Treatment of peripheral arterial disease

Arterial and venous peripheral vascular assessment using wearable electro-resistive morphic sensors

Peripheral vascular diseases (PVDs) represent a significant burden on global human health and healthcare systems. With continued growth in obesity and diabetes, it is likely that the incidence of these conditions will increase. As many PVDs remain undiagnosed, low-cost and easy to use diagnostic methods are required. This work uses newly developed wearable electro-resistive morphic sensors to assess venous and arterial competence in the lower limbs of 36 healthy subjects. Comparison of this HeMo device was made to currently available benchtop light reflection rheography and photoplethymography devices. Results indicate that HeMo can detect the physiological signals of interest for both chronic venous insufficiency and peripheral arterial disease and all subjects were interpreted as healthy by each system. However, measurement repeatability of HeMo was highlighted as an issue that requires further system development. Furthermore, as HeMo captures changes in a section of limb circumference due to changes in underlying blood movement, rather than at a single point, the recorded signal is typically damped by comparison. This factor should be considered in any future developments.

Intermittent Claudication in Physiotherapists' Practice

Intermittent claudication is a symptom of atherosclerosis of the lower limbs (peripheral arterial disease (PAD)) and is characterized by pain and cramps of lower limb muscles during exercise. Claudication leads to a reduction in physical activity of patients. PAD is a systemic disease. Atherosclerotic lesions located in the arteries of the lower limbs not only pose the risk of the ischemic limb loss, but above all, they are an important prognostic factor. Patients with claudication are at significant risk of cardiovascular complications such as infarcts or strokes. Comprehensive rehabilitation of patients with intermittent claudication based on the current TASC II (Inter-Society Consensus for the Management of Peripheral Arterial Disease) guidelines, ESC (European Society of Cardiology) guidelines, and AHA (American Heart Association) guidelines includes supervised treadmill training, training on a bicycle ergometer, Nordic Walking, resistance exercises of lower limb muscles, and exercises of upper limbs. A trained, educated, and motivated patient has a chance to improve life quality as well as life expectancy.

Peripheral vascular disease assessment in the lower limb: a review of current and emerging non-invasive diagnostic methods

BACKGROUND

Worldwide, at least 200 million people are affected by peripheral vascular diseases (PVDs), including peripheral arterial disease (PAD), chronic venous insufficiency (CVI) and deep vein thrombosis (DVT). The high prevalence and serious consequences of PVDs have led to the development of several diagnostic tools and clinical guidelines to assist timely diagnosis and patient management. Given the increasing number of diagnostic methods available, a comprehensive review of available technologies is timely in order to understand their limitations and direct future development effort.

MAIN BODY

This paper reviews the available diagnostic methods for PAD, CVI, and DVT with a focus on non-invasive modalities. Each method is critically evaluated in terms of sensitivity, specificity, accuracy, ease of use, procedure time duration, and training requirements where applicable.

CONCLUSION

This review emphasizes the limitations of existing methods, highlighting a latent need for the development of new non-invasive, efficient diagnostic methods. Some newly emerging technologies are identified, in particular wearable sensors, which demonstrate considerable potential to address the need for simple, cost-effective, accurate and timely diagnosis of PVDs.

Risk Modification in Patients with Peripheral Arterial Disease: A Retrospective Survey

Peripheral arterial disease (PAD) is underdiagnosed and undertreated. This is despite the high vascular morbidity and mortality rates associated with PAD. There is also evidence that quitting smoking, improving the lipid profile, lowering the blood pressure, and administering antiplatelet drugs reduce the risk of vascular events in these patients. Secondary prevention for patients with PAD is yet to meet the standard of care for those with ischemic heart disease. The authors surveyed 200 claudicants attending a vascular clinic with additional follow-up in a risk modification clinic. After a median follow-up of 28 months (range: 6-65) there was a significant (p=0.001) improvement in walking distance; 34 patients (17%) had a vascular ischemic event. Of those, 11 patients (5.5%) had worsening intermittent claudication and 9 had a stroke/transient ischemic attack; 9 events (4.5%) were fatal. The lipid targets were met in 76% the patients. Half the smokers quit smoking and 94% of the patients were taking antiplatelet drugs or anticoagulants. Blood pressure reached the accepted target in 87% of the patients. Secondary prevention in patients with PAD may reduce the risk of vascular events. Aggressive risk modification is therefore recommended.

