Surgeon experience versus volume differentially affects lower extremity bypass outcomes in contemporary practice.

BACKGROUND: Calls for minimum case thresholds to guide surgeon credentialing paradigms are increasing in contemporary practice. To date, the volume-outcome relationship and the role of surgeon experience as a proxy for quality have remained primarily focused on nonvascular extirpative surgery and aneurysm repair. However, it is unclear whether these data can be rightly extrapolated to predict lower extremity bypass (LEB) outcomes. Thus, the purpose of the present study was to examine whether the annualized case volume vs surgeon experience is more consequential in predicting for successful LEB reconstruction. METHODS: A total of 25,852 procedures with sufficient 1-year follow-up data from the Society for Vascular Surgery Vascular Quality Initiative infrainguinal bypass registry (2003-2019) were reviewed for chronic limb threatening ischemia among patients undergoing infrageniculate reconstruction. The procedures were categorized according to surgeon years of practice experience at surgery (ie, 0-5, 6-10, 11-15, >15 years) and the number of LEB procedures performed by the surgeon during the year of surgery (volume quartiles: 1-8, 9-14, 15-21, and >21). Mixed effects logistic and Cox regression models were used to assess the effects of experience, volume, and their interaction on outcomes. RESULTS: Increasing practice experience was more significantly associated with a reduction of in-hospital complications (odds ratio, 0.97; 95% confidence interval [CI], 0.96-0.99; P = .002) and the risk of major adverse limb events (odds ratio, 0.94; 95% CI, 0.92-0.97; P < .0001) compared with the volume. Increasing experience and volume were both associated with increased freedom from thrombosis (hazard ratio, 0.95; 95% CI, 0.93-0.98; P = .001). In contrast, neither experience nor volume had any significant association with early mortality. However, a higher volume was associated with diminished long-term survival (hazard ratio, 1.04; 95% CI, 1.0-1.1; P = .01). The most experienced surgeons (>15 years' experience) were significantly more likely to perform LEB for rest pain (P < .0001). No significant differences were found in the bypass rates among patients with tissue loss. The most experienced and highest volume surgeons were more likely to use an autogenous and/or composite conduit, in situ reconstruction, and/or pedal targets (P < .05). Similarly, more experienced and higher volume surgeons had less blood loss and shorter procedure times (P < .0001). Overall, the most experienced surgeons (>15 years' experience) were significantly more likely to have a higher volume with a diminished risk for all LEB outcomes. CONCLUSIONS: Surgeon experience appears to have the most important role in predicting for overall LEB performance with improved in-hospital outcomes and major adverse limb events. The more experienced surgeons performed more complex reconstructions with fewer complications. These findings have significant clinical and educational implications as our most experienced surgeons approach retirement. Mentorship strategies to facilitate ongoing technical development among less experienced surgeons are imperative to sustain optimal limb salvage outcomes and have significant ramifications regarding expectations for regulatory and credentialing paradigms.

In-Hospital Outcomes and Trends of Endovascular Intervention vs Surgical Revascularization in Octogenarians With Peripheral Artery Disease.

It is unknown whether endovascular intervention (EVI) is associated with superior outcomes when compared with surgical revascularization in octogenarian. National Inpatient Sample (NIS) database was used to compare the outcomes of limb revascularization in octogenarians who had surgical revascularization versus EVI. The NIS database's information on PAD patients ≥80-year-old who underwent limb revascularization between 2002 and 2014 included 394,504 octogenarian patients, of which 184,926 underwent surgical revascularization (46.9%) and 209,578 underwent EVI (53.1%). Multivariate analysis was performed to examine in-hospital outcomes. Trend over time in limb revascularization utilization was examined using Cochrane-Armitage test. EVI group had lower odds of in-hospital mortality (adjusted odds ratio [aOR]: 0.61 [95% CI: 0.58 to 0.63], myocardial infarction (aOR: 0.84 [95% CI: 0.81 to 0.87]), stroke (aOR: 0.93 [95% CI: 0.89 to 0.96]), acute kidney injury (aOR: 0.79 [95% CI: 0.77 to 0.81]), and limb amputation (aOR: 0.77 [95% CI: 0.74 to 0.79]) compared with surgical group (p < 0.001 for all). EVI group had higher risk of bleeding (aOR: 1.20 [95% CI: 1.18 to 1.23]) and vascular complications (3.2% vs 2.7%, aOR: 1.25 [95% CI: 1.19 to 1.30]) compared with surgical group (p < 0.001 for all). Within study period, EVI utilization increased in octogenarian patients from 2.6% to 8.9% (ptrend < 0.001); whereas use of surgical revascularization decreased from 11.6% to 5.2% (ptrend < 0.001). In conclusion, the utilization of EVI in octogenarians is increasing, and associated with lower risk of in-hospital mortality and adverse cardiovascular and limb outcomes as compared with surgical revascularization.

