Embolization complicating coronary angioplasty in the presence of an intracoronary thrombus

In vivo distribution of particulate matter from coated angioplasty balloon catheters

Most catheter-based vascular medical devices today have hydrophilic lubricious coatings. This study was designed to perform a territory-based downstream analysis of end organs subsequent to angioplasty with coated balloon catheters to better understand the potential in vivo physiological consequence of coating wear materials. Coronary angioplasty was performed on swine using balloon catheters modified with two polyvinylpyrrolidone (PVP)-based coatings of similar lubricity, but different levels of particulates (5-fold) when tested in a tortuous path model. Myocardial tissues examined 28 days post-angioplasty revealed no visible particulates in the animals treated with the lower particulate catheters while 3 of 40 sections from higher particulate catheters contained amorphous foreign material, and 1 of 40 sections from tissue treated with uncoated catheters had amorphous foreign material. Non-target organs and downstream muscle revealed no particulates for any of the treatments. Histological analysis showed that the overall number of vessels with embolic foreign material was low and evidence of myocyte necrosis was rare with either of the coatings investigated in this study.

Synergism of rheolytic thrombectomy and embolic distal protection using the percusurge guard wire for fresh thrombus removal: an in vitro study

OBJECTIVES

To test the effectiveness of Rheolytic Thrombectomy (RT) and distal protection balloon wires when used synergistically in an in vitro model.

BACKGROUND

Although effective, currently available technologies may not be individually ideal for fresh clots removal.

METHODS

Fourteen, fresh blood samples were placed in 14 plastic tubes and left to clot for 6 h. A Percusurge Guardwire balloon was inflated distal to the clot and aspiration was performed using RT in seven tubes and manual aspiration (MA) with the Export catheter in seven tubes. The residual clot in each tube was dried and weighed. Both aspiration systems were advanced over the Guardwire.

RESULTS

During RT, none of the protection balloons ruptured and no retrograde clot embolization were observed. MA was most effective when the Export catheter tip was not in direct contact with the clot. The residual clot mass post RT was significantly less than post MA (9.7+/-2.2 versus 59.2+/-45.9, P = 0.01).

CONCLUSION

RT is compatible with Distal Protection Balloon Wires and results in more complete clot removal than manual aspiration with the export catheter. Although manual aspiration results in a large variation in extraction efficacy, it is most effective when direct catheter-clot contact is kept to a minimum.

Distal protection in cardiovascular medicine: current status

Iatrogenic and spontaneous downstream microembolization of atheromatous material is increasingly recognized as a source of cardiovascular morbidity and mortality. Devising ways of reducing this distal embolization using a variety of mechanical means--distal protection--is currently under intense and diverse investigation. This review therefore summarizes the present status of distal protection. It examines the problem of distal embolization, describes the available distal protection devices, reviews those areas of cardiovascular medicine where distal protection devices are being investigated, and discusses potential future developments.

Distal protection of bifurcating vessels: a novel approach

Distal protection devices protect only a single distal vessel. We describe a novel technique to protect both branches following a thrombus-containing bifurcation lesion. The combination of an occlusive balloon and an arterial filter system provides an attractive solution to the challenging environment of a lesion at high risk for distal embolization supplying more than a single major branch.

Predicting angiographic distal embolization following percutaneous coronary intervention in patients with acute myocardial infarction

The aim of this study was to investigate the relation between lesion morphology identified by intravascular ultrasound (IVUS) before intervention and angiographic distal embolization after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). PCI for AMI has already been established as beneficial therapy, although some complications remain unresolved. Distal embolization is 1 of the important complications of PCI. Recently, some new devices have been developed for the prevention of distal embolization. However, few studies exist that look into the relation between lesion morphology and distal embolization. IVUS was performed safely in 140 consecutive patients with AMI before coronary intervention. No patient received thrombolytic therapy. From the incidence of angiographic distal embolization, patients were divided into 2 groups--an embolization group and a nonembolization group--and clinical background, IVUS, and angiographic information were evaluated. Distal embolization was observed in 12 patients (9%). Peak creatine kinase levels (3,877 +/- 2,285 vs 2,293 +/- 1,792 IU/L, p <0.05) and the incidence of angiographic thrombus (25% vs 5%, p <0.05) and intracoronary mobile mass detected by IVUS (75% vs 16%, p <0.001) were higher for patients in the embolization group. From the multivariate logistic regression analysis, only an intracoronary mobile mass detected by IVUS emerged as a predictor of distal embolization (odds ratio 53, 95% confidence interval 2.7 to 1,040, p <0.01). Patients with an intracoronary mobile mass detected by IVUS are prone to distal embolization after PCI and larger infarction. IVUS imaging before PCI may be useful for determining which patients need a distal protection device.

Prevention of distal embolization during coronary angioplasty in saphenous vein grafts and native vessels using porous filter protection

BACKGROUND

Although distal embolization and the "no-reflow" phenomenon are well described in saphenous vein graft (SVG) interventions, the frequency, magnitude, and characterization of embolized debris have not been evaluated in routine coronary interventions. A unique embolus protection device described herein provides a means of containing and retrieving plaque material dislodged during percutaneous coronary interventions. This report details the first clinical experience of the effectiveness and safety of an emboli protection system in 11 SVG lesions and 15 native coronary artery lesions.

