Cost-effectiveness analysis of routine computed tomography angiography (CTA) for lower extremity penetrating trauma.

BACKGROUND: Routine evaluation with CTA for patients with isolated lower extremity penetrating trauma and normal ankle-brachial-indices (ABI) remains controversial. While prior literature has found normal ABI's (≥0.9) and a normal clinical examination to be adequate for safe discharge, there remains concern for missed injuries which could lead to delayed surgical intervention and unnecessary morbidity. Our hypothesis was that routine CTA after isolated lower extremity penetrating trauma with normal ABIs and clinical examination is not cost-effective. METHODS: We performed a decision-analytic model to evaluate the cost-effectiveness of obtaining a CTA routinely compared to clinical observation and ABI evaluation in hemodynamically normal patients with isolated penetrating lower extremity trauma. Our base case was a patient that sustained penetrating lower extremity trauma with normal ABIs that received a CTA in the trauma bay. Costs, probability, and Quality-Adjusted Life Years (QALYs) were generated from published literature. RESULTS: Clinical evaluation only (no CTA) was cost-effective with a cost of $2056.13 and 0.98 QALYs gained compared to routine CTA which had increased costs of $7449.91 and lower QALYs 0.92. Using one-way sensitivity analysis, routine CTA does not become the cost-effective strategy until the cost of a missed injury reaches $210,075.83. CONCLUSIONS: Patients with isolated, penetrating lower extremity trauma with normal ABIs and clinical examination do not warrant routine CTA as there is no benefit with increased costs.

Longitudinal assessment of health-related quality of life and clinical outcomes with at home advanced pneumatic compression treatment of lower extremity lymphedema.

OBJECTIVE: This prospective, longitudinal, pragmatic study describes at home treatment with a proprietary advanced pneumatic compression device (APCD) for patients with lower extremity lymphedema (LED). METHODS: Following institutiona review board approval, four participating Veterans Affairs centers enrolled LED patients from 2016 to 2022. The primary outcome measures were health-related quality of life (HR-QoL) questionnaires (lymphedema quality of life-leg and the generic SF-36v2) obtained at baseline and 12, 24, and 52 weeks. The secondary outcome measures were limb circumference, cellulitis events, skin quality, and compliance with APCD and other compression therapies. RESULTS: Because a portion of the trial was conducted during the coronavirus disease 2019 pandemic, 179 patients had 52 weeks of follow-up, and 143 had complete measurements at all time points. The baseline characteristics were a mean age of 66.9 ± 10.8 years, 91% were men, and the mean body mass index was 33.8 ± 6.9 kg/m2. LED was bilateral in 92.2% of the patients. Chronic venous insufficiency or phlebolymphedema was the most common etiology of LED (112 patients; 62.6%), followed by trauma or surgery (20 patients; 11.2%). Cancer treatment as a cause was low (4 patients; 2.3%). Patients were classified as having International Society for Lymphology (ISL) stage I (68.4%), II (27.6%), or III (4.1%). Of the primary outcome measures, significant improvements were observed in all lymphedema quality of life-leg domains of function, appearance, symptoms, and emotion and the overall score after 12 weeks of treatment (P < .0001) and through 52 weeks of follow-up. The SF-36v2 demonstrated significant improvement in three domains at 12 weeks and in the six domains of physical function, bodily pain, physical component (P < .0001), social functioning (P = .0181), role-physical (P < .0005), and mental health (P < .0334) at 52 weeks. An SF-36v2 score <40 indicates a substantial reduction in HR-QoL in LED patients compared with U.S. norms. Regarding the secondary outcome measures at 52 weeks, compared with baseline, the mean limb girth decreased by 1.4 cm (P < .0001). The maximal reduction in mean limb girth was 1.9 cm (6.0%) at 12 weeks in ISL stage II and III limbs. New episodes of cellulitis in patients with previous episodes (21.4% vs 6.1%, P = .001) were reduced. The 75% of patients with skin hyperpigmentation at baseline decreased to 40% (P < .01) at 52 weeks. At 52 weeks, compliance, defined as use for 5 to 7 days per week, was reported for the APCD by 72% and for elastic stockings by 74%. CONCLUSIONS: This longitudinal study of Veterans Affairs patients with LED demonstrated improved generic and disease-specific HR-QoL through 52 weeks with at home use of an APCD. Limb girth, cellulitis episodes, and skin discoloration were reduced, with excellent compliance.

Prosthetic outcomes after amputation and the impact of mobility level on survival.

