Contemporary outcomes of endovascular interventions for acute limb ischemia

Predicting Amputation Rates in Acute Limb Ischemia: Is the Neutrophil-Lymphocyte Ratio a Reliable Indicator?

Objective This study aimed to investigate the causes of amputation and the associated biochemical parameters in patients with acute limb ischemia (ALI). Methods Patients who presented to our clinic with ALI between January 2012 and January 2022 were deemed eligible for participation. Patients who developed ALI owing to atherosclerosis or atrial fibrillation were included in the study. In contrast, patients who developed ALI owing to trauma, iatrogenic causes, or popliteal artery aneurysms were excluded. Patients' demographic data, biochemical parameters, and hemogram values at the time of admission were retrospectively analyzed. Results A total of 374 patients were included in the study. Of them, 57.82% (n = 218) were male and 42.18% (n= 156) were female. Amputation was required in 7.95% (n = 30) of the patients after presenting with ALI and receiving necessary surgical or medical intervention. Multivariate analysis revealed the symptom-to-door time to be the primary factor determining the need for amputation in patients. With each passing hour following the manifestation of symptoms, the risk of amputation increased by 1.3 times [odds ratio (OR): 1.289%, 95% confidence interval (CI): 1.079-1.540 p = 0.05]. The neutrophil-to-lymphocyte ratio (NLR) and other hematological parameters had no effect on amputation in both univariate and multivariate analyses (OR: 1.49%; 95% CI: 0.977-2.287 p = 0.512). Conclusions Based on our findings, the main factor affecting the need for amputation in ALI patients was the symptom-to-door time. Biochemical and hematological parameters had no effect on amputation in ALI.

Short-term outcomes of endovascular management of acute limb ischemia using aspiration mechanical thrombectomy

OBJECTIVE

Management of acute limb ischemia (ALI) has seen greater utilization of catheter-based interventions over the last two decades. Data on their efficacy is largely based on comparisons of catheter-directed thrombolysis (CDT) and open thrombectomy. During this time, many adjuncts to CDT have emerged with different mechanisms of action, including pharmacomechanical thrombolysis (PMT) and aspiration mechanical thrombectomy (AMT). However, the safety and efficacy of newer adjuncts like AMT have not been well established. This study is a retrospective analysis of the contemporary management of ALI comparing patients treated with aspiration mechanical thrombectomy to patients treated with the more established CDT adjunct, pharmacomechanical thrombolysis.

METHODS

Patients undergoing peripheral endovascular intervention for ALI using an adjunctive device were identified through query of the Vascular Quality Initiative (VQI) Peripheral Vascular Intervention (PVI) module from 2014 to 2019. Patients with a nonviable extremity (Rutherford ALI Stage 3), prior history of ipsilateral major amputation, popliteal aneurysm, procedures that were deemed elective (>72 h from admission), procedures that did not utilize an endovascular adjunctive device, and patients without short-term follow-up were all excluded from analysis. The primary outcome was a composite outcome of freedom from major amputation and/or death in the perioperative time period.

RESULTS

We identified 528 patients with Rutherford ALI Stage 1 or 2 who were treated with an endovascular adjunct. 433 patients did not undergo aspiration mechanical thrombectomy (no AMT group) and 95 patients did undergo aspiration mechanical thrombectomy (AMT group). The amputation-free survival across all patients was 93.4%. There were significant differences in demographic, comorbidity, and treatment variables between groups (e.g., gender, prior percutaneous coronary intervention (PCI), history of prior peripheral artery disease intervention, and history of prior infra-inguinal PVI), so a propensity score matched analysis was included to account for these group differences. In the propensity score matched analysis, there was no significant difference in major amputation (AMT 7.4% vs no AMT 3.2%, p = 0.13) or death (AMT 95.8% survival vs no AMT 98.4% survival, p = 0.23) with the use of aspiration mechanical thrombectomy. However, there was significantly worse amputation-free survival with the use of aspiration mechanical thrombectomy (AMT 88.4% vs no AMT 95.3%, p = 0.03). On multivariate analysis, prior supra-inguinal bypass (OR 4.85, 1.70-13.84, p = 0.003), Rutherford ALI Stage 2B (OR 3.13, 1.47-6.67, p = 0.003), and aspiration mechanical thrombectomy (OR 2.71, 1.03-7.17, p = 0.05) were associated with the composite outcome.

CONCLUSIONS

Short-term amputation-free survival rates of endovascular management of acute limb ischemia are adequate across all modalities. However, aspiration mechanical thrombectomy was associated with significantly worse amputation-free survival compared to other endovascular adjuncts alone (i.e., pharmacomechanical thrombolysis). Severe limb ischemia (Rutherford ALI Stage 2B) and prior supra-inguinal bypass were associated with worse amputation-free survival regardless of the choice of endovascular intervention.

Core-Shell Droplet-Based Angiogenic Patches for the Treatment of Ischemic Diseases: Ultrafast Processability, Physical Tunability, and Controlled Delivery of an Angiogenic Cocktail

The patch-based delivery system has been a promising therapeutic approach for treating various vascular diseases. However, conventional methods face several challenges, including labor-intensive and time-consuming processes associated with patch fabrication or factor incorporation, inadequate physical properties, and uncontrolled release of factors. These limitations restrict the potential applications in clinical settings. To overcome these issues, we propose a novel core-shell-shaped droplet patch system called an angiogenic patch (AP). Our system offers several distinct advantages over conventional patches. It enables a rapid and straightforward fabrication process utilizing only two biodegradable ingredients [alginate and ε-poly(l-lysine)], ensuring minimal toxicity. Moreover, the AP exhibits excellent physical integrity to match and withstand physiological mechanics and allows for customizable patch dimensions tailored to individual patients' pathological conditions. Notably, the AP enables facile loading of angiogenic cytokines during patch fabrication, allowing sustained release at a controlled rate through tunable network cross-linking. Subsequently, the AP, delivering a precisely formulated cocktail of angiogenic cytokines (VEGF, bFGF, EGF, and IGF), demonstrated significant effects on endothelial cell functions (migration and tubule formation) and survival under pathological conditions simulating ischemic injury. Likewise, in in vivo experiments using a mouse model of hindlimb ischemia, the AP encapsulating the angiogenic cocktail effectively restored blood flow following an ischemic insult, promoting muscle regeneration and preventing limb loss. With its simplicity and rapid processability, user-friendly applicability, physical tunability, and the ability to efficiently load and control the delivery of angiogenic factors, the AP holds great promise as a therapeutic means for treating patients with ischemic diseases.

Acute ischemia of the upper and lower limbs: Tailoring the treatment to the underlying etiology

Acute limb ischemia (ALI) can be a devastating clinical emergency with potentially limb- or life-threatening consequences. It is defined as a quickly developing or sudden decrease in limb perfusion producing new or worsening symptoms and signs, often threatening limb viability. ALI is commonly related to an acute arterial occlusion. Rarely, extensive venous occlusion can lead to upper and lower extremities ischemia (ie, phlegmasia). The incidence of acute peripheral arterial occlusion causing ALI is approximately 1.5 cases per 10,000 people per year. The clinical presentation depends on the etiology and whether the patient has underlying peripheral artery disease. Except for traumas, the most common etiologies are embolic or thrombotic events. Peripheral embolism, likely related to embolic heart disease, is the most common cause of acute upper extremity ischemia. However, an acute thrombotic event may occur in native arteries, at the site of a pre-existing atherosclerotic plaque, or as a failure of previous vascular interventions. The presence of an aneurysm may predispose to ALI for both embolic and thrombotic mechanisms. Immediate diagnosis, accurate assessment of limb viability, and prompt intervention, when needed, play important roles in salvaging the affected limb and preventing major amputation. Severity of symptoms is usually dependent on the amount of surrounding arterial collateralization, which may often reflect a pre-existing chronic vascular disease. For this reason, early recognition of the underlying etiology is crucial for choice of best management and definitely for treatment success. Any error in the initial evaluation may negatively affect the functional prognosis of the limb and endanger the patient's life. The aim of this article was to discuss diagnosis, etiology, pathophysiology, and treatment of patients with acute ischemia of the upper and lower limbs.

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.

The Management of Patients with Popliteal Artery Aneurysms Presenting with Acute Limb Ischemia

INTRODUCTION

Endovascular popliteal artery aneurysm (PAA) repair has acceptable outcomes compared to open repair for elective therapy. Endovascular repair for urgent PAA causing acute limb ischemia (ALI) has not been well studied. This project compares outcomes of urgent endovascular and open repair of PAA with ALI.

METHODS

The Vascular Quality Initiative database for peripheral vascular interventions and infrainguinal bypass were reviewed for PAA with ALI from 2010 to 2021. Only patients entered as having symptoms of ALI in the PVI module and ALI as indication in the infrainguinal bypass module were included. In addition, patients undergoing elective treatment were excluded and the sample analyzed was restricted to patients undergoing urgent and emergent open and endovascular repair. Patient demographics and comorbidities as well as procedural details were compared between the two groups. Perioperative complications up to 30 days were compared as well as long-term outcomes including major amputation and mortality at one year.

RESULTS

Urgent PAA repair for ALI constituted 10.5% (N=571) of all PAA. Most urgent repairs were open (80.6%, n=460) with 19.4% (n=111) endovascular. The proportion of endovascular repair significantly increased from 16.7% in 2010 to 85.7% in 2021. Patients undergoing endovascular repair were older (71.2 ± 12.5 vs 68.0 ± 11.8, p=0.011) than patients undergoing open repair. They were also more likely to have coronary artery disease (32.4% vs 21.7%, p=0.006). Open PAA repair was associated with more bleeding complications (20.8% vs 2.7%, p<0.001), longer post-op length of stay (8.1 ± 9.3 days vs 4.9 ± 5.6 days, p<0.001), and less likelihood of discharge to home (64.9% vs 70.3%, p=0.051). Perioperative major amputation rate was 7.5% with no difference between the two treatment strategies up to one year. However, patients receiving endovascular repair had higher inpatient (1.1% vs 0%, p<0.001), 30-day (6.3% vs 0.4%, p<0.001), and 1-year (16.5% vs 8.4%. P=0.02) mortality. Multivariable regression analysis suggested that endovascular repair was possibly associated with increased 30-day mortality, but not 1-year mortality.

