Hepatic Hemodynamic Changes Following Stepwise Liver Resection

Aim

Extended liver resection has increased during the last decades. However, hepatic hemodynamic changes after resection and the consequent complications like post hepatectomy liver failure are still a challenging issue. The aim of this study was to systematically evaluate the role of stepwise liver resection on hepatic hemodynamic changes.

Methods

To evaluate this effect we performed 25, 50, and 75 % sequential liver resections in 10 pigs. Before and after each resection, the hepatic artery flow and portal vein flow in relation to the remnant liver volume (RLV) as well as hepatic vascular pressures were measured and compared between the groups.

Results

Following sequential liver resection, the hepatic artery flow /100 g decreases and the portal vein flow increases up to 17 and 167 % following extended liver resection (75 %), respectively. Also, during stepwise liver resection, the portal vein pressure increases gradually up to 33 % following extended hepatectomy (75 %).

Conclusion

Sequential decrease in the RLV decreases the hepatic artery flow /100 g and increases the portal vein flow /100 g and portal vein pressure. As the consequence, the liver goes under more poor-oxygenated blood supply and higher pressure. This may be one of the most important mechanisms of the post hepatectomy liver failure in case of extended liver resection.

     

Three-dimensional MR imaging and display of intracranial disease: Improvements with the MP-RAGE sequence and gadolinium

Three-dimensional (3D) image rendering was performed in 14 patients who had undergone magnetic resonance (MR) imaging for focal brain lesions. The MR study included the magnetization-prepared rapid gradient-echo (MP-RAGE) sequence with 64 or 128 partitions. Resultant contiguous sections 2.5 or 1.25 mm thick, respectively, were obtained. Images were acquired before and after administration of gadopen-letate dimeglumine. Resultant 3D data sets were processed on a commercially available workstation. Correlative surgical observation was performed in four cases. All data sets were successfully processed into 3D images. The precontrast images proved superior to gadolinium-enhanced images for brain surface rendering. Postcontrast images proved superior for reconstruction of tumors and vascular structures. The 64-partition data set proved sufficient for all postprocessing. Coronal orientation was preferred to sagittal orientation for surface rendering because it provided optimal orthogonal orientation of sulcal and gyral brain surface features. Three-dimensional rendition allowed easy superposition of lesion, brain, vessels, and scalp features-all useful for surgical planning. The central sulcus was easily recognized in the mid-line partitions and traced mediolaterally for projection on the cortical surface. MP-RAGE provides a 3D data set that can be obtained in just over 3 minutes, from which clinically useful 3D renderings are possible. The rapidity of acquisition and capability for 3D rendering provides additional clinical utility.