Trends, complications, and mortality in peripheral vascular surgery

Association of Human Immunodeficiency Virus Infection and Risk of Peripheral Artery Disease

BACKGROUND

The effect of human immunodeficiency virus (HIV) on the development of peripheral artery disease (PAD) remains unclear. We investigated whether HIV infection is associated with an increased risk of PAD after adjustment for traditional atherosclerotic risk factors in a large cohort of HIV-infected (HIV+) and demographically similar HIV-uninfected veterans.

METHODS

We studied participants in the Veterans Aging Cohort Study from April 1, 2003 through December 31, 2014. We excluded participants with known prior PAD or prevalent cardiovascular disease (myocardial infarction, stroke, coronary heart disease, and congestive heart failure) and analyzed the effect of HIV status on the risk of incident PAD events after adjusting for demographics, PAD risk factors, substance use, CD4 cell count, HIV-1 ribonucleic acid, and antiretroviral therapy. The primary outcome is incident peripheral artery disease events. Secondary outcomes include mortality and amputation in subjects with incident PAD events by HIV infection status, viral load, and CD4 count.

RESULTS

Among 91 953 participants, over a median follow up of 9.0 years, there were 7708 incident PAD events. Rates of incident PAD events per 1000 person-years were higher among HIV+ (11.9; 95% confidence interval [CI], 11.5-12.4) than uninfected veterans (9.9; 95% CI, 9.6-10.1). After adjustment for demographics, PAD risk factors, and other covariates, HIV+ veterans had an increased risk of incident PAD events compared with uninfected veterans (hazard ratio [HR], 1.19; 95% CI, 1.13-1.25). This risk was highest among those with time-updated HIV viral load >500 copies/mL (HR, 1.51; 95% CI, 1.38-1.65) and CD4 cell counts <200 cells/mm³ (HR, 1.91; 95% CI, 1.71-2.13). In contrast, HIV+ veterans with time updated CD4 cell count ≥500 cells/mm³ had no increased risk of PAD (HR, 1.03; 95% CI, 0.96-1.11). Mortality rates after incident PAD events are high regardless of HIV status. HIV infection did not affect rates of amputation after incident PAD events.

CONCLUSIONS

Infection with HIV is associated with a 19% increased risk of PAD beyond that explained by traditional atherosclerotic risk factors. However, for those with sustained CD4 cell counts <200 cells/mm³, the risk of incident PAD events is nearly 2-fold higher whereas for those with sustained CD4 cell counts ≥500 cells/mm³ there is no excess risk of incident PAD events compared with uninfected people.

Sonographic Evaluation of Complications of Extracranial Carotid Artery Interventions

Carotid endarterectomy and carotid artery stenting are among the most common peripheral vascular procedures performed worldwide. Sonography is the initial and often only imaging modality used in the evaluation of iatrogenic carotid arterial injuries. This pictorial essay provides an overview of the clinical and sonographic findings of complications after interventions in the extracranial carotid arteries, including dissection, fluid collections, pseudoaneurysm, thrombosis, thromboembolism, restenosis, and stent deformation. Grayscale, color, and pulsed Doppler imaging findings are reviewed, and correlations with computed tomography, magnetic resonance imaging, and angiography are provided.

Epidemiology of abdominal aortic aneurysms in a Chinese population during introduction of endovascular repair, 1994 to 2013: A retrospective observational study

The aim of this study was to examine changes in abdominal aortic aneurysm repair and mortality during a period when endovascular aneurysm repair (EVAR) was introduced.Open repair surgery was the mainstay of treatment for abdominal aortic aneurysm (AAA), but EVAR is increasingly utilized. Studies in the Western population have reported improved short-term or postoperative mortality and shorter length of hospital stay with EVAR. However, scant data are available in the Chinese population.We conducted a retrospective observational study using the database of the Hospital Authority, which provides public health care to most of the Hong Kong population. AAA patients admitted to public hospitals for intact repair or rupture from 1994 to 2013 were included in this study. We calculated the incidence of ruptured AAA, annual repair rates according to type of AAA and surgery, as well as death rates (operative and overall short-term). We calculated whether there were significant changes over time and compared short-term mortality between open surgery and EVAR.One thousand eight hundred eighty-five patients were admitted for intact repair and 1306 patients were admitted for AAA rupture, of whom 795 underwent rupture repair. Intact repair rates significantly increased in all age groups (7.3-37.8%, P < .001) over the study period.The incidence of ruptured AAA increased, in all age groups, except in < 64 years old. By 2013, 85% of intact repairs and 55.4% of rupture repair were done by EVAR. Over time, there was a significant decrease in operative mortality for intact repair (16.5 in 1994 to 7.1 in 2013, P = .01) and rupture repair (59.7 in 1994 to 30.8 in 2013, P = .003). Over the same time period, short-term AAA-related deaths decreased by more than half (73% in 1994 to 24% in 2013, P < .001), with a significant decline in all age groups, except < 64 years old. Short-term mortality was significantly lower for EVAR than for open repair (17.2% vs 40.3%, P < .01).Short-term AAA-related deaths have declined likely due to decreased operative mortality and rupture deaths during the period of EVAR introduction and expansion.

Risk and outcomes of fracture in peripheral arterial disease patients: two nationwide cohort studies

Using national insurance claims data of Taiwan, we found that patients with peripheral arterial disease (PAD) had increased risk of fracture during the follow-up period of 2000-2013. History of PAD was also associated with adverse outcomes in hospitalized fracture patients. Prevention strategies were needed in this susceptible population.

INTRODUCTION

Limited information was available on the association between PAD and fracture. The purpose of this study is to evaluate fracture risk and post-fracture outcomes in patients with PAD.

METHODS

We identified 6647 adults aged ≥ 20 years with newly diagnosed PAD using the Taiwan National Health Insurance Research Database in 2000-2004. Comparison cohort consisted of 26,588 adults without PAD randomly selected with frequency matching in age and sex. Events of fracture were identified during the follow-up period from January 1, 2000 until December 31, 2013, to evaluate adjusted hazard ratios (HR) and 95% confidence interval (CI) of fracture associated with PAD. Another nested cohort study of 799,463 hospitalized fracture patients analyzed adjusted odds ratios (ORs) and 95% CIs of adverse events after fracture among patients with and without PAD in 2004-2013.

RESULTS

Incidences of fracture in people with and without PAD were 22.1 and 15.5 per 1000 person-years, respectively (P < .0001). Compared with control, the adjusted HR of fracture was 1.59 (95% CI, 1.48-1.69) for PAD patients. In the nested cohort study, patients with PAD had higher post-fracture mortality (OR = 1.16; 95% CI, 1.09-1.25) and various complications. PAD patients also had comparatively higher medical expenditure (2691 vs. 2232 USD, P < .0001) and longer hospital stay (10.6 vs. 9.0 days, P < 0.0001) during fracture admission.

CONCLUSIONS

Increased risk of fracture and post-fracture adverse outcomes were associated with PAD. This susceptible population needs care to prevent fracture and to minimize adverse outcomes after it occurs.

Surgical and endovascular venous arterialization for treatment of critical limb ischaemia

Patients with critical limb ischaemia have a poor life expectancy. Aggressive revascularization is accepted in order to preserve their independence in the final phase of their lives. Bypass surgery and more recently endovascular interventions with angioplasty and stenting have become the treatment of choice to prevent amputation and to resolve pain. However, as many as 20 % of patients with critical limb ischaemia are unsuitable candidates for a vascular intervention because of extensive occlusions of outflow in the crural and pedal vessels. Such "no-option critical limb ischaemia" may be treated with venous arterialization. In the present review, we discuss the history of the venous arterialization procedure, the mechanisms, the different techniques, and complications of venous arterialization.

