Infrapopliteal Endovascular Interventions for Claudication Are Associated with Poor Long-Term Outcomes in Medicare-Matched Registry Patients.

BACKGROUND: There are limited data supporting or opposing the use of infrapopliteal peripheral vascular interventions (PVI) for the treatment of claudication. OBJECTIVES: We aimed to evaluate the association of infrapopliteal PVI with long-term outcomes compared with isolated femoropopliteal PVI for the treatment of claudication. METHODS: We conducted a retrospective analysis of all patients in the Medicare-matched Vascular Quality Initiative database who underwent an index infrainguinal PVI for claudication from January 2004-December 2019 using Cox proportional hazards models. RESULTS: Of 14,261 patients (39.9% female; 85.6% age ≥65 years, 87.7% non-Hispanic white) who underwent an index infrainguinal PVI for claudication, 16.6% (N=2,369) received an infrapopliteal PVI. The median follow-up after index PVI was 3.7 years (IQR 2.1-6.1). Compared to patients who underwent isolated femoropopliteal PVI, patients receiving any infrapopliteal PVI had a higher 3-year cumulative incidence of conversion to CLTI (33.3% vs. 23.8%; P<0.001); repeat PVI (41.0% vs. 38.2%; P<0.01); and amputation (8.1% vs. 2.8%; P<0.001). After risk-adjustment, patients undergoing infrapopliteal PVI had a higher risk of conversion to CLTI (aHR 1.39, 95% CI, 1.25-1.53); repeat PVI (aHR 1.10, 95% CI, 1.01-1.19); and amputation (aHR 2.18, 95% CI, 1.77-2.67). Findings were consistent after adjusting for competing risk of death; in a 1:1 propensity-matched analysis; and in subgroup analyses stratified by TASC disease, diabetes, and end-stage kidney disease. CONCLUSIONS: Infrapopliteal PVI is associated with worse long-term outcomes than femoropopliteal PVI for claudication. These risks should be discussed with patients.

Infrapopliteal Peripheral Vascular Interventions for Claudication are Performed Frequently in the USA and Are Associated with Poor Long Term Outcomes.

OBJECTIVE: Infrapopliteal peripheral vascular interventions (PVIs) for claudication are still performed in the USA. This study aimed to evaluate whether infrapopliteal PVI is associated with worse long term outcomes than isolated femoropopliteal PVI for treatment of claudication. METHODS: A retrospective analysis of fee for service claims in a national administrative database was conducted using 100% of the Medicare fee for service claims between 2017 and 2019 to capture all Medicare beneficiaries who underwent an index infra-inguinal PVI for claudication. Hierarchical Cox proportional hazards models were performed to assess the association of infrapopliteal PVI with conversion to chronic limb threatening ischaemia (CLTI), repeat PVI, and major amputation. RESULTS: In total, 36 147 patients (41.1% female; 89.7% age ≥ 65 years; 79.0% non-Hispanic White ethnicity) underwent an index PVI for claudication, of whom 32.6% (n = 11 790) received an infrapopliteal PVI. Of these, 61.4% (n = 7 245) received a concomitant femoropopliteal PVI and 38.6% (n = 4 545) received an isolated infrapopliteal PVI. The median follow up time was 3.5 years (interquartile range 2.7, 4.3). Patients receiving infrapopliteal PVI had a higher three year cumulative incidence of conversion to CLTI (26.0%; 95% confidence interval [CI] 24.9 - 27.2% vs. 19.9%; 95% CI 19.1 - 20.7%), repeat PVI (56.0%; 95% CI 54.8 - 57.3% vs. 45.7%; 95% CI 44.9 - 46.6%), and major amputation (2.2%; 95% CI 1.8 - 2.6% vs. 1.3%; 95% CI 1.1 - 1.5%) compared with patients receiving isolated femoropopliteal PVI. After adjusting for patient and physician level characteristics, the risk of conversion to CLTI (adjusted hazard ratio [aHR] 1.31, 95% CI 1.23 - 1.39), repeat PVI (aHR 1.12, 95% CI 1.05 - 1.20), and major amputation (aHR 1.72, 95% CI 1.42 - 2.07) remained significantly higher for patients receiving infrapopliteal PVI. An increasing number of infrapopliteal vessels treated during the index intervention was associated with increasingly poor outcomes (p < .001 for trend). CONCLUSION: Infrapopliteal PVI for claudication is associated with worse long term outcomes relative to isolated femoropopliteal PVI.

Investigating the impact of suboptimal prescription of preoperative antiplatelets and statins on race and ethnicity-related disparities in major limb amputation.

