The Global Limb Anatomic Staging System is associated with outcomes of infrainguinal revascularization in chronic limb threatening ischemia

Midterm Outcomes and Predictors of Failure of Lower Extremity Bypass to Para-Malleolar and Pedal Targets

BACKGROUND

The frequency of distal lower extremity bypass (LEB) for infrapopliteal critical limb threatening ischemia (IP-CLTI) has significantly decreased. Our goal was to analyze the contemporary outcomes and factors associated with failure of LEB to para-malleolar and pedal targets.

METHODS

We queried the Vascular Quality Initiative infrainguinal database from 2003 to 2021 to identify LEB to para-malleolar or pedal/plantar targets. Primary outcomes were graft patency, major adverse limb events [vascular reintervention, above ankle amputation] (MALE), and amputation-free survival at 2 years. Standard statistical methods were utilized.

RESULTS

We identified 2331 LEB procedures (1,265 anterior tibial at ankle/dorsalis pedis, 783 posterior tibial at ankle, 283 tarsal/plantar). The prevalence of LEB bypasses to distal targets has significantly decreased from 13.37% of all LEB procedures in 2003-3.51% in 2021 (P < 0.001). The majority of cases presented with tissue loss (81.25. Common postoperative complications included major adverse cardiac events (8.9%) and surgical site infections (3.6%). Major amputations occurred in 16.8% of patients at 1 year. Postoperative mortality at 1 year was 10%. On unadjusted Kaplan-Meier survival analysis at 2 years, primary patency was 50.56% ± 3.6%, MALE was 63.49% ± 3.27%, and amputation-free survival was 71.71% ± 0.98%. In adjusted analyses [adjusted for comorbidities, indication, conduit type, urgency, prior vascular interventions, graft inflow vessel (femoral/popliteal), concomitant inflow procedures, surgeon and center volume] conduits other than great saphenous vein (P < 0.001) were associated with loss of primary patency and increased MALE. High center volume (>5 procedures/year) was associated with improved primary patency (P = 0.015), and lower MALE (P = 0.021) at 2 years.

CONCLUSIONS

Despite decreased utilization, open surgical bypass to distal targets at the ankle remains a viable option for treatment of IP-CLTI with acceptable patency and amputation-free survival rates at 2 years. Bypasses to distal targets should be performed at high volume centers to optimize graft patency and limb salvage and minimize reinterventions.

Employing Magnetic Resonance Histology for Precision Chronic Limb-Threatening Ischemia Treatment Planning

OBJECTIVE

Recent randomized controlled trials have demonstrated a notable prevalence of immediate technical failures (ITFs) in percutaneous vascular interventions (PVIs) for complex arterial lesions associated with chronic limb-threatening ischemia (CLTI). Current imaging modalities present inherent limitations in identifying these lesions, making it challenging to determine the most suitable candidates for PVI. We present a novel preprocedural magnetic resonance imaging (MRI) histology protocol for identifying lesions that might present a higher rate of immediate and mid-term PVI failure.

METHODS

22 patients (13 females, average age 65.8±9.72 years) scheduled for PVI were prospectively enrolled and underwent 3T MRI using ultrashort echo time and 'Steady-State Free Precession' contrasts to characterize target lesions prior to PVI. Lesions were scored as 'hard' if >50% of the lumen was occluded by hard components (calcium/dense collagen) on MRI in the hardest cross-section. Two readers evaluated MRI datasets. TASC/GLASS/WIFi scoring was performed based on intraprocedural angiograms and chart review. The relationship between MRI scoring, TASC/GLASS scoring and procedural outcomes was investigated using univariate analysis. Mid-term follow-up (revascularization and amputation rate) was recorded at 3 months and 6 months, post-intervention.

RESULTS

Our cohort of 22 patients yielded 40 target lesions. 5 lesions were excluded (2 non-diagnostic image quality, 3 PVIs were ultimately diagnostic only). 6 lesions (17%) were scored as 'hard'. MRI-scored 'hard' lesions had higher proportion of ITF ('hard' vs 'soft' 83% (n/N=5/6) vs. 3% (n/N=1/29), p<.001). 'Hard' versus 'soft' MRI scoring was the only factor significantly associated with immediate PVI technical success (p < .001), as opposed to TASC/GLASS scoring. Both at 3 months and 6 months after PVI, the re-intervention rate was significantly higher among those lesions which were scored 'hard' on MRI (3-month: hard: 80% vs. soft: 16%, p =.011 6-month: hard: 80%, soft: 27%, p=.047).

