Factors Associated with Amputation after Peripheral Vascular Intervention for Intermittent Claudication

Outcomes and predictors of amputation-free survival in patients undergoing below-knee popliteal-distal bypass

OBJECTIVE

The infrageniculate popliteal artery is a potential source for inflow in lower extremity bypass surgery in patients with isolated tibial artery disease. The objective of our study was to assess the short- and long-term outcomes of popliteal-distal bypasses using data from the Vascular Quality Initiative (VQI).

METHODS

The VQI registry was queried between 2003 and 2021 for patients undergoing surgical revascularizations with the below-knee popliteal artery serving as inflow. Demographics, comorbidities, intraoperative characteristics, and postoperative complications were analyzed. Kaplan-Meier models were used to estimate amputation-free survival, survival, and freedom from amputation. Cox regression analysis was conducted to determine factors associated with major amputation or death.

RESULTS

A total of 1884 procedures were analyzed. The mean age of the included patients was 67.7 years. The most frequently observed preoperative comorbidities included insulin-dependent diabetes (52.3%), coronary disease (32.4%), and end-stage renal disease (14.4%). Of all the patients, 670 (35.6%) had a history of ipsilateral endovascular intervention. The procedures were performed for a variety of indications, including tissue loss (84.3%), rest pain (10.9%), and claudication (4.8%). Intraoperatively, the outflow targets were the dorsalis pedis (31.4%), the posterior tibial (24.4%), and the anterior tibial arteries (15.6%). Vein conduit was used in 92.1% of cases. The rate of perioperative myocardial infarction (MI) was 2.4%, and the 30-day mortality was 1.9%. The median length of follow up was 371 days. Amputation-free survival was found to be 85.6% (95% confidence interval [CI], 84.0%-87.2%) at 6 months and 78.6% (95% CI, 76.6%-80.4%) at 12 months. Survival was found to be 93.4% (95% CI, 92.2%-94.5%) at 6 months and 88.6% (95% CI, 87.1%-90.0%) at 12 months. Freedom from amputation was found to be 92.0% (95% CI, 90.7%-93.3%) at 6 months and 89.0% (95% CI, 87.3%-90.4%) at 12 months. Cox regression analysis demonstrated that age greater than 65 years, congestive heart failure, coronary artery disease, and end-stage renal disease were associated with a higher risk of major amputation or death (P < .05).

CONCLUSIONS

Below-knee popliteal-distal bypass is a safe and effective approach to treat severe tibial vessel occlusive disease in this challenging patient cohort. Patients exhibited low perioperative complication rates and good amputation-free survival at 1 year.

The Double Burden: Deciphering Chronic Limb-Threatening Ischemia in End-Stage Renal Disease

BACKGROUND

Chronic limb-threatening ischemia (CLTI) in patients with end-stage renal disease (ESRD) poses significant challenges in clinical management due to its unique pathology and poor treatment outcomes. This review calls for a tailored classification and risk assessment for these patients to guide better revascularization choices with early minor amputation as a first-line strategy in advanced stages.

METHODS

This review consolidates key findings from recent literature on CLTI in ESRD, focusing on disease mechanisms, treatment options, and patient outcomes. It evaluates the literature to clarify the decision-making process for managing CLTI in ESRD.

RESULTS

CLTI in ESRD patients often results in worse clinical outcomes, such as nonhealing wounds, increased limb loss, and higher mortality rates. While the literature reveals ongoing debates regarding the optimal revascularization method, recent retrospective studies and meta-analyses suggest potential benefits of endovascular treatment (EVT) over open bypass surgery (OB) in reducing mortality and wound complications, with comparable amputation-free survival rates.

CONCLUSIONS

The selection of revascularization methods in ESRD patients with CLTI is complex, necessitating individualized strategies. The importance of early detection and timely intervention is critical to decelerate disease progression and improve revascularization outcomes. There is a shift in these treatment strategies toward less invasive endovascular procedures, acknowledging the limitations these patients face with open revascularization surgeries. Considering early minor amputations after revascularization could prevent worse consequences, reflecting a shift in the approach to managing CLTI in ESRD patients.

