Factors associated with amputation or graft occlusion one year after lower extremity bypass in northern New England

Mortality and amputation outcomes of infrainguinal bypass versus endovascular therapy based on body mass index

OBJECTIVE

Obese patients have higher rates of cardiovascular disease and associated risk factors, but lower rates of peripheral artery disease and better outcomes after revascularization. This results in an obesity paradox, where obese patients have the lowest risk of adverse outcomes following treatment, while underweight and morbidly obese patients are at the highest risk. No previous studies have compared outcomes of endovascular vs open bypass within each body mass index (BMI) group. Our study aims to compare outcomes of peripheral vascular intervention (PVI) with infrainguinal bypass (IIB) stratified by patient BMI group.

METHODS

The Vascular Quality Initiative database was queried for patients presenting with claudication or chronic limb-threatening ischemia (CLTI) undergoing PVI or IIB (using the great saphenous vein) from 2012 to 2023. Patients were categorized into five BMI groups: underweight (BMI ≤ 18.5 kg/m2), normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), obese (BMI 30.0-39.9 kg/m2), and morbidly obese (BMI 40.0-49.9 kg/m2). Multivariable logistic compared 30-day mortality for IIB vs PVI within each BMI group. Cox regression, Kaplan-Meier survival analysis, and log-rank tests assessed 1-year mortality, 1-year amputation, and 1-year amputation/death rates. Subgroup analysis was performed by indication (CLTI or claudication).

RESULTS

There were 118,622 patients meeting the study criteria, including 3542 underweight (3%), 33,009 normal weight (28%), 40,582 overweight (34%), 36,494 obese (31%), and 4995 morbidly obese (4%) patients. There was no significant difference in 30-day mortality between PVI and IIB in underweight patients. IIB was associated with lower 30-day mortality in normal weight (adjusted odds ratio [aOR], 0.45; 95% confidence interval [CI], 0.33-0.62) and obese (aOR, 0.78; 95% CI, 0.24-0.75) patients. Bypass was associated with lower 1-year mortality in all BMI groups, except for morbidly obese patients. It was also associated with a lower risk of 1-year amputation for normal weight (aOR, 0.82; 95% CI, 0.70-0.96) and a lower risk of 1-year amputation/death for normal weight, overweight, and obese patients. Among CLTI patients, bypass was associated with decreased 30-day and 1-year mortality risks in all but underweight patients.

CONCLUSIONS

This study shows significant differences in 30-day and 1-year mortality, amputation, and amputation/death rates between PVI and IIB based on BMI depending on patient BMI. Bypass was associated with better outcomes for normal weight and obese patients, and for CLTI patients across most BMI groups. This finding suggests a long-term survival benefit after IIB compared with PVI, an effect potentiated by symptom severity, except for patients otherwise at a higher operative risk regardless of procedure choice.

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.

A Systematic Review and Meta-Analysis of Heparin-Bonded Expanded Polytetrafluoroethylene Grafts for Below-The-Knee Femoral Bypass Surgery

BACKGROUND

Heparin-bonded expanded polytetrafluoroethylene (hb-ePTFE) synthetic grafts are an alternative to autologous vein grafts (AVG) for surgical bypass interventions in lower limb peripheral arterial disease (LLPAD). However, the clinical benefits of hb-ePTFE grafts have not been reviewed systematically for patients undergoing below-the-knee (BK) surgical bypass. This study aimed to meta-analyze available data on the utility of hb-ePTFE in patients undergoing BK surgical bypass.

METHODS

Medline, Embase, and Cochrane databases were searched, restricted to material in English with no date restriction. In addition, proceedings from relevant congresses were screened going back 2 years. The search was performed in December 2021. Eligible studies included prospective or retrospective comparative studies or prospective single-arm cohorts with an hb-ePTFE arm. Methodological quality was assessed with the ROBINS-I criteria. Outcomes included primary patency, amputation/limb salvage, and overall survival. Clinical outcomes were expressed as event rates. Studies were compared using meta-analysis to generate a standardized mean event rate for each outcome, with its 95% confidence interval (95% CI), using a random-effects model.

RESULTS

Following deduplication, 10,263 records were identified and 261 were assessed as full texts. No prospective comparative studies were identified. The level of evidence was uniformly low. Seventeen publications describing data from 9 individual patient cohorts met the inclusion criteria. These cohorts included a total of 1,452 patients undergoing BK surgical bypass with hb-ePTFE. The primary patency rate was 78.9% [95% CI: 72.2-85.7%] at 1 year, 68.2% [95% CI: 62.8-73.6%] at 2 years, decreasing to 48.0% [95% CI: 27.3-68.7%] at 5 years. The secondary patency rate was 84.8% [95% CI: 77.0-92.5%] at 1 year and 68.9% [95% CI: 43.0-94.9%] at 3 years; the 1-year limb salvage rate was 88.3% [95% CI: 79.6-97.1%] at 1 year and 79.0% [95% CI: 56.7-100%] at 3 years.

CONCLUSIONS

In patients undergoing BK bypass surgery, hb-ePTFE synthetic grafts, compared to uncoated grafts, perform well for patency and limb salvage. However, the quality of the evidence is low, and well-performed randomized clinical trials are needed to inform clinical decision-making on the choice of synthetic graft.

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.

A Systematic Review and Meta-Analysis on Sex-Based Disparities in Patients with Chronic Limb Threatening Ischemia Undergoing Revascularization

BACKGROUND

This systematic review and meta-analysis sought to describe the prognostic implications of sex on the clinical outcomes of patients undergoing interventions for chronic limb threatening ischemia (CLTI).

METHODS

Studies were systematically searched across 7 databases from inception to August 25, 2021 and rerun on October 11, 2022. Studies focusing on patients with CLTI undergoing open surgery, endovascular treatment (EVT), or hybrid procedures were included if sex-based differences were associated with a clinical outcome. Two independent reviewers screened studies for inclusion, extracted data, and assessed risk of bias using the Newcastle-Ottawa scale. Primary outcomes included inpatient mortality, major adverse limb events (MALE), and amputation-free survival (AFS). Meta-analyses were performed using random effects models and reported pooled odds ratio (pOR) and 95% confidence interval (CI).

RESULTS

A total of 57 studies were included in the analysis. A meta-analysis of 6 studies demonstrated that female sex was associated with statistically higher inpatient mortality compared to male sex undergoing open surgery or EVT (pOR, 1.17; 95% CI: 1.11-1.23). Female sex also demonstrated a trend toward increased limb loss in those undergoing EVT (pOR, 1.15; 95% CI: 0.91-1.45) and open surgery (pOR 1.46; 95% CI: 0.84-2.55). Female sex also had a trend toward higher MALE (pOR, 1.06; 95% CI, 0.92-1.21) in 6 studies. Finally, female sex had a trend toward worse AFS (pOR, 0.85; 95% CI, 0.70-1.03) in 8 studies.

CONCLUSIONS

Female sex was significantly associated with higher inpatient mortality and a trend toward higher MALE following revascularization. Female sex trended toward worse AFS. The reasons for these disparities are likely multifaceted on patient, provider, and systemic levels and should be explored to identify solutions for decreasing these health inequities across this vulnerable patient population.

OUP accepted manuscript

Background

The relationship between anaesthetic technique and graft patency after open lower limb revascularization is unclear. The aim of this study was to evaluate the association between 30-day graft patency after elective infrainguinal bypass and anaesthetic technique (regional anaesthesia (RA, i.e. neuraxial and/or peripheral nerve blockade) compared with general anaesthesia (GA)).

