Fifteen-year trends in lower limb amputation, revascularization, and preventive measures among medicare patients

Trends in Demographics and Surgical Treatment of Weapon-Related Limb Injuries Over Two Decades in a Resource-Scarce Setting

BACKGROUND

In the past decades, surgical management of limb injuries in high-resource settings has improved. The possibility of limb salvage has increased. It is not known whether similar changes have transpired in resource-scarce conflict settings.

METHODS

Retrospective cohort study using routinely collected patient data from the International Committee of the Red Cross hospitals in Pakistan was conducted. Consecutive data from 2009 to 2012 (535 patients) and randomly selected data from 1992 to 1995 (463 patients) were used. Only patients with weapon-related limb injuries were included. Differences in surgical procedures were assessed with logistic regression to adjust for confounding factors.

RESULTS

Less injuries were related to mines in 2009-2012 than in 1992-1995 (3.7% vs. 20.3%, p < 0.0001), but injuries from bombs, shells and fragments were more frequent (38.5% vs. 19.4%, p  < 0.0001) as were injuries with only a small degree of tissue damage (42.0% vs. 31.1%, p  = 0.0004). In the logistic regression, the time period did not affect the risk of amputation, debridement, length of hospital stay or in-hospital mortality. The use of external fixation (OR 0.56, 95% CI 0.33-0.96, p  = 0.04), split skin grafts (OR 0.31, 95% CI 0.21-0.45, p  < 0.0001) and blood transfusion (OR 0.43, 95% CI 0.28-0.66, p  = 0.0001) was less frequent in 2009-2012.

CONCLUSION

In this resource-scarce conflict setting, the risk of amputation appears unchanged over time, while the use of external fixation and split skin grafts was less common in 2009-2012 than in 1992-1995. These results contrast with the improved limb salvage results seen in high-resource settings. It likely reflects the challenges of providing advanced limb-preserving techniques in a resource-scarce setting.

Epidemiology and Risk of Amputation in Patients With Diabetes Mellitus and Peripheral Artery Disease

Peripheral artery disease (PAD) stems from atherosclerosis of lower extremity arteries with resultant arterial narrowing or occlusion. The most severe form of PAD is termed chronic limb-threatening ischemia and carries a significant risk of limb loss and cardiovascular mortality. Diabetes mellitus is known to increase the incidence of PAD, accelerate disease progression, and increase disease severity. Patients with concomitant diabetes mellitus and PAD are at high risk for major complications, such as amputation. Despite a decrease in the overall number of amputations performed annually in the United States, amputation rates among those with both diabetes mellitus and PAD have remained stable or even increased in high-risk subgroups. Within this cohort, there is significant regional, racial/ethnic, and socioeconomic variation in amputation risk. Specifically, residents of rural areas, African-American and Native American patients, and those of low socioeconomic status carry the highest risk of amputation. The burden of amputation is severe, with 5-year mortality rates exceeding those of many malignancies. Furthermore, caring for patients with PAD and diabetes mellitus imposes a significant cost to the healthcare system-estimated to range from $84 billion to $380 billion annually. Efforts to improve the quality of care for those with PAD and diabetes mellitus must focus on the subgroups at high risk for amputation and the disparities they face in the receipt of both preventive and interventional cardiovascular care. Better understanding of these social, economic, and structural barriers will prove to be crucial for cardiovascular physicians striving to better care for patients facing this challenging combination of chronic diseases.

Epidemiology of the vascular assessment and correlation of the WIfI Classification in lower limb amputee patients at Martinique university hospital in 2018

BACKGROUND

The precise epidemiological evaluation of amputations is difficult. It is a serious public health and economic problem with a high death rate. The proportion of amputees with pre-amputation vascular status remains unknown. The main objective of our study was to evaluate the proportion of patients with lower limb amputation who had a pre-procedural vascular assessment. The secondary objectives were to evaluate the risk of amputation at the admission of these patients, estimate the incidence of amputations in Martinique, and to collect epidemiological data on this category of patients.

MATERIAL AND METHODS

We conducted an epidemiological, retrospective, and observational study, over the year 2018 between January 01 and December 31, including all adults' patients who underwent an amputation of the lower limb at the university hospital center of Martinique.

RESULTS

Among the 170 included patients, 79 (46%) patients had a major lower limb amputation. The incidence of amputations in 2018 was estimated at 48.9/100,000 inhabitants. The vascular assessment was performed for 110 (65%) patients. For the other 60 (35%) patients who did not have a vascular assessment, 53 (88%) had a severe infection. This assessment was significantly related to the amputation level: a vascular assessment was performed in 97 (70%) patients with below the knee amputation versus 13 (41%) patients with above the knee amputation (P<0.01). The WIfI classification system found a high risk of amputation for 152 (89%) of patients but also a benefit of revascularization ranked high for 138 (81%) of them. The origin of amputation was limb ischemia for 125 (68%) patients.

CONCLUSION

A significant number of patients who underwent lower limb amputation did not have a pre-procedural vascular assessment. Many improvements in the health care are therefore to be implemented. The upcoming M@diCICAT project in Martinique will contribute in the improvement of patient management. The incidence of amputation in Martinique is considered high compared to other countries (French national incidence in 2003=24.8/100,000 inhabitants), and it seems to have remained stable since 2008. Our population is considered to be at high risk of amputation by the SVS-WIfI classification. This score seems adapted to anticipate the evolution of these patients and could be useful in daily practice.

Acute Renal Failure/Acute Kidney Injury (AKI) Associated with Endovascular Procedures

AKI is one of the most common yet underdiagnosed postoperative complications that can occur after any type of surgery. Contrast-induced nephropathy (CIN) is still poorly defined and due to a wide range of confounding individual variables, its risk is difficult to determine. CIN mainly affects patients with underlying chronic kidney disease, diabetes, sepsis, heart failure, acute coronary syndrome and cardiogenic shock. Further research is necessary to better understand pathophysiology of contrast-induced AKI and consequent implementation of effective prevention and therapeutic strategies. Although many therapies have been tested to avoid CIN, the only potent preventative strategy involves aggressive fluid administration and reduction of contrast volume. Regardless of surgical technique—open or endovascular—perioperative AKI is associated with significant morbidity, mortality and cost. Endovascular procedures always require administration of a contrast media, which may cause acute tubular necrosis or renal vascular embolization leading to renal ischemia and as a consequence, contribute to increased number of post-operative AKIs.

Innovative endovascular approach for limb salvage in critical limb ischemia

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

One-Year Outcomes of Peripheral Endovascular Device Intervention in Critical Limb Ischemia Patients: Sub-Analysis of the LIBERTY 360 Study

Background

High-risk patients with advanced peripheral artery disease (PAD), including critical limb ischemia (CLI), are often excluded from peripheral endovascular device intervention clinical trials, leading to difficulty in translating trial results into real-world practice. There is a need for prospectively assessed studies to evaluate peripheral endovascular device intervention outcomes in CLI patients.