CONCLUSION

Endovascular PAA has exponentially increased from 2010 to 2021. Endovascular repair is associated with decreased complications and hospital length of stay. The increased perioperative mortality seen in this group is likely due to selection bias.

Short-term complications and outcomes in pharmaco-mechanical thrombolysis first and catheter-directed thrombolysis first in patients with acute lower limb ischemia

BACKGROUND

Pharmaco-mechanical thrombolysis (PMT) has emerged as a treatment option in patients with acute lower limb ischemia (ALI), especially Rutherford IIb (motor deficit) for rapid revascularization, but supportive data is scarce. The aim of the present study was to compare effect of thrombolysis, complications, and outcomes of PMT first versus catheter-directed thrombolysis (CDT) first in a large cohort of patients with ALI.

BASIC PROCEDURES

All endovascular thrombolytic/thrombectomy events in patients with ALI performed between January 1^st 2009 and December 31^st 2018 (n=347) were included. Successful thrombolysis/thrombectomy was defined as complete or partial lysis. Reasons for use of PMT was described. Complications such as major bleeding, distal embolization, and new onset of renal impairment, and major amputation and mortality at 30 days were compared between PMT (AngioJet™) first and CDT first groups in a multi-variable logistic regression model with adjustment for age, gender, atrial fibrillation, and Rutherford IIb.

MAIN FINDINGS

The most common reason for initial use of PMT was need of rapid revascularization, and the most common reason for use of PMT after CDT was insufficient effect of CDT. Presentation of Rutherford IIb ALI was more common in the PMT first group (36.2% vs 22.5%, respectively, p=0.027). Among 58 patients receiving PMT first, 36 (62.1%) were terminated within a single session of therapy without need of CDT. The median duration of thrombolysis was shorter (p<0.001) for the PMT first group (n=58) compared to the CDT first (n=289) group (4.0 hours vs 23.0 hours, respectively). There was no significant difference in amount of tissue plasminogen activator given, successful thrombolysis/thrombectomy (86.2% and 84.8%), major bleeding (15.5% and 18.7%), distal embolization (25.9% and 16.6%), major amputation or mortality at 30-day (13.8% and 7.7%) in the PMT first compared to the CDT first group, respectively. The proportion of new onset of renal impairment was higher in the PMT first compared to the CDT first group (10.3% versus 3.8%, respectively), and the increased odds (Odds ratio 3.57, 95% CI 1.22 - 10.41) was maintained in the adjusted model. In Rutherford IIb ALI, no difference in rate of successful thrombolysis/thrombectomy (76.2% and 73.8%), complications or 30-day outcomes was found between PMT first (n=21) and CDT (n=65) first group.

CONCLUSION

PMT first appears to be a good treatment alternative to CDT first in patients with ALI, including Rutherford IIb. The found renal function deterioration in the PMT first group needs to be evaluated in a prospective, preferably, randomized trial.

Endovascular Bailout Repair After Intraprocedural Thrombosis of a Bifurcated Unimodular Stent-graft During Aorto-iliac Revascularization in a Patient with Sars CoV-2 Infection

To describe a case of endovascular bailout strategy during stent-graft thrombotic complication in an endovascular procedure for complex TASC II D aortoiliac lesion. A 77-year-old patient was admitted at our institution with bilateral lower limb rest pain due to aortoiliac obstructive disease in a previous aortobifemoral bypass grafting with an asymptomatic Sars-CoV-2 infection. We planned an anatomic reconstruction of the aortoiliac segment with an unimodular bifurcated stent-graft. During the procedure, we observed a preocclusive thrombosis of the aortic portion requiring endovascular thrombectomy with vacuum assisted system followed by a successfully kissing-stent endolining. The post-operative period was uneventful and patient was discharged on the 14^th post-operative day. Endovascular thrombectomy may be a helpful strategy during thrombotic complication of complex reconstructions of obstructive aortoiliac disease avoiding surgical conversion to laparotomy.

Sex-related differences in the effect of rotational thrombectomy for thrombus-containing lower limbs ischemic lesions

BACKGROUND

To assess the immediate effect and factors affecting the efficacy of rotational thrombectomy (RT) in patients with thrombus-containing lower-limb ischaemic lesions.

METHODS

Patients were retrospectively divided into two groups: RT and RT+ CDT (Catheter-directed thrombolysis). The RT group included patients in whom intraoperative thrombus aspiration was successful, while the RT + CDT group included patients in whom intraoperative thrombus aspiration was less effective and remedial CDT treatment was used. The primary outcome was the immediate effect of RT on thrombus-containing lower-limb ischaemic lesions.

RESULTS

From May 2015 to July 2021, 170 patients (113 men, 57 women; mean age, 74.0 years) with thrombus-containing lower-limb ischaemic lesions were treated in our centre. Of these patients, 113 received RT only, while 57 received RT + CDT. There were no significant intergroup differences in terms of age, disease duration, or comorbidities, but a higher proportion of male patients and higher preoperative plasma D-dimer levels (1.23 vs. 0.84; p = .017) was observed in the RT + CDT group. There were no significant intergroup differences in terms of diagnosis, lesion characteristics, lesion location, or lesion length. Multivariate logistic regression analysis revealed that male sex (odds ratio [OR], 2.65; 95% confidence interval [CI], 1.098-6.410; p = .030) and poor distal runoff (OR, 2.94; 95% CI, 1.439-5.988; p = .003) were associated with higher rates of additional CDT. Male patients also had a significantly longer onset time, more thrombotic occlusions, and a greater frequency of in-stent restenosis.

CONCLUSIONS

RT alone or with CDT is a feasible primary treatment option for thrombus debulking. Sex significantly influences the effect of RT on thrombus-containing lower-limb ischaemic lesions.

Young patients without prior vascular disease are at increased risk of limb loss and reintervention after acute limb ischemia

BACKGROUND

The objective of the present study was to categorize the presentation and treatment of acute limb ischemia (ALI) in young patients and compare the adverse outcomes after revascularization compared with that of older patients.

METHODS

All the patients who had presented to a multi-institution healthcare system with ALI from 2016 to 2020 were identified. The presenting features, operative details, and outcomes were included in the present analysis. Patients with existing peripheral arterial disease (acute on chronic) were analyzed separately from those without (de novo thrombosis or embolus). Within these groups, younger patients (age, ≤50 years) were compared with older patients (age, >50 years). The 3-month major adverse limb event-free survival was the primary outcome.

RESULTS

A total of 232 patients (age, 60 ± 16 years; 44% female sex, 87% white race) were included in the analysis. Of the 232 patients, 119 were in the acute on chronic cohort and 113 were in the de novo thrombosis/embolism cohort. Age did not affect the overall outcomes (P = .45) or the outcomes for the acute on chronic group (P = .17). However, in the de novo thrombosis/embolism cohort, patients aged ≤50 years had worse major adverse limb event-free survival compared with patients aged >50 years (hazard ratio, 2.47; 95% confidence interval, 1.08-5.68; P = .03) after adjustment for Rutherford class, interval from presentation to the operating room, and smoking status. In the de novo thrombosis/embolism group, the operative approach was similar across the age groups (endovascular, 12% vs 14%; open, 48% vs 41%; hybrid, 41% vs 45%; P = .78). In the younger patients, embolism was more likely from a proximal arterial source (71%). In contrast, in the older patients, the source of embolism was more often a cardiac source (86%). The rates of hypercoagulable disease were equal across the age groups (10% vs 10%; P = .95). The In-hospital mortality was 3% overall (acute on chronic, 5%; de novo, 3%).

CONCLUSIONS

Despite advances in interventional options, for patients with ALI due to de novo thrombosis or embolus, younger age was associated with worse short-term limb-related outcomes.

High Rates of Recurrent Revascularization in Acute Limb Ischemia - a National Surgical Quality Improvement Program Study

OBJECTIVES

We queried the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to review outcomes of acute limb ischemia (ALI) patients following open surgical intervention for ALI.

METHODS

A previously validated tool was used to identify ALI patients in NSQIP undergoing open surgical revascularization from 2012-2017. Multivariable analysis was performed for the primary outcome of reoperation and secondary outcome of readmission and infection.

RESULTS

2,878 ALI patients underwent open revascularization; 35.7% were transfers from another acute care hospital. 13.8% required reoperation and 7.9% required readmission within 30 days. 32% of reoperations were recurrent revascularization, representing 4.4% of all ALI patients. 58.7% of patients were female and either overweight or obese. Younger age (OR 0.991 [0.984-0.999], p=0.02), underweight patients (OR 1.159 [0.667-2.01], p=0.05), pre-operative steroid use (OR 1.61 [1.07-2.41], p=0.02), and perioperative transfusion (OR 2.02 [1.04-3.95], p=0.04) predicted reoperations.

CONCLUSIONS

This registry series demonstrates all-cause ALI patients are a different population than PAD with different risk factors. Despite being a time-critical condition, ALI has higher interhospital transfer rates than ACS or ruptured aneurysm. Following open revascularization, ALI outcomes are worse than ACS but better than ruptured AAA. These outcomes do not appear related to patient factors in contrast to revascularization for chronic PAD.

Association of Chronic Kidney Disease with perioperative outcomes following acute lower limb revascularization

Background

There is a paucity of data examining the impact of advancing chronic kidney disease stages on outcomes following revascularization for acute limb ischemia. The present study examined the association of chronic kidney disease with in-hospital mortality, amputation, and resource utilization following revascularization for acute limb ischemia using a nationally representative cohort.