Methods

Patients who underwent elective infrainguinal bypass in the 2014–2019 National Surgical Quality Improvement Program Vascular Procedure Targeted Lower Extremity Open data set were included. Excluded patients were those under 18 years old, those who did not receive RA or GA, and/or had an international normalized ratio of 1.5 of greater, a partial thromboplastin time more than 35 s, or a platelet count less than 80 × 10⁹/L. The primary outcome was primary graft patency without reintervention. The relationship between anaesthetic technique and patency was analysed with multivariable logistic regression.

Results

Included were 8893 patients with a mean(s.d.) age of 68(11) years and 31.5 per cent female. Within the cohort, 7.7 per cent (n = 688) patients received RA only, 90.4 per cent (n = 8039) GA only, and 1.9 per cent (n = 166) both GA and RA. In the RA-only group, 91.7 per cent (631 of 688) received neuraxial anaesthesia. The primary patency rate was 93.2 per cent (573 of 615) for RA only, and 91.5 per cent (6390 of 6983) for GA only (standardized mean difference, 0.063). RA was not associated with a higher rate of patency compared with GA (adjusted OR, 1.16; 95 per cent c.i., 0.83 to 1.63; P = 0.378).

Conclusion

There was no association between anaesthetic technique and 30-day graft patency after elective infrainguinal bypass surgery. Further prospective studies would be useful to study the impact of anaesthesia technique on important patient-centred outcomes such as long-term patency and non-home discharge.

Post-surgical wireless monitoring of arterial health progression

Early detection of limb ischemia, strokes, and heart attacks may be enabled via long-term monitoring of arterial health. Early stenosis, decreased blood flow, and clots are common after surgical vascular bypass or plaque removal from a diseased vessel and can lead to the above diseases. Continuous arterial monitoring for the early diagnosis of such complications is possible by implanting a sensor during surgery that is wirelessly monitored by patients after surgery. Here, we report the design of a wireless capacitive sensor wrapped around the artery during surgery for continuous post-operative monitoring of arterial health. The sensor responds to diverse artery sizes and extents of occlusion in vitro to at least 20 cm upstream and downstream of the sensor. It demonstrated strong capability to monitor progression of arterial occlusion in human cadaver and small animal models. This technology is promising for wireless monitoring of arterial health for pre-symptomatic disease detection and prevention.

Prognostic models for predicting the risk of foot ulcer or amputation in people with type 2 diabetes: a systematic review and external validation study

AIMS/HYPOTHESIS

Approximately 25% of people with type 2 diabetes experience a foot ulcer and their risk of amputation is 10-20 times higher than that of people without type 2 diabetes. Prognostic models can aid in targeted monitoring but an overview of their performance is lacking. This study aimed to systematically review prognostic models for the risk of foot ulcer or amputation and quantify their predictive performance in an independent cohort.

METHODS

A systematic review identified studies developing prognostic models for foot ulcer or amputation over minimal 1 year follow-up applicable to people with type 2 diabetes. After data extraction and risk of bias assessment (both in duplicate), selected models were externally validated in a prospective cohort with a 5 year follow-up in terms of discrimination (C statistics) and calibration (calibration plots).

RESULTS

We identified 21 studies with 34 models predicting polyneuropathy, foot ulcer or amputation. Eleven models were validated in 7624 participants, of whom 485 developed an ulcer and 70 underwent amputation. The models for foot ulcer showed C statistics (95% CI) ranging from 0.54 (0.54, 0.54) to 0.81 (0.75, 0.86) and models for amputation showed C statistics (95% CI) ranging from 0.63 (0.55, 0.71) to 0.86 (0.78, 0.94). Most models underestimated the ulcer or amputation risk in the highest risk quintiles. Three models performed well to predict a combined endpoint of amputation and foot ulcer (C statistics >0.75).

CONCLUSIONS/INTERPRETATION

Thirty-four prognostic models for the risk of foot ulcer or amputation were identified. Although the performance of the models varied considerably, three models performed well to predict foot ulcer or amputation and may be applicable to clinical practice.

Clinical outcomes of patients with and without chronic kidney disease undergoing endovascular revascularization of infrainguinal peripheral artery disease: Insights from the XLPAD registry

OBJECTIVES

The purpose of the present study was to define clinical outcomes of chronic kidney disease (CKD) patients undergoing endovascular revascularization of infrainguinal peripheral artery disease (PAD).

BACKGROUND

CKD is an established predictor of advanced PAD. However, clinical outcomes for these patients following endovascular revascularization remain inadequately defined.

METHODS

Using the ongoing multicenter Excellence in Peripheral Artery Disease (XLPAD) registry (NCT01904851), we analyzed all-cause death, target limb amputation, and need for repeat revascularization for patients with and without CKD undergoing infrainguinal endovascular revascularization between the years 2005 and 2018.

RESULTS

Of 3,699 patients, 15.1% (n = 559) had baseline CKD. CKD patients had significantly higher incidence of heavily calcified lesions (48.4% vs. 38.1%, p < .001) and diffuse disease (66.9% vs. 61.5%, p = .007). Kaplan-Meier analysis showed significant differences between CKD and non-CKD patient outcomes at 12 months for freedom from target limb amputation (79.9% vs. 92.7%, p < .001) and all-cause death (90.1% vs. 97.6%, p < .001). However, freedom from target vessel revascularization was similar between the groups. After adjusting for baseline comorbidities in the CKD and non-CKD groups, the hazard ratios for target limb amputation and death at 12 months were 2.28 (95% confidence interval or CI 1.25-4.17, p < .001) and 4.38 (95% CI 2.58-7.45, p < .001), respectively.

CONCLUSIONS

Following endovascular revascularization for infrainguinal PAD, CKD was an independent predictor of all-cause death and target limb amputation at 12 months.

A Review and Proposed Classification System for the No-Option Patient With Chronic Limb-Threatening Ischemia

A growing, but poorly defined subset of patients with chronic limb-threatening ischemia (CLTI) have "no option" for revascularization. One notable subgroup includes patients with severe ischemia and advanced pedal artery occlusive disease, termed "desert foot," who are at high risk for major amputation due to a lack of conventional revascularization options. Although new therapies are being developed for no-option patients with desert foot anatomy, this subgroup and the broader group of no-option patients are not well defined, limiting the ability to evaluate outcomes. Based on a systematic review, a classification of the no-option CLTI patient was constructed for use in clinical practice and studies. Several no-option conditions were identified, including type I-severe and pedal occlusive disease (desert foot anatomy) for which there is no accepted method of repair; type II-lack of suitable venous conduit for bypass in the setting of an acceptable target for bypass; type III-extensive tissue loss with exposure of vital structures that renders salvage impossible; type IV-advanced medical comorbidities for which available revascularization options would pose a prohibitive risk; and type V-presence of a nonfunctional limb. While type I and type II patients may have no option for revascularization, type III and type V patients have wounds, infection, comorbidities, or functional status that may leave them with few options for revascularization. As treatment strategies continue to evolve and novel methods of revascularization are developed, the ability to identify no-option patients in a standardized fashion will aid in treatment selection and assessment of outcomes.

The Role of Lower Extremity Amputation in Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia (CLTI) is a severe form of peripheral artery disease associated with high rates of limb loss. The primary goal of treatment in CLTI is limb salvage via revascularization. Multidisciplinary teams provide improved care for those with CLTI and lead to improved limb salvage rates. Not all patients are candidates for revascularization, and a subset will require major amputation. This article highlights the role of amputations in the management of CLTI, and describes the patients who should be offered primary amputation.

Clinical factors that influence the cellular responses of saphenous veins used for arterial bypass

OBJECTIVE

When an autogenous vein is harvested and used for arterial bypass, it suffers physical and biologic injuries that may set in motion the cellular processes that lead to wall thickening, fibrosis, stenosis, and ultimately graft failure. Whereas the injurious effects of surgical preparation of the vein conduit have been extensively studied, little is known about the influence of the clinical environment of the donor leg from which the vein is obtained.

