The Prevalence of Chronic Critical Lower Limb Ischaemia in a Population of 20,000 Subjects 40–69 Years of Age

The Impact of Diabetes in Intermittent Claudication: A Prospective Cohort Study

The aim of this study was to determine the lower-limb outcome in patients with intermittent claudication (IC) and to identify predictors for deterioration. This study employed a prospective observational cohort single-centre design. One hundred fifty patients with IC attending a vascular surgery unit for the first time were recruited. Lower limb perfusion was assessed utilising ankle brachial index (ABI) measures, toe-brachial index (TBI) measures, Doppler waveform analysis and the walking impairment questionnaire. Follow-up was conducted after 1 year and 2 years following recruitment to assess haemodynamic parameters, symptom severity and outcome. Recruited participants had a mean age of 69.7 (±9.3) years, BMI 27.8(±4.2) and 79.3% were men. Significant haemodynamic decline (decline in ABPI by ≥0.15 and/or decline in TBPI by ≥0.1) occurred in 50.6% of the cohort within 2 years of whom 23.3% developed chronic limb threatening ischaemia (CLTI) with rest pain and/or tissue loss. Baseline ABPI, ABPI ≤ 0.5, TBPI ≤ 0.39, infrapopliteal artery (IPA) disease and high Haemoglobin A1c were identified as significant predictors for deterioration to CLI. (P < .05, binomial logistic regression). Patients with IC are at a high risk of developing CLTI within 2 years. Risk of lower limb adverse events is tripled in patients with IPA disease, low ankle and toe pressures and poorly controlled diabetes. Early identification of those at high risk for early deterioration may justify a paradigm shift in the management of this subgroup.

Patient and clinician experiences and opinions of the use of a novel home use medical device in the treatment of peripheral vascular disease - a qualitative study

BACKGROUND

Peripheral vascular diseases have a significant impact on functional quality of life. Previous research has demonstrated the complex, limiting and costly economic implications of these conditions such as lower limb ulceration chronicity and ischaemic amputation. These complex, limb and life threatening conditions demand the development of novel interventions with objective research as part of that development. Hence, a novel intermittent negative pressure medical device in the form of a wearable boot (FlowOx™) was developed. As part of the development process, this study aimed to explore patient and clinician opinions of the boot.

METHODS

A qualitative approach was used to collect patient and clinician experiences in Norway. An advisory group informed the semi-structured questions used in seven patient interviews and one clinician focus group (n = 5). The data were recorded digitally and transcribed verbatim. Patient and clinician data were analysed as distinct groups using a thematic process.

RESULTS

Data analysis resulted in five themes from the patients which gave insight into; the impact of the disease process; practicalities of using the boot, positive experiences of use; perceived outcomes; reflecting on use. Six themes were created from the clinicians. These gave insight into; ideal outcomes and how to measure them; ways to potentially use the boot; using research in healthcare; positives of the device; observed effects and next steps; potential improvements to the device.

CONCLUSION

This study provides insight into the experiences and opinions of FlowOx™. Patients and clinicians were positive about the device due to its ease of use. Those patients with peripheral arterial disease experienced significantly more benefit, especially for ischaemic ulceration than those with a chronic venous condition. Clinicians placed value on the patient reported outcomes in the treatment decision-making process. This preliminary study into experiences of FlowOx™ use provides valuable feedback that will inform design modification and ongoing research into implementation points and prospective user groups. FlowOx™ demonstrates potential as a conservative therapy offering users a convenient, home use, self-care management solution for improving symptomatic peripheral arterial disease and quality of life.

Local intramuscular administration of ANG1 and VEGF genes using plasmid vectors mobilizes CD34+ cells to peripheral tissues and promotes angiogenesis in an animal model

INTRODUCTION

Patients with peripheral artery disease have poor prognosis despite advances in vascular surgery. Therefore, attempts have been made at using gene and cell therapy to stimulate angiogenesis in the lower limbs in patients with critical lower limb ischemia (CLI).

METHODS

The study included 30 rats divided into 3 groups. An intramuscular injection of a therapeutic gene or cells in the right hind limb was administered in each group: angiopoietin-1 (ANG1) plasmid in group 1, ANG1/vascular endothelial growth factor (ANG1/VEGF) bicistronic construct in group 2, and naked plasmid in group 3 (control). After 3 months of follow-up, tissue samples were harvested, and vessels that stained positively for CD34 cells were quantified.

RESULTS

The highest CD34+ cell count was noted in the ANG1/VEGF group (98.26 cells), followed by the ANG1 group (80.31) and control group (47.93). The CD34+ cell count was significantly higher in the ANG1/VEGF and ANG1 groups than in the control group. There was no significant difference in the CD34+ cell count between the ANG1/VEGF and ANG1 groups.

