Global Limb Anatomic Staging System Research Articles

Anatomical and clinical factors associated with infrapopliteal arterial bypass outcomes in patients with chronic limb-threatening ischemia.

The aim of this study was to identify anatomical and clinical factors associated with limb-based patency (LBP) loss, major adverse limb events (MALEs), and poor amputation-free survival (AFS) after an infrapopliteal arterial bypass (IAB) surgery according to the Global Limb Anatomic Staging System. A retrospective analysis of patients undergoing IAB surgery between January 2010 and December 2021 at a single institution was performed. Two-year AFS, freedom from LBP loss, and freedom from MALEs were assessed using the Kaplan-Meier method. Anatomical and clinical predictors were assessed using multivariate analysis. The total number of risk factors was used to calculate risk scores for subsequent categorization into low-, moderate-, and high-risk groups. IABs were performed on 103 patients. The rates of two-year freedom from LBP loss, freedom from MALEs, and AFS were 71.3%, 76.1%, and 77.0%, respectively. The multivariate analysis showed that poor run-off beyond the ankle and a bypass vein caliber of < 3mm were significantly associated with LBP loss and MALEs. Moreover, end-stage renal disease, non-ambulatory status, and a body mass index of < 18.5 were significantly associated with poor AFS. The rates of freedom from LBP loss and MALEs and the AFS rate were significantly lower in the high-risk group than in the other two groups (12-month low-risk rates: 92.2%, 94.8%, and 94.4%, respectively; 12-month moderate-risk rates: 58.6%, 84.6%, and 78.3%, respectively; 12-month high-risk rates: 11.1%, 17.6%, and 56.2%, respectively; p < 0.001, p < 0.001, and p < 0.001, respectively). IAB is associated with poor clinical outcomes in terms of LBP, MALEs, and AFS in high-risk patients. Risk stratification based on these predictors is useful for long-term prognosis.

Stratification of Endovascular Revascularization Technical Outcomes Using the Global Limb Anatomic Staging System

Stratification of Endovascular Revascularization Technical Outcomes Using the Global Limb Anatomic Staging System

Smartphone Camera for Angiographic Computer Vision in Vascular Medicine

Aim: This study aimed to develop a TensorFlow Lite algorithm for angiography classification and to deploy it on a basic mobile smartphone device, thereby verifying the proof of concept for creating a comprehensive end-to-end mobile computer vision application for vascular medicine. Materials and Methods: After ethical approval by the local ethics committee, we collected institutional and open source peripheral angiograms of lower limbs. The angiograms were labeled by a researcher with more than 10 years of experience in vascular surgery. The labeling included dividing the angiograms according to their anatomical pattern into the Global Limb Anatomic Staging System (GLASS). The model was developed using the open-source TensorFlow framework for general image classification and deployed as an Android application. Results: The model utilized 700 angiograms, distributed as follows within the femoropoliteal GLASS disease (fp) categories: fp0 – 187 images, fp1 – 136 images, fp2 – 128 images, fp3 – 97 images, fp4 – 152 images. The reference dataset included 372 non-angiographic images (not_angio). Consequently, the entire model included 1,072 images. After training and deployment, the model demonstrated the following performance: a mean accuracy of 0.72. The best self-reported accuracy per class was for fp0 0.72, fp4 0.83 and not_angio 1.0 classes. Conclusion: We discovered that a smartphone camera could be utilized for angiographic computer vision through end-to-end applications accessible to every healthcare professional. However, the predictive abilities of the model are limited and require improvement. The development of a robust angiographic computer vision smartphone application should incorporate an upload function, undergo validation through head-to-head human-machine comparisons, potentially include segmentation, and feature a prospective design with explicit consent for using collected data in the development of AI models.

Navigating complexity: The Supera's triumph in femoropopliteal lesions.

The femoropopliteal sector endovascular treatment is particularly challenging due to its high tortuosity and torsional forces. Better results are still needed to ensure the long-term patency of stenting in this area. The Supera stent appears to change this paradigm. This single-center retrospective cohort study aims to evaluate the efficacy and safety of femoropopliteal stenting with Supera in a real-world population. Seventy-nine patients were treated between January 2015 and December 2020, and the results are reported with a median follow-up of 28 months. Indications for revascularization were chronic limb-threatening ischemia with tissue loss (73.6%) or ischemic rest pain (17.7%) and claudication (7.6%). Thirty-six patients (45.6%) were classified as GLASS stage III according to the Global Limb Anatomic Staging System, with 65.8% and 30.4% in grades 3 and 4 of femoropopliteal and infrapopliteal sectors, respectively. The 36-month primary, primary-assisted, and secondary patency rates were 68.6%, 72.0%, and 79.0%, respectively, with an amputation-free survival rate of 86.6%. There was no significant difference between primary patency rates in GLASS stages I-II compared with GLASS stage III (36-month primary patency rates of 72% vs 63% respectively, p = 0.342) nor in amputation-free survival (88% vs 84%, p = 0.877). After adjusting for potential confounders, only the stent conformation significantly affected the primary patency rates, with a higher hazard of reintervention for the elongated (HR = 3.179; p = 0.36; CI 1.081-9.347) and the compressed (HR = 3.014; p = 0.42; CI 1.039-8.746) forms. The 36-month patency of the Supera stents in our real-world cohort was similar to other reported series. The GLASS stage did not interfere with the stent patency, proving it is a good choice even in the most adverse anatomy patients. Only the non-nominal stent conformation affected the primary patency rates in our patients.

