Critical limb ischemia, first defined in 1982, was intended to delineate a subgroup of patients with a threatened lower extremity primarily because of chronic ischemia. It was the intent of the ...original authors that patients with diabetes be excluded or analyzed separately. The Fontaine and Rutherford Systems have been used to classify risk of amputation and likelihood of benefit from revascularization by subcategorizing patients into two groups: ischemic rest pain and tissue loss. Due to demographic shifts over the last 40 years, especially a dramatic rise in the incidence of diabetes mellitus and rapidly expanding techniques of revascularization, it has become increasingly difficult to perform meaningful outcomes analysis for patients with threatened limbs using these existing classification systems. Particularly in patients with diabetes, limb threat is part of a broad disease spectrum. Perfusion is only one determinant of outcome; wound extent and the presence and severity of infection also greatly impact the threat to a limb. Therefore, the Society for Vascular Surgery Lower Extremity Guidelines Committee undertook the task of creating a new classification of the threatened lower extremity that reflects these important considerations. We term this new framework, the Society for Vascular Surgery Lower Extremity Threatened Limb Classification System. Risk stratification is based on three major factors that impact amputation risk and clinical management: Wound, Ischemia, and foot Infection (WIfI). The implementation of this classification system is intended to permit more meaningful analysis of outcomes for various forms of therapy in this challenging, but heterogeneous population.
Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall rates of intervention for PAD ...have been rising steadily in recent years. Changing demographics, evolution of technologies, and an expanding database of outcomes studies are primary forces influencing clinical decision making in PAD. The management of PAD is multidisciplinary, involving primary care physicians and vascular specialists with varying expertise in diagnostic and treatment modalities. PAD represents a broad spectrum of disease from asymptomatic through severe limb ischemia. The Society for Vascular Surgery Lower Extremity Practice Guidelines committee reviewed the evidence supporting clinical care in the treatment of asymptomatic PAD and intermittent claudication (IC). The committee made specific practice recommendations using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system. There are limited Level I data available for many of the critical questions in the field, demonstrating the urgent need for comparative effectiveness research in PAD. Emphasis is placed on risk factor modification, medical therapies, and broader use of exercise programs to improve cardiovascular health and functional performance. Screening for PAD appears of unproven benefit at present. Revascularization for IC is an appropriate therapy for selected patients with disabling symptoms, after a careful risk-benefit analysis. Treatment should be individualized based on comorbid conditions, degree of functional impairment, and anatomic factors. Invasive treatments for IC should provide predictable functional improvements with reasonable durability. A minimum threshold of a >50% likelihood of sustained efficacy for at least 2 years is suggested as a benchmark. Anatomic patency (freedom from restenosis) is considered a prerequisite for sustained efficacy of revascularization in IC. Endovascular approaches are favored for most candidates with aortoiliac disease and for selected patients with femoropopliteal disease in whom anatomic durability is expected to meet this minimum threshold. Conversely, caution is warranted in the use of interventions for IC in anatomic settings where durability is limited (extensive calcification, small-caliber arteries, diffuse infrainguinal disease, poor runoff). Surgical bypass may be a preferred strategy in good-risk patients with these disease patterns or in those with prior endovascular failures. Common femoral artery disease should be treated surgically, and saphenous vein is the preferred conduit for infrainguinal bypass grafting. Patients who undergo invasive treatments for IC should be monitored regularly in a surveillance program to record subjective improvements, assess risk factors, optimize compliance with cardioprotective medications, and monitor hemodynamic and patency status.