Comparison of Endovascular Versus Bypass Surgery in Femoropopliteal TASC II D Lesions: A Single-Center Study

BACKGROUND

In patients with severe occlusive disease (Trans-Atlantic Inter-Society Consensus II D [TASC II D]) of the femoropopliteal segment, the advantages of endovascular versus bypass revascularization still remain debated. Most reports available in literature comparing percutaneous transluminal angioplasty (PTA) ± bare metal stent (BMS) versus synthetic bypass analyze patients with heterogeneous anatomical lesions creating possible bias when results of different treatments are matched. In this study, we compared early and midterm outcomes of PTA ± BMS versus heparin-bonded expanded polytetrafluoroethylene graft (Propaten-Gore) + Linton patch in patient affected by symptomatic femoropopliteal TASC II-D lesions.

METHODS

Eighty limbs with symptomatic severe occlusive disease (TASC II D) of the femoropopliteal segment observed from January 2013 to January 2017 were included in this retrospective study. Indication to treatment was severe claudication in 17 limbs (21.2%) and critical limb ischemia (CLI) in 63 (78.8%). 36.2% of limbs presented at least 2 distal patent vessels, and 63.8% had only 1 patent vessel. Of these limbs, 40 were treated by means of PTA ± BMS (group A), and 40 were treated by means of femoropopliteal bypass with Propaten-Gore graft + Linton patch (group B). Patients were followed with a clinical assessment and duplex at 1, 6, and 12 months after procedure and then annually. A closer follow-up was performed in case of any complication. Patency, reintervention rate, and limb salvage were compared in the 2 groups.

RESULTS

The mean length of arterial occlusion was 22.1 cm (range, 8-37) in group A versus 25.2 cm (range, 9-41) in group B, P = ns. A slight difference in mean procedural time was observed (83.5 min of group A versus 114 min of group B, minutes, P = 0.02). Mean follow-up was 26.7 months (range, 3-46). Primary patency at 6, 12, and 24 months of group A versus group B was 76.9% vs. 97.5% (P = 0.007), 65.7% vs. 89.1% (P = 0.05), and 52.6% vs. 78.1% (P = 0.005), respectively. Assisted primary patency was 76.9% vs. 97.5% (P = 0.007), 68.5% vs. 91.8% (P = 0.02), and 57.8% vs. 87.5% (P = 0.001), respectively. Secondary patency was 94.8% vs. 97.5% (P = ns), 85.7% vs. 97.2% (P = ns), 73.6% vs. 93.7% (P = 0.004), respectively. Rate of reintervention at 24 months was 45% in group A vs. 20% in group B (P = 0.03). Limb salvage rate at 24 months was 90% for group A vs. 92.5% for group B (P = ns). Univariate analysis showed CLI and poor runoff to be independent risk factors for significant restenosis/occlusion of target artery and reintervention.

CONCLUSIONS

In patients with severe femoropopliteal occlusive disease (TASC II D), the surgical revascularization by means of Propaten-Gore bypass + Linton patch can be considered safe and effective. Early and midterm results of this approach seem to be superior to PTA ± BMS in terms of restenosis/occlusion and reintervention rates. Larger cohort and longer term results are mandatory to better define this advantage.

Validation of an assessment tool for pre-operative EVAR planning

INTRODUCTION

Current methods of teaching endovascular aortic aneurysm repair (EVAR) planning involve non-criteria-based observations that lack validity. The primary aim of this study was to validate an EVAR Planning Objective Structured Assessment of Skill (EpOSAS) tool for the assessment of pre-operative EVAR planning skills.

METHODS

Content analysis was performed in order to inform the formulation of EpOSAS domains. Thirty-five participants planned two cases of infra-renal abdominal aortic aneurysm for EVAR, using the OsiriX 7 platform. EVAR planning measurements, with accompanying screenshots, were uploaded onto an electronic data collection sheet. Performance was assessed by three blinded assessors using the EpOSAS tool. Construct and concurrent validity were evaluated.

RESULTS

Inter-observer reliability for the three assessors for total EpOSAS scores was high (Cronbach's α 0.89). There were statistically significant differences in total EpOSAS scores between the different experience groups, demonstrating construct validity (Novice (5.3, IQR 5-5.3), Intermediate (15.3, IQR 14.8-16.8) and Experts (17.5, IQR 17-17.7), p<0.001). A statistically significant correlation was found between total EpOSAS scores and percentage error in measurements, demonstrating concurrent validity (Spearman's rank correlation coefficient: R=-0.250, p<0.001). Receiver-operator characteristics analysis established a cut-off point of 16 out of 18 for determining competence.

CONCLUSION

We have developed and validated a tool that can be used for the assessment of pre-operative EVAR planning skills.

Electrospun vascular scaffold for cellularized small diameter blood vessels: A preclinical large animal study

The strategy of vascular tissue engineering is to create a vascular substitute by combining autologous vascular cells with a tubular-shaped biodegradable scaffold. We have previously developed a novel electrospun bilayered vascular scaffold that provides proper biological and biomechanical properties as well as structural configuration. In this study, we investigated the clinical feasibility of a cellularized vascular scaffold in a preclinical large animal model. We fabricated the cellularized vascular construct with autologous endothelial progenitor cell (EPC)-derived endothelial cells (ECs) and smooth muscle cells (SMCs) followed by a pulsatile bioreactor preconditioning. This fully cellularized vascular construct was tested in a sheep carotid arterial interposition model. After preconditioning, confluent and mature EC and SMC layers in the scaffold were achieved. The cellularized constructs sustained the structural integrity with a high degree of graft patency without eliciting an inflammatory response over the course of the 6-month period in sheep. Moreover, the matured EC coverage on the lumen and a thick smooth muscle layer were formed at 6months after transplantation. We demonstrated that electrospun bilayered vascular scaffolds in conjunction with autologous vascular cells may be a clinically applicable alternative to traditional prosthetic vascular graft substitutes.

STATEMENT OF SIGNIFICANCE

This study demonstrates the utility of tissue engineering to provide platform technologies for rehabilitation of patients recovering from severe, devastating cardiovascular diseases. The long-term goal is to provide alternatives to vascular grafting using bioengineered blood vessels derived from an autologous cell source with a functionalized vascular scaffold. This novel bilayered vascular construct for engineering blood vessels is designed to offer "off-the-shelf" availability for clinical translation.

Laser-assisted transprosthesial coil embolization combined with thrombin injection for treatment of an endoleak type II after endovascular aneurysm repair

The treatment of endoleaks type II had to be adapted to the anatomy of each individual patient. The laser-assisted perforation of the prosthesis can be an easier method to reach the aneurysm sac directly than using transarterial or translumbar approaches.

One Year Primary Patency of Infrapopliteal Angioplasty Using Drug- Eluting Balloons: Single Center Experience at King Hussein Medical Center

Objective:

Conventional percutaneous transluminal angioplasty (PTA) for long lesions in the below-the-knee (BTK) arteries in patients presenting with critical limb ischemia (CLI) has high restenosis rates at 1 year. Our goal is to evaluate whether paclitaxel drug-eluting balloons (DEB) have higher 1 year primary patency rates compared to conventional PTA.

Methods:

This is a single-center, prospective, randomized trial that was conducted from June 2013 to December 2015. The aim of the study was to compare 1 year primary patency rates of DEB and PTA in BTK arteries in CLI patients. Inclusion criteria were patients presenting with CLI (Rutherford class 4 or greater), stenosis or occlusion ≥30 mm of at least one tibial artery, and agreement to 12-month evaluation. Exclusion criteria were life expectancy <1 year, allergy to paclitaxel, and contraindication to combined antiplatelet treatment. Follow-up was performed by clinical assessment, ankle brachial pressure index, Doppler ultrasound imaging, and conventional angiogram if indicated. Primary end point was 1 year primary patency, and secondary end points were target lesion revascularization (TLR) and major amputation. Statistical analysis was performed using Fischer's exact test.