Methods

The 2016–2018 National Inpatient Sample was queried to identify all adult hospitalizations with lower extremity acute limb ischemia requiring surgical and/or endovascular interventions. Patients were grouped according to the presence of chronic kidney disease and its severity: no chronic kidney disease, chronic kidney disease 1–3 (chronic kidney disease stages 1 through 3), chronic kidney disease 4–5 (chronic kidney disease stages 4 through 5), and end-stage renal disease. Multivariable logistic and linear models were used to evaluate association of chronic kidney disease stage with outcomes of interest.

Results

Of an estimated 82,610 patients meeting study criteria, 14.8% had chronic kidney disease (chronic kidney disease 1–3: 63.4%, chronic kidney disease 4–5: 12.1%, end-stage renal disease: 24.5%). Compared to those with chronic kidney disease, chronic kidney disease patients were on average older, were more frequently female, and had a higher median Elixhauser Comorbidity Index. Increasing severity of chronic kidney disease was associated with a stepwise increase in unadjusted mortality rates (4.7% in no chronic kidney disease to 12.6% in end-stage renal disease, P < .001). Following risk adjustment, only end-stage renal disease was associated with increased odds of mortality (adjusted odds ratio 3.10, 95% confidence interval 2.28–4.22) and limb amputation (adjusted odds ratio 1.99, 95% confidence interval 1.59–2.48) compared to patients with no chronic kidney disease. Similarly, advancing chronic kidney disease stage conferred increased odds of prolonged length of stay and greater hospitalization costs.

Conclusion

Advanced renal dysfunction demonstrated inferior perioperative outcomes and greater health care expenditures in the study population. These findings imply that quality improvement efforts in acute limb ischemia revascularization should target patients with chronic kidney disease 4–5 and end-stage renal disease.

Imaging in extremity vascular trauma: can MDCT angiography predict the nature of injury?

OBJECTIVE

This study aims to evaluate the utility of computed tomography angiography (CTA) signs of vascular injury in the differentiation of vessel transection from pure thrombosis with intact vessel wall.

METHODS

Retrospective analysis was done on 146 consecutive patients who had undergone CTA and surgical exploration from January 2015 to September 2019. Twelve imaging parameters were assessed. Chi-square was used to test the difference between groups. In addition, a scoring system was devised where one point each was added for the presence of 5 signs and absence of 3 signs. ROC analysis was done for the variables which had shown significant difference between groups and for the composite score.

RESULTS

On surgical exploration, 87 patients had transection of vessel, while 59 had thrombosis. Significant difference was found among the two groups in non-opacification, pseudoaneurysm, extravasation (p = 0.04 each), thrombosed cord (p < 0.001), collaterals (p = 0.001) and hematoma (p = 0.002), while other signs did not show significant difference. The AUC value for each of these variables was < 0.650, while for the score, AUC was .843(.773-.913). A cut-off value of ≥ 1.5 gave 83.1% sensitivity and 70% specificity for diagnosing transection.

CONCLUSION

CTA is a useful tool to classify the nature of vascular injury. It is advisable to use a composite score for maximum diagnostic value.

Major adverse limb events in patients with femoro-popliteal and below-the-knee peripheral arterial disease treated with either sirolimus-coated balloon or standard uncoated balloon angioplasty: a structured protocol summary of the "SirPAD" randomized controlled trial

BACKGROUND

Peripheral arterial disease is a progressive atherosclerotic disease with symptoms ranging from an intermittent claudication to acute critical limb ischemia and amputations. Drug-coated balloons and stents were developed to prevent neo-intimal proliferation and restenosis after percutaneous transluminal angioplasty. Randomized controlled trials showed that drug-coated, notably paclitaxel-coated, devices reduce restenosis, late lumen loss, and the need for target lesion re-vascularization compared with uncoated ones. However, the size of these trials was too small to prove superiority for "hard" clinical outcomes. Moreover, available studies were characterized by too restrictive eligibility criteria. Finally, it remains unclear whether paclitaxel-coated balloons may impair long-term survival. Alternative drug-coated balloons, the so-called limus-based analogs, have been approved for clinical use in patients with peripheral arterial disease. By encapsulating sirolimus in phospholipid drug nanocarriers, they optimize adhesion properties of sirolimus and provide better bioavailability.

METHODS

In this investigator-initiated all-comer open-label phase III randomized controlled trial, we will evaluate whether sirolimus-coated balloon angioplasty is non-inferior and eventually superior, according to a predefined hierarchical analysis, to uncoated balloon angioplasty in adults with infra-inguinal peripheral arterial disease requiring endovascular angioplasty. Key exclusion criteria are pregnancy or breastfeeding, known intolerance or allergy to sirolimus, and participation in a clinical trial during the previous 3 months. The primary efficacy outcome is the composite of two clinically relevant non-subjective "hard" outcomes: unplanned major amputation of the target limb and endovascular or surgical target lesion re-vascularization for critical limb ischemia occurring within 1 year of randomization. The primary safety outcome includes death from all causes.

DISCUSSION

By focusing on clinically relevant outcomes, this study will provide useful information on the efficacy and safety of sirolimus-coated balloon catheters for infra-inguinal peripheral arterial disease in a representative ("all-comer") population of unselected patients. As regulatory agencies had raised safety concerns in patients exposed to paclitaxel-coated devices (versus uncoated ones), collect mortality data up to 5 years after randomization will be collected.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04238546.

Comparison of pharmaco-mechanical thrombolysis and catheter-directed thrombolysis for treating thrombotic or embolic arterial occlusion of the lower limb

BACKGROUND

Whether pharmaco-mechanical thrombolysis (PMT) results in superior outcomes to catheter-directed thrombolysis (CDT) in treating thrombotic or embolic arterial occlusion of the lower limbs is unclear.

METHODS

We enrolled 94 patients with Rutherford class I-IIb due to thrombotic or embolic arterial occlusion in the lower limbs and who received emergency endovascular treatment. Baseline demographics, laboratory data, angiography and clinical outcomes were collected through chart reviews and fluoroscopic imaging. The procedural characteristics (thrombolytic drug dosage, treatment duration, and additional procedures), immediate angiographic outcomes (patency of calf vessels, and complete lysis), complications (major bleeding, and fasciotomy), and primary composite end-points (30-day mortality, amputation, and reocclusion) were compared between patients who received CDT versus PMT.

RESULTS

Compared with CDT, PMT was independently associated with lower total UK dosage (standardised coefficientβ= - 0.44; p < 0.01) and higher prevalence of complete lysis (odds ratio = 1.78, 95% confidence interval: 1.03 - 3.06; p = 0.04) after adjustments of covariates. The PMT group had significantly shorter treatment duration (23.00 [7.25 - 39.13] vs. 41.00 [27.00 - 52.50]; p < 0.01). No significant intergroup differences were observed for the primary composite end point (10.7% vs. 9.1%; p = 0.81), or prevalence of the major bleeding (9.1% vs. 0.0%; p = 0.10) despite the PMT group comprising patients with more.advanced chronic kidney disease and more diffuse thrombosis.

CONCLUSIONS

PMT with a Rotarex is a safe and effective strategy for treating thrombotic or embolic lower limb ischemia. It significantly reduced the thrombolytic drug dosage, and resulted in the complete lysis being more likely.

Percutaneous mechanical atherothrombectomy using the Rotarex®S device in acute ischemic disease of lower limbs: a China retrospective multicenter study on 186 patients

OBJECTIVES

To evaluate the efficacy and safety of the Rotarex mechanical thrombectomy device in treating acute lower extremity arterial ischemia and to explore the appropriate indication of Rotarex device.

METHODS

A retrospective analysis was performed in 186 patients with acute lower extremity arterial ischemia treated with Rotarex mechanical thrombectomy device from April 2015 to March 2020 in three vascular surgery centers of Tianjin. According to the comprehensive judgment of the etiology, onset time, imaging of ultrasonography (US) and angiography, as well as findings during treatment, the patients were divided into the embolization group (69 cases), thrombosis group (primary artery stenosis with thrombosis, 86 cases), and restenosis group (stent restenosis with thrombosis, 31 cases). The primary study outcomes included the success rate of Rotarex mechanical thrombectomy device alone, percutaneous transluminal angioplasty (PTA), stent, catheter-directed thrombolysis (CDT) auxiliary rate, target vessel patency rate, and freedom from clinically-driven target lesion revascularization rate (f-CD-TLR). The secondary study outcomes included intraoperative distal arterial embolization, postoperative 30-day bleeding, deterioration of renal function, amputation, and mortality.

RESULTS

The success rate of Rotarex mechanical thrombectomy device alone in the embolization group (44.93%) was significantly higher than that in the thrombosis group (13.95%) and restenosis group (0%) (P < 0.01). The PTA auxiliary rate in the embolization group (26.09%) was significantly lower than that in the thrombosis group (72.09%) and restenosis group (100%, P < 0.01). The stent implantation rates in the embolization group and restenosis group (11.60% and 33.30%, respectively) were significantly lower than that in the thrombosis group (72.09%, P < 0.01). There were no significant differences in the CDT auxiliary rate, distal arterial embolization, hemorrhage, renal function deterioration, amputation rate, and mortality among the three groups (P > 0.05). The primary patency at 3 months, 6 months, and 12 months postoperatively was 98.6%, 98.6%, and 84.3% in the embolization group, 96.4%, 89.5%, and 74.9% in the thrombosis group and 93.2%, 84.7%, and 67.5% in the restenosis group respectively (P < 0.01). The f-CD-TLR at 12 months postoperatively was 88.9% in the embolization group, which was higher than 77.8% in the thrombosis group and 67.5% in the restenosis group (P < 0.01).

