Trends, complications, and mortality in peripheral vascular surgery

Comparative evaluation of transcutaneous oxygen tension and ankle-brachial index as predictors of reoperation following below-knee amputation

OBJECTIVE

Decision-making regarding level of lower extremity amputation is sometimes challenging. Selecting an appropriate anatomic level for major amputation requires consideration of tradeoffs between postoperative function and risk of wound complications that may require additional operations, including debridement and/or conversion to above-knee amputation (AKA). We evaluated the utility of common, non-invasive diagnostic tests used in clinical practice to predict the need for reoperations among patients undergoing primary, elective, below knee-amputations (BKAs) by vascular surgeons.

METHODS

Patients undergoing elective BKA over a 5-year period were identified using Current Procedural Terminology codes. Medical records were reviewed to characterize demographics, pre-amputation testing transcutaneous oxygen tension (TcPO2), and ankle-brachial index (ABI). The need for ipsilateral post-BKA reoperation (including BKA revision and/or conversion to AKA) regardless of indication was the primary outcome. Associations were evaluated using univariable and multivariable logistic regression models. Cutpoints for TcPO2 values associated with amputation reoperation were evaluated using receiver operating characteristic curves.

RESULTS

We identified 175 BKAs, of which 46 (26.3%) required ipsilateral reoperation (18.9% BKA revisions and 14.3% conversions to AKA). The mean age was 63.3 ± 14.8 years. Most patients were male (65.1%) and White (72.0%). Mean pre-amputation calf TcPO2 was 40.0 ± 20.5 mmHg, and mean ABI was 0.64 ± 0.45. In univariable models, post-BKA reoperation was associated with calf TcPO2 (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.94-0.99; P = .013) but not ABI (OR, 0.53; 95% CI, 0.19-1.46; P = .217). Univariable associations with reoperation were also identified for age (OR, 0.97; 95% CI, 0.94-0.990; P = .003) and diabetes (OR, 0.43; 95% CI, 0.21-0.87; P = .019). No associations with amputation revision were identified for gender, race, end-stage renal disease, or preoperative antibiotics. Calf TcPO2 remained associated with post-BKA reoperation in a multivariable model (OR, 0.97; 95% CI, 0.94-0.99; P = .022) adjusted for age (OR, 0.98; 95% CI, 0.94-1.01; P = .222) and diabetes (OR, 0.98; 95% CI, 0.94-1.01; P = .559). Receiver operating characteristic analysis suggested a TcPO2 ≥38 mmHg as an appropriate cut-point for assessing risk for BKA revision (area under the curve = 0.682; negative predictive value, 0.91).

CONCLUSIONS

Reoperation after BKA is common, and reoperation risk was associated with pre-amputation TcPO2. For patients undergoing elective BKA, higher risk of reoperation should be discussed with patients with an ipsilateral TcPO2 <38 mmHg.

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.

General Surgery Trainee Cases Over Time: Postgraduate Year Matters

BACKGROUND

Trainees and attending surgeons alike have concerns about resident and fellow operative volume/breadth, competency, and overall readiness for practice. This is an important topic within surgical graduate medical education. Our goal was to analyze the change in general surgery trainee operative experience over time by postgraduate year.

METHODS

Institutional operative records from two corresponding three-month time periods in 2009 and 2018 at the residency program's main hospital site were reviewed. Cases assisted on by general, vascular, or thoracic surgery trainees were included. The number of cases per level, combination of trainees in each case, and categories of cases were compared over time.

RESULTS

There were 1940 cases in 2009 and 1967 cases in 2018 over the respective time periods. The distribution of trainees was different (P < .001), with a similar number of PGY-1 and fellow cases, a decrease in PGY-2 and PGY-5 cases, and an increase in PGY-3 and PGY-4 cases. The number of cases with two trainees, double scrubbed cases, increased from 19.6% to 26.8% (P < .001). In addition, there were differences in the resident years that double scrubbed cases together, an increase in robotic and endovascular surgery, and a decrease in open cases.

CONCLUSIONS

This analysis of cases shows that resident operative volume over approximately a decade has been largely preserved, with some change in the distribution of cases based on trainee level, an increase in cases with more than one trainee, and a rise of minimally invasive surgery with a corresponding decrease in open cases.

Specialist access and leg amputations among Texas Medicaid patients

Medicaid coverage among patients with peripheral artery disease (PAD) has been associated with higher rates of primary amputations. We sought to determine the relative contributions of clinical, demographic, and hospital factors to leg amputations among Texas Medicaid patients. Patient-level data were used to identify patients who underwent treatment for PAD-related foot complications in Texas. Patients were categorized into groups by insurance provider (Medicaid, Medicare, dual-enrollee, commercial, and provider network). Individual- and area-level multivariate analyses were used to find associations with primary amputation. Of 21,592 patients identified, 8.8% were covered by Medicaid, 35.3% by Medicare, 27.8% by Medicare and Medicaid, 7.3% by commercial insurance, and 20.7% by a provider network. Compared with commercially insured patients, Medicaid patients more often underwent amputation (33% v 49%), were categorized as Black or Hispanic (45% v 64%), presented with gangrene (61% v 71%), were admitted through an emergency department (61% v 73%), and were admitted to a safety net hospital (3% v 16%). They had lower relative rates of outpatient evaluation (1.33 v 0.55) and their hospitalizations were less centralized (Gini coefficient 0.43 v 0.39) (P < .001 for all). Amputations among Medicaid patients were associated with infection and gangrene, care at safety net hospitals, rate of outpatient visits, and Black and Hispanic race, even after risk-adjustment (P < .001). Leg amputations among Medicaid patients were associated with race, disease severity, hospital characteristics, and outpatient evaluation rates, but not with provider density and location. Focusing efforts on preventative care and early outpatient referrals could help address this disparity.

Socioecological model-based design and implementation principles of lower limb preservation programs as partners for limb-loss rehabilitation programs- A mini-review

People with lower limb loss, especially of dysvascular etiology, are at substantial risk for both ipsilateral and contralateral reamputation. Additionally, while not as well documented for reamputation, there is recognition that amputation incidence is influenced by not only sociodemographic factors such as sex, race, socioeconomic status, but also by system factors such as service access. A systems strategy to address this disparity within the field of limb-loss rehabilitation is for Limb-loss Rehabilitation Programs (LRP) to partner with medical specialists, mental health professionals, and Limb Preservation Programs (LPP) to provide comprehensive limb care. While LPPs exist around the nation, design principles for such programs and their partnership role with LRPs are not well established. Using a socioecological model to incorporate hierarchical stakeholder perspectives inherent in the multidisciplinary field of limb care, this review synthesizes the latest evidence to focus on LPP design and implementation principles that can help policymakers, healthcare organizations and limb-loss rehabilitation and limb-preservation professionals to develop, implement, and sustain robust LPP programs in partnership with LRPs.

StOP? II trial: cluster randomized clinical trial to test the implementation of a toolbox for structured communication in the operating room-study protocol

Background

Surgical care, which is performed by intensely interacting multidisciplinary teams of surgeons, anesthetists, and nurses, remains associated with significant morbidity and mortality. Intraoperative communication has been shown to be associated with surgical outcomes, but tools ensuring efficient intraoperative communication are lacking. In a previous study, we developed the StOP?-protocol that fosters structured intraoperative communication. Before the critical phases of the operation, the responsible surgeon initiates and leads one or several StOP?s. During a StOP?, the surgeon informs about the progress of the operation (status), next steps and proximal goals (objectives), and possible problems (problems) and encourages all team members to voice their observations and ask questions (?). In a before-after study performed mainly in visceral surgery, we found effects of the StOP?-protocol on mortality, length of hospital stay, and reoperation. We intend to assess the impact of the StOP?-protocol in a cluster randomized trial, in a wider variety of surgical specialties (i.e., general, visceral, thoracic, vascular surgery, surgical urology, and gynecology). The primary hypothesis is that the consistent use of the StOP?-protocol by the main surgeon reduces patient mortality within 30 days after the operation. The secondary hypothesis is that the consistent use of the StOP?-protocol by the main surgeon reduces unplanned reoperations, length of hospital stay, and unplanned hospital readmissions.

Methods

This study is designed as a multicenter, cluster-randomized parallel-group trial. Board-certified surgeons of participating clinical departments will be randomized 1:1 to the StOP? intervention group or to the standard of care (control) group. The intervention group will undergo a training to use the StOP?-protocol and receive regular feedback on their compliance with the protocol. The surgeons in the control group will communicate as usual during their operations. The unit of observation will be operations performed by cluster surgeons. Consecutive patients will be enrolled over 4 months per cluster. A total of 400 surgeons will be recruited, and we expect to collect patient outcome data for 14,000 surgical procedures.

