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

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

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.

Pounce Thrombectomy System to Treat Acute and Chronic Peripheral Arterial Occlusions

Peripheral arterial occlusions are composed of variable amounts of thrombus. Endovascular techniques should initially address the variably aged thrombus prior to treating plaque (percutaneous transluminal angioplasty (PTA) ± stenting). This should ideally be accomplished in a single procedural session. Forty-four consecutive patients treated with the Pounce thrombectomy system (PTS) as captured in a retrospective database, who presented with acute (n = 18), subacute (n = 7), or chronic (n = 19) lower extremity ischemia, were treated and followed for a mean of 7 months. The peripheral occlusions were considered thrombus-dominant by the feel and ease of wire traversal. They were treated with PTS along with complimentary PTA/stenting when appropriate. The mean number of passes with PTS was 4.0 ± 2.7. Sixty-five percent (29/44) were successfully revascularized in a single setting with only 2 requiring concomitant thrombolysis for incomplete thrombus removal from the PTS target artery. An additional 15 patients (34%) had thrombolysis for tibial thrombus that was not attempted with PTS. PTA ± stenting after PTS occurred in 57% of limbs. Technical success was 83% and procedural success was 95%. Reintervention rate throughout follow-up was 22.7%. Major amputation occurred in 4.5%. Complications were limited to minor groin hematomas (n = 3). Outcomes were equally effective in patients with pre-existing stents or denovo arterial occlusions as evidenced with ankle brachial index improvement from 0.48 pre-to 0.93 postintervention and 0.95 at latest follow-up (P < 0.001). PTS coupled with PTA/stenting is expeditiously safe and effective in patients with thrombus-associated lower limb occlusion.

Assessment of atherectomy treatment for Thromboangiitis Obliterans: A single center experience

BACKGROUND AND AIMS

Endovascular recanalizaiton (ER) has been proven to be a feasible method for Thromboangiitis Obliterans (TAO). The aims of this study were to evaluate the effectiveness and safety of atherectomy for TAO compared to nonatherectomy ER in our center.

METHODS

Patients diagnosed as TAO were reviewed from January 2016 to June 2021 in our center. Basic characteristics of patients before ER and perioperative data were collected and compared between the atherectomy and nonatherectomy groups. The vascular event-free survival and limb salvage were calculated to evaluate the prognosis of TAO patients after ERs. Logistic Regression and Cox Regression were used to identify the risk factors for technical failure and prognosis, respectively.

RESULTS

Seventy-two TAO patients with 79 lower limbs who met the criteria were included in this report. Compared with the nonatherectomy group, no significant improvement was identified in ER technical success, vascular event-free survival, or limb salvage in the atherectomy group. The total technical success rate was 91.1% (atherectomy group, 95.2%; nonatherectomy group, 89.7%), and the multiple limb involvement (p = 0.005; odds ratio [OR], 28.16; confidence interval [CI], 3.28-241.55) was the independent risk factor for technical failure. The total vascular event-free survival proportion was 66.05% and 58.40% at 1 and 3 years, respectively. Technical failure (OR, 5.61; 95% CI, 1.57-20.04; p = 0.008), and runoff grade 0 (OR, 3.28; 95% CI, 1.09-9.85; p = 0.034) were independent risk factors for vascular events. The total limb salvage proportion at 1 and 3 years was 95.84% and 92.53%, respectively. Technical failure (OR, 8.54; 95% CI, 1.71-40.73; p = 0.02) was identified as an independent risk factor for above ankle amputation.

CONCLUSIONS

No significant difference in prognosis was found between the atherectomy group and the nonatherectomy group during a midterm follow-up. The technical success of ER was crucial for TAO prognosis.

Safety and efficacy of interventional treatment of acute limb ischemia in Germany 2021

PURPOSE

Interventional procedures have become a mainstay in the therapy of acute limb ischemia caused by embolism or arterial thrombosis. Treatment options include pharmacological thrombolysis (PT) and mechanical thrombectomy (MT). The aim of this study was to evaluate success and major complication rates of interventional radiological treatments of arterial embolism and thrombosis in Germany in 2021 and to compare their results with accepted international quality standards.

MATERIALS AND METHODS

Data for PT and MT for 2021 was obtained from the quality management system of the German interventional radiological society (DeGIR). 2431 PT and 1582 MT procedures were documented for 2021, with 459 combinations of PT and MT. Data was analysed for technical and clinical success rates, as well as major complication rates such as intracranial bleeding, major bleeding, distal embolization, aneurysm formation, organ-failure and cardiac-decompensation.

