Vascular imaging and intervention in peripheral arteries in the diabetic patient

Aspirin Versus Clopidogrel Monotherapy for the Secondary Prevention of Recurrent Cerebrovascular Attack Following Previous Ischemic Stroke in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

INTRODUCTION

Type 2 diabetes mellitus (T2DM) and stroke are two different diseases, but have many aspects in common. Aspirin is recommended as an initial treatment for the secondary prevention of recurrent ischemic stroke in patients with T2DM. However, clopidogrel is an oral antiplatelet drug that might be another choice in case of aspirin intolerance. In this analysis, we aimed to systematically compare aspirin versus clopidogrel monotherapy for the secondary prevention of recurrent cerebrovascular attack following previous ischemic stroke in patients with T2DM.

METHODS

Online medical databases including Web of Science, MEDLINE, Cochrane central, EMBASE and http://www.ClinicalTrials.com were searched for published articles that satisfied the inclusion and exclusion criteria of this study. Recurrent stroke, fatal stroke, cerebral hemorrhage, myocardial infarction and mortality were considered the main end points in these patients with T2DM. RevMan 5.3 software was used to statistically analyze the data representing each subgroup. Risk ratios (RRs) with 95% confidence intervals (CIs) were used to represent the results following analysis.

RESULTS

A total of 9218 participants with T2DM who were previously affected by ischemic stroke were included in this analysis, whereby 4917 were assigned to aspirin and 4301 to clopidogrel. This current analysis showed that there was no significant difference in recurrent stroke rate (RR: 0.79, 95% CI: 0.61-1.02; P = 0.07) observed with aspirin versus clopidogrel in these patients with T2DM. The risk of fatal stroke (RR: 0.88, 95% CI: 0.39-1.98; P = 0.76), cerebral hemorrhage (RR: 0.65, 95% CI: 0.38-1.11; P = 0.12), myocardial infarction (RR: 0.88, 95% CI: 0.43-1.79; P = 0.71) and mortality (RR: 1.07, 95% CI: 0.90-1.27; P = 0.44) were also similarly manifested.

CONCLUSION

Clopidogrel monotherapy was neither inferior nor superior to aspirin monotherapy for the secondary prevention of recurrent cerebrovascular attack following previous ischemic stroke in patients with T2DM. Hence, clopidogrel or aspirin monotherapy is equally safe and effective in these patients with T2DM.

Predictive factors for successful limb salvage surgery in diabetic foot patients

Background

The goal of salvage surgery in the diabetic foot is maximal preservation of the limb, but it is also important to resect unviable tissue sufficiently to avoid reamputation. This study aims to provide information on determining the optimal amputation level that allows preservation of as much limb length as possible without the risk of further reamputation by analyzing several predictive factors.

Methods

Between April 2004 and July 2013, 154 patients underwent limb salvage surgery for distal diabetic foot gangrene. According to the final level of amputation, the patients were divided into two groups: Patients with primary success of the limb salvage, and patients that failed to heal after the primary limb salvage surgery. The factors predictive of success, including comorbidity, laboratory findings, and radiologic findings were evaluated by a retrospective chart review.

Results

The mean age of the study population was 63.9 years, with a male-to-female ratio of approximately 2:1. The mean follow-up duration was 30 months. Statistical analysis showed that underlying renal disease, limited activity before surgery, a low hemoglobin level, a high white blood cell count, a high C-reactive protein level, and damage to two or more vessels on preoperative computed tomography (CT) angiogram were significantly associated with the success or failure of limb salvage. The five-year survival rate was 81.6% for the limb salvage success group and 36.4% for the limb salvage failure group.

Conclusion

This study evaluated the factors predictive of the success of limb salvage surgery and identified indicators for preserving as much as possible of the leg of a patient with diabetic foot. This should help surgeons to establish the appropriate amputation level for a case of diabetic foot and help prevent consecutive operations.