METHODS

We studied the cellular responses of fresh saphenous vein samples obtained before implantation in 46 patients undergoing elective lower extremity bypass surgery. Using an ex vivo model of response to injury, we quantified the outgrowth of cells from explants of the adventitial and medial layers of the vein. We correlated this cellular outgrowth with the clinical characteristics of the patients, including the Wound, Ischemia, and foot Infection classification of the donor leg for ischemia, wounds, and infection as well as smoking and diabetes.

RESULTS

Cellular outgrowth was significantly faster and more robust from the adventitial layer than from the medial layer. The factors of leg ischemia (P < .001), smoking (P = .042), and leg infection (P = .045) were associated with impaired overall outgrowth from the adventitial tissue on multivariable analysis. Only ischemia (P = .046) was associated with impaired outgrowth of smooth muscle cells (SMCs) from the medial tissue. Co-culture of adventitial cells and SMCs propagated from vein explants revealed that adventitial cells significantly inhibited the growth of SMCs, whereas SMCs promoted the growth of adventitial cells. The AA genotype of the -838C>A p27 polymorphism (previously associated with superior graft patency) enhanced these effects, whereas the factor of smoking attenuated adventitial cell inhibition of SMC growth. Comparing gene expression, the cells cultured from the media overexpress Kyoto Encyclopedia of Genes and Genomes pathways associated with inflammation and infection, whereas those from the adventitia overexpress gene families associated with development and stem/progenitor cell maintenance.

CONCLUSIONS

The adverse clinical environment of the leg may influence the biologic behavior of the cells in the vein wall, especially the adventitial cells. Chronic ischemia was the most significant factor that retards adventitial cell outgrowth. The cells arising from the vein adventitia may be key players in determining a healthy adaptive or a pathologic response to the injuries associated with vein grafting.

Predictive factors for better bypass patency and limb salvage after prosthetic above-knee bypass reconstruction

BACKGROUND

Peripheral arterial disease (PAD) is one of the most underestimated diseases because of its high prevalence and unfavorable prognosis. Many PAD patients without suitable autologous veins or options for endovascular treatment receive prosthetic above-knee femoropopliteal bypass (PAKB). Until now predictors of prosthetic bypass failure and of increased amputation risk remain indistinct. This study aimed to identify predictive factors associated with better bypass patency and limb salvage to achieve a more favorable outcome after PAKB reconstruction.

METHODS

Pre-, intra-, and postoperative data of 244 PAKB procedures performed at a German university medical center were collected and analyzed using univariate and multivariate methods. To our knowledge this 12-year experience is the largest retrospective study to identify predictors for patency and limb salvage after PAKB reconstruction.

RESULTS

Of the PAD patients 94% (229/244) were followed for an average of 34.9 months. Patient cohorts characteristics were: mean age, 66.1 years, 181 men (74%), claudication (64%), rest pain (16%), ischemic lesions (20%), arterial hypertension (92%), smoking (79%), hyperlipidemia (65%) and type 2 diabetes (43%). Cumulative primary 1- and 3-year graft patency rates were 60.8% and 50.7%, respectively, and cumulative 1- and 3-year limb salvage rates were 89.3% and 86.1%, respectively. One hundred seven bypasses (43.9%) failed, 26 patients (10.7%) required a major and seven patients (2.9%) required a minor amputation. Overall survival rates of PAD patients after 1- and 3-years were 94.4% and 82.9%, respectively. Subjective symptom improvement was found to be the most important prognostic follow-up factor for graft patency and limb salvage. Patients with recurrent symptoms in the follow-up had an increased risk of emerging bypass failure compared with patients with subjective symptom improvement (patency at 1 year: 40.8% vs 100% and at 3 years: 26% vs 100%; P < .001). No patient with subjective improvement in symptoms during follow-up underwent an amputation (limb salvage at 1 year: 100% vs 79% and at 3 years: 100% vs 72.8%; P < .001). Therefore, subjective symptom improvement should be the decisive criterion to determine follow-up intervals of PAD patients. In univariate analysis further significant factors associated with better graft patency and limb salvage rates were: claudication compared with critical ischemia, larger graft diameter (>6 mm), pre- and postoperative antiplatelet therapy, statin therapy independent from lipid values after PAKB revascularization, and an experienced vascular surgeon.

CONCLUSIONS

In our study, we determined the subjective improvement in symptoms as the most important prognostic factor for bypass function and limb salvage after PAKB. Furthermore, disease stage of critical ischemia, graft diameter, preoperative aspirin use, and postoperative statin medication were independent predictive factors. Therefore, PAD patients should be treated with aspirin pre- and postoperatively as well as with a statin postoperatively. In case of PAKB reconstruction only prostheses with a large diameter (>6 mm) should be used and the procedure should be performed by an experienced surgeon. Considering these results with regard to the predictive factors for better graft patency and limb salvage rates a significant more favorable outcome during the follow-up and an increased 5-year patency rate for PAKB reconstructions can be expected.

Impact of Chronic Renal Failure on Safety and Effectiveness of Paclitaxel-Eluting Stents for Femoropopliteal Artery Disease: Subgroup Analysis from Zilver PTX Post-Market Surveillance Study in Japan

Purpose

Favorable long-term outcomes of the Zilver PTX drug-eluting stent (DES) in femoropopliteal lesions have been demonstrated. Chronic renal failure (CRF) has been shown to be a risk factor for restenosis and decreased limb salvage. The results of the DES in patients with CRF have not previously been reported. This study compares the results with the DES in patients with CRF and those without CRF.

Methods

This retrospective analysis from the Zilver PTX Japan Post-Market Surveillance Study included 321 patients with CRF and 584 patients without CRF. Outcomes included freedom from target lesion revascularization (TLR) and patency.

Results

Of the patients included in this subgroup analysis, 2-year data were available for 209 patients in the CRF group and 453 patients in the non-CRF group. The two groups were similar in terms of lesion length and the frequency of in-stent restenosis. Critical limb ischemia, severe calcification, and diabetes were more common in patients with CRF, whereas total occlusion was more common in patients without CRF. Freedom from TLR rates were 81.4 versus 84.9% (p = 0.24), and patency rates were 70.7 versus 70.3% (p = 0.95) in patients with and without CRF at 2 years, respectively.

Conclusion

This is the first comparative study of the DES in femoropopliteal artery lesions in patients with and without CRF. These results indicate that the DES placed in femoropopliteal artery lesions of CRF patients is safe and effective with similar patency and TLR rates to patients without CRF.

Level of Evidence

Level 3, Post-Market Surveillance Study.

Validation of the Risk Score of the Mortality and Lower Limb Loss Considering Ambulatory Status after Surgical Revascularization in Maintaining Patients with Dialysis

Surgical revascularization is performed to preserve limb and to maintain functional status of patients with critical limb ischemia (CLI). The PREVENT III risk score helps to predict the postoperative course of CLI. However, this score is not available to estimate the risk of amputation or death properly in patients with hemodialysis (HD) and tissue loss (HD: 4 points, Tissue loss: 3 points), because they are classified as a high-risk group. Therefore, we investigated 213 patients with revascularized HD for CLI and proposed prognosis amputation or death for patients with HD risk score (PAD for HD risk score). PAD for HD risk score (non-ambulation: 3 points, ulcer/gangrene: 2 points, GNRI<92: 2 points, CRP>0.3 mg/dl: 1 point, Age≥75: 1 point) is more accurate for the prediction of amputation or death than the PREVENT III risk score (area under the curve [AUC]: 0.79 [95% confidence interval: CI: 0.71-0.87], p<0.01 vs. AUC: 0.63 [95%CI: 0.56-0.71]). The patients were stratified into three groups by total score in ascending order. The rate of 1-year amputation-free survival and independent ambulatory status were significantly different among three groups. PAD for HD risk score is useful for rehabilitation planning in patients with HD and CLI. (This is a translation of J Jpn Coll Angiol 2016; 56: 85-91.).

