Multi-detector computed tomography in coronary artery bypass graft assessment: a meta-analysis

Multi-detector computed tomography (MDCT) has become an alternative to coronary angiography in diagnosis of graft occlusion and stenosis after coronary artery bypass. A literature search was performed for studies comparing angiography to 8-slice, 16-slice, and 64-slice MDCT in the assessment of coronary grafts. In assessing occlusion, 14 studies produced pooled sensitivity of 97.6%, specificity of 98.5%, diagnostic odds ratio of 934.2, area under the curve of 0.996, and Q* of 0.977. Ninety-six percent of all grafts were visualized for occlusion assessment. Beta blockers, symptomatic status, and postoperative period did not significantly affect diagnostic performance. Stenosis assessment produced sensitivity of 88.7% and specificity of 97.4%. Eighty-eight percent of patent grafts could be assessed for stenosis. The diagnostic accuracy of MDCT approaches angiography for diagnosing graft occlusion and stenosis in patients with venous and arterial coronary bypass grafts. Our findings show that cardiac surgeons will need to interpret MDCT images of both native and grafted vessels soon in preparation for primary or re-do coronary bypass grafting procedures.     

Results of the national pilot screening program for venous disease by the American Venous Forum

OBJECTIVE: This report describes the pilot of a free comprehensive national screening program for venous disease. METHODS: The screening process consisted of a venous thromboembolism (VTE) risk assessment, abbreviated duplex examination for venous obstruction and reflux, inspection for signs of chronic venous insufficiency (CVI), and an exit interview. Physicians coordinating the screenings were members of the American Venous Forum. RESULTS: Seventeen institutions screened 476 people (mean, 28 per site; range, 6 to 71). Mean age was 60 years (range, 40 to 91 years), with 78% women and 68% with a body mass index of > or =25. If placed in a situation conducive for VTE, 22 participants (5%) were low risk, 87 (18%) were moderate risk, 186 (39%) were high risk, and 179 (38%) were at very high risk. In 26 people (6%), one or more segments had venous obstruction, and 190 (40%) had one or more segments of venous reflux in the lower extremities. Varicose veins were present in 32%, edema without skin changes in 11%, skin changes attributable to venous disease in 8%, and healed or active venous stasis ulcer in 1.3% (CEAP classification 2, 3, 4, 5, and 6, respectively). Increasing age and increasing deep venous thrombosis risk score significantly correlated with increasing clinical classification, r = 0.09, P = .04, and r = 0.16, P = .0004, respectively. Those participants with reflux in one or more segments were significantly more likely to have a higher clinical classification compared with those with no reflux (P = .0001). CONCLUSION: The first comprehensive national screening for venous disease was performed. Participants were informed of their risk for VTE if placed in a situation conducive to VTE, screened for evidence of obstruction, reflux, and CVI, and empowered to share their results with their primary care provider.     

Brief review: Anesthetic implications of long QT syndrome in pregnancy

PURPOSE: To review the effects of the long QT syndrome (LQTS) in the parturient and the current anesthetic management of patients with LQTS. SOURCE: Relevant articles were obtained from a MEDLINE search spanning the years 1980-2006 and a PubMed search spanning the years 1949-2006. Bibliographies of retrieved articles were searched for additional articles. PRINCIPAL FINDINGS: The prevalence of LQTS in the developed world is one per 1,100 to 3,000 of the population. Clinically, LQTS is characterized by syncope, cardiac arrest and occasionally, by a history of seizures. The QT interval can also be prolonged by drugs, electrolyte imbalances, toxins and certain medical conditions. Long QT syndrome patients are at risk of torsades de pointes and ventricular fibrillation. Medical management aims to reduce dysrhythmia frequency. The LQTS is subdivided into different groups (LQT1-6) depending on the cardiac ion channel abnormality. Torsades can be precipitated by adrenergic stimuli such as stress or pain (LQT1 and 2), sudden noises (LQT2) or whilst sleeping (LQT3). Patients with LQTS require careful anesthetic management as they are at high risk of torsades perioperatively despite minimal data on the effects of anesthetic agents on the QT interval. While information on effects of LQTS in pregnancy is limited, the incidence of dysrhythmia increases postpartum. Isolated case reports of patients with LQTS women highlight several peripartum dysrhythmias. CONCLUSION: An understanding of LQTS and the associated risk factors contributing to dysrhythmias is important for anesthesthesiologists caring for parturients with LQTS.     

Response to glucose tolerance testing and solid high carbohydrate challenge: comparison between Roux-en-Y gastric bypass, vertical sleeve gastrectomy, and duodenal switch

Background

Hyperinsulinemic hypoglycemia is common after Roux-en-Y gastric bypass (RYGB) and may result in weight regain. The purpose of our investigation was to compare the effect of RYGB, vertical sleeve gastrectomy (VSG), and duodenal switch (DS) on insulin and glucose response to carbohydrate challenge.

Methods

Patients meeting National Institutes of Health criteria for bariatric surgery selected their bariatric procedure after evaluation and education in this prospective nonrandomized study. Preoperatively and at 6, 9, and 12 months’ follow-up, patients underwent blood draw to determine levels of fasting glucose, fasting insulin, glycated hemoglobin (HbA1c), C-peptide, and 2-h oral glucose challenge test. Homoeostatic Model Assessment (HOMA)-IR, fasting to 1-h and 1- to 2-h ratios of glucose and insulin, were calculated. Statistical analysis was performed using ANOVA and Student’s paired t test. All procedures were performed via a laparoscopic technique at a single institution.