BACKGROUND: Non-Hispanic Black and Hispanic patients with symptomatic PAD may receive different treatments than White patients with symptomatic PAD. The delivery of guideline-directed medical treatment may be a modifiable upstream driver of race and ethnicity-related disparities in outcomes such as limb amputation. The purpose of our study was to investigate the prescription of preoperative antiplatelets and statins in producing disparities in the risk of amputation following revascularization for symptomatic peripheral artery disease (PAD). METHODS: We used data from the Vascular Quality Initiative, a vascular procedure-based registry in the United States (2011-2018). We estimated the probability of preoperative antiplatelet and statin prescriptions and 1-year incidence of amputation. We then estimated the amputation risk difference between race/ethnicity groups that could be eliminated under a hypothetical intervention. RESULTS: Across 100,579 revascularizations, the 1-year amputation risk was 2.5% (2.4%, 2.6%) in White patients, 5.3% (4.9%, 5.6%) in Black patients, and 5.3% (4.7%, 5.9%) in Hispanic patients. Black (57.5%) and Hispanic patients (58.7%) were only slightly less likely than White patients (60.9%) to receive antiplatelet and statin therapy. However, the effect of antiplatelets and statins was greater in Black and Hispanic patients such that, had all patients received these medications, the estimated risk difference comparing Black to White patients would have reduced by 8.9% (-2.9%, 21.9%) and the risk difference comparing Hispanic to White patients would have been reduced by 17.6% (-0.7%, 38.6%). CONCLUSION: Even though guideline-directed care appeared evenly distributed by race/ethnicity, increasing access to such care may decrease health care disparities in major limb amputation.

Disparities in healthcare utilization by insurance status among patients with symptomatic peripheral artery disease.

BACKGROUND: Peripheral artery disease (PAD) is a common circulatory disorder associated with increased hospitalizations and significant health care-related expenditures. Among patients with PAD, insurance status is an important determinant of health care utilization, treatment of disease, and treatment outcomes. However, little is known about PAD-costs differences across different insurance providers. In this study we examined possible disparities in length of stay and total charge of inpatient hospitalizations among patients with PAD by insurance type. METHODS: We conducted a cross-sectional analysis of length of stay and total charge by insurance provider for all hospitalizations for individuals with PAD in South Carolina (2010-2018). Cross-classified multilevel modeling was applied to account for the non-nested hierarchical structure of the data, with county and hospital included as random effects. Analyses were adjusted for patient age, race/ethnicity, county, year of admission, admission type, all-patient refined diagnostic groups, and Charlson comorbidity index. RESULTS: Among 385,018 hospitalizations for individuals with PAD in South Carolina, the median length of stay was 4 days (IQR: 5) and the median total charge of hospitalization was $43,232 (IQR: $52,405). Length of stay and total charge varied significantly by insurance provider. Medicare patients had increased length of stay (IRR = 1.08, 95 CI%: 1.07, 1.09) and higher total charges (ß: 0.012, 95% CI: 0.007, 0.178) than patients with private insurance. Medicaid patients also had increased length of stay (IRR = 1.26, 95% CI: 1.24,1.28) but had lower total charges (ß: -0.022, 95% CI: -0.003. -0.015) than patients with private insurance. CONCLUSIONS: Insurance status was associated with inpatient length of stay and total charges in patients with PAD. It is essential that Medicare and Medicaid individuals with PAD receive proper management and care of their PAD, particularly in the primary care settings, to prevent hospitalizations and reduce the excess burden on these patients.

Surgical site infection after open lower extremity revascularization associated with doubled rate of major limb amputation.

OBJECTIVE: Surgical site infection (SSI) after open lower extremity revascularization is a relatively common complication associated with increased hospital stays, graft infection, and in severe cases, graft loss. Although the short-term effects of SSI can be significant, it has not been considered a complication that increases major limb amputation. The purpose of this study was to determine the association of SSI with outcomes in patients undergoing surgical revascularization for peripheral arterial disease. METHODS: We analyzed nationwide Vascular Quality Initiative (VQI) data from the infrainguinal bypass module from 2003 to 2017. The cohort included adults who underwent open lower extremity bypass for symptomatic peripheral arterial disease and had at least one follow-up record. Weighted Kaplan-Meier curves and Cox proportional hazards regression were used to assess the association between SSI and 1-year mortality and major limb amputation. Inverse-probability of treatment weights were used to account for differences in demographics and patient characteristics and allow for 'adjusted' Kaplan-Meier curves. RESULTS: The analysis included 21,639 patients, and 1155 (5%) had a reported SSI within 30 days of surgery. Patients with SSI were more likely be obese (41% vs 30%), but there were no other clinically relevant differences between demographics, comorbidities, and bypass details. After weighting, patients with SSI were almost twice as likely to undergo major amputation by 6 months (hazard ratio, 1.84; 95% confidence interval, 1.07-3.17). The association with SSI and increased amputation rates persisted at 1 year. The association of SSI on amputation was no different based on preoperative Rutherford class (P = .91). The association between SSI and 1-year mortality rate was not statistically significant (hazard ratio, 1.15; 95% confidence interval, 0.91-1.46). CONCLUSIONS: SSI is more common in obese patients, and patients who develop an SSI are observed to have a significantly increased rate of limb amputation after open lower extremity revascularization.

Fibrosis and Inflammatory Markers and Long-Term Risk of Peripheral Artery Disease: The ARIC Study.

