Subintimal angioplasty is superior to SilverHawk atherectomy for the treatment of occlusive lesions of the lower extremities

[Current Strategy in Endovascular Management for Below-the-Knee Arterial Lesions]

The below-the-knee arterial tree is the thinnest of all the leg vessels and is an important path for blood flow to the foot. Hence, lesions including stenosis, especially obstruction, may lead to critical limb ischemia which represents the most severe clinical manifestation of peripheral arterial disease. It is characterized by the presence of ischemic rest pain, ischemic lesions, or gangrene attributable to the objectively proven arterial occlusive disease. Typically, the atherosclerotic disease process involving the below-the-knee arterial tree is diffuse in the majority of patients. The cornerstone of therapy is vascular reconstruction and limb salvage. Revascularization should be attempted whenever technically possible, without delay, in patients presenting critical limb ischemia and when the clinical status is not hopelessly non-ambulatory. Therefore, endovascular treatment can become the gold standard for the full range of patients including below-the-knee, limiting the clinical role of the classically trained surgeons.

Atherectomy for peripheral arterial disease

BACKGROUND

Symptomatic peripheral arterial disease (PAD) has several treatment options, including angioplasty, stenting, exercise therapy, and bypass surgery. Atherectomy is an alternative procedure, in which atheroma is cut or ground away within the artery. This is the first update of a Cochrane Review published in 2014.

OBJECTIVES

To evaluate the effectiveness of atherectomy for peripheral arterial disease compared to other established treatments.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Allied and Complementary Medicine (AMED) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 12 August 2019.

SELECTION CRITERIA

We included all randomised controlled trials that compared atherectomy with other established treatments. All participants had symptomatic PAD with either claudication or critical limb ischaemia and evidence of lower limb arterial disease.

DATA COLLECTION AND ANALYSIS

Two review authors screened studies for inclusion, extracted data, assessed risk of bias and used GRADE criteria to assess the certainty of the evidence. We resolved any disagreements through discussion. Outcomes of interest were: primary patency (at six and 12 months), all-cause mortality, fatal and non-fatal cardiovascular events, initial technical failure rates, target vessel revascularisation rates (TVR; at six and 12 months); and complications.

MAIN RESULTS

We included seven studies, with a total of 527 participants and 581 treated lesions. We found two comparisons: atherectomy versus balloon angioplasty (BA) and atherectomy versus BA with primary stenting. No studies compared atherectomy with bypass surgery. Overall, the evidence from this review was of very low certainty, due to a high risk of bias, imprecision and inconsistency. Six studies (372 participants, 427 treated lesions) compared atherectomy versus BA. We found no clear difference between atherectomy and BA for the primary outcomes: six-month primary patency rates (risk ratio (RR) 1.06, 95% confidence interval (CI) 0.94 to 1.20; 3 studies, 186 participants; very low-certainty evidence); 12-month primary patency rates (RR 1.20, 95% CI 0.78 to 1.84; 2 studies, 149 participants; very low-certainty evidence) or mortality rates (RR 0.50, 95% CI 0.10 to 2.66, 3 studies, 210 participants, very low-certainty evidence). One study reported cardiac failure and acute coronary syndrome as causes of death at 24 months but it was unclear which arm the participants belonged to, and one study reported no cardiovascular events. There was no clear difference when examining: initial technical failure rates (RR 0.48, 95% CI 0.22 to 1.08; 6 studies, 425 treated vessels; very low-certainty evidence), six-month TVR (RR 0.51, 95% CI 0.06 to 4.42; 2 studies, 136 treated vessels; very low-certainty evidence) or 12-month TVR (RR 0.59, 95% CI 0.25 to 1.42; 3 studies, 176 treated vessels; very low-certainty evidence). All six studies reported complication rates (RR 0.69, 95% CI 0.28 to 1.68; 6 studies, 387 participants; very low-certainty evidence) and embolisation events (RR 2.51, 95% CI 0.64 to 9.80; 6 studies, 387 participants; very low-certainty evidence). Atherectomy may be less likely to cause dissection (RR 0.28, 95% CI 0.14 to 0.54; 4 studies, 290 participants; very low-certainty evidence) and may be associated with a reduction in bailout stenting (RR 0.26, 95% CI 0.09 to 0.74; 4 studies, 315 treated vessels; very low-certainty evidence). Four studies reported amputation rates, with only one amputation event recorded in a BA participant. We used subgroup analysis to compare the effect of plain balloons/stents and drug-eluting balloons/stents, but did not detect any differences between the subgroups. One study (155 participants, 155 treated lesions) compared atherectomy versus BA and primary stenting, so comparison was extremely limited and subject to imprecision. This study did not report primary patency. The study reported one death (RR 0.38, 95% CI 0.04 to 3.23; 155 participants; very low-certainty evidence) and three complication events (RR 7.04, 95% CI 0.80 to 62.23; 155 participants; very low-certainty evidence) in a very small data set, making conclusions unreliable. We found no clear difference between the treatment arms in cardiovascular events (RR 0.38, 95% CI 0.04 to 3.23; 155 participants; very low-certainty evidence). This study found no initial technical failure events, and TVR rates at six and 24 months showed little difference between treatment arms (RR 2.27, 95% CI 0.95 to 5.46; 155 participants; very low-certainty evidence and RR 2.05, 95% CI 0.96 to 4.37; 155 participants; very low-certainty evidence, respectively).

