Gold Nanorod-Loaded Nano-Contrast Agent with Composite Shell-Core Structure for Ultrasonic/Photothermal Imaging-Guided Therapy in Ischemic Muscle Disorders.

Purpose: This study aims to broaden the application of nano-contrast agents (NCAs) within the realm of the musculoskeletal system. It aims to introduce novel methods, strategies, and insights for the clinical management of ischemic muscle disorders, encompassing diagnosis, monitoring, evaluation, and therapeutic intervention. Methods: We developed a composite encapsulation technique employing O-carboxymethyl chitosan (OCMC) and liposome to encapsulate NCA-containing gold nanorods (GNRs) and perfluoropentane (PFP). This nanoscale contrast agent was thoroughly characterized for its basic physicochemical properties and performance. Its capabilities for in vivo and in vitro ultrasound imaging and photothermal imaging were authenticated, alongside a comprehensive biocompatibility assessment to ascertain its effects on microcirculatory perfusion in skeletal muscle using a murine model of hindlimb ischemia, and its potential to augment blood flow and facilitate recovery. Results: The engineered GNR@OCMC-liposome/PFP nanostructure exhibited an average size of 203.18±1.49 nm, characterized by size uniformity, regular morphology, and a good biocompatibility profile. In vitro assessments revealed NCA's potent photothermal response and its transformation into microbubbles (MBs) under near-infrared (NIR) irradiation, thereby enhancing ultrasonographic visibility. Animal studies demonstrated the nanostructure's efficacy in photothermal imaging at ischemic loci in mouse hindlimbs, where NIR irradiation induced rapid temperature increases and significantly increased blood circulation. Conclusion: The dual-modal ultrasound/photothermal NCA, encapsulating GNR and PFP within a composite shell-core architecture, was synthesized successfully. It demonstrated exceptional stability, biocompatibility, and phase transition efficiency. Importantly, it facilitates the encapsulation of PFP, enabling both enhanced ultrasound imaging and photothermal imaging following NIR light exposure. This advancement provides a critical step towards the integrated diagnosis and treatment of ischemic muscle diseases, signifying a pivotal development in nanomedicine for musculoskeletal therapeutics.

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.

Proximal Arterial Inflow Revascularization Improves Pedal Arch Quality and Its Impact on Ischemic Diabetic Foot Ulcer Healing.

BACKGROUND: Arterial perfusion is a key factor in diabetic foot ulcer (DFU) healing. Although it is associated with pedal arch patency, not all patients are amenable to pedal artery angioplasty. This study aims to determine the impact of angiographic improvement of the pedal arch quality after proximal arterial inflow revascularization (PAIR) and its association with wound healing. METHODS: One hundred and fifty diabetic patients with tissue loss in 163 limbs who had digital subtraction angiography were studied. Cox regression analysis was used to determine independent predictors of wound healing. Wound healing rates in association with pedal arch patency were calculated by Kaplan-Meier analysis. RESULTS: End-stage renal disease, minor amputation, and complete pedal arch patency were significant independent predictors of wound healing following PAIR with hazard ratios for failure: 3.02 (P = 0.008), 0.54 (P = 0.023), and 0.40 (P = 0.039), respectively. The prevalence of complete pedal arches increased by 24.1% with successful intervention (P < 0.001). The overall rates of wound healing at 6, 12, and 24 months were 36%, 64%, and 72%, respectively. The wound healing rate at 1 year in patients with a complete pedal arch was 73% compared to 45% in those with an absent pedal arch (P = 0.017). CONCLUSIONS: PAIR increases complete pedal arch patency, a significant predictor of wound healing in DFU.

Poor Limb Prognosis of Patients with Chronic Limb-Threatening Ischemia on Hemodialysis: A Retrospective Observational Study Based on the Global Limb Anatomic Staging System.