Validation of the global limb anatomical staging system in Vietnamese patients treated for chronic limb-threatening ischemia

BackgroundChronic limb-threatening ischemia (CLTI) is the most severe clinical form of peripheral artery disease (PAD), accounting for approximately 11%, and is strongly associated with the incidence of amputation, cardiovascular events, and mortality. The Global Vascular Guideline (GVG) proposed a new Global Anatomic Staging System (GLASS) for evaluating the anatomic complexity of arterial lesions. However, more research is required to evaluate outcomes after endovascular intervention in CLTI patients using the GLASS.ObjectiveOur study aimed to describe clinical characteristics, arterial lesions, and endovascular interventions according to three grades of GLASS in the Vietnamese population. We evaluated the technical success, mortality rate, and probability to preserve the limb according to the GLASS.MethodsAll patients were diagnosed with CLTI and underwent infrainguinal endovascular intervention at the Department of Thoracic and Vascular Surgery, University Medical Center, Ho Chi Minh City from June 2020 to June 2022. All patients were evaluated before intervention and follow-up at 6 and 12 months after intervention. Patients were divided into three groups according to the GLASS, thereby comparing the technical success, mortality, and amputation rates. This retrospective study describes a series of cases.ResultsThe study sample evaluated 82 lower limbs of 82 patients, in which GLASS class I, II, and III lesions accounted for 36.6%, 43.9%, and 19.5% of the patients, respectively. The rates of technical success in the groups gradually decreased according to the complexity of the lesions (90%, 86.11%, and 56.25% for GLASS I, II, and III, respectively; p = 0.012). Notably, limb-based patency (LBP) at 12 months was significantly lower in the GLASS III group than in the GLASS I and II groups (22.22% vs 88.89% and 67.74%, respectively; p = 0.001). The amputation rates at 12 months in GLASS groups I, II, and III were 13.3%, 22.2%, and 50%, respectively (p = 0.021), while the mortality rates at 12 months were 0%, 8.33%, and 25%, respectively (p = 0.015).ConclusionIn patients with CLTI of higher GLASS stages, the rates of technical success were lower and the amputation and mortality rates were higher.

Classification of anatomic patterns of peripheral artery disease with automated machine learning (AutoML).

The aim of this study was to investigate the potential of novel automated machine learning (AutoML) in vascular medicine by developing a discriminative artificial intelligence (AI) model for the classification of anatomical patterns of peripheral artery disease (PAD). Random open-source angiograms of lower limbs were collected using a web-indexed search. An experienced researcher in vascular medicine labelled the angiograms according to the most applicable grade of femoropopliteal disease in the Global Limb Anatomic Staging System (GLASS). An AutoML model was trained using the Vertex AI (Google Cloud) platform to classify the angiograms according to the GLASS grade with a multi-label algorithm. Following deployment, we conducted a test using 25 random angiograms (five from each GLASS grade). Model tuning through incremental training by introducing new angiograms was executed to the limit of the allocated quota following the initial evaluation to determine its effect on the software's performance. We collected 323 angiograms to create the AutoML model. Among these, 80 angiograms were labelled as grade 0 of femoropopliteal disease in GLASS, 114 as grade 1, 34 as grade 2, 25 as grade 3 and 70 as grade 4. After 4.5h of training, the AI model was deployed. The AI self-assessed average precision was 0.77 (0 is minimal and 1 is maximal). During the testing phase, the AI model successfully determined the GLASS grade in 100% of the cases. The agreement with the researcher was almost perfect with the number of observed agreements being 22 (88%), Kappa = 0.85 (95% CI 0.69-1.0). The best results were achieved in predicting GLASS grade 0 and grade 4 (initial precision: 0.76 and 0.84). However, the AI model exhibited poorer results in classifying GLASS grade 3 (initial precision: 0.2) compared to other grades. Disagreements between the AI and the researcher were associated with the low resolution of the test images. Incremental training expanded the initial dataset by 23% to a total of 417 images, which improved the model's average precision by 11% to 0.86. After a brief training period with a limited dataset, AutoML has demonstrated its potential in identifying and classifying the anatomical patterns of PAD, operating unhindered by the factors that can affect human analysts, such as fatigue or lack of experience. This technology bears the potential to revolutionize outcome prediction and standardize evidence-based revascularization strategies for patients with PAD, leveraging its adaptability and ability to continuously improve with additional data. The pursuit of further research in AutoML within the field of vascular medicine is both promising and warranted. However, it necessitates additional financial support to realize its full potential.

