An embolization containment device

Thrombosuction utilizing an export aspiration catheter during primary percutaneous coronary intervention in acute myocardial infarction

PURPOSE

Effective myocardial reperfusion after primary PCI for an AMI in lesions with a thrombus is limited by distal embolization and the slow/no reflow phenomenon. We evaluated the efficacy of a thrombus reduction technique using an export aspiration catheter for thrombosuction during primary PCI.

MATERIALS AND METHODS

We analyzed 62 patients with AMIs who underwent primary PCI and had a thrombi burden during thrombosuction using an EAC (EAC group; n=31) or without thrombosuction (control group; n=31).

RESULTS

Thrombosuction with an EAC was performed safely in all the patients in EAC group without any complications. After the PCI, restoration to a TIMI flow grade 3 was significantly more frequent in the EAC group (26/31 vs. 20/31, p < 0.05). However, the TIMI perfusion grade did not differ between the two groups. Further, the corrected TIMI frame counts were lower in the EAC group (23.9 +/- 15.1 vs. 34.8 +/- 22.5, p < 0.05). Although there was no statistical significance, a greater incidence of distal embolization was observed in the control group (16.1%, 5/31) as compared to the EAC group (0/31) (p= 0.056). However, the incidence of major adverse cardiac events at 1 and 6 months did not differ between the two groups.

CONCLUSION

For AMIs, thrombosuction with an EAC before or during PCI is a safe and potentially effective method for restoration of the coronary flow.

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.

Heterogeneity of Myocardial Perfusion in Distal Coronary Embolism with Different Particle Sizes

BACKGROUND

We hypothesized that altered myocardial perfusion distribution patterns could be seen with coronary distal emboli of different particle sizes using myocardial contrast echocardiography.

METHODS

In 16 open-chest anesthetized dogs, microsphere suspensions of 9 or 500 microm in diameter were injected into the left anterior descending coronary artery until the mean left anterior descending coronary artery flow rate was reduced to less than 30% of baseline flow. During baseline conditions and after maximal embolization, real-time myocardial contrast echocardiography was performed by intravenous infusion of an echocontrast agent.

RESULTS

In animals infused with 9-microm microspheres, a transmural perfusion defect was seen at the time of maximal embolization. In contrast, in animals infused with 500-microm microspheres, a subendocardial perfusion defect was observed.

CONCLUSIONS

The particle size of coronary distal emboli affects myocardial perfusion distribution.

In vivo volumetric analysis of coronary stent using optical coherence tomography with a novel balloon occlusion-flushing catheter: a comparison with intravascular ultrasound

Optical coherence tomography (OCT) is limited as an intravascular imaging tool because of interference with blood. This study tested a new balloon occlusion-flushing catheter for OCT scanning of stented coronary arteries and compared stent measurements between OCT and intravascular ultrasound (IVUS). Motorized pullback with OCT and IVUS was examined in coronary stents deployed in swine. Quantitative measurements were obtained and compared between both groups. In addition, stent strut thickness was compared among OCT, IVUS and actual measurement. The occlusion catheter successfully provided motorized pullback OCT images in the stented coronary arteries without any complications. There were no differences in calculated lumen volume. However, stent volumes were significantly smaller with OCT than with IVUS (p < 0.05). OCT significantly underestimated the stent strut thickness compared with the actual measurement. Although OCT underestimates the stent strut thickness, motorized pullback OCT imaging with the occlusion catheter can provide appropriate in-stent images in the porcine coronary arteries.

Inflammatory markers at the site of ruptured plaque in acute myocardial infarction: locally increased interleukin-6 and serum amyloid A but decreased C-reactive protein

BACKGROUND

Acute myocardial infarction (AMI) is associated with inflammation. However, it remains unclear whether it originates from the ruptured plaque or represents a systemic process.

