Mechanical thrombectomy of inferior vena cava filter-associated caval thrombosis using FlowTriever and ClotTriever systems

OBJECTIVE

Chronically indwelling inferior vena cava filters (IVCFs) can have multiple adverse sequelae, including IVCF-associated thrombosis. The Inari ClotTriever and FlowTriever mechanical and aspiration thrombectomy systems (Inari Medical) can be used for acute caval thrombosis associated with IVCFs if appropriate proximal IVCF protection is used intraprocedurally. The present study reports a single institution's outcomes after ClotTriever and FlowTriever thrombectomy of acute IVCF-associated iliocaval thrombus.

METHODS

A retrospective review was conducted of all patients who underwent ClotTriever or FlowTriever thrombectomy for IVCF-associated caval thrombosis. The patient demographics, clinical characteristics, and postprocedural outcomes of a 15-patient cohort were compiled and described.

RESULTS

A total of 15 patients were identified as presenting with acute IVCF-associated caval thrombosis and having undergone intervention with either the ClotTriever or FlowTriever system from 2019 to 2022. Of the 15 patients in the cohort, 3 (20%) had presented with a threatened extremity (phlegmasia cerulea dolens), and 12 had presented with severe, debilitating, but non-limb-threatening, lower extremity edema. The preprocedural clot burden was significant and involved the cava, iliac veins, and femoropopliteal veins in 7 of 15 patients (47%) in the cohort. The procedure was technically successful in 11 patients (73.33%). Resolution of acute symptoms was noted in 100% of the technically successful procedures. The 30-day mortality rate was 13% (2 of 15 patients). One intraprocedural death occurred from pulmonary embolism, and one patient died of malignancy complications. The surviving patients not lost to follow-up experienced stable or improving venous disease, with only one patient presenting with post-phlebitic syndrome.

CONCLUSIONS

Mechanical and aspiration thrombectomy of IVCF-associated thrombus with the FlowTriever and ClotTriever systems have good technical success and resulted in significant improvement in acute symptoms with adequate clot clearance. Proximal embolic protection maneuvers for pulmonary embolism prophylaxis and preexisting filter protection are required intraprocedurally.

Factors Associated with Preference of Choice of Aortic Aneurysm Repair in the PReference for Open Versus Endovascular repair of AAA (PROVE-AAA) study

OBJECTIVE

Patients can choose between open repair and endovascular repair of abdominal aortic aneurysm (AAA). However, the factors associated with patient preference for one repair type over another are not well characterized. Here we assess the factors associated with preference of choice for open or endovascular AAA repair among veterans exposed to a decision aid to help with choosing surgical treatment.

METHODS

Across 12 VA hospitals, veterans received a decision aid covering domains including patient information sources and understanding preference. Veterans were then given a series of surveys at different timepoints examining their preferences for open versus endovascular AAA repair. Questions from the preference survey were used in analyses of patient preference. Results were analyzed using chi-squared tests. A logistic regression was performed to assess factors associated with preference for open repair or preference for endovascular repair.

RESULTS

A total of 126 veterans received a decision aid informing them of their treatment choices, after which 121 completed all preference survey questions; five veterans completed only part of the instruments. Overall, veterans who preferred open repair were typically younger (70 vs 73, p=0.02), with similar rates of common comorbidities (coronary disease 16% vs 28%, p=0.21), and similar aneurysms compared to those who preferred endovascular repair (6.0 cm versus 5.7 cm, p=0.50). Veterans in both preference categories (28% of veterans preferring EVAR, 48% of veterans preferring open repair) reported "taking their doctor's" advice as the "top-box" response for the single most important factor influencing their decision. When comparing the tradeoff between less invasive surgery and higher risk of long-term complications, more than half of veterans preferring EVAR reported invasiveness as more important compared with approximately one in ten of those preferring open repair (53% versus 12%, p<0.001). Shorter recovery was an important factor for the endovascular repair group (74%) and not important in the open repair group (76%), p=0.5). In multivariable analyses, valuing a short hospital stay (OR=12.4, 95% CI 1.13-135.7) and valuing a shorter recovery (OR15.72, 95% CI 1.03-240.2) were associated with greater odds of preference for endovascular repair, while finding these characteristics not important were associated with greater odds of preference for open repair.