Rapid increase in hybrid surgery for the treatment of peripheral artery disease in the Vascular Quality Initiative database.

OBJECTIVE: Advances in technology have increased the use of endovascular therapy for lower extremity revascularization (LER), but the impact on hybrid surgery has not been studied. This study aims to (1) investigate the contemporary national trends in frequency of hybrid LER and (2) compare the outcomes of open bypass (BYP) and hybrid surgery for isolated femoropopliteal revascularization. METHODS: Using the national Vascular Quality Initiative database from 2010 to 2017, all patients receiving bypass or hybrid LER for PAD were identified. A trend of all hybrid LER compared with open LER was obtained. Next, only patients who underwent hybrid or open isolated femoropopliteal LER were identified. Patients treated with hybrid surgery underwent femoral endarterectomy and antegrade endovascular intervention of the femoropopliteal vessels (HYB), whereas patients treated with BYP underwent femoral endarterectomy and femoropopliteal bypass. These two groups of patients were matched based on age, gender, race, indication, ambulatory status, emergency status, diabetes, hypertension, coronary artery disease, chronic obstructive pulmonary disease, and hemodialysis. Patient characteristics and the perioperative and 1-year outcomes of the two groups were compared. RESULTS: The overall rate of hybrid LER procedures increased from 6.1% in 2010 to 32% in 2017 (P = .03). Hybrid LER was significantly more commonly used in patients with claudication (47%) and BYP surgery was used in patients with tissue loss (38.5%; P = .019). There were 456 HYB and 2665 BYP for isolated femoropopliteal revascularization. After propensity matching, the cohort comprised 425 patients in each group. HYB was associated with lower rate of myocardial infarction (1.9% vs 5.7%; P = .005) and renal complications (2.1% vs 6.7%; P = .003), length of stay (4.7 vs 6.1 days; P = .001), and higher rate of discharge to home (90.8% vs 81.4%; P < .001) compared with BYP. There was no significant difference in 30-day mortality (HYB 1.5% vs BYP, 2.5%; P = .44). The 1-year outcomes comparison suggested that patients in the BYP group had a higher likelihood of improvement in ambulatory status compared with patients in HYB group (16.7% vs 7.7%; P = .044). However, Kaplan-Meier analysis showed no difference in overall survival (P = .13) or amputation-free survival (P = .057) between the two groups. There was no statistical difference in graft patency, limb loss, or secondary interventions. CONCLUSIONS: Hybrid LER for PAD has been increasingly used and accounts for up to one-third of open LER in the Vascular Quality Initiative. Hybrid femoropopliteal revascularization improves perioperative outcomes compared with femoropopliteal bypass. However, the 1-year outcomes between the two procedures are comparable, suggesting that hybrid femoropopliteal revascularization should be favored in high-risk patients because of its perioperative advantages.

Contemporary (2009-2014) clinical outcomes after femoropopliteal bypass surgery for chronic limb threatening ischemia are inferior to those reported in the UK Bypass versus Angioplasty for Severe Ischaemia of the Leg (BASIL) trial (1999-2004).