Not All Patients with Critical Limb Ischaemia Require Revascularisation

OBJECTIVES

International guidelines recommend revascularisation as the preferred treatment for patients with critical limb ischaemia (CLI). Most contemporary research focuses on the outcome of invasive procedures for CLI, but little is known about the outcome of conservative management. Amputation free survival (AFS) and overall survival (OS) was investigated in patients with CLI who did or did not receive revascularisation, and characteristics associated with clinical outcomes were explored.

METHODS

This was a retrospective cohort study of consecutive patients with chronic CLI between 2010 and 2014 in a Dutch university hospital. CLI was defined as the presence of ischaemic rest pain or tissue loss in conjunction with an absolute systolic ankle pressure < 50 mmHg or a toe pressure < 30 mmHg. Patients were divided into invasive (revascularisation within 6 weeks), deferred invasive (revascularisation after 6 weeks), or permanently conservative treatment groups. Univariable and multivariable survival analyses were used to identify factors associated with AFS and OS.

RESULTS

The majority (66.7%; N = 96) of the identified 144 patients with CLI (mean age 71.2 years; median follow-up 99 weeks) underwent revascularisation within 6 weeks of diagnosis. Deferred invasive treatment was provided in 18.1% (N = 26) patients and 22 patients (15.3%) were treated permanently conservatively. AFS and OS did not differ significantly between the three groups (Breslow-Wilcoxon p = .16 for AFS and p = .09 for OS). Age, chronic obstructive pulmonary disease (COPD), and heart disease were significant independent predictors of AFS. Age, COPD, and hypertension were significant independent predictors of OS. Treatment was not a significant predictor of either AFS or OS.

CONCLUSIONS

Not all patients with CLI require revascularisation to achieve an AFS that is similar to patients undergoing revascularisation, although the efficacy of conservative versus invasive treatment in CLI patients is still unclear. Further prospective studies should determine subgroups of patients in whom revascularisation may be omitted.

Predictors of major amputation despite patent bypass grafts

OBJECTIVE

Despite patent vein bypass grafts, some patients with critical limb ischemia (CLI) receive major amputations. We analyzed the predictive factors leading to major amputation in the presence of patent lower extremity bypass (LEB) grafts.

METHODS

Data from the Project of Ex-Vivo vein graft Engineering via Transfection III (PREVENT III), a large prospective randomized trial of 1404 patients who underwent LEB with vein graft for CLI, were queried for outcomes. The primary outcome was major amputation with patent (PMA) LEB compared with patients with patent LEB who achieved limb salvage (PLS). The population excluded those who received amputation for occluded grafts. A Cox proportional hazard model identified independent predictors.

RESULTS

Of 1404 LEB patients, 162 (11.5%) had major amputation: 89 (6.3%) with patent and 73 (5.2%) with occluded LEB. For PMA, 21 of 89 (23.6%) developed critical stenosis and 11 of 21 (52.4%) were revised. For PLS, 460 of 1242 (37.0%) developed critical stenosis and 351 of 460 (76.3%) were revised. Predictive patient factors included having preoperative gangrene (vs rest pain; hazard ratio [HR], 3.504; 95% confidence interval [CI], 1.533-8.007; P = .0029), diabetes (HR, 1.800; 95% CI, 1.006-3.219; P = .0477), black (vs white) race (HR, 1.779; 95% CI, 1.051-3.011; P = .0321), baseline creatinine clearance <25 mL/min (vs >65 mL/min; HR, 1.759; 95% CI, 1.016-3.048; P = .0439), prior history of coronary artery bypass grafting (HR, 1.702; 95% CI, 1.080-2.683; P = .0221), and lower baseline activity quality of life score (HR, 1.401; 95% CI, 1.105-1.778; P = .0054). Postoperative wound factors included gangrenous changes (HR, 5.830; 95% CI, 1.647-20.635; P = .0063), surgical wound necrosis (HR, 5.319; 95% CI, 1.478-19.146; P = .0105), deep (vs superficial) wound infection (HR, 3.815; 95% CI, 1.220-11.927; P = .0213), and wound healing abnormally (HR, 3.754; 95% CI, 1.061-13.278; P = .0402). Associated postoperative consequences leading to PMA included having recurrent CLI symptoms (HR, 2.915; 95% CI, 1.816-4.681; P < .0001), a severe (vs mild) adverse event (HR, 2.751; 95% CI, 1.391-5.443; P = .0036), fewer percutaneous revisions (HR, 2.425; 95% CI, 1.573-3.740; P < .0001), discharge on low-molecular-weight heparin (HR, 2.087; 95% CI, 1.309-3.326; P = .0020), and decreasing days to critical stenosis/occlusion/revision/amputation (HR, 1.010; 95% CI, 1.007-1.012; P < .0001).

CONCLUSIONS

Whereas a patent vein graft is important to all vascular surgeons, additional factors should be considered in trying to attain limb salvage for patients with CLI. These factors include intervening surgically before CLI has progressed to a state of gangrene or limited activity and optimizing nutrition, diabetes control, cardiac conditions, and activity level. Revision offers hope for clinical improvement but may be delayed when there is no graft lesion identified. The absence of a graft lesion to revise may also portend amputation despite a patent graft because of nongraft-related factors such as infection. Finally, the experience of a severe (vs mild) adverse event may also result in limb loss despite a patent graft. Systematic efforts to reduce severe adverse events among patients may also lead to increased limb salvage.

Functional Imaging of the Foot with Perfusion Angiography in Critical Limb Ischemia

Purpose

To report on the first clinical experience with perfusion angiography (PA) of the foot in patients with chronic critical limb ischemia.

Materials and Methods

PA is a post-processing software algorithm and no extra digital subtraction angiography (DSA) has to be performed for this analysis. The data used to test the feasibility of PA were obtained from a consecutive group of 89 patients with CLI who were treated with standard below the knee angioplasty and 12 separate patients who were not suitable for endovascular revascularization.

Results

Motion artifacts in the dataset of the DSA made post-procedural analysis impossible in 10 % intervention. In the majority of patients (59/68) PA showed an increase in volume flow in the foot after successful angioplasty of the crural vessels. However, in 9/68 patients no increase was seen after successful angioplasty. With the use of a local administered competitive α-adrenergic receptor antagonist, it is also possible to test and quantify the capillary resistance index which is a parameter for the remaining functionality of the microcirculation in CLI patients.

Conclusion

PA might be used as a new endpoint for lower limb revascularization and can also be used to test the functionality the microcirculation to identify sub-types of patients with CLI. Clinical evaluation and standardization of PA is mandatory before introduction in daily practice.

Outcomes of lower extremity revascularization among the hemodialysis-dependent

OBJECTIVE

Optimal patient selection for lower extremity revascularization remains a clinical challenge among the hemodialysis-dependent (HD). The purpose of this study was to examine contemporary real world open and endovascular outcomes of HD patients to better facilitate patient selection for intervention.

METHODS

A regional multicenter registry was queried between 2003 and 2013 for HD patients (N = 689) undergoing open surgical bypass (n = 295) or endovascular intervention (n = 394) for lower extremity revascularization. Patient demographics and comorbidities were recorded. The primary outcome was overall survival. Secondary outcomes included graft patency, freedom from major adverse limb events, and amputation-free survival (AFS). Multivariate analysis was performed to identify independent risk factors for death and amputation.

