Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT00481780 |
| Other study ID # |
2004 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
June 1, 2007 |
| Last updated |
September 10, 2007 |
| Start date |
November 2004 |
| Est. completion date |
April 2007 |
Study information
| Verified date |
May 2007 |
| Source |
Vienna General Hospital |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
Austria: Agency for Health and Food Safety |
| Study type |
Interventional
|
Clinical Trial Summary
Percutaneous transluminal angioplasty (PTA) is a minimally invasive technique for treatment
of superficial femoropopliteal artery (SFA) obstructions or occlusions in patients with
intermittent claudication as well as critical limb ischemia. Initial technical success rates
of above 95% can be achieved and acceptably low rates of complications are consistently
reported in the literature. There is a direct relation between treated vessel length and
patency rates. One year patency of lesions longer than 10cm has only been 22% at one-year
follow up. This major drawback limits a widespread applicability of PTA, and the indication
of PTA particularly in patients with intermittent claudication is discussed
controversially.With the introduction of endovascular stents, the problems of elastic recoil
and residual stenoses due to arterial dissection could be resolved and initial reports of
stenting for the treatment of occlusive atherosclerotic disease of the SFA showed promising
results with primary and secondary patency rates of 87% to 90% after 18 months. However,
subsequent studies demonstrated that exaggerated neo-intimal hyperplasia in the stented
segment frequently leads to instent restenosis. This condition will be of greater importance
with increasing number of stent implantation procedures during the last years. The concept
of cutting balloon seems appealing for this indication, as the balloon-mounted microtomes
guarantee smooth lumen gain within the stent, without the risk of vessel wall perforation.
Initial reports of the use of the cutting balloon for the treatment of occlusive
atherosclerotic disease of the SFA show promising results, indicating that the problems of
elastic recoil and residual stenoses due to arterial dissection might be resolved. The
cutting balloon has four tiny microtomes (< 0.1mm height) on the outside, which cut the
fibrous plaque during expansion of the balloon. Consequently the problem of elastic recoil
is ideally addressed, additionally less trauma is exercised on the vessel wall during
dilatation of the balloon. This might be achieved by a reduction of vessel wall trauma,
vessel wall inflammation and consequently reduced neointimal formation. Although the
indications for CB-PTA in the SFA includes significant residual stenosis or in-stent
restenosis, there are currently no published randomized controlled trials (RCT) comparing
PTA vs. cutting balloon angioplasty (CB-PTA) for any specific condition. This lack of data
led us to initiate a RCT comparing primary PTA vs. CB-PTA for treatment of in-stent
restenoses in patients with intermittent claudication or critical limb ischemia with TASC
category A-B in the femoropopliteal artery .
Description:
Percutaneous transluminal angioplasty (PTA) is a minimally invasive technique for treatment
of superficial femoropopliteal artery (SFA) obstructions or occlusions in patients with
intermittent claudication as well as critical limb ischemia. Initial technical success rates
of above 95% can be achieved and acceptably low rates of complications are consistently
reported in the literature. There is a direct relation between treated vessel length and
patency rates. One year patency of lesions longer than 10cm has only been 22% at one-year
follow up. This major drawback limits a widespread applicability of PTA, and the indication
of PTA particularly in patients with intermittent claudication is discussed controversially.
With the introduction of endovascular stents, the problems of elastic recoil and residual
stenoses due to arterial dissection could be resolved and initial reports of stenting for
the treatment of occlusive atherosclerotic disease of the SFA showed promising results with
primary and secondary patency rates of 87% to 90% after 18 months. However, subsequent
studies demonstrated that exaggerated neo-intimal hyperplasia in the stented segment
frequently leads to instent restenosis. This condition will be of greater importance with
increasing number of stent implantation procedures during the last years. Repeated PTA of
instent restenosis is performed for revascularisation in these patients, but the gold
standard for treatment of instent restenosis is unknown and the rate of recurrence after
repeat treatment of instent restenosis remains high. The concept of cutting balloon seems
appealing for this indication, as the balloon-mounted microtomes guarantee smooth lumen gain
within the stent, without the risk of vessel wall perforation (due to the protecting effect
of the stent as the outer limit for the microtomes).
