Predictors of Early Graft Failure After Infrainguinal Bypass Surgery: A Risk-adjusted Analysis from the NSQIP

Descriptive Analysis of Amputation-Free Survival After First Time Infra-Inguinal Bypass Occlusion

INTRODUCTION

Occlusion after infra-inguinal bypass surgery for peripheral artery disease is a major complication with potentially devastating consequences. In this descriptive analysis, we sought to describe the natural history and explore factors associated with long-term major amputation-free survival following occlusion of a first-time infra-inguinal bypass.

METHODS

Using a prospective database from a tertiary care vascular center, we conducted a retrospective cohort study of all patients with peripheral artery disease who underwent a first-time infra-inguinal bypass and subsequently suffered a graft occlusion (1997-2021). The primary outcome was longitudinal rate of major amputation-free survival after bypass occlusion. Cox proportional hazard models were used to generate hazard ratios (HRs) and 95% confidence intervals (CIs) to explore predictors of outcomes.

RESULTS

Of the 1318 first-time infra-inguinal bypass surgeries performed over the study period, 255 bypasses occluded and were included in our analysis. Mean age was 66.7 (12.6) years, 40.4% were female, and indication for index bypass was chronic limb threatening ischemia (CLTI) in 89.8% (n = 229). 48.2% (n = 123) of index bypass conduits used great saphenous vein, 29.0% (n = 74) prosthetic graft, and 22.8% (n = 58) an alternative conduit. Median (interquartile range) time to bypass occlusion was 6.8 (2.3-19.0) months, and patients were followed for median of 4.3 (1.7-8.1) years after bypass occlusion. Following occlusion, 38.04% underwent no revascularization, 32.94% graft salvage procedure, 25.1% new bypass, and 3.92% native artery recanalization. Major amputation-free survival following occlusion was 56.9% (50.6%-62.8%) at 1 y, 37.1% (31%-43.3%) at 5 y, and 17.2% (11.9%-23.2%) at 10 y. In multivariable analysis, factors associated with lower amputation-free survival were older age, female sex, advanced cardiorenal comorbidities, CLTI at index procedure, CLTI at time of occlusion, and distal index bypass outflow. Initial treatment after occlusion with both a new surgical bypass (HR 0.44, CI: 0.29-0.67) or a graft salvage procedure (HR 0.56, CI: 0.38-0.82) showed improved amputation-free survival. One-year rate of major amputation or death were 59.8% (50.0%-69.6%) for those who underwent no revascularization, 37.9% (28.7%-49.0%) for graft salvage, and 26.7% (17.6%-39.5%) for new bypass.

CONCLUSIONS

Long-term major amputation-free survival is low after occlusion of a first-time infra-inguinal bypass. While several nonmodifiable risk factors were associated with lower amputation-free survival, treatment after graft occlusion with either a new bypass or a graft salvage procedure may improve longitudinal outcomes.

Contemporary outcomes of initial treatment strategy of endovascular intervention or bypass in patients with critical limb ischemia

OBJECTIVE

The optimal management for revascularization after critical limb ischemia (CLI) is controversial due to limited studies comparing long-term results of endovascular and open techniques. This study compares long-term outcomes after initial management of CLI via lower extremity bypass (LEB) and percutaneous vascular intervention (PVI).

METHODS

This retrospective cohort study investigates outcomes of patients who underwent endovascular or open surgical management for CLI at a single institution from 2013-2018. All patients with diagnosis of CLI were included and separated based on initial therapy of PVI or LEB. Demographic, procedural, and follow-up data were assessed. Primary endpoints included major adverse limb events (MALE), specifically the need for major amputation and reintervention. Secondary endpoints included mortality at 30 days and one year. A multivariable Cox Proportional Hazard regression model was used to assess the relationship between Surgery group and time to MALE/death while controlling for confounding variables.

RESULTS

This study identified 338 patients with an initial diagnosis of CLI who underwent either LEB (n = 108, 32%) or PVI (n = 230, 68%). The average age was 71.4, 54.4% were male, 30% were African American, 53.6% were diabetic, and 93.2% had hypertension. Patients who underwent LEB were more predominantly smokers (p = .003) and less predominantly on dialysis at time of surgery (p = .01). Re-intervention rates in the bypass group (11%) were not significantly different than the PVI group (9%; p = .95). In the bypass group, 20 (19%) patients had a major amputation with a median time of 189.5 days compared to 23 (10%) patients at a median time of 113 days in the PVI group; however, this difference was not significant (p = .16). There was no significant difference in 1-year mortality between the LEB (2%) and PVI group (4%; p = .2). The cumulative incidence of MALE/death at 30 days was 4.0% in the bypass group and 3.7% in the PVI group (p = .2). Incidences of MALE/death were 21.1% and 48.5% in the bypass group and 19.7 and 45.9% in the PVI group at one and 2 years, respectively. Intervention type was not found to be significantly associated with MALE/death after controlling for possible confounders (HR = 0.82, p = .43).

CONCLUSIONS

In the initial management of CLI, there is no significant difference in long-term outcomes in terms of major amputation, need for reintervention, limb-salvage, and 1-year mortality.

Sex and Racial Disparities in Peripheral Artery Disease

Several studies have shown that women and racial and ethnic minority patients are at increased risk of developing lower extremity peripheral artery disease and suffering adverse outcomes from it, but a knowledge gap remains regarding the underlying causes of these increased risks. Both groups are more likely to be underdiagnosed, have poorly managed contributory comorbidities, and incur disparities in treatment and management postdiagnosis. Opportunities for improvement in the care of women and racial and ethnic minorities with peripheral artery disease include increased rates of screening, higher rates of clinical suspicion (particularly in the absence of typical symptoms of intermittent claudication), and more aggressive risk factor management before and after the diagnosis of peripheral artery disease.