Successful Treatment of a Patient With Complicated Diabetic Foot Wound: A Case Report

Foot ulceration is one of the most serious complications of diabetes mellitus and may lead to amputation of the lower extremity. Timely prophylaxis and treatment of diabetic foot ulceration are important to maintain a good quality of life. This article reports a complicated diabetic patient with severe limb-threatening necrotizing infection. We successfully applied endovascular stent insertion, digit amputation, negative pressure wound therapy, and advanced dressings in different wound phases to achieve definitive wound healing after 12 months of treatment. Based on this case report, we would like to emphasize the importance of combined multiple therapies and patient compliance for severe diabetic foot ulcers.

The interventional therapy for diabetic peripheral artery disease

Background

Diabetic peripheral arterial disease is the main cause of lower limb amputation in patients with diabetes. To summarize the technique and experiences and evaluate the clinical effects of blood vessel intervention operation on diabetic peripheral artery disease.

Methods

81 patients with diabetic peripheral artery disease from October 2007 to September 2011, 81 cases of the observation group were treated by balloon PTA. By adopting the Seldinger puncture technology, intubation was placed into a cobra catheter or a pig tail artery catheter and directed to the ipsilateral lower extremity artery. A guidewire was used to reach the lesion part of patients and a long balloon with a diameter of 4–6 mm was used to expand the artery with a pressure of 6–10 atm.

Results

81 patients in the observation group received the PTA surgery. The technical succesful rate was 100%, no complication happened. The skin temperature increased after treatment. The blood supply improved significantly. The pulsation of the foot dorsal artery was strengthened. The numbness and pain symptoms were moderated significantly. We observed better results in the observation group in lower limb vessel diameter and foot ulceration healing. None of the patients received amputation surgery. Its short-term effects were satisfactory.

Conclusion

PTA is a feasible technique for diabetic peripheral artery disease. It has great clinical significance in treating diabetic peripheral arterial disease. Although its short-term effects is satisfactory, the long-term effects is necessary for follow up.

What the radiologist needs to know about the diabetic patient

Diabetes mellitus (DM) is recognised as a major health problem. Ninety-nine percent of diabetics suffer from type 2 DM and 10% from type 1 and other types of DM. The number of diabetic patients worldwide is expected to reach 380 millions over the next 15 years. The duration of diabetes is an important factor in the pathogenesis of complications, but other factors frequently coexisting with type 2 DM, such as hypertension, obesity and dyslipidaemia, also contribute to the development of diabetic angiopathy. Microvascular complications include retinopathy, nephropathy and neuropathy. Macroangiopathy mainly affects coronary arteries, carotid arteries and arteries of the lower extremities. Eighty percent of deaths in the diabetic population result from cardiovascular incidents. DM is considered an equivalent of coronary heart disease (CHD). Stroke and peripheral artery disease (PAD) are other main manifestations of diabetic macroangiopathy. Diabetic cardiomyopathy (DC) represents another chronic complication that occurs independently of CHD and hypertension. The greater susceptibility of diabetic patients to infections completes the spectrum of the main consequences of DM. The serious complications of DM make it essential for physicians to be aware of the screening guidelines, allowing for earlier patient diagnosis and treatment.

Peripheral arterial disease in a symptomatic diabetic population: prospective comparison of rapid unenhanced MR angiography (MRA) with contrast-enhanced MRA

OBJECTIVE

The joint guidelines of the American College of Cardiology and American Heart Association support the use of contrast-enhanced MR angiography (CEMRA) to diagnose the location and degree of stenosis in patients with known or suspected peripheral arterial disease (PAD). The high prevalence of chronic renal impairment in diabetic patients with PAD and the need for high doses of gadolinium-based contrast agents place them at risk for nephrogenic systemic fibrosis. The purpose of our study was to evaluate the accuracy of the rapid technique of quiescent-interval single-shot (QISS) unenhanced MR angiography (MRA) compared with CEMRA for the diagnosis in diabetic patients referred with symptomatic chronic PAD.

SUBJECTS AND METHODS

This prospective two-center study evaluated 25 consecutive diabetic patients with documented or suspected symptomatic PAD. Both centers used identical imaging protocols. Images were independently analyzed by two radiologists. A subgroup analysis was performed of patients who were also assessed with digital subtraction angiography (DSA) as part of the standard-of-care protocol before revascularization.