CONCLUSIONS

MRI histology could be a valuable tool for optimizing PVI patient selection and treatment strategies.

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 < 3 mm 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.

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

BACKGROUND

Chronic 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.

OBJECTIVE

Our 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.

METHODS

All 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.

RESULTS

The 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).

CONCLUSION

In patients with CLTI of higher GLASS stages, the rates of technical success were lower and the amputation and mortality rates were higher.

Treatment Location Variation for Chronic Limb-Threatening Ischemia in Patients With Kidney Failure

INTRODUCTION

End-stage kidney disease (ESKD) is an established risk factor for chronic limb-threatening ischemia (CLTI). Procedural location for ESKD patients has not been well described. This study aims to examine variation in index procedural location in ESKD versus non-ESKD patients undergoing peripheral vascular intervention for CLTI and identify preoperative risk factors for tibial interventions.

METHODS

Chronic limb-threatening ischemia (CLTI) patients were identified in the Vascular Quality Initiative (VQI) peripheral vascular intervention dataset. Patient demographics and comorbidities were compared between patients with and without ESKD and those undergoing index tibial versus nontibial interventions. A multivariable logistic regression evaluating risk factors for tibial intervention was conducted.

RESULTS

A total of 23,480 procedures were performed on CLTI patients with 13.6% (n = 3154) with ESKD. End-stage kidney disease (ESKD) patients were younger (66.56 ± 11.68 versus 71.66 ± 12.09 y old, P = 0.019), more often Black (40.6 versus 18.6%, P < 0.001), male (61.2 versus 56.5%, P < 0.001), and diabetic (81.8 versus 60.0%, P < 0.001) than non-ESKD patients. Patients undergoing index tibial interventions had higher rates of ESKD (19.4 versus 10.6%, P < 0.001) and diabetes (73.4 versus 57.5%, P < 0.001) and lower rates of smoking (49.9 versus 73.0%, P < 0.001) than patients with nontibial interventions. ESKD (odds ratio (OR) 1.67, 95% confidence interval (CI) 1.52-1.86, P < 0.001), Black race (OR 1.19, 95% CI 1.09-1.30, P < 0.001), and diabetes (OR 1.82, 95% CI 1.71-2.00, P < 0.001) were risk factors for tibial intervention.

CONCLUSIONS

Patients with ESKD and CLTI have higher rates of diabetes and tibial disease and lower rates of smoking than non-ESKD patients. Tibial disease was associated with ESKD, diabetes, and Black race.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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 ± 2.40 years. 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).

CONCLUSIONS

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.

Revascularization prevents amputation among patients with diabetic foot during the COVID-19 era

OBJECTIVE

The COVID-19 pandemic has led to significant changes in healthcare systems that impact the management of chronic diseases such as diabetic foot (DF). We hypothesized that lack of access to healthcare would increase the severity of disease and lead to worse outcomes.

METHODS

The medical records of patients with DF were reviewed to determine demographic data and outcomes including wound healing, major amputation (MA), and death. Groups were divided into the pre-COVID-19 era (15 March 2019-15 March 2020) and the COVID-19 era (16 March 2020-16 March 2021); multivariable logistic analysis was performed to identify risk factors for MA.

RESULTS

261 patients with DF were included, 163 in the pre-COVID-19 era and 98 during the COVID-19 era. Patients in the COVID-19 presented with increased cardiovascular disease (19 vs 7%, p = 0.01), increased mean HbA1C (9.1 ± 2.1 vs 8.2 ± 2.1, p = 0.008) and higher WIFI-IV stage (78 vs 53%, p ≤ 0.0001). Patients with DF in the COVID-19 era were more likely to require MA (41 vs 21%, p ≤ 0.0001). Revascularization (OR = 0.12; 95% CI, 0.038-0.38) was a protective factor to reduce MA.

