Use Of Atherectomy Devices Research Articles

Abstract 17124: Comparative Outcomes of Below-the-Knee Atherectomy Interventions: A Report From the XLPAD Registry

Background: Atherectomy devices are used during below-the-knee (BTK) artery interventions to tackle the calcium burden in peripheral arteries. Methods: We examined 1542 patients from the XLPAD Registry (NCT01904851) from 2006-2021 who underwent BTK endovascular intervention, stratified by use of atherectomy device or not. The primary outcome was the incidence of major adverse limb events (MALE), a composite of all-cause death, clinically driven revascularization, amputation, non-fatal myocardial infarction (MI), and stroke. Results: 710 (46%) patients were treated with an atherectomy device and 832 were not. Mean age 68 years, predominantly male (72%) and Caucasian (58%). Cardiovascular risk factors were equally distributed among both groups, except hyperlipidemia was more prevalent in the atherectomy group (83% vs. 78%, p=0.01). Both groups had similar Ankle-Brachial Indexes. Atherectomy group had more multivessel interventions (2.5 vs 1.9 lesions per case, p<0.001) and SFA (54% vs. 38%, p<0.001) and popliteal artery (31% vs. 26%, p<0.001). Exclusive BTK interventions were evenly distributed between the groups. Atherectomy patients had greater calcification burden (32% vs 21%, p<0.001), diffuse disease (58% vs. 47%, p<0.001) and in-stent restenosis (9% vs. 4%, p<0.001). Stents and conventional balloon use were evenly distributed, but atherectomy patients received more drug-coated balloon treatments (10% vs 7%, p=0.04). Fluoroscopy time was longer in atherectomy group (33 min vs. 30 min, p= 0.04) with higher rates of procedural (94% vs. 91%, p=0.01) and technical success (98% vs. 93%, p<0.001). Only 30-day rate of amputation was higher among non-atherectomy patients (2% vs. 6%, p<0.001). There were no differences in the MALE (24% vs. 22%, p=NS), only surgical revascularization at 12-month follow-up more frequent in the non-atherectomy group (1% vs. 2%, p=0.01). Conclusion: Atherectomy use is high at 46% of all BTK artery interventions in the XLPAD Registry with higher technical success than non-atherectomy interventions without differences in MALE events at 12-month follow-up.

Factors Associated With Early and Late Restenosis Following Drug-Coated Balloon Treatment for Patients With Femoropopliteal Lesions.

Clinical trials have demonstrated the superiority of drug-coated balloon (DCB) to noncoated balloon angioplasty for the treatment of femoropopliteal (FP) lesions. In those trials, the difference of primary patency between DCB and noncoated angioplasty widens especially after 6 months, speculating that the antirestenosis effect of paclitaxel is manifested after 6 months. Factors associated with restenosis after 6 months differ from those associated with restenosis within 6 months. This study aimed to elucidate the prognostic factors associated with early (within 6 months) and late (after 6 months) restenosis following DCB treatment in real-world FP practice. This multicenter, retrospective study analyzed 486 FP lesions (mean lesion length, 11.9±10.1 cm; chronic total occlusion, 21.0%) in 423 patients (diabetes mellitus, 59.3%; hemodialysis, 37.1%; chronic limb-threatening ischemia, 41.6%) who underwent successful DCB treatment between January 2018 and December 2019. The outcome measure was restenosis which is defined as a peak systolic velocity ratio >2.4 based on duplex ultrasound findings. Early and late restenosis were classified by the cutoff period of 6 months after the procedure. The associations of baseline and procedural characteristics with early and late restenosis were explored using Cox proportional hazards regression analysis. The mean follow-up period was 25.3±12.1 months. The 6, 12, 18, and 24 month cumulative incidences of restenosis were 7.4%±2.4%, 20.9%±3.9%, 29.9%±4.5%, and 38.4%±5.1%, respectively. During the follow-up period, early and late restenosis was evident in a total of 31 lesions and 138 lesions, respectively. Multivariate analysis revealed that chronic total occlusion (hazard ratio [HR], 2.29; 95% confidence interval [CI], 1.07-4.92; p=0.033) and superficial femoral artery ostial lesion (HR, 2.73; 95% CI, 1.28-5.80; p=0.009) were significantly associated with early restenosis. On the other hand, calcification circumference over 270° (HR, 1.67; 95% CI, 1.17-2.37; p=0.004), distal external elastic membrane diameter under 5 mm assessed by intravascular ultrasound (HR, 1.90; 95% CI, 1.29-2.79; p=0.001), and involving popliteal arterial lesion (HR, 1.54; 95% CI, 1.08-2.21; p=0.017) were significantly associated with late restenosis. The prognostic factors associated with late restenosis differed from those associated with early restenosis in the real-world FP-DCB practice. The current multicenter, retrospective study revealed that factors associated with early restenosis differed from those with late restenosis in the real-world FP-DCB practice. CTO and SFA ostial lesion were associated with early restenosis, while severe calcification, smaller vessel, and involving popliteal arterial lesions were associated with late restenosis.Early restenosis indicates "balloon failure" and would potentially result from recoil, which primary stent implantation might be required. On the other hand, late restenosis after 6 months would be attributed to "DCB failure", with inadequate drug uptake into the arterial wall, which might be minimized by the use of atherectomy devices.