RESULTS

For this study, 775 segments were analyzed. On a per-segment basis, the mean values of the diagnostic accuracy of unenhanced MRA compared with reference CEMRA for two reviewers, reviewers 1 and 2, were as follows: sensitivity, 87.4% and 92.1%; specificity, 96.8% and 96.0%; positive predictive value, 90.8% and 94.0%; and negative predictive value, 95.5% and 94.6%. Substantial agreement was found when overall DSA results were compared with QISS unenhanced MRA (κ = 0.68) and CEMRA (κ = 0.63) in the subgroup of patients who also underwent DSA. There was almost perfect agreement between the two readers for stenosis scores, with Cohen's kappa values being greater than 0.80 for both MRA techniques.

CONCLUSION

The results of our study indicate that QISS unenhanced MRA is an accurate noncontrast alternative to CEMRA for showing clinically significant arterial disease in patients with diabetes with symptomatic PAD.

Peripheral arterial disease in diabetes--a review

Diabetic patients are at high risk for peripheral arterial disease (PAD) characterized by symptoms of intermittent claudication or critical limb ischaemia. Given the inconsistencies of clinical findings in the diagnosis of PAD in the diabetic patient, measurement of ankle-brachial pressure index (ABI) has emerged as the relatively simple, non-invasive and inexpensive diagnostic tool of choice. An ABI < 0.9 is not only diagnostic of PAD even in the asymptomatic patient, but is also an independent marker of increased morbidity and mortality from cardiovascular diseases. With better understanding of the process of atherosclerosis, avenues for treatment have increased. Modification of lifestyle and effective management of the established risk factors such as smoking, dyslipidaemia, hyperglycaemia and hypertension retard the progression of the disease and reduce cardiovascular events in these patients. Newer risk factors such as insulin resistance, hyperfibrinogenaemia, hyperhomocysteinaemia and low-grade inflammation have been identified, but the advantages of modifying them in patients with PAD are yet to be proven. Therapeutic angiogenesis, on the other hand, represents a promising therapeutic adjunct in the management of PAD in these patients. Outcomes after revascularization procedures, such as percutaneous transluminal angioplasty and surgical bypasses in diabetic patients, are poorer, with increased perioperative morbidity and mortality compared with that in non-diabetic patients. Amputation rates are higher due to the distal nature of the disease. Efforts towards increasing awareness and intensive treatment of the risk factors will help to reduce morbidity and mortality in diabetic patients with PAD.