Discussion

The StOP?-protocol was designed as a tool to structure communication during surgical procedures. Testing its effects on patient outcomes will contribute to implementing evidenced-based interventions to reduce surgical complications.

Trial registration

ClinicalTrials.gov NCT05356962. Registered on May 2, 2022

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06775-y.

Clinical significance of early venous enhancement on CT angiography of the ischemic lower limbs

The authors observed good clinical courses in patients with lower limb ulcers and extensive skin inflammation who showed early venous enhancement at contrast-enhanced lower extremity computed tomographic angiography. The author hypothesized that these early venous enhancements tend to occur in conditions of healthier vascular status. A total of 145 patients who met the inclusion criteria were classified based on the degree of arterial occlusion and early venous enhancement according to lower extremity angiography. Early venous enhancement correlated with age over 65 (t-score = 0.001), absence of ulcer history (t-score = 0.003), absence of amputation history (t-score = 0.004), and low ankle-brachial index (P value = .001). We confirmed that the factors related with early venous enhancement differ from the factor inducing arterial occlusion. Prior to this study, early enhancement of veins in the lower limb was thought to be an artifact. However, in this study, veins that show early enhancement are suspected of being healthier and more responsive to inflammation than those that do not show early enhancement. These findings may help to predict the clinical course and to determine therapeutic planning without additional studies. Also, it can be easily reproduced in other facilities.

The In-Hospital Care of Patients With Peripheral Arterial Occlusive Disease

BACKGROUND

Studies from Denmark and the USA have shown differences in treatment outcomes for patients with peripheral arterial occlusive disease (PAOD) between hospitals of different size and certification status. For Germany, it is not known whether certification as a specialist center for vascular diseases or hospital size is associated with differences in the primary treatment outcome.

METHODS

Using data from the German Federal Statistical Office, all hospitalizations due to PAOD of Fontaine stage IIb or higher were included in our study and the hospitals were classified according to their size and certification status. PAOD stage, age, sex, and comorbidities were documented for each hospitalization. Univariate and multivariate logistic regressions were performed to identify independent variables that predict various treatment endpoints.

RESULTS

A total of 558 785 hospitalizations were included for analysis, of which 29% were in hospitals with certified vascular centers. In multivariate analysis, admissions to certified hospitals were associated with lower rates of major amputation (odds ratio [OR] 0.95, 95% confidence interval [0.92; 0.98], p = 0.003) and higher rates of minor amputation (OR 1.04 [1.01; 1.06], p = 0.004) with no difference observed in mortality (OR 0.99 [0.96; 1.03], p = 0.791). Admissions to larger hospitals were associated with more comorbidities, longer hospital stays, and higher rates of mortality and amputations.

CONCLUSION

Treatments in certified hospitals are associated with fewer major and more minor amputations. This may reflect intensification of therapy targeting preservation of functional limbs.

Factors affecting patency of in situ saphenous vein bypass: 2-year results from LIMBSAVE (Treatment of critical Limb IscheMia with infragenicular Bypass adopting in situ SAphenous VEin technique) registry

OBJECTIVES

Aim is to demonstrate contemporary outcomes of in situ saphenous vein bypass with the use of a valvulotome.

DESIGN

Analysis of two-year outcomes of a multicenter registry based on the treatment of critical Limb IscheMia with infragenicular Bypass adopting in situ SAphenous VEin technique (LIMBSAVE).

MATERIALS

Between January 2018 and December 2019 541 patients in 43 centers have been enrolled. In all patients an innovative valvulotome was used.

METHODS

Early outcomes were assessed. Two-year outcomes according to Kaplan-Meier curves in terms of patencies, and limb salvage were evaluated. Associations of patient and procedure variables were analysed with univariate and multivariate analyses.

RESULTS

In all cases valvulotome was able to lyse the valves. Vein injuries due to the in situ technique was 3.5%. Thirty-day mortality and major amputation rates were 3% and 0.9%, respectively. Mean follow-up was 12.1 months. Two-year estimated primary patency, primary assisted patency, secondary patency, and limb salvage were 69.1%, 81.4%, 86.5%, and 94.5%, respectively. Multivariate analysis showed association of preoperative vein diameter < 3 mm with lower primary patency (HR 14.3, p < .001), primary assisted patency (HR 9.4, p = .002), secondary patency (HR 7.2, p = .007), and limb salvage (HR 7.8, p = .005) rates. Distal anastomosis on a tibial/foot vessel also had association with lower primary patency (HR 4.8, p = .033), and primary assisted patency (HR 6, p = .011) rates. Use of a suprafascial tributary collateral as a graft confirmed association with lower primary patency (HR 6.7, p = .013), and primary assisted patency (HR 4.2, p = .042) rates.

CONCLUSIONS

Vein diameter < 3 mm, distal anastomosis on a tibial/foot vessel, and use of a suprafascial tributary collateral as a graft were significantly associated with loss of patency and limb loss during follow-up.

Outcomes of Acute Limb Ischemia in COVID-19

Objective

The inflammatory cascade caused by severe acute respiratory syndrome coronavirus 2 infection may result in arterial thrombosis and acute limb ischemia (ALI) with devastating consequences. The aims of this study were to compare outcomes of ALI in the lower extremities in patients with and without coronavirus disease 2019 (COVID-19), and to determine if ALI development in the context of COVID-19 portends a worse prognosis compared with COVID-19 without ALI.

Methods

Queries were built on TriNetX, a federated network of health care organizations across the United States that provides de-identified patient data. International Classification of Diseases, 10th revision diagnostic codes were used to identify patients with acute limb ischemia of the lower extremities and COVID-19. The study timeframe was defined as January 20, 2020 to May 20, 2021. Statistical analyses, including propensity-score matching, were done through TriNetX’s internal software. Outcomes looked at are rates of mortality, stroke, myocardial infarction, major adverse limb events, re-intervention, respiratory failure, sepsis, mental health complications, and acute renal failure. Baseline cohort characteristics were also collected.

Results

Patients with ALI with COVID-19 (ALI C19+; n = 526) were significantly less likely than patients with ALI without COVID-19 (ALI; n = 14,131) to have baseline comorbidities, including nicotine dependence (18% vs 33%; P < .0001). In contrast, ALI C19+ patients had significantly more comorbidities than hospitalized patients with COVID-19 without ALI (n = 275,903), including nicotine dependence (18% vs 10%; P < .0001). After propensity matching was performed, ALI C19+ patients had significantly higher rates of mortality (24.9% vs 9.2%; P < .0001), major adverse limb events (5.8% vs 2.9%; P = .0223), and acute renal failure (22.2% vs 14.9%; P = .0025) than patients with ALI. Compared with hospitalized patients with COVID-19 without ALI, ALI C19+ patients had higher propensity-matched rates of respiratory failure and being placed on assisted ventilation (32.9% vs 27%; P = .0369), sepsis (16.9% vs 12.2%; P = .0288), acute renal failure (22.1% vs 14.6%; P = .0019), and mortality (24.7% vs 14.4%; P < .0001).

Conclusions

Patients who developed ALI following COVID-19 present with significantly different demographics and comorbidities from those who develop ALI without COVID-19. After controlling for these variables, higher rates of major adverse limb events, acute renal failure, and mortality in patients with ALI with COVID-19 suggest that not only may COVID-19 precipitate ALI, but it may also exacerbate ALI sequelae. Furthermore, development of ALI in COVID-19 portends worse prognosis compared with patients with COVID-19 without ALI.

Two-Step Geometry Design Method, Numerical Simulations and Experimental Studies of Bioresorbable Stents

The stent-implantation process during angioplasty procedures usually involves clamping the stent onto a catheter to a size that allows delivery to the place inside the artery. Finding the right geometrical form of the stent to ensure good functionality in the open form and to enable the clamping process is one of the key elements in the stent-design process. In the first part of the work, an original two-step procedure for stent-geometry design was proposed. This was due to the necessary selection of a geometry that would provide adequate support to the blood-vessel wall without causing damage to the vessel. Numerical simulations of the crimping and deployment processes were performed to verify the method. At the end of this stage, the optimal stent was selected for further testing. In addition, numerical simulations of selected experimental tests (catheter-crimping process, compression process) were used to verify the obtained geometrical forms. The results of experimental tests on stents produced by the microinjection method are presented. The digital image correlation (DIC) method was used to compare the results of numerical simulation and experimental tests. The two-step modeling approach was found to help select the appropriate geometry of the expanded stent, which is an extremely important step in the design of the crimping process. In the part of the paper where the results obtained by numerical simulation were compared with those gained by experiment and using the DIC method, a good compatibility of the displacement results can be observed. For both longitudinal and transverse (pinch) stent compression, the results practically coincide. The paper presents also the application of the DIC method which significantly expands the research possibilities, allowing for a detailed inspection of the deformation state and, above all, verification of local dangerous areas. This approach significantly increases the possibility of assessing the quality of the stents.