Methods

LIBERTY 360 is a prospective, observational, multi-center study designed to evaluate the procedural and long-term clinical outcomes of peripheral endovascular device intervention in real-world patients with symptomatic lower-extremity PAD. One thousand two hundred and four patients were enrolled and stratified based on Rutherford Classification (RC): RC2-3 (N=501), RC4-5 (N=603), and RC6 (N=100). For this sub-analysis, RC5 and RC6 patients (RC5-6; N=404) were pooled and 1-year outcomes were assessed.

Results

Procedural complications rarely (1.7%) resulted in post-procedural hospitalization and 89.1% of RC5-6 patients were discharged to home. Considering the advanced disease state in RC5-6 patients, there was a high freedom from 1-year major adverse event rate of 65.5% (defined as target vessel revascularization, death to 30 days, and major target limb amputation). At 1 year, freedom from major amputation was 89.6%. Wounds identified at baseline on the target limb had completely healed in 172/243 (70.8%) of the RC5-6 subjects by 1 year. Additionally, the overall quality of life, as measured by VascuQoL, improved from baseline to 1 year.

Conclusion

LIBERTY investigated real-world PAD patients with independent oversight of outcomes. This analysis of LIBERTY RC5-6 patients demonstrates that peripheral endovascular device intervention can be successful in CLI patients, with low rates of major amputation and improvement in wound healing and quality of life through 1-year follow-up.

LIBERTY 360, https://clinicaltrials.gov/ct2/show/NCT01855412, ClinicalTrials.gov Identifier: NCT01855412.

[Modern trends in development of surgical and endovascular treatment of patients with arterial pathology]

The last decade has seen distinct dynamics of the worldwide growth of the number of endovascular interventions and a decrease in the number of 'open' surgical operations for pathology of the aorta and peripheral arteries. The world trends of treatment of patients presenting with pathology of the aorta and peripheral arteries are indicative of a steadily growing amount of operations, most of which are performed in an endovascular manner. In the Russian Federation, the past decade has also witnessed a noticeable jump of the amounts of endovascular interventions. Thus, the number of operations from 2008 to 2017 increased from 15 094 to 37 109 (2.5-fold). Nevertheless, in Russia there is a significant lag in both the total amount and the ratio of the performed surgical and endovascular operations in patients with pathology of the aorta and peripheral arteries. The article analyses the world and Russian trends in the development of surgical and endovascular treatment of patients with pathology of the aorta and peripheral arteries.

Potentials, challenges, and limitations of the analysis of administrative data on vascular limb amputations in health care

Although more and more data on lower limb amputations are becoming available by leveraging the widening access to health care administrative databases, the applicability of these data for public health decisions is still limited. Problems can be traced back to methodological issues, how data are generated and to conceptual issues, namely, how data are interpreted in a multidimensional environment. The present review summarised all of the steps from converting the claims data of administrative databases into the analytical data and reviewed the wide array of sources of potential biases in the analysis of such data. The origins of uncertainty of administrative data analysis include uncontrolled confounding due to a lack of clinical data, the left- and right-censored nature of data collection, the non-standardized diagnosis/procedure-based data extraction methods (i.e., numerator/denominator problems) and additional methodological problems associated with temporal and spatial analyses. The existence of these methodological challenges in the administrative data-based analysis should not deter the analysts from using these data as a powerful tool in the armamentarium of clinical research. However, it must be done with caution and a thorough understanding and respect of the methodological limitations. In addition to this requirement, there is a profound need for pursuing further research on methodology and widening the search for other indicators (structural, process or outcome) that allow a deeper insight how the quality of vascular care may be assessed. Effective research using administrative data is based on strong collaboration in three domains, namely expertise in claims data handling and processing, the clinical field, and statistical analysis. The final interpretations of results and the countermeasures on the level of vascular care ought to be grounded on the integrity of research, open discussions and institutionalized mechanisms of science arbitration and honest brokering.

Effects of Remote Ischaemic Preconditioning on Arterial Stiffness in Patients Undergoing Lower Limb Angiographic Procedures: A Randomised Clinical Trial

OBJECTIVES

Remote ischaemic preconditioning (RIPC) is a phenomenon that promotes protection of tissues and organs against ischaemia reperfusion injury. RIPC has been shown to reduce myocardial and renal injury but its effect on arterial stiffness in patients undergoing lower limb digital subtraction angiography (DSA) is unknown. The aim of this study was to evaluate the effect of RIPC on arterial stiffness in patients with peripheral arterial disease (PAD) undergoing lower limb DSA.

METHODS

In the RIPC intervention, the blood pressure cuff on the arm was inflated to 200 mmHg or to 20 mmHg above systolic pressure, and in the sham intervention to 20 mmHg. For both, the procedure was repeated for four five minute cycles at five minute intervals between the cycles. Changes in heart rate corrected augmentation index (AIx@75), augmentation index (AIx), carotid femoral pulse wave velocity (PWV), and haemodynamic parameters were measured before and 24 h after DSA.

RESULTS

111 (RIPC 54, sham 57) patients with symptomatic lower limb PAD scheduled for DSA were randomised. 102 patients (RIPC 47, sham 55) were included in final analysis. RIPC significantly improved AIx (-5.46% in RIPC and -1.45% in sham group; p = .05), but not AIx@75 (-4.88% in RIPC and -1.38% in sham group; p = .07) or PWV (-0.41 m/s in RIPC and -0.27 m/s in sham group; p = .74). In the RIPC group a significant reduction in AIx (p = .002) and AIx@75 (p = .003) was noted after stenting when compared with the sham intervention. AIx (p = .001), AIx@75 (p = .002), mean arterial (p = .01), peripheral (p = .02), and central systolic blood pressure (p = .006) were significantly reduced only in the RIPC group 24 h after DSA.

CONCLUSION

This study evaluates for the first time the effects of RIPC on arterial stiffness parameters in patients with symptomatic PAD following DSA. RIPC may modulate arterial stiffness following a DSA procedure and is more pronounced in patients after stent placement.

Trends in Lower Limb Amputation in Patients with Diabetic Foot Based on Vascular Intervention of Peripheral Arterial Disease in Korea: a Population-based Nationwide Study

BACKGROUND

Peripheral arterial disease (PAD) is known as the greatest risk factor affecting the amputation of diabetic foot. Thus, it is crucial to understand the epidemiology of PAD associated with diabetic foot and the relationship between PTA and amputation in predicting prognosis. However, no such multi-year data are available in Korea. Thus, the purpose of this study was to investigate trends of amputation involving diabetic foot based on vascular interventions for PAD in Korea.

