Management of Peripheral Arterial Disease

Platelet function testing and clinical outcomes in peripheral arterial disease: Systematic review and narrative synthesis

OBJECTIVE

This systematic review aims to comprehensively assess the contemporary literature on platelet function testing (PFT) in individuals undergoing revascularization therapy for peripheral arterial disease (PAD). The goal is to identify whether PFT can aid in detecting antiplatelet resistance, predicting post-procedural thrombotic complications, and informing tailored treatment strategies.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a literature review was conducted using PubMed databases. Search terms included relevant medical subject headings (MeSH) terms. Eligible articles published in English between 1990 and 2023 were analyzed. Studies that examined PFT outcomes in patients with PAD after lower extremity revascularization were included.

RESULTS

Ten studies met the inclusion criteria. Various PFT methods were used, including thromboelastography with platelet mapping, multiplate analyzer, Cytochrome P450 2C19 testing, VerifyNow, corrected whole blood aggregometry, platelet function analyzer-100, and light transmission aggregometry. PFT identified individuals who were resistant or non-sensitive to antiplatelet therapy, with such patients facing increased risks of graft/stent thrombosis, amputation, and reintervention. However, substantial heterogeneity in surgical procedures, drug regimens, and testing methods was observed among the studies.

CONCLUSIONS

PFTs can play a crucial role in detecting resistance and non-sensitivity to antiplatelet drugs in patients with PAD post-revascularization. However, heterogeneity of data and methods underlines the need for standardized protocols and consensus-building among PFTs. Enhancing clinical utility and reliability could help optimize antiplatelet thromboprophylaxis, minimize thrombotic complications, and improve treatment strategies in vascular surgery. Further research is necessary to solidify the role of PFTs in guiding antiplatelet therapy post-revascularization in patients with PAD.

Continuous peripheral nerve block for in-patients with lower limb ischemic pain

OBJECTIVES

Demonstrate that continuous peripheral nerve block (CPNB) may be an alternative with adequate analgesia and a lower incidence of side effects for ischemic pain due peripheral obstructive arterial disease (POAD).

METHODS

Retrospective cohort study with 21 patients with POAD, Fontaine IV graded, with foot pain. Patients were submitted to continuous sciatic nerve block (CSNB), through a perineural catheter. Primary outcomes were pain intensity (by numerical rating scale) and opioid consumption (in oral morphine equivalents).

RESULTS

During CSNB, pain scores markedly decreased in comparison to the pre-block period.

CONCLUSIONS

CPNB may be a good option for ischemic pain treatment in in-patients, as it provides effective pain control with fewer adverse effects.

Relationship Between Psychological Factors and Wound Occurrence in Patients With Peripheral Arterial Disease in the Leg

This prospective study investigated psychological factors affecting wound healing in patients with peripheral arterial disease (PAD). Fifty patients with PAD in a local hospital were enrolled. The Geriatric Depression Scale short version, Type-D scale 14, Medical Outcome Study 36-Item Short-Form Health Survey (SF-36), Functional Independence Measure, Self-efficacy for Managing Chronic Disease Scale, Barriers Self-Efficacy Scale, and Mini Nutritional Assessment were applied to assess physical and psychological factors. Wound occurrence and healing were evaluated at 6 months after discharge, and 34 and 30 patients could be followed, respectively. The patient group with wound occurrence showed poorer mental component score (MCS) and better role/social component score (RCS) category scores of SF-36, and a higher stage in the Fontaine classification, than those without wound occurrence. On comparing Fontaine classification-matched subgroups, patients with wound occurrence showed poorer general health factor and MCS and better RCS of SF-36 than those without wound occurrence. Logistic analysis showed that MCS and RCS predicted wound occurrence and needs for local medical treatment, respectively. Among the psychological factors tested, MCS was a major factor associated with wound occurrence in the present study, with wide variation in clinical conditions and factors associated with PAD. Psychological factors were important as biological, physical, and social factors for patients with PAD during the long-term follow-up period, and an appropriate battery to evaluate psychological factors focused on patients with PAD should be developed.

A Single-Center Experience With Phoenix Atherectomy System in Patients With Moderate to Heavily Calcified Femoropopliteal Lesions

PURPOSE

To evaluate efficacy and safety of a new rotational atherectomy (RA), the Phoenix Atherectomy™ System, for the treatment of de novo and re-stenotic or occlusions atherosclerotic moderate-heavily lesions of the femoro-popliteal axis.

MATERIAL AND METHODS

From January 2015 to August 2017, 52 patients with heavily calcified femoro-popliteal lesions causing severe stenosis or occlusions were enrolled in our center to be treated using Phoenix catheters. Primary endpoints of this study were acute efficacy and safety at 30 days. Secondary endpoints were freedom from restenosis and target lesion revascularization (TLR)/target vessel revascularization (TVR) at 1-, 6- and 12- months.

RESULTS

The mean lesion length was 9.2 cm (range 5-23 cm). The lesions were located in superficial femoral artery (SFA) in 61.5% (Fig. 1-A), in popliteal artery in 21.1% and involved femoral-popliteal axis in 15.4%. A primary technical success was achieved in 51/52 patients, with an optimal working channel after RA alone. Using Kaplan-Meyer analysis, primary vessel patency rates at 1, 6 and 12 -months was 96.1%, 86.5% and 76.9% respectively. Assisted primary patency at 1, 6- and 12 -months was 100%, 90.3% and 86.5% respectively.

CONCLUSIONS

Recanalisation with the Phoenix Atherectomy System is simple and safe, with a high technical success rate.