A Focus on Amputation Level: Factors Preventing Length Preservation in the National Inpatient Sample

BACKGROUND

Diabetic lower-extremity disease is the primary driver of mortality in patients with diabetes. Amputations at the forefoot or ankle preserve limb length, increase function, and, ultimately, reduce deconditioning and mortality compared with higher-level amputations, such as below-the-knee amputations (BKAs). We sought to identify risk factors associated with amputation level to understand barriers to length-preserving amputations (LPAs).

METHODS

Diabetic lower-extremity admissions were extracted from the 2012-2014 National Inpatient Survey using ICD-9-CM diagnosis codes. The main outcome was a two-level variable consisting of LPAs (transmetatarsal, Syme, and Chopart) versus BKAs. Logistic regression analysis was used to determine contributions of patient- and hospital-level factors to likelihood of undergoing LPA versus BKA.

RESULTS

The study cohort represented 110,355 admissions nationally: 42,375 LPAs and 67,980 BKAs. The population was predominantly white (56.85%), older than 50 years (82.55%), and male (70.38%). On multivariate analysis, living in an urban area (relative risk ratio [RRR] = 1.48; P < .0001) and having vascular intervention in the same hospital stay (RRR = 2.96; P < .0001) were predictive of LPA. Patients from rural locations but treated in urban centers were more likely to receive BKA. Minorities were more likely to present with severe disease, limiting delivery of LPAs. A high Elixhauser comorbidity score was related to BKA receipt.

CONCLUSIONS

This study identifies delivery biases in amputation level for patients without access to large, urban hospitals. Rural patients seeking care in these centers are more likely to receive higher-level amputations. Further examination is required to determine whether earlier referral to multidisciplinary centers is more effective at reducing BKA rates versus satellite centers in rural localities.

Porous Bilayer Vascular Grafts Fabricated from Electrospinning of the Recombinant Human Collagen (RHC) Peptide-Based Blend

Cardiovascular diseases, including coronary artery and peripheral vascular pathologies, are leading causes of mortality. As an alternative to autografts, prosthetic grafts have been developed to reduce the death rate. This study presents the development and characterization of bilayer vascular grafts with appropriate structural and biocompatibility properties. A polymer blend of recombinant human collagen (RHC) peptides and polycaprolactone (PCL) was used to build the inner layer of the graft by electrospinning and co-electrospinning the water-soluble polyethylene oxide (PEO) as sacrificial material together with PCL to generate the porous outer layer. The mechanical test demonstrated the bilayer scaffold’s appropriate mechanical properties as compared with the native vascular structure. Human umbilical vein endothelial cells (HUVEC) showed enhanced adhesion to the lumen after seeding on nanoscale fibers. Meanwhile, by enhancing the porosity of the microfibrous outer layer through the removal of PEO fibers, rat smooth muscle cells (A7r5) could proliferate and infiltrate the porous layer easily.

Multimodal Prehabilitation to Improve Quality of Life and Functional Capacity in Peripheral Arterial Disease: A Case Series

Objectives

To assess feasibility and effect of multimodal prehabilitation in patients with severe life-limiting intermittent claudication and complex infrainguinal disease.

Design

Case series of patients who underwent a 12-week prehabilitation program.

Setting

Outpatient clinic of a public tertiary hospital

Participants

Patients with a diagnosis of severe life-limiting intermittent claudication (Fontaine stage IIb and III) with complex infrainguinal disease or previous failed bypass attempts (N=5) who were referred to the prehabilitation clinic by a vascular surgeon.

Interventions

Patients underwent a baseline assessment that included quality of life questionnaires and functional capacity tests. After baseline assessment, they received a 12-week prehabilitation program that consisted of (1) a supervised exercise session 1 time per week; (2) home-based exercise prescription; (3) nutritional counseling; (4) smoking cessation; and (5) psychosocial intervention. Adherence to all components was recorded as well as the occurrence of any adverse event. After completion of the 12-week program, patients were reassessed.

Main Outcome Measure

Feasibility of prehabilitation measured by adherence to the different components of the program and occurrence of adverse events.

Results

All 5 patients completed the program. No serious adverse events occurred during the length of prehabiliation. Median adherence to each prehabilitation component was 91.7% (interquartile range [IQR], 33.5%) for supervised training, 91.7% (IQR, 40%) for home-based exercise, and 75% (IQR, 50%) for nutrition. Three of the 5 patients underwent psychosocial intervention and all who were active smokers enrolled in the smoking cessation program. Functional capacity measured with the 6-minute walk distance improved by 70 m (IQR, 99 m), and disease-specific quality of life measured with the Vascular Quality of Life Questionnaire improved by 25%.

Conclusion

Multimodal prehabilitation appears to be a feasible tool that could be used to increase functional capacity and quality of life for patients with complex infrainguinal disease and expected poor revascularization outcome or previous failed bypass attempts.

Exploring the Utility of Brain Natriuretic Peptide Measurement in Vascular Surgery

BACKGROUND

The Canadian Cardiovascular Society 2016 guidelines recommend pre-operative measurement of brain natriuretic peptide (BNP) to risk-stratify patients for a 30-day composite outcome of death, myocardial infarction, or asymptomatic myocardial injury after noncardiac surgery (MINS). Whether this practice affects outcomes is unclear. The aim of this study was to examine the clinical utility of brain natriuretic peptide and myocardial injury after noncardiac surgery.

METHODS

Analysis of a prospectively maintained database identified all elective open vascular surgery cases at an academic teaching hospital from January 2015 to December 2018. Pre-operative BNP values were available from June 2018 onward after becoming institutionally mandated. Co-morbidities were also collected to stratify patients using the Revised Cardiac Risk Index. The composite outcome of 30-day mortality, myocardial infarction, or MINS was determined.

RESULTS

Prior to BNP becoming an institutionally required test, data was available from 1176 open cases. The 30-day mortality was 1.3% (15/1176) and post-operative myocardial infarction rate was 2.3% (27/1176). BNP measurements were collected in 91 consecutive patients. Ten patients (11%) experienced the composite outcome of mortality, myocardial infarction, or MINS. Elevated BNP was associated with increased odds of the composite outcome (P = 0.04), but not with mortality or myocardial infarction. Revised Cardiac Risk Index score was not predictive of outcomes. The majority of patients who qualified for the composite outcome experienced only an asymptomatic troponin rise (80%). Two patients met the universal definition of myocardial infarction, one of whom died. No other deaths occurred within 30 days. Detection of MINS did not result in any significant changes to patient management.

CONCLUSIONS

Elevated BNP correlates with increased MINS. An asymptomatic troponin rise is the most commonly observed event, with unclear clinical implications. BNP may over-estimate surgical risk. Further studies on the long-term outcomes of patients with elevated BNP and MINS are required before widely adopting this strategy in vascular surgery patients.

A Robotically Steerable Guidewire With Forward-Viewing Ultrasound: Development of Technology for Minimally-Invasive Imaging

OBJECTIVE

The current standard of care for peripheral chronic total occlusions involves the manual routing of a guidewire under fluoroscopy. Despite significant improvements in recent decades, navigation remains clinically challenging with high rates of procedural failure and iatrogenic injury. To address this challenge, we present a proof-of-concept robotic guidewire system with forward-viewing ultrasound imaging to allow visualization and maneuverability through complex vasculature.

METHODS

A 0.035" guidewire-specific ultrasound transducer with matching layer and acoustic backing was designed, fabricated, and characterized. The effect of guidewire motion on signal decorrelation was assessed with simulations and experimentally, driving the development of a synthetic aperture beamforming approach to form images as the transducer is steered on the robotic guidewire. System performance was evaluated by imaging wire targets in water. Finally, proof-of-concept was demonstrated by imaging an ex vivo artery.