Treatment Location Variation for Chronic Limb-Threatening Ischemia in Patients With Kidney Failure

INTRODUCTION

End-stage kidney disease (ESKD) is an established risk factor for chronic limb-threatening ischemia (CLTI). Procedural location for ESKD patients has not been well described. This study aims to examine variation in index procedural location in ESKD versus non-ESKD patients undergoing peripheral vascular intervention for CLTI and identify preoperative risk factors for tibial interventions.

METHODS

Chronic limb-threatening ischemia (CLTI) patients were identified in the Vascular Quality Initiative (VQI) peripheral vascular intervention dataset. Patient demographics and comorbidities were compared between patients with and without ESKD and those undergoing index tibial versus nontibial interventions. A multivariable logistic regression evaluating risk factors for tibial intervention was conducted.

RESULTS

A total of 23,480 procedures were performed on CLTI patients with 13.6% (n = 3154) with ESKD. End-stage kidney disease (ESKD) patients were younger (66.56 ± 11.68 versus 71.66 ± 12.09 y old, P = 0.019), more often Black (40.6 versus 18.6%, P < 0.001), male (61.2 versus 56.5%, P < 0.001), and diabetic (81.8 versus 60.0%, P < 0.001) than non-ESKD patients. Patients undergoing index tibial interventions had higher rates of ESKD (19.4 versus 10.6%, P < 0.001) and diabetes (73.4 versus 57.5%, P < 0.001) and lower rates of smoking (49.9 versus 73.0%, P < 0.001) than patients with nontibial interventions. ESKD (odds ratio (OR) 1.67, 95% confidence interval (CI) 1.52-1.86, P < 0.001), Black race (OR 1.19, 95% CI 1.09-1.30, P < 0.001), and diabetes (OR 1.82, 95% CI 1.71-2.00, P < 0.001) were risk factors for tibial intervention.

CONCLUSIONS

Patients with ESKD and CLTI have higher rates of diabetes and tibial disease and lower rates of smoking than non-ESKD patients. Tibial disease was associated with ESKD, diabetes, and Black race.

Revascularization for claudication: Changing the natural history of a benign disease!

OBJECTIVE

The benign natural history of intermittent claudication was first documented in 1960 and has been reconfirmed in several subsequent studies. Excellent outcomes in patients with intermittent claudication can be achieved with exercise therapy and optimal medical management. Professional society guidelines have clearly stated that revascularization procedures should be performed only in patients with incapacitating claudication who have failed conservative therapy. Despite these guidelines, revascularization procedures, primarily percutaneous interventions, have been increasingly utilized in patients with claudication. Many of these patients are not even offered an attempt at medical therapy, and those who are often do not undergo a full course of treatment. Many studies document significant reintervention rates following revascularization, which are associated with increased rates of acute and chronic limb ischemia that may result in significant rates of amputation. The objectives of this study were to compare outcomes of conservative therapy to those seen in patients undergoing revascularization procedures and to determine the impact of revascularization on the natural history of claudication.

METHODS

Google Scholar and PubMed were searched for manuscripts on the conservative management of claudication and for those reporting outcomes following revascularization for claudication.

RESULTS

Despite early improvement in claudication symptoms following revascularization, multiple studies have demonstrated that long-term outcomes following revascularization are often no better than those obtained with conservative therapy. High reintervention rates (up to 43% for tibial atherectomies) result in high rates of both acute and chronic limb ischemia as compared with those patients undergoing medical therapy. In addition, amputation rates as high as 11% on long-term follow-up are seen in patients undergoing early revascularization. These patients also have a higher incidence of adverse cardiovascular events such as myocardial infarctions compared with patients treated medically.

CONCLUSIONS

Revascularization procedures negatively impact the natural history of claudication often resulting in multiple interventions, an increase in the incidence of acute and chronic limb ischemia, and an increased risk of amputation. Accordingly, informed consent requires that all patients undergoing early revascularization must be appraised of the potential negative impact of revascularization on the natural history of claudication.

Investigation of center-specific saphenous vein utilization rates in femoral popliteal artery bypass and associated impact of conduit on outcomes

OBJECTIVE

The purpose of this study is to investigate variation in great saphenous vein (GSV) use among the various centers participating in the Vascular Quality Initiative infrainguinal bypass modules. Further, differences in outcomes in femoral-popliteal artery bypass with single segment GSV conduit vs prosthetic conduit will be documented. Center GSV use rate impact on outcomes will be investigated.