Abstract Objective The Kidney Disease Outcome Quality Initiative and Fistula First Breakthrough Initiative call for the indiscriminate creation of arteriovenous fistulas (AVFs) over arteriovenous ...grafts (AVGs) without providing patient-specific criteria for vascular access selection. Although the U.S. AVF rate has increased dramatically, several reports have found that this singular focus on increasing AVFs has resulted in increased AVF nonmaturation/early failure and a high prevalence of catheter dependence. The objective of this study was to determine the appropriateness of vascular access procedures in clinical scenarios constructed with combinations of relevant factors potentially influencing outcomes. Methods The RAND/UCLA Appropriateness Method was used. Accordingly, a comprehensive literature search was performed and a synthesis of results compiled. The RAND/UCLA Appropriateness Method was applied to 2088 AVF and 1728 AVG clinical scenarios with varying patient characteristics. Eleven international vascular access experts rated the appropriateness of each scenario in two rounds. On the basis of the distribution of the panelists' scores, each scenario was determined to be appropriate, inappropriate, or indeterminate. Results Panelists achieved agreement in 2964 (77.7%) scenarios; 860 (41%) AVF and 588 (34%) AVG scenarios were scored appropriate, 686 (33%) AVF and 480 (28%) AVG scenarios were scored inappropriate, and 542 (26%) AVF and 660 (38%) AVG scenarios were indeterminate. Younger age, larger outflow vein diameter, normal or obese body mass index (vs morbidly obese), larger inflow artery diameter, and higher patient functional status were associated with appropriateness of AVF creation. Older age, dialysis dependence, and smaller vein size were associated with appropriateness of AVG creation. Gender, diabetes, and coronary artery disease were not associated with AVF or AVG appropriateness. Dialysis status was not associated with AVF appropriateness. Body mass index and functional status were not associated with AVG appropriateness. To simulate the surgeon's decision-making, scenarios were combined to create situations with the same patient characteristics and both AVF and AVG options for access. Of these 864 clinical situations, 311 (36%) were rated appropriate for AVG but inappropriate or indeterminate for AVF. Conclusions The results of this study indicate that patient-specific situations exist wherein AVG is as appropriate as or more appropriate than AVF. These results provide patient-specific recommendations for clinicians to optimize vascular access selection criteria, to standardize care, and to inform payers and policy. Indeterminate scenarios will guide future research.
Objective To develop a set of suggested objective performance goals (OPG) for evaluating new catheter-based treatments in critical limb ischemia (CLI), based on evidence from historical controls. ...Methods Randomized, controlled trials of surgical, endovascular, and pharmacologic/biologic treatments for CLI were reviewed according to specified criteria regarding study population and data quality. Line-item data were obtained for selected studies from the sponsor/funding agency. A set of specific outcome measures was defined in accordance with the treatment goals for the CLI population. Risk factors were examined for their influence on key endpoints, and models of stratification based on specific clinical and anatomic variables developed. Sample size estimates were made for single-arm trial designs based on comparison to the suggested OPG. Results Bypass with autogenous vein was considered the established standard, and data compiled from three individual randomized, controlled trials (N = 838) was analyzed. The primary efficacy endpoint was defined as perioperative (30-day) death or any major adverse limb event (amputation or major reintervention) occurring within one year. Results of open surgery controls demonstrated freedom from the primary endpoint in 76.9% (95% confidence interval CI 74.0%-79.9%) of patients at one year, with amputation-free survival (AFS) of 76.5% (95% CI 73.7%-79.5). An additional 3% non-inferiority margin was suggested in generating OPG for catheter-based therapies. Defined clinical (age > 80 years and tissue loss) and anatomic (infra-popliteal anatomy or lack of good quality saphenous vein) risk subgroups provided significantly different point estimates and OPG threshold values. Conclusions For new catheter-based therapies in CLI, OPGs offer a feasible approach for pre-market evaluation using non-randomized trial designs. Such studies should incorporate risk stratification in design and reporting as the CLI population is heterogeneous with respect to baseline variables and expected outcomes. Guidelines for CLI trial design to address consistency in study cohorts, methods of assessment, and endpoint definitions are provided.
Recognizing the impact of the decision making by the dialysis access surgeon on the successful placement of autogenous arteriovenous hemodialysis access, the Society for Vascular Surgery assembled a ...multispecialty panel to develop practice guidelines in arteriovenous access placement and maintenance with the aim of maximizing the percentage and functionality of autogenous arteriovenous accesses that are placed. The Society commissioned the Knowledge and Encounter Research Unit of the Mayo Clinic College of Medicine, Rochester, Minnesota, to systematically review the available evidence in three main areas provided by the panel: timing of referral to access surgeons, type of access placed, and effectiveness of surveillance. The panel then formulated practice guidelines in seven areas: timing of referral to the access surgeon, operative strategies to maximize the placement of autogenous arteriovenous accesses, first choice for the autogenous access, choice of arteriovenous access when a patient is not a suitable candidate for a forearm autogenous access, the role of monitoring and surveillance in arteriovenous access management, conversion of a prosthetic arteriovenous access to a secondary autogenous arteriovenous access, and management of the nonfunctional or failed arteriovenous access. For each of the guidelines, the panel stated the recommendation or suggestion, discussed the evidence or opinion upon which the recommendation or suggestion was made, detailed the values and preferences that influenced the group's decision in formulating the relevant guideline, and discussed technical remarks related to the particular guideline. In addition, detailed information is provided on various configurations of autogenous and prosthetic accesses and technical tips related to their placement.