RESULTS

The designed custom transducer was fabricated with a center frequency of 15.7 MHz, 45.4% fractional bandwidth, and 31 dB SNR. In imaging 20 μm wire targets at a depth of 6 mm, the lateral -6 dB target width was 0.25 ± 0.03 mm. The 3D artery reconstruction allowed visualization of vessel wall structure and lumen.

CONCLUSION

Initial proof-of-concept for an ultrasound transducer-tipped steerable guidewire including 3D image formation without an additional sensor to determine guidewire position was demonstrated for a sub-mm system with an integrated ultrasound transducer and a robotically-steered guidewire.

SIGNIFICANCE

The developed forward-viewing, robotically-steered guidewire may enable navigation through occluded vascular regions that cannot be crossed with current methods.

Gene Expression Signature in Patients With Symptomatic Peripheral Artery Disease

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Use of Flap Salvage for Lower Extremity Chronic Wounds Occurs Most Often in Competitive Hospital Markets

Wounds in the comorbid population require limb salvage to prevent amputation. Extensive health economics literature demonstrates that hospital activities are influenced by level of market concentration. The impact of competition and market concentration on limb salvage remains to be determined.

Methods

Admissions for chronic lower extremity wounds in nonrural hospitals were identified in the 2010-2011 National Inpatient Survey using ICD-9-CM diagnosis codes. The study cohort consisted of admitted patients receiving amputations, salvage without flap techniques (eg, skin grafts), or salvage with flap techniques. The all-service Herfindahl-Hirschman Index (HHI), which is a commonly used tool for market and antitrust analyses, was used to measure hospital competition. Multinomial regression analysis accounting for the complex survey design of the NIS was used to determine the relationship between the HHI and hospital adoption of limb salvage controlling for patient, hospital, and market factors.

Results

The study cohort represents 124,836 admissions nationally: 89,880 amputations, 26,715 salvage without flap techniques, and 8241 salvage flap techniques. Diabetics accounted for 64.1% of all study admissions. Hospitals in highly competitive markets performed more flaps for chronic lower extremity wounds than noncompetitive markets. Controlling for other factors, hospitals in highly competitive markets, relative to those in highly concentrated markets, were 2.48 percentage points more likely to perform limb salvage with flaps (P < 0.01). Other factors were less predictive.

Conclusion

Increased hospital competition is the strongest systems-level predictor of receipt of lower extremity flaps among patients with chronic wounds. Improving access to reconstructive limb services must consider the competitive structure of hospital markets.

The epidemiology of lower extremity amputations, strategies for amputation prevention, and the importance of patient-centered care

Dysvascular amputations, defined as those secondary to the complications of peripheral arterial disease or diabetes mellitus, are the most common cause of lower extremity amputations. Despite recent advancements in diabetes mellitus treatments and the many modern innovations in endovascular therapies, the incidence of dysvascular lower extremity amputations has not improved. In this article, we will review the most recent epidemiological data on lower extremity amputations, discuss the latest recommendations from different medical societies for the prevention of limb loss, and explore the role of the vascular surgeon as part of a multidisciplinary team in providing comprehensive care for patients at risk of undergoing amputations for ischemic or diabetic complications. We will also discuss the importance of considering patient perspectives and patient-reported outcomes to better understand the impact of amputations on the patient experience.

Contemporary Trends in Hospital Admissions and Outcomes in Patients With Critical Limb Ischemia: An Analysis From the National Inpatient Sample Database

BACKGROUND

Critical limb ischemia (CLI) morbidity and mortality rates have historically been disproportionately higher than for other atherosclerotic diseases, however, recent trends have not been reported. In patients admitted with CLI, we aimed to examine trends in in-hospital mortality, major amputations, length of stay, and cost of hospitalizations overall and stratified by type of revascularization procedures.

METHODS

Using 2011 to 2017 National Inpatient Sample data, we identified CLI-related admissions based on International Classification of Diseases, Ninth and Tenth Edition, Clinical Modification codes. Primary outcomes of interest were in-hospital mortality and major amputations. Secondary outcomes were the length of stay and cost of hospitalization. We stratified outcomes based on endovascular or open surgical interventions. We also performed hierarchical multivariable regression analyses of outcomes based on age, sex, race, hospital size, type, and location.

RESULTS

We identified 2 643 087 CLI-related admissions between 2011 and 2017. CLI admissions increased from 0.9% to 1.4% P_trend<0.0001 as well as overall peripheral artery disease admissions (4.5%-8.9%, P_trend<0.0001). In-hospital mortality for the entire CLI cohort decreased from 3.3% to 2.7%, P_trend<0.0001, and major amputations decreased from 10.9% to 7%, P_trend<0.0001. A decline was also noted for the length of stay from 5.7 (3.1-10.1) to 5.4 (3.0-9.2) days (P_trend<0.0001), whereas admission costs increased from USD $11 791 ($6676-$21 712) to $12 597 ($7248-$22 748; P_trend<0.0001). Endovascular interventions increased (P_trend<0.0001) against a decline in surgical interventions (P_trend<0.0001). Black race, female sex, and age ≥60 years were associated with higher in-hospital mortality, whereas Black race, male sex, and age<60 years were associated with higher major amputations.

CONCLUSIONS

A relatively small decrease in absolute numbers for mortality and major amputations were observed against a backdrop of increasing CLI admissions over recent years. Patients with CLI received more endovascular interventions than surgical interventions over time. However, admissions for endovascular interventions were characterized by higher risk patient profiles and a higher risk of major amputations as compared with surgical interventions.

Editor's Choice - Regional Versus General Anaesthesia in Peripheral Vascular Surgery: a Propensity Score Matched Nationwide Cohort Study of 17 359 Procedures in Denmark

OBJECTIVE

Cardiopulmonary comorbidity is common in vascular surgery. General anaesthesia (GA) may impair perfusion and induce respiratory depression. Regional anaesthesia (RA), including neuraxial or peripheral nerve blocks, may therefore be associated with a better outcome.

METHODS

This was a nationwide retrospective cohort study. All open inguinal and infra-inguinal arterial surgical reconstructions from 2005 to 2017 were included. Data were extracted from national registries. Multivariable linear and logistic regression models and propensity score matching were used. The propensity score was derived by developing a model that predicted the probability that a given patient would receive GA based on age, comorbidity, anticoagulant medication, procedure type, and the urgency of surgery. Matching was performed in four groups based on American Society of Anesthesiologists' score I - II, score III - V, and gender. Outcome parameters included surgical and general complications (bleeding, thrombosis/embolus, cardiac, pulmonary, renal, cerebral, and >3 days intensive care therapy), length of stay, and 30 day mortality, hypothesising a better outcome after RA.

RESULTS

There were 10 509 procedures in the GA group and 6 850 in the RA group. After propensity score matching, 6 267 procedures were included in each group. Surgical and general complications were significantly more common after GA in both matched (3.8 vs. 2.5%, p < .001 and 6.5 vs. 4.2%, p < .001) and unmatched analyses (3.8 vs. 2.5%, p < .001 and 6.5 vs. 4.2%, p < .001). The 30 day mortality rate was significantly higher after GA, in matched and un matched analyses (3.1 vs. 2.4%, p = .019 and 4.1 vs. 2.4%, p < .001). There was no difference in length of stay.

CONCLUSION

RA may be associated with a better outcome, compared with GA, after open inguinal and infra-inguinal peripheral vascular surgery. In the clinical context when RA is not feasible, GA can still be considered safe.

The impact of surgical site infection on hospitalisation, treatment costs, and health-related quality of life after vascular surgery

Surgical site infections (SSI) substantially increase costs for healthcare providers because of additional treatments and extended patient recovery. The objective of this study was to assess the cost and health-related quality of life impact of SSI, from the perspective of a large teaching hospital in England. Data were available for 144 participants undergoing clean or clean-contaminated vascular surgery. SSI development, length of hospital stay, readmission, and antibiotic use were recorded over a 30-day period. Patient-reported EQ-5D scores were obtained at baseline, day 7 and day 30. Linear regressions were used to control for confounding variables. A mean SSI-associated length of stay of 9.72 days resulted in an additional cost of £3776 per patient (including a mean antibiotic cost of £532). Adjusting for age, smoking status, and procedure type, SSI was associated with a 92% increase in length of stay (P < 0.001). The adjusted episode cost was £3040. SSI reduced patient utility between baseline and day 30 by 0.156 (P = 0.236). Readmission rates were higher with SSI (P = 0.017), and the rate to return to work within 90 days was lower. Therefore, strategies to reduce the risk of surgical site infection for high-risk vascular patients should be investigated.