CONCLUSIONS

MA among DF patients increased two-fold during the COVID-19 era. Revascularization avoids MA in diabetic patients even during the COVID-19 pandemic, suggesting that revascularization should be performed when possible.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

A systematic review and meta-analysis of GLASS staging system in the endovascular treatment of chronic limb-threatening ischemia

OBJECTIVE

The objective of this study was to evaluate the application of the Global Anatomic Staging System (GLASS) in the endovascular treatment of chronic limb-threatening ischemia (CLTI).

METHODS

We performed systematic research between June 2019 and February 2022, including articles investigating the relationship of GLASS classification with the outcomes of endovascular interventions in the treatment of CLTI. Data from the included studies were pooled and meta-analyzed. The primary endpoints were limb-based patency (LBP) at 1-year follow-up and immediate technical failure (ITF). Secondary endpoints included major amputation. We performed subgroup analysis between studies that reported on calcium modifier inclusion during GLASS classification and studies that did not.

RESULTS

Eleven studies, including 1816 patients (1975 limbs) met the inclusion criteria. The pooled ITF rates for GLASS stages I, II, and III are 5.52% (95% confidence interval [CI], 3.74%-8.07%), 7.39% (95% CI, 5.32%-10.18%), and 21.07% (95% CI, 13.48%-31.39%) respectively. The pooled LBP for GLASS stages I, II, and III are 68.43% (95% CI, 53.44%-80.37%), 41.52% (95% CI, 18.91%-68.37%), and 38.64% (95% CI, 19.83%-61.57%). The relative risk (RR) for ITF regarding composite GLASS I and II stages vs GLASS III is 3.96 (95% CI, 1.96-7.98). The RR for LBP of GLASS I and II versus GLASS stage III is 1.51 (95% CI, 0.86-2.64). Pooled major amputation rates for the composite GLASS I, II and GLASS III stages are 7.62% (95% CI, 5.44%-10.58%) and 15.43% (95% CI, 11.72%-20.05%) respectively, whereas the RR between GLASS I, II, and GLASS III stages is 1.84 (95% CI, 1.18-2.87).

CONCLUSIONS

Our study demonstrated that patients with CLTI undergoing endovascular interventions classified as GLASS stage III had almost a four-fold risk increase for ITF and 1.84 times the risk of major amputation compared with stages I and II. Additionally, GLASS classification correctly predicted ITF for all three stages, whereas it failed to predict stage I and II LBP outcomes. Safe conclusions regarding LBP cannot be drawn due to the low quality and small number of the included studies, necessitating further research. Furthermore, we displayed the importance of calcium moderator inclusion in the accurate classification of GLASS.

Global Limb Anatomic Staging System Inframalleolar Modifier Predicts Limb Salvage and Wound Healing in Patients with Chronic Limb Threatening Ischaemia Undergoing Endovascular Infrainguinal Revascularisation

OBJECTIVE

This study aimed to analyse the influence of the Global Anatomic Staging System (GLASS) and inframalleolar (IM) disease on the treatment outcomes of patients with chronic limb threatening ischaemia (CLTI) who undergo endovascular treatment (EVT) METHODS: Data of patients who underwent infrainguinal endovascular therapy (EVT) for CLTI between 2015 and 2019 at two centres were analysed retrospectively. The endpoints were major amputation, major adverse limb events (MALE), and wound healing.

RESULTS

Overall, 276 patients and 340 limbs were analysed. The number of revascularisations for an infrapopliteal lesion was 48 (70.6%), 63 (63.0%), and 142 (82.6%) in the GLASS I, GLASS II, and GLASS III stages, respectively (p < .001). There was no statistically significant difference in limb salvage among the GLASS stages (p = .78). The limb salvage rates at one year were 94.6%, 88.0%, and 70.0% in the IM P0 P1, and P2 groups, respectively (p < .001). Multivariable analysis showed that Wound, Ischemia, and foot Infection (WIfI) stage, and IM grade were risk factors for major amputation. The freedom from MALE rates at two years were 60.5%, 45.3%, and 41.1% in the GLASS I, II, and III stages, respectively (p = .003) and 64.1%, 43.5%, and 18.4% in the IM P0, P1, and P2 groups, respectively (p < .001). Multivariable analysis demonstrated that WIfI stage, GLASS stage, IM grade, and infrapopliteal revascularisation were risk factors for MALE. There was no significant difference in wound healing among GLASS I - III (p = .75). The wound healing rates at 365 days were 78.6%, 68.6%, and 42.0% in the IM P0, P1, and P2 groups, respectively (p = .065). Multivariable analysis showed that WIfI stage and IM P2 were risk factors for incomplete wound healing.