A quantitative real-time assessment of Buerger exercise on dorsal foot peripheral skin circulation in patients with diabetes foot

Buerger exercise can improve the peripheral circulation of lower extremities. However, the evidence and a quantitative assessment of skin perfusion immediately after this exercise in patients with diabetes feet are still rare.We recruited 30 patients with unilateral or bilateral diabetic ulcerated feet in Chang Gung Memorial Hospital, Chia-Yi Branch, from October 2012 to December 2013. Real-time dorsal foot skin perfusion pressures (SPPs) before and after Buerger exercise were measured and analyzed. In addition, the severity of ischemia and the presence of ulcers before exercise were also stratified.A total of 30 patients with a mean age of 63.4 ± 13.7 years old were enrolled in this study. Their mean duration of diabetes was 13.6 ± 8.2 years. Among them, 26 patients had unilateral and 4 patients had bilateral diabetes foot ulcers. Of the 34 wounded feet, 23 (68%) and 9 (27%) feet were classified as Wagner class II and III, respectively. The real-time SPP measurement indicated that Buerger exercise significantly increased the level of SPP by more than 10 mm Hg (n = 46, 58.3 vs 70.0 mm Hg, P < 0.001). In terms of pre-exercise dorsal foot circulation condition, the results showed that Buerger exercise increased the level of SPP in severe ischemia (n = 5, 22.1 vs 37.3 mm Hg, P = 0.043), moderate ischemia (n = 14, 42.2 vs 64.4 mm Hg, P = 0.001), and borderline-normal (n = 7, 52.9 vs 65.4 mm Hg, P = 0.028) groups, respectively. However, the 20 feet with SPP levels more than 60 mm Hg were not improved significantly after exercise (n = 20, 58.3 vs 71.5 mm Hg, P = 0.239). As to the presence of ulcers, Buerger exercise increased the level of SPP in either unwounded feet (n = 12, 58.5 vs 66.0 mm Hg, P = 0.012) or wounded feet (n = 34, 58.3 vs 71.5 mm Hg, P < 0.001). The majority of the ulcers was either completely healed (9/34 = 27%) or still improving (14/34 = 41%).This study quantitatively demonstrates the evidence of dorsal foot peripheral circulation improvement after Buerger exercise in patients with diabetes.

Burden of peripheral arterial disease in Europe and the United States: a patient survey

BACKGROUND

The aim of the current study was to quantify the burden of peripheral arterial disease (PAD) with respect to health-related quality of life, work productivity and activity impairment, and healthcare resource utilization.

METHODS

Data were obtained from the 2010 EU National Health and Wellness Survey (NHWS), which included participants from France, Germany, Italy, Spain, and the UK (5 EU, N = 57,805) as well as the 2010 US NHWS (N = 75,000). The NHWS is an annual, cross-sectional, self-administered Internet survey which employs a stratified random sampling frame to match the age and gender characteristics of the NHWS sample with known population statistics. Participants who self-reported a diagnosis of PAD were compared with participants who did not self-report a diagnosis of PAD on health-related quality of life (mental and physical component summary scores and health utilities from the Short Form-12v2), work productivity and activity impairment (Work Productivity and Activity Impairment questionnaire), and healthcare resource use in terms of the number of physician visits, emergency room visits, and hospitalizations in the past six months through regression modeling adjusting for demographics and health characteristics.

RESULTS

A total of 743 (1.29%) and 777 (1.04%) participants self-reported a diagnosis of PAD in the 5 EU and US, respectively. After adjusting for demographics and health characteristics, patients with PAD reported worse health-related quality of life, as measured by health utilities (5 EU: 0.66 vs. 0.70; US: 0.66 vs. 0.72; all p < .05), greater overall work impairment percentage (5 EU: 38.27% vs. 27.48%; US: 23.89% vs. 14.26%) and greater healthcare resource use compared to participants without PAD (all p < .05).

CONCLUSIONS

These results suggest a significant burden for patients with PAD in both the 5 EU countries and the US with respect to both quality of life and economic outcomes. Improved management of these patients may have profound effects from both patient and societal perspectives.

Effect of normalization of fasting glucose by intensified insulin therapy and influence of eNOS polymorphisms on the incidence of restenosis after peripheral angioplasty in patients with type 2 diabetes: a randomized, open-label clinical trial

Primary objective was to evaluate whether an intensified insulin therapy (IIT) incorporating the target of normal fasting glucose and HbA1c levels could halve the incidence of restenosis/amputation/SCA/death at 6 months after peripheral angioplasty compared with standard care (SC) in patients with type 2 diabetes (DMT2) affected by critical limb ischemia (CLI). Forty-six consecutive patients with DMT2 and CLI were randomly assigned to a parallel, open-label study with IIT (basal-bolus glulisine + glargine administrations) or SC (glargine administration + oral antidiabetic drugs). A SNP of eNOS (rs753482-A>C) and circulating CD34(+) and CD34(+)KDR(+) progenitor cells were determined. At the end of the study, although HbA1c levels were lower in IIT than in SC (6.9 ± 1.3 % vs. 7.6 ± 1.2 %, p < 0.05), IIT did not reduce the cumulative incidence of restenosis/amputation/SCA/death (52 and 65 %, respectively, odd ratio 0.59; CI 95 %: 0.21-1.62, p = 0.59). rs753482AC+CC as compared with rs753482AA increased the cumulative incidence of restenosis/amputation/SCA/death (79 and 42 %; odd ratio 5.3; CI 95 %: 1.41-19.5, p < 0.02). Baseline CD34(+)KDR(+) were higher in rs753482AA (166.2 ± 154.0 × 10(6) events) than in rs753482AC+CC (63.1 ± 26.9 × 10(6) events, p < 0.01). At the end of the study, the highest circulating CD34(+)KDR(+) were found in IIT rs753482AA (246.9 ± 194.0 × 10(6) events) while the lowest levels were found in SC rs753482AC+CC (70.9 ± 45.0 × 10(6) events). IIT did not decrease the cumulative incidence of restenosis/amputation/SCA/death in DMT2 and CLI patients. These patients correspond to a class of fragile subjects at high risk of cardiovascular events, and new predictors of restenosis should be contemplated, such as of eNOS polymorphism, (rs753482-A>C SNP) and circulating endothelial progenitor cells.

Chronic hindlimb ischemia impairs functional vasodilation and vascular reactivity in mouse feed arteries

Vasodilation of lower leg arterioles is impaired in animal models of chronic peripheral ischemia. In addition to arterioles, feed arteries are a critical component of the vascular resistance network, accounting for as much as 50% of the pressure drop across the arterial circulation. Despite the critical importance of feed arteries in blood flow control, the impact of ischemia on feed artery vascular reactivity is unknown. At 14 days following unilateral resection of the femoral–saphenous artery–vein pair, functional vasodilation of the profunda femoris artery was severely impaired, 11 ± 9 versus 152 ± 22%. Although endothelial and smooth muscle-dependent vasodilation were both impaired in ischemic arteries compared to control arteries (Ach: 40 ± 14 versus 81 ± 11%, SNP: 43 ± 12 versus and 85 ± 11%), the responses to acetylcholine and sodium nitroprusside were similar, implicating impaired smooth muscle-dependent vasodilation. Conversely, vasoconstriction responses to norepinephrine were not different between ischemic and control arteries, −68 ± 3 versus −66 ± 3%, indicating that smooth muscle cells were functional following the ischemic insult. Finally, maximal dilation responses to acetylcholine, ex vivo, were significantly impaired in the ischemic artery compared to control, 71 ± 9 versus 97 ± 2%, despite a similar generation of myogenic tone to the same intravascular pressure (80 mmHg). These data indicate that ischemia impairs feed artery vasodilation by impairing the responsiveness of the vascular wall to vasodilating stimuli. Future studies to examine the mechanistic basis for the impact of ischemia on vascular reactivity or treatment strategies to improve vascular reactivity following ischemia could provide the foundation for an alternative therapeutic paradigm for peripheral arterial occlusive disease.

