Results for primary bypass versus primary angioplasty/stent for intermittent claudication due to superficial femoral artery occlusive disease

Prosthetic Conduits have Worse Outcomes compared to Great Saphenous Vein Conduits in Femoropopliteal and Infrapopliteal Bypass in Patients with Chronic Limb Threatening Ischemia

OBJECTIVES

Single segment great saphenous vein (SSGSV) has traditionally been considered the gold standard conduit for infrainguinal bypass. There are data supporting similar outcomes with prosthetic femoral-popliteal bypass. Moreover, some have advocated for prosthetic conduit for femoral tibial bypass when GSV is inadequate or unavailable. We sought to evaluate long-term outcomes of infrainguinal bypass based on conduit type for treating chronic limb threatening ischemia (CLTI).

METHODS

Data from the Best Endovascular versus Best Surgical Therapy of Patients with CLTI (BEST-CLI) multicenter, prospective, randomized controlled trial, comparing infrainguinal bypass with endovascular therapy in patients with CLTI, were evaluated. In this as-treated analysis, we compared outcomes of infrainguinal bypass using prosthetic, alternative autogenous vein (AAV), and cryopreserved vein (Cryo) with SSGSV bypass. Kaplan-Meier and multivariable analyses were performed to examine the associations of conduit type with major adverse limb event (MALE) events, reinterventions, above-ankle amputations, and all-cause death.

RESULTS

In total, 784 bypasses were analyzed (120 prosthetic, 33 AAV, 21 Cryo, 610 SSGSV). For prosthetic and SSGSV, the distribution was 357 femoropopliteal (93 prosthetic and 264 GSV) and 373 infrapopliteal (27 prosthetic and 346 GSV). Mean age for the overall cohort was 67.1 years; 27.4% were female gender, 29.9% were non-White, and 11.5% were of Hispanic ethnicity. Patients undergoing prosthetic bypass were older (69.2 vs. 66.7 years), more likely to have chronic obstructive pulmonary disease (22.5% vs. 14%), prior coronary artery bypass grafting (88.9% vs. 66.5%), prior stroke (23.3% vs. 14%), but less often were of Hispanic ethnicity (5.8% vs. 12.6%) and had diabetes (59.2% vs. 71.3%) (P<.05 for all). For femoropopliteal bypass, use of prosthetic conduit was associated with increased major reinterventions at 3 years overall (19% vs. 11.5%, P=.06) and on risk adjusted analysis (HR 2.13, 95% CI 1.09 - 4.2, P=.028). No significant differences in MALE or death, above-ankle amputation, or death were observed. Outcomes were similar for bypasses to above knee popliteal targets and below knee popliteal targets. For infrapopliteal bypass, use of prosthetic conduit was associated with increased major reintervention (25.3% vs. 10.3%, P=.005), death (68.6% vs. 34.8%, P<.001), MALE or death (90% vs. 48.1%, P<.001) at 3 years. After risk adjustment, infrapopliteal bypass with prosthetic conduit was associated with higher major reintervention (HR 4.14, 95% CI 1.36 - 12.6, P=.012), above-ankle amputation (HR 4.64, 95% CI 1.59 - 13.5, P=.005), death (HR 2.96, 95% CI 1.4 - 6.2, P=.004), and MALE or death (HR 3.59, 95% CI 1.64 - 7.86, P=.001) compared to bypass with SSGSV. Overall, AAV had similar outcomes at 3 years to SSGSV, however Cryo had significantly higher above ankle amputation (50% vs 12.8%) (HR 4.2, 95% CI 1.68 - 10.5, P=.002), major reintervention (41.9% vs. 10.7%) (HR 3.12, 95% CI 1.18 - 8.22, P=.02), and MALE/death (88.8% vs. 37.8%) (HR 2.96, 95% CI 1.43-6.14, P=.004).

CONCLUSIONS

Use of prosthetic conduit in infrainguinal bypass is associated with inferior outcomes compared to bypass using SSGSV, particularly for bypass to infrapopliteal targets. Cryo grafts were infrequent and also demonstrated inferior outcomes. SSGSV remains the preferred conduit of choice for infrainguinal bypass.

Markers of optimal medical therapy are associated with improved limb outcomes after elective revascularization for intermittent claudication

BACKGROUND

Optimal medical therapy (OMT) is a modifiable factor that decreases mortality and cardiovascular events in patients with severe peripheral arterial disease. We hypothesized that preintervention OMT would be associated with improved 1-year reintervention and major adverse limb event (MALE) rates after elective endovascular revascularization for intermittent claudication (IC).

METHODS

Using the Vascular Quality Initiative (2010-2020), we identified patients with IC undergoing elective endovascular, hybrid, and open surgical interventions. Preoperative antiplatelet, statin, and nonsmoking status defined OMT components and created three groups: complete (all components), partial (1-2 components), and no OMT. The primary outcome was 1-year reintervention. Secondary outcomes included MALE and factors associated with OMT usage. Multivariable logistic regression generated adjusted odds ratios (aOR).

RESULTS

There were 39,088 patients (14,907 [38.1%] complete, 22,054 [56.4%)] partial, 2127 [5.4%] no OMT) who met our criteria. Patients with any OMT were more frequently older with more cardiovascular diseases and diabetes (P < .0001). Patients without OMT were more likely to be Black or with Medicare or Medicaid (P < .05). Observed 1-year reintervention (5.3% complete OMT, 6.1% partial OMT, 8.3% no OMT; P < .001) and MALE (5.6% complete OMT, 6.3% partial OMT, 8.8% no OMT; P < .001) were decreased by partial or complete OMT compared with no OMT. Complete OMT significantly decreased the adjusted odds of reintervention and MALE by 28% (aOR, 0.72, 95% confidence interval [95% CI], 0.59-0.88) and 30% (aOR, 0.70; 95% CI, 0.58-0.85), respectively, compared with no OMT. Partial OMT decrease the adjusted odds of reintervention and MALE by 24% (aOR, 0.76; 95% CI, 0.63-0.92) and 26% (aOR, 0.74; 95% CI, 0.62-0.89), respectively.

CONCLUSIONS

Preintervention OMT is an underused, modifiable risk factor associated with improved 1-year reintervention and MALE. Vascular surgeons are uniquely positioned to initiate and maintain OMT in patients with IC before revascularization to optimize patient outcomes.

Retrograde Peroneal Artery Approach to Treat Infra-Inguinal Arterial Chronic Total Occlusions: A Multicentre Experience and Technical Considerations

Background/Objectives: Retrograde access of the peroneal artery (PA) is considered technically challenging and at risk of bleeding. The aim of this multicentre retrospective study was to assess the safety, feasibility, and technical success of this access route for infrainguinal endovascular recanalizations. Methods: We retrospectively analyzed 186 consecutive patients treated over a 7-year period (May 2014-August 2021) who underwent endovascular recanalization of infra-inguinal lesions using a PA access route. In all cases, retrograde PA access was obtained following a failed attempt to cross the occlusion via the antegrade route. Results: Among the 186 patients, 120 were males (60.5%) and the mean age was 76.8 ± 10.7 years old (44-94 years). One hundred and thirteen patients (60.7%) suffered from chronic limb threatening ischemia (CLTI). All patients presented with chronic total occlusions (CTO) and a failed conventional antegrade recanalization attempt. Retrograde access was performed under angiographic guidance in 185 cases (99.5%). It was successfully established in 171 cases (91.9%). The total rate of retrograde puncture-related complications was 2.1% (two puncture site bleedings of which one necessitated fasciotomy and two cases of arteriovenous fistulas managed conservatively). The Major Adverse Event (MAE) rate at 30 days was 1.6% (3/186). Conclusions: Retrograde recanalization of challenging infra-inguinal lesions via PA is safe and effective in experienced hands.

Revascularization for claudication: Changing the natural history of a benign disease!

OBJECTIVE

The benign natural history of intermittent claudication was first documented in 1960 and has been reconfirmed in several subsequent studies. Excellent outcomes in patients with intermittent claudication can be achieved with exercise therapy and optimal medical management. Professional society guidelines have clearly stated that revascularization procedures should be performed only in patients with incapacitating claudication who have failed conservative therapy. Despite these guidelines, revascularization procedures, primarily percutaneous interventions, have been increasingly utilized in patients with claudication. Many of these patients are not even offered an attempt at medical therapy, and those who are often do not undergo a full course of treatment. Many studies document significant reintervention rates following revascularization, which are associated with increased rates of acute and chronic limb ischemia that may result in significant rates of amputation. The objectives of this study were to compare outcomes of conservative therapy to those seen in patients undergoing revascularization procedures and to determine the impact of revascularization on the natural history of claudication.

METHODS

Google Scholar and PubMed were searched for manuscripts on the conservative management of claudication and for those reporting outcomes following revascularization for claudication.

RESULTS

Despite early improvement in claudication symptoms following revascularization, multiple studies have demonstrated that long-term outcomes following revascularization are often no better than those obtained with conservative therapy. High reintervention rates (up to 43% for tibial atherectomies) result in high rates of both acute and chronic limb ischemia as compared with those patients undergoing medical therapy. In addition, amputation rates as high as 11% on long-term follow-up are seen in patients undergoing early revascularization. These patients also have a higher incidence of adverse cardiovascular events such as myocardial infarctions compared with patients treated medically.

