The Concept of Risk Assessment and Being Unfit for Surgery.

The concept of risk assessment and the identification of surgical unfitness for vascular intervention is a particularly controversial issue today as the minimally invasive surgical population has increased not only in volume but also in complexity (comorbidity profile) and age, requiring an improved pre-operative selection and definition of high risk. A practical step by step (three steps, two points for each) approach for surgical risk assessment is suggested in this review. As a general rule, the identification of a "high risk" patient for vascular surgery follows a step by step process where the risk is clearly defined, quantified (when too "high"?), and thereby stratified based on the procedure, the patient, and the hospital, with the aid of predictive risk scores. However, there is no standardized, updated, and objective definition for surgical unfitness today. The major gap in the current literature on the definition of high risk in vascular patients explains the lack of sound validated predictive systems and limited generalizability of risk scores in vascular surgery. In addition, the concept of fitness is an evolving tool and many traditional high risk criteria and definitions are no longer valid. Given the preventive purpose of most vascular procedures performed in elderly asymptomatic patients, the decision to pursue or withhold surgery requires realistic estimates not only regarding individual peri-operative mortality, but also life expectancy, healthcare priorities, and the patient's primary goals, such as prolongation of life versus maintenance of independence or symptom relief. The overall "frailty" and geriatric risk burden, such as cognitive, functional, social, and nutritional status, are variables that should be also included in the analyses for stratification of surgical risk in elderly vascular patients.

Arbitrary Palliation of Ruptured Abdominal Aortic Aneurysms in the Elderly is no Longer Warranted.

OBJECTIVE/BACKGROUND: A consistent number of elderly patients with ruptured abdominal aortic aneurysms (rAAAs) are deemed unfit for repair and excluded from any treatment. The objective of this study was to examine the impact on survival of endovascular repair and open surgery with restricted turndown in acute AAA repair. METHODS: A prospective database for patients treated for rAAA was established. None of the patients admitted alive with rAAA were denied treatment. Multivariate regression models, the predictive risk assessment Glasgow Aneurysm Score (GAS), and subgroup analyses in older patients were applied to identify indicators of excessive 30 day mortality risk that could affect the decision for turndown. RESULTS: From 2006 to 2015, 113 consecutive patients (93 males; mean age 77.2 years) with rAAAs were treated (69 open surgery; 44 EVAR). Overall peri-operative (30 day) mortality was 38.9% (44/113): 40.6% (28/69), and 36.4% (16/44) after open surgery and EVAR, respectively (p = .70). Multivariate logistic regression identified old age as an indicator of increased peri-operative mortality (odd ratio [OR] 1.2, 95% confidence interval [CI] 1.1-1.3; p = .001), as well as free aneurysm rupture (OR 5.0, 95% CI 1.3-19.9; p = .02). GAS was higher in patients who died (97.75 vs. 86.62), but the score failed to identify increased peri-operative mortality risk in adjusted analyses (OR 1.0; p = .06). Almost two thirds of the patients (n = 71) were older than 75 at the time of aneurysm rupture (48.6% octogenarians) and EVAR was more commonly applied than open surgery (86.4% vs. 47.8%; p < .0001). Peri-operative mortality in > 75 year old patients was 46.5% compared with 26.2% in younger patients (p = .05), with rates increased after open surgery (54.5% vs. 27.8%, p = .03) but not after EVAR (39.5% vs. 16.7%; p = .39). According to Kaplan-Meier estimates, mean survival was 39.7 ± 4.8 months. Patients older than 75 years of age survived for a mean of 23.0 ± 4.47 months after rupture. CONCLUSION: In this study aggressive treatment with a very restricted or no turndown strategy for any rAAA, also applied to older patients, allowed for an additional mean 40 months of survival after aneurysm rupture. In the contemporary endovascular era the decision to deny repair arbitrarily to older patients with rAAAs must be revisited.

Diabetes and abdominal aortic aneurysms.

