Longitudinal Changes in Iron and Myelination Within Ischemic Lesions Associate With Neurological Outcomes: A Pilot Study.

BACKGROUND: Combined quantitative susceptibility mapping and R2* relaxometry can distinguish iron and myelin components in ischemic lesions. We aimed to investigate whether longitudinal changes in magnetic susceptibility and R2* values within ischemic lesions were associated with neurological outcomes. METHODS: In this single-center prospective study, we included patients, 20 to 90 years of age, who were consecutively admitted to the stroke care unit between August 2020 and March 2022 due to acute ischemic stroke. The participants underwent 2 instances of quantitative susceptibility mapping and R2* relaxometry scanning before and after stroke rehabilitation. We compared the changes in these quantitative measures across different subtypes of acute ischemic stroke. Multiple linear regression models were used to investigate the associations between the National Institutes of Health Stroke Scale scores and the mean magnetic susceptibility and R2* values in ischemic lesions. RESULTS: Among a total of 112 patients with acute ischemic stroke, 32 participants (aged 73.3±9.4 years; 20 men and 12 women) were evaluated. The median time from stroke onset to the first imaging was 5 days and that to the second imaging was 102 days. The changes in magnetic susceptibility values of branch atheromatous disease were higher than those of cardioembolism (mean difference, 0.018 [95% CI, 0.009-0.027] ppm; P<0.001) and lacunar (mean difference, 0.013 [95% CI, 0.005-0.020] ppm; P=0.004). Across all patients, the changes in National Institutes of Health Stroke Scale scores were associated with those of magnetic susceptibility values (coefficient, 0.311 [95% CI, 0.098-0.520]; P=0.017) but not with R2* values (coefficient, 0.114 [95% CI, -0.127 to 0.345]; P=0.291). CONCLUSIONS: The longitudinal changes in the magnetic susceptibility values within ischemic lesions were associated with neurological outcomes during the restorative stages poststroke in patients experiencing acute ischemic stroke. REGISTRATION: URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN000050719.

Specific and rapid guanidinium CEST imaging using double saturation power and QUASS analysis in a rodent model of global ischemia.

PURPOSE: Guanidinium CEST is sensitive to metabolic changes and pH variation in ischemia, and it can offer advantages over conventional pH-sensitive amide proton transfer (APT) imaging by providing hyperintense contrast in stroke lesions. However, quantifying guanidinium CEST is challenging due to multiple overlapping components and a close frequency offset from water. This study aims to evaluate the applicability of a new rapid and model-free CEST quantification method using double saturation power, termed DSP-CEST, for isolating the guanidinium CEST effect from confounding factors in ischemia. To further reduce acquisition time, the DSP-CEST was combined with a quasi-steady state (QUASS) CEST technique to process non-steady-state CEST signals. METHODS: The specificity and accuracy of the DSP-CEST method in quantifying the guanidinium CEST effect were assessed by comparing simulated CEST signals with/without the contribution from confounding factors. The feasibility of this method for quantifying guanidinium CEST was evaluated in a rat model of global ischemia induced by cardiac arrest and compared to a conventional multiple-pool Lorentzian fit method. RESULTS: The DSP-CEST method was successful in removing all confounding components and quantifying the guanidinium CEST signal increase in ischemia. This suggests that the DSP-CEST has the potential to provide hyperintense contrast in stroke lesions. Additionally, the DSP-CEST was shown to be a rapid method that does not require the acquisition of the entire or a portion of the CEST Z-spectrum that is required in conventional model-based fitting approaches. CONCLUSION: This study highlights the potential of DSP-CEST as a valuable tool for rapid and specific detection of viable tissues.

Impact of wound management strategies after revascularization for chronic limb-threatening ischemia.

OBJECTIVE: There is no established consensus or guidelines for wound management after revascularization for patients with chronic limb-threatening ischemia (CLTI) without severe infection. This study is designed to evaluate the clinical effect of the wound management strategy on toe wounds after revascularization for CLTI. METHODS: This retrospective cohort study was performed at eight institutions affiliated with Keio University School of Medicine in Japan and included 261 patients who underwent revascularization for CLTI between April 2019 and July 2021. We identified 132 patients with toe wounds from the database who had restored in-line blood flow to the foot. Patients were divided into two groups by the timing of toe resection after revascularization, which dictated the wound management policy. Group A (62 patients) underwent early toe amputation for suspected osteomyelitis, whereas group B (70 patients) underwent watchful waiting. The primary outcome was wound healing after revascularization; the secondary outcome was major amputation. We compared outcomes between groups A and B after propensity score matching. RESULTS: Using propensity score matching, each patient in group A (33 patients) was matched with a patient in group B (33 patients). Wound healing in matched group A was significantly better than that in matched group B (respectively: 1-year wound healing rate: 90.0% vs 68.2%, P < .001; median wound healing time: 65 days vs 258 days, P < .01). Although five major amputations were necessary in matched group B, none were required in matched group A (P = .05). The high rate of major amputations in group B was attributed to the sudden exacerbation of infection. Limb salvage rate in matched group A exceeded matched group B (100.0% vs 90.5%: 1-year limb salvage rate, P = .02). CONCLUSIONS: Early toe amputation for highly suspected osteomyelitis in patients with CLTI with toe wounds may expedite wound healing compared with watchful waiting, potentially avoiding unnecessary major amputation. Considering the wound management strategy is crucial when evaluating wound healing outcomes in patients with CLTI with revascularization.