Relevance of BEST-CLI trial endpoints in a tertiary care limb preservation program

ObjectiveMajor adverse limb event-free survival (MALE-FS) differed significantly by initial revascularization approach in the BEST-CLI randomized trial. The BEST-CLI trial represented a highly selected subgroup of patients seen in clinical practice; thus, we examined the endpoint of MALE-FS in an all-comers tertiary care practice setting. MethodsThis is a single-center retrospective study of consecutive, unique patients who underwent technically successful infrainguinal revascularization for chronic limb-threatening ischemia (2011-2021). MALE was major amputation (transtibial or above) or major reintervention (new bypass, open bypass revision, thrombectomy, or thrombolysis). ResultsAmong 469 subjects, the mean age was 70 years, and 34% were female. Characteristics included diabetes (68%), end-stage renal disease (ESRD) (16%), Wound, Ischemia, and foot Infection (WIfI) stage 4 (44%), Global Limb Anatomic Staging System (GLASS) stage 3 (62%), and high pedal artery calcium score (pMAC) (22%). Index revascularization was autogenous vein bypass (AVB) (30%), non-autogenous bypass (NAB) (13%), or endovascular (ENDO) (57%). The composite endpoint of MALE or death occurred in 237 patients (51%) at a median time of 189 days from index revascularization. In an adjusted Cox model, factors independently associated with MALE or death included younger age, ESRD, WIfI stage 4, higher GLASS stage, and moderate-severe pMAC, whereas AVB was associated with improved MALE-FS. Freedom from MALE-FS, MALE, and major amputation at 30 days were 90%, 92%, and 95%; and at 1 year were 63%, 70%, and 83%, respectively. MALE occurred in 144 patients (31%) and was associated with ESRD, WIfI stage, GLASS stage, pMAC score, and index revascularization approach. AVB had superior durability, with adjusted 2-year freedom from MALE of 72%, compared with 66% for ENDO and 51% for NAB. Within the AVB group, spliced vein conduit had higher MALE compared with single-segment vein (hazard ratio, 1.8; 95% confidence interval, 0.9-3.7; P = .008 after inverse propensity weighting), but there was no statistically significant difference in major amputation. Of the 144 patients with any MALE, the first MALE was major reintervention in 47% and major amputation in 53%. Major amputation as first MALE was associated with non-AVB index approach. Indications for major reintervention were symptomatic stenosis/occlusion (54%), lack of clinical improvement (28%), asymptomatic graft stenosis (16%), and iatrogenic events (3%). Conversion to bypass occurred after 6% of ENDO cases, two-thirds of which involved distal bypass targets at the ankle or foot. ConclusionsIn this consecutive, all-comers cohort, disease complexity was associated with procedural selection and MALE-FS. AVB independently provided the greatest MALE-FS and freedom from MALE and major amputation. Compared with the BEST-CLI randomized trial, MALE after ENDO in this series was more frequently major amputation, with relatively few conversions to open bypass.

Using Isolated Femoral Bifurcation Endarterectomy or Combined with Bypass Surgery for Patients with Chronic Limb-Threatening Ischemia.

Background and Objectives: The aim of this study was to evaluate the clinical outcomes of patients suffering from chronic limb-threatening ischemia (CLTI) and tissue loss treated with primary isolated femoral bifurcation endarterectomy (FBE) or with FBE combined with bypass surgery. Materials and Methods: This retrospective study was performed in a tertiary university-based care centre. Between January 2008 and December 2019, a prospectively collected database of patients suffering from CLTI and tissue loss and undergoing either primary FBE (group A) or FBE in combination with bypass surgery (group B) was analysed. Study endpoints were ulcer healing, primary and secondary patency rate, limb salvage, and survival. Results: In total, FBE was performed in 73 patients and FBE with bypass in 60 patients. Between both groups, there were no significant differences regarding demographic data or the Global Limb Anatomic Staging System (GLASS) grade III and IV of femoropopliteal lesions. After 3 years, ulcer healing could be achieved in 72% of FBE and in 75% of FBE with bypass patients. The primary patency rate was 95% and 91% for FBE and 83% and 80% for FBE with bypass after one and three years, respectively. The 3-year limb-salvage rate was 78% for FBE and 84% for FBE with bypass. The secondary patency rate after one and three years was 99% and 97% for FBE and 93% and 88% for FBE with bypass. Conclusions: FBE and FBE with bypass are equally effective for ulcer healing in cases of combined CFA and superficial femoral artery lesions. There was no significant difference between both groups regarding primary and secondary patency rates, limb salvage rates and ulcer healing. Isolated FBE could be an alternative strategy in patients with higher operative risk.

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

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. 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. 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. 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.

Dichotomous grouping of peripheral arterial calcification grades: A practical predictor of outcome after endovascular therapy in peripheral arterial disease.

