Massimo Lenti

The role of carotid artery stenting and carotid endarterectomy in cognitive performance: a systematic review.

Background and Purpose— Change in cognition is being increasingly recognized as an important outcome measure; however, the role of carotid revascularization on this issue remains to be determined. It is still under debate whether carotid artery stenting and carotid endarterectomy have the same influence on neuropsychological functions. Summary of Review— This article systematically reviews recent literature in an attempt to clarify this issue. A total of 32 papers reporting on neurocognition after carotid endarterectomy (n=25), carotid artery stenting (n=4), or carotid artery stenting versus carotid endarterectomy (n=3) were identified. The studies were different for many methodological factors, eg, sample size, type of patients and control group, statistical measure, type of test, timing of assessment, and so on. There was a lack of consensus in defining the improvement or impairment after either carotid artery stenting or carotid endarterectomy. Furthermore, there were nonuneqivocal results regarding the same domain of assessment (memory, visuomotor, attention). Based on available evidence, it is probable that carotid endarterectomy as well as carotid artery stenting do not change neuropsychological function “per se.” Conclusions— Assessment of cognition after carotid revascularization is probably influenced by many confounding factors such as learning effect, type of test, type of patients, and control group, which are often minimized in their importance. The role of carotid revascularization is to prevent stroke in patients with severe carotid stenosis as highlighted by previous large randomized trials. Although an effect of carotid revascularization on cognition could be missed as a consequence of underpowered studies included in this review, at this time, no prediction can be done regarding its repercussions on higher intellectual functions. Larger studies appropriately designed and powered to assess cognition after carotid revascularization might change this view.

Treatment of acute occlusion of peripheral arteries

Acute lower-extremity peripheral arterial occlusion is responsible for a wide variety of complications culminating in limb loss or death. The real incidence of acute limb ischemia (ALI) in the general population is not well known even though recent epidemiological data estimated that it occurs in 14 out of a population of 100,000 and that it accounts for 10-16% of the vascular workload. The two main causes of acute occlusion of peripheral arteries are: (i) embolism and (ii) thrombosis, which usually occurs in cases of severe atherosclerotic stenoses. Arterial flow can be restored through operative revascularization or pharmacological dissolution of thrombus. Immediate surgical revascularization is indicated in the profoundly ischemic limb. Catheter embolectomy is also usually preferred for emboli to a non-atherosclerotic limb. Catheter-directed thrombolysis has become a commonly employed technique in the treatment of ALI. It may offer definitive treatment without the need of major surgery in a significant subset of patients with acute occlusion of a native leg artery or a bypass graft. A number or reports from individual centers and three large prospective studies, which compared intra-arterial thrombolysis to surgical intervention, suggest that thrombolytic therapy may be an appropriate initial treatment of ALI, provided that the limb is not immediately or irreversibly threatened. Using this approach, the underlying lesions can be further defined by angiography, and the percutaneous or surgical revascularization procedure can be performed. However, severe bleeding is still a non-rare complication of intra-arterial thrombolysis and the risk of intracranial hemorrhage is 1-2%.

Eversion versus Conventional Carotid Endarterectomy: A Prospective Study

OBJECTIVES To analyse comparatively eversion and conventional CEA for later association with restenosis, perioperative stroke/death and ipsilateral cerebrovascular events (early, late, disabling and non-disabling). DESIGN Prospective non-randomised clinical study. MATERIALS AND METHODS A total of 469 patients underwent 514 procedures; 274 (53%) eversion CEA and 240 (47%) conventional CEA. Perioperative monitoring was carried out by clinical evaluation under local anaesthesia or by transcranial Doppler under general anaesthesia. Follow-up was carried out by clinical evaluation and Duplex scanning. RESULTS Clamping time was significantly shorter in the eversion group (25.5 +/- 7.4 vs. 28.3 +/- 10.1 min; p = 0.0001; CI delta 4.40/1.12). The perioperative disabling stroke/death rate was 0.7% for eversion vs. 1.2% for conventional CEA, p = 0.6; odds ratio (OR), 0.58. There were two early carotid occlusions (within 30 days) in both groups. According to life-table analysis, after 3 years the probability of > 50% carotid restenosis was significantly lower in the eversion group (2.2% vs. 6.9%, p = 0.03; relative risk reduction 67%). There were no significant differences between the two groups relative to new cerebrovascular events (92% in both groups, p = 0.6). Using multivariate analysis (Cox regression), eversion CEA, and to a lesser extent standard CEA with patch, appeared to protect the vessel from restenosis. CONCLUSIONS The eversion technique was associated with reduced clamping time and probability of restenosis. However, because of the nature of a non-randomised study, the present analysis should be confirmed by a multicentre randomised trial.