CONCLUSION

Our study confirmed that therapy with ANG1 plasmid alone or ANG1/VEGF bicistronic construct is safe and effective in a rat model. The therapy resulted in the recruitment of more CD34+ vascular endothelial cells than in the control group receiving naked plasmid.

Multiple Reinterventions for Claudication are Associated with Progression to Chronic Limb-Threatening Ischemia

BACKGROUND

Claudication has a relatively benign natural history, associated with a low risk of limb loss. However, rates of progression to chronic limb-threatening ischemia (CLTI) following lower extremity revascularization (LER) for claudication remain unclear. This study examines the long-term outcomes and risk factors associated with progression to CLTI after LER for claudication.

METHODS

A single-center retrospective review of patients undergoing LER for claudication was performed from 2013-2016. Patients were stratified based on whether they progressed to CLTI or not.

RESULTS

There were 448 patients (502 limbs) treated for claudication, and 57 (12.7%) progressed to CLTI with a mean follow up time of 3.7 ± 1.5 years. Among patients who progressed, 23 (5.1%) developed tissue loss, 34 (7.6%) developed rest pain, and 6 (1.2%) underwent major amputation. The mean time of progression to CLTI was 1.6 ± 1.5 years after index LER. Patients who progressed to CLTI were more likely to have a history of congestive heart failure and prior open revascularizations compared with those who did not progress. There was no difference in type or level of index revascularization between the two groups and no difference in perioperative complications. Patients who developed CLTI had significantly higher rates of reinterventions and a mean number of reinterventions after index LER prior to developing CLTI compared to those who did not progress. Multivariable logistic regression demonstrated that history of congestive heart failure (OR = 2.8 [1.2-6.6]), stroke (OR = 2.6 [1.1-6.1]), prior open procedure (OR = 2.8 [1.3-5.9]) and increasing number of reinterventions after index LER (OR = 2.9 [1.5-5.7]) were independently associated with disease progression to CLTI.

CONCLUSIONS

Multiple reinterventions and previous open revascularization are associated with progression to CLTI following LER for claudication. Patients with atherosclerosis in the coronary and cerebrovascular beds are also more likely to have a progression of claudication to CLTI after LER.

Efficacy of nonviral gene transfer of human hepatocyte growth factor (HGF) against ischemic-reperfusion nerve injury in rats

Ischemic neuropathy is common in subjects with critical limb ischemia, frequently causing chronic neuropathic pain. However, neuropathic pain caused by ischemia is hard to control despite the restoration of an adequate blood flow. Here, we used a rat model of ischemic-reperfusion nerve injury (IRI) to investigate possible effects of hepatocyte growth factor (HGF) against ischemic neuropathy. Hemagglutinating virus of Japan (HVJ) liposomes containing plasmids encoded with HGF was delivered into the peripheral nervous system by retrograde axonal transport following its repeated injections into the tibialis anterior muscle in the right hindlimb. First HGF gene transfer was done immediately after IRI, and repeated at 1, 2 and 3 weeks later. Rats with IRI exhibited pronounced mechanical allodynia and thermal hyperalgesia, decreased blood flow and skin temperature, and lowered thresholds of plantar stimuli in the hind paw. These were all significantly improved by HGF gene transfer, as also were sciatic nerve conduction velocity and muscle action potential amplitudes. Histologically, HGF gene transfer resulted in a significant increase of endoneurial microvessels in sciatic and tibial nerves and promoted nerve regeneration which were confirmed by morphometric analysis. Neovascularization was observed in the contralateral side of peripheral nerves as well. In addition, IRI elevated mRNA levels of P2X3 and P2Y1 receptors, and transient receptor potential vanilloid receptor subtype 1 (TRPV1) in sciatic nerves, dorsal root ganglia and spinal cord, and these elevated levels were inhibited by HGF gene transfer. In conclusion, HGF gene transfer is a potent candidate for treatment of acute ischemic neuropathy caused by reperfusion injury, because of robust angiogenesis and enhanced nerve regeneration.

Fascia Iliaca Block as an Anesthetic Technique for: Acute Lower Limb Ischemia

Purpose

The purpose of this study is to evaluate the efficacy of preoperative fascia iliaca block (FIB) as a sole anesthetic technique in transfemoral thromboembolectomy of unilateral acute lower limb ischemia compared to unilateral spinal anesthesia (SA) as a primary outcome. Hemodynamic variation, postoperative pain score, and the first demand for analgesia with the total postoperative analgesic required in the 1^st postoperative day were considered as the secondary outcome.

Patients and Methods

This prospective randomized controlled study included two groups of patients aged between 40 and 70 years, who underwent transfemoral thrombectomy for acute unilateral lower limb ischemia. Patients in the spinal group (SA) (n = 56): underwent unilateral SA using 10 mg bupivacaine 0.5% and patients in the group FIB (n = 56): received FIB with 30 mL of 0.25% bupivacaine. Sensory block was evaluated over the incisional area with 3-point scale. If the sensory block did not reach zero grade after 30 min, the patient received general anesthesia.

