The effect of demographic factors and lesion severity on iliac stent patency

Outcomes of covered vs bare metal stents for the treatment of aortoiliac occlusive disease

OBJECTIVE

We retrospectively compared the clinical outcomes of self-expanding covered stents (CSs) and bare metal stents (BMSs) in the treatment of aortoiliac occlusive disease (AIOD) at a single center between 2016 and 2022.

METHODS

All patients with AIOD receiving endovascular therapy at a single center from January 2016 to October 2022 were continuously analyzed, including patients with lesions of all classes according to the Trans-Atlantic Inter-Society Consensus II (TASC-II). Relevant clinical and baseline data were collected, and propensity score matching was performed to compare CSs and BMSs in terms of baseline characteristics, surgical factors, 30-day outcomes, 5-year primary patency, and limb salvage. The follow-up results were analyzed by Kaplan-Meier curves. Cox proportional hazard models were used to identify predictors of primary patency.

RESULTS

A total of 209 patients with AIOD were enrolled in the study, including 135 patients (64.6%) in the CS group and 74 patients (35.4%) in the BMS group. Surgical success rates (100% vs 100%; P = 1.00), early (<30-day) mortality rates (0% vs 0%; P = 1.00), cumulative surgical complication rate (12.0% vs 8.0%; P = .891), 5-year primary patency rate (83.4% vs 86.9%; P = .330), secondary patency rate (96% vs 100%; P = .570), and limb salvage rate (100% vs 100%; P = 1.00) did not exhibit significant differences between the two groups. Patients in the CS group had a lower preoperative ankle-brachial index (0.48 ± 0.26 vs 0.52 ± 0.19; P = .032), more cases of complex AIOD (especially TASC D) (47.4% vs 9.5%; P < .001), more chronic total occlusive lesions (77.0% vs 31.1%; P < .001), and more severe calcification (20.7% vs 14.9%; P < .036). After propensity score matching, 50 patients (25 with CS and 25 with BMS) were selected. The results showed that only severe calcification (32.0% vs 8.0%; P = .034) and ankle-brachial index increase (0.45 ± 0.15 vs 0.41 ± 0.22; P = .038) were significantly different between the groups. In terms of surgical factors, patients in the CS group had more use of bilateral femoral or combined brachial artery percutaneous access (60.0% vs 12.0%; P < .001), more number of stents used (2.3 ± 1.2 vs 1.3 ± 0.7; P < .001), longer mean stent length (9.3 ± 3.3 vs 5.8 ± 2.6 cm; P < .001), and more catheter-directed thrombolysis treatment (32.0% vs 4.0%; P = .009). Multivariate Cox survival analysis showed that severe calcification (hazard ratio, 1.32; 95% confidence interval, 1.04-1.85; P = .048) was the only independent predictor of the primary patency rate.

CONCLUSIONS

All patients with AIOD who underwent endovascular therapy were included and achieved good outcomes with both CSs and BMSs. The influence of confounding factors in the two groups was minimized by propensity score matching, and the 5-year patency rates were generally similar in the unmatched and matched cohorts. Postoperative hemodynamic improvement was more obvious in patients in the CS group. For more complex lesions, CS is recommended to be preferred. Especially for severe calcification lesions, which is the only independent predictor of primary patency, CS showed obvious advantages. Further studies with more samples are needed to investigate the role of stent types in AIOD treatment.

Midterm Outcomes on Primary Endovascular Treatment of 395 Aortoiliac Occlusive Disease Patients: A Single-Center Experience