CONCLUSIONS

Rotarex mechanical thrombectomy device is a minimally invasive, safe, and effective treatment option for acute lower extremity arterial ischemia, particularly acute arterial embolization. For acute thrombosis secondary to primary artery stenosis and in-stent restenosis, Rotarex device can effectively reduce the thrombus burden and create favorable conditions for other concurrent interventions.

Thromboembolectomy for acute lower limb ischemia: Contemporary outcomes of two surgical methods from a single tertiary center

OBJECTIVES

The current treatment of acute lower limb ischemia (ALLI) includes open surgical and percutaneous pharmaco-mechanical thromboembolectomy (TE). We hereby report our results with open surgical TE over a 10-year period and compare our outcomes using routine fluoroscopic assisted TE (FATE) with blind and selective on demand fluoroscopic-assisted TE (BSTE).

METHODS

This is a retrospective analysis of all patients who underwent open surgical TE for acute lower limb ischemia at a single tertiary center between 2008 and 2018. Patients were divided into a group who underwent BSTE and another who underwent routine FATE. Data on presentation, medical history, surgery performed, and short-term outcomes were retrieved from medical record. Comparison between baseline characteristics and outcomes of both groups were made using t-test and chi-square analysis.

RESULTS

Over 10 years, 108 patients underwent surgical TE. Thirty-day mortality rate and 30-day major lower extremity amputation rate in the cohort were 12.0% and 6.5%, respectively. On subgroup analysis, 53 patients were treated by BSTE and 55 patients by FATE. There was no significant difference in 30-day mortality rate (11.3% vs 12.7%, p-value = .82) and 30-day major amputation rate (9.4% vs 3.6%, p-value = .454) between the two groups. Local anesthesia was more frequently performed in patients undergoing FATE (58.2% vs 24.5%, p-value < .001). More than one arteriotomy was more frequently required in patients undergoing BSTE (2.6% vs 45.5%, p-value < .001). Patients with infrapopliteal involvement undergoing FATE required less further interventions such as patch angioplasty (2.6% vs 36.4%, p-value < .001) and bypass (2.6% vs 22.7%, p-value = .01).

CONCLUSION

ALLI remains a disease of high morbidity and mortality. Open surgical TE offers an effective approach to treat ALLI. The addition of fluoroscopy to the conduction of TE could be associated with valuable benefits, especially in patients with infra-popliteal involvement. Randomized controlled trials are needed to objectively assess the therapeutic potential of FATE.

Breaking the fibrinolytic speed limit with microwheel co-delivery of tissue plasminogen activator and plasminogen

BACKGROUND

To reestablish blood flow in vessels occluded by clots, tissue plasminogen activator (tPA) can be used; however, its efficacy is limited by transport to and into a clot and by the depletion of its substrate, plasminogen.

OBJECTIVES

To overcome these rate limitations, a platform was designed to co-deliver tPA and plasminogen based on microwheels (µwheels), wheel-like assemblies of superparamagnetic colloidal beads that roll along surfaces at high speeds.

METHODS

The biochemical speed limit was determined by measuring fibrinolysis of plasma clots at varying concentrations of tPA (10-800 nM) and plasminogen (1-6 µM). Biotinylated magnetic mesoporous silica nanoparticles were synthesized and bound to streptavidin-coated superparamagnetic beads to make studded beads. Studded beads were loaded with plasminogen and tPA was immobilized on their surface. Plasminogen release and tPA activity were measured on the studded beads. Studded beads were assembled into µwheels with rotating magnetic fields and fibrinolysis of plasma clots was measured in a microfluidic device.

RESULTS

The biochemical speed limit for plasma clots was ~15 µm/min. Plasminogen-loaded, tPA-immobilized µwheels lyse plasma clots at rates comparableto the biochemical speed limit. With the addition of a corkscrew motion, µwheels penetrate clots, thereby exceeding the biochemical speed limit (~20 µm/min) and achieving lysis rates 40-fold higher than 50 nM tPA.

CONCLUSIONS

Co-delivery of an immobilized enzyme and its substrate via a microbot capable of mechanical work has the potential to target and rapidly lyse clots that are inaccessible by mechanical thrombectomy devices or recalcitrant to systemic tPA delivery.

Successful Treatment of Subacute Limb Ischemia by Thromboaspiration with an 8-Fr Long Sheath in a 10-Fr Short Sheath

A 79-year-old man with a history of atrial fibrillation presented for evaluation of sudden onset of intermittent claudication of the left lower limb. An angiogram revealed thrombotic total occlusion of the left superficial femoral artery (SFA). A 10-Fr sheath was antegradely inserted into the left common femoral artery (CFA), and the guidewire penetrated the lesion. Thromboaspiration using an 8-Fr long sheath inserted into a 10-Fr short sheath was performed repeatedly. Intravenous anticoagulant was administrated immediately after endovascular treatment. Follow-up angiography performed 12 days after the procedure confirmed the absence of residual thrombus in the SFA. Thromboaspiration using a large-diameter catheter is a feasible, cost-effective strategy for treatment of acute and subacute limb ischemia.

Endovascular revascularization strategies using catheter-based thrombectomy versus conventional catheter-directed thrombolysis for acute limb ischemia

Background

Acute limb ischemia (ALI) is an important clinical event threatening both life and the affected limbs, but the optimal treatment for ALI remains undefined. The aim of this study was to compare the safety and effectiveness of thrombectomy approaches via either catheter-based thrombectomy (CBT) or catheter-directed thrombolysis (CDT).

Methods

A total of 98 patients (mean age 69.7 years, 60 male) who underwent endovascular intervention for ALI from January 2015 to July 2019 were included. Of these, 57 were treated with primary CBT via a large-bore catheter, an AngioJet catheter or Rotarex catheter, and/or underwent low-dose CDT, and 41 were treated with primary CDT. The safety and effectiveness of CBT compared to conventional CDT and other various endovascular techniques were evaluated.

Results

More Rutherford IIb patients were treated with primary CBT (68.4%) than CDT (26.8%; P < .001). Patients who underwent primary CDT achieved a higher technical success rate than those who underwent primary CBT in a shorter procedure time (P < .001), whereas 42.1% of patients who underwent CBT did not need adjunctive CDT. The duration and dosage of adjunctive CDT in the CBT group were significantly decreased compared with those in the primary CDT group (both P < .001), and the CBT group achieved a shorter in-hospital length of stay (P < .001). Subgroup analysis revealed that patients treated with AngioJet and Rotarex catheters achieved slightly lower dosages, shorter CDT durations and shorter in-hospital stay lengths than those treated with large-bore catheters (P > .05). Clinical success was estimated to be achieved in 98.2% of patients who underwent CBT, which is similar to the 97.6% estimated in those who underwent primary CDT (P = 1.000), and this finding was similar among the CBT subgroups. Patients who underwent CBT had a higher procedure-related distal embolization rate and economic cost than those who underwent primary CDT (P < .05), but it had slightly fewer complications than those who underwent primary CDT (P = .059), especially minor complications (P = .036). The freedom from amputation at 6 and 12 months for CBT and CDT was assessed (93.0% vs 90.2% respectively, P = .625; 89.5% vs 82.9%, respectively, P = .34,). Comparable limb salvage was found for different techniques of large bore catheters, AngioJet catheters and Rotarex catheters. The Kaplan-Meier table analysis also showed similar limb salvage rates between groups.

Conclusions

Endovascular treatment of ALI with the use of catheter-based therapies is an effective modality that can reduce the requirement for thrombolysis, with expected reductions in hemorrhagic complications, but at the risk of remediable distal emboli and increased economic cost. It has a similar clinical outcome to conventional CDT alone. Different CBT techniques have comparable efficacy but different adverse event profiles.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00349-9.

Infusion techniques for peripheral arterial thrombolysis

BACKGROUND

Acute limb ischaemia usually is caused by a blood clot blocking an artery or a bypass graft. Severe acute ischaemia will lead to irreversible damage to muscles and nerves if blood flow is not restored in a few hours. Once irreversible damage occurs, amputation will be necessary and the condition can be life-threatening. Infusion of clot-busting drugs (thrombolysis) is a useful tool in the management of acute limb ischaemia. Fibrinolytic drugs are used to disperse blood clots (thrombi) to clear arterial occlusion and restore blood flow. Thrombolysis is less invasive than surgery. A variety of techniques are used to deliver fibrinolytic agents. This is an update of a review first published in 2004.

OBJECTIVES

To compare the effects of infusion techniques during peripheral arterial thrombolysis for treatment of patients with acute limb ischaemia.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries to 20 October 2020. We undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing infusion techniques for fibrinolytic agents in the treatment of acute limb ischaemia.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane. We assessed the risk of bias in included trials using the Cochrane 'Risk of bias' tool. We evaluated certainty of evidence using GRADE. For dichotomous outcomes, we calculated the odds ratio (OR) with the corresponding 95% confidence interval (CI). We were not able to carry out meta-analyses due to clinical heterogeneity, so we have reported the results and performed the comparisons narratively. The main outcomes of interest were amputation-free survival or limb salvage, amputation, mortality, vessel patency, duration of thrombolysis, and complications such as cerebrovascular accident and major and minor bleeding.

