Liver dialysis 2196198 210541334 2008-05-06T10:57:51Z Kjarlbaek 7047531 /* Prometheus */ {{Interventions infobox | Name = {{PAGENAME}} | Image = | Caption = | ICD10 = | ICD9 = 50.92 | MeshID = | OtherCodes = | }} '''Liver dialysis''' is a detoxification treatment for [[liver failure]] and has shown promise for patients with [[hepatorenal syndrome]]. It is similar to [[hemodialysis]] and based on the same principles. Like a [[bioartificial liver device]], it is a form of [[artificial extracorporeal liver support]]. A critical issue of the clinical syndrome in [[liver failure]] is the accumulation of toxins not cleared by the failing [[liver]]. Based on this hypothesis, the removal of [[lipophilic]], albumin-bound substances such as [[bilirubin]], [[bile acids]], metabolites of [[aromatic amino acids]], medium-chain [[fatty acids]] and [[cytokines]] should be beneficial to the clinical course of a patient in liver failure. This led to the development of artificial filtration and adsorption devices. Hemodialysis is used for [[renal failure]] and primarily removes water soluble toxins, however it does not remove toxins bound to [[human serum albumin|albumin]] that accumulate in liver failure. == Liver dialysis prognosis/survival == Whilst the technique is in its infancy, the prognosis of patients with liver failure remains guarded. Liver dialysis, currently, is only considered to be a bridge to [[liver transplantation|transplantation]] or liver regeneration (in the case of [[acute liver failure]])<ref>O'grady J. Personal view: current role of artificial liver support devices. Aliment Pharmacol Ther. 2006 Jun 1;23(11):1549-57. PMID 16696802.</ref><ref>van de Kerkhove MP, Hoekstra R, Chamuleau RA, van Gulik TM. Clinical application of bioartificial liver support systems. Ann Surg. 2004 Aug;240(2):216-30. PMID 15273544. [http://www.pubmedcentral.gov/articlerender.fcgi?tool=pubmed&pubmedid=15273544 Free Full Text].</ref><ref>Neuberger J. Prediction of survival for patients with fulminant hepatic failure. Hepatology. 2005 Jan;41(1):19-22. PMID 15690476.</ref> and, unlike [[kidney dialysis]] (for [[renal failure]]), cannot support a patient for an extended period of time (months to years). == Liver dialysis devices == Artificial detoxification devices currently under clinical evaluation include the Molecular Adsorbent Recirculating System (MARS), Single Pass Albumin Dialysis (SPAD) and the Prometheus system. === Molecular Adsorbents Recirculation System (MARS) ===<!-- This section is linked from [[Mars (disambiguation)]] --> The '''Molecular Adsorbents Recirculation System (MARS)''', developed by Teraklin AG of [[Germany]], is the best known extracorporal liver dialysis system and has existed for approximately ten years. It consists of two separate dialysis circuits. The first circuit consists of [[human serum albumin]], is in contact with the patient's blood through a semipermeable membrane and has two special filters to clean the albumin after it has absorbed toxins from the patient's blood. The second circuit consists of a hemodialysis machine and is used to clean the albumin in the first circuit, before it is recirculated to the semipermeable membrane in contact with the patient's blood. The MARS system can remove a number of toxins, including [[ammonia]], [[bile acids]], [[bilirubin]], [[copper]], [[iron]] and [[phenols]]. MARS development started at the University of [[Rostock]] in [[Germany]]. It has 510 (k) approval from the [[Food and Drug Administration]] (FDA) for drug overdoses and poisoning as of June [[2005]] and is available in the [[USA]] since the end of 2005.[http://www.gambro.com/upload/Press%20Releases/2005/MARS_510k.pdf] Canada's first MARS unit arrived at the [[Toronto General Hospital]] in 2005. === Single Pass Albumin Dialysis (SPAD) === '''Single pass albumin dialysis (SPAD)''' is a simple method of [[human serum albumin|albumin]] dialysis using standard renal replacement therapy machines without an additional perfusion pump system: The patient’s blood flows through a circuit with a high-flux hollow fiber hemodiafilter, identical to that used in the MARS system. The other side of this membrane is cleansed with an albumin solution in counter-directional flow, which is discarded after passing the filter. Hemodialysis can be performed in the first circuit via the same high-flux hollow fibers. === Comparing SPAD, MARS and CVVHDF === SPAD, MARS and continuous veno-venous haemodiafiltration (CVVHDF) were compared [[in vitro]] with regard to detoxification capacity.<ref>Sauer IM, Goetz M, Steffen I, Walter G, Kehr DC, Schwartlander R, Hwang YJ, Pascher A, Gerlach JC, Neuhaus P.: In vitro comparison of the molecular adsorbent recirculation system (MARS) and single-pass albumin dialysis (SPAD). Hepatology. 2004 May;39(5):1408-14. PMID 15122770.