AUTHORS' CONCLUSIONS

This review update shows that the evidence is very uncertain about the effect of atherectomy on patency, mortality and cardiovascular event rates compared to plain balloon angioplasty, with or without stenting. We detected no clear differences in initial technical failure rates or TVR, but there may be reduced dissection and bailout stenting after atherectomy although this is uncertain. Included studies were small, heterogenous and at high risk of bias. Larger studies powered to detect clinically meaningful, patient-centred outcomes are required.

Use, Safety and Effectiveness of Subintimal Angioplasty and Re-Entry Devices for the Treatment of Iliac Artery Chronic Total Occlusions: A Systematic Review of 30 Studies and 1112 Lesions

BACKGROUND

Management of iliac artery occlusive disease has changed dramatically over the past few decades. Secondary to advancement in endovascular technologies and techniques, percutaneous interventions have gradually replaced open surgical approaches even for the most difficult cases. In difficult to cross chronic total occlusions (CTO) of the iliac artery, subintimal angioplasty (SIA) with or without the use of re-entry devices (RED) offers a valuable alternative to intra-luminal crossing.

OBJECTIVE

To systematically review the literature for studies reporting procedural or short- and long-term clinical outcomes after the use of SIA, with or without RED use for iliac CTOs.

METHODS

PRISMA guidelines were followed. Literature search (PubMed, Cochrane CENTRAL and EMBASE) and data extraction were performed by two independent researchers. Quantitative synthesis of the reported outcomes was applied when possible.

RESULTS

Thirty studies met the inclusion criteria and were selected as eligible for this systematic review, with a total of 1002 patients (61.3% males) and 1112 lesions treated with SIA. RED were used in 21.9% of the lesions. Critical limb ischemia was the indication in 51.4%. The overall procedural success rates were 85.8% for SIA and 88.5% for RED. The complication rate ranged from 0 to 10% among different series, but overall it was similar among the two groups (6.9% in the RED group and 6.7% among the SIA group). One year primary patency rates were around 60% in the RED. In the SIA only arm, there was a large heterogeneity, with patency rates ranging from 51.7% to 96.8%.

CONCLUSION

SIA with or without RED use is a safe and effective treatment for the treatment of iliac artery CTOs. Future studies are needed to delineate whether intraluminal crossing or SIA is more effective for endovascular treatment of iliac CTOs.

Subintimal angioplasty for lower limb arterial chronic total occlusions

BACKGROUND

In recent years subintimal angioplasty (SIA) has become an established percutaneous procedure for the treatment of symptomatic lower limb arterial chronic total occlusions. However, the clinical benefits of this practice remain unclear. The aim of the review was to determine the effectiveness of SIA on clinical outcomes. This is an update of a review first published in 2013.

OBJECTIVES

To assess the effectiveness of SIA versus other treatment for people with lower limb arterial chronic total occlusions, determined by the effects on clinical improvement, technical success rate, patency rate, limb salvage rate, and morbidity rates.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register (last searched January 2016) and Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 12). We also searched clinical trials registries.