There is a general agreement that arterial calcification affects the results of endovascular therapy for peripheral arterial disease (PAD). In addition to lacking evidence for their impact, existing calcification scores are complex, and not practical in everyday decision making. The global limb anatomic staging system (GLASS) adopted dichotomous grouping of calcification grades. In this study we aim to investigate the impact of peripheral arterial calcification scoring after dichotomous grouping on midterm outcomes following endovascular therapy for PAD. This prospective study included all consecutive patients with PAD indicated for endovascular therapy procedure who presented to our tertiary referral center in the period between October 2020 and October 2021. Patients were grouped into Group A (n = 40): with no-to mild calcification (PACSS grade 0,1 and 2), and Group B (n = 53): with severe calcification (PACSS grades 3 and 4). Primary endpoints included technical success rate, primary patency rates, and major adverse limb events rate (MALE) during 2years of follow-up. The mean age of the studied cases (n = 93) was 59.31 ± 6.46years (range 50-75). 70 patients (75.3%) were males, and 23 (24.7%) were females. There was no statistically significant difference between the two groups regarding technical success rate (97.5% in group A versus 94.33% in Group B, p = .457). The Primary patency rate after 1year was lower in group B (74%) compared to group A (89.7%), but this difference was not statistically significant (p = .059). However, the 2-year primary patency rate was significantly lower in group B compared to group A (64% versus 84.6% respectively, p = .034). MALE rate after 2years was significantly higher in group B (28%) as compared to group A (10.4%), P = .048. Studying suspected risk factors revealed that severe calcification was more common in patients with ischemic heart disease (34%) and chronic kidney disease (11%), P= .003 and .002 respectively. Logistic regression analysis showed that patients suffered from IHD and those with length of lesion ≥ 5cm are about five times more likely to have severe calcification compared to their counterparts (OR = 4.875, 95%CI = 1.293-18.383, p = .019, and OR = 4.513, 95% CI = 11.138-17.893, p = .032), respectively. The presence of severe calcification is associated with significantly lower midterm primary patency rates and higher rate of major adverse limb events after endovascular intervention for lower limb denovo arterial lesions.

Infrapopliteal 3-Vessel Occlusive Disease Is the Only Predictor of Wound Recurrence After Complete Wound Healing via Endovascular Therapy in Patients With Chronic Limb-threatening Ischemia.

To determine the predictors of wound recurrence after complete wound healing in patients with chronic limb-threatening ischemia (CLTI) who underwent endovascular therapy (EVT) for infrapopliteal (IP) lesions with consideration of IP arterial anatomic severity, including classification by the Global Limb Anatomic Staging System (GLASS). This retrospective single-center study assessed patients with de novo CLTI limbs with tissue loss treated via EVT for IP lesions from September 2016 to May 2021. Among these patients, 149 consecutive limbs from 133 patients who achieved complete wound healing were enrolled. The Kaplan-Meier method was used to estimate the wound recurrence rate after complete wound healing. The Cox proportional hazard model was used to assess the association between baseline characteristics and wound recurrence. The cumulative wound recurrence rate 1 year after complete wound healing was 30%. The mean time for wound recurrence was 7±5 months. Only IP arterial anatomic characteristics remained as a predictor of wound recurrence, whereas wound status and management, including the Wound, Ischemia, and foot Infection (WIfI) clinical stage and minor amputation, were not associated with wound recurrence. Multivariate analysis revealed independent associations between wound recurrence and IP 3-vessel occlusive disease (hazard ratio, 2.97; 95% confidence interval, 1.39-6.35), but not poor below-the-ankle runoff, IP Peripheral Arterial Calcium Scoring System (PACSS) grade, and the GLASS IP grade. The only independent predictor of wound recurrence after complete wound healing via EVT in patients with CLTI was IP 3-vessel occlusive disease. In patients with chronic limb-threatening ischemia (CLTI), wound recurrence after complete wound healing remains a challenge, and studies focused exclusively on wound recurrence are still limited. The present study aimed to determine the risk factors for wound recurrence after complete wound healing in patients with CLTI who underwent endovascular therapy (EVT) for infrapopliteal (IP) lesions, with consideration of IP arterial anatomic severity for the first time. The results showed that IP 3-vessel occlusive disease was the only predictor of wound recurrence, whereas wound status/management and other arterial anatomic characteristics including WIfI clinical stages and GLASS grades were not predictors.

Topicality of the fundamental and determining importance of chronic critical ischemia of the extremities and its restorative treatment using crural/pedal bypasses in Germany and in Saxony-Anhalt

Currently, there is an increase in severe stages of peripheral arterial occlusive disease (PAOD) with critical ischemia. This seems to correspond to the general demographic change as well as aconsequence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic of the last 3years. The now established and accepted interventional/endovascular approach for severe lower leg PAOD in experienced hands is still considered the first-line treatment but from the authors' perspective crural/pedal venous bypass is experiencing arenaissance. Compact narrative review of the current state of crural/pedal bypass surgery in Germany and Saxony-Anhalt (SA) combined with selective references from the current scientific medical literature and own clinical experiences. The current statistics of case-related diagnosis-related groups (DRG) data show that, especially with the occurrence of the corona pandemic, adecrease in inpatient case numbers of patients with PAOD stage IIB can be observed nationwide and also in SA. The severe PAOD stages have remained approximately the same in case numbers but increased in SA. The risk stratification based on the wound, ischemia and foot infection (WIFI) classification offers the possibility to be able to make statements about the risk of amputation, benefits and type of revascularization measures. The length of the occlusion, occlusion site of the affected vessels and degree of calcification are taken into account in the global limb anatomic staging system (GLASS) to assess the prognosis. The evaluation of the case-based hospital statistics from 2015 to 2020 showed aconstant use of femorocrural/femoropedal bypass surgery in Germany as well as aslight increase in reconstruction using femorocrural bypasses in SA, which seems to correlate with the tendency for an increase in the number of cases of severe PAOD. Parameter-based objectification of the severity of critical limb ischemia should be included in the indications for placement of a crural/pedal bypass. The WIFI classification and GLASS are suitable for this purpose as arelative prognosis of success is also possible. The treatment of critical limb ischemia by crural/pedal bypass surgery continues to find aconstant application in Germany and SA.

