What Is the Best Treatment for Acute Limb Ischemia?

Mid-term Outcomes of Image-Guided Surgical Thromboembolectomy and Routine Intraoperative Angiography for Native Vessel Acute Lower-Limb-Threatening Ischemia

BACKGROUND

Standard balloon-catheter thromboembolectomy (TE) is an established effective treatment for acute lower-limb ischemia (ALI) with recognized limitations when there is an underlying arterial lesion or thromboembolism of the infrapopliteal arteries. The aim of this study was to evaluate the efficacy and safety of image-guided surgical TE combined with routine intraoperative completion angiography in the treatment of ALI patients.

METHODS

Between September 2020 and August 2022, this prospective study included all consecutive adult patients presenting to a tertiary center with unilateral ALI of Rutherford class II due to thromboembolic occlusion of native arteries who underwent image-guided surgical TE and routine completion intraoperative angiography. Adjunctive endovascular techniques (hybrid revascularization) including plain balloon angioplasty (PTA)±stenting or on-table lysis were used if underlying arterial lesions or residual thrombosis were detected on the intraoperative angiography, respectively. The primary outcome measures included technical success and 30-day major amputation rate. Perioperative complications, 1-year primary and secondary patency, limb salvage, mortality, and amputation-free survival rates were endorsed as secondary outcome measures.

RESULTS

Image-guided surgical thrombectomy was done for 109 ALI patients (109 limbs), provisionally diagnosed as embolic (57 patients, 52.3%) or thrombotic (52 patients, 47.7%) arterial occlusion. Thromboembolectomy without adjunctive endovascular treatment was done in 38 patients (34.86%), whereas 71 patients (65.14%) required adjunctive PTA±stenting of underlying arterial lesions (60, 55.05%) or on-table lysis±PTA of residual thrombosis (11, 10.09%). The overall technical success rate was 92.66%. At 30 days, amputation and mortality rates were 3.67% and 5.5%, respectively. None of the patients had thrombectomy-induced arterial injuries. One-year follow-up data were available for 81 patients (74.3%). The Kaplan-Meier estimate of the 12-month primary and secondary patency, limb salvage, and amputation-free survival rates was 76.5%±0.04, 91.5%±0.03, 90.6±0.03, and 91.4±0.03%, respectively.

CONCLUSIONS

Image-guided TE combined with routine intraoperative angiography is a safe and effective technique for surgical TE in acute lower-limb ischemia patients with the advantage of immediate identification and treatment of underlying arterial lesions or residual thrombosis for optimal revascularization.

CLINICAL IMPACT

The present study has confirmed the safety and effectiveness of image-guided thromboembolectomy combined with routine use of intraoperative angiography during surgical treatment of acute lower limb ischemia in terms of immediate identification and treatment of underlying arterial lesions or residual thrombosis for optimal revascularization. This technique also facilitates selective passage of Fogarty balloon catheter into infrapopliteal arteries from the femoral approach which is traditionally done by exploration of the popliteal trifurcation or tibial arteries under regional or general anesthesia. Using this technique can guide the operating surgeon for adequate balloon manipulation and inflation to avoid iatrogenic vessel injury.

Percutaneous thrombectomy for acute limb ischemia is associated with equivalent limb and mortality outcomes compared with open thrombectomy

BACKGROUND

Acute limb ischemia (ALI) carries a 15% to 20% risk of combined death or amputation at 30 days and 50% to 60% at 1 year. Percutaneous mechanical thrombectomy (PT) is an emerging minimally invasive alternative to open thrombectomy (OT). However, ALI thrombectomy cases are omitted from most quality databases, limiting comparisons of limb and survival outcomes between PT and OT. Therefore, our aim was to compare in-hospital outcomes between PT and OT using the National Inpatient Sample.

METHODS

We analyzed survey-weighted National Inpatient Sample data (2015-2020) to include emergent admissions of aged adults (50+ years) with a primary diagnosis of lower extremity ALI undergoing index procedures within 2 days of hospitalization. We excluded hospitalizations with concurrent trauma or dissection diagnoses and index procedures using catheter-directed thrombolysis. Our primary outcome was composite in-hospital major amputation or death. Secondary outcomes included in-hospital major amputation, death, in-hospital reintervention (including angioplasty/stent, thrombolysis, PT, OT, or bypass), and extended length of stay (eLOS; defined as LOS >75th percentile). Adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs) were generated by multivariable logistic regression, adjusting for demographics, frailty (Risk Analysis Index), secondary diagnoses including atrial fibrillation and peripheral artery disease, hospital characteristics, and index procedure data including the anatomic thrombectomy level and fasciotomy. A priori subgroup analyses were performed using interaction terms.