Compression therapy in peripheral artery disease: a literature review

OBJECTIVE

Our objective is to examine the pathophysiology of oedema in the ischaemic and post-revascularised limb, compare compression stockings to pneumatic compression devices, and summarise compression regimens in patients with severe peripheral artery disease (PAD) without revascularisation, after revascularisation, and in mixed arterial and venous disease.

METHOD

A scoping literature review of the aforementioned topics was carried out using PubMed.

RESULTS

Compression therapy has been shown to increase blood flow and aid in wound healing through a variety of mechanisms. Several studies suggest that intermittent pneumatic compression (IPC) devices can be used to treat critical limb ischaemia in patients without surgical options. Additionally, compression stockings may have a role in preventing oedema after peripheral artery bypass surgery, thereby diminishing pain and reducing the risk of surgical wound dehiscence.

CONCLUSION

Oedema may occur in the ischaemic limb after revascularisation surgery, as well as in combination with venous disease. Clinicians should not fear using compression therapy in PAD.

Gender Differences in Iliofemoral Vein Stenting for Chronic Venous Insufficiency

INTRODUCTION

Little is known about gender's role in chronic venous insufficiency (CVI). The aim of this study was to evaluate the impact of gender on outcomes of iliac vein stenting(IVS) for CVI.

METHODS

866 patients who underwent vein stenting for CVI at one institution from August 2011 to June 2021 were analyzed via retrospective review. Patients were followed up to 5 years after initial stent placement. Presenting symptoms were quantified using Venous Clinical Severity Score(VCSS), Clinical Assessment Score(CAS), and Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) class. Reoperations after initial IVS were recorded. Major reoperations were defined as iliac interventions using venography. Minor reoperations were defined as thermal ablation. Multivariate logistic regression models were used determine odds of any and major reintervention.

RESULTS

Compared to females, males pre-operatively presented with a higher mean CEAP class (3.6 vs .3.3; P < .001), VCSS composite (11.3 vs .9.9; P < .001), and smoking history (134 vs .49; P < .001). The 2 groups were similar in age (P = .125), BMI(P = .898), previous DVT (P = .085), diabetes (P = .386), hypertension (P = 1.0), and CAD (P = .499). Multivariate analyses revealed no association between gender and any reintervention (OR, 1.02; 95%CI, .71-1.46; P = .935) or gender and major reintervention (OR, 1.39; 95% CI, .86-2.23 P = .177). There were no differences in number of stents placed (P = .736) or symptomatic improvement at 1 month (P = .951), 3 months (P = .233), 6 months(P = .068), and greater than 1 year (P = .287). At the 1 year follow-up, the male cohort had higher CAS values than females P = .034). Males had larger reduction in composite VCSS than women at 1 year (5.1 vs. 3.8; P = .003) and 3 years (5.3 vs .3.7; P = .031) of follow-up and similar levels of improvement in post-op (4.0 vs .3.5; P = .059), 2 years (4.3 vs .3.8; P = .295), 4-years (5.1 vs .4.6; P = .529), 5 years (5.6 vs .4.2; P = .174), and 6 years (5.93vs.3.3 P = .089).

CONCLUSIONS

In a single site study of IVS in patients with CVI, males tended to present worse symptoms than females. After surgery, however, both cohorts showed improvement, and both seemed to improve to the same degree of residual symptoms.

Bovine pericardial patch: A good alternative in femoral angioplasty

OBJECTIVE

Bovine pericardial patch (BPP) is currently used in femoral angioplasty as an alternative for autologous vein patch (AVP), but studies comparing the results of the two methods are scarce. In this retrospective study, we aimed to discover the differences between BPP and AVP closure in long-term durability.

METHODS

This study consisted of all femoral endarterectomies with BPP closure performed in Helsinki University Hospital from January 1, 2014, to December 31, 2017. For comparison, the same number of consecutive patients who underwent femoral endarterectomy with AVP closure from January 1, 2014, to October 16, 2016, were reviewed. Follow-up ended December 31, 2020. The mean follow-up was 19 months (range, 0-74 months) in the BPP group and 22 months (range, 0-79 months) in the AVP group. The primary endpoint was primary patency. Secondary endpoints were restenosis at patch site detected by imaging or perioperatively, patch rupture, and deep surgical wound infection. Propensity score analysis was performed for adjustment of differences between the AVP and BPP groups.

RESULTS

Overall primary patency was superior in the AVP group compared with the BPP group: at 1 year, 96.5% vs 85.0% and at 5 years, 83.0% vs 72.3% (P = .04). In propensity score-matched pairs (n = 92), no difference was found between the groups in primary patency: 95.7% and 95.7% at 1 year and 92.5% and 78.6% at 5 years (P = .861) or in freedom from restenosis: 100% and 100% at 1 year and 89.1% and 84.0% at 5 years (P = .057). Deep wound infections occurred slightly more often after BPP closure (8%) than after AVP closure (4%), but the difference was not statistically significant (P = .144). There were no patch ruptures in the BPP group, but in the AVP group, there were five ruptures (3.5%) (P = .024).

CONCLUSIONS

BPP is compatible to AVP in femoral endarterectomy in patency and can be regarded as the safer choice considering the risk of patch rupture.