Coronary artery endothelial transcriptome in vivo: identification of endoplasmic reticulum stress and enhanced reactive oxygen species by gene connectivity network analysis

BACKGROUND

Endothelial function is central to the localization of atherosclerosis. The in vivo endothelial phenotypic footprints of arterial bed identity and site-specific atherosusceptibility are addressed.

METHODS AND RESULTS

Ninety-eight endothelial cell samples from 13 discrete coronary and noncoronary arterial regions of varying susceptibilities to atherosclerosis were isolated from 76 normal swine. Transcript profiles were analyzed to determine the steady-state in vivo endothelial phenotypes. An unsupervised systems biology approach using weighted gene coexpression networks showed highly correlated endothelial genes. Connectivity network analysis identified 19 gene modules, 12 of which showed significant association with circulatory bed classification. Differential expression of 1300 genes between coronary and noncoronary artery endothelium suggested distinct coronary endothelial phenotypes, with highest significance expressed in gene modules enriched for biological functions related to endoplasmic reticulum (ER) stress and unfolded protein binding, regulation of transcription and translation, and redox homeostasis. Furthermore, within coronary arteries, comparison of endothelial transcript profiles of susceptible proximal regions to protected distal regions suggested the presence of ER stress conditions in susceptible sites. Accumulation of reactive oxygen species throughout coronary endothelium was greater than in noncoronary endothelium consistent with coronary artery ER stress and lower endothelial expression of antioxidant genes in coronary arteries.

CONCLUSIONS

Gene connectivity analyses discriminated between coronary and noncoronary endothelial transcript profiles and identified differential transcript levels associated with increased ER and oxidative stress in coronary arteries consistent with enhanced susceptibility to atherosclerosis.

Use of implantable cardioverter-defibrillators

The implantable cardioverter-defibrillator (ICD) is the most effective treatment for patients with life-threatening ventricular tachycardia or ventricular fibrillation not due to reversible causes. The American College of Cardiology/American Heart Association class I and IIa indications for an ICD are discussed. Patients with ICDs who need pacing should be treated with biventricular pacing, not with dual-chamber rate-responsive pacing, at a rate of 70/min. Patients with ICDs should be treated with β-blockers, statins and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers.

Endovascular procedures for aorto-iliac occlusive disease are associated with superior short-term clinical and economic outcomes compared with open surgery in the inpatient population

OBJECTIVES

There has been a rapid increase in the number of endovascular procedures performed for peripheral artery disease, and especially aorto-iliac occlusive disease (AIOD). Results from single-center reports suggest a benefit for endovascular procedures; however, these benefits may not reflect general practice. We used a population-based analysis to determine predictors of clinical and economic outcomes following open and endovascular procedures for inpatients with AIOD.

METHODS

All patients with AIOD who underwent open and endovascular procedures in the Healthcare Cost and Utilization Project Nationwide Inpatient Sample, 2004 to 2007, were identified. Independent patient- and provider-related characteristics were analyzed. Clinical outcomes included complications and mortality; economic outcomes included length of stay (LOS) and cost (2007 dollars). Outcomes were compared using χ2, ANOVA, and multivariate regression analysis.

RESULTS

Four thousand, one hundred nineteen patients with AIOD were identified. Endovascular procedures increased by 18%. Patients who underwent endovascular procedures were more likely to be ≥65 years of age (46% vs 37%), female (54% vs 49%), and in the highest quartile of household income (20% vs 16%), all P<.05. Endovascular patients were more likely to be non-elective (41% vs 20%), in the highest comorbidity index group (8% vs 5%), and with iliac artery disease (67% vs 33%), all P≤.05. In bivariate analysis, endovascular procedures were associated with lower complication rates (16% vs 25%), shorter LOS (2.2 vs 5.8 days), and lower hospital costs ($13,661 vs $17,161), all P<.001. In multivariate analysis, endovascular procedures had significantly lower complication rates and cost, and shorter LOS.

CONCLUSIONS

Endovascular procedures have superior short-term clinical and economic outcomes compared with open procedures for the treatment of AIOD in the inpatient setting. Further studies are needed to examine long-term outcomes and access-related issues.

Pain management in peripheral arterial obstructive disease: oral slow-release oxycodone versus epidural l-bupivacaine

OBJECTIVES

To compare the effectiveness of oral slow-release oxycodone (group OX, n=18) with that of epidural l-bupivacaine (group LRA, n=13) for the control of moderate/severe pain of advanced-stage peripheral arterial obstructive disease (PAOD) patients.

DESIGN

Observational and retrospective analysis of advanced stage and hospitalised PAOD patients treated for pain management for at least 7 days prior to surgery or discharged from the hospital without surgery.

METHODS

The outcome measures were pain intensity using the visual analogue scale under static, (VASs) and dynamic (VASd) conditions; vital signs, treatment side effects and patient satisfaction.

RESULTS

In both groups, pain control was satisfactory and VAS scores median were VASs<3 and VASd<4; under dynamic conditions, pain control was better in the LRA group (p<0.01). Against few and transient side effects, most patients (n=30) found both pain treatments good or excellent. Results should be confirmed by studies with larger samples.

CONCLUSIONS

In the perioperative setting, the epidural infusion of local anaesthetics, such as l-bupivacaine, is an effective technique for pain control in PAOD patients; for patients with contraindication for this technique or for non-surgical or outpatients, slow-release oxycodone is suggested as a possible alternative for the control of severe pain in these patients.

Smoking cessation: the role of the foot and ankle surgeon

Tobacco cigarette smoking causes many negative effects on the body, and it is the leading preventable cause of death in the United States. These negative effects are a concern for the foot and ankle surgeon, as smoking can increase the risk of diabetes and peripheral artery disease and delay healing of surgical incisions and ulcerations of the lower extremities. Tobacco cigarette smoking can also increase the risk of avascular necrosis and delayed union and nonunions of fractures and osteotomies. Smoking cessation is an important component in the overall treatment of conditions affecting the foot and ankle. Smoking cessation can be a difficult goal to achieve, but proper education and support can help patients reach this goal.

