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

Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia

BACKGROUND

Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI.

METHODS

A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0 mm (1 point), lesion length>300 mm (1 point), and poor pedal runoff score (1 point). Patients were then divided into 3 groups: low risk (0 or 1 points), moderate risk (2 points), and high risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis [>70%], or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-oriented outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; above ankle amputation of the index limb or major reintervention: new bypass graft, jump/interposition graft revision) were evaluated.

RESULTS

1,607 patients (55% male, average age 60 years, 3,846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic origin. Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day major amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate risk and high risk exceeded the goal threshold. For the OPG, freedom from MALE was 60 ± 5%, 46 ± 5%, and 22 ± 9% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.008). Overall AFS was 55 ± 5%, 37 ± 6%, and 18 ± 7% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.003).

CONCLUSIONS

Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short- and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

Post hoc analysis of the SuperB and Zilverpass trials for treatment of long and complex superficial femoral artery lesions

OBJECTIVE

In two randomized controlled trials, the outcomes of endovascular treatment of complex femoropopliteal arterial lesions were compared with bypass surgery and considered a valid alternative treatment. The aim of this study was to compare both endovascular treatment options with the hypothesis that implantation of heparin-bonded self-expanding covered stents (Viabahn [SECS]) or drug-eluting stents (ZilverPTX [DES]) are related to similar clinical outcomes at 1-year follow-up.

METHODS

In a post-hoc analysis, the SuperB trial and Zilverpass databases were merged. Patients in the endovascular treatment arms were included, and data was analyzed in an intention-to-treat (ITT) and a per-protocol (PP) fashion. Data included baseline and lesion characteristics, procedural details, and follow-up data. The primary endpoint of this study was primary patency at 1-year follow-up. The secondary endpoints were secondary patency, target lesion revascularization (TLR), limb loss, and all-cause mortality.

RESULTS

A total of 176 patients were included; 63 in the SECS arm and 113 in the DES arm. Through 1-year follow-up, there were no significant differences in primary patency (ITT: 63.4% vs 71.1%: P = .183 and PP: 60.8% vs 71.1%; P = .100). Secondary patency rates were not significantly different in the ITT analysis (86.5% vs 95.1%; P = .054), but in the PP analysis, there was a significant difference in favor of the DES group (SECS, 85.6% vs DES, 95.1%; P = .038). There was no significant difference in freedom from TLR between groups (79.6% vs 77.0%; P = .481). No major amputations were performed in the SECS group, and two were performed in the DES group (1.8%). Survival rate was 98.2% in the SECS group, and 91.3% in the DES group after 1-year follow-up (P = .106). Based on diagnosis (intermittent claudication vs chronic limb-threatening ischemia) no differences between patients with intermittent claudication and chronic limb-threatening ischemia were observed in primary patency, secondary patency and freedom from TLR.

CONCLUSIONS

Treatment of complex femoropopliteal arterial disease with the heparin-bonded Viabahn endoprosthesis and the Zilver PTX drug-eluting stent are related to similar primary and secondary patency, and TLR rates at 1 year, except for secondary patency in the PP analysis. This study further supports the endovascular treatment of long complex lesions in the femoropopliteal artery.

Long-Term Outcomes of Anatomical and Extra-Anatomical Bypass for the Treatment of Unilateral Iliac Artery Lesions a Systematic Review Aggregated Data and Individual Participant Data Meta-Analysis

BACKGROUND

We investigated the long-term safety and efficacy of anatomical and extra-anatomical bypass for the treatment of unilateral iliac artery disease.

METHODS

A systematic search on PubMed, Scopus and Web of science for articles published by June 2023 was performed. We implemented a 2-stage individual participant data meta-analysis and pooled survival probabilities using the multivariate methodology of DerSimonian and Laird. The primary endpoint was primary patency at 5 and 10 years of follow-up.