Effect of Direct Oral Anticoagulants versus Warfarin on Patency in High-Risk Bypass Patients

OBJECTIVES

The use of warfarin for anticoagulation in thromboembolic disease has been the mainstay of treatment. Direct oral anticoagulants (DOACs) have demonstrated equivalent anticoagulant effects, without increased bleeding risks or need for frequent monitoring. However, the role of DOACs remains unclear in the setting of replacing warfarin for high-risk peripheral artery disease (PAD) interventions. The purpose of this study is to evaluate the efficacy of DOACs compared to warfarin during the postoperative period in patients that underwent a lower extremity high risk bypass (HRB).

METHODS

The study is a single institution, retrospective review of all lower extremity HRBs be-tween January 2012 and June 2021, who were previously placed on or started on anticoagulation with a DOAC or warfarin. The HRB group included all patients undergoing femoral to above or below knee bypass with an adjunct procedure, or below knee bypass with synthetic or composite vein conduit. All demographics, preoperative factors, and complications were evaluated with respect to DOAC versus warfarin.

RESULTS

A total of 44 patients (28 males; average age 68.8 ± 10.9) underwent a HRB during the study period. There were no significant differences in demographics and preoperative characteristics between the two groups. Among patient comorbidities, coronary artery disease was found to be significantly higher in patients on DOACs (p=0.03). The 12-month primary patency rate was 83.3% vs 57.1%, for DOAC vs warfarin respectively (p=0.03). Multivariate analyses revealed that <30-day reinterventions contribute to 12-month patency (p=0.02).

CONCLUSION

Patients who underwent lower extremity HRB with postoperative DOAC appeared to exhibit higher graft patency rates than those who were placed on warfarin. Due to their low incidence of undesirable side effects and the lack of frequent monitoring, DOACs could be considered a safe alternative to warfarin in the postoperative period for patients with HRB.

Sex-Specific Differences in Cardiovascular Risk, Risk Factors and Risk Management in the Peripheral Arterial Disease Population

Cardiovascular disease (CVD) is the leading cause of mortality in women worldwide but has been primarily recognised as a man’s disease. The major components of CVD are ischaemic heart disease (IHD), stroke and peripheral arterial disease (PAD). Compared with IHD or stroke, individuals with PAD are at significantly greater risk of major cardiovascular events. Despite this, they are less likely to receive preventative treatment than those with IHD. Women are at least as affected by PAD as men, but major sex-specific knowledge gaps exist in the understanding of relevant CVD risk factors and efficacy of treatment. This prompted the American Heart Association to issue a “call to action” for PAD in women, in 2012. Despite this, PAD and CVD risk in women continues to be under-recognised, leading to a loss of opportunity to moderate and prevent CVD morbidity. This review outlines current evidence regarding cardiovascular risk in women and men with PAD, the relative significance of traditional and non-traditional risk factors and sex differences in cardiovascular risk management.

Frailty as a Predictor of Adverse Outcomes After Peripheral Vascular Surgery in Patients With End-Stage Renal Disease

BACKGROUND

Frailty and end-stage renal disease (ESRD) are each independently associated with adverse outcomes in patients who undergo lower extremity vascular bypass operations (LEOs). It is not known whether frailty imparts additional risk to patients with ESRD having LEO.

METHODS

The study was a retrospective cohort study of 29 203 patients without ESRD and 1718 with ESRD who had LEO surgery between the years 2014 and 2018 extracted from the American College of Surgeons National Surgical Quality Improvement Program database. Preoperative frailty was assessed using a simplified frailty index based on a history of diabetes, heart failure, chronic obstructive pulmonary disease, hypertension, and functional status. Adverse outcomes measured were 30-day mortality, surgical complications, reoperation, length of stay, readmission, discharge destination, and any ("composite") adverse outcome. Odds ratios (ORs) for adverse outcomes were calculated with logistic regression.

RESULTS

Among patients with ESRD, the OR for having the composite adverse outcome was greater for frailty than for any of the other preoperative risk factors studied (OR 2.191, CI 1.569-3.061, P < .001). Adverse outcomes occurred in 84.3% of frail patients with ESRD, but in only 39.6% of the non-frail patients without ESRD.

CONCLUSIONS

Frailty imparts additional risk for adverse outcomes to patients with ESRD undergoing LEO.

Sex-related disparities in intervention rates and type of intervention in patients with aortic and peripheral arterial diseases in the National Inpatient Sample Database

OBJECTIVE

The first annual Women's Vascular Summit highlighted sex- and gender-related knowledge gaps in vascular disease diagnosis and treatment. This finding suggests an opportunity for further research to improve care and outcomes in people who identify as women, specifically. The purpose of this study was to a large national dataset to identify all operations performed for abdominal aortic aneurysm (AAA), carotid artery stenosis (CAS), and peripheral arterial disease (PAD) in the United States, and to provide data on sex-related disparities in treatment.

METHODS

All hospitalizations of adult patients (≥18 years old) diagnosed with AAA, CAS, or PAD who underwent vascular surgery from 2000 to 2016 were identified in the Healthcare Cost and Utilization Project National Inpatient Sample. Sex-stratified U.S. Census data and sex-specific population disease prevalence estimates from the National Institute of Health and Agency for Healthcare Research and Quality were used to calculate the number of U.S. adults with AAA, CAS, and PAD. Sex-stratified rates of surgery and incidence rate ratios were estimated using Poisson regression. Among those undergoing surgery, multivariable logistic regression was used to assess differences in endovascular vs open approach.

