Endovascular management of visceral artery aneurysms: When to watch,when to intervene?

Visceral artery aneurysms (VAA) include splanchnic and renal artery aneurysms. They represent a rare clinical entity, although their detection is rising due to an increased use of cross-sectional imaging. Rupture is the most devastating complication, and is associated with a high morbidity and mortality. In addition, increased percutaneous endovascular interventions have raised the incidence of iatrogenic visceral artery pseudoaneurysms (VAPAs). For this reason, elective repair is preferable in the appropriately chosen patient. Controversy still exists regarding their treatment. Over the past decade, there has been steady increase in the utilization of minimally invasive, non-operative interventions, for vascular aneurysmal disease. All VAAs and VAPAs can technically be fixed by endovascular techniques but that does not mean they should. These catheter-based techniques constitute an excellent approach in the elective setting. However, in the emergent setting it may carry a higher morbidity and mortality. The decision for intervention has to take into account the size and the natural history of the lesion, the risk of rupture, which is high during pregnancy, and the relative risk of surgical or radiological intervention. For splanchnic artery aneurysms, we should recognize that we are not, in reality, well informed about their natural history. For most asymptomatic aneurysms, expectant treatment is acceptable. For large, symptomatic or aneurysms with a high risk of rupture, endovascular treatment has become the first-line therapy. Treatment of VAPAs is always mandatory because of the high risk of rupture. We present our point of view on interventional radiology in the splanchnic arteries, focusing on what has been achieved and the remaining challenges.     

Dendritic spine morphology determines membrane-associated protein exchange between dendritic shafts and spine heads

The purpose of this study was to examine whether variability in the shape of dendritic spines affects protein movement within the plasma membrane. Using a combination of confocal microscopy and the fluorescence loss in photobleaching technique in living hippocampal CA1 pyramidal neurons expressing membrane-linked GFP, we observed a clear correlation between spine shape parameters and the diffusion and compartmentalization of membrane-associated proteins. The kinetics of membrane-linked GFP exchange between the dendritic shaft and the spine head compartment were slower in dendritic spines with long necks and/or large heads than in those with short necks and/or small heads. Furthermore, when the spine area was reduced by eliciting epileptiform activity, the kinetics of protein exchange between the spine compartments exhibited a concomitant decrease. As synaptic plasticity is considered to involve the dynamic flux by lateral diffusion of membrane-bound proteins into and out of the synapse, our data suggest that spine shape represents an important parameter in the susceptibility of synapses to undergo plastic change.     

Characterisation of carotid plaques with ultrasound elastography: feasibility and correlation with high-resolution magnetic resonance imaging

Objectives

To evaluate the ability of ultrasound non-invasive vascular elastography (NIVE) strain analysis to characterise carotid plaque composition and vulnerability as determined by high-resolution magnetic resonance imaging (MRI).

Methods

Thirty-one subjects with 50 % or greater carotid stenosis underwent NIVE and high-resolution MRI of internal carotid arteries. Time-varying strain images (elastograms) of segmented plaques were generated from ultrasonic raw radiofrequency sequences. On MRI, corresponding plaques and components were segmented and quantified. Associations between strain parameters, plaque composition and symptomatology were estimated with curve-fitting regressions and Mann–Whitney tests.

Results

Mean stenosis and age were 72.7 % and 69.3 years, respectively. Of 31 plaques, 9 were symptomatic, 17 contained lipid and 7 were vulnerable on MRI. Strains were significantly lower in plaques containing a lipid core compared with those without lipid, with 77–100 % sensitivity and 57–79 % specificity (P?<?0.032). A statistically significant quadratic fit was found between strain and lipid content (P?<?0.03). Strains did not discriminate symptomatic patients or vulnerable plaques.

Conclusions

Ultrasound NIVE is feasible in patients with significant carotid stenosis and can detect the presence of a lipid core with high sensitivity and moderate specificity. Studies of plaque progression with NIVE are required to identify vulnerable plaques.