CONCLUSIONS

When faced with the decision of open repair versus endovascular repair, veterans who valued a shorter hospital stay and a shorter recovery were more likely to prefer endovascular repair, while those more concerned about long-term complications preferred open repair. Veterans typically value the advice of their surgeon over their own beliefs and preference. These findings need to be considered by surgeons as they guide their patients to a shared decision.

Short-Term Concerns Primarily Determine Patient Preference for Abdominal Aortic Aneurysm Repair

INTRODUCTION

Abdominal aortic aneurysm (AAA) repair may be performed through open or endovascular approaches, but the factors influencing a patient's repair-type preference are not well characterized. Here we performed a qualitative analysis to better understand factors influencing patient preference within the Preference for Open Versus Endovascular Repair of AAA Trial.

METHODS

Open-ended responses regarding primary (n = 21) and secondary (n = 47) factors influencing patient preference underwent qualitative analysis using the constant comparative method with iterative reviews. Codes were used to generate themes and themes grouped into categories, with each step conducted via consensus agreement between three researchers. Relative prevalence of themes were compared to ascertain trends in patient preference.

RESULTS

Patient responses regarding both primary and secondary factors fell into four categories: Short-term concerns, long-term concerns, advice & experience, and other. Patients most frequently described short-term concerns (23) as their primary influence, with themes including post-op complications, hospitalization & recovery, and intraoperative concerns. Long-term concerns were more prevalent (20) as secondary factors, which included themes such as survival, and chronic management. The average age of patients voicing only long-term concerns as a primary factor was 11 years younger than those listing only short-term concerns.

CONCLUSION

Short-term concerns relating to the procedure and recovery are more often the primary factor influencing patient preference, while long term concerns play a more secondary role. Long-term concerns are more often a primary factor in younger patients. Vascular surgeons should consider this information in shared decision making to reach an optimal outcome.

Exploring Factors Associated With Morbidity and Mortality in Patients With Do-Not-Resuscitate Orders: A National Surgical Quality Improvement Program Database Analysis Within Surgical Groups

BACKGROUND

Anesthesiologists caring for patients with do-not-resuscitate (DNR) orders may have ethical concerns because of their resuscitative wishes and may have clinical concerns because of their known increased risk of morbidity/mortality. Patient heterogeneity and/or emphasis on mortality outcomes make previous studies among patients with DNR orders difficult to interpret. We sought to explore factors associated with morbidity and mortality among patients with DNR orders, which were stratified by surgical subgroups.

METHODS

Exploratory retrospective cohort study in adult patients undergoing prespecified colorectal, vascular, and orthopedic surgeries was performed using the American College of Surgeons National Surgical Quality Improvement Program Participant Use File data from 2010 to 2013. Among patients with preoperative DNR orders (ie, active DNR order written in the patient's chart before surgery), factors associated with 30-day mortality, increased length of stay, and inpatient death were determined via penalized regression. Unadjusted and adjusted estimates for selected variables are presented.

RESULTS

After selection as above, 211,420 patients underwent prespecified procedures, and of those, 2755 (1.3%) had pre-existing DNR orders and met above selection to address morbidity/mortality aims. By specialty, of these patients with a preoperative DNR, 1149 underwent colorectal, 870 vascular, and 736 orthopedic surgery. Across groups, 36.2% were male and had a mean age 79.9 years (range 21-90). The 30-day mortality was 15.4%-27.2% and median length of stay was 6-12 days. Death at discharge was 7.0%, 13.1%, and 23.0% in orthopedics, vascular, and colorectal patients with a DNR, respectively. The strongest factors associated with increased odds of 30-day mortality were preoperative septic shock in colorectal patients, preoperative ascites in vascular patients, and any requirement of mechanical ventilation at admission in orthopedic patients.