RESULTS

We included 23,795 survey-weighted ALI hospitalizations (mean age: 72.2 years, 50.4% female, 79.2% White, and 22.3% frail), with 7335 (30.8%) undergoing PT. Hospitalization characteristics for PT vs OT differed by atrial fibrillation (28.7% vs 36.5%, P < .0001), frequency of intervention at the femoropopliteal level (86.2% vs 88.8%, P = .009), and fasciotomy (4.8% vs 6.9%, P = .006). In total, 2530 (10.6%) underwent major amputation or died. Unadjusted (10.1% vs 10.9%, P = .43) and adjusted (aOR = 0.96 [95% CI, 0.77-1.20], P = .74) risk did not differ between the groups. PT was associated with increased odds of reintervention (aOR = 2.10 [95% CI, 1.72-2.56], P < .0001) when compared with OT, but this was not seen in the tibial subgroup (aOR = 1.31 [95% CI, 0.86-2.01], P = .21, Pinteraction < .0001). Further, 79.1% of PT hospitalizations undergoing reintervention were salvaged with endovascular therapy. Lastly, PT was associated with significantly decreased odds of eLOS (aOR = 0.80 [95% CI, 0.69-0.94], P = .005).

CONCLUSIONS

PT was associated with comparable in-hospital limb salvage and mortality rates compared with OT. Despite an increased risk of reintervention, most PT reinterventions avoided open surgery, and PT was associated with a decreased risk of eLOS. Thus, PT may be an appropriate alternative to OT in appropriately selected patients.

Effect of miR-206 on lower limb ischemia-reperfusion injury in rat and its mechanism

Lower limb ischemia-reperfusion is a common pathological process during clinical surgery. Because lower limb ischemia-reperfusion usually aggravates ischemia-induced skeletal muscle tissue injury after lower limb ischemia-reperfusion, it also causes remote organ heart, intestine, liver, lung and other injuries, and there is no effective clinical treatment for lower limb ischemia-reperfusion injury, so it is urgent to study its injury mechanism. In this study, the rat model of lower limb ischemia-reperfusion was established by clamping the femoral artery with microarterial clips, and the wall destruction such as intimal injury, cell edema, collagen degeneration, neutrophil infiltration, and elastic fiberboard injury of the femoral artery wall was detected. The expression of inflammatory factors was detected by immunohistochemistry. miR-206 preconditioning was used to observe the expression of inflammatory factors, redox status and apoptosis in the vascular wall of rats after acute limb ischemia-reperfusion. Our findings suggest that vascular endothelial cell edema increases, wall thickening, neutrophil infiltration, and elastic fiber layer damage during IRI. Inflammatory factor expression was increased in femoral artery tissue, and miR-206 expression levels were significantly down-regulated. Further studies have found that miR-206 attenuates lower limb IRI by regulating the effects of phase inflammatory factors. In this study, we investigated the effect of miR-206 on inflammatory factors and its possible role in the development of lower limb IRI, providing new research ideas for the regulatory mechanism of lower limb IRI, and providing a certain theoretical basis for the treatment of lower limb ischemia-reperfusion injury after surgery or endovascular intervention.

Acute Coronary Syndrome: Disparities of Pathophysiology and Mortality with and without Peripheral Artery Disease

There are a number of devastating complications associated with peripheral artery disease, including limb amputations and acute limb ischemia. Despite the overlap, atherosclerotic diseases have distinct causes that need to be differentiated and managed appropriately. In coronary atherosclerosis, thrombosis is often precipitated by rupture or erosion of fibrous caps around atheromatous plaques, which leads to acute coronary syndrome. Regardless of the extent of atherosclerosis, peripheral artery disease manifests itself as thrombosis. Two-thirds of patients with acute limb ischemia have thrombi associated with insignificant atherosclerosis. A local thrombogenic or remotely embolic basis of critical limb ischemia may be explained by obliterative thrombi in peripheral arteries of patients without coronary artery-like lesions. Studies showed that thrombosis of the above-knee arteries was more commonly due to calcified nodules, which are the least common cause of luminal thrombosis associated with acute coronary events in patients with acute coronary syndrome. Cardiovascular mortality was higher in peripheral artery disease without myocardial infarction/stroke than in myocardial infarction/stroke without peripheral artery disease. The aim of this paper is to gather published data regarding the disparities of acute coronary syndrome with and without peripheral artery disease in terms of pathophysiology and mortality.