OBJECTIVE: Inflammatory markers, such as hs-CRP (high-sensitivity C-reactive protein), have been reported to be related to peripheral artery disease (PAD). Galectin-3, a biomarker of fibrosis, has been linked to vascular remodeling and atherogenesis. However, its prospective association with incident PAD is unknown; as is the influence of inflammation on the association between galectin-3 and PAD. Approach and Results: In 9851 Atherosclerosis Risk in Communities Study participants free of PAD at baseline (1996-1998), we quantified the association of galactin-3 and hs-CRP with incident PAD (hospitalizations with PAD diagnosis [International Classification of Diseases-Ninth Revision: 440.2-440.4] or leg revascularization [eg, International Classification of Diseases-Ninth Revision: 38.18]) as well as its severe form, critical limb ischemia (PAD cases with resting pain, ulcer, gangrene, or leg amputation) using Cox models. Over a median follow-up of 17.4 years, there were 316 cases of PAD including 119 critical limb ischemia cases. Log-transformed galectin-3 was associated with incident PAD (adjusted hazard ratio, 1.17 [1.05-1.31] per 1 SD increment) and critical limb ischemia (1.25 [1.05-1.49] per 1 SD increment). The association was slightly attenuated after further adjusting for hs-CRP (1.14 [1.02-1.27] and 1.22 [1.02-1.45], respectively). Log-transformed hs-CRP demonstrated robust associations with PAD and critical limb ischemia even after adjusting for galectin-3 (adjusted hazard ratio per 1 SD increment 1.34 [1.18-1.52] and 1.34 [1.09-1.65], respectively). The addition of galectin-3 and hs-CRP to traditional atherosclerotic predictors (C statistic of the base model 0.843 [0.815-0.871]) improved the risk prediction of PAD (ΔC statistics, 0.011 [0.002-0.020]). CONCLUSIONS: Galectin-3 and hs-CRP were independently associated with incident PAD in the general population, supporting the involvement of fibrosis and inflammation in the pathophysiology of PAD.

The impact of phased university reopenings on mitigating the spread of COVID-19: a modeling study.

BACKGROUND: Several American universities have experienced COVID-19 outbreaks, risking the health of their students, employees, and local communities. Such large outbreaks have drained university resources and forced several institutions to shift to remote learning and send students home, further contributing to community disease spread. Many of these outbreaks can be attributed to the large numbers of active infections returning to campus, alongside high-density social events that typically take place at the semester start. In the absence of effective mitigation measures (e.g., high-frequency testing), a phased return of students to campus is a practical intervention to minimize the student population size and density early in the semester, reduce outbreaks, preserve institutional resources, and ultimately help mitigate disease spread in communities. METHODS: We develop dynamic compartmental SARS-CoV-2 transmission models to assess the impact of a phased reopening, in conjunction with pre-arrival testing, on minimizing on-campus outbreaks and preserving university resources (measured by isolation bed capacity). We assumed an on-campus population of N = 7500, 40% of infected students require isolation, 10 day isolation period, pre-arrival testing removes 90% of incoming infections, and that phased reopening returns one-third of the student population to campus each month. We vary the disease reproductive number (Rt) between 1.5 and 3.5 to represent the effectiveness of alternative mitigation strategies throughout the semester. RESULTS: Compared to pre-arrival testing only or neither intervention, phased reopening with pre-arrival testing reduced peak active infections by 3 and 22% (Rt = 1.5), 22 and 29% (Rt = 2.5), 41 and 45% (Rt = 3.5), and 54 and 58% (improving Rt), respectively. Required isolation bed capacity decreased between 20 and 57% for values of Rt ≥ 2.5. CONCLUSION: Unless highly effective mitigation measures are in place, a reopening with pre-arrival testing substantially reduces peak number of active infections throughout the semester and preserves university resources compared to the simultaneous return of all students to campus. Phased reopenings allow institutions to ensure sufficient resources are in place, improve disease mitigation strategies, or if needed, preemptively move online before the return of additional students to campus, thus preventing unnecessary harm to students, institutional faculty and staff, and local communities.

Poor glycemic control is associated with significant increase in major limb amputation and adverse events in the 30-day postoperative period after infrainguinal bypass.

OBJECTIVE: Understanding modifiable risk factors to improve surgical outcomes is increasingly important in value-based health care. There is an established association between peripheral artery disease (PAD), diabetes, and limb loss, but less is known about expected outcomes after revascularization relative to the degree of glycemic control. The purpose of this study was to determine the association between hemoglobin A1c (HbA1c) management in diabetics and surgical outcomes after open infrainguinal bypass. METHODS: The Vascular Quality Initiative infrainguinal bypass module was used to identify adult patients (≥18 years) with a history of diabetes who underwent bypass for PAD between 2011 and 2018. Exclusion criteria included missing or illogical HbA1c values and if the indication for the limb treated was not PAD. Patients were categorized by preoperative HbA1c levels as low severity/controlled (<7.0%), high severity (7.0%-10.0%), and very high severity (>10.0%). Primary outcomes were 30-day incidence of major adverse cardiac events (MACEs), major adverse limb events (MALEs), ipsilateral amputation, and 1-year all-cause mortality. Thirty-day outcomes were calculated using multivariable regression to compute odds ratios; hazard ratios were calculated for all-cause mortality. All analyses were adjusted for demographics, comorbidities, and clinical characteristics. RESULTS: The final sample included 30,813 operations (27,988 unique patients): 17,517 (57%) nondiabetic patients, 5194 patients with low-severity/controlled diabetes, and 8102 (26%) patients with poorly controlled diabetes, including 5531 (70%) treated with insulin. There were 6439 (21%) patients with high-severity HbA1c values and 1663 (5%) patients with very-high-severity HbA1c values. Those with a very high HbA1c level were more likely to be nonwhite, insulin dependent, and active smokers. Compared with nondiabetics, patients with very-high-severity HbA1c had an 81% increase in MACEs and 31% increase in MALEs, whereas patients with high-severity HbA1c only had a 49% increase in MACEs and a 12% increase in MALEs. Each one-step increase in severity category (eg, low to high to very high) was associated with an average 29% increase in the odds of MACEs and an 8% increase in the odds of MALEs. CONCLUSIONS: Uncontrolled diabetes with an HbA1c value >10.0% was associated with significantly worse 30-day surgical outcomes. Patients with incrementally better glycemic control (HbA1c level of 7.0%-10.0%) did not suffer the same rate of complications, suggesting that preoperative attempts at improving diabetes management even slightly could lead to improved surgical outcomes in open infrainguinal bypass patients.