Epidemiologic evidence suggests that patients with diabetes may have a lower incidence of abdominal aortic aneurysm (AAA); however, the link between diabetes and AAA development and expansion is unclear. The aim of this review is to analyze updated evidence to better understand the impact of diabetes on prevalence, incidence, clinical outcome, and expansion rate of AAA. A systematic review of literature published in the last 20 years using the PubMed and Cochrane databases was undertaken. Studies reporting appropriate data were identified and a meta-analysis performed using the generic inverse variance method. Sixty-four studies were identified. Methodological quality was "fair" in 16 and "good" in 44 studies according to a formal assessment checklist (Newcastle-Ottawa). In 17 large population prevalence studies there was a significant inverse association between diabetes and AAA: pooled odds ratio (OR) 0.80; 95% confidence intervals (CI) 0.70-0.90 (p = .0009). An inverse association was also confirmed by pooled analysis of data from smaller prevalence studies on selected populations (OR 0.59; 95% CI 0.35-0.99; p = .05), while no significant results were provided by case-control studies. A significant lower pooled incidence of new AAA in diabetics was found over six prospective studies: OR 0.54; 95% CI 0.31-0.91; p = .03. Diabetic patients showed increased operative (30-day/in-hospital) mortality after AAA repair: pooled OR 1.26; 95% CI 1.10-1.44; p = .0008. The increased operative risk was more evident in studies with 30-day assessment. In the long-term, diabetics showed lower survival rates at 2-5 years, while there was general evidence of lower growth rates of small AAA in patients with diabetes compared to non-diabetics. There is currently evidence to support an inverse relationship between diabetes and AAA development and enlargement, even though fair methodological quality or unclear risk of bias in many available studies decreases the strength of the finding. At the same time, operative and long-term survival is lower in diabetic patients, suggesting increased cardiovascular burden. The higher mortality in diabetics raises the question as to whether AAA repair should be individualized in selected diabetic populations at higher AAA rupture risk.

Safety of chronic anticoagulation therapy after endovascular abdominal aneurysm repair (EVAR).

OBJECTIVE: Current data supporting the effect of anticoagulation drug use on aneurysm sealing and the durability of endovascular abdominal aneurysm repair (EVAR) are conflicting. This study assessed the safety of chronic anticoagulation therapy after EVAR. METHODS: Records of 1409 consecutive patients having elective EVAR during 1997-2011 who were prospectively followed were reviewed. Survival, reintervention, conversion, and endoleak rates were analyzed in patients with and without chronic anticoagulants. Cox proportional hazards models were used to estimate the effect of anticoagulation therapy on outcomes. RESULTS: One-hundred and three (7.3%) patients were on chronic anticoagulation drugs (80 on vitamin K antagonists) at the time of EVAR. An additional 46 patients started on anticoagulants after repair were identified. Patients on chronic anticoagulation therapy at repair (mean age 73.6 years; 91 males) had more frequent cardiac disease (74.8% vs. 44.2%; p < 00001), but no other differences in demographic and major baseline comorbidities with respect to the others. At baseline, mean abdominal aortic aneurysm (AAA) diameter was 56.43 mm vs. 54.65 mm (p = .076) and aortic neck length 26.54 mm vs. 25.21 mm (p = .26) in patients with and without anticoagulants, respectively. At 5 years, freedom from endoleak rates were 55.5% vs. 69.9% (p < .0001), and freedom from reintervention/conversion rates were 69.4% vs. 82.4% (p < .0001) in patients with (including those with delayed drug use) and without chronic anticoagulants, respectively. Controlling for covariates with the Cox regression method, at a mean follow-up of 64.3 ± 45.2 months after EVAR, use of anticoagulation drugs was independently associated with an increased risk of endoleak (odds ratio, OR 1.6; 95% confidence interval, CI: 1.23-2.07; p < .0001) and reintervention or late conversion rates (OR 1.8; 95% CI: 1.31-2.48; p < .0001). CONCLUSIONS: The safety of anticoagulation therapy after EVAR is debatable. Chronic anticoagulation drug use risks exposure to a poor long-term outcome. A critical and balanced decision-making approach should be applied to patients with AAA and cardiac disease who may require prolonged anticoagulation treatment.

Safety of carotid stenting (CAS) is based on institutional training more than individual experience in large-volume centres.