METHODS

This study was conducted using six-year data obtained from Health Insurance Review and Assessment Service from January 1, 2011 to December 31, 2016. Our study included data pertaining to diabetic foot, PAD, and vascular intervention codes (percutaneous transluminal angioplasty [PTA, M6597], percutaneous intravascular installation of stent-graft [PIISG, M6605], and percutaneous intravascular atherectomy [PIA, M6620]). We analyzed the number of vascular interventions and minor and major amputations each year. The relationship between annual amputation and vascular intervention was analyzed using χ² test.

RESULTS

The overall number of vascular interventions increased from 253 (PTA, 111; PIISG, 140; and PIA, 2) in 2011 to 1,230 (PTA, 745; PIISG, 470; and PIA, 15) in 2016. During the same period, the number of minor amputations increased from 2,534 to 3,319 while major amputations decreased from 980 to 956. The proportion of minor amputations among patients who underwent vascular intervention was significantly increased from 19.34% in 2011 to 21.45% in 2016 while the proportion of major amputations among these patients was significantly reduced from 9.88% to 4.27%. In addition, the association between vascular intervention and amputation increased from 0.56 (spearman correlation coefficient) in 2011 to 0.62 in 2016.

CONCLUSION

In diabetic foot patients, increase in vascular intervention resulted in a change in amputation pattern, showing statistically significant correlation.

A Lack of Decline in Major Nontraumatic Amputations in Texas: Contemporary Trends, Risk Factor Associations, and Impact of Revascularization

OBJECTIVE

Nontraumatic major lower extremity amputations (LEAs) have been reported to be declining nationally; however, trends in Texas have been less well described. We evaluated demographic and clinical risk factors and revascularization associations for LEAs by using inpatient hospital discharge data in Texas from 2005 to 2014.

RESEARCH DESIGN AND METHODS

Inpatient hospital discharge data were obtained from the Texas Center for Health Statistics. Multivariate logistic regression analyses were performed to evaluate clinical, ethnic, and socioeconomic risk factors associated with LEA. The impact of revascularization (surgical and/or endovascular) on LEA was analyzed.

RESULTS

Between 2005 and 2014, of 19,939,716 admissions, 46,627 were for nontraumatic major LEAs. Over time, LEAs were constant, and revascularization rates during index admission declined. The majority of LEAs occurred in males and in individuals aged 60-79 years. Risk factors associated with LEA included diabetes, peripheral arterial disease, chronic kidney disease, and male sex (P < 0.001). Insurance status, hyperlipidemia, coronary artery disease, and stroke/transient ischemic attack were associated with lower odds of amputation (P < 0.001). Hispanic (odds ratio [OR] 1.51 [95% CI 1.48, 1.55], P < 0.001) and black (OR 1.97 [95% CI 1.92, 2.02], P < 0.001) ethnicities were associated with a higher risk for amputation when compared with non-Hispanic whites. Revascularization, either surgical or endovascular (OR 0.52 [95% CI 0.5, 0.54], P < 0.001), was also associated with lower odds for amputation.

CONCLUSIONS

Amputation rates in Texas have remained constant, whereas revascularization rates are declining. A higher risk for LEA was seen in minorities, including Hispanic ethnicity, which is the fastest growing demographic in Texas. Revascularization and having insurance were associated with lower odds for amputation.

Epidemiology and Burden of Diabetic Foot Ulcer and Peripheral Arterial Disease in Korea

Information about the epidemiology of diabetic foot ulcer (DFU) with peripheral arterial disease (PAD) is likely to be crucial for predicting future disease progression and establishing a health care budget. We investigated the incidence and prevalence of DFU and PAD in Korea. In addition, we examined costs of treatments for DFU and PAD. This study was conducted using data from Health Insurance Review and Assessment Service from 1 January 2011 to 31 December 2016. The incidence of DFU with PAD was 0.58% in 2012 and 0.49% in 2016. The prevalence of DFU with PAD was 1.7% in 2011 to 1.8% in 2016. The annual amputation rate of DFU with PAD was 0.95% in 2012 and 1.10% in 2016. Major amputation was decreased, while minor amputation was increased. The direct cost of each group was increased, especially the limb saving group. which was increased from 296 million dollars in 2011 to 441 million dollars in 2016. The overall incidence of DFU with PAD was about 0.5% of total population in Korea, from 2012 to 2016. Furthermore, costs for treatments of diabetic foot ulcer are increasing, especially those for the limb saving group.

The BEST-CLI trial is nearing the finish line and promises to be worth the wait

There is significant variability and equipoise in the management of critical limb ischemia (CLI). The Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) trial, funded by the National Heart, Lung, and Blood Institute, is a prospective, open label, multicenter, multispecialty randomized controlled trial designed to compare treatment efficacy, functional outcomes, cost-effectiveness, and quality of life for 2100 patients suffering from CLI. BEST-CLI is enrolling those patients who are determined to be candidates for open surgical or endovascular revascularization and is designed to be comprehensive, pragmatic, and balanced. Enrollment is occurring at >130 sites across the world, and BEST-CLI is nearing the finish line. Although the trial has encountered a number of obstacles, they are being successfully navigated. This trial promises to establish an evidence-based standard of care in the management of this population of vulnerable patients.

Lower extremity critical limb ischemia: A review of clinical features and management

Lower extremity critical limb ischemia (CLI) represents symptoms related to end-stage atherosclerotic peripheral arterial disease manifested by rest pain and tissue loss. It is associated with increased risk of limb amputation and cardiovascular-related mortality. The prevalence and cost of CLI are expected to increase with both the aging of the U.S. population and continued influence of smoking and diabetes. Treatments encompass measures to reduce cardiovascular risk and preserve limb viability. Despite increasing popularity of endovascular modalities, revascularization with either surgical bypass or endovascular intervention is the cornerstone of therapy. Adequate Level I data to guide decisions regarding optimal strategies to treat CLI, particularly in patients who are candidates for both open and percutaneous approaches, are currently lacking. Ongoing randomized controlled trials aim to resolve the clinical equipoise.

Association of Ankle-Brachial Indices With Limb Revascularization or Amputation in Patients With Peripheral Artery Disease

IMPORTANCE

The prevalence and morbidity of peripheral artery disease (PAD) are high, with limb outcomes including revascularization and amputation. In community-dwelling patients with PAD, the role of noninvasive evaluation for risk assessment and rates of limb outcomes have not been established to date.

OBJECTIVE

To evaluate whether ankle-brachial indices are associated with limb outcomes in community-dwelling patients with PAD.

DESIGN, SETTING, AND PARTICIPANTS

A population-based, observational, test-based cohort study of patients was performed from January 1, 1998, to December 31, 2014. Data analysis was conducted from July 15 to December 15, 2017. Participants included a community-based cohort of 1413 patients with PAD from Olmsted County, Minnesota, identified by validated algorithms deployed to electronic health records. Automated algorithms identified limb outcomes used to build Cox proportional hazards regression models. Ankle-brachial indices and presence of poorly compressible arteries were electronically identified from digital data sets. Guideline-recommended management strategies within 6 months of diagnosis were also electronically retrieved, including therapy with statins, antiplatelet agents, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and smoking abstention.