We report the results of endovascular treatment of Trans-Atlantic Inter-Society Consensus II (TASC) A&B, TASC C, and TASC D aortoiliac lesions in a single vascular center. In this retrospective, observational cohort study, we analyzed 395 patients (mean age 61.2 ± 9.0; 359 men) between January 2015 and December 2017. Technical success was achieved in 96.5%; in-hospital mortality was 1.2% (n = 5). Median follow-up was 36 months (range 24-49 months). After 1 and 5 years, the primary patency rates were 99% and 85% for TASC A&B, 90%, and 78% for TASC C, and 90% and 74% for TASC D. Secondary patency rates were 99% and 90% for TASC A&B, 98% and 65% for TASC C, and 97% and 65% for TASC D. Previous peripheral revascularization (hazard ratio: 1.76, 95% CI: 1.01-3.08, P = .04) was associated with decreased primary patency along with lower age, TASC C, and TASC D class. This analysis reported the acceptable effectiveness and safety of stenting for all types of aortoiliac occlusive disease in a modern setting, with few complications and excellent long-term primary and secondary patency rates.

Covered versus bare metal kissing stents for reconstruction of the aortic bifurcation in the ILIACS registry

OBJECTIVE

We compared the early and midterm outcomes of polytetrafluoroethylene covered stents (CSs) vs bare metal stents (BMSs) used in the kissing conformation for the reconstruction of the aortic bifurcation in aortoiliac obstructive disease.

METHODS

A multicenter cohort registry (2015-2019) collected data from 1306 patients who had undergone endovascular treatment of aortoiliac arterial obstructive disease. Only patients who had received bilateral iliac kissing stents for TransAtlantic Inter-Society Consensus (TASC) class C and D lesions were included in the present analysis. The 30-day outcomes, midterm primary patency, and limb salvage rates were compared between the CSs and BMSs in matched patient cohorts after propensity score matching. The follow-up results were analyzed using Kaplan-Meier curves. Cox proportional hazards models were used to identify the predictors of primary patency.

RESULTS

A total of 336 patients were treated with kissing stents, 201 with CSs (60%) and 135 with BMSs (40%). In the unmatched cohort, patients receiving CSs were more likely to have critical limb ischemia (41% vs 30%; P = .038), complex iliac lesions, such as TASC D (90% vs 56%; P < .01), and iliac occlusions (59% vs 44%; P < .01). After propensity score matching, 220 patients were selected (110 with CSs and 110 with BMSs), without differences in the clinical presentation (critical limb ischemia, 41% vs 33%; P = .167), or anatomic complexity (TASC D, 66% vs 60%, P = .21; iliac occlusion, 48% vs 49%, P = .89). The 30-day mortality was 0%. The early medical (unmatched, 5% vs 4%, P = 1.00; matched, 5% vs 4%, P = .75) and surgical (unmatched, 5% vs 5%, P = 1.00; matched, 5% vs 3%, P = .72) complication rates were similar between the CSs and BMSs. However, the CSs resulted in a lower risk of intraoperative iliac rupture (0% vs 3.5%; P = .013) and greater ankle-brachial index improvement (0.43 ± 0.22 vs 0.36 ± 0.24; P = .02). At 36 months, the overall primary patency (92% ± 7% vs 92% ± 8%; P = .38), secondary patency (98% ± 3% vs 98% ± 4%; P = .50), and limb salvage (93% ± 9% vs 97% ± 5%; P = .20) rates were similar. In cases of moderate to severe iliac calcification, the CSs showed better results in the matched cohort (100% vs 89% ± 9%; P = .048). On multivariate analysis, CS use (hazard ratio [HR], 1.67; P = .45) did not significantly affect primary patency, but older age (HR, 0.93; P = .03) and kissing stent diameter ≥8 mm (HR, 0.25; P = .03) were significantly associated.

CONCLUSIONS

In the present multicenter study, the use of kissing stents for the treatment of the aortic bifurcation provided good early and midterm results. CSs were preferred for more complex lesions, were protective from iliac rupture, and allowed for greater ankle-brachial index improvement. The 3-year patency rates were similar between the CSs and BMSs. However, CSs showed improved results in the case of moderate to severe calcification.

Effectiveness and long-term outcomes of different crossing strategies for the endovascular treatment of iliac artery chronic Total occlusions

Background

The iliac occlusive disease is usually treated with endovascular procedures in recent years. The effectiveness of different crossing approaches for these occlusions is not precisely known. We performed a retrospective study to explore the optimal crossing approach (antegrade versus retrograde) for iliac artery chronic total occlusions (CTOs) and to examine the long-term outcomes.