CONCLUSIONS

Revascularization procedures negatively impact the natural history of claudication often resulting in multiple interventions, an increase in the incidence of acute and chronic limb ischemia, and an increased risk of amputation. Accordingly, informed consent requires that all patients undergoing early revascularization must be appraised of the potential negative impact of revascularization on the natural history of claudication.

Outcomes of lower extremity revascularization in octogenarians and nonagenarians for intermittent claudication

OBJECTIVE

Revascularization for intermittent claudication (IC) due to infrainguinal peripheral arterial disease (PAD) is dependent on durability and expected benefit. We aimed to assess outcomes for IC interventions in octogenarians and nonagenarians (age ≥80 years) and those younger than 80 years (age <80 years).

METHODS

The Vascular Quality Initiative was queried (2010-2020) for peripheral vascular interventions (PVIs) and infrainguinal bypasses (IIBs) performed to treat IC. Baseline characteristics, procedural details, and outcomes were analyzed (comparing age ≥80 years and age <80 years).

RESULTS

There were 84,210 PVIs (12.1% age ≥80 years and 87.9% age <80 years) and 10,980 IIBs (7.4% age ≥80 years and 92.6% age <80 years) for IC. For PVI, patients aged ≥80 years more often underwent femoropopliteal (70.7% vs 58.1%) and infrapopliteal (19% vs 9.3%) interventions, and less often iliac interventions (32.1% vs 48%) (P < .001 for all). Patients aged ≥80 years had more perioperative hematomas (3.5% vs 2.4%) and 30-day mortality (0.9% vs 0.4%) (P < .001). At 1-year post-intervention, the age ≥80 years cohort had fewer independently ambulatory patients (80% vs 91.5%; P < .001). Kaplan-Meier analysis showed patients aged ≥80 years had lower reintervention/amputation-free survival (81.4% vs 86.8%), amputation-free survival (87.1% vs 94.1%), and survival (92.3% vs 96.8%) (P < .001) at 1-year after PVI. Risk adjusted analysis showed that age ≥80 years was associated with higher reintervention/amputation/death (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.1-1.35), amputation/death (HR, 1.85; 95% CI, 1.61-2.13), and mortality (HR, 1.92; 95% CI, 1.66-2.23) (P < .001 for all) for PVI. For IIB, patients aged ≥80 years more often had an infrapopliteal target (28.4% vs 19.4%) and had higher 30-day mortality (1.3% vs 0.5%), renal failure (4.1% vs 2.2%), and cardiac complications (5.4% vs 3.1%) (P < .001). At 1 year, the age ≥80 years group had fewer independently ambulatory patients (81.7% vs 88.8%; P = .02). Kaplan-Meier analysis showed that the age ≥80 years cohort had lower reintervention/amputation-free survival (75.7% vs 81.5%), amputation-free survival (86.9% vs 93.9%), and survival (90.4% vs 96.5%) (P < .001 for all). Risk-adjusted analysis showed age ≥80 years was associated with higher amputation/death (HR, 1.68; 95% CI, 1.1-2.54; P = .015) and mortality (HR, 1.85; 95% CI, 1.16-2.93; P = .009), but not reintervention/amputation/death (HR, 1.1; 95% CI, 0.85-1.44; P = .47) after IIB.

CONCLUSIONS

Octogenarians and nonagenarians have greater perioperative morbidity and long-term ambulatory impairment, limb loss, and mortality after PVI and IIB for claudication. Risks of intervention on elderly patients with claudication should be carefully weighed against the perceived benefits of revascularization. Medical and exercise therapy efforts should be maximized in this population.

A systematic review of simulation training for lower extremity bypass procedures

OBJECTIVES

Simulation is used across surgical specialties for skill enhancement. The choice and assessment method of a simulator varies across literature. In the age of endovascular approach, trainees have limited exposure to open lower limb bypass procedures which needs attention. This review aims to assess the utility of simulation training in lower limb bypass surgery using Kirkpatrick's model.

METHODS

Using PRISMA statement, we included all the studies done on simulators in lower limb bypass surgical procedures for this systematic review. The primary outcome was to assess the effectiveness of different types of simulation used for lower limb bypass surgery using the Kirkpatrick's model for training evaluation.

RESULTS

An initial search identified 295 articles out of which 7 articles were found to be eligible for this systematic review. A variety of simulators were used including cadavers and synthetic models. Most studies (n=5) found the use of simulation as an effective tool in achieving technical competence. All the five studies we found at level 2 on Kirpatrick's model evaluation.

CONCLUSION

Most of the existing studies are at level 2 of Kirkpatrick's model which reflects learning changes in trainees after simulation. Feedback mechanism needs to be evolved where the improvement after simulation training can be gauged by its replication in clinical practice and improved patient care practices corresponding to the highest level of Kirkpatrick's model.

Vein Bypass Versus Nitinol Stent in Long Femoropopliteal Lesions: 4-Year Results of a Randomized Controlled Trial

OBJECTIVES

The aim of this study was to compare technical success, patency rates and clinical outcomes of vein bypass (VBP) with angioplasty and nitinol stents (NS) in femoropopliteal Trans-Atlantic Intersociety Consensus (TASC) II C and D lesions.

SUMMARY BACKGROUND DATA

Guidelines widely recommend an endovas-cular-first strategy for long femoropopliteal lesions without sufficient data comparing it with vein bypass surgery.

METHODS

A single-center prospective, randomized controlled trial (RCT) was performed, after approval of the local ethics committee, with technical success, primary and secondary patency as primary endpoints. Secondary endpoints were limb salvage, survival, complications, and clinical improvement.

RESULTS

Between 2016 and 2020, 218 limbs (109 per group) in 209 patients were included. Baseline and lesion characteristics were similar in both groups with a mean lesion length of 268 mm. The indication for treatment was chronic limb threatening ischemia in 53% of limbs in both groups. Technical success was feasible in 88% in the stent group. During a 4-year follow-up, primary patency, freedom from target lesion revascularizations, limb salvage, survival and complications showed no significant differences between the groups. At 48 months secondary patency for the bypass group was 73% versus 50% in the stent group ( P = 0.021). Clinical improvement was significantly superior in the bypass group with 52% versus 19% reaching a Rutherford 0 category ( P < 0.001).

CONCLUSIONS

This is the largest RCT comparing angioplasty with NS and vein bypass in femoropopliteal TASC II C and D lesions and the first to report 4-year results. The data underline the feasibility of endovascular treatment in long lesions but also emphasize the advantages of VBP.

Female Sex is Associated with More Reinterventions after Endovascular and Open Interventions for Intermittent Claudication

BACKGROUND

Intermittent claudication (IC) is a commonly treated vascular condition. Patient sex has been shown to influence outcomes of interventions for other vascular disorders; however, whether outcomes of interventions for IC vary by sex is unclear. We sought to assess the association of patient sex with outcomes after IC interventions.

METHODS

The Vascular Quality Initiative was queried from 2010-2020 for all peripheral endovascular interventions (PVI), infra-inguinal bypasses (IIB), and supra-inguinal bypasses (SIB) for any degree IC. Univariable and multivariable analyses compared peri-operative and long-term outcomes by patient sex.

RESULTS

There were 24,701 female and 40,051 male patients undergoing PVI, 2,789 female and 6,525 male patients undergoing IIB, and 1,695 female and 2,370 male patients undergoing SIB for IC. Guideline-recommended pre-operative medical therapy differed with female patients less often prescribed aspirin for PVI (73.4% vs. 77.3%), IIB (71.5% vs. 74.8%), and SIB (70.9% vs. 74.3%) or statins for PVI (71.8% vs. 76.7%) and IIB (73.1% vs. 76.0%) (all P < 0.05). Female compared with male patients had lower 1-year reintervention-free survival after PVI (84.4% ± 0.3% vs. 86.3% ± 0.2%, P < 0.001), IIB (79.0% ± 0.9% vs. 81.2% ± 0.6%, P = 0.04), and SIB (89.4% ± 0.9% vs. 92.6% ± 0.7%, P = 0.005), but similar amputation-free survival and survival across all procedures. Multivariable analysis confirmed that female sex was associated with increased 1-year reintervention for PVI (HR 1.16, 95% CI 1.09-1.24, P < 0.001), IIB, (HR 1.16, 95% CI 1.03-1.31, P = 0.02), and SIB (HR 1.60, 95% CI 1.20-2.13, P = 0.001).

CONCLUSIONS

Female patients undergoing interventions for IC were less often pre-operatively medically optimized than male patients, though the difference was small. Furthermore, female sex was associated with more reinterventions after interventions. Interventionists treating female patients should increase their efforts to maximize medical therapy. Future research should clarify reasons for poorer intervention durability in female patients.

Outcomes of Femoropopliteal Bypass for Lifestyle-Limiting Claudication in the Endovascular Era

INTRODUCTION

Outcomes after femoropopliteal bypass for intermittent claudication (IC) remain unclear in the endovascular era.

