An experimental approach of the Doppler perfusion index of the liver in detecting occult hepatic metastases: histological findings related to the hemodynamic measurements in Wistar rats.

Image-directed colour Doppler sonography has been successfully introduced for the detection of hepatic haemodynamic changes in the presence of liver metastases. The aim of our study was to correlate these haemodynamic changes with the liver histology at the time of measurement. We experimentally induced liver metastases in 30 male Wistar rats by inoculating Walker 256 tumour subcutaneously. The animals were assigned into three groups of ten and were studied sonographically at 4, 7 and 15 days after tumour implantation. Another group of ten normal animals were used as controls. Portal vein and hepatic artery measurements included resistance index (PVRI, HARI) and flow volume (PVFV, HAFV). Doppler perfusion index (DPI) of the liver was calculated as the ratio of HAFV/PVFV + HAFV. Liver histology followed each Doppler measurement. Metastases were first encountered on day 4, as small groups of cells in the connective tissue of the porta hepatis and the portal triads without apparent vascular association. Distinct elevation of HAFV and DPI was recorded in comparison with the controls (p = 0.0004 and p = 0.0005, respectively). PVFV reduction was subtle. Up to day 15 there were no significant changes in the measurements. Our data suggest that HAFV and DPI can efficiently detect early liver metastases and this is in accordance with existing clinical reports. Haemodynamic changes seem to originate from the early non-vascular phase of the metastases.

A novel radiological approach for the experimental study of angiogenesis: angiography of the chick embryo and its chorioallantoic membrane.

We use a modification of the digital substraction angiography (DSA) technique to visualize the vascular system of the chorioallantoic membrane (CAM) of the developing chick embryo. After catheterization of the central vein of the CAM with a metallic needle and injection of contrast medium, angiography was performed at specified follow-up intervals (1-2.5 images per second) using the Philips DVI-S Angiography Unit. By applying the vascular casting technique we were able to visualize the vessels of the CAM and to study the existing complex vascular-anatomical relationships. Our results show that DSA demonstrates the development of the circulatory system of the chick embryo (heart and vessels) and the vessels of its CAM effectively. By applying for the first time interventional radiology techniques on the chick embryo system, it has been possible to study morphological changes of the vessels during angiogenesis in vivo. These results suggest that this technique can be a proven and valuable tool in the quantitative assessment of angiogenesis.

Fibrin glue for sealing the needle track in fine-needle percutaneous lung biopsy using a coaxial system: Part II--Clinical study.

PURPOSE: Following percutaneous lung biopsy (PLB), we used fibrin glue as a sealant in 26 patients for the purpose of decreasing the incidence of pneumothorax. METHODS: All 26 patients (group A) had chronic obstructive pulmonary disease (COPD). The results for group A were compared with a control group of 32 patients (group B), also with COPD and in whom fibrin glue was not used. All biopsies were conducted under computed tomography (CT) using a coaxial needle system consisting of 19-gauge and 22-gauge needles. RESULTS: Pneumothorax developed in five patients (19.2%) in group A and in one instance, drainage was required (3.8%). In group B, pneumothorax developed in 13 patients (40.6%) and in six instances (18.8%) drainage was required. Comparing the use of chest-tube drainage in the two groups, a statistical significance was observed, p < 0.0025). No adverse reactions related to the fibrin glue were observed. CONCLUSION: Our results indicate that fibrin glue is a safe sealing material for lung PLB and serves to decrease the incidence and, in particular, the severity of pneumothorax, especially in high-risk patients.