BACKGROUND: Bypass surgery (BS) remains the gold standard revascularization strategy in patients with chronic limb-threatening ischemia (CLTI) owing to infrainguinal disease. The Bypass versus Angioplasty for Severe Ischaemia of the Leg (BASIL)-1 trial showed that, in patients with CLTI who survived for 2 years or more, BS resulted in better clinical outcomes. Despite this finding, there has been an increasing trend toward an endovascular-first approach to infrainguinal CLTI. Our aim was to investigate whether changes in practice have impacted the clinical outcomes of BS in our unit 10 years after BASIL-1. METHODS: Data for patients who underwent femoropopliteal (FP) BS in BASIL-1 (1999-2004) were retrieved from trial case record forms. The comparator contemporary series (CS) comprised all patients undergoing FP BS for CLTI in our unit between 2009 and 2014. Demographic and clinical outcome data on patients in the CS were collected from the prospectively collected hospital electronic notes. Anatomic patterns of disease in the BASIL-1 and CS cohorts were scored using the Bollinger and GLASS criteria. Statistical analysis was performed in SAS v9.4. RESULTS: There were 128 patients from BASIL-1 and 50 patients in the CS. Baseline age, gender, affected limb, and diabetes prevalence were similar, as were days spent in hospital out to 12 months and length of follow-up. BASIL-1 patients were more likely to be current smokers (P = .000) and had a higher creatinine (P = .04). The 30-day morbidity and mortality were higher in BASIL-1 (45.3% vs 22%; P = .004). There was no significant difference between BASIL-1 and CS with regard to run-off Bollinger (37.7 vs 32.1; P = .167) and IP GLASS (0 vs 0; P = .390) scores, with both groups having a median of two runoff vessels. Amputation-free survival (62% vs 28%; hazard ratio [HR], 1.86; 95% confidence interval [CI], 1.18-2.93; P = .007), limb salvage (85% vs 69%; HR, 2.31; 95% CI, 1.14-4.68; P = .02), overall survival (69% vs 35%; HR, 1.66; 95% CI, 1.00-2.74; P = .05) and major adverse limb events (67% vs 47%; HR, 1.93; 95% CI, 1.15-3.22; P = .01) were all significantly better in BASIL-1. CONCLUSIONS: Although 30-day mortality and morbidity were significantly lower, all of the examined longer term clinical outcomes after FP BS were significantly worse in the CS group a decade on from BASIL-1. Further research in the form of prospective cohort studies and randomized controlled trials is urgently required to determine if the CS data reported herein are generalizable to current vascular surgical practice and, if so, to determine the reasons for these unexpected outcomes.

Routine use of bilateral internal thoracic artery grafting in women does not increase in-hospital mortality and could improve long-term survival.

BACKGROUND: Bilateral internal thoracic artery (BITA) grafting is underused in women. METHODS: Outcomes of 798 consecutive women with multivessel coronary disease who underwent isolated coronary surgery (1999-2016) using BITA (n=530, 66.4%) or single internal thoracic artery (SITA) grafting (n=268, 33.6%) were reviewed retrospectively. Differences between BITA and SITA cohort were adjusted by propensity score matching. For both series, late survival was estimated with the Kaplan-Meier method. RESULTS: One-to-one propensity score matching resulted in 247 BITA/SITA pairs with similar baseline characteristics and risk profile. According to the propensity matching, BITA grafting was associated with a trend towards reduced in-hospital mortality (3.2% vs. 5.7%, p=0.19). However, BITA women had an increased chest tube output (p=0.0076) as well as higher rates of any (13% vs. 5.3%, p=0.003) and deep sternal wound infections (9.3% vs. 4.9%, p=0.054), this translating in a longer in-hospital stay (10 vs. 9days, p=0.029). Test for interaction showed that body mass index >30kg/m2 and extracardiac arteriopathy were associated with a higher risk of deep sternal wound infection in BITA than in SITA women (23.4% vs. 13.7%, p<0.001 and 23.9% vs. 3.4%, p=0.001, respectively). Freedom from all-cause death and cardiac or cerebrovascular death were improved in BITA cohort, even though the differences were not quite significant (p=0.16 and 0.076, respectively). CONCLUSIONS: When routinely performed, BITA grafting does not increase in-hospital mortality in women and could improve long-term survival. However, its use should be avoided in obese women with extracardiac arteriopathy because of increased risk of deep sternal wound infection.

Clinical findings after bioresorbable vascular scaffold implantation in an unrestricted cohort of patients with ST-segment elevation myocardial infarction (from the RAI registry).