Diagnostic pitfalls in spine surgery: masqueraders of surgical spine disease

Disorders of the spine are common in clinical medicine, and spine surgery is being performed with increasing frequency in the US. Although many patients with an established diagnosis of a true surgically treatable lesion are referred to a neurosurgeon, the evaluation of patients with spinal disorders can be complex and fraught with diagnostic pitfalls. While “common conditions are common,” astute clinical acumen and vigilance are necessary to identify lesions that masquerade as surgically treatable spine disease that can lead to erroneous diagnosis and treatment. In this review, the authors discuss musculoskeletal, peripheral nerve, metabolic, infectious, inflammatory, and vascular conditions that mimic the syndromes produced by surgical lesions. It is possible that nonsurgical and surgical conditions coexist at times, complicating treatment plans and natural histories. Awareness of these diagnoses can help reduce diagnostic error, thereby avoiding the morbidity and expense associated with an unnecessary operation.

Inhibition of cyclic nucleotide phosphodiesterases by methylxanthines and related compounds

Naturally occurring methylxanthines were the first inhibitors of cyclic nucleotide (cN) phosphodiesterases (PDEs) to be discovered. To improve potency and specificity for inhibition of various PDEs in research and for treatment of diseases, thousands of compounds with related structures have now been synthesized. All known PDE inhibitors contain one or more rings that mimic the purine in the cN substrate and directly compete with cN for access to the catalytic site; this review focuses on inhibitors that contain a nucleus that is closely related to the xanthine ring of theophylline and caffeine and the purine ring of cNs. The specificity and potency of these compounds for blocking PDE action have been improved by appending groups at positions on the rings as well as by modification of the number and distribution of nitrogens and carbons in those rings. Several of these inhibitors are highly selective for particular PDEs; potent and largely selective PDE5 inhibitors are used clinically for treatment of erectile dysfunction [sildenafil (Viagra™), tadalafil (Cialis™) and vardenafil (Levitra™)] and pulmonary hypertension [sildenafil (Revatio™) and tadalafil (Adenocirca)]. Related compounds target other PDEs and show therapeutic promise for a number of maladies.

Peripheral arterial disease: Pathophysiology, risk factors, diagnosis, treatment, and prevention

Peripheral Artery Disease (PAD) is a strong predictor of MI, stroke and death due to vascular causes. PAD affects 8-12 million people in the United States. As the population lives longer with chronic diseases, researchers estimate that the incidence of PAD will increase, likely increasing myocardial infarction, stroke and death. This paper reviews the epidemiology, pathophysiology, risk factors, treatment and management of PAD. With improved understanding of the disease process, risk factors and treatment, clinicians will be able to detect PAD earlier, provide diagnosis, treat and manage this disease. PAD is associated with reduced quality of life, and persons with PAD are also at risk of developing coronary artery disease and cerebrovascular disease. Better clinical evaluation and routine screening are important in identifying and treating patients at risk for PAD. All patients with PAD should receive risk-factor modification, such as treatment and education, about smoking cessation, blood pressure control and lowering of cholesterol. Appropriate pharmacological management includes antiplatelet therapy of aspirin, use of clopidogrel for those individuals who are sensitive to aspirin. Patients who have had bypass surgery or stent placement require dual antiplatelet therapy of aspirin and clopidogrel. The American Heart Association (AHA) states that treatment with beta-blockers and ACE inhibitors is appropriate pharmacotherapy to treat PAD. Other FDA approved medications such as Cilostazol and Pentoxifylline are also used in the treatment of pain associated with intermittent claudication.

Clinical evaluation of the Zilver vascular stent for symptomatic iliac artery disease

PURPOSE

To evaluate the safety and effectiveness of the Zilver vascular stent in the treatment of de novo or restenotic lesions in the external and common iliac arteries.

MATERIALS AND METHODS

Regardless of the results of an initial percutaneous transluminal angioplasty (PTA), 151 consecutive patients were implanted with Zilver vascular stents (Cook, Bloomington, Ind) in up to two stenotic (< or =10 cm) or occluded (< or =5 cm) atherosclerotic lesions of the external or common iliac arteries. The primary endpoint was the rate of major adverse events within 9 months after the procedure. Major adverse events were defined as death, myocardial infarction, target lesion revascularization, and limb loss. Secondary endpoints included acute procedural success, 30-day clinical success, 9-month patency rate, 9-month functional status (on the basis of the validated Walking Impairment Questionnaire), and ankle-brachial index (ABI).

RESULTS

of 1-, 6-, and 9-month follow-up are reported. Results The 9-month device and/or procedural-related major adverse event rate (adjudicated by an independent clinical events committee) was 2.7%. The all-cause major adverse event rate was 7.5%. Both rates were substantially below the prespecified objective performance criterion of 16%. The acute procedure success rate and 30-day clinical success rate were 98.0% and 94.0%, respectively. The 9-month patency rate, measured with duplex ultrasonography, was 92.9%. Significant improvement in the ABI and walking distance and walking speed scores, relative to preprocedural values, was seen at 1 month and was maintained through 9-month follow-up.

CONCLUSIONS

The Zilver vascular stent is safe and effective as an adjunct to PTA in the treatment of symptomatic disease of the iliac arteries.