OBJECTIVE: Lower extremity amputation continues to be necessary in a significant number of patients with peripheral vascular disease. The 5-year survival following lower limb loss is markedly reduced. Many of these patients are never fitted with a prosthesis, and there is a dearth of knowledge regarding the barriers to prosthetic attainment. The goal of this study was to identify the risk factors for not receiving a prosthesis and the effect of mobility level on survival following major amputation. METHODS: This was a retrospective analysis of all patients that underwent lower extremity amputation by surgeons in our practice from January 1, 2010, to December 31, 2019. Abstracted data included: age, sex, race, body mass index, comorbidities, American Society of Anesthesiologists score, statin use, level of amputation, stump revision, fitting for prosthesis, type of prosthesis, and the United States' Medicare Functional Classification Level, also called K level. Survival was determined using a combination of sources, including the Social Security Death Master File, searches of multiple genealogic registries, and general internet searches. Multivariable logistic regression was used to determine risk factors associated with prosthesis attainment. Multivariable Cox proportional hazard regression with time-dependent covariates was performed to assess risk factors associated with 5-year mortality. RESULTS: A total of 464 patients were included in this study. The mean age was 65 years, and mean body mass index was 27 kg/m2. The majority of patients were male (68%), White (56%), diabetic (62%), and hypertensive (76%), and underwent below-the-knee amputation (69%). Prosthetic attainment occurred in 185 (40%). On multivariable analysis, age >81 years and current tobacco use were associated with no prosthetic fitting. Overall 5-year survival was 41.9% (95% confidence interval [CI], 37.6%-46.6%) (below-the-knee amputation, 47.7% [95% CI, 42.5%-53.5%]; above-the-knee amputation, 28.7% [95% CI, 22.1%-37.2%]). On multivariable analysis, age >60 years, congestive heart failure, above-the-knee amputation, and no prosthetic attainment were associated with decreased survival. Increasing K level was incrementally associated with improved survival. CONCLUSIONS: This study has identified several patient factors associated with prosthetic attainment, as well as multiple factors predictive of reduced survival after amputation. Being referred for prosthetic fitting was associated with improved survival not explained by patient characteristics and comorbidities. The Medicare Functional Classification Level K level predicts survival. More research is needed to determine the barriers to prosthetic attainment and if improving a patients K level will improve survival.

Association Between Diagnosis-to-Limb Revascularization Time and Clinical Outcomes in Outpatients With Chronic Limb-Threatening Ischemia: Insights From the CLIPPER Cohort.

BACKGROUND: The extent and consequences of ischemia in patients with chronic limb-threatening ischemia (CLTI) may change rapidly, and delays from diagnosis to revascularization may worsen outcomes. We sought to describe the association between time from diagnosis to endovascular lower extremity revascularization (diagnosis-to-limb revascularization [D2L] time) and clinical outcomes in outpatients with CLTI. METHODS AND RESULTS: In the CLIPPER cohort, comprising patients between 66 and 86 years old diagnosed with CLTI betweeen 2010 and 2019, we used Medicare claims data to identify patients who underwent outpatient endovascular revascularization within 180 days of diagnosis. We described the risk-adjusted association between D2L time and clinical outcomes. Among 1 130 065 patients aged between 66 and 86 years with CLTI, 99 221 (8.8%) underwent outpatient endovascular lower extremity revascularization within 180 days of their CLTI diagnosis. Among patients with D2L time <30 days, there was no association between D2L time and all-cause death or major lower extremity amputation. However, among patients with D2L time >30 days, each additional 10-day increase in D2L time was associated with a 2.5% greater risk of major amputation (hazard ratio, 1.025 [95% CI, 1.014-1.036]). There was no association between D2L time and all-cause death. CONCLUSIONS: A delay of >30 days from CLTI diagnosis to lower extremity endovascular revascularization was associated with an increased risk of major lower extremity amputation among patients undergoing outpatient endovascular revascularization. Improving systems of care to reduce D2L time could reduce amputations.

Factors Associated with Urgent Amputation Status and Its Impact on Mortality.

BACKGROUND: Thirty-day mortality is higher after urgent major lower extremity amputations compared to elective lower extremity amputations. This study aims to identify factors associated with urgent amputations and to examine their impact on perioperative outcomes and long-term mortality. METHODS: Patients undergoing major lower limb amputation from 2013 to 2020 in the Vascular Quality Initiative were included. Urgent amputation was defined as occurring within 72 hr of admission. Associations with sociodemographic characteristics, comorbidities, and outcomes including postoperative complication, inpatient death, and long-term survival were compared using univariable tests and multivariable logistic regression. Long-term survival between groups was compared using Kaplan-Meier analysis. RESULTS: Of the 12,874 patients included, 4,850 (37.7%) had urgent and 8,024 (62.3%) had elective amputations. Non-White patients required urgent amputation more often than White patients (39.8% vs. 37.9%, P = 0.03). A higher proportion of Medicaid and self-pay patients presented urgently (Medicaid: 13.0% vs. 11.0%; self-pay: 3.4% vs. 2.5%, P < 0.001). Patients requiring urgent amputation were less often taking aspirin (55.6% vs. 60.1%, P < 0.001) or statin (62.2% vs. 67.2%, P < 0.001), had fewer prior revascularization procedures (41.0% vs. 48.8%, P < 0.001), and were of higher American Society of Anesthesiologists (ASA) class 4-5 (50.9% vs. 40.1%, P < 0.001). Urgent amputations were more commonly for uncontrolled infection (48.1% vs. 29.4%, P < 0.001) or acute limb ischemia (14.3% vs. 6.2%, P < 0.001). Postoperative complications were higher after urgent amputations (34.7% vs. 16.6%, P < 0.001), including need for return to operating room (23.8% vs. 8.4%, P < 0.001) and need for higher revision (15.2% vs. 4.5%, P < 0.001). Inpatient mortality was higher after urgent amputation (8.9% vs. 5.4%, P < 0.001). Multivariable analysis revealed non-White race, self-pay, homelessness, current smoking, ASA class 4-5, and amputations for uncontrolled infection or acute limb ischemia were associated with urgent status, whereas living in a nursing home or prior revascularization were protective. Furthermore, urgent amputation was associated with an increased odds of postoperative complication or death (odds ratio 1.86 [1.69-2.04], P < 0.001) as well as long-term mortality (odds ratio: 1.24 [1.13-1.35], P < 0.001). Kaplan-Meier analysis corroborated that elective status was associated with improvement of long-term survival. CONCLUSIONS: Patients requiring urgent amputations are more often non-White, uninsured, and less frequently had prior revascularization procedures, revealing disparities in access to care. Urgency was associated with a higher postoperative complication rate, as well as increased long-term mortality. Efforts should be directed toward reducing these disparities to improve outcomes following amputation.

