François Becker

Chapter IV: Treatment of Critical Limb Ischaemia

Recommendations stated in the TASC II guidelines for the treatment of peripheral arterial disease (PAD) regard a heterogeneous group of patients ranging from claudicants to critical limb ischaemia (CLI) patients. However, specific considerations apply to CLI patients. An important problem regarding the majority of currently available literature that reports on revascularisation strategies for PAD is that it does not focus on CLI patients specifically and studies them as a minor part of the complete cohort. Besides the lack of data on CLI patients, studies use a variety of endpoints, and even similar endpoints are often differentially defined. These considerations result in the fact that most recommendations in this guideline are not of the highest recommendation grade. In the present chapter the treatment of CLI is not based on the TASC II classification of atherosclerotic lesions, since definitions of atherosclerotic lesions are changing along the fast development of endovascular techniques, and inter-individual differences in interpretation of the TASC classification are problematic. Therefore we propose a classification merely based on vascular area of the atherosclerotic disease and the lesion length, which is less complex and eases the interpretation. Lesions and their treatment are discussed from the aorta downwards to the infrapopliteal region. For a subset of lesions, surgical revascularisation is still the gold standard, such as in extensive aorto-iliac lesions, lesions of the common femoral artery and long lesions of the superficial femoral artery (>15 cm), especially when an applicable venous conduit is present, because of higher patency and limb salvage rates, even though the risk of complications is sometimes higher than for endovascular strategies. It is however more and more accepted that an endovascular first strategy is adapted in most iliac, superficial femoral, and in some infrapopliteal lesions. The newer endovascular techniques, i.e. drug-eluting stents and balloons, show promising results especially in infrapopliteal lesions. However, most of these results should still be confirmed in large RCTs focusing on CLI patients. At some point when there is no possibility of an endovascular nor a surgical procedure, some alternative non-reconstructive options have been proposed such as lumbar sympathectomy and spinal cord stimulation. But their effectiveness is limited especially when assessing the results on objective criteria. The additional value of cell-based therapies has still to be proven from large RCTs and should therefore still be confined to a research setting. Altogether this chapter summarises the best available evidence for the treatment of CLI, which is, from multiple perspectives, completely different from claudication. The latter also stresses the importance of well-designed RCTs focusing on CLI patients reporting standardised endpoints, both clinical as well as procedural.

Chapter V: Diabetic Foot

Ulcerated diabetic foot is a complex problem. Ischaemia, neuropathy and infection are the three pathological components that lead to diabetic foot complications, and they frequently occur together as an aetiologic triad. Neuropathy and ischaemia are the initiating factors, most often together as neuroischaemia, whereas infection is mostly a consequence. The role of peripheral arterial disease in diabetic foot has long been underestimated as typical ischaemic symptoms are less frequent in diabetics with ischaemia than in non-diabetics. Furthermore, the healing of a neuroischaemic ulcer is hampered by microvascular dysfunction. Therefore, the threshold for revascularising neuroischaemic ulcers should be lower than that for purely ischaemic ulcers. Previous guidelines have largely ignored these specific demands related to ulcerated neuroischaemic diabetic feet. Any diabetic foot ulcer should always be considered to have vascular impairment unless otherwise proven. Early referral, non-invasive vascular testing, imaging and intervention are crucial to improve diabetic foot ulcer healing and to prevent amputation. Timing is essential, as the window of opportunity to heal the ulcer and save the leg is easily missed. This chapter underlines the paucity of data on the best way to diagnose and treat these diabetic patients. Most of the studies dealing with neuroischaemic diabetic feet are not comparable in terms of patient populations, interventions or outcome. Therefore, there is an urgent need for a paradigm shift in diabetic foot care; that is, a new approach and classification of diabetics with vascular impairment in regard to clinical practice and research. A multidisciplinary approach needs to implemented systematically with a vascular surgeon as an integrated member. New strategies must be developed and implemented for diabetic foot patients with vascular impairment, to improve healing, to speed up healing rate and to avoid amputation, irrespective of the intervention technology chosen. Focused studies on the value of predictive tests, new treatment modalities as well as selective and targeted strategies are needed. As specific data on ulcerated neuroischaemic diabetic feet are scarce, recommendations are often of low grade.