METHODS AND RESULTS

In 42 patients with AMI, a balloon-based embolization protection device and aspiration catheter (PercuSurge) were used during acute coronary interventions. Samples from the site of the ruptured plaque were taken under distal balloon occlusion. Systemic samples were taken from the aorta. Sera, plaques, and thrombi were analyzed for inflammatory markers and lipoproteins. Systemic levels of C-reactive protein (CRP), interleukin-6 (IL-6), and serum amyloid A (SAA) in the aorta amounted to 3.0 mg/L, 5.0 ng/L, and 22.1 mg/L, respectively (interquartile ranges [IQRs], 1.1 to 7.4 mg/L, 5.0 to 6.5 ng/L, and 13.9 to 27.0 mg/L, respectively). In blood surrounding ruptured plaques, local levels of IL-6 (8.9 ng/L; IQR, 5.0 to 16.9 ng/L) and SAA (24.3 mg/L; IQR, 16.3 to 44.0 mg/L) were significantly higher, whereas CRP levels (2.5 mg/L; IQR, 0.9 to 7.7 mg/L) were decreased compared with the aorta (all P<0.0001). The coronary levels of IL-6 determined in vivo showed biological activity in vitro. Harvested thrombus contained CD68-positive monocytes expressing IL-6 and showed extracellularly and intracellularly positive staining for SAA, whereas CRP was found exclusively in the cytoplasm of phagocyting white blood cells.

CONCLUSIONS

Coronary levels of IL-6 and SAA at the site of plaque rupture were increased relative to the systemic circulation, indicating local production of biologically active inflammatory mediators. In contrast, CRP was locally decreased, at least in part by uptake by the phagocyting cells, suggesting a systemic origin of the protein.

Embolic Protection With Filtering or Occlusion Balloons During Saphenous Vein Graft Stenting Retrieves Identical Volumes and Sizes of Particulate Debris

Background— Distal embolization of plaque particulate liberated during stenting may cause periprocedural complications. The number, size, and volume of debris released during stenting, however, have not been quantified, rendering embolic protection approaches empiric. We used a novel method of microparticle size assessment to measure volume and characterize individual sizes of particles captured by the PercuSurge GuardWire balloon or a vascular filter during saphenous vein graft stenting.

Methods and Results— Braided nitinol filters (average distal pore size 100 μm) were used in 47 saphenous vein grafts in 44 patients. The PercuSurge GuardWire was used in 17 saphenous vein grafts in 16 patients. Particulate debris was subjected to microparticle size analysis (RapidVue, Beckman Coulter). All samples contained particulate debris. For both filter and GuardWire populations, most particles were <100 μm in longest dimension (87% and 90% of particles, respectively), and the distribution of particle sizes was identical. Total embolic load per lesion for both filters and GuardWire aspirates was also similar: median embolic load per filter was 16 mm 3 (range 2 to 84 mm 3 ). Median embolic load per GuardWire was also 16 mm 3 (range 7 to 42 mm 3 ). Histopathologic analysis demonstrated that most samples contained plaque elements and platelet-rich thrombus.

Conclusions— During saphenous vein graft interventions, particulate retrieved with a vascular filtering device or an occlusion balloon was similar in amount and character. This supports the notion that unless soluble mediators play an important role in adverse acute clinical events after stenting, the clinical efficacy of filtering devices may be equal to that of occlusion devices.

Formation of a coronary artery aneurysm after inflation of a PercuSurge GuardWire distal protection balloon

Formation of aneurysms in the coronary arteries with the use of the PercuSurge distal protection system has not been reported. We describe a 54-year-old man with acute myocardial infarction who was treated with the PercuSurge system. Angiography performed 2 weeks later revealed an aneurysm in the area of inflation of the distal protection balloon.

Carotid angioplasty under cerebral protection with the percusurge guardwire system