RESULTS

PT alone had technical and clinical success rate of 90.21% and 81.08%, respectively. MT alone had technical and clinical success rates of 97.41% and 95.39%, respectively. MT&PT had technical and clinical success rates of 91.07% and 84.75%, respectively. Major complications were: distal embolization (PT:2.02%; MT:1.74%; PT&MT:2.61%), major bleeding (PT:0.94%; MT:1.14%; PT&MT:0.87%), aneurysm formation (PT:0.33%;MT: 1.14%;PT&MT: 0%), intracranial bleeding (PT:0.16%;MT:0%;PT&MT:0.22%), cardiac-decompensation (PT:0.21%;MT: 0.06%;PT&MT:0%) and organ-failure (PT:0%;MT:0.06%;PT&MT:0.22%). Technical and clinical success rates were higher, while complication rates were lower than the corresponding threshold recommended by the Society of Interventional Radiology for percutaneous management of acute lower-extremity ischemia.

CONCLUSION

Treatment of arterial embolism and thrombosis performed by interventional radiologists in Germany is effective and safe with outcomes exceeding internationally accepted standards.

Patients with Acute Limb Ischemia Might Benefit from Endovascular Therapy-A 17-Year Retrospective Single-Center Series of 985 Patients

Acute lower limb ischemia (ALI) is a common vascular emergency, requiring urgent revascularization by open or endovascular means. The aim of this retrospective study was to evaluate patient demographics, treatment and periprocedural variables affecting the outcome in ALI patients in a consecutive cohort in a tertiary referral center. Primary outcome events (POE) were 30-day (safety) and 180-day (efficacy) combined mortality and major amputation rates, respectively. Secondary outcomes were perioperative medical and surgical leg-related complications and the 5-year combined mortality and major amputation rate. Statistical analysis used descriptive and uni- and multivariable Cox regression analysis. In 985 patients (71 ± 9 years, 56% men) from 2004 to 2020, the 30-day and 180-day combined mortality and major amputation rates were 15% and 27%. Upon multivariable analysis, older age (30 d: aHR 1.17; 180 d: 1.27) and advanced Rutherford ischemia stage significantly worsened the safety and efficacy POE (30 d: TASC IIa aHR 3.29, TASC IIb aHR 3.93, TASC III aHR 7.79; 180 d: TASC IIa aHR 1.97, TASC IIb aHR 2.43, TASC III aHR 4.2), while endovascular treatment was associated with significant improved POE after 30 days (aHR 0.35) and 180 days (aHR 0.39), respectively. Looking at five consecutive patient quintiles, a significant increase in endovascular procedures especially in the last quintile could be observed (17.5% to 39.5%, p < 0.001). Simultaneously, the re-occlusion rate as well as the number of patients with any previous revascularization increased. In conclusion, despite a slightly increasing early re-occlusion rate, endovascular treatment might, if possible, be favorable in ALI treatment.

Treating a limb-threatening arterial clot in a newborn with catheter-directed thrombolysis

Non-catheter related arterial thromboembolism in the neonatal population is rare and carries a significant risk of organ damage or limb loss. Thrombolysis, whether systemic or catheter- directed, is reserved either for limb or life-threatening thrombosis due to risk of bleeding especially in premature neonates. In this case, an infant male born at 34 weeks and 4 days gestational age presented with limb-threatening clot in the distal right subclavian artery and proximal right axillary artery with no known cause. After discussion of risks and benefits of various treatment options, he received thrombolysis treatment with low dose recombinant TPA via an umbilical artery catheter. There was complete resolution of the thrombus with this treatment and the patient had no significant bleeding while receiving treatment. Further investigation is needed to identify the patient population that will benefit from catheter-directed thrombolytic therapy and how to best monitor these patients.

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.

Unexpected arterial thrombosis and acute limb ischemia in a young male patient with COVID-19: A case report

Introduction

The spread of severe acute respiratory syndrome coronavirus 2 has resulted in coronavirus disease 2019 (COVID-19) pandemic, raising significant concerns. COVID-19 can lead to thrombotic complications such as acute limb ischemia (ALI). In patients with COVID-19, thrombotic complications may increase the risk of morbidity and mortality.