RESULTS

Over 16 years, there were 1,021,684 hospitalizations for vascular surgery: 13% AAA (21% female, 79% male), 40% CAS (42% female, 58% male), and 47% PAD (42% female, 58% male). Females were older than males at time of surgery (median age, 71.3 years vs 69.7 years) and less likely to have private insurance (18% vs 23%); minimal differences were seen across race/ethnicity, comorbidities, and hospital characteristics. After accounting for disease prevalence, females were still 25% less likely to undergo surgery for AAA and 30% less likely to undergo surgery for PAD compared with males with the same disease. These results were consistent over time. After adjustment, females, compared with males, were less likely to receive an endovascular procedure compared with open for AAA or CAS, and more likely to receive one for PAD.

CONCLUSIONS

From 2000 to 2016 in the United States, females were less likely to undergo intervention for AAA and PAD than males. This finding is particularly significant for PAD, because the prevalence is the same for both sexes, indicating that females are likely undertreated for PAD. Additionally, females were less likely to undergo endovascular surgery for AAA and more likely to undergo endovascular surgery for PAD than males. These findings suggest that improvement in AAA and PAD identification and management in females may improve outcomes.

Factors associated with infrainguinal bypass graft patency at 1-year; a retrospective analysis of a single centre experience

INTRODUCTION

The aim of this study was to identify factors associated with primary graft patency 1 year following open lower limb revascularisation (LLR) at a tertiary referral vascular service.

METHODS

A retrospective analysis of patients undergoing infra-inguinal bypass surgery between January 2016 and May 2017 at a tertiary vascular centre (St Mary's Hospital, London) was performed. Data regarding patient demographics, comorbidities, type of operation and post-operative anti-thrombotic strategy were collected. Quality of run-off score was assessed from pre-operative imaging.

RESULTS

Seventy-seven cases were included in the analysis. Overall, the primary patency rate at 1-year was 63.6% (n = 49/77) and the secondary patency rate was 67.5% (n = 52/77). Independent variables with statistically significant inferior patency rates at 1-year were (1) bypasses with below knee targets (p = 0.0096), (2) chronic limb threatening ischaemia indication (p = 0.038), (3) previous ipsilateral revascularisation (p < 0.001) and (4) absence of hypertension history (p = 0.041). There was also a trend towards significance for American Society of Anesthesiologists (ASA) grade (p = 0.06). Independent variables with log-rank test p values of <0.1 were included in a Cox proportional hazards model. The only variable with a statistically significant impact on primary patency rates was previous open or endovascular ipsilateral revascularisation (HR 2.44 (1.04-5.7), p = 0.04).

CONCLUSION

At 1-year follow-up, previous ipsilateral revascularisation was the most significant factor in affecting patency rates. Patients in this subgroup should therefore be deemed high-risk, which should be reflected in the informed consent and peri-operative management.

Active smoking is associated with higher rates of incomplete wound healing after endovascular treatment of critical limb ischemia

The association between active smoking and wound healing in critical limb ischemia (CLI) is unknown. Our objective was to examine in a retrospective cohort study whether active smoking is associated with higher incomplete wound healing rates in patients with CLI undergoing endovascular interventions. Smoking status was assessed at the time of the intervention, comparing active to no active smoking, and also during follow-up visits at 6 and 9 months. Cox regression analysis was conducted to compare the incomplete wound healing rates of the two groups during follow-up. A total of 264 patients (active smokers: n = 41) were included. Active smoking was associated with higher rates of incomplete wound healing in the 6-month univariate Cox regression analysis (hazard ratio (HR) for incomplete wound healing: 4.54; 95% CI: 1.41-14.28; p = 0.012). The 6-month Kaplan-Meier (KM) estimates for incomplete wound healing were 91.1% for the active smoking group versus 66% for the non-current smoking group. Active smoking was also associated with higher rates of incomplete wound healing in the 9-month univariable (HR for incomplete wound healing: 2.32; 95% CI: 1.11-4.76; p = 0.026) and multivariable analysis (HR for incomplete wound healing: 9.09; 95% CI: 1.06-100.0; p = 0.044). The 9-month KM estimates for incomplete wound healing were 75% in the active smoking group versus 54% in the non-active smoking group. In conclusion, active smoking status at the time of intervention in patients with CLI is associated with higher rates of incomplete wound healing during both 6- and 9-month follow-up.

Long-Term Outcome of Common Femoral Artery Endarterectomy In Octogenarians and Non-Octogenarians

OBJECTIVE

Arteriosclerotic disease of the common femoral artery can be treated by surgical or endovascular intervention. Elderly patients are said to have a worse outcome if treated by surgical means; however, data to support this theory are missing.

METHODS

Retrospective analysis of all patients who underwent common femoral artery endarterectomy between March 2007 and July 2018 in our clinic. Group 1 included all patients <80 years and Group 2 included all patients ⩾80 years. Endpoints were patency rates, limb salvage, and overall survival.

RESULTS

During this time period, 977 common femoral artery endarterectomies were performed. Indication was claudication in 61.5% and critical limb ischemia in 38.5%. Group 1 included 805 cases (82.4%) and Group 2 included 172 cases (17.6%). Thirty-day mortality was 2.7% (Group 1 = 1.6% versus Group 2 = 7.6%; p < 0.001) and 30-day major amputation was 1.1% (Group 1 = 0.7% versus Group 2 = 2.9%; p = .043). Primary patency and secondary patency were 84.2% and 96.8%, respectively, after 7 years. Limb salvage (93.7%, Group 1 = 94.1% versus Group 2 = 91.8%; p = .088) and overall survival (52.0%, Group 1 = 59.1% versus Group 2 = 15.7%; p = .006) were significantly different after the same time period. Multivariable analysis showed female gender to be a risk factor for loss of primary patency. Age ⩾ 80 years and ulcer or gangrene were risk factors for death. Statin use was beneficial to survival.

