoropopliteal Vascular System Using an In Vitro Flow Model

PURPOSE

In this in vitro study, the effectiveness and safety of four aspiration-based techniques for thrombectomy are evaluated for three types of thrombi in a flow model simulating the femoropopliteal segment.

MATERIAL AND METHODS

Red, white, and mixed thrombi were produced in a standardized manner and used to simulate occlusion of a superficial femoral artery using a pulsatile flow model. Four techniques were compared: aspiration alone, aspiration + stent retriever, exposing thrombus to laser by an excimer laser system and a laser catheter + aspiration, and aspiration + mechanical fragmentation by a separator. Rate of first-pass recanalization, embolic events, and number of embolized fragments > 1 mm were compared.

RESULTS

Aspiration alone, stent retriever, laser, and separator differed in rates of first-pass recanalization (53.3%; 86.6%; 20%; and 100%) and embolic events (40%; 93.3%; 73.3%; and 60%). Number of embolized fragments was lowest with aspiration and higher with separator, laser, and stent retriever. Rates of first-pass-recanalization (75%; 75%; and 45%) and embolic events (65%; 60%; and 75%) differed for red, white, and mixed thrombi. The mixed thrombus caused the highest number of embolized fragments, which was particularly high using the stent retriever.

CONCLUSION

Additional use of mechanical techniques significantly enhances the effectiveness of thrombectomy but simultaneously provokes more embolism. Laser seems to negatively alter the structure of a thrombus and thus diminishes the effectiveness, while provoking embolism. All techniques had lowest effectiveness, but highest embolism with the mixed thrombus. This was particularly striking when a stent retriever was used with the mixed thrombus.

Characterization of Novel P-Selectin Targeted Complement Inhibitors in Murine Models of Hindlimb Injury and Transplantation

The complement system has long been recognized as a potential druggable target for a variety of inflammatory conditions. Very few complement inhibitors have been approved for clinical use, but a great number are in clinical development, nearly all of which systemically inhibit complement. There are benefits of targeting complement inhibition to sites of activation/disease in terms of efficacy and safety, and here we describe P-selectin targeted complement inhibitors, with and without a dual function of directly blocking P-selectin-mediated cell-adhesion. The constructs are characterized in vitro and in murine models of hindlimb ischemia/reperfusion injury and hindlimb transplantation. Both constructs specifically targeted to reperfused hindlimb and provided protection in the hindlimb ischemia/reperfusion injury model. The P-selectin blocking construct was the more efficacious, which correlated with less myeloid cell infiltration, but with similarly reduced levels of complement deposition. The blocking construct also improved tissue perfusion and, unlike the nonblocking construct, inhibited coagulation, raising the possibility of differential application of each construct, such as in thrombotic vs. hemorrhagic conditions. Similar outcomes were obtained with the blocking construct following vascularized composite graft transplantation, and treatment also significantly increased graft survival. This is outcome may be particularly pertinent in the context of vascularized composite allograft transplantation, since reduced ischemia reperfusion injury is linked to a less rigorous alloimmune response that may translate to the requirement of a less aggressive immunosuppressive regime for this normally nonlife-threatening procedure. In summary, we describe a new generation of targeted complement inhibitor with multi-functionality that includes targeting to vascular injury, P-selectin blockade, complement inhibition and anti-thrombotic activity. The constructs described also bound to both mouse and human P-selectin which may facilitate potential translation.

Hematological, Micro-Rheological, and Metabolic Changes Modulated by Local Ischemic Pre- and Post-Conditioning in Rat Limb Ischemia-Reperfusion

In trauma and orthopedic surgery, limb ischemia-reperfusion (I/R) remains a great challenge. The effect of preventive protocols, including surgical conditioning approaches, is still controversial. We aimed to examine the effects of local ischemic pre-conditioning (PreC) and post-conditioning (PostC) on limb I/R. Anesthetized rats were randomized into sham-operated (control), I/R (120-min limb ischemia with tourniquet), PreC, or PostC groups (3 × 10-min tourniquet ischemia, 10-min reperfusion intervals). Blood samples were taken before and just after the ischemia, and on the first postoperative week for testing hematological, micro-rheological (erythrocyte deformability and aggregation), and metabolic parameters. Histological samples were also taken. Erythrocyte count, hemoglobin, and hematocrit values decreased, while after a temporary decrease, platelet count increased in I/R groups. Erythrocyte deformability impairment and aggregation enhancement were seen after ischemia, more obviously in the PreC group, and less in PostC. Blood pH decreased in all I/R groups. The elevation of creatinine and lactate concentration was the largest in PostC group. Histology did not reveal important differences. In conclusion, limb I/R caused micro-rheological impairment with hematological and metabolic changes. Ischemic pre- and post-conditioning had additive changes in various manners. Post-conditioning showed better micro-rheological effects. However, by these parameters it cannot be decided which protocol is better.