A pilot study showing an association between platelet hyperactivity and the severity of peripheral arterial disease

Peripheral arterial disease (PAD) is a chronic fibroproliferative inflammatory condition associated with progressive vascular stenosis. We set out to determine the relationship between spontaneous stirring-induced platelet aggregation in whole blood and the severity of lower-limb PAD, represented by the ankle-brachial pressure index (ABPI). ABPI was determined pre- and post-exercise in 31 subjects (20 men and 11 women) with established PAD. Platelets counts were determined in EDTA blood (total count) and in citrated whole blood after stirring in the absence of added ADP (spontaneous aggregation) and in the presence of added ADP (ADP-induced) for 3 min at 37 degrees C. Aggregation was calculated as a percentage of the total platelet count. Spontaneous platelet aggregation showed an inverse correlation with pre-exercise ABPI (r = -0.32; P < 0.05) and ADP-induced aggregation correlated inversely with post-exercise ABPI (r = -0.34; P < 0.05). These results indicate that platelet hyperactivity is associated with increasing severity of PAD. Increased platelet aggregation may result in thromboembolic events in the affected limb.

Dual roles of tumor necrosis factor-alpha receptor-1 in a mouse model of hindlimb ischemia

Signals in the tumor necrosis factor alpha (TNF-alpha) pathway are upregulated after ischemia, yet its role in peripheral ischemia remains unclear. We investigated the effect of TNF-alpha receptor 1 (TNFR-1) in acute limb ischemia of TNFR-1 knockout (TNFR-1-/-) and wild type (WT, TNFR-1+/+) mice. Laser Doppler scanning showed that although pre-ischemia blood flow levels were similar in these mice, the limb reperfusion after ischemia was significantly higher in TNFR-1-/- mice 1-7 days after injury. Consistently, fewer TUNEL-positive cells, less DNA fragmentation, and a lower ischemic score were detected in the TNFR-1-/- group when compared to WT controls. Western blot analysis revealed less expression of pro-apoptotic markers Bax and cleaved caspase-3 in TNFR-1-/- mice 1 day after ischemia, supporting the hypothesis that the absence of TNFR-1 results in a reduction of apoptosis. The rate of post-ischemia amputation was 50% in WT mice versus 0% in TNFR-1-/- mice. However, immunohistochemical co-staining of microvessel marker CD31 and cellular proliferation marker BrdU 21 days after ischemia showed an impaired angiogenic activity in the TNFR-1-/- mice. These data were supported by Western blot analysis, which indicated a decreased expression of angiopoietin-1 (Ang-1) and its receptor Tie-2 in TNFR-1-/- mice. Our results suggest that a deficiency in TNFR-1 prevents the activation of death-related proteins downstream to TNF-alpha and attenuates apoptosis in acute limb ischemia, but the lack of TNFR-1 signaling hinders the belated angiogenesis mediated by the Ang-1/Tie-2 pathway.

Predictors for institutionalization and prosthetic ambulation after major lower extremity amputation during an eight-year follow-up

BACKGROUND AND AIMS

Major lower extremity amputation (LEA) leads to great loss in mobility, exposing old people to the risk of losing their independent living status. This study applies predictors for institutionalization and considers prosthesis use by major lower leg amputees with peripheral arterial disease (PAD).

METHODS

119 PAD patients admitted from home (mean age 73.6, SD 11.5 years, 48% men) underwent their first major LEA, 1998- 2002, and survived at least one month after the operation. Logistic regression analysis was run to clarify institutionalization predictors. Prosthesis use and ambulatory capacity were recorded during the follow-up.

RESULTS

Older age, living alone, and unilateral above-knee amputation (AKA) or bilateral amputation predicted institutionalization. Of prosthesis users, 69% (27/39) were younger than 75 and 44% (17/39) were able to walk both in- and outdoors. Reasons for not receiving a prosthesis after amputation were: 1) short expected survival; 2) old age, combined with unilateral AKA or bilateral amputation; 3) unilateral AKA or bilateral amputation and a comorbid condition such as hemiparesis, paraplegia, uremia, dementia, or alcohol misuse. After one year, 72% (36/50) of amputees who were able to return home and 9% (3/32) of amputees in institutional care used a prosthesis.

CONCLUSION

The majority of amputated patients cannot return home after their first LEA. Comorbid conditions particularly influencing functional capacity also hinder ambulation with a prosthesis.

A prospective, masked 18-month minimum follow-up on neurophysiologic changes in persons with spinal stenosis, low back pain, and no symptoms

OBJECTIVES

To describe neurophysiologic changes over time in persons with and without spinal complaints and to assess whether paraspinal denervation predicts change in stenosis on magnetic resonance imaging (MRI) and clinical course.

DESIGN

Prospective, controlled, masked trial.

SETTING

University spine program.

PARTICIPANTS

Persons aged 55 to 80 years, screened for polyneuropathy and determined on clinical examination to have spinal stenosis, mechanical low back pain, or no spinal symptoms.

INTERVENTIONS

A comprehensive codified history was obtained and subjects underwent physical examination, ambulation testing, masked electrodiagnostic testing including paraspinal mapping, and MRI, repeated at greater than 18 months. This study presents detailed technical information and additional analyses not reported previously.

MAIN OUTCOME MEASUREMENTS

Change in electrodiagnostic findings. Among persons with clinical stenosis, relationship of change in paraspinal mapping scores to MRI findings and clinical changes.

RESULTS

Of 149 initial subjects, 83 (79.3% of eligible subjects) repeated testing at 20 (+/-2 SDs) months. No significant change in limb muscle spontaneous activity or motor unit pathology was noted in any group. In 23 persons with initial diagnosis of stenosis, paraspinal mapping electromyography related to change in diagnosis over time (analysis of variance F = 3.77, P = .037), but not to most initial magnetic resonance imaging measurements or to change in spinal canal diameter.

CONCLUSIONS

Clinical spinal stenosis is neurophysiologically stable in most persons. Paraspinal electromyographic changes reflect large changes in clinical course, but neither neurophysiologic nor clinical changes relate to change in spinal geometry over 20 months.