MAIN RESULTS

Nine studies with a total of 671 participants are included in this update. Trials covered a variety of infusion techniques, dosage regimens, and adjunctive agents. We grouped trials according to types of techniques assessed (e.g. intravenous and intra-arterial delivery of the agent, 'high-' and 'low-dose' regimens of the agent, continuous infusion and 'forced infusion' of the agent, use of adjunctive antiplatelet agents). We assessed the certainty of evidence as very low to low due to the limited power of individual studies to deliver clinically relevant results, small and heterogeneous study populations, use of different inclusion criteria by each study in terms of severity and duration of ischaemia, considerably different outcome measures between trials, and use of different fibrinolytic agents. This heterogeneity prevented pooling of data in meta-analyses. No regimen has been shown to confer benefit in terms of amputation-free survival (at 30 days), amputation, or death. For vessel patency, complete success was more likely with intra-arterial (IA) than with intravenous (IV) infusion (odds ratio (OR) 13.22, 95% confidence interval (CI) 2.79 to 62.67; 1 study, 40 participants; low-certainty evidence); radiological failure may be more likely with IV infusion (OR 0.02, 95% CI 0.00 to 0.38; 1 study, 40 participants; low-certainty evidence). Due to the small numbers involved in each arm and design differences between arms, it is not possible to conclude whether any technique offered any advantage over another. None of the treatment strategies clearly affected complications such as cerebrovascular accident or major bleeding requiring surgery or blood transfusion. Minor bleeding complications were more frequent in systemic (intravenous) therapy compared to intra-arterial infusion (OR 0.03, 95% CI 0.00 to 0.56; 1 study, 40 participants), and in high-dose compared to low-dose therapy (OR 0.11, 95% CI 0.01 to 0.96; 1 study, 63 participants). Limited evidence from individual trials appears to indicate that high-dose and forced-infusion regimens reduce the duration of thrombolysis. In one trial, the median duration of infusion was 4 hours (range 0.25 to 46) for the high-dose group and 20 hours (range 2 to 46) for the low-dose group. In a second trial, treatment using pulse spray was continued for a median of 120 minutes (range 40 to 310) compared with low-dose infusion for a median of 25 hours (range 2 to 60). In a third trial, the median duration of therapy was reduced with pulse spray at 195 minutes (range 90 to 1260 minutes) compared to continuous infusion at 1390 minutes (range 300 to 2400 minutes). However, none of the studies individually showed improvement in limb salvage at 30 days nor benefit for the amputation rate related to the technique of drug delivery. Similarly, no studies reported a clear difference in occurrence of cerebrovascular accident or major bleeding. Although 'high-dose' and 'forced-infusion' techniques achieved vessel patency in less time than 'low-dose' infusion, more minor bleeding complications may be associated (OR 0.11, 95% CI 0.01 to 0.96; 1 study, 72 participants; and OR 0.48, 95% CI 0.17 to 1.32; 1 study, 121 participants, respectively). Use of adjunctive platelet glycoprotein IIb/IIIa antagonists did not improve outcomes, and results were limited by inclusion of participants with non-limb-threatening ischaemia.

AUTHORS' CONCLUSIONS

There is insufficient evidence to show that any thrombolytic regimen provides a benefit over any other in terms of amputation-free survival, amputation, or 30-day mortality. The rate of CVA or major bleeding requiring surgery or blood transfusion did not clearly differ between regimens but may occur more frequently in high dose and IV regimens. This evidence was limited and of very low certainty. Minor bleeding may be more common with high-dose and IV regimens. In this context, thrombolysis may be an acceptable therapy for patients with marginally threatened limbs (Rutherford grade IIa) compared with surgery. Caution is advised for patients who do not have limb-threatening ischaemia (Rutherford grade I) because of risks of major haemorrhage, cerebrovascular accident, and death from thrombolysis.

Distal arteriovenous fistula to preserve patency in COVID-19-associated acute limb ischemia

The purpose of this study was to report our institutional experience with patients with COVID-19 who developed acute limb ischemia during hospitalization and to determine the characteristics and clinical outcomes. Between March 2020 and January 2021, we treated 3 patients who were COVID-19–positive and developed acute limb ischemia after they received thromboprophylaxis. We performed an embolectomy by exposing the popliteal artery below the knee to treat an occlusion of the popliteal and tibial arteries. An infusion of unfractionated heparin was initiated immediately after surgery, maintaining a partial thromboplastin time ratio > 2.5 times the normal value and transferred the patients to the intensive care unit. However, after these patients developed recurrent acute limb ischemia in the same leg, we decided to perform an embolectomy of popliteal and tibial arteries at the ankle and created an arteriovenous fistula (AVF) with tibial veins using polypropylene 7-0. The first patient died from pneumonia after 3 weeks in the intensive care unit; at that time, the foot was viable with triphasic flow in the distal posterior tibial artery and the AVF was patent. The second and third patients are doing well, they can walk without any problems, and the tibial arteries and AFV were patent on duplex ultrasound after 6 months. The AVF allowed part of the flow of tibial arteries to divert into the small veins of the foot that have a low resistance to maintain patency of tibial vessels, despite a hypercoagulable state and extensive thrombotic microangiopathy in patients with COVID-19.

Acute Compartment Syndrome Following Thrombolysis For Acute Lower Limb Ischemia

BACKGROUND

Acute Compartment syndrome (ACS) with subsequent need for fasciotomy is a serious and insidious complication after revascularization for acute lower limb ischemia (ALI). The development of ACS during endovascular catheter directed thrombolysis is particularly difficult to identify. The aim was to identify the incidence, predisposing factors, wound treatment, and outcome in terms of amputation and survival for patients presenting with ALI that develop ACS during catheter directed thrombolysis. Patients who did not develop ACS after thrombolysis were analyzed as controls.

METHODS

Descriptive retrospective analysis of prospective databases from two large tertiary-referral vascular centers. Patients with ACS after thrombolysis for ALI between 2001-2017 were analyzed.

RESULTS

Seventy-eight cases and 621 controls were identified. Mean age was 72 years and 30 (38.5%) were women in the ACS group. Patients that developed ACS presented with significantly more severe preoperative ischemia. With 38.5% having Rutherford 2b classification as compared to 22.7 % in the control group (P = 0.002). Occluded popliteal artery aneurysms were also associated with a higher incidence of ACS (P = 0.041). Treatment of the fasciotomy wound was most commonly treated with regular wound dressing in 45 (58%) of cases, while wound dressing and foot pump and vacuum assisted closure were used in 14 (18%) and 19 (24%) respectively. These differing approaches did not affect the number of wound infections and amputations, which was similar regardless of treatment type. Vacuum assisted closure was associated with a higher degree of skin graft closure (P = 0.001). The median time to complete wound closure was 10 days. One year after thrombolysis, the major amputation rate in the ACS group was 31% as opposed to 17% in control group, P = 0.003. Mortality measured at 16.7% and 15.3%, respectively, P = 0.872. Amputation-free survival in the ACS group was 62% vs. 73% in the control group, P = 0.035. These differences level out, however, when applying long-term analysis of amputation-free survival in Kaplan-Meier analysis (log-rank 0.103).

CONCLUSIONS

Patients that developed ACS during endovascular CDT presented with a more severe pre-operative ischemia, more occluded popliteal artery aneurysms and had a higher amputation rate during the first year, compared to controls. The development of ACS during endovascular treatment of ALI with thrombolysis is not uncommon and warrants both clinical awareness and rapid treatment.

A Comparison of Outcomes Based on Vessel Type (Native Artery vs. Bypass Graft) and Artery Location (Below-Knee Artery vs. Non-Below-Knee Artery) Using a Combination of Multiple Endovascular Techniques for Acute Lower Limb Ischemia

BACKGROUND

To evaluate outcomes of endovascular treatment (EVT) using a combination of multiple endovascular techniques for acute lower limb ischemia (ALLI) and to compare outcomes based on vessel type and artery location.

METHODS

A total of 95 consecutive patients with ALLI (mean age, 72.0 years; 65 males; 104 lower limbs) who received emergency EVT using a combination of multiple endovascular techniques including thrombolysis, aspiration thrombectomy, stenting, and balloon angioplasty with or without surgical thromboembolectomy, between January 2005 and December 2017 were included. Vessel type was classified into native artery occlusion (native occlusion) and bypass graft occlusion (graft occlusion), including prosthetic and vein graft. Additionally, native arteries were categorized into below-knee occlusion and non-below-knee occlusion. Technical success, perioperative death (POD), ALLI-related death, amputation, amputation-free survival (AFS), and complications were compared according to vessel type (native occlusion vs. graft occlusion) and artery location (below-knee occlusion vs. non-below-knee occlusion).

RESULTS

Of all patients with ALLI, 16.8% underwent a single endovascular technique, whereas 83.2% underwent a combination of multiple endovascular techniques. The technicalsuccess, POD, and ALLI-related death rates in the total number of patients were 94.7%, 11.6%, and 4.2%, respectively. A total of 67 patients (75 limbs) and 28 patients (29 limbs) were classified as having native occlusion and graft occlusion (prosthetic, 24 limbs; vein, 5 limbs), respectively. No significant differences in technical success (native occlusion: 92.5% vs. graft occlusion: 100%), POD (14.9% vs. 3.6%), and ALLI-related death (6.0% vs. 0%) were noted between native occlusion and graft occlusion. However, the 30-day AFS rate of native occlusion was significantly lower than that of graft occlusion (75.2% vs. 96.3%, P=0.01). The amputation rate (P=0.03) and AFS rate (P=0.03) of below-knee occlusion were significantly worse for below-knee occlusion patients than for non-below-knee occlusion patients.

CONCLUSIONS

EVT using multiple endovascular techniques for ALLI is effective and safe. A combination of multiple endovascular techniques is crucial for successful treatment. However, native occlusion may have a lower AFS rate than graft occlusion, and below-knee occlusion may have a higher risk of amputation than non-below-knee occlusion.

Safety and Efficacy of Vacuum Assisted Thrombo-Aspiration in Patients with Acute Lower Limb Ischaemia: The INDIAN Trial

OBJECTIVE

The aim was to evaluate the short term safety and effectiveness of the Penumbra/Indigo aspiration thrombectomy Systems (Penumbra Inc.) in patients with acute lower limb ischaemia. (ALLI). Recently, endovascular vacuum assisted thrombectomy devices, similar to those used in the management of acute ischaemic stroke, have become available for peripheral arteries, but data are still scarce.

