Infrainguinal Arterial Intervention: Is There a Role for an Atherectomy Device?

Excision of atheromatous plaque is an attractive option for the minimally invasive treatment of peripheral arterial disease. Approved for use in 2003, the SilverHawk Plaque Exicison System (FoxHollow Technologies, Redwood City, CA) is a catheter-based plaque excision device allowing percutaneous removal of atheromatous material. This device represents the most recent generation of atherectomy tools. Overall experience with plaque debulking in the peripheral arteries spans almost two decades, and understanding of the technique continues to evolve. This article reviews the technology, current practices, and data on plaque excision.

Lower extremity revascularization using directional atherectomy: 12-month prospective results of the DEFINITIVE LE study

OBJECTIVES

The aim of this study was to assess the safety and effectiveness of directional atherectomy (DA) for endovascular treatment of peripheral arterial disease (PAD) in infrainguinal arteries in patients with claudication or critical limb ischemia.

BACKGROUND

To date, no prospective, multicenter, independently-adjudicated study has evaluated the effectiveness and durability of DA in the treatment of PAD. Previous DA studies have not been prospectively powered to evaluate any differences in outcomes in patients with and without diabetes.

METHODS

DEFINITIVE LE (Determination of EFfectiveness of the SilverHawk(®) PerIpheral Plaque ExcisioN System (SIlverHawk Device) for the Treatment of Infrainguinal VEssels / Lower Extremities) prospectively enrolled subjects at 47 multinational centers with an infrainguinal lesion length up to 20 cm. Primary endpoints were defined as primary patency at 12 months for claudicants and freedom from major unplanned amputation for critical limb ischemia (CLI) subjects. A pre-specified statistical hypothesis evaluated noninferiority of primary patency in diabetic versus nondiabetic claudicants. Independent angiographic and sonographic core laboratories assessed outcomes, and events were adjudicated by a clinical events committee.

RESULTS

A total of 800 subjects were enrolled. The 12-month primary patency was 78% (95% confidence interval: 74.0% to 80.6%) in claudicants, with a 77% rate in the diabetic subgroup versus 78% in the nondiabetic subgroup (noninferior, p < 0.001). The rate of freedom from major unplanned amputation of the target limb at 12 months in CLI subjects was 95% (95% confidence interval: 90.7% to 97.4%). Periprocedural adverse events included embolization (3.8%), perforation (5.3%), and abrupt closure (2.0%). The bail-out stent rate was 3.2%.

CONCLUSIONS

The DEFINITIVE LE study demonstrated that DA is a safe and effective treatment modality at 12 months for a diverse patient population with either claudication or CLI. Furthermore, DA was shown to be noninferior for treating PAD in patients with diabetes compared with those without diabetes. (Study of SilverHawk/TurboHawk in Lower Extremity Vessels [DEFINITIVE LE]; NCT00883246).

One-Year Outcomes Following Directional Atherectomy of Infrapopliteal Artery Lesions: Subgroup Results of the Prospective, Multicenter DEFINITIVE LE Trial

PURPOSE

To report a subgroup analysis of the prospective, multicenter, single-arm DEFINITIVE LE trial to assess the effectiveness of directional atherectomy for the treatment of infrapopliteal artery lesions at 1 year.

METHODS

In the DEFINITIVE LE trial, follow-up assessments occurred up to 1 year postprocedure. Of the 800 patients enrolled, 145 subjects with 189 infrapopliteal lesions met the criteria for this analysis. Seventy (48.3%) and 75 (51.7%) patients were suffering critical limb ischemia (CLI) and intermittent claudication, respectively; 68.3% (99/145) had diabetes. The mean lesion length was 58±44 mm (all lesions); 20.2% were occluded. The primary endpoint for patients with claudication was duplex ultrasound-derived primary patency, while for subjects with CLI it was freedom from major amputation of the target limb at 1 year. Endpoints and adverse events were independently assessed.