METHODS

Primary exclusions were patients undergoing redo bypass, urgent or emergent bypass, and those in whom prosthetic graft was used while having undergone prior coronary artery bypass grafting. The distribution of GSV use across the 260 centers participating in Vascular Quality Initiative infrainguinal bypass module was placed into histogram and variance in mean GSV use evaluated with analysis of variance analysis. Centers that used GSV in >50% of bypasses were categorized as high use centers and centers that used the GSV in <30% of cases were categorized as low use centers. Baseline differences in patient characteristics and comorbidities in those undergoing bypass with GSV vs prosthetic conduit were analyzed with χ2 testing and the Student t test, as were those undergoing treatment in high vs low use centers. Multivariable time-dependent Cox regression analyses were then performed for the primary outcomes of major amputation ipsilateral to the operative side and mortality in long-term follow-up. High vs low use center was a dichotomous variable in these regressions. Secondary outcomes of freedom from graft infection and freedom from loss of primary patency were performed with Kaplan-Meier analysis.

RESULTS

Among centers with >50 patients meeting inclusion criteria for this study, GSV use ranged from 15% to 93% (analysis of variance P < .001). When considering all centers irrespective of number of patients, the range was 0% to 100%. On Kaplan-Meier analysis, GSV conduit use was associated with improved freedom from loss of primary or primary assisted patency, improved freedom from major amputation after index hospitalization, improved freedom from graft infection after the index hospitalization, and improved freedom from mortality in long-term follow-up (log-rank P < .001 for all four outcomes). Both low use center (hazard ratio, 1.35; P < .001) and prosthetic graft use (hazard ratio, 1.24; P < .001) achieved multivariable significance as risks for mortality in long-term follow-up. Other variables with a multivariable mortality association are presented in the manuscript. Low use center and prosthetic bypass were significant univariable but not multivariable risks for major amputation after index hospitalization.

CONCLUSIONS

There is remarkably wide variation in GSV use for femoral popliteal artery bypass among various medical centers. GSV use is associated with enhanced long-term survival as well as freedom from loss of bypass patency and graft infection. The data herein indicate institutional patterns of prosthetic conduit choice, which has the potential to be altered to enhance outcomes.

Phantom limb syndrome: Assessment of psychiatric and medical comorbidities associated with Phantom pain in 44,028 below knee amputees

INTRODUCTION

Phantom limb syndrome is a debilitating complication after extremity amputation that poses significant challenges to recovery. This study aims to examine the relationship between phantom limb syndrome and mental and physical comorbidities, including a comparison between phantom limb pain and phantom limb syndrome without pain in below knee amputees.

METHODS

This is a retrospective cohort study of patients who underwent below knee amputation of the lower extremity in the PearlDiver database, as identified using CPT codes. Analysis was carried out to evaluate the absence or presence of phantom limb syndrome. Matched bivariate analysis accounting for age, sex, Charlson Comorbidity Index score, and region was used to assess whether the presence of pain in phantom limb syndrome patients was associated with increased comorbidity.

RESULTS

In total, 44,028 patients with below knee amputation were examined: 95% (42,493 patients) did not develop phantom limb syndrome while 4.8% (1,535 patients) of patients did develop phantom limb syndrome. Phantom limb syndrome was significantly associated with increased odds of coexistent major depressive disorder (OR = 1.86, p <0.0001), generalized anxiety disorder (OR = 2.14, p = 0.04), posttraumatic stress disorder (OR = 1.7, p <0.0001), suicidal ideation (OR = 1.62, p <0.0001), obesity (OR = 1.28, p = 0.0007), osteoarthritis (OR = 1.53, p <0.0001), osteoporosis (OR = 1.64, p <0.0001), and low back pain (OR = 2.31, p <0.0001). Analysis of patient cohorts of phantom limb syndrome with pain and those without pain did not reveal a statistically significant relationship between the presence of pain and any dependent variable.