Bypass Surgery Provides Better Outcomes Compared with Endovascular Therapy in Patients with Chronic Limb-Threatening Ischemia Classified as Indeterminate Category According to the Global Vascular Guidelines

The present study aimed to determine the preferred initial revascularization procedure between bypass surgery and endovascular therapy (EVT) in patients with chronic limb-threatening ischemia (CLTI) categorized as indeterminate according to the Global Vascular Guidelines (GVG). We retrospectively analyzed the multicenter data of patients who underwent infrainguinal revascularization for CLTI categorized as indeterminate according to the GVG between 2015 and 2020. The end point was the composite of relief from rest pain, wound healing, major amputation, reintervention, or death. A total of 255 patients with CLTI and 289 limbs were analyzed. Of the 289 limbs, 110 (38.1%) and 179 (61.9%) underwent bypass surgery and EVT, respectively. The 2-year event-free survival rates with respect to the composite end point were 63.4% and 28.7% in the bypass and EVT groups, respectively (P<0.01). Multivariate analysis revealed that increased age (P=0.03); decreased serum albumin level (P=0.02); decreased body mass index (P=0.02); dialysis-dependent end-stage renal disease (P<0.01); increased Wound, Ischemia, and foot Infection (WIfI) stage (P<0.01); Global Limb Anatomic Staging System (GLASS) III (P=0.04); increased inframalleolar grade (P<0.01); and EVT (P<0.01) were independent risk factors for the composite end point. In the WIfI-GLASS 2-III and 4-II subgroups, bypass surgery was superior to EVT with regard to 2-year event-free survival (P<0.01). Bypass surgery is superior to EVT in terms of the composite end point in patients classified as indeterminate according to the GVG. Bypass surgery should be considered an initial revascularization procedure, especially in the WIfI-GLASS 2-III and 4-II subgroups.

Young Patients with Claudication and Chronic Limb-threatening Ischemia Have Worse Limb-specific Outcomes After Infrainguinal Bypasses

Although the prevalence of claudication and chronic limb-threating ischemia (CLTI) has increased in younger patients, less is known about the age-based differences in treatment and outcomes. This study compares the differences in limb-specific outcomes and predictors of complications in younger patients who undergo open operative intervention. The American College of Surgeons National Surgical Quality Improvement Project targeted lower extremity bypass database was used from 2012 to 2021. Bypasses for claudication and CLTI were analyzed separately. A histogram of limb-specific outcomes vs age showed adverse events markedly dropped around 65 years old. Thus, we stratified cases into younger patients (≤65 years old) and older patients (>65 years old). Primary outcomes included 30-day mortality, major organ dysfunction, and major amputations. To supplement the lack of long-term data and angiographic details in the National Surgical Quality Improvement Project, institutional data from 2017 to 2022 with 6-month follow-up was also analyzed. There were 5789 patients with claudication (2526 younger vs 3263 older) and 16,675 patients with CLTI (5948 younger vs 10,205 older). In both cohorts, younger patients were more likely to be obese and smokers but have independent function. Younger patients were less likely to have significant comorbidities including hypertension, chronic obstructive pulmonary disorders, and high-risk physiologic factors. Although younger age was independently associated with lower mortality in both claudication and CLTI (aOR, 0.32; P = .013; aOR, 0.40; P ≤ .001, respectively), patients had significantly worse limb-specific outcomes. Younger age was associated with increased untreated loss of patency (aOR, 2.68; P ≤ .001) and reoperation (aOR, 1.35; P = .045) in the claudication cohort and increased wound complications (aOR, 1.11; P = .038) and major amputation (aOR, 1.47; P ≤ .001) in the CLTI cohort (Table). A total of 96 institutional patients with CLTI were reviewed, of which 58 (60.4%) were younger than 65. There was no difference in graft material, orientation, or preoperative wounds, ischemia, and foot Infection score among age groups. Young patients, however, had significantly worse Global Limb Anatomic Staging System pedal scores. Although young patients have lower 30-day mortality after infrainguinal bypass, they have higher risk of limb-specific complications. Worse pedal Global Limb Anatomic Staging System scores may suggest the presence of more aggressive disease. Bypass for young patients with claudication should be done with extreme caution whereas bypass for CLTI may require more diligent postoperative follow-up.TableYounger patients are more likely to have limb-specific complications after infrainguinal open bypass than older patientsClaudicationCLTIYounger (n = 2526) vs older (n = 3263) patientsYounger (n = 5948) vs older (n = 10205) patientsAdjusted odds ratio95% Confidence intervalP valueAdjusted odds ratio95% Confidence intervalP valueMortality0.320.130.78.0120.500.310.54<.001MACE0.911.350.61.6130.800.670.79.009Pulmonary complications0.981.682.69.9420.860.951.05.130Wound complications1.040.871.23.6811.111.001.23.038Untreated loss of patency2.681.594.55<.0011.050.831.32.686Major amputation1.580.773.27.2161.481.231.76<.001Reoperation1.361.011.83.0461.150.991.32.052MACE, Major adverse cardiac events, including myocardial infarction, stroke, and cardiac arrest.Boldface entries indicate statistical significance. Open table in a new tab