CONCLUSIONS

In patients with DNR orders undergoing common surgical procedures, the association of characteristics with morbidity and mortality varies in both direction and magnitude. The DNR order itself should not be the defining measure of risk.

Development and Performance of a Clinical Decision Support Tool to Inform Resource Utilization for Elective Operations

IMPORTANCE

Hospitals ceased most elective procedures during the height of coronavirus disease 2019 (COVID-19) infections. As hospitals begin to recommence elective procedures, it is necessary to have a means to assess how resource intensive a given case may be.

OBJECTIVE

To evaluate the development and performance of a clinical decision support tool to inform resource utilization for elective procedures.

DESIGN, SETTING, AND PARTICIPANTS

In this prognostic study, predictive modeling was used on retrospective electronic health records data from a large academic health system comprising 1 tertiary care hospital and 2 community hospitals of patients undergoing scheduled elective procedures from January 1, 2017, to March 1, 2020. Electronic health records data on case type, patient demographic characteristics, service utilization history, comorbidities, and medications were and abstracted and analyzed. Data were analyzed from April to June 2020.

MAIN OUTCOMES AND MEASURES

Predicitons of hospital length of stay, intensive care unit length of stay, need for mechanical ventilation, and need to be discharged to a skilled nursing facility. These predictions were generated using the random forests algorithm. Predicted probabilities were turned into risk classifications designed to give assessments of resource utilization risk.

RESULTS

Data from the electronic health records of 42 199 patients from 3 hospitals were abstracted for analysis. The median length of stay was 2.3 days (range, 1.3-4.2 days), 6416 patients (15.2%) were admitted to the intensive care unit, 1624 (3.8%) received mechanical ventilation, and 2843 (6.7%) were discharged to a skilled nursing facility. Predictive performance was strong with an area under the receiver operator characteristic ranging from 0.76 to 0.93. Sensitivity of the high-risk and medium-risk groupings was set at 95%. The negative predictive value of the low-risk grouping was 99%. We integrated the models into a daily refreshing Tableau dashboard to guide decision-making.

CONCLUSIONS AND RELEVANCE

The clinical decision support tool is currently being used by surgical leadership to inform case scheduling. This work shows the importance of a learning health care environment in surgical care, using quantitative modeling to guide decision-making.

Design of the PReferences for Open Versus Endovascular Repair of Abdominal Aortic Aneurysm (PROVE-AAA) Trial

For patients with abdominal aortic aneurysm (AAA), randomized trials have found endovascular AAA repair (EVAR) is associated with lower perioperative morbidity and mortality than open surgical repair (OSR). However, OSR has fewer long-term aneurysm-related complications, such as endoleak or late rupture. Patients treated with EVAR and OSR have similar survival rates within two years after surgery, and OSR does not require intensive surveillance. Few have examined if patient preferences are aligned with the type of treatment they receive for their AAA. Although many assume that patients may universally prefer the less-invasive nature of EVAR, our preliminary work suggests that patients who value the lower risk of late complications may prefer OSR. In this study, called The PReferences for Open Versus Endovascular Repair of Abdominal Aortic Aneurysm (PROVE-AAA) trial, we describe a cluster-randomized trial to test if a decision aid can better align patients' preferences and their treatment type for AAA. Patients enrolled in the study are candidates for either endovascular or open repair and are followed up at VA hospitals by vascular surgery teams who regularly perform both types of repair. In Aim 1, we will determine patients' preferences for endovascular or open repair and identify domains associated with each repair type. In Aim 2, we will assess alignment between patients' preferences and the repair type elected and then compare the impact of a decision aid on this alignment between the intervention and control groups. This study will help us to accomplish two goals. First, we will better understand the factors that affect patient preference when choosing between EVAR and OSR. Second, we will better understand if a decision aid can help patients be more likely to receive the treatment strategy they prefer for their AAA. Study enrollment began on June 1, 2017. Between June 1, 2017 and November 1, 2018, we have enrolled 178 of a total goal of 240 veterans from 20 VA medical centers and their vascular surgery teams across the country. We anticipate completing enrollment in PROVE-AAA in June 2019, and study analyses will be performed thereafter.