METHODS

To assess vessel patency, a modified Thrombolysis in Myocardial Infarction (TIMI) classification, called TIPI (Thrombo-aspiration In Peripheral Ischaemia), is proposed. The TIPI flow is assessed at presentation, immediately after treatment with the study device, and after all adjuvant procedures. The primary outcome is the technical success of the thrombo-aspiration with the investigative system, defined as near complete or complete revascularisation TIPI 2 - 3. Safety and clinical success rate were collected at one month.

RESULTS

One hundred and fifty patients were enrolled. The mean age was 72.4 years and 73.3% were male. Rutherford grade on enrolment was I in 16%, IIa in 40.7%, and IIb in 43.3% with a mean ankle brachial index of 0.19. Primary technical success (TIPI 2 - 3 flow) was achieved in 88.7% of patients. Adjunctive procedures included angioplasty/stenting of chronic atherosclerotic lesions (n = 39), thrombolysis (n = 31), covered stenting (n = 15), and supplementary Fogarty embolectomy (n = 6). After all interventions, assisted primary technical success was 95.3% (TIPI 2 - 3 in 143/150). No systemic bleeding complications or device related serious adverse events were reported. At one month follow up, one death, and one below the knee amputation were recorded. Primary patency was 92% (138/150), and the re-intervention rate was 7.33%, resulting in an assisted primary and secondary patency of 94% and 99.33%, respectively.

CONCLUSION

Results from the INDIAN registry reveal that mechanical thrombectomy using the Indigo system is safe and effective for revascularisation of ALLI as a primary therapy.

Thrombectomy of Femoro-Femoral Bypass Graft Occlusion Using the AngioJet Rheolytic Thrombectomy System and Embolic Protection Device: A Case Report

저자들은 대퇴-대퇴동맥 우회 인조혈관 폐색 환자에서 AngioJet Rheolytic Thrombectomy System (이하 AngioJet)과 색전보호기구를 이용하여 성공적으로 혈전제거술을 시행한 1예를 보고하고자 한다. 하지 혈관 전산화단층촬영에서 좌측에서 우측으로의 대퇴-대퇴 우회 인조혈관 폐색 소견을 보였다. AngioJet을 이용한 흐름 용해 혈전제거술과 풍선 혈관성형술을 시행하여 우측 하지 혈류를 재개통 시켰으며, 시술 중 우측 표재성 대퇴동맥에 색전보호기구를 거치시켜 효과적으로 원위부 색전을 예방할 수 있었다.

Safety and efficacy of an endovascular-first approach to acute limb ischemia

BACKGROUND

The optimal techniques to manage acute limb ischemia (ALI) remain unclear. Previous reports have suggested that the decreased morbidity and mortality of endovascular approaches are mitigated by the limited technical success rates relative to open or hybrid approaches for ALI. However, these data failed to include newer technologies that might improve the technical success rates. We, therefore, sought to describe the current outcomes for an endovascular-first approach to ALI.

METHODS

We performed a single-center, single-arm, retrospective cohort study of consecutive patients with ALI from 2015 to 2018. Technical success, limb salvage, survival, patency, and length of stay were quantified using Kaplan-Meier (KM) analysis. Cox regression analysis was used to identify the predictors of amputation-free survival.

RESULTS

During the 3 years, 60 consecutive patients (39 men [65%]; median age, 65 years) presented with ALI. The Rutherford class was I in 15 patients (25%), IIa in 23 (38%), IIb in 13 (22%), and III in 9 patients (15%). Of the 60 patients, 34 had a history of previous failed ipsilateral revascularization (56%), including open bypass for 8 (13%), endovascular for 8 (13%), and both open and endovascular intervention for 18 (30%). The endovascular-first approach procedures included catheter-directed thrombolysis only (n = 19; 3%), catheter-directed thrombolysis plus aspiration and/or rheolytic thrombectomy (n = 19; 32%), and aspiration and/or rheolytic thrombectomy (n = 16; 26%). Six patients (10%) underwent covered stent placement only. The underlying occlusive process was most often thrombosis of a previous bypass graft or stent in 32 patients (53%), followed by native vessel thrombosis in 15 (25%). ALI had resulted from embolism in 13 patients (21.7%), including 2 (3%) with embolization to occlude a previous bypass graft or stent. Technical success was achieved in 58 patients (97%), with open conversion required in two patients (3%). At 30 days postoperatively, 52 patients (87%) survived, and 53 (88%) had successful limb salvage. Five patients (8%) had required four-compartment fasciotomy. No major hemorrhagic complications developed. The median length of stay overall and in the intensive care unit was 9 days (interquartile range, 4-14 days) and 2 days (interquartile range, 1-5 days), respectively. At 1 year, the KM estimates were as follows: amputation-free survival, 58% ± 0.08%; limb salvage, 74.3% ± 0.07%; and survival, 73.3% ± 0.07%. The 1-year KM estimates for primary and secondary patency were 39.4% ± 0.08% and 78.2% ± 0.07%, respectively. On multivariable Cox regression analysis, only age independently predicted for death and/or amputation at the last follow-up (hazard ratio, 1.06; 95% confidence interval, 1.01-1.10; P = .01).

CONCLUSIONS

The current endovascular approaches to ALI have high technical success rates. Survival, limb salvage, perioperative complications, and length of stay were similar to those from previous reports of historical open cohorts. Further prospective, appropriately powered, multicenter cohort studies are warranted to evaluate the efficacy of endovascular vs open approaches to ALI.

Two effective cases of additional pedal artery angioplasty for severe lower limb ischemia following acute thrombotic artery occlusion with hypercoagulable state diseases

Background

Acute limb ischemia (ALI) and critical limb ischemia (CLI) following ALI are life-threatening diseases. The rare potential causes of ALI include hypercoagulable state diseases, such as antiphospholipid syndrome (APS) and essential thrombocythemia (ET). Hypercoagulability often make revascularization for arterial occlusion, especially associated with infrapopliteal lesions, difficult. This is because the vessels have poor run-off, and elevated peripheral vascular resistance associated with microcirculation failure, due to a high thrombus burden. There is no established treatment for this issue.

Case presentation

A 45 years-old and a 56 years-old male suffered from thrombotic arterial occlusion as a first manifestation of APS and ET, respectively. Combination therapy with aggressive anti-thrombotic therapy and revascularization, such as endovascular therapy and surgical thrombectomy based on the angiosome concept, was performed. However, the high thrombus burden caused a poor pedal outflow, and significant limb ischemia remained. Additional pedal artery angioplasty was performed to improve residual limb ischemia in each case and provided sufficient blood flow to the foot.

Conclusion

The pedal artery angioplasty for thrombotic pedal artery occlusion cases, associated with hypercoagulable state diseases, seems to be a treatment option for relieving residual limb ischemia.

Waist Training Corset: An Unusual Cause of Acute Lower Limb Ischemia

Acute limb ischemia (ALI) can occur due to many causes. This article illustrates a novel case of a very rare presentation and etiology of acute lower extremity ischemia. This case involves a middle-aged female with a history of smoking and obesity who presented with right lower extremity (RLE) pain. The patient had undergone a liposuction procedure a few days prior to her presentation and had been wearing a waist training corset. The patient was found to have multivessel thrombotic occlusive plaques starting from the right common iliac to the right tibial arteries. She was fully worked up and no other etiologies of her presentation was found. Thus, we concluded that her presentation was very likely precipitated by wearing the training corset, leading to right iliac artery thrombosis or perhaps a formal iliac atherosclerotic plaque destabilization and ipsilateral limb showering with athero-thrombi.

Endovascular approach for acute limb ischemia without thrombolytic therapy

Background:

Endovascular therapy for acute lower limb ischemia (ALLI) has developed and demonstrated safety and efficacy. The purpose of this study was to assess clinical outcomes in patients treated for ALLI with conventional endovascular or surgical revascularization.

Method:

This study was a retrospective single-center review. Consecutive patients with ALLI treated with conventional endovascular revascularization (ER) without thrombolytic agent or surgical revascularization (SR) between 2008 and 2014 were investigated. The 1 year and 3 year amputation rate and mortality rate were assessed by time-to-event methods, including Kaplan–Meier estimation.

Result:

A total of 64 limbs in 62 patients with ALLI due to thromboembolism or thrombosis of a native artery, bypass graft, or previous stented vessel were included. The majority of limbs (90.9%) presented with Rutherford clinical categories 1 to 2 ischemia. Technical success rate was 95.5% in ER and 92.9% in SR group (p = 0.547). Overall amputation rates were 9.1% in ER versus 9.5% in SR after 1 year (p = 0.971) and 9.1% in ER versus 11.9% in SR after 3 year (p = 0.742). Overall mortality rates were 15% in ER versus 7.1% in SR after 1 year (p = 0.491) and 15% in ER versus 11.2% in SR after 3 year (p = 0.878).

Conclusion:

Endovascular or surgical revascularization of ALLI resulted in comparable outcomes in limb salvage and mortality rate at 1 year and 3 year. Conventional endovascular therapy without thrombolytic agent such as stenting, balloon angioplasty, or catheter-directed thrombosuction may be considered as a treatment option for ALLI.

Contemporary Management of Acute Lower Limb Ischemia: Determinants of Treatment Choice

The role of endovascular procedures in the treatment of acute lower limb ischemia (ALI) is expanding. For treatment, the choice between surgical or endovascular is still debated. The aim of this study was to identify factors that determine the selection of treatment. This study included 307 ALI patients (209 with thrombosis). Patient details, factors affecting the procedure choice, and outcomes were analyzed. The majority of patients were operated on (52.4%). Surgery was more frequent in embolic patients with embolus (odds ratio (OR) 33.85; 95% confidence interval (CI) 6.22–184.19, p < 0.0001), severe ischemia (OR 1.79; 95% CI 1.2–2.66, p = 0.0041), and active cancer (OR 4.99; 95% CI 1.26–19.72, p = 0.02). Tibial arteries involvement was negatively related to surgery (OR 0.25; 95% CI 0.06–0.95, p = 0.04). The complications and amputation rates were comparable. Reinterventions were more common in the endovascular group (19 (20.2%) vs. 17 (8.9%), p = 0.007). The six-month mortality was higher in the operated patients (12.6% vs. 3.2%, respectively, p = 0.001). The determinants of the treatment path are ischemia severity, concurrent cancer, embolus, and peripheral lesion location. Modification of the Rutherford acute lower limb ischemia classification is required to improve the decision-making in patients with profound ischemia.