Results

The incidence of the successful block was 100% in the SA group compared to 80.35% in the FIB group. There was a significant decrease in recorded heart rate and mean blood pressure within the SA group at 3, 10, and 20 min and 3, 20, and 45 min, respectively. Values of visual analog scale decreased significantly in SA group compared to that of the FIB group immediately and 1 h postoperative. However, the time for the first postoperative analgesic requirement and morphine consumption was comparable between the groups.

Conclusion

Preoperative FIB could be considered as a promising alternative anesthetic technique to SA with better hemodynamic parameters in patients undergoing transfemoral thrombectomy for acute lower limb ischemia. It could be also due to limited precautions considered the first choice over SA for patients on perioperative anticoagulants.

Pain management in patients with vascular disease

Vascular disease covers a wide range of conditions, including arterial, venous, and lymphatic disorders, with many of these being more common in the elderly. As the population ages, the incidence of vascular disease will increase, with a consequent increase in the requirement to manage both acute and chronic pain in this patient population. Pain management can be complex, as there are often multiple co-morbidities to be considered. An understanding of the underlying pain mechanisms is helpful in the logical direction of treatment, particularly in chronic pain states, such as phantom limb pain or complex regional pain syndrome. Acute pain management for vascular surgery presents a number of challenges, including coexisting anticoagulant medication, that may preclude the use of regional techniques. Within the limited evidence base, there is a suggestion that epidural analgesia provides better pain relief and reduced respiratory complications after major vascular surgery. For carotid endarterectomy, there is again some evidence supporting the use of local anaesthetic analgesia, either by infiltration or by superficial cervical plexus block. Chronic pain in vascular disease includes post-amputation pain, for which well-known risk factors include high pain levels before amputation and in the immediate postoperative period, emphasizing the importance of good pain control in the perioperative period. Complex regional pain syndrome is another challenging chronic pain syndrome with a wide variety of treatment options available, with the strongest evidence being for physical therapies. Further research is required to gain a better understanding of the underlying pathophysiological mechanisms in pain associated with vascular disease and the best analgesic approaches to manage it.

Current accepted hemodynamic criteria for critical limb ischemia do not accurately stratify patients at high risk for limb loss

OBJECTIVE

Critical limb ischemia (CLI) has been defined as rest pain or tissue loss in patients who have an ankle-brachial index (ABI) ≤0.50, ankle pressure (AP) <70 mm Hg, or toe pressure (TP) <50 mm Hg. Data suggesting that these patients are at high risk for limb loss without successful revascularization are limited. This study was designed to identify limb loss and mortality rates in patients who did not respond to revascularization or who were not revascularized to determine whether CLI hemodynamic criteria accurately identify patients at high risk for limb loss.

METHODS

Between 2008 and 2010, all patients undergoing lower extremity arterial duplex ultrasound testing at our hospital were identified. Those with ABI <0.50, AP <70 mm Hg, or TP <50 mm Hg were retrospectively reviewed to determine whether they had symptoms of rest pain, ischemic ulceration, or gangrene qualifying them for analysis in the database. Patients who underwent revascularization and subsequently had postrevascularization ABI, AP, or TP greater than the CLI criteria were removed from the cohort. Demographic factors, wound healing, amputation rates, and mortality were obtained and analyzed in relation to the initial APs and TPs. Outcomes were measured by Kaplan-Meier life-table analysis and Cox proportional hazards models.

RESULTS

In 381 patients identified in the study, 443 limbs met CLI criteria. After revascularization, 98 limbs with ABI or TP that improved to >0.5 and >50 mm Hg, respectively, were removed from the study cohort. In 45 limbs, patients did not respond to initial revascularization as their ABI, AP, or TP remained within CLI criteria. These limbs remained in the patient cohort, yielding a final group of 296 patients and 345 limbs. Mean follow-up was 2 years. In the entire patient cohort, limb loss occurred in 24% at 1 year and in 31% at 3 years. Mortality was 32% at 1 year and 56% at 3 years. Amputation-free survival was 54% at 1 year and 28% at 3 years. Lower TPs were associated with a statistically higher incidence of amputation. Among those with an initial TP ≤10 mm Hg (n = 85), limb loss occurred in 46% at 1 year and 60% at 3 years. This limb loss was significantly greater than limb loss among those with a TP of 31 to 50 mm Hg (n = 115; 18% at 3 years; P < .001) Amputation-free survival in patients with a TP ≤10 mm Hg was 8% at 3 years.