METHODS

A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures performed between 1995 and 2020. Demographics, operative details, and outcomes were documented. A statistical analysis included Kaplan-Meier curves and Cox proportional hazards ratios (HR).

RESULTS

A total of 282 patients underwent femoropopliteal bypass surgery for IC. Median age was 68 y (interquartile range, 61-73 y). Bypass conduits included great saphenous vein (GSV) (48.2%), prosthetic grafts (48.9%), and non-GSV autogenous grafts (2.8%). Distal bypass target was above-knee in 62.1% and below-knee in 37.9% of patients. The most common postoperative complications were wound infections (14.2%) followed by unplanned 30-d hospital readmissions (12.4%). Mortality rates were low at 0.4% (30 d) and 3.2% (1 y). Five-year primary patency rates trended highest for claudicants undergoing above-knee bypass with GSV conduit (log-rank P = 0.065). Five-year amputation-free survival rates were highest using GSV conduit regardless of distal bypass target (log-rank P = 0.017). On a multivariable analysis, age (HR 1.02 [1.00-1.04], P = 0.023) and active smoking (HR 1.48 [1.06-2.06], P = 0.021) were identified as risk factors for diminished primary graft patency. Risk factors for amputation-free survival included age (HR 1.03 [1.01-1.05], P < 0.001) and GSV conduit type (HR 0.65 [0.46-0.90], P = 0.011).

CONCLUSIONS

Femoropopliteal bypass among claudicants is associated with high rates of wound infection and hospital readmission. Active smoking portends worse outcomes in this population. These data may inform clinical decision-making regarding surgical intervention for claudication in the endovascular era.

Comparative Analysis of Endovascular Intervention and Endarterectomy in Patients with Femoral Artery Disease: A Systematic Review and Meta-Analysis

Peripheral artery disease is a prevalent illness affecting more than 200 million people worldwide. A commonly used technique to manage the condition has been open endarterectomy. However, in recent times, a shift towards minimally invasive techniques has resulted in endovascular intervention as a popular alternative. This review aims to assess the safety and efficacy of endovascular intervention when compared with endarterectomy. A systematic review of the articles published in PubMed, Ovid, Embase, and Scopus within the last 10 years was conducted. The PRISMA guidelines were adhered to, and the Newcastle-Ottawa and NICE quality assessment scales were used. A meta-analysis of proportions was performed using the RStudio software (RStudio Team (2021). RStudio: Integrated Development Environment for R, PBC, Boston, MA, USA). Twenty-six studies were included, with a total of 7126 patients (endovascular, 2496; endarterectomy, 4630). Technical success was greater for endarterectomy than endovascular intervention with an odds ratio of 0.38; 95% CI [0.27–0.54]. In terms of safety as well endovascular intervention was better than endarterectomy with an odds ratio of 0.22; 95% CI [0.15 to 0.31] for wound infection. Endovascular intervention is a safe and effective procedure; however, it cannot be considered superior to endarterectomy.

Risk Factors and Consequences of Graft Infection after Femoropopliteal Bypass: A 25-year Experience

INTRODUCTION

In this multi-institutional series, we aimed to determine the incidence, risk factors, and long-term outcomes of graft infection in patients post-femoropopliteal bypass.

METHODS

A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures from 1995-2020. Cumulative incidence function estimated the long-term rate of bypass graft infection (BGI) and Fine-Gray model was used to determine independent risk factors for BGI to account for death as a competing risk.

RESULTS

Over the 25-year period, 1315 femoral popliteal bypasses were identified with a median follow-up of 2.89 years (IQR 0.75-6.55). BGI was diagnosed in 34 (2.6%) patients. BGI occurred between 9 days and 11.2 years postoperatively, with a median 109 days. Estimated 1- and 5-year incidence of BGI was 2.1% (95% CI, 1.4-3.1%) and 2.8% (95% CI, 1.9-3.9%) respectively. Medical comorbidities, indications for bypass, and popliteal bypass targets (above- vs below-knee) were similar between BGI patients and all patients (p=NS each). Patients with BGI were more frequently complicated by postoperative hematoma (14.7% vs 3.7%), superficial wound infection (38.2% vs 19.2%), lymphocele/lymphorrhea (8.8% vs 2.1%), and 30-day readmission rates (47.1% vs 21.3%) (p<0.05 each). Most commonly isolated pathogens were Staphylococcus aureus (n=19, 55.9%) and polymicrobial cultures (n=5, 14.7%). Reoperation for BGI involved incision and drainage (n=7, 20.6%), graft excision without reconstruction (n=12, 35.3%), graft excision with in-line reconstruction (n=11, 32.4%), and graft excision with extra-anatomic reconstruction (n=2, 5.9%). Nine BGI patients (26.5%) ultimately required major amputation. Prosthetic bypass (subdistribution hazard ratio [SHR] 3.73 [1.64-8.51], p=0.002), postoperative hematoma (SHR 3.44 [1.23-9.61], p=0.018), and 30-day readmission (SHR 2.75 [1.27-5.44], p=0.010) were independently associated with BGI. One-year amputation-free survival was 50% (95% CI, 31.9-65.7%) after BGI.

CONCLUSIONS

BGI is a rare complication of femoral-popliteal bypass with significant morbidity. Graft infection is associated with the use of prosthetic grafts, postoperative hematoma, and unplanned hospital readmission. Mitigation of these risk factors may decrease the risk of this dreaded complication.

Prophylactic paclitaxel-eluting stent placement does not improve covered femoropopliteal stent patency

OBJECTIVE

Covered stents are an important tool in managing femoropopliteal peripheral arterial disease. However, their performance is impaired by edge neointimal hyperplasia and restenosis. We examined the effectiveness of prophylactic deployment of paclitaxel-eluting stents to prevent edge restenosis.

METHODS

A retrospective case-control study was performed. Patients with femoropopliteal peripheral arterial disease who were treated with Viabahn stent placement were compared to patients treated with Viabahn stents deployed in conjunction with paclitaxel-eluting stents (PTX). The primary outcome was time to loss of stent primary patency. The Kaplan-Meier method was used.

RESULTS

A total of 36 Viabahn and 25 Viabahn + paclitaxel-eluting stent procedures were evaluated, with mean follow-up periods of 27 and 18 months, respectively. The Viabahn + paclitaxel-eluting stent group had a longer length of vessel stented (P = .0023). Twelve-month primary patency was 74% in the Viabahn group and 75% in the Viabahn + paclitaxel-eluting stent group. Pre-existing dyslipidemia correlated with earlier loss of primary patency across the combined cohort (P = .0193).

CONCLUSION

Viabahn stent primary patency is unaffected by the addition of paclitaxel-eluting stents.

Outcomes of Axillofemoral Bypass for Intermittent Claudication

OBJECTIVE

While endovascular therapy is often first-line treatment for medically refractory intermittent claudication (IC) caused by aorto-femoral disease, suprainguinal bypass is commonly performed. Although this is often aorto-femoral bypass (AoFB), axillo-femoral bypass (AxFB) is still sometimes performed despite limited data evaluating its utility in the management of IC. Our goal was to assess the safety and durability of AxFB performed for IC.

METHODS

The Vascular Quality Initiative (2009-2019) was queried for suprainguinal bypass performed for IC. Univariable and multivariable analyses were used to compare perioperative and one-year outcomes between AxFB and a comparison cohort of AoFB.

RESULTS

We identified 3,261 suprainguinal bypasses performed for IC: 436 AxFB and 2,825 AoFB. Overall, mean age was 61.4 ± 9.1 years, 58.8% of patients were male sex, and 59.7% currently smoked. Patients undergoing AxFB, compared with AoFB, were more often older, male, never-smokers, and ambulated with assistance (all P<.001). They more often had hypertension, diabetes, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, end-stage renal disease, previous outflow peripheral endovascular interventions, and previous inflow or outflow bypass. AxFB, compared with AoFB, were more often uni-femoral (all P<.05). Patients undergoing AxFB, compared with AoFB, had shorter postoperative length of stay (median 4 vs. 6 days) and fewer perioperative pulmonary (3% vs. 7.9%) and renal complications (5.5% vs. 9.9%), but more perioperative ipsilateral major amputations (.9% vs. 0.04%) (all P<.05). There were no significant differences in perioperative myocardial infarction (2.8% vs. 2.7%), stroke (.7% vs. 1.1%), and death (1.8% vs. 1.7%) rates, respectively. At one year, Kaplan-Meier analysis demonstrated that the AxFB, compared with AoFB cohort, exhibited higher rates of death (7.3% vs. 3.6%, P=.002); graft occlusion or death (14.3% vs. 7.2%, P=.001); ipsilateral major amputation or death (12.5% vs. 5.6%, P<.001); and reintervention, amputation, or death (19% vs. 8.6%, P<.001). On multivariable analysis, AxFB was independently associated with increased risk of one-year reintervention, amputation, or death (HR 1.6, 95% CI 1.03-2.4, P=.04).