Presentation of case

We report the case of a 37-year-old man who presented with a 2 weeks history of right foot pain, toes blackish discoloration, and numbness. He tested positive for COVID-19 10 days prior to his presentation. Computed tomography angiography (CTA) of the lower limbs revealed near-complete occlusion of the right popliteal artery with single-vessel posterior tibial artery runoff. The patient was brought to a hybrid operating room, and diagnostic angiography confirmed the diagnosis. He underwent popliteal artery thromboembolectomy and intraoperative thrombolysis through a posterior approach. A completion angiography demonstrated a patent popliteal artery with a 2-vessels patency to the foot. His postoperative recovery was uneventful. After surgery, the popliteal, anterior tibial, and posterior tibial arteries were all palpable. The patient was discharged home on antiplatelet therapy with frequent postoperative follow-ups during the last 1 year in our outpatient clinic.

Discussion

The frequency of ALI has reduced worldwide, and the hypercoagulable condition remains an infrequent cause of limb ischemia. Patients with COVID-19 have a 35%-45% thromboembolic complication rate. In many studies, the virus launches a second attack between 7 and 14 days after symptom onset, possibly causing hypercoagulability. If conservative treatment fails, various surgical methods, including thromboembolectomy, thrombolysis, and thrombosuction, can be performed to treat ALI.

Conclusion

In mild ALI symptoms, unfractionated heparin can be used with vigilant follow-up. Open and endovascular procedures are currently used to treat patients with acute limb ischemia, and technological advancements continue to make interventions easier and safer.

Percutaneous mechanical thrombectomy using the Rotarex®S device for the treatment of acute lower limb artery embolism: A retrospective single-center, single-arm study

Objective

Acute limb embolism (ALE) is a challenging, highly morbid, and frequently fatal vascular emergency. Percutaneous mechanical thrombectomy (PMT) devices are an alternative treatment to restore perfusion by removing emboli in the limb arterial system. We evaluated the outcomes of treatment of ALE patients using PMT devices in our center.

Methods

A retrospective review of ALE patients treated with Rotarex S (Straub Medical) at a single institution from 2018 to 2022 was performed. The primary outcome was technical success, defined as complete recanalization of the occluded segment with satisfactory outflow and good capillary filling of the distal parts of the foot without any major or obstructing residual emboli or thrombi either in the treated segment or in the outflow tract without the need for additional catheter-directed thrombolysis (CDT) or conversion to open surgery. Embolized segments treated, treatment outcomes, and perioperative complications were reviewed.

Results

A total of 17 ALE patients (29% men, 71% women; mean age, 73 years) underwent PMT procedures. The femoral arteries and popliteal arteries are the most commonly treated vessels, with both present in 59% of the patients. The technical success rate was 100%, but the majority of cases (82%) had concurrent percutaneous transluminal angioplasty or stent grafting, and two patients were treated with urokinase during the operation. There was one thrombotic recurrence that required amputation. There were no 30-day deaths. Complications included extravasation after PMT (two), intraoperative embolization of the outflow tract (one), access site hematoma (one), target artery thrombosis (one), and acute kidney injury (one). There were no severe bleeding complications.

Conclusions

The Rotarex S device has a satisfactory success rate, although complementary use of various adjunctive techniques is frequently required. It seems to be a moderately effective tool for treating ALE to avoid CDT or open surgery. The device appears safe, with low risks of amputation and mortality rates, but special attention should be given to the potential for extravasation and distal embolism.

What Is the Best Treatment for Acute Limb Ischemia?

Acute limb ischemia (ALI) is a vascular emergency associated with high rates of limb loss and mortality. Management of these patients is challenging given the severe systemic illness resulting from tissue ischemia and the high incidence of preexisting comorbid conditions and underlying peripheral arterial disease. Expeditious diagnosis, anticoagulation, and revascularization are of utmost importance in reducing morbidity. Revascularization may be accomplished using open, endovascular, or hybrid techniques. Approach to revascularization depends on the severity of ischemia, location of occlusion, cause, chance of recovery, comorbidities, and available resources.