Peripheral arterial disease (PAD) in diabetics: diagnosis and management- a narrative review.

Peripheral arterial disease (PAD) in diabetic patients is often overlooked due to associated neuropathy. The very first presentation of these patients is with an Ischaemic ulcer or toe gangrene. Diabetics have a very high amputation rate compared to non-diabetic patients due to diffuse multi-segmental disease in the calcified tibial arteries. Early detection of the condition is a challenge in these patients. Even ankle-brachial pressure index may not be reliable. Both surgical and endovascular options are effective in wound healing. Endovascular techniques include percutaneous transluminal angioplasty with and without stenting, sub-intimal angioplasty, percutaneous transluminal angioplasty with drug-coated balloons, covered stents, and use of atherectomy devices. The current narrative review was planned to discuss the essentials of diagnosing PAD in diabetic patients and its various treatment options.

Outcomes of elective peripheral endovascular interventions for peripheral arterial disease performed in hospital outpatient departments, ambulatory surgical centers and office-based labs

BackgroundA recent shift in the location where peripheral endovascular interventions (PVI) are performed has occurred, from traditional settings such as hospital outpatient departments (HOPD), to ambulatory surgical centers (ASC) and outpatient-based laboratories (OBL). Different settings may influence the safety and efficacy of the PVI, as well as how it is done. This study aims to compare the postprocedural outcomes and intraprocedural details between the three settings. MethodsThe Vascular Quality Initiative database was queried for all elective infrainguinal PVIs for occlusive peripheral arterial disease between January 2016 and December 2021. The primary outcomes were rates of postprocedural hospital admissions, postprocedural medical complications, and access site complications. Secondary outcomes included technical success and intraprocedural details, such as types and number of devices used, amount of contrast, and fluoroscopy time. The χ2 test, analysis of variance, and multivariate logistic regression were used to analyze the outcomes. ResultsA total of 66,101 PVI cases (HOPD, 57,062 [83.33%]; ASC, 4591 [6.95%]; OBL, 4448 [6.73%]) were included in the study. There were 445 cases requiring hospital admission (HOPD, 398 [0.70%]; ASC, 26 [0.57%]; OBL, 21 [0.47%]; P = .126). There were no significant differences in cardiac, pulmonary, or renal complications. Access site complications occurred in less than 1.7% of all cases and were significantly higher in OBLs when compared with ASCs (adjusted odds ratio [aOR], 3.70; 95% confidence interval [CI], 1.70-8.03; P = .001) and significantly lower in ASCs in comparison to HOPDs (aOR, 0.27; 95% CI, 0.18-0.41; P < .001). Technical success occurred in at least 92% of all cases, regardless of setting. There was a 16-fold increase in the use of atherectomy devices in an OBL vs HOPD setting (aOR, 16.79; 95% CI, 11.77-23.95; P < .001) and a five-fold increase in the use of atherectomy devices in an ASC vs HOPD setting (aOR, 5.37; 95% CI, 2.47-11.65; P < .001). There was a five-fold decrease in the use of special balloons in an OBL vs HOPD setting (aOR, 0.20; 95% CI, 0.10-0.39; P < .001) and a four-fold decrease when comparing ASCs with HOPDs (aOR, 0.25; 95% CI, 0.12-0.51; P < .001). ConclusionsElective PVIs performed in any outpatient setting proved to be safe and technically successful. However, there are significant differences in the way PVIs are performed in each setting, such as the greater use of atherectomy devices in OBLs and greater use of special balloons in HOPDs. Long-term studies are needed to evaluate the durability and reintervention outcomes and understand factors associated with practice pattern variability across these different settings.