Comparison of limb outcomes between bypass surgery and endovascular therapy in dialysis-dependent and -independent patients with chronic limb-threatening ischemia.

OBJECTIVE: To examine limb salvage (LS) and wound healing in dialysis-dependent and -independent patients with chronic limb-threatening ischemia (CLTI) after infrainguinal bypass surgery or endovascular therapy (EVT). METHODS: We retrospectively analyzed the multi-center data of patients who underwent infrainguinal revascularization for CLTI with Wound, Ischemia, and foot Infection (WIfI) stage 2 to 4 between 2015 and 2020. The primary endpoint was LS. The secondary endpoint included wound healing, amputation-free survival (AFS), periprocedural complications, and 2-year survival. Comparison of these outcomes were made after propensity score matching. RESULTS: We analyzed 252 dialysis-dependent (318 limbs) and 305 dialysis-independent (354 limbs) patients. Propensity score matching extracted 202 pairs with no significant differences in characteristics. The LS rate in bypass surgery was better than that in EVT in dialysis-dependent patients (P < .001). There was no significant difference in the LS rates between bypass surgery and EVT in dialysis-independent patients (P = .168). The wound healing rate of bypass surgery was better than that of EVT both dialysis-dependent and -independent patients with CLTI. The AFS rate of bypass surgery was better than that of EVT in dialysis-dependent patients (P < .001). There was no significant difference in the AFS rates between bypass surgery and EVT in dialysis-independent patients (P = .099). There was no significant difference in the occurrence of Clavien-Dindo ≥ IV and V between bypass surgery and EVT in dialysis-dependent and -independent patients. Age ≥75 years, serum albumin levels <3.5 g/dL, and non-ambulatory status were risk factors for 2-year mortality in dialysis-dependent patients. The 2-year survival rates in dialysis-dependent patients with risk factors of 0, 1, 2, and 3 were 82.5%, 67.1%, 49.5%, and 10.2%, respectively (P < .001). CONCLUSIONS: For LS and wound healing, bypass surgery was preferred for revascularization in dialysis-dependent patients with WIfI stage 2 to 4. Although dialysis dependency was one of the risk factors for 2-year mortality, dialysis-dependent patients, who have 0 to 1 risk factors, may benefit from bypass surgery, as 2-year survival of >50% is expected.

Comparison of endovascular therapies for chronic limb-threatening ischemia and claudication.

OBJECTIVE: Analysis of regional data from the Vascular Quality Initiative (VQI) suggested improved survival for patients undergoing stent placement compared with balloon angioplasty and atherectomy. Using national data from the VQI linked to Medicare claims data through the Vascular Implant Surveillance and Interventional Outcomes Network program, this study aimed to compare the rates of mortality, reintervention, and amputation after endovascular interventions (atherectomy, stenting, and balloon angioplasty) for two separate cohorts: patients with chronic limb-threatening ischemia (CLTI) and patients with claudication. METHODS: This was a secondary data analysis of Society for Vascular Surgery National VQI data linked to Medicare claims, between October 2016 and December 2019. Patients aged ≥65 years with symptoms of claudication or CLTI and a diagnosis of occlusive disease were included. Urgent or emergent interventions or those with concurrent procedures (endarterectomy, bypass, or bilateral intervention) were excluded. Interventions were grouped into (1) balloon angioplasty only; (2) stent (with or without balloon angioplasty); or (3) atherectomy (alone, with or without stent, with or without balloon angioplasty). Propensity score-matched cohorts were constructed to conduct pairwise intervention comparisons of mortality, reintervention, and amputation rates. Multivariable logistic regression was used to derive propensity scores for each patient. Kaplan-Meier estimates and Cox proportional hazards ratios (HRs) (95% confidence interval [CI]) analyses were performed. RESULTS: A total of 9785 (2665 claudication, 7120 CLTI) eligible patients were identified. After propensity score matching for the CLTI group, 2826, 3608, and 2796 pairs of cases were used to compare balloon angioplasty vs atherectomy, balloon angioplasty vs stent, and stent vs atherectomy, respectively. No statistically significant difference in mortality was observed among all interventions. However, atherectomy was associated with a significant increase in reintervention rate compared with balloon angioplasty (HR, 1.22; 95% CI, 1.06-1.39; P = .01) and compared with stenting (HR, 1.27; 95% CI, 1.10-1.46; P < .01) within the first year after the index procedure. Of note, both atherectomy (HR, 0.82; 95% CI, 0.68-0.98; P < .05) and stenting (HR, 0.76; 95% CI, 0.64-0.90; P < .01) showed lower rates of major amputation when compared with balloon angioplasty within 1 year after the index procedure. In the claudication group, there were no significant differences observed among interventions for peripheral arterial disease for mortality, reintervention, or amputation rates. CONCLUSIONS: Further studies are needed to identify appropriate indications for atherectomy, because there may be a subset of patients with CLTI who benefit from this therapy with respect to amputation rates. Until then, caution should be exercised when using atherectomy because it is also associated with higher reintervention rates.