Percutaneous thrombectomy or ultrasound-accelerated thrombolysis for initial management of acute limb ischaemia

BACKGROUND

Acute limb ischaemia (ALI), the sudden and significant reduction of blood flow to the limb, is considered a vascular emergency. In the general population, the incidence is estimated as 14 per 100,000. Prognosis depends on the time it takes to diagnose the condition and begin appropriate treatment. Standard initial interventional treatments include conventional open surgery and endovascular interventions such as catheter-directed thrombolysis (CDT). Percutaneous interventions, such as percutaneous thrombectomy (PT, including mechanical thrombectomy or pharmomechanical thrombectomy) and ultrasound-accelerated thrombolysis (USAT), are also performed as alternative endovascular techniques. The proposed advantages of PT and USAT include reduced time to revascularisation and when combined with catheter-directed thrombolysis, a reduction in dose of thrombolytic agents and infusion time. The benefits of PT or USAT versus open surgery or thrombolysis alone are still uncertain. In this review, we compared PT or USAT against standard treatment for ALI, in an attempt to determine if any technique is comparatively safer and more effective.

OBJECTIVES

To assess the safety and effectiveness of percutaneous thrombectomy or ultrasound-accelerated thrombolysis for the initial management of acute limb ischaemia in adults.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, the World Health Organization (WHO) International Clinical Trials Registry Platform, and ClinicalTrials.gov to 3 March 2021. We searched reference lists of relevant studies and papers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared PT (any modality, including mechanical thrombectomy (aspiration, rheolysis, rotation) or pharmomechanical thrombectomy) or USAT with open surgery, thrombolysis alone, no treatment, or another PT modality for the treatment of ALI.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies, assessed risk of bias, extracted data, performed data analysis, and assessed the certainty of evidence according to GRADE. Outcomes of interest were primary patency, amputation rate, major bleeding, clinical success, secondary patency, and adverse effects.

MAIN RESULTS

We included one RCT in this review. This study had a total of 60 participants and compared USAT with standard treatment (CDT). The study included 32 participants in the CDT group and 28 participants in the USAT group. We found no evidence of a difference between USAT and CDT alone for the following evaluated outcomes: amputation rate (risk ratio (RR) 1.14, 95% confidence interval (CI) 0.17 to 7.59); major bleeding (RR 1.71, 95% CI 0.31 to 9.53); clinical success (RR 1.00, 95% CI 0.94 to 1.07); and adverse effects (RR 5.69, 95% CI 0.28 to 113.72). We rated the certainty of the evidence as very low for these outcomes. We downgraded the certainty of the evidence for amputation rate, major bleeding, clinical success, and adverse effects by two levels due to serious limitations in the design (there was a high risk of bias in critical domains) and by two further levels due to imprecision (a small number of participants and only one study included). The study authors reported 30-day patency, but did not report primary and secondary patency separately. The patency rate in the successfully lysed participants was 71% (15/21) in the USAT group and 82% (22/27) in the CDT group. The study authors did not directly report secondary patency, which is patency after secondary procedures, but they did report on secondary procedures. Secondary procedures were subdivided into embolectomy and bypass grafting. Embolectomy was performed on 14% (4/28) of participants in the USAT group versus 3% (1/32) of participants in the CDT group. Bypass grafting was performed on 4% (1/28) of participants in the USAT group versus 0% in the CDT group. As we did not have access to the specific participant data, it was not possible to assess these outcomes further. We did not identify studies comparing the other planned interventions.

AUTHORS' CONCLUSIONS

There is insufficient evidence to assess the safety and effectiveness of USAT versus CDT alone for ALI for our evaluated outcomes: amputation rate, major bleeding, clinical success, and adverse effects. Primary and secondary patency were not reported separately. There was no RCT evidence for PT. Limitations of this systematic review derive from the single included study, small sample size, short clinical follow-up period, and high risk of bias in critical domains. For this reason, the applicability of the results is limited. There is a need for high-quality studies to compare PT or USAT against open surgery, thrombolysis alone, no treatment, or other PT modalities for ALI. Future trials should assess outcomes, such as primary patency, amputation rate, major bleeding, clinical success, secondary patency, and adverse effects.

Acute limb ischemia among patients with COVID-19 infection

OBJECTIVE/BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been associated with thrombotic complications such as deep vein thrombosis or stroke. Recently, numerous cases of acute limb ischemia (ALI) have been reported although pooled data are lacking.

METHODS

We systematically searched PubMed, Embase, Scopus, and the Cochrane Library for studies published online up to January 2021 that reported cases with SARS-CoV-2 infection and ALI. Eligible studies should have reported early outcomes including mortality. Primary endpoints included also pooled amputation, clinical improvement, and reoperation rates.