SELECTION CRITERIA

We included data from randomized controlled trials comparing the effectiveness of SIA and any other management method in the treatment of lower limb arterial chronic total occlusions. The primary intervention of interest was SIA, with or without a stent, for the restoration of vessel patency in people with occlusions of a lower limb artery. We compared SIA against alternative modalities used to restore vessel patency, including conventional percutaneous transluminal angioplasty, surgical bypass, or any other treatments. We compared different SIA devices and techniques against each other.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trials for eligibility and methodological quality, and extracted data. The third review author resolved disagreements.

MAIN RESULTS

Two studies, involving a total of 147 participants with TransAtlantic Inter-Society Consensus (TASC)-II D femoropopliteal lesions, met our inclusion criteria and were included in the review. Both studies were small but otherwise of high methodological quality. However, the treatment techniques and control groups of the two studies differed, precluding the combining of study results and resulting in the evidence being less applicable. We therefore considered the quality of the evidence to be low.In one study, participants with TASC-II D lesions were randomized to receive either SIA with stenting of the superficial femoral artery or remote endarterectomy (RE) with stenting of the superficial femoral artery. Three-year follow-up results showed a Rutherford classification improvement of 64% in the SIA group compared to 80% in the RE group (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.61 to 1.03; 95 participants; P = 0.079). Postexercise ankle brachial index improvements (defined as an increased value of 0.2) were reported in 70% of participants in the SIA group compared to 82% in the RE group (RR 0.86, 95% CI 0.68 to 1.08; 95 participants; P = 0.18). The study reported the technical success rate was 93% for the SIA group and 96% for the RE group (RR 0.97, 95% CI 0.88 to 1.07; 95 participants; P = 0.91). Primary patency at 12 months was 59.1% in the SIA group compared to 78.4% in the RE group (RR 0.75, 95% CI 0.57 to 1.00; 95 participants; P = 0.05). Primary patency at 24 months was 56.8% in the SIA group compared to 76.5% in the RE group (RR 0.74, 95% CI 0.55 to 1.00; 95 participants; P = 0.05) and 47.7% in the SIA group and 62.7% in the RE group at 36 months (RR 0.76, 95% CI 0.52 to 1.11; 95 participants; P = 0.15). Assisted primary patency was 52.3% in the SIA group compared to 70.6% in the RE group (P = 0.01) at 36 months. Secondary patency was better for the RE group (P = 0.03) at 36 months. Limb salvage at three years' follow-up was 95% in the SIA group and 98% in the RE group (RR 0.97, 95% CI 0.90 to 1.05; 95 participants; P = 0.4). There were no perioperative deaths, but complications occurred in two SIA participants (femoral pseudoaneurysm and pulmonary edema) and in three RE participants (seroma, femoral pseudoaneurysm, superficial femoral artery acute occlusion).In the second study, the effects of the SIA OUTBACK re-entry catheter device in people affected by TASC-II D superficial femoral artery chronic total occlusion were compared with the SIA manual re-entry technique. This study did not report clinical improvement and limb salvage. Technical success was achieved in all cases in both the OUTBACK device and manual groups. The primary 6-month patency rate was 100% in the OUTBACK group (26 of 26 participants) compared to 96.2% in the manual group (25 of 26 participants) (RR 1.04, 95% CI 0.94 to 1.15). The primary 12-month patency rate was 92.3% in the OUTBACK group (24 of 26 participants) compared to 84.6% in the manual group (22 of 26 participants) (RR 1.09, 95% CI 0.90 to 1.33). Patency rates at 24 and 36 months were not reported. The study reported that there were no complications.

AUTHORS' CONCLUSIONS

Using the GRADE approach, we classified the quality of the evidence presented by both studies in this review as low due to small study size and the small number of studies. In addition, the two included trials differed from each other in the techniques and control used, and we were therefore unable to combine the data. Consequently there is currently insufficient evidence to support SIA over other techniques. Evidence from more randomized controlled trials is needed to assess the role of SIA in people with chronic lower limb arterial total occlusions.

Atherectomy for peripheral arterial disease

BACKGROUND

Symptomatic peripheral arterial disease may be treated by a number of options including exercise therapy, angioplasty, stenting and bypass surgery. Atherectomy is an alternative technique where atheroma is excised by a rotating cutting blade.