Systemic immunosuppression does not affect revascularization outcomes in patients with chronic limb-threatening ischemia.

OBJECTIVE: Many patients with chronic limb-threatening ischemia (CLTI) have additional comorbidities requiring systemic immunosuppression. Few studies have analyzed whether these medications may inhibit graft integration and effectiveness, or conversely, whether they may prevent inflammation and/or restenosis. Therefore, our study aim was to examine the effect of systemic immunosuppression vs no immunosuppression on outcomes after any first-time lower extremity revascularization for CLTI. METHODS: We identified all patients undergoing first-time infrainguinal bypass graft (BPG) or percutaneous transluminal angioplasty with or without stenting (PTA/S) for CLTI at our institution between 2005 and 2014. Patients were stratified by procedure type and immunosuppression status, defined as ≥6 weeks of any systemic immunosuppression therapy ongoing at the time of intervention. Immunosuppression vs nonimmunosuppression were the primary comparison groups in our analyses. Primary outcomes included perioperative complications, reintervention, primary patency, and limb salvage, with Kaplan-Meier and Cox proportional hazard models used for univariate and multivariate analyses, respectively. RESULTS: Among 1312 patients, 667 (51%) underwent BPG and 651 (49%) underwent PTA/S, of whom 65 (10%) and 95 (15%) were on systemic immunosuppression therapy, respectively. Whether assessing BPG or PTA/S patients, there were no differences noted in perioperative outcomes, including perioperative mortality, myocardial infarction, stroke, hematoma, or surgical site infection (P > .05). For BPG patients, Kaplan-Meier analysis and log-rank testing demonstrated no significant difference in three-year reintervention (37% vs 33% [control]; P = .75), major amputation (27% vs 15%; P = .64), or primary patency (72% vs 66%; P = .35) rates. Multivariate analysis via Cox regression confirmed these findings (immunosuppression hazard ratio [HR] for reintervention, 0.95; 95% CI, 0.56-1.60; P = .85; for major amputation, HR, 1.44; 95% CI, 0.70-2.96; P = .32; and for primary patency. HR, 0.97; 95% CI, 0.69-1.38; P = .88). For PTA/S patients, univariate analysis revealed similar rates of reintervention (37% vs 39% [control]; P = .57) and primary patency (59% vs 63%; P = .21); however, immunosuppressed patients had higher rates of major amputation (23% vs 12%; P = .01). After using Cox regression to adjust for baseline demographics, as well as operative and anatomic characteristics, immunosuppression was not associated with any differences in reintervention (HR, 0.75; 95% CI, 0.49-1.16; P = .20), major amputation (HR, 1.46; 95% CI, 0.81-2.62; P = .20), or primary patency (HR, 0.84; 95% CI, 0.59-1.19; P = .32). Sensitivity analyses for the differences in makeup of immunosuppression regimens (steroids vs other classes) did not alter the interpretation of any findings in either BPG or PTA/S cohorts. CONCLUSIONS: Our findings demonstrate that patients with chronic systemic immunosuppression, as compared with those who are not immunosuppressed, does not have a significant effect on late outcomes after lower extremity revascularization, as measured by primary patency, reintervention, or major amputation.

Long-term value in open and endovascular repair of chronic mesenteric ischemia.

OBJECTIVE: Guidelines recommend open revascularization (OR) over endovascular revascularization (ER) for the treatment of chronic mesenteric ischemia (CMI) for younger, healthier patients. However, little is known about the long-term costs of these recommendations with respect to patients' overall life expectancy. This study investigated whether 5-year value differs between these treatment modalities. METHODS: Patient data were extracted from the Statewide Planning and Research Cooperative System, the New York statewide all-payor database containing demographics, diagnoses, treatments, and charges. The database was queried for patients with an International Classification of Diseases, ninth revision, code for CMI, with the specific exclusion of acute ischemia cases. A propensity score match was performed using the Charlson Comorbidity Index, age, sex, race, renal status, and pulmonary disease for the final cohort of patients. Multiple linear regression and mixed effects linear regression were used to determine factors associated with 5-year value, calculated as life-years/$100k in charges. Charges were gathered from the index admission and subsequent admissions for acute or CMI, mesenteric angiography, or follow-up reintervention. Kaplan-Meier estimation was performed for survival and reintervention-free survival. RESULTS: From 2000 to 2014, 875 patients underwent intervention for CMI. Of those meeting inclusion criteria, 209 (28.1%) underwent OR and 535 (71.9%) ER. After propensity score matching (n = 209 in each group), the ER group showed higher value at 5 years after the procedure (8.04 ± 11.42 life-years/$100k charges vs 4.89 ± 5.28 life-years/$100k charges; P < .01). More patients underwent reintervention in the ER group (37 patients vs 17 patients; P < .01), with 55 reinterventions in the ER group and 19 in the OR group (P < .01). Multiple linear regression analysis showed that age, congestive heart failure, dysrhythmia, cancer, and days spent in the intensive care unit were negatively associated with value at 5 years, whereas ER was positively associated. Survival was 59.6 ± 3.76% vs 62.3% ± 3.49% at 5 years (P = .91), and reintervention-free survival was 43.7 ± 3.86% vs 58.1 ± 3.53% (P = .04), for ER and OR respectively. CONCLUSIONS: Despite increased reinterventions and lower reintervention-free survival, the value for patients with CMI was higher in those who underwent ER in the largest propensity score-matched cohort to date looking at long-term value. Factors negatively associated with value were OR, age, days in intensive care, congestive heart failure, dysrhythmia, and cancer. In patients with amenable anatomy, ER is validated as the first-choice treatment for CMI based on the superior procedural value.