A Novel Score Predicts Need of Open Revascularization Following Endovascular Revascularization in Patients with Infrainguinal Chronic Limb-threatening Ischemia

This study aims to assess the ability of a novel score, the infrainguinal successful endovascular treatment (iSET) score in predicting risk of open revascularization in patients undergoing endovascular revascularization (ER) for infrainguinal chronic limb-threatening ischemia (CLTI). A retrospective analysis of consecutive patients undergoing ER for CLTI between January 2015 and December 2018. The iSET is a score between 1 and 63. It combines components of the Global Vascular Guidelines evidence-based revascularization as follows: iSET = Wound, Ischemia, foot Infection (WIfI) × WIFI + inflow disease + 4 × Global limb anatomic staging system (GLASS) FP + 6 × GLASS IP + 3 × IM pedal modifier. It stratifies patients into low (0-21), moderate (22-42), and high (43-63). The primary outcome was freedom from open revascularization at 2 years. Secondary outcomes were 30-day and 1-year endovascular reintervention, major amputations (above the ankle joint), minor amputations (below the ankle joint) and mortality. Kaplan-Meier estimates and Cox proportional hazard model assessed ability of iSET to predict open revascularization risk. A P value < .05 was significant. The study included 159 limbs in 150 patients with 12% (n = 19), 53% (n = 84), and 35% (n = 56) having a low, moderate, and high iSET scores, respectively. Most patients presented with tissue loss (86%), WIfI stage 4 (64%), and GLASS III (47%). Patients with a high iSET were more likely to have received antibiotics prior to ER (odds ratio, 1.35; 95% confidence interval [CI], 1.08-1.70; P = .013) and less likely to have elective ER (odds ratio, 0.36; 95% CI, 0.18-0.72; P = .003). Most ER involved the femoropopliteal segment (84%), with 55% of these including concomitant infrapopliteal revascularization. Kaplan-Meier survival curves showed that 2-year freedom from open revascularization was 100%, 93%, and 79% with low, moderate, and high iSET, respectively (Fig). Mortality, reinterventions, and major amputations were similar at 30 days and 1 year (Table). There was an increase in minor amputations at 1 year with high iSET patients (38%; n = 20) compared with low (6%; n = 1) and moderate (21%; n = 15) iSET (P = .016). High iSET score predicted increased risk of open revascularization (hazard ratio, 4.75; 95% CI, 1.67-13.48; P = .003). The iSET is a novel comprehensive score incorporating guideline-driven parameters. The score correlated significantly with ER failure at 2 years with progressively lower freedom from open revascularization between low, moderate, and high iSET scores. Additionally, a high iSET score independently predicted subsequent open revascularization after ER. Further studies are needed to validate it as an adjunctive decision-making tool in patients with CLTI.TableThirty-day and 1-year outcomes in patients stratified by groupsOverallLowModerateHighP-value30-day Death2 (3)03 (2)2 (1).775 Endovascular reintervention8 (11)08 (6)10 (5).447 Major amputation2 (2)02 (1)3 (1).848 Minor amputation13 (18)6 (1)8 (6)21 (11).0861-year Death11 (15)013 (9)11 (6).334 Endovascular reintervention34 (48)31 (5)33 (24)37 (19).885 Major amputation13 (18)014 (10)15 (8).262 Minor amputation25 (36)6 (1)21 (15)38 (20).016Data is presented as percentage (number). Open table in a new tab

Treatment outcomes between bypass surgery and endovascular therapy in patients with chronic limb-threatening ischemia classified as bypass-preferred category based on Global Vascular Guidelines