CONCLUSION

GLASS IM was associated with major amputation, MALE, and wound healing, while GLASS stage was associated with only MALE.

High Global Limb Anatomic Staging System Femoropopliteal Grade is Positively Associated with Wound Healing in Patients with Chronic Limb-Threatening Ischemia Undergoing Endovascular Therapy Only for Femoropopliteal Disease

BACKGROUND

To investigate the prognostic impact of femoropopliteal (FP) arterial anatomic severity including classification by the global limb anatomic staging system (GLASS) on wound healing in patients with chronic limb-threatening ischemia (CLTI) who had undergone endovascular therapy (EVT) only for FP lesions.

METHODS

This was a retrospective single-center study. We treated 349 consecutive de novo CLTI limbs with tissue loss from January 2017 to May 2021. Among these, 91 limbs treated via EVT only for FP lesions were enrolled. We compared the clinical background, infrapopliteal (IP)/FP arterial anatomical characteristics, and EVT results between the limbs with GLASS FP grade 1 or 2 (low GLASS FP, n = 20) and those with GLASS FP grade 3 or 4 (high GLASS FP, n = 71). The Kaplan-Meier method was used to estimate the wound healing rate. The Cox proportional hazard model was used to assess the association between baseline characteristics and wound healing.

RESULTS

No patient underwent EVT for IP lesions. IP arterial anatomical characteristics did not show any significant difference between the low and high GLASS FP groups. The cumulative wound healing rate after EVT was significantly higher in the high GLASS FP group than in the low GLASS FP group (88% vs. 39% at 6 months; P < 0.001). Multivariate analysis revealed that low wound, ischemia, and foot infection (WIfI) clinical stage (stage 1 or 2) (hazard ratio [HR] 2.33; 95% confidence interval [CI] 1.32-4.17) and high GLASS FP (grade 3 or 4) (HR 5.18; 95% CI 1.99-13.51) were independent factors for wound healing.

CONCLUSIONS

High GLASS FP grade was positively associated with wound healing after EVT only for FP lesions.

The Relationship Between the Global Limb Anatomic Staging System Inframalleolar Modifier and the Outcomes of Diabetic Foot Ulcer with Peripheral Artery Disease

BACKGROUND

We aimed to investigate the relationship between the condition of the inframalleolar (IM) arteries, as assessed by the Global Limb Anatomic Staging System Inframalleolar (GLASS IM) modifier, and the outcomes of patients with diabetic foot ulcers.

METHODS

The data of 215 patients, who underwent endovascular therapy from January 2016 to May 2020 at our center, were retrospectively reviewed. Patients were divided into the P0, P1, and P2 groups according to the angiography results. The rates of ulcer healing, limb salvage, survival, and amputation-free survival were compared during the 2-year period after discharge.

RESULTS

Of the 216 affected limbs, 35 (16%) were classed as P0, 122 (57%) as P1, and 59 (27%) as P2. Compared with the P2 group, the P0 + P1 group had a higher ulcer healing rate (P = 0.001), a shorter ulcer healing time (P = 0.004), and a higher survival rate (P = 0.044). GLASS IM Modifier classification P2 was an independent predictor of nonhealing ulcers. No significant difference was observed between the P0 versus P1 groups.

CONCLUSIONS

GLASS IM modifier classification P2 is an independent risk factor for a poor outcome. GLASS IM modifier classification P0 versus P1 demonstrates similar outcomes to each other.

Open Proximal Endarterectomy with Retrograde Access and Stenting: A Novel Technique for Lower Extremity Revascularization

BACKGROUND

Treatment of chronic limb threatening ischemia (CLTI) poses a significant clinical challenge despite recent medical advancements. Chronic total occlusion (CTO) lesions make endovascular approaches to CLTI particularly challenging. Open proximal exposure with retrograde access and stenting (OPERAS) aims to solve this challenge through retrograde subintimal crossing of a CTO with direct visualization of proximal re-entry into the true lumen. We describe this novel technique and present its efficacy in eight patients.