RESULTS

Among the 689 HD patients undergoing lower extremity revascularization, 66% were male, and 83% were white. Ninety percent of revascularizations were performed for critical limb ischemia and 8% for claudication. Overall survival at 1, 2, and 5 years survival remained low at 60%, 43%, and 21%, respectively. Overall 1- and 2-year AFS was 40% and 17%. Mortality accounted for the primary mode of failure for both open bypass (78%) and endovascular interventions (80%) at two years. Survival, AFS, and freedom from major adverse limb event outcomes did not differ significantly between revascularization techniques. At 2 years, endovascular patency was higher than open bypass (76% vs 26%; 95% confidence interval [CI], 0.28-0.71; P = .02). Multivariate analysis identified age ≥80 years (hazard ratio [HR], 1.9; 95% CI, 1.4-2.5; P < .01), indication of rest pain or tissue loss (HR, 1.8; 95% CI, 1.3-2.6; P < .01), preoperative wheelchair/bedridden status (HR, 1.5; 95% CI, 1.1-2.1; P < .01), coronary artery disease (HR, 1.5; 95% CI, 1.2-1.9; P < .01), and chronic obstructive pulmonary disease (HR, 1.4; 95% CI, 1.1-1.8; P = .01) as independent predictors of death. The presence of three or more risk factors resulted in predicted 1-year mortality of 64%.

CONCLUSIONS

Overall survival and AFS among HD patients remains poor, irrespective of revascularization strategy. Mortality remains the primary driver for these findings and justifies a prudent approach to patient selection. Focus for improved results should emphasize predictors of survival to better identify those most likely to benefit from revascularization.

Clinical registries and quality measurement in surgery: a systematic review

BACKGROUND

Surgical clinical registries provide clinical information with the intent of measuring and improving quality. This study aimed to describe how surgical clinical registries have been used to measure surgical quality, the reported findings, and the limitations of registry measurements.

METHODS

Medline, CINAHL, and Cochrane were queried for English articles with the terms: "registry AND surgery AND quality." Eligibility criteria were studies explicitly assessing quality measurement with registries as the primary data source. Studies were abstracted to identify registries, define registry structure, uses for quality measurement, and limitations of the measurements used.

RESULTS

A total of 111 studies of 18 registries were identified for data abstraction. Two registries were financed privately, and 5 registries were financed by a governmental organization. Across registries, the most common uses of process measures were for monitoring providers and as platforms for quality improvement initiatives. The most common uses of outcome measures were to improve quality modeling and to identify preoperative risk factors for poor outcomes. Eight studies noted improvements in risk-adjusted mortality with registry participation; one found no change. A major limitation is bias from context and means of data collection threatening internal validity of registry quality measurement. Conversely, the other major limitation is the cost of participation, which threatens the external validity of registry quality measurement.

CONCLUSION

Clinical registries have advanced surgical quality definition, measurement, and modeling as well as having served as platforms for local initiatives for quality improvement. The implication of this finding is that subsidizing registry participation may improve data validity as well as engage providers in quality improvement.

Surveillance and follow-up after revascularization for critical limb ischemia

The purpose of a structured and cost-effective surveillance program after surgical or endovascular intervention for critical limb ischemia is to optimize limb salvage and preserve arterial repair function. Surveillance programs should include clinical, vascular laboratory, and radiographic follow-up, and, when a high-grade progressive stenosis is identified, appropriately timed intervention should be performed. Because many patients with critical limb ischemia are older and many are frail with limited mobility, optimizing the durability of arterial intervention and keeping these patients ambulatory is an important factor in retaining an independent lifestyle and quality of life. Despite the importance of surveillance after arterial intervention, there is a lack of consensus in the literature regarding the efficacy of surveillance, how it should be performed, and well-defined evidence-based guidelines. This review provides an up-to-date scrutiny on this topic and provides recommendations for optimal testing methods, limitations of surveillance testing, and when and how to intervene. These recommendations should be considered in the care of the patient with critical limb ischemia, but with the understanding that patients vary widely and care should be individualized.

Endovascular therapy is effective treatment for focal stenoses in failing infrapopliteal vein grafts

BACKGROUND

To evaluate the efficacy of endovascular therapy for maintaining patency and preserving limbs among patients with failing infrapopliteal bypass grafts.

METHODS

We gathered data from a registry of catheter-based procedures for peripheral artery disease. Of 1554 arteriograms performed from 2006 to 2012, 30 patients had interventions for failing bypass vein grafts to infrapopliteal target vessels. The first intervention for each patient was used in this analysis. Duplex ultrasonography was used within 30 days after intervention and subsequently at 3- to 6-month intervals for graft surveillance.

RESULTS

Interventions were performed for duplex ultrasonography surveillance findings in 21 patients and for symptoms of persistent or recurrent critical limb ischemia in 9 patients. Procedural techniques included cutting balloon angioplasty (83%), conventional balloon angioplasty (7%), and stent placement (10%). Procedural success was achieved in all cases. There were no procedure-related complications, amputations, or deaths within 30 days. By Kaplan-Meier analysis, 37% of the patients were free from graft restenosis at 12 months and 31% were at 24 months. Receiver-operating characteristic analysis indicated that a lesion length of 1.75 cm best predicted freedom from restenosis (C statistic: 0.74). Residual stenosis (P = 0.03), patency without reintervention (P = 0.01), and assisted patency with secondary intervention (P = 0.02) rates were superior for short lesions compared with long lesions. The cohort had acceptable rates of adverse clinical outcomes, with 96% of patients free from amputation at both 12 and 24 months; clinical outcomes were also better in patients with short lesions.

CONCLUSIONS

In this single-center experience with endovascular therapies to treat failing infrapopliteal bypass grafts, rates of limb preservation were high, but the majority of patients developed graft restenosis within 12 months. Grafts with longer stenoses fared poorly by comparison. These data suggest that endovascular interventions to restore or prolong graft patency may be associated with maintained graft patency and that close follow-up with vascular laboratory surveillance is essential.

Defining utility and predicting outcome of cadaveric lower extremity bypass grafts in patients with critical limb ischemia

OBJECTIVE

Despite poor long-term patency, acceptable limb salvage has been reported with cryopreserved saphenous vein bypass (CVB) for various indications. However, utility of CVB in patients with critical limb ischemia (CLI) remains undefined. The purpose of this analysis was to determine the role of CVB in CLI patients and to identify predictors of successful outcomes.

METHODS

A retrospective review of all lower extremity bypass (LEB) procedures at a single institution was completed, and CVB in CLI patients were further analyzed. The primary end point was amputation-free survival. Secondary end points included primary patency and limb salvage. Life tables were used to estimate occurrence of end points. Cox regression analysis was used to determine predictors of limb salvage.

