Intraoperative sonography: a technique for localizing focal forms of congenital hyperinsulinism in the pancreas.

Congenital hyperinsulinism (CHI), syn. nesidioblastosis, is the most frequent cause of persistent, recurrent hypoglycemia in infancy. One third of patients show a single circumscribed focus. Enucleation of the focus and the removal of all affected ß-cells with preservation of healthy tissue is the treatment of choice. The intrapancreatic choledochus as well as the ductus pancreaticus major must remain intact. The diagnostic gold standard is 18F-DOPA-PET/CT. Intraoperative sonography is carried out to correctly visualize the focus preoperatively localized by PET/CT in situ during the operation. The enucleation of the focus was carried out 3 - 20 days after PET/CT in 5 patients at an age of 3.5 - 14 months. Intraoperative ultrasound was carried out with high-capacity devices of different manufacturers under use of broadband probes (9 - 14 MHz). The localization by intraoperative ultrasound was accurate in all 5 patients with focal CHI, with regard to the intraoperative localization as previously described by PET/CT and histology. D. choledochus and D. pancreaticus major were separated intraoperatively by ultrasound. 3 of 5 patients were cured by complete enucleation of the focus. Nevertheless, the entire intraoperative identification of the segmented focus is still problematic. Characteristic sonographic features of a CHI focus are: hypoechogenicity, variable homogeneous and inhomogenous texture, blurred, irregular limitation without capsule, filiform, lobular processes, and insular dispersal into the surrounding tissue. Intraoperative high-resolution sonography helps the pediatric surgeon to determine size, configuration and topography of a CHI focus.

[18F]-DOPA positron emission tomography for preoperative localization in congenital hyperinsulinism.

In recent years, considerable progress has been made in the biochemical, morphological and molecular genetic differentiation of congenital hyperinsulinism (CHI). Fluorine-18 L-3,4-dihydroxyphenylalanine positron emission tomography ((18)F-DOPA-PET) has been introduced for differentiation between focal and diffuse CHI. The ability to take up L-DOPA and convert it into dopamine is correlated with the activity of the aromatic amino acid decarboxylase and increased in the hyperfunctional affected pancreatic area in comparison to normally functioning pancreas. The high sensitivity of this method allows the surgeon to perform a curative limited resection of a focus without the risk of long-term diabetes. The exact preoperative planning by (18)F-DOPA-PET/CT computer tomography allows laparoscopic operation in selected cases with the focus in the tail and limits necessity to open the pancreatic duct in cases with focus in the head. Patients with persistent CHI should be managed within a strong network of diagnostic, treatment, and research institutions.

[Sedation of infants with congenital hyperinsulinism during PET CAT scanning. A case collection]. / Sedierung von Kindern zum PET-CT bei kongenitalem Hyperinsulinismus. Eine Fallsammlung.

Infants with congenital hyperinsulinism may require a positron emission tomography examination with 18F-labeled L-DOPA for the evaluation and planning of surgical interventions. To obtain optimal results it is important for the child to be in a stress-free situation because a stable glucose homoeostasis must be maintained by intravenous glucose infusion. The infant needs to lie calm over a long period of time to obtain optimal results. Sedation for this purpose can be achieved with a continuous infusion of propofol and should be carried out by an anesthesiologist. Additionally blood glucose measurements must be regularly carried out and the glucose infusion must be adjusted to prevent hypoglycemia.

The rise and fall of PET and PET/CT: a German perspective.

PET is being considered a diagnostic commodity in clinical practice worldwide and thus receives increasing attention by health insurances and governmental organizations. In Germany, however, neither PET nor PET/CT are subject to reimbursement. This renders clinical PET and PET/CT imaging a challenge both in a general hospital environment and in private practice. This article describes briefly these challenges, which are not solely related to turf battles and associated costs.

[Studies on central and peripheral hemodynamics using radiocardiography and Xenon-133 muscle clearance in patients with essential hypertension]. / Untersuchungen zur zentralen und peripheren Hämodynamik mit Hilfe der Radiokardiographie und der Xenon-133-Muskelclearance bei Patienten mit essentieller Hypertonie.

Examination of 80 patients with essential hypertension revealed a significant correlation between the tonus of peripheral muscular arterioles on the one hand, and the stage and duration of hypertension and age of the patients, on the other hand. The correlation between arteriolar tonus and indicators of cardiac pump function was less marked. The results confirmed the close relationship between changes of peripheral blood bed and development of hypertension. The use of 133Xe half-period for measuring the peripheral arteriolar tonus proved a simple, but informative method adding an important indicator of peripheral haemodynamics to the results of haemodynamic examination.

Nitrendipine treatment in so-called therapy-resistant arterial hypertension; effect as monotherapy and in combination with propranolol on blood pressure, heart rate, other hemodynamic parameters, plasma renin activity, and catecholamines.

Twenty-three patients [mean age 49.7 +/- 5.6 years (WHO II-III)] with severe hypertension and not responding to previous drug treatment were included in the study to evaluate the effect of nitrendipine (NTP) as monotherapy and also in combination with propranolol (PRO). After a control period of 10 days, NTP was started with 20 mg twice a day and titrated to the maximal dosage of 2 X 40 mg/day. After 1 week of NTP treatment, PRO was added in increasing dosage to a maximal 2 X 100 mg/day. NTP lowered systolic and diastolic blood pressure (BP) significantly (supine BP from 182/119 +/- 19/9 to 157/98 +/- 16/9 mm Hg). After combination with PRO, systolic BP was decreased additionally (supine BP from 157/98 +/- 16/9 to 150/97 +/- 19/9 mm Hg). Plasma norepinephrine (NE) was increased by NTP (from 1.82 +/- 0.78 to 2.38 +/- 1.08 nmol/l, p less than 0.01) and remained elevated during PRO treatment (2.76 +/- 1.10 nmol/l). Plasma renin activity (PRA) showed no significant changes by NTP. Additional effect of PRO on BP correlated significantly with NE and PRA after the NTP period. Plasma epinephrine and dopamine beta-hydroxylase remained unchanged. NTP decreased systemic resistance, calculated from isotope dilution technique (p less than 0.05); after combination with PRO no additional significant changes were registered. Nitrendipine is an effective alternative in so-called therapy-resistant hypertension.

An evaluation of coronary regulation by the 99mTc bolus technique.

A new non-invasive method for investigating total coronary blood supply is presented. This method is based on the principle of indicator dilution of a radio-nuclide bolus (99Tc), requiring a scintillation camera with high sensitivity and high picture resolution. The first findings obtained from 83 patients are shown. With 4.61 +/- 1.19% of cardiac output the mean values of the rates of coronary perfusion obtained at rest in subjects with a normal heart differed significantly from those obtained for patients with certain coronary occlusions (8.18 +/- 3.99% of cardiac output) and from those obtained for hypertensive patients (Stages I-III). Double examinations carried out on 20 patients yielded an adequate reproducibility. The mean deviation of the double examinations from one another was 16%.