Results:

Ninety-three patients with 106 lesions in the BTK arteries were enrolled in this study. One year primary patency was achieved in 26 (65%) and seven (17%) in the DEB and PTA groups (P = 0.006), respectively. TLR was performed in nine lesions (23%) and 29 lesions (71%) in DEB and PTA groups (P = 0.009), respectively. Major amputations occurred in one limb (2%) and two limbs (4%) in DEB and PTA groups (P = 0.6), respectively.

Conclusion:

Paclitaxel DEB has significantly higher 1 year primary patency rate associated with significantly less TLR than conventional PTA, following endovascular recanalization of BTK arteries in patients presenting with CLI.

Production and hemocompatibility assessment of novel electrospun polyurethane nanofibers loaded with dietary virgin coconut oil for vascular graft applications

To develop biodegradable polymer scaffolds suitable for vascular tissue engineering applications, the bioengineering community has invested an extensive effort. The most common cause for the failure of vascular graft scaffolds is thrombosis. In this work, the scaffold based on polyurethane and virgin coconut oil was produced by electrospinning process for vascular tissue engineering applications with improved antithrombogenicity. The diameter of this electrospun polyurethane/virgin coconut oil composite was found to be reduced in the range of 886 ± 207 nm compared to pristine polyurethane which was in the range of 969 ± 217 nm. The Fourier transform infrared spectroscopy analysis revealed the interaction between polyurethane and virgin coconut oil as indicated by phase shifting of CH bond along with the formation of hydrogen bond. The contact angle measurement of fabricated composites was found to be increased owing to hydrophobic nature and also exhibited enhanced thermal stability as noted in thermogravimetric analysis. The atomic force microscopy analysis insinuated the increased surface roughness of the composite in comparison with the pure polyurethane. Developed scaffold resulted in delayed blood clotting as revealed by activated partial thromboplastin time and partial thromboplastin time assay. The hemolytic index of fabricated composites was found to be low indicating the enhanced safety of red blood cells. Hence, the newly developed nanofibrous composite scaffold could open the door for a suitable alternative for vascular graft applications.

How to define the hemodynamic significance of an equivocal iliofemoral artery stenosis: Review of literature and outcomes of an international questionnaire

Purpose

The goal of the study was to review current literature regarding the diagnosis of equivocal (50–70%) iliofemoral artery stenosis and compare these findings with the daily practice of an international panel of endovascular experts.

Methods

The Medline Database was searched for relevant publications, and an electronic survey was sent to experts in the field covering the following topics: definition of an equivocal iliofemoral artery stenosis, angiographic visualization and investigation protocols of an equivocal stenosis, intra-arterial pressure measurements, and definition of hemodynamic significance of an equivocal iliofemoral artery stenosis using a physiologic measure.

Results

Of the 37 invited endovascular experts, 21 (53.8%) agreed to participate in the survey. Analysis of existing literature shows that the level of evidence for diagnosing equivocal iliofemoral artery stenosis is mediocre and is not being implemented by experts in the field.

Conclusion

Studies have shown that a stenosis of between 50% and 70% iliofemoral lumen diameter reduction shows a wide range of trans-stenotic pressure gradients. Equivocal iliofemoral artery stenosis can best be identified using three-dimensional quantitative vascular analysis software. Although evidence for a clear hemodynamic cutoff point is weak, performing trans-lesion intra-arterial pressure measurements at rest and during maximal hyperemia is preferred. Diagnosing iliofemoral artery stenosis solely on lumen diameter reduction is inadequate.

Outcomes for critical limb ischemia are driven by lower extremity revascularization volume, not distance to hospital

OBJECTIVE

The objective of this study was to identify relationships among geographic access to care, vascular procedure volume, limb preservation, and survival in patients diagnosed with critical limb ischemia (CLI).

METHODS

Using New York State administrative data from 2000 to 2013, we identified a patient's first presentation with CLI defined by International Classification of Diseases, Ninth Revision diagnosis and procedure codes. Distance from the patient's home to the index hospital was calculated using the centroids of the respective ZIP codes. A multivariable logistic regression model was employed to estimate the impact of distance, major lower extremity amputation (LEA) volume, and lower extremity revascularization (LER) volume on major amputation and 30-day mortality. Volumes and distances were analyzed in quintiles. The farthest distance quintile and the highest procedure volume quintiles were used as references for generating odds ratios (ORs).

RESULTS

There were 49,576 patients identified with an initial presentation of CLI. The median age was 73 years, 35,829 (73.2%) had Medicare as a primary insurer, 11,395 (23.0%) had a major amputation, and 4249 (8.6%) died within 30 days of admission. Patients in the closest distance quintile were more likely to undergo amputation (OR, 1.53 [1.39-1.68]; P < .0001). Patients who visited hospitals in the lowest LER volume quintile with at least one procedure per year faced higher 30-day mortality rates (OR, 2.05 [1.67-2.50]; P < .0001) and greater odds of amputation (OR, 9.94 [8.5-11.63]; P < .0001). Patients who visited hospitals in the lowest LEA volume quintile had lower odds of 30-day mortality (OR, 0.66 [0.50-0.87]; P = .0033) and lower odds of amputation (OR, 0.180 [0.142-0.227]; P < .0001).

CONCLUSIONS

Rates of major amputation are inversely associated with distance from the index hospital, whereas rates of both major amputation and mortality are inversely associated with LER volume. Rates of major amputation and mortality are directly associated with LEA volume. We believe that unless it is otherwise contraindicated, these data support consideration for selective referral of CLI patients to high-volume centers for LER regardless of distance. Within the context of value-based health care delivery, policy supporting regionalization of CLI care into centers of excellence may improve outcomes for these patients.

Effectiveness of open versus endovascular abdominal aortic aneurysm repair in population settings: A systematic review of statewide databases

BACKGROUND

Patient outcomes after open abdominal aortic aneurysm and endovascular aortic aneurysm repair have been widely reported from several large, randomized, controlled trials. It is not clear whether these trial outcomes are representative of abdominal aortic aneurysm repair procedures performed in real-world hospital settings across the United States. This study was designed to evaluate population-based outcomes after endovascular aortic aneurysm repair versus open abdominal aortic aneurysm repair using statewide inpatient databases and examine how they have helped improve our understanding of abdominal aortic aneurysm repair.

METHODS

A systematic search of MEDLINE, EMBASE, and CINAHL databases was performed to identify articles comparing endovascular aortic aneurysm repair and open abdominal aortic aneurysm repair using data from statewide inpatient databases. This search was limited to studies published in the English language after 1990, and abstracts were screened and abstracted by 2 authors.

RESULTS

Our search yielded 17 studies published between 2004 and 2016 that used data from 29 different statewide inpatient databases to compare endovascular aortic aneurysm repair versus open abdominal aortic aneurysm repair. These studies support the randomized, controlled trial results, including a lower mortality associated with endovascular aortic aneurysm repair extended from the perioperative period up to 3 years after operation, as well as a higher complication rate after endovascular aortic aneurysm repair. The evidence from statewide inpatient database analyses has also elucidated trends in procedure volume, patient case mix, volume-outcome relationships, and health care disparities associated with endovascular aortic aneurysm repair versus open abdominal aortic aneurysm repair.

CONCLUSION

Population analyses of endovascular aortic aneurysm repair and open abdominal aortic aneurysm repair using statewide inpatient databases have confirmed short- and long-term mortality outcomes obtained from large, randomized, controlled trials. Moreover, these analyses have allowed us to assess the effect of endovascular aortic aneurysm repair adoption on population outcomes and patient case mix over time.