OBJECTIVES

The objective of this review was to analyse randomised controlled trials comparing atherectomy against any established treatment for peripheral arterial disease in order to evaluate the effectiveness of atherectomy.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched November 2013) and CENTRAL (2013, Issue 10). Trials databases were searched for details of ongoing or unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing atherectomy and other established treatments were selected for inclusion. All participants had symptomatic peripheral arterial disease with either claudication or critical limb ischaemia and evidence of lower limb arterial disease.

DATA COLLECTION AND ANALYSIS

Two review authors (GA and CT) screened studies for inclusion, extracted data and assessed the quality of the trials. Any disagreements were resolved through discussion.

MAIN RESULTS

Four trials were included with a total of 220 participants (118 treated with atherectomy, 102 treated with balloon angioplasty) and 259 treated vessels (129 treated with atherectomy, 130 treated with balloon angioplasty). All studies compared atherectomy with angioplasty. No study was properly powered or assessors blinded to the procedures and there was a high risk of selection, attrition, detection and reporting biases.The estimated risk of success was similar between the treatment modalities although the confidence interval (CI) was compatible with small benefits of either treatment for the initial procedural success rate (Mantel-Haenszel risk ratio (RR) 0.92, 95% CI 0.44 to 1.91, P = 0.82), patency at six months (Mantel-Haenszel RR 0.92, 95% CI 0.51 to 1.66, P = 0.79) and patency at 12 months (Mantel-Haenszel RR 1.17, 95% CI 0.72 to 1.90, P = 0.53) following the procedure. The reduction in all-cause mortality with atherectomy was most likely due to an unexpectedly high mortality in the balloon angioplasty group in one of the two trials that reported mortality (Mantel-Haenszel RR 0.24, 95% CI 0.06 to 0.91, P = 0.04). Cardiovascular events were not reported in any study. There was a reduction in the rate of bailout stenting following atherectomy (Mantel-Haenszel RR 0.45, 95% CI 0.24 to 0.84, P = 0.01), and balloon inflation pressures were lower following atherectomy (mean difference -2.73 mmHg, 95% CI -3.48 to -1.98, P < 0.00001). Complications such as embolisation and vessel dissection were reported in two trials indicating more embolisations in the atherectomy group and more vessel dissections in the angioplasty group, but the data could not be pooled. From the limited data available, there was no clear evidence of different rates of adverse events between the atherectomy and balloon angioplasty groups for target vessel revascularisation and above-knee amputation. Quality of life and clinical and symptomatic outcomes such as walking distance or symptom relief were not reported in the studies.

AUTHORS' CONCLUSIONS

This review has identified poor quality evidence to support atherectomy as an alternative to balloon angioplasty in maintaining primary patency at any time interval. There was no evidence for superiority of atherectomy over angioplasty on any outcome, and distal embolisation was not reported in all trials of atherectomy. Properly powered trials are recommended.

Subintimal angioplasty for chronic lower limb arterial occlusion

BACKGROUND

Subintimal angioplasty (SIA) has become an established percutaneous procedure for the treatment of symptomatic lower limb arterial occlusions in recent years. However, the clinical benefits of this practice remain unclear. The aim of the review was to determine the effectiveness of SIA on clinical outcomes.

OBJECTIVES

To assess the effectiveness of SIA versus any other treatment for patients with chronic lower limb artery occlusion. This will be determined by the effects on clinical improvement, technical success rate, patency rate, limb salvage rate, and morbidity rates.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (last searched January 2013) and CENTRAL (2012, Issue 12). Clinical trials databases were also searched.

SELECTION CRITERIA

We planned to include data from randomized controlled trials comparing the effectiveness of SIA and any other management method in the treatment of chronic lower limb arterial occlusion.

DATA COLLECTION AND ANALYSIS

Two authors evaluated the trials identified from the searches for appropriateness of inclusion.

MAIN RESULTS

There were no randomized controlled trials in which SIA was compared with any other treatment.

AUTHORS' CONCLUSIONS

Randomized controlled trial evidence for the effectiveness of SIA is lacking. There is a need for high-quality randomized controlled trials comparing SIA with any other treatment.