BACKGROUND: The bioresorbable vascular scaffold (BVS) technology may be an appealing option in ST-segment elevation myocardial infarction (STEMI) patients. However, the available evidence on its use in this challenging subset is limited. METHODS: Registro Absorb Italiano (RAI) is a multicenter, prospective registry that aims to assess BVS performance through a 5-year follow-up of all consecutive patients who undergone at least 1 successful BVS implantation. As a part of it, a subgroup analysis in STEMI patients was performed and the outcomes of this cohort compared to the remaining population (defined as "non-STEMI") are reported here. RESULTS: Among the 1505 patients enrolled, 317 (21.1%) had STEMI on admission. Among those, 232 (73.2%) underwent primary percutaneous coronary intervention (PCI) within 12 h from symptom onset; 64 (20.2%) were late-comers (>12 h); 16 (5%) underwent PCI after successful thrombolysis while 5 (1.6%) underwent rescue-PCI. At a median follow-up time of 12 months (IQR 6-20 months) no differences were noticed between STEMI and "non-STEMI" groups in terms of device-oriented composite endpoint (4.1% vs. 5.6%; p = 0.3) and its singular components: ischemia-driven target lesion revascularization (3.2% vs. 3.6%; p = 0.7), target-vessel myocardial infarction (3.2% vs. 2.8%; p = 0.7) and cardiac death (0.6% vs. 0.6%; p = 0.9). The rate of definite/probable scaffold thrombosis (ScT) was numerically higher but not significant in the STEMI group (2.5% vs. 1.3%; p = 0.1). CONCLUSIONS: BVS implantation in an unrestricted cohort of STEMI patients is associated with a numerically higher rate of ScT compared to the non-STEMI group. Further studies exploring the potential clinical impact of a pre-specified BVS implantation strategy in this high-risk clinical setting are needed.

Improving 1-Year Outcomes of Infrainguinal Limb Revascularization: Population-Based Cohort Study of 104 000 Patients in England.

BACKGROUND: The availability and diversity of lower limb revascularization procedures have increased in England in the past decade. We investigated whether these developments in care have translated to improvements in patient pathways and outcomes. METHODS: Individual-patient records from Hospital Episode Statistics were used to identify 103 934 patients who underwent endovascular (angioplasty) or surgical (endarterectomy, profundaplasty, or bypass) lower limb revascularization for infrainguinal peripheral artery disease in England between January 2006 and December 2015. Major lower limb amputations and deaths within 1 year after revascularization were ascertained from Hospital Episode Statistics and Office for National Statistics mortality records. Competing risks regression was used to estimate the cumulative incidence of major amputation and death, adjusted for patient age, sex, comorbidity score, indication for the intervention (intermittent claudication, severe limb ischemia without record of tissue loss, severe limb ischemia with a record of ulceration, severe limb ischemia with a record of gangrene/osteomyelitis), and comorbid diabetes mellitus. RESULTS: The estimated 1-year risk of major amputation decreased from 5.7% (in 2006-2007) to 3.9% (in 2014-2015) following endovascular revascularization, and from 11.2% (2006-2007) to 6.6% (2014-2015) following surgical procedures. The risk of death after both types of revascularization also decreased. These trends were observed for all indication categories, with the largest reductions found in patients with severe limb ischemia with ulceration or gangrene. Overall, morbidity increased over the study period, and a larger proportion of patients was treated for the severe end of the peripheral artery disease spectrum using less invasive procedures. CONCLUSIONS: Our findings show that from 2006 to 2015, the overall survival increased and the risk of major lower limb amputation decreased following revascularization. These observations suggest that patient outcomes after lower limb revascularization have improved during a period of centralization and specialization of vascular services in the United Kingdom.

Regional variation in the cost of infrainguinal lower extremity bypass surgery in the United States.

BACKGROUND: Lower extremity bypass (LEB) remains the gold standard revascularization procedure in patients with peripheral arterial disease. The cost of LEB substantially varies based on patient's characteristics and comorbidities. The aim of this study was to assess regional variation in infrainguinal LEB cost and to identify the specific health care expenditures per service that are associated with the highest cost in each region. METHODS: We identified adult patients who underwent infrainguinal LEB in the Premier database between June 2009 and March 2015. Generalized linear regression models were used to report differences between regions in total in-hospital cost and service-specific cost adjusting for patient's demographics, clinical characteristics, and hospital factors. RESULTS: A total of 50,131 patients were identified. The median in-hospital cost was $13,259 (interquartile range, $9308-$19,590). The cost of LEB was significantly higher in West and Northeast regions with a median cost of nearly $16,000. The high cost in the Northeast region was driven by the fixed (indirect) cost, whereas the driver of the high cost in the West region was the variable (direct) cost. The adjusted total in-hospital cost was significantly higher in all regions compared with the South (mean difference, West, $3752 [95% confidence interval (CI), 3477-4027]; Northeast, $2959 [95% CI, 2703-3216]; Midwest, 1586 [95% CI, 1364-1808]). CONCLUSIONS: In this study, we show the marked regional variability in LEB costs. This disparity was independent from patient clinical condition and hospital factors. Cost inequality across the US represents a financial burden on both the patient and the health system.

