Okka W. Hamer

Prosthesis sizing for transcatheter aortic valve implantation — Comparison of three dimensional transesophageal echocardiography with multislice computed tomography

BACKGROUNDnThe complex anatomy of the aortic annulus warrants the use of three dimensional (3D) modalities for prosthesis sizing in transcatheter aortic valve implantation (TAVI). Multislice computed tomography (MSCT) has been used for this purpose, but its use may be restricted because of contrast administration. 3D transesophageal echocardiography (3D-TEE) lacks this limitation and data on comparison with MSCT is scarce. We compared 3D-TEE with MSCT for prosthesis sizing in TAVI.nnnMETHODSnAortic annulus diameters in the sagittal and coronal plane and annulus areas in 3D-TEE and MSCT were compared in 57 patients undergoing TAVI. Final prosthesis size was left at the operators discretion and the agreement with 3D-TEE and MSCT was calculated.nnnRESULTSnSagittal diameters on 3D-TEE and MSCT correlated well (r=.754, p<.0001) and means were comparable (22.3±2.1 vs. 22.5±2.3 mm; p=0.2; mean difference: -0.3 mm [-3.3-2.8]). On 3D-TEE, coronal diameter and annulus area were significantly smaller (p<.0001 for both) with moderate correlation (r=0.454 and r=0.592). Interobserver variability was comparable for both modalities. TAVI was successful in all patients with no severe post-procedural insufficiency. Final prosthesis size was best predicted by sagittal annulus diameters in 84% and 79% by 3D-TEE and MSCT, respectively. Agreement between both modalities was 77%.nnnCONCLUSIONSnAnnulus diameters and areas for pre-procedural TAVI assessment by 3D-TEE are significantly smaller than MSCT with exception of sagittal diameters. Using sagittal diameters, both modalities predicted well final prosthesis size and excellent procedural results were obtained. 3D-TEE can thus be a useful alternative in patients with contraindications to MSCT.

Admission resistin levels predict peripancreatic necrosis and clinical severity in acute pancreatitis

OBJECTIVES:Peripancreatic necrosis determines clinical severity in acute pancreatitis. Early markers predicting peripancreatic necrosis and clinical severity are lacking. Because adipocytes of peripancreatic adipose tissue secret highly active adipocytokines, the aim of the study was to investigate whether adipocytokines are able to serve as early markers predicting peripancreatic necrosis and clinical severity.METHODS:A total of 50 patients (20 women, 30 men) with acute pancreatitis were included in this noninterventional, prospective, and monocentric cohort study on diagnostic accuracy. Clinical severity was classified by the Ranson score and the APACHE (Acute Physiology And Chronic Health Evaluation) II score. Pancreatic and peripancreatic necrosis were quantified by using the computed tomography-based Balthazar score, the Schroeder score, and the pancreatic necrosis score. Adiponectin, leptin, and resistin were measured at admission and daily for at least 10 days by enzyme-linked immunosorbent assay.RESULTS:In contrast to admission C-reactive protein values, admission resistin values were significantly correlated with clinical severity and even with clinical end points such as death and need for interventions. Admission resistin levels were significantly elevated in patients with higher pancreatic and extrapancreatic necrosis scores. It was shown by receiver–operator characteristics that admission resistin concentration provides a positive predictive value of 89% in predicting the extent of peripancreatic necrosis (area under the curve, 0.8; P=0.002; sensitivity, 80%; specificity, 70%) by using a cutoff value of 11.9u2009ng/ml.CONCLUSIONS:Admission resistin concentration serves as an early predictive marker of peripancreatic necrosis and clinical severity in acute pancreatitis. Resistin may have potential for clinical use as a new and diagnostic serum marker.