Outcomes of lower extremity arterial bypass using the Human Acellular Vessel in patients with chronic limb-threatening ischemia.

OBJECTIVE: Patients with chronic limb-threatening ischemia (CLTI) and no great saphenous vein to use as a conduit for arterial bypass have a high risk for amputation despite advances in medical and endovascular therapies. This report presents findings from a U.S. Food and Drug Administration (FDA) supported study of the Human Acellular Vessel (HAV) (Humacyte Inc.) used as a conduit for arterial bypass in patients with CLTI and inadequate or absent autologous conduit. METHODS: The HAV is a 6-mm, 40-cm vessel created from human vascular smooth muscle cells seeded onto a polyglycolic acid scaffold pulsed in a bioreactor for 8 weeks as cells proliferate and the scaffold dissolves. The resultant vessel is decellularized, creating a nonimmunogenic conduit composed of collagen, elastin, and extracellular matrix. The FDA issued an Investigational New Drug for an intermediate-sized, single-center study of the HAV under the agency's Expanded Access Program in patients with advanced CLTI and inadequate or absent autologous conduit. Technical results and clinical outcomes were analyzed and reported. RESULTS: Between March 2021 and July 2023, 29 patients (20 males; mean age, 71 ± 11 years) underwent limb salvage operation using the HAV as a bypass conduit. Most patients had advanced CLTI (Rutherford class 5/6 in 72%; wound, ischemia, and foot infection stage 3/4 in 83%), and 97% had previously failed revascularization(s) of the extremity. Two HAVs were sewn together to attain the needed bypass length in 24 patients (83%). Bypasses were to tibial arteries in 23 patients (79%) and to the popliteal artery in 6 (21%). Technical success was 100%, and the 30-day mortality rate was 7% (2 patients). With 100% follow-up (median, 9.3 months), the limb salvage rate was 86% (25/29 patients). There were 16 reinterventions to restore secondary patency, of which 15 (94%) were successful. Primary and secondary patency of the HAV at 9 months were 59% and 71%, respectively. CONCLUSIONS: The HAV has demonstrated short- to intermediate-term safety and efficacy as an arterial bypass conduit in a complex cohort of patients with limb-threatening ischemia and no autologous options. This experience using the FDA's Expanded Access Program provides real-world data to inform regulatory deliberations and future trials of the HAV, including the study of the vessel as a first-line bypass conduit in less severe cases of chronic limb ischemia.

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.

Safety and efficacy of mechanical aspiration thrombectomy for patients with acute lower extremity ischemia.

OBJECTIVE: Acute limb ischemia (ALI) is associated with high rates of amputation and consequent morbidity and mortality. The objective of this study is to report on the safety and efficacy of aspiration thrombectomy using the Indigo Aspiration System in patients with lower extremity (LE) ALI. METHODS: The STRIDE study was an international, multicenter, prospective, study that enrolled 119 participants presenting with LE-ALI. Patients were treated firstline with mechanical thrombectomy using the Indigo Aspiration System, before stenting or angioplasty, or other therapies as determined by treating physician. The primary end point was target limb salvage at 30 days after the procedure. Secondary end points within 30 days included technical success, defined as core laboratory-adjudicated Thrombolysis in Myocardial Infarction (TIMI) 2/3 flow rate immediately after the procedure, changes in modified Society for Vascular Surgery runoff score, improvement of Rutherford classification compared with before the procedure, patency, rate of device-related serious adverse events, and major periprocedural bleeding. Secondary end points that will be evaluated at 12 months include target limb salvage and mortality. RESULTS: Of the 119 participants enrolled at 16 sites, the mean age was 66.3 years (46.2% female). At baseline (n = 119), ischemic severity was classified as Rutherford I in 10.9%, Rutherford IIa in 54.6%, and Rutherford IIb in 34.5%. The mean target thrombus length was 125.7 ± 124.7 mm. Before the procedure, 93.0% (of patients 107/115) had no flow (TIMI 0) through the target lesion. The target limb salvage rate at 30 days was 98.2% (109/111). The rate of periprocedural major bleed was 4.2% (5/119) and device-related serious adverse events was 0.8% (1/119). Restoration of flow (TIMI 2/3) was achieved in 96.3% of patients (105/109) immediately after the procedure. The median improvement in the modified Society for Vascular Surgery runoff score (before vs after the procedure) was 6.0 (interquartile range, 0.0-11.0). Rutherford classifications also improved after discharge in 86.5% of patients (83/96), as compared with preprocedural scores. Patency at 30 days was achieved in 89.4% of patients (101/113). CONCLUSIONS: In the STRIDE (A Study of Patients with Lower Extremity Acute Limb Ischemia to Remove Thrombus with the Indigo Aspiration System) study, aspiration thrombectomy with the Indigo System provided a safe and effective endovascular treatment for patients with LE-ALI, resulting in a high rate (98.2%) of successful limb salvage at 30 days, with few periprocedural complications.