Chapter II: Diagnostic Methods

Non-invasive vascular studies can provide crucial information on the presence, location, and severity of critical limb ischaemia (CLI), as well as the initial assessment or treatment planning. Ankle-brachial index with Doppler ultrasound, despite limitations in diabetic and end-stage renal failure patients, is the first-line evaluation of CLI. In this group of patients, toe-brachial index measurement may better establish the diagnosis. Other non-invasive measurements, such as segmental limb pressure, continuous-wave Doppler analysis and pulse volume recording, are of limited accuracy. Transcutaneous oxygen pressure (TcPO(2)) measurement may be of value when rest pain and ulcerations of the foot are present. Duplex ultrasound is the most important non-invasive tool in CLI patients combining haemodynamic evaluation with imaging modality. Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are the next imaging studies in the algorithm for CLI. Both CTA and MRA have been proven effective in aiding the decision-making of clinicians and accurate planning of intervention. The data acquired with CTA and MRA can be manipulated in a multiplanar and 3D fashion and can offer exquisite detail. CTA results are generally equivalent to MRA, and both compare favourably with contrast angiography. The individual use of different imaging modalities depends on local availability, experience, and costs. Contrast angiography represents the gold standard, provides detailed information about arterial anatomy, and is recommended when revascularisation is needed.

The assessment of deep vein thromboses for therapeutic trials.

In the current paper, we provide recommendations for the assessment of deep vein throm boses for the purpose of therapeutic trials evaluating antithrombotic drugs in the prevention of deep venous thrombosis. We have reviewed recently published articles on diagnostic and therapeutic studies, and we have evaluated methods of assessments. Ascending venography has been considered as the reference test for the confirmation of DVT. A roentgenographic image is subsequently available for review and allows classification by blinded, objective observers. However, venography poses substantial clinical and methodological limitations, particularly in the setting of systematic screening for all patients enrolled in a randomized clinical trial. Compression ultrasonography may replace venography for systematic screening of DVT in clinical trials, provided that specific methodological details are specified in the protocol and are fulfilled to ensure high and comparable sensitivity and specificity from all participating centers. This non-invasive technique has virtually no contraindications, and therefore more patients can be enrolled and evaluated. Furthermore, the compression ultra sonograph can be videotaped for central reading. Compression ultrasonography has already been adopted as the principal method for evaluating DVT in several ongoing large scale preven tion trials with the approval of major drug agencies.

Recent findings in the epidemiology, diagnosis and treatment of superficial-vein thrombosis

Recent data on lower-limb superficial-vein thrombosis (SVT) may substantially impact its clinical management. Thus, the clear confirmation that SVT is closely linked to deep-vein thrombosis (DVT) or pulmonary embolism (PE) highlights the potential severity of the disease. DVT or PE are diagnosed in 20-30% of SVT patients. Moreover, clinically relevant symptomatic thromboembolic events complicate isolated SVT (without concomitant DVT or PE at diagnosis) in 4-8% of patients. For the first time, an anticoagulant treatment, once-daily 2.5 mg fondaparinux for 45 days, was demonstrated to be effective and safe for preventing these symptomatic thromboembolic events in patients with lower-limb isolated SVT in the randomized placebo-controlled CALISTO study. Based on these recent findings, new recommendations on the management of SVT patients, including complete ultrasonography examination of the legs, and in patients with isolated SVT, prescription of once-daily 2.5 mg fondaparinux subcutaneously for 45 days on top of symptomatic treatments, may be proposed.

Novel risk factors for premature peripheral arterial occlusive disease in non-diabetic patients: a case-control study.