CONCLUSIONS

This investigation of over 44,000 patients with below knee amputation revealed that patients with phantom limb syndrome exhibit significantly higher rate of psychiatric comorbidities compared to those without documented phantom limb pain. Suicidal ideation, major depressive disorder, generalized anxiety disorder, and post-traumatic stress disorder were especially common, and consequently a multi-disciplinary approach to management is essential.

Cardiovascular and Limb Events Following Endovascular Revascularization Among Patients ≥65 Years Old: An American College of Cardiology PVI Registry Analysis

Background We aimed to characterize the occurrence of major adverse cardiovascular and limb events (MACE and MALE) among patients with peripheral artery disease (PAD) undergoing peripheral vascular intervention (PVI), as well as associated factors in patients with chronic limb threatening ischemia (CLTI). Methods and Results Patients undergoing PVI in the American College of Cardiology's (ACC) National Cardiovascular Data Registry's PVI Registry who could be linked to Centers for Medicare and Medicaid Services data were included. The primary outcomes were MACE, MALE, and readmission within 1 month and 1 year following index CLTI-PVI or non-CLTI-PVI. Cox proportional hazards regression was used to identify factors associated with the development of the primary outcomes among patients undergoing CLTI-PVI. There were 1758 (49.7%) patients undergoing CLTI-PVI and 1779 (50.3%) undergoing non-CLTI-PVI. By 1 year, MACE occurred in 29.5% of patients with CLTI (n=519), and MALE occurred in 34.0% of patients with CLTI (n=598). By 1 year, MACE occurred in 8.2% of patients with non-CLTI (n=146), and MALE occurred in 26.1% of patients with non-CLTI (n=465). Predictors of MACE at 1 year in CLTI-PVI included end-stage renal disease on hemodialysis, congestive heart failure, prior CABG, and severe lung disease. Predictors of MALE at 1 year in CLTI-PVI included treatment of a prior bypass graft, profunda femoral artery treatment, end-stage renal disease on hemodialysis, and treatment of a previously treated lesion. Conclusions Patients ≥65 years old undergoing PVI experience high rates of MACE and MALE. A range of modifiable and non-modifiable patient factors, procedural characteristics, and medications are associated with the occurrence of MACE and MALE following CLTI-PVI.

Progress in aorta and peripheral cardiovascular disease research

Although coronavirus disease 2019 seems to be the leading topic in research number of outstanding studies have been published in the field of aorta and peripheral vascular diseases likely affecting our clinical practice in the near future. This review article highlights key research on vascular diseases published in 2020. Some studies have shed light in the pathophysiology of aortic aneurysm and dissection suggesting a potential role for kinase inhibitors as new therapeutic options. A first proteogenomic study on fibromuscular dysplasia (FMD) revealed a promising novel disease gene and provided proof-of-concept for a protein/lipid-based FMD blood test. The role of NADPH oxidases in vascular physiology, and particularly endothelial cell differentiation, is highlighted with potential for cell therapy development. Imaging of vulnerable plaque has been an intense field of research. Features of plaque vulnerability on magnetic resonance imaging as an under-recognized cause of stroke are discussed. Major clinical trials on lower extremity peripheral artery disease have shown added benefit of dual antithrombotic (aspirin plus rivaroxaban) treatment.

Advances in Revascularization for Peripheral Artery Disease: Revascularization in PAD

Effective revascularization of the patient with peripheral artery disease is about more than the procedure. The approach to the patient with symptom-limiting intermittent claudication or limb-threatening ischemia begins with understanding the population at risk and variation in clinical presentation. The urgency of revascularization varies significantly by presentation; from patients with intermittent claudication who should undergo structured exercise rehabilitation before revascularization (if needed) to those with acute limb ischemia, a medical emergency, who require revascularization within hours. Recent years have seen the rapid development of new tools including wires, catheters, drug-eluting technology, specialized balloons, and biomimetic stents. Open surgical bypass remains an important option for those with advanced disease. The strategy and techniques employed vary by clinical presentation, lesion location, and lesion severity. There is limited level 1 evidence to guide practice, but factors that determine technical success and anatomic durability are largely understood and incorporated into decision-making. Following revascularization, medical therapy to reduce adverse limb outcomes and a surveillance plan should be put in place. There are many hurdles to overcome to improve the efficacy of lower extremity revascularization, such as restenosis, calcification, microvascular disease, silent embolization, and tools for perfusion assessment. This review highlights the current state of revascularization in peripheral artery disease with an eye toward technologies at the cusp, which may significantly impact current practice.

