Prerequisites for fetal neurosurgery: management of central nervous system anomalies toward the 21st century.

With the dramatic technical advances in neuroimaging, it has become possible to diagnose central nervous system (CNS) anomalies in the fetus in utero with more precise morphological analysis. A new technique, high-resolution magnetic resonance (MR) imaging using heavily T2-weighted fast spin echo sequences, has been reported to solve motion artifact of the fetus. However, it has also been recognized that the morphological fetal CNS findings detected in early development are not always the final features: occasionally they may not be determined in diagnosis and may change developmentally or chronologically during the fetal life in utero. Certain factors of the fetal chronology of CNS anomalies can cause irreversible changes during fetal life. These include: (1) significant delay in the neuronal maturation process in fetal hydrocephalus developed in clinicoembryological stage II in the Perspective Classification of Congenital Hydrocephalus (PCCH), (2) secondary neural injury in the intactly developing spinal cord above the neural placode in fetus with spina bifida aperta (myeloschisis), (3) histological "evolution" of tumors or dysgenetic CNS, and (4) deformity of the normally developed intracranial or intraspinal CNS structures. Considering the current status of fetal surgery in general and technical advances promising improved outcomes, fetal neurosurgery can also be applied in the above-mentioned progressive pathology or pathophysiology in the fetal CNS. However, since the failure of the first trial of fetal neurosurgery in the 1980s, the prerequisites have still not been clarified. In order to use advanced neurosurgery techniques in the management of fetal CNS anomalies, these prerequisites have to be established.

[3D and color Doppler ultrasound evaluation of cystic space-occupying lesion near the head of the pancreas]. / 3D- und Farbdopplersonographische Evaluation einer am Pankreaskopf gelegenen zystischen Raumforderung.

AIM: Differential diagnosis of cystic lesions in the abdomen may be very difficult. We present the clinical manifestation and the diagnostic steps of a rare case of an aneurysm of the gastroduodenal artery mimicking a cystic lesion. We also discuss the imaging methods we used to verify the diagnosis such as colour Doppler sonography and 3D-sonography. METHOD AND PATIENT: A 42-year old woman with chronic pancreatitis was admitted to our hospital after an extended diagnostic program (sonography, computed tomography and laparoscopy) with the diagnosis of a pancreatic pseudocyst with vascular erosion. Using conventional sonography we found a cystic lesion of 5 x 5 cm diameter with parietal deposits between pancreas and coeliac trunk. After colour Doppler sonography we found an arterial jet in the cystic tumor; initially the source of the jet seemed to be the hepatic artery. We referred the patient to our department of radiology with the diagnosis of hepatic artery aneurysm. The aneurysm was confirmed by the angiography and was embolised with coils in the same session. However, the source of the aneurysm was not the hepatic, but the gastroduodenal artery. By postangiographical 3D-sonography we could clearly reconstruct the relation of the aneurysm to the gastroduodenal artery. CONCLUSION: Colour Doppler sonography should be the first imaging tool for clarifying cystic lesions in the abdomen. 3D-sonography is a reliable and useful method to identify visceral vessels of the abdomen. Nowadays the "gold standard" angiography should preferably be used as a therapeutic procedure.