Aortic neck evolution after endovascular repair with TriVascular Ovation stent graft

OBJECTIVE Aortic neck dilation has been reported after endovascular aneurysm repair (EVAR) with self-expanding devices. With a core laboratory analysis of morphologic changes, this study evaluated midterm results of aortic neck evolution after EVAR by endograft with no chronic outward force. METHODS This was a multicenter registry of all patients undergoing EVAR with the Ovation endograft (TriVascular, Santa Rosa, Calif). Inclusion criteria were at least 24 months of follow-up. Standard computed tomography (CT) scans were reviewed centrally using a dedicated software with multiplanar and volume reconstructions. Proximal aortic neck was segmented into zone A (suprarenal aorta/fixation area), zone B (infrarenal aorta, from lowest renal artery to the first polymer-filled ring), and zone C (infrarenal aorta, at level of the first polymer-filled ring/sealing zone). Images were analyzed for neck enlargement (≥2 mm), graft migration (≥3 mm), endoleak, barb detachment, neck bulging, and patency of the celiac trunk and superior mesenteric and renal arteries. RESULTS Inclusion criteria were met in 161 patients (mean age, 75.2 years; 92% male). During a mean follow-up period of 32 months (range, 24-50), 17 patients died (no abdominal aortic aneurysm-related death). Primary clinical success at 2 years was 95.1% (defined as absence of aneurysm-related death, type I or type III endoleak, graft infection or thrombosis, aneurysm expansion >5 mm, aneurysm rupture, or conversion to open repair). Assisted primary clinical success was 100%. CT scan images at a minimum follow-up of 2 years were available in 89 cases. Patency of visceral arteries at the level of suprarenal fixation (zone A) was 100%. Neither graft migration nor barb detachment or neck bulging was observed. None of the patients had significant neck enlargement. The mean change in the diameter was 0.18 ± 0.22 mm at zone A, -0.32 ± 0.87 mm at zone B, and -0.06 ± 0.97 mm at zone C. Changes at zone B correlated significantly with changes at zone C (correlation coefficient, 0.183; P = .05), whereas no correlation was found with zone A (correlation coefficient, 0.000; P = 1.0). CONCLUSIONS No aortic neck dilation occurred in this series at CT scan after a minimum 24-month follow-up. This may suggest that aortic neck evolution is not associated with EVAR at midterm follow-up when an endograft with no chronic outward radial force is implanted.

Effects of diabetes on small aortic aneurysms under surveillance according to a subgroup analysis from a randomized trial

BACKGROUND This study aims to investigate the impact of diabetes in the management of patients with small abdominal aortic aneurysms (AAA). METHODS Three-hundred sixty patients with small AAA (4.1-5.4 cm), enrolled in a randomized trial comparing early endovascular repair versus surveillance and delayed repair (after achievement of >5.5 cm or growth>1 cm/yr), were analyzed with standard survival methods to assess the relation between diabetes and risk of all-cause mortality, complications, and aneurysm growth (on computed tomography as per trial protocol) at 36 months. Baseline covariates were selected with partial likelihood stepwise method to investigate factors (demographic, morphologic, medications) associated with risk of aneurysm growth during surveillance. RESULTS Prevalence of diabetes was 13.6%. The hazard ratio (HR) for all-cause mortality at 36 months was higher in diabetic compared with nondiabetic patients: (HR, 7.39; 95% confidence interval [CI], 1.55-35.13; P=.012). Baseline aneurysm diameter was comparable between diabetic and nondiabetic patients enrolled in the surveillance arm and was related to subsequent aneurysm growth in covariance analyses adjusted for diabetes (49.3 mm for nondiabetic; 50.2 mm for diabetic). Cox analyses found diabetes as the strongest independent negative predictor of 63% lower probability of aneurysm growth>5 mm during surveillance (HR, 0.37; 95% CI, 0.15-0.92; P=.003). Kaplan-Meier cumulative probability of aneurysm growth>5 mm at 36 months was 40.8% in diabetics versus 85.1% in nondiabetics (HR, 0.32; 95% CI, 0.17-0.61). CONCLUSIONS Progression of small AAA seems to be more than 60% lower in patients with diabetes. This may help to identify high-risk subgroups at higher likelihood of AAA enlargement, such as nondiabetics, for surveillance protocols in patients with small AAA.

