Distal protection devices during percutaneous coronary and carotid interventions

Endovascular Thrombus Aspiration and Catheter-Directed Thrombolysis for Acute Thromboembolic Renal Artery Occlusion

PURPOSE

We report a case of revascularization for an occluded renal artery using endovascular renal thrombus aspiration followed by catheter-directed thrombolysis.

CASE REPORT

A 56-year-old man presented with sudden onset severe left-sided abdominal and loin pain for 6 hours. Urgent computed tomography (CT) angiogram showed occlusion of left renal artery. Emergency selective left renal angiogram and thrombus aspiration using a 5-French Cobra catheter was performed. Catheter-directed thrombolysis with urokinase was initiated after aspiration thrombectomy. Angiogram 24 hours after thrombolysis showed the left renal artery and its segmental branches were successfully revascularized. Patient was put on anticoagulation after operation and his renal function recovered well.

CONCLUSION

Percutaneous aspiration thrombectomy with conventional catheters combined with intra-arterial local fibrinolysis could be used to salvage the renal function in case of complete renal artery thromboembolic occlusion.

Percutaneous mechanical thrombectomy and pharmacologic thrombolysis for renal artery embolism: case report and review of endovascular treatment

Renal artery embolism (RAE) is an uncommon event that is associated with a high rate of renal loss. We present a case of RAE to a solitary kidney that was treated with combined percutaneous rheolytic thrombectomy, intra-arterial thrombolysis, and supplemental renal artery stent placement.

Predictors of embolization during protected renal artery angioplasty and stenting: Role of antiplatelet therapy

OBJECTIVE

The objective of this study was to identify the predictors of distal embolization (DE) during protected renal artery angioplasty and stenting.

BACKGROUND

DE may contribute to worsening renal function after renal artery stenting. The factors associated with DE, rates of platelet-rich emboli, and treatments that may prevent DE during renal stenting have not been evaluated.

METHODS

The current study evaluated patients randomized to receive an embolic protection device (EPD) in the RESIST trial. Forty-two patients were identified for inclusion in this study. These patients were further randomized to abciximab (N = 22) or placebo (N = 20). Modification in Diet in Renal Disease glomerular filtration rate (GFR) was used as the primary measure of renal function. Creatinine was measured by a modified Jaffe reaction using the IDMS-traceable assay. The primary endpoint was capture of platelet rich emboli in the angioguard basket.

RESULTS

DE occurred in 15/42 (35%) of the patients and platelet rich DE in 10 (24%) of the patients who received an EPD. Of the angiographic characteristics only lesion length was significantly higher in patients with DE (16 +/- 7 mm vs. 10 +/- 5 mm, P = 0.04). Preprocedural abciximab reduced DE from 42 to 8% (P = 0.02). The rate of platelet rich emboli was 50% with neither abciximab nor a thienopyridine, 36% with thienopyridine only, 15% abciximab only, and 0% in patients who received both a thienopyridine and abciximab. Only Abciximab use was associated with improved renal function at 1-month, thienopyridine was not. Angiographic characteristics including percent stenosis, minimal luminal diameter (MLD), reference diameter, change in MLD, contrast volume, and procedure time were not predictors of DE during renal stenting.

CONCLUSION

Capture of DE and specifically platelet DE are common during protected renal stenting using a filter-type EPD. Abciximab use, and potentially combined thienopyridine and abciximab use, decreased the rate of platelet rich DE; however, only abciximab improved renal function at 1-month.

Postprocedural microembolic events following carotid surgery and carotid angioplasty and stenting

OBJECTIVE

The relative safety of percutaneous carotid interventions remains controversial. Few studies have used diffusion-weighted magnetic resonance imaging (DW-MRI) to evaluate the safety of these interventions. We compared the incidence and distribution of cerebral microembolic events after carotid angioplasty and stenting (CAS) with distal protection to standard open carotid endarterectomy (CEA) using DW-MRI.

METHODS

From November 2004 through August 2006, 69 carotid interventions (27 CAS, and 42 CEA) were performed in 68 males at a single institution. Pre- and postprocedure DW-MRI exams were obtained on each patient undergoing CAS and the 20 most recent CEA operations. These 46 patients (47 procedures as one patient underwent bilateral CEAs in a staged fashion) constitute our study sample, and the hospital records of these patients (27 CAS and 20 CEA) were retrospectively reviewed. The incidence and location of acute, postprocedural microemboli were determined using DW-MRIs and assessed independently by two neuroradiologists without knowledge of the subjects' specific procedure.

