Contrast-Enhanced Abdominal Angiographic CT for Intra-abdominal Tumor Embolization: A New Tool for Vessel and Soft Tissue Visualization

C-Arm cone-beam computed tomography (CACT), is a relatively new technique that uses data acquired with a flat-panel detector C-arm angiography system during an interventional procedure to reconstruct CT-like images. The purpose of this Technical Note is to present the technique, feasibility, and added value of CACT in five patients who underwent abdominal transarterial chemoembolization procedures. Target organs for the chemoembolizations were kidney, liver, and pancreas and a liposarcoma infiltrating the duodenum. The time for patient positioning, C-arm and system preparation, CACT raw data acquisition, and data reconstruction for a single CACT study ranged from 6 to 12 min. The volume data set produced by the workstation was interactively reformatted using maximum intensity projections and multiplanar reconstructions. As part of an angiography system CACT provided essential information on vascular anatomy, therapy endpoints, and immediate follow-up during and immediately after the abdominal interventions without patient transfer. The quality of CACT images was sufficient to influence the course of treatment. This technology has the potential to expedite any interventional procedure that requires three-dimensional information and navigation.     

Application of whole‐brain CBV‐weighted fMRI to a cognitive stimulation paradigm: Robust activation detection in a stroop task experiment using 3D GRASE VASO

Brain activation studies generally utilize blood oxygenation level dependent (BOLD) contrast, most commonly measured using the gradient‐echo echo‐planar imaging (EPI) technique. BOLD contrast arises from regional changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and the local metabolic rate of oxygen consumption. An alternative to BOLD is the detection of activation through direct measurement of these parameters. A noninvasive approach to measure activation‐related CBV changes is the vascular space occupancy (VASO) method, which exploits blood as an endogenous contrast agent by selectively nulling the magnetization of the water spins in the blood. Using a recently developed multislice variant of VASO that enables single‐shot whole‐brain coverage by virtue of a three‐dimensional GRASE readout, we here present the first application of VASO to an fMRI study with a whole‐brain cognitive task. Within acceptable measurement times (～12 minutes), brain activation during a Stroop color‐word matching task could be detected reliably both on the group (N = 12) and single subject level, as evident from a qualitative comparison with separately acquired BOLD data and literature reports. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.     

Effects of halothane, sevoflurane and desflurane on the force-frequency relation in the dog heart in vivo

PURPOSE: Frequency potentiation is the increase in force of contraction induced by an increased heart rate (HR). This positive staircase phenomenon has been attributed to changes in Ca2+ entry and loading of intracellular Ca2+ stores. Volatile anesthetics interfere with Ca2+ homeostasis of cardiomyocytes. We hypothesized that frequency potentiation is altered by volatile anesthetics and investigated the influence of halothane (H), sevoflurane (S) and desflurane (D) on the positive staircase phenomenon in dogs in vivo. METHODS: Dogs were chronically instrumented for measurement of left ventricular (LV) pressure and cardiac output. Heart rate was increased by atrial pacing from 120 to 220 beats x min(-1) and the LV maximal rate of pressure increase (dP/dt(max)) was determined as an index of myocardial performance. Measurements were performed in conscious dogs and during anesthesia with 1.0 minimal alveolar concentrations of each of the three inhaled anesthetics. RESULTS: Increasing HR from 120 to 220 beats x min(-1) increased dP/dt(max) from 3394 +/- 786 (mean +/- SD) to 3798 +/- 810 mmHg sec(-1) in conscious dogs. All anesthetics reduced dP/dt(max) during baseline (at 120 beats x min(-1): H, 1745 +/- 340 mmHg x sec(-1); S, 1882 +/- 418; D, 1928 +/- 454, all P < 0.05 vs awake) but did not influence the frequency potentiation of dP/dt(max) (at 220 beats x min(-1): H, 1981 +/- 587 mmHg x sec(-1); S, 2187 +/- 787; D, 2307 +/- 691). The slope of the regression line correlating dP/dt(max) and HR was not different between awake and anesthetized dogs. Increasing HR did not influence cardiac output in awake or anesthetized dogs. CONCLUSION: These results indicate that volatile anesthetics do not alter the force-frequency relation in dogs in vivo.     