Comparison of Long Term Outcomes After Endovascular Treatment Versus Bypass Surgery in Chronic Limb Threatening Ischaemia Patients with Long Femoropopliteal Lesions

OBJECTIVE

There are currently two treatments available for patients with chronic limb threatening ischaemia (CLTI): open surgical bypass (OSB) and percutaneous transluminal angioplasty with/without stenting (PTA/S). The aim of this study was to compare short and long term outcomes between PTA/S and OSB in CLTI patients with long (GLASS grade III and IV) femoropopliteal disease.

METHODS

This was a two centre retrospective study including all consecutive patients with CLTI undergoing first time lower extremity intervention at two distinct vascular surgical centres. Between 1 January 2012 and 1 January 2018, 1 545 CLTI consecutive limbs were treated for femoropopliteal GLASS grade III and IV lesions at two vascular surgical centres. Using covariables from baseline and angiographic characteristics, a propensity score was calculated for each limb. Thus, comparable patient cohorts (235 in PTA/S and 235 in OSB group) were identified for further analysis. The primary outcomes were freedom from re-intervention in the treated extremity and major amputation. Secondary outcomes were all hospital complications among the two patient groups.

RESULTS

Total overall complication rates were significantly higher in the OSB group (20.42% vs. 5.96%, p < .001), especially wound infection/seroma rate that required prolonged hospitalisation and further treatment (7.65% vs. 0%, p < .001). After the median follow up of 61 months, re-intervention rates were significantly higher in the PTA/S group (log rank test, 44.68% vs. 29.79%, p = .002), but there was no significant difference in terms of major amputation rates between the two group of patients (log rank test, PTA/S 27.23% vs. OSB 22.13%, p = .17).

CONCLUSION

Bypass surgery seems to be superior to PTA/S for GLASS grade III and IV femoropopliteal lesions in patients with CLTI in terms of long term re-intervention rates, but with considerably higher rates of post-operative complications. A larger cohort of patients in currently ongoing randomised trials, as well as prospective cohort studies are necessary to confirm these findings.

Percutaneous brachial access associated with increased incidence of complications compared with open exposure for peripheral vascular interventions in a contemporary series

OBJECTIVE

Although percutaneous brachial access has been used more often for peripheral vascular interventions (PVIs), previous studies have suggested that open brachial artery exposure for access is associated with fewer complications than percutaneous access. The present study sought to determine the incidence of complications for each access method and identify the predictors of access site complications after brachial access.

METHODS

The Vascular Quality Initiative national database was queried for all patients who had undergone PVI with brachial artery access from 2016 to 2019. Procedures with simultaneous thrombolysis or open procedures were excluded. The primary outcome was any perioperative brachial artery access complications. Multivariable logistic regression was used to identify any associated predictors.

RESULTS

A total of 1400 procedures had been performed for 1242 patients; 189 procedures (13.5%) had used an open exposure. The mean patient age was 67.3 ± 9.5 years, and 55.7% of the procedures were on men. No significant demographic differences were found between the open and percutaneous groups. Open exposure procedures were more likely to have used sheaths >5F (79.4% vs 59.0%; P < .001) and treated more arteries (2.0 ± 1.8 vs 1.7 ± 0.9; P < .001) but less likely to have used multiple access sites (8.5% vs 20.1%; P < .001). Access complications occurred in 7.5% of the percutaneous procedures and 1.6% of the open exposures (P = .003). Percutaneous access was independently associated with the occurrence of brachial access complications (odds ratio [OR], 5.92; 95% confidence interval [CI], 1.76-19.9; P = .004). Other associated factors included female sex (OR, 2.23; 95% CI, 1.44-3.44; P < .001), congestive heart failure (OR, 2.02; 95% CI, 1.26-3.24; P = .003), and increasing sheath size (OR, 1.36 per each 1F increase in size; 95% CI, 1.07-1.72; P = .011); diabetes was protective (OR, 0.53; 95% CI, 0.33-0.83; P = .006).

CONCLUSIONS

Open exposure might be advantageous compared with percutaneous access for preventing complications after brachial access. However, the difference in complications was driven by hematomas that were managed nonoperatively. Operative complications were more common in the percutaneous group, although this did not reach statistical significance. Percutaneous access should be used cautiously in women, patients with a history of congestive heart failure, those without diabetes, and interventions in which larger sheaths are required.

Survival and factors predicting mortality after major and minor lower-extremity amputations among patients with diabetes: a population-based study using health information systems

INTRODUCTION

The aim of the study was to identify the sociodemographic and clinical factors associated with death after the first lower-extremity amputation (LEA), minor and major separately, using data from regional health administrative databases.

RESEARCH DESIGN AND METHODS

We carried out a population-based cohort study including patients with diabetes residing in the Lazio region and undergoing a primary amputation in the period 2012-2015. Each individual was followed up for at least 2 years. Kaplan-Meier analysis was used to evaluate long-term survival; Cox proportional regression models were applied to identify factors associated with all-cause mortality.

RESULTS

The cohort included 1053 patients, 72% were male, 63% aged ≥65 years, and 519 (49%) died by the end of follow-up. Mortality rates at 1 and 4 years were, respectively, 33% and 65% for major LEA and 18% and 45% for minor LEA. Significant risk factors for mortality were age ≥65, diabetes-related cardiovascular complications, and chronic renal disease for patients with minor LEA, and age ≥75 years, chronic renal disease and antidepressant drug consumption for subjects with major LEA.

CONCLUSIONS

The present study confirms the high mortality rates described in patients with diabetes after non-traumatic LEA. It shows differences between minor and major LEA in terms of mortality rates and related risk factors. The study highlights the role of depression as specific risk factor for death in patients with diabetes after major LEA and suggests including its definition and management in strategies to reduce the high mortality rate observed in this group of patients.

Effect of Transfer Status on Outcomes of Emergency General Surgery Patients

INTRODUCTION

Transferred emergency general surgery (EGS) patients are a vulnerable, high acuity population. The outcomes of and health care utilization among transferred (TRAN) as compared to directly admitted (DA) patients have been studied primarily using single institution or hospital system data which limits generalizability. We evaluated these outcomes among EGS patients using a national database.

METHODS

We identified encounters of patients aged ≥18 years with a diagnosis of EGS as defined by the American Association for the Surgery of Trauma in the 2008-2011 Nationwide Inpatient Sample (NIS). Multivariable regression analyses determined if transfer status independently predicted in-hospital mortality (logistic regression) and morbidity (presence of any complication among those who survived to discharge; logistic regression), cost (log-linear regression), and duration of stay (among those who survived to discharge; log-linear regression) accounting for the NIS sampling design.

RESULTS

We identified 274,145 TRAN (57,885 unweighted) and 10,456,100 DA (2,187,132 unweighted) encounters. On univariate analysis, TRAN patients were more likely to have greater comorbidity scores, have Medicare insurance, and reside in an area with a lesser median household income compared to DA patients (p<0.0001). Mortality was greater in the TRAN vs DA groups (4.4% vs 1.6%; p<0.0001). Morbidity (presence of any complication) was also greater among TRAN patients (38.8% vs 26.1%; p<0.0001). Morbidity among TRAN patients was primarily due to urinary- (13.7%), gastrointestinal- (12.9%), and pulmonary-related (13.3%) complications. Median duration of hospital stay was 4.3 days for TRAN vs 3.0 days for DA (p<0.0001) patients. Median cost was greater for TRAN patients ($8,935 vs $7,167; p<0.0001). Regression analyses determined that after adjustment, TRAN patients had statistically significantly greater mortality, morbidity, and cost as well as longer durations of stay.

CONCLUSIONS

EGS patients who are transferred experience increased in-hospital morbidity and mortality as well as increased durations of stay and cost. As the population and age of patients diagnosed with EGS conditions increase while the EGS workforce decreases, the need for inter-hospital transfers will increase. Identifying risk factors associated with worse outcomes among transferred patients can inform the design of initiatives in performance improvement and direct the finite resources available to this vulnerable patient population.