Regional Anaesthesia Alone is Reasonable for Major Lower Extremity Amputation in High Risk Patients and May Initiate a More Efficacious Enhanced Recovery Programme.

OBJECTIVE: Major limb amputations are physiologically stressful and subject patients to peri-operative cardiovascular risk. Up to 90% of major lower extremity amputations (LEAMP) are being performed under general anaesthesia, despite regional anaesthesia being an acceptable option in most cases. Obtaining a better understanding of who would benefit from regional vs. general anaesthesia could reduce complications and help establish best evidence based practice. It was hypothesised that patients undergoing LEAMP with regional anaesthesia would have better post-operative outcomes than patients receiving general anaesthesia. METHODS: This retrospective cohort study used the U.S. Vascular Quality Initiative lower extremity amputation module to identify patients (≥18 years) who underwent LEAMP from 2013 to 2018. Outcomes included 30 day incidence of major adverse cardiac events (MACE) and all cause mortality. Multivariable logistic regression models were used to compute odds ratios (OR) and 95% confidence intervals (CI). Time to death was analysed using standard survival analysis. RESULTS: The final sample included 5 567 patients (median age: 65 years, 67% white, 65% male). Only 719 (13%) of patients received regional anaesthesia. Compared with patients undergoing general anaesthesia, patients in the regional group were older (67 vs. 65 years, p < .001) and more likely to have diabetes (78% vs. 69%; p < .001), end stage renal disease (26% vs. 18%; p < .001), congestive heart failure (33% vs. 27%; p < .01) and coronary artery disease (35% vs. 30%; p < .01). The overall incidence of MACE, death, and MACE or death was 5%, 6%, and 9%, respectively. There was no statistically significant difference by anaesthesia groups for MACE (OR 0.98, 95% CI 0.69-1.39) or mortality (HR 1.03, 95% CI 0.90-1.17). CONCLUSION: There was no difference in outcomes between regional or general anaesthesia techniques in patients undergoing LEAMP, despite the regional group having more comorbidities. Regional anaesthesia may be under used for high risk patients undergoing LEAMP. Further studies are needed to establish best practices in LEAMP procedures.

Trends in Surgical Indications for Major Lower Limb Amputation in the USA from 2000 to 2016.

OBJECTIVE: Major lower limb amputation is an important cause of morbidity and mortality in the USA. Little is known about the prevalence of the various indications for amputation, or if these indications have changed over time. The purpose of this study was to assess the indications for major amputation over a 17 year period and to determine whether surgical indications have shifted over this time period. METHODS: A retrospective, population based analysis of patients undergoing major amputation between 2000 and 2016 was performed using the National Inpatient Sample. Surgical indications for major amputation were classified as chronic ischaemia, acute limb ischaemia (ALI), infection, oncological, trauma, other, or any combination of these indications. Prevalence rates of surgical indications were calculated using logistic regression. Prevalence differences across years were assessed using likelihood ratio tests to determine statistical significance. RESULTS: Of 1 002 119 weighted hospitalisations for patients undergoing major amputation during the study period, the majority had chronic ischaemia (72%) or infection (15%) as the primary indication for amputation. Patients were predominantly male (60%) and diabetic (61%). Renal insufficiency was the only measured comorbidity that changed significantly over time (from 6% to 39%), although changes in coding procedures are partially responsible for the increase. From 2000 to 2016, the proportion of amputations done for chronic ischaemia alone decreased from 60% to 40% (p < .001), while the proportion of amputations that included infection in the presence of chronic ischaemia nearly doubled from 20% to 40% (p < .001). Major amputation due to ALI, oncology, or trauma was stable across the study period. CONCLUSION: Surgical indications for major amputation have changed between 2000 and 2016. Infection related amputations increased significantly during the study period. Further evaluation and modification of treatment protocols for limb infection are crucial to decreasing infection related major limb amputation.

The role of selective stenting for superior mesenteric artery scallops during fenestrated endovascular aneurysm repair.