Key points

? Non-invasive vascular elastography (NIVE) provides additional information in vascular ultrasound ? Ultrasound NIVE is feasible in patients with significant carotid stenosis ? Ultrasound NIVE detects a lipid core with high sensitivity and moderate specificity ? Studies on plaque progression with NIVE are required to identify vulnerable plaques     

Automatic prediction of infarct growth in acute ischemic stroke from MR apparent diffusion coefficient maps

RATIONALE AND OBJECTIVES: We introduce a new approach to the prediction of final infarct growth in human acute ischemic stroke based on image analysis of the apparent diffusion coefficient (ADC) maps obtained from magnetic resonance imaging. Evidence from multiple previous studies indicate that ADC maps are likely to reveal brain regions belonging to the ischemic penumbra, that is, areas that may be at risk of infarction in the few hours following stroke onset. MATERIALS AND METHODS: In a context where "time is brain," and contrarily to the alternative-and still-debated-perfusion-diffusion weighted image (PWI/DWI) mismatch approach, the DWI magnetic resonance sequences are standardized, fast to acquire, and do not necessitate injection of a contrast agent. The image analysis approach presented here consists of the segmentation of the ischemic penumbra using a fast three-dimensional region-growing technique that mimics the growth of the infarct lesion during acute stroke. RESULTS: The method was evaluated with both numerical simulations and on two groups of 20 ischemic stroke patients (40 patients total). The first group of patient data was used to adjust the parameters of the model ruling the region-growing procedure. The second group of patient data was dedicated to evaluation purposes only, with no subsequent adjustment of the free parameters of the image-analysis procedure. Results indicate that the predicted final infarct volumes are significantly correlated with the true final lesion volumes as revealed by follow-up measurements from DWI sequences. CONCLUSION: The DWI-ADC mismatch method is an encouraging fast alternative to the PWI-DWI mismatch approach to evaluate the likeliness of infarct growth during the acute stage of ischemic stroke.     

Association of bone activity, calcium load, aortic stiffness, and calcifications in ESRD

An inverse relationship between arterial calcifications and bone activity has been documented in patients with ESRD. Calcium overload is associated with arterial calcification, which is associated with arterial stiffening. Whether bone activity interacts with calcium load, aortic stiffness, or arterial calcification is unknown. This study assessed the impact of bone activity on the relationships between the dosage of calcium-containing phosphate binders and aortic stiffness (measured by pulse wave velocity) or abdominal aorta calcification score. Aortic stiffness and calcification were both positively associated with calcium load and negatively associated with bone activity. A significant interaction was found between dosage of calcium-containing phosphate binders and bone activity such that calcium load had a significantly greater influence on aortic calcifications and stiffening in the presence of adynamic bone disease. Independent of any other factor, including dosage of calcium-containing phosphate binders, adynamic bone was associated with greater aortic stiffening, suggesting cross-talk between the bone and arterial walls.     

In vitro mitogen-stimulated T-cell from hepatitis C virus-positive liver transplantation candidates, increases T-cell activation markers and T-cell proliferation

The incidence of acute rejection is significantly higher in hepatitis C virus (HCV) liver-transplant patients than in patients who have received a graft for other liver diseases, i.e., mainly alcoholic cirrhosis. The aim of this study was to assess T-cell function, i.e., intralymphocyte cytokine expression (IL-2 and TNF-alpha), T-cell activation [i.e., transferrin receptor (CD71) and interleukin (IL)-2 alpha-chain (CD25) expression], and T-cell proliferation using a flow-cytometry whole-blood assay in patients waiting for a liver transplantation (n=49). Our data suggest that, in mitogen-stimulated T-cells, (i) intra-lymphocyte cytokine expression is significantly higher in patients with liver disease than in healthy volunteers (n=25); (ii) the expression of T-cell activation markers is decreased in patients with liver cirrhosis compared to healthy volunteers, and (iii) the expression of T-cell activation markers and T-cell proliferation are increased in patients with HCV infection (n=15) compared to those without HCV infection (n=34), particularly compared to patients with alcoholic liver disease (n=19). Circulating CD19-positive cells count was also significantly higher in HCV-positive patients. In conclusion, in vitro, mitogen-stimulated T-cell seem to induce a higher immune response in the blood from patients waiting for a liver transplant for HCV-related liver disease than those without HCV infection, and particularly those with alcoholic liver disease.     

