Hybrid intravascular ultrasound and optical coherence tomography catheter for imaging of coronary atherosclerosis.

OBJECTIVE: To demonstrate the feasibility of imaging human coronary atherosclerosis using a novel hybrid intravascular ultrasound (IVUS) and optical coherence tomography (OCT) imaging catheter. BACKGROUND: IVUS and OCT have synergistic advantages and recent studies involving both modalities suggest the use of a hybrid imaging catheter may offer improved guidance of coronary interventions and plaque characterization. METHODS: A 1.3 m custom hybrid IVUS-OCT imaging probe was built within a 4F catheter using a 42 MHz ultrasound transducer and an OCT imaging fiber. Coplanar images were simultaneously acquired ex vivo by both modalities in 31 arterial segments from 11 cadaveric human coronaries. IVUS and OCT images were acquired at 250 µm intervals, of which 13 of the arterial segments were selected as representative of a diverse set of pathological findings. The selected segments were then imaged with either digital X-ray or micro-CT, processed for histological analysis and compared with the corresponding IVUS and OCT images. RESULTS: Images of human coronary atherosclerosis using the hybrid IVUS-OCT catheter demonstrated a range of vascular pathologies that were confirmed on histology. The anticipated synergistic advantages of each modality were qualitatively apparent, including the deeper tissue penetration of IVUS and the superior contrast, resolution and near-field image quality of OCT. CONCLUSIONS: Preliminary ex vivo images using a hybrid IVUS-OCT catheter demonstrated feasibility in using the device for intracoronary imaging of atherosclerosis. Future studies will include in vivo imaging and larger samples sizes to enable quantitative comparisons of tissue characterization and feature identification using hybrid imaging catheters versus standalone IVUS and OCT imaging techniques. © 2012 Wiley Periodicals, Inc.

Evidence for treatment of lower limb in-stent restenosis with drug eluting balloons.

INTRODUCTION: Restenosis by myointimal hyperplasia after peripheral arterial angioplasty or stenting often limits long term patency. Drug-eluting balloons (DEBs) which inhibit the proliferation of neo-intimal growth of vascular smooth muscle cells may prevent restenosis. The aim of this paper was to examine the evidence in published literature on the use of DEBs in the treatment of peripheral arterial in-stent restenosis (ISR). EVIDENCE ACQUISITION: A systematic literature review was undertaken of all published literature on the treatment of peripheral ISR with drug eluting balloon using Medline and cross-referenced. All published papers on the use of DEBs in peripheral arterial disease (PAD) were used. Cochrane Central Register of Controlled Trials and electronic databases were also searched for on-going studies. EVIDENCE SYNTHESIS: There were no level 1 or 2 evidence published on this subject. The number of high-quality publications is few, and consequently a sufficient analysis is not possible. Recently data from non-randomized cohort studies showed encouraging results with DEB as treatment modality for ISR, whether used alone or as combined strategies. CONCLUSIONS: Evidence from the published literature suggests that DEBs are safe in preventing peripheral ISR. Despite strong corporate pressure for the use of DEBs, there is only circumstantial evidence that this is a useful modality for ISR. Results from on-going studies may allow further meta-analysis for efficiency and cost-effectiveness.