Near-Infrared Spectroscopy During Reactive Hyperemia for the Assessment of Lower Limb Vascular Function.

Vascular diseases of the lower limb contribute substantially to the global burden of cardiovascular disease and comorbidities such as diabetes. Importantly, microvascular dysfunction can occur prior to, or alongside, macrovascular pathology, and both potentially contribute to patient symptoms and disease burden. Here, we describe a non-invasive approach using near-infrared spectroscopy (NIRS) during reactive hyperemia, which provides a standardized assessment of lower limb vascular (dys)function and a potential method to evaluate the efficacy of therapeutic interventions. Unlike alternative methods, such as contrast-enhanced ultrasound, this approach does not require venous access or sophisticated image analysis, and it is inexpensive and less operator-dependent. This description of the NIRS method includes representative results and standard terminology alongside the discussion of measurement considerations, limitations, and alternative methods. Future application of this work will improve standardization of vascular research design, data collection procedures, and harmonized reporting, thereby enhancing translational research outcomes in the areas of lower limb vascular (dys)function, disease, and treatment.

Intraoperative Pedal Pressure Changes Offers Another Quantitative Assessment for Revascularization.

BACKGROUND: Lower extremity angiography is one of the most prevalent vascular procedures performed, generally via the contralateral common femoral artery. The use of retrograde pedal artery access to perform angiography has long been reserved as a "bail-out" technique to help cross chronic total occlusions that were not amenable from an antegrade approach. Recently, there have been reports and discussions involving increased utilization of pedal access for primary revascularization. The purpose of this study is to describe the outcomes of pedal access as a primary approach and to propose a novel evaluation of distal perfusion changes associated with interventions using direct pressure measurements. METHODS: A retrospective observational study evaluating all patients who underwent lower extremity angiography via retrograde pedal access between December 1, 2020, and June 30, 2021, within a single health-care system spanning 3 hospitals was performed. Demographics, comorbidities, procedural indications, and details were all recorded. Hemodynamic measurements were obtained and recorded upon initial pedal access and post intervention with a pressure transducer connected directly to the access sheath. Outcomes were analyzed with paired t-test. RESULTS: Twenty-eight angiograms using primary pedal access for endovascular intervention were performed during the study period. Most patients were African American (75%) females (57.1%) with hypertension (89.3%), hyperlipidemia (78.6%), diabetes (85.7%), coronary artery disease (64.3%), and current tobacco users (57.1%). The most prevalent indication for angiography was nonhealing wounds (67.9%). Pedal access was mostly achieved via the anterior tibial artery (79%). Sixty-three vessels were treated during the 28 angiograms (averaging 2.3 vessels per angiogram), most commonly the superficial femoral (27%), anterior tibial (25%), and popliteal (22%) arteries. Balloon angioplasty with or without stenting (98.5%) was predominately performed with an overall technical success rate of 94%. The mean preintervention and postintervention pressures were 36.5 mm Hg (standard deviation [SD] 25.7) and 83.4 mm Hg (SD 19.5), respectively. The mean change in pressure after intervention was 46.9 mm Hg (SD 23.3) (Table 3). There was a statistically significant difference detected between preintervention and postintervention pressure (P < 0.001) (Figure 1). There were no major amputations or adverse cardiovascular events at a mean first follow-up duration of 89 days. Six of the total 28 patients (21.4%) underwent repeat endovascular intervention on the ipsilateral extremity within a median of 45 (interquartile range 22.5-62.3) days. CONCLUSIONS: Primary pedal access is a viable option for performing lower extremity angiographic interventions. A significant increase in pedal artery pressure can be observed after angiographic intervention from retrograde pedal artery access. Further studies are necessary to define the clinical prognostic importance of these findings in relation to wound healing rates.

Disparities in access to endovenous treatment options in chronic lower extremity superficial venous insufficiency: A national 7-year analysis.