Background Common femoral endarterectomy (CFE) for limited arterial occlusive disease is considered a fairly low-risk operation of short duration. This study investigated the timing of 30-day ...outcomes as they related to hospital discharge and predicted the risk of operative mortality of this procedure. Methods All patients in the National Surgical Quality Improvement Program database who underwent isolated CFE between 2005 and 2010 were selected for the test sample. We identified postoperative mortality and morbidities occurring before and after hospital discharge. A risk calculator for 30-day mortality, developed in the test sample using logistic regression, was validated in a new sample of cases from 2011 to 2012. Results A total of 1843 CFEs reported from 2005 to 2010 met the inclusion and exclusion criteria. The average operative time was 146 ± 69.5 minutes (median, 133; interquartile range, 98-179 minutes), and 10% of patients needed to return to the operating room. The average length of stay was 4 ± 7.5 days (median, 3; interquartile range, 2-5 days); 91% of patients were discharged ≤1 week of surgery. Occurrences of cardiovascular events, renal dysfunction, and pulmonary complication were relatively low. There was 3.4% mortality and 8% wound-related complications, 30% and 86% of which occurred after hospital discharge, respectively. Overall, there was a 15% risk of combined mortality/morbidity, and >60% of these events occurred after discharge. The independent predictors of 30-day mortality were age, nonindependent functional status, preoperative dialysis, sepsis, emergency status, and American Society of Anesthesiologists Physical Status Classification 4 or 5, and the association between risk strata and death in the validation sample was strong (φ = 0.29) and significant ( P < .001). Conclusions CFE is not as “benign” a procedure as previously believed. The risks of death and wound complications are not insignificant, and a high percentage of these complications occurred after patients were discharged from the hospital. Patients should be carefully selected, especially in the elderly population, and close postoperative follow-up should be considered.
English language citations reporting complications of arteriovenous access for hemodialysis are critically reviewed and discussed. Venous hypertension, arterial steal syndrome, and high-output ...cardiac failure occur as a result of hemodynamic alterations potentiated by access flow. Uremic and diabetic neuropathies are common but may obfuscate recognition of potentially correctable problems such as compression or ischemic neuropathy. Mechanical complications include pseudoaneurysm, which may develop from a puncture hematoma, degeneration of the wall, or infection. Dysfunctional hemostasis, hemorrhage, noninfectious fluid collections, and access-related infections are, in part, manifestations of the adverse effects of uremia on the function of circulating hematologic elements. Impaired erythropoiesis is successfully managed with hormonal stimulation; perhaps, similar therapies can be devised to reverse platelet and leukocyte dysfunction and reduce bleeding and infectious complications.
Objective Chronic nonhealing wounds are a major health problem for patients in the United States and worldwide. Diabetes and ischemia are two major risk factors behind impaired healing of chronic ...lower extremity wounds. Poly-ADP-ribose polymerase (PARP) is found to be overactivated with both ischemic and diabetic conditions. This study seeks a better understanding of the role of PARP in ischemic and diabetic wound healing, with a specific focus on angiogenesis and vasculogenesis. Methods Ischemic and diabetic wounds were created in FVB/NJ mice and an in vitro scratch wound model. PARP inhibitor PJ34 was delivered to the animals at 10 mg/kg/d through implanted osmotic pumps or added to the culture medium, respectively. Animal wound healing was assessed by daily digital photographs. Animal wound tissues, peripheral blood, and bone marrow cells were collected at different time points for further analysis with Western blot and flow cytometry. Scratch wound migration and invasion angiogenesis assays were performed using human umbilical vein endothelial cells (HUVECs). Measurements were reported as mean ± standard deviation. Continuous measurements were compared by t -test. P < .05 was considered statistically significant. Results A significant increase in PARP activity was observed under ischemic and diabetic conditions that correlated with delayed wound healing and slower HUVEC migration. The beneficial effect of PARP inhibition with PJ34 on ischemic and diabetic wound healing was observed in both animal and in vitro models. In the animal model, the percentage of wound healing was significantly enhanced from 43% ± 6% to 71% ± 9% ( P < .05) by day 7 with the addition of PJ34. PARP inhibition promoted angiogenesis at the ischemic and diabetic wound beds as evidenced by significantly higher levels of endothelial cell markers (vascular endothelial growth factor receptor 2 VEGFR2 and endothelial nitric oxide synthase) in mice treated with PJ34 compared with controls. Flow cytometry analysis of peripheral blood mononuclear cells showed that PARP inhibition increased mobilization of endothelial progenitor cells (VEGFR2+ /CD133+ and VEGFR2+ /CD34+ ) into the systemic circulation. Furthermore, under in vitro hyperglycemia and hypoxia conditions, PARP inhibition enhanced HUVEC migration and invasion in Boyden chamber assays by 80% and 180% ( P < .05), respectively. Conclusions Delayed healing in ischemic and diabetic wounds is caused by PARP hyperactivity, and PARP inhibition significantly enhanced ischemic and diabetic wound healing by promoting angiogenesis.