Single-center experience with the JETi Hydrodynamic Thrombectomy System for acute limb ischemia.

OBJECTIVE: Acute limb ischemia (ALI) remains a vascular emergency with high morbidity and mortality. While the JETi Hydrodynamic Thrombectomy System (Abbott) offers a percutaneous approach to fragment and aspirate the thrombus in patients with arterial occlusions, data on its efficacy and safety are limited. This study reports our early experience using the JETi device to treat ALI at our institution. METHODS: This is a single-center, retrospective review of patients with ALI treated with the JETi device between September 2020 and December 2022. Patients were included if the JETi device was used either as a primary intervention or as an adjunct procedure. The primary endpoint was technical success defined as <50% residual thrombus after intervention. Secondary endpoints included achieving complete resolution of the thrombus on angiogram, acute kidney injury (AKI), major bleeding, 30-day major amputation, and 30-day mortality. RESULTS: A total of 59 JETi procedures for ALI (median age 62 years [interquartile range: 56-71 years]) were performed on 39 male and 20 female patients. The median time from onset of symptoms to hospitalization was 24 hours (interquartile range: 4-168 hours). Rutherford classifications were I (10), IIa (27), IIb (14), and undocumented (8). Etiology of ALI was native vessel thrombosis (27), embolism (16), graft/stent thrombosis (14), and iatrogenic (2). A total of 124 vessels were treated, with an average of 2.1 vessels per procedure. The primary outcome was achieved in 86% (107/124) of the arteries, with 82% (102/124) successfully opened using the JETi device alone without the need for any adjunctive therapy. Complete resolution of the thrombus using JETi was achieved in 81% (101/124) arteries, with or without the use of adjunctive therapy. A total of 6.7% (4/59) patients required a major limb amputation within 30 days despite successful recanalization, and one 30-day mortality was recorded. Complications included distal embolization (5), access site hematoma (2), and AKI (4). No major bleeding, hemolysis-induced AKI, or vessel dissection or perforation was observed. CONCLUSIONS: The JETi device appears to be a safe and effective percutaneous treatment option in the management of ALI. It provides definitive treatment with a high technical success rate of 86% and a good safety profile.

Surgery or endovascular therapy for patients with chronic limb-threatening ischemia requiring infrapopliteal interventions.

OBJECTIVE: The recent publication of randomized trials comparing open bypass surgery to endovascular therapy in patients with chronic limb-threatening ischemia, namely, Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) and Bypass versus Angioplasty in Severe Ischaemia of the Leg-2 (BASIL-2), has resulted in potentially contradictory findings. The trials differed significantly with respect to anatomical disease patterns and primary end points. We performed an analysis of patients in BEST-CLI with significant infrapopliteal disease undergoing open tibial bypass or endovascular tibial interventions to formulate a relevant comparator with the outcomes reported from BASIL-2. METHODS: The study population consisted of patients in BEST-CLI with adequate single segment saphenous vein conduit randomized to open bypass or endovascular intervention (cohort 1) who additionally had significant infrapopliteal disease and underwent tibial level intervention. The primary outcome was major adverse limb event (MALE) or all-cause death. MALE included any major limb amputation or major reintervention. Outcomes were evaluated using Cox proportional regression models. RESULTS: The analyzed subgroup included a total of 665 patients with 326 in the open tibial bypass group and 339 in the tibial endovascular intervention group. The primary outcome of MALE or all-cause death at 3 years was significantly lower in the surgical group at 48.5% compared with 56.7% in the endovascular group (P = .0018). Mortality was similar between groups (35.5% open vs 35.8% endovascular; P = .94), whereas MALE events were lower in the surgical group (23.3% vs 35.0%; P<.0001). This difference included a lower rate of major reinterventions in the surgical group (10.9%) compared with the endovascular group (20.2%; P = .0006). Freedom from above ankle amputation or all-cause death was similar between treatment arms at 43.6% in the surgical group compared with 45.3% the endovascular group (P = .30); however, there were fewer above ankle amputations in the surgical group (13.5%) compared with the endovascular group (19.3%; P = .0205). Perioperative (30-day) death rates were similar between treatment groups (2.5% open vs 2.4% endovascular; P = .93), as was 30-day major adverse cardiovascular events (5.3% open vs 2.7% endovascular; P = .12). CONCLUSIONS: Among patients with suitable single segment great saphenous vein who underwent infrapopliteal revascularization for chronic limb-threatening ischemia, open bypass surgery was associated with a lower incidence of MALE or death and fewer major amputation compared with endovascular intervention. Amputation-free survival was similar between the groups. Further investigations into differences in comorbidities, anatomical extent, and lesion complexity are needed to explain differences between the BEST-CLI and BASIL-2 reported outcomes.