CONCLUSIONS

Common femoral artery endarterectomy is a safe procedure with excellent long-term results. Octogenarians have an increased risk for perioperative mortality and major amputation.

Innovative endovascular approach for limb salvage in critical limb ischemia

In the absence of feasible revascularization, nearly one third of patients with critical limb ischemia experienced major amputation at 6 months. In patients with an independent living status, this decision is difficult to support without exhausting all chances to attain limb salvage and preserve functional autonomy. The present report describes a new procedure of revascularization by performing a full endovascular extra-anatomic femoropopliteal bypass for the treatment of limb-threatening ischemia. The patient presented with extensive tissue loss and a short-term risk of major amputation. She had experienced previous failure of conventional surgical and endovascular revascularization procedures and ligation of proximal femoral artery precluded any further revascularization attempt. Limb salvage was achieved with this endovascular revascularization procedure with complete wound closure. The patient still presents an independent living status and preserved functional autonomy without wound recurrence after a follow-up of more than 5 years.

High plateletcrit is associated with early loss of patency after open and endovascular interventions for chronic limb ischemia

OBJECTIVE

Plateletcrit (PCT) reflects the total platelet mass in blood and can be calculated from a complete blood count. We examined the effect of PCT on outcomes of endovascular and open interventions for chronic limb ischemia.

METHODS

Patients who underwent revascularization for chronic limb ischemia (Rutherford categories 3-6) between June 2001 and December 2014 were retrospectively identified. PCT on admission was recorded. Patients and limbs were divided into tertiles of low (0.046-0.211), medium (0.212-0.271), and high (0.272-0.842) PCT. Patency, limb salvage, major adverse limb events, major adverse cardiac events, and survival rates were calculated using Kaplan-Meier analysis and compared with log-rank test. Cox regression analysis was used for multivariate analysis.

RESULTS

A total of 1431 limbs (1210 patients) were identified and divided into low PCT (477 limbs in 407 patients), medium PCT (477 limbs in 407 patients), and high PCT (477 limbs in 396 patients) groups. The patients in the high tertile were 2 years older that the patients in the other two tertiles (P = .009). Five-year primary patency was 65% ± 3% in the low-PCT group compared with 55% ± 3% and 51% ± 3% in the medium and high PCT groups, respectively (P = .004). Five-year secondary patency was 81% ± 2% in the low PCT group compared with 82% ± 2% and 72% ± 3% in the medium and high PCT groups, respectively (P = .02). Five-year limb salvage rate was 86% ± 2% in the low PCT group compared with 79% ± 3% and 74% ± 3% in the medium PCT and high PCT groups, respectively (P = .004). Multivariate regression analysis showed that low PCT was independently associated with primary patency after endovascular interventions (hazard ratio, 0.67 [0.47-0.95]; P = .02) but not after open interventions (hazard ratio, 0.72 [0.43-1.21]; P = .21).

CONCLUSIONS

High PCT is associated with poor patency and limb salvage rates after interventions for lower extremity chronic limb ischemia. Multivariate regression analysis confirmed association of low PCT with improved primary patency after endovascular interventions but not after open interventions. High PCT may be a marker of increased platelet reactivity and could be used to identify patients at high risk for early thrombosis and failure after interventions.

Patient doses in endovascular and hybrid revascularization of the lower extremities

OBJECTIVE:

Hybrid surgical methods such as remote endarterectomy and endovascular revascularization are fluoroscopy-guided procedures successfully replacing conventional open surgery for treatment of peripheral artery disease (PAD). The aim of this study was to: (1) evaluate the dose parameters describing exposure of patients undergoing endovascular or hybrid revascularization of the lower limb (below the inguinal ligament); (2) compare the data available in the literature with the evaluations of patients' dose values and related factors for patients undergoing such procedures; (3) examine the correlation of doses with certain parameters; (4) estimate the peak skin dose and assess the potential for radiation-induced skin injuries during the procedures.

METHODS:

Data for 259 patients were extracted retrospectively and analyzed. The procedures were grouped by type of intervention, vascular approach, and level of complexity. The analyses included the correlation of dose values with the operating team.

RESULTS:

The air kerma-area product (KAP) and fluoroscopy time (FT) values greatly varied depending on the procedure type but also among patients undergoing the same procedure. The type of vascular access has the largest impact on patients' doses. The KAP and FT values for brachial artery were: 347 Gy.cm² and FT: NA; for contralateral common femoral artery (CFA) approach: 207 Gy.cm² and 153 s; e.g. significantly higher than for ipsilateral CFA: 96 Gy.cm² and 78 s; for hybrid surgery: 77 Gy.cm² and 41 s; and for ipsilateral retrograde popliteal approach: 61 Gy.cm² and 53 s. The same tendency is observed for the peak skin dose (PSD) values: the highest are for brachial artery (2053 mGy) and contralateral CFA (1325 mGy) approach, followed by the ipsilateral CFA (748 mGy), hybrid surgery (649 mGy), and ipsilateral retrograde popliteal approach (566 mGy).

CONCLUSION:

Registered dose values and FT for the different procedures do not exceed the International Atomic Energy Agency (IAEA) proposed trigger values for patients' follow-up for radiation-induced skin injuries. The type of vascular access has the highest negative impact on radiation dose levels and resultant KAP, PSD, and FT values. There is a significant increase of the dose values with increase of the number of inserted stents and the level of complexity. This should be considered in planning, especially for patients who undergo multiple diagnostic and therapeutic procedures.