Endovascular Versus Open Revascularization for Peripheral Arterial Disease

OBJECTIVE

The aim of this study was to determine whether endovascular or open revascularization provides an advantageous approach to symptomatic peripheral arterial disease (PAD) over the longer term.

SUMMARY OF BACKGROUND DATA

The optimal revascularization strategy for symptomatic lower extremity PAD is not established.

METHODS

We evaluated amputation-free survival, overall survival, and relative rate of subsequent vascular intervention after endovascular or open lower extremity revascularization for propensity-score matched cohorts of Medicare beneficiaries with PAD from 2006 through 2009.

RESULTS

Among 14,685 eligible patients, 5928 endovascular and 5928 open revascularization patients were included in matched analysis. Patients undergoing endovascular repair had improved amputation-free survival compared with open repair at 30 days (7.4 vs 8.9%, P = 0.002). This benefit persisted over the long term: At 4 years, 49% of endovascular patients had died or received major amputation compared with 54% of open patients (P < 0.001). An endovascular procedure was associated with a risk-adjusted 16% decreased risk of amputation or death compared with open over the study period (hazard ratio: 0.84; 95% confidence interval, 0.79-0.89; P < 0.001). The amputation-free survival benefit associated with an endovascular revascularization was more pronounced in patients with congestive heart failure or ischemic heart disease than in those without (P = 0.021 for interaction term). The rate of subsequent intervention at 30 days was 7.4% greater for the endovascular vs the open revascularization cohort. At 4 years, this difference remained stable at 8.6%.

CONCLUSIONS

Using population-based data, we demonstrate that an endovascular approach is associated with improved amputation-free survival over the long term with only a modest relative increased risk of subsequent intervention.

Electroacupuncture for the prevention of postoperative gastrointestinal dysfunction in participants undergoing vascular laparotomy under general anesthesia: a randomized controlled trial

Background

Postoperative gastrointestinal dysfunction (PGD) is a common complication following laparotomy under general anesthesia (GA). Abdominal distension occurs in 8–28% of surgeries within 24 h postoperatively. The present study aimed to analyze the efficacy of electroacupuncture (EA) for the prevention of PGD by applying preoperative EA stimulation of PC6 (Neiguan), ST36 (Zusanli), and ST37 (Shangjuxv) bilaterally twice within 24 h prior to surgery, compared with no acupuncture treatment.

Methods

The study participants were assessed and selected from participants undergoing vascular laparotomy under GA at the Liver and Vascular Surgery Unit in West China Hospital of Sichuan University. The selected participants were randomly allocated to two groups: routine-treatment (RT) and EA group receiving EA at PC6, ST36, and ST37. A computer-generated list of random numbers was used to determine the allocation of the participants, with numbered opaque sealed envelopes containing the randomization schedule. Eligible participants were all adults aged 18 years or above who were scheduled to undergo vascular laparotomy under GA within 24 h and had no history of EA treatment. The exclusion criteria included participants with serious systemic disease and history of EA treatment. While the RT group received standard treatments, the EA group received additional EA treatments. During each treatment session, EA stimulation was performed for a duration of 20 min at a frequency of 15 Hz with a continuous wave. All such participants received two EA treatments within 24 h before surgery. The outcomes were measured in three metrics: incidence and degree of abdominal distension; first times of flatus and defecation; and duration of hospitalization.

Results

Forty-three participants were recruited, of whom 42 participants successfully completed the study. Each group contained 21 participants. The incidence of abdominal distension (42.8, 76.2%) and degree of abdominal distension were significantly reduced in the EA group (P = 0.03 and P = 0.03, respectively). In comparisons of the first times of flatus (3.05 ± 0.58, 3.29 ± 0.42 days) and defecation (2.81 ± 0.51, 3.20 ± 0.55 days) and duration of hospitalization (5.33 ± 0.68, 5.75 ± 0.66 days), the EA group was superior to the RT group to some extent (P = 0.13, P = 0.02, and P = 0.04, respectively).

Conclusions

Preoperative EA at PC6, ST36, and ST37 might be useful for preventing PGD, thereby improving gastrointestinal function recovery.

Trial registration This study is registered with the Chinese Clinical Trial Registry: ChiCTR-TRC-13003649

Electronic supplementary material

The online version of this article (doi:10.1186/s13020-016-0122-9) contains supplementary material, which is available to authorized users.

Temporal variability of readmission determinants in postoperative vascular surgery patients

Introduction:

Clinical information continues to be limited regarding changes in the temporal risk profile for readmissions during the initial postoperative year in vascular surgery patients. We set out to describe the associations between demographics, clinical outcomes, comorbidity indices, and hospital readmissions in a sample of patients undergoing common extremity revascularization or dialysis access (ERDA) procedures. We hypothesized that factors independently associated with readmission will evolve from “short-term” to “long-term” determinants at 30-, 180-, and 360-day postoperative cutoff points.

Methods:

Following IRB approval, medical records of patients who underwent ERDA at two institutions were retrospectively reviewed between 2008 and 2014. Abstracted data included patient demographics, procedural characteristics, the American Society of Anesthesiologists score, Goldman Criteria for perioperative cardiac assessment, the Charlson comorbidity index, morbidity, mortality, and readmission (at 30-, 180-, and 360-days). Univariate analyses were performed for readmissions at each specified time point. Variables reaching statistical significance of P < 0.20 were included in multivariate analyses for factors independently associated with readmission.

Results:

A total of 450 of 744 patients who underwent ERDA with complete medical records were included. Patients underwent either an extremity revascularization (e.g. bypass or endarterectomy, 406/450) or a noncatheter dialysis access procedure (44/450). Sample characteristics included 262 (58.2%) females, mean age 61.4 ± 12.9 years, 63 (14%) emergent procedures, and median operative time 164 min. Median hospital length of stay (index admission) was 4 days. Cumulative readmission rates at 30-, 180-, and 360-day were 12%, 27%, and 35%, respectively. Corresponding mortality rates were 3%, 7%, and 9%. Key factors independently associated with 30-, 180-, and 360-day readmissions evolved over the study period from comorbidity and morbidity-related issues in the short-term to cardiovascular and graft patency issues in the long-term. Any earlier readmission elevated the risk of subsequent readmission.

Conclusions:

We noted important patterns in the temporal behavior of hospital readmission risk in patients undergoing ERDA. Although factors independently associated with readmission were not surprising (e.g. comorbidity profile, cardiovascular status, and graft patency), the knowledge of temporal trends described in this study may help determine clinical risk profiles for individual patients and guide readmission reduction strategies. These considerations will be increasingly important in the evolving paradigm of value-based healthcare.

Endovascular Therapy Research in Lower Limb Peripheral Arterial Disease Published Over a 5-Year Period: Who is Publishing and Where?

INTRODUCTION

Peripheral arterial disease (PAD) is being increasingly managed by endovascular therapies. In this study, we identified the clinical services publishing research as well as the journals of publication over a 5-year period.

METHODS

Twenty keywords and phrases related to endovascular intervention were identified, and a literature search was performed through the PubMed database from January 2009 to January 2014. Inclusion criteria were English language, study population more than five patients, and matching the keyword search. Eligible studies were collated into a database and classified by journal of publication, PubMed number, article title, publishing clinical service, type of publication, country of origin, and authors.

RESULTS

825 studies from 114 different journals were identified. 297 papers were excluded. Of the 528 included papers, 204 (39%) were published by Vascular Surgery (VS), 157 (30%) by Interventional Radiology (IR), 101 (19%) by Cardiology, 43 (8%) by Angiology, 6 (1%) by Vascular Medicine, and 17 (3%) from miscellaneous services. 283 (54%) studies originated from Europe, 157 (30%) from North America, 76 (14%) from Asia, 6 from Australia, 3 each from South America and Africa. IR published the most papers on PAD endovascular intervention in Europe with VS second while this trend was reversed in the USA. The 528 papers were published in 98 different journals with retrospective case series (72%), the majority.