METHODS

We conducted a retrospective case series at a single tertiary academic center. Data for patients who received OPERAS intervention included demographics, peri-operative details, and follow-up information. Statistical analysis was performed on length of stay, major post-operative complications, further intervention, clinical progression at 1 year, and amputation-free survival at 1 year. Immediate technical failure (ITF) and limb-based patency (LBP) at 1 year were calculated.

RESULTS

Nine limbs underwent OPERAS between January 2019 and March 2020. Inflow was achieved with common femoral artery endarterectomy. All limbs underwent balloon angioplasty and stenting of the SFA, and seven underwent the same procedure in the popliteal artery. ITF was 0% for all nine cases. There were no major post-operative complications, and ankle-brachial index significantly improved pre-and post-operatively (P < .001). Eight limbs (88.9%) sustained amputation-free survival at 1 year, and overall LBP was 67% at 1 year.

CONCLUSION

Our study presents a hybrid revascularization option to address severe, anatomically complex limbs (GLASS III) that lack a single autogenous conduit for open surgical revascularization. OPERAS addresses a main point of technical failure of subintimal techniques by directly visualizing the wire in the true lumen. Our data suggest that OPERAS can be effective to: (1) improve technical success of luminal re-entry following a subintimal approach; (2) address inflow concurrently with severe femoropopliteal disease; and (3) can be utilized when distal tissue loss is involved.

Aortic calcification index predicts mortality and cardiovascular events in operatively treated patients with peripheral artery disease A prospective PUREASO cohort follow-up study

OBJECTIVE

Present study evaluates the association of aortic calcification to mortality and major adverse cardiovascular and leg events (MACE and MALE) in patients with peripheral artery disease (PAD). The risk for mortality and MACE and MALE events is considered in clinical decision making.

METHODS

This cohort found in 2012 - 2013 consists of 226 symptomatic PAD patients referred to Turku University Hospital for invasive treatment. Follow-up data about mortality and survival without MACEs and MALEs was collected up to 5 years from inclusion date and aortic calcification index (ACI) was measured from patients with available imaging studies (164 of 226). ACIs association with events and mortality was evaluated in Cox regression, Kaplan-Meier and Classification and regression tree analysis.

RESULTS

All-cause mortality at 1, 3 and 5 years was 13.7%, (31), 26.1% (59) and 46.9% (106), respectively. In multivariable Cox regression analysis ACI and ACI>43 were independent risk factors for all-cause mortality (HR 1.13 per 10 units 95%CI, 1.00-1.22 and HR 1.83, 95%CI, 1.01-3.32, respectively) and for MACE (HR 1.10 per 10 units, 95%CI, 1.00-1.22 and HR 3.14, 95%CI, 1.67-5.91, respectively), but not for MALES. Classification and regression tree analysis showed that ACI 43 best divides cohort in relation to mortality. Kaplan-Meier analyses showed that ACI>43 is associated with greater mortality and occurrence of MACEs compared to those who have ACI≤43 (log-rank p-value 0.005 and 0.0012, respectively).

CONCLUSION

Risk for mortality and MACEs is associated with high ACI. ACI can expose PAD patients' risk for further cardiovascular events and mortality.

EVALUATION OF GLASS STAGE IN PATIENTS WITH CHRONIC LIMB THREATENING ISCHEMIA TREATED WITH AUTOGENOUS BYPASS GRAFTS

OBJECTIVE

To evaluate the relationship of GLASS stages with clinical outcomes in patients with chronic limb threatened ischemia (CLTI) submitted to distal bypasses using venous graft.

METHODS

A single-center retrospective analysis of patients with CLTI submitted to distal bypasses with vein graft between January 2012 and December 2019 were included. The primary end point was freedom from CLTI (amputation-free survival, with complete wound healing and without ischemic rest pain). Secondary end points included a composite outcome of recurrence (patients that achieved freedom from CLTI but developed a new wound or ischemic rest pain), major limb amputation, amputation free-survival, overall survival, major adverse limb events (MALE), limb-based patency (LBP) and primary and secondary patency rates.