CONCLUSIONS

CLI is associated with a high mortality, but not all patients with currently defined hemodynamic criteria for CLI are at high risk of limb loss. Patients with a TP between 31 and 50 mm Hg (41% of the cohort) and not receiving revascularization or not responding hemodynamically to revascularization experienced a low risk of limb loss. We recommend revising the hemodynamic criteria for CLI to better identify patients at high risk for limb loss who require intervention to improve outcomes.

Outcomes of infrainguinal bypass determined by age in the Vascular Study Group of New England

BACKGROUND

Many believe extremes of age correlate with poorer outcomes in treatment for lower extremity peripheral arterial disease (PAD). We hypothesized that the youngest patients would have significantly poorer outcomes compared with older cohorts due to the precocious nature of their PAD.

METHODS

We studied all patients in the Vascular Study Group of New England database undergoing infrainguinal bypass for PAD between 2003 and 2013. Age was grouped by <50 years, 50 to 79 years, and ≥80 years. Our primary outcomes were 1-year freedom from a major adverse limb event (MALE), defined as ipsilateral amputation or need for secondary intervention, and amputation-free survival. A second analysis was performed to analyze the subgroup of patients aged <50 years with critical limb ischemia (CLI), which included a Cox regression model to determine risk factors for MALE or death at 1 year.

RESULTS

Of 5265 patients who were treated with infrainguinal bypass for PAD, 324 (6.2%) were aged <50 years. The mean age was 44.6 years, and 66.4% were male. The proportion of African Americans was significantly higher in the youngest age group (<50 years: 6.8% vs 50-79 years: 3.5%, P = .002; vs ≥80 years: 3.5%, P = .013). More bypasses were done for claudication than acute limb ischemia in patients aged <50 years (33.3% vs 11.4%). More vein grafts were used vs prosthetic (<50 years: 72.1% vs 50-79 years: 65.9%, P = .024; vs ≥80 years: 62.6%, P = .002). Fewer concomitant proximal procedures were performed compared with the older groups (<50 years: 37.7% vs 50-79 years: 51.1%, P < .001; vs ≥80 years: 39.5%, P = .045). More young patients returned to the operating room within their initial hospitalization for early graft thrombosis (<50 years: 5.6% vs 50-79 years: 2.9%, P = .001; vs ≥80 years: 2.4%, P = .009) and revision (<50 years: 4.7% vs 50-79 years: 2.2%, P = .012; vs ≥80 years: 1.4%, P = .002) compared with the older patients. Overall, MALE-free survival was similar across age groups (P = .323), as were patency and amputation rates. When considering only patients with CLI, MALE-free survival in the youngest patients was again similar (P = .171) but with significantly more major amputations at 1 year (P = .022).

CONCLUSIONS

For patients aged <50 undergoing infrainguinal bypass surgery, this large series demonstrates similar overall medium-term graft-related outcomes compared with older cohorts. Further, although the youngest patients with CLI have similar MALEs, their amputation rates are higher than in older cohorts.

Validation of the Guy's scoring system in patient selection for femoro-distal bypass grafting to a single calf or pedal artery

OBJECTIVES

First external validation of a preoperative scoring system (Guy's) in patient selection for femoro-distal bypass grafting to single calf or pedal artery in critical limb ischemia (Fontaine III & IV/Rutherford grade IV, V & VI).

MATERIAL AND METHODS

A prospective study of 76 (n = 76) consecutive femoro-crural/pedal bypass grafts on 72 individuals (n = 72) from 2008 to 2011 with 36 months mean follow-up was performed. All cases were scored against a previously designed and published scoring system (ranging from 0 to 10) based on: inflow, outflow, graft material, flow type, patent pedal vessels and diabetes mellitus.

RESULTS

Preoperative score of 0-4 (n = 37) demonstrated the primary patency of 27% at 10.3 months. This value for intermediate group 5-7 (n = 34) was 70.6% at 18.9 months. The high-score group 8-10 (n = 4) showed the longest primary patency (80%) at 27.3 months. Kaplan-Meier survival analysis exhibited a consistent and significant difference in primary assisted, secondary patency and overall limb/foot salvage amongst all individual scoring groups (p < 0.001).

CONCLUSION

This study validates and complements the Guy's scoring system and provides a platform for the identification of critical limb ischemia patients in whom the result of femoro-crural/distal bypass grafting is so poor that primary amputation may be both clinically and economically more justified.

Hydrogen Sulfide Levels and Nuclear Factor-Erythroid 2-Related Factor 2 (NRF2) Activity Are Attenuated in the Setting of Critical Limb Ischemia (CLI)

Background

Cystathionine γ-lyase, cystathionine β-synthase, and 3-mercaptopyruvate sulfurtransferase are endogenous enzymatic sources of hydrogen sulfide (H₂S). Functions of H₂S are mediated by several targets including ion channels and signaling proteins. Nuclear factor-erythroid 2-related factor 2 is responsible for the expression of antioxidant response element–regulated genes and is known to be upregulated by H₂S. We examined the levels of H₂S, H₂S-producing enzymes, and nuclear factor-erythroid 2-related factor 2 activation status in skeletal muscle obtained from critical limb ischemia (CLI) patients.