RESULTS

Nineteen CAS patients (70%, 95% confidence interval [CI]: 42%-81%) demonstrated evidence of postoperative, acute, cerebral microemboli by DW-MRI vs none of the CEA patients (0%, 95% CI: 0%-17%) (P < .0001). Of the 19 CAS patients with postoperative emboli, nine (47%) were ipsilateral to the index carotid lesion, three (16%) contralateral, and seven (36%) bilateral. The median number of ipsilateral microemboli identified in the CAS group was 1 (interquartile ranges [IQR]: 0-2, range 0-21). The median number of contralateral microemboli identified in the CAS group was 0 (IQR: 0-1, range 0-5). Three (11%) CAS patients experienced temporary neurologic sequelae lasting less than 36 hours. These patients suffered 12 (six ipsilateral and six contralateral), 20 (19 ipsilateral and one contralateral), and zero microemboli, respectively. By univariate analysis, performing an arch angiogram prior to CAS was associated with a higher risk of microemboli (median microemboli 5 vs none, P =.04)

CONCLUSIONS

Although our early experience suggests that CAS may be performed safely (no permanent neurologic deficits following 27 consecutive procedures), cerebral microembolic events occurred in over two-thirds of the procedures despite the uniform use of distal protection. Open carotid surgery in this series seems to offer a lower risk of periprocedural microembolic events detected by DW-MRI.

Distal embolism during percutaneous revascularization of infra-aortic arterial occlusive disease: an underestimated phenomenon

PURPOSE

To investigate distal embolism during endovascular procedures of the infra-aortic arteries by utilizing a commercial filter basket and unveil any correlation between the baseline clinical and procedural variables and the histopathological findings of the collected particles.

METHODS

In a prospective study, 48 patients (37 men; mean age 70.8+/-7.8 years, range 50- 83) underwent endoluminal therapy of infra-aortic lesions (stenosis >75% or occlusion; mean lesion length 52.2+/-38.0 mm) with standard endovascular procedures. A nitinol filter basket (n=50) was employed for distal protection. The collected particles were histopathologically analyzed. The harvested specimens were quantified after digital image post processing.

RESULTS

Procedural success of filter-protected revascularization was 93.8%. Three failures included 1 vasospasm, 1 distal embolus, and 1 side-branch occlusion. The total area of retrieved particles per basket was 2.76+/-6.49 mm(2) (range 0.0-40.3). Particles with a major axis >1 and >3 mm were detected in 29 (58.0%) and 6 (12.0%), respectively, of the examined filters. Collected particles consisted primarily of platelets and fibrin conglomerates, trapped erythrocytes, inflammatory cells, and extracellular matrix. Increased lesion length, increased reference vessel diameter, acute thromboses, and total occlusions were positively correlated with higher amounts of captured particles (p<0.05). Multivariate analysis incriminated declotting procedures as the only independent predictor of increased embolic burden (p<0.05).

CONCLUSION

The embolism phenomenon during infra-aortic interventions is frequent and underestimated. The liberated particles consisted primarily of atheromatous plaque elements and thrombus. The reported data might support the application of a protective filter basket in selected subsets of lesions with a riskier embolic profile and whenever declotting procedures are performed.

Sestamibi single photon emission computed tomography immediately after primary percutaneous coronary intervention identifies patients at risk for large infarcts

BACKGROUND

Primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction results in TIMI 3 flow in most patients. However, despite TIMI 3 flow, some patients do not achieve adequate tissue perfusion and have large infarctions. Techniques that, in the acute setting, could identify these patients at increased risk would potentially enable specific interventions to enhance perfusion. The object of the present study was to test whether corrected TIMI frame count (CTFC), myocardial blush grade (MBG), ST-segment resolution, and myocardial perfusion imaging (MPI) can identify those patients who, despite successful treatment with primary PCI for ST-elevation myocardial infarction, are at risk for large infarcts.

METHODS

In 61 patients with TIMI 3 flow after primary PCI, CTFC, MBG, ST-segment resolution, and quantitative MPI by technetium Tc 99m sestamibi single photon emission computed tomography were estimated immediately after primary PCI. Infarct size was assessed by peak lactate dehydrogenase (LDH) and by MPI after 3 months.

RESULTS

Infarct size by MPI was 12% (4, 23), and peak LDH was 1410 U/L (870, 2220); these measures correlated (rho = 0.80, P < .001). The acute perfusion defect predicted infarct size using either method (MPI rho = 0.88, P < .001; LDH rho = 0.77, P < .001); ST-segment residual correlated weakly to infarct size, whereas CTFC and MBG did not. In multivariate analysis, the acute perfusion defect was the only significant predictor of infarct size.

