Bosiers 2009.

Methods	Country: Absorbable Metal Stents (AMS) INSIGHT investigators (13 clinical sites in Austria, Belgium, Germany, and The Netherlands) Setting: multi‐centre tertiary hospital Study design: RCT Level of randomisation: participant
Participants	No. of participants randomised: 57 were randomised to the percutaneous transluminal angioplasty (PTA) group, and 60 to the AMS group. In total, 149 lesions were treated in 117 participants, which resulted in a total of 74 lesions in the AMS arm and 75 lesions in the PTA control arm Exclusions post randomisation: none Shifted to another treatment arm: if stenosis persisted to be > 50% or a flow‐limiting dissection occurred, the participant underwent implantation of the AMS study stent and ended up in the cross‐over group. Seven PTA group participants (7/57) with 11 lesions (11/75) crossed over to the other treatment arm due to dissections in at least 1 of the lesions and, in the case of 1 participant, due to significant residual stenosis Number of participants evaluated: 7 PTA group participants (7/57) with 11 lesions (11/75) crossed over to the other treatment arm due to dissection in at least 1 of the lesions and, in the case of 1 patient, due to significant residual stenosis. These participants were included in the PTA + AMS group, which was not considered in the on‐treatment data analysis performed by study authors. One participant randomised for stenting (1/60) with a double lesion (2/74) underwent implantation of a non‐study stent (self‐expanding) due to severe tortuosity of the iliac artery. Therefore, this participant was not considered in the on‐treatment analysis performed by study authors. The final on‐treatment cohort consisted of 50 participants with 64 lesions treated with PTA only and 59 participants with 72 lesions who underwent implantation of the study stent. Therefore, according to the study authors, ITT technical success, which was based on visual assessment, was achieved in 60 of 60 participants in the AMS group (100%), and in 55 of 57 participants in the PTA group (96.4%). For one PTA lesion, data on technical success were not provided by the investigator, and this participant's treatment was considered a non‐success Age (mean), years: PTA only 73.1, AMS 74.7 Gender: PTA group: 41 male/16 female, AMS stent group: 31 male/29 female Inclusion criteria: stenotic (> 50%) or occlusive atherosclerotic disease of the infrapopliteal arteries, length of lesion < 15 mm (< 1 stent length), reference vessel diameter 3.0 mm to 3.5 mm, maximum of 2 lesions in 1 infrapopliteal vessel treated in the study or in 2 vessels of 2 different legs, symptomatic critical limb ischaemia (Rutherford 4 and 5), patient ≥ 50 years of age, life expectancy > 6 months, no child‐bearing potential or negative serum pregnancy test within 7 days of the index procedure, participant willing and able to return at appropriate follow‐up times for the duration of the study, patient provision of written patient informed consent that is approved by the ethics committee Exclusion criteria: patient refusal of treatment; reference segment diameter not suitable for available stent design; length of lesion requiring more than 1 stent implantation; previously implanted stent(s) or PTA at the same lesion site; lesion lying within or adjacent to an aneurysm; inflow‐limiting arterial lesions left untreated; known allergy to heparin, aspirin, or other anticoagulant/antiplatelet therapies or bleeding diatheses, or unable or unwilling to tolerate such therapies; taking phenprocoumon (Marcumar); history of prior life‐threatening contrast medium reaction; currently enrolled in another investigational device or drug trial; currently breastfeeding, pregnant, or intending to become pregnant; mentally ill or retarded; liable for military or civilian service
Interventions	AMS stenting group: Target lesion was pre‐dilated with the Pleon Explorer balloon mandatory in this study. After dilatation, the stenosed area was treated with 1 AMS implant. Post‐dilatation was allowed at the discretion of the physician, for cases where angiographic control revealed suboptimal apposition of the AMS to the vessel wall or flow‐limiting residual stenosis PTA group (control): Pleon Explorer balloon Medication: Clopidrogel saturation was obtained before the procedure Heparin was administered during the procedure according to standard practice Post‐procedure antithrombotic regimen was that used according to the protocol (clopidogrel 75 mg daily for 1 month and aspirin 75 to 300 mg daily lifelong)
Outcomes	Primary outcomes: Absence of clinical complications at 1 month post procedure. Complications were defined as major amputations or any cause of death. Major amputations were defined as amputations at or above the ankle 6‐month angiographic patency rate after PTA alone or PTA followed by AMS implantation in patients with stenotic or occlusive atherosclerotic disease of the infrapopliteal arteries. Patency was defined as the absence of a haemodynamically significant re‐stenosis (50%) documented by digital subtraction angiography and confirmed by core‐lab QVA Secondary outcomes: Immediate angiographic technical success, which was defined in both therapy groups as 30% final residual diameter stenosis of the target segment based on visual assessment of the planned treatment area Late lumen loss (LLL) as diagnosed at 6‐month angiographic control and defined by the difference between in‐stent minimal lumen diameter (MLD) post procedure and MLD at follow‐up measured by angiography Limb salvage rate, defined as lack of major amputations at different prescheduled follow‐up visits until 12 months after index intervention Primary patency rates at each visit as determined by colour flow Doppler ultrasound (CFDU) and defined as the absence of a haemodynamically significant re‐stenosis (50%) derived from the ratio of peak systolic velocity (PSV) at the lesion segment to that at the proximal part, a major amputation, or a TLR
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Patients were randomly assigned to either PTA or AMS implantation. The randomization list was generated using PROC PLAN of SAS (Statistical Analysis Software)"
Allocation concealment (selection bias)	Low risk	Quote: "Sequentially numbered sealed envelopes contained information on the treatment to be applied. The sealed envelopes were opened only after the lesion was successfully crossed with the guidewire, and then patients were allocated either to stent or to PTA alone"
Blinding of participants and personnel (performance bias) All outcomes	High risk	None
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not mentioned
Incomplete outcome data (attrition bias) All outcomes	Low risk	Primary safety endpoint at 1 month reported for 57/57 in the PTA group and for 59/60 in the AMS group Primary efficacy endpoint at 6 months reported for 40/57 in the PTA group and for 37/60 in the AMS group 7 participants in the PTA group crossed over to other treatment (included in PTA + AMS group for on‐treatment analysis) 1 participant in the AMS group underwent implantation of a non‐study stent (not included in on‐treatment analysis) Sudy authors provide on‐treatment and ITT analyses
Selective reporting (reporting bias)	Low risk	None
Other bias	High risk	Quote: "The devices used in the study were the first‐generation AMS and the Pleon Explorer angioplasty balloon catheter, both developed by BIOTRONIK AG (Switzerland). The sponsor, BIOTRONIK AG, funded the total study costs and was responsible for the study administration and monitoring of the study"