OBJECTIVE: The goal of this study was to analyze trends in treatment access for chronic superficial venous disease and to identify disparities in care. METHODS: This retrospective study was exempt from institutional review board approval. The American College of Surgeon National Surgical Quality Improvement Program database was used to identify patients who underwent vein stripping (VS) and endovenous procedures for treatment of chronic superficial venous disease. Endovenous options included radiofrequency ablation (RFA) and laser ablation. Data was available from 2011 to 2018 and demographic information was extracted for each patient identified by Current Procedural Terminology codes. For all racial and ethnic groups, trend lines were plotted, and the relative rate of change was determined within each specified demographic. RESULTS: There were 21,025 patients included in the analysis. The overall mean age was 54.2 years, and the majority of patients were female (64.8%). In total, 27.9%, 55.2%, and 16.9% patients underwent VS, RFA, and laser ablation, respectively. Patients who received laser ablation were older (P < .001). Hispanic ethnicity was associated with significantly lower odds of receiving endovascular thermal ablation (EVTA) over VS (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.64-0.78; P < .001). American Indian/Alaska Native patients were more likely to receive EVTA over VS (OR, 4.02; 95% CI, 2.48-6.86); similarly, Native Hawaiian/Pacific Islander patients were more likely to receive EVTA over VS, although this difference was not statistically significant (OR, 1.44; 95% CI, 0.93-2.27). On multinomial regression, Hispanic patients were less likely to receive RFA over VS, whereas American Indian/Alaskan Native patients were more likely to receive RFA over VS. In all racial and ethnic groups, the percentage of endovenous procedures increased, whereas vein stripping decreased. CONCLUSIONS: Based on a hospital-based dataset, demographic indicators, including age, sex, race, and ethnicity, are associated with differences in endovenous treatments for chronic superficial venous insufficiency suggesting disparities in obtaining minimally invasive treatment options among certain patient groups.

Rate of Emergency Lower Extremity Amputations in the United States Among Medicare Beneficiaries.

OBJECTIVE: To determine the rate of emergency versus elective lower extremity amputations in the United States. BACKGROUND: Lower extremity amputation is a common endpoint for patients with poorly controlled diabetes and multilevel peripheral vascular disease. Although the procedure is ideally performed electively, patients with limited access may present later and require an emergency operation. To what extent rates of emergency amputation for lower extremities vary across the United States is unknown. METHODS: Evaluation of Medicare beneficiaries who underwent lower extremity amputation between 2015 and 2020. The rate was determined for each zip code and placed into rank order from lowest to highest rate. We merged each beneficiary's place of residence and location of care with the American Hospital Association Annual Survey using Google Maps Application Programming Interface to determine the travel distance for patients to undergo their procedure. RESULTS: Of 233,084 patients, 66.3% (154,597) were men, 69.8% (162,786) were White. The average age (SD) was 74 years (8). There was wide variation in rates of emergency lower extremity amputation. The lowest quintile of zip codes demonstrated an emergency amputation rate of 3.7%, whereas the highest quintile demonstrated 90%. The median travel distance in the lowest emergency surgery rate quintile was 34.6 miles compared with 10.5 miles in the highest quintile of emergency surgery ( P < 0.001). CONCLUSIONS: There is wide variation in the rate of emergency lower extremity amputations among Medicare beneficiaries, suggesting variable access to essential vascular care. Travel distance and rate of amputation have an inverse relationship, suggesting that barriers other than travel distance are playing a role.

Impact of Intensity of Vascular Care Preceding Major Amputation Among Patients With Chronic Limb-Threatening Ischemia.

BACKGROUND: Lower-limb amputation rates in patients with chronic limb-threatening ischemia vary across the United States, with marked disparities in amputation rates by gender, race, and income status. We evaluated the association of patient, hospital, and geographic characteristics with the intensity of vascular care received the year before a major lower-limb amputation and how intensity of care associates with outcomes after amputation. METHODS: Using Medicare claims data (2016-2019), beneficiaries diagnosed with chronic limb-threatening ischemia who underwent a major lower-limb amputation were identified. We examined patient, hospital, and geographic characteristics associated with the intensity of vascular care received the year before amputation. Secondary objectives evaluated all-cause mortality and adverse events following amputation. RESULTS: Of 33 036 total Medicare beneficiaries undergoing major amputation, 7885 (23.9%) were due to chronic limb-threatening ischemia; of these, 4988 (63.3%) received low-intensity and 2897 (36.7%) received high-intensity vascular care. Mean age, 76.6 years; women, 38.9%; Black adults, 24.5%; and of low income, 35.2%. After multivariable adjustment, those of low income (odds ratio, 0.65 [95% CI, 0.58-0.72]; P<0.001), and to a lesser extent, men (odds ratio, 0.89 [95% CI, 0.81-0.98]; P=0.019), and those who received care at a safety-net hospital (odds ratio, 0.87 [95% CI, 0.78-0.97]; P=0.012) were most likely to receive low intensity of care before amputation. High-intensity care was associated with a lower risk of all-cause mortality 2 years following amputation (hazard ratio, 0.79 [95% CI, 0.74-0.85]; P<0.001). CONCLUSIONS: Patients who were of low-income status, and to a lesser extent, men, or those cared for at safety-net hospitals were most likely to receive low-intensity vascular care. Low-intensity care was associated with worse long-term event-free survival. These data emphasize the continued disparities that exist in contemporary vascular practice.

