BEST-CLI Surgery or Endovascular Therapy for Chronic Limb-Threatening Ischemia
PubMed • Full text
Clinical Question
For patients with chronic limb-threatening ischemia (CLTI) does surgical revascularization or endovascular revascularization lead to superior limb outcomes?
Bottom Line
In the cohort of patients with adequate great saphenous vein (GSV) for surgical revascularization, surgical revascularization lead to reduced major adverse limb events and death when compared to the endovascular group.
Major Points
There has been much controversy regarding whether an endovascular first vs surgical bypass first approach to patients with CLTI leads to better outcomes for patients, both from a limb salvage and morbidity/mortality perspective. The only previous RCT investigating choice of revascularization strategy is BASIL a multi-centre analysis which found broadly similar outcomes between both cohorts.
Best CLI is the largest RCT to date investigating CLTI revascularization strategies and has demonstrated significantly lower major adverse limb events and death in the surgical group than endovascular group. Importantly these findings are specific for the cohort who had adequate GSV for bypass.
In a second cohort of analysed patients who lacked adequate GSV conduit for bypass, the outcomes in both surgical and endovascular groups were similar.
The results suggest the importance in preoperative planning with determination of saphenous-vein availability to guide operative decision making, as it appears that amongst patients suitable for either a bypass or endovascular intervention, ipsilateral saphenous vein harvest may offer better outcomes.
Design
- International, prospective, randomised, open-label, multi-center superiority trial
- N=1,434
- Cohort 1: Adequate single segment of great saphenous vein (n=1,434)
- Cohort 2: Needed alternative conduit (n=396)
- Setting: 150 sites in United States, Canada, Finland, Italy and New Zealand
- Enrolment: August 2013 to October 2019
- Mean follow-up:
- Cohort 1: 2.7 years
- Cohort 2: 1.6 years
- Analysis: Intention-to-treat
- Primary outcome: Major adverse limb events or death from any cause
Population
Inclusion Criteria
- >18 years old
- Diagnosis of CLTI
- Diagnosed as arterial insufficiency of lower limb with ischaemic foot pain at rest, a non healing ischaemic ulcer, or gangrene
Exclusion Criteria
- Patient not a candidate for both surgery and endovascular therapy
Baseline Characteristics
Baseline demographic and medical characteristics were collected for all included patients
- Cohort 1 Overall
- Mean Age: 66.9 +/- 9.9
- Female sex 28.5%
- BMI 28.2 +/- 6
Comment: In cohort 1 there was a well balanced mix of other baseline characteristics (Hypertension, Hyperlipidaemia, Diabetes, Current smoker, Coronary artery disease, Congestive heart failure, Stroke, Chronic obstructive pulmonary disease, End stage kidney disease). The only difference noted by the authors was more Black patients in the surgical group than in the endovascular group (21.9% vs 16.7%)
- Cohort 2 Overall
- Mean Age: 68.6 +/- 9.2
- Female sex 28%
- BMI 26.98 +/- 5.7
Comment: In cohort 2 there was a well balanced baseline characteristics (same as listed prior) except for higher baseline toe pressures in the surgical group 37 vs 25.5
Interventions
- Initial enrolment to one of two cohorts as listed previously (suitable great saphenous vein for bypass cohort 1, not suitable in cohort 2)
- The patients were then randomly assigned in 1:1 ratio to surgical or endovascular treatment
- There had to be agreement between an 'expert' in Endovascular therapy and an 'expert' in open surgical treatment agree that the patient would be suitable for either bypass or endovascular intervention
In the surgical group surgeons could use any bypass technique. In the endovascular group interventionists were allowed to choose any available endovascular technique.
Outcomes
Comparisons are bypass surgery vs endovascular therapy.
Primary Outcomes
- Major adverse limb events or death from any cause
- 42.6% (surgical) vs. 57.4% (HR 0.68; 95% CI 0.59-0.79; P<0.001)
Secondary Outcomes
- Major reinterventions
- 9.2%% vs. 23.5% (HR 0.35 CI 0.27-0.47)
- Above-ankle amputation of the index limb
- 10.4% vs. 14.9% (HR 0.73j; 95% CI 0.54-0.98)
Subgroup Analysis
There was subgroup analysis however this has just been summarised in the body of the manuscript, suggesting a treatment effect that favoured the surgical group across most pre-specified groups (inclusive of demographics, and pre specified clinical stratification (ischemic crest pain or tissue loss, presence of absence of considerable infrapopliteal arterial occlusive disease)
Criticisms
This study can't be blinded due to the nature of the intervention.
Randomisation rested upon agreement between local investigators (including in an expert in endovascular and open revascularisation) that there was clinical equipoise between endovascular intervention and bypass surgery. This may have limited inclusion of 'end of the spectrum' anatomical complexity, both major and minor.
There may have been reduced use of paclitaxel-coated balloons and stents due to a controversial meta-analysis published in 2018 raising concerns about increased all cause mortality - these balloons and stents have the potential to reduce the need for vascular reintervention rates.
Critics have questioned the high success rates of bypass surgery (98%) quoted in the article, and the (relatively) low rates of endovascular success rates (~85%).
Funding
Funded by the National Heart, Lung, and Blood Institute
Further Reading
BASIL BASIL 2