Atherectomy overuse is a real problem

Atherectomy overuse is a real problem

National trends and variability of atherectomy use for peripheral vascular interventions from 2010 to 2019

ObjectiveSmall, older studies have suggested that the use of atherectomy devices has become common in peripheral vascular interventions (PVIs) despite the paucity of strong clinical guidelines. We analyzed the 10-year trends in the use of atherectomy for PVIs across the United States and identified the main predictors of atherectomy use. MethodsUsing the Vascular Quality Initiative registry, we identified all patients who had undergone endovascular PVIs for occlusive lower extremity arterial disease from 2010 to 2019. Procedures in which an atherectomy device had been used as the primary or secondary device were classified as the atherectomy group. We calculated the frequency of atherectomy use over time and across geographic regions. Using regression modeling, we identified the factors that were independently associated with atherectomy use. ResultsA total of 205,377 PVIs had been performed for 152,693 unique patients. During the 10-year period, 16.6% of the PVI procedures had used atherectomy, increasing from 8.5% in 2010 to 19.7% in 2019 (Ptrend < .0001). Across 17 geographic regions, we found a significant difference in the prevalence of atherectomy use, ranging from 8.2% to 29%. The strongest predictor of atherectomy use was performance of PVI in an office setting (odds ratio [OR], 10.08; 95% confidence interval [CI], 9.17-11.09) or ambulatory center (OR, 4.0; 95% CI, 3.65-4.39) vs a hospital setting. The presence of severe (OR, 2.6; 95% CI, 2.4-2.85) or moderate (OR, 1.5; 95% CI, 1.4-1.69) lesion calcification was also predictive of atherectomy use. Other predictive factors included elective status, insurance provider, lesion length, prior PVI, claudication symptoms, and diabetes mellitus. ConclusionsAtherectomy use in PVI significantly increased from 2010 to 2019. We found wide regional variability in the use of atherectomy that seemed to be driven more strongly by nonclinical factors.

Contemporary Trends, Predictors and Outcomes of Perforation During Percutaneous Coronary Intervention (From the NCDR Cath PCI Registry)