Regional variation in outcomes for lower extremity vascular disease in the Vascular Quality Initiative.

BACKGROUND: Increased focus has been placed on perioperative and long-term outcomes in the treatment of peripheral artery disease (PAD), both for purposes of quality improvement and for assessment of performance at a surgeon and institutional level. This study evaluates regional variation in outcomes after treatment for PAD within the Vascular Quality Initiative (VQI). By describing the variation in practice patterns and outcomes across regions, we hope that each regionally based quality group can select which areas are most important for them to focus on as they will have access to their regional data to compare. METHODS: We identified all patients in the VQI who had infrainguinal bypass or endovascular intervention from 2009 to 2014. We compared variation in perioperative and 1-year outcomes stratified by symptom status and revascularization type among the 16 regional groups of the VQI. We analyzed variation in perioperative end points using χ2 analysis, and 1-year end points were analyzed using Kaplan-Meier and life-table analysis. RESULTS: We identified 15,338 bypass procedures for symptomatic PAD: 27% for claudication, 59% for chronic limb-threatening ischemia (CLI; 61% of these for tissue loss), and 14% for acute limb ischemia. We identified 33,925 endovascular procedures for symptomatic PAD: 42% for claudication, 48% for CLI (73% of these for tissue loss), and 10% for acute limb ischemia. Thirty-day mortality varied significantly after endovascular intervention for CLI (0.5%-3%; P < .001) but not for claudication (0.0%-0.5%, P = .77) or for bypass for claudication (0.0%-2.6%; P = .37) or CLI (0.0%-5.0%; P = .08). After bypass, rates of >2 units transfused red blood cells (claudication, 0.0%-13% [P < .001]; CLI, 6.9%-27% [P < .001]) varied significantly. In-hospital major amputation was variable after bypass for CLI (0.0%-4.3%; P = .004) but not for claudication (0.0%-0.6%; P = .98), as was postoperative myocardial infarction (claudication, 0.0%-4% [P = .36]; CLI, 0.8%-6% [P = .001]). One-year survival varied significantly for endovascular interventions for claudication (92%-100%; P < .001), bypass for CLI (85%-94% [P < .001]), and endovascular interventions for CLI (77%-96%; P < .001) but not after bypass for claudication (95%-100%; P = .57). CONCLUSIONS: In this real-world comparison among VQI regions, we found significant variation in perioperative and 1-year end points for patients with PAD undergoing bypass or endovascular intervention. This study highlights opportunities for quality improvement efforts to reduce variation and to improve outcomes.

Trends in Treatment and Mortality for Mesenteric Ischemia in the United States from 2000 to 2012.

BACKGROUND: It is unknown whether increased endovascular treatment of chronic mesenteric ischemia has led to decreases in open surgery, acute mesenteric ischemia, or overall mortality. The present study evaluates the trends in endovascular and open treatment over time for chronic and acute mesenteric ischemia. METHODS: We identified patients with chronic or acute mesenteric ischemia in the Nationwide Inpatient Sample and Center for Disease Control and Prevention database from 2000 to 2012. Trends in revascularization, mortality, and total deaths were evaluated over time. Data were adjusted to account for population growth. RESULTS: There were 14,810 revascularizations for chronic mesenteric ischemia (10,453 endovascular and 4,358 open) and 11,294 revascularizations for acute mesenteric ischemia (4,983 endovascular and 6,311 open). Endovascular treatment increased for both chronic (0.6-4.5/million, P < 0.01) and acute mesenteric ischemia (0.6-1.8/million, P < 0.01). However, concurrent declines in open surgery did not occur (chronic: 1-1.1/million, acute: 1.8-1.7/million). Among patients with acute mesenteric ischemia, the proportion with atrial fibrillation (18%) and frequency of embolectomy (1/million per year) remained stable. In-hospital mortality rates decreased for both endovascular (chronic: 8-3%, P < 0.01; acute: 28-17%, P < 0.01) and open treatment (chronic: 21-9%, P < 0.01; acute: 40-25%, P < 0.01). Annual population-based mortality remained stable for chronic mesenteric ischemia (0.7-0.6 deaths per million/year), but decreased for acute mesenteric ischemia (12.9-5.3 deaths per million/year, P < 0.01). CONCLUSIONS: Population mortality from acute mesenteric ischemia declined from 2000 to 2012, correlated with dramatic increases in endovascular intervention for chronic mesenteric ischemia, and in spite of a stable rate of embolization. However, open surgery for both chronic and acute ischemia remained stable.