Admission Visfatin Levels Predict Pancreatic and Peripancreatic Necrosis in Acute Pancreatitis and Correlate With Clinical Severity

OBJECTIVES:Adipocytes of peripancreatic and intrapancreatic adipose tissue secret adipocytokines such as leptin, adiponectin, and resistin. For resistin, a role as an early predictor of peripancreatic necrosis and clinical severity in acute pancreatitis has been reported. It was the aim of this study to investigate whether the adipocytokine visfatin is able to serve as an early marker predicting peripancreatic necrosis and clinical severity.METHODS:A total of 50 patients (20 females and 30 males) with acute pancreatitis were included in this noninterventional, prospective, and monocentric cohort study on diagnostic accuracy. Clinical severity was classified by the Ranson score and APACHE-II (Acute Physiology and Chronic Health Evaluation II) score. Pancreatic and peripancreatic necrosis were quantified by the computed tomography-based Balthazar score, the Schroeder score, and the pancreatic necrosis score. Visfatin was measured at admission and daily for 10 days by enzyme-linked immunosorbent assay (ELISA).RESULTS:Visfatin values were significantly and positively correlated with clinical severity (APACHE-II score and Ranson score) and with clinical end points such as death and need for interventions. Admission visfatin levels were significantly elevated in patients with higher pancreatic and extrapancreatic necrosis scores. It was shown by receiver operator characteristics that admission visfatin concentration provides a positive predictive value of 93.3% in predicting the extent of peripancreatic necrosis (area under the curve (AUC): 0.89, P<0.001, sensitivity: 93.3%, specificity: 81.8%, likelihood ratio: 5.1, post-test probability: 93%) by using a cutoff value of 1.8u2009ng/ml.CONCLUSIONS:Admission visfatin concentration serves as an early predictive marker of peripancreatic necrosis and clinical severity in acute pancreatitis. Visfatin may have potential for clinical use as a new and diagnostic serum marker.

Sarcopenia in the aging high-fat fed rat: a pilot study for modeling sarcopenic obesity in rodents

Obesity has been suggested as a risk factor for sarcopenia. However, the underlying pathogenic concept of sarcopenic obesity is mainly based on phenotypical data from clinical observation. The present pilot study describes a rodent animal model which opens up prospects to carry out translational research of sarcopenic obesity in an experimental setting. Starting with 2xa0months, male Wistar rats were fed with a diet containing either 25 enxa0% (control diet, CD) versus 45 enxa0% (high fat diet, HFD) of neutral fat. At the age of 20 and 23xa0months quadriceps muscles were examined in vivo by magnetic resonance techniques which revealed a positive correlation between muscular fat and body weight (rxa0=xa00.639) and a negative correlation between muscular fat content and muscle volume (rxa0=xa0−0.742). Expression and phosphorylation status of proteins within the PKB/Akt and AMPK-dependent signaling pathway were examined in muscles of the 24xa0month-old animals which significantly showed a 50 percent upregulation of Ser473P-PKB/Akt and a 90xa0% constitutive downregulation of S6K1 in the HFD rats. Notably, S6K1 is a key mediator for muscular protein biosynthesis with additional negative feedback on PKB/Akt. Furthermore, muscular expression of the mitochondrial key regulator PGC-1α in the aged HFD rats was only 25xa0% of that concurrent controls (pxa0=xa00.029). These explorative findings in the aging high-fat fed rat might serve as a firm starting point for controlled longitudinal observations in a larger animal cohort of both sexes studying the natural history of sarcopenic obesity.

Safety and efficacy of the Perclose suture-mediated closure device following carotid artery stenting under clopidogrel platelet blockade

