G. de Donato

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.

Subintimal Angioplasty with the Aid of a Re-entry Device for TASC C and D Lesions of the SFA

AIM The aim of this prospective study was to assess the clinical effectiveness and related midterm patency of subintimal angioplasty (SAP) in patients suffering from critical limb ischaemia (CLI) in a single tertiary care university centre. The secondary aim was to evaluate the safety and clinical effectiveness of using a re-entry device when re-canalisation by SAP was unsuccessful. METHODS From January 2005 to December 2007, consecutive patients suffering from CLI (Rutherford clinical categories: 4-6) were treated with SAP. All patients included in the study had occluded SFA (TASC C and D) and underwent clinical and ultrasound follow-up examinations at day 30 and at 3, 6, 9 and 12 months, and then yearly. A re-entry device (Outback, Cordis Corporation, Miami Lakes, Florida, USA in all cases) was only used when re-canalisation by simple SAP was unsuccessful, and stenting was used when residual stenosis was >30% or there was a flow-limiting dissection. Factors that could modify the outcome were analysed. RESULTS In this study, 145 patients were treated, with a technical success rate of 83.5% (121 of 145) for simple SAP. Stenting was performed in 43% (n=62) of successful SAP procedures. No death occurred in the perioperative period, while the 30-day mortality was 4.8% (7 of 145). The re-entry device (Outback) was used in 24 cases (16.5%). The technical success of the re-entry device was 79% (19 of 24), with a 90% success rate of stent placement at the site of re-entry. Complications occurred in 6.2% of all procedures (n=9) (three arterial perforations (2.1%), three distal embolisations (2.1%), two femoral artery pseudo-aneurysms (1.4%) and one arterio-venous fistula (0.7%)). Factors capable of independently affecting the patency were renal insufficiency (p=0.03), current smoking (p=0.01) and diabetes (p=0.04). The primary patency at 1 and 3 years was 70% and 34% and the secondary patency at 1 and 3 years was 77% and 43%, respectively. At the same time intervals, the limb-salvage rate was 88% and 49%. CONCLUSIONS SAP with the aid of a re-entry device for TASC C and D lesions of the SFA seems to be safe and clinically effective in patients suffering from CLI, according to the experience at our centre. Further follow-up and more data are necessary to confirm these findings.

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.

Optical Coherence Tomography after Carotid Stenting: Rate of Stent Malapposition, Plaque Prolapse and Fibrous Cap Rupture According to Stent Design

OBJECTIVES This study aims to evaluate the rate of stent malapposition, plaque prolapse and fibrous cap rupture detected by optical coherence tomography (OCT) imaging according to carotid stent design. DESIGN It was a prospective single-centre study. MATERIALS AND METHODS Forty consecutive patients undergoing protected carotid artery stenting (CAS) and high-definition OCT image acquisition were enrolled in the study. OCT frames were analysed off-line, in a dedicated core laboratory by two independent physicians. Cross-sectional OCT images within the stented segment of the internal carotid artery were evaluated at 1-mm intervals for the presence of strut malapposition, plaque prolapse and fibrous cap rupture according to stent design. RESULTS Closed-cell design stents (CC) were used in 17 patients (42.5%), open-cell design stents (OC) in 13 (32.5%) and hybrid design stents (Hyb) in 10 (25%). No procedural or post-procedural neurological complications occurred (stroke/death 0% at 30 days). On OCT analysis the frequencies of malapposed struts were higher with CC compared to OC and Hyb (34.5% vs 15% and 16.3%, respectively; p < 0.01). Plaque prolapse was more frequent with OC vs CC (68.6% vs 23.3%; p < 0.01) and vs Hyb stents (30.8%; p < 0.01). Significant differences were also noted in the rates of fibrous cap rupture between CC and OC (24.2% vs 43.8%; p < 0.01), and between CC and Hyb (24.2% vs 39.6%; p < 0.01), but not between OC and Hyb stents (p = 0.4). CONCLUSION Intravascular OCT after CAS revealed that micro-defects after stent deployment are frequent and are related to the design of implanted stents. Stent malapposition is more frequent with CC stents, while plaque prolapse is more common with OC stents. It remains, however, unknown whether these figures now detected with OCT are of any clinical and prognostic significance.