RESULTS

Procedure success (≤30% residual stenosis) was achieved in 84% of treated lesions. The 1-year primary patency rate was 84% (claudicants 89.6% and CLI patients 78%, p=0.11), and the freedom from major amputation rate was 97.1% (claudicants 100% and CLI 93.8%, p=0.03). In both claudication and CLI patients, significant improvements in Rutherford category and objective measures of walking distance and quality of life were seen at 1 year in comparison to baseline.

CONCLUSION

This study demonstrates that directional atherectomy in infrapopliteal arteries results in promising technical and clinical results at 1 year for claudicant as well as CLI patients.

A Comparison of Clinical Outcomes for Diabetic and Nondiabetic Patients Following Directional Atherectomy in the DEFINITIVE LE Claudicant Cohort

PURPOSE

To report a subset analysis that evaluated the hypothesis that directional atherectomy for peripheral artery disease in diabetic claudicants has noninferior primary patency at 12 months compared with nondiabetic claudicants.

METHODS

DEFINITIVE LE, a US/European multicenter study, assessed the effectiveness of directional atherectomy using SilverHawk/TurboHawk systems for treatment of peripheral artery disease in the superficial femoral, popliteal, and infrapopliteal arteries. Of the 800 patients enrolled in the study, only the 598 claudicant patients (mean age 69.5±10.4 years; 336 men) who were classified at baseline as Rutherford category 1-3 were eligible for this subset analysis. Of these, 46.8% (280/598) had diabetes. Follow-up to 12 months included duplex ultrasound examination, functional assessments, and adverse event evaluations. Independent angiographic and duplex ultrasound core laboratories assessed primary patency and secondary endpoints; a clinical events committee adjudicated adverse events.

RESULTS

Although diabetics had significantly more baseline comorbidities, 12-month primary patency (77.0%) was no different than for nondiabetics (77.9%; superiority p=0.98; noninferiority p<0.001) across all anatomic territories treated. Freedom from clinically driven target lesion revascularization was no different between diabetics (83.8%) and nondiabetics (87.5%) overall (p=0.19) or by lesion locations. Secondary clinical outcomes (Rutherford category, ankle-brachial index, and walking impairment) improved at 12 months for both diabetics and nondiabetics.

CONCLUSION

Noninferior 12-month patency rates demonstrate that directional atherectomy is an effective treatment in diabetic as well as nondiabetic claudicants. Directional atherectomy remains an attractive treatment option, improving luminal diameters without stents, which preserves future treatment options for both diabetic and nondiabetic patients with progressive, diffuse vascular disease.

Trend, Risk Factors, and Costs of Clostridium difficile Infections in Vascular Surgery

BACKGROUND

Starting in December 2013, the Hospital Inpatient Quality Reporting Program included Clostridium difficile infection (CDI) rates as a new publically reported quality measure. Our goal was to review the trend, hospital variability in CDI rates, and associated risk factors and costs in vascular surgery.

METHODS

The rates of CDI after major vascular procedures including aortic abdominal aneurysm (AAA) repair, carotid endarterectomy or stenting, lower extremity revascularization (LER), and LE amputation were identified using Nationwide Inpatient Sample database for 2000-2011. Risk factors associated with CDI were analyzed with hierarchical multivariate logistic regression. Extra costs, length of stay (LOS), and mortality were assessed for propensity-matched hospitalizations with and without CDI.

RESULTS

During the study period, the rates of CDI after vascular procedures had increased by 74% from 0.6 in 2000 to 1.05% in 2011, whereas the case fatality rate was stable at 9-11%. In 2011, the highest rates were after ruptured aortic abdominal aneurysm (rAAA) repair (3.3%), followed by lower extremity amputations (2.3%) and elective open AAA (1.3%). The rates of CDI increased after all vascular procedures during the 12 years. The highest increase was after endovascular LER (151.8%) and open rAAA repair (135.7%). In 2011, patients who had experienced CDI had median LOS of 15 days (interquartile range, 9-25 days) compared with 8.3 days for matched patients without CDI, in-hospital mortality 9.1% (compared with 5.0%), and $13,471 extra cost per hospitalization. The estimated cost associated with CDI in vascular surgery in the United States was ∼$98 million in 2011. Hospital rates of CDI varied from 0 to 50% with 3.5% of hospitals having infection rates ≥5%. Factors associated with CDI included multiple chronic conditions, female gender, surgery type, emergent and weekend hospitalizations, hospital transfers, and urban locations.

