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Page 8 of 22 Andò et al. Vessel Plus 2023;7:15 https://dx.doi.org/10.20517/2574-1209.2023.26

advent of the stent era and the awareness that the residual plaque burden at the time of stent implantation
was directly proportional to the degree of neointimal proliferation, the cause of intrastent restenosis, it was
hypothesized that maximum mechanical debulking could reduce the risk of restenosis, increasing the
minimum luminal diameter (MLD) obtained at the end of the procedure and limiting the degree of
barotrauma to the vessel . Observational data confirmed the efficacy and safety of a pre-PTCA RA strategy
[52]
for heavily calcified lesions, with success rates ≥ 90% and a low incidence of procedural complications and
out-of-hospital Major Adverse Cardiac Events (MACE) . Despite these procedural premises, studies did
[53]
not demonstrate a lower rate of long-time mortality or target lesion revascularization (TLR) with the use of
mechanical debulking compared to conventional balloon intervention , thus slowing down the diffusion of
[54]
this technique at the beginning of the new millennium. The introduction of the first-generation DES led to a
[55]
reduction in intrastent restenosis rates below 10% . As a result, interventional cardiologists began to
confidently treat more and more complex lesions such as tortuous and calcific vessels percutaneously, thus
showing a renewed interest in atherectomy techniques, revisited, however, from a more modern perspective
in order to obtain an optimal preparation of the vessel rather than and extensive plaque debulking. In the
current era of 2nd and 3rd generation DES, RA is used as a technique for modifying heavy CAC to increase
the number of lesions suitable for PCI and optimizing procedural results rather than as a technique aimed at
preventing restenosis , in a strategy known as "Rota-stent". In the first decade of the 2000s, RA confirmed
[56]
excellent results in terms of procedural success , even if this hardly translated into a consistent long-term
[57]
benefit in terms of restenosis and MACE [58-60] . Indeed, the 2018 ESC/EACTS (European Society of
Cardiology/European Association for Cardio-Thoracic Surgery) guidelines on myocardial revascularization
only mention, without providing a clear recommendation, the use of RA in selected lesions, in particular
markedly calcific ones, in order to adequately dilate the lesions before stent implantation . In patients
[61]
undergoing PCI, RA is currently used in less than 5% of cases , excluding some high-volume centers in
[62]
North America where the prevalence of use exceeds 10% .
[63]
Technical fundamentals of Rotational Atherectomy
The Rotablator system (Boston Scientific Corporation, Natick, Boston, MA, USA) is the most widely used
atherectomy device in current interventional practice for the treatment of calcified atherosclerotic lesions in
the coronary arteries. It consists of an elliptical-shaped diamond-coated metal burr that rotates at very high
speed and, advancing into the coronary lumen, acts as an abrasive surface against the calcified plaque. The
burr is available in diameters ranging from 1.25 to 2.5 mm and is mounted on a transmission shaft
(advancer) connected to a system that converts compressed gas into rotational energy. The burr size should
be chosen according to a burr-to-artery ratio of 0.5-0.6. Commonly, a single 1.5 mm burr represents the
right compromise to obtain sufficient plaque modification; however, a step-up approach starting with a
1.25 mm burr up to 1.5 mm or 1.75 mm burr might be a safer strategy if no budget constraints are present.
The burr advances on a dedicated 0.009” guidewire (Rotawire, Boston Scientific) while being constantly
irrigated with a solution that cools and lubricates it. Most procedures can be safely performed with the
Floppy Rotawire, which has a long tapered shaft allowing greater flexibility and facilitating lesion crossing,
while the Extra Support Rotawire, with its shorter tapered shaft, may be useful for aorto-ostial lesions as it
provides more support to maximize vessel straightening and device delivery. New, more-performing wires
will be available soon. The recent RotaPro system (Boston Scientific) represents an updated and simplified
version of the RA system, offering an improved visual interface and new electronic controls integrated into
the device. The advancement of the metal burr rotating at high speed against a calcified plaque determines
its mechanical ablation and its structural modification according to the principles of “differential cutting”
and orthogonal “displacement” of the friction, while sparing adjacent non-calcifying tissue . Differential
[64]
cutting is the ability to ablate one type of material while saving another with a different substrate
composition. With this mechanism, the rotating burr preferably ablates the inelastic atherosclerotic plaque
(in its fibrotic and calcific components) without exerting a traumatic action on the adjacent wall of the