Materials and methods

We performed a study on 107 patients (116 iliac occlusive lesions, mean age 64.0 ± 11.1, 88 men) who underwent an iliac CTO endovascular intervention attempted with the use of both crossing strategies but were managed with one final crossing approach between August 2012 and August 2018. Baseline data, procedural characteristics, and outcomes were described. A Cox proportional hazard model and Kaplan-Meier method were developed to assess the differences in the two crossing approaches in terms of the 1-year and 5-year primary patency rates, target lesion revascularization (TLR) and major adverse limb events (MALEs).

Results

Common iliac artery (CIA) lesions were more likely to be crossed successfully in the retrograde direction (6.8% for antegrade vs. 20.9% for retrograde, p = 0.005), while lesions in the CIA/ external iliac artery (EIA) were more prone to be crossed successfully in the antegrade direction (58.9% for antegrade vs. 39.5% for retrograde, p = 0.016). There were no significant differences in the crossing approach for EIA lesions between the two groups. The two crossing approaches were associated with similar estimates of 1- and 5-year primary patency, TLR and MALE rates.

Conclusion

The antegrade approach was associated with a higher rate of successful crossing in CIA/EIA CTO lesions, while the CIA-only CTOs were more likely to be crossed successfully with the retrograde approach.

Younger patients have worse outcomes after peripheral endovascular interventions for suprainguinal arterial occlusive disease

OBJECTIVE

The choice of intervention for treating suprainguinal arterial disease, open bypass vs endovascular intervention, is often tempered by patient age and comorbidities. In the present study, we compared the association of patient age with 1-year major adverse limb events (MALE)-free survival and reintervention-free survival (RFS) rates among patients undergoing intervention for suprainguinal arterial disease.

METHODS

The Vascular Quality Initiative datasets for bypass and peripheral endovascular intervention (PVI; aorta and iliac only) were queried from 2010 to 2017. The patients were divided into two age groups: <60 and ≥60 years at the procedure. Age-stratified propensity matching of patients in bypass and endovascular procedure groups by demographic characteristics, comorbidities, and disease severity was used to identify the analysis samples. The 1-year MALE-free survival and RFS rates were compared using the log-rank test and Kaplan-Meier plots. Proportional hazard Cox regression was used to perform propensity score-adjusted comparisons of MALE-free survival and RFS.

RESULTS

A total of 14,301 cases from the Vascular Quality Initiative datasets were included in the present study. Propensity matching led to 3062 cases in the ≥60-year group (1021 bypass; 2041 PVI) and 2548 cases in the <60-year group (1697 bypass; 851 PVI). In the crude comparison of the matched samples, the older patients undergoing bypass had had significantly greater in-hospital (4.6% vs 0.9%; P < .001) and 1-year (10.5% vs 7.5%; P = .005) mortality compared with those who had undergone endovascular intervention. The rates of MALE (7.5% vs 14.3%; P < .001) and reintervention (6.7% vs 12.7%; P < .001) or death were significantly higher for the younger group undergoing PVI than bypass at 1 year. However, the rates of MALE (12.9% vs 14.3%; P = .298) and reintervention (12.7% vs 12.9%; P = .881) or death for were similar both procedures for the older group. Both log-rank analyses and the adjusted propensity score analyses of MALE-free survival and RFS in the two age groups confirmed these findings. The adjusted comparison of outcomes using propensity score matching favored PVI at 1-year survival (hazard ratio, 1.4; 95% confidence interval, 1.1-1.9; P = .003) for the older group but was not different for the younger group (hazard ratio, 0.6; 95% confidence interval, 0.3-1.0; P = .054).

CONCLUSIONS

Among the patients aged <60 years undergoing intervention for suprainguinal arterial disease, the choice of therapy should be open surgical intervention given the higher risk of reintervention and MALE with endovascular intervention. Endovascular intervention should be favored for patients aged ≥60 years because of reduced perioperative mortality.

