Early and medium-term results after modified Fontan operation in adults.

OBJECTIVE: Single ventricle palliation is rarely performed in adults and the results are less optimal than in children. In this article we analyze our experience with the modified Fontan operation in this age group. METHODS: Data of 15 consecutive patients with single ventricle with a mean age of 26 (range 16-38) years, who underwent Fontan operation between 3/92 and 1/2000 were retrospectively analyzed. Five patients had previously had an aortopulmonary shunt in childhood and two patients had previously received a bi-directional cavopulmonary shunt as adults. Eleven patients were preoperatively in NYHA class III and four in class II. The main factors for the selection of the patients before surgery were well-developed pulmonary arteries with lower lobe index 120+30 mm/m(2), pulmonary artery pressure <18 mmHg, good cardiac function and enddiastolic systemic ventricular pressure <12 mmHg. The lateral tunnel Fontan operation (LTFO) was performed in ten patients and extracardiac Fontan operation (ECFO) in five. A fenestration 4-5 mm in size was constructed in all patients with LTFO and in three of five patients with ECFO. RESULTS: There was one intraoperative and one late death (total mortality 13%). The mean extubation time and hospital stay were 24 h and 21 days, respectively. Severe postoperative complications were observed in three patients (20%). Two LTFO patients out of a total of eight patients (53%) with perioperative arrhythmias received a permanent pacemaker due to bradyarrhythmia. During the median follow-up of 5.0 (range 2.3-10.1) years, four patients developed arrhythmias; one of them had new onset bradyarrhythmia after LTFO and required permanent pacemaker implantation. The median postoperative oxygen saturation was 93% (range 90-98%). NYHA class improved significantly in 12 survivors. Cardiac catheterization (0.5-4 years postoperatively, n=12) showed excellent Fontan hemodynamics in all patients. CONCLUSIONS: The modified Fontan operation can be performed in adults with acceptable early and midterm mortality and morbidity and leads to either complete or marked relief of cyanosis and enhanced exercise tolerance in all survivors. Postoperative arrhythmias are one of the main drawbacks but the incidence of arrhythmias after ECFO seems to be lower. The long-term follow-up has yet to be established.     

Non-isotropic noise correlation in PET data reconstructed by FBP but not by OSEM demonstrated using auto-correlation function

Background  

Positron emission tomography (PET) is a powerful imaging technique with the potential of obtaining functional or biochemical information by measuring distribution and kinetics of radiolabelled molecules in a biological system, both in vitro and in vivo. PET images can be used directly or after kinetic modelling to extract quantitative values of a desired physiological, biochemical or pharmacological entity. Because such images are generally noisy, it is essential to understand how noise affects the derived quantitative values. A pre-requisite for this understanding is that the properties of noise such as variance (magnitude) and texture (correlation) are known.     

Intraoperative assessment of acute hemodynamic changes after partial left ventriculectomy

Partial left ventriculectomy (PLV) has been introduced as an alternative surgical therapy for patients with end-stage dilated cardiomyopathy. The physiological benefits of PLV are relatively unknown. Therefore, the objective of this study was to determine the acute effects of PLV by measuring cardiac function before and after PLV. Aortic and left ventricular pressures and aortic flow were measured in eight patients. Continuous, beat-to-beat data were recorded and compared pre-PLV and post-PLV with and without inferior vena cava (IVC) occlusions. PLV increased cardiac output (0.93+/-0.5, p = 0.01) as a result of increased stroke volume (5.12+/-4.24, p = 0.06) and heart rate (14.5+/-8.44, p = 0.02). Contractility (+/- dP/dt, 240.33+/-74.28, p = 0.001) and external work (650.8+/-320.4, p = 0.01) were also improved. Left ventricular end-diastolic elastance (0.15+/-0.14, p = 0.10) nearly doubled after PLV. Our results indicated an improved cardiac function as measured by increased cardiac output, stroke volume, ejection fraction (EF), and contractility.     

Erste klinische Erfahrungen mit dreidimensionalem Ultraschall des Gehirns bei Neugeborenen

Zusammenfassung Fragestellung: Ausgehend von eigenen Erfahrungen mit der 3dimensionalen Echokardiographie wurde versucht, auch ultrasonographische transfontanelle Studien 3dimensional zu rekonstruieren und auf ihren Informationsgehalt zu untersuchen. Methode: Es wurden 16 Neugeborene und S?uglinge (Alter 4 Tage – 3 Monate, Median 12 Tage) untersucht. Ein konventioneller 5-MHz-Schallkopf wurde auf der anterioren Fontanelle plaziert und von einem computergesteuerten Motor im inneren Lumen eines offenen Zylinders um 180° um seine vertikale Achse gedreht. Bei jeder Drehung um jeweils 1° wurde eine Schicht des Gehirns aufgenommen, so da? 180 Schichten erhalten wurden, welche den 3dimensionalen Datensatz bilden. Innerhalb des Datensatzes k?nnen beliebig im Raum orientierte Schnittebenen rekonstruiert werden. Ergebnisse: Bei allen Patienten gelang es, Datens?tze aufzunehmen, welche qualitativ so gut waren, da? sie sp?ter 3dimensional rekonstruiert werden konnten. Die Daten konnten ohne Sedierung und in weniger als 60 s aufgenommen werden. Rekonstruktionen des Gehirns dauerten 2–33 min. Es konnten neue transversale Schnittebenen des Sch?dels rekonstruiert werden, welche bisher nicht erh?ltlich waren. Neue Informationen konnten über subarachnoidal gelegene Hirnl?sionen sowie die r?umliche Ausdehnung von Parenchymblutungen gewonnen werden. Schlu?folgerungen: Dieses neue bildgebende Verfahren k?nnte in Zukunft quantitative und qualitative diagnostische Informationen der herk?mmlichen Ultrasonographie verbessern.      

Long-term effects of bilateral pallidal deep brain stimulation in dystonia: a follow-up between 8 and 16 years

Journal of Neurology - Observational study to evaluate the long-term motor and non-motor effects of deep brain stimulation (DBS) of the globus pallidus internus (GPi) on medically refractory...