Patient information sources when facing repair of abdominal aortic aneurysm

OBJECTIVE

Shared medical decision making is most important when there are competing options for repair such as in treatment of abdominal aortic aneurysm (AAA). We sought to understand the sources of patients' pre-existing knowledge about AAA to better inform treating physicians about patients' needs for preoperative counseling.

METHODS

We performed a multicenter survey of patients facing AAA repair at 20 Veterans Affairs hospitals across the United States as part of the Preferences for Open Versus Endovascular Repair of AAA study. A validated survey instrument was administered to examine the sources of information available and commonly used by patients to learn about their repair options. The survey was administered by study personnel before the patient had any interaction with the vascular surgeon because survey data were collected before the vascular clinic visit.

RESULTS

Preliminary analysis of data from 99 patients showed that our cohort was primarily male (99%) and elderly (mean age 73 years). Patients commonly had a history of hypertension (86%), prior myocardial infarction (32%), diabetes (32%), and were overweight (58%). Patients arrived at their surgeon's office appointment with limited information. A majority of patients (52%) reported that they had not talked to their primary care physician at all about their options for AAA repair, and one-half (50%) reported that their view of the different surgical options had not been influenced by anyone. Slightly less than one-half of patients reported that they did not receive any information about open surgical aneurysm repair and endovascular aortic aneurysm repair (41% and 37%, respectively). Few patients indicated using the internet as their main source of information about open surgical aneurysm repair and endovascular aortic aneurysm repair (10% and 11%, respectively).

CONCLUSIONS

Patients are commonly referred for AAA repair having little to no information regarding AAA pathology or repair options. Fewer than one in five patients searched the internet or had accessed other sources of information on their own. Most vascular surgeons should assume that patients will present to their first vascular surgery appointment with minimal understanding of the treatment options available to them.

Low mortality rates after endovascular aortic repair expand use to high-risk patients

OBJECTIVE

The 2010 endovascular aneurysm repair (EVAR) trial 2 (EVAR 2) reported that patients with comorbidity profiles rendering them unfit for open aneurysm repair who underwent EVAR did not experience a survival advantage compared with those who did not undergo intervention. These patients experienced a 30-day mortality of 7.3%, whereas reports from similar cohorts reported far lower mortality rates. The primary objective of our study was to compare the incidence of 30-day mortality in low- and high-risk patients undergoing EVAR in a contemporary data set, using patient risk stratification criteria from EVAR 2. Secondarily, we sought to identify risk factors associated with a disproportionate contribution to 30-day mortality risk.

METHODS

Data were obtained from the 2005 to 2013 American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Participant Use Data Files (N = 24,813). Patients were included in the high-risk cohort with the presence of renal, respiratory, or cardiac preoperative criteria alone or in combination. Renal impairment criteria were defined as dialysis and creatinine concentration >2.26 mg/dL. Respiratory impairment criteria included history of chronic obstructive pulmonary disease and preoperative ventilator support. Cardiac impairment criteria included history of myocardial infarction, congestive heart failure, angina, and prior coronary intervention. Patient and procedural characteristics and 30-day postoperative outcomes were compared using Pearson χ2 tests for categorical variables and Wilcoxon rank sum tests for continuous variables.

RESULTS

Among 24,813 patients undergoing EVAR, 12,043 (48%) patients were characterized as high risk (at least one impairment criterion); 12,770 (52%) patients were stratified as low risk. The 30-day mortality rate was 1.9% in the high-risk cohort compared with the 7.3% reported by EVAR 2, and it was higher in the high-risk cohort compared with the low-risk cohort (1.9% vs 0.9%; P < .001). Whereas the presence of each comorbidity increased the odds of 30-day mortality (respiratory odds ratio [OR], 1.62; 95% confidence interval [CI], 1.16-2.26; P = .005; cardiac OR, 1.55; 95% CI, 1.14-2.10; P = .005), the presence of renal criteria disproportionately increased the odds of mortality threefold (OR, 3.42; 95% CI, 2.31-5.09; P < .001).