Medicare Facility Diagnosis-Related Groups Have Outpaced Individual Physician Payment.

BACKGROUND: We set out to compare the rates of Medicare reimbursement to physicians versus hospitals for several major vascular procedures over a period of 5 years. METHODS: We queried the Wolters Kluwer MediRegs database to collect Medicare reimbursement data from fiscal years 2011 to 2015. We surveyed reimbursements for carotid endarterectomy, carotid angioplasty and stenting, femoropopliteal bypass, and lower extremity fem-pop revascularization with stenting. Based on data availability, we surveyed physician reimbursement data on the national level and in both medically overserved and underserved areas. Hospital reimbursement rates were examined on a national level and by hospitals' teaching and wage index statuses. RESULTS: We found that for all 4 vascular procedures, Medicare reimbursements to hospitals increased by a greater percentage than to physicians. By region, underserved areas had lower physician reimbursements than the national average, while the opposite was true for overserved areas. Additionally, for hospital Medicare reimbursements, location in a high wage index accounted for a significant increase in reimbursement over the national average, with teaching status contributing to this increase in a smaller extent. CONCLUSIONS: These data on Medicare reimbursements indicate that payments to hospitals are increasing more significantly than to physicians. This disparity in pay changes affects both independent and academic vascular surgeons. Medicare should consider pay increases to independent providers in accordance to the hospital pay increase.

Contemporary Management of Acute Aortic Occlusion Has Evolved but Outcomes Have Not Significantly Improved.

BACKGROUND: Most existing series of acute aortic occlusion (AAO) predate the changes in surgical and endovascular therapy of the last 2 decades. We examined the contemporary management and outcomes of AAO. METHODS: We reviewed consecutive patients with AAO at a tertiary referral center from 2004 to 2012. Outcomes were stratified and compared according to etiology and procedure performed. RESULTS: AAO in 29 patients was due to in situ thrombosis in 21 (72%) and embolism in 8 (28%) patients. Vascular patients with embolism were on average older (77 ± 7 vs. 66 ± 12 years, P = 0.02) and had higher rates of atrial fibrillation (100% vs. 20%, P = 0.0002) and congestive heart failure (75% vs. 0%, P = 0.0001) in comparison with those with in situ thrombosis. Neurologic deficit was present in 16 (55%) patients. Six patients (21%) presented with bilateral paresis/paralysis secondary to spinal cord or lumbosacral plexus ischemia, and primary neurologic etiology was investigated before vascular consultation was obtained in 4 of these 6 patients. Of the 29 patients, 28 (97%) underwent revascularization including transfemoral embolectomy (n = 6), transperitoneal aortoiliac thrombectomy (n = 2), axillobifemoral bypass (n = 10), aortobifemoral bypass (n = 6), and endovascular therapy including thrombolysis, angioplasty ± stenting (n = 4). In-hospital mortality was 31% and did not vary significantly according to etiology (embolism 38% vs. in situ thrombosis 29%, P = 0.67). In-hospital mortality varied widely according to procedure (transfemoral embolectomy 50%, aortoiliac thrombectomy 100%, axillobifemoral bypass 30%, aortobifemoral bypass 0%, and endovascular therapy 25%, P = 0.08). Major morbidity (59%), length of stay (8.6 ± 8.0 days), and discharge to a rehabilitation facility (50%) did not vary by etiology or procedure. At a media follow-up of 361 ± 460 days (range 3-2014), overall survival was 42%. There were no amputations among 20 survivors of initial hospitalization. CONCLUSIONS: AAO is now more commonly caused by in situ thrombosis rather than embolism. A high index of suspicion for AAO is required for prompt diagnosis and treatment, particularly when patients present with profound lower extremity neurologic deficit. In comparison with previous reports, the contemporary management of AAO includes increased use of axillobifemoral bypass and now involves endovascular revascularization, although a variety of open surgical procedures are utilized. However, the in-hospital mortality and morbidity of AAO has not decreased significantly over the last 2 decades and mid-term survival remains limited. Further study is required to identify strategies that improve outcomes after AAO.