Fast-track thrombolysis protocol for acute limb ischemia

OBJECTIVE

Catheter-directed thrombolysis in the treatment of acute lower extremity arterial occlusions often requires several interventional sessions to generate successful outcomes. It is typically an expensive procedure, necessitating extended hospital length of stay (LOS) that may be associated with an increase in both local and systemic hemorrhagic complications. Five years ago, we created the fast-track thrombolysis protocol for arteries (FTTP-A) to deal with these concerns. The goal of our protocol is to re-establish patency during the first session of thrombolysis, thus decreasing costs and complications associated with prolonged periods of thrombolytic exposure.

METHODS

A retrospective study of 42 patients who were treated for acute limb ischemia at our institution by FTTP-A from January 2014 to February 2019 was performed. FTTP-A includes periadventitial lidocaine injection at the arterial puncture site under ultrasound guidance, contrast arteriography of the entire targeted segment, pharmacomechanical rheolytic thrombectomy of the occluded arterial segment, tissue plasminogen activator infusion along the occluded segment, balloon maceration of the thrombus, and (if deemed necessary) placement of a stent in an area of significant (≥30%) stenosis that is refractory to balloon angioplasty and thrombolysis. After the stenosis or thrombus is cleared, patients are prescribed an oral anticoagulant agent.

RESULTS

Primary FTTP-A (50 total interventions) was performed in 42 patients. The median age of patients was 67.2 ± 12.2 years (range, 41-98 years), and 54.8% were male; 59.5% of the procedures were performed on the left lower extremity. Initial arterial access was obtained through the common femoral artery in 39 of 42 cases (92.9%); in the remaining 3 cases, it was obtained in a left bypass access site, a right femoral-popliteal graft, and a right femoral-femoral graft. The mean operative time was 148.9 ± 62.9 minutes (range, 83-313 minutes), and the mean volume of tissue plasminogen activator infused was 9.7 ± 4.0 mg (range, 2-20 mg). The median cost including medications and interventional tools was $4673.19 per procedure. The mean postoperative LOS was 3.1 ± 4.5 days (range, 1-25 days). Median postoperative LOS was 1 day. Mean postoperative follow-up was 27 ± 19.2 months (range, 0-62 months). Single-session FTTP-A was successful in 81% (n = 34/42) of patients; the remaining 8 patients (19%) required a single additional session. Of the 42 patients, 34 (81%) required arterial stenting. Periprocedural complications consisted of one patient with hematuria, which resolved, and one patient with thrombocytopenia, which resolved. No patients experienced rethrombosis within 30 days of FTTP-A. During the 5-year study period, there was no significant local or systemic hemorrhage, limb loss, or mortality related to this protocol.

CONCLUSIONS

FTTP-A appears to be a safe, efficacious, and cost-effective procedure in the resolution of acute lower extremity arterial occlusions.

Isquemia arterial aguda de las extremidades: ¿cómo abordarla?

La isquemia arterial aguda de las extremidades se define como la interrupción abrupta del flujo sanguíneo a determinado tejido, lo cual afecta la integridad, la viabilidad de la extremidad, o ambas. Las causas son múltiples y pueden resumirse en dos procesos fisiopatológicos, trombóticos o embólicos, con lo que se puede establecer el pronóstico y el tratamiento según su causa. El cuadro sindrómico es variable, y típicamente, se identifica con las cinco “P” de Pratt (pain, pallor, pulselessness, paralysis and paresthesia); se cuenta con múltiples ayudas diagnósticas, pero la arteriografía sigue siendo el método estándar para el diagnóstico. Con el advenimiento de los avances tecnológicos y los procedimientos vasculares, el salvamento de las extremidades ha venido en aumento y ha disminuido la extensión de las amputaciones, lo cual conlleva una mayor tasa de rehabilitación y de reincorporación a la vida social.

One-year limb outcome and mortality in patients undergoing revascularization therapy for acute limb ischemia: short-term results of the Edo registry

The present study aimed to clarify the current status, therapeutic strategy, and 1-year outcome in acute limb ischemia (ALI) patients in Japan. The EnDOvascular treatment (Edo) registry database includes 324 patients from 10 institutes who were registered between November 2011 and October 2013. A total of 70 ALI patients (mean age 74.0 years) from the Edo registry database were enrolled in this study. Of the 70 included patients, 72.9% were male and 35.7% had embolism. Of patients, 38.6%, 42.9%, and 18.6% underwent EVT, surgery, and hybrid thrombectomy, respectively, in primary revascularization strategy. Limb ischemia was categorized into four classes at initial evaluation: SVS/ISCVS class I (n = 13, 18.6%), SVS/ISCVS class IIa (n = 36, 51.4%), SVS/ISCVS class IIb (n = 21, 30%), and SVS/ISCVS class III (n = 0, 0%). Three patients with SVS/ISCVS class IIb limb ischemia developed myonephropathic metabolic syndrome. No catheter-directed thrombolysis was employed as a primary revascularization strategy. The 1-year rates of all-cause death, major amputation, and a composite of perioperative death or major adverse limb event were 28.6%, 5.7%, and 40.0%, respectively. Lower age, male sex, dyslipidemia, high estimated glomerular filtration rate, high albumin level, and low C-reactive protein level were independent positive predictors of all-cause death. In this registry, SVS/ISCVS class IIa ALI was predominant. Approximately 40% of primary revascularization strategy was surgery and EVT, followed by hybrid therapy. All-cause death and major amputation rates at 1 year were less than 30% and 6%, respectively.

"Squid-Capture" Modified In Situ Stent-Graft Fenestration Technique for Recurrent Abdominal Aortic Occlusive Disease after Collapse of Balloon-Expandable Stent

We present a case of an 85-year-old woman with bilateral limb-threatening ischemia caused by acute-on-chronic occlusion of the infrarenal aorta. The patient once underwent endovascular recanalization using nitinol and stainless-steel bare-metal stent implantation; however, the stainless-steel stent collapsed 3 months later. In the second endovascular therapy, "Squid-Capture" modified in situ stent-graft fenestration technique followed by stent-in-stent implantation with stent graft and bare-metal stent was successfully applied, and it can be regarded as a promising treatment option for the repair of abdominal aortic occlusive disease in some limited anatomical conditions.

Real-World Outcomes of EKOS Ultrasound-Enhanced Catheter-Directed Thrombolysis for Acute Limb Ischemia

BACKGROUND

Ultrasound-enhanced catheter-directed thrombolysis (UET) using the Ekosonic® Endovascular System device for acute, peripheral arterial ischemia has been purported in clinical trials to accelerate the fibrinolytic process to reduce treatment time and lytic dosage. We aim to describe outcomes of UET in a real-world clinical setting.

METHODS

We performed a retrospective review of all patients undergoing UET for acute limb ischemia at a single institution. Data collected included patient demographics, procedural details, and 30-day and 1-year outcomes. The primary endpoints for analysis were major adverse limb events (MALEs; reintervention and/or amputation) and mortality within 30-days and 1-year. Secondary endpoints included technical success, use of adjunctive therapies, and postoperative complications.

RESULTS

A total of 32 patients (mean age 67.4 ± 14.9 years; 25% women) underwent UET for acute limb ischemia between 2014 and 2018. The Rutherford Acute Limb Ischemia Classification was Rutherford (R) 1 in 56.3%, R2a in 31.3%, and R2b in 12.5%. Etiology was thrombosis of native artery in 12.5% of patients, prosthetic bypass in 31.3%, autogenous bypass in 6.3%, and stented native vessel in 50.0%. Mean duration of thrombolytic therapy was 22.2 ± 11.3 hr, and mean tissue plasminogen activator dose was 24.5 ± 15.3 mg. MALEs occurred in 16.7% of patients within the first 30 days and 38.9% experienced a MALE by 1 year. Limb salvage at 30 days and 1 year was 93.8% and 87.5%, respectively. Ipsilateral reintervention was required in 12.5% of patients within 30 days and 37.5% of patients within 1 year. Overall mortality was 6.2% at 30 days and 13.5% at 1 year. In-line flow to the foot was re-established in 90.6% of patients, with a significant improvement in preoperative to postoperative ankle-brachial index (0.31 ± 0.29 vs. 0.78 ± 0.34, P < 0.001) and number of patent tibial runoff vessels (1.31 ± 1.20 vs. 1.96 ± 0.86, P < 0.001). There was no significant difference in revascularization success between occluded vessel types. All but one patient required adjunctive therapy such as further thromboaspiration, stenting, or balloon angioplasty. Major bleeding complications occurred in 3 patients (9.4%), including 1 intracranial hemorrhage (3.1%).

CONCLUSIONS

UET with the EKOS device demonstrates acceptable real-world outcomes in the treatment of acute limb ischemia. UET is generally safe and effective at re-establishing in-line flow to yield high limb salvage rates. However, UET is associated with a high rate of reintervention. Further investigation is needed into specific predictors of limb salvage and need for reintervention, as well as cost-efficacy of this technology compared with that of traditional methods.

Prognostic risk factors for recurrent acute lower limb ischemia in patients treated with intra-arterial thrombolysis

OBJECTIVE

The objective of this study was to assess factors predisposing patients to recurrent acute lower limb ischemia (RALLI).