MAIN OUTCOMES AND MEASURES

Ankle-brachial index (index ≤0.9 indicates PAD; <.05, severe PAD; and ≥1.40, poorly compressible arteries) and limb revascularization or amputation.

RESULTS

Of 1413 patients, 633 (44.8%) were women; mean (SD) age was 70.8 (13.3) years. A total of 283 patients (20.0%) had severe PAD (ankle-brachial indices <0.5) and 350 (24.8%) had poorly compressible arteries (ankle-brachial indices ≥1.4); 780 (55.2%) individuals with less than severe disease formed the reference group. Only 32 of 283 patients (11.3%) with severe disease and 68 of 350 patients (19.4%) with poorly compressible arteries were receiving 4 guideline-recommended management strategies. In the severe disease subgroup, the 1-year event rate for revascularization was 32.4% (90 events); in individuals with poorly compressible arteries, the 1-year amputation rate was 13.9% (47 events). In models adjusted for age, sex, and critical limb ischemia, poorly compressible arteries were associated with amputation (hazard ratio [HR], 3.12; 95% CI, 2.16-4.50; P < .001) but not revascularization (HR, 0.91; 95% CI, 0.69-1.20; P = .49). In contrast, severe disease was associated with revascularization (HR, 2.69; 95% CI, 2.15-3.37; P < .001) but not amputation (HR, 1.30; 95% CI, 0.82-2.07; P = .27).

CONCLUSIONS AND RELEVANCE

Community-dwelling patients with severe PAD or poorly compressible arteries have high rates of revascularization or limb loss, respectively. Guideline-recommended management strategies for secondary risk prevention are underused in the community.

Lower Limb Amputation in Germany

BACKGROUND

Declining amputation rates have been reported in multiple countries in recent years. It is not yet known whether amputation rates have declined in Germany as well.

METHODS

On the basis of DRG (diagnosis-related group) data, we received a list from the German Federal Statistical Office of all major and minor amputations documented in German hospitals from 2005 to 2014. Changes over this period were studied with linear regression.

RESULTS

The absolute number of amputations per year in Germany rose slightly from 55 689 in 2005 to 57 637 (+3.5%) in 2014. After the exclusion of cases in which the main diagnosis was trauma, intoxication, musculoskeletal disease, diseases of the skin and subcutaneous tissue, or neoplasia, the corresponding numbers were 48 043 in 2005 and 48 561 in 2014 (+1.1%). The age-adjusted rate of major amputations per 100 000 persons per year fell from 23.3 to 16.1 (-30.9%), while the rate of minor amputations rose from 35.0 to 43.9 (+25.4%). The percentage of major amputations that took place in patients with diabetes mellitus as the main diagnosis or a side diagnosis declined from 70.2% to 63.7%. For all of these changes, p <0.0001.

CONCLUSION

From 2005 to 2014, the major amputation rate fell by 30.9% while the minor amputation rate rose by 25.4%. The goal of lowering amputation rates still further will be best served not only by applying the recognized preventive measures in patients with foot lesions, but also by further research into the causes of the recent changes in amputation numbers. Prospective registries will be needed.

Neutrophil to Lymphocyte Ratio as a Predictor of Outcomes after Amputation

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) has become a prognostic marker for proinflammatory states. It is associated with outcomes in many clinical processes including critical limb ischemia. We sought to identify predictors of amputation failure and mortality, in addition to the role of NLR in patients undergoing above-knee amputations (AKAs) or below-knee amputations (BKAs).

METHODS

All patients undergoing BKA or AKA between 2004 and 2014 at 3 institutions were identified and analyzed (n = 513). Patients were excluded if they did not have a complete blood count with differential within 7 days prior to their operations. Comparison groups were formed between patients requiring unplanned revision and those who did not, and additionally between survivors and nonsurvivors at 30 days postamputation. Patient demographics, intraoperative data, and postoperative courses were compared. A multinomial logistic regression model was created to further compare the groups.

RESULTS

Four hundred and ten patients were included for analysis, of which 142 (35%) required unplanned revision. Nearly 5% of patients (19/410) died within 30 days of the initial amputation. On univariate analysis, those requiring revision were more likely to be current smokers compared to former smokers (P = 0.004 and P = 0.021, respectively), have a lower ankle-brachial index (ABI) (P = 0.019), and have undergone a BKA (P < 0.001). Patients with congestive heart failure (CHF) were less likely to require a revision after an amputation (P = 0.007). Postoperative NLR was higher in patients requiring revision (9.9 vs. 7.0, P < 0.001) and both preoperative and postoperative NLRs were higher in those with 30-day mortality (21.0 vs. 7.0, P < 0.001; 19.4 vs. 7.5, P < 0.001). A multinomial logistic regression model identified CHF (P = 0.004), ABI (P = 0.041), and elevated body mass index (BMI, P = 0.045) as predictors of revision, while coronary artery disease (CAD, P = 0.031), CHF (P = 0.029), and postoperative NLR (P < 0.001) were predictive of 30-day mortality.

CONCLUSIONS

Postoperative elevated NLR, CAD, and CHF are predictors of 30-day mortality in patients undergoing major limb amputation, while CHF, elevated ABI, and high BMI are predictors of revision. This study suggests that NLR may have a role as a biomarker for poor outcomes in patients with underlying peripheral vascular disease and warrants further investigation.

Etiology of Above-knee Amputations in the United States: Is Periprosthetic Joint Infection an Emerging Cause?

BACKGROUND

Above-knee amputation (AKA) is a morbid procedure and is performed for a number of conditions. Although AKA is usually performed for dysvascular disease, trauma, and malignancy, AKA is also considered in patients who have failed multiple salvage attempts at treating periprosthetic joint infection (PJI) of TKA. Although aggressive measures are being taken to treat PJI, the huge volume of TKAs might result in a large number of AKAs being performed for PJI in the United States. However, the national trends in the incidence of AKAs from different etiologies and the relative contribution of different etiologies to AKA are yet to be studied.

QUESTIONS/PURPOSES

(1) What are the temporal trends in the incidence of AKAs (from all causes) in the US population from 1998 to 2013? (2) What are the temporal trends in the incidence of AKAs by etiology (dysvascular disease, trauma, malignancy, and PJI)? (3) What are the temporal trends in the relative contribution of different etiologies to AKA?

METHODS

Using the Nationwide Inpatient Sample (NIS) from 1998 to 2013, AKAs were identified using International Classification of Diseases, 9 Revision (ICD-9) procedure code 84.17. The NIS database is the largest all-payer database in the United States containing information on approximately 20% of all the hospital admissions in the country. As a result of its sampling design, it allows for estimation of procedural volumes at the national level. All AKAs were grouped into one of the following five etiologies in a sequential manner using ICD-9 diagnosis codes: malignancy, PJI, trauma, dysvascular disease (peripheral vascular disease, diabetic, or a combination), and others. All of the numbers were converted to national estimates using sampling weights provided by the NIS, and the national incidence of AKAs resulting from various etiologies was calculated using the US population as the denominator. Poisson and linear regression analyses were used to analyze the annual trends.