RESULTS

From 2000 to 2012, 1059 patients underwent LEB for various indications, of whom 81 received CVB for either ischemic rest pain or tissue loss. Mean age (± standard deviation) was 66 ± 10 years (male, 51%; diabetes, 51%; hemodialysis dependence, 12%), and 73% (n = 59) had history of failed ipsilateral LEB or endovascular intervention. None had sufficient autogenous conduit for even composite vein bypass. Infrainguinal CVB (infrapopliteal target, 96%; n = 78) was completed for multiple indications including Rutherford class 4 (42%; n = 34), class 5 (40%; n = 32), and class 6 (18%; n = 15). Eleven (14%) had CLI and concomitant graft infection (n = 8) or acute on chronic ischemia (n = 3). Intraoperative adjuncts (eg, profundaplasty, suprainguinal stent or bypass) were completed in 49% (n = 40) of cases. Complications occurred in 36% (n = 29), with 30-day mortality of 4% (n = 3). Median follow-up for CLI patients was 11.8 (interquartile range, 0.4-28.4) months with corresponding 1- and 3-year actuarial estimated survival (± standard error mean) of 84% ± 4% and 62% ± 6%. Primary patency of CVB for CLI was 27% ± 6% and 17% ± 6% at 1 and 3 years, respectively. Amputation-free survival was 43% ± 6% and 23% ± 6% at 1 and 3 years, respectively, and significantly higher for rest pain (59% ± 9%, 36% ± 10%) compared with tissue loss (31% ± 7%, 14% ± 7%; log-rank, P = .04). Freedom from major amputation after CVB for CLI was 57% ± 6% and 43% ± 7% at 1 and 3 years. Multivariable predictors of limb salvage for the CVB CLI cohort included postoperative warfarin (hazard ratio [HR], 0.4; 95% confidence interval [CI], 0.2-0.8), dyslipidemia (HR, 0.4; 95% CI, 0.2-0.9), and rest pain (HR, 0.4; 95% CI, 0.2-0.9). Predictors of major amputation included graft infection (HR, 3.1; 95% CI, 1.1-9.0).

CONCLUSIONS

In CLI patients with no autologous conduit and prior failed infrainguinal bypass, CVB outcomes are disappointing. CVB performs best in patients with rest pain, particularly those who can be anticoagulated with warfarin. However, it may be an acceptable option in patients with minor tissue loss or concurrent graft infection, but consideration should be weighed against the known natural history of nonrevascularized CLI and nonbiologic conduit alternatives, given potential cost implications.

Relationship between regional spending on vascular care and amputation rate

IMPORTANCE

Although lower extremity revascularization is effective in preventing amputation, the relationship between spending on vascular care and regional amputation rates remains unclear.

OBJECTIVE

To test the hypothesis that higher regional spending on vascular care is associated with lower amputation rates for patients with severe peripheral arterial disease.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of 18,463 US Medicare patients who underwent a major peripheral arterial disease-related amputation during the period between 2003 and 2010.

EXPOSURE

Price-adjusted Medicare spending on revascularization procedures and related vascular care in the year before lower extremity amputation, across hospital referral regions.

MAIN OUTCOMES AND MEASURES

Correlation coefficient between regional spending on vascular care and regional rates of peripheral arterial disease-related amputation.

RESULTS

Among patients who ultimately underwent an amputation, 64% were admitted to the hospital in the year prior to the amputation for revascularization, wound-related care, or both; 36% were admitted only for their amputation. The mean cost of inpatient care in the year before amputation, including costs related to the amputation procedure itself, was $22,405, but it varied from $11,077 (Bismarck, North Dakota) to $42,613 (Salinas, California) (P < .001). Patients in high-spending regions were more likely to undergo vascular procedures as determined by crude analyses (12.0 procedures per 10,000 patients in the lowest quintile of spending and 20.4 procedures per 10,000 patients in the highest quintile of spending; P < .001) and by risk-adjusted analyses (adjusted odds ratio for receiving a vascular procedure in highest quintile of spending, 3.5 [95% CI, 3.2-3.8]; P < .001). Although revascularization was associated with higher spending (R = 0.38, P < .001), higher spending was not associated with lower regional amputation rates (R = 0.10, P = .06). The regions that were most aggressive in the use of endovascular interventions were the regions that were most likely to have high spending (R = 0.42, P = .002) and high amputation rates (R = 0.40, P = .004).

CONCLUSIONS AND RELEVANCE

Regions that spend the most on vascular care perform the most procedures, especially endovascular interventions, in the year before amputation. However, there is little evidence that higher regional spending is associated with lower amputation rates. This suggests an opportunity to limit costs in vascular care without compromising quality.

Peripheral arterial testing before lower extremity amputation among Medicare beneficiaries, 2000 to 2010

BACKGROUND

Despite mild reductions in rates of lower extremity amputation over the past decade, few data exist on the use of arterial testing in patients before amputation.

METHODS AND RESULTS

Using Medicare claims from 2000 through 2010, we examined rates of preamputation arterial testing between 0 to 12 and 0 to 24 months before amputation. We used multivariable, modified Poisson regression models to identify patient and clinical predictors of preamputation arterial testing. The main outcome measures were rates of preamputation arterial testing. Among 17 463 patients undergoing nontraumatic amputation, 68.4% underwent some type of arterial testing. Of these patients, 47.5% underwent ankle-brachial index measurement, 38.7% duplex ultrasound, 31.1% invasive angiography, 6.7% computed tomographic angiography, and 5.6% magnetic resonance angiography. Temporal analysis revealed an increase in testing from 65.7% in 2002 to 69.2% in 2010 (P<0.001). The use of preamputation arterial testing varied significantly by location of amputation and was lowest for foot amputation (62.5%), followed by above-knee amputation (69.0%) and below-knee amputation (76.7%; P<0.001). After multivariable adjustment, older age, male sex, black race, renal disease, diabetes mellitus, known peripheral arterial disease, evaluation by a vascular specialist, and living in the East North Central region were associated with greater rates of preamputation arterial testing.

CONCLUSIONS

Rates of evaluation for peripheral arterial disease before amputation were low, and testing varied by patient, provider, and regional characteristics.

Growing impact of restenosis on the surgical treatment of peripheral arterial disease

Background

Patients with peripheral arterial disease often experience treatment failure from restenosis at the site of a prior peripheral endovascular intervention (PVI) or lower extremity bypass (LEB). The impact of these treatment failures on the utilization and outcomes of secondary interventions is poorly understood.

Methods and Results

In our regional vascular quality improvement collaborative, we compared 2350 patients undergoing primary infrainguinal LEB with 1154 patients undergoing secondary infrainguinal LEB (LEB performed after previous revascularization in the index limb) between 2003 and 2011. The proportion of patients undergoing secondary LEB increased by 72% during the study period (22% of all LEBs in 2003 to 38% in 2011, P<0.001). In‐hospital outcomes, such as myocardial infarction, death, and amputation, were similar between primary and secondary LEB groups. However, in both crude and propensity‐weighted analyses, secondary LEB was associated with significantly inferior 1‐year outcomes, including major adverse limb event‐free survival (composite of death, new bypass graft, surgical bypass graft revision, thrombectomy/thrombolysis, or above‐ankle amputation; Secondary LEB MALE‐free survival = 61.6% vs primary LEB MALE‐free survival = 67.5%, P=0.002) and reintervention or amputation‐free survival (composite of death, reintervention, or above‐ankle amputation; Secondary LEB RAO‐free survival = 58.9% vs Primary LEB RAO‐free survival 64.1%, P=0.003). Inferior outcomes for secondary LEB were observed regardless of the prior failed treatment type (PVI or LEB).

Conclusions

In an era of increasing utilization of PVI, a growing proportion of patients undergo LEB in the setting of a prior failed PVI or surgical bypass. When caring for patients with peripheral arterial disease, physicians should recognize that first treatment failure (PVI or LEB) affects the success of subsequent revascularizations.

Endovascular-first approach is not associated with worse amputation-free survival in appropriately selected patients with critical limb ischemia

OBJECTIVE

Endovascular interventions for critical limb ischemia are associated with inferior limb salvage (LS) rates in most randomized trials and large series. This study examined the long-term outcomes of selective use of endovascular-first (endo-first) and open-first strategies in 302 patients from March 2007 to December 2010.

METHODS

Endo-first was selected if (1) the patient had short (5-cm to 7-cm occlusions or stenoses in crural vessels); (2) the disease in the superficial femoral artery was limited to TransAtlantic Inter-Society Consensus II A, B, or C; and (3) no impending limb loss. Endo-first was performed in 187 (62%), open-first in 105 (35%), and 10 (3%) had hybrid procedures.