OBJECTIVE: Stenting of small fenestrations of the Zenith fenestrated endograft (ZFEN; Cook Medical, Bloomington, Ind) is necessary during fenestrated endovascular aneurysm repair (FEVAR) of complex abdominal aortic aneurysms to avoid malalignment. However, stenting of superior mesenteric artery (SMA) scallops of ZFEN devices is optional according to the instructions for use. The objective of this study was to assess the early and midterm outcomes of selective use of stents in SMA scallops of ZFEN during FEVAR procedures. METHODS: This study is a single-institution retrospective review of prospectively enrolled patients treated at the University of North Carolina at Chapel Hill between July 2010 and August 2014. Only patients with SMA scallops were included for analysis. We compared results between patients grouped as stented or unstented SMA scallops. The scallops were stented when one or more of the following criteria were present: misalignment of scallop determined by balloon testing intraoperatively; configuration consisting of an SMA scallop and a single renal fenestration or stent; and pre-existing stenosis in the vessel adjacent to the graft scallop. The study was approved by the local Institutional Review Board. Primary outcomes addressed were mortality, vessel patency, early and late complications, and reintervention rates. Baseline characteristics of the patients and procedure data were also described. RESULTS: During the 48-month study period, 61 patients were treated for complex abdominal aortic aneurysms at the University of North Carolina with a mean age of 73 years, and 74.3% of patients were male. Thirty-nine of 61 patients (63.9%) had a device design with an SMA scallop and were included for analysis. Eleven of 39 patients (28%) had the SMA primarily stented and 28 (72%) were unstented. There was only one death (2.5%) during the 30-day postoperative period, with 100% technical success and branch patency. In the unstented group, there were three SMA complications during follow-up, two requiring reintervention; however, there were no associated deaths. Among the stented group, there was one branch-related complication that occurred during the procedure but no stent stenosis or occlusion during the long-term follow-up. During the mean follow-up period of 21.7 months, no SMA stent thrombosis occurred. There was no statistical difference in outcomes between groups. CONCLUSIONS: Single-wide SMA scallops of ZFEN during FEVAR procedures may be selectively stented using specific criteria and rigorous follow-up, without compromising the safety and efficacy of the SMA.

Comparison of commercially available versus customized branched-fenestrated devices in the treatment of complex aortic aneurysms.

OBJECTIVE: To evaluate and compare the early outcomes of patients treated for complex aortic aneurysms using a commercially available Zenith fenestrated endograft (ZFEN) or an advanced customized fenestrated-branched endovascular repair, which includes custom-made device or off-the-shelf p-branch devices available for use in a physician-sponsored investigational device exemption (PSIDE). METHODS: Between July 2012 and July 2015, patients who underwent to complex aortic aneurysms repair at University of North Carolina-Chapel Hill were retrospectively analyzed using data prospectively collected in electronically maintained aortic database. Patients were separated in two groups: ZFEN and PSIDE (custom-made device and p-branch). Demographics data, cardiac risk factors, comorbidities, computed tomography angiography anatomic measurements (aneurysm diameter, length of aortic coverage above the celiac artery), procedural data (operative time, estimated blood loss, intraoperative complications), and 30-day outcomes (mortality, major adverse cardiac events, stroke/transient ischemic attack, paraplegia, gastrointestinal complications, visceral branch complications, and endoleak) were analyzed. RESULTS: Among the 131 repairs for complex aortic aneurysms (juxtarenal or thoracoabdominal), there were 60 ZFEN and 71 PSIDE devices. Demographics and risk factors had similar distribution between groups, except that PSIDE patients more commonly had a history of previous aortic surgery (33% vs 5% [ZFEN]; P = .0001). PSIDE patients had a greater number of stented vessels (3.4 vs 2.2; P < .001) and length of aortic coverage (72 mm vs -13.4 mm) than ZFEN; however, no differences were seen in operative time, estimated blood loss or fluoroscopic time. Early outcomes were similar between groups, except for duration of hospital stay, which was significantly longer in PSIDE cohort (4.4 days vs 3.3 days; P = .05). CONCLUSIONS: More advanced fenestrated-branched endovascular repair does not seem to increase the complications associated with repair compared with patients receiving a ZFEN device in an experienced treatment center. Although mortality and morbidity were comparable between the groups, further studies evaluating long-term outcomes are needed.

Renal volumes and estimated glomerular filtration rate changes after fenestrated-branched endovascular aortic repair.