Trends of Concomitant Diabetes and Peripheral Artery Disease and Lower Extremity Amputation in US Medicare Patients, 2007 to 2019.

BACKGROUND: Previous studies demonstrate geographic and racial/ethnic variation in diagnosis and complications of diabetes and peripheral artery disease (PAD). However, recent trends for patients diagnosed with both PAD and diabetes are lacking. We assessed the period prevalence of concurrent diabetes and PAD across the United States from 2007 to 2019 and regional and racial/ethnic variation in amputations among Medicare patients. METHODS: Using Medicare claims from 2007 to 2019, we identified patients with both diabetes and PAD. We calculated period prevalence of concomitant diabetes and PAD and incident cases of diabetes and PAD for every year. Patients were followed to identify amputations, and results were stratified by race/ethnicity and hospital referral region. RESULTS: 9 410 785 patients with diabetes and PAD were identified (mean age, 72.8 [SD, 10.94] years; 58.6% women, 74.7% White, 13.2% Black, 7.3% Hispanic, 2.8% Asian/API, and 0.6% Native American). Period prevalence of diabetes and PAD was 23 per 1000 beneficiaries. We observed a 33% relative decrease in annual new diagnoses throughout the study. All racial/ethnic groups experienced a similar decline in new diagnoses. Black and Hispanic patients had on average a 50% greater rate of disease compared with White patients. One- and 5-year amputation rates remained stable at ≈1.5% and 3%, respectively. Native American, Black, and Hispanic patients were at greater risk of amputation compared with White patients at 1- and 5-year time points (5-year rate ratio range, 1.22-3.17). Across US regions, we observed differential amputation rates, with an inverse relationship between the prevalence of concomitant diabetes and PAD and overall amputation rates. CONCLUSIONS: Significant regional and racial/ethnic variation exists in the incidence of concomitant diabetes and PAD among Medicare patients. Black patients in areas with the lowest rates of PAD and diabetes are at disproportionally higher risk for amputation. Furthermore, areas with higher prevalence of PAD and diabetes have the lowest rates of amputation.

Area Deprivation Index is not predictive of worse outcomes after open lower extremity revascularization.

OBJECTIVE: Prior research has shown that socioeconomic status (SES) is associated with higher rates of diabetes, peripheral vascular disease, and amputation. We sought to determine whether SES or insurance type increases the risk of mortality, major adverse limb events (MALE), or hospital length of stay (LOS) after open lower extremity revascularization. METHODS: We conducted a retrospective analysis of patients who underwent open lower extremity revascularization at a single tertiary care center from January 2011 to March 2017 (n = 542). SES was determined using state Area Deprivation Index (ADI), a validated metric determined by income, education, employment, and housing quality by census block group. Patients undergoing amputation in this same time period (n = 243) were included to compare rates of revascularization to amputation by ADI and insurance status. For patients undergoing revascularization or amputation procedures on both limbs, each limb was treated individually for this analysis. We performed a multivariate analysis of the association between ADI and insurance type with mortality, MALE, and LOS using Cox proportional hazard models, including confounding variables such as age, gender, smoking status, body mass index, hyperlipidemia, hypertension, and diabetes. The cohort with an ADI quintile of 1, meaning least deprived, and the Medicare cohort were used for reference. P values of <.05 were considered statistically significant. RESULTS: We included 246 patients undergoing open lower extremity revascularization and 168 patients undergoing amputation. Controlling for age, gender, smoking status, body mass index, hyperlipidemia, hypertension, and diabetes, ADI was not an independent predictor of mortality (P = .838), MALE (P = .094), or hospital LOS (P = .912). Controlling for the same confounders, uninsured status was independently predictive of mortality (P = .033), but not MALE (P = .088) or hospital LOS (P = .125). There was no difference in the distribution of revascularizations or amputations by ADI (P = .628), but there was higher proportion of uninsured patients undergoing amputation compared with revascularization (P < .001). CONCLUSIONS: This study suggests that ADI is not associated with an increased risk of mortality or MALE in patients undergoing open lower extremity revascularization, but that uninsured patients are at higher risk of mortality after revascularization. These findings indicate that individuals undergoing open lower extremity revascularization at this single tertiary care teaching hospital received similar care, regardless of their ADI. Further study is warranted to understand the specific barriers that uninsured patients face.

Community-wide feasibility of the Lower Extremity Amputation Protocol amongst vascular amputees.