BACKGROUND: The Global Limb Anatomic Staging System (GLASS) has been widely used to evaluate patients with chronic limb-threatening ischemia (CLTI). As end-stage kidney disease (ESKD) is a well-known CLTI risk factor, we aimed to determine whether patients on hemodialysis (HD) have a worse limb prognosis than those without ESKD, considering the same GLASS background. METHODS: The data of 445 patients who underwent surgical and/or endovascular revascularization procedures for lower extremity ischemia were retrospectively collected in our division between 2005 and 2018. The major amputation rate and amputation-free survival (AFS) were compared between HD and non-HD patients. RESULTS: Among the 215 (48%) patients receiving HD, 58 limbs required major amputation (27% limb loss rate). Among the non-HD group, the limb loss rate was 13% (P < 0.0001). The overall AFS was significantly worse in patients receiving HD than those not (P < 0.0001). The AFS was significantly worse in HD patients when comparing GLASS-standardized subgroups. CONCLUSIONS: Patients with CLTI who were receiving HD had a worse limb prognosis than those not receiving, even when considering the same GLASS classification. Furthermore, there is a need for an ideal guideline focused on ESKD-directed peripheral artery disease.

Insulin Requirement and Infrainguinal Bypass Outcomes in Patients with Peripheral Arterial Disease.

BACKGROUND: Diabetes mellitus (DM) is a major risk factor for peripheral artery disease. The association of DM with major adverse limb events (MALE) after lower extremity revascularization remains controversial, as patients with diabetes are typically analyzed as a single, homogenous group. Using a large national database, this study examines the impact of insulin use and glycemic control on the outcomes following infrainguinal bypass. The hypothesis is that prevalent insulin therapy and elevated hemoglobin A1c (HbA1c) are associated with an increased risk of MALEs after infrainguinal bypass in patients with DM and could therefore be used for risk stratification. METHODS: The Vascular Quality Initiative database files for infrainguinal bypass (2007-2021) were retrospectively reviewed. Patients with DM undergoing bypass for peripheral artery disease were included. Patients on dialysis or with prior kidney transplantation were excluded. The characteristics and outcomes of patients with insulin-requiring diabetes mellitus (IRDM) were compared to those of patients not requiring insulin (noninsulin-requiring diabetes mellitus [NIRDM]) prior to the bypass procedure. RESULTS: A total of 9,686 patients with DM (56% IRDM) underwent bypass. Patients with IRDM were significantly younger than patients with NIRDM, more likely to be female (P < 0.01), African American (P < 0.01), and Hispanic (P = 0.031), and more likely to have comorbidities and be categorized into American Society of Anesthesiologist classes IV-V. They were more likely to be treated for chronic limb-threatening ischemia (P < 0.001). Patients with IRDM had significantly higher perioperative complications with no difference in perioperative mortality between the 2 groups. Beyond the perioperative period, with a mean follow-up of 427 days, patients with IRDM had significantly lower crude rates of primary patency and higher crude rates of major amputation, MALE, and mortality compared to patients with NIRDM. Regression analyses demonstrated that insulin requirement, but not HbA1c, was independently associated with a higher risk of MALE (hazard ratio = 1.17 [1.06-1.29]) and mortality (hazard ratio = 1.28 [1.16-1.43]). CONCLUSIONS: Insulin requirement, but not HbA1c, is significantly associated with MALEs and survival after infrainguinal bypass in the Vascular Quality Initiative. Stratification of patients with DM based on their prevalent insulin use prior to infrainguinal bypass surgery could improve the prediction of outcomes of peripheral arterial bypass surgery in patients with diabetes.

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.

Evaluation of intestinal necrosis with laser Doppler in experimental mesenteric ischemia model.

