Clinical Studies; Complications; Clinical Trial Results; Description Of The Rotablator Rotational Atherectomy System - Boston Scientific Rotablator Gebrauchsanweisung

CLINICAL STUDIES

Complications

As with all interventional cardiology devices, serious complications, sometimes
leading to death, may be associated with the use of the Rotablator™ System. In
addition, complications due to individual patient reaction to an angioplasty device
may occur, necessitating coronary artery bypass graft surgery (CABG).
Complications associated with the use of the Rotablator System have been
compiled from literature, clinical trials, and reports received through the complaint
handling system. Complications include: access site bleeding of significance,
distal embolization, intimal dissection, acute vessel closure, vessel perforation or
tear, ventricular perforation, emergency surgery, contrast media reaction, stroke,
slow flow, no flow, myocardial infarction, arrhythmia requiring treatment, cardiac
tamponade, and death.
Slow flow represents a reduction of flow, post Rotablator System treatment, by one
to two TIMI grades from the baseline antegrade egress of dye. No flow represents
the complete cessation of flow into the distal circulation of the treated vessel not
associated with mechanical obstruction (dissection flap). Both these events may
be associated with a combination of several factors working in synergy, including
vasospasm and overburdening of the distal microcirculation with particulate
debris. Slow flow and no flow can be minimized by using a technique of slow
advancement of the burr, and by limiting the decrement in revolutions per minute
to no greater than 5,000. The time of treatment and the interval between treatments
should be balanced to allow adequate ablation of the plaque and permit clearance
of the debris. A strategy of undersizing the initial burr, and advancing to larger
burrs, the use of side hole catheters, maintaining adequate perfusion pressure,
and use of vasodilators such as nitroglycerin all act to reduce the incidence and
adverse effects of this phenomenon.
Therapies for slow flow should be directed at maintaining and enhancing perfusion
pressure. These therapies include volume expansion, bolus flushes of saline or
arterial blood through the guiding catheter, intracoronary nitroglycerin to relieve
vasospasm, and distal to proximal low pressure balloon inflations. Balloons other
than perfusion balloons should be chosen for this purpose, as perfusion balloons
may exacerbate the slow flow. Balloon inflations should be short, 20 - 30 seconds.
If a perfusion balloon is chosen for other reasons, special attention should be
given to maintaining short inflation times.
In addition to these clinical complications there have been complications
associated with the guidewire including distortion, kinks, and fracture. Additionally,
physical deterioration or malfunction of the device, including detachment of the
burr, has been reported.

Clinical Trial Results

Occurrences of complications associated with the use of the Rotablator System
were compiled following 1 year follow-up from the Multi-Center Registry
(2,736 procedures and 3,424 lesions at 22 centers). This list includes the
following:
Table 1: Rotablator System Multi-Center Registry - Safety Results at 1 Year
Follow-Up
Major Complications
Death
Q-Wave Myocardial Infarction
Coronary Artery Bypass Grafting
Angiographic Complications
Intimal Dissection
Acute Vessel Closure
Vessel Perforation or Tear
Arrhythmia
Angiographic success (defined as a luminal diameter of greater than or equal to
50% of the native lumen, a 20% absolute reduction in percent stenosis, and no
major complications) was achieved with the Rotablator System alone in 83% of the
lesions. Overall success was 95% with the use of adjunctive balloon angioplasty.
The data showed no statistical difference in the overall primary success rate
when segmented by lesion characteristics.
Restenosis, which is the reoccurrence of narrowing or occlusion in a previously
ablated vessel, may occur within hours, days, or months of the procedure. The
results of the coronary clinical study indicate that the restenosis rate for patients
treated with the Rotablator System is not proven to be different in comparison
to the restenosis rate obtained for patients treated with balloon angioplasty or
other interventional devices. Long-term complications of percutaneous rotational
angioplasty with the Rotablator System are not fully known at this time.

DESCRIPTION OF THE ROTABLATOR ROTATIONAL ATHERECTOMY SYSTEM

The Rotablator Rotational Atherectomy System has four main components. These
include the Rotawire™ guidewire, advancer, catheter, and control console system,
which includes the control console, foot pedal and compressed gas supply. The
Rotablator System has been designed to allow the catheter to be separated from
the advancer to allow multiple catheters with various burr sizes to be attached
to a single advancer during a procedure. The catheter connects to the advancer
to provide an integral system. The advancer and catheter are described below.
For descriptions and specifications of the Rotawire guidewires, see the Rotawire
guidewire "Instructions for Use". For descriptions and specifications of the control
console system, refer to the "Console Operations Manual".
DESCRIPTION OF THE COMPONENTS OF THE ROTABLATOR ROTATIONAL
ATHERECTOMY SYSTEM
Rotablator Advancer: Illustrated in Figure 1, the advancer acts as a support
for the air turbine and as a guide for the sliding elements which control burr
extension. A brake within the advancer body holds the guidewire firmly during
burr rotation, except in Dynaglide™ mode, to prevent the wire from spinning or
moving. Manipulation of the advancer knob allows independent extension of the
burr, and manipulation of the wireClip™ torquer allows independent movement of
the guidewire tip.
The air turbine uses compressed gas to generate the high rotational speeds
necessary for ablation. Using compressed gas allows for the use of low, inertial,
mass-driving elements which can be quickly started and stopped. The Rotablator
advancer air hose is flexible, allowing convenient placement of the advancer.
The Rotablator advancer must be used only with guidewires especially designed
for and approved for use with the Rotablator System.
5
Frequency
1.0%
1.1%
2.5%
Frequency
13.7%
5.1%
0.7%
2.7%