</ref> SPAD and CVVHDF showed a significantly greater reduction of ammonia compared with MARS. No significant differences could be observed between SPAD, MARS and CVVHDF concerning other water-soluble substances. However, SPAD enabled a significantly greater [[bilirubin]] reduction than MARS. [[Bilirubin]] serves as an important marker substance for albumin-bound (non water-soluble) substances. Concerning the reduction of [[bile acids]] no significant differences between SPAD and MARS were seen. It was concluded that the detoxification capacity of SPAD is similar or even higher when compared with the more sophisticated, more complex and hence more expensive MARS. As albumin dialysis is a costly procedure, financial aspects are important: For a seven-hour treatment with MARS, approximately € 300 for 600 ml [[human serum albumin]] solution (20%), € 1740 for a MARS treatment kit and € 125 for disposables used by the dialysis machine have to be spent. The cost of this therapy adds up to approximately € 2165. Performing SPAD according to the protocol by Sauer et al., however, requires 1000 ml of human albumin solution (20%) at a cost of € 500. A high-flux dialyzer costing approximately € 40 and the tubings (€ 125) must also be purchased. The overall costs of a SPAD treatment is approximately € 656 - 30% of the costs of an equally efficient MARS therapy session. The expenditure for the MARS monitor necessary to operate the MARS disposables is not included in this calculation. === Prometheus === The '''Prometheus''' system ([[Fresenius AG|Fresenius]] Medical Care, [[Bad Homburg]], [[Germany]]) is a new device based on the combination of [[human serum albumin|albumin]] [[adsorption]] with high-flux [[hemodialysis]] after selective filtration of the albumin fraction through a specific polysulfon filter (AlbuFlow). It has been studied<ref>Rifai K, Ernst T, Kretschmer U, Bahr MJ, Schneider A, Hafer C, Haller H, Manns MP, Fliser D. Prometheus--a new extracorporeal system for the treatment of liver failure. J Hepatol. 2003 Dec;39(6):984-90. PMID 14642616.</ref> in a group of eleven patients with [[hepatorenal syndrome]] ([[acute-on-chronic liver failure]] and accompanying renal failure). The treatment for two consecutive days for more than four hours significantly improved serum levels of conjugated bilirubin, bile acids, ammonia, cholinesterase, creatinine, urea and blood pH. Prometheus was proven to be a safe supportive therapy for patients with liver failure. ==References== <references/> ==See also== *[[American Society for Artificial Internal Organs]] and [http://www.esao.org/ European Society for Artificial Organs] *[[Artificial extracorporeal liver support]] *[[Bioartificial liver device]] ==External links== * Sen S, Williams R, Jalan R. Emerging indications for albumin dialysis. Am J Gastroenterol. 2005 Feb;100(2):468-75. Review. PMID 15667509 * [http://lab.blogs.com/lswg/ Liver Support Working Group of the European Society for Artficial Organs (ESA0)] ===MARS=== * [http://gambro.com/Pages/InfoPage.aspx?id=9068 Gambro] - the manufacturer of the MARS. * [http://biomed.brown.edu/Courses/BI108/BI108_2002_Groups/liver/webpage/MARSpg.htm MARS - Molecular Adsorbent Recycling System (Teraklin)] - a description of the MARS. * [http://www.chirurgieinfo.com/de/mars.html MARS-Leberdialyse] - has a picture of the MARS in action. * Evenepoel P, Maes B, Wilmer A, Nevens F, Fevery J, Kuypers D, Bammens B, Vanrenterghem Y. Detoxifying capacity and kinetics of the molecular adsorbent recycling system. Contribution of the different inbuilt filters. Blood Purif. 2003;21(3):244-52. PMID 12784051 * Mitzner S, Klammt S, Stange J, Noldge-Schomburg GF, Schmidt R. [Extracorporeal blood purification in severe liver failure with the albumin dialysis MARS -- impact on relevant intensive care parameters] Anasthesiol Intensivmed Notfallmed Schmerzther. 2005 Apr;40(4):199-206. PMID 15832238 ===SPAD=== * [http://www.charite.de/avt/research/sauer/projects/mels_lab/detox_module/detox_start.html Artificial Liver Support Systems] - [http://www.charite.de/avt/research/sauer/ Charité Berlin - Campus Virchow - Division of Experimental Surgery and Regenerative Medicine] - gives detailed descriptions on artificial and bioarticial liver support concepts and - in particular - on SPAD * [http://www.charite.de/avt/research/sauer/projects/mels_lab/mels_start.html Modular Extracorporeal Liver Support (MELS)] - [http://www.charite.de/avt/research/sauer/ Charité Berlin - Campus Virchow - Division of Experimental Surgery and Regenerative Medicine] ===Prometheus=== * [http://www.fmc-ag.com/internet/fmc/fmcag/neu/fmcpub.nsf/content/home Fresenius Medical Care] - Manufactor of the Prometheus system * [http://www.fresenius.se/internet/fag/com/faginpub.nsf/Content/Liver+Support+Therapy The Prometheus System] - Product description with pictures of the system * [http://www.donau-uni.ac.at/en/department/kmbt/forschung/biomedizinischetechnologie/projekte/id/01241/index.php The Prometheus System - Development of an Adsorptive Blood Purification System called Prometheus] - Donau-Universität Krems {{Digestive system surgical procedures}} [[Category:Organ failure]] [[Category:Medical treatments]] [[Category:Medical equipment]] [[Category:Hepatology]] [[de:Leberdialyse]] [[es:Diálisis de hígado]]