RESULTS

Ten studies encompassing 1,907 patients were included. The 5- and 10-year pooled patency rates for anatomical bypass were 83.27% (95% confidence interval (CI): 69.99-99.07) and 77.30% (95% CI: 60.32-99.04), respectively, with a mean primary patency time representing the duration individuals remained event-free for 10.08 years (95% CI: 8.05-10.97). The 5- and 10-year pooled primary patency estimates for extra-anatomical bypass were 77.02% (95% CI: 66.79-88.80) and 68.54% (95% CI: 53.32-88.09), respectively, with a mean primary patency time of 9.25 years, (95% CI: 7.21-9.68). Upon 2-stage individual participant data meta-analysis, anatomical bypass displayed a decreased risk for loss of primary patency compared to extra-anatomical bypass, hazard ratio 0.51 (95% CI: 0.30-0.85). The 5- and 10-year secondary patency estimates for anatomical bypass were 96.83% (95% CI: 90.28-100) and 96.13% (95% CI: 88.72-100), respectively. The 5- and 10-year secondary patency estimates for extra-anatomical bypass were 91.39% (95% CI: 84.32-99.04) and 85.05% (95% CI: 74.43-97.18), respectively, with non-statistically significant difference between the 2 groups. The 5- and 10-year survival for patients undergoing anatomical bypass were 67.99% (95% CI: 53.84-85.85) and 41.09% (95% CI: 25.36-66.57), respectively. The 5- and 10-year survival for extra-anatomical bypass were 70.67% (95% CI: 56.76-87.98) and 34.85% (95% CI: 19.76-61.44), respectively. The mean survival time was 6.92 years (95% CI: 5.56-7.89) for the anatomical and 6.78 years (95% CI: 5.31-7.63) for the extra-anatomical groups. The pooled overall 30-day mortality was 2.32% (95% CI: 1.12-3.87) with metaregression analysis displaying a negative association between the year of publication and mortality (β =-0.0065, P < 0.01). Further analysis displayed a 30-day mortality of 1.29% (95% CI: 0.56-2.26) versus 4.02% (95% CI: 1.78-7.03), (P = 0.02) for studies published after and before the year 2000. Non-statistically significant differences were identified between the 2 groups concerning long-term and 30-day mortality outcomes.

CONCLUSIONS

While we have demonstrated favorable long-term primary and secondary patency outcomes for both surgical techniques, anatomical bypass exhibited a reduced risk of primary patency loss potentially reflecting its inherent capacity to circumvent the anticipated disease progression in the distal aorta and the contralateral donor artery. The reduction in perioperative mortality observed in our review, coupled with the anachronistic demographic characteristics and inclusion criteria presented in the existing literature, underscores the imperative necessity for contemporary research.

Secondary interventions following open vs endovascular revascularization for chronic limb threatening ischemia in the BEST-CLI trial

OBJECTIVES

Patients undergoing revascularization for chronic limb-threatening ischemia experience a high burden of target limb reinterventions. We analyzed data from the Best Endovascular versus Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) randomized trial comparing initial open bypass (OPEN) and endovascular (ENDO) treatment strategies, with a focus on reintervention-related study endpoints.

METHODS

In a planned secondary analysis, we examined the rates of major reintervention, any reintervention, and the composite of any reintervention, amputation, or death by intention-to-treat assignment in both trial cohorts (cohort 1 with suitable single-segment great saphenous vein [SSGSV], n = 1434; cohort 2 lacking suitable SSGSV, n = 396). We also compared the cumulative number of major and all index limb reinterventions over time. Comparisons between treatment arms within each cohort were made using univariable and multivariable Cox regression models.

RESULTS

In cohort 1, assignment to OPEN was associated with a significantly reduced hazard of a major limb reintervention (hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.28-0.49; P < .001), any reintervention (HR, 0.63; 95% CI, 0.53-0.75; P < .001), or any reintervention, amputation, or death (HR, 0.68; 95% CI, 0.60-0.78; P < .001). Findings were similar in cohort 2 for major reintervention (HR, 0.53; 95% CI, 0.33-0.84; P = .007) or any reintervention (HR, 0.71; 95% CI, 0.52-0.98; P = .04). In both cohorts, early (30-day) limb reinterventions were notably higher for patients assigned to ENDO as compared with OPEN (14.7% vs 4.5% of cohort 1 subjects; 16.6% vs 5.6% of cohort 2 subjects). The mean number of major (mean events per subject ratio [MR], 0.45; 95% CI, 0.34-0.58; P < .001) or any target limb reinterventions (MR, 0.67; 95% CI, 0.57-0.80; P < .001) per year was significantly less in the OPEN arm of cohort 1. The mean number of reinterventions per limb salvaged per year was lower in the OPEN arm of cohort 1 (MR, 0.45; 95% CI, 0.35-0.57; P < .001 and MR, 0.66; 95% CI, 0.55-0.79; P < .001 for major and all, respectively). The majority of index limb reinterventions occurred during the first year following randomization, but events continued to accumulate over the duration of follow-up in the trial.

CONCLUSIONS

Reintervention is common following revascularization for chronic limb-threatening ischemia. Among patients deemed suitable for either approach, initial treatment with open bypass, particularly in patients with available SSGSV conduit, is associated with a significantly lower number of major and minor target limb reinterventions.

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.