CONCLUSIONS

Contemporary 30-day mortality after EVAR in high-risk patients is substantially lower than that reported in the EVAR 2 trial. Whereas low- and high-risk stratification by current comorbidity criteria is appropriate, attention needs to be paid to disproportionate risk contribution from renal disease to mortality compared with cardiac and pulmonary comorbidities. Given the lower mortality risk than previously described, patients stratified as high risk should be thoughtfully considered for definitive EVAR.

2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health. These guidelines, based on systematic methods to evaluate and classify evidence, provide a cornerstone of quality cardiovascular care.

In response to reports from the Institute of Medicine1 ,2 and a mandate to evaluate new knowledge and maintain relevance at the point of care, the ACC/AHA Task Force on Clinical Practice Guidelines (Task Force) modified its methodology.3 –5 The relationships among guidelines, data standards, appropriate use criteria, and performance measures are addressed elsewhere.5

2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health. These guidelines, based on systematic methods to evaluate and classify evidence, provide a cornerstone of quality cardiovascular care.

In response to reports from the Institute of Medicine^1,2 and a mandate to evaluate new knowledge and maintain relevance at the point of care, the ACC/AHA Task Force on Clinical Practice Guidelines (Task Force) modified its methodology.^3–5 The relationships among guidelines, data standards, appropriate use criteria, and performance measures are addressed elsewhere.⁵

Platelet Function and Pharmacologic Inhibition

Platelets have traditionally been understood within the context of hemostasis and hemorrhagic disorders. However, with increasing procedures being performed in smaller vessels and with an increasing incidence of atherosclerosis, the often critical role platelets play is more evident. Platelets are no longer viewed as “scaffolding” for the events of the coagulation cascade but rather as important catalysts in hemostasis, thrombosis, and fibrinolysis. Improved understanding of platelet physiology has led to developments of pharmacologic adjuncts resulting in improved patency rates and improved patient outcomes. This review addresses the physiology of platelet function and the impact of new pharmacologic agents in percutaneous intervention.

Hypercoagulable States: A Review

Vascular surgeons are often asked to evaluate patients with recurrent thromboses or thromboses in unusual locations either arterial or venous. There may be obvious inciting factors, but in many of these patients the possibility of a previously undiagnosed hypercoagulable state must be considered. Hypercoagulable states can be acquired (smoking, medication, change in physiologic status as occurs with pregnancy) or congenital. Congenital hypercoagulable disorders are more prevalent in families or patients with a history of thromboembolic events early in life or multiple miscarriages and include conditions such as protein C or S deficiencies, factor V Leiden mutation, and prothrombin gene variant. This article reviews the hypercoagulable states that are encountered in clinical practice as well as guidelines for testing and goals of therapy.

Perioperative Optimization of Geriatric Lower Extremity Bypass in the Era of Increased Performance Accountability

BACKGROUND

The initiation of bundled payment for care improvement by Centers for Medicare and Medicaid Services (CMS) has led to increased financial and performance accountability. As most vascular surgery patients are elderly and reimbursed via CMS, improving their outcomes will be critical for durable financial stability. As a first step in forming a multidisciplinary pathway for the elderly vascular patients, we sought to identify modifiable perioperative variables in geriatric patients undergoing lower extremity bypass (LEB).

METHODS

The 2011-2013 LEB-targeted American College of Surgeons National Surgical Quality Improvement Program database was used for this analysis (n = 5316). Patients were stratified by age <65 (n = 2171), 65-74 (n = 1858), 75-84 (n = 1190), and ≥85 (n = 394) years. Comparisons of patient- and procedure-related characteristics and 30-day postoperative outcomes stratified by age groups were performed with Pearson χ² tests for categorical variables and Wilcoxon rank-sum tests for continuous variables.

