The Fluid-Dynamics of Endo Vascular Aneurysm Sealing (EVAS) System failure.

PURPOSE: The main objective of this work is to investigate hemodynamics phenomena occurring in EVAS (Endo Vascular Aneurysm Sealing), to understand if and how they could lead to type 1a endoleaks and following re-intervention. To this aim, methods based on computational fluid mechanics are implemented as a tool for checking the behavior of a specific EVAS configuration, starting from the post-operative conditions. Pressure and velocity fields are detailed and compared, for two configurations of the Nellix, one as attained after correct implantation and the other in pathological conditions, as a consequence of migration or dislocation of endobags. METHODS: The computational fluid dynamics (CFD) approach is used to simulate the behavior of blood within a segment of the aorta, before and after the abdominal bifurcation. The adopted procedure allows reconstructing the detailed vascular geometry from high-resolution computerized tomography (CT scan) and generating the mesh on which the equations of fluid mechanics are discretized and solved, in order to derive pressure and velocity field during heartbeats. RESULTS: The main results are obtained in terms of local velocity fields and wall pressures. Within the endobags, velocities are usually quite regular during the whole cardiac cycle for the post-implanted condition, whereas they are more irregular for the migrated case. The largest differences among the two cases are observed in the shape and location of the recirculation region in the rear part of the aorta and the region between the endobags, with the formation of a gap due to the migration of one or both of the two. In this gap, the pressure fields are highly different among the two conditions, showing pressure peaks and pressure gradients at least four times larger for the migrated case in comparison to the post-implanted condition. CONCLUSIONS: In this paper, the migration of one or both endobags is supposed to be related to the existing differential pressures acting in the gap formed between the two, which could go on pushing the two branches one away from the other, thus causing aneurysm re-activation and endoleaks. Regions of flow recirculation and low-pressure drops are revealed only in case of endobag migration and in presence of an aneurysm. These regions are supposed to lead to possible plaque formation and atherosclerosis.

The Influence of Diabetes Mellitus on the Outcome of Superficial Femoral Artery Recanalization is Debatable.

Notwithstanding technological improvements in endovascular devices treatment of steno-obstructive lesions of the superficial femoral artery (SFA) remains a challenge for today's vascular surgeon. Current opinion dictates that the diabetic population may have worse outcome after revascularization of the lower extremities. Herein we examine the effects of endovascular treatment on steno-obstructive lesions of the SFA in diabetic and non-diabetic patients. METHODS: A retrospective analysis was carried out on 110 patients who had undergone endovascular treatment of the SFA from 2010 to 2017 comparing outcomes in diabetic (DM) vs non-diabetic patients (nDM). RESULTS: 56 (50.9%) of the patients were diabetic and 54 were non-diabetic (49.1%). 52.7% (62.7% DM vs 35.2% nDM, p = 0.0003) were patients with critical limb ischemia. SFA occlusion was present in 65.5% (60.7% DM vs 70.4% nDM, p = 0.29) of all patients. All had undergone PTA of the SFA and 40.9% had received adjunctive stenting (44.6% DM vs 37.0% nDM, p = 0.41). A multilevel treatment was executed in 39.1% (51.8% DM vs 25.9% nDM) of the cases whereas an infra-popliteal procedure was associated in 27.3% (37.5% DM vs 16.7% nDM). In both groups the presence of diabetes was significantly associated (p = 0.005 e p = 0.014, respectively). Reintervention rate was 22.7%; 13 in the diabetic group (23.2%) and 12 in the non-diabetic group (22.2%). Of those who had had reintervention (p = 0.77); 9 patients (8.2%) had undergone an open surgical operation, 6 of whom had diabetes (p = 0.32). 5 patients (4.5%) had had major amputation, 4 of whom were diabetic (p = 0.20). Curves assessing freedom from target lesion restenosis were substantially overlapping between the two groups. CONCLUSION: No statistical associations between diabetes and reintervention or amputation rates were found. Indication to treat the SFA were not influenced by the presence of diabetes but further investigation is required to verify our hypothesis.