Major lower extremity amputation in elderly patients with peripheral arterial disease: incidence and survival rates

BACKGROUND AND AIMS

The methods of treating peripheral arterial disease (PAD) have changed and become more prophylactic. This study describes and analyzes 1) the incidence rates of major lower extremity amputation (LEA) due to PAD, 2) occurrence of re-amputation, and 3) the survival of amputees and factors predicting survival.

METHODS

The series consisted of 210 patients (mean age 76.6, SD 10.7 yrs, 45.2% men) who underwent their first, i.e. index, major leg amputation because of PAD, in 1998-2002, in the city of Turku, Finland, population 175,000.

RESULTS

The age-and gender-standardized incidence rate of combined above-knee and below-knee amputations was 24.1/100,000 person-years during 1998-2002. Thirty-four per cent of amputees underwent repetitive amputation. One-month mortality was 21% (n=45), one-year mortality 52% (n=109) and overall mortality 80% (n=168). Cardiovascular diseases predicted equally well 31-day, one-year, and overall mortality in age- and gender- adjusted analysis. Multiple co-morbidities (p=0.023) and unilateral above-knee amputations (p=0.047) were significant predictors for overall mortality in age- and gender-adjusted analysis. Cardiovascular diseases remained a significant predictor for 31-day and overall mortality in multivariate analysis (p=0.008 and p=0.015, respectively). Amputated patients' previous vascular procedures did not have any effect on mortality in the Cox model. Most revascularizations were performed less than six months before the index/first major LEA.

CONCLUSION

Major LEAs seem to have been done late, and mainly for pain relief in the end-stage of patients with peripheral arterial disease.

Estudo comparativo da evolução e sobrevida de pacientes com claudicação intermitente, com ou sem limitação para exercícios, acompanhados em ambulatório específico

CONTEXTO: Os fatores de risco para doença aterosclerótica, que influenciam na evolução natural dessa doença, estão bem estabelecidos, assim como o benefício do programa de exercícios para pacientes claudicantes. Entretanto, faltam informações sobre a relação entres limitações clínicas e fatores de risco, com desempenho do programa de caminhadas e suas implicações na evolução e mortalidade destes pacientes. OBJETIVO: Comparar, ao longo do tempo, a distância de claudicação e sobrevida de pacientes claudicantes em ambulatório específico, com ou sem limitação para exercícios. MÉTODOS: Foi feito um estudo tipo coorte retrospectivo de 185 pacientes e 469 retornos correspondentes, no período de 1999 a 2005, avaliando-se dados demográficos, distância média de claudicação (CI) e óbito. Os dados foram analisados nos programas Epi Info, versão 3.2, e SAS, versão 8.2. RESULTADOS: A idade média foi de 60,9±11,1 anos, sendo 61,1% do sexo masculino e 38,9% do sexo feminino. Oitenta e sete por cento eram brancos, e 13%, não-brancos. Os fatores de risco associados foram: hipertensão (69,7%), tabagismo (44,3%), dislipidemia (32,4%) e diabetes (28,6%). Nos claudicantes para menos de 500 m, a CI inicial em esteira foi de 154,0±107,6 m, e a CI final, de 199,8±120,5 m. Cerca de 45% dos pacientes tinham alguma limitação clínica para realizar o programa de exercícios preconizado, como: angina (26,0%), acidente vascular cerebral (4,3%), artropatia (3,8%), amputação menor ou maior com prótese (2,1%) ou doença pulmonar obstrutiva crônica (1,6%). Cerca de 11,4% dos pacientes tinham infarto do miocárdio prévio, e 5,4% deles usavam cardiotônico. O tempo de seguimento médio foi de 16,0±14,4 meses. A distância média de CI referida pelos pacientes aumentou 100% (de 418,47 m para 817,74 m) ao longo de 2 anos, nos grupos não-limitante (p < 0,001) e não-tabagista (p < 0,001). A sobrevida dos claudicantes foi significativamente menor no grupo com limitação. A análise de regressão logística mostrou que a limitação para realização de exercícios, isoladamente, influenciou significativamente na mortalidade (p < 0,001). CONCLUSÃO: A realização correta e regular dos exercícios e o abandono do fumo melhoram a distância de claudicação, além de reduzir a mortalidade nesses casos, seja por meio de efeitos positivos próprios do exercício, seja por meio de controle dos fatores de risco e de seus efeitos adversos.

[Risk status of patients with peripheral arterial disease (PAD)]

The authors have analyzed clinical and laboratory risk factors of 168 patients with PAD and 82 control persons. Among the patients the prevalences of diabetes, coronary heart disease (CHD), and cerebrovascular disease (CVD) were 30.4%, 39.9%, and 6.5%, respectively. 7.1% of the patients had CHD and CVD. Among patients with PAD and control persons, the prevalences of hypertension and current smoking were 76.2% vs 46.3% and 49.4% vs 28%. HDL-cholesterol and ApoA1 levels were significantly lower, while the triglycerides, fibrinogen, hsCRP, homocysteine, creatinine, uric acid levels, and white blood cell count as well as plasma viscosity were significantly higher in the patient group compared with the values of control persons. Among the PAD patients the diabetics and the smokers had further unfavourable significant differencies in the laboratory findings compared with the data of non-diabetics and non-smokers. Correlations were detected between the hsCRP level and the white blood cell count, the plasma viscosity and the fibrinogen level, respectively. Examining 16 selected risk factors the average risk factor count of the patients was 7.79. 118 patients had lipid-lowering, and 142 patients had antithrombotic therapy. Our results emphasize the necessity of the secondary prevention among PAD patients.

Therapeutic effects of autologous bone marrow cells and metabolic intervention in the ischemic hindlimb of spontaneously hypertensive rats involve reduced cell senescence and CXCR4/Akt/eNOS pathways

Peripheral arterial disease (PAD) is a major health problem, especially when associated with severe hypertension. Administration of autologous bone marrow cells (BMCs) is emerging as a novel intervention to induce neoangiogenesis in ischemic limb models and in patients with PAD. This study evaluates the neovascularization capacity of BMCs alone or in combination with metabolic cotreatment (0.8% vitamin E, 0.05% vitamin C, and 5% of L-arginine) in a rat model of ischemic hindlimbs of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Molecular mechanisms were investigated in bone marrow-derived endothelial progenitor cells (BM-EPC) derived from rats. BMC therapy increased blood flow and capillary densities and Ki67 proliferative marker, and it decreased interstitial fibrosis. These effects were amplified by metabolic cotreatment, an intervention that induces vascular protection at least partly through the nitric oxide (NO)/endothelial nitric oxide synthase (eNOS) pathway, reduction of systemic oxidative stress, and macrophage activation. In addition, BMC therapy alone and, more consistently, in combination with metabolic treatment, ameliorated BM-EPC functional activity via decreased cellular senescence and improved homing capacity by increasing CXCR4-expression levels. These data suggest potential therapeutic effects of autologous BMCs and metabolic treatment in hypertensive PAD patients.