RESULTS

A total of 190 patients were submitted to 211 distal bypasses with a median follow up of 30 months. Eighty percent of the cases had diabetes or end-stage kidney disease requiring dialysis. Most patients (63%) had major or extensive tissue loss (Wound class ≥ 2) with more than half of these with some degree of infection of the foot. Severe anatomic pattern (GLASS stage III) was predominant with a prevalence of 78%. There were no significant differences between GLASS I-II and GLASS III stage groups for all the outcomes analysed. About 80% of the 211 revascularized limbs were free from CLTI at 12 months. At 4 years of follow up we observed that 25% of the cases had recurrence of CLTI, 83% were free from major amputation and 61% were free from MALE. LBP, primary patency, and secondary patency were 79%, 80% and 93% at one year, and 64%, 65% and 81% at four years, respectively.

CONCLUSIONS

GLASS stage was not related with patency and clinical outcomes after distal bypasses with vein graft. Distal open revascularization presents excellent rates of freedom from CLTI with low rates of recurrence of CLTI, two key time-integrated outcomes of clinical disease severity in patients with CLTI.

Limb-based patency as a measure of effective revascularization for chronic limb-threatening ischemia

OBJECTIVE

In 2019, the Global Vascular Guidelines on chronic limb-threatening ischemia (CLTI) introduced the concept of limb-based patency (LBP) defined as maintained patency of a target artery pathway (TAP) following intervention. The purpose of this study was to investigate the relationship between LBP and major adverse limb events following infrainguinal revascularization for CLTI.

METHODS

Consecutive patients undergoing revascularization for CLTI between 2016 and 2019 at a single tertiary institution with a dedicated limb preservation team were included. Subjects with aorto-iliac disease, prior infrainguinal stents or existing bypass grafts were excluded. Demographics, Global Limb Anatomic Staging System (GLASS) scores, Wound, Ischemia, foot Infection (WIfI) stages, revascularization details, and limb-specific outcomes were reviewed. LBP was defined by the absence of re-intervention, occlusion, critical stenosis (>70%), or hemodynamic compromise with ongoing symptoms of CLTI. Major adverse limb events (MALE) included thrombectomy or thrombolysis, new bypass, open surgical graft revision and/or major amputation.

RESULTS

184 unique limbs in 163 patients were analyzed. This cohort was composed of 66.9% male patients with a mean age of 72. Baseline characteristics included diabetes (66%), tissue loss (91%) and advanced WIfI stages (30% stage 3, 51% stage 4). GLASS stage 3 anatomic patterns were common (n=119; 65%). 60 limbs were treated with open bypass (65% involving tibial targets) while 124 underwent endovascular intervention (70% including infrapopliteal targets). 12-month freedom from MALE and loss of LBP were 74.0%±3.7% and 48.6%±4.2%, respectively. Diabetes (HR=2.56 [1.13-5.83]; p=.025) and loss of LBP (4.12 [1.96-8.64]; p<.001) were independent predictors of MALE in a Cox proportional hazard model. Loss of LBP was the sole independent predictor of major limb amputation after revascularization (HR=4.97 [1.89-13.09]; p=.001). Loss of LBP impacted both intermediate-risk limbs (HR=2.85 [1.02-7.97]; p=.047 in WIfI stages 1-3) and high-risk limbs (HR=3.99 [1.32-12.11]; p=.014 in WIfI stage 4). However, loss of LBP had the greatest impact on patients presenting with WIfI stage 4 disease (31% vs. 8% major limb amputation at 12-months in limbs without vs. with maintained LBP).

CONCLUSIONS

Anatomic durability of revascularization, as measured by LBP, is a key determinant of treatment outcomes in CLTI regardless of the initial mode of intervention undertaken. Loss of LBP is most detrimental in patients presenting with advanced limb threat (WIfI stage 4).