CONCLUSIONS

This retrospective analysis suggests that long-term complications were more frequent in patients who underwent AxFB as compared to AoFB, although patients treated with AxFB were at higher risk with more comorbidities. Since AxFB is associated with significant perioperative morbidity, mortality, and long-term complications, serious consideration should be given prior to its use for IC.

Statins and Peripheral Arterial Disease: A Narrative Review

Peripheral arterial disease (PAD) is a highly prevalent atherosclerotic condition. In patients with PAD, the presence of intermittent claudication leads to a deterioration in quality of life. In addition, even in asymptomatic cases, patients with PAD are at high risk of cardiac or cerebrovascular events. Treatment of PAD is based on lifestyle modifications; regular exercise; smoking cessation; and control of cardiovascular risk factors, including hypercholesterolemia. A growing number of studies have shown that statins reduce cardiovascular risk and improve symptoms associated with PAD. Current guidelines recommend the use of statins in all patients with PAD in order to decrease cardiovascular events and mortality. However, the prescribing of statins in patients with PAD is lower than in those with coronary heart disease. This review provides relevant information from the literature that supports the use of statins in patients with PAD and shows their potential benefit in decreasing lower limb complications as well as cardiovascular morbidity and mortality.

C-reactive Protein, Free Fatty Acid, and Uric Acid as Predictors of Adverse Events after Endovascular Revascularization of Arterial Femoropopliteal Occlusion Lesions

OBJECTIVES

This study aimed to investigate the relationship between pre-procedure high-sensitivity C-reactive protein (hsCRP), free fatty acid (FFA), and uric acid (UA) levels and post-procedure mortality and morbidity of endovascular revascularization of arterial femoropopliteal occlusion lesions.

METHODS

This was a retrospective review of clinical data retrieved from a prospectively held database in Peking Union Medical College Hospital. A total of 71 Patients who underwent endovascular treatment (EVT) for femoropopliteal occlusive disease between January 1, 2014 and November 1, 2017, were included in this study. Endpoints were defined as major adverse limb events (MALE; target vessel revascularization, amputation, or disease progression) and major adverse cardiovascular events (MACE; stroke, myocardial infarction, or all-cause death) during the entire follow-up period. Univariate and multivariate Cox proportional hazards regression models were used to evaluate the relationship of elevated biomarker levels (hsCRP, FFA and UA, measured by immunoturbidimetry assay, enzymatic assay and enzymatic assay, respectively) to MALE and MACE outcomes.

RESULTS

Seventy-one patients (72 limbs) with sufficient follow-up information were included in the analysis. The mean age was 69.7 ± 8.6 years; 21.1% were female. The Rutherford class of target limbs were ≥ 3. The median follow-up was 36 (range 18-59 months). Univariate analyses revealed that patients with elevated hsCRP levels had an increased risk of MALE (hazard ratio [HR], 2.682; 95% confidence interval [CI], 1.281-5.617, P = 0.009). High FFA levels were associated with an increased risk of MALE (HR, 2.658; 95% CI, 1.075-6.573; P = 0.034). Multivariate analyses demonstrated that elevated hsCRP values (HR, 4.015; 95% CI, 1.628-10.551; P = 0.003) and FFA value (HR, 3.034; 95% CI, 1.102-8.354; P = 0.032) were both significantly associated with increased MALE. Elevated UA levels predicted MACE in the presence of confounders (HR, 11.446; 95% CI, 1.367-95.801 P = 0.023).

CONCLUSION

Pre-procedure hsCRP and FFA levels could serve as predictors of adverse events after EVT in patients with arterial femoropopliteal occlusive disease. The role of UA in MACE may warrant further investigation, because the correlation is not as powerful as the other two in the study.

Critical appraisal of evidence on bypass surgery versus endovascular treatment for intermittent claudication: a systematic review and meta-analysis

INTRODUCTION

Intermittent claudication (IC) stage of peripheral artery disease (PAD) is associated with significant impairment of quality of life. In the subset of patients with disabling IC refractory to best medical treatment (BMT), revascularization procedures may be considered. However, evidence comparing open revascularization surgery, endovascular treatment and BMT focussing on the impact on quality of life is very sparse. We aim to review clinical, anatomical and hemodynamic outcomes after bypass surgery compared to BMT and/or endovascular treatment in IC patients.

EVIDENCE ACQUISITION

We systematically reviewed controlled trials and comparative cohort studies assessing quality of life, walking performance, clinical/symptomatic improvement, symptom recurrence, patency rates, ankle-brachial index (ABI) improvement and adverse events after bypass surgery versus endovascular treatment/BMT in IC patients.

EVIDENCE SYNTHESIS

Eleven studies involving 16,608 patients were included. Compared to BMT, bypass surgery was associated with a significantly greater improvement on Short-Form 36 (SF-36) physical functioning score (mean difference (MD), -14.0; 95% confidence interval (CI), -21.2 to -6.8), Walking Impairment Questionnaire (WIQ) walking distance score (MD, -0.23; 95% CI, -0.29 to -0.16) and SF-36 bodily pain score (MD, -13.0; 95% CI, -20.2 to -5.8). There were no significant differences between bypass and endovascular treatment regarding the three scores. Bypass surgery presented better primary patency rates at 1 (odds ratio (OR), 0.47; 95% CI, 0.29 to 0.76) and 5 years (OR, 0.44; 95% CI, 0.34 to 0.57) and better ABI improvement (MD, -0.07; 95% CI, -0.12 to -0.03) when compared to endovascular treatment. There were no statistically significant differences between bypass and endovascular patients regarding secondary patency rates, 30-day mortality and major amputation.

CONCLUSIONS

Lower limb revascularization may be beneficial in patients with disabling and refractory IC when the primary goal is to improve quality of life and walking capacity. Bypass surgery is associated to better symptomatic status, long-term primary patency and ABI improvement when compared to endovascular surgery, especially in anatomically extensive disease. Further studies addressing patient-reported outcomes and including a BMT group are paramount for more robust evidence on IC treatment and, consequently, better decision making.

Comparison of Prosthetic and Vein Bypass with Nitinol Stents in Long Femoropopliteal Lesions

BACKGROUND

Guidelines for the treatment of long femoropopliteal lesions are not based on a high level of evidence and recent randomized controlled trials (RCTs) challenge vein bypass (VBP) as the recommended therapy. This study compared prosthetic (PTFE) bypass, VBP and angioplasty with nitinol stents in long femoropopliteal lesions.

METHODS

Pooled data from a RCT and a retrospective database with the same inclusion criteria were analyzed with primary and secondary patency as well as freedom from target lesion revascularization (TLR) as primary endpoints.

RESULTS

Between 2016 and 2018 a total of 172 lesions were treated in three groups (PTFE: n = 62, VBP: n = 55, stent: n = 55). Clinical and lesion characteristics were similar with mean lesion lengths between 260 and 279mm. Technical success rate in the stent group was 87%. There were no significant differences between the groups in patency rates, freedom from TLR, limb salvage and survival during 2-year follow-up. The primary patency rates for the PTFE, VBP and stent groups were 50%, 56% and 60% at 2 years. The PTFE group had significantly less complications compared to the other groups and a shorter hospital-stay compared to the VBP group. Clinical improvement was significantly better in the PTFE and VBP group compared to the stent group.

CONCLUSIONS

The 2-year results indicate that the role of VBP as the recommended therapy for long femoropopliteal lesions may not be unchallenged due to the similar results in all three groups. Further RCTs are needed to determine the best revascularization modality for long femoropopliteal lesions.

Outcomes of bypass and endovascular interventions for advanced femoropopliteal disease in patients with premature peripheral artery disease

OBJECTIVE

Patients with premature peripheral artery disease (PAD), defined as age ≤50 years at presentation, have had poor outcomes with open and endovascular lower extremity revascularization. It is unclear whether either strategy is associated with better outcomes because comparative studies have been limited to case series in this patient population. The aim of the present study was to compare the outcomes of patients with premature PAD who had undergone bypass or endovascular revascularization for advanced femoropopliteal disease. Our hypothesis was that open bypass would provide superior long-term outcomes compared with endovascular intervention for patients with premature advanced femoropopliteal PAD.

METHODS

All the patients with premature PAD who had undergone isolated femoropopliteal lower extremity revascularization and included in the Vascular Quality Initiative infrainguinal bypass and peripheral vascular intervention files were reviewed from 2003 through 2019. Propensity score matching (1:1) was performed between patients who had undergone femoropopliteal bypass and endovascular interventions for isolated femoropopliteal Trans-Atlantic Classification System C or D lesions. The 1-year outcomes, including reintervention, patency, major amputation, and mortality, were analyzed.