The purpose of this study was to examine the possible beneficial effect of the PercuSurge GuardWire cerebral protection device based on balloon occlusion of the distal internal carotid artery and debris aspiration for patients undergoing carotid artery stenting (CAS). A total of 268 CAS procedures were attempted under cerebral protection using the PercuSurge GuardWire system in 242 patients (194 men; mean age, 71.2 +/- 9.4 years; range, 40-91). The lesions were mainly atherosclerotic; 64% were symptomatic. Technical success was 99.3%. All lesions were stented except three postangioplasty restenoses. Prophylactic occlusion during balloon dilatation and stenting was well tolerated in 255 patients (95.9%). Microscopic analysis of the aspirated blood showed different types of particles numbering between 7 and 145 per procedure, with a mean diameter of 250 microm (mean, 56-2,652 microm). The 30-day stroke and death rate was 2.3%, with four periprocedural complications at < 48 hr (one retinal embolism and three transient ischemic attacks), one intracerebral hemorrhage at 3 days, and one death of cardiac failure at 3 weeks. This technique appears safe and efficient with a low rate of periprocedural embolic events. Protection devices seem indispensable to perform CAS and expand the applicability of the procedure. Randomized studies (surgery vs. CAS with and without cerebral protection) are awaited.

Evaluation of the percusurge guardwire plus temporary occlusion and aspiration system during primary angioplasty in acute myocardial infarction

Thirty patients with acute myocardial infarction (AMI) underwent primary angioplasty under distal protection of PercuSurge GuardWire Plus Temporary Occlusion and Aspiration System. Before angioplasty, protection of the distal circulation was achieved with the system, followed by balloon angioplasty and/or stenting and debris aspiration. Technical device success was 100%. Distal occlusion was well tolerated in all patients. Mean total distal occlusion time was 7.3 +/- 5.4 min. Macroscopically visible debris was aspirated from 29 cases (96.7%). Postprocedural Thrombolysis in Myocardial Infarction flow grade 3 was achieved in all cases (100%, vs. 16.7% at baseline). Myocardial blush flow grade 3 was achieved in 26 cases (86.7%). Regression of ST segment elevation >/= 50% was shown in 23 cases (76.7%). No patient developed angiographic evidence of no-reflow or distal embolization. Both angiographic and procedural success were 100%. The system is feasible, safe, and effective for distal protection against embolism during primary angioplasty in AMI.

Rapid thrombectomy for treatment of macroembolization during percutaneous coronary intervention in the setting of acute myocardial infarction

We report the use of the Export catheter as an urgent modality to aspirate thrombus that embolized down the left anterior descending artery during acute myocardial infarction.

Trauma induced by nontraumatic coronary devices and its impact on vascular reactivity and morphology

This study evaluated the impact of low-pressure balloon devices on coronary morphology and function. An active coronary perfusion catheter (2.5-mm balloon diameter, inflation with 1 bar for 30 min) was placed in the left anterior descending coronary artery of 12 German landrace pigs under general anesthesia. After 3 mo, coronary segments with balloon contact were compared with control segments taken from the right coronary artery as to histology, vascular reactivity, and expression of endothelial nitric oxide synthase. Thirty-three balloon treated segments were analyzed. Twenty of these segments (61%) showed neointima formation. In these segments endothelium-independent relaxation induced by sodium nitroprusside was preserved. However, endothelium-dependent bradykinin-induced relaxation was significantly attenuated compared with both the control segments and the balloon-treated segments without neointima formation. In >60% of the ballooned arterial segments examined, low-pressure balloon devices induced neointima formation accompanied by reduced endothelium-dependent relaxation. Thus interventions with so-called nontraumatic coronary devices can induce relevant vascular injury, with potential adverse clinical consequences.

Export aspiration catheter thrombosuction before actual angioplasty in primary coronary intervention for acute myocardial infarction

Primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) in lesions with a large thrombus load increases the procedural complication rate. We describe a thrombus reduction technique in this setting using the Export aspiration catheter (EAC) for primary thrombosuction before actual angioplasty. The EAC is a component of the GuardWire Plus system (PercuSurge, Sunnyvale, CA), which was originally developed for emboli containment in saphenous vein graft and peripheral vessel interventions. Primary EAC thrombosuction was performed successfully in 12 patients undergoing primary PCI, and gross thrombi were obtained from 9 patients (75%). After definitive treatment with balloon angioplasty and/or stenting, TIMI 3 flow was restored in all target vessels. There was no angiographic evidence of distal branch loss or vessel injury. No major procedural or in-hospital complication occurred in any patients. This primary EAC thrombosuction technique may offer a new, potentially effective method for thrombus burden reduction in treating AMI patients.