OBJECTIVE: To describe changes in renal volumes (RV) and renal function after fenestrated-branched endovascular repair (F-BEVAR) for complex aortic aneurysms. METHODS: The data from patients enrolled in a physician-sponsored investigational device exemption clinical trial for endovascular treatment of complex aortic aneurysms from July 2012 to April 2017 were retrospectively analyzed. Descriptive statistics were calculated using the mean ± standard deviation. The mean estimated glomerular filtration rate (eGFR) and RV were calculated at baseline and 6, 12, and 18 months after F-BEVAR. Variable distributions were evaluated for skewness, and all models required log-transformation. Linear models using generalized estimating equations were used to assess the association between the RV and eGFR over time after adjustment for relevant covariates. We used Kaplan-Meier life-table analysis to calculate survival and branch patency. RESULTS: A total of 139 patients were followed up for 18 months or until death. The mean age was 71 ± 8 years (70% male). The most common risk factor was hypertension (92%). Chronic kidney disease (CKD; eGFR <60 mL/min) was present in 56 patients (40%). Thirty-one patients (22%) had ≥1 accessory renal artery. Of these 31 accessory arteries, 27 (87%) were embolized or covered. On average, the eGFR had decreased over time compared with baseline, with a median change of -4.4 mL/min (interquartile range [IQR], -11.4 to 4.9 mL/min), -2.6 mL/min (IQR, -11.9 to 6.5 mL/min), and -3.4 mL/min (IQR, -11.9 to 5.5 mL/min) at 6, 12, and 18 months postoperatively, respectively. Similarly, the RV had decreased from baseline by 8% ± 17%, 10% ± 17%, and 11% ± 22% at 6, 12, and 18 months, respectively. An increase in the baseline patient age of 5 years was estimated to be associated with a 3% (95% confidence interval [CI], 0.2%-6.0%) decrease in the mean eGFR during the follow-up period, collapsing over time. This change is similar to the natural history of renal deterioration with age. We estimated that an increase in the log-RV of 1 U would be associated with an estimated 26% (95% CI, 3%-52%) increase in the mean eGFR. Preexisting CKD did not affect the average change in RV. Of the 56 patients with previous CKD, 9 (16.1%) showed improvement in the eGFR to >60 mL/min. The median follow-up period was 17.9 months (IQR, 6.3-24.8). The Kaplan-Meier survival rate at 1 and 2 years was 84.7% (95% CI, 78.3%-91.1%) and 78.8% (95% CI, 71.0%- 86.6%), respectively. CONCLUSIONS: The RV and eGFR decreased in patients undergoing repair at the rates expected for patients with complex aortic disease. The eGFR correlated with the RV. Most of the decline in renal function occurred within the first 6 months postoperatively, after which, the renal function had stabilized.

Stenting of superior mesenteric and celiac arteries does not increase complication rates after fenestrated-branched endovascular aneurysm repair.

OBJECTIVE: This study compared complications in patients undergoing fenestrated-branched endovascular aneurysm repair (F-BEVAR) without and with stenting of the superior mesenteric artery (SMA) or celiac artery (CA), with particular attention to the length of coverage above the CA. METHODS: A retrospective review was performed of a prospectively maintained database of patients treated with F-BEVAR for thoracoabdominal aortic aneurysms between July 2012 and May 2017. Data included demographics, risk factors, comorbidities, preoperative aneurysm characteristics, procedural data, and outcomes. Patients were grouped as follows: group 1, no SMA or CA stent; group 2, SMA or CA stent and <5 cm of coverage above the CA; and group 3, SMA or CA stent and ≥5 cm of coverage above the CA. Complications measured included death, myocardial infarction, respiratory failure, stroke or transient ischemic attack, paraplegia, acute kidney injury, mesenteric ischemia, and vascular complications. Individual and composite complications were compared between groups. RESULTS: There were 223 patients who had data analyzed (group 1, 53 [24%]; group 2, 101 [45%]; and group 3, 69 [31%]). Mean age was 72 years (76% male). There was no difference in patients' characteristics between groups, except for hypertension (less common in group 2) and history of previous aortic surgery (more common in group 3). Group 2 (15%) and group 3 (90%) had higher spinal drain use than group 1 (2%; P < .0001). Mean operative time was longer in groups 2 and 3 compared with group 1 (group 1, 224 minutes; group 2, 253 minutes; and group 3, 313 minutes; P < .0001). Group 1 had more intraoperative complications, without difference in the technical success and mortality rates. Failure to deliver a bridging stent occurred in only 3 of 695 vessels (0.4%) intended, without difference between groups (P = .79). The incidence of major complications (individually and composite analysis) was similar between groups. On 30-day computed tomography angiography, there was no difference in type I or type III endoleaks (2%, 3%, and 6%) and branch patency (98%, 99%, and 99%) for groups 1, 2, and 3, respectively. At 3 years of follow-up, there was no difference in survival, stent patency, and branch instability. Group 3 had a higher reintervention rate compared with groups 1 and 2 (P < .0001); however, there was no difference between groups 1 and 2 (P = .31). CONCLUSIONS: Patients who needed SMA or CA incorporation with stents during F-BEVAR for aortic repair had more complex procedures, as assessed by operative time, brachial access, number of vessels incorporated, and spinal drain use. However, the extension of the repair did not affect the outcomes, demonstrated by similar mortality and morbidity rates between groups.

Outcomes and complications after fenestrated-branched endovascular aortic repair.