The aim of this study was evaluation of a closure device (Perclose, Menlo Park, Calif.) for closure of the femoral artery access site in patients undergoing aggressive anticoagulation and platelet blockade after carotid stenting. Fifty-five patients who received clopidogrel in addition to aspirin and heparin as medication for carotid stenting were included for suture of the femoral access site after using 7- or 8-F guide catheters. The technical success, the time for suture, the clotting parameters, and complications were examined. Follow-up investigations, including ultrasound and clinical examinations, were performed. The groin was checked for possible hematoma, pseudoaneurysm, arteriovenous fistula, and local infection. Technical success was obtained in 51 of 54 patients (94%) after a mean procedure time of 6xa0min (range 5–10xa0min). The suture device was not used in one patient (2%) for anatomical reasons and failed to obtain hemostasis in 3 of 54 (6%) patients. In 4 of 54 patients (7%) bleeding was observed at the punctured site 4–6xa0h after intervention which was treated by a compression bandage. The mean dedicated activated clotting time was 137xa0s (range 29–287xa0s) before intervention and 349xa0s (150–958xa0s) just before deploying the Perclose device. During follow-up after 2xa0days (range 2–6xa0days) and 6xa0months no further complications of the puncture site were observed except for two large groin hematomas. No major complications occurred. Closure of the femoral access site after carotid stenting using a Perclose closure device is safe and effective even in patients receiving an aggressive anticoagulation and antiplatelet therapy.

Multidetector computed tomography for detection and characterization of pulmonary hypertension in consideration of WHO classification.

Objective We evaluated the reliability of various multidetector computed tomography (MDCT) parameters for diagnosis and severity assessment of pulmonary hypertension (PH) with consideration of World Health Organization (WHO) classification. Methods A total of 172 patients were included in this retrospective study. One hundred fourteen patients had a diagnosis of PH (mean pulmonary artery pressure ≥25 mm Hg), and 58 patients without PH (mean pulmonary artery pressure <20 mm Hg) served as control subjects. The patients with PH were grouped according to the WHO classification based on PH etiology. Results The patients with PH had significantly greater main, left, and right pulmonary artery diameters than the control subjects (P < 0.001). No significant differences within the PH subgroups were found. Receiver operating characteristic analysis showed reasonable sensitivity and specificity for selected MDCT parameters. The severity of PH did not correlate with MDCT parameters. Conclusions Easy-to-determine MDCT parameters allow detection of PH independent of the WHO group. In patients with dilated aorta, the vertebra can be an alternative internal standard. Severity of PH cannot be estimated by MDCT parameters.

The impact of gas exchange measurement during exercise in pulmonary sarcoidosis

BACKGROUNDnPulmonary sarcoidosis shows a remarkable heterogeneity of phenotypes ranging from bihilar lymphadenopathy to progressive fibrosis. Individual disease assessment is demanding and requires sensible, practical measures. We tested whether gas exchange measurements during exercise reflects disease activity and clinical course in sarcoidosis.nnnMETHODSnIn 149 patients with proven pulmonary sarcoidosis the alveolar-arterial oxygen pressure gradient (P(A-a)O(2)) during exercise was assessed and compared with chest X-ray typing, pulmonary function, single breath-diffusing capacity for carbon monoxide (DL(CO)), serological markers, cell composition of bronchoalveolar lavage fluid (BALF) and clinical course. Patients were categorized according to thresholds of P(A-a)O(2) during exercise.nnnMEASUREMENTS AND MAIN RESULTSnChest X-ray typing, pulmonary function, DL(CO) and the need for immunosuppressive treatment differed between the disease categories based on P(A-a)O(2) during exercise (pxa0<xa00.0001 each). Patients with an impairment of gas exchange during exercise also showed elevated levels of neopterin (pxa0=xa00.002) and higher percentages of neutrophils (pxa0=xa00.013) and eosinophils (pxa0<xa00.0001) in BALF. Multivariate regression analysis showed that forced vital capacity (FVC) (pxa0=xa00.009) and P(A-a)O(2) during exercise (pxa0<xa00.0001) were independently associated with a prolonged need for immunosuppressive treatment (>1 year), but not DL(CO). About 50% (nxa0=xa075) of the study population showed a normal spirometry. Even in this subgroup 23% had an impaired gas exchange during exercise, which correlated with chest X-ray types (pxa0<xa00.0001) and the need for immunosuppressive treatment (pxa0<xa00.005).nnnCONCLUSIONSnImpaired gas exchange during exercise reflects disease activity and its extent and is associated with a prolonged need for immunosuppressive treatment during follow-up in patients with pulmonary sarcoidosis.