Applicability of the Vascular Quality Initiative (VQI) mortality prediction model for infrainguinal revascularization in a tertiary limb preservation center population

OBJECTIVE

Patients undergoing revascularization for chronic limb-threatening ischemia (CLTI) are at elevated risk for both mortality and limb loss. To facilitate therapeutic decision-making, a mortality prediction model derived from the Vascular Quality Initiative (VQI) database has stratified patients into low, medium, and high risk, defined by 30-day mortality estimated of ≤3%, 3-5%, or >5% and 2-year mortality estimates of ≤30%, 30-50%, or ≥50%, respectively. The purpose of this study was to compare expected mortality risk derived from this model with observed outcomes in a tertiary center.

METHODS

Consecutive patients treated at a single center between 2016 and 2019 were analyzed. Baseline demographics, approach, and mortality events were reviewed. Observed mortality was obtained using life-table methods and compared using a log-rank test with the expected mortality risk which was calculated using the VQI model.

RESULTS

This study cohort consisted of 195 revascularization procedures in 169 unique patients stratified into 128 (66%) low, 50 (26%) medium, and 17 (8%) high-risk cases based on the VQI model. 90% of revascularizations were performed for tissue loss. Compared with the VQI population, comorbidities were prevalent and included unstable angina or myocardial infarction within 6 months (6% vs. 2.4% in VQI; p<0.001), congestive heart failure (30% vs. 23%; p<0.001), and dialysis dependence (14% vs. 0.9%; p<0.001). Patients were also older (31% vs. 21% ≥80 years old; p<0.001) and more likely to be frail (45% vs. 64% independent; p<0.001). High-risk patients were more prevalent in the endovascular group (11% of 132 endovascular interventions vs. 3% of 63 bypasses; p=0.056). 30-day observed mortality exceeded expected VQI prediction model mortality in all groups, although was not statistically significant. The VQI model adequately stratified the studied population into risk groups (p<0.001). Low risk CLTI patients (65% of the overall cohort) experienced 2- year mortality of 18.9%. However, observed mortality for medium and high-risk VQI strata were similar. After a median follow-up of 28 months, medium-risk patients incurred a significantly higher mortality than predicted (53.5%±2.1% vs. 36.8%±1.1%; p=0.016).

CONCLUSIONS

The VQI mortality prediction model discriminates mortality risk after limb revascularization in CLTI, accurately identifying a majority subgroup of patients who are suitable for either open or endovascular intervention. However, it may underestimate mortality in a tertiary referral population with high comorbidity burden and was not well calibrated for the medium-risk group. It may be more appropriate to dichotomize CLTI patients who are candidates for limb salvage into an average risk and high-risk group.

Validation of the GLASS Staging Systems in Patients With Chronic Limb-Threatening Ischemia Undergoing De Novo Infrainguinal Revascularization

OBJECTIVES

The Global Limb Anatomic Staging System (GLASS) was proposed for evaluating the anatomic complexity of arterial disease in patients with chronic limb-threatening ischemia (CLTI). We aimed to examine the relationship between GLASS stage and treatment outcomes after infrainguinal revascularization in patients with CLTI.

METHODS

We retrospectively analyzed data of patients undergoing infrainguinal revascularization for CLTI between 2010 and 2018 to examine whether GLASS stage affects the limb salvage, wound healing, and overall survival (OS).

RESULTS

Throughout the study period, 153 CLTI patients and 190 limbs with Fontaine classification III and IV were analyzed for major amputation and OS, and 125 patients and 157 limbs of Fontaine classification IV were analyzed for wound healing. The number of patients with WIfI stage 1, 2, 3, and 4 was 14 (7.4%), 44 (23.2%), 65 (34.2%), and 67 (53.3%), respectively. The number of patients with GLASS stage I, II, and III was 23 (12.1%), 48 (25.3%), and 119 (62.6%), respectively. Among the 190 limbs, the number subject to bypass surgery, endovascular therapy, and hybrid therapy was 132 (69.5%), 39 (20.5%), and 19 (10.0%), respectively. A multivariate analysis showed that only WIfI stage and inframalleolar (IM) disease were risk factors for major amputation and impaired wound healing. There was no relationship between GLASS stage and limb salvage or wound healing. A multivariate analysis revealed that age, geriatric nutritional risk index and GLASS stage were risk factors for 2-year OS (P < 0.01). Patients with all risk factors had a poor prognosis (35.3% at 2 years).