METHODS

Acute lower limb ischemia patients treated with catheter-directed thrombolysis (CDT) at Tampere University Hospital and Turku University Hospital between March 2002 and December 2015 were included. The patients' baseline demographics, comorbidities, and other characteristics were assessed retrospectively. Significant factors revealed by univariable analysis were tested in a multivariable model for associations with RALLI. A patency analysis was performed, and the risks of reocclusion were identified. The limb salvage rates after reocclusion were evaluated.

RESULTS

Altogether, 303 consecutive patients with a mean age of 71 years (standard deviation, 11.8 years) were included. Of them, 159 (52.5%) were men. A total of 164 (54.1%) native arterial and 139 (45.9%) bypass graft occlusions were initially treated with CDT. On completion of CDT, 204 additional endovascular or conventional surgical procedures on 203 patients were performed to obtain adequate distal perfusion. During a median follow-up of 40 months (interquartile range, 69 months), 40 (24.4%) cases of RALLI occurred in native arteries and 90 (64.7%) in bypass graft patients (P < .001). In native arteries, the absence of appropriate anticoagulant and antiplatelet medication was independently associated with the development of acute reocclusions (hazard ratio, 6.51) in the Cox multivariable regression analysis. The patency rates were 86.6%, 72.2%, and 68.0% at 1 year, 5 years, and 9 years, respectively. In bypass grafts, worsened tibial runoff (crural index III: hazard ratio, 2.40) was independently associated with RALLI. The respective patency rates were 60.5%, 34.0%, and 29.2% for synthetic conduits and 30.8%, 20.5%, and 13.7% for autologous vein grafts at 1 year, 5 years, and 9 years. Altogether, 38 (29.2%) major amputations were performed on patients with reocclusions. Patients with synthetic conduits demonstrated superior limb salvage rates after reocclusion in comparison to native arteries or vein grafts (P = .025).

CONCLUSIONS

Appropriate post-thrombolytic antiplatelet or anticoagulant treatment after native arterial events is of great importance, but additional data are needed to improve treatment algorithms. Adequate outflow in bypass graft patients is crucial. Patients with prosthetic bypass grafts have superior limb salvage rates after reocclusion.

A systematic review and meta-analysis of endovascular and surgical revascularization techniques in acute limb ischemia

BACKGROUND

The initial treatment of patients with acute limb ischemia (ALI) remains undefined. The aim of this article was to compare the safety and effectiveness of catheter-driven thrombolysis (CDT) with surgical revascularization and evaluate the various fibrinolytic agents, endovascular, and pharmacochemical approaches that aim for thrombectomy.

METHODS

PubMed, Embase, and the Cochrane Library were searched for studies on the management of ALI by means of surgical or endovascular recanalization, returning 520 studies. All randomized, controlled trials, nonrandomized prospective, and retrospective studies were included comparing treatment of ALI.

RESULTS

Twenty-five studies, investigating a total of 4689 patients, were included for meta-analysis spread across nine different comparisons. No differences were found in limb salvage between thrombectomy and thrombolysis. More major vascular events were seen in the thrombolysis group (6.5% compared with 4.4% in the surgically treated group; odds ratio [OR], 0.33; 95% confidence interval [CI], 0.13-0.87; P = .02; I² = 20%). Comparable limb salvage was found for high- and low-dose recombinant tissue plasminogen activator (r-tPA). No significant differences were found in major vascular event between low r-tPA (14%) and high r-tPA (10.5%; P = .13). The 30-day limb salvage rate was 79.7% for r-tPA treatment and 60.4% for streptokinase (OR, 3.14; 95% CI, 1.26-7.85; P = .01; I² = 0%). AngioJet showed more limb salvage at 6 months compared with r-tPa (OR, 2.21; 95% CI, 1.17-4.18; P = .01; I² = 0%).

CONCLUSIONS

Both CDT and surgery have comparable limb salvage rates in patients with ALI; however, CDT is associated with a higher risk of hemorrhagic complications. No conclusions can be drawn regarding the risk of hemorrhagic complications regarding thrombolytic therapy by means of r-tPA, streptokinase, or urokinase. Insufficient data are available to conclude the preference of using a hybrid approach, ultrasound-accelerated CDT, heated r-tPA. or novel endovascular (rheolytical) thrombectomy systems. Future trials regarding ALI need to be constructed carefully, ensuring comparable study groups, and should follow standardized practices of outcome reporting.

ANTIOXIDANT ENZYMES ACTIVITY IN EXPERIMENTAL ISCHEMIA-REPERFUSION INJURY

Background. Blood loss during civil and military limb trauma is the most common cause of preventable death. Complications due to the use of a hemostatic tourniquet are widely investigated nowadays. Therefore, the standards of the past have to be improved. Objective. The aim of the research is to study the reaction of the enzyme chain of the liver antioxidant system in the presence of modifications of ischemia-reperfusion injury (IRI). Methods. 210 white male-rats, aged 5-5.5 months, were used in the research. The dynamics of antioxidant enzymes activity catalase (Cat) and superoxide dismutase (SOD) in liver tissue in cases of modifications of ischemia-reperfusion injury (IRI) were studied. The period of investigation was in 24 hours, 3, 7, 14 days after the injury. Results. In cases of simulated IRI the catalase level mainly decreased at each period of the experiment. The peak of SOD activity was evidenced on the 1st, 3rd or 7th days after the experimental IRI according to the degree of trauma severity. Thus, IRI combined with severe blood loss and mechanical trauma caused the severest affection of the antioxidant system. Even a single application of hemostatic tourniquet caused similar wavelike reactions at different times. Conclusions. The development of IRI is accompanied by a significant depression of the liver antioxidant system. The most significant changes were evidenced in cases of IRI combined with blood loss and mechanical trauma, but even a single application of a tourniquet caused active response of the antioxidant enzymes.

A comprehensive report of long-term outcomes after catheter-directed thrombolysis for occluded infrainguinal bypass grafts

OBJECTIVE

The objective of this study was to assess the technical and short- and long-term clinical outcomes of catheter-directed thrombolysis (CDT) with urokinase for occluded infrainguinal bypass grafts. In addition, factors associated with technical success and amputation-free survival were assessed.

METHODS

A retrospective analysis of a cohort of patients treated with catheter-directed urokinase-based thrombolysis for occluded infrainguinal bypass grafts was conducted between January 2000 and December 2015. Demographics, procedural data, and short- and long-term outcome data, including patency rates of the bypasses, limb salvage, and overall survival, were collected. Statistical models for clustered data were applied to assess predictive factors.

RESULTS

In 177 patients, 251 CDTs were performed on 204 bypasses. In 209 procedures (83.3%), the occluded bypass was reopened; clinical disappearance of ischemic symptoms occurred after 157 procedures (62.6%). Premature cessation of thrombolysis occurred in 33 procedures (13.2%), and periprocedural and postprocedural complications were noted in 91 patients (36.3%). Factors associated with long-term limb salvage are fewer vascular interventions before CDT (P = .0003), higher number of patent outflow vessels before start of CDT (P < .0001), and higher number of patent outflow vessels after CDT (P < .0001). The 1- and 5-year patency rates of bypasses after successful CDT were 64.6% and 48.9%; amputation-free survival after 1 year, 5 years, and 7 years was 81.5%, 71.3%, and 70.5%, respectively.

CONCLUSIONS

Clinical success after CDT was observed in 62% of procedures with an associated complication rate of 36%. Patent outflow vessels before and after CDT are factors associated with long-term limb salvage. Amputation-free survival after 5 years is 71.3%.

Limb Salvage After Percutaneous Mechanical Thrombectomy in Patients with Acute Lower Limb Ischemia: A Retrospective Analysis from Two Institutions

BACKGROUND

To evaluate the short-term outcomes of percutaneous mechanical thrombectomy (PMT) in patients with acute lower limb ischemia (ALI) and to analyze the effect of ALI of different etiologies on the limb salvage.

MATERIALS AND METHODS

From January 2015 to December 2017, a retrospective analysis was performed on 112 patients (mean age: 66.5 years; 117 limbs in total; 66 limbs in 61 males) with ALI treated with PMT at 2 vascular institutions. Of the 117 limbs, 44 (41 patients) had acute arterial embolism, 36 (34 patients) had acute arterial thrombosis, and 37 (37 patients) had acute stent (31 limbs in 31 patients) or graft (6 limbs in 6 patients) thrombosis. The primary end point was limb salvage rate, and subgroups were analyzed by etiological factors. The secondary end points included patency rates, major bleeding complications, 30-day mortality, and reintervention rates.

RESULTS

The 30-day mortality rate was 3.6%. The incidence of major bleeding complications was 2.7%. During the follow-up, the limb salvage rates at 1 year and 2 years were 83.8% and 74.7%, respectively. Subgroup analysis showed that the limb salvage rate in patients with acute arterial embolism was 92.9% at 2 years after PMT, which was higher than that in patients with acute arterial thrombosis (73.3%, P = 0.04, hazard ratio [HR]: 3.6, 95% confidence interval [CI]: 1.1-11.7) and acute stent/graft thrombosis (62.5%, P = 0.01, HR: 4.7, 95% CI: 1.5-13.6).

CONCLUSIONS

PMT in patients with ALI is effective in preventing amputations over the 3-year study period with a reasonable safety profile, especially in patients with acute arterial embolism.

Acute Limb Ischemia Therapies: When and How to Treat Endovascularly

Acute limb ischemia is an emergent limb and life-threatening condition with high morbidity and mortality. An understanding of the presentation, clinical evaluation, and initial workup, including noninvasive imaging evaluation, is critical to determine an appropriate management strategy. Modern series have shown endovascular revascularization for acute limb ischemia to be safe and effective with success rates approaching surgical series and with similar, or even decreased, perioperative morbidity and mortality. A thorough understanding of endovascular techniques, associated pharmacology, and perioperative care is paramount to the endovascular management of patients presenting with acute limb ischemia. This article discusses the diagnosis and strategies for endovascular treatment of acute limb ischemia.