Methods and Results

Gastrocnemius tissues were attained postamputation from human CLI and healthy control patients. We found mRNA and protein levels of cystathionine γ-lyase, cystathionine β-synthase, and 3-mercaptopyruvate sulfurtransferase were significantly decreased in skeletal muscle of CLI patients as compared to control. H₂S and sulfane sulfur levels were significantly decreased in skeletal muscle of CLI patients. We also observed significant reductions in nuclear factor-erythroid 2-related factor 2 activation as well as antioxidant proteins, such as Cu, Zn-superoxide dismutase, catalase, and glutathione peroxidase in skeletal muscle of CLI patients. Biomarkers of oxidative stress, such as malondialdehyde and protein carbonyl formation, were significantly increased in skeletal muscle of CLI patients as compared to healthy controls.

Conclusions

The data demonstrate that H₂S bioavailability and nuclear factor-erythroid 2-related factor 2 activation are both attenuated in CLI tissues concomitant with significantly increased oxidative stress. Reductions in the activity of H₂S-producing enzymes may contribute to the pathogenesis of CLI.

Reduced intraepidermal nerve fiber density in patients with chronic ischemic pain in peripheral arterial disease

Chronic ischemic pain in peripheral arterial disease (PAD) is a leading cause of pain in the lower extremities. A neuropathic component of chronic ischemic pain has been shown independent of coexisting diabetes. We aimed to identify a morphological correlate potentially associated with pain and sensory deficits in PAD. Forty patients with symptomatic PAD (Fontaine stages II-IV), 20 with intermittent claudication (CI), and 20 with critical limb ischemia (CLI) were enrolled; 12 volunteers served as healthy controls. All patients were examined using pain scales and questionnaires. All study participants underwent quantitative sensory testing (QST) at the distal calf and skin punch biopsy at the distal leg for determination of intraepidermal nerve fiber density (IENFD). Additionally, S100 beta serum levels were measured as a potential marker for ischemic nerve damage. Neuropathic pain questionnaires revealed slightly higher scores and more pronounced pain-induced disability in CLI patients compared to CI patients. QST showed elevated thermal and mechanical detection pain thresholds as well as dynamic mechanical allodynia, particularly in patients with advanced disease. IENFD was reduced in PAD compared to controls (P<0.05), more pronounced in the CLI subgroup (CLI: 1.3 ± 0.5 fibers/mm, CI: 2.9 ± 0.5 fibers/mm, controls: 5.3 ± 0.6 fibers/mm). In particular, increased mechanical and heat pain thresholds negatively correlated with lower IENFD. Mean S100 beta levels were in the normal range but were higher in advanced disease. Patients with chronic ischemic pain had a reduced IENFD associated with impaired sensory functions. These findings support the concept of a neuropathic component in ischemic pain.

Critical and acute limb ischemia: an overview

Some patients with peripheral arterial disease may present with critical limb ischemia, a condition associated with high rates of morbidity and mortality. Early diagnosis and effective medical therapy and revascularization are indicated to avoid amputation and reduce mortality. Ideally, a multidisciplinary approach with collaboration between endovascular interventionist, vascular surgeons, podiatrist, infectious disease, and wound care specialist is recommended for these patients.

Autonomy following revascularisation in 80-year-old patients with critical limb ischaemia

OBJECTIVES

We wanted to compare autonomy recovery after open and endovascular infrainguinal surgery for critical limb ischaemia (CLI) in octogenarians.

MATERIALS AND METHODS

We performed a retrospective analysis of 167 consecutive CLI octogenarians who underwent infrainguinal open surgery (OS) or endovascular surgery (ES) between 2003 and 2008. OS and ES groups were compared in terms of autonomy level (Parker score), survival, limb salvage and patency rates.

RESULTS

Preoperative autonomy level was similar in both groups (OS n = 109, ES n = 58) but 6-month postoperative autonomy level was better after ES (p = 0.01). There was a trend towards better survival after OS (74% at 1 year, 62% at 2 years, 32% at 4 years with OS and 68%, 50%, 17% respectively for ES p = 0.06), but no difference regarding limb salvage (91% at 1 year, 90% at 2 years, 89% at 4 years for OS and 94%, 87%, 86% respectively for ES, p = 0.939) and primary patency (76% at 1 year, 59% at 2 years, 50% at 4 years for OS and 82%, 75%, 32% respectively for ES, p = 0.467).

CONCLUSIONS

ES is justified in CLI octogenarians, because it allows restoring a higher autonomy level, with limb salvage and patency rates comparable to OS.