BACKGROUND: Operator training is a key factor for the safety of carotid stenting (CAS). Whether institutional practice is associated with improved individual operator outcomes is debated. OBJECTIVE: To evaluate the effect of the institutional experience on outcomes of new trainees with CAS, a retrospective analysis of a prospectively held database was performed. METHODS: The overall study period, 2004-2012, was divided into two sequential time frames: 2004-April 2006 (leaders-team phase) and May 2006-2012 (expanded team phase). In the first frame, a single leader-operators team that first approached CAS and passed the original institutional learning curve, performed all the procedures; in the following expanded-team phase, five new trainees joined. Institutional CAS training for new trainees was based on a team-working approach including selection of patients, devices and techniques and collegial meetings with critical review and discussion of all procedural steps and imaging. RESULTS: A total of 431 CAS procedures were performed in the leaders-team phase and 1026 in the sequential expanded-team phase. Periprocedural complication rates in the two time frames were similar: stroke/death (3.0% vs. 2.1%; P = 0.35), stroke (2.8% vs. 2.1%; P = 0.45) major stroke (0.9% vs. 0.6%, P = 0.49), death (0.2% vs. 0%; P = 0.29) during the leaders-team and expanded-team phase, respectively. However, rates of CAS failure requiring surgical conversions (3.7% vs. 0.8%; P < 0.0001) and mean contrast use (91.6 vs. 71.1 ml; P = 0.0001) decreased in the expanded phase. In the expanded-team frame (May 2006-2012), there was no mortality, and stroke rates were comparable between the leader and new operator teams: 2.6% vs. 1.2%; P = 0.17. CONCLUSIONS: Institutional experience, including instruction on selection of patients and materials best suited for the procedure, is a primary factor driving outcomes of CAS. An effective team-working approach can reliably improve the training of new trainees preserving CAS safety and efficacy.

Effect of stentgraft model on aneurysm shrinkage in 1,450 endovascular aortic repairs.

BACKGROUND: Regression of the aneurysmal sac after endovascular repair of abdominal aortic aneurysm (AAA) is an accepted indicator of aneurysm exclusion. This study evaluated the spontaneous decrease in sac diameter over a 10-year period in patients undergoing endovascular aneurysm repair (EVAR) with different stentgrafts. METHODS: 1,450 patients (mean age 73.1 ± 7.7 years; 1,325 male) undergoing EVAR and with a minimum of 1-year computed tomography (CT) imaging were included. Different implanted stentgrafts (n = 622 [42.9%] Zenith, n = 236 [16.3%] AneuRx, n = 179 [12.3%] Talent, n = 83 [5.7%] Endurant, n = 236 [16.3%] Excluder, n = 36 [2.5%] Fortron, 53 [3.7%] Anaconda, n = 5 [0.3%] others) were employed. "Persisting shrinkage" was measured as ≥ 5 mm AAA diameter regression spontaneously persisting or increasing until the end of follow-up without reintervention. Persisting shrinkage among devices was compared with survival and Cox regression analyses. RESULTS: During a median follow-up of 45 months (interquartile range, IQR, 21-79) persisting shrinkage was detected in 768 (53%) aneurysms. Kaplan-Meier estimates of persisting shrinkage were 25.8% at 1 year, 63% at 3 years and 72.6% at 10 years. Persisting shrinkage rates were significantly higher for Zenith (p < .0001), Endurant (p = .013) and new generation Excluder (p < .0001) devices. Cox analyses confirmed that persisting shrinkage rates were independently associated with Zenith (OR 1.33; 95% CI: 1.176-1.514) and Endurant (OR 1.52; 95% CI: 1.108-2.092) stentgrafts and negatively associated with the AneuRx (OR 0.57; 95% CI: 0.477-0.688) device. Survival rates were higher in the persisting shrinkage group: 84.1% vs. 77.8% at 3 years, and 53% vs. 38.1% at 10 years (p < .0001). Freedom from AAA-related-death rate was 100% at 3 years and 99.7% at 10 years in the persisting shrinkage group. CONCLUSIONS: Aneurysm diameter shrinkage can be achieved in most current EVARs with persisting effect at 10 years from repair and indicates the benefit and safety of treatment. Last generation devices seem to be important factors in inducing aneurysm sac shrinkage with similar clinically relevant effects among single models.

Long-term results of iliac aneurysm repair with iliac branched endograft: a 5-year experience on 100 consecutive cases.

