Coronary artery aneurysm formation after paclitaxel-coated balloon-only intervention for de novo coronary chronic total occlusion

A Giant Coronary Aneurysm Formation After RCA CTO Recanalization

Formation of a coronary artery aneurysm (CAA), especially a giant CAA, after percutaneous coronary intervention for chronic total occlusion (CTO) is a rare complication. Therapeutic approaches include surgical procedure, covered stent, and medical treatment. Here, we report a 47-year-old man readmitted due to chest distress who had undergone right coronary artery CTO recanalization 6 months earlier. Diagnostic coronary artery angiography revealed a giant aneurysm at the stented middle segment of the right coronary artery; it was >20 mm in diameter. This is the first report on a secondary giant CAA after CTO recanalization that was subsequently excluded with deployment of a covered stent.

Application of Drug-Coated Balloons in Complex High Risk and Indicated Percutaneous Coronary Interventions

There is a growing trend of patients with significant comorbidities among those referred for percutaneous coronary intervention (PCI). Consequently, the number of patients undergoing complex high risk indicated PCI (CHIP) is rising. CHIP patients frequently present with factors predisposing to extensive drug-eluting stent (DES) implantation, such as bifurcation and/or heavily calcified coronary lesions, which exposes them to the risks associated with an increased stent burden. The drug-coated balloon (DCB) may overcome some of the limitations of DES, either through a hybrid strategy (DCB and DES combined) or as a leave-nothing-behind strategy (DCB-only). As such, there is a growing interest in extending the application of DCB to the CHIP population. The present review provides an outline of the available evidence on DCB use in CHIP patients, which comprise the elderly, comorbid, and patients with complex coronary anatomy. Although the majority of available data are observational, most studies support a lower threshold for the use of DCBs, particularly when multiple CHIP factors coexist within a single patient. In patients with comorbidities which predispose to bleeding events (such as increasing age, diabetes mellitus, and hemodialysis) DCBs may encourage shorter dual antiplatelet therapy duration-although randomized trials are currently lacking. Further, DCBs may simplify PCI in bifurcation lesions and chronic total coronary occlusions by reducing total stent length, and allow for late lumen enlargement when used in a hybrid fashion. In conclusion, DCBs pose a viable therapeutic option in CHIP patients, either as a complement to DES or as stand-alone therapy in selected cases.

Hydrophilic Coating Microstructure Mediates Acute Drug Transfer in Drug-Coated Balloon Therapy

Drug-coated balloon (DCB) therapy is a promising endovascular treatment for obstructive arterial disease. The goal of DCB therapy is restoration of lumen patency in a stenotic vessel, whereby balloon deployment both mechanically compresses the offending lesion and locally delivers an antiproliferative drug, most commonly paclitaxel (PTX) or derivative compounds, to the arterial wall. Favorable long-term outcomes of DCB therapy thus require predictable and adequate PTX delivery, a process facilitated by coating excipients that promotes rapid drug transfer during the inflation period. While a variety of excipients have been considered in DCB design, there is a lack of understanding about the coating-specific biophysical determinants of essential device function, namely, acute drug transfer. We consider two hydrophilic excipients for PTX delivery, urea (UR) and poly(ethylene glycol) (PEG), and examine how compositional and preparational variables in the balloon surface spray-coating process impact resultant coating microstructure and in turn acute PTX transfer to the arterial wall. Specifically, we use scanning electron image analyses to quantify how coating microstructure is altered by excipient solid content and balloon-to-nozzle spray distance during the coating procedure and correlate obtained microstructural descriptors of coating aggregation to the efficiency of acute PTX transfer in a one-dimensional ex vivo model of DCB deployment. Experimental results suggest that despite the qualitatively different coating surface microstructures and apparent PTX transfer mechanisms exhibited with these excipients, the drug delivery efficiency is generally enhanced by coating aggregation on the balloon surface. We illustrate this microstructure-function relation with a finite element-based computational model of DCB deployment, which along with our experimental findings suggests a general design principle to increase drug delivery efficiency across a broad range of DCB designs.