Chapter I: Definitions, epidemiology, clinical presentation and prognosis

The concept of chronic critical limb ischaemia (CLI) emerged late in the history of peripheral arterial occlusive disease (PAOD). The historical background and changing definitions of CLI over the last decades are important to know in order to understand why epidemiologic data are so difficult to compare between articles and over time. The prevalence of CLI is probably very high and largely underestimated, and significant differences exist between population studies and clinical series. The extremely high costs associated with management of these patients make CLI a real public health issue for the future. In the era of emerging vascular surgery in the 1950s, the initial classification of PAOD by Fontaine, with stages III and IV corresponding to CLI, was based only on clinical symptoms. Later, with increasing access to non-invasive haemodynamic measurements (ankle pressure, toe pressure), the need to prove a causal relationship between PAOD and clinical findings suggestive of CLI became a real concern, and the Rutherford classification published in 1986 included objective haemodynamic criteria. The first consensus document on CLI was published in 1991 and included clinical criteria associated with ankle and toe pressure and transcutaneous oxygen pressure (TcPO(2)) cut-off levels <50 mmHg, <30 mmHg and <10 mmHg respectively). This rigorous definition reflects an arterial insufficiency that is so severe as to cause microcirculatory changes and compromise tissue integrity, with a high rate of major amputation and mortality. The TASC I consensus document published in 2000 used less severe pressure cut-offs (≤ 50-70 mmHg, ≤ 30-50 mmHg and ≤ 30-50 mmHg respectively). The thresholds for toe pressure and especially TcPO(2) (which will be also included in TASC II consensus document) are however just below the lower limit of normality. It is therefore easy to infer that patients qualifying as CLI based on TASC criteria can suffer from far less severe disease than those qualifying as CLI in the initial 1991 consensus document. Furthermore, inclusion criteria of many recent interventional studies have even shifted further from the efforts of definition standardisation with objective criteria, by including patients as CLI based merely on Fontaine classification (stage III and IV) without haemodynamic criteria. The differences in the natural history of patients with CLI, including prognosis of the limb and the patient, are thus difficult to compare between studies in this context. Overall, CLI as defined by clinical and haemodynamic criteria remains a severe condition with poor prognosis, high medical costs and a major impact in terms of public health and patients' loss of functional capacity. The major progresses in best medical therapy of arterial disease and revascularisation procedures will certainly improve the outcome of CLI patients. In the future, an effort to apply a standardised definition with clinical and objective haemodynamic criteria will be needed to better demonstrate and compare the advances in management of these patients.

Spinal cord stimulation for patients with inoperable chronic critical leg ischemia

BACKGROUND

Because of the prevalence of diabetes, the treatment of diabetic foot is still challenging. Even an exactly proved effective and practical method can't be listed except vascular surgery which is not a long-term way for it. Spinal cord stimulation (SCS) is a very promising option in the treatment algorithm of inoperable chronic critical leg ischemia (CLI).

DATA SOURCES

We searched Pubmed database with key words or terms such as "spinal cord stimulation", "ischemic pain" and "limb ischemia" appeared in the last five years.

RESULTS

The mechanism of SCS is unclear. Two theories have emerged to interpret the benefits of SCS. Pain relief from SCS can be confirmed by a majority of the studies, while limb salvage and other more ambitious improvements have not come to an agreement. The complications of SCS are not fatal, but most of them are lead migration, lead connection failure, and local infection.

CONCLUSIONS

SCS is a safe, promising treatment for patients with inoperable CLI. It is effective in pain reduction compared with traditional medical treatment.

Spinal cord stimulation: Current applications for treatment of chronic pain

Spinal cord stimulation (SCS) is thought to relieve chronic intractable pain by stimulating nerve fibers in the spinal cord. The resulting impulses in the fibers may inhibit the conduction of pain signals to the brain, according to the pain gate theory proposed by Melzack and Wall in 1965 and the sensation of pain is thus blocked. Although SCS may reduce pain, it will not eliminate it. After a period of concern about safety and efficacy, SCS is now regaining popularity among pain specialists for the treatment of chronic pain. The sympatholytic effect of SCS is one of its most interesting therapeutic properties. This effect is considered responsible for the effectiveness of SCS in peripheral ischemia, and at least some cases of complex regional pain syndrome. The sympatholytic effect has also been considered part of the management of other chronic pain states such as failed back surgery syndrome, phantom pain, diabetic neuropathy, and postherpetic neuralgia. In general, SCS is part of an overall treatment strategy and is used only after the more conservative treatments have failed. The concept of SCS has evolved rapidly following the technological advances that have produced leads with multiple contact electrodes and battery systems. The current prevalence of patients with chronic pain requiring treatment other than conventional medical management has significantly increased and so has been the need for SCS. With the cost benefit analysis showing significant support for SCS, it may be appropriate to offer this as an effective alternative treatment for these patients.