Lower limb ischaemia in patients with diabetic foot ulcers and gangrene: recognition, anatomic patterns and revascularization strategies.

The confluence of several chronic conditions--in particular ageing, peripheral artery disease, diabetes, and chronic kidney disease--has created a global wave of lower limbs at risk for major amputation. While frequently asymptomatic or not lifestyle limiting, at least 1% of the population has peripheral artery disease of sufficient severity to be limb threatening. To avoid the critical error of failing to diagnose ischaemia, all patients with diabetic foot ulcers and gangrene should routinely undergo physiologic evaluation of foot perfusion. Ankle brachial index is useful when measurable, but may be falsely elevated or not obtainable in as many as 30% of patients with diabetic foot ulcers primarily because of medial calcinosis. Toe pressures and skin perfusion pressures are applicable to such patients.

Effectiveness of revascularization of the ulcerated foot in patients with diabetes and peripheral artery disease: a systematic review.

Symptoms or signs of peripheral artery disease (PAD) can be observed in up to 50% of the patients with a diabetic foot ulcer and is a risk factor for poor healing and amputation. In 2012, a multidisciplinary working group of the International Working Group on the Diabetic Foot published a systematic review on the effectiveness of revascularization of the ulcerated foot in patients with diabetes and PAD. This publication is an update of this review and now includes the results of a systematic search for therapies to revascularize the ulcerated foot in patients with diabetes and PAD from 1980 to June 2014. Only clinically relevant outcomes were assessed. The research conformed to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, and Scottish Intercollegiate Guidelines Network methodological scores were assigned. A total of 56 articles were eligible for full-text review. There were no randomized controlled trials, but there were four nonrandomized studies with a control group. The major outcomes following endovascular or open bypass surgery were broadly similar among the studies. Following open surgery, the 1-year limb salvage rates were a median of 85% (interquartile range of 80-90%), and following endovascular revascularization, these rates were 78% (70-89%). At 1-year follow-up, 60% or more of ulcers had healed following revascularization with either open bypass surgery or endovascular techniques. Studies appeared to demonstrate improved rates of limb salvage associated with revascularization compared with the results of conservatively treated patients in the literature. There were insufficient data to recommend one method of revascularization over another. There is a real need for standardized reporting of baseline demographic data, severity of disease and outcome reporting in this group of patients.

Trends in hospital treatments for peripheral arterial disease in the United States and association between payer status and quality of care/outcomes, 2007-2011.

OBJECTIVE: This study sought to identify the temporal trends of presenting diagnoses and vascular procedures performed for peripheral arterial disease (PAD) along with the rates of procedures and in-hospital outcomes by payer status. BACKGROUND: Previous studies suggest that patients with Medicare, Medicaid, or lack of insurance receive poorer quality of care leading to worse outcomes. METHODS: We analyzed 196,461,055 discharge records to identify all hospitalized patients with PAD records (n=1,687,724) from January 2007 through December 2011 in the Nationwide Inpatient Sample database. RESULTS: The annual frequency of vascular procedures remained unchanged during the study period. Patients with Medicaid were more likely to present with gangrenes, whereas patients with Medicare were more likely to present with ulcers. After adjustment, patients with Medicare and Medicaid were more likely to undergo amputations when compared with private insurance/HMO (OR=1.13, 95% CI=1.10-1.16 and OR=1.24, 95% CI=1.20-1.29, respectively). Patients with both Medicare and Medicaid were less likely to undergo bypass surgery (OR=0.82, 95% CI=0.81-0.84 and OR=0.87, 95% CI=0.85-0.90, respectively), but more likely to undergo endovascular procedures (OR=1.18, 95% CI=1.17-1.20 and OR=1.03, 95% CI=1.01-1.06, respectively). Medicare and Medicaid status versus private insurance/HMO was associated with worse adjusted odds of in-hospital outcomes, including mortality after amputations, endovascular procedures, and bypass surgeries. CONCLUSIONS: In this analysis, patients with Medicare and Medicaid had more comorbid conditions at baseline when compared with private insurance/HMO cohorts, were more likely to present with advanced stages of PAD, undergo amputations, and develop in-hospital complications. These data unveil a critical gap and an opportunity for quality improvement in the elderly and those with poor socioeconomic status.