Lag3+ regulatory T lymphocytes in critical carotid artery stenosis.

The aim of this study was to evaluate CD25+ and Lag3+ T regulatory subpopulations in patients with critical carotid artery stenosis (CAS) and Stanford-A acute aortic dissection (AAD). CD25+ and Lag3+ were measured in 36 patients affected by CAS and 24 patients with Stanford type A AAD. Based on neurological symptoms, patients affected by CAS were further divided in 25 asymptomatic (CAS-A) and 11 symptomatic (CAS-S) subjects. Twenty-five patients with traditional cardiovascular risk factors (RF), matched for age and sex, were used as control group. Interleukin (IL)-10, IL-6 and transforming growth factor-ß-levels were also measured. CD25+ T cells were significantly increased in CAS-S versus CAS-A (p > 0.05), AAD (p > 0.05) and RF (p > 0.05). Moreover, a significant increase in Lag3+ Tregs was observed in CAS e CAS-S versus AAD (p < 0.05) and RF (p < 0.05), whereas no significant difference was observed between CAS-S and CAS-A. IL-6 was higher in AAD compared to the other groups. Patients with neurological symptoms display a peculiar expansion of CD25+ T cells, strongly confirming a relationship between ischemic brain damage and this regulatory subpopulation, whereas Lag3+ Tregs early distinguish CAS from AAD and probably exert protective actions against aortic wall rupture throughout their anti-inflammatory functions.

Hemodynamic changes in Chevalier eversion versus conventional carotid endarterectomy.

OBJECTIVES: The eversion carotid endartectomy (E-CEA), mainly performed by means of Vanmaele technique, has been associated with loss of the baroreceptor reflex and postoperative hypertension. The purpose of this paper is to determine whether the eversion endarterectomy performed by means of Chevalier technique (C-CEA) modifies the function and the efficiency of baroreceptors, leading to lower postoperative hemodynamic change. METHODS: A retrospective review of 380 patients who underwent carotid endarterectomy (120 Chevalier-CEA; 260 Standard-CEA) from December 2002 to November 2012 has been performed. The changes of blood pressure baseline during the postoperative course in C-CEA and S-CEA group were analysed and compared. Postoperative hypertension was defined as an elevation of systolic pressure >180 mm Hg or >40% rise above baseline. RESULTS: The patients with Chevalier eversion technique did not develop a significantly higher blood pressure in the postoperative course compared to those operated with the standard technique. In the recovery room, the mean systolic blood pressure was 134 ± 21.9 mm Hg in C-CEA group versus 132 ± 24.6 mm Hg in S-CEA group. In the first postoperative day it was 132 ± 17.2 mm Hg in C-CEA versus 133 ± 17.4 mm Hg in S-CEA group. During the first six hours in the recovery room, the need for intravenous antihypertensive drugs was similar in the two groups. Fourteen patients in C-CEA group (11%) and thirty patients (11.5%) in the S-CEA group required vasodilators, without any significant difference (p = 1). The dosage of current preoperative antihypertensive therapy was increased in six patients (4.9%) of C-CEA group and in twelve patients (4.9%) of S-CEA group, without significant difference (p = 1). CONCLUSIONS: C-CEA has the same rate of postoperative hypertension of standard-CEA, which is probably related to the sparing of baroreceptor apparatus, compared to standard E-CEA. The Chevalier procedure could represent an E-CEA technique with its inherent advantages, without penalties related to postoperative hypertension, commonly observed after E-CEA.

Pulmonary embolism due to popliteal vein aneurysm: approach and surgical treatment - a case report.

Pulmonary embolism is the first presentation in 70-80% in patients with aneurysm of popliteal vein. We present a case of young man admitted in our hospital with respiratory distress, tachycardia and D-dimer >3000 mg/dL. The observation of pulmonary embolism required the placement of a caval temporary filter before the surgical treatment. The use of temporary filter is recommended in symptomatic patients for thromboembolic phenomena, and when ultrasound detects the presence of floating thrombus.