Plasma concentrations of Gas6 and soluble Axl correlate with disease and predict mortality in patients with critical limb ischemia

INTRODUCTION

Critical limb ischemia (CLI) is a severe peripheral arterial disease, characterized by rest pain, ulcers and gangrene in the legs. Gas6 is a vitamin K-dependent protein, which binds and activates the tyrosine kinase receptor Axl. Gas6-mediated Axl-signaling influences endothelial activation, neointima formation and immune regulation. Axl can be cleaved and soluble Axl (sAxl) is detectable in circulation.

DESIGN AND METHODS

We quantified plasma concentrations of Gas6 and sAxl in 189 CLI patients and 204 controls.

RESULTS

Gas6 and sAxl concentrations were increased in the CLI patients (p<0.0001) and correlated to C-reactive protein, interleukin-6, tumor necrosis factor alpha and neopterin. Patients who died within 3years of sampling (n=84) had increased concentrations of Gas6 and sAxl as compared to survivors (p=0.0009 and p=0.0011).

CONCLUSIONS

Plasma concentrations of Gas6 and sAxl correlate to inflammation and predict survival. This indicates that Gas6 and sAxl have a role in CLI, presumably connected to the inflammatory process.

Nonoperative active management of critical limb ischemia: initial experience using a sequential compression biomechanical device for limb salvage

Critical limb ischemia (CLI) patients are at high risk of primary amputation. Using a sequential compression biomechanical device (SCBD) represents a nonoperative option in threatened limbs. We aimed to determine the outcome of using SCBD in amputation-bound nonreconstructable CLI patients regarding limb salvage and 90-day mortality. Thirty-five patients with 39 critically ischemic limbs (rest pain = 12, tissue loss = 27) presented over 24 months. Thirty patients had nonreconstructable arterial outflow vessels, and five were inoperable owing to severe comorbidity scores. All were Rutherford classification 4 or 5 with multilevel disease. All underwent a 12-week treatment protocol and received the best medical treatment. The mean follow-up was 10 months (SD +/- 6 months). There were four amputations, with an 18-month cumulative limb salvage rate of 88% (standard error [SE] +/- 7.62%). Ninety-day mortality was zero. Mean toe pressures increased from 38.2 to 67 mm Hg (SD +/- 33.7, 95% confidence interval [CI] 55-79). Popliteal artery flow velocity increased from 45 to 47.9 cm/s (95% CI 35.9-59.7). Cumulative survival at 12 months was 81.2% (SE +/- 11.1) for SCBD, compared with 69.2% in the control group (SE +/- 12.8%) (p = .4, hazards ratio = 0.58, 95% CI 0.15-2.32). The mean total cost of primary amputation per patient is euro29,815 ($44,000) in comparison with euro13,900 ($20,515) for SCBD patients. SCBD enhances limb salvage and reduces length of hospital stay, nonoperatively, in patients with nonreconstructable vessels.

Risk factor profiles and use of cardiovascular drug prevention in women and men with peripheral arterial disease

OBJECTIVE

To determine cardiovascular comorbidities and use of cardiovascular disease preventive drugs in patients with peripheral arterial disease (PAD), with special attention to sex differences.

DESIGN

A cross-sectional point-prevalence study.

PATIENTS

A population sample of patients that are 60-90 years old.

SETTING

Primary care areas in four Swedish regions.

MAIN OUTCOME MEASURES

Prevalence of PAD stages, comorbidities and medication use.

RESULTS

The prevalence of any type of PAD was 18.0% (range 16-20), of asymptomatic peripheral arterial disease (APAD) was 11.1% (range 9-13), intermittent claudication was 6.8% (range 6.5-7.1), and of critical limb ischemia (CLI) was 1.2% (range 1.0-1.5). APAD and CLI were more common in women. Statins were used by 17.5% (range 16.9-18.2), 29.4% (range 29.0-30.1), and 30.3% (range 29.9-30.8) of the patients with APAD, intermittent claudication, and CLI, respectively, and antiplatelet therapy was reported by 34.1% (range 33.7-34.3), 47.6% (range 47.3-47.9), and 60.2% (range 59.1-60.7). The odds ratio for having APAD was 1.7 (range 1.2-2.4) for women with a smoking history of 10 years in relation to nonsmokers. This association was observed only in men who had smoked for at least 30 years or more. Preventive drug use was more common in men with PAD. Compared with women they had an odds ratio of 1.3 (range 1.1-1.5) for lipid-lowering therapy, 1.3 (range 1.0-1.7) for [beta]-blockers or angiotensin-converting enzyme inhibitors, and 1.5 (range 1.2-1.9) for antiplatelet therapy.

CONCLUSION

The patients' risk factor profiles differed among the PAD stages. Smoking duration already seemed to be a risk factor for women with PAD after 10 years of smoking, as compared with 30 years for men, and fewer women reported use of preventive medication. These observations may partly explain the sex differences in prevalence that were observed.