Coronary perforation as a potential complication derived from coronary thrombectomy with the X-Sizer device

We report a case of coronary perforation after failed atherectomy with a 2 mm X-Sizer catheter in recent totally occluded right coronary artery. The perforation was successfully managed with a polytetrafluoroethylene-covered stent with satisfactory final angiographic results. Possible predictors of this complication with this new device are discussed.

Carotid artery stenting protected with an emboli containment system

BACKGROUND AND PURPOSE

Fear of distal embolization and stroke has aroused concern regarding carotid stenting. Devices to protect the cerebral circulation may make carotid stenting safer.

METHODS

A multidisciplinary study group tested a balloon occlusion-aspiration emboli entrapment device in conjunction with carotid stenting. The device consists of an elastomeric balloon on a steerable wire with a detachable adapter that inflates and deflates the distal temporary occlusion balloon. An aspiration catheter is used to remove trapped emboli after stenting and before occlusion balloon deflation.

RESULTS

Seventy-five patients with severe internal carotid artery stenosis were treated with stents deployed with this cerebrovasculature protection system. All 75 patients (100%) had grossly visible particulate material aspirated, and all were treated successfully without major or minor stroke or death at 30 days. Preintervention stenosis was 81+/-10%, and residual stenosis was 5+/-7%. Nine patients (12%) had angiographic evidence of thrombus before intervention, but no patient had thrombus or vessel cutoff after the procedure. Four patients (5%) developed transient neurological symptoms during protection balloon occlusion, but symptoms resolved with balloon deflation. The 22 to 667 particles aspirated per patient ranged from 3.6 to 5262 microm in maximum diameter (mean, 203+/-256 microm). These particles included fibrous plaque debris, lipid or cholesterol vacuoles, and calcific plaque fragments.

CONCLUSIONS

Protected carotid stenting was performed successfully and safely in this study early in the experience with cerebrovascular protection devices. Particulate emboli are frequent with stenting, and cerebral protection will likely be necessary to minimize stroke. Randomized trials comparing protected carotid stenting with endarterectomy are warranted.

Evaluation of a balloon occlusion and aspiration system for protection from distal embolization during stenting in saphenous vein grafts

Distal embolization after angioplasty in degenerated saphenous vein grafts (SVGs) results in high rates of periprocedural myonecrosis and mortality. Temporary protection of the distal microcirculation with aspiration of dislodged debris may improve the safety of SVG intervention. To evaluate the feasibility, safety, and efficacy of distal protection using the PercuSurge GuardWire Occlusion and Aspiration System, 103 consecutive patients undergoing planned stenting of 105 SVG lesions were prospectively enrolled in a multinational, multicenter study. Before angioplasty, protection of the distal circulation was achieved with the PercuSurge GuardWire distal balloon occlusion system, followed by stenting and debris aspiration. Quality assurance measures in the study included independent on-site data monitoring, clinical event adjudication, data analysis, and use of multiple core laboratories. Mean graft age was 8.9 +/- 4.0 years. The duration of distal balloon inflation was 5.4 +/- 3.7 minutes; premature balloon deflation for ischemia was not required in any patient. Macroscopically visible red and/or yellow debris was extracted in 91% of patients. By core lab analysis, postprocedural Thrombolysis In Myocardial Infarction-III flow was present in 98.9% of grafts (vs 83.5% before intervention). No patient developed angiographic evidence of no reflow or distal embolization. Postprocedural creatine phosphokinase MB isozyme levels were elevated to >3 x normal in only 5 patients (5%), and 97 patients (94%) were free of major adverse events at 30 days. We conclude that the GuardWire distal balloon occlusion and aspiration system is an effective and safe method for protecting distal microcirculation from the adverse consequences of embolization during mechanical intervention of degenerated SVGs.

Benefits of cerebral protection during carotid stenting with the PercuSurge GuardWire system: midterm results

PURPOSE

To examine the possible beneficial effect of a new cerebral protection device based on balloon occlusion of the distal internal carotid artery (ICA) and debris aspiration for patients undergoing carotid artery stenting (CAS).