ADVANCES IN KNOWLEDGE:

This study gives a systematic understanding for patient radiation exposure in endovascular and hybrid revascularization of the lower extremities, thus far absent in the literature.

Gender Differences in Peripheral Vascular Disease

In the past 20 years, peripheral artery disease (PAD) has been increasingly recognized as a significant cause of morbidity and mortality in the United States. PAD has traditionally been identified as a male-dominant disease; however, recent population trends and studies in PAD suggest that women are affected at least as often as men. Women comprise a larger population of the elderly than men, as well as an increasing proportion of patients with PAD. Much of the existing research on PAD has focused on whole populations, and gender-specific data on PAD is sparse. This review focuses on gender-specific differences in presentation, management, and outcomes of PAD intervention that are important considerations for the interventional radiologist.

External Validation and Evaluation of Reliability of the FARP2 Score to Predict Early Graft Failure after Infrainguinal Bypass

BACKGROUND

To evaluate the accuracy of the FARP₂ (female gender [F], bypass after a previous angioplasty [A], Redo bypass [R], and Pedal bypass [P₂]) scoring system in predicting early graft failure (EGF) after infrainguinal bypass surgery (IBS).

METHODS

Charts of patients who underwent IBS between January 2014 and January 2017 in 2 tertiary academic centers were evaluated retrospectively. In follow-ups, 1 week after operation, detailed physical examination was done, Doppler ultrasonography was performed 1 month after operation, and integrity of the graft was evaluated. Calculation of FARP₂ score was performed by a single surgeon (M.S.) who was well informed regarding FARP₂ scoring system. The FARP₂ scoring system was evaluated as following: female gender 1 point, bypass after a previous angioplasty 1 point, redo bypass 1 point, and pedal bypass 2 points.

RESULTS

Totally, 231 patients (180 men and 51 women) were enrolled in the study. The mean FARP₂ score was 0.52 ± 0.73. The graft occlusion occurred in 23 patients (10%). Presence of critical leg ischemia was lower in patients who faced early graft occlusion (P = 0.002). On the other hand, Rutherford classification score was significantly higher in patients who did not face graft occlusion (4.1 vs. 3.4, P = 0.007). Moreover, unsuccessful angioplasty history and history of previous surgery were more common in that group (P < 0.001 and P < 0.001, respectively). None of the patients faced acute pulse loss, numbness loss, or ulcerative lesion after unsuccessful angioplasty. The mean interval between unsuccessful angioplasty and bypass was 1 ± 1.2 days in our study, which may have a role to prevent undesirable clinical consequences. The FARP₂ score was 1.5 ± 1.2 and 0.4 ± 0.6 in patients who faced graft occlusion and in patients without occlusion (P < 0.001). Multivariate regression analysis identified that critical leg scheme, presence of unsuccessful angioplasty history, and history of previous bypass operation were found as a predictive factor for EGF (P = 0.044, P < 0.001, and P = 0.003, respectively). Finally, our study demonstrated that patients with FARP₂ score 3-4 have 2.88-fold increased graft occlusion risk when compared with patients with FARP₂ score 1-2.

CONCLUSIONS

Our study externally validates that the FARP₂ scoring system is related with EGF after IBS. The FARP₂ score may be an effective practice in prediction of EGF in patients with peripheral arterial bypass surgery.

Development of a Scoring System for the Prediction of Early Graft Failure after Peripheral Arterial Bypass Surgery

BACKGROUND

An occluded lower limb arterial bypass is associated with poor prognosis for the limb. Currently, no risk assessment method to estimate the risk of early graft failure exists. Aim of this study was to investigate the effect of various potential factors on early graft failure of infrainguinal bypass surgery and to develop a risk-scoring model to predict it.

METHODS

A prospective observational clinical study was performed. One hundred infrainguinal bypass procedures (60 autologous and 40 synthetic grafts), throughout a 3-year period were included. Nearly, 84 patients suffered by chronic limb ischemia, whereas 16 by acute limb ischemia or popliteal aneurysm disease. Various possible factors including demographic data, atherosclerosis predisposing factors, and technical details of the procedure were examined as possible causes of early graft failure. Using a combination of univariable and multivariable analysis techniques, the most significant factors were extracted, and a simple predicting risk-scoring system of early graft failure was calculated.

RESULTS

The overall early graft failure rate was 14%. The factors related to it at a statistically significant level, 0.05, were the female gender, a bypass performed after a previous ipsilateral lower limb angioplasty, a redo procedure on the same limb, and a distal anastomosis at an inframalleolar level (pedal bypass). After internal validation, the FARP₂-predicting scoring system was formed as following: Female gender 1 point (F), bypass after a previous Angioplasty 1 point (A), Redo bypass 1 point (R), and Pedal bypass 2 points (P₂). An overall score equal or greater than 2, provided an early graft failure prediction with sensitivity of 100%, specificity 86%, positive predictive value 54%, and negative predictive value of 100% (area under the receiver operator characteristic curve: 0.959).

CONCLUSIONS

FARP₂ is a simple scoring system for predicting early graft failure after an infrainguinal bypass procedure. Further external validation in larger populations is needed.

Coagulation, Fibrinolysis, and Platelet Activation Following Open Surgical or Percutaneous Angioplasty Revascularization for Symptomatic Lower Limb Chronic Ischemia

Introduction:

Critical limb ischemia (CLI) is associated with a prothrombotic diathesis that involves a complex balance between the coagulation and fibrinolytic systems. Knowledge of this is essential when considering revascularization procedures but is often overlooked. The aim of this review is to summarize the available literature and provide an overview of the effects of lower limb angioplasty and open surgical revascularization on coagulation, fibrinolysis, and platelet activation.