Successful Treatment of Acute Limb Ischemia Secondary to Iatrogenic Distal Embolization Using Catheter Directed Aspiration Thrombectomy

Objective: Acute limb ischemia (ALI) due to thromboembolism is a limb- and life-threatening condition regularly encountered by vascular surgeons. Iatrogenic distal embolization is occasionally seen as a complication of various endovascular procedures. We present a series of four patients who developed ALI due to arterial embolization during cardiovascular procedures that were successfully treated via catheter directed aspiration embolectomy. Methods: Retrospective review of demographics, risk factors, and procedural outcomes was completed for 4 patients who presented with ALI due to distal embolization following cardiovascular procedures. All patients were successfully treated with catheter directed aspiration embolectomy using the Penumbra Indigo System (Penumbra Inc., Alameda, California). All patients had high-quality angiography demonstrating successful embolectomy and end-procedure patency. Results: Three patients presented with Rutherford 2A and one with Rutherford 2B ALI secondary to intraoperative distal embolization. Three patients presented with ALI secondary to distal embolization during peripheral vascular interventions, and one following emergent intra-aortic balloon pump (IABP) placement for myocardial infarction. All emboli were located in the infra-inguinal vasculature. Median post-operative ABIs were 0.94 (n = 4). Median length of stay was 2 days. There were no mortalities and no need for adjunctive fasciotomy, amputation, or bypass for limb salvage. All patients improved clinically after intervention, and returned to their reported pre-hospitalization functional status. Conclusion: All procedures achieved technical success with catheter-directed aspiration thrombectomy with or without adjunctive lysis. Catheter-directed aspiration embolectomy with the Penumbra Indigo System for ALI following an iatrogenic embolic event is a safe, less-invasive treatment option. The use of this technology may reduce the need for traditional open thrombectomy or thrombolytic therapy to address ALI.

Impact of Therapeutic Angiogenesis Using Autologous Bone Marrow-derived Mononuclear Cell Implantation in Patients with No-option Critical Limb Ischemia

Recently, the limb salvage rate of patients with critical limb ischemia (CLI) has been improved due to the development of revascularization and wound care treatment. However, many patients with CLI are refractory to standard treatments, including revascularization such as endovascular treatment or surgical bypass. Establishment of a new cell therapy is required to improve the limb salvage rate and prognosis in patients with CLI. In 1997, endothelial progenitor cells were found to be derived from the bone marrow to circulate as CD34 surface antigen positive cells in peripheral blood and to affect therapeutic angiogenesis in ischemic tissues. Later, therapeutic angiogenesis using autologous bone marrow-derived mononuclear cell (BM-MNC) implantation was performed for patients with no-option CLI in clinical practice. Several reports showed the safety and efficacy of the BM-MNC implantation in patients with CLI caused by arteriosclerosis obliterans, thromboangiitis obliterans (TAO), and collagen diseases. In particular, in patients with CLI caused by TAO, limb salvage rate was significantly improved compared with standard treatments. The BM-MNC implantation may be feasible and safe in patients with no-option CLI. Here, we review the efficacy of BM-MNC implantation in no-option CLI, with a focus on therapeutic angiogenesis.

Current opinions about the definition of critical limb ischemia: A debate still open after three decades

Critical limb ischemia (CLI) is the most advanced stage of peripheral arterial disease. It is clinically defined as rest pain with or without skin ulcer or gangrene and carries a very poor prognosis with a high rates of limb amputation and cardiovascular mortality. Despite the first definition of CLI has been published more than 30 years ago, the debate about what it really is, is still open. Over the years the hemodynamic parameters utilised to define the critical level of limb perfusion have changed. This has raised some question about the apparent confusion about the definition of CLI. Moreover, a new term such as "limb threatening ischemia" has replaced the definition of CLI in recent guideline. Therefore, it becomes necessary to understand the evolution of the concept and the definition of CLI, to interpret the future trend.Hence, this work analysing the guideline documents on peripheral arterial disease that have defined the CLI to date, aims to clarify the path that has brought to the current conceptual changes of the definition of CLI.

Trends in peripheral arterial disease incidence and mortality in EU15+ countries 1990-2017

AIMS

The aim was to assess trends in peripheral arterial disease (PAD) incidence and mortality rates in European Union(15+) countries between 1990 and 2017.

METHODS AND RESULTS

This observational study used data obtained from the 2017 Global Burden of Disease study. Age-standardised mortality and incidence rates from PAD were extracted from the Global Health Data Exchange for EU15+ countries for the years 1990-2017. Trends were analysed using Joinpoint regression analysis. Between 1990 and 2017, the incidence of PAD decreased in all 19 EU15+ countries for females, and in 18 of 19 countries for males. Increasing PAD incidence was observed only for males in the United States (+1.4%). In 2017, the highest incidence rates were observed in Denmark and the United States for males (213.6 and 202.3 per 100,000, respectively) and in the United States and Canada for females (194.8 and 171.1 per 100,000, respectively). There was a concomitant overall trend for increasing age-standardised mortality rates in all EU15+ countries for females, and in 16 of 19 EU15+ countries for males between 1990 and 2017. Italy (-25.1%), Portugal (-1.9%) and Sweden (-0.6%) were the only countries with reducing PAD mortality rates in males. The largest increases in mortality rates were observed in the United Kingdom (males +140.4%, females +158.0%) and the United States (males +125.7%, females +131.2%).

CONCLUSIONS

We identify shifting burden of PAD in EU15+ countries, with increasing mortality rates despite reducing incidence. Strong evidence supports goal-directed medical therapy in reducing PAD mortality - population-wide strategies to improve compliance to optimal goal-directed medical therapy are warranted.

Race and socioeconomic differences associated with endovascular peripheral vascular interventions for newly diagnosed claudication

BACKGROUND

Despite guidelines cautioning against the use of endovascular peripheral vascular interventions (PVI) for claudication, more than 1.3 million PVI procedures are performed annually in the United States. We aimed to describe national rates of PVI for claudication, and identify patient and county-level risk factors associated with a high rate of PVI.

METHODS

We used the Medicare claims database to identify all Medicare beneficiaries with a new diagnosis of claudication between January 2015 and June 2017. A hierarchical logistic regression model accounting for patient age, sex, comorbidities; county region and setting; and a patient race-county median income interaction was used to assess the associations of race and income with a high PVI rate.

RESULTS

We identified 1,201,234 patients with a new diagnosis of claudication for analysis. Of these, 15,227 (1.27%) underwent a PVI. Based on hierarchical logistic regression accounting for patient and county-level factors, black patients residing in low-income counties had a significantly higher odds of undergoing PVI than their white counterparts (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.20-1.40), whereas the odds of PVI for black versus white patients was similar in high-income counties (OR, 1.06; 95% CI, 0.99-1.14). PVI rates were higher for low versus high-income counties in both the black (OR, 1.46; 95% CI, 1.31-1.64) and white (OR, 1.19; 95% CI, 1.12-1.27) groups. There were no significant associations of Hispanic, Asian, North American native, or other races with PVI in either low- or high-income counties after risk adjustment (all P ≥ .09).

CONCLUSIONS

In the Medicare population, the mean rate of PVI of 12.7 per 1000 claudication patients varies significantly based on race and income. Our data suggest there are racial and socioeconomic differences in the treatment of claudication across the United States.

Changes in rates of vascular procedure types and lower extremity amputations in Finland for 2007-2017 inclusive, a population cohort study of 69,523 revascularizations

INTRODUCTION

Since 2000 the numbers of both open and endovascular revascularization procedures have increased. Despite these increases, the number of major lower extremity amputations (LEAs) has remained relatively constant. The aim of the present study was to assess the number of vascular procedures in relation to the frequency of major LEAs in Finland.

METHODS

The Finnish National Institute for Health and Welfare (THL) administers a national registry of all procedures conducted by official healthcare providers in Finland. Data regarding all revascularization procedures and major LEAs between 2007 and 2017 inclusive, were collected from the THL registry. The rates of both open and endovascular procedures were analyzed.

RESULTS

A total of 69,523 revascularization procedures were registered over the 11-year period. Of all revascularizations, 22.6% were endovascular in 2007, which rose to 60.5% in 2017. The annual rates of vascular procedures per 100,000 inhabitants increased from 66 in 2007 to 172 in 2017 (increase 10 procedures per year, 95% CI 8.6-12.3, P < 0.01) There was a significant increase (by 141 per year, 95% CI 110-174, P < 0.01) for open revascularizations (2705 operations in 2007, 3992 operations in 2017) and (by 491 per year, 95% CI 433-550, P < 0.01) for endovascular revascularizations (791 in 2007-5514 in 2017). Open aorto-iliac segment revascularization decreased, whereas the numbers of procedures increased for all other arterial segments. The overall frequency of amputations was 18-20 per 100,000. The frequency of amputations in the subpopulation over 65 years old decreased from 93 in 2007 to 72 in 2017 (P < 0.01).