METHODS

One hundred and eighty-four CAS procedures were attempted under cerebral protection using the PercuSurge GuardWire system in 167 patients (129 men; mean age 70.5 +/- 9.2 years, range 40-91)). The lesions were mainly atherosclerotic, and half (n = 93) were asymptomatic. Eighteen restenotic and 7 post-radiation stenoses were also treated.

RESULTS

Technical success was 99.5%. All lesions were stented except 3 postangioplasty restenoses. Prophylactic occlusion during balloon dilation and stenting was well tolerated in 176 (95.7%) patients. Microscopic analysis of the aspirated blood showed different types of particles numbering between 7 and 145 per procedure with a mean diameter of 250 microm (56-2652 microm). The 30-day stroke and death rate was 2.7%: 3 periprocedural complications at <48 hours (1 major stroke and 2 transient ischemic attacks), 1 intracerebral hemorrhage at 3 days, and 1 death of cardiac failure at 3 weeks.

CONCLUSIONS

This study yielded a favorably low rate of periprocedural embolic events comparable with standard CAS series. Protection devices may play an important role in future carotid interventions and expand the applicability of the procedure. Randomized studies (surgery versus CAS with and without cerebral protection) are awaited.

Combined use of retrograde myocardial and distal coronary protection for last vessel intervention in an aortocoronary vein graft

Feasibility, safety, and clinical efficacy of the combined application of the PercuSurge system and the Myoprotect SSR device was demonstrated in a patient with high-risk anatomy undergoing saphenous vein graft intervention. This combined approach of coronary and myocardial protection may be considered in high-risk aortocoronary vein graft interventions.

The use of mechanical devices as adjuncts to intracoronary stenting

A number of mechanical adjuncts to intracoronary stenting are now available to the interventional cardiologist. These devices have assisted in the development of a safer and more effective stenting practice. Intravascular ultrasound-guided stenting has been shown to reduce the rate of subacute thrombosis and subsequent restenosis. It allows a greater appreciation of lesion structure and severity so that an appropriate intervention strategy can be devised. Debulking techniques may allow the optimal deployment of stents so that restenosis is reduced; however, the results of large randomized studies are still awaited. The use of thrombectomy and distal embolization protection devices is emerging as a safer alternate to stenting alone in difficult patient subsets, such as those with thrombus-laden lesions and degenerated vein grafts. Doppler and pressure wires may be useful in determining optimal stent deployment and predict subsequent patient outcomes. An understanding of the indications and limitations of these devices is of increasing importance to the interventional cardiologist as the coming decade threatens to yield an impressive array of high-tech innovations.

Role of the distal balloon protection technique in the prevention of cerebral embolic events during carotid stent placement

BACKGROUND AND PURPOSE

We sought to quantitatively and qualitatively evaluate the release of atheromatous plaque debris induced by carotid stenting procedures.

METHODS

Eight patients with severe carotid atheromatous stenoses were treated by stent implantation under distal balloon protection. Blood samplings were obtained after stent deployment in the blood pooled below the inflated protection balloon. The samples were centrifuged and evaluated for plaque debris with the use of light microscopy. The debris release was quantitatively estimated by dividing the total volume of debris obtained by the mean debris size. Five patients without endovascular procedure were used as a control group.

RESULTS

The 2 main debris types found were nonrefringent cholesterol crystals (4 to 389 microm; 115 to 8697 in number) and lipoid masses (7 to 600 microm; 341 to 34 000 in number). There was a statistically significant difference compared with the samples obtained in the control group (P:=0.017).

CONCLUSIONS

Blood samples collected during stent implantation procedures contain a large quantity of atheromatous plaque debris. This emphasizes the role of distal protection techniques in avoiding migration of this plaque material into the cerebral circulation.

Balloon occlusion and transluminal aspiration of saphenous vein grafts to prevent distal embolization

Distal embolization is a common complication of percutaneous intervention in saphenous vein grafts. This may lead to the "no reflow" phenomenon and subsequent myocardial infarction. We describe a case in which we occluded the distal portion of a saphenous vein graft with a balloon to prevent distal embolization, performed percutaneous transluminal coronary angioplasty, and then successfully aspirated the particulate debris with a Dorros/Probing catheter.