RESULTS

Of the 2538 included patients, 902 had undergone isolated femoropopliteal endovascular intervention and 1636 had undergone femoropopliteal bypass. The endovascular intervention group were more likely to have diabetes (68.9% vs 54.0%; P < .001), coronary artery disease (31.0% vs 23.0%; P < .001), renal failure requiring dialysis (14.2% vs 7.2%; P < .001), and claudication (45.1% vs 36.6%; P < .001) compared with the bypass group. After propensity score matching, 466 patients were in each group with no significant differences in the baseline characteristics. Perioperative morbidity was higher with femoropopliteal bypass compared with endovascular intervention (12.0% vs 7.9%; P = .038); however, the rates of major amputation and mortality were not different. At 1 year, patients who had undergone femoropopliteal bypass were less likely to require reintervention (17.0% vs 25.2%; P = .012). However, no differences were found in major amputation (7.7% vs 7.9%; P = .928) or mortality (5.2% vs 5.2%; P = 1.00). Propensity score matching was also performed between femoropopliteal bypass with the great saphenous vein and isolated femoropopliteal endovascular interventions, and the outcomes were similar.

CONCLUSIONS

For patients with premature PAD and advanced femoropopliteal disease, bypass surgery decreased the reintervention rate at 1 year but was associated with increased perioperative morbidity and hospital length of stay compared with endovascular therapy. No differences were found in major amputation or mortality between the two strategies.

A systematic review of the ipsilateral retrograde approach to the treatment of femoropopliteal arterial lesions

OBJECTIVE

The endovascular treatment of femoropopliteal lesions is an integral part of managing peripheral arterial disease. The antegrade approach is the most widely used technique with good evidence for its safety and efficacy. However, crossing a lesion, particularly chronic total occlusions (CTO), can be technically challenging and so the retrograde approach is increasingly used to maximize the chances of procedural success. The objective of this systematic review was, therefore, to assess the safety and effectiveness of the ipsilateral retrograde approach to femoropopliteal lesions.

METHODS

A systematic review conforming to the PRISMA standards was undertaken. MEDLINE, EMBASE, and The Cochrane Register were searched between January 1, 1988, and January 1, 2020. Full-text, English-language, peer-reviewed articles pertaining to peripheral arterial disease, endovascular intervention and access site were included.

RESULTS

A total of 8599 articles were screened, of which 38, involving 1940 patients undergoing 2184 retrograde procedures, were included. The mean number of patients per study was 51.1, with three studies including fewer than 10 and four more than 100 patients. The reported follow-up ranged from 30 days to 3 years, and six articles did not report any long-term outcome data. A retrograde approach was used as the primary access route in 45.% of procedures (648/1438) with relevant data. Primary technical success was achieved in 88% (1920/2184; 64%-100%) with a reported complication rate of 11% (235/2117; 0%-27%). Overall, the quality of evidence was poor, with just seven articles deemed to be of high quality with a low risk of bias. A meta-analysis was not deemed appropriate owing to heterogeneity of data.

CONCLUSIONS

An ipsilateral retrograde approach to femoropopliteal lesions has good primary technical success and a low rate of complications. It has a promising role as a bailout, or even a primary access technique, in complex lesions. Patient positioning, puncture site and technique, lesion anatomy, and the size of catheters and devices used are important considerations to achieve the best outcomes. There remains a paucity of robust evidence for its superiority over traditional antegrade approaches, and further work is required to identify the optimal technique and those patients who would benefit most from the approach.

Smaller Superficial Femoral Artery is Associated with Worse Outcomes after Percutaneous Transluminal Angioplasty for De Novo Atherosclerotic Disease

BACKGROUND

With the exponential increase in the use of endovascular techniques in the treatment of peripheral artery disease, our understanding of factors that affect intervention failures continues to grow. We sought to assess the outcomes of percutaneous transluminal angioplasty for isolated de novo superficial femoral artery (SFA) disease based on balloon diameter.

METHODS

The Vascular Quality Initiative database was queried for patients undergoing percutaneous balloon angioplasty for isolated de novo atherosclerotic SFA disease. Based on the diameter of the angioplasty balloon as a surrogate measure of arterial diameter, patients were stratified into 2 groups: group 1, balloon diameter <5 mm (354 patients) and group 2, balloon diameter ≥5 mm (1,550 patients). The primary patency and major adverse limb event (MALE) were estimated by the Kaplan-Meier method and compared with the log-rank test, based on vessel diameter. Multivariable Cox regression analysis was used to determine factors associated with the primary patency.

RESULTS

From January 2010 through December 2018, a total of 1,904 patients met criteria for analysis, with a mean follow-up of 13.3 ± 4.5 months. The mean balloon diameters were 3.92 ± 0.26 mm and 5.47 ± 0.55 mm in group 1 and 2, respectively (P < 0.001). The mean length of treatment and distribution of TASC lesions were not statistically different between the groups. Primary patency at 18 months was significantly lower in group 1, compared with group 2 (55% vs. 67%; log-rank P < 0.001). The MALE rate was higher in group 1 than group 2 (33% vs. 26%; log-rank P < 0.001). Among patients with claudication, there was no significant difference in the primary patency (61% vs 68%; log-rank P = 0.073) and MALE (27% vs. 22%; log-rank P = 0.176) at 18 months between groups 1 and 2, respectively. However, in patients with CLTI, group 1 had significantly lower 18-month primary patency (47% vs. 64%; log-rank P < 0.014) and higher MALE rates (41% vs. 35%; log-rank P = 0.012) than group 2. Cox proportional hazard analysis confirmed that balloon diameter < 5 mm was independently associated with increased risks of primary patency loss (HR 1.35; 95% CI, 1.04-1.72; P = 0.021) and MALE (HR 1.29; 95% CI, 1-1.67; P = 0.048) at 18-months.

CONCLUSIONS

In patients undergoing isolated SFA balloon angioplasty for CLTI, smaller SFA (<5 mm) was associated with worse primary patency and MALE. Using balloon size as a surrogate, our findings suggest that patients with a smaller SFA diameter appear to be at increased risk for treatment failure and warrant closer surveillance. Furthermore, these patients may also be considered for alternative approaches, including open revascularization.

Intermittent claudication treatment patterns in the commercially insured non-Medicare population

OBJECTIVE

Despite published guidelines and data for Medicare patients, it is uncertain how younger patients with intermittent claudication (IC) are treated. Additionally, the degree to which treatment patterns have changed over time with the expansion of endovascular interventions and outpatient centers is unclear. Our goal was to characterize IC treatment patterns in the commercially insured non-Medicare population.

METHODS

The IBM MarketScan Commercial Database, which includes more than 8 billion US commercial insurance claims, was queried for patients newly diagnosed with IC from 2007 to 2016. Patient demographics, medication profiles, and open/endovascular interventions were evaluated. Time trends were modeled using simple linear regression and goodness-of-fit was assessed with coefficients of determination (R²). A patient-centered cohort sample and a procedure-focused dataset were analyzed.

RESULTS

Among 152,935,013 unique patients in the database, there were 300,590 patients newly diagnosed with IC. The mean insurance coverage was 4.4 years. The median patients age was 58 years and 56% of patients were male. The prevalence of statin use was 48% among patients at the time of IC diagnosis and increased to 52% among patients after one year from diagnosis. Interventions were performed in 14.3%, of whom 20% and 6% underwent two or more and three or more interventions, respectively. The median time from diagnosis to intervention decreased from 230 days in 2008 days to 49 days in 2016 (R² = 0.98). There were 16,406 inpatient and 102,925 ambulatory interventions for IC over the study period. Among ambulatory interventions, 7.9% were performed in office-based/surgical centers. The proportion of atherectomies performed in the ambulatory setting increased from 9.7% in 2007 to 29% in 2016 (R² = 0.94). In office-based/surgical centers, 57.6% of interventions for IC used atherectomy in 2016. Atherectomy was used in ambulatory interventions by cardiologists in 22.6%, surgeons in 15.2%, and radiologists in 13.6% of interventions. Inpatient atherectomy rates remained stable over the study period. Open and endovascular tibial interventions were performed in 7.9% and 7.8% of ambulatory and inpatient IC interventions, respectively. Tibial bypasses were performed in 8.2% of all open IC interventions.

CONCLUSIONS

There has been shorter time to intervention in the treatment of younger, commercially insured patients with IC, with many receiving multiple interventions. Statin use was low. Ambulatory procedures, especially in office-based/surgical centers, increasingly used atherectomy, which was not observed in inpatient settings.

Comparison of morphometric, structural, mechanical, and physiologic characteristics of human superficial femoral and popliteal arteries

Peripheral arterial disease differentially affects the superficial femoral (SFA) and the popliteal (PA) arteries, but their morphometric, structural, mechanical, and physiologic differences are poorly understood. SFAs and PAs from 125 human subjects (age 13-92, average 52±17 years) were compared in terms of radii, wall thickness, and opening angles. Structure and vascular disease were quantified using histology, mechanical properties were determined with planar biaxial extension, and constitutive modeling was used to calculate the physiologic stress-stretch state, elastic energy, and the circumferential physiologic stiffness. SFAs had larger radii than PAs, and both segments widened with age. Young SFAs were 5% thicker, but in old subjects the PAs were thicker. Circumferential (SFA: 96→193°, PA: 105→139°) and longitudinal (SFA: 139→306°, PA: 133→320°) opening angles increased with age in both segments. PAs were more diseased than SFAs and had 11% thicker intima. With age, intimal thickness increased 8.5-fold, but medial thickness remained unchanged (620μm) in both arteries. SFAs had 30% more elastin than the PAs, and its density decreased ~50% with age. SFAs were more compliant than PAs circumferentially, but there was no difference longitudinally. Physiologic circumferential stress and stiffness were 21% and 11% higher in the SFA than in the PA across all ages. The stored elastic energy decreased with age (SFA: 1.4→0.4kPa, PA: 2.5→0.3kPa). While the SFA and PA demonstrate appreciable differences, most of them are due to vascular disease. When pathology is the same, so are the mechanical properties, but not the physiologic characteristics that remain distinct due to geometrical differences.