CONCLUSION

IR continues to play a significant research role in endovascular intervention in PAD, particularly in Europe, and specifically in below the knee intervention, pedal intervention, and drug-eluting technologies.

Risk stratification for the development of respiratory adverse events following vascular surgery using the Society of Vascular Surgery's Vascular Quality Initiative

OBJECTIVE

Postoperative respiratory adverse events (RAEs) are associated with high rates of morbidity and mortality in general surgery, however, little is known about these complications in the vascular surgery population, a frail subset with multiple comorbidities. The objective of this study was to describe the contemporary incidence of RAEs in vascular surgery patients, the risk factors for this complication, and the overall impact of RAEs on patient outcomes.

METHODS

The Vascular Quality Initiative was queried (2003-2014) for patients who underwent endovascular abdominal aortic repair, open abdominal aortic aneurysm repair, thoracic endovascular aortic repair, suprainguinal bypass, or infrainguinal bypass. A mixed-effects logistic regression model determined the independent risk factors for RAEs. Using a random 85% of the cohort, a risk prediction score for RAEs was created, and the score was validated using the remaining 15% of the cohort, comparing the predicted to the actual incidence of RAE and determining the area under the receiver operating characteristic curve. The independent risk of in-hospital mortality and discharge to a nursing facility associated with RAEs was determined using a mixed-effects logistic regression to control for baseline patient characteristics, operative variables, and other postoperative adverse events.

RESULTS

The cohort consisted of 52,562 patients, with a 5.4% incidence of RAEs. The highest rates of RAEs were seen in current smokers (6.1%), recent acute myocardial infarction (10.1%), symptomatic congestive heart failure (9.9%), chronic obstructive pulmonary disease requiring oxygen therapy (11.0%), urgent and emergent procedures (6.4% and 25.9%, respectively), open abdominal aortic aneurysm repairs (17.6%), in situ suprainguinal bypasses (9.68%), and thoracic endovascular aortic repairs (9.6%). The variables included in the risk prediction score were age, body mass index, smoking status, congestive heart failure severity, chronic obstructive pulmonary disease severity, degree of renal insufficiency, ambulatory status, transfer status, urgency, and operative type. The predicted compared with the actual RAE incidence were highly correlated, with a correlation coefficient of 0.943 (P < .0001) and a c-statistic = 0.818. RAEs had a significantly higher rates of in-hospital mortality (25.4% vs 1.2%; P < .0001; adjusted odds ratio, 5.85; P < .0001), and discharge to a nursing facility (57.8% vs 19.0%; P < .0001; adjusted odds ratio, 3.14; P < .0001).

CONCLUSIONS

RAEs are frequent and one of the strongest risk factors for in-hospital mortality and inability to be discharged home. Our risk prediction score accurately stratifies patients based on key demographics, comorbidities, presentation, and operative type that can be used to guide patient counseling, preoperative optimization, and postoperative management. Furthermore, it may be useful in developing quality benchmarks for RAE following major vascular surgery.

Associated Risk Factors and Complications in Vascular Surgery Patients Requiring Unplanned Postoperative Reintubation

OBJECTIVE

To determine the frequency of reintubation within 30 days in vascular surgery patients and the associated risk factors and complications.

DESIGN

Retrospective cohort study with univariate and multivariate analyses of risk factors and outcomes from data collected by the American College of Surgeons National Surgical Quality Improvement Program.

SETTING

All institutions participating in the American College of Surgeons National Surgical Quality Improvement Program.

PARTICIPANTS

All patients older than 18 undergoing vascular surgery.

INTERVENTIONS

Not applicable.

MEASUREMENTS AND MAIN RESULTS

A reintubation rate of 2.2% among vascular surgery patients within the first 30 days was demonstrated. Reintubation was associated positively with increased age, low body mass index, poor functional status, smoking status, chronic obstructive pulmonary disease, congestive heart failure, and increased anesthesia and surgical times. In addition, specific procedures were found to have significantly increased rates of reintubation, including bypass surgery, thrombectomy, and open thoracic and abdominal aorta surgery. Reintubation was associated positively with all measured complications, including a quadrupled length of average hospital stay (19.8 v 5.5 days), a 10-fold risk of mortality (33.9% v 2.6%), and a 40-fold risk of cardiac arrest (22.4% v 0.5%).

CONCLUSIONS

Patients undergoing major vascular surgery represent a high-risk population for unplanned postoperative reintubation. Preoperative evaluation should include the consideration of the positively associated risk factors found in this study. Due to the significant morbidity associated with unplanned reintubation, additional work is needed to identify risk factors amenable to optimization in the preoperative period.

Impact of Glycoprotein IIb/IIIa Inhibitors Use on Outcomes After Lower Extremity Endovascular Interventions From Nationwide Inpatient Sample (2006-2011)

OBJECTIVE

The aim of our study was to study the impact of glycoprotein IIb/IIIa inhibitors (GPI) on in-hospital outcomes.

BACKGROUND

There is paucity of data regarding the impact of GPI on the outcomes following peripheral endovascular interventions.

METHODS

The study cohort was derived from Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) database between the years 2006 and 2011. Peripheral endovascular interventions and GPI utilization were identified using appropriate ICD-9 Diagnostic and procedural codes. Two-level hierarchical multivariate mixed models were created. The study outcomes were: primary (in-hospital mortality and amputation studied separately) and secondary (composite of in-hospital mortality and postprocedural complications). Hospitalization costs were also assessed.

RESULTS

GPI utilization (OR, 95% CI, P-value) was independently predictive of lower amputation rates (0.36, 0.27-0.49, <0.001). There was no significant difference in terms of in-hospital mortality (0.59, 0.31-1.14, P 0.117), although GPI use predicted worse secondary outcomes (1.23, 1.03-1.47, 0.023). Following propensity matching, the amputation rate was lower (3.2% vs. 8%, P < 0.001), while hospitalization costs were higher in the cohort that received GPI ($21,091 ± 404 vs. 19,407 ± 133, P < 0.001).

CONCLUSIONS

Multivariate analysis revealed GPI use in peripheral endovascular interventions to be suggestive of an increase in composite end-point of in-hospital mortality and postprocedural complications, no impact on in-hospital mortality alone, significantly lower rate of amputation, and increase in hospitalization costs. © 2016 Wiley Periodicals, Inc.

Significant variation in P2Y12 inhibitor use after peripheral vascular intervention in Medicare beneficiaries

There is no consensus regarding whether to use antithrombotic medications in patients with peripheral artery disease after lower-extremity peripheral vascular intervention.

OBJECTIVES

The main hypothesis is that significant variation exists regarding use of antithrombotic medications after lower-extremity peripheral vascular intervention. We sought to examine the patterns of postprocedural antithrombotic medication use and associated factors in Medicare patients.

METHODS

We measured rates of P2Y12 inhibitor use after peripheral vascular intervention in a 100% national sample of Medicare beneficiaries with Part D prescription drug coverage. We used logistic regression modeling to examine associations between patient and clinical factors and P2Y12 inhibitor use.

RESULTS

Between 2010 and 2012, a total of 85,830 patients underwent peripheral vascular intervention and had prescription drug claims. Overall, 18.3% of patients were treated with an oral anticoagulant, 19.1% received no P2Y12 inhibitor, 30.8% received a P2Y12 inhibitor before and after the procedure, 6.2% received a P2Y12 inhibitor for up to 30 days after the procedure, and 25.6% received a P2Y12 inhibitor for more than 30 days after the procedure. After adjustment, factors associated with P2Y12 inhibitor use included male sex; black race; history of renal disease, dementia, or heart failure; physician specialty; and clinical setting of the procedure. We observed a strong interaction effect between clinical setting and physician specialty (P < .001).