RESULTS

From 1998 to 2013, the incidence of AKAs decreased by 47% from 174 to 92 AKAs per 1 million adults (incidence rate ratio [IRR]; change in the number of AKAs per 1 million adults per year; 0.96; 95% confidence interval [CI], 0.96-0.96; p < 0.001). The incidence of AKAs resulting from PJI increased by 263% (IRR, 1.07; 95% CI, 1.06-1.07; p < 0.001). An increase was also observed for AKAs from malignancy (IRR, 1.01; 95% CI, 1.00-1.02; p = 0.007), although to a smaller extent. AKAs from dysvascular causes (IRR, 0.96; 95% CI, 0.95-0.96; p < 0.001) and other etiologies (IRR, 0.97; 95% CI, 0.96-0.97; p < 0.001) decreased. There was no change in the incidence of AKAs related to trauma (IRR, 1.00; 95% CI, 0.99-1.00; p = 0.088). The proportion of AKAs resulting from PJI increased by 589% from 1998 to 2013 (coefficient = 0.18; 95% CI, 0.15-0.22; p < 0.001). The proportion of AKAs resulting from dysvascular causes decreased (coefficient = 0.18; 95% CI, 0.15-0.22; p < 0.001), whereas that resulting from malignancy (coefficient = 0.04; 95% CI, 0.03-0.05; p < 0.001) and trauma (coefficient = 0.13; 95% CI, 0.09-0.18; p < 0.001) increased.

CONCLUSIONS

The incidence of AKAs has decreased in the United States. AKAs related to dysvascular disease and other etiologies such as trauma and malignancy have either substantially decreased or remained fairly constant, whereas that resulting from PJI more than tripled. Given the increased resource utilization associated with limb loss, the results of this study suggest that national efforts to reduce disability should prioritize PJI. Further studies are required to evaluate the risk factors for AKA from PJI and to formulate better strategies to manage PJI.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Incidence rates of dysvascular lower extremity amputation changes in Northern Netherlands: A comparison of three cohorts of 1991-1992, 2003-2004 and 2012-2013

Objective

To analyze the incidence rates of dysvascular major lower extremity amputations (LEA) in Northern Netherlands in 2012–2013 compared to previous cohorts in 1991–1992 and 2003–2004.

Design

Retrospective cohort study.

Participants

Adults (N = 343) with first ever dysvascular LEA at ankle disarticulation or more proximal levels. The median age (interquartile range) was 74.2 years (64.5–81.9), 64% were male and 55% had been diagnosed with diabetes mellitus (DM).

Main outcome measures

Crude and age-standardized incidence rates of major LEA per 100.000 person-years.

Results

Crude incidence rate (IR) of first ever major LEA in 2012–2013 was 9.9 per 100.000 person-years, while the age-standardized IR was 7.7 per 100.000 person-years. A Poisson regression analysis showed that amputation rates among men were 2.3 times higher compared to women (95%CI 1.9–2.6), while in 2012–2013 the population aged >63 years had decreased amputation rates compared to 1991–1992. In the DM population the crude IR decreased from 142.6 per 100.000 person-years in 2003–2004 to 89.2 per 100.000 person-years in 2012–2013 (p<0.001).

Conclusions

In 2012–2013 a decrease in age-standardized IR for the general population and a decrease in crude IR for the DM population were observed compared to cohorts from the previous two decades, despite considerable shifts in the age distribution of the Dutch population towards more elderly people and increased prevalence of DM. These findings might suggest that improved treatment of patients at risk of dysvascular amputations is associated with reduced incidence rates of major LEA at the population level.

Trends in Rates of Lower Extremity Amputation Among Patients With End-stage Renal Disease Who Receive Dialysis

IMPORTANCE

Patients with end-stage renal disease (ESRD) who receive dialysis are at high risk of lower extremity amputation. Recent studies indicate decreasing rates of lower extremity amputation in non-ESRD populations, but contemporary data for patients with ESRD who receive dialysis are lacking.

OBJECTIVES

To assess rates of lower extremity amputation among patients with ESRD who receive dialysis during a recent 15-year period; to analyze whether those rates differed by age, sex, diabetes, or geographic region; and to determine 1-year mortality rates in this population after lower extremity amputation.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective study of 3 700 902 records obtained from a US national registry of patients with ESRD who receive dialysis assessed cross-sectional cohorts for each calendar year from 2000 through 2014. Adult patients with prevalent ESRD treated with hemodialysis or peritoneal dialysis covered by Medicare Part A and B on January 1 of each cohort year were included. Data analysis was conducted from August 2017 to April 2018.

EXPOSURES

Age, sex, diabetes, and hospital referral region.

MAIN OUTCOMES AND MEASURES

Annual rates per 100 person-years of nontraumatic major (above- or below-knee) and minor (below-ankle) amputations.

RESULTS

For each annual cohort, there were fewer women (47.5% in 2000, 46.2% in 2005, 44.9% in 2010, and 44.0% in 2014) than men, more than half the patients were white individuals (58.1% in 2000, 56.9% in 2005, 56.9% in 2010, and 56.7% in 2014), and a small proportion were employed (13.9% in 2000, 15.1% in 2005, 16.1% in 2010, and 16.5% in 2014). The rate of lower extremity amputations for patients with ESRD who receive dialysis decreased by 51.0% from 2000 to 2014, driven primarily by a decrease in the rate of major amputations (5.42 [95% CI, 5.28-5.56] in 2000 vs 2.66 [95% CI, 2.59-2.72] per 100 person-years in 2014). Patients with diabetes had amputation rates more than 5 times as high as patients without diabetes. Patients younger than 65 years had higher adjusted amputation rates than older patients, and men had consistently higher adjusted amputation rates than women. Adjusted 1-year mortality rates after lower extremity amputation for patients with ESRD who receive dialysis decreased from 52.2% (95% CI, 50.9%-53.4%) in 2000 to 43.6% (95% CI, 42.5%-44.8%) in 2013. In general, amputation rates decreased among all regions from 2000 to 2014, but regional variability persisted across time despite adjustment for differences in patient demographics and comorbid conditions.

CONCLUSIONS AND RELEVANCE

Although rates of lower extremity amputations among US patients with ESRD who receive dialysis decreased by 51% during a recent 15-year period, mortality rates remained high, with nearly half of patients dying within a year after lower extremity amputation. Our results highlight the need for more research on ways to prevent lower extremity amputation in this extremely high-risk population.