Constitutive modeling using structural information on collagen fiber direction and dispersion in human superficial femoral artery specimens of different ages

Arterial mechanics plays an important role in vascular pathophysiology and repair, and advanced imaging can inform constitutive models of vascular behavior. We have measured the mechanical properties of 14 human superficial femoral arteries (SFAs) (age 12-70, mean 48±19 years) using planar biaxial extension, and determined the preferred collagen fiber direction and dispersion using multiphoton microscopy. The collagen fiber direction and dispersion were evaluated using second-harmonic generation imaging and modeled using bivariate von Mises distributions. The microstructures of elastin and collagen were assessed using two-photon fluorescence imaging and conventional bidirectional histology. The mechanical and structural data were used to describe the SFA mechanical behavior using two- and four-fiber family invariant-based constitutive models. Older SFAs were stiffer and mechanically more nonlinear than younger specimens. In the adventitia, collagen fibers were undulated and diagonally-oriented, while in the media, they were straight and circumferentially-oriented. The media was rich in collagen that surrounded the circumferentially-oriented smooth muscle cells, and the elastin was present primarily in the internal and external elastic laminae. Older SFAs had a more circumferential collagen fiber alignment, a decreased circumferential-radial fiber dispersion, but the same circumferential-longitudinal fiber dispersion as younger specimens. Both the two- and the four-fiber family constitutive models were able to capture the experimental data, and the fits were better for the four-fiber family formulation. Our data provide additional details on the SFA intramural structure and inform structurally-based constitutive models.

Multiple Reinterventions for Claudication are Associated with Progression to Chronic Limb-Threatening Ischemia

BACKGROUND

Claudication has a relatively benign natural history, associated with a low risk of limb loss. However, rates of progression to chronic limb-threatening ischemia (CLTI) following lower extremity revascularization (LER) for claudication remain unclear. This study examines the long-term outcomes and risk factors associated with progression to CLTI after LER for claudication.

METHODS

A single-center retrospective review of patients undergoing LER for claudication was performed from 2013-2016. Patients were stratified based on whether they progressed to CLTI or not.

RESULTS

There were 448 patients (502 limbs) treated for claudication, and 57 (12.7%) progressed to CLTI with a mean follow up time of 3.7 ± 1.5 years. Among patients who progressed, 23 (5.1%) developed tissue loss, 34 (7.6%) developed rest pain, and 6 (1.2%) underwent major amputation. The mean time of progression to CLTI was 1.6 ± 1.5 years after index LER. Patients who progressed to CLTI were more likely to have a history of congestive heart failure and prior open revascularizations compared with those who did not progress. There was no difference in type or level of index revascularization between the two groups and no difference in perioperative complications. Patients who developed CLTI had significantly higher rates of reinterventions and a mean number of reinterventions after index LER prior to developing CLTI compared to those who did not progress. Multivariable logistic regression demonstrated that history of congestive heart failure (OR = 2.8 [1.2-6.6]), stroke (OR = 2.6 [1.1-6.1]), prior open procedure (OR = 2.8 [1.3-5.9]) and increasing number of reinterventions after index LER (OR = 2.9 [1.5-5.7]) were independently associated with disease progression to CLTI.

CONCLUSIONS

Multiple reinterventions and previous open revascularization are associated with progression to CLTI following LER for claudication. Patients with atherosclerosis in the coronary and cerebrovascular beds are also more likely to have a progression of claudication to CLTI after LER.

Outcomes of open and endovascular interventions in patients with chronic limb threatening ischemia

OBJECTIVES

Widespread adoption of endovascular therapy for the treatment of chronic limb-threatening ischemia has transformed the field of vascular surgery. In this modern era, we aimed to define where open surgical interventions are of greatest benefit for limb salvage.

METHODS

Patients who underwent interventions for chronic limb-threatening ischemia were identified in the vascular-targeted lower extremity National Surgical Quality Improvement Program database for open surgical interventions (OPEN) and endovascular surgical interventions (ENDO) from 2011 to 2017. Patients were further stratified based on the criteria of chronic limb-threatening ischemia (rest pain or tissue loss), and the location of the diseased arteries (femoropopliteal or tibioperoneal). The main outcomes measured included 30-day mortality, amputation, and major adverse cardiovascular events.

RESULTS

A total of 17,193 patients were revascularized for chronic limb-threatening ischemia: 10,532 were OPEN and 6661 were ENDO. OPEN had higher 30-day mortality, major adverse cardiovascular events, pulmonary, renal dysfunction, and wound complications. However, OPEN resulted in significantly lower 30-day major amputation (3.8% vs. 5.0%, odds ratio (OR): 0.83 [0.72-0.97], P = .018). Subgroup analysis revealed a higher mortality rate in OPEN was observed only in tibioperoneal intervention for tissue loss. Major adverse cardiovascular event was higher in OPEN for most subgroups. OPEN for patients with tissue loss had significantly lower amputation rate than ENDO in both femoropopliteal and tibioperoneal subgroups (3.7% vs. 5.1%, OR: 0.76 [0.59-0.98], P = .036, and 4.7% vs. 6.6%, OR: 0.74 [0.57-0.96], P = .024, respectively). The benefit of open surgery in reducing the amputation rate was not seen in patients with rest pain.

CONCLUSIONS

Open surgical intervention is associated with significantly better limb salvage than endovascular intervention in patients with tissue loss. Surgical options should be given more emphasis as the first-line option in this cohort of patients unless the cardiopulmonary risk is prohibitive.

Lipid-lowering therapies in peripheral artery disease: A review

Peripheral artery disease (PAD) is estimated to affect approximately 8.5 million individuals in the US above the age of 40, and is associated with significant morbidity, mortality, and impairment. Despite the significant adverse limb and cardiovascular (CV) outcomes seen in patients with PAD, there is typically less attention paid to risk factor modification relative to other atherosclerotic diseases such as coronary artery disease (CAD) or stroke. In the current literature, statins have been shown to reduce mortality, major adverse CV events, major adverse limb events, and improve symptomatic outcomes in patients with PAD. In addition, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are emerging as an additional lipid-lowering therapy for patients with PAD. However, despite current guideline recommendations based on growing evidence, patients with PAD are consistently undertreated with lipid-lowering therapies. We provide an extensive literature review and evidence-based recommendations for the use of statins and PCSK9 inhibitors in patients with PAD.

Comparative Analysis of Outcomes in Patients Undergoing Femoral Endarterectomy plus Endovascular (Hybrid) or Bypass for Femoropopliteal Occlusive Disease

INTRODUCTION

The gold-standard for management of combined common femoral artery (CFA) and superficial femoral artery (SFA) atherosclerotic occlusive disease has traditionally been open femoral endarterectomy and femoral-popliteal bypass. Hybrid approaches involving an open and endovascular component are increasingly common. The aim of this study was to compare perioperative outcomes in patients who underwent an open versus hybrid revascularization.

METHODS

NSQIP data, years 2012-2017, were queried for patients who underwent nonemergent CFA endarterectomy with either SFA transluminal intervention or bypass. The primary outcome of interest was a composite of cardiovascular, pulmonary, and renal complications (systemic) and mortality. Two propensity-weight adjusted analyses were performed: 1) comparing hybrid and prosthetic bypass 2) comparing hybrid and vein bypass.

RESULTS

There were 4,478 patients included (1,537 hybrid, 1,408 prosthetic, 1,533 vein); 64.8% were men, and the mean age was 67.8 ± 9.7 years; 29.9% had claudication, 38.8% had tissue loss, and 31.3 were unspecified. In the propensity-weighted analysis comparing hybrid to prosthetic bypass, there was no difference in systemic complications (OR = 1.29 for prosthetic vs. hybrid; 95% CI: 0.95-1.76; P = 0.107) or mortality (OR = 1.54; 95% CI: 0.71-3.33; P = 0.275). Prosthetic bypass was associated with more deep surgical-site infections (OR = 2.02; 95% CI: 1.19-3.45; P = 0.010), postoperative sepsis (OR = 2.07; 95% CI: 1.13-3.76; P = 0.018), unplanned 30-day readmission (OR = 1.28; 95% CI: 1.04-1.58; P = 0.021), and the composite of any complication (OR = 1.38; 95% CI: 1.18-1.61; P < 0.001). In the propensity-weighted analysis comparing hybrid to vein bypass, there was no difference in systemic complications (OR = 1.10 for vein vs. hybrid; 95% CI: 0.81-1.49; P = 0.552) or mortality (OR = 0.91; 95% CI: 0.42-2.00; P = 0.819). Vein bypass was associated with more superficial surgical-site infections (OR = 1.45; 95% CI: 1.04-2.02; P = 0.028), and the composite of any complication (OR = 1.32; 95% CI: 1.13-1.54; P = 0.001). Overall mortality was significantly higher patients with systemic complications (13.9% vs 0.1%; P < 0.001). Systemic complications were less common in patients with claudication undergoing hybrid revascularization than vein or prosthetic bypass.