Angioplasty in Critical Limb Ischaemia: One-year Limb Salvage Results

Introduction: Lower extremity amputation prevention (LEAP) is an ongoing programme in our institution aimed at limb salvage in patients with critical limb ischaemia (CLI). Patients in the LEAP programme with reconstructible anatomy on initial Doppler imaging received either bypass surgery or percutaneous transluminal balloon angioplasty (PTA). We describe the 1-year limb salvage rates in 46 consecutive patients with CLI who received PTA in 2005. Clinical Picture: A total of 46 patients, 28 women and 18 men, between the ages of 40 and 91 years old (mean age, 70.8) received PTA in 2005. The most common presenting symptom was rest pain (n = 23), followed by pre-existing gangrene (n = 20), non-healing ulcer (n = 17) and cellulitis (n = 8). The majority of the patients (57%) had 3 to 4 risk factors. Diabetes mellitus (91%) and hypertension (80%) were the 2 most common risk factors. The patients were kept under surveillance for periods ranging from 12 to 21 months with a mean of 13.3 months, both clinically and with haemodynamic measurements [ankle-brachial index (ABI), toe pressure (TP) and digital-brachial index (DBI)]. Treatment: The aim of PTA is to achieve straight-line flow from the abdominal aorta down to either a patent dorsalis pedis or plantar arch with limb salvage as the ultimate goal. The patterns of the treated segments were as follows: aorto-iliac occlusions (n = 3), pure infrapopliteal disease (n = 5), femoropopliteal disease with at least 1 good infrapopliteal run-off vessel (n = 16) and combined femoropopliteal and infrapopliteal disease (n = 25). Technical success was achieved in 89% of patients (41 out of 46 patients). The most common cause of technical failure is the inability to cross long chronic total occlusions. Outcome: Paired T test was performed and showed statistically significant improvement in haemodynamic markers within the technically successful group. This included increase in the mean ABI from 0.62 (pre-angioplasty) to 0.91 (Day 1 post-angioplasty), an increase of 0.29 [95% confidence interval (95% CI), 0.1953 to 0.3875; P <0.001]. One year post-angioplasty, the mean ABI was 0.84, an increase of 0.22 (95% CI 0.1512 to 0.3121; P <0.001). There was also significant increase in the mean DBI of 0.17 from 0.23 to 0.41 (pre-angioplasty versus Day 1 post angioplasty – 95% CI of 0.1006 to 0.2433; P <0.001). In addition, significant increase in the mean TP of 28.2 mmHg from 36.8 to 63.2 mmHg (pre-angioplasty versus Day 1 post angioplasty – 95% CI, 18.493 to 37.939; P <0.001) was also noted. Of the 23 patients who presented with rest pain, total abolishment of symptoms was achieved in 21 patients (91%). Healing of pre-existing gangrene was attained in 15 patients (66%). Five patients subsequently received minor amputation for pre-existing gangrene. Clinical improvement in all the patients who presented with non-healing ulcers (n = 17) and cellulitis (n = 8) was attained. More importantly, all healed ulcers remained healed throughout the study period. The limb salvage rates were 93% at 1 month, 87% at 3 months, 82% at 6 months and 78% at 1 year. Conclusion: Angioplasty is a safe and effective limb salvage method in patients with CLI and has a high 1-year limb salvage rate. Key words: Angioplasty, Arterial occlusive diseases, Balloon, Lower extremity, Treatment outcome

The treatment of diabetic foot ulcers: reviewing the literature and a surgical algorithm

PURPOSE

To provide an overview of the literature related to the treatment of diabetic foot ulcers.

TARGET AUDIENCE

This continuing education activity is intended for physicians and nurses with an interest in wound care.

OBJECTIVES

After reading this article and taking this test, the reader should be able to:

Peripheral arteries in diabetic patients: standard bolus-chase and time-resolved MR angiography

PURPOSE

To prospectively determine the diagnostic performance of a combination of standard bolus-chase magnetic resonance (MR) angiography and MR angiography with time-resolved imaging of contrast kinetics (TRICKS) for depicting severity of peripheral vascular disease of the lower extremity, including the pedal arteries, in diabetic patients with digital subtraction angiography (DSA) as the reference standard.

MATERIALS AND METHODS

An ethical committee approved this study; written informed consent was obtained from patients. Standard three-station and TRICKS MR angiography of the calf and foot were performed in 31 consecutive diabetic patients (23 men, eight women; mean age, 67 years; range, 43-81 years). Two readers separately assessed images of arterial segments as diagnostic or nondiagnostic and graded stenosis. Results were compared with those at DSA when the corresponding arterial segments were considered diagnostic at DSA. Wilcoxon signed rank test was used to determine if a significant difference between imaging techniques existed, and kappa statistics were used to determine interobserver agreement.

RESULTS

The difference between standard MR angiography and DSA regarding the number of diagnostic segments in the thigh was not significant (P = .50). A significantly higher number of calf and foot segments was considered diagnostic at TRICKS MR angiography than at standard MR angiography (P < .025). Sixteen of 26 segments in the foot that were considered nondiagnostic at DSA were considered diagnostic at TRICKS MR angiography. Average sensitivity of standard MR angiography for depicting hemodynamically significant arterial stenosis was 84% (reader 1) and 83% (reader 2) in the thigh and 78% (reader 1) and 80% (reader 2) in the calf. For both readers, average specificity was 97% in the thigh and 90% in the calf. Sensitivity and specificity of TRICKS MR angiography in the calf and foot were improved compared with those at standard MR angiography.