No Clinical Benefit of Intramuscular Delivery of Bone Marrow-derived Mononuclear Cells in Nonreconstructable Peripheral Arterial Disease: Results of a Phase-III Randomized-controlled Trial

BACKGROUND AND AIMS

Prospects for no-option, end-stage peripheral artery disease (PAD) patients remain poor. Although results from open and semiblinded studies fuel hope for cell-based strategies in no-option patients, so far conclusions from the available placebo-controlled studies are not supportive. With the intention to end the remaining controversy with regard to cell therapy for PAD we conducted a confirmatory, double-blinded randomized placebo-controlled phase 3 trial.

STUDY DESIGN

This randomized controlled trial was registered (NCT00539266). Inclusion criteria included stable or progressive disabling PAD, no imminent need for amputation, absent accepted options for revascularization. Diabetic disease was an exclusion criterion. Bone marrow (500-700 mL) was harvested and bone marrow-derived mononuclear cells were concentrated to 40 mL. Concentrated cells or placebo (diluted blood) were intramuscularly injected at 40 locations of the calf muscle.

RESULTS

Fifty-four patients (mean (sd) age 58.2 (14.2) yrs, 58% males) were randomized. Twenty-eight patients received BM-MNCs, 26 placebo. Baseline criteria were similar in the 2 groups. No significant differences were observed for the primary (number of amputations, (pain free) walking distance) and secondary outcome parameters (ankle brachial index, pain scores, quality of life (SF-36)).

DISCUSSION

This fully blinded replication trial of autologous BM-MNC fails to confirm a benefit for cell therapy in no-option PAD patients, consequently BM-MNC therapy should not be offered as a clinical treatment. Apparent contrasting conclusions from open and controlled studies underscore the importance of a controlled trial design in evaluating cell-based interventions in PAD.

The role of the microbiome in nonhealing diabetic wounds

Wound healing is a highly coordinated and complex process, and there can be devastating consequences if it is interrupted. It is believed that, in combination with host factors, microorganisms in a wound bed can not only impair wound healing but can lead to stalled, chronic wounds. It is hypothesized that the wound microbiota persists in chronic wounds as a biofilm, recalcitrant to antibiotic and mechanical intervention. Cultivation-based methods are the gold standard for identification of pathogens residing in wounds. However, these methods are biased against fastidious organisms, and do not capture the full extent of microbial diversity in chronic wounds. Thus, the link between specific microbes and impaired healing remains tenuous. This is partially because local infection and, more specifically, the formation of a biofilm, is difficult to diagnose. This has led to research efforts aimed at understanding if biofilm formation delays healing and leads to persistent and chronic infection. Circumventing challenges associated with culture-based estimations, advances in high-throughput sequencing analysis has revealed that chronic wounds are host to complex, diverse microbiomes comprising multiple species of bacteria and fungi. Here, we discuss how the use of genomic methodologies to study wound microbiomes has advanced the current understanding of infection and biofilm formation in chronic wounds.

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.

Comparison of Outcomes in Below-Knee Amputation between Vascular and General Surgeons

BACKGROUND

There is evidence to suggest outcomes may be related to surgeon experience or skill level. Lower extremity amputations are performed by both general surgeons (GSs) and vascular surgeons (VSs); however, the effect of specialty on postoperative outcome in below-knee amputation is not known. This retrospective study compares outcomes in below-knee amputations (BKA) between VS and GS.

METHODS

Patients who underwent below-knee amputations between 2005 and 2014 were identified from the American College of Surgeons National Surgical Quality Improvement Project database. Data collected included patient demographics, comorbid conditions, and indication for procedures. Univariate and multivariate unconditional logistic regression models and linear regression models were employed to evaluate the associations between various outcomes and indications for surgery, emergency and teaching status, and surgical specialty.

RESULTS

Amputations performed by GSs experienced an increased risk of developing pneumonia (odds ratio [OR] = 1.49, 95% confidence interval [CI]: 1.19-1.86), pulmonary embolism (OR = 2.10, 95% CI: 1.10-4.01), and sepsis (OR = 1.29, 95% CI: 1.05-1.59). When stratified by indications for BKA, similar outcomes were noted between GS and VS if indication for surgery was diabetes or peripheral vascular disease; however, there was increased risk of pneumonia (OR = 1.86, 95% CI: 1.26-2.74), sepsis (OR = 1.96, 95% CI: 1.39-2.75), and death (OR = 1.47, 95% CI: 1.04-2.07, P = 0.027) when GS performed BKA for infectious indications. Overall complications were higher when GS performed BKA emergently (OR = 1.17, 95% CI: 1.01-1.36).

CONCLUSION

There are less postoperative complications when VSs performed BKA for infectious indications, during emergencies, and at nonteaching hospitals. Clinicians should consider vascular consultation for these specific scenarios.

Fewer Complications in the Obese Following Lower Extremity Endovascular Interventions

BACKGROUND

The prevalence of obesity is increasing in the United States; however, its impact on adverse outcomes in patients with peripheral vascular disease is not well studied. Obesity is associated with higher rates of complications following open bypass surgery, but limited data are available on its effect on endovascular intervention. This study aimed to identify whether obese patients suffer the same complications when undergoing lower extremity endovascular interventions.

METHODS

All patients who underwent femoropopliteal or tibial endovascular interventions between 2011 and 2013 were identified in the Targeted Vascular Module of the National Surgical Quality Improvement Program. Patients were stratified into 5 groups based on their body mass index (BMI): underweight (<18.6), normal weight (18.6-24.9), overweight (25-29.9), obese (30-34.9), and morbidly obese (≥35). Those patients without a documented BMI or a defined target lesion were excluded. Baseline demographics, patient characteristics, operative details, and outcomes were compared using univariate analysis between the BMI groups. Multivariable logistic regression was used to account for patient demographics and operative details.

RESULTS

3,246 patients underwent endovascular interventions (78% femoropopliteal and 22% tibial). Of these, 137 (4%) were underweight, 881 (27%) were normal weight, 1,193 (37%) were overweight, 647 (20%) were obese, and 388 (12%) were morbidly obese. There were no differences in 30-day mortality; however, surgical site infection (SSI) was higher in the morbidly obese (5% vs. normal weight: 2%, P = 0.02), whereas untreated patency loss was lower (morbidly obese: 0.5%, obese: 1%, normal weight: 2%, P = 0.02). Other important 30-day outcomes, including bleeding and amputation, were similar across the BMI groups. Following multivariate analysis, SSI remained more common in the morbidly obese (odds ratio [OR]: 2.6, 95% confidence interval [CI]: 1.4-5.0), whereas untreated patency loss remained lower in both overweight and morbidly obese patients (overweight: OR 0.5, 95% CI: 0.2-0.9 and morbidly obese: OR: 0.2, 95% CI: 0.05-0.85). Length of stay >1 day was significantly lower in the overweight, obese, and morbidly obese (OR 0.7, 95% CI: 0.6-0.8; OR 0.6, 95% CI: 0.5-0.7; and OR 0.7, 95% CI: 0.5-0.9, respectively).