RESULTS

During the study period, 5316 total patients were identified. There were 2171 patients aged <65 years, 1858 patients in the 65-74 years age group, 1190 patients in the 75-84 years age group, and 394 patients in the ≥85 years age group. Increasing age was associated with an increased frequency of cardiopulmonary disease (P < 0.001) and a decreased frequency of diabetes, tobacco use, and prior surgical intervention (P < 0.001). Only 79% and 68% of all patients were on antiplatelet and statin therapies, respectively. Critical limb ischemia occurred more frequently in older patients (P < 0.001). Length of hospital stay, transfusion requirements, and discharge to a skilled nursing facility increased with age (P < 0.001). Thirty-day amputation rates did not differ significantly with age (P = 0.12).

CONCLUSIONS

Geriatric patients undergoing LEB have unique and potentially modifiable perioperative factors that may improve postoperative outcomes. These modifiers will be the basis of a multidisciplinary care path targeting the geriatric vascular surgery patients.

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.

Spliced arm vein grafts are a durable conduit for lower extremity bypass

BACKGROUND

Many patients with peripheral vascular disease (PAD) requiring revascularization do not have adequate ipsilateral great saphenous vein (GSV) for constructing a bypass because of intrinsic vein disease or prior harvesting for limb or coronary bypass. Prosthetic conduits have poor long-term patency, especially for distal bypass. With advancing endovascular sophistication, tibial angioplasty may be a good revascularization option, but we hypothesize that using spliced arm vein for distal lower extremity bypass is still a well-tolerated and more durable solution.

METHODS

A retrospective chart review was conducted of all PAD patients undergoing lower extremity bypass or tibial angioplasty for lifestyle-limiting claudication or critical limb ischemia at a single institution over a 7-year period. Statistical analysis was conducted by Kaplan-Meier survival analysis and Cox proportional hazards model. Statistical significance was set at P = 0.05.

RESULTS

From 2005 to 2012, there were 120 patients who underwent infrageniculate revascularization with conduit other than GSV. Over half of the patients (66 patients, 71.2% male, mean age 62 years) underwent bypass operations using arm vein conduit, and 88% of those bypasses were to tibial vessels. Patency was 100% at 1 year and 85% at 2 years. There was no impact on patency or amputation rate based on the source of vein or the number of splices. Forty-three patients underwent tibial angioplasty and patency was 70% at 1 year and 50% at 2 years.

CONCLUSIONS

When GSV is not available, spliced arm vein grafts provide durable lower extremity revascularization with favorable patency and limb preservation rates. Spliced arm vein grafts should be considered over prosthetic grafts and angioplasty alone in patients with distal occlusive disease.

Current insights on the biology and clinical aspects of VEGF regulation

Vascular endothelial growth factor (VEGF) is a key molecule that orchestrates the formation and function of vascular networks. Impaired regulation of angiogenesis is implicated in a number of pathologic states. For instance, neoplasias exhibit uncontrolled angiogenesis, whereas ischemia and states of vascular insufficiency involve reduced VEGF activity. As the role of VEGF has been elucidated in these disease processes, its therapeutic role has been developed. The Food and Drug Administration has approved several anti-VEGF agents for treating colorectal, lung, and kidney cancer. VEGF-inducing agents have also been used experimentally to induce angiogenesis in patients with critical limb ischemia. As more knowledge is gathered about the biology of VEGF and its receptors, there is greater promise for therapeutic modulation of VEGF expression. The purpose of this review is to describe the various therapeutic and biologic factors that regulate the expression of VEGF.

Direct thrombin inhibitors: alternatives to heparin

After more than 70 years of effective clinical use, heparin remains the most common anticoagulant in use and one of the most commonly prescribed drugs to hospitalized patients. However, the biologic variability and immunogenicity limit its utility. With increasing volumes of vascular intervention and an aging population, an increase in the need for anticoagulation can be anticipated. This article reviews current viable options and barriers to the use of heparin.

