Percutaneous revascularization of chronic coronary occlusions: An overview

Abstract

Patients with a chronic coronary occlusion often undergo coronary angiography after weeks to months of occlusion. The published reports underestimate the extent of this problem because such patients are often arbitrarily assigned to receive medical therapy or undergo bypass surgery as a result of poor success with percutaneous revascularization and substantial restenosis. Thus, there is controversy about the role of angioplasty in this patient cohort. The goal of this overview was to evaluate the available information about angioplasty in chronic coronary occlusions. The primary indication for attempted recanalization of a chronic coronary occlusion has been symptomatic angina pectoris. Anginal status often improves after successful procedures (70% vs. 31% with a failed procedure); left ventricular function may improve; and subsequent referral for coronary artery bypass graft surgery is uncommon (3% vs. 28% in unsuccessful cases). Successful recanalization is achieved in approximately 65% of attempted procedures. Inability to cross the stenosis with a guide wire is the most common cause of procedural failure. Statistically significant predictors of procedural success include older occlusions (75% < 3 months old vs. 37% > or = 3 months old), absence of any anterograde flow through the occlusion (76% with vs. 58% without), angiographically abrupt-appearing occlusions (50% vs. 77% with tapered occlusions), presence of bridging collateral vessels (23% with vs. 71% without) and lesions > 15 mm. Procedural complications occur at a slightly lower incidence than in angioplasty of high grade subtotal stenoses. Long-term success is limited, and restenosis can be expected in > 50% of the patients. The experience with chronic total occlusions of saphenous vein bypass grafts is small, but there appear to be limited procedural success and significant procedural complications, particularly associated with distal emboli. The role of new pharmacologic agents has yet to be defined and that of new devices has been disappointing so far, but further technologic advances are on the horizon.

Optical coherent reflectometry: A new technique to guide invasive procedures

“…Successful recanalization is achieved in less than 65% of attempted procedures. Inability to cross the lesion with a guidewire is the reason for failure in more than 75% of unsuccessful attempts [1]. To facilitate guidewire crossing, new guidewires have been developed, including a ball-tipped wire [2], the laserwire [3], guidewires with hydrophilic coating [4], and stiff wires with high-torque control (Athlete wire, Asahi Intech, Japan).…”

Angioscopic Observation After Coronary Angioplasty for Chronic Coronary Occlusion Comparison With Severe Stenotic Lesion

“…cohort was reported in 1982 [1], many studies dealing with chronic total occlusions has been reported [2]. The beneficial effects of successful angioplasty for the chronic total occlusion has been reported: Anginal state often improves after successful angioplasty; left ventricular functions may improve [3][4][5]; and subsequent referral for coronary bypass graft surgery is uncommon [6][7][8].…”

“…The angioscopic observation showed that fewer incidence of thrombus in the CTO group compared with non-CTO group. Total occlusion comprises athrosclerotic plaque and a single or multiple layers of clot formed by repeat injury repair process [2]. Angioscope can recognize fresh clots as a thrombus, however as the older and more fibrosed clot were present in the lesion with total occlusion, angioscope cannot detect the thrombus.…”

“…In spite of these beneficial effects, two major problems are existed. One is the initial success rate, which has reached over 70% in recent reports [2,9]. Selection of the lesions for more favorable outcome and newer devices may improve the initial success rate [10].…”

Doppler optical coherence tomography for interventional cardiovascular guidance: in vivo feasibility and forward-viewing probe flow phantom demonstration

“…The principal challenge of performing angioplasty for a CTO is the safe navigation of a guidewire through the dense collagen blockage without perforating the arterial wall. 2,3 While some experimental imaging guidance technologies have been suggested to differentiate between the blockage and the arterial wall. 4 and hence guide this procedure, these methods are not generally available to interventional cardiologists.…”