ObjectiveThe aim of this study was to examine outcomes between bypass surgery and endovascular therapy (EVT) in patients with chronic limb-threatening ischemia (CLTI), classified as bypass-preferred according to the Global Vascular Guidelines (GVG). MethodsWe retrospectively analyzed the multi-center data of patients who underwent infrainguinal revascularization for CLTI with Wound, Ischemia, and foot Infection (WIfI) Stage 3 to 4 and Global Limb Anatomical Staging System (GLASS) Stage III, which is classified as bypass-preferred category by the GVG between 2015 and 2020. The endpoints were limb salvage and wound healing. ResultsWe analyzed 301 patients and 339 limbs following 156 bypass surgeries and 183 EVTs. The 2-year limb salvage rates were 92.2% in the bypass surgery group and 76.3% in the EVT group, respectively (P < .01). The 1-year wound healing rates were 86.7% in the bypass surgery group and 67.8% in the EVT group (P < .01). Multivariate analysis shows decreased serum albumin level (P < .01), increased wound grade (P = .04), and EVT (P < .01) were risk factors for major amputation. Decreased serum albumin level (P < .01), increased wound grade (P < .01), GLASS infrapopliteal grade (P = .02), inframalleolar (IM) P grade (P = .01), and EVT (P < .01) were risk factors for impaired wound healing. Subgroup analysis of limb salvage in patients after EVT, decreased serum albumin level (P < .01), increased wound grade (P = .03), increased IM P grade (P = .04), and congestive heart failure (P < .01) were risk factors for major amputation. According to scoring by existence of these risk factors, 2-year limb salvage rates following EVT were 83.0% and 42.8% for the total score of 0 to 2 and of 3 to 4, respectively (P < .01). ConclusionsBypass surgery provides better limb salvage and wound healing in patients with WIfI Stage 3 to 4 and GLASS Stage III, which is classified as bypass-preferred category by the GVG. In patients after EVT, serum albumin level, wound grade, IM P grade, and congestive heart failure were related to major amputation. Although bypass surgery may be considered as initial revascularization procedure in patients classified as bypass-preferred category, in case that EVT has to be selected, relatively acceptable outcomes can be expected in patients with less of these risk factors.

Angiosome Oriented or Least Diseased Vessel, Which Is the Optimal Target Arterial Path for Endovascular Revascularisation in Patients With Diabetic Foot Ulcers?

The aims were to determine whether, when treating diabetic foot ulcers (1), selecting an angiosome directed (AD) vessel as the target arterial path (TAP) when candidate vessels have comparably severe disease impacts outcomes and (2) whether a more severely affected AD vessel or a less severely affected non-angiosome directed (NAD) vessel should be chosen. This was a retrospective observational study. Patients with diabetic foot ulcers who had undergone endovascular revascularisation in the institution between January 2016 and May 2020 and had been followed up for two years were included. Eligible patients were identified retrospectively and relevant data were collected from the institution's electronic medical records. The severity of the lesions was classified using the Global Limb Anatomic Staging System (GLASS). Outcomes between various subgroups were compared according to the severity of the lesions to determine the optimal TAP choice in each case. The study cohort comprised 215 patients (216 limbs). The affected limbs were classified as follows: 93 (43.1%) as GLASS 1 - 2 AD; 27 (12.5%) as GLASS 1 - 2 NAD, 62 (28.7%) as GLASS 3 AD, and 34 (15.7%) as GLASS 3 NAD groups. In the GLASS 1 - 2 group, rates of ulcer healing, survival, and amputation free survival were higher and time to healing shorter in the AD than NAD group. In the GLASS 3 group, there were no significant differences between the AD and NAD groups for any studied outcome measures, including ulcer healing and overall survival. Using a more severely diseased AD as the TAP did not achieve significantly better outcomes than using a less severely affected NAD vessel. Selecting the AD vessel may achieve better outcomes when two candidate TAPs belong to GLASS 1-2, whereas selecting the least diseased vessel as the TAP regardless of AD or NAD status may be preferable in other situations.

Role of the Global Limb Anatomic Staging System in predicting outcomes of chronic limb-threatening ischemia in patients treated by drug-coated balloons.

The Global Limb Anatomic Staging System (GLASS) was proposed to assess the procedural complexity and technical failure rate and stratify the anatomic pattern of chronic limb-threatening ischemia (CLTI). However, more evidence is needed to validate the GLASS in staging outcomes after endovascular therapy in patients with CLTI treated with drug-coated balloons (DCBs). This study aims to evaluate the role of the GLASS in predicting outcomes of CLTI patients treated with DCBs. This multicenter, retrospective cohort study enrolled patients with CLTI treated with DCBs from July 2016 to June 2019. GLASS stages were assigned for every limb. The limb-based patency (LBP) rate, clinically driven target lesion revascularization (CD-TLR) rate, clinical improvement, and safety endpoints were analyzed and compared across the GLASS stages over 12 months of follow-up. Risk factors for the loss of LBP were identified using Cox regression analysis. A total of 90 limbs were enrolled, with 55 (61.1%) having isolated femoropopliteal lesions and 35 (38.9%) having femoropopliteal and infrapopliteal lesions. Of the limbs, 17 (18.9%), 12 (13.3%), and 61 (67.8%) were assigned to GLASS stages I, II, and III, respectively. The Kaplan-Meier estimate of the 12-month LBP was 65.4%, and no difference was found among the different stages (stage I 81.1%; stage II 85.2%; stage III 54.4%; P=0.080). The LBP was lower in stage III than in stages I and II combined (stage I and II 83.5%; stage III 54.4%; P=0.027). Similar results were found for the freedom from CD-TLR rates among the different stages. The ankle-brachial index values improved from 0.42±0.29 to 0.78±0.35 at follow-up (P<0.001). The rates of mortality, any amputation, and major amputation were similar among the groups. GLASS stage III and coronary heart disease were identified as independent risk factors for the loss of LBP at 12 months. The 1-year LBP and freedom from CD-TLR rates were lower in GLASS stage III than in stages I and II. The GLASS classification could predict the outcomes of CLTI patients with femoropopliteal lesions treated with DCB.