CONCLUSIONS

One-fifth of patients who underwent lower-extremity peripheral vascular intervention did not fill a prescription for a P2Y12 inhibitor. Patients whose operators were surgeons or radiologists had lower odds of P2Y12 inhibitor use. More research to determine the optimal use and duration of antithrombotic medications after the procedure is warranted.

Endovascular Electrodes for Electrical Stimulation of Blood Vessels for Vasoconstriction - a Finite Element Simulation Study

Hemorrhagic shock accounts for 30-40 percent of trauma mortality, as bleeding may sometimes be hard to control. Application of short electrical pulses on blood vessels was recently shown to elicit robust vasoconstriction and reduction of blood loss following vascular injury. In this study we present a novel approach for vasoconstriction based on endovascular application of electrical pulses for situations where access to the vessel is limited. In addition to ease of access, we hypothesize that this novel approach will result in a localized and efficient vasoconstriction. Using computer modeling (COMSOL Multiphysics, Electric Currents Module), we studied the effect of endovascular pulsed electrical treatment on abdominal aorta of pigs, and compared the efficiency of different electrodes configurations on the electric field amplitude, homogeneity and locality when applied on a blood vessel wall. Results reveal that the optimal configuration is the endovascular approach where four electrodes are used, spaced 13 mm apart. Furthermore, computer based temperature investigations (bio-heat model, COMSOL Multiphysics) show that the maximum expected temperature rise is of 1.2 degrees; highlighting the safety of the four endovascular electrodes configuration. These results can aid in planning the application of endovascular pulsed electrical treatment as an efficient and safe vasoconstriction approach.

Techniques in Vascular and Interventional Radiology Drug Delivery Technologies in the Superficial Femoral Artery

Peripheral arterial disease (PAD) affects over 8 million people in the United States alone. Although great strides have been made in reducing the burden of cardiovascular disease the prevalence of PAD is expected to rise with the age of global population. PAD characterized by narrowing of arterial blood can be asymptomatic or cause limb threatening claudication. It has been classically treated with bypass, but these techniques have been supplanted by endovascular therapy. Plain old balloon angioplasty has been successful in helping revascularize lesions, but its effect has not been durable because of restenosis. This prompted the creation of several technologies aimed at reducing restenosis. These advances slowly improved outcomes and the durability of endovascular management. Among the main tools used in current endovascular practice are drug-delivery devices aimed at inhibiting the inflammatory and proliferative pathways that lead to restenosis. This article examines the current drug-delivery technologies used in the superficial femoral artery.

Two-year results from a randomized clinical trial of revascularization in patients with intermittent claudication

Background

Intermittent claudication is associated with significant impairment of health-related quality of life. The use of revascularization techniques to improve health-related quality of life remains controversial.

Methods

Patients with intermittent claudication due to iliac or femoropopliteal peripheral artery disease were enrolled in the IRONIC trial. They were randomized to either best medical therapy (BMT), including a structured, non-supervised exercise programme, or revascularization with either endovascular or open techniques in addition to BMT. The primary outcome was health-related quality of life at 2 years assessed using the Short Form 36 (SF-36®) questionnaire. Secondary outcomes included VascuQoL questionnaire results, treadmill walking distances and achievement of patient-specified treatment goals.

Results

Both randomized groups had improved health-related quality of life and treadmill walking distance at 2-year follow-up. Overall SF-36® physical component summary score, three SF-36® physical domain scores, overall VascuQoL score, and three of five VascuQoL domain scores showed significantly greater improvement in the group that also received invasive treatment. Intermittent claudication distance on a graded treadmill improved more in the revascularization + BMT group (117 versus 55 m; P = 0·003) whereas maximum walking distance and 6-min walk test distance were similar. Some 44 per cent of patients in the revascularization + BMT group reported they had fully achieved their treatment goal versus 10 per cent in the BMT group.

Conclusion

A revascularization strategy with unsupervised exercise improved health-related quality of life and intermittent claudication distance more than standard BMT and an unsupervised exercise programme in patients with lifestyle-limiting claudication. Registration number: NCT01219842 (http://www.clinicaltrials.gov).

Biodegradable polymeric stents for vascular application in a porcine carotid artery model: English version

Over the past years the development of biodegradable polymeric stents has made great progress; nevertheless, essential problems must still be solved. Modifications in design and chemical composition should optimize the quality of biodegradable stents and remove the weaknesses. New biodegradable poly-L-lactide/poly-4-hydroxybutyrate (PLLA/P4HB) stents and permanent 316L stents were implantedendovascularly into both common carotid arteries of 10 domestic pigs. At 4 weeks following implantation, computed tomography (CT) angiography was carried out to identify the distal degree of stenosis. The PLLA/P4HB group showed a considerably lower distal degree of stenosis by additional oral application of atorvastatin (mean 39.81 ± 8.57 %) compared to the untreated PLLA/P4HB group without atorvastatin (mean 52.05 ± 5.80 %). The 316L stents showed no differences in the degree of distal stenosis between the group treated with atorvastatin (mean 44.21 ± 2.34 %) and the untreated group (mean 35.65 ± 3.72 %). Biodegradable PLLA/P4HB stents generally represent a promising approach to resolving the existing problems in the use of permanent stents. Restitutio ad integrum is only achievable if a stent is completely degraded.

Impact of Expanded Insurance Coverage on Racial Disparities in Vascular Disease: Insights From Massachusetts

OBJECTIVE

To evaluate the impact of health insurance expansion on racial disparities in severity of peripheral arterial disease.

BACKGROUND

Lack of insurance and non-white race are associated with increased severity, increased amputation rates, and decreased revascularization rates in patients with peripheral artery disease (PAD). Little is known about how expanded insurance coverage affects disparities in presentation with and management of PAD. The 2006 Massachusetts health reform expanded coverage to 98% of residents and provided the framework for the Affordable Care Act.

METHODS

We conducted a retrospective cohort study of nonelderly, white and non-white patients admitted with PAD in Massachusetts (MA) and 4 control states. Risk-adjusted difference-in-differences models were used to evaluate changes in probability of presenting with severe disease. Multivariable linear regression models were used to evaluate disparities in disease severity before and after the 2006 health insurance expansion.

RESULTS

Before the 2006 MA insurance expansion, non-white patients in both MA and control states had a 12 to 13 percentage-point higher probability of presenting with severe disease (P < 0.001) than white patients. After the expansion, measured disparities in disease severity by patient race were no longer statistically significant in Massachusetts (+3.0 percentage-point difference, P = 0.385) whereas disparities persisted in control states (+10.0 percentage-point difference, P < 0.001). Overall, non-white patients in MA had an 11.2 percentage-point decreased probability of severe PAD (P = 0.042) relative to concurrent trends in control states.

CONCLUSIONS

The 2006 Massachusetts insurance expansion was associated with a decreased probability of patients presenting with severe PAD and resolution of measured racial disparities in severe PAD in MA.

Current aortic endografts for the treatment of abdominal aortic aneurysms

Endovascular Aneurysm Repair is a widely adopted method of treatment for patients with abdominal aortic aneurysms. The minimally invasive approach offered with EVAR has become popular not only among physicians and patients, but in the medical device industry as well. Over the past 25 years the global market for aortic endografts has increased rapidly, resulting in a wide range of devices from various companies. Currently, there are seven endografts approved by the FDA for the treatment of abdominal aortic aneurysms. These devices offer a wide range of designs intended to increase inclusion criteria while decreasing technical complications such as endoleak and migration. Despite advances in device design, secondary interventions and follow-up requirements remain a significant issue. New devices are currently being studied in the U.S. and abroad and may significantly reduce complications and secondary interventions.