Coronary artery perforation (CP) is a rare but potentially life-threatening complication of percutaneous coronary intervention (PCI). Given the marked increase in high-risk and complex PCIs, careful review and understanding of PCI complications may help to improve procedural and clinical outcomes. Our aim was to study the trends, predictors and outcomes of CP in the contemporary era. This cross-sectional multicenter analysis included data collected from institutions participating in the National Cardiovascular Data Registry CathPCI Registry between July 2009 and June 2015. Multivariable logistic regression models were created to identify predictors of CP and compare the in-hospital outcomes of CP and non-CP patients. Of 3,759,268 PCIs performed during the study period, there were 13,779 CP (0.37%). During the study period, the proportion of PCI that developed CP remained unchanged (0.33% to 0.4%) (p for trend 0.16). Chronic total occlusion (CTO) PCI as percentage of total PCI volume increased over the study period (3% to 4%) (p for trend <0.001) with a concomitant significant increase in CTOs with perforation (1.2% to 1.5%, p for trend = 0.02). CTO PCI (Odds Ratio [OR] 2.59) female gender (OR 1.38), saphenous vein graft PCI (OR 1.2), ACC Type C lesion (1.48), cardiogenic shock on presentation (1.15), and use of atherectomy (laser/ rotational) (OR 2.38) were significant predictors of CP. CP patients had significantly higher rates of cardiogenic shock (7.73% vs 1.02%), tamponade (9.6% vs 0.05%) and death (4.87% vs 1.14%) compared with those without CP. Strongest predictors of any adverse events amongst CP were cardiogenic shock (OR 3.93), cardiac arrest (OR 2.02) and use of atherectomy device (OR 2.5). Use of covered stents was also strongly associated with adverse events (OR 3.67) reflecting severity of these CPs. CP in CTO PCI had higher rates of any adverse event than non-CTO CP (26.8% vs 22%, p < 0.001). However non-CTO CP had higher rates of coronary artery bypass grafting (CABG) (urgent, emergent, or salvage) (5.8% vs 4.5%, p = 0.03) and death (6.9% vs 5.6%, p = 0.04). CP in CABG PCI had fewer adverse events compared with those without previous CABG (16.1% vs 24.7%). In a large real world experience, we identified several clinical and procedural factors associated with increased risk of CP and adverse outcomes. The trends in CP remained constant over the study period.

Intraprocedural Stent Thrombosis: Case Series of a Rare Complication Managed Successfully

Intra-procedural stent thrombosis (IPST) is defined as the development of occlusive or non-occlusive new thrombus in or adjacent to a recently implanted stent before the PCI procedure is completed. The frequency of occurrence currently ranges between 0.5 – 1.7% of all PCI procedures and it seems to be considerably reduced with newer drug eluting stents and improved techniques. The occurrence of IPST is relatively rare, even in ACS patients, and is related strongly to clinical presentation and procedural factors (e.g., anticoagulation regimen, lesion type, presence of thrombus at baseline, stent under expansion and edge dissection etc.) than to baseline demographic characteristics. Imaging modalities like IVUS or OCT can prevent as well as identify the underlying cause for IPST. IPST not only decreases success rate of PCI but is also associated with higher rates of slow flow or no reflow, distal embolization and side branch closure. It is also associated with higher mortality, myocardial infarction, ischemia driven revascularisation and stent thrombosis on follow up. IPST can be managed immediately in cath lab and involves use of GP2b3a inhibitors, optimising stent apposition by repeat balloon dilatation, use of imaging to identify the cause and accordingly corrective measures to be taken. Rarely emergency CABG may be required if underlying cause cannot be corrected. Prevention is the key. IPST can be prevented by using newer anti-platelets, use of GP2b3a inhibitors especially in presence of ACS or high thrombus load, preparing the lesion well before stenting, use of atherectomy devices when needed, appropriate stent size selection and use of imaging modalities in complex lesions to optimise stent selection and apposition. We describe three cases of the intra procedural stent thrombosis under different clinical scenarios and its management.

TCT-113 Effectiveness of Atherectomy Vs. Balloon Angioplasty for Limb Salvage in Occlusive Tibioperoneal Arterial Disease

The use of atherectomy devices for the treatment of lower extremity arterial disease has been increasing despite sparse evidence of clinical benefit. The primary goal of intervention on occlusive arterial disease of tibial and peroneal arteries (TPA) is to prevent limb loss. We sought to compare

Utilization and in-hospital outcomes associated with atherectomy in the treatment of peripheral vascular disease: An observational analysis from the National Inpatient Sample.