BACKGROUND: Acute mesenteric ischemia (AMI) is responsible for one in a thousand emergency hospital admissions in America and Europe and is associated with high morbidity and mortality rates. Current diagnostic and treatment methods fall short of desired outcomes, often resulting in delayed diagnoses and difficulties in detecting ischemic bowel tissue during treatment. This study evaluates the diagnostic value of commonly used biochemical markers in clinical practice-creatine kinase, C-reactive protein (CRP), and lactate dehydrogenase (LDH)-alongside blood flow measurements using laser Doppler in a rat model of experimental mesenteric ischemia. We also compare these markers with pathological ischemia scoring. METHODS: Rats were divided into five groups: control, 1 hour, 2 hours, 3 hours, and 4 hours. Mesenteric ischemia was induced for the respective durations in each group. After these periods, we measured blood flow using laser Doppler. We also collected blood samples and intestinal biopsies for biochemical parameter analysis. These values were assessed in relation to intestinal viability using the Chiu ischemia scoring system. RESULTS: Blood flow measurement with laser Doppler correlated with both the duration and severity of bowel ischemia. No significant relationship was found between CRP levels and the duration of ischemia. However, creatine kinase and lactate dehydrogenase (LDH) levels were significantly higher in ischemia lasting into the third and fourth hours. CONCLUSION: Creatine kinase and lactate dehydrogenase (LDH) levels may be useful biomarkers in patients with suspected acute mesenteric ischemia (AMI). Blood flow measurements using laser Doppler can accurately identify intestinal loops for resection during surgery.

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.

Below-the-Knee Endovascular Revascularization: A Position Statement.

Patients with chronic limb-threatening ischemia, the terminal stage of peripheral artery disease, are frequently afflicted by below-the-knee disease. Although all patients should receive guideline-directed medical therapy, restoration of inline flow is oftentimes necessary to avoid limb loss. Proper patient selection and proficiency in endovascular techniques for below-the-knee revascularization are intended to prevent major amputation and promote wound healing. This review, a consensus among an international panel of experienced operators, provides guidance on these challenges from an endovascular perspective and offers techniques to navigate this complex disease process.

Study of ischemic progression in different intestinal tissue layers during acute intestinal ischemia using swept-source optical coherence tomography angiography.

In acute intestinal ischemia, the progression of ischemia varies across different layers of intestinal tissue. We established a mouse model and used swept-source optical coherence tomography (OCT) to observe the intestinal ischemic process longitudinally in different tissue layers. Employing a method that combines asymmetric gradient filtering with adaptive weighting, we eliminated the vessel trailing phenomenon in OCT angiograms, reducing the confounding effects of superficial vessels on the imaging of deeper vasculature. We quantitatively assessed changes in vascular perfusion density (VPD), vessel length, and vessel average diameter across various intestinal layers. Our results showed a significant reduction in VPD in all layers during ischemia. The mucosa layer experienced the most significant impact, primarily due to disrupted capillary blood flow, followed by the submucosa layer, where vascular constriction or decreased velocity was the primary factor.

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.

Microvascular permeability and texture analysis of bone marrow in diabetic rabbits with critical limb ischemia based on dynamic contrast-enhanced magnetic resonance imaging.

BACKGROUND: Early on in the development of diabetes, skeletal muscles can exhibit microarchitectural changes that can be detected using texture analysis (TA) based on volume transfer constant (Ktrans) maps. Nevertheless, there have been few studies and thus we evaluated microvascular permeability and the TA of the bone marrow in diabetics with critical limb ischemia (CLI). METHODS: Eighteen male rabbits were randomly assigned equally into an operation group with hindlimb ischemia and diabetes, a sham-operated group with diabetes only, and a control group. Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) was performed on all rabbits at predetermined intervals (1, 5, 10, 15, 20, and 25 days post-surgery). The pharmacokinetic model was used to generate the permeability parameters, while the textural parameters were derived from the Ktrans map. Data analysis methods included the independent sample t-test, Mann-Whitney U test, repeated-measures analysis of variance, and Pearson correlation tests. RESULTS: The Ktrans values reached a minimum on day 1 after ischemia induction, then gradually recovered, but remained lower than those of the sham-operated group. The volume fraction only showed a significant difference between the operation group and the sham-operated group on day 5 post-surgery, but not in the extravascular extracellular space volume fraction at all time points. A significantly reduced Ktrans on day 1, a decreased number of bone trabeculae (Tb.N), and the area of bone trabeculae (Tb.Ar), and an increased microvessel density on day 25 in the operation group compared with the sham-operated group were observed. At each time point, there was a discernible difference between the two groups in the mean value, mean of positive pixels, and sumAverage. CONCLUSIONS: The early stages of diabetic bone marrow with CLI can be evaluated by DCE-MRI for microvascular permeability. Texture analysis based on DCE-MRI could act as an imaging discriminator and new radiological analysis tool for critical limb ischemia in diabetes mellitus.