Update on the use of abdominal and thoracic endografts for treating aortic aneurysms

Endovascular abdominal and thoracic aneurysm repair has heralded a paradigm shift in the management of abdominal and thoracic aortic aneurysms. Randomized controlled trials have suggested superior short-term and equivalent long-term outcomes of endovascular repair compared with open surgery. Existing endografts have undergone several modifications to meet anatomic challenges and improve patient results. In the past, endovascular repair has been limited to infrarenal abdominal aortic aneurysms and isolated thoracic aortic aneurysms. The advent of fenestrated and branched endografts have made endovascular repair of thoracoabdominal and juxtarenal aneurysms possible. Continued evolution of endograft technology will maximize the benefit and minimize complications in patients with a range of aneurysmal disease.

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.

Physician specialty and variation in carotid revascularization technique selected for Medicare patients

OBJECTIVE

Carotid artery stenting (CAS) has become an alternative to carotid endarterectomy (CEA) for select patients with carotid atherosclerosis. We hypothesized that the choice of CAS vs CEA varies as a function of treating physician specialty, which would result in regional variation in the relative use of these treatment types.

METHODS

We used Medicare claims (2002-2010) to calculate annual rates of CAS and CEA and examined changes by procedure type over time. To assess regional preferences surrounding CAS, we calculated the proportion of revascularizations by CAS, across hospital referral regions, defined according to the Dartmouth Atlas of Healthcare. We then examined relationships between patient factors, physician specialty, and regional use of CAS.

RESULTS

The annual number of all carotid revascularization procedures decreased by 30% from 2002 to 2010 (3.2 to 2.3 per 1000; P = .005). Whereas rates of CEA declined by 35% during these 8 years (3.0 to 1.9 per 1000; P < .001), CAS utilization increased by 5% during the same interval (0.30 to 0.32 per 1000; P = .014). Variation in utilization of carotid revascularization varied across the Unites States, with some regions performing as few as 0.7 carotid procedure per 1000 beneficiaries (Honolulu, Hawaii) and others performing nearly 8 times as many (5.3 per 1000 in Houma, La). Variation in procedure type (CEA vs CAS) was evident as well, as the proportion of carotid revascularization procedures that were constituted by CAS varied from 0% (Casper, Wyo, and Meridian, Miss) to 53% (Bend, Ore). The majority of CAS procedures were performed by cardiologists (49% of all CAS cases), who doubled their rates of CAS during the study period from 0.07 per 1000 in 2002 to 0.15 per 1000 in 2010.

CONCLUSIONS

Variation in rates of carotid revascularization exists. Whereas rates of carotid revascularization have declined by more than 30% in recent years, utilization of CAS has increased. The proportion of all carotid revascularization procedures performed as CAS varies markedly by geographic region, and regions with the highest proportion of cardiologists perform the most CAS procedures. Evidence-based guidelines for carotid revascularization will require a multidisciplinary approach to ensure uniform adoption across specialties that care for patients with carotid artery disease.

Objective performance goals after endovascular intervention for critical limb ischemia

OBJECTIVE

During the last decade, primary endoluminal therapy for critical limb ischemia (CLI), assessed as rest pain and tissue loss of the lower extremity, has significantly increased. Reporting of patient-centered outcomes using the new Society for Vascular Surgery objective performance goals (OPGs) has been limited. This study examined the OPGs for infrainguinal endovascular management of CLI.

METHODS

A prospective database of patients undergoing endovascular treatment of the lower extremity for CLI between 2000 and 2011 was queried. Evaluated were clinical efficacy (absence of recurrent symptoms, maintenance of ambulation and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (MALEs; above-ankle amputation of the index limb or major reintervention - new bypass graft, jump/interposition graft revision).

RESULTS

A total of 728 patients (60% male; age, 68 ± 14 years) underwent lower extremity interventions for CLI (66% tissue loss); of these, 39% had superficial femoral artery and tibial interventions. Diabetes mellitus was present in 71%, hyperlipidemia in 64%, and chronic renal insufficiency in 37%. Technical success was 96%. The overall rate at 30 days of major adverse cardiovascular events (MACEs) was 3% and MALEs was 12%. At 5 years, clinical efficacy was (mean ± standard error of the mean) 42% ± 5%, amputation-free survival was 41% ± 7%, and freedom from MALEs was 51% ± 4%. Clinical efficacy was significantly different in those presenting with rest pain and tissue loss and in the anatomic high-risk group compared with the clinical high-risk group, and both were worse compared with the group without clinical or high-risk criteria.

CONCLUSIONS

Endoluminal therapy for CLI is associated with early low MACE rates but high MALE rates. When the key outcome of amputation free survival is considered, predictors of a better outcome were absence of current smoking, a lower modified Edifoligide for the Prevention of Infrainguinal Vein Graft Failure (PREVENT III) amputation risk score, better preoperative ambulation status, lower MACEs, and discharge disposition to home. The presence of tissue loss and anatomic risk factors negatively affect outcomes. Longer-term outcomes after endovascular intervention for CLI remain relatively poor, with <40% success in objective performance outcomes at 5 years.

Anatomic runoff score predicts cardiovascular outcomes in patients with lower extremity peripheral artery disease undergoing revascularization

BACKGROUND

Although the presence, extent, and severity of obstruction in patients with lower extremity peripheral artery disease (LE PAD) affect their functional status, quality of life, and treatment, it is not known if these factors are associated with future cardiovascular events. We empirically created an anatomic runoff score (ARS) to approximate the burden of LE PAD and determined its association with clinical outcomes.

METHODS

We evaluated all patients with LE PAD and bilateral angiography undergoing revascularization in a community-based clinical study. Primary clinical outcomes of interest were (1) a composite of all-cause death, myocardial infarction (MI), and stroke and (2) amputation-free survival. Cox proportional hazards models were created to identify predictors of clinical outcomes.

RESULTS

We evaluated 908 patients undergoing angiography, and a total of 260 (28.0%) patients reached the composite end point (45 MI, 63 stroke, and 152 death) during the study period. Anatomic runoff score ranged from 0 to 15 (mean 4.7; SD 2.5) with higher scores indicating a higher burden of disease, and an optimal cutpoint analysis classified patients into low ARS (<5) and high ARS (≥5). The unadjusted rates of the primary composite end point and amputation-free survival were nearly 2-fold higher in patients with a high ARS when compared with patients with a low ARS. The most significant predictors of the composite end point (death/MI/stroke) were age (δ 10 years; hazard ratio [HR] 1.53; CI 1.32-1.78; P < .001), diabetes mellitus (HR 1.65; CI 1.26-2.18; P < .001), glomerular filtration rate <30 (HR 2.23; CI 1.44-3.44; P < .001), statin use (HR 0.66; CI 0.48-0.88; P < .001), and ARS (δ 2 points; HR 1.21; CI 1.08-1.35; P < .001).

CONCLUSIONS

After adjustment for clinical factors, the LE PAD ARS was an independent predictor of future cardiovascular morbidity and mortality in a broadly representative patient population undergoing revascularization for symptomatic PAD. A clinically useful anatomic scoring system, if validated, may assist clinicians in risk stratification during the course of clinical decision making.

Determinants of survival and major amputation after peripheral endovascular intervention for critical limb ischemia

OBJECTIVE

Our objective was to analyze periprocedural and 1-year outcomes of peripheral endovascular intervention (PVI) for critical limb ischemia (CLI).