[Predictive factors of amputation after iliac angioplasty in patients with severe artery disease]

INTRODUCTION

Despite the success of angioplasty of the iliac artery, this technique remains associated with significant amputation rates. The purpose of this study was to identify predictive factors for lower limb amputation after iliac angioplasty in patients with critical ischemia.

METHODS

We reported a retrospective study including patients who successfully underwent angioplasty of the iliac artery between 2014 and 2018. The primary endpoint was limb salvage at 1 month. The variables were studied in univariate and multivariate analysis.

RESULTS

Our study included 86 patients. The median age was 57±10 and the sex ratio was 4.7. Cardiovascular risk factors were represented by smoking in 14 cases (16.3%), diabetes in 25 cases (29.1%), arterial hypertension in 2 cases (2.3%) and dyslipidemia in 2 cases (2.3%). Seventy patients (81.3%) were classified as stage 4 according to the Leriche and Fontaine classification and 16 patients (18.7%) were classified as stage 3. The lesions were stenosing in 48 cases (55.8%) and occlusive in 38 cases (44.2%). These lesions were classified according to the TASC classification "Trans-Atlantic-Society-Consensus" in TASC A-B in 61 cases (70.9%) and TASC C-D in 35 cases (29.1%). Distal arteritis was found in 8 cases (9.3%). Balloon angioplasty was performed in 36 cases (41.8%) and angioplasty stenting in 50 cases (58.2%). At 1 month, the amputation rate was 9.3%. Univariate analysis showed that diabetes and smoking were the most important factors associated with amputation (respectively P=0.007, OR=9.31, 95% CI=[1.73-50.07] and P=0.022; OR=6.8; 95% CI=[1.46 to 31.61]). Multivariate analysis showed that diabetes and distal arteritis were the predictive factors for amputation (respectively P=0.034, OR=21.06, 95% CI=[1.25 to 354.46] and P=0.008, OR=11,61, 95% CI=[1.88 to 71.69]).

CONCLUSION

Diabetes and distal arteritis are the predictive factors for lower limb amputation after iliac angioplasty.

Inflammation and myointimal hyperplasia. Correlation with hemodynamic forces

OBJECTIVES

The aim of our study was to correlate flow dynamics and the release of inflammatory cytokines Interleukin 1, 2, 6, TNF (Tumour Necrosis Factor) alfa, both in vitro and in vivo.

MATERIALS AND METHODS

Endothelial cells were exposed to laminar flow (6dyne/cm²) in an in vitro circulatory system and the release of Interleukin 1, 2, 6 and TNF alfa was quantified by ELISA. Interleukin 1, 2, 6 and TNF alfa release was also assessed in vein grafts implanted in the arterial circulation of Lewis rats. Arterial vein grafts were explanted at different time intervals from 3days to 12weeks after surgery. Vein grafts implanted in the arterial circulation for 4weeks, were re implanted in the venous circulation of syngenic Lewis rats, and the release of Interleukin 1, 2, 6 and TNF alfa, was assessed in an organ culture. Six vein grafts (4 occluded, 2 patent) implanted in humans as femorodistal bypass were examined for the presence of myointimal hyperplasia and perigraft inflammatory cells.

RESULTS

In vitro, endothelial cells exposed to laminar flow released an increased amount of Interleukin 1, 2, 6 and TNF alfa in comparison to endothelial cells not exposed to flow. In experimental vein grafts implanted in the arterial circulation there was an increased release of inflammatory cytokines associated to inflammatory changes in the adventitia. Once the vein grafts were re implanted in the venous circulation, the release of these cytokines diminished, while the inflammatory changes in the adventitia regressed.

CONCLUSIONS

Increased shear stress induces release of cytokines and inflammatory changes in the adventitia. These inflammatory changes can contribute to plaque progression and to un stable plaque. These findings support the use of anti-inflammatory therapy in patients prone to develop atherosclerosis and in those who had arterial reconstructive surgery.