CONCLUSIONS

Despite potential reduction of infection rates as evidenced by the experience of hospitals with effective interventions, CDI is increasing among vascular surgery patients. It is associated with prolonged LOS, increased mortality, and higher costs.

Endovascular treatment of lesions in the below-knee popliteal artery

BACKGROUND

Endovascular interventions are increasing; however, there are little data regarding outcomes of complex interventions involving the below-knee popliteal/P3 artery. This study evaluated the short-term and long-term results and predictors of success of below-knee popliteal artery endovascular interventions.

METHODS

This was a retrospective review of a prospectively maintained endovascular lower extremity database of all patients with below-knee popliteal interventions from 2004 to 2012. Patient demographics, angiographic findings, interventions, primary and secondary patency, limb loss, and mortality were recorded. Analysis was performed using Kaplan-Meier life-table and multivariate analysis, with P < .05 indicating significance.

RESULTS

There were 221 patients (56% male) with below-knee popliteal/P3 artery lesions. Mean age was 73 ± 11.2 years. Claudication was present in 22% and critical limb ischemia (CLI) in 78%. Mean lesion length was 10 ± 8.5 cm, with 45% having total occlusions. Treatment included percutaneous transluminal angioplasty (PTA) with or without a stent (47%), atherectomy (ATH) with or without PTA/stent (52%), and stenting with PTA and ATH (3%). Complications included embolization (0.4%), hematoma (2.7%), pseudoaneurysm (1.3%), and dissection (7%). Freedom from restenosis (peak systolic velocity ratio >2.4) was 65% at 1 year. Independent predictors of restenosis were CLI (hazard risk [HR], 4.4; 95% confidence interval [CI], 1.9-9.9) and stenting combined with PTA and ATH (HR, 2.7; 95% CI, 1.01-7.4). Primary assisted and secondary patencies were 95% and 85% at 1 year. ATH with PTA had lower short-term restenosis in diabetic patients compared with nondiabetic patients (95% vs 78% at 4 months). Limb loss was 18% at 4 years. Mortality was 24% at 4 years. Statin use was protective against primary restenosis (HR, 0.39; 95% CI, 0.23-0.67) and death (HR, 0.5; 95% CI, 0.28-1.0).

CONCLUSIONS

Endovascular intervention for lesions involving the below-knee popliteal artery is a safe and effective therapy for claudication and CLI. Diabetic patients benefit most from ATH with PTA. Statin use is protective against restenosis and mortality and should be the standard of care in patients undergoing peripheral endovascular interventions.

Statins reduce neurologic injury in asymptomatic carotid endarterectomy patients

BACKGROUND AND PURPOSE

Statins are neuroprotective in a variety of experimental models of cerebral injury. We sought to determine whether patients taking statins before asymptomatic carotid endarterectomy exhibit a lower incidence of neurological injury (clinical stroke and cognitive dysfunction).

METHODS

A total of 328 patients with asymptomatic carotid stenosis scheduled for elective carotid endarterectomy consented to participate in this observational study of perioperative neurological injury.

RESULTS

Patients taking statins had a lower incidence of clinical stroke (0.0% vs 3.1%; P=0.02) and cognitive dysfunction (11.0% vs 20.2%; P=0.03). In a multivariate regression model, statin use was significantly associated with decreased odds of cognitive dysfunction (odds ratio, 0.51 [95% CI, 0.27-0.96]; P=0.04).

CONCLUSIONS

Preoperative statin use was associated with less neurological injury after asymptomatic carotid endarterectomy. These observations suggest that it may be possible to further reduce the perioperative morbidity of carotid endarterectomy. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00597883.