CONCLUSION

WIfI stage and IM disease predicted limb salvage and wound healing after infrainguinal revascularization in patients with CLTI. Although GLASS stage did not affect limb salvage or wound healing, it was a prognostic factor for poor OS. The GLASS staging could be useful for deciding between bypass surgery and endovascular therapy in prediction of prognosis.

Does the Global Limb Anatomic Staging System Inframalleolar Modifier Influence Long Term Outcomes of Chronic Limb Threatening Ischaemia after Distal Bypass?

OBJECTIVE

The purpose of this study was to evaluate the influence of inframalleolar disease (Global Limb Anatomic Staging System Inframalleolar [GLASS IM] modifier) on long term outcomes of patients with chronic limb threatening ischaemia (CLTI) after distal bypass.

METHODS

Patients who underwent distal bypass for CLTI from January 2012 to December 2019 at a single centre were reviewed retrospectively. Comparisons including baseline characteristics, procedural details, and long term outcomes were made between patients with an intact pedal arch (GLASS IM modifier P0), an absent or severely diseased pedal arch (P1), and no target artery crossing the ankle into the foot (P2), diagnosed by pre- and intra-operative high quality angiography. The primary endpoint was limb salvage. The secondary endpoints were graft patency and wound healing.

RESULTS

A total of 254 distal bypasses were performed in 206 patients (139 males; median age, 76 years). The GLASS IM modifier was P0 in 80 (32%) limbs, P1 in 127 (50%), and P2 in 47 (18%). During the follow up period, 22 limbs (9%) required major amputation. The limb salvage rates at three years in P0, P1, and P2 cases were 94%, 89%, and 93%, respectively, with no significant differences among the modifiers. The primary patencies at three years in P0, P1, and P2 cases were 49%, 38% and 24%, respectively. The primary patency in P2 cases was significantly lower than that in P0 cases (p < .050). The respective wound healing rates at 12 months were 97%, 93%, and 79%, and again the wound healing rate in P2 cases was significantly lower than those in other cases (p < .050).

CONCLUSION

Long term outcomes including patency, limb salvage, and wound healing after distal bypass for CLTI patients with an infrapopliteal lesion were acceptable in cases in each GLASS IM modifier.

The Global Limb Anatomic Staging System (GLASS) for CLTI: Improving Inter-Observer Agreement

Objective: The 2020 Global Vascular Guidelines aim at improving decision making in Chronic Limb-Threatening Ischemia (CLTI) by providing a framework for evidence-based revascularization. Herein, the Global Limb Anatomic Staging System (GLASS) serves to estimate the chance of success and patency of arterial pathway revascularization based on the extent and distribution of the atherosclerotic lesions. We report the preliminary feasibility results and observer variability of the GLASS. GLASS is a part of the new global guideline and posed as a promising additional tool for EBR strategies to predict the success of lower extremity arterial revascularization. This study reports on the consistency of GLASS scoring to maximize inter-observer agreement and facilitate its application. Methods: GLASS separately scores the femoropopliteal (FP) and infrapopliteal (IP) segment based on stenosis severity, lesion length and the extent of calcification within the target artery pathway (TAP). In our stepwise approach, we used two angiographic datasets. Each following step was based on the lessons learned from the previous step. The primary outcome was inter-observer agreement measured as Cohen’s Kappa, scored by two (step 1 + 2) and four (step 3) blinded and experienced observers, respectively. Steps 1 (n = 139) and 2 (n = 50) were executed within a dataset of a Dutch interventional RCT in CLTI. Step 3 (n = 100) was performed in randomly selected all-comer CLTI patients from two vascular centers in the United States. Results: In step 1, kappa values were 0.346 (FP) and 0.180 (IP). In step 2, applied in the same dataset, the use of other experienced observers and a provided TAP, resulted in similar low kappa values 0.406 (FP) and 0.089 (IP). Subsequently, in step 3, the formation of an altered stepwise approach using component scoring, such as separate scoring of calcification and adding a ruler to the images resulted in kappa values increasing to 0.796 (FP) and 0.730 (IP). Conclusion: This retrospective GLASS validation study revealed low inter-observer agreement for unconditioned scoring. A stepwise component scoring provides acceptable agreement and a solid base for further prospective validation studies to investigate how GLASS relates to treatment outcomes.