The association between diabetes mellitus and the prevalence of intermittent claudication: the HUNT study

The objective of this study was to investigate the association between diabetes mellitus (DM) and the prevalence of intermittent claudication (IC). Between 1995 and 1997, all residents aged 20 years or older in Nord-Trøndelag County, Norway were mailed an invitation to participate in a health survey (HUNT 2). A total of 19,712 participants aged 40-69 years old completed and returned the questionnaire included with the invitation. They also attended an examination where brachial blood pressure was measured and non-fasting venous blood was collected. The venous blood sample was subsequently analysed for concentrations of blood lipids. Responses to 12 questions on IC were previously tested against ankle blood pressure measurements (ABPI < 0.9) and the algorithm with the best test properties was used to identify individuals with IC. Participants reported a history of DM by simple questions in the questionnaire. Logistic regression analysis was then used to compute age-adjusted prevalence odds ratios for the association between exposure variables and the prevalence of IC. Potential confounding by smoking, blood lipids and brachial blood pressure was investigated in multivariate analyses. For both sexes IC was more common in individuals with DM (OR(women) = 3.8, CI, 1.9-7.6; OR(men) = 2.8, CI, 1.4-5.8) compared to participants without DM. Adjustment for smoking, blood lipids and brachial blood pressure did not substantially change these results. In conclusion, the prevalence of IC was more than three times higher in patients with DM compared to non-diabetic participants.

[Chronic critical ischemia of the legs. Definition and management]

The term "Chronic critical ischemia ", CCI, of lower limb defines a very advanced state of chronic LL arterial insufficiency with deleterious effect of low perfusion pressure rate. This diagnosis has serious consequences for the patient (high risk of major amputation, high risk of cardiovascular events and death, high risk of reduced quality of life for survivals even non-amputated). The diagnosis must be precise. We discuss the evolution of the concept and the definitions of CCI from Fontaine classification, the epidemiology of CCI and its risk factors, the diagnosis of CCI (clinical, haemodynamical, anatomical) and the treatment of CCI which the main goal is to increase as much as possible the arterial pressure in the foot.

[Chronic critical ischemia of the lower leg: pretherapeutic imaging and methods for revascularization]

Each year 1-2% of patients with peripheral arterial occlusive disease (pAOD) develop critical limb ischemia (CLI), characterized by rest pain and peripheral ulcer or gangrene. This aggravation of the disease is accompanied by an increase of the 1-year mortality rate up to 25% and a similarly increased frequency of major amputation. We can choose between conservative, endovascular, and surgical procedures for an adequate therapy of the underlying vascular stenoses or occlusions. Yet, clear therapeutic recommendations only exist for suprapopliteal lesions. However, in a number of cases, especially in diabetics, target lesions have an infrapopliteal location. Since endovascular procedures have undergone significant improvement in the last few years, the following review discusses methods for infrapopliteal revascularization taking into consideration the newest publications on this topic.

Acute lower limb ischemia is a frequent complication of severe diabetic hyperosmolarity

AIM

To describe the outcome of intensive care unit (ICU) patients admitted with a hyperglycaemic hyperosmolar non-ketotic syndrome (HHNS), with a specific analysis of precipitating conditions and complications including lower limb ischemia.

METHODS

Retrospective review of patients admitted in a university-hospital ICU for HHNS.

RESULTS

Seventeen consecutive patients (9F/8M, age: 75 years [57-81] (median [25-75% percentiles], Glasgow Coma score: 13 [12-14]) were admitted for HHNS over an 8-year period (1998-2005). On admission, the blood glucose level was 40.0 mmol/l [26.3-60.8], the corrected serum sodium concentration 167 mmol/l [158-174], and the calculated plasma osmolarity 384 mosmol/l [365-405]. All the patients presented with renal failure due to severe dehydration. An infection was identified as the precipitating factor in 8/17 cases. Three (18%) patients died in the ICU. Non-survivors were significantly older than survivors (P=0.02). Using univariate analysis, no other parameter measured on admission was related to mortality. Four patients (24%) presented with lower limb ischemia. They had a significantly more elevated blood urea nitrogen (P=0.03), creatinine phosphokinase level (P=0.04), and leukocyte count (P=0.02). The bilateral, symmetrical, and distal extremity involvement suggested diminished blood flow due to hyperviscosity, hypotension, vasoconstrictors, or cholesterol emboli rather than a proximal arterial obstruction as causative mechanisms. No patient was treated surgically. Ischemia reversed with fluid loading and resulted in toe dry digital necrosis.

CONCLUSION

HHNS is a rare but life-threatening cause of ICU admission. There is a high incidence of lower limb ischemia in HHNS patients, which may be related to dehydration and blood hyperviscosity.