Background This study aimed to determine the prevalence of genetic and environmental vascular risk factors in non diabetic patients with premature peripheral arterial disease, either peripheral arterial occlusive disease or thromboangiitis obliterans, the two main entities of peripheral arterial disease, and to established whether some of them are specifically associated with one or another of the premature peripheral arterial disease subgroups. Methods and Results This study included 113 non diabetic patients with premature peripheral arterial disease (diagnosis <45-year old) presenting either a peripheral arterial occlusive disease (N = 64) or a thromboangiitis obliterans (N = 49), and 241 controls matched for age and gender. Both patient groups demonstrated common traits including cigarette smoking, low physical activity, decreased levels of HDL-cholesterol, apolipoprotein A–I, pyridoxal 5′-phosphate (active form of B6 vitamin) and zinc. Premature peripheral arterial occlusive disease was characterized by the presence of a family history of peripheral arterial and carotid artery diseases (OR 2.3 and 5.8 respectively, 95% CI), high lipoprotein (a) levels above 300 mg/L (OR 2.3, 95% CI), the presence of the factor V Leiden (OR 5.1, 95% CI) and the glycoprotein Ia807T,837T,873A allele (OR 2.3, 95% CI). In thromboangiitis obliterans group, more patients were regular consumers of cannabis (OR 3.5, 95% CI) and higher levels in plasma copper has been shown (OR 6.5, 95% CI). Conclusions According to our results from a non exhaustive list of study parameters, we might hypothesize for 1) a genetic basis for premature peripheral arterial occlusive disease development and 2) the prevalence of environmental factors in the development of thromboangiitis obliterans (tobacco and cannabis). Moreover, for the first time, we demonstrated that the 807T/837T/873A allele of platelet glycoprotein Ia may confer an additional risk for development of peripheral atherosclerosis in premature peripheral arterial occlusive disease.

Predicting deep venous thrombosis in pregnancy: external validation of the LEFT clinical prediction rule

The assessment of clinical probability represents an important step in the diagnostic strategy of patients with suspected deep vein thrombosis. The recently derived LEFt clinical prediction rule for pregnant women combines three variables: symptoms in the left leg (L), calf circumference difference of 2 centimeters or over (E for edema) and first trimester presentation (Ft) but is lacking an external validation. The LEFt rule was computed among pregnant women with suspected deep vein thrombosis who were included in a multicenter prospective diagnostic management outcome study. We calculated the proportion of women and the prevalence of deep vein thrombosis in each probability group, along with the diagnostic performances of the LEFt rule. All variables needed to compute the rule could be retrieved in 157 of the 167 pregnant women with suspected deep vein thrombosis. The prevalence of confirmed deep vein thrombosis was 13 of 157 (8.3%). The LEFt rule was negative in 46 (29%) women. A deep vein thrombosis was diagnosed in 13 of 111 (11.7%, 95% Confidence Interval (CI): 8.3-20.9%) of women with at least one of the LEFt criteria, as compared with none of 46 (0.0%, 95%CI: 0.0-7.9%) of women with none of the LEFt criteria. These results suggest that a negative LEFt rule accurately identifies pregnant women in whom the proportion of confirmed deep vein thrombosis appears to be very low. The rule should not be used as stand-alone test for excluding DVT during pregnancy, but might rather be implemented in a diagnostic strategy in association with D-dimer measurement and compression ultrasonography. The original trial was registered at clinicaltrials.gov (NCT 00740454).

Chapter VI: Follow-up after revascularisation.