METHODS

We reviewed 1244 patients undergoing 1414 PVIs for CLI (rest pain, 29%; tissue loss, 71%) within the Vascular Study Group of New England (VSGNE) from January 2010 to December 2011. Overall survival (OS), amputation-free survival (AFS), and freedom from major amputation at 1 year were analyzed using the Kaplan-Meier method. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

The number of arteries treated during each procedure were 1 (49%), 2 (35%), 3 (12%), and ≥4 (5%). Target arterial segments and TransAtlantic Inter-Society Consensus classifications were aortoiliac, 27% (A, 48%; B, 28%; C, 12%; and D, 12%); femoral-popliteal, 48% (A, 29%; B, 34%; C, 20%; and D, 17%); and infrapopliteal, 25% (A, 17%; B, 14%; C, 25%; D, 44%). Technical success was 92%. Complications included access site hematoma (5.0%), occlusion (0.3%), and distal embolization (2.4%). Mortality and major amputation rates were 2.8% and 2.2% at 30 days, respectively. Overall percutaneous or open reintervention rate was 8.0% during the first year. At 1-year, OS, AFS, and freedom from major amputation were 87%, 87%, and 94% for patients with rest pain and 80%, 71%, and 81% for patients with tissue loss. Independent predictors of reduced 1-year OS (C index = .74) included dialysis (HR, 3.8; 95% CI, 2.8-5.1; P < .01), emergency procedure (HR, 2.5; 95% CI, 1.0-6.2; P = .05), age >80 years (HR, 2.2; 95% CI, 1.7-2.8; P < .01), not living at home preoperatively (HR, 2.0; 95% CI, 1.4-2.8; P < .01), creatinine >1.8 mg/dL (HR, 1.9; 95% CI, 1.3-2.8; P < .01), congestive heart failure (HR, 1.7; 95% CI, 1.3-2.2; P < .01), and chronic β-blocker use (HR, 1.4; 95% CI, 1.0-1.9; P = .03), whereas independent preoperative ambulation (HR, 0.7; 95% CI, 0.6-0.9; P = .014) was protective. Independent predictors of major amputation (C index = .69) at 1 year included dialysis (HR, 2.7; 95% CI, 1.6-4.5; P < .01), tissue loss (HR, 2.0; 95% CI, 1.1-3.7; P = .02), prior major contralateral amputation (HR, 2.0; 95% CI, 1.1-3.5; P = .02), non-Caucasian race (HR, 1.7; 95% CI, 1.0-2.9; P = .045), and male gender (HR, 1.6; 95% CI, 1.1-2.6; P = .03), whereas smoking (HR, .60; 95% CI, 0.4-1.0; P = .042) was protective.

CONCLUSIONS

Survival and major amputation after PVI for CLI are associated with different patient characteristics. Dialysis dependence is a common predictor that portends especially poor outcomes. These data may facilitate efforts to improve patient selection and, after further validation, enable risk-adjusted outcome reporting for CLI patients undergoing PVI.

Acute Kidney Injury in Critically Ill Vascular Surgery Patients is Common and Associated with Increased Mortality

INTRODUCTION

Vascular surgery patients have multiple risk factors for renal dysfunction, but acute kidney injury (AKI) is poorly studied in this group. The purpose of this study was to define the incidence, risk factors, and outcomes of AKI in high-risk vascular patients.

METHODS

Critically ill vascular surgery patients admitted during January-December 2012 were retrospectively analyzed with 1-year follow-up. The endpoint was AKI by established RIFLE creatinine criteria. The primary analysis was between patients with or without AKI, with secondary analysis of post-operative AKI. Outcomes were inpatient and 1-year mortality, inpatient lengths of stay, and discharge renal function.

RESULTS

One-hundred and thirty six vascular surgery patients were included, representing 27% of all vascular surgery admissions during the study period. Sixty-five (48%) developed AKI. Independent global risk factors for AKI were diabetes, increasing critical illness severity, and sepsis. While intraoperative blood loss and hypotension were associated with subsequent renal dysfunction, post-operative AKI rates were similar for patients undergoing aortic, carotid, endovascular, or peripheral vascular procedures. All RIFLE grades of AKI were associated with worse outcomes. Overall, patients with AKI had significantly increased short- and long-term mortality, longer inpatient lengths of stay, and worse discharge renal function.

CONCLUSION

AKI is common among critically ill vascular surgery patients. Importantly, the type of surgical procedure appears to be less important than intra- and perioperative management in determining renal dysfunction. Regardless of its severity, AKI is a clinically significant complication that is associated with substantially worse patient outcomes.

Electroacupuncture for the prevention of postoperative gastrointestinal dysfunction in patients undergoing vascular surgery under general anesthesia: study protocol for a prospective practical randomized controlled trial

BACKGROUND

Postoperative gastrointestinal dysfunction (PGD) is one of the most common complications following major surgeries under general anesthesia (GA). Despite ongoing research and new drug treatments, abdominal distension within 24 h postoperatively occurs in 8%-28% of all surgeries. We aim to analyze the effectiveness of preventing PGD by preoperatively stimulating Neiguan (PC6), Zusanli (ST36) and Shangjuxu (ST37) bilaterally twice a day compared with sham-acupuncture treatment and standard treatment.

METHODS AND DESIGN

This is a single-center, prospective practical randomized controlled trial. All groups will be given standard treatments. Patients undergoing vascular surgery under GA will be included from the Vascular Surgery Unit in West China Hospital of Sichuan University, China, and divided into three groups. The experimental group will receive routine treatments and acupuncture at PC6, ST36 and ST37 bilaterally with electrical stimulation twice a day for 20 min preoperatively. The sham-acupuncture group will receive pseudo-electroacupuncture at sham acupoints of PC6, ST36 and ST37, which are 1 cun away from the real acupoints. The routine-treatment group will not receive electroacupuncture. The outcomes include the incidence of abdominal distention, abdominal circumference, the degree of abdominal distension, the first time of flatus and defecation, and hospitalization duration.

DISCUSSION

The results from this study will demonstrate whether preoperative electroacupuncture is an effective method for the prevention of PGD in patients undergoing vascular surgery under GA. This study may also provide a standardized acupuncture treatment for reduction of PGD.

Superiority of Stent-Grafts for In-Stent Restenosis in the Superficial Femoral Artery

Purpose: To evaluate the short- and midterm outcomes of the Viabahn endoprosthesis with Propaten Bioactive Surface vs. standard balloon angioplasty for treatment of in-stent restenosis in the superficial femoral artery. Methods: Between June 2010 and February 2012, 83 patients with superficial femoral artery in-stent and Rutherford category 2 to 5 ischemia were enrolled at 7 sites participating in this prospective randomized controlled study (RELINE; ClinicalTrials.gov; identifier NCT01108861). The patients were randomized to treatment with either the heparin-bonded Viabahn endoprosthesis (n=39: 29 men; mean age 67.7±9.8 years) or a standard angioplasty balloon (n=44: 32 men; mean age 69.0±9.7 years). The primary effectiveness outcome was primary patency at 12 months, defined as no restenosis/occlusion within the target lesion based on duplex ultrasound and no target lesion revascularization. The primary safety endpoint was the incidence of serious device-related adverse events within 30 days of the procedure. Results: All patients randomized to receive dilation or the Viabahn stent-graft were treated according to their assignment. The technical success was 100% for the Viabahn group and 81.8% for the angioplasty group (p=0.002) owing to 9 patients requiring a bailout procedure after unsuccessful angioplasty. The 12-month primary patency rates were 74.8% for the Viabahn group and 28.0% for the angioplasty group (p<0.001). Excluding the 9 angioplasty patients who received bailout stenting, the primary patency for optimal balloon angioplasty was 37.0% (p<0.001). Three patients experienced device-related adverse events within 30 days: occlusion of the target lesion (Viabahn group), peripheral embolization (angioplasty group), and reocclusion of the target lesion (angioplasty group). Conclusion: In this study, the treatment of femoropopliteal in-stent restenosis with a Viabahn endoprosthesis showed significantly better results than treatment with a standard balloon at 1 year.