BACKGROUND: The Lower Extremity Amputation Protocol (LEAP) is a multidisciplinary enhanced recovery after surgery pathway for vascular amputees. The objective of this study was to examine feasibility and outcomes of community-wide implementation of LEAP. METHODS: LEAP was implemented at three safety net hospitals for patients with peripheral artery disease or diabetes requiring major lower extremity amputation. Patients who underwent LEAP (LEAP) were matched 1:1 with retrospective controls (NOLEAP) on hospital location, need for initial guillotine amputation, and final amputation type (above- vs below-knee). Primary endpoint was postoperative hospital length of stay (PO-LOS). RESULTS: A total of 126 amputees (63 LEAP and 63 NOLEAP) were included with no difference between baseline demographics and co-morbidities between the groups. After matching, both groups had the same prevalence of amputation level (76% below-knee vs 24% above-knee). LEAP patients had shorter duration of postamputation bed rest (P = .003) and were more likely to receive limb protectors (100% vs 40%; P ≤ .001), prosthetic counseling (100% vs 14%; P ≤ .001), perioperative nerve blocks (75% vs 25%; P ≤ .001), and postoperative gabapentin (79% vs 50%; P ≤ .001). Compared with NOLEAP, LEAP patients were more likely to be discharged to an acute rehabilitation facility (70% vs 44%; P = .009) and less likely to be discharged to a skilled nursing facility (14% vs 35%; P = .009). The median PO-LOS for the overall cohort was 4 days. LEAP patients had a shorter median PO-LOS (3 [interquartile range, 2-5] vs 5 [interquartile range, 4-9] days; P < .001). On multivariable logistic regression, LEAP decreased the odds of a PO-LOS of ≥4 days by 77% (odds ratio, 0.23; 95% confidence interval, 0.09-0.63). Overall, LEAP patients were significantly less likely to have phantom limb pain (5% vs 21%; P = .02) and were more likely to receive a prosthesis (81% vs 40%; P ≤ .001). In a multivariable Cox proportional hazards model, LEAP was associated with an 84% reduction in time to receipt of prosthesis (hazard ratio, 0.16; 95% confidence interval, 0.085-0.303; P < .001). CONCLUSIONS: Community wide implementation of LEAP significantly improved outcomes for vascular amputees demonstrating that utilization of core ERAS principles in vascular patients leads to decreased PO-LOS and improved pain control. LEAP also affords this socioeconomically disadvantaged population a greater opportunity to receive a prosthesis and return to the community as a functional ambulator.

Comparison of lower extremity bypass and peripheral vascular intervention for chronic limb-threatening ischemia in the Medicare-linked Vascular Quality Initiative.

OBJECTIVE: There is a relative lack of comparative effectiveness research on revascularization for patients with chronic limb-threatening ischemia (CLTI). We examined the association between lower extremity bypass (LEB) vs peripheral vascular intervention (PVI) for CLTI and 30-day and 5-year all-cause mortality and 30-day and 5-year amputation. METHODS: Patients undergoing LEB and PVI of the below-the-knee popliteal and infrapopliteal arteries between 2014 and 2019 were queried from the Vascular Quality Initiative, and outcomes data were obtained from the Medicare claims-linked Vascular Implant Surveillance and Interventional Outcomes Network database. Propensity scores were calculated on 15 variables using a logistic regression model to control for imbalances between treatment groups. A 1:1 matching method was used. Kaplan-Meier survival curves and hierarchical Cox proportional hazards regression with a random intercept for site and operator nested in site to account for clustered data compared 30-day and 5-year all-cause mortality between groups. Thirty-day and 5-year amputation were subsequently compared using competing risk analysis to account for the competing risk of death. RESULTS: There was a total of 2075 patients in each group. The overall mean age was 71 ± 11 years, 69% were male, and 76% were white, 18% were black, and 6% were of Hispanic ethnicity. Baseline clinical and demographic characteristics in the matched cohort were balanced between groups. There was no association between all-cause mortality over 30 days and LEB vs PVI (cumulative incidence, 2.3% vs 2.3% by Kaplan Meier; log-rank P-value = .906; hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.62-1.44; P-value = .80). All-cause mortality over 5 years was lower for LEB vs PVI (cumulative incidence, 55.9% vs 60.1% by Kaplan Meier; log-rank P-value < .001; HR, 0.77; 95% CI, 0.70-0.86; P-value < .001). Accounting for competing risk of death, amputation over 30 days was also lower in LEB vs PVI (cumulative incidence function, 1.9% vs 3.0%; Fine and Gray P-value = .025; subHR, 0.63; 95% CI, 0.42-0.95; P-value = .025). There was no association between amputation over 5 years and LEB vs PVI (cumulative incidence function, 22.6% vs 23.4%; Fine and Gray P-value = .184; subHR, 0.91; 95% CI, 0.79-1.05; P-value = .184). CONCLUSIONS: In the Vascular Quality Initiative-linked Medicare registry, LEB vs PVI for CLTI was associated with a lower risk of 30-day amputation and 5-year all-cause mortality. These results will serve as a foundation to validate recently published randomized controlled trial data, and to broaden the comparative effectiveness evidence base for CLTI.

Association of Health Care Utilization and Access to Care With Vascular Assessment Before Major Lower Extremity Amputation Among US Veterans.