Role of Advanced Glycation End Products in Hypertension and Atherosclerosis: Therapeutic Implications

The vascular diseases, hypertension and atherosclerosis, affect millions of individuals worldwide, and account for a large number of deaths globally. A better understanding of the mechanism of these conditions will lead to more specific and effective therapies. Hypertension and atherosclerosis are both characterized by insulin resistance, and we suggest that this plays a major role in their etiology. The cause of insulin resistance is not known, but may be a result of a combination of genetic and lifestyle factors. In insulin resistance, alterations in glucose and lipid metabolism lead to the production of excess aldehydes including glyoxal and methylglyoxal. These aldehydes react non-enzymatically with free amino and sulfhydryl groups of amino acids of proteins to form stable conjugates called advanced glycation end products (AGEs). AGEs act directly, as well as via receptors to alter the function of many intra- and extracellular proteins including antioxidant and metabolic enzymes, calcium channels, lipoproteins, and transcriptional and structural proteins. This results in endothelial dysfunction, inflammation and oxidative stress. All these changes are characteristic of hypertension and atherosclerosis. Human and animal studies have demonstrated that increased AGEs are also associated with these conditions. A pathological role for AGEs is substantiated by studies showing that therapies that attenuate insulin resistance and/or lower AGEs, are effective in decreasing oxidative stress, lowering blood pressure, and attenuating atherosclerotic vascular changes. These interventions include lipoic acid and other antioxidants, AGE breakers or soluble receptors of AGEs, and aldehyde-binding agents like cysteine. Such therapies may offer alternative specific means to treat hypertension and atherosclerosis. An adjunct therapy may be to implement lifestyle changes such as weight reduction, regular exercise, smoking cessation, and increasing dietary intake of fruits and vegetables that also decrease insulin resistance as well as oxidative stress.

The effect of the controlled release of basic fibroblast growth factor from ionic gelatin-based hydrogels on angiogenesis in a murine critical limb ischemic model

The localized delivery of exogenous, angiogenic growth factors has become a promising alternative treatment of peripheral artery disease (PAD) and critical limb ischemia. In the present study, we describe the development of a novel controlled release vehicle to promote angiogenesis in a murine critical limb ischemic model. Ionic, gelatin-based hydrogels were prepared by the carbodiimide-mediated amidation reaction between the carboxyl groups of gelatin or poly-L-glutamic acid molecules and the amine groups of poly-L-lysine or gelatin molecules, respectively. The degree of swelling of the synthesized hydrogels was assessed as a function of EDC/NHS ratios and the pH of the equilibrating medium, while the release kinetic profile of basic fibroblast growth factor (FGF-2) was evaluated in human fibroblast cultures. The degree of swelling (DS) decreased from 26.5+/-1.7 to 18.5+/-2.4 as the EDC concentration varied from 0.75 to 2.5 mg/ml. Eighty percent of the FGF-2 was released at controlled rates from gelatin-polylysine (gelatin-PLL) and gelatin-polyglutamic acid (gelatin-PLG) hydrogel scaffolds over a period of 28 days. Cell adhesion studies revealed that the negatively charged surface of the gelatin-PLG hydrogels exhibited superior adhesion capabilities in comparison to gelatin-PLL and control gelatin surfaces. Laser Doppler perfusion imaging as well as CD31(+) capillary immunostaining demonstrated that the controlled release of FGF-2 from ionic gelatin-based hydrogels is superior in promoting angiogenesis in comparison to the bolus administration of the growth factor. Over 4 weeks, FGF-2 releasing gelatin-PLG hydrogels exhibited marked reperfusion with a Doppler ratio of 0.889 (+/-0.04) which was 69.3% higher than in the control groups.

Gene therapy progress and prospects: therapeutic angiogenesis for ischemic cardiovascular disease

During the past decade, both in vitro and in vivo studies have provided new insights into the cellular and molecular mechanisms that govern angiogenesis and arteriogenesis. However, therapeutic angiogenesis clinical trials using recombinant protein or gene therapy formulations of single angiogenic growth factors have yielded at best only modest success to date. Among the second generation of angiogenic agents are therapeutic transgenes that enhance expression of two or more proangiogenic cytokines. These include synthetic constructs that mimic that activity of endogenous transcriptional regulators and other upstream, regulatory factors that have the potential to induce formation of morphologically and physiologically functional vessels. These agents are now beginning to be evaluated in clinical trials for patients with advanced ischemic cardiac and peripheral vascular disease.

Coronary endothelium expresses a pathologic gene pattern compared to aortic endothelium: Correlation of asynchronous hemodynamics and pathology in vivo

Coronary arteries are the most disease prone arteries in the circulation and are characterized by unique hemodynamic features, wherein wall shear stress (WSS) induced by blood flow and circumferential strain (CS) driven by pressure are highly out-of-phase temporally (asynchronous hemodynamics). To investigate whether there is a correlation between asynchronous hemodynamics and pathology in vivo, we examined endothelial cell (EC) gene expression and nuclear morphology in two distinct hemodynamic regions of male New Zealand rabbits: coronary arteries (left anterior descending artery cLAD), and aorta (aortic arch inner curvature, outer curvature, and straight descending aorta). En face imaging showed strong similarities in EC nuclear length:width ratio and angle of orientation in the cLAD and aorta. Real-time RT-PCR, however, showed that coronary arteries had significantly reduced (>5-fold) eNOS mRNA levels compared to all aortic regions, while ET-1 showed an opposite trend ( approximately 2.5-fold). Coronary arteries with characteristic asynchronous hemodynamics displayed pro-atherogenic eNOS and ET-1 gene expression profiles while the EC nuclei morphology did not differ from non-atherogenic regions in the aorta. This study demonstrates a correlation between asynchronous hemodynamics and pro-atherogenic gene expression patterns in vivo that is induced by hemodynamics inherent to the circulation.