Endotension-related aortic sac rupture treated by endograft relining.

Endovascular aortic aneurysm repair is an effective alternative to open surgical repair in high risk patient. Endotension is an unpredictable late and rare complication of EVAR. Clinical significance and choice of technique for treatment are controversial. At present, there are no cases of endotension-related aneurysmal sac rupture reported in literature, altough it is frequently associated with late surgical conversion. In this case report is described a case of a patient treated with a first generation Gore Excluder(TM) endograft for abdominal aortic aneurysm, with late aneurysmal sac enlargement without evidence of endoleak and subsequent contained rupture without anemia and shock. We have successfully treated the patient by endovascular procedure, through bilateral percutaneous femoral approach, with relining technique. Three years CT scan follow-up showed the endograft patency and size sac reduction.

Transcranial Doppler and diffusion-weighted magnetic resonance evaluation of cerebral embolization occurring during transfemoral carotid stenting with proximal flow blockage.

AIM: Transfemoral carotid artery stenting (CAS) with endovascular proximal flow blockage is deemed able to reduce the cerebral embolization observed during filter-protected CAS. We evaluated clinical outcome and intraoperative embolization rates, measured by diffusion-weighted magnetic resonance imaging (DW-MRI) and transcranial Doppler monitoring, in a series of patients undergoing CAS with proximal flow blockage. METHODS: A series of 35 consecutive patients with symptomatic or asymptomatic internal carotid artery stenosis ≥70% were included to undergo CAS with proximal flow blockage, obtained with the Mo.Ma system. All patients underwent preoperative and postoperative DW-MRI in order to detect new ischemic lesions. Of the 35 patients, 31 (89%) underwent intraoperative transcranial Doppler monitoring to record the microembolic signals (MES) produced during each procedure. RESULTS: The MoMa system was successfully used in 34 patients (technical success: 97%). Intolerance to balloon occlusion was observed in 4 patients (12%), but never compromised the completion of the procedure. No deaths or neurological events occurred in the postoperative period. DW-MRI disclosed 74 new ischemic lesions in 8 patients (8/34, 23.5%). All lesions except one were ipsilateral to the treated carotid artery. MES were detected in all procedures, with a mean number of 33.2±23.2 (range 3-103). In 20 procedures (20/31, 65%), MES were detected also during flow blockage (mean: 9.1±7; range 2-28). CONCLUSION: While achieving good technical and clinical results, CAS with proximal flow blockage is still accompanied by a non-negligible cerebral embolization. The detection of MES during ICA flow blockage suggests the need for a better selection of patients.

Urgent Carotid Surgery: Is It Still out of Debate?

Patients with symptomatic tight carotid stenosis have an increased short-time risk of stroke and an increased long-term risk of ischaemic vascular events compared with the general population. The aim of this study is to assess the safety, efficacy, and limitations of urgent CEA or CAS, in patients with carotid stenosis greater than 70% and clinically characterized by recurrent TIA or brain damage following a stroke (<2.5 cm). This study involved 28 patients divided into two groups. Group A consisted of sixteen patients who had undergone CEA, and group B consisted of twelve patients who had undergone CAS. Primary endpoints were mortality, neurological morbidity (by NIHSS) and postoperative hemorrhagic cerebral conversion, at 30 days. Ten patients (62.5%) of group A experienced an improvement in their initial neurological deficit while in 4 cases (26%) the deficit remained stable. Two cases of neurologic mortality are presented. At 1 month, 9 patients (75%) of group B experienced an improvement in their initial neurological deficit while 3 patients (25%) had a neurological impairment. Urgent or deferred surgical or endovascular treatment have a satisfactory outcome considering the profile in very high-risk patient population. Otherwise in selected patients CEA seems to be preferred to CAS.

Detecting microcalcifications in atherosclerotic plaques by a simple trichromic staining method for epoxy embedded carotid endarterectomies.