Initial reports of the use of the cutting balloon for the treatment of occlusive
atherosclerotic disease of the SFA show promising results, indicating that the problems of
elastic recoil and residual stenoses due to arterial dissection might be resolved. The
cutting balloon has four tiny microtomes (< 0.1mm height) on the outside, which cut the
fibrous plaque during expansion of the balloon. Consequently the problem of elastic recoil
is ideally addressed, additionally less trauma is exercised on the vessel wall during
dilatation of the balloon. This might be achieved by a reduction of vessel wall trauma,
vessel wall inflammation and consequently reduced neointimal formation. The cutting balloon
can be used for pre-dilatation with diameters slightly less than the target vessel diameter,
but still cuts the fibrous plaque, the desired target vessel diameter is then achieved by
final touch up dilatation with a standard angioplasty balloon. In the coronary arteries the
cutting balloon has been used in randomized studies comparing CB-PTCA to PTCA, as well as in
trials for the treatment of in-stent restenosis. All of these trials demonstrated the safety
and efficacy of the cutting balloon, only larger randomized trials failed to proof
superiority to conventional PTCA. Data in the peripheral arteries are at least scarce.
Although the indications for CB-PTA in the SFA includes significant residual stenosis or
in-stent restenosis, there are currently no published randomized controlled trials (RCT)
comparing PTA vs. cutting balloon angioplasty (CB-PTA) for any specific condition. This lack
of data led us to initiate a RCT comparing primary PTA vs. CB-PTA for treatment of in-stent
restenoses in patients with intermittent claudication or critical limb ischemia with TASC
category A-B in the femoropopliteal artery . The primary endpoint is the occurrence of
restenosis as an ultrasonographic reduction of the vessel lumen diameter >50% within 6
months after endovascular treatment. In addition, the course of postintervention
inflammation as indicated by serum levels of C-reactive protein (CRP), serum amyloid A (SAA)
and fibrinogen will be assessed.
STUDY DESIGN, INCLUSION AND EXCLUSION CRITERIA. Patients with in-stent restenosis
(ultrasonographic stenosis > 50% of the vessel lumen diameter) after prior PTA and Stent
placement of the SFA will be enrolled to this single-center prospective RCT. The protocol
has to be approved by the institutional ethics committee and all patients have to provide
written informed consent before enrollment. Entry criteria include symptomatic peripheral
artery disease with intermittent claudication (Fontaine stage IIa or b), or critical limb
ischemia related to a recurrent stenosis in a previously stented segment of up to 20 cm
length. Exclusion criteria history of intolerance of anti-platelet therapy, or adverse
reaction to heparin, bleeding diathesis, creatinine >2.5 mg/dL, hemodialysis, active
bacterial infection, and allergy to contrast media, pregnancy and disability to give
informed consent.
FOLLOW-UP. ABI testing, treadmill exercise, and Duplex-sonography of the treated vessels
will be performed in all patients at 1, 3, and 6 months after treatment. A peak systolic
velocity of ≥ 2.4 was considered indicative of a >50% narrowing and was defined as
indicative of a restenosis10. Reintervention or surgical bypass at the treated segment are
also defined as a restenosis and loss of primary patency. An improvement of at least one
Fontaine category above baseline is used to define clinical success in association with
maintenance of at least a 0.15 increase in exercise ABI from the preprocedure level.
COMPLICATIONS are classified as either major or minor (as described in Appendix A). Major
complications are e.g. bleedings at the puncture side with hematoma and a decrease of serum
hemoglobin more than 2 g/dl, loss of stent in the artery , vessel rupture, amputation,
macroembolisation with need for further revascularisation and life threatening bleeding
complications.
STUDY ENDPOINTS. The primary study endpoint is the occurrence of a >50% restenosis at the
treated segment at 6 months post-intervention as determined by duplex ultrasound (in-segment
restenosis). Secondary objectives are primary technical success rates (residual stenosis
<30% without need for secondary stent implantation, primary assisted and secondary patency,
clinical patency, target vessel and target lesion revascularization, and cardiovascular
adverse events at 1, 3, and 6 months after the procedure. Furthermore, the course of
inflammatory parameters will be assessed.
