A rotational ablation tool for calcified atherosclerotic plaque removal

Abstract

Atherosclerosis is a major cardiovascular disease involving accumulations of lipids, white blood cells, and other materials on the inside of artery walls. Since the calcification found in the advanced stage of atherosclerosis dramatically enhances the mechanical properties of the plaque, restoring the original lumen of the artery remains a challenge. High-speed rotational atherectomy, when performed with an ablating grinder to remove the plaque, produces much better results in the treatment of calcified plaque compared to other methods. However, the high-speed rotation of the Rotablator commercial rotational atherectomy device produces microcavitation, which should be avoided because of the serious complications it can cause. This research involves the development of a high-speed rotational ablation tool that does not generate microcavitation. It relies on surface modification to achieve the required surface roughness. The surface roughness of the tool for differential cutting was designed based on lubrication theory, and the surface of the tool was modified using Nd:YAG laser beam engraving. Electron microscope images and profiles indicated that the engraved surface of the tool had approximately 1 μm of root mean square surface roughness. The ablation experiment was performed on hydroxyapatite/polylactide composite with an elastic modulus similar to that of calcified plaque. In addition, differential cutting was verified on silicone rubber with an elastic modulus similar to that of a normal artery. The tool performance and reliability were evaluated by measuring the ablation force exerted, the size of the debris generated during ablation, and through visual inspection of the silicone rubber surface.

Removing vascular obstructions: a challenge, yet an opportunity for interventional microdevices

“…As mentioned in Section 3.4, cooling system is required: it is achieved by a saline flush on the rotating burr. Derived devices exploiting a laser-structured grinding surface (instead of grains) are being investigated (Kim et al 2011).…”

“…(Kim et al 2011)) is credited to bring valuable results, especially in the short-and mid-term. Nevertheless, based on the carried out analysis of the literature and the review of commercial devices, the above scenario combining external powering and triggering/actuation of internal micro tools/devices/ robots appears as a really remarkable trend for future developments in the considered field.…”

Feasibility study for removing calcified material using a planar rectangular ultrasound transducer

“…In order to ensure that nonthermal ultrasound was used, the protocols were designed so that the temperature does not exceed 1°C. Hydroxyapatite-polylactide (HA-PLA) was investigated as a possible material for atherosclerotic plaque [32]. Recently an ablation experiment was performed on an HA-PLA composite using a high-speed rotational ablation tool [32].…”

“…Hydroxyapatite-polylactide (HA-PLA) was investigated as a possible material for atherosclerotic plaque [32]. Recently an ablation experiment was performed on an HA-PLA composite using a high-speed rotational ablation tool [32]. In this particular research, a rotational atherectomy technique was used in which a small grinder is inserted into the coronary arteries to ablate plaque and increase blood flow to the heart.…”

Magnetic dragging of vascular obstructions by means of electrostatic and antibody binding

“…In this context, several instrumented catheters are used to mechanically remove vascular obstructions (namely atherosclerotic plaques and clots) [6]; however they typically produce debris which must be collected or size-limited, to minimize post-intervention complications. Moreover, some robotic systems for improving catheter-based procedures already exist, mainly aimed at enhancing tip steering capabilities of traditional catheters [7].…”