CONCLUSION

The present study demonstrated increases in vascular surgery procedures over the 11-year study-period. The increase was greatest for endovascular procedures. During the same period, there was a significant decrease in the frequency of major LEAs in the >65-year-old subpopulation.

Altered Metabolomic Profile in Patients with Peripheral Artery Disease

Peripheral artery disease (PAD) is a common atherosclerotic disease characterized by narrowed or blocked arteries in the lower extremities. Circulating serum biomarkers can provide significant insight regarding the disease progression. Here, we explore the metabolomics signatures associated with different stages of PAD and investigate potential mechanisms of the disease. We compared the serum metabolites of a cohort of 26 PAD patients presenting with claudication and 26 PAD patients presenting with critical limb ischemia (CLI) to those of 26 non-PAD controls. A difference between the metabolite profiles of PAD patients from non-PAD controls was observed for several amino acids, acylcarnitines, ceramides, and cholesteryl esters. Furthermore, our data demonstrate that patients with CLI possess an altered metabolomic signature different from that of both claudicants and non-PAD controls. These findings provide new insight into the pathophysiology of PAD and may help develop future diagnostic procedures and therapies for PAD patients.

A pilot feasibility randomised clinical trial comparing dialkylcarbamoylchloride-coated dressings versus standard care for the primary prevention of surgical site infection

A surgical site infection (SSI) may occur in up to 30% of procedures and results in significant morbidity and mortality. We aimed to assess the feasibility of conducting a randomised controlled trial (RCT) examining the use of dialkylcarbamoylchloride (DACC)-impregnated dressings, which bind bacteria at the wound bed, in the prevention of SSI in primarily closed incisional wounds. This pilot RCT recruited patients undergoing clean or clean-contaminated vascular surgery. Participants were randomised intraoperatively on a 1:1 basis to either a DACC-coated dressing or a control dressing. Outcomes were divided into feasibility and clinical outcomes. The primary clinical outcome was SSI at 30 days (assessed using Centers for Disease Control criteria and Additional treatment, Serous discharge, Erythema, Purulent exudate, Separation of the deep tissues, Isolation of bacteria and duration of inpatient Stay scoring methods). This study recruited 144 patients in 12 months at a median rate of 10 per month. Eligibility was 73% and recruitment 60%. At 30 days, there was a 36.9% relative risk reduction in the DACC-coated arm (16.22% versus 25.71%, odds ratio 0.559, P = 0.161). The number needed to treat was 11 patients. A large-scale RCT is both achievable and desirable given the relative risk reduction shown in this study. Further work is needed to improve the study protocol and involve more centres in a full-scale RCT.

Analysis of Thirty-Day Readmission after Infrainguinal Bypass

BACKGROUND

The Vascular Study Group of New England (VSGNE) conducted a pilot study evaluating the feasibility of 30-day data collection in patients undergoing infrainguinal bypass (INFRA) which was subsequently expanded to include a limited number of additional sites within the Vascular Quality Initiative (VQI). The purpose of our study was to use these data to evaluate the incidence of 30-day readmission after infrainguinal bypass. A secondary goal of the study was to perform a critical appraisal of the data elements and definitions in the 30-day dataset.

METHODS

All infrainguinal bypass procedures performed during the pilot study period (7/2008 and 4/2016) were identified and merged with a dataset containing the 30-day data. Incidence and types of readmission were assessed. The primary endpoint was 30-day readmission, defined as any hospital readmission within 30 days of index operation; unplanned 30-day readmission was the secondary endpoint. Covariates tested for association with the primary and secondary endpoints included patient demographics, comorbidities, procedural, and postoperative characteristics. Variables significant on univariate screen (P < 0.2) were evaluated with logistic regression to identify independent determinants.

RESULTS

Of 9,847 infrainguinal bypass patients, 5,842 (59%) patients were identified with 30-day data, and 907 (16%) were readmitted within 30 days. Of readmissions, 675 (85%) were unplanned. Potentially modifiable independent determinants of any 30-day readmission included 30-day surgical site infection (SSI) (odds ratio [OR]: 10, 95% confidence interval [CI]: 8.2-12, P < 0.0001), postoperative acute kidney injury (OR: 1.7, 95% CI: 1.2-2.5, P = 0.002), and discharge anticoagulation (OR: 1.2, 95% CI: 1.04-1.5; P = 0.02). Predictors of unplanned 30-day readmission were very similar but identified in-hospital major amputation as an additional independent predictor (OR: 2.8, 95% CI: 1.6-4.9, P = 0.0002).

CONCLUSIONS

This study demonstrates the interest in, and value of, 30-day data collection in VSGNE/VQI and documents the frequency of readmission after infrainguinal bypass. Readmission within 30 days is strongly associated with SSI, stressing the importance of efforts to decrease this complication. Given that many other predictors are unmodifiable, 30-day readmission is only appropriate as a quality metric if it is risk adjusted using large, real-world datasets such as VQI. Lessons learned from this analysis can be used to select optimal 30-day data elements.

Long-Term In Vivo Oxygen Sensors for Peripheral Artery Disease Monitoring

Tracking of tissue oxygenation around chronic foot wounds may help direct therapy decisions in patients with peripheral artery disease (PAD). Novel sensing technology to enable such monitoring was tested over 9 months in a Sinclair mini-pig model. No adverse events were observed over the entire study period. Systemic and acute hypoxia challenges were detected during each measurement period by the microsensors. The median time to locate the sensor signal was 13 s. Lumee Oxygen microsensors appear safe for long-term repeated oxygen measurements over 9 months.

Drug-eluting stents for the treatment of complex femoro-popliteal disease: a systematic review and meta-analysis

INTRODUCTION

Endovascular methods have emerged as an appealing alternative to bypass for the treatment of patients not suitable for surgery. Drug eluting stents (DES) have been developed to address the limitations of angioplasty and stenting. There is a paucity of data in the literature on their performance for the treatment of patients with long femoro- popliteal segment lesions. We aimed to analyse the evidence supporting the use of DES in patients with complex femoro-popliteal disease.

EVIDENCE ACQUISITION

A systematic review and meta-analysis was conducted according to the recommendations of the Preferred Reporting Items for Systematic reviews and Meta- Analyses (PRISMA) statement.

EVIDENCE SYNTHESIS

A total of 1255 potentially relevant articles were initially selected. After reviewing at title or abstract level, 22 articles were read in full and 10 were included. These studies reported on the use of DES for 1539 patients. In all studies the DES that was employed was a paclitaxel-eluting stent (Zilver PTX, Cook Medical). Average lesion length ranged from 114mm to 400mm. The pooled technical success rate was 0.964 (95% confidence interval [CI]: 0.936 - 0.980). The pooled estimate of limb loss at 12 months was 0.019 (95% CI: 0.012 - 0.030), stent fracture at 12 months 0.035 (95% CI: 0.007 - 0.155), primary patency at 12 months 0.705 (95% CI: 0.576 - 0.807) and secondary patency at 12 months 0.898 (95% CI: 0.815 - 0.946).

CONCLUSIONS

The short-term outcomes of DES for TASC C & D femoro-popliteal lesions are encouraging. Caution is advised in extrapolating the results of the included studies due to the large heterogeneity and lack of reporting of subgroup specific outcomes.

Nationally Representative Readmission Factors Associated with Endovascular versus Open Repair of Abdominal Aortic Aneurysm

BACKGROUND

Hospital readmissions are tied to financial penalties and thus significantly influence health-care policy. Many current studies on readmissions lack national representation by not tracking readmissions across hospitals. The recently released Nationwide Readmission Database is one of the most comprehensive national sources of readmission data available, making it an invaluable resource to understand this critically important health policy issue.

METHODS

The Nationwide Readmission Database for 2013 and 2014 was queried for adult patients with abdominal aortic aneurysm (441.4) undergoing endovascular (39.71) or open (38.44) repair. Outcomes examined were overall/initial admission mortality and overall/30-day readmissions. Multivariate logistic regression for these outcomes was also performed on multiple readmission factors.

RESULTS

Fifty-three thousand four hundred seventeen patients underwent abdominal aortic aneurysm repair (47,431 endovascular aortic repair [EVAR] versus 5,986 open surgical repair [OSR]). Significant differences were found for EVAR versus OSR on overall readmissions, initial admission cost, readmission costs, length of stay, days to readmission, and overall/initial admission mortality. Multivariate logistic regression analysis found that length of stay > 30, Charlson Comorbidity Index > 1, discharge disposition, and female sex were all significant predictors of 30-day readmission. Repair type was significantly associated with 30-day readmissions; however, it was not a significant factor for overall readmissions.