Importance: Patient-level characteristics alone do not account for variation in care among US veterans with peripheral artery disease (PAD). Presently, the extent to which health care utilization and regional practice variation are associated with veterans receiving vascular assessment prior to major lower extremity amputation (LEA) is unknown. Objective: To assess whether demographics, comorbidities, distance to primary care, the number of ambulatory clinic visits (primary and medical specialty care), and geographic region are associated with receipt of vascular assessment prior to LEA. Design, Setting, and Participants: This national cohort study used US Department of Veterans Affairs' Corporate Data Warehouse data from March 1, 2010, to February 28, 2020, for veterans aged 18 or older who underwent major LEA and who received care at Veterans Affairs facilities. Exposures: The number of ambulatory clinic visits (primary and medical specialty care) in the year prior to LEA, geographic region of residence, and distance to primary care. Main Outcomes and Measures: The main outcome was receipt of a vascular assessment (vascular imaging study or revascularization procedure) in the year prior to LEA. Results: Among 19 396 veterans, the mean (SD) age was 66.78 (10.20) years and 98.5% were male. In the year prior to LEA, 8.0% had no primary care visits and 30.1% did not have a vascular assessment. Compared with veterans with 4 to 11 primary care clinic visits, those with fewer visits were less likely to receive vascular assessment in the year prior to LEA (1-3 visits: adjusted odds ratio [aOR], 0.90; 95% CI, 0.82-0.99). Compared with veterans who lived less than 13 miles from the closest primary care facility, those who lived 13 miles or more from the facility were less likely to receive vascular assessment (aOR, 0.88; 95% CI, 0.80-0.95). Veterans who resided in the Midwest were most likely to undergo vascular assessment in the year prior to LEA than were those living in other regions. Conclusions and Relevance: In this cohort study, health care utilization, distance to primary care, and geographic region were associated with intensity of PAD treatment before LEA, suggesting that some veterans may be at greater risk of suboptimal PAD care practices. Development of clinical programs, such as remote patient monitoring and management, may represent potential opportunities to improve limb preservation rates and the overall quality of vascular care for veterans.

Assessment of chronic limb threatening ischemia using thermal imaging.

OBJECTIVES: Current chronic limb threatening ischemia (CLTI) diagnostics require expensive equipment, using ionizing radiation or contrast agents, or summative surrogate methods lacking in spatial information. Our aim is to develop and improve contactless, non-ionizing and cost-effective diagnostic methods for CLTI assessment with high spatial accuracy by utilizing dynamic thermal imaging and the angiosome concept. APPROACH: Dynamic thermal imaging test protocol was suggested and implemented with a number of computational parameters. Pilot data was measured from 3 healthy young subjects, 4 peripheral artery disease (PAD) patients and 4 CLTI patients. The protocol consists of clinical reference measurements, including ankle- and toe-brachial indices (ABI, TBI), and a modified patient bed for hydrostatic and thermal modulation tests. The data was analyzed using bivariate correlation. RESULTS: The thermal recovery time constant was on average higher for the PAD (88%) and CLTI (83%) groups with respect to the healthy young subjects. The contralateral symmetry was high for the healthy young group and low for the CLTI group. The recovery time constants showed high negative correlation to TBI (ρ = -0.73) and ABI (ρ = -0.60). The relation of these clinical parameters to the hydrostatic response and absolute temperatures (|ρ|<0.3) remained unclear. CONCLUSION: The lack of correlation for absolute temperatures or their contralateral differences with the clinical status, ABI and TBI disputes their use in CLTI diagnostics. Thermal modulation tests tend to augment the signs of thermoregulation deficiencies and accordingly high correlations were found with all reference metrics. The method is promising for establishing the connection between impaired perfusion and thermography. The hydrostatic modulation test requires more research with stricter test conditions.

Quantitative model for assessment of lower-extremity perfusion in patients with diabetes.

BACKGROUND: Although diabetic and atherosclerotic vascular diseases have different pathophysiological mechanisms, the screening methods currently used for diabetic lower-extremity vascular diseases are mainly based on the evaluation methods used for atherosclerotic vascular diseases. Thus, assessment of microvascular perfusion is of great importance in early detection of lower-extremity ischemia in diabetes. PURPOSE: This cross-sectional study aimed to develop a quantitative model for evaluating lower-extremity perfusion. METHODS: We recruited 57 participants (14 healthy participants and 43 diabetes patients, of which 16 had lower-extremity arterial disease [LEAD]). All participants underwent technetium-99 m sestamibi (99mTc-MIBI) scintigraphy and ankle-brachial index (ABI) examination. We derived two key perfusion kinetics indices named activity perfusion index (API) and basal perfusion index (BPI). This study was registered in ClinicalTrials.gov (URL: https://www. CLINICALTRIALS: gov, NCT02752100). RESULTS: The estimated limb perfusion values in our lower-extremity perfusion assessment (LEPA) model showed excellent consistency with the actual measured data. Diabetes patients showed reduced lower-extremity perfusion in comparison with the control group (BPI: 106.21 ± 11.99 vs. 141.56 ± 17.38, p < 0.05; API: 12.34 ± 3.27 vs. 14.56 ± 3.12, p < 0.05). Using our model, the reductions in lower-extremity perfusion could be detected early in approximately 96.30% of diabetes patients. Patients with LEAD showed more severe reductions in lower-extremity perfusion than diabetes patients without LEAD (BPI: 47.85 ± 20.30 vs. 106.21 ± 11.99, p < 0.05; API: 7.06 ± 1.70 vs. 12.34 ± 3.27, p < 0.05). Discriminant analysis using API and BPI could successfully screen all diabetes patients with LEAD with a sensitivity of 100% and specificity of 80.77%. CONCLUSIONS: We established a LEPA model that could successfully assess lower-extremity microvascular perfusion in diabetes patients. This model has important application value for the recognition of early-stage LEAD in patients with diabetes.