METHODS AND RESULTS

The AngioGuard Emboli Capture Guidewire (Cordis) consists of a PTCA wire with an expandable filter at the distal tip. The porous membrane permits normal distal blood flow, while trapping potential emboli by filtration. After crossing the lesion, the filter is expanded, and routine angioplasty is performed over the same wire. Emboli retrieval is achieved by collapsing the filter and retracting the emboli capture wire (ECW). In 26 patients, standard angioplasty was performed over the ECW; 20 of these 26 patients received a stent. Collected debris was sent for histopathological analysis. Plaque debris was retrieved after native coronary and SVG interventions in all cases. The ECW was positioned and retrieved without complications. No major adverse events occurred. Myocardial infarctions and no-reflow were not observed.

CONCLUSIONS

The embolization of plaque fragments frequently occurs during coronary and SVG intervention. Distal embolization leading to microvascular obstruction and no-reflow could be successfully minimized by using the ECW.

Coronary artery and saphenous vein graft remodeling: a review of histologic findings after various interventional procedures--Part IV

Catheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effects on the site of obstruction has been termed "remodeling." Part IV of this six-part series focuses on morphologic correlates of coronary angiographic patterns of remodeling after balloon angioplasty and discusses effects of angioplasty on adjacent, nondilated vessels.

Coronary embolization after balloon angioplasty or thrombolytic therapy: an autopsy study of 32 cases

OBJECTIVES

This study was undertaken to examine the nature, extent and clinical relevance of coronary embolism after balloon angioplasty or thrombolytic therapy, or both.

BACKGROUND

Histopathologic documentation of postinterventional coronary embolization has been reported in only 10 patients from five studies.

METHODS

This retrospective autopsy-based study included 32 patients, treated with balloon angioplasty or thrombolysis, or both, who died within 3 weeks of the procedure and underwent autopsy at the Mayo Clinic. Clinical variables included patient age and gender, artery treated, site and type of obstruction, type of intervention, success of the procedure, and postprocedural changes in the electrocardiogram (ECG), cardiac enzymes and hemodynamic status. Histopathologic variables included characteristics of treated plaques, acutely infarcted myocardium and coronary microemboli. Associations between microemboli and clinical and microscopic factors were evaluated by t tests and simple and multiple linear regression.

RESULTS

Emboli were observed in 26 (81%) of the 32 patients. Among 83 emboli, 95% were thrombotic or atheromatous. The presence of microemboli was associated statistically with the development of postprocedural infarct extension, new myocardial infarction or new ECG abnormalities. Moreover, the greatest number of microemboli were associated with intervention in the left anterior descending coronary artery, multiple interventional sites, postprocedural medial dissection and plaque rupture or extrusion.

CONCLUSIONS

Among patients undergoing balloon angioplasty or thrombolytic therapy who die and undergo autopsy, coronary microemboli occur in a substantial percent. The frequency in survivors is unknown. However, in living patients who develop acute myocardial ischemia or new ECG abnormalities after these interventions, coronary microembolization should be considered a potential cause.

Histologic and morphologic effects of rotary atherectomy on human cadaver arteries

Intimal splitting and medial dissection caused by balloon angioplasty and thermal burns and subintimal vacuolization caused by laser angioplasty have been proposed as potential causes of failure from these respective procedures. The purpose of this study was to evaluate the histologic and morphologic effects of a new high speed rotary atherectomy device (the Rotoblator) on human cadaver arteries. Fifteen stenotic human cadaver superficial femoral and popliteal arteries were harvested and atherectomized using the Rotoblator. Histologically, on cross-section, the atherectomized arteries exhibited a denuded endothelial layer, a smooth rounded luminal contour, minute plaque separation from the media, absence of plaque fragmentation, and variable remaining rim of atheromatous plaque. The media showed variable loss of the internal elastic lamina, normal remaining elastin, and normal smooth muscle cells. The adventitia was normal and completely intact in all sections with no media/adventitia separation or perforations. Scanning electron microscopy revealed endothelial peeling, etching from the atherectomy devices within the smooth muscle layer, and a tapered atherectomy distal endpoint. The arterial branches were preserved without evidence of any disruption of the branch artery orifice. Compared to balloon angioplasty and laser angioplasty, the Rotoblator atherectomy device appears to leave a smoother, more rounded luminal surface that may result in less risk of embolic complications and arterial wall damage.

Percutaneous transluminal coronary angioplasty

The relief of coronary obstruction by surgical grafting was the first effective treatment to be directed at the cause of ischemic heart disease. PTCA represents the second major step in relieving coronary stenosis. It seems timely to review where this second step has led in order to understand how percutaneous transluminal coronary angioplasty (PTCA) relates to surgery and to understand future implications of this procedure. This review will reflect many of the authors biases and prejudices derived from their experience at Mayo Clinic. It will also be a somewhat practical assessment. Such a pragmatic approach can be defended because PTCA itself is built on pragmatism. It is more of the world of craftsmen than of the world of scientists. We are still waiting for science to "catch up" to help solve important remaining problems such as the issue of acute rethrombosis and restenosis. Our ability to review the Mayo Clinic experience is made possible only by having a dedicated team of colleagues in the catheterization laboratory and a dedicated support group managing our PTCA Registry. Experience with other large registries (the NHLBI CASS Registry and the PTCA Registry) has taught us that this is a valuable method of collecting and reviewing the experience with a new procedure as it develops. This approach is likely to be more widely applied in the future.