CONCLUSIONS

Few major complications occur in the obese in the first 30 days following endovascular interventions, and obesity is not an independent predictor of 30-day mortality. Rates of postoperative SSIs are low overall, although they are highest in morbidly obese patients (5%, compared to 2% in normal weight patients). Given this knowledge, endovascular interventions are a prudent treatment option for this patient population.

Critical limb ischemia update and the evolving role of drug-elution technologies

INTRODUCTION

Critical limb ischemia (CLI) is a prevalent condition associated with cardiovascular mortality and limb loss. Areas covered: This review discusses the epidemiology of CLI, revascularization options, and drug-elution therapies. Expert commentary: Drug-eluting stents (DES) and drug-coated balloons (DCB) improve patency rates in the femoropopliteal segment, and are generally used as first-line therapies. For below-knee disease, angioplasty is the default strategy unless lesions are focal whereby DES can be used to reduce restenosis risk.

Risk of major amputation or death among patients with critical limb ischemia initially treated with endovascular intervention, surgical bypass, minor amputation, or conservative management

AIMS

Patients with critical limb ischemia (CLI) have an increased risk of major amputation. The initial treatment approach for CLI may significantly impact the subsequent risk of major amputation or death. The objective of this study was to describe the initial treatment approaches of patients with CLI and the limb outcomes associated with each approach.

METHODS

Data from MarketScan Commercial and Medicare Supplemental Databases from January 2006-December 2014 was utilized. Cohorts of CLI patients were defined as follows: (1) peripheral vascular intervention (PVI); (2) peripheral vascular surgery (PVS); (3) minor amputation without concomitant PVI or PVS (MinAMP); and (4) Patients without PVI, PVS, or MinAMP (conservative therapy). The odds of major amputation or inpatient death were estimated using the Cox proportional hazards model. For those patients requiring a major amputation, the incremental expenditures per member per month (PMPM) were estimated using a gamma log-link model.

RESULTS

Conservative therapy was associated with significantly higher odds of major amputation or inpatient death compared to patients who underwent minor amputation (1.59-times), PVI (2.08-times), or PVS (2.12-times). Patients treated with an initial strategy of minor amputation also had higher odds of major amputation or inpatient death compared to PVS (1.31-times) or PVI (1.33-times). The estimated incremental expenditures PMPM for patients with a major amputation was $5,165.

CONCLUSIONS

Revascularization reduces the risk of a major amputation or inpatient death for patients with CLI when compared to conservative therapy. Major amputation is also associated with significantly higher healthcare expenditures.

Risk factors for unplanned readmission and stump complications after major lower extremity amputation

OBJECTIVE

The unplanned 30-day readmission rate is a marker of quality of patient care across many disciplines. Data regarding risk factors for unplanned readmission after major lower extremity amputation (LEA) are limited. We evaluated predictors of readmission at our institution after major LEA.

METHODS

We conducted a retrospective review of all patients undergoing above-knee amputation (AKA) or below-knee amputation (BKA) between November 2009 and November 2014. Patient demographic variables were collected. Predictors of unplanned 30-day readmission and stump complications were determined by multivariable logistic regression.

RESULTS

A total of 811 patients were identified (AKA, 325; BKA, 486). Of these, 739 patients were included in the final analysis after excluding 30-day decedents without readmission. The overall 30-day readmission rate was 28.8% (AKA 27.9%; BKA 29.4%; P = .730). Stump complications accounted for 28.6% of readmissions (16.5% of AKA; 35.8% of BKA; P = .004). Other common diagnoses included nonsurgical site infection (33.8%), exacerbation of congestive heart failure (7.0%), and diabetes-related complications (6.1%). Surgical intervention was performed on 61% of stump complications (35.9% of AKA readmitted with stump complications; 68.7% of BKA readmitted with stump complications). BKA stump complications were converted to AKAs in 34.1% of cases (3.2% of the total BKA). None of the AKA stump complications required a higher level of amputation (ie, hip disarticulation). Independent predictors of all 30-day readmission included coronary artery disease and end-stage renal disease. American Society of Anesthesiologists class 3 as compared with class 4 was protective. Independent predictors of 30-day readmission for stump complications included rest pain and BKA. Patients who underwent BKA, rest pain as an indication for amputation, and having an occluded bypass graft were predictors of having a stump complication requiring surgery.

CONCLUSIONS

The 30-day readmission rate after major LEA is high, with wound infections accounting for a significant proportion of these readmissions. There was no difference in readmission rates based on level of amputation. Those undergoing BKA were more likely to present with stump complications requiring a surgical intervention, and often a higher level of amputation. Identification of high-risk patients may play a role in reducing postoperative readmissions and stump complications.

Diagnosis, classification, and treatment of femoropopliteal artery in-stent restenosis

In-stent restenosis is a pervasive challenge to the durability of stenting for the treatment of lower extremity ischemia. There is considerable controversy about the criteria for diagnosis, indications for treatment, and preferred algorithm for addressing in-stent restenosis. This evidence summary seeks to review existing information on strategies for the treatment of this difficult problem.

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.

Hemoglobin A1c Testing and Amputation Rates in Black, Hispanic, and White Medicare Patients

BACKGROUND

Major (above-knee or below-knee) amputation is a complication of diabetes and is seen more common among black and Hispanic patients. While amputation rates have declined for patients with diabetes in the last decade, it remains unknown if these improvements have equitably extended across racial groups and if measures of diabetic care, such as hemoglobin A1c testing, are associated with these improvements. We set out to characterize secular changes in amputation rates among black, Hispanic, and white patients, and to determine associations between hemoglobin A1c testing and amputation risk.

METHODS

We identified 11,942,840 Medicare patients (55% female) with diabetes over the age of 65 years between 2002 and 2012 and followed them for a mean of 6.6 years. Of these, 86% were white, 11.5% were black, and 2.5% were Hispanic. We recorded the occurrence of major amputation and hemoglobin A1c testing during this time period and studied secular changes in amputation rate by race (black, Hispanic, and white). Finally, we examined associations between amputation risk and hemoglobin A1c testing. We measured both the presence of any testing and testing consistency using 3 categories: poor consistency (hemoglobin A1c testing in 0-50% of years), medium consistency (testing in 50-90% of years), and high consistency (testing in >90% of the years in the cohort).