BACKGROUND: Iliac branch device (IBD) technique has been introduced as an appealing and effective solution to avoid complications occurring during repair of aorto-iliac aneurysm with extensive iliac involvement. Nevertheless, no large series with long-term follow-up of IBD are available. The aim of this study was to analyse safety and long-term efficacy of IBD in a consecutive series of patients. METHODS: Between 2006 and 2011, 100 consecutive patients were enrolled in a prospective database on IBD. Indications included unilateral or bilateral common iliac artery aneurysms combined or not with abdominal aneurysms. Patients were routinely followed up with computed tomography. Data were reported according to the Kaplan-Meier method. RESULTS: There were 96 males, mean age 74.1 years. Preoperative median common iliac aneurysm diameter was 40 mm (interquartile range (IQR): 35-44 mm). Sixty-seven patients had abdominal aortic aneurysm >35 mm (IQR: 40-57 mm) associated with iliac aneurysm. Eleven patients presented hypogastric aneurysm. Twelve patients underwent isolated iliac repair with IBD and 88 patients received associated endovascular aortic repair. Periprocedural technical success rate was 95%, with no mortality. Two patients experienced external iliac occlusion in the first month. At a median follow-up of 21 months (range 1-60) aneurysm growth >3 mm was detected in four iliac (4%) arteries. Iliac endoleak (one type III and two distal type I) developed in three patients and buttock claudication in four patients. Estimated patency rate of internal iliac branch was 91.4% at 1 and 5 years. Freedom from any reintervention rate was 90% at 1 year and 81.4% at 5 years. No late ruptures occurred. CONCLUSIONS: Long-term results show that IBD use can ensure persistent iliac aneurysm exclusion at 5 years, with low risk of reintervention. This technique can be considered as a first endovascular option in patients with extensive iliac aneurysm disease and favourable anatomy.

No benefit from carotid intervention in fatal stroke prevention for >80-year-old patients.

BACKGROUND: Invasive management of patients ≥80 years of age with carotid stenosis may be questionable. The higher likelihood of stroke needs to be balanced with the increased perioperative risk and the reduced life expectancy of this ageing population. The purpose of this study was to evaluate the clinical relevance of carotid stenosis revascularisation in octogenarians. METHODS: All patients ≥80 years of age who received carotid revascularisation in 2001-2010 were reviewed for perioperative and 5-year outcomes. The experience was comprehensive of carotid endarterectomy (CEA) and carotid stenting (CAS) performed during the training frame when age was not a contraindication for this procedure. Mortality rates were compared to those of octogenarians of the same geographical territory according to all-cause and stroke-related mortality national statistics datasets. RESULTS: A total of 348 procedures performed in ≥80-year-old patients (272 males) were reviewed: 162 (46.6%) were by CAS and 169 (48.6%) were for symptomatic disease. Perioperative stroke/death rate was 5.5% and was non-significantly higher for symptomatic disease (7.1% vs. 3.9% asymptomatic; p = 0.24), after CAS (6.2% vs. 4.8% CEA; p = 0.64) and in females (6.6% vs. 5.1% males; p = 0.57). At median follow-up of 36.18 months, 95 deaths and 21 new ischaemic strokes (12 fatal) occurred with 5-year Kaplan-Meier freedom from stroke of 84.8% (78.7%, symptomatic vs. 90.3% asymptomatic; p = 0.003). According to national datasets, in 80-85-year-old resident population 5-year mortality was 29.9% (23.4% females, 40.6% males) and ischaemic stroke-related mortality was 14.9% (16.8% females, 13.0% males). Corresponding figures from treated population showed a 5-year mortality of 49.4%, higher in males (39.5% females, 52.5% males) and ischaemic stroke-related mortality of 20.2%, higher in females (40.0% females, 15.6% males). Comparing data from the study population with residents' figures, ischaemic stroke-related mortality hazard was significantly higher in the study females: odds ratio (OR) 3.2, 95% confidence interval (CI) 1.16-9.17; p = 0.029 (for males: OR 0.97, 95%CI 0.89-1.10; p = 0.99). CONCLUSIONS: Despite perioperative stroke/death risks being lower compared with CAS, the benefit of surgical carotid revascularisation in old patients remains controversial due to limited life expectancy and high fatality of stroke in this ageing population. Invasive treatment of carotid stenosis may not be warranted in most patients ≥80 years of age with carotid stenosis, especially when female and asymptomatic.

Comparison of surveillance versus aortic endografting for small aneurysm repair (CAESAR): results from a randomised trial.