CONCLUSIONS

Claudicants undergoing bypass experienced more systemic complications than those undergoing hybrid procedures, but there appears to be no increased risk of systemic complications or mortality with open reconstruction when compared to hybrid procedures for other indications. Other complications, such as infection, postoperative transfusion, and readmission, were more common in the bypass groups.

Tibial bypass in patients with intermittent claudication is associated with poor outcomes

OBJECTIVE

Given that intermittent claudication (IC) rarely progresses to chronic limb-threatening ischemia and limb loss, safety and durability of elective interventions for IC are essential. Whether patients with IC benefit from tibial intervention is controversial, and data supporting its utility are limited. Despite endovascular therapy expansion, surgical bypass is still commonly performed. We sought to assess outcomes of bypass to tibial arteries for IC.

METHODS

The Vascular Quality Initiative (2003-2018) was queried for infrainguinal bypasses performed for IC. Perioperative and 1-year outcomes were compared between bypasses constructed to tibial and popliteal arteries.

RESULTS

Of 5347 infrainguinal bypasses, 1173 (22%) and 4184 (78%) were tibial and popliteal bypasses, respectively. Overall, mean age was 65 ± 10 years, and patients were often men (72%) and current smokers (42%). Tibial bypasses commonly targeted posterior tibial (40%), tibioperoneal trunk (23%), and anterior tibial (19%) arteries. Great saphenous vein was more often used for tibial bypass than for popliteal bypass (78% vs 54%; P < .001). Patients undergoing tibial compared with popliteal bypass more often had impaired ambulation and prior ipsilateral bypasses and were less often taking antiplatelets and statins (all P < .05). In the perioperative period, tibial bypass patients had longer postoperative length of stay (4.5 ± 3.5 vs 3.5 ± 2.8 days), more pulmonary complications (1.3% vs 0.6%), and higher return to the operating room (7% vs 4%; all P < .05). Perioperative myocardial infarction (1.2% vs 0.8%; P = .19), stroke (0.4% vs 0.4%; P = .91), and mortality (0.3 vs 0.3%; P = .86) rates were similar between the cohorts. At 1 year, tibial compared with popliteal bypasses exhibited lower freedom from occlusion/death (81% vs 89%; P < .001), ipsilateral major amputation/death (90% vs 94%; P < .001), and reintervention/amputation/death (73% vs 80%; P < .001), but patient survival was similar (96% vs 97%; P = .07). On multivariable analysis, tibial compared with popliteal bypass was independently associated with increased occlusion/death (hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.28-2.11; P < .001), major ipsilateral amputation/death (HR, 1.6; 95% CI, 1.12-2.19; P = .003), and ipsilateral reintervention/amputation/death (HR, 1.51; 95% CI, 1.28-1.79; P < .001), with similar patient survival.

CONCLUSIONS

In patients with IC, tibial bypass was associated with poor outcomes, including major amputation. Surgeons should exhaust nonoperative therapies and present realistic outcome expectations to their patients before offering such intervention.

Endovascular Intervention for the Treatment of Trans-Atlantic Inter-Society Consensus (TASC) D Femoropopliteal Lesions: A Systematic Review and Meta-Analysis

PURPOSE

Advancements in the endovascular treatment of femoropopliteal atherosclerotic lesions have led to treatment of more complex lesions, particularly long lesions. The aim of this study was to determine the meta-analytic primary patency and need for re-intervention among patients treated for very long lesions (>200 mm) at the femoropopliteal segment and to identify potential risk factors for loss of patency.

METHODS

This study was performed according to the PRISMA guidelines. A random effects model meta-analysis was conducted, and the I-square was used to assess heterogeneity.

RESULTS

Fifty-one studies comprised of 3029 patients were included. The mean lesion length was 269 mm. The primary patency rate at 30 days, 6 m, 1-, 2- and 5-years of follow-up was 98%, 76%, 62%, 55%, and 39% respectively. The incidence of TLR was 16% at one year and 32% at two years. The secondary patency rate at 1, 2, 3 and 5 years was 85%, 71%, 64%, and 64% respectively. Heparin bonded ePTFE covered stents (69%) and paclitaxel eluting stents (73%) demonstrated higher 1-year primary patency rates than self-expanding nitinol stents (55%) or uncoated percutaneous transluminal angioplasty (PTA) with provisional stenting (54%). Lesions treated with a heparin bonded ePTFE covered stent had statistically significant higher odds of remaining patent at 1-year of follow-up (OR: 2.74; 95%CI: 1.63-4.61; p < 0.001) than lesions treated with BMS or PTA. Patients with long femoropopliteal lesions causing critical limb ischemia (CLI) developed restenosis or occlusion more often than patients treated for claudication (HR: 1.63; 95%CI: 1.06-2.49; p = 0.026) during an average follow-up of 26 months.

CONCLUSION

Primary stenting of femoropopliteal TASC D lesions using drug eluting stents or covered stents results in sustained patency over time. PTA or uncoated nitinol stents demonstrated lower patency rates. However, additional comparative studies are needed to determine the efficacy of newer technologies for the treatment of complex femoropopliteal lesions and provide evidence for the most optimal treatment approach.

Endovascular Therapy Provides Similar Results of Bypass Graft Surgery in the Treatment of Infrainguinal Multilevel Arterial Disease in Patients with Chronic Limb-Threatening Ischemia in All GLASS Stages

BACKGROUND

Extensive infrainguinal arterial disease still pose a challenge for technical and clinical success of percutaneous angioplasty. The purpose of this study was to compare the results of concomitant femoropopliteal and infrapopliteal percutaneous angioplasty/stenting (PTA/S) with distal bypass graft surgery (BGS) in patients with chronic limb-threatening ischemia (CLTI).

METHOD

In a single-center retrospective investigation between 2011 and 2017, 668 revascularization procedures for CLTI were reviewed. Concomitant femoropopliteal and infrapopliteal disease was identified in 153 CLTI patients, treated with BGS (48) using autogenous veins as substitute or PTA/S in a single procedure (105). A subgroup of patients with complex, extensive arterial lesions (GLASS stage III) received additional analysis. Primary outcomes were limb salvage and survival.

RESULTS

The mean follow-up time was 21.4 months. Patients treated with PTA/S were significantly older and with predominance of females, diabetes and chronic kidney disease. Smoking was more common in patients treated with BGS. The BGS group showed a 36-month survival rate of 73.4%, whereas the PTA/S group presented a survival of 61.3% in the same interval (P = 0.25). The 36-month cumulative limb salvage rate was 53.3 and 59.7% for BGS and PTA/S, respectively (P = 0.24). For GLASS stage III patients, 36-month limb salvage rates were 54.4% for the PTA/S group and 50.2% for the BGS group (P = 0.29). Multivariate analysis pointed poor runoff status (all endovascular patients) and diabetes (GLASS III endovascular patients) as risk factors for limb loss.

CONCLUSION

PTA/S and BGS presented similar results of limb salvage and survival in the treatment of concomitant femoropopliteal and infrapopliteal arterial disease in patients with CLTI, even for patients with extensive and complex arterial disease.

Nitinol Stent Versus Bypass in Long Femoropopliteal Lesions: 2-Year Results of a Randomized Controlled Trial

OBJECTIVES

This study sought to compare patency rates and clinical outcomes of nitinol stents and primary vein bypass in long femoropopliteal lesions.

BACKGROUND

An endovascular-first strategy for long femoropopliteal lesions is widely recommended without sufficient data comparing it with bypass surgery. Nitinol stents are widely used as the standard endovascular therapy.

METHODS

A single-center randomized controlled trial was performed with the primary endpoints of technical success, primary and secondary patency. Secondary endpoints were limb salvage, survival, complications, and clinical improvement.

RESULTS

A total of 110 limbs (55 per group) in 103 patients were treated. Baseline and lesion characteristics were similar, with a mean lesion length of 276 mm. Critical limb threatening ischemia was the indication for treatment in 49% of limbs in both groups. Technical success was achieved in 87% in the stent group. During a 2-year follow-up, patency rates, limb salvage, survival and complications showed no significant differences between both groups. At 24 months, primary and secondary patency rates for the stent group were 60% and 72% versus 56% and 73% in the bypass group, respectively. Clinical improvement was significantly better in the bypass group.

CONCLUSIONS

There were no significant differences regarding patency rates, limb salvage, survival, or complications after 2 years. Technical success and clinical improvement in the bypass group were significantly better, but the promising results of the stent group suggest that an endovascular-first strategy for femoropopliteal lesions up to 30 cm may be reasonable. Mid- as well as long-term results need to be awaited.