CONCLUSION

Myocardial perfusion imaging performed immediately after successful PCI can identify patients at increased risk for large infarcts due to impaired tissue perfusion. Acute MPI might serve as a tool for early identification of patients, who, despite epicardial TIMI 3 flow, have inadequate tissue level perfusion.

Outflow protection filters during percutaneous recanalization of lower extremities' arterial occlusions: a pilot study

PURPOSE

Filter devices are already employed for the protection of carotid, coronary and renal distal vascular bed during endovascular procedures. This is a pilot study investigating their feasibility, safety and distal emboli protection capability during recanalization of lower extremities' acute and subacute occlusions.

MATERIALS AND METHODS

Study population included 16 patients, 11 with a subacute arterial occlusion and 5 with an acute episode. The Trap filter (Microvena, USA) and its successor the Spider filter (EV3, USA) were utilized. Subacute occlusions were dealt with standard angioplasty and stenting procedures, while acute ones were managed primarily with Angiojet rheolytic thrombectomy. Outflow arterial tree was checked angiographically in-between consequent procedural steps. Embolic material collected after filter recovery was analyzed histopathologically. Patients' follow-up was scheduled at 1 month.

RESULTS

Seventeen filter baskets were applied in the recanalization of 16 target lesions in total. Mean length of the occluded segments was 6.1 (range: 2-15 cm; S.D. = 3.7 cm). Mean in situ time of the filters was 38.75 min (range: 20-60 min; S.D. = 12.71 min). Technical success rate of deployment and utilization of the filtration devices was 100% (17/17). Procedural success rate of the recanalization was 100% (16/16) without any clinical or angiographic evidence of periprocedural distal embolization. Macroscopic particulate debris was extracted from all the filters (17/17) containing fresh thrombus, calcification minerals, cholesterol and fibrin. Mean diameter of the largest particle per specimen was 1702.80 (range: 373.20-4680.00 microm; S.D. = 1155.12 microm). No adverse clinical events occurred at 1-month follow-up with 100% limb salvage (16/16).

CONCLUSION

The application of outflow protection filters is safe, feasible and efficacious in hindering distal embolization complications and safeguarding the distal capillary bed. Nevertheless, this is a pilot study in a limited group. Further studies have to be contacted in order to provide evidence for a more general use of these devices.

Distal Myocardial Protection During Percutaneous Coronary Intervention

The discrepancy between angiographic success and microvascular perfusion has been recognized for some time. In the face of an open artery, the degree of microvascular perfusion determines post-infarct prognosis. Despite successful epicardial recanalization, tissue perfusion may be absent in up to 25% patients with acute myocardial infarction. Historically associated with saphenous vein graft intervention, embolization is increasingly recognized in native coronary arteries, particularly in patients undergoing primary percutaneous coronary intervention (PCI). With more than two million PCI procedures performed worldwide each year, there is enormous interest in protecting the left ventricular myocardium from embolization during PCI. This article reviews the evidence for distal myocardial protection and discusses the relative merits of the different available techniques.

Techniques for Passing the PercuSurge Guardwire System Through Severe and Tortuous Stenotic Lesions-Technical Note-

Distal embolism is one of the major causes of morbidity and mortality associated with treating stenotic lesions by endovascular procedures, such as percutaneous angioplasty and stenting. Many devices have been designed and used to prevent this complication. The PercuSurge Guardwire system is recognized as the best system available to prevent distal embolism during stenting. However, this system is sometimes hard to pass through severe stenotic, tortuous lesions because of the poor selectivity and support. The PercuSurge device was safely introduced into two cases of severe stenotic and tortuous lesions with a triple coaxial system and the buddy wire technique, and stenting was performed successfully. These techniques are very helpful for introducing and maintaining this system in the correct position across stenoses with unfavorable configurations.