RESULTS

The endo-first group was older, with more diabetes and tissue loss. Bypass was used more to infrapopliteal targets (70% vs 50%, P = .031). The 5-year mortality was similar (open, 48%; endo, 42%; P = .107). Secondary procedures (endo or open) were more common after open-first (open, 71 of 105 [68%] vs endo, 102 of 187 [55%]; P = .029). Compared with open-first, the 5-year LS rate for endo-first was 85% vs 83% (P = .586), and amputation-free survival (AFS) was 45% vs 50% (P = .785). Predictors of death were age >75 years (hazard ratio [HR], 3.3; 95% confidence interval [CI], 1.7-6.6; P = .0007), end-stage renal disease (ESRD) (HR, 3.4; 95% CI, 2.1-5.6; P < .0001), and prior stroke (HR, 1.6; 95% CI, 1.03-2.3; P = .036). Predictors of limb loss were ESRD (HR, 2.5; 95% CI, 1.2-5.4; P = .015) and below-the-knee intervention (P = .041). Predictors of worse AFS were older age (HR, 2.03; 95% CI, 1.13-3.7; P = .018), ESRD (HR, 3.2; 95% CI, 2.1-5.11; P < .0001), prior stroke (P = .0054), and gangrene (P = .024).

CONCLUSIONS

At 5 years, endo-first and open-first revascularization strategies had equivalent LS rates and AFS in patients with critical limb ischemia when properly selected. A patient-centered approach with close surveillance improves long-term outcomes for both open and endo approaches.

Regional intensity of vascular care and lower extremity amputation rates

OBJECTIVE

Because patient-level differences do not fully explain the variation in lower extremity amputation rates across the United States, we hypothesized that variation in intensity of vascular care may also affect regional rates of amputation and examined the relationship between the intensity of vascular care and the population-based rate of major lower extremity amputation (above-knee or below-knee) from vascular disease.

METHODS

Intensity of vascular care was defined as the proportion of Medicare patients who underwent any vascular procedure in the year before amputation, calculated at the regional level (2003 to 2006), using the 306 hospital referral regions in the Dartmouth Atlas of Healthcare. The relationship between intensity of vascular care and major amputation rate, at the regional level, was examined between 2007 and 2009.

RESULTS

Amputation rates varied widely by region, from one to 27 per 10,000 Medicare patients. Compared with regions in the lowest quintile of amputation rate, patients in the highest quintile were commonly African American (50% vs 13%) and diabetic (38% vs 31%). Intensity of vascular care also varied across regions: <35% of patients underwent revascularization in the lowest quintile of intensity, whereas nearly 60% underwent revascularization in the highest quintile. Overall, an inverse correlation was found between intensity of vascular care and the amputation rate, ranging from R = -0.36 for outpatient diagnostic and therapeutic procedures to R = -0.87 for inpatient surgical revascularizations. Analyses adjusting for patient characteristics and socioeconomic status found patients in high-intensity vascular care regions were significantly less likely to undergo amputation without an antecedent attempt at revascularization (odds ratio, 0.37; 95% confidence interval, 0.34-0.37; P < .001).

CONCLUSIONS

The intensity of vascular care provided to patients at risk for amputation varies, and regions with the most intensive vascular care have the lowest amputation rate, although the observational nature of these associations do not impart causality. High-risk patients, especially African American diabetic patients residing in low-intensity vascular care regions, represent an important target for systematic efforts to reduce amputation risk.

Aspirin usage is associated with improved prosthetic infrainguinal bypass graft patency

The American Heart Association recommends that, unless contraindicated, all patients undergoing surgical revascularization for critical limb ischemia should be placed postoperatively on antiplatelet therapy and remain on it indefinitely. The goal of this study was to evaluate if preoperative use of aspirin was associated with improved bypass grafting patency rates and limb salvage. We performed a four-year, retrospective review of one center's experience with open infra-inguinal bypass. We examined the effect pre- and postoperative usage of antiatherosclerotic agents (i.e. aspirin, statin, etc.) have on graft outcomes such as two-year secondary patency, stenosis and limb salvage via univariate Kaplan–Meir survival curve analysis and multiple regression analysis. Our cohort included 165 bypasses in individuals with multiple co-morbidities. The most frequent indication was critical limb ischemia (79%) and most bypasses crossed the knee (63%). Pre- and postoperative aspirin usage was associated with increased two-year secondary prosthetic graft patency over control (preoperative: 78% versus 44%, P < 0.002 and postoperative: 72% versus 50%, P < 0.01). Preoperative aspirin usage was associated with an improvement in the rate of amputation (odds ratio [OR] = 0.44 [95% CI 0.198–0.997]) and stenosis (OR = 0.45 [95% CI 0.217–0.956]). Medications commonly prescribed for atherosclerosis such as aspirin are associated with a significant patency benefit when administered pre- and postoperatively. In a population undergoing infrainguinal bypass with prosthetic graft for predominantly critical limb ischemia, medical optimization should include both pre- and postoperative antiatherosclerotic drug regimens.

Using risk models to improve patient selection for high-risk vascular surgery

Vascular surgeons frequently perform procedures aimed at limiting death, stroke, or amputation on patients who present with diseases such as aortic aneurysms, carotid atherosclerosis, and peripheral arterial occlusive disease. However, now more than ever surgeons must balance the potential benefits associated with these interventions with the risks of physiologic insult for these elderly patients, who often have significant comorbidity burdens and the potential for costly complications. In this paper, we highlight how regional and national datasets can help surgeons identify which patients are most likely to benefit from vascular operations and which patients are most likely to suffer complications in the postoperative period. By using these guidelines to improve patient selection, our risk models can help patients, physicians, and policymakers improve the clinical effectiveness of surgical and endovascular treatments for vascular disease.

Surveillance after distal revascularization for critical limb ischaemia

Patients with critical limb ischaemia (CLI) are usually elderly and suffer from several co-morbidities. The goal of surveillance after both endovascular and surgical revascularization for CLI is not only the protection of re-established distal perfusion and sustained ambulation but also the reduction of systemic atherothrombotic risk and mortality by ensuring continued best medical care. However, preferred format and rhythm of structured follow-up programs have remained controversial, mainly because of lack of compelling evidence. This review aims to summarize and to appraise available information critically. Thereby, it underlines the importance of systematic surveillance after both surgical and endovascular revascularization for CLI. Recent European guidelines are considered and areas of uncertainty are highlighted and discussed. According to currently available literature and recent guidelines, the early duplex scan is justified in all patients undergoing endovascular or surgical distal revascularization for CLI. There is no best level evidence supporting continued long term duplex surveillance of revascularizations with normal findings at early duplex scan, whereas those patients with abnormal early duplex scan or high risk revacularization are likely to benefit from continued duplex surveillance. Regular clinical follow-up is suggested and clinical deterioration should trigger duplex scanning to ensure revascularization patency.

Prior contralateral amputation predicts worse outcomes for lower extremity bypasses performed in the intact limb

INTRODUCTION

To date, history of a contralateral amputation as a potential predictor of outcomes after lower extremity bypass (LEB) for critical limb ischemia (CLI) has not been studied. We sought to determine if a prior contralateral lower extremity amputation predicts worse outcomes in patients undergoing LEB in the remaining intact limb.

METHODS

A retrospective analysis of all patients undergoing infrainguinal LEB for CLI between 2003 and 2010 within hospitals comprising the Vascular Study Group of New England was performed. Patients were stratified according to whether or not they had previously undergone a contralateral major or minor amputation before LEB. Primary end points included major amputation and graft occlusion at 1 year postoperatively. Secondary end points included in-hospital major adverse events, discharge status, and mortality at 1 year.