A modified fluorescent microsphere-based approach for determining resting and hyperemic blood flows in individual murine skeletal muscles

The goal of this study was to develop a modified fluorescent microsphere-based approach for measuring resting and hyperemic blood flows in individual mouse skeletal muscles. Absolute resting blood flow in the left gracilis posterior was 1.04+/-0.12 ml x min(-1).g(-1), while functional hyperemia following muscle activity was 5.94+/-1.33 ml x min(-1) x g(-1). Measuring absolute blood flow requires sampling arterial blood that serves as a flow-rate and concentration reference to the fluorescent microsphere (FMS) content in the tissue-of-interest for calculating the flow value. Because sampling arterial blood can impair cardiovascular function in the mouse, we also modified our FMS approach to determine relative blood flows in the left gracilis posterior by using the contralateral muscle as our reference in blood flow calculations. Absolute and relative hyperemia measurements detect similar increases in blood flow - 521.93+/-216.76% and 555.24+/-213.82%, respectively. However, sampling arterial blood during absolute blood flow measurements significantly decreased mean arterial pressure from the beginning to the end of our experiments, from 102.7+/-2.18 to 75.5+/-9.71 mm Hg. This decrease was not seen when measuring relative blood flows. This approach provides critical advantages over contemporary blood flow measurement approaches by allowing blood flow measurements in small and non-superficial tissues.

Atherogenic Endothelial Cell eNOS and ET-1 Responses to Asynchronous Hemodynamics are Mitigated by Conjugated Linoleic Acid

Although local wall shear stress (WSS) induced by blood flow has been implicated in atherogenesis, another prominent and often neglected hemodynamic feature, circumferential strain (CS) driven by pressure, is induced concurrently. To investigate endothelial cell (EC) responses to pathologic hemodynamics and their possible manipulation by pharmaceuticals, we simulated complete hemodynamic conditions comprised of simultaneous WSS and CS during treatment with conjugated linoleic acid (CLA), a known PPAR (-alpha and -gamma) activator and anti-atherogenic agent, on cultured EC and examined effects on gene and metabolite expression. Two hemodynamic conditions representative of distinct regions of the circulation, coronary arteries: pro-atherogenic (asynchronous WSS and CS) and straight descending aorta: non-atherogenic (synchronous WSS and CS), were applied to cultured EC during treatment with the nutraceutical CLA. Competitive-quantitative RT-PCR showed that asynchronous hemodynamics significantly reduced ( approximately 2-fold) eNOS and PPAR-gamma mRNA levels compared to synchronous hemodynamics at 5 and 12 h. ET-1 showed an opposite trend at 12 h. CLA treatment mitigated pro-atherogenic eNOS, ET-1, PPAR-alpha and -gamma mRNA expression profiles and NO and ET-1 secretion patterns during asynchronous hemodynamics. This study demonstrates the potential for a pharmacological treatment (CLA) to normalize pro-atherogenic gene expression profiles induced by hemodynamics inherent to the circulation.

Optimal medical management of peripheral arterial disease

Patients with peripheral vascular disease are less likely to receive optimal medical management than patients with coronary artery disease. However, early medical treatment is critical because it is profoundly beneficial and the benefits are maximized. Even in patients with advanced disease requiring invasive intervention, medical management has been proven to improve outcome, prolong the success of the intervention, improve functional capacity, and prolong life. The vascular surgeon should be knowledgeable enough to initiate basic medical therapy and to define for their patients the goals that need to be met to optimize their medical management. The vascular surgeon should be instrumental in assuring that the peripheral vascular patient receives medical therapy of the same standard as the patient with coronary disease. The major modifiable risk factors in the vascular patient are: smoking, high blood pressure, hyperlipidemia, physical inactivity, obesity, and diabetes. In addition, the use of beta blockers for patients with coronary disease and antiplatelet therapy as well as angiotensin-converting enzyme (ACE) inhibitors are recommended for all patients with peripheral vascular disease. Statins have favorable effects on multiple interrelated aspects of vascular biology important in atherosclerosis. In particular they have beneficial effects on inflammation, plaque stabilization, endothelial dysfunction, and thrombosis. Statins have also been shown to be beneficial in acute vascular events. Angiotensin-converting enzyme inhibitors have been shown to reduce cardiovascular morbidity and mortality in patients with peripheral arterial disease regardless of the presence or absence of hypertension. A number of the pleiotropic effects of statins are shared by ACE inhibitors. In summary, patients with known vascular disease should be treated aggressively with a combination of a HMG CoA reductase inhibitor, an angiotensin-converting enzyme inhibitor, an antiplatelet agent and a beta blocker if there is a history of coronary disease. They should also receive tight control of their blood pressure and blood sugar. Smokers should be encouraged to stop smoking and should be provided with pharmaceutical and emotional support by their physicians. All of these patients should have their body mass index as close to normal as possible and be on a therapeutic lifestyle diet. Regular aerobic exercise is also indicated. Patients with symptomatic claudication should be considered for cilostazol. Patients with multiple risk factors for vascular disease, but who do not have documented disease should also be on statin therapy. As more studies define the linear relationship between lower LDL-C levels and lowered risk of vascular events, indicating that the lower the LDL-C level, the lower the risk, experts are advocating more aggressive lipid-lowering therapy. In patients with peripheral arterial disease, some experts now advocate lowering the goal of LDL therapy to 70 mg/dL.

Thrombospondin-1 limits ischemic tissue survival by inhibiting nitric oxide-mediated vascular smooth muscle relaxation

The nitric oxide (NO)/cGMP pathway, by relaxing vascular smooth muscle cells, is a major physiologic regulator of tissue perfusion. We now identify thrombospondin-1 as a potent antagonist of NO for regulating F-actin assembly and myosin light chain phosphorylation in vascular smooth muscle cells. Thrombospondin-1 prevents NO-mediated relaxation of precontracted vascular smooth muscle cells in a collagen matrix. Functional magnetic resonance imaging demonstrated that an NO-mediated increase in skeletal muscle perfusion was enhanced in thrombospondin-1-null relative to wild-type mice, implicating endogenous thrombospondin-1 as a physiologic antagonist of NO-mediated vasodilation. Using a random myocutaneous flap model for ischemic injury, tissue survival was significantly enhanced in thrombospondin-1-null mice. Improved flap survival correlated with increased recovery of oxygen levels in the ischemic tissue of thrombospondin-1-null mice as measured by electron paramagnetic resonance oximetry. These findings demonstrate an important antagonistic relation between NO/cGMP signaling and thrombospondin-1 in vascular smooth muscle cells to regulate vascular tone and tissue perfusion.