Atherosclerotic plaques have a high probability of undergoing rapid progression to stenosis, becoming responsible of acute coronary syndrome or stroke. Microcalcifications may act as enhancers of atherosclerotic plaque vulnerability. Considering that calcifications with a diameter smaller than 10 mm in paraffin embedded tissue are rather difficult to detect, our aim was to analyze microcalcifications on semithin sections from epoxy resin embedded samples of carotid endarterectomies using an original trichromic stain (methylene blue--azur B--basic fuchsine--alizarin red). We have compared samples stained either with our method, methylene blue-azur B alone or with Von Kossa staining, and methylene blue-azur B -basic fuchsine alone or with Von Kossa staining. Our method resulted to be simple and fast (ca. 2 min), it gives a sharp general contrast for all structures and allows to easy identify collagen and elastin. In addition, gray-green colour associated to intracellular lipid droplets evidences foam cells, which are particularly abundant in endarterectomies samples. Mast cells and their metachromatic granules are also well recognized. Calcifications over 0,5 mm are clearly recognizable. In conclusion, microcalcifications are clearly distinguished from the extracellular matrix in spite of their reduced dimensions. Methylene blue--azur B--basic fuchsine--alizarin red method is easy to use, reproducible, and is particularly suitable for the identification of microcalcifications in the morphological analysis of atherosclerotic plaques.

Aortic arch catheterization during transfemoral carotid artery stenting: an underestimated source of cerebral emboli.

Cerebral embolization is still a major concern in patients undergoing transfemoral carotid artery stenting. Intraoperative transcranial Doppler (TCD) monitoring and diffusion-weighted magnetic resonance imaging (DW-MRI), two techniques currently used to study this phenomenon, have provided data suggesting the importance of aortic arch catheterization in determining the overall embolic load observed during this procedure. In order to reduce this cerebral embolization, some Authors have proposed the performance of carotid artery stenting through a cervical access, either surgical or percutaneous. We review in this article the available TCD and DW-MRI data supporting transcervical CAS, along with its clinical results.

Cervical access for filter-protected carotid artery stenting: a useful tool to reduce cerebral embolisation.

BACKGROUND: Filter-protected transcervical carotid artery stenting (CAS) has been suggested to reduce the intraoperative cerebral embolisation observed during transfemoral CAS. We therefore evaluated clinical outcome and incidence of ischaemic lesions at diffusion-weighted magnetic resonance imaging (DW-MRI) after transcervical and transfemoral CAS. METHODS: From March 2007 to May 2009, we performed filter-protected CAS in 135 patients with symptomatic (30%) or asymptomatic (70%) carotid stenosis above 70% and below 95%. In 44 patients with risky femoral access or unfavourable aortic arch anatomy, access to common carotid artery was achieved by a small cervical incision. In another 91 procedures we used a classic percutaneous femoral access. Preoperative and postoperative DW-MRI scans were obtained after 111 procedures (82%) - 35 transcervical and 76 transfemoral. RESULTS: The incidence of clinical events (transient ischaemic attack (TIA) and stroke) was 2.3% after transcervical CAS and 19.8% after transfemoral CAS (P<0.01), without any deaths. DW-MRI disclosed new ischaemic lesions in five patients (5/35, 14.3%) after transcervical CAS and in 28 patients (28/76, 36.8%) after transfemoral CAS (P=0.015). All ischaemic lesions depicted after transcervical procedures were ipsilateral to the treated artery. CONCLUSIONS: Transcervical filter-protected CAS, compared with classic percutaneous procedures, seems to reduce clinical events and DW-MRI ischaemic damage and may be useful in selected patients.

Safety and effectiveness of combining carotid artery stenting with cardiac surgery: preliminary results of a single-center experience.