Structured follow-up after revascularisation for chronic critical limb ischaemia (CLI) aims at sustained treatment success and continued best patient care. Thereby, efforts need to address three fundamental domains: (A) best medical therapy, both to protect the arterial reconstruction locally and to reduce atherosclerotic burden systemically; (B) surveillance of the arterial reconstruction; and (C) timely initiation of repeat interventions. As most CLI patients are elderly and frail, sustained resolution of CLI and preserved ambulatory capacity may decide over independent living and overall prognosis. Despite this importance, previous guidelines have largely ignored follow-up after CLI; arguably because of a striking lack of evidence and because of a widespread assumption that, in the context of CLI, efficacy of initial revascularisation will determine prognosis during the short remaining life expectancy. This chapter of the current CLI guidelines aims to challenge this disposition and to recommend evidentially best clinical practice by critically appraising available evidence in all of the above domains, including antiplatelet and antithrombotic therapy, clinical surveillance, use of duplex ultrasound, and indications for and preferred type of repeat interventions for failing and failed reconstructions. However, as corresponding studies are rarely performed among CLI patients specifically, evidence has to be consulted that derives from expanded patient populations. Therefore, most recommendations are based on extrapolations or subgroup analyses, which leads to an almost systematic degradation of their strength. Endovascular reconstruction and surgical bypass are considered separately, as are specific contexts such as diabetes or renal failure; and critical issues are highlighted throughout to inform future studies.

Chapter III: Management of cardiovascular risk factors and medical therapy

Critical limb ischaemia (CLI) is a particularly severe manifestation of lower limb atherosclerosis posing a major threat to both limb and life of affected patients. Besides arterial revascularisation, risk-factor modification and administration of antiplatelet therapy is a major goal in the treatment of CLI patients. Key elements of cardiovascular risk management are smoking cessation and treatment of hyperlipidaemia with dietary modification or statins. Moreover, arterial hypertension and diabetes mellitus should be adequately treated. In CLI patients not suitable for arterial revascularisation or subsequent to unsuccessful revascularisation, parenteral prostanoids may be considered. CLI patients undergoing surgical revascularisation should be treated with beta blockers. At present, neither gene nor stem-cell therapy can be recommended outside clinical trials. Of note, walking exercise is contraindicated in CLI patients due to the risk of worsening pre-existing or causing new ischaemic wounds. CLI patients are oftentimes medically frail and exhibit significant comorbidities. Co-existing coronary heart and carotid as well as renal artery disease should be managed according to current guidelines. Considering the above-mentioned treatment goals, interdisciplinary treatment approaches for CLI patients are warranted. Aim of the present manuscript is to discuss currently existing evidence for both the management of cardiovascular risk factors and treatment of co-existing disease and to deduct specific treatment recommendations.

Value of a Planned Compression Ultrasonography after an Isolated Superficial Vein Thrombosis: Results from a Prospective Multicentre Study

OBJECTIVES To assess the efficiency of a systematically planned compression ultrasonography (SP-CUS) to detect venous thrombotic complications (VTCs) in patients with symptomatic isolated superficial vein thrombosis (SVT). DESIGN Post hoc analysis of a prospective, multicentre, cohort study (POST). PATIENTS As many as 537 patients with CUS-confirmed isolated SVT undergoing an SP-CUS 8-15 days after the initial CUS. OUTCOMES Asymptomatic VTC (extension or recurrence of SVT, deep-vein thrombosis (DVT) of the lower limbs) diagnosed by the SP-CUS and symptomatic thromboembolic complications (VTC and pulmonary embolism (PE)) up to 3 months. RESULTS VTC was suspected before or on the day of the SP-CUS in 18 patients (3.0%). Among the 519 asymptomatic patients (97%) undergoing SP-CUS, this revealed asymptomatic VTC in 12 patients (2.3%; 4 DVT, 4 SVT recurrences, 4 SVT extensions), none of whom subsequently experienced symptomatic thromboembolic events up to 3 months. Among the 507 patients with a normal SP-CUS, 29 (5.7%) presented symptomatic thromboembolic events during follow-up: 2 PE, 7 DVT, 9 SVT recurrences and 11 SVT extensions. CONCLUSIONS In this study, the SP-CUS detected a few asymptomatic VTC, but failed to identify patients at risk of thromboembolic events during follow-up. Use of an SP-CUS was therefore neither efficient nor cost effective.