Objective Percutaneous revascularization for patients with peripheral arterial disease has become a treatment of choice for many symptomatic patients. The presence of severe arterial calcification presents many challenges for successful revascularization. Atherectomy is an adjunctive treatment option for patients with severe calcification undergoing percutaneous intervention. We sought to analyze the impact of atherectomy on in-hospital outcomes, length of stay, and cost in the percutaneous treatment of peripheral arterial disease. Methods Patients with lower extremity peripheral arterial disease undergoing percutaneous revascularization were assessed, utilizing the National Inpatient Sample (2012-2014) and appropriate International Classification of Diseases, 9th Revision, Clinical Modification diagnostic and procedural codes. Patients who were not treated with atherectomy ( n = 51,037) were compared to those treated with atherectomy ( n = 11,408). Propensity score-matched analysis was performed to address baseline differences. Results After performing propensity score-matched analysis, 11,037 patients were included in each group. Utilization of atherectomy was associated with lower in-hospital mortality (2% vs. 1.4% p = 0.0006). All secondary outcomes were lower when using atherectomy except acute renal failure. Length of stay was slightly lower when using atherectomy (7.2 vs. 7.0 days, p = 0.0494). However, median cost was higher in patients treated with atherectomy ($21,589 vs. $24,060, p = <0.0001). Conclusion The use of atherectomy was associated with significantly decreased in-hospital mortality, adverse events, and length of stay. Though, cost associated with atherectomy use is increased, this is offset by decreased in-hospital adverse outcomes. Appropriate use of atherectomy devices is an important tool in revascularization of peripheral arterial disease in select patients.

Gender difference with the use of percutaneous left ventricular assist device in patients undergoing complex high-risk percutaneous coronary intervention: From pVAD Working Group.

The interventional treatment of complex high-risk indicated patients is technically difficult and can result in poor outcomes. Thus, percutaneous left ventricular assist devices are being increasingly used to provide hemodynamic support. No data is available comparing male and female for Complex High-risk Indicated Patients treated with percutaneous left ventricular assist devices. Our goal was to evaluate in-hospital as well as short term outcomes comparing males and females. There were 160 complex high-risk indicated patients with percutaneous left ventricular assist device use who were not in cardiogenic shock. A total of 132 male and 28 female patients were included. Ejection fraction below 35% with one additional criterion such as use of atherectomy device or treatment on unprotected left main disease or multi-vessel disease were our inclusion criteria. An Impella 2.5 or Impella CP (Abiomed Inc.) device was used as a left ventricular support device. There was no difference in in-hospital mortality between the genders after performing a propensity score matched analysis (8.3% vs. 12.5%, p=0.54). Secondary outcomes of myocardial infarction, cardiogenic shock, congestive heart failure, dysrhythmia, major adverse cardiac events and composite of all complications were higher in males. Furthermore, 30-day survival was similar in males and females (88.9% vs. 87.5%, p=0.31). In addition, worse complications rates and survival were noted in patients with incomplete revascularization compared with those patients with complete revascularization in both gender. This study demonstrated no gender difference in clinical outcomes when using percutaneous left ventricular assist device support for the treatment of complex high-risk indicated patients. Overall, males had higher secondary outcomes compared with females with no difference in in-hospital mortality or 30-day survival rates.

Percutaneous Versus Surgical Management of Lower Extremity Peripheral Artery Disease

Lower extremity peripheral artery disease (PAD) is highly prevalent and can manifest as intermittent claudication or, in the most advanced form, critical limb ischemia. Revascularization, which can be accomplished by an endovascular or surgical approach, is performed to improve quality of life or, in severe cases, for limb salvage. Over the past decade, percutaneous catheter-based techniques have improved such that acute procedural success is high even in complex anatomy. Patency rates have also increased with the use of atherectomy devices and drug-eluting stents. Often, patients with PAD have comorbidities that increase the risk of cardiovascular complications with surgical procedures. These factors have led to the adoption of an endovascular first strategy with surgical management reserved for selected patients. This review focuses on the most current clinical trials of endovascular therapy for PAD. In addition, older but relevant studies comparing endovascular and surgical approaches and contemporary surgical trials are presented for reference.