OBJECTIVE: To report the outcomes of patients enrolled in a physician-sponsored investigational device exemption trial for endovascular treatment of complex thoracoabdominal aortic aneurysms with fenestrated and/or branched devices. METHODS: This study represents a retrospective analysis of a prospectively maintained database of patients enrolled in a physician-sponsored investigational device exemption trial for endovascular treatment of complex thoracoabdominal aneurysms between July 2012 and July 2017. Subjects included high-risk patients for open repair and patients with unsuitable anatomy for either standard endovascular aneurysm repair or Zenith (Cook Medical, Bloomington, Ind) fenestrated device. Aneurysm classification was based upon Crawford classification. We included the pararenal and paravisceral aneurysms in the type IV aneurysm group, because the repair of these aneurysms usually involved treatment of all four visceral branches. The endografts implanted were custom manufactured devices or off-the-shelf devices based on the Cook Zenith platform. Variables analyzed included preoperative demographics and comorbidities, anatomic aneurysmal characteristics, procedural details, and perioperative complications. RESULTS: One -hundred fifty patients with a mean age of 71 ± 7.9 years were treated; 69% were male. Tobacco use (93%) and hypertension (91%) were the most common risk factors. Fifty-seven patients (38%) had a history of previous aortic repair. The mean aneurysm diameter was 62 ± 12 mm and 14 (9%) aneurysms were associated with chronic dissection. A total of 573 visceral vessels were incorporated (celiac artery/superior mesenteric artery [287 vessels], renal arteries [275 vessels], and 11 additional vessels) and 539 were stented. The celiac artery/superior mesenteric artery received a fenestrated design in 76.1% of cases. Branch designs were used in the renal artery in 13.2%, with the remainder treated with fenestrations. Spinal cord drainage was used in 51% of patients (76/150). The mean operative time, fluoroscopy time, and estimated blood loss were 283 ± 89 minutes, 83 ± 38 minutes, and 417 ± 404 mL, respectively. There were five patients (3.3%) with intraoperative complications, resulting in one intraoperative death. The early mortality was 2.7% (4/150). Major complications included respiratory failure in 7% (10/150), stroke and myocardial infarction in 0.7% each (1/150), and paraplegia in 2.7% (4/150). Acute kidney injury occurred in 4.7% of patients (7/150), two of whom required temporary dialysis. Thirty-nine percent of patients experienced at least one complication. Early branch vessel patency was 99.8% (525/526). Survival, primary, and primary-assisted branch patency at 2 years of follow-up were 79%, 97%, and 99%, respectively. CONCLUSIONS: Endovascular repair of complex aneurysms is safe and effective when performed in a high-volume center experienced in aortic disease management. Branch vessels patency and the low incidence of paraplegia and mortality support expanded use to treat most complex thoracoabdominal aortic aneurysms.

Cigarette smoking intensity informs outcomes after open revascularization for peripheral artery disease.

OBJECTIVE: Cigarette smoking is the leading risk factor for peripheral artery disease (PAD). Existing literature often defines smoking history in broad categories of current, former, and never smokers, which may not sufficiently identify patients at the highest risk for poor outcomes. The purpose of this study was to examine the use of more informative categorization of smoking and to determine the association with important revascularization outcomes. METHODS: We conducted a retrospective review of all patients undergoing open lower extremity revascularization for symptomatic PAD, defined as claudication (Rutherford 3) or critical limb ischemia (Rutherford 4-6), during a 5-year period (2013-2017). Smoking history, demographics, and comorbidities were abstracted from electronic health records from seven hospitals within our health care system. Smoking history was defined by intensity (packs/day), duration (years), pack-year history, and cessation time. Outcomes included major adverse limb events (MALEs), death, limb loss, and amputation-free survival. Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals (CIs) for each parameter adjusted for patients' demographics and comorbidities. Cumulative incidence is reported for outcomes at 30, 180, and 365 days of follow-up. RESULTS: We identified 693 patients undergoing open lower extremity revascularization for PAD (66% critical limb ischemia; 46% diabetes). The 1-year cumulative incidence of MALEs was 29.9% (95% CI, 26.4-33.9), whereas the 1-year incidence of death was 9.8% (95% CI, 7.5-12.7). The broad classification of current and former smokers identified no statistically significant differences in any measured outcomes. Patients who smoked more than one pack/day had 1.48 (95% CI, 1.01-2.16) times increase in risk of MALEs at 1 year compared with patients who smoked one or fewer packs/day. Patients who smoked more than one pack/day also had the highest 1-year amputation incidence (12.7%). Each of the four parameters was associated with increased risk of poor outcomes, although small sample size limited the precision of our estimates. CONCLUSIONS: We found that smoking intensity is particularly informative of outcomes of patients undergoing open lower extremity revascularization for symptomatic PAD. These findings lay the groundwork for future research on relevant smoking history parameters and benefits of smoking reduction and cessation for clinicians to discuss with patients and to better understand and inform patients of intervention risks and expected outcomes.

The impact of current smoking on outcomes after infrainguinal bypass for claudication.

OBJECTIVE: Although smoking cessation is a benchmark of medical management of intermittent claudication, many patients require further revascularization. Currently, revascularization among smokers is a controversial topic, and practice patterns differ institutionally, regionally, and nationally. Patients who smoke at the time of revascularization are thought to have a poor prognosis, but data on this topic are limited. The purpose of this study was to evaluate the impact of smoking on outcomes after infrainguinal bypass for claudication. METHODS: Data from the national Vascular Quality Initiative from 2004 to 2014 were used to identify infrainguinal bypasses performed for claudication. Patients were categorized as former smokers (quit >1 year before intervention) and current smokers (smoking within 1 year of intervention). Demographic and comorbid differences of categorical variables were assessed. Significant predictors were included in adjusted Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) by smoking status for outcomes of major adverse limb event (MALE), amputation-free survival, limb loss, death, and MALE or death. Cumulative incidence curves were created using competing risks modeling. RESULTS: We identified 2913 patients (25% female, 9% black) undergoing incident infrainguinal bypass grafting for claudication. There were 1437 current smokers and 1476 former smokers in our study. Current smoking status was a significant predictor of MALE (HR, 1.27; 95% CI, 1.00-1.60; P = .048) and MALE or death (HR, 1.22; 95% CI, 1.03-1.44; P = .02). Other factors found to be independently associated with poor outcomes in adjusted models included black race, below-knee bypass grafting, use of prosthetic conduit, and dialysis dependence. CONCLUSIONS: Current smokers undergoing an infrainguinal bypass procedure for claudication experienced more MALEs than former smokers did. Future studies with longer term follow-up should address limitations of this study by identifying a data source with long-term follow-up examining the relationship of smoking exposure (pack history and duration) with outcomes.