AIM: Optimal strategy (staged or combined) for the treatment of patients with concurrent severe carotid and cardiac disease is still controversial. Moreover, carotid artery stenting (CAS), has become a valid alternative to carotid endarterectomy (CEA) and has been proposed for the treatment of cardiac patients. The authors report the preliminary results of a new therapeutic strategy consisting in combined CAS and cardiac surgery. METHODS: An initial series of 22 patients underwent combined CAS and cardiac surgery in the same operating room and under general anesthesia. All filter-protected CAS procedures were performed under only heparin and aspirin. A cervical approach (3-cm cervicotomy) was used in patients with documented vessel tortuosity or severe aorto-iliac occlusive arteriopathy. In all the other cases a femoral access was used. A double antiplatelet regimen was initiated in the early postoperative period, once major bleedings were excluded. RESULTS: Among the 22 patients who underwent this combined procedure, no deaths, no myocardial infarctions and one controlateral stroke (overall complication rate: 4.5%) were observed. This stroke was observed after transcervical CAS, coronary artery bypass and mitral valve replacement. No major postoperative bleedings nor stent thrombosis were observed. CONCLUSIONS: Combined carotid stenting and cardiac surgery, performed in the same operating room under only heparin and aspirin, seems a safe and effective strategy for the treatment of patients with concomitant carotid and cardiac disease.

Late evaluation of silent cerebral ischemia detected by diffusion-weighted MR imaging after filter-protected carotid artery stenting.

BACKGROUND AND PURPOSE: Postoperative diffusion-weighted MR imaging (DWI) often discloses new lesions after carotid artery stent placement (CAS), most of them asymptomatic. Our aim was to investigate the fate of these silent ischemic lesions. MATERIALS AND METHODS: We prospectively studied 110 patients undergoing protected transfemoral CAS, 98 of whom underwent DWI before and after the intervention. Patients in whom DWI disclosed silent postoperative lesions also had delayed MR imaging. Preoperative, postoperative, and delayed scans were compared. RESULTS: Of the 92 patients without postoperative symptoms, DWI disclosed 33 new silent ischemic lesions in 14 patients (15.2%), 13 of whom (30 lesions) underwent delayed MR imaging after a mean follow-up of 6.2 months. In 8 of these 13 patients (61%), MR imaging disclosed 12 persistent lesions (12/30, 40%). The reversibility rate depended significantly on the location (cortical versus subcortical) and size (0-5 versus 5-10 mm) of the lesions (P < .05 by chi(2) test). CONCLUSIONS: Because many silent ischemic lesions seen on postoperative DWI after CAS reverse within months, the extent of permanent CAS-related cerebral damage may be overestimated.

Cerebral embolization in patients undergoing protected carotid-artery stenting and carotid surgery.

AIM: Intraoperative cerebral embolization is a greater concern in patients undergoing carotid-artery stenting (CAS) than in those undergoing the reference standard treatment carotid endarterectomy (CEA). We evaluated cerebral embolism with diffusion-weighted magnetic resonance imaging (DW-MRI) and transcranial Doppler monitoring during CAS and CEA. METHODS: A series of 75 patients with carotid stenosis, 40 undergoing CEA and 35 transfemoral protected CAS, underwent preoperative and postoperative cerebral DW-MRI. Of the 75 patients, 64 (85%) underwent intraoperative transcranial Doppler monitoring to evaluate the mean number of microembolic signals (MES) recorded in each procedure. RESULTS: None of the patients died. No patient in the CEA but two in the CAS group had strokes (5.7%, P=NS). The mean MES count on transcranial Doppler monitoring was higher in the CAS than in the CEA group (330.0 MES, range 2754 vs 13.2, range 0-49 MES; P<0.01). DW-MRI disclosed a significantly larger number of new ischemic lesions in the CAS than in the CEA group (40 lesions in 12/35 patients, 34.3% vs 4 lesions in 3/40 patients, 7.5%; P<0.01). In the CEA group, all patients with ischemic lesions were asymptomatic whereas in the CAS group 5 were symptomatic (14.3%) and 7 asymptomatic (20%). The cerebral distribution also differed in the two groups: no CEA but 20% of CAS lesions were contralateral. CONCLUSION: CAS is associated with a significantly higher rate of cerebral embolization than CEA. Even though the clinical meaning of new postoperative ischemic lesions remains debatable, it seems prudent to reduce the embolic load by improving procedural techniques and cerebral protection devices.