Educational ExhibitAbstract No. 363 - Protecting the runoff during lower extremity arterial interventions using embolic protection devices

1. Identifying lesions and procedures at risk for distal embolization. 2. Discussing the risks and benefits in using protection devices during lower limb interventions. Embolic protection devices were first introduced in 1990 to prevent cerebral infarcts during carotid artery stenting. The routine use of protection devices significantly decreased stroke risk and have also been implemented in other vascular beds. Percutaneous endovascular lower limb arterial interventions are increasingly being done for the treatment of peripheral arterial disease. Identifying vulnerable lesions and high risk procedures more likely to cause distal embolization is important to minimize periprocedural complications, maximize procedural success and minimize re-interventions. Distal embolization during lower extremity interventions is a variably reported complication with incidence varying from 1.5% to 19% for clinically significant embolic events depending on the case series of patients. Unstable lesions more at risk for distal embolization include intervening on chronic total occlusive disease, in-stent lesions, complex long complex lesions, heavily calcified lesions, ulcerated friable atheromatous plaque or thrombus-laden/occluded bypass grafts. High risk procedures include catheter-directed pharmacomechanical thrombolysis, use of atherectomy devices and recanalization of occluded stents and bypass grafts. Subclinical microemboli are near ubiquitously dislodged even during simplest interventions including crossing the target lesion with a wire or during balloon/stent angioplasty. It is important to note that protection devices are not complication free nor do they completely negate the risk of distal embolization. The profile of individual devices can limit the crossability past certain lesions which in of itself may propagate distal emboli during manipulation or allow emboli to pass unhindered if there is an incomplete seal against the vessel. Embolic protection devices can prevent embolic debris during lower limb interventions. Knowledge of at-risk lesions and interventions can assist the inteventionalist in choosing to employ these devices on a case-by-case basis.

Evolving trends in interventional device use and outcomes: results from the National Cardiovascular Network Database.

Although multiple new coronary interventional devices have been approved for marketing in the United States, use of these technologies in general clinical practice and their associated outcomes have not been reported. Using the National Cardiovascular Network's Coronary Interventional Database, we examined temporal trends in the use and outcomes of coronary stents, lasers, directional atherectomy, and rotational atherectomy devices at 12 US hospitals between January 1994 and December 1997 (n = 76,904). Over this period, the percentage of cases involving coronary stents rose more than 12-fold (from 5.4% in 1994 to 69.0% in 1997). In contrast, use of atherectomy-type devices declined significantly. Device selection was strongly influenced by the patient's coronary anatomy and procedural indication, but less by age, sex, or race. Device use also varied significantly among individual centers (4-fold variation among sites in stent use and 6-fold variation in atherectomy use) even after adjusting for patient characteristics. Although overall mortality rates were unchanged during this 4-year period, procedural success rates have improved and complication rates have declined significantly. Lengths of postprocedure hospital stay also fell significantly for all patients undergoing coronary intervention in this time period. Percutaneous interventional strategies are rapidly changing with the explosive growth of coronary stent use and the decline in use of atherectomy devices. Patient outcomes, including complication rates and postprocedure lengths of stay, have also improved as the new interventional strategies have been refined in clinical practice.

Evolving trends in interventional device use and outcomes: Results from the National Cardiovascular Network database

Background Although multiple new coronary interventional devices have been approved for marketing in the United States, use of these technologies in general clinical practice and their associated outcomes have not been reported. Methods and Results Using the National Cardiovascular Network's Coronary Interventional Database, we examined temporal trends in the use and outcomes of coronary stents, lasers, directional atherectomy, and rotational atherectomy devices at 12 US hospitals between January 1994 and December 1997 (n = 76,904). Over this period, the percentage of cases involving coronary stents rose more than 12-fold (from 5.4% in 1994 to 69.0% in 1997). In contrast, use of atherectomy-type devices declined significantly. Device selection was strongly influenced by the patient's coronary anatomy and procedural indication, but less by age, sex, or race. Device use also varied significantly among individual centers (4-fold variation among sites in stent use and 6-fold variation in atherectomy use) even after adjusting for patient characteristics. Although overall mortality rates were unchanged during this 4-year period, procedural success rates have improved and complication rates have declined significantly. Lengths of postprocedure hospital stay also fell significantly for all patients undergoing coronary intervention in this time period. Conclusions Percutaneous interventional strategies are rapidly changing with the explosive growth of coronary stent use and the decline in use of atherectomy devices. Patient outcomes, including complication rates and postprocedure lengths of stay, have also improved as the new interventional strategies have been refined in clinical practice.

