Mechanical-Chemical Combined Atherectomy in a Topologically Isolated Arterial Segment

This work extends a closed-loop extracorporeal vascular cleaning architecture, introduced in a prior publication, with four refinements that address practical and safety considerations not handled in the prior protocol. First, atheroma is hypothesized to consist of two mechanically distinct fractions: a weakly adhered fraction removable by gentle mechanical contact within the isolated chamber, and a structurally integrated fraction requiring chemical action. Mechanical pre-cleaning with a pointed balloon under inline pressure feedback addresses the weakly adhered fraction first; chemistry then operates against an exposed substrate. The two-regime model bounds the residual chemistry burden at the structurally integrated mass fraction, hypothesized at 40%-60% of total plaque mass and corresponding to an upper bound of 60% of the chemistry-only collagenase specification; exposed-substrate kinetics may permit further reduction, though the magnitude of any such enhancement is undefended at the concept stage and must be established empirically. Second, the pressure differential between the bypass and treatment circuits is made stage-dependent: inward-biased during chemistry and outward-biased during saline phases, with a bounded outward sweep during the final flush. Third, direct percutaneous needle access through the overlying tissue extends the architecture to deep vessels (renal, mesenteric, and retroperitoneal) currently inaccessible to catheter-based intervention. Fourth, a localized biodegradable protective coating applied to the cleaned vessel wall before blood reintroduction bridges the re-endothelialization window with local protection rather than systemic antithrombotic therapy. Each refinement uses approved or near-approved components in new combinations. Two architectural extensions are also developed: a hemodynamic synergy with systemic therapy in which cleaned segments serve as preferential redeposition sites for material mobilized from inaccessible regions, and an organ as chamber primitive generalizing topological isolation to organs with discrete arterial inflow and venous outflow. Five testable predictions are specified for validation in a porcine atherosclerosis model.