Adjunctive thrombus aspiration and mechanical protection from distal embolization in primary percutaneous intervention for acute myocardial infarction

Primary percutaneous intervention for acute occlusion of a native coronary artery may be complicated by distal embolization of plaque or thrombotic debris, with infarct extension. We tested the clinical application of a new therapeutic strategy combining maximal antiplatelet therapy, with glycoprotein IIb/IIIa inhibition, and adjunctive mechanical protection from distal embolization and direct aspiration of thrombus with a new balloon and catheter system (PercuSurgetrade mark). Successful aspiration of thrombus could be obtained in 7 out of 8 attempted procedures, with inability to negotiate the angulated take-off of the circumflex coronary artery in one patient. The current mechanical characteristics of the device, primarily developed for use in larger saphenous vein grafts, and certain caveats and limitations are discussed. New dedicated systems should be available in the near future for the native coronary circulation. Excellent immediate angiographic results were obtained in all treated patients, without evidence of loss of distal branches and no intraprocedural complications.

Facilitation of stent retention and retrieval with an emboli containment device

A potential consequence of unsuccessful stent delivery is dislodgment of the stent from the delivery catheter resulting in embolization. Recently, an angioplasty guidewire incorporating a distal occlusion balloon (GuardWire) has become available. We describe how, when used for the prevention of distal embolization of atheromatous or thrombotic particles, this device may facilitate retention and retrieval of undeployed stents.

Coronary microembolization--its role in acute coronary syndromes and interventions

The diagnosis coronary artery disease is classically based on patient's symptoms and morphology, as analyzed by angiography. The importance of risk factors for the development of coronary atherosclerosis and disturbance of coronary vasomotion is clearly established. However, microembolization of the coronary circulation has also to be taken into account. Microembolization may occur as a single or as multiple, repetitive events, and it may induce inflammatory responses. Spontaneous microembolization may occur, when the fibrous cap of an atheroma or fibroatheroma (Stary i.v. and Va) ruptures and the lipid pool with or without additional thrombus formation is washed out of the atheroma into the microcirculation. Such events with progressive thrombus formation are known as cyclic flow variations. Plaque rupture occurs more frequently than previously assumed, i.e. in 9% of patients without known heart disease suffering a traffic accident and in 22% of patients with hypertension and diabetes. Also, in patients dying from sudden death microembolization is frequently found. Patients with stable and unstable angina show not only signs of coronary plaque rupture and thrombus formation, but also microemboli and microinfarcts, the only difference between those with stable and unstable angina being the number of events. Appreciation of microembolization may help to better understand the pathogenesis of ischemic cardiomyopathy, diabetic cardiomyopathy and acute coronary syndromes, in particular in patients with normal coronary angiograms, but plaque rupture detected by intravascular ultrasound. Also, the benefit from glycoprotein IIb/IIIa receptor antagonist is better understood, when not only the prevention of thrombus formation in the epicardial atherosclerotic plaque, but also that of microemboli is taken into account. Microembolization also occurs during PTCA, inducing elevations of troponin T and I and elevations of the ST segment in the EKG. Elevated baseline coronary blood flow velocity, as a potential consequence of reactive hyperemia in myocardium surrounding areas of microembolization, is more frequent in patients with high frequency rotablation than in patients with stenting and in patients with PTCA. The hypothesis of iafrogenic microembolization during coronary interventions is now supported by the use of aspiration and filtration devices, where particles with a size of up to 700 microns have been retrieved. In the experiment, microembolization is characterized by perfusion-contraction mismatch, as the proportionate reduction of flow and function seen with an epicardial stenosis is lost and replaced by contractile dysfunction in the absence of reduced flow. The analysis of the coronary microcirculation, in addition to that of the morphology and function of epicardial coronary arteries, and in particular appreciation of the concept of microembolization will further improve the understanding of the pathophysiology and clinical symptoms of coronary artery disease.