Analysis of Outcomes Following Failed Endovascular Treatment of Chronic Limb Ischemia

Despite recent studies highlighting the advantages of endoluminal intervention in the management of chronic limb ischemia (CLI), outcomes following failed peripheral angioplasty remain less well described. We present a retrospective analysis of failed transluminal infrainguinal percutaneous arterial angioplasty with or without stenting (PTA/S) in patients with CLI. A database of patients undergoing infrainguinal PTA/S between 2002 and 2005 was maintained. Patients underwent duplex scanning follow-up at 2 weeks, 3 months, and every 6 months after the intervention. Angiograms were reviewed in all cases to assess lesion characteristics. Results were standardized to current Transatlantic Inter-Society Consensus (TASC) criteria. Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. In total, our analysis involved 246 patients who underwent treatment for CLI using PTA/S. Eighteen percent of procedures (n = 46) were considered an intervention failure secondary to restenosis by duplex ultrasound, returning clinical symptoms, a nonhealing foot lesion, or the absence of a prior palpable pulse. Indications for the original procedure in patients whose PTA/S failed were tissue loss in 44%, claudication in 44%, and rest pain in 12%, while TASC lesion grades were A (0%), B (18%), C (18%), and D (64%). Of patients failing PTA/S, 4% failed in the first 30 days, 78% failed between 1 and 18 months, while 18% failed following 18 months, with a mean time to failure of 8.7 months. Also, 82% of PTA/S failures were candidates for a second endovascular procedure, 11% were suitable for only traditional open bypass, and 4% demonstrated progression of disease necessitating amputation. Of patients undergoing a second endovascular procedure, limb salvage rates were 86% at 12-month follow-up and there was a single periprocedural mortality and complication rate of 6.6%. Of patients requiring open surgical bypass after failed PTA/S, 20% (n = 1) required a major amputation and there were no mortalities. Failure of endoluminal therapy for treatment of lower extremity arterial occlusive disease is amenable to subsequent endovascular intervention for limb salvage with limited morbidity and mortality.

Analysis of anatomic factors and age in patients undergoing carotid angioplasty and stenting

Recent data suggest that patient age >80 years may be associated with increased risk of periprocedural complications from carotid angioplasty and stenting (CAS). In this study, we analyzed anatomic risk factors in patients undergoing CAS based on age >80 or <80 years. Our hypothesis was that patients >80 would have more challenging anatomy. Between February 2003 and August 2004, 82 patients underwent CAS. Images for 57 lesions were available for review. Eighteen patients were > or =80 years old and 39 were <80. Cerebral protection devices, including EPI Filterwire, Percusurge, Accunet, and Angioguard, were used in all but two cases; and self-expanding stents (Wallstent, NexStent, Acculink, Precise) were placed in all. Arterial anatomic characteristics were assigned a score based on complexity and associated procedural risk. Characteristics evaluated using angiographic images were aortic arch elongation classification, arch calcification, common carotid/innominate stenosis, common carotid tortuosity, internal carotid tortuosity, index lesion length, index lesion calcification, and index lesion stenosis. Statistical analysis was performed using Fisher's exact test. CAS was successfully completed in 98% of cases. The two patients in whom we could not perform CAS were 79 and 83 years old. The anatomic characteristics that were statistically significantly more complex/severe in patients > or =80 were arch calcification (p = 0.045), common carotid/innominate stenosis (p = 0.023), common carotid tortuosity (p = 0.049), and internal carotid tortuosity (p = 0.032). There was no statistically significant difference in arch elongation classification, lesion length, lesion calcification, or stenosis severity (p = nonsignificant). Overall, patients > or =80 years had an increased incidence of complex anatomic risk factors compared to younger patients (p < 0.001). Cerebrovascular accident without residual deficits occurred in two patients; both were >80 years old. Complex arterial anatomy is more often present in patients >80 years and may explain the increased complication rates associated with CAS. Pre- or intraoperative consideration of these characteristics may help provide better risk assessment in candidates for CAS.