RESULTS

Of 2636 LEB procedures, 228 (8.6%) were performed in the setting of a prior contralateral amputation. Patients with a prior amputation compared to those without were younger (66.5 vs 68.7; P = .034), more like to have congestive heart failure (CHF; 25% vs 16%; P = .002), hypertension (94% vs 85%; P = .015), renal insufficiency (26% vs 14%; P = .0002), and hemodialysis-dependent renal failure (14% vs 6%; P = .0002). They were also more likely to be nursing home residents (8.0% vs 3.6%; P = .036), less likely to ambulate without assistance (41% vs 80%; P < .0002), and more likely to have had a prior ipsilateral bypass (20% vs 12%; P = .0005). These patients experience increased in-hospital major adverse events, including myocardial infarction (MI; 8.9% vs 4.2%; P = .002), CHF (6.1% vs 3.4%; P = .044), deterioration in renal function (9.0% vs 4.7%; P = .006), and respiratory complications (4.2% vs 2.3%; P = .034). They were less likely to be discharged home (52% vs 72%; P < .0001) and less likely to be ambulatory on discharge (25% vs 55%; P < .0001). Although patients with a prior contralateral amputation experienced increased rates of graft occlusion (38% vs 17%; P < .0001) and major amputation (16% vs 7%; P < .0001) at 1 year, there was not a significant difference in mortality (16% vs 10%; P = .160). On multivariable analysis, prior contralateral amputation was an independent predictor of both major amputation (odds ratio, 1.73; confidence interval, 1.06-2.83; P = .027) and graft occlusion (odds ratio, 1.93; confidence interval, 1.39-2.68; P < .0001) at 1 year.

CONCLUSIONS

Patients with prior contralateral amputations who present with CLI in the intact limb represent a high-risk population, even among patients with advanced peripheral arterial disease. When considering LEB in this setting, both physicians and patients should expect increased rates of perioperative adverse events, increased rates of 1-year graft occlusion, and decreased rates of limb salvage, when compared with patients who have not undergone a contralateral amputation.

Chapter VI: Follow-up after revascularisation

Structured follow-up after revascularisation for chronic critical limb ischaemia (CLI) aims at sustained treatment success and continued best patient care. Thereby, efforts need to address three fundamental domains: (A) best medical therapy, both to protect the arterial reconstruction locally and to reduce atherosclerotic burden systemically; (B) surveillance of the arterial reconstruction; and (C) timely initiation of repeat interventions. As most CLI patients are elderly and frail, sustained resolution of CLI and preserved ambulatory capacity may decide over independent living and overall prognosis. Despite this importance, previous guidelines have largely ignored follow-up after CLI; arguably because of a striking lack of evidence and because of a widespread assumption that, in the context of CLI, efficacy of initial revascularisation will determine prognosis during the short remaining life expectancy. This chapter of the current CLI guidelines aims to challenge this disposition and to recommend evidentially best clinical practice by critically appraising available evidence in all of the above domains, including antiplatelet and antithrombotic therapy, clinical surveillance, use of duplex ultrasound, and indications for and preferred type of repeat interventions for failing and failed reconstructions. However, as corresponding studies are rarely performed among CLI patients specifically, evidence has to be consulted that derives from expanded patient populations. Therefore, most recommendations are based on extrapolations or subgroup analyses, which leads to an almost systematic degradation of their strength. Endovascular reconstruction and surgical bypass are considered separately, as are specific contexts such as diabetes or renal failure; and critical issues are highlighted throughout to inform future studies.

Variation in the use of lower extremity vascular procedures for critical limb ischemia

BACKGROUND

Many believe that variation in vascular practice may affect limb salvage rates in patients with severe peripheral arterial disease. However, the extent of variation in procedural vascular care obtained by patients with critical limb ischemia (CLI) remains unknown.

METHODS AND RESULTS

By using Medicare 2003 to 2006 data, we identified all patients with CLI who underwent major lower extremity amputation in the 306 hospital referral regions described in the Dartmouth Atlas of Healthcare. For each patient, we studied the use of lower extremity vascular procedures (open surgery or endovascular intervention) in the year before amputation. Our main outcome measure was the intensity of vascular care, defined as the proportion of patients in the hospital referral region undergoing a vascular procedure in the year before amputation. Overall, 20,464 patients with CLI underwent major lower extremity amputations during the study period, and collectively underwent 25,800 vascular procedures in the year before undergoing amputation. However, these procedures were not distributed evenly: 54% of patients had no vascular procedures performed in the year before amputation, 14% underwent 1 vascular procedure, and 32% underwent >1 vascular procedure. In the regions in the lowest quintile of vascular intensity, vascular procedures were performed in 32% of patients. Conversely, in the regions in the highest quintile of vascular intensity, revascularization was performed in 58% of patients in the year before amputation (P<0.0001). In analyses accounting for differences in age, sex, race, and comorbidities, patients in high-intensity regions were 2.4 times as likely to undergo revascularization in the year before amputation than patients in low-intensity regions (adjusted odds ratio, 2.4; 95% CI, 2.1-2.6; P<0.001).

CONCLUSIONS

Significant variation exists in the intensity of vascular care provided to patients in the year before major amputation. In some regions, patients receive intensive care, whereas in other regions, far less vascular care is provided. Future work is needed to determine the association between intensity of vascular care and limb salvage.

Validation of the Society for Vascular Surgery's objective performance goals for critical limb ischemia in everyday vascular surgery practice

BACKGROUND

To develop standardized metrics for expected outcomes in lower extremity revascularization for critical limb ischemia (CLI), the Society for Vascular Surgery (SVS) has developed objective performance goals (OPGs) based on aggregate data from randomized trials of lower extremity bypass (LEB). It remains unknown, however, if these targets can be achieved in everyday vascular surgery practice.

METHODS

We applied SVS OPG criteria to 1039 patients undergoing 1039 LEB operations for CLI with autogenous vein (excluding patients on dialysis) within the Vascular Study Group of New England (VSGNE). Each of the individual OPGs was calculated within the VSGNE dataset, along with its surrounding 95% confidence intervals (CIs) and compared to published SVS OPGs using χ(2) comparisons and survival analysis.

RESULTS

Across most risk strata, patients in the VSGNE and SVS OPG cohorts were similar (clinical high-risk [age >80 years and tissue loss]: 15.3% VSGNE; 16.2% SVS OPG; P = .58; anatomic high risk [infrapopliteal target artery]: 57.8% VSGNE; 60.2% SVS OPG; P = .32). However, the proportion of VSGNE patients designated as conduit high-risk (lack of single-segment great saphenous vein) was lower (10.2% VSGNE; 26.9% SVS OPG;P < .001). The primary safety endpoint, major adverse limb events (MALE) at 30 days, was lower in the VSGNE cohort (3.2%; 95% CI, 2.3-4.6) than the SVS OPG cohort (6.2%; 95% CI, 4.2-8.1; P = .05). The primary efficacy OPG endpoint, freedom from any MALE or postoperative death within the first year (MALE + postoperative death [POD]), was similar between VSGNE and SVS OPG cohorts (77%; 95% CI, 74%-80%) SVS OPG, 74% (95% CI, 71%-77%) VSGNE, P = .58). In the remaining safety and efficacy OPGs, the VSGNE cohort met or exceeded the benchmarks established by the SVS OPG cohort.

CONCLUSION

Community and academic centers in everyday vascular surgery practice can meet OPGs derived from centers of excellence in LEB. Quality improvement initiatives, as well as clinical trials, should incorporate OPGs in their outcome measures to facilitate communication and comparison of risk-adjusted outcomes in the treatment of CLI.