RESULTS

In total, 34 studies (19 case reports and 15 case series/cohort studies) including a total of 540 patients (199 patients were eligible for analysis) were evaluated. All studies were published in 2020. Mean age of patients was 61.6 years (range, 39-84 years; data from 32 studies) and 78.4% of patients were of male gender (data from 32 studies). There was a low incidence of comorbidities: arterial hypertension, 49% (29 studies); diabetes mellitus, 29.6% (29 studies); dyslipidemia, 20.5% (27 studies); chronic obstructive pulmonary disease, 8.5% (26 studies); coronary disease, 8.3% (26 studies); and chronic renal disease, 7.6% (28 studies). Medical treatment was selected as first-line treatment for 41.8% of cases. Pooled mortality rate among 34 studies reached 31.4% (95% confidence interval [CI], 25.4%%-37.7%). Pooled amputation rate among 34 studies reached 23.2% (95% CI, 17.3%-29.7%). Pooled clinical improvement rate among 28 studies reached 66.6% (95% CI, 55.4%%-76.9%). Pooled reoperation rate among 29 studies reached 10.5% (95% CI, 5.7%%-16.7%). Medical treatment was associated with a higher death risk compared with any intervention (odds ratio, 4.04; 95% CI, 1.075-15.197; P = .045) although amputation risk was not different between the two strategies (odds ratio, 0.977; 95% CI, 0.070-13.600; P = .986) (data from 31 studies).

CONCLUSIONS

SARS-CoV-2 infection is associated with a high risk for thrombotic complications, including ALI. COVID-associated ALI presents in patients with a low incidence of comorbidities, and it is associated with a high mortality and amputation risk. Conservative treatment seems to have a higher mortality risk compared with any intervention, although amputation risk is similar.

Popliteal artery entrapment syndrome

Popliteal artery entrapment syndrome (PAES) is an uncommon cause of lower extremity exertional claudication due to external compression of vascular structures in the popliteal fossa. A developmental anomaly due to an aberrant relationship of the artery with the surrounding myofascial structures contributes to the vascular compromise. PAES presents in younger, athletic patients without atherosclerotic risk factors. Typical presentation of unilateral or bilateral, intermittent claudication in the feet and calves specifically after exercise and relieved by rest in a young person should prompt further evaluation. Early diagnosis and intervention is essential for preventing thromboembolic complication and in worst cases limb loss. Initial tests with Ankle Brachial indices or Doppler ultrasound with provocative maneuvers will prompt more definitive cross sectional imaging studies. CTA or MRA also with provocative maneuvers has a high sensitivity and specificity and will clinch the diagnosis. There are six subtypes based on the relationship of the vascular structure with surround myofascial structures. CTA and MRA can characterize the subtypes and guide surgical planning. Catheter directed thrombolysis may be attempted adjunctively to reduce surgical thrombectomy or resolve distal emboli; however, myotendinous decompression with or without vascular repair is the definitive treatment. Long term surgical outcomes are satisfactory when the distal circulation is preserved.

Pharmacological Preconditioning Improves the Viability and Proangiogenic Paracrine Function of Hydrogel-Encapsulated Mesenchymal Stromal Cells

The efficacy of cell therapy is limited by low retention and survival of transplanted cells in the target tissues. In this work, we hypothesize that pharmacological preconditioning with celastrol, a natural potent antioxidant, could improve the viability and functions of mesenchymal stromal cells (MSC) encapsulated within an injectable scaffold. Bone marrow MSCs from rat (rMSC) and human (hMSC) origin were preconditioned for 1 hour with celastrol 1 μM or vehicle (DMSO 0.1% v/v), then encapsulated within a chitosan-based thermosensitive hydrogel. Cell viability was compared by alamarBlue and live/dead assay. Paracrine function was studied first by quantifying the proangiogenic growth factors released, followed by assessing scratched HUVEC culture wound closure velocity and proliferation of HUVEC when cocultured with encapsulated hMSC. In vivo, the proangiogenic activity was studied by evaluating the neovessel density around the subcutaneously injected hydrogel after one week in rats. Preconditioning strongly enhanced the viability of rMSC and hMSC compared to vehicle-treated cells, with 90% and 75% survival versus 36% and 58% survival, respectively, after 7 days in complete media and 80% versus 64% survival for hMSC after 4 days in low serum media (p < 0.05). Celastrol-treated cells increased quantities of proangiogenic cytokines compared to vehicle-pretreated cells, with a significant 3.0-fold and 1.8-fold increase of VEGFa and SDF-1α, respectively (p < 0.05). The enhanced paracrine function of preconditioned MSC was demonstrated by accelerated growth and wound closure velocity of injured HUVEC monolayer (p < 0.05) in vitro. Moreover, celastrol-treated cells, but not vehicle-treated cells, led to a significant increase of neovessel density in the peri-implant region after one week in vivo compared to the control (blank hydrogel). These results suggest that combining cell pretreatment with celastrol and encapsulation in hydrogel could potentiate MSC therapy for many diseases, benefiting particularly ischemic diseases.