Clinical, angiographic, and procedural correlates of abrupt vascular closure during coronary intervention: a 10-year experience at Mayo Clinic.

A large matched-cohort study was carried out to determine correlates of in-hospital abrupt vascular closure (AC). Univariate analysis identified current cigarette smoking (P = 0.021), myocardial infarction within 24 hr prior to procedure (P = 0.0035), emergency procedure (P = 0.02), lesion thrombus (P = 0.0001), and lesion angulation (P = 0.021) as significant clinical and angiographic variables. Relative to balloon angioplasty (PTCA), use of atherectomy (P = 0.015) and laser devices (P = 0.018) but not elective stent placement (P = 0.97) were associated with increased risk of AC. In the multivariate model, current cigarette smoking (P = 0.0474), lesion thrombus (P = 0.0001), lesion angulation (P = 0.0124), use of atherectomy devices (P = 0.001), and laser devices (P = 0.0037) remained as significant correlates of increased AC events. In conclusion, the risk of AC appears associated primarily with lesion characteristics and use of nonballoon devices other than stents. Elective stent placement did not appear to reduce AC risk over conventional PTCA; the small number of patients studied may have prevented any benefit from being observed.

Effects of endoluminal coronary stents on the frequency of coronary artery bypass grafting after unsuccessful percutaneous transluminal coronary revascularization

Coronary artery stents have been rapidly incorporated into clinical practice so that they are currently deployed in nearly 50% of all patients undergoing angioplasty procedures in a busy laboratory. A decline in the frequency of coronary bypass surgery for unsuccessful angioplasty is associated with this change in practice—a decline in the use of atherectomy devices, and no increase in length of stay for angioplasty patients.

Permanent Vascular Access: A Nephrologist's View

Vascular access complications are the greatest cause of morbidity in hemodialysis patients in the United States. Although arteriovenous fistulas have been recommended as the preferred mode of vascular access, recent data indicate that the majority of patients on hemodialysis in the United States have prosthetic graft fistulas. The most frequent complications of prosthetic graft fistulas are thrombosis and stenosis. Hospitalization rates for fistula complications are higher in patients with diabetes mellitus and of black race. Pathogenesis of intimal hyperplasia may include elaboration of platelet-derived growth factor and mechanical endothelial injury. Screening for stenosis and impaired blood flow in fistulas can be carried out with recirculation measurements, venous and intra-access pressure measurements, and Doppler ultrasound. A combination of the techniques is probably the best current strategy for fistula screening and further evaluation. Surgical thrombectomy and fistula revision remain the standard for comparison of newer approaches to management of complications. Percutaneous angioplasty with or without stent placement, thrombolysis, and use of atherectomy devices may play an increasing role in the treatment of complications, although comparative trials of these modalities need to be performed. No satisfactory long-term pharmacologic means of preventing thrombosis, stenosis, or restenosis have been found for graft arteriovenous fistulas. It is hoped that future directions in the field of vascular access placement and management will include better strategies for allowing primary arteriovenous fistula development, advances in graft materials, improved understanding of the pathogenesis of thrombosis and stenosis, and development strategies to prevent complications.

Techniques in Cardiac Care: Lasers, Stents, and Atherectomy Devices

Various new technologies are currently being investigated to treat cardiovascular disease less invasively than with conventional open heart surgery. Although lasers have been used in other health disciplines, their use in the cardiovascular field is relatively new. Even newer is the use of atherectomy devices and endovascular stents. It is important for the critical care nurse to be knowledgeable concerning these techniques in order to provide optimal patient care.