Argatroban for anticoagulation during cardiopulmonary bypass in an infant

Heparin induced thrombocytopenia (HIT) is a rare, but potentially life-threatening complication of heparin therapy. In patients with HIT, alternative means of anticoagulation are necessary. The authors present an infant with HIT who required anticoagulation during cardiopulmonary bypass for tricuspid valve excision in the treatment of bacterial endocarditis. The direct thrombin inhibitor, argatroban, was successfully used. Previous reports regarding the use of argatroban and other nonheparin anticoagulants for anticoagulation are reviewed and suggestions regarding argatroban dosing in infants are presented.

Heparin-induced thrombocytopenia in the pediatric intensive care unit population

OBJECTIVES

To report the occurrence of heparin-induced thrombocytopenia (HIT), discuss its pathophysiology, and outline an approach to management in the pediatric intensive care unit (ICU) patient.

DESIGN

Retrospective case reports.

SETTING

Pediatric ICU in a tertiary-care center.

PATIENTS AND RESULTS

Two pediatric ICU patients (2 and 6 mos of age) who developed HIT in the pediatric ICU. One was receiving heparin as a flush solution through a central line and the other had full heparinization during cardiopulmonary bypass. Both had received heparin during their neonatal course and developed thrombocytopenia; however, HIT was not considered as a possible diagnosis. HIT was diagnosed using a heparin-induced platelet aggregation study. The thrombocytopenia resolved with the cessation of heparin administration. One of the patients developed a deep vein thrombosis around a femoral venous catheter.

CONCLUSION

Although well described in the adult literature, there have been a limited number of reports of HIT in pediatric-aged patients. Given its potential for morbidity, HIT should be considered in the differential diagnosis of thrombocytopenia in the pediatric ICU patient.

Pharmacomechanical thrombectomy for treatment of symptomatic lower extremity deep venous thrombosis: Safety and feasibility study

PURPOSE

The current standard of care for deep venous thromboembolism (DVT) is anticoagulation; however, this treatment method does not rapidly relieve clot burden or clinical symptoms. We describe a rapid and effective method of thrombus removal, with simultaneous percutaneous mechanical thrombectomy (PMT) and thrombolysis.

METHODS

Over 26 months 20 patients (22 men, 2 women; mean age, 52 +/- 6 years [range, 38-79 years]) with extensive lower extremity DVT were treated with PMT with the AngioJet thrombectomy device in combination with lytic agent (urokinase, tissue plasminogen activator, or reteplase) added to the infusion. Three patients underwent treatment twice, because of recurrent DVT. The primary end point was angiographic evidence of restoration of venous patency at completion of the procedure. Complications, recurrent ipsilateral DVT, and improvement in clinical symptoms were evaluated.

RESULTS

Complete thrombus removal was obtained in 15 procedures (65%), and partial resolution in the remaining 8 procedures (35%). Inciting occlusive lesions responsible for acute DVT were revealed in 14 patients (61%), and angioplasty with or without stenting was performed when necessary. In the 8 procedures with partial resolution additional catheter-directed thrombolysis was carried out on average for 5.7 hours, with further thrombus reduction. Overall, immediate (<24 hours) improvement in clinical symptoms was noted in 17 patients (74%). There were no complications related to either PMT or the short duration of lytic agent infusion. At average follow-up of 10.2 +/- 0.3 months (range, 3-26 months), 3 patients had recurrent ipsilateral DVT, and underwent repeat treatment.

CONCLUSIONS

Addition of lytic agent to PMT facilitates thrombus extraction, decreases overall interventional treatment time, and improves patient outcomes. In addition, definitive management of underlying anatomic lesions can be performed in the same setting. Further outcome measures are necessary to study the long-term efficacy of this treatment method on preservation of valve function, reduction of chronic venous insufficiency, and improved quality of life.