Spinal cord, bowel, and buttock ischemia after endovascular aneurysm repair

A 66-year-old man with multiple comorbidities presented with a juxtarenal perianastomotic aortic aneurysm 10 years after open abdominal aortic aneurysm repair. The aneurysmal disease also involved both iliac bifurcations, the right internal iliac artery, the left common femoral artery (CFA) up to its bifurcation, and the homolateral popliteal artery. We performed bilateral internal iliac artery coil embolization 1-month apart. Later, we performed aortouniiliac endografting extending to the right external iliac artery and placement of an endovascular plug in the left external iliac artery. A right CFA to left femoral bifurcation bypass graft was then constructed after ligation of the left CFA aneurysm. After recovering from anesthesia and despite sequential hypogastric embolization, the patient developed postoperative paraplegia, buttock ischemia, and ischemic colitis and died on postoperative day 5. The possible pathogenic mechanisms involved in the onset of these ischemic complications are discussed in this article.     

Association between the HLA-A2 allele and Alzheimer disease

In the elderly, the most common cause of dementia is Alzheimer disease (AD), which is responsible for the age-related progressive neurodegenerative inflammatory condition mediated by the disease. It has been seen that several genetic and environmental factors are involved in AD onset. Epidemiologic data suggest that some genetic determinants of AD might reside in those polymorphisms that regulate immune inflammatory responses, such as the major histocompatibility complex (MHC). Therefore, several MHC polymorphisms have been in the spotlight of a large number of AD association studies. A possible association of HLA-A2 allele with increased susceptibility to AD has been the subject of debate for more than 20 years, even if the results of these studies, in the various populations, are discordant. Thus, to gain insight in this matter, the authors have studied the HLA-A2 allele for a possible association with sporadic AD in a homogeneous population of Italian patients. For this reason, the distribution of HLA-A2 allele in patients with sporadic AD and controls was analyzed by PCR-SSP assay. The results demonstrated a significant difference in the frequency of HLA-A2 allele between patients with sporadic AD and controls (46% versus 38%). Thus, these data confirm a positive role of HLA-A2 allele in the risk of developing AD. However, some of the observed discrepancies may result from clinical or genetic heterogeneity of the populations under study or methodologic biases. Besides, whenever external agents such as viruses play a role, these might different in the various populations leading to various associations. However, it has to be taken into account that there are many molecular HLA-A2 subtypes with different frequencies in various populations. Therefore, further studies should include molecular typing of HLA-A2 subtypes.     

The nACHR4 594C/T polymorphism in Alzheimer disease

Alzheimer disease (AD) is the most common form of dementia with complex etiology and multifactorial origin. Although several neurochemical deficits have been described in AD patients, explanation of the nature of the cognitive disturbance is focused on the "cholinergic hypothesis." The neuronal nicotinic acetylcholine receptor (neuronal nAChR) belongs to the superfamily of ionic channel activated by ligand. This paper presents a population-based population association study, testing the hypothesis that variants of the nAChR gene confer genetic susceptibility to AD. The authors analyzed two cohorts constituted by 60 controls and 80 AD patients in which significant increase of 594T polymorphism in patients affected by AD versus controls was found. However, further studies are necessary to confirm this polymorphism trend and to establish the polymorphism functionality and its correlation with behavioral and cognitive deficit.     

Strain rate dobutamine echocardiography for prediction of recovery after revascularization in patients with ischemic left ventricular dysfunction

BackgroundThe purpose of the present study was to assess the accuracy of quantitative segmental analysis by strain rate imaging (SRI) technique during dobutamine test for detecting myocardial recovery after revascularization in patients with chronic ischemic regional left ventricular (LV) dysfunction and compare results with those of 2-dimensional echocardiography (2D) and tissue Doppler imaging (TDI) as well as rest-4 hours-24 hours redistribution thallium SPECT (Tl SPECT).Methods and ResultsForty-one patients with chronic ischemic regional LV dysfunction (EF 29 ± 8%) underwent dobutamine 2D/TDI/SRI and Tl SPECT before and after myocardial revascularization. The sensitivity, specificity, and accuracy for the recovery of regional LV function were 73%, 81%, and 77% for dobutamine 2D; 77%, 82%, and 80% for dobutamine TDI; 86%, 88%, and 85% for dobutamine SRI; and 94%, 76%, and 84% for Tl tomography. The area under the ROC curve (AUC), which reflects the overall performance for the prediction of recovery, was 0.79 for systolic-SR, 0.81 for Tl SPECT, 0.83 for postsystolic strain, and 0.87 for isovolumic-SR. If both systolic and postsystolic SRI indexes were combined with Tl SPECT, the AUC was improved to 0.94.ConclusionsDobutamine SRI is more accurate than TDI in identifying hibernating myocardium. Systo-diastolic values obtained using dobutamine SRI echocardiography and values derived from nuclear perfusion techniques may be complementary in assessing myocardial viability.     

Erythrocyte deformability and white blood cell count are associated with aspirin resistance in high-risk vascular patients

Recently the phenomenon of aspirin resistance has been object of several studies, but no data are available on the possible role of the haemorheologic parameters in affecting platelet function and resistance to antiplatelet agents. Aim of our study was to evaluate platelet function and haemorheology in patients with acute coronary syndromes (ACS), receiving double antiplatelet therapy with aspirin and clopidogrel. The study population included 301 (231M/70F; age: 66 +/- 13 yrs) consecutive adult patients admitted to the Coronary Care Unit of the Azienda Ospedaliero-Universitaria Careggi, with diagnosis of acute myocardial infarction or unstable angina. We assessed: whole blood viscosity (WBV) at shear rates of 0.512 s(-1) and 94.5 s(-1), plasma viscosity (PLV) at 94.5 s(-1) shear rate, erythrocyte deformability index (DI) and PFA-100 closure times with ADP (PFA/ADP) and epinephrine (PFA/EPI). We considered any PFA-100-EPI result < 203 sec (95th percentile of control distribution) to be indicative of aspirin resistance. 104/301 patients (34.5%) had PFA/EPI CTs in the reference range (group 1) whereas the remaining had values higher than 203 sec (group 2). WBV at 94.5 sec (-1) s.r. was similar in group 1 and 2 (WBV: 4.43 +/- 0.25 vs 4.45 +/- 0.61 mPa.sec, respectively). PLV and WBV at 0.512 sec (-1) s.r. were slightly higher, but not significantly, in group 1 than in group 2 (PLV: 1.47+/-0.13 vs 1.44 +/- 0.15 mPa.sec; p = 0.08 and WBV: 23.37 +/- 4.6 vs 22.54 +/- 3.90 mPa.sec; p = 0.07). DI was significantly lower in group 1 with respect to group 2 (4.05 +/- 2.93 vs 5.71 +/- 3.30, p < 0.0001). White blood count (WBC) was significantly higher in group 1 than in group 2 (11464 +/- 3504 vs 7867 +/- 2162, p < 0.0001). In conclusion, these results demonstrate that in patients with acute coronary syndromes the antiaggregant effect of aspirin is modulated not only by the direct action on platelets, but also by erythrocyte deformability and white blood cell count.