Association of Renin-Angiotensin-Aldosterone System Inhibitor Usage Patterns with Midterm Amputation-Free Survival after Lower Extremity Bypass for Peripheral Arterial Disease.

BACKGROUND: Different renin-angiotensin-aldosterone system inhibitor (RAASI) usage patterns exist among patients undergoing lower extremity bypass (LEB) for peripheral arterial disease. We studied the association of RAASI usage patterns with LEB outcomes to determine which pattern is associated with improved survival after LEB. METHODS: We evaluated peripheral arterial disease patients who underwent LEB between January 2014 and December 2018 in the Vascular Quality Initiative-Medicare matched database. Study cohorts included no RAASI use, preoperative RAASI use only, postoperative RAASI use only, and continuous RAASI use both preoperatively and postoperatively. Logistic and Cox regression was used to adjust for potential confounders. Primary outcome was 2-year amputation-free survival (AFS). RESULTS: Of 19,012 patients included, 1,574 (8.3%) were on RAASIs preoperatively only, 1,051 (5.5%) postoperatively only, and 8,484 (45.2%) continuously. Compared to no RAASI use, isolated preoperative RAASI use was associated with 2.8-fold increased odds of 30-day mortality (adjusted Odds Ratio, 2.75; 95% confidence interval [CI], 2.15-3.51; P < 0.001) whereas continuous RAASI use had 56% lower odds of 30-day mortality (adjusted Odds Ratio, 0.44; 95% CI, 0.34-0.58; P < 0.001). Two-year AFS was 63.2% for no RAASI use and 60.4%, 66.2%, and 73.4% for preoperative, postoperative, and continuous RAASI use, respectively (P < 0.001). While no RAASI use and postoperative RAASI use had comparable adjusted risks of 2-year major amputation or death (adjusted Hazard Ratio [aHR], 0.94; 95% CI, 0.83-1.06; P = 0.312), this risk was 14% higher for preoperative RAASI use only (aHR, 1.14; 95% CI, 1.04-1.26; P = 0.006) and 23% lower for continuous RAASI use (aHR, 0.77; 95% CI, 0.72-0.82; P < 0.001). CONCLUSIONS: Isolated preoperative RAASI use was associated with worse 30-day mortality and 2-year AFS, while continuous RAASI use was associated with improved 30-day mortality and 2-year AFS. Optimum survival benefit may be derived from continuous RAAS inhibition in the preoperative and postoperative periods.

Assessment of microcirculatory changes in local tissue oxygenation after revascularization for peripheral arterial disease with the Hyperview®, a portable hyperspectral imaging device.

OBJECTIVES: The Hyperview® is a hyperspectral camera, which can be used to assess the microcirculation of patients with peripheral arterial disease (PAD) and/or diabetes mellitus (DM). It measures local tissue oxygenation in concentrations of oxyhemoblobin (OXY), deoxyhemoglobin (DEOXY), and O2-saturation (O2-SAT) in arbitrary units. The aim of this validation study is to assess whether the Hyperview® is able to monitor microcirculatory changes after revascularization in patients with PAD. METHODS: In this prospective observational cohort study, 50 patients with PAD were included who were scheduled for endovascular, hybrid, or open revascularization. The ankle-brachial index (ABI), systolic toe pressure (TP) (in case of DM), and a set of Hyperview® measurements of the plantar region were recorded before and after treatment. Changes in pre- and postoperative measurements were assessed with the paired t-test. RESULTS: Some 38 patients underwent endovascular revascularization and eight patients underwent hybrid or open vascular surgical revascularization. After revascularization, the ABI improved from 0.58 to 0.80 (p < 0.001). OXY increased from 72.6 to 77.8 (p = 0.134). DEOXY decreased from 69.1 to 55.0 (p < 0.001). O2-SAT increased from 51.3 to 58.1 (p < 0.001). TP improved from 50.6 to 61.9 mmHg (p = 0.065) but was measured in only 16 patients. CONCLUSION: The Hyperview® is able to observe changes in the microcirculation after revascularization in terms of DEOXY and O2-SAT. The results of this study are a promising step into the validation of the Hyperview®.