Value of peripheral perfusion index to predict acute limb ischaemia in newborns after peripheral artery cannulation

AIMS AND OBJECTIVES

To investigate the feasibility of using peripheral perfusion index (PPI) to monitor acute limb ischaemia (ALI) in newborns after catheterisations.

BACKGROUND

ALI is common complication of neonatal peripheral artery cannulation. It is important to address as soon as the early signs of ALI. PPI could aid in noninvasive evaluation of distal extremity perfusion in an effort to notify risk of potential ischaemic injury from catheterisations.

DESIGN

A nested case-control study.

METHODS

Clinical information of newborns who had been admitted to the Neonatal Intensive Care Unit of Jiangxi Provincial Children's Hospital and had received peripheral artery cannulation from January 2018 to January 2020 was prospectively collected. Transcutaneous blood oxygen saturation (TcSO₂ ), PPI and delta-PPI (ΔPPI1; the difference in PPI values of the two arms. ΔPPI2; difference in the PPI values before and after cannulation) were recorded. We used STROBE checklist as an EQUATOR in this study.

RESULTS

A total of 25 newborns with ALI were included in the study. These were then paired with 100 newborns without ALI. The PPI and TcSO₂ of the cannulated limb were significantly lower in the ALI group than in the non-ALI (NALI) group (p < .05). The area under the receiver-operating characteristic curve was significant for ΔPPI1. The ΔPPI1 had a sensitivity and specificity of 92% and 87%, respectively, for diagnosing ALI. ΔPPI1 greater than 0.315 suggested that the infant was at risk of ALI.

CONCLUSIONS

Monitoring the change in the PPI in newborns after catheterisations helped in the early assessment of ALI.

RELEVANCE TO CLINICAL PRACTICE

Drops in the PPI and TcSO₂ of the cannulated limbs might, to some extent, reflect the possibility of ALI in newborns. ΔPPI1 (the difference in PPI values of the two arms) proved to be a simple, objective parameter to predict the presence of ALI.

Balloon-Assisted Endovascular Thrombectomy for Tibial Thromboembolism

We present a novel approach to endovascular thrombectomy using the Penumbra Indigo® Aspiration System with balloon assistance for a thromboembolic occlusion to the tibioperoneal trunk and tibial arteries causing acute limb ischemia. This technique allows for effective suction thrombectomy of distal vessels into a shorter, large-diameter aspiration catheter, thereby overcoming the limitations of the longer but smaller aspiration catheters.

Acute limb ischemia in a patient with Covid-19 pneumonia: a case report

Coronavirus disease 2019 (COVID-19) has emerged as a pandemic across the world. Hypercoagulability status in COVID-19 is one of the causes of complication from severe COVID-19 with a high risk of arterial thrombosis. Acute Limb Ischemia is a vascular emergency caused by sudden decrease in the arterial perfusion. We report the case of a 53-year-old male patient with COVID-19 Pneumonia, diagnosed with Acute Limb Ischemia. From clinical examination, which included anamnesis, physical examination, and laboratory results as well as chest X-rays, a suspicion of Acute Limb Ischemia was found in a patient with COVID-19 pneumonia. The SARS-CoV-2 real time PCR examination showed positive results. In this patient, the diagnosis of Acute Limb Ischemia with Covid-19 Pneumonia was established through a multidisciplinary approach covering the fields of pulmonology, cardiology, and thoracic and cardiovascular surgery.