The increased use of computed tomography angiography and magnetic resonance angiography as the sole imaging modalities prior to infrainguinal bypass has had no effect on outcomes.

BACKGROUND: Angiography remains the gold standard imaging modality before infrainguinal bypass. Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) have emerged as noninvasive alternatives for preoperative imaging. We sought to examine contemporary trends in the utilization of CTA and MRA as isolated imaging modalities before infrainguinal bypass and to compare outcomes following infrainguinal bypass in patients who underwent CTA or MRA versus those who underwent conventional arteriography. METHODS: Patients undergoing infrainguinal bypass within the Vascular Study Group of New England were identified (2003-2012). Patients were stratified by preoperative imaging modality: CTA/MRA alone or conventional angiography. Trends in utilization of these modalities were examined and demographics of these groups were compared. Primary end points included primary patency, secondary patency, and major adverse limb events (MALE) at 1 year as determined by Kaplan-Meier analysis. Multivariable Cox proportional hazards models were constructed to evaluate the effect of imaging modality on primary patency, secondary patency, and MALE after adjusting for confounders. RESULTS: In 3123 infrainguinal bypasses, CTA/MRA alone was used in 462 cases (15%) and angiography was used in 2661 cases (85%). Use of CTA/MRA alone increased over time, with 52 (11%) bypasses performed between 2003 and 2005, 189 (41%) bypasses performed between 2006 and 2009, and 221 (48%) bypasses performed between 2010 and 2012 (P < 0.001). Patients with CTA/MRA alone, compared with patients with angiography, more frequently underwent bypass for claudication (33% vs. 26%, P = 0.001) or acute limb ischemia (13% vs. 5%, P < 0.0001), more frequently had prosthetic conduits (39% vs. 30%, P = 0.001), and less frequently had tibial/pedal targets (32% vs. 40%, P = 0.002). After adjusting for these and other confounders, multivariable analysis demonstrated that the use of CTA/MRA alone was not associated with a significant difference in 1 year primary patency (hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.78-1.16), secondary patency (HR 1.30, 95% CI 0.99-1.72), or MALE (HR 1.08, 95% CI 0.89-1.32). CONCLUSIONS: CTA and MRA are being increasingly used as the sole preoperative imaging modality before infrainguinal bypass. This shift in practice patterns appears to have no measurable effect on outcomes at 1 year.

Contrasting biofunctionalization strategies for the enhanced endothelialization of biodegradable vascular grafts.

Surface modification of biodegradable vascular grafts is an important strategy to improve the in situ endothelialization of tissue engineered vascular grafts (TEVGs) and prevent major complications associated with current synthetic grafts. Important strategies for improving endothelialization include increasing endothelial cell mobilization and increased endothelial cell capture through biofunctionalization of TEVGs. The objective of this study was to assess two biofunctionalization strategies for improving endothelialization of biodegradable polyester vascular grafts. These techniques consisted of cross-linking heparin to graft surfaces to immobilize vascular endothelial growth factor (VEGF) or antibodies against CD34 (anti-CD34Ab). To this end, heparin, VEGF, and anti-CD34Ab attachment and quantification assays confirmed the efficacy of the modification strategy. Cell attachment and proliferation on these groups were compared to unmodified grafts in vitro and in vivo. To assess in vivo graft functionality, the grafts were implanted as inferior vena cava interpositional conduits in mice. Modified vascular grafts displayed increased endothelial cell attachment and activity in vivo, according to microscopy techniques, histological results, and eNOS expression. Inner lumen diameter of the modified grafts was also better maintained than controls. Overall, while both functionalized grafts outperformed the unmodified control, grafts modified with anti-CD34Ab appeared to yield the most improved results compared to VEGF-loaded grafts.