Methods:

A MEDLINE and EMBASE search was conducted between 1973 and 2014 for articles relating to the effects of revascularization for patients with CLI on the fibrinolytic and coagulation pathways. Studies with a small cohort of patients (<5) were rejected.

Results:

Many of the studies included in this analysis had small cohorts. Multiple markers were assessed across the published literature including von Willebrand factor, tissue factor, prothrombin fragments 1 and 2, platelets, soluble platelet selectin, plasminogen activator inhibitor 1, tissue plasminogen activator, and thrombin–antithrombin complex. Percutaneous intervention causes an exaggerated prothrombotic and a disturbed fibrinolytic effect. Surgery seems to cause a similar prothrombotic derangement with reduced fibrinolysis and platelet hyperactivity, but this appears to be maintained for a considerable amount of time postoperatively.

Conclusion:

There is a sparse amount published on the effects of the coagulation and fibrinolytic systems in patients undergoing intervention for CLI. Much of these studies are small, historical, and completely heterogeneous, making it difficult to draw meaningful conclusions. The literature does identify a prothrombotic state in patients with CLI, which appears to be exacerbated by any form of intervention and prolonged in those having surgery. Understanding this may allow us to tailor the intervention offered to patients and prevent limb loss.

Tibial bypass salvage with eptifibatide in a patient with thrombocythemia

Early graft failure is a complex and challenging clinical condition faced by vascular surgeons performing infrainguinal bypass surgery. This case describes a patient with undiagnosed thrombocytosis undergoing urgent open revascularization for critical limb ischemia. The operative case was complicated by recurrent on-table acute thrombosis that was successfully managed with intravenous glycoprotein IIb/IIIa antagonism with eptifibatide. This is a novel case of its use for on-table salvage of an infrainguinal bypass graft. This case report outlines this challenging clinical problem and a novel use for glycoprotein IIb/IIIa antagonists.

Necrotizing soft tissue infection following a peripheral bypass

BACKGROUND

Necrotizing soft tissue infection (NSTI), formerly referred to as necrotizing fasciitis, is a rare but serious postoperative complication. NSTI following arterial bypass is seen only once in the literature (for a coronary artery bypass) and is not mentioned following peripheral bypass. Although surgical site infections have been studied extensively, there are limited published data on postoperative NSTI and no data for NSTI following peripheral arterial bypass.

CASE PRESENTATION

Here we present the first, to our knowledge, reported instance of an NSTI following a lower extremity peripheral bypass. Despite the continued function of the bypass, the patient became rapidly systemically ill with a focus at the surgical site. Because of prompt surgical debridement, the patient survived this severe infection, though did require an above the knee amputation to control the rapid spread of the disease. The patient, a native of American Samoa, was infected with organisms infrequently associated with NSTI, Morganella morganii and Aeromonas hydrophila. This article discusses the diagnosis and treatment of this rare postoperative complication, along with a brief review of the microbiology of the disease.

CONCLUSIONS

NSTI is a rare but lethal postoperative complication. To our knowledge, this is the first reported case of an NSTI following an arterial peripheral bypass. This patient survived because of prompt and aggressive intervention.

Use of completion imaging during infrainguinal bypass in the Vascular Quality Initiative

OBJECTIVE

The purpose of this study was to examine the practice patterns of intraoperative completion imaging (CI) for lower extremity bypass (LEB) in the Vascular Quality Initiative (VQI).

METHODS

A retrospective review of all LEB procedures in the VQI database from January 2003 to October 2013 was performed. Regions with fewer than 200 LEB procedures were excluded from the regional analysis. The modality of CI was defined as duplex ultrasound, angiography, or both.

RESULTS

A total of 14,140 LEBs were captured, with the rate of CI being 43%. After exclusion of three regions for insufficient volume (<200 LEBs), 13,945 LEB operations across 13 regions were available for regional analysis. Use of any type of intraoperative CI varied across regions from a low of 8% to a high of 70%, with angiography being performed most frequently. When CI was performed, the type of imaging modality varied between regions from a high of 99% for angiography to a high of 75% for duplex ultrasound. CI was more common in male patients (44% of male patients vs 42% of female patients; P = .032), diabetics (44% of diabetic patients vs 42% of nondiabetic patients; P = .026), and patients with coronary artery disease (45% of patients with coronary artery disease vs 42% of patients with no coronary artery disease; P = .0015). CI was performed less frequently in LEB using single-segment great saphenous vein vs LEB using lesser saphenous, arm, or composite vein (48% vs 57%; P < .0001). CI was used in 51% of LEBs with a tibial or pedal target vessel vs 38% of LEBs with a more proximal target vessel (P < .0001). Patients with an indication of critical limb ischemia underwent CI in 45% of LEBs vs 39% with an indication other than critical limb ischemia (P < .0001).

CONCLUSIONS

Within the VQI database, considerable practice pattern variation exists in the use of CI. Currently, CI is most commonly employed for patients with critical limb ischemia, infrageniculate target vessel, and disadvantaged venous conduit. Further study is required to standardize and to define the appropriate use of CI for LEBs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Gender-specific risk factors for peripheral artery disease in a voluntary screening population

Background

Women have high rates of peripheral artery disease (PAD) despite fewer cardiovascular disease (CVD) risk factors, compared to men. We sought to determine the gender‐specific prevalence of low ankle brachial index (ABI) and the relationship to C‐reactive protein (CRP) levels and CVD risk factors in the Life Line Screening population.