Increased collateral flow by rescue femorofemoral bypass dissolved residual thrombus in implanted iliofemoral artery stents: a case report

Background

Failed aortofemoral and femoropopliteal bypass grafts in the lower extremity artery usually result in acute limb ischemia. Endovascular treatment and surgical revascularization have been reported for limb salvage.

Case presentation

A 72-year-old Japanese man was admitted with acute limb ischemia due to failed aortofemoral and femoropopliteal bypass grafts. Endovascular treatment with balloon angioplasty, thrombectomy, and stent implantation in the long chronic total occlusion from the right common iliac artery to the superficial femoral artery did not result in efficient flow due to thrombus transfer from a failed aortofemoral bypass graft. However, a rescue femorofemoral bypass (the left femoral to the right deep femoral artery) improved his symptoms, and implanted in-stent flow was gradually recovered. Lower extremity angiography performed 5 months later confirmed the patency of the iliofemoral in-stent flow. However, the femorofemoral bypass graft was unfortunately occluded due to the progression of left external iliac artery stenosis. The patency of the iliofemoral in-stent flow was confirmed at 1 year by ultrasonography.

Conclusions

Improvement of the deep femoral artery flow plays an important role in the treatment of acute limb ischemia due to failed aortofemoral and femoropopliteal bypass grafts. Thus, increased collateral circulation to the periphery through the deep femoral artery dissolved the remaining in-stent thrombus in the iliofemoral artery.

Ultrasound-Guided Retrograde Infrapopliteal Artery Access for Recanalization of Complex Femoral-Popliteal Artery Occlusions

BACKGROUND

The aim of the study was to review the outcomes of femoral-popliteal artery (FPA) interventions using an ultrasound (US)-guided retrograde infrapopliteal artery access after the failure of an antegrade recanalization.

METHODS

From Jan 2016 to Jan 2019, 37 patients with chronic total occlusion (CTO) of the FPA underwent ultrasound (US)-guided retrograde infrapopliteal artery access after failure of an antegrade procedure. Treated limbs were classified as Rutherford class 5 or 6 (29.7%) and class 4 (62.2%). Data collected included success rate and time to access using US. Immediate in-hospital and follow-up outcomes were also documented.

RESULTS

US-guided retrograde infrapopliteal artery access was successful in 100% of the patients (anterior tibial = 11, posterior tibial = 19, Peroneal = 4, Dorsalis pedis = 3). Retrograde revascularization was achieved in all 37 patients (100%) using balloon angioplasty (17/37, 45.9%) and additional stent placement (20/37, 54.1%). Ankle-brachial index (ABI) measurements changed from 0.25 ± 0.1 preinterventionally to 0.75 ± 0.07 at 1 day postinterventionally (<0.001). Minor complications occurred in 2/37 patients (5.4%) including one bleeding and vasospasm at the posterior tibial artery, both of which were treated conservatively. No patient experienced access-related thrombosis, aneurysm, compartment syndrome or death. Thirty of 37 (81%) patients completed for at least 12 months of follow-up. None of the successful revascularized patients had major or minor amputations during the follow-up period.

CONCLUSIONS

US-guided retrograde infrapopliteal artery access is a safe and successful technique, which expands revascularization options after the failure of conventional endovascular antegrade approaches.

A systematic review and meta-analysis of outcomes after acute limb ischemia in patients with cancer

BACKGROUND

Cancer results in a hypercoagulable state that is associated with both venous and arterial thromboses. However, little is known about the effects of acute limb ischemia (ALI) in this cohort of patients. In the present systematic review and meta-analysis, we analyzed the available clinical data on cancer and its association with ALI and evaluated the outcomes in these patients after a diagnosis of ALI.