Neutrophil-to-Lymphocyte Ratio Could Predict Outcome in Patients Presenting with Acute Limb Ischemia

Introduction: Acute limb ischemia (ALI), classified according to Rutherford’s classification (RC), is a vascular emergency burdened by high rates of mortality and morbidity. The need of new and different prognostic values for ALI has emerged, and, among all, the neutrophil-to-lymphocyte ratio (NLR) has been proven as a strong outcome predictor in vascular disease. The aim of this study is to investigate the role of preoperative NLR in predicting clinical outcomes in patients presenting acute limb ischemia. Material and Methods: A single-center retrospective study was conducted between January 2015 and December 2019. Demographic and clinical characteristics, procedural technical aspects, postoperative and early (up to 30-day) outcomes were recorded. All enrolled patients were categorized into low- and high-NLR at baseline, using a cut-off value of 5. Study outcomes were 30-day all-cause mortality and amputation rates. Results: A total of 177 ALI patients were included in the final analysis (6 RC I, 44 RC IIA, 108 RC IIB, and 19 RC III), 115 males (65%), mean age 78.9 ± 10.4 years. Mean NLR at hospital presentation was 6.65 ± 6.75 (range 0.5–35.4), 108 (61.1%) patients presented a low-NLR, 69 (38.9%) a high-NLR. Immediate technical success was achieved in 90.1% of cases. At 30 days, freedom from amputation and freedom from death rates were 87.1% and 83.6%, respectively. At the univariate analysis, amputation (p < 0.0001, OR: 9.65, 95%CI: 3.7–25.19), mortality (p = 0.0001, OR: 9.88, 95%CI: 3.19–30.57), and cumulative event rates (p < 0.001, OR: 14.45, 95%CI: 6.1–34.21), were significantly different between the two groups according to NLR value. Multivariate analysis showed that a high baseline NLR value was an independent predictor of unfavorable outcomes in all enrolled patients. Consistently, at ROC analysis, a preoperative NLR > 5 was strongly associated with all outcome occurrences. Conclusion: Preoperative NLR value seems to be strongly related to ALI outcomes in this unselected population. The largest series should be evaluated to confirm present results.

Antithrombotic Therapy in Peripheral Artery Disease: Stepping in the Right Direction

We reviewed the various antithrombotic therapies available to treat peripheral artery disease (PAD). A literature review using the PubMed and MEDLINE databases used the following keywords: antithrombotic therapy, anticoagulation, peripheral artery disease, and peripheral vascular disease. Randomized studies written in English that assessed the use of antithrombotic therapy in patients with PAD were evaluated. PAD is a worldwide condition that limits blood flow in the lower extremities, leading to a risk of major adverse cardiovascular events and major adverse limb events. Antithrombotic therapy is necessary to prevent these complications, and the choice of therapy depends upon the stage of disease progression. For symptomatic patients in the beginning stage, single antiplatelet therapy (SAPT) is the preferred therapy, specifically, aspirin. For patients undergoing endovascular revascularization, the preferred therapy is dual antiplatelet therapy using aspirin and clopidogrel combined for at least the first month followed by long-term SAPT. For patients undergoing surgical revascularization, the preferred choice of therapy depends upon the type of graft used, with better results obtained with antiplatelet therapy for prosthetic grafts and anticoagulation for venous grafts. New studies have shown that therapy using both antiplatelets and anticoagulation in the form of aspirin plus low-dose rivaroxaban can reduce complications in all three patient populations, which has paved the way for future studies featuring direct oral anticoagulants with the potential to change current guideline recommendations.

Beneficial postoperative micro-rheological effects of intraoperative administration of diclophenac or ischemic preconditioning in patients with lower extremity operations -Preliminary data

BACKGROUND

Ischemia-reperfusion (I/R) may worsen blood rheology that has been demonstrated by clinical and experimental data. It is also known that anti-inflammatory agents and preconditioning methods may reduce I/R injury.

OBJECTIVE

We aimed to analyze hemorheological alterations in elective knee operations and the effects of intraoperative nonsteroidal anti-inflammatory drug (NSAID) administration and application of ischemic preconditioning.

METHODS

Hemorheological variables of 17 patients with total knee replacement or anterior crucial ligament replacement were analyzed. The ischemic (tourniquet) time was 92±15 minutes. Seven patients did not receive NSAID (Control group), 5 patients got i.v. sodium-diclophenac 10 minutes before and 6 hours after reperfusion. Five patients had ischemic preconditioning (3×15 minutes). Blood samples were collected before the ischemia, 10 minutes after reperfusion, on the 1st and 2nd p.o. day.

RESULTS

Whole blood viscosity didn't show notable inter-group differences, except for a slight decrease in the preconditioning group. RBC deformability decreased, erythrocyte aggregation enhanced by the 1st and 2nd p.o. days in Control group. In NSAID and preconditioning groups the changes were moderate, aggregation values significantly lowered compared to the Control group.

CONCLUSION

Intraoperatively administered diclophenac or ischemic preconditioning could moderate the deterioration in micro-rheological parameters caused by I/R in patients.