Midterm results of proximal aneurysm sealing with the ovation stent-graft according to On-vs off-label use

Purpose: To compare the use of the Ovation stent-graft according to the ≥7-mm neck length specified by the original instructions for use (IFU) vs those treated off-label (OL) for necks <7 mm long. Methods: A multicenter retrospective registry (TriVascular Ovation Italian Study) database of all patients who underwent endovascular aneurysm repair with the Ovation endograft at 13 centers in Italy was interrogated to identify patients with a minimum computed tomography (CT) follow-up of 24 months, retrieving records on 89 patients (mean age 76.4±2.4 years; 84 men) with a mean follow-up of 32 months (range 24–50). Standard CT scans (preoperative, 1-month postoperative, and latest follow-up) were reviewed by an independent core laboratory for morphological changes. For analysis, patients were stratified into 2 groups based on proximal neck length ≥7 mm (IFU group, n=57) or <7 mm (OL group, n=32). Outcome measures included freedom from type Ia endoleak, any device-related reintervention, migration, and neck enlargement (>2 mm). Results: At 3 years, there was no aneurysm-related death, rupture, stent-graft migration, or neck enlargement. There were no differences in terms of freedom from type Ia endoleak (98.2% IFU vs 96.8% OL, p=0.6; hazard ratio [HR] 0.55, 95% CI 0.02 to 9.71 or freedom from any device-related reintervention (92.8% IFU vs 96.4% OL, p=0.4; HR 2.42, 95% CI 0.34 to 12.99). In the sealing zone, the mean change in diameters was −0.05±0.8 mm in the IFU group and −0.1±0.5 mm in the OL group. Conclusion: Use of the Ovation stent-graft in patients with neck length <7 mm achieved midterm outcomes similar to patients with ≥7-mm-long necks. These midterm data show that the use of the Ovation system for the treatment of infrarenal abdominal aortic aneurysm is not restricted by the conventional measurement of aortic neck length, affirming the recent Food and Drug Administration–approved changes to the IFU.

Pulmonary sequestration supplied by giant aneurysmal aortic branch.

We report a case of an intralobar sequestration supplied by a 13-cm aneurysmal vessel originating from the abdominal aorta. The malformation was discovered during a roentgenogram investigation of an abdominal infrarenal aneurysm. During the endovascular repair of the abdominal aneurysm, the giant feeding vessel of the pulmonary sequestration was embolized. Two days later the patient underwent an uneventful resection of the malformation en bloc with the right lower lobe through a standard right thoracotomy.

Matrix metalloproteinase-2 of human carotid atherosclerotic plaques promotes platelet activation. Correlation with ischaemic events.

Purified active matrix metalloproteinase-2 (MMP-2) is able to promote platelet aggregation. We aimed to assess the role of MMP-2 expressed in atherosclerotic plaques in the platelet-activating potential of human carotid plaques and its correlation with ischaemic events. Carotid plaques from 81 patients undergoing endarterectomy were tested for pro-MMP-2 and TIMP-2 content by zymography and ELISA. Plaque extracts were incubated with gel-filtered platelets from healthy volunteers for 2 minutes before the addition of a subthreshold concentration of thrombin receptor activating peptide-6 (TRAP-6) and aggregation was assessed. Moreover, platelet deposition on plaque extracts immobilised on plastic coverslips under high shear-rate flow conditions was measured. Forty-three plaque extracts (53%) potentiated platelet aggregation (+233 ± 26.8%), an effect prevented by three different specific MMP-2 inhibitors (inhibitor II, TIMP-2, moAb anti-MMP-2). The pro-MMP-2/TIMP-2 ratio of plaques potentiating platelet aggregation was significantly higher than that of plaques not potentiating it (3.67 ± 1.21 vs 1.01 ± 0.43, p<0.05). Moreover, the platelet aggregation-potentiating effect, the active-MMP-2 content and the active MMP-2/pro-MMP-2 ratio of plaque extracts were significantly higher in plaques from patients who developed a subsequent major cardiovascular event. In conclusion, atherosclerotic plaques exert a prothrombotic effect by potentiating platelet activation due to their content of MMP-2; an elevated MMP-2 activity in plaques is associated with a higher rate of subsequent ischaemic cerebrovascular events.