Validity of the Global Vascular Guidelines in Predicting Outcomes Based on First-Time Revascularization Strategy

The Global Vascular Guidelines (GVG) recommend selecting an endovascular versus open-surgical approach to revascularization for chronic limb-threatening ischemia (CLTI), based on the Global Limb Anatomic Staging System (GLASS) and wound, ischemia, and foot infection (WIfI) classification systems. We assessed the utility of GVG-recommended strategies in predicting clinical outcomes. We conducted a single-center, retrospective review of first-time lower-extremity revascularizations within a comprehensive limb-preservation program from 2010 to 2018. Procedures were stratified by (1) treatment concordance with GVG-recommended strategy (concordant versus nonconcordant groups), (2) GLASS stages I-III, and (3) endovascular versus open strategies. The primary outcome was 5-year freedom from major adverse limb events (FF-MALE), defined as freedom from reintervention or major amputation, and secondary outcomes included 5-year overall survival, freedom from major amputation, freedom from reintervention, and immediate technical failure (ITF) during initial revascularization. Kaplan-Meier (KM) survival analysis and multivariate analysis with Cox proportional hazard models were performed on the primary and secondary outcomes. Of 281 first-time revascularizations for CLTI, 251 (89.3%) were endovascular and 186 (66.2%) were in the concordant group, with a mean clinical follow-up of 3.02±2.40years. Within the concordant group alone, 167 (89.8%) of revascularizations were endovascular. The concordant group had a higher rate of chronic kidney disease (60.8% vs. 45.3%, P=0.02), WIfI foot infection grade (0.81±1.1 vs. 0.56±0.80, P=0.03), and WIfI stage (3.1±0.79 vs. 2.8±1.2, P<0.01) compared to the non-concordant group. After both KM and multivariate analyses, there were no significant differences in 5-year FF-MALE or overall survival between concordant and non-concordant groups. There was higher freedom from major amputation in the non-concordant group on KM analysis (83.9% vs. 74.2%, P=0.025), though this difference was non-significant on multivariate analysis (hazard ratio [HR]: 0.49, 95% confidence interval [CI]: 0.21-1.15, P=0.10). The open group had lower MALE compared to the endovascular group (HR: 0.39, 95% CI: 0.17-0.91, P=0.029) attributed to a lower reintervention rate in the open group (HR: 0.31, 95% CI: 0.11-0.87, P=0.026). GLASS stage was not associated with significant differences in outcomes, but the severity of GLASS stage was associated with ITF (2.1% in stage 1, 6.4% in stage 2, and 11.7% in stage 3, P=0.01). In this study, CLTI treatment outcomes did not differ significantly based on whether treatment was received in concordance with GVG-recommended strategy. There was no difference in overall survival between the endovascular and open groups, though there was a higher reintervention rate in the endovascular group. The GVG guidelines are an important resource to help guide the management of CLTI patients. However, in this study, both concordance with GVG guidelines and GLASS staging were found to be indeterminate in differentiating outcomes between complex CLTI patients treated primarily with an endovascular-first approach. The revascularization approach for a CLTI patient is a nuanced decision that must take into account patient anatomy and clinical status, as well as physician skill and experience and institutional resources.

Lower-extremity pressure, staging, and grading thresholds to identify chronic limb-threatening ischemia.

The Society for Vascular Surgery Threatened Limb Classification System ('WIfI') is used to predict risk of limb loss and identify peripheral artery disease in patients with foot ulcers or gangrene. We estimated the diagnostic sensitivity of multiple clinical and noninvasive arterial parameters to identify chronic limb-threatening ischemia (CLTI). We performed a single-center review of 100 consecutive patients who underwent angiography for foot gangrene or ulcers. WIfI stages and grades were determined for each patient. Toe, ankle, and brachial pressure measurements were performed by registered vascular technologists. CLTI severity was characterized using Global Limb Anatomic Staging System (GLASS stages) and angiosomes. Medial artery calcification in the foot was quantified on foot radiographs. GLASS NA (not applicable), I, II, and III angiographic findings were seen in 21, 21, 23, and 35 patients, respectively. A toe-brachial index < 0.7 and minimum ipsilateral ankle-brachial index < 0.9 performed well in identifying GLASS II and III angiographic findings, with sensitivity rates 97.8% and 91.5%, respectively. The diagnostic accuracy rates of noninvasive measures peaked at 74.7% and 89.3% for identifying GLASS II/III and GLASS I+ angiographic findings, respectively. The presence of medial artery calcification significantly diminished the sensitivity of most noninvasive parameters. The use of alternative noninvasive arterial testing parameters improves sensitivity for detecting PAD. Abnormal noninvasive results should suggest the need for diagnostic angiography to further characterize arterial anatomy of the affected limb. Testing strategies with better accuracy are needed.