CONCLUSION

There are significant differences in costs, prognosis, and readmission rates for EVAR versus OSR. Given that these differences are being used to create "acceptable" readmission rates, disbursement quotas among hospitals, and subsequent penalties for providers outside the expected rates, it is only prudent to obtain the most accurate information to guide those policies.

LEVEL OF EVIDENCE

Care management/epidemiological, level IV.

Preventing Major Amputations in Patients with Critical Limb Ischemia

PURPOSE OF REVIEW

This review summarizes the risks of lower extremity amputation associated with critical limb ischemia (CLI) and discusses current therapies that can prevent amputation in CLI.

RECENT FINDINGS

CLI remains an under-recognized condition associated with high rates of major amputation and disparities in care. Optimal medical therapy can reduce the risk of major adverse cardiovascular and limb events, but revascularization combined with close wound care remains the cornerstone of amputation prevention. Endovascular revascularization has become more common over time and has been associated with a reduction in amputation rates. Ongoing clinical trials will help inform best practices for revascularization strategies and techniques. Vascular care is inconsistent across the USA, with significant variation in access to care revascularization rates and rates of major amputation. Major amputation can be prevented in patients with CLI when optimal medical therapy, lifestyle modification, and revascularization are provided in a multidisciplinary setting.

Thirty-year trends in aortofemoral bypass for aortoiliac occlusive disease

OBJECTIVE

Endovascular intervention has supplanted open bypass as the most frequently used approach in patients with aortoiliac segment atherosclerosis. We sought to determine whether this trend together with changing demographic and clinical characteristics of patients undergoing aortobifemoral bypass (ABFB) for aortoiliac occlusive disease (AOD) have an association with postoperative outcomes.

METHODS

Using a prospectively maintained institutional database, we identified patients who underwent ABFB for AOD from 1985 to 2015. Patients were divided into two cohorts: the historical cohort (HC) included patients who underwent ABFB for AOD from 1985 to 1999 and the contemporary cohort (CC) who underwent ABFB for AOD from 2000 to 2015. Medical and demographic data, procedural information, postoperative complications, and follow-up data were extracted. Cox proportional hazards regression was used to evaluate associations with the end point of primary patency. A similar analysis was performed for major adverse limb events (MALEs; the composite of above-ankle amputation, major reintervention, graft revision, or new bypass graft of the index limb) in the subset of patients with critical limb ischemia.

RESULTS

There were a total of 359 cases: 226 in the HC and 133 in the CC. The CC had more women (56.4% vs 43.8%; P = .02), smokers (87.2% vs 67.7%; P = .001), and patients who failed prior aortoiliac endovascular intervention (17.3% vs 4.8%; P = .0001), but fewer patients with coronary artery disease (32.3% vs 47.3%; P = .005). Thirty-day mortality was less than 1% in both cohorts, but 10-year survival was higher in the CC (67.7% vs 52.6%; P = .02). Five-year primary, primary-assisted, and secondary patency were higher in the HC (93.3% vs 82.2%; P = .005; 93.8% vs 85.7%; P = .02; 97.5% vs 90.4%; P = .02, respectively). CC membership, decreasing age, prior aortic surgery, and decreasing graft diameter were significant independent predictors of loss of primary patency after adjustment (hazard ratio [HR], 7.03; 95% confidence interval [CI], 2.80-17.63; P < .0001; HR, 0.93; 95% CI, 0.90-0.96; P < .0001; HR, 18.80; 95% CI, 5.94-59.58; P < .0001; and HR, 0.73; 95% CI, 0.55-0.95; P = .02, respectively). Similarly, CC membership, prior aortic surgery, and decreasing graft diameter were significant independent predictors of MALE in the critical limb ischemia cohort after adjustment (HR, 21.13; 95% CI, 4.20-106.40; P = .0002; HR, 40.40; 95% CI, 3.23-505.61; P = .004; and HR, 0.51; 95% CI, 0.30-0.86; P = .01, respectively).

CONCLUSIONS

Compared with the pre-endovascular era, demographic and clinical characteristics of patients undergoing ABFB for AOD in the CC have changed. Although long-term patency is slightly lower among patients in the CC during which a substantial subset of AOD patients are being treated primarily via the endovascular approach, durability remains excellent and limb salvage unchanged. After adjustment, the time period of index ABFB independently predicted primary patency and MALE, as did graft diameter and prior aortic surgery. These changing characteristics should be considered when counseling patients and benchmarking for reintervention rates and other outcomes.

Nationwide Trends in Hospital Outcomes and Utilization After Lower Limb Revascularization in Patients on Hemodialysis

OBJECTIVES

This study aimed to describe the temporal trends and outcomes of endovascular and surgical revascularization in a large, nationally representative sample of patients with end-stage renal disease on hemodialysis hospitalized for peripheral artery disease (PAD).

BACKGROUND

PAD is prevalent among patients with end-stage renal disease on hemodialysis and is associated with significant morbidity and mortality. There is a paucity of information on trends in endovascular and surgical revascularization and post-procedure outcomes in this population.

METHODS

We used the Nationwide Inpatient Sample (2002 to 2012) to identify hemodialysis patients undergoing endovascular or surgical procedures for PAD using diagnostic and procedural codes. We compared trends in amputation, post-procedure complications, mortality, length of stay, and costs between the 2 groups using trend tests and logistic regression.

RESULTS

There were 77,049 endovascular and 29,556 surgical procedures for PAD in hemodialysis patients. Trend analysis showed that endovascular procedures increased by nearly 3-fold, whereas there was a reciprocal decrease in surgical revascularization. Post-procedure complication rates were relatively stable in persons undergoing endovascular procedures but nearly doubled in those undergoing surgery. Surgery was associated with 1.8 times adjusted odds (95% confidence interval: 1.60 to 2.02) for complications and 1.6 times the adjusted odds for amputations (95% confidence interval: 1.40 to 1.75) but had similar mortality (adjusted odds ratio: 1.05; 95% confidence interval: 0.85 to 1.29) compared with endovascular procedures. Length of stay for endovascular procedures remained stable, whereas a decrease was seen for surgical procedures. Overall costs increased marginally for both procedures.

CONCLUSIONS

Rates of endovascular procedures have increased, whereas those of surgeries have decreased. Surgical revascularization is associated with higher odds of overall complications. Further prospective studies and clinical trials are required to analyze the relationship between the severity of PAD and the revascularization strategy chosen.

Primary Stenting of the Superficial Femoral Artery in Patients with Intermittent Claudication Has Durable Effects on Health-Related Quality of Life at 24 Months: Results of a Randomized Controlled Trial

BACKGROUND

Intermittent claudication (IC) is commonly caused by lesions in the superficial femoral artery (SFA), yet invasive treatment is still controversial and longer term patient-reported outcomes are lacking. This prospective randomized trial assessed the 24-month impact of primary stenting with nitinol self-expanding stents compared to best medical treatment (BMT) alone in patients with stable IC due to SFA disease on health-related quality of life (HRQoL).

METHODS

One hundred patients with stable IC due to SFA disease treated with BMT were randomized to either stent (n = 48) or control (n = 52) group. HRQoL assessed by Short Form 36 Health Survey (SF-36) and EuroQoL 5-dimensions (EQ5D) 24 months after treatment were primary outcome measures. Walking Impairment Questionnaire, ankle-brachial index (ABI), and walking distance were secondary outcomes.

RESULTS

Significantly better SF-36 Physical Component Summary (P = 0.024) and physical domain scores such as Physical Function (P = 0.012), Bodily Pain (P = 0.002), General Health (P = 0.037), and EQ5D (P = 0.010) were reported in intergroup comparison between the stent and the control group. Both ABI (from 0.58 ± 0.11 to 0.85 ± 0.18; P < 0.001 in the stent group and from 0.63 ± 0.17 to 0.69 ± 0.18; P = 0.036 in the control group) and walking distance (from 170 ± 90 m to 616 ± 375 m; P < 0.001 in the stent group and from 209 ± 111 m to 331 ± 304 m; P = 0.006 in the control group) improved significantly in intragroup comparisons.

CONCLUSIONS

In patients with IC caused by lesions in the SFA, primary stenting compared to BMT alone was associated with significant improvements in HRQoL, ABI, and walking distance durable up to 24 months of follow-up. Clinical Trial Registration http://www.clinicaltrials.gov . Unique Identifier: NCT01230229.