Pedal medial arterial calcification influences the outcomes of isolated infra-malleolar interventions for chronic limb-threatening ischemia.

OBJECTIVE: Inframalleolar disease is present in most diabetic patients presenting with tissue loss. Inframalleolar (pedal) artery disease and pedal medial arterial calcification (pMAC) are associated with major amputation in patients with chronic limb-threatening ischemia (CLTI). This study aimed to examine the impact of pMAC on the outcomes after isolated inframalleolar (pedal artery) interventions. METHODS: A database of lower extremity endovascular intervention for patients with tissue loss between 2007 and 2022 was retrospectively queried. Patients with CLTI were selected, and those undergoing isolated inframalleolar intervention on the dorsalis pedis and medial and lateral tarsal arteries and who had foot x-rays were identified. X-rays were assessed blindly for pMAC and scored on a scale of 0 to 5. Patients with concomitant superficial femoral artery and tibial interventions were excluded. Intention to treat analysis by the patient was performed. Amputation-free survival (survival without major amputation) was evaluated. RESULTS: A total of 223 patients (51% female; 87% Hispanic; average age, 66 years; 323 vessels) underwent isolated infra-malleolar intervention for tissue loss. All patients had diabetes, 96% had hypertension, 79% had hyperlipidemia, and 63% had chronic renal insufficiency (55% of these were on hemodialysis). Most of the patients had Wound, Ischemia, and foot Infection (WIfI) stage 3 disease and had various stages of pMAC: severe (score = 5) in 48%, moderate (score = 2-4) in 31%, and mild (score = 0-1) in 21% of the patients. Technical success was 94%, with a median of one vessel treated per patient. All failures were in severe pMAC. Overall, major adverse cardiovascular events was 0.9% at 90 days after the procedure. Following the intervention, most patients underwent a planned forefoot amputation (single digit, multiple digits, ray amputation, or trans-metatarsal amputation). WIfI ischemic grade was improved by 51%. Wound healing at 3 months was 69%. Those not healing underwent below-knee amputations. The overall 5-year amputation-free survival rate was 35% ± 9%. The severity of pMAC was associated with decreased AFS. CONCLUSIONS: Increasing severity of pMAC influences the technical and long-term outcomes of infra-malleolar intervention in diabetes. Severe pMAC is associated with amputation and should be considered as a variable in the shared decision-making of diabetic patients with CLTI.

Outcomes of revascularization of stenotic inframalleolar lesions in chronic limb-threatening ischemia.

BACKGROUND: For chronic limb-threatening ischemia, revascularization has been reported for occlusions but not for stenosis in the inframalleolar (IM) lesions. We investigated the clinical outcomes of balloon dilation for stenotic IM lesions distal to the treatment target in the infrapopliteal (IP) legion. METHODS: We conducted a retrospective analysis of patients who had chronic limb-threatening ischemia and underwent revascularization of stenotic IM lesions distal to the target IP lesions between January 2015 and August 2022. The outcome measures were amputation-free survival, wound healing rate, and freedom from target IM reintervention. RESULTS: The 87 patients had a mean age of 72.7 ± 10.7 years and comprised 67.8% men, 74.7% with diabetes mellitus, 55.2% on dialysis, 33.3% who had Rutherford six classification. The amputation-free survival (AFS), wound healing, and freedom from target IM reintervention rates at 1 year were 82.9%, 53.3%, and 58.4%, respectively. On Cox proportional multivariate analysis, the predictors were Wound, Ischemia, and foot Infection (WIfI) ≥3 and diffuse stenosis in the target IM vessels for delayed wound healing and Global Limb Anatomic Staging System stage Ⅲ and ≥3 diseased IM vessels before endovascular therapy for target IM reintervention. At the time of reintervention, the lesion morphology had progressed from stenosis to occlusion in 50% of cases. CONCLUSIONS: In patients with chronic limb-threatening ischemia, revascularization of stenosis in IM lesions showed a high reintervention rate and progression of lesion morphology, although AFS and wound-healing rates were acceptable.

Real-World Vein Mapping Practice Patterns Before Endovascular Treatment of Limb Ischemia.