CONCLUSION

TRICKS MR angiography of the distal calf and pedal vessels is superior to standard MR angiography regarding the number of diagnostic segments and assessment of the degree of luminal narrowing.

An integrated care pathway to save the critically ischaemic diabetic foot

This prospective study describes and evaluates the efficacy of an integrated care pathway for the management of the critically ischaemic diabetic foot patients by a multidisciplinary team. A weekly joint diabetes/vascular/podiatry ward round and outpatient clinic was established where patients were assessed within 7 days of referral by clinical examination, ankle-brachial-index-pressures, duplex angiogram and transcutaneous oxygen pressures. An angiogram +/- angioplasty or alternatively a magnetic resonance angiography prior to surgical revascularisation was performed in patients deemed not suitable for angioplasty based on the above vascular assessment. Between January 2002 and June 2003(18 months), 128 diabetic patients with lower limb ischaemia were seen. Thirty-four (26.6%) patients received medical treatment alone, and 18 (14.1%) were deemed 'palliative' due to their significant co-morbidities. The remaining 76 (59.4%) patients underwent either angioplasty (n = 56), surgical reconstruction (n = 18), primary major amputation (n = 2) or secondary amputation after surgical revascularisation (n = 1). Minor toe amputations were required in 35 patients. The mortality in the intervention group was 14% (11/76). This integrated multidisciplinary approach offers a consistent and equitable service to diabetic patients with critically ischaemic feet and appears to have a beneficial major/minor amputation ratio.

Assessment of critical limb ischemia in patients with diabetes: comparison of MR angiography and digital subtraction angiography

OBJECTIVE

The purpose of our study was to evaluate the diagnostic accuracy of hybrid MR angiography by comparison with digital subtraction angiography (DSA) in diabetic patients with critical limb ischemia.

SUBJECTS AND METHODS

Thirty-one patients prospectively underwent both hybrid MR angiography and DSA. The hybrid MR angiography study consisted of high-resolution MR angiography of a single calf and foot using a contrast-enhanced 3D gradient-echo volumetric interpolated breath-hold examination with surface coils, followed by three-station bolus chase MR angiography with a dedicated peripheral vascular coil. Two blinded reviewers separately analyzed maximum-intensity-projection hybrid MR angiograms and DSA images. The peripheral vessels were divided into 10 anatomic segments for review. The status of each segment was graded as normal, stenosis less than 50% in diameter, stenosis greater than 50%, or occluded. The sensitivity and specificity of hybrid MR angiography were determined using DSA as the gold standard. Treatment options were considered separately from the results of each examination.

RESULTS

Among 310 analyzed segments, the sensitivities of hybrid MR angiography for stenosis and occlusion were, respectively, 95% and 95% for reviewer 1 and 96% and 90% for reviewer 2. The specificities of hybrid MR angiography for stenosis and occlusion were, respectively, 98% and 98% for reviewer 1 and 98% and 99% for reviewer 2. In 25 patients (81%), the quality of bolus chase MR angiography images was insufficient to assess runoff arteries. All treatments proposed on the basis of DSA findings were endorsed by hybrid MR angiography findings. Eleven more treatments were formulated on the basis of hybrid MR angiography findings. Of these, four were due to overestimation of stenosis on MR angiography and seven were due to the detection of patent infrageniculate arteries on hybrid MR angiography that were not detected on DSA.

CONCLUSION

Hybrid MR angiography depicts runoff arteries not seen on DSA. Hybrid MR angiography may be useful for treatment planning in selected diabetic patients with critical limb ischemia.

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.

Diabetic foot ulcerations: management and adjunctive therapy

Foot ulcerations, infections, gangrene, and lower extremity amputation are major causes of disability to the patient who has diabetes mellitus, often resulting in significant morbidity, extensive periods of hospitalization, and mortality. Although not all such lesions can be prevented, it is possible to dramatically reduce their incidence through appropriate management and prevention protocols incorporating a multidisciplinary team approach.