RESULTS

Between 2002 and 2012, the average major lower-extremity amputation rate in diabetic Medicare patients was 1.78 per 1,000 per year for black patients, 1.15 per 1,000 per year for Hispanic patients, and 0.56 per 1,000 per year for white patients (P < 0.001). Over the study period, the incidence of major amputation in Medicare patients with diabetes declined by 54%, from 1.15 per 1,000 in 2002 to 0.53 per 1,000 in 2012 (rate ratio = 0.53, 95% CI = 0.51-0.54). The reduction in amputation rate was similar across racial groups: 52% for black patients, 61% for Hispanic patients, and 55% for white patients. In multivariable analysis adjusting for patient characteristics, including race, any use of hemoglobin A1c testing was associated with a 15% decline in amputation risk (hazard ratio, 0.85; 95% CI, 0.83-0.87; P < 0.001). High consistency hemoglobin A1c testing was associated with a 39% decline in amputation (hazard ratio, 0.61; 95% CI, 0.59-0.62; P < 0.0001).

CONCLUSIONS

Although more frequent among racial minorities, major lower-extremity amputation rates have declined similarly across black, Hispanic, and white patients over the last decade. Hemoglobin A1c testing, particularly the consistency of testing over time, may be an effective component metric of longitudinal quality measures toward limiting amputation in all races.

Design and Rationale of the Best Endovascular Versus Best Surgical Therapy for Patients With Critical Limb Ischemia (BEST-CLI) Trial

BACKGROUND

Critical limb ischemia (CLI) is increasing in prevalence, and remains a significant source of mortality and limb loss. The decision to recommend surgical or endovascular revascularization for patients who are candidates for both varies significantly among providers and is driven more by individual preference than scientific evidence.

METHODS AND RESULTS

The Best Endovascular Versus Best Surgical Therapy for Patients With Critical Limb Ischemia (BEST-CLI) Trial is a prospective, randomized, multidisciplinary, controlled, superiority trial designed to compare treatment efficacy, functional outcomes, quality of life, and cost in patients undergoing best endovascular or best open surgical revascularization. Approximately 140 clinical sites in the United States and Canada will enroll 2100 patients with CLI who are candidates for both treatment options. A pragmatic trial design requires consensus on patient eligibility by at least 2 investigators, but leaves the choice of specific procedural strategy within the assigned revascularization approach to the individual treating investigator. Patients with suitable single-segment of saphenous vein available for potential bypass will be randomized within Cohort 1 (n=1620), while patients without will be randomized within Cohort 2 (n=480). The primary efficacy end point of the trial is Major Adverse Limb Event-Free Survival. Key secondary end points include Re-intervention and Amputation-Free-Survival and Amputation Free-Survival.

CONCLUSIONS

The BEST-CLI trial is the first randomized controlled trial comparing endovascular therapy to open surgical bypass in patients with CLI to be carried out in North America. This landmark comparative effectiveness trial aims to provide Level I data to clarify the appropriate role for both treatment strategies and help define an evidence-based standard of care for this challenging patient population.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02060630.

Trends in the epidemiology of osteomyelitis: a population-based study, 1969 to 2009

BACKGROUND

The epidemiology of osteomyelitis in the United States is largely unknown. The purpose of this study was to determine long-term secular trends in the incidence of osteomyelitis in a population-based setting.

METHODS

The study population comprised 760 incident cases of osteomyelitis first diagnosed between January 1, 1969, and December 31, 2009, among residents of Olmsted County, Minnesota. The complete medical records for each potential subject were reviewed to confirm the osteomyelitis diagnosis and to extract details on anatomical sites, infecting organisms, etiological risk factors, and outcomes.

RESULTS

The overall age and sex-adjusted annual incidence of osteomyelitis was 21.8 cases per 100,000 person-years. The annual incidence was higher for men than for women and increased with age (p < 0.001). Rates increased with the calendar year (p < 0.001) from 11.4 cases per 100,000 person-years in the period from 1969 to 1979 to 24.4 per 100,000 person-years in the period from 2000 to 2009. The incidence remained relatively stable among children and young adults but almost tripled among individuals older than sixty years; this was partly driven by a significant increase in diabetes-related osteomyelitis from 2.3 cases per 100,000 person-years in the period from 1969 to 1979 to 7.6 cases per 100,000 person-years in the period from 2000 to 2009 (p < 0.001). Forty-four percent of cases involved Staphylococcus aureus infections.

CONCLUSIONS

The reasons for the increase in osteomyelitis between 1969 and 2009 are unclear but could comprise a variety of factors, including changes in diagnosing patterns or increases in the prevalence of risk factors (e.g., diabetes) in this population.

Combined transpedal and transradial approach for treatment of iliac artery chronic total occlusion

We present a case of a patient with total chronic occlusion of the right common iliac artery that underwent percutaneous stenting with combined transpedal and transradial approaches. With this novel strategy, femoral access can be avoided.

CARBON DIOXIDE ANGIOGRAPHY: SIMULATION OF OPERATIVE CONDITIONS FOR DIAGNOSTIC IMAGE OPTIMIZATION

Carbon dioxide angiography is based on the visualization (i.e., the radiographic contrast) of gas bubbles injected in blood vessels. By using an experimental X-ray bench, the energy response of a flat panel detector has been measured (Varian CB4030) and, with a dedicated phantom and a software simulation, the image contrast of vessels is injected with Iodine and CO 2. Moreover, the dynamical behavior of a moving gas bubble has been studied with the software simulator. The results show that the contrast generated by carbon dioxide is about one fourth of that obtained with iodine, demonstrating that CO 2 angiography should use different radiological settings with respect to iodine angiography. In particular, a kVp increase has a lower reduction of contrast-to-noise-ratio (CNR) with carbon dioxide than with iodinated contrast medium (CM), suggesting possible technological improvements both on radiological emission and image enhancement methods.

Trends in Major Lower Limb Amputation Related to Peripheral Arterial Disease in Hungary: A Nationwide Study (2004-2012)

OBJECTIVES

To assess the trends of peripheral arterial disease associated major lower limb amputation in Hungary over a 9 year period (2004-2012) in the whole Hungarian population.

METHODS

This was a retrospective cohort study employing administrative health care data. Major amputations were identified in the entire Hungarian population during a 9 year period (2004-2012) using the health care administrative data. Direct standardization was used to eliminate the potential bias induced by the different age and sex structure of the compared populations. For external direct standardization, the ESP 2013 was chosen as reference.

RESULTS

76,798 lower limb amputations were performed. The number of major amputations was 38,200; these procedures affected 32,084 patients. According to case detection, 50.4% of the amputees were diabetic. The overall primary amputation rate was 71.5%. The annual crude and age adjusted major amputation rates exhibited no significant long-term pattern over the observation period. The major lower limb amputation incidence for the overall period was 42.3/10(5) in the total population and 317.9/10(5) in diabetic population.

CONCLUSION

According to this whole population based study from Hungary, the incidence of lower limb major amputation is high with no change over the past 9 years. An explanation for this remains to be determined, as the traditional risk factors in Hungary do not account for it. The characteristics of major amputation (the rate of primary amputation, the ratio of below to above knee amputation and the age of the affected population) underline the importance of screening, early detection, improved vascular care and an optimal revascularization policy. Standardization and validation of amputation detection methods and reporting is essential.