Procedural results and distal embolization after saphenous vein graft stenting and angioplasty for in-stent restenosis of grafts

Saphenous vein graft (SVG) angioplasty is associated with frequent periprocedural complications due to distal embolization and a high risk of restenosis. The purpose of this single-center, retrospective study was to determine the distal embolization incidences and outcomes of stenting for SVG lesions and percutaneous angioplasty for in-stent restenosis of these SVGs. We studied 48 consecutive patients (mean age, 62 +/- 7 years, 92% men) who had prior CABG and underwent stent deployment to SVG lesions detected at our institution over a period of 4 years. Mean lesion length was 12.4 +/- 3.2 mm. The minimal lumen diameter increased from 0.7 +/- 0.3 mm to 3.2 +/- 0.4 mm after stenting. Distal embolization as no reflow/slow flow phenomenon occurred in 5 (10%) patients. Angiographic success was achieved in 98% of the patients. Procedural success was achieved in 96% of the patients. No reflow/slow flow phenomenon was observed, particularly in patients with acute coronary syndrome. During the follow-up, 11 patients (23%) had angiographic evidence of restenosis. Lesions were treated with balloon angioplasty and the minimal lumen diameter increased from 2.6 +/- 1.1 mm to 3.1 +/- 0.3 mm. The angiographic and procedural success rates were both 100%. There were no cases of "no" reflow/slow flow. Restenosis was particularly frequent in patients with diabetes mellitus, hypercholesterolemia, and acute coronary syndrome. Stent implantation in patients with de novo SVG lesions can be achieved with a high rate of angiographic and procedural success. The distal embolization risk is lower during angioplasty of in-stent restenosis lesions of SVGs compared to de novo SVG lesions.

Current concepts of mechanical cerebral protection during precutaneous carotid intervention

Major advances in the endovascular treatment of carotid artery stenosis are underway, with an emphasis on improving the safety profile of the technique. This review highlights key areas in the concepts and design of available mechanical neuroprotection devices utilized during carotid stenting to minimize procedural cerebral embolization. The advantages and disadvantages of each system are explored and the available clinical experience is given. The size threshold of particulate material likely to be clinically relevant is examined and compared with pathological analysis of particles trapped by protection systems reported in the world literature. It is shown that the adverse neurological event rate in those protected is lower than that in historical studies of unprotected carotid stenting. Furthermore, the size range and numbers of particles trapped by protections systems are sufficient to cause potential neurological injury if allowed passage to the brain. Further improvements in outcomes may require further refinement of protection technology.

Combined distal embolization protection and rheolytic thrombectomy to facilitate percutaneous revascularization of totally occluded saphenous vein grafts

Totally occluded saphenous vein grafts are difficult to treat percutaneously with a higher likelihood of distal embolization and slow-flow or no-reflow during percutaneous interventions. The PercuSurge system, which utilizes a distal balloon occlusive device, has been shown to improve clinical outcomes during saphenous vein graft (SVG) interventions. This device may not be optimal in the setting of heavy thrombus or debris burden, a situation frequently encountered in totally occluded SVGs. Rheolytic thrombectomy facilitates percutaneous interventions by effectively removing intraluminal thrombus and debris but lacks distal embolization protection. We report our experience with the synergistic use of balloon-based distal embolization protection (PercuSurge) and rheolytic thrombectomy (AngioJet) to optimize percutaneous revascularization of totally occluded SVGs.

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.

Neurological outcomes after carotid stenting protected with the NeuroShield filter compared to unprotected stenting

PURPOSE

To compare outcomes for two nonrandomized cohorts of patients with high-grade carotid disease who underwent either unprotected carotid stenting or stent implantation protected by the NeuroShield filter.

METHODS

Under this protocol, symptomatic patients with carotid stenoses >70% or asymptomatic patients with bilateral carotid stenoses who were being evaluated for coronary artery bypass grafting were eligible for carotid stenting. Between December 1998 and November 2001, 75 consecutive patients (57 men; median age 67 years range 45-85) underwent carotid stenting without cerebral protection; concurrently, 75 carotid stent procedures protected with the NeuroShield filter were performed in 73 patients (51 men; median age 66 years, range 47-83). A neurologist reviewed all patients before and after treatment. The groups were comparable for age, sex, and symptoms, but the protected group had a higher proportion of postsurgical restenoses (14.7% versus 1.3%; p=0.003). Outcome measures included death and neurological events at 24 hours and 30 days.

RESULTS

There were minor technical difficulties in 12 of the protected group, but none were clinically relevant. The procedural all-stroke/death rates in the unprotected versus protected groups, respectively, were 5.3% (4/75) and 2.7% (2/75; p=0.681), while the disabling stroke/death rates were 4% (3/75) and 1.3% (1/75; p=0.620). At 30 days, the all-stroke/death rates were 10.7% (8/75) in the unprotected group and 4.0% (3/75) in the protected group (p=0.117); the death/major-disability-from-stroke rates were 6.7% (5/75) and 2.7% (2/75), respectively (p=0.442).

CONCLUSIONS

Filter-related complications are well tolerated. Neuroprotection devices have the potential to reduce the procedural neurological event rate. Larger series and/or randomized trials are required for further evaluation.