Salmonella reinfection manifesting as a fistula between the duodenum and an aortic stump pseudoaneurysm.

Despite the worldwide increase in Salmonella infections, a Salmonella infection of an aortic graft is an exceptional event. A Salmonella reinfection manifesting as a fistula between the duodenum and an aortic stump pseudoaneurysm 30 months after prosthetic excision, aortic ligature and extra-anatomic bypass for a Salmonella graft infection is a unique event. This unusual late complication described in this case report developed in 1 of the 5 patients whose Salmonella aortic graft infections have been previously reported. The reinfection causing septic aortitis responded to conventional surgery.

[Role of aortofemoral bypass in the management of unilateral iliac occlusive disease. A follow-up study of 95 patients over a 25-year period]. / Terapia endoscopica del sanguinamento non varicoso del tratto digestivo superiore.

BACKGROUND: To evaluate the results in a series of patients submitted to aortofemoral bypass due to an unilateral iliac occlusion. METHODS: Retrospective follow-up study. A total of 95 patients underwent, between 1975 and 2000, aortofemoral bypass because of unilateral iliac occlusion. Most of them (71 patients) were claudicants, Fontaine stage II b, while 12 complained rest pain and 12 suffered ischemic ulcers. Mean follow-up was 128 months (min 2.5 - max 292). RESULTS: Immediate success was obtained in 88 cases (92.6%), 7 patients were submitted to early redo with restored patency in 6 cases. One month global patency was gained in 98.9% (94 cases). The mean Ankle-brachial index (ABI) improvement was 0.35. At a mean follow-up of 128 months the cumulative patency was 90.8%. During the follow-up, 15 graft occlusions were observed, followed by 9 successful reoperations achieving a 5-year secondary patency of 92.1%. The contralateral iliac artery evolved toward an occlusion in 10 patients (10.5%) during a long time observation (104 months average). CONCLUSIONS: The unilateral aortofemoral bypass confirmed an excellent long term outcome regarding effectiveness and graft related complications. The low contralateral occlusion rate, in our series, does not justify a more aggressive approach as first surgical option.

Non-atherosclerotic saccular aneurysmal degeneration of a saphenous-vein graft inserted for repair of a popliteal aneurysm.

The Authors describe a case of a saccular aneurysm formation in a femoropopliteal autologous saphenous vein graft, inserted 12 years before. The patient was initially treated for a popliteal aneurysm. The graft revealed no microscopic signs of atherosclerosis. In spite of the widespread use of the autologous saphenous vein as arterial substitute, this complication is extremely rare.

Immunoscintigraphy of atherosclerotic uncomplicated lesions in vivo with a monoclonal antibody against D-dimers of insoluble fibrin.

To test the effectiveness of a new F(ab')2 monoclonal antibody against human fragment D-dimer of cross-linked fibrin in the detection of uncomplicated atherosclerotic lesions of the carotid vessel previously documented at echo-color-Doppler and selective arteriographic study, 8 patients underwent a scintigraphic study including dynamic and early and delayed (3 h later) static imaging of the neck after injection of a bolus of 99mTc-labeled monoclonal antibody, and were subsequently operated. Vessel specimens and blood samples were drawn at operation and counted. No adverse reaction occurred after administration of the monoclonal antibody. The atherosclerotic lesion appeared as a focal area of asymmetrical tracer uptake, already visible at early images in four patients, and at delayed images in five. The average tracer uptake ratio between pathological and normal vessels was 1.40+0.24 (P < 0.05) at time-activity curves derived from dynamic images, 2.17+/-0.97 (P < 0.05) at early static images and 2.05+/-0.98 (P < 0.05) at delayed static images, respectively. Mean vessel to blood uptake rate of specimens obtained at operation was 2.22+/-0.59 (P < 0.001). The study shows that the 99mTc-labeled antibody was found to be safe and capable of detecting atherosclerotic plaques in humans.