Percutaneous treatment of a patient with infected necrotizing pancreatitis

Background A 50-year-old man with an acute episode of alcohol-induced chronic edematous pancreatitis and an inflammatory stenosis of the biliary tract was treated by implantation of a plastic endoprosthesis at a rural hospital in Germany. Because of his worsening condition, the patient was referred to the intensive care unit of the University Hospital, Regensburg, Germany. Contrast-enhanced CT revealed complete necrosis of the body and tail of the pancreas, formation of large retrogastric and paraduodenal fluid collections, and fluid along Gerotas fascia, as well as in the paracolic gutters. Antibiotic treatment was adjusted according to the results of microbiological testing after diagnostic puncture of the necrotic cavity.Investigations CT scan, CT-guided fine-needle aspiration and fluoroscopy.Diagnosis Infected acute necrotizing pancreatitis.Management Interventional treatment using large-bore percutaneous catheters to perform percutaneous necrosectomy, fragmentation of necrotic pancreatic tissue with a snare catheter and dormia basket, and aspiration. Parenteral nutrition and antibiotics were also administered.

Successful treatment of erectile dysfunction and infertility by venesection in a patient with primary haemochromatosis.

A 36-year-old patient with primary haemochromatosis presented with erectile dysfunction. Laboratory findings revealed reduced levels of luteinizing hormone (0.4 IU/l; normal range 2–12 IU/l), follicle-stimulating hormone (0.1 IU/l; normal range 1–12 IU/l) and testosterone (0.49 μg/l; normal range 2–8.1 μg/l). We made the diagnosis of secondary hypogonadism due to haemochromatosis, which is generally supposed to be irreversible. Due to consequent venesection therapy, levels of ferritin and transferrin saturation could be normalized, and levels of luteinizing hormone and follicle-stimulating hormone increased to normal ranges. Also, testosterone levels became normal and remained so without any androgen substitution. The patient subsequently regained erectile function and potency. This case underlines the fact that a hypogonadotrophic hypogonadism caused by iron overload can be reversed by a consequent venesection therapy.

Diet-Induced and Age-Related Changes in the Quadriceps Muscle: MRI and MRS in a Rat Model of Sarcopenia

Background: Knowledge about the molecular pathomechanisms of sarcopenia is still sparse, especially with regard to nutritional risk factors and the subtype of sarcopenic obesity. Objective: The aim of this study was to characterize diet-induced and age-related changes on the quality and quantity of the quadriceps muscle in a rat model of sarcopenia by different magnetic resonance (MR) techniques. Methods: A total of 36 6-month-old male Sprague-Dawley rats were randomly subdivided into 2 groups and received either a high-fat diet (HFD) or a control diet (CD). At the age of 16 months, 15 HFD and 18 CD rats underwent MR at 1.5 T. T1-weighted images as well as T2 relaxation time maps were acquired perpendicular to the long axis of the quadriceps muscles. Maximum cross-sectional area (CSA) of the quadriceps muscle was measured on T1-weighted images, and T2 relaxation times of muscle were assessed in a region without visible intramuscular fat (T2lean muscle) and across the complete CSA (T2muscle). Furthermore, 1H-MR spectroscopy was performed to evaluate the relative lipid content of the quadriceps muscles. These measurements were repeated 5 months later in the surviving 8 HFD and 14 CD rats. Results: HFD rats revealed significantly decreased CSA and CSA per body weight (BW) as well as prolonged T2 relaxation times of muscle. A higher weight gain (upper tertile during the first 6 months of diet in CD rats) resulted in a significant change of T2muscle, but had no relevant impact on CSA. Advancing age up to 21 months led to significantly decreased BW, CSA and CSA/BW, significantly prolonged T2muscle and T2lean muscle and enlarged lipid content in the quadriceps muscle. Conclusions: In an experimental setting a chronically fat-enriched diet was shown to have a relevant and age-associated influence on both muscle quantity and quality. By translational means the employed MR techniques give rise to the possibility of an early detection and noninvasive quantification of sarcopenia in humans, which is highly relevant for the field of geriatrics.