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.

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.

Management of Acute Lower Limb Ischemia Without Surgical Revascularization - A Population-Based Study.

OBJECTIVES: To evaluate outcomes of management without surgical revascularization in patients with acute lower limb ischemia (ALI) in a population-based setting. DESIGN: Retrospective observational population-based study. MATERIALS: Patients from Malmö, Sweden, hospitalized for ALI between 2015 and 2018. METHODS: In-hospital, surgical, radiological, and autopsy registries were scrutinized for descriptive data on ALI patients managed by endovascular and open vascular surgery, conservative vascular therapy, primary major amputation, and palliative care. RESULTS: Among 161 patients, 73 (45.3%) did not undergo any operative revascularization. Conservative vascular therapy, primary amputation, and palliative care were conducted in 25 (15.5%), 26 (16.1%), and 22 (13.7%) patients, respectively. Conservatively treated patients had Rutherford class ≥ IIb ischemia and embolic occlusion in 33% and 68% of cases, respectively. Their median C-reactive protein level at admission was 7 mg/L (interquartile range 2 - 31 mg/L). Among conservatively treated patients, anticoagulation therapy in half to full dose was given to 22 (88%) patients for six weeks or longer, and analgesics in low or moderate doses were given to twelve (48%) patients at discharge. The major amputation rate at 1 year was 8% among conservatively treated patients, and four patients with foot embolization had not undergone amputation at 1 year. CONCLUSION: Patients selected for initial conservative therapy of ALI with anticoagulation alone may have a good outcome, even when admitted with Rutherford class IIb ischemia. A low C-reactive protein level at admission seems to be a favorable marker when choosing conservative therapy. A prospective, preferably multicenter, study with a predefined protocol in these conservatively treated patients is warranted to better define the dose and length of anticoagulation therapy.

Peak Aortic Valve Jet Velocity is an Independent Predictor of Mortality of Dialysis Patients Undergoing Open Surgery for Chronic Limb Threatening Ischemia.

BACKGROUND: To investigate the impact of peak aortic jet velocity (Vmax) on the prognosis of patients undergoing open surgery for chronic limb threatening ischemia (CLTI). METHODS: Between April 2015 and March 2022, 352 patients underwent infrainguinal open surgery for CLTI. Patients who met the following exclusion criteria were excluded: subsequent infrainguinal surgeries in the registered period, no record of Vmax, history of aortic valve intervention, and Vmax ≥3.0 m/s (moderate or severe aortic valve stenosis). The remaining patients were dichotomized into 2 groups based on their Vmax values. The Youden index calculated from the receiver operating characteristic curve (ROC) was set as the cutoff value. The 2-year overall survival (OS), calculated using the Kaplan-Meier's method, was compared between the 2 groups. A Cox proportional hazards regression analysis was performed using perioperative factors including Vmax to identify independent predictors separately for dialysis and nondialysis patients and the quantitative relationship between Vmax and OS. RESULTS: One hundred and ninety-one patients, including 100 dialysis and 91 nondialysis patients, were included in the analysis. The Youden index was 1.7 m/s. The 2-year OS rates of the group with Vmax >1.7 m/s and with Vmax ≤1.7 m/s were 49% and 76% (P = 0.007), respectively, in the dialysis cohort, while they were 71% and 78% (P = 0.680) in the nondialysis cohort, respectively. Multivariate analysis identified Vmax and ejection fraction as independent predictors in the dialysis cohort and the Barthel Index at admission in the nondialysis cohort. There was a stepwise increase in the risk of death in patients with Vmax of ≥1.5 m/s and a significantly higher risk of death in dialysis patients with Vmax >2.5 m/s. CONCLUSIONS: Vmax was a significant independent predictor of all-cause death within 2 years after open surgery for CLTI in dialysis patients but not in patients managed without dialysis.