Objective As the first operational societal registry of carotid procedures, the Outcomes Committee of the Society for Vascular Surgery (SVS) developed the Vascular Registry (VR) in response to the ...Centers for Medicare and Medicaid Services' (CMS) National Coverage Decision on carotid artery stenting (CAS). Although CMS requires data submission only on CAS, the VR collects similar data on carotid endarterectomy (CEA) to allow comparison of outcomes, as well as potential for expansion to other procedures. Methods SVS-VR on-line provider-reported data include baseline through follow-up visits to better understand long-term risks and benefits associated with CAS and CEA. The primary outcomes are combined death, stroke, and myocardial infarction (MI). An independent data coordinating center maintains the database, which is Health Insurance Portability and Accountability Act (HIPAA)-compliant and auditable. Results As of December 26, 2007, 6403 procedures with discharge data were entered by 287 providers at 56 centers on 2763 CAS patients (1450 with 30-day outcomes, 52.5%) and 3259 CEA patients (1368 with 30-day outcomes, 42%). Of the total cohort, 98% of CEA and 70.7% of CAS ( P < .001) were performed for atherosclerotic disease. Restenosis accounted for 22.3% and post-radiation induced stenosis in 4.5% of CAS patients. Preprocedure lateralizing neurologic symptoms were present in a greater proportion of CAS patients (49.2%) than CEA patients (42.4%, P < .001). CAS patients also had higher preprocedure prevalence of coronary artery disease (CAD), MI, congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), and cardiac arrhythmia. For CAS, death/stroke/MI at 30 days was 7.13% for symptomatic patients and 4.60% for asymptomatic patients ( P = .04). For CEA, death/stroke/MI at 30 days was 3.75% in symptomatic patients and 1.97% in asymptomatic patients ( P = .05). After risk-adjustment for age, history of stroke, diabetes, and American Society of Anesthesiologists (ASA) grade (ie, factors found to be significant confounders in outcomes using backwards elimination), logistic regression analysis suggested better outcomes following CEA. There were no statistically significant differences when examining CAS outcomes based on center volume. CAS in atherosclerotic disease had significantly worse outcomes than in nonatherosclerotic stenosis. When CAS and CEA were compared in the treatment of atherosclerotic disease only, the difference in outcomes between the two procedures was more pronounced, with death/stroke/MI 6.42% after CAS vs 2.62% following CEA, P < .0001. Conclusion Following best possible risk adjustment of these unmatched groups, symptomatic and asymptomatic CAS patients had significantly higher 30-day postprocedure incidence of death/stroke/MI when compared with CEA patients. The initial 1.5 years of data collection provide proof of concept that a specialty society based VR can succeed in meeting regulatory and scientific goals. With continued enrollment and follow-up, analysis of SVS-VR will supplement randomized trials by providing real-world comparisons of CAS and CEA with sufficient numbers to serve as an outcome assessment tool of important patient subsets and across the spectrum of peripheral vascular procedures.
AbstractWe report the case of an 82-year-old patient with an infected abdominal aortic endograft who presented with a right psoas abscess and lumbar osteomyelitis. The psoas abscess was drained ...percutaneously. Fluid obtained grew Fusobacterium nucleatum. The patient, an active and highly functional individual, wished to pursue definitive management. The infected endograft was surgically removed, and the aorta was ligated above the renal arteries after staged axillary-bifemoral, hepatorenal, and splenorenal bypasses.
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