BACKGROUND: Randomised trials have failed to demonstrate benefit from early surgical repair of small abdominal aortic aneurysm (AAA) compared with surveillance. This study aimed to compare results after endovascular aortic aneurysm repair (EVAR) or surveillance in AAA <5.5 cm. METHODS: Patients (50-79 years) with AAA of 4.1-5.4 cm were randomly assigned, in a 1:1 ratio, to receive immediate EVAR or surveillance by ultrasound and computed tomography (CT) and repair only after a defined threshold (diameter ≥5.5 cm, enlargement >1 cm /year, symptoms) was achieved. The main end point was all-cause mortality. Recruitment is closed; results at a median follow-up of 32.4 months are here reported. RESULTS: Between 2004 and 2008, 360 patients (early EVAR = 182; surveillance = 178) were enrolled. One perioperative death after EVAR and two late ruptures (both in the surveillance group) occurred. At 54 months, there was no significant difference in the main end-point rate [hazard ratio (HR) 0.76; 95% confidence interval (CI) 0.30-1.93; p = 0.6] with Kaplan-Meier estimates of all-cause mortality of 14.5% in the EVAR and 10.1% in the surveillance group. Aneurysm-related mortality, aneurysm rupture and major morbidity rates were similar. Kaplan-Meier estimates of aneurysms growth ≥5 mm at 36 months were 8.4% in the EVAR group and 67.5% in the surveillance group (HR 10.49; 95% CI 6.88-15.96; p < 0.01). For aneurysms under surveillance, the probability of delayed repair was 59.7% at 36 months (84.5% at 54 months). The probability of receiving open repair at 36 months for EVAR feasibility loss was 16.4%. CONCLUSION: Mortality and rupture rates in AAA <5.5 cm are low and no clear advantage was shown between early or delayed EVAR strategy. However, within 36 months, three out of every five small aneurysms under surveillance might grow to require repair and one out of every six might lose feasibility for EVAR. Surveillance is safe for small AAA if close supervision is applied. Long-term data are needed to confirm these results. CLINICAL TRIAL REGISTRATION INFORMATION: This study is registered, NCT Identifier: NCT00118573.

Quality of life in patients with small abdominal aortic aneurysm: the effect of early endovascular repair versus surveillance in the CAESAR trial.

OBJECTIVE: To evaluate and compare changes over time in health-related quality of life reported by patients with small (4.1-5.4 cm) abdominal aortic aneurysms (AAAs) undergoing endovascular aortic aneurysm repair (EVAR) or surveillance. METHODS: Participants were randomly assigned to receive either early EVAR or surveillance within a multicentre, randomised clinical trial on small AAA (Comparison of surveillance vs. Aortic Endografting for Small Aneurysm Repair, CAESAR). Patient-reported health-related quality of life was assessed before randomisation, at 6 months and yearly thereafter using the Short Form 36 (SF-36) Health Survey. RESULTS: Between 2004 and 2008, 360 patients (345 males, mean age 68.9 years) were randomised, 182 to early EVAR and 178 to surveillance. There was one perioperative death. Mean follow-up was 31.8 months. No significant difference in survival was found. At baseline, comparable quality of life scores were recorded in both treatment groups: Total SF-36: 73.0 versus 75.5 (p = 0.18), Physical domain: 71.4 versus 73.3 (p = 0.33); Mental health domain: 70.9 versus 72.7 (p = 0.33), in the EVAR arm versus the surveillance arm, respectively. Six months after randomisation, Total SF-36 and Physical and Mental domain scores were all significantly higher with respect to baseline in the EVAR group, while patients of the surveillance group scored lower. The differences between EVAR and surveillance arms in score changes at 6 months were significant and in favour of EVAR: Total score: difference 5.4; p = 0.0017; Physical: difference 3.8; p = 0.02; and Mental: difference 6.0; p = 0.0005. Differences between EVAR and surveillance diminished over time. At the last assessment, patients in both groups had decreased scores with a significant drop with respect to the baseline (-3.9 in EVAR, -6.3 in surveillance). There were no significant differences between the EVAR and surveillance arms: Total score: p = 0.25; Physical: p = 0.47; and Mental: p = 0.38. CONCLUSIONS: Patients with small AAA under surveillance compared with early EVAR had significant impaired functional health at 6 months after assignment. After a mean of 31.8 months, SF-36 health-related quality of life in patients allocated to early EVAR and surveillance was similar.

Functional ability in patients with critical limb ischaemia is unaffected by successful revascularisation.