METHODS

Three databases, including PubMed, EMBASE, and the Cochrane Library, were queried. Studies that met the inclusion criteria were included regardless of the publication year, language, sample size, or follow-up length. All the steps of the meta-analysis were conducted in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) and MOOSE (meta-analysis of observational studies in epidemiology) guidelines.

RESULTS

Seven studies from 6222 references with a total of 2899 patients were included. Of the 2899 patients, 1195 (41%) had had a diagnosis of ALI before their cancer diagnosis, and 1704 (59%) had presented with ALI after a cancer diagnosis. Nearly three quarters of ALI events were among patients with cancer of the skin and soft tissue (19%), genitourinary (18%), lung (17%), and gastrointestinal (16%) systems. ALI recurrence was similar between the two groups, and major amputation was more likely in patients with a diagnosis of ALI after a cancer diagnosis (7.4% vs 4.6%; P < .01). The incidence of mortality at 1 year was significantly greater for patients with established cancer who had presented with ALI compared with the patients who had presented with ALI before a cancer diagnosis (50.6% vs 29.9%; P < .01). After adjusting for study variability using the random effects model, the mortality at 1 year for all patients was 52.3% (95% confidence interval, 37.7%-66.5%). No significant heterogeneity (P = .73) was found between the two groups of patients, which varied by the timing of the ALI diagnosis in relation to the cancer diagnosis.

CONCLUSIONS

The 1-year mortality after the development of ALI in patients with cancer was >50%. For patients presenting with ALI of unclear etiology, the presence of an underlying cancer should be considered.

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.

Fístula arteriovenosa como tratamento adjunto na revascularização arterial do membro em risco

Acute arterial occlusion remains a major challenge for the vascular surgeon. The therapeutic approach depends mostly upon the severity of the tissue injury and the duration of symptoms. Several techniques are available in the current therapeutic arsenal, however, regardless of the technique chosen, postoperative factors frequently observed, such as poor outflow status, or even low graft flow, can contribute negatively to the outcome of revascularization. We describe a case of acute limb ischemia, in the postoperative period of a femoral-tibial bypass, which was occluded due to outflow limitation and high peripheral vascular resistance. The patient underwent a second tibial revascularization combined with construction of an arteriovenous fistula, followed by forefoot amputation and partial skin graft. An energetic approach to the at-risk limb makes it possible to reduce unfavorable outcomes, such as amputation and death, and accelerates recovery of tissues affected by acute ischemia.

In-hospital mortality in patients with acute limb ischemia over a 12-year period in the Brazilian public health-care system

Background

Arterial diseases represent a severe public health problem in the 21st century. Although men have a higher overall prevalence, reports have suggested that women may exhibit atypical manifestations, be asymptomatic, and have hormonal peculiarities, resulting in worse outcomes and severe emergencies, such as acute limb ischemia (ALI).

Objectives

To analyze the morbidity and mortality profile of ALI emergencies in Brazil between 2008 and 2019.

Methods

An ecological study was carried out with secondary data from SIH/SUS, using ICD-10 code I.74 The proportions of emergency hospital admissions and in-hospital mortality rates (HMR) by gender, ethnicity, and age were extracted from the overall figures. P<0.05 was considered significant.

Results

From 2008 to 2019, there were 195,567 urgent hospitalizations due to ALI in Brazil, 111,145 (56.8%) of which were of men. Women had a higher HMR (112:1,000 hospitalizations) than men (85:1,000 hospitalizations) (p<0.05), and a higher chance of death (OR=1.36; p<0.05). Furthermore, mean survival was significantly higher among men (8,483/year versus 6,254/year; p<0.05). Stratified by ethnicity, women who self-identified as white (OR=1.44; p<0.05), black (OR=1.33; p<0.05), and brown (RR=1.25; p <0.05) had greater chances of death than men in the same ethnicity categories. Moreover, women over the age of 50 years had a higher chance of death, with a progressive increment in risk as age increased.

Conclusions

There was a trend to worse prognosis in ALI emergencies associated with women, especially in older groups. The literature shows that the reasons for these differences are still poorly investigated and more robust studies of this relevant disease in the area of vascular surgery are encouraged.