Effect of statins on survival in patients undergoing dialysis access for end-stage renal disease

The benefit of statin therapy in patients with advanced chronic kidney disease remains uncertain. Randomized trials have questioned the efficacy of the drug in improving outcomes for on-dialysis populations, and many patients with end-stage renal disease are not currently taking statins. This study aimed to investigate the impact of statin use on survival of patients with vascular access performed at a vascular center for chronic dialysis. Consecutive end-stage renal disease patients admitted for vascular access surgery in 2006 to 2013 were reviewed. Information on therapy was retrieved and patients on statins were compared to those who were not on statins. Primary endpoint was 5-year survival. Independent predictors of mortality were assessed with Cox regression analysis adjusting for covariates (ie, age, sex, hyperlipidemia, hypertension, cardiac disease, cerebrovascular disease, chronic obstructive pulmonary disease, obesity, diabetes, and statins). Three hundred fifty-nine patients (230 males; mean age 68.9 ± 13.7 years) receiving 554 vascular accesses were analyzed: 127 (35.4%) were on statins. Use of statins was more frequent in patients with hypertension (89.8% v 81%; P = .034), hyperlipidemia (52.4% v 6.2%; P < .0001), coronary disease (54.1% v 42.6%; P = .043), diabetes (39.4% v 21.6%; P = .001), and obesity (11.6% v 2.0%; P < .0001). Mean follow-up was 35 months. Kaplan-Meier survival rates at 3 and 5 years were 84.4% and 75.9% for patients taking statins and 77.0% and 65.1% for those not taking statins (P = .18). Cox regression analysis selected statins therapy as the only independent negative predictor (odds ratio = 0.55; 95% confidence interval = 0.32-0.95; P = .032) of mortality, while age was an independent positive predictor (odds ratio = 1.05; 95% confidence interval = 1.03-1.08; P < .0001). Vascular access patency was comparable in statin takers and those not taking statins (P = .60). Use of statins might halve the risk of all-cause mortality at 5 years in adult patients with vascular access for chronic dialysis. Statins therapy should be considered in end-stage renal disease populations requiring dialysis access placement.

Fourteen-year outcomes of abdominal aortic endovascular repair with the Zenith stent graft

Objective: Long‐term results of abdominal aortic aneurysm (AAA) endovascular repair are affected by graft design renewals that tend to improve the performance of older generation prostheses but usually reset the follow‐up times to zero. The present study investigated the long‐term outcomes of endovascular AAA repair (EVAR) using the Zenith graft, still in use without major modification, in a single center experience. Methods: Between 2000 and 2011, 610 patients underwent elective EVAR using the Zenith endograft (Cook Inc, Bloomington, Ind) and represent the study group. Primary outcomes were overall survival, freedom from AAA rupture, and freedom from AAA‐related death. Secondary outcomes included freedom from late (>30 days) reintervention, freedom from late (>30 days) conversion to open repair, freedom from aneurysm sac enlargement >5.0 mm and freedom from EVAR failure, defined as a composite of AAA‐related death, AAA rupture, AAA growth >5 mm, and any reintervention. Results: Mean age was 73.2 years. Mean aneurysm diameter was 55.3 mm. There were five perioperative deaths (0.8%) and three intraoperative conversions. At a mean follow‐up of 99.2 (range, 0‐175) months, seven AAA ruptures occurred, all fatal except one. Overall survival was 92.8% ± 1.1% at 1 year, 70.1% ± 1.9% at 5 years, 37.8% ± 2.9% at 10 years, and 24 ± 4% at 14 years. Freedom from AAA‐rupture was 99.8% ± 0.02 at 1 year (one case), 99.4% ± 0.04 at 5 years (three cases), and 98.1% ± 0.07 at 10 and 14 years. Freedom from late reintervention and conversion was 98% ± 0.6 at 1 year, 87.7% ± 1.5 at 5 years, 75.7% ± 3.2 at 10 years, and 69.9% ± 5.2 at 14 years. Freedom from aneurysm sac growth >5.0 mm was 99.8% at 1 year, 96.6% ± 0.7 at 5 years, 81.0% ± 3.4 at 10 years, and 74.1% ± 5.8% at 14 years. EVAR failure occurred in 132 (21.6%) patients at 14 years. At multivariate analysis, independent predictors of EVAR failure resulted type I and III endoleak (hazard ratio [HR], 6.7; 95% confidence interval [CI], 4.6‐ 9.7; P < .001], type II endoleak (HR, 2.3; 95% CI, 1.6‐3.4; P < .001), and American Society of Anesthesiologists grade 4 (HR, 1.6; 95% CI, 1.0‐2.6; P = .034). Conclusions: EVAR with Zenith graft represents a safe and durable repair. Risk of rupture and aneurysm‐related death is low, whereas overall long‐term survival remains poor. Novel endograft models should be tested and evaluated considering that one‐fourth of the operated patients will still be alive after 14 years.