OBJECTIVE: Patient- and society-oriented measures of outcome have a critical role in determining the effectiveness of any treatment in patients with critical limb ischaemia (CLI). In particular, the impact of an intervention on patient's dependency and functional performance is relevant but is largely unknown. The aim of the study was to investigate whether the limitations encountered in the activities of daily living (ADLs) measured with the Katz Index (KI) in patients with CLI were changed by the treatment. METHODS: During the period 2006-2008, 248 consecutive patients undergoing repair for CLI were investigated with an ADL questionnaire for assessing KI before and after a mean of 16.19 months from treatment. Changes in KI were stratified by type of treatment and outcome. RESULTS: There were 165 males and 83 females, mean age 73.3 ± 8.3 years; 125 patients showed tissue loss and 123 rest pain alone, 98 received surgical bypass and 150 endovascular repair. Pre-operative KI mean was 10.42. At the post-operative assessment, there was significant worsening in patients' functional outcome (mean KI decreased to 9.78) despite relief of pain (81.5%), tissue healing (72%), good vessel patency (83.8%) and low amputation rate (9.7%). Deterioration of KI was not significantly higher in patients undergoing endovascular repair. Patients receiving major amputation started with worse pre-operative functional score (KI mean 9.42) and did further deteriorate (KI mean 7.71) after demolition surgery. However, patients who received successful revascularisation showed deterioration in the dependence index. CONCLUSIONS: Successful vascular treatment is not associated with improved functional ability in patients with CLI, especially when already highly dependent in their activities. Large nationwide preventive and educational programmes should be implemented to prevent irreversible and severe health deterioration in populations with CLI.

Second-generation thienopyridine use is not associated with better early perioperative outcome during carotid stenting.

OBJECTIVE: Management of anti-platelet therapy during carotid artery stenting (CAS) is mainly based on indirect evidence from coronary stenting experience. There is common agreement on the use of thienopyridine (mainly second-generation) during CAS, but some patients are unsuitable for clopidogrel treatment and data on the benefit of its use in large CAS populations are lacking. The aim of this study was to investigate whether clopidogrel was associated with reduced perioperative morbidity in patients undergoing CAS. METHODS: Consecutive patients undergoing CAS for primary carotid stenosis from 2004 to 2009 were reviewed. The independent association of clopidogrel and perioperative morbidity was assessed using multivariable analysis. RESULTS: A total of 1083 patients were treated (29% females, mean age 71.6 years); 825 (76%) patients were given clopidogrel starting before treatment. Clopidogrel use was associated with a non-significant reduction of perioperative stroke/death (4.3% vs. 2.4%; p = 0.13) and disabling stroke (1.2% vs. 1.0%; p = 1) rates. The non-significant stroke/death difference was similar in symptomatic (5.8% vs. 4.0%, p = 0.37) and asymptomatic (3.7% vs. 1.9%; p = 0.17) patients. After adjusting for demographics, co-morbidities and other therapies with multivariable analysis, clopidogrel use failed to show any significant independent association in decreasing operative risks. The only independent protective factor was use of statins (p = 0.010). The additional use of dual anti-platelet therapy did not add any advantage to the use of clopidogrel alone. CONCLUSIONS: The suggested benefit of clopidogrel in decreasing the incidence of complications in patients undergoing CAS may be overestimated due to the overlapping effect of other more relevant factors (e.g., pleiotropy and plaque stabilisation from statins). More data and level I evidence are needed to understand which is the best medical management of CAS that will help improve outcomes of the procedure.

Operative outcomes using a side-branched thoracoabdominal aortic graft (STAG) for thoraco-abdominal aortic repair.

BACKGROUND: Pre-manufactured branched grafts now allow an endovascular approach to the repair of thoraco-abdominal aortic aneurysm (TAAA) with visceral vessels' involvement. Similar grafts have been employed in open surgery, generally as a second choice for TAAAs, which are not amenable to patch/inclusion technique for visceral vessel attachment. Results with branched grafts have not been reported in series of open TAAA repairs. The purpose of this report is to describe perioperative risks and outcomes in a consecutive series of patients with pre-manufactured side-branched thoracoabdominal aortic grafts (STAGs) for surgical TAAA repair. METHODS: Between 1996 and 2009, pre-manufactured STAGs were used in 50 patients with TAAA that required reattachment of the visceral and renal arteries. Operative details, perioperative mortality and ischaemic complications were examined. RESULTS: Mean age was 53 years; 18 patients were females. The cases included redo (n = 24), patients affected by genetic disorder (Marfan) (n = 20) and patients with aortic dissection (n = 27). The mean clamp time was 84.1 min. Perioperative mortality was 12.0% (6/50). Neurologic deficits occurred in 2% (1/50). Postoperative renal dysfunction was detected in 19 patients (38%). CONCLUSION: The use of a STAG produced acceptable mortality, bowel and neurological ischaemic risks. Improved strategies to prevent renal ischaemia before and during repair of TAAA with visceral involvement are needed.

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.

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.

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.