Characteristics and clinical indicators of concomitant venous thromboembolism in acute limb ischemia

BACKGROUND

Venous thromboembolism (VTE) concomitant to acute limb ischemia (ALI) is rarely reported. The aim of the study was to investigate characteristics and identify clinical indicators of VTE in patients with ALI.

METHODS

Electronic medical record was used to identify patients diagnosed with ALI from January 2013 to June 2019. Eligible patients were categorized as VTE or non-VTE based on the presence or absence of concomitant VTE. Univariate analysis and multivariate analysis for indicators of VTE were performed.

RESULTS

A total of 153 patients with 161 ischemic limbs were enrolled. Venous duplex ultrasound (DUS) for 149 patients (157 ischemic limbs) revealed deep vein thrombosis (DVT) in 38 (24.2%) ischemic limbs of 37 (24.8%) patients. Five femoral DVTs were found intraoperatively. Six patients had pulmonary embolism (PE) and three of them died. In all, 43 (28.1%) ALI patients were diagnosed with VTE. They were treated with trans-arterial catheter-directed thrombolysis (N.=22), embolectomy (N.=9), primary amputation (N.=4) and anticoagulation alone (N.=8). The univariate analysis indicated that symptoms ≥ 2 days [odds ratio (OR): 3.42, 95%CI:1.54-7.62], Rutherford classification IIb-III (OR: 9.17, 95%CI: 2.10-40.12), leg swelling (OR: 4.44, 95%CI: 2.07-9.53), neutrophil ratio ≥0.80 (OR: 3.92, 95%CI: 1.72-8.93) and positive D-dimer (OR: 8.44, 95%CI: 3.65-19.53) were indicators of VTE concomitant to ALI. In the multivariate analysis, leg swelling and positive D-dimer appeared to be independent indicators.

CONCLUSIONS

VTE commonly occurs to ALI. Venous DUS for DVT screening should be considered for ALI patients who present one or more of these indicators.

Revascularization Outcomes in Patients With Acute Limb Ischemia and Active Neoplastic Disease

PURPOSE

To report the outcomes of surgical (ST), endovascular (ET), and hybrid (HT) treatment in cancer patients with acute limb ischemia (ALI).

MATERIALS AND METHODS

A multicenter retrospective registry collected 139 patients (mean age 72.3±12.4 years; 73 men) with ALI and active malignancy treated by ET (41, 29%), ST (70, 51%), or HT (28, 20%) in 7 European centers between July 2007 and February 2019. In 22 cases (16%) ALI was the first manifestation of the malignancy. Lung cancer was the most common diagnosis (38, 27%). The primary composite outcome was amputation-free survival (AFS). Overall survival, amputation-free time (AFT), and reintervention-free time (RFT) were also assessed. Cox regression analysis was applied to identify independent risk factors for the primary and secondary outcomes. Results are presented as the hazard ratio (HR) and 95% confidence intervals (CIs).

RESULTS

ET was associated with improved 12-month AFS compared with both ST (HR 2.27, 95% CI 1.20 to 4.28, p=0.002) and HT (HR 2.14, 95% CI 1.09 to 4.18, p=0.008). ST (HR 2.50, 95% CI 1.19 to 5.53, p=0.003) and HT (HR 3.10, 95% CI 1.45 to 6.65, p<0.001) were related to an increased risk for mortality compared with ET. At 12 months, the AFT was similar between the 3 groups (ET vs ST: HR 1.52, 95% CI 0.51 to 4.53, p=0.45 and ET vs HT: HR 1.21, 95% CI 0.36 to 4.11, p=0.73). The 12-month RFT also did not differ significantly between the 3 treatment options (ET vs ST: HR 1.10, 95% CI 0.49 to 2.46, p=0.79 and ET vs HT: HR 0.51, 95% CI 0.22 to 1.17, p=0.19). ST and/or HT increased the risk for the major amputation and/or death (HR 1.76, 95% CI 1.05 to 2.05, p=0.03), while Rutherford class I ischemia (HR 0.12, 95% CI 0.02 to 0.90, p=0.04) and previous vascular interventions on the index limb (HR 0.55, 95% CI 0.32 to 0.97, p=0.04) showed a protective effect.

CONCLUSION

In patients with ALI and active malignant disease, ET was associated with increased AFS and overall survival compared with both ST and HT, while the limb salvage and reintervention rates were comparable among the 3 groups.

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.