AAA with a Challenging Neck: Early Outcomes Using the Endurant Stent-Graft System

OBJECTIVES The efficacy and safety of endovascular aneurysm repair is disputable in aneurysms with a short, angulated, wide, conical, or thrombus-lined neck making a reliable seal difficult to achieve. The influence of a challenging neck on early results using the Endurant stent-graft system in high risk patients was investigated. MATERIALS AND METHODS A retrospective study conducted on a prospectively compiled database of 72 elective patients with challenging neck treated with the Endurant system (Endurant Stent Graft, Medtronic AVE, Santa Rosa, CA, USA). These patients were compared to a control group (n = 65) without significant neck problems. Endpoints were early technical and clinical success, deployment accuracy and differences in operative details at one month follow-up. Data are reported as mean and standard deviation or as absolute frequency and percentage (%). Normality distribution and homogeneity of variances were tested by Shapiro-Wilks and Levene tests, respectively. Inter-group comparisons for each variable were made by t-test or χ2-test or Fisher exact test. A p < 0.05 was considered statistically significant. RESULTS Mean age was 76.12 years; 76.6% were males. Risk factors and pre-operative variables did not differ significantly between the two groups. Mean neck length was 10.56 mm in patients with challenging anatomies and 22.85 mm in controls. Patients with a challenging neck differed significantly (p < 0.001) from controls in terms of mean infrarenal (37.67° vs. 20.12°) and suprarenal angle (19.63° vs. 15.57°); 82% of patients with a challenging neck were ASA III/IV (vs. 86%). Technical success was 100%, with four unplanned proximal extension in challenging group. No type I endoleaks or aneurysm-related deaths occurred in either group; major complications were 1.54% vs. 1.39% (p = 0.942). Operative details were similar in both groups. CONCLUSION Treatment with the Endurant stent-graft is technically feasible and safe, yielding satisfactory results even in challenging anatomies. Medium- and long-term data are needed to verify durability, but early results are promising.

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.

Deferred Urgency Carotid Artery Stenting in Symptomatic Patients: Clinical Lessons and Biomarker Patterns from a Prospective Registry

INTRODUCTION The aim of this prospective observational registry was to study the outcome of symptomatic patients presenting with recent TIA or minor stroke and severe carotid stenosis, submitted to early percutaneous treatment by stenting. A secondary aim was to evaluate the biological activity of the symptomatic carotid plaques by serial serum and urinary markers (PAPP-A, hs-CRP, MMP-2/MMP-9, IL-6/IL-8, TNF alpha, CD40L) measured by enzyme-linked immunosorbent assay before and after treatment. METHODS From May 2005 to June 2006, 57 patients were enrolled in this prospective registry. All patients underwent carotid stenting using a concentric filter for cerebral protection. The procedure was performed within 24-48hrs of the last attack in patients with TIA (n=24, 42%) and between 14 and 30 days in patients with stroke (n=33, 58%). RESULTS Successful stent implantation was achieved in all cases (100%). Adverse events at 1 month were 1 death (1.7%) and 2 TIAs (3.5%). Some of the vulnerability markers, in particular those reflecting an active systemic inflammatory process of the plaque (PAPP-A, hs-CR, and IL-6), were significantly elevated at the time of enrolment, increased after stenting and decreased after 30 days. CONCLUSION Deferred CAS is feasible and safe in selected patients with symptomatic carotid stenosis. This preliminary study in a limited series of patients with unstable carotid plaques revealed that endovascular treatment has a satisfactory outcome considering the very high risk profile of the patient population. The evaluation of some biomarkers suggested an inflammatory role in the process of an unstable carotid plaque generating an acute cerebral event.

Ruptured abdominal aortic aneurysm in the elderly patient.

Abstract The authors discuss several aspects of the management of ruptured abdominal aortic aneurysm in elderly patients. The cost-effectiveness and indications of repair of rAAA in elderly patients are analysed. A literature survey of risk-factors and results of open treatment of rAAA in elderly patients is made. The challenge of endovascular repair of rAAA in the elderly patient is discussed. Finally, the authors report their personnal experience with AAA repair in 163 patients aged 75 years and older, operated on between January 2003 and September 2005(89 endoaneurysmal stent-grafts and 74 open repairs, 42 rAAA,23 symptomatic AAA and 98 selective asymptomatic AAA).