Aortic cusp extension valvuloplasty for rheumatic aortic valve disease: midterm results

BACKGROUND: The introduction of composite graft repair of aortic root aneurysm by Hugh Bentall in 1968 promised Marfan patients the choice for a normal life expectancy. We performed our first Bentall composite graft procedure in 1976 and herein report our 24-year experience with 271 Marfan patients. METHODS: Between September 1976 and August 2000, 232 Marfan patients had a composite graft replacement of the aortic root, 15 patients received a homograft, and 24 had a valve-sparing procedure. RESULTS: Two hundred thirty-five Marfan patients underwent elective aortic root replacement with no 30-day mortality. Two early deaths occurred among 36 patients who underwent urgent or emergent operation. Eighty-three percent of patients in this series are currently alive. The actuarial freedom from thromboembolism, endocarditis, and reoperation on the residual aorta 20 years postoperatively was 93%, 90%, and 74%. Twenty-four patients have undergone valve-sparing procedures with encouraging results. CONCLUSIONS: Elective aortic root replacement for Marfan patients can be performed with low operative risk. Elective repair before the aortic root reaches 6 cm in diameter is recommended to minimize risk of dissection and rupture.     

Chronic active gastritis in X-linked lymphoproliferative disease

Gastric lesions in primary constitutive immune deficiencies include multifocal atrophic gastritis, erosive pangastritis, and a pattern of gastric lesions reminiscent of graft-versus-host disease. We describe the genetic anomalies in 2 monozygotic twins with an X-linked lymphoproliferative disease (XLP; MIM 308240), a rare familial setting of high susceptibility to Epstein-Barr virus (EBV). Since early childhood, both twin brothers exhibited a severe chronic active atrophic pangastritis. A germline screening of the SH2D1A (MIM 300490) and BIRC4 (MIM 300079) genes was performed, and also a high-resolution whole-genome SNP profiling (Infinium Sentrix Human-1 Genotyping BeadChip, Illumina). A 3 Megabase deletion in the Xq25 region, encompassing the SH2D1A gene, was defined by SNP array genotyping. Histologic analysis of yearly or twice yearly gastric biopsies in both children showed a Helicobacter pylori-negative, Epstein-Barr virus-negative chronic active atrophic pangastritis, with superficial ulcer formation, foveolar hyperplasia, glandular dilatation and ultimately pseudopyloric and intestinal metaplasia. No such chronic active inflammatory gastric lesions have been reported to date in XLP. The similarities between XLP and common variable immunodeficiency (MIM 240500) underscore the need for early recognition and close monitoring of these gastric lesions, with special regard to their neoplastic potential. No infectious cause was determined. We favor a dysimmune mechanism in the development of this chronic atrophic gastritis, presenting a striking similarity to the recently described atrophic autoimmune pangastritis.     

Pediatric Single‐Lumen Cannula Venovenous Extracorporeal Membrane Oxygenation: A French Center Experience

Single‐lumen cannula venovenous (VV) extracorporeal membrane oxygenation (ECMO) is a special extracorporeal life support (ECLS) technique used for neonatal and pediatric refractory hypoxemia. This is an alternative flow rate ECLS that consists of successive clamping on the drainage and the injection lines. Currently, the Armand‐Trousseau's pediatric intensive care unit remains the only pediatric ECMO center proposing this partial assistance. This article details a technical note and a retrospective analysis of our experience in refractory hypoxemia. The retrospective study, from 2007 to 2011, included all pediatric and neonatal patients treated by single‐lumen cannula VV ECMO. The study was focused on pre‐ECMO patient characteristics and complications during ECMO course. During the last 5 years, 67 pediatric patients were assisted by this single‐lumen cannula VV ECMO. Sixty‐one patients (91%) were newborns. Thirty‐nine patients presented with meconium aspiration syndrome (58%), which was the most frequent etiology. Before cannulation, mean oxygenation index (OI) was 32 ± 11, alveolar‐arterial oxygen difference was 604 ± 47 mm Hg, and partial pressure arterial oxygen/fraction inspired oxygen ratio was 59.2 ± 35.8. Forty‐eight patients (72%) presented pulmonary hypertension, and 66 patients were treated by nitric oxide (98%). Fifty patients (75%) were treated by vasopressors or inotropic drugs. Average duration of ECMO was 13.2 ± 7.8 days. There were forty‐six survivors (69%). The worst prognosis was for respiratory syncytial virus pneumonia. Complications like acute renal injury and hematologic and transfusion acts were not so different than those observed in classical ECMO techniques. Nevertheless, 19 patients presented a stroke (28% of the overall population), but this high rate did not seem to be due to the ECLS technique used. Single‐lumen cannula VV ECMO is a partial and efficient ECMO support. Our experience shows that this technique is as efficient and less invasive than two cannulas ECMO. The single‐lumen cannula VV ECMO is a simple and safe ECLS support used for neonatal or pediatric refractory hypoxemia. Because this is a partial assistance, it is a promising ECLS support.