Molecular mechanisms transducing the anesthetic, analgesic, and organ-protective actions of xenon

The anesthetic properties of xenon have been known for more than 50 yr, and the safety and efficacy of xenon inhalational anesthesia has been demonstrated in several recent clinical studies. In addition, xenon demonstrates many favorable pharmacodynamic and pharmacokinetic properties, which could be used in certain niche clinical settings such as cardiopulmonary bypass. This inert gas is capable of interacting with a variety of molecular targets, and some of them are also modulated in anesthesia-relevant brain regions. Besides these anesthetic and analgesic effects, xenon has been shown to exert substantial organoprotective properties, especially in the brain and the heart. Several experimental studies have demonstrated a reduction in cerebral and myocardial infarction after xenon application. Whether this translates to a clinical benefit must be determined because preservation of myocardial and cerebral function may outweigh the significant cost of xenon administration. Clinical trials to assess the impact of xenon in settings with a high probability of injury such as cardiopulmonary bypass and neonatal asphyxia should be designed and underpinned with investigation of the molecular targets that transduce these effects.     

Electron beam sterilization does not have a detrimental effect on the ability of extracellular matrix scaffolds to support in vivo ligament healing

Extracellular matrix (ECM) scaffolds have been used to enhance anterior cruciate ligament (ACL) repair in large animal models. To translate this technology to clinical care, identifying a method which effectively sterilizes the material without significantly impairing in vivo function is desirable. Sixteen Yorkshire pigs underwent ACL transection and were randomly assigned to bridge‐enhanced ACL repair—primary suture repair of the ACL with addition of autologous blood soaked ECM scaffold—with either (i) an aseptically processed ECM scaffold, or (ii) an electron beam irradiated ECM scaffold. Primary outcome measures included sterility of the scaffold and biomechanical properties of the scaffold itself and the repaired ligament at 8 weeks after surgery. Scaffolds treated with 15 kGy electron beam irradiation had no bacterial or fungal growth noted, while aseptically processed scaffolds had bacterial growth in all tested samples. The mean biomechanical properties of the scaffold and healing ligament were lower in the electron beam group; however, differences were not statistically significant. Electron beam irradiation was able to effectively sterilize the scaffolds. In addition, this technique had only a minimal impact on the in vivo function of the scaffolds when used for ligament healing in the porcine model. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1015–1023, 2015.     

Postpunktionskopfschmerz in der Geburtshilfe

Die Anaesthesiologie - Der Postpunktionskopfschmerz („postdural puncture headache“, PDPH) zählt zu den wesentlichen Komplikationen der peripartalen neuroaxialen Analgesie. Als...     

Massive blood transfusion after the first cut in liver transplantation predicts renal outcome and survival

Introduction

Transfusion requirements of blood products may provide useful prognostic factors for the prediction of short-term patient mortality and renal outcome after liver transplantation.

Patients and methods

Two hundred ninety-one consecutive liver transplants in adults were analysed retrospectively. Combined and living-related liver transplants were excluded. The amount of transfused packed red blood cells (PRBC) and units of platelets (UP) within the first 48 h were investigated as prognostic factors to predict short-term patient mortality and renal outcome. Receiver operating characteristic (ROC) curve analysis with area under the curve (AUC), Hosmer-Lemeshow tests and Brier scores were used to calculate overall model correctness, model calibration and accuracy of prognostic factors. Cut-off values were determined with the best Youden index.

Results

The potential clinical usefulness of PRBC as a prognostic factor to predict 30-day mortality (cut-off 17.5 units) and post-transplant haemodialysis (cut-off 12.5 units) could be demonstrated with AUCs >0.7 (0.712 and 0.794, respectively). Hosmer-Lemeshow test results and Brier scores indicated good overall model correctness, model calibration and accuracy. The UP proved as an equally clinically useful prognostic factor to predict end-stage renal disease (cut-off 3.5 units; AUC?=?0.763). The association of cut-off levels of PRBC with patient survival (p?<?0.001, log-rank test) and dialysis-free survival (p?<?0.001, log-rank test) was significant (cut-off levels 17.5 and 12.5 units, respectively) as well as the association of UP with dialysis-free survival (p?<?0.001, log-rank test) (cut-off level 3.5 units).

Conclusions

The impressive discriminative power of these simple prognostic factors for the prediction of outcome after liver transplantation emphasizes the relevance of strategies to avoid excessive transfusion requirements.