Spatial inequalities of major lower limb amputation rates in Paraná state, Brazil

OBJECTIVE

The aim of this observational cross-sectional study was to analyse the spatial distribution of major lower limb amputation (MLLA) rates and associate them to socioeconomic, demographic and public healthcare access-related variables in the State of Paraná, Brazil, from 2012 to 2017.

METHOD

Data on MLLA, revascularisation surgeries, diagnostic exams and healthcare coverage were obtained from the Brazilian Public Hospital Information System. Socioeconomic data were obtained from the Brazilian Institute of Geography and Statistics. Spatial autocorrelation of the MLLA rates was tested using Moran's I method. Multivariate spatial regression models using ordinary least squares regression (OLS) and geographically weighted regression (GWR) were used to identify the variables significantly correlated with MLLA.

RESULTS

A total of 5270 MLLA were included in the analysis. Mean MLLA rates were 24.32 (±18.22)/100 000 inhabitants, showing a positive global spatial autocorrelation (Moran's I=0.66; p<0.001). Queen contiguity matrix demonstrates that MLLA rates ranged from 7.6 to 46.6/100 000 with five large clusters of high MLLA rates. OLS showed that four of the nine studied variables presented significant spatial correlation with MLLA rates. Colour Doppler ultrasound showed a negative association (p<0.001), while revascularisation surgeries and illiteracy showed a positive correlation (p<0.01). GWR presented the best model (adjusted R²=0.77) showing that the predictors differentially affect the MLLA rates geographically.

CONCLUSION

The high MLLA rates in some regions of the state are influenced by the high rate of illiteracy and low utilisation rate of colour Doppler, indicating a social problem and difficulty in accessing health. On the other hand, the high rates of revascularisation surgeries are related to higher MLLA rates, possibly due to delayed access to specialised hospitals. This indicates that attention must be given to population access to public healthcare in the State of Paraná in order to ensure proper and timely medical attention.

Multiple Reinterventions for Claudication are Associated with Progression to Chronic Limb-Threatening Ischemia

BACKGROUND

Claudication has a relatively benign natural history, associated with a low risk of limb loss. However, rates of progression to chronic limb-threatening ischemia (CLTI) following lower extremity revascularization (LER) for claudication remain unclear. This study examines the long-term outcomes and risk factors associated with progression to CLTI after LER for claudication.

METHODS

A single-center retrospective review of patients undergoing LER for claudication was performed from 2013-2016. Patients were stratified based on whether they progressed to CLTI or not.

RESULTS

There were 448 patients (502 limbs) treated for claudication, and 57 (12.7%) progressed to CLTI with a mean follow up time of 3.7 ± 1.5 years. Among patients who progressed, 23 (5.1%) developed tissue loss, 34 (7.6%) developed rest pain, and 6 (1.2%) underwent major amputation. The mean time of progression to CLTI was 1.6 ± 1.5 years after index LER. Patients who progressed to CLTI were more likely to have a history of congestive heart failure and prior open revascularizations compared with those who did not progress. There was no difference in type or level of index revascularization between the two groups and no difference in perioperative complications. Patients who developed CLTI had significantly higher rates of reinterventions and a mean number of reinterventions after index LER prior to developing CLTI compared to those who did not progress. Multivariable logistic regression demonstrated that history of congestive heart failure (OR = 2.8 [1.2-6.6]), stroke (OR = 2.6 [1.1-6.1]), prior open procedure (OR = 2.8 [1.3-5.9]) and increasing number of reinterventions after index LER (OR = 2.9 [1.5-5.7]) were independently associated with disease progression to CLTI.

CONCLUSIONS

Multiple reinterventions and previous open revascularization are associated with progression to CLTI following LER for claudication. Patients with atherosclerosis in the coronary and cerebrovascular beds are also more likely to have a progression of claudication to CLTI after LER.