Current accepted hemodynamic criteria for critical limb ischemia do not accurately stratify patients at high risk for limb loss.

OBJECTIVE: Critical limb ischemia (CLI) has been defined as rest pain or tissue loss in patients who have an ankle-brachial index (ABI) ≤0.50, ankle pressure (AP) <70 mm Hg, or toe pressure (TP) <50 mm Hg. Data suggesting that these patients are at high risk for limb loss without successful revascularization are limited. This study was designed to identify limb loss and mortality rates in patients who did not respond to revascularization or who were not revascularized to determine whether CLI hemodynamic criteria accurately identify patients at high risk for limb loss. METHODS: Between 2008 and 2010, all patients undergoing lower extremity arterial duplex ultrasound testing at our hospital were identified. Those with ABI <0.50, AP <70 mm Hg, or TP <50 mm Hg were retrospectively reviewed to determine whether they had symptoms of rest pain, ischemic ulceration, or gangrene qualifying them for analysis in the database. Patients who underwent revascularization and subsequently had postrevascularization ABI, AP, or TP greater than the CLI criteria were removed from the cohort. Demographic factors, wound healing, amputation rates, and mortality were obtained and analyzed in relation to the initial APs and TPs. Outcomes were measured by Kaplan-Meier life-table analysis and Cox proportional hazards models. RESULTS: In 381 patients identified in the study, 443 limbs met CLI criteria. After revascularization, 98 limbs with ABI or TP that improved to >0.5 and >50 mm Hg, respectively, were removed from the study cohort. In 45 limbs, patients did not respond to initial revascularization as their ABI, AP, or TP remained within CLI criteria. These limbs remained in the patient cohort, yielding a final group of 296 patients and 345 limbs. Mean follow-up was 2 years. In the entire patient cohort, limb loss occurred in 24% at 1 year and in 31% at 3 years. Mortality was 32% at 1 year and 56% at 3 years. Amputation-free survival was 54% at 1 year and 28% at 3 years. Lower TPs were associated with a statistically higher incidence of amputation. Among those with an initial TP ≤10 mm Hg (n = 85), limb loss occurred in 46% at 1 year and 60% at 3 years. This limb loss was significantly greater than limb loss among those with a TP of 31 to 50 mm Hg (n = 115; 18% at 3 years; P < .001) Amputation-free survival in patients with a TP ≤10 mm Hg was 8% at 3 years. CONCLUSIONS: CLI is associated with a high mortality, but not all patients with currently defined hemodynamic criteria for CLI are at high risk of limb loss. Patients with a TP between 31 and 50 mm Hg (41% of the cohort) and not receiving revascularization or not responding hemodynamically to revascularization experienced a low risk of limb loss. We recommend revising the hemodynamic criteria for CLI to better identify patients at high risk for limb loss who require intervention to improve outcomes.

Living in a medically underserved county is an independent risk factor for major limb amputation.

OBJECTIVE: Despite an increase in the incidence of hospital admissions for comorbid conditions, such as diabetes, the incidence of major limb amputation in North Carolina has decreased. The decline in amputation rate has not been uniformly realized across the state. The objective of this study was to determine the association between major vascular limb amputation and living in an underserved county in North Carolina. METHODS: We analyzed discharges aged 18 to 100 years old with a peripheral arterial disease (PAD)-related admission from the North Carolina Inpatient Discharge Database from 2006 to 2009. Medically underserved counties are defined by the United States Health Resources and Services Administration as having too few primary care providers, high infant mortality, high poverty, or high elderly population. The association between major amputation prevalence and medically underserved counties was calculated using a binomial regression model adjusted for sex, age, diabetes, end-stage renal disease, PAD, and critical limb ischemia. Each confounder was assessed using backward elimination modeling. RESULTS: Among the 222,920 discharges with a PAD-related hospital admission from 2006 to 2009, 8601 (3.9%) were from medically underserved counties. There were 7328 major amputations. The adjusted prevalence odds ratio of the association between underserved counties and major vascular limb amputation is 1.29 (95% confidence interval, 1.16-1.44). None of the confounders significantly affected the association between underserved counties and number of amputations. CONCLUSIONS: Living in an underserved county in North Carolina is associated with a 29% increase in the odds of undergoing major limb amputation. Gender, age, and comorbidities, including diabetes, end-stage renal disease, and PAD, do not significantly affect the relationship.