INTRODUCTION: The Best Endovascular versus Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) trial results suggest that in patients with chronic limb-threatening ischemia (CLTI) and adequate single-segment great saphenous vein (SSGSV) by preoperative duplex ultrasonography, a surgical-first treatment strategy is superior to an endovascular-first strategy. However, the utilization of vein mapping prior to endovascular-first revascularization for CLTI in actual clinical practice is not known. METHODS: Data from a multicenter clinical data warehouse (2008-2019) were linked to Medicare claims data for patients undergoing endovascular-first treatment of infra-inguinal CLTI. Only patients who would have otherwise been eligible for enrollment in BEST-CLI were included. Adequate SSGSV was defined as healthy vein >3.0 mm in diameter from the groin through the knee. Logistic regression was used to estimate associations between preprocedure characteristics and vein mapping. Survival methods were used to estimate the risk of major adverse limb events and death. RESULTS: A total of 142 candidates for either surgical or endovascular treatment underwent endovascular-first management of CLTI. Ultrasound assessment for SSGSV was not performed in 76% of patients prior to endovascular-first revascularization. Of those who underwent preprocedure vein mapping, 44% had adequate SSGSV for bypass. Within one year postprocedure, 12.0% (95% confidence interval 7.4-18.0%) of patients underwent open surgical bypass and 54.7% (95% confidence interval 45.3-62.4%) experienced a major adverse limb event or death. CONCLUSIONS: In a real-world cohort of BEST-CLI-eligible patients undergoing endovascular-first intervention for infra-inguinal CLTI, three-quarters of patients had no preprocedure ultrasound assessment of great saphenous vein conduit. Practice patterns for vein conduit assessment in the real-world warrant reconsideration in the context of BEST-CLI trial results.

Percutaneous Deep Venous Arterialization in Patients with No-Option Critical Limb Ischemia Performed in an Office-Based Laboratory Setting.

PURPOSE: To evaluate the feasibility and safety of percutaneous deep venous arterialization (pDVA) performed in an office-based laboratory (OBL) for patients with no-option critical limb ischemia (CLI). MATERIALS AND METHODS: A retrospective chart review was performed of all patients who underwent pDVA using commercially available devices from January 2018 to November 2021 in a single OBL. In total, 22 patients (10 males and 12 females; Rutherford 4, 5, and 6: n = 1, 8, and 13, respectively) were identified with a median follow-up of 140 days. Amputation-free survival, wound healing, pDVA patency, and overall survival were evaluated at 30 days, 6 months, and throughout the remaining follow-up period. RESULTS: All patients had undergone failed previous attempts at endovascular arterial reconstruction. At 6 months after procedure, 6.4% of arteriovenous conduits remained patent; 83.3% (10/12) of patients experienced complete or partial wound healing. In addition, 78.6% of patients avoided an above-ankle amputation, and overall survival was 83.6%. Nine patients underwent endovascular reinterventions at 6 months. One mild adverse event and 4 moderate adverse events occurred after procedure, and 1 cardiac death occurred 5 days after procedure. CONCLUSIONS: pDVA is safe and feasible in the OBL for patients with no-option CLI. Many patients avoided an above-ankle amputation during the study period despite low overall pDVA patency.

Percutaneous Management of Dialysis Access Steal Syndrome: Interventions and Outcomes from a Single Institution's 20-Year Experience.

PURPOSE: To determine safety and effectiveness of percutaneous interventions performed by interventional radiologists at a single institution over 2 decades in patients with dialysis access steal syndrome (DASS). MATERIALS AND METHODS: A retrospective review of fistulograms from 2001 to 2021 (N = 11,658) was performed. In total, 286 fistulograms in 212 patients with surgically created dialysis accesses met inclusion criterion of fistulography for suspected DASS. Chart review collected data regarding patient demographics, comorbidities, access characteristics, fistulography findings, intervention(s) performed, and outcomes. Procedures with and without DASS intervention were compared. Odds ratios (ORs), adjusted for age, sex, comorbidities, access characteristics, and multiple within-patient events, were calculated using logistic regression to determine associations between steal intervention status and outcome variables: (a) major adverse events, (b) access preservation, and (c) follow-up surgery. A percutaneously treatable cause of DASS was present in 128 cases (45%). Treatment of DASS lesions was performed in 118 cases. Fifteen embolizations were also performed in patients without DASS lesions. RESULTS: Technical success of DASS interventions, defined by the Society of Interventional Radiology (SIR) reporting standards, was 94%; 54% of interventions resulted in DASS symptom improvement at a median follow-up of 15 days. Patients with steal intervention had 60% lower odds of follow-up surgery (OR, 0.4; P = .007). There was no difference in major adverse events (P = .98) or access preservation (P = .13) between groups. CONCLUSIONS: In this retrospective cohort study, approximately half of DASS fistulograms revealed a percutaneously treatable cause of steal. Over half of DASS interventions resulted in symptomatic relief. Percutaneous intervention was associated with lower odds of follow-up surgery without compromising access preservation.