Results

Data from a total of 38 patients (13 RYGB, 12 VSG, 13 DS) were available for analysis. At baseline, all groups were similar; the only statistically significant difference was that DS patients had a higher preoperative weight and body mass index (BMI). All operations caused weight loss (BMI 47.7 ± 10–30.7 ± 6.4 kg/m² in RYGB; 45.7 ± 8.5–31.1 ± 5.5 kg/m² in VSG; 55.9 ± 11.4–27.5 ± 5.6 kg/m² in DS), reduction of fasting glucose, and improved insulin sensitivity. RYGB patients had a rapid rise in glucose with an accompanying rise in 1-h insulin to a level that exceeded preoperative levels. This was followed by a rapid decrease in glucose level. In comparison, DS patients had a lower increase in glucose and 1-h insulin, and the lowest HbA1c. These differences were statistically significant at various data points. For VSG, the results were intermediary.

Conclusions

Compared to gastric bypass, DS results in greater weight loss and improves insulin sensitivity and glucose homeostasis without causing a hyperinsulinemic response. Because the response to challenge after VSG is intermediary, pyloric preservation alone cannot account for this difference.     

Arterial “inflammaging” drives vascular calcification in children on dialysis

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Preservation of porcine non-heart-beating donor livers by sequential cold storage and warm perfusion

BACKGROUND: Normothermic perfusion has been shown to resuscitate and maintain viability of non-heart-beating donor (NHBD) livers that have undergone significant warm ischemic injury. However, the logistics of clinical organ retrieval are complex, and a period of cold storage before warm preservation would simplify the process. We have investigated the effects of short duration of cold preservation before normothermic preservation on the function of porcine NHBD livers. METHODS: Porcine livers were subjected to 60 minutes of warm ischemia and then assigned to the following groups: group W (n=5), normothermic preservation for 24 hours; and group C (n=4), cold preservation in University of Wisconsin solution for 4 hours followed by normothermic preservation for 20 hours (total preservation time 24 hours). Outcome parameters that were measured included bile production, serum transaminases and hyaluronic acid levels (cellular damage), and base deficit and glucose use (metabolic function). RESULTS: Group W livers had superior bile production, metabolic activity (base deficit and greater glucose use), and less evidence of hepatocellular damage (alanine aminotransferase, aspartate aminotransferase), and sinusoidal endothelial cell dysfunction (hyaluronic acid). Group C livers showed greater necrosis and destruction of architecture on histology. CONCLUSION: Normothermic perfusion failed to resuscitate porcine livers after 60 minutes of warm ischemia and 4 hours of cold preservation. Even a short period of cold ischemia is significantly deleterious to the function of ischemically damaged (NHBD) livers.     

Reproducibility of proton MR spectroscopic imaging (PEPSI): comparison of dyslexic and normal-reading children and effects of treatment on brain lactate levels during language tasks

BACKGROUND AND PURPOSE: We repeated a proton echo-planar spectroscopic imaging (PEPSI) study to test the hypothesis that children with dyslexia and good readers differ in brain lactate activation during a phonologic judgment task before but not after instructional treatment. METHODS: We measured PEPSI brain lactate activation (TR/TE, 4000/144; 1.5 T) at two points 1-2 months apart during two language tasks (phonologic and lexical) and a control task (passive listening). Dyslexic participants (n = 10) and control participants (n = 8) (boys and girls aged 9-12 years) were matched in age, verbal intelligence quotients, and valid PEPSI voxels. In contrast to patients in past studies who received combined treatment, our patients were randomly assigned to either phonologic or morphologic (meaning-based) intervention between the scanning sessions. RESULTS: Before treatment, the patients showed significantly greater lactate elevation in the left frontal regions (including the inferior frontal gyrus) during the phonologic task. Both patients and control subjects differed significantly in the right parietal and occipital regions during both tasks. After treatment, the two groups did not significantly differ in any brain region during either task, but individuals given morphologic treatment were significantly more likely to have reduced left frontal lactate activation during the phonologic task. CONCLUSION: The previous finding of greater left frontal lactate elevation in children with dyslexia during a phonologic judgment task was replicated, and brain activation changed as a result of treatment. However, the treatment effect was due to the morphologic component rather than the phonologic component.     

Biliary atresia--a fifteen-year review of clinical and pathologic factors associated with liver transplantation

Purpose

The aim of this study was to identify clinical and pathologic factors associated with liver transplantation in infants with biliary atresia initially treated with Kasai hepatic portoenterostomy (KHPE).

Methods

Institutional Review Board approval was obtained. Records of patients with biliary atresia diagnosed between January 1986 and December 2000 were reviewed. Patients were divided into those who never required transplantation, those who underwent transplant in the first year after KHPE, and those who required transplantation later in childhood. Analysis of variance (ANOVA) compared multiple factors among the 3 groups. Proportional analysis compared those who required transplantation against those who did not. Statistical significance was considered achieved if P was less than .05.

Results

Forty-five patients were identified. Survival after KHPE was 96% (43 of 45). Sixteen (37%) never required transplantation, 13 (30%) underwent transplant within 1 year after KHPE, and 14 (33%) underwent transplant more than 1 year after KHPE. ANOVA comparison showed that the duration of jaundice before KHPE as a predictor for liver transplantation approached significance (P = .082). Proportional analysis found that a longer initial duration of jaundice before KHPE (P = .016) and failure to establish biliary flow (P = .033) were also significant predictive factors. An initial requirement for phototherapy (P = .057) and ductules less than 200 μm in diameter (P = .060) showed a trend toward predictor of liver transplantation.

Conclusions

A longer duration of jaundice before KHPE, failure to establish bile flow, requirement for phototherapy in the neonatal period, and ductules smaller than 200 μm are associated with liver transplant after KHPE.