Protein kinase C beta/early growth response-1 pathway: a key player in ischemia, atherosclerosis, and restenosis

Atherosclerosis, restenosis, and the consequences of ischemia are the major causes of morbidity and mortality worldwide. Elucidation of key contributing pathways in animal models of ischemia-reperfusion injury, atherosclerosis, and restenosis consequent to vascular injury may lead to great interest in determining if blocking these pathways could prevent vascular disease in human subjects. This review details the evidence that the protein kinase C (PKC) beta/early growth response-1 axis plays a central role in the response to both acute and chronic vascular stresses in animal models and also indicates the clinical implications of a specific inhibitor of PKCbeta, ruboxistaurin (LY333531).

Statins and Peripheral Arterial Disease: Potential Mechanisms and Clinical Benefits

Peripheral arterial disease (PAD) is a manifestation of widespread atherosclerosis. Lipid modification (especially with statins) is a component of the treatment of patients with PAD since this condition is considered a coronary heart disease equivalent. This review considers the mechanism of action of statins in PAD. Statins have been shown to reduce the incidence of new coronary events in patients with PAD. However, surveys suggest that many such patients remain undertreated. Statins can also increase walking distance in patients with PAD. There is also evidence that statins can improve renal function in these patients. Several other actions of statins are considered in this review. PAD patients have an increased morbidity and mortality, largely due to myocardial infarction and stroke. Recognizing and treating these high-risk patients as early as possible should be a priority.

Drug treatment of peripheral arterial disease in the elderly

Peripheral arterial disease (PAD) may be asymptomatic, may be associated with intermittent claudication or may be associated with critical limb ischaemia. Coronary artery disease (CAD) and other atherosclerotic vascular disorders may coexist with PAD. Persons with PAD are at increased risk for all-cause mortality, cardiovascular mortality and mortality from CAD. Smoking should be stopped and hypertension, diabetes mellitus, dyslipidaemia and hypothyroidism treated. HMG-CoA reductase inhibitors (statins) reduce the incidence of intermittent claudication and improve exercise duration until the onset of intermittent claudication in persons with PAD and hypercholesterolaemia. Antiplatelet drugs such as aspirin or clopidogrel (especially the latter), ACE inhibitors and statins should be given to all persons with PAD. beta-Adrenoceptor antagonists should be given if CAD is present. The phosphodiesterase type 3 inhibitor cilostazol improves exercise time until intermittent claudication. Chelation therapy should be avoided. Correct implementation of medical therapy significantly reduces the excess mortality associated with PAD. In addition, medical therapy may result in significant improvements in walking ability that may obviate the need for lower extremity angioplasty with stenting and bypass surgery.

Therapeutic effects of concurrent autologous bone marrow cell infusion and metabolic intervention in ischemia-induced angiogenesis in the hypercholesterolemic mouse hindlimb

Lower-limb ischemia is a major health problem especially when associated to hypercholesterolemia. Because of the absence of effective treatment in the advanced stages of the disease, amputation is undertaken to alleviate unbearable symptoms. Since tissue ischemia and hypercholesterolemia are associated with an overwhelming generation of oxygen radicals, metabolic intervention with antioxidants and l-arginine can induce beneficial effects beyond those achieved by a novel therapeutic approach represented by the use of autologous bone marrow cells (BMCs). The protective effect of BMCs and vascular protection by metabolic cotreatment (1.0% vitamin E added to the chow, 0.05% vitamin C and 6% l-arginine added to the drinking water) were examined in ischemia-induced angiogenesis in the hypercholesterolemic mouse hindlimb. Intravenous BMC therapy improved blood flow and increased capillary densities. This beneficial effect was amplified by metabolic cotreatment, an intervention inducing vascular protection, at least in part, through the nitric oxide pathway, reduction of systemic oxidative stress and macrophage activation.

Beneficial effects of concurrent autologous bone marrow cell therapy and metabolic intervention in ischemia-induced angiogenesis in the mouse hindlimb

Lower-limb ischemia is a major health problem. Because of the absence of effective treatment in the advanced stages of the disease, amputation is undertaken to alleviate unbearable symptoms. Novel therapeutic approaches include the intramuscular use of autologous bone marrow cells (BMCs). Because tissue ischemia is associated with an overwhelming generation of oxygen radicals and negative effects due to perturbed shear-stress, metabolic intervention with antioxidants and l-arginine could potentially induce beneficial effects beyond those achieved by BMCs. The protective effect of autologous BMCs and vascular protection by metabolic cotreatment (1.0% vitamin E added to the chow and 0.05% vitamin C and 6% l-arginine added to the drinking water) were examined in ischemia-induced angiogenesis in the mouse hindlimb, a model of extensive acute peripheral arterial occlusion. i.v. BMC therapy improved blood flow and increased capillary densities and expression of Ki-67, a proliferation-associated protein. This beneficial effect was amplified by metabolic cotreatment, an intervention inducing vascular protection, at least in part, through the nitric oxide pathway, reduction of systemic oxidative stress, and macrophage activation. Therefore, although a cautious approach is mandatory when experimental findings are extended to human diseases, autologous BMCs together with metabolic intervention could be an effective clinical treatment for peripheral arterial disease.

Treatment for diabetic foot ulcers

People with diabetes develop foot ulcers because of neuropathy (sensory, motor, and autonomic deficits), ischaemia, or both. The initiating injury may be from acute mechanical or thermal trauma or from repetitively or continuously applied mechanical stress. Patients with clinically significant limb ischaemia should be assessed by a vascular surgeon to determine the need for angioplasty, stenting, or femorodistal bypass. When infection complicates a foot ulcer, the combination can be limb or life-threatening. Infection is defined clinically, but wound cultures reveal the causative pathogens. Tissue specimens are strongly preferred to wound swabs for wound cultures. Antimicrobial therapy should be guided by culture results, and should aim to cure the infection, not to heal the wound. Alleviation of the mechanical load on ulcers (off-loading) should always be a part of treatment. Neuropathic ulcers typically heal in 6 weeks with total contact casting, because it effectively relieves pressure at the ulcer site and enforces patient compliance. The success of other approaches to off-loading similarly depends on the patients' adherence to the effectiveness of pressure relief. Surgery to heal ulcers and prevent recurrence can include tenotomy, tendon lengthening, reconstruction, or removal of bony prominences. However, these procedures may result in secondary ulceration and other complications. Ulcer recurrence rates are high, but appropriate education for patients, the provision of posthealing footwear, and regular foot care can reduce rates of re-ulceration.