Association between End-Stage Renal Disease and Major Adverse Limb Events after Peripheral Vascular Intervention.

PURPOSE: To examine the effect of end-stage renal disease (ESRD) on the likelihood of major adverse limb events (MALEs) in patients with Rutherford Category 4-6 critical limb ischemia (CLI) who underwent percutaneous vascular intervention (PVI). MATERIALS AND METHODS: Two contemporaneous cohorts of patients who underwent PVI for symptomatic CLI from 2012 to 2022, differing in ESRD status, were matched using propensity score methods. This database identified 628 patients who underwent 1,297 lower extremity revascularization procedures; propensity score matching yielded 147 patients (180 limbs, 90 limbs in each group). Kaplan-Meier and Cox proportional hazard analyses were used to assess the effect of ESRD status on MALEs, stratified into major amputation (further stratified into above-knee amputation and below-knee amputation [BKA]) and reintervention (PVI or bypass). RESULTS: After PVI, 31.3% of patients in the matched cohorts experienced a MALE (45.7% ESRD vs 18.2% non-ESRD), and 15.6% experienced a major amputation (27.1% ESRD vs 5.2% non-ESRD). Cox proportional hazards analysis revealed that ESRD was an independent predictor of MALE (hazard ratio [HR], 3.15; 95% CI, 1.58-6.29; P = .001), major amputation (HR, 7.00; 95% CI, 2.06-23.79; P = .002), and BKA (HR, 7.56; 95% CI, 1.71-33.50; P = .008). CONCLUSIONS: ESRD is strongly predictive of MALE and major amputation risk, specifically BKA, in patients undergoing PVI for Rutherford Category 4-6 CLI. These patients warrant closer follow-up, and new methods may become necessary to predict and further reduce their amputation risk.

Evaluation of short-term mortality in patients with Medicare undergoing endovascular interventions for chronic limb-threatening ischemia.

INTRODUCTION: Patients with chronic limb-threatening ischemia (CLTI) have high mortality rates after revascularization. Risk stratification for short-term outcomes is challenging. We aimed to develop machine-learning models to rank predictive variables for 30-day and 90-day all-cause mortality after peripheral vascular intervention (PVI). METHODS: Patients undergoing PVI for CLTI in the Medicare-linked Vascular Quality Initiative were included. Sixty-six preprocedural variables were included. Random survival forest (RSF) models were constructed for 30-day and 90-day all-cause mortality in the training sample and evaluated in the testing sample. Predictive variables were ranked based on the frequency that they caused branch splitting nearest the root node by importance-weighted relative importance plots. Model performance was assessed by the Brier score, continuous ranked probability score, out-of-bag error rate, and Harrell's C-index. RESULTS: A total of 10,114 patients were included. The crude mortality rate was 4.4% at 30 days and 10.6% at 90 days. RSF models commonly identified stage 5 chronic kidney disease (CKD), dementia, congestive heart failure (CHF), age, urgent procedures, and need for assisted care as the most predictive variables. For both models, eight of the top 10 variables were either medical comorbidities or functional status variables. Models showed good discrimination (C-statistic 0.72 and 0.73) and calibration (Brier score 0.03 and 0.10). CONCLUSION: RSF models for 30-day and 90-day all-cause mortality commonly identified CKD, dementia, CHF, need for assisted care at home, urgent procedures, and age as the most predictive variables as critical factors in CLTI. Results may help guide individualized risk-benefit treatment conversations regarding PVI.

Imaging of Ischemic Cholangiopathy Following Donation after Circulatory Death Liver Transplant.

Ischemic cholangiopathy (IC) is the leading cause of inferior long-term outcomes following donation after circulatory death (DCD) liver transplant. Biliary strictures related to IC are nonanastomotic strictures (NASs) by definition and involve the donor hepatic ducts proximal to the anastomosis, compared with postsurgical anastomotic strictures that form due to fibrotic healing. IC-related NASs can be microangiopathic with patent hepatic artery or macroangiopathic with occluded or stenotic hepatic artery. Recently, IC with NASs have been described to have four distinct patterns at imaging: diffuse necrosis, multifocal progressive, confluence dominant, and minor form, which correlate clinically with graft prognosis. Severe IC can lead to ductal wall breakdown with subsequent bile leaks that can cause significant patient morbidity, with imaging playing a vital role in diagnosis and guiding intervention. IC also predisposes the transplanted liver to biliary stasis and subsequent formation of stones, casts, and sludge. Some cases of posttransplant biliary stricturing are not IC but are a sequela of reflux cholangitis seen with choledochojejunal anastomosis. Other biliary findings in the posttransplant liver can be explained by sphincter of Oddi dysfunction that results from denervation. The authors describe and comprehensively categorize the various IC types and their imaging patterns at MRI and MR cholangiopancreatography, review the prognostic significance of these imaging patterns, and discuss imaging features of additional biliary complications associated with IC after DCD liver transplant. ©RSNA, 2024 Supplemental material is available for this article.