Patient specific characterization of artery and plaque material properties in peripheral artery disease

Patient-specific finite element (FE) modeling of atherosclerotic plaque is challenging, as there is limited information available clinically to characterize plaque components. This study proposes that for the limited data available in vivo, material properties of plaque and artery can be identified using inverse FE analysis and either a simple neo-Hookean constitutive model or assuming linear elasticity provides sufficient accuracy to capture the changes in vessel deformation, which is the available clinical metric. To test this, 10 human cadaveric femoral arteries were each pressurized ex vivo at 6 pressure levels, while intravascular ultrasound (IVUS) and virtual histology (VH) imaging were performed during controlled pull-back to determine vessel geometry and plaque structure. The VH images were then utilized to construct FE models with heterogeneous material properties corresponding to the vessel plaque components. The constitutive models were then fit to each plaque component by minimizing the difference between the experimental and the simulated geometry using the inverse FE method. Additionally, we further simplified the analysis by assuming the vessel wall had a homogeneous structure, i.e. lumping artery and plaque as one tissue. We found that for the heterogeneous wall structure, the simulated and experimental vessel geometries compared well when the fitted neo-Hookean parameters or elastic modulus, in the case of linear elasticity, were utilized. Furthermore, taking the median of these fitted parameters then inputting these as plaque component mechanical properties in the finite element simulation yielded differences between simulated and experimental geometries that were on average around 2% greater (1.30-5.55% error range to 2.33-11.71% error range). For the homogeneous wall structure the simulated and experimental wall geometries had an average difference of around 4% although when the difference was calculated using the median fitted value this difference was larger than for the heterogeneous fits. Finally, comparison to uniaxial tension data and to literature constitutive models also gave confidence to the suitability of this simplified approach for patient-specific arterial simulation based on data that may be acquired in the clinic.

Major adverse limb events and major adverse cardiac events after contemporary lower extremity bypass and infrainguinal endovascular intervention in patients with claudication

OBJECTIVE

Major adverse limb events (MALEs) and major adverse cardiovascular events (MACEs) at 30 days provide standardized metrics for comparison and have been adopted by the Society for Vascular Surgery's objective performance goals for critical limb ischemia. However, MALEs and MACEs have not been widely adopted within the claudication population, and the comparative outcomes after lower extremity bypass (LEB) and infrainguinal endovascular intervention (IEI) remain unclear. The purpose of this study was to compare MALEs and MACEs after LEB and IEI in a contemporary national cohort and to determine predictors of MALEs and MACEs after revascularization for claudication.

METHODS

A national data set of LEB and IEI performed for claudication was obtained using National Surgical Quality Improvement Program vascular targeted Participant Use Data Files from 2011 to 2014. Patients were stratified by LEB vs IEI and compared by appropriate univariate analysis. The primary outcomes were MALE (defined as untreated loss of patency, reintervention on the index arterial segment, or amputation of the index limb) and MACE (defined as stroke, myocardial infarction, or death). Multivariable logistic regression was used to identify predictors of MALEs and MACEs.

RESULTS

A total of 3925 infrainguinal revascularization procedures (2155 LEB and 1770 IEI) were performed for claudication. There was no difference in 30-day MALEs between LEB and IEI (4.0% vs 3.2%; P = .17). On multivariable logistic regression, predictors of 30-day MALEs included tibial revascularization (odds ratio [OR], 2.2; P < .0001) and prior LEB on the same arterial segment (OR, 1.8; P = .004). LEB had significantly higher 30-day MACEs (2.0% vs 1.0%; P = .01) but similar mortality (0.5% vs 0.4%; P = .6). Predictors of MACEs included LEB vs IEI (OR, 2.1; P = .01), chronic obstructive pulmonary disease (OR, 2.2; P = .01), dialysis dependence (OR, 4.4; P = .003), and diabetes (OR, 1.9; P = .02).

CONCLUSIONS

In this large national cohort, LEB and IEI for claudication are associated with similar 30-day MALEs. Tibial revascularization and revascularization after prior failed bypass predict MALEs in claudicants and should therefore be undertaken with caution. LEB was associated with more 30-day MACEs but comparable 30-day mortality compared with IEI. Patients with end-stage renal disease, chronic obstructive pulmonary disease, and diabetes are at high risk for MACEs. The risk of 30-day MACEs after LEB should be weighed against the longer term outcomes of LEB vs IEI and conservative management, particularly in these higher risk patients. This analysis helps define contemporary 30-day outcomes after infrainguinal revascularization performed for claudication and serves as a baseline with which the short-term outcomes of future treatments can be compared.

Targeted Delivery of Bioactive Molecules for Vascular Intervention and Tissue Engineering

Cardiovascular diseases are the leading cause of death in the United States. Treatment often requires surgical interventions to re-open occluded vessels, bypass severe occlusions, or stabilize aneurysms. Despite the short-term success of such interventions, many ultimately fail due to thrombosis or restenosis (following stent placement), or incomplete healing (such as after aneurysm coil placement). Bioactive molecules capable of modulating host tissue responses and preventing these complications have been identified, but systemic delivery is often harmful or ineffective. This review discusses the use of localized bioactive molecule delivery methods to enhance the long-term success of vascular interventions, such as drug-eluting stents and aneurysm coils, as well as nanoparticles for targeted molecule delivery. Vascular grafts in particular have poor patency in small diameter, high flow applications, such as coronary artery bypass grafting (CABG). Grafts fabricated from a variety of approaches may benefit from bioactive molecule incorporation to improve patency. Tissue engineering is an especially promising approach for vascular graft fabrication that may be conducive to incorporation of drugs or growth factors. Overall, localized and targeted delivery of bioactive molecules has shown promise for improving the outcomes of vascular interventions, with technologies such as drug-eluting stents showing excellent clinical success. However, many targeted vascular drug delivery systems have yet to reach the clinic. There is still a need to better optimize bioactive molecule release kinetics and identify synergistic biomolecule combinations before the clinical impact of these technologies can be realized.

Limb flexion-induced axial compression and bending in human femoropopliteal artery segments

BACKGROUND

High failure rates of femoropopliteal artery (FPA) interventions are often attributed in part to severe mechanical deformations that occur with limb movement. Axial compression and bending of the FPA likely play significant roles in FPA disease development and reconstruction failure, but these deformations are poorly characterized. The goal of this study was to quantify axial compression and bending of human FPAs that are placed in positions commonly assumed during the normal course of daily activities.

METHODS

Retrievable nitinol markers were deployed using a custom-made catheter system into 28 in situ FPAs of 14 human cadavers. Contrast-enhanced, thin-section computed tomography images were acquired with each limb in the standing (180 degrees), walking (110 degrees), sitting (90 degrees), and gardening (60 degrees) postures. Image segmentation and analysis allowed relative comparison of spatial locations of each intra-arterial marker to determine axial compression and bending using the arterial centerlines.

RESULTS

Axial compression in the popliteal artery (PA) was greater than in the proximal superficial femoral artery (SFA) or the adductor hiatus (AH) segments in all postures (P = .02). Average compression in the SFA, AH, and PA ranged from 9% to 15%, 11% to 19%, and 13% to 25%, respectively. The FPA experienced significantly more acute bending in the AH and PA segments compared with the proximal SFA (P < .05) in all postures. In the walking, sitting, and gardening postures, average sphere radii in the SFA, AH, and PA ranged from 21 to 27 mm, 10 to 18 mm, and 8 to 19 mm, whereas bending angles ranged from 150 to 157 degrees, 136 to 147 degrees, and 137 to 148 degrees, respectively.

CONCLUSIONS

The FPA experiences significant axial compression and bending during limb flexion that occur at even modest limb angles. Moreover, different segments of the FPA appear to undergo significantly different degrees of deformation. Understanding the effects of limb flexion on axial compression and bending might assist with reconstructive device selection for patients requiring peripheral arterial disease intervention and may also help guide the development of devices with improved characteristics that can better adapt to the dynamic environment of the lower extremity vasculature.

When Are Endovascular and Open Bypass Treatments Preferred for Femoropopliteal Occlusive Disease?

Several meta-analyses and multicenter trials have shown that chronic limb ischemia did not occur for up to 5 years in 50%–70% of patients who underwent saphenous vein grafts, with limb salvage and perioperative mortality rates of >80% and 3%, respectively. However, open surgical bypass can have limitations, including postoperative morbidity/wound complications of 10%–20% and prolonged length of hospital stay and outpatient care. Several studies have analyzed clinical outcomes for patients with critical limb ischemia treated with endovascular therapies, but they have been mainly retrospective with significant heterogeneity or were single center. Only few randomized trials have compared surgical vs. endovascular therapy. These included the Bypass vs. Angioplasty in Severe Ischemia of the Leg (BASIL) trial, with no differences found in amputation-free or overall survival rates at 1 year; however, late outcomes favored the surgical group. The Bypass or Angioplasty in Severe Intermittent Claudication (BASIC) trial concluded that the 1-year patency rates were 82% and 43% for bypass and angioplasty, respectively. The BEST Endovascular vs. Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) trial is currently enrolling patients. This review analyzed studies comparing open vs. endovascular therapy in patients with femoropopliteal disease. (This is a review article based on the invited lecture of the 45th Annual Meeting of Japanese Society for Vascular Surgery.)