Wim Laleman

Analyzing the human liver vascular architecture by combining vascular corrosion casting and micro-CT scanning : a feasibility study

Although a full understanding of the hepatic circulation is one of the keys to successfully perform liver surgery and to elucidate liver pathology, relatively little is known about the functional organization of the liver vasculature. Therefore, we materialized and visualized the human hepatic vasculature at different scales, and performed a morphological analysis by combining vascular corrosion casting with novel micro‐computer tomography (CT) and image analysis techniques. A human liver vascular corrosion cast was obtained by simultaneous resin injection in the hepatic artery (HA) and portal vein (PV). A high resolution (110u2005μm) micro‐CT scan of the total cast allowed gathering detailed macrovascular data. Subsequently, a mesocirculation sample (starting at generation 5; 88u2005×u200568u2005×u200580u2005mm³) and a microcirculation sample (terminal vessels including sinusoids; 2.0u2005×u20051.5u2005×u20051.7u2005mm³) were dissected and imaged at a 71‐μm and 2.6‐μm resolution, respectively. Segmentations and 3D reconstructions allowed quantifying the macro‐ and mesoscale branching topology, and geometrical features of HA, PV and hepatic venous trees up to 13 generations (radii ranging from 13.2u2005mm to 80u2005μm; lengths from 74.4u2005mm to 0.74u2005mm), as well as microvascular characteristics (mean sinusoidal radius of 6.63u2005μm). Combining corrosion casting and micro‐CT imaging allows quantifying the branching topology and geometrical features of hepatic trees using a multiscale approach from the macro‐ down to the microcirculation. This may lead to novel insights into liver circulation, such as internal blood flow distributions and anatomical consequences of pathologies (e.g. cirrhosis).

Hemodynamic Effects of Albumin Dialysis in Patients With Liver Failure: For Better or For Worse?

Liver failure, irrespective of is cause, is frequently associated with multi‐organ dysfunction, including hemodynamic instability, and renal and cerebral insufficiency. As a result of the combined impact of these complications, liver failure carries an exceptionally high risk of mortality. A central role in the etiopathogenesis of different end‐organ manifestations, as well as in the aggravation of the underlying liver failure, has been attributed to the hyperdynamic (hypotensive) state, which is characterized by a reduced systemic vascular resistance and mean arterial pressure, as well as an increased cardiac index, heart rate, and total plasma volume. Since the accumulation of toxins due to the decreased detoxification capacity by the failing liver is considered vital herein, the emergence of extracorporeal liver support has provided a rational basis for the potential reversal of these phenomena. The present article critically reviews data with regard to the hemodynamic effects of artificial liver support in the context of liver failure. Although these are scarce for acute liver failure, several uncontrolled series and small randomized trials have clearly documented that artificial liver support is able to improve both portal hypertension and the associated systemic circulatory dysfunction in patients with acute‐on‐chronic liver failure. The molecular basis for these effects have been related to temporary changes and/or elimination in endogenous vasoactive substances, improved albumin binding capacity, or restoration of oxidative stress‐mediated damage to albumin.

Outcomes of Long-Term Administration of Intravenous Hepatitis B Immunoglobulins for the Prevention of Recurrent Hepatitis B After Liver Transplantation

PURPOSEnThe aim of this study was to investigate the safety and efficacy of lifelong therapy with intravenous hepatitis B immunoglobulins (i.v. HBIg) to prevent recurrence of hepatitis B after orthotopic liver transplantation (OLT).nnnMETHODSnThis was a single-center retrospective study of the long-term outcome of 56 patients who were transplanted for active hepatitis B-related liver disease. In addition to i.v. HBIg, patients received antiviral therapy for at least 1 year.nnnRESULTSn1-, 5-, and 10-year survival rates were 95%, 82%, and 80%, respectively. None of the patients died due to hepatitis B virus (HBV)-related complications. In 3 patients (5%), a hepatitis B surface antigen (HBsAg)-negative status was not reached. All of these patients had a very high viral load at the time of OLT. HBsAg and HBV DNA reappeared in 6 patients (11%): In 1 patient, recurrence occurred 9 months after OLT while still under combination treatment with lamivudine, and 2 patients were temporarily treated abroad with intramuscular HBIg. Only 3 patients suffered from HBV recurrence while under monotherapy with i.v. HBIg. No serious side effects to i.v. HBIg were reported during this long-term follow-up.nnnCONCLUSIONnLifelong administration of i.v. HBIg is safe, and recurrence of HBV disease occurred only in a minority of the patients during long-term follow-up. Prognosis of HBV-related OLT with this therapy is excellent.

178 A PROSPECTIVE STUDY COMPARING THE DIFFERENT INDIRECT METHODS TO MEASURE PORTAL PRESSURE

[Maleux, G; Willems, E; Heye, S; Vaninbroukx, J] Katholieke Univ Leuven Hosp, Dept Radiol, B-3000 Louvain, Belgium. [Laleman, W; Cassiman, D; Verslype, C; Nevens, F] Katholieke Univ Leuven Hosp, Dept Hepatol, B-3000 Louvain, Belgium. [Fieuws, S] Katholieke Univ Leuven, Interuniv Inst Biostat & Stat Bioinformat, Louvain, Belgium. Univ Hasselt, Louvain, Belgium. ngeert.maleux@uzleuven.be

A rare and reversible cause of acute dilatation of the pancreatic duct

chronic pancreatitis was treated endo− scopically at our institution at the end of 2006 for a pancreatic duct stone and ste− nosis. After stone removal and temporary stenting, the main pancreatic duct re− turned to normal (l Fig. 1 a). In March 2007, a cholecystectomy was performed after an acute cholecystitis had occurred in January 2007. In May 2007, she was admitted with up− per abdominal pain irradiating towards the back. Clinical examination revealed tenderness at the left hypochondrium and jaundice. Biochemical work−up showed marked inflammation (white blood cell count 15 000/mm3, C−reactive protein 132 mg/l), and cholestasis (biliru− bin 6 mg/dl). The patient was scheduled for endoscopic retrograde cholangiopan− creatography, which demonstrated a con− gested periampullary region with mas− sive evacuation of pus after cannulation of the Wirsung. Pancreatography showed pronounced dilatation of the main pan− creatic duct with inhomogeneous content and cystically dilated secondary branches (l Fig. 1 b). Computed tomography scan of the pancreas confirmed a congestive pancreatic head with pseudo−tumoral as− pect, cystically dilated side−branches, and secondary compression of the extrahepa− tic bile duct (l Fig. 2). Cytology and Ziehl±Nielsen staining of aspirated pus were negative. Microbial culture docu− mented the presence of Staphylococcus aureus and Streptococcus anginosus. Anti− biogram−directed antibiotic treatment was initiated with penicillin and levoflox− acin, leading to rapid recovery. Control pancreatography after 14 days showed complete restoration of the pancreatic duct without evidence of (sub)obstruc− tive lesions (l Fig. 3).. In conclusion, we report the case of a bacterial infection of the main pancreatic duct and its side branches, leading to a transient pro− nounced dilatation of the pancreatic duct with massive evacuation of pus from the papilla. This is a rarely reported [1, 2] en− tity involving a chronically damaged pan− creas, pancreatic outflow obstruction, and subsequent bacterial infection. The pathogenesis of this syndrome in this pa− tient might be related to previous endo− scopic interventions for chronic pancrea− titis, although lymphatic and hematoge− neous bacterial spread from a previously existing acute cholecystitis or intercur− rent infection cannot be completely ex− cluded.