Methods and Results

Between April 2005 and August 2011, 133 750 women and 71 996 men had ABI and CRP measured at a Life Line Screening Center. Women were slightly older than men, whereas men were more likely to be current smokers, have diabetes mellitus (DM), and coronary artery disease (CAD) (P<0.001 for each). Women were more likely to have ABI≤1.0, compared to men (26.6% versus 14.4%, respectively; P<0.001), as well as ABI≤0.9 (4.1% women versus 2.6% men; P<0.001). Women had higher median CRP levels (1.94 mg/L; interquartile range [IQR], 0.89, 4.44 mg/L), compared to men (1.35 mg/L; IQR, 0.73, 2.80 mg/L; P<0.001). Men and women shared similar risk factors for ABI≤0.9, including older age, black race, smoking, DM, hypertension, hypercholesterolemia, CAD, and elevated CRP levels. In an adjusted model, there were significant interactions between gender and age (P<0.001), CRP (P<0.001), CAD (P=0.03), and DM (P=0.06) with ABI as the outcome. The associations between age, CRP, CAD, and DM with ABI≤0.9 were stronger in men than in women.

Conclusions

Women participating in the Life Line Screening had higher CRP levels and a higher prevalence of PAD, compared to men. Neither higher CRP levels nor conventional CVD risk factors explained the excess prevalence of PAD in women.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Diagnosis and management of peripheral artery disease in women

Peripheral artery disease (PAD) is a significant cause of morbidity and mortality in the USA. Not only is it a major cause of functional impairment and limb loss, but it is also strongly associated with an increased risk of myocardial infarction, stroke, and death. Large population studies have demonstrated high rates of PAD in women, but this is not widely recognized by the public or by clinicians. One potential reason for this is that women with PAD are more likely than men to be asymptomatic or have atypical symptoms. In addition, women with PAD experience higher rates of functional decline and may have poorer outcomes after surgical treatment for PAD compared with men. Currently, it is not known if there are sex-specific differences in risk factors for the onset, progression, and surgical outcomes of PAD. This review will focus on the diagnosis and management of PAD in women and examine sex-specific differences in the prevalence, risk factors, presentation, and outcomes of this disease.

Prevalence of thrombocytosis in critically ill patients and its association with symptomatic acute pulmonary embolism. A multicentre registry study

It is uncertain whether thrombocytosis without underlying myeloproliferative diseases is associated with an increased risk of acute pulmonary embolism (PE). We investigated the relationship between thrombocytosis and risk of symptomatic acute PE, and whether Pulmonary Embolism Severity Index (PESI) was reliable in predicting mortality of acute PE. This multicentre registry study involved a total of 609,367 critically ill patients admitted to 160 intensive care units (ICUs) in Australia or New Zealand between 2006 and 2011. Forward stepwise logistic regression was used to assess the relationship between risk of acute PE and platelet counts on intensive care unit (ICU) admission. Acute PE (n=3387) accounted for 0.9% of all emergency ICU admissions. Over 20% of all PE required mechanical ventilation, 4.2% had cardiac arrest, and the mortality was high (14.8%). Thrombocytosis, defined by a platelet count >500x10⁹ per litre, occurred in 2.1% of the patients and was more common in patients with acute PE than other diagnoses (3.4 vs. 2.0%). The platelet counts explained about 4.5% of the variability and had a linear relationship with the risk of acute PE (odds ratio 1.19 per 100x10⁹ per litre increment in platelet count, 95% confidence interval 1.06-1.34), after adjusting for other covariates. The PESI had a reasonable discriminative ability (area under receiver-operating-characteristic curve = 0.78) and calibration to predict mortality across a wide range of severity of acute PE. In summary, thrombocytosis was associated with an increased risk of symptomatic acute PE. PESI was useful in predicting mortality across a wide range of severity of acute PE.

Reactive thrombocytosis and risk of subsequent venous thromboembolism: a cohort study

BACKGROUND

It is uncertain whether reactive thrombocytosis is associated with an increased risk of venous thromboembolism. This study assessed the incidence of reactive thrombocytosis, defined as platelet count ≥ 500 × 10(9)  L(-1) , at intensive care unit discharge and its association with subsequent venous thromboembolism.

METHODS AND RESULTS

This cohort study involved linkage of routinely collected intensive care unit, laboratory, radiology and death registry data of critically ill patients admitted to the intensive care unit between January 2009 and March 2010. The census date for survival and radiologically confirmed venous thromboembolism was 31 October 2011. Of the 1446 patients who survived to intensive care unit discharge, 139 patients had reactive thrombocytosis (9.6%, 95% confidence interval [CI] 8.2-11.2%). Twenty-nine patients developed venous thromboembolism after discharge (2%, 95% CI 1.4-2.9%; 67 per 100 person-years, 95% CI 45-97) and the median time to develop venous thromboembolism was 25 days (interquartile range 8-148). Reactive thrombocytosis was associated with an increased risk of subsequent venous thromboembolism (hazard ratio 5.3, 95% CI 1.7-16.4), after adjusting for other covariates. Platelet counts explained about 34% of the variability in the risk of venous thromboembolism and had a relatively linear relationship with the risk of venous thromboembolism when the platelet counts were > 400 × 10(9)  L(-1) . Venous thromboembolism after intensive care unit discharge was associated with an increased risk of mortality (hazard ratio 2.0, 95% CI 1.1-3.9), after adjusting for reactive thrombocytosis.

CONCLUSIONS

Reactive thrombocytosis during the recovery phase of critical illness was associated with an increased risk of subsequent venous thromboembolism.