We thank the veterinarians, nurses, and animal keepers at the Center of Biomedical Research for their continuous support during our research projects. The authors acknowledge the important input of all reviewers of this protocol. Some of the research was funded by the &#34;Young Science Award&#34; of the Austrian Society of Gastroenterology and Hepatology (&#214;GGH) to PS and the &#34;Skoda Award&#34; of the Austrian Society of Internal Medicine to TR.

All methods described here have been approved by the ethics committee of the Medical University of Vienna and the Austrian Ministry of Science, Research and Economy (BMWFW). Procedures must be performed in aseptic conditions in an operation room or similar clean working area since the hemodynamic measurements represent surgical interventions. Generally, working in sterile conditions is recommended. When using an inhalation anesthesia, consider adequate ventilation of the surgery room for work safety. A time period of 40&...

<ol>
	<li>Ripoll, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hepatic+venous+pressure+gradient+predicts+clinical+decompensation+in+patients+with+compensated+cirrhosis.">Hepatic venous pressure gradient predicts clinical decompensation in patients with compensated cirrhosis.</a> Gastroenterology. 133 (2), 481-488 (2007).</li><li>Bosch, J., Groszmann, R. J., Shah, V. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+in+the+understanding+of+the+pathophysiological+basis+of+portal+hypertension:+How+changes+in+paradigm+are+leading+to+successful+new+treatments.">Evolution in the understanding of the pathophysiological basis of portal hypertension: How changes in paradigm are leading to successful new treatments.</a> J Hepatol. 62, S121-S130 (2015).</li><li>Blachier, M., Leleu, H., Peck-Radosavljevic, M., Valla, D. C., Roudot-Thoraval, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+burden+of+liver+disease+in+Europe:+a+review+of+available+epidemiological+data.">The burden of liver disease in Europe: a review of available epidemiological data.</a> J Hepatol. 58 (3), 593-608 (2013).</li><li>Colle, I., Geerts, A. M., Van Steenkiste, C., Van Vlierberghe, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hemodynamic+Changes+in+Splanchnic+Blood+Vessels+in+Portal+Hypertension.">Hemodynamic Changes in Splanchnic Blood Vessels in Portal Hypertension.</a> Advances in Integrative Anatomy and Evolutionary Biology. 291 (6), 699-713 (2008).</li><li>Laleman, W., Van Landeghem, L., Wilmer, A., Fevery, J., Nevens, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Portal+hypertension:+from+pathophysiology+to+clinical+practice.">Portal hypertension: from pathophysiology to clinical practice.</a> Liver International. 25 (6), 1079-1090 (2005).</li><li>Franchis, R. d. . <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Updating+Consensus+in+Portal+Hypertension:+Report+of+the+Baveno+III+Consensus+Workshop+on+definitions,+methodology+and+therapeutic+strategies+in+portal+hypertension.">Updating Consensus in Portal Hypertension: Report of the Baveno III Consensus Workshop on definitions, methodology and therapeutic strategies in portal hypertension.</a> Journal of Hepatology. 33 (5), 846-852 (2000).</li><li>Zardi, E. M., Di Matteo, F. M., Pacella, C. M., Sanyal, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Invasive+and+non-invasive+techniques+for+detecting+portal+hypertension+and+predicting+variceral+bleeding+in+cirrhosis:+a+review.">Invasive and non-invasive techniques for detecting portal hypertension and predicting variceral bleeding in cirrhosis: a review.</a> Annals of medicine. 46 (1), 8-17 (2014).</li><li>Kumar, A., Sharma, P., Sarin, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hepatic+venous+pressure+gradient+measurement:+time+to+learn.">Hepatic venous pressure gradient measurement: time to learn.</a> Indian J Gastroenterol. 27 (2), 74-80 (2008).</li><li>Tsochatzis, E. A., Bosch, J., Burroughs, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liver+cirrhosis.">Liver cirrhosis.</a> Lancet. 383 (9930), 1749-1761 (2014).</li><li>Abraldes, J. G., Pasar&#237;n, M., Garc&#237;a-Pag&#225;n, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+portal+hypertension.">Animal models of portal hypertension.</a> World Journal of Gastroenterology : WJG. 12 (41), 6577-6584 (2006).</li><li>Reiberger, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sorafenib+attenuates+the+portal+hypertensive+syndrome+in+partial+portal+vein+ligated+rats.">Sorafenib attenuates the portal hypertensive syndrome in partial portal vein ligated rats.</a> Journal of Hepatology. 51 (5), 865-873 (2009).</li><li>Schwabl, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pioglitazone+decreases+portosystemic+shunting+by+modulating+inflammation+and+angiogenesis+in+cirrhotic+and+non-cirrhotic+portal+hypertensive+rats.">Pioglitazone decreases portosystemic shunting by modulating inflammation and angiogenesis in cirrhotic and non-cirrhotic portal hypertensive rats.</a> Journal of Hepatology. 60 (6), 1135-1142 (2014).</li><li>Reiberger, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nebivolol+treatment+increases+splanchnic+blood+flow+and+portal+pressure+in+cirrhotic+rats+via+modulation+of+nitric+oxide+signalling.">Nebivolol treatment increases splanchnic blood flow and portal pressure in cirrhotic rats via modulation of nitric oxide signalling.</a> Liver International. 33 (4), 561-568 (2013).</li><li>Schwabl, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+FXR+agonist+PX20606+ameliorates+portal+hypertension+by+targeting+vascular+remodelling+and+sinusoidal+dysfunction.">The FXR agonist PX20606 ameliorates portal hypertension by targeting vascular remodelling and sinusoidal dysfunction.</a> Journal of Hepatology. 66 (4), 724-733 (2017).</li><li>Mandorfer, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sustained+virologic+response+to+interferon-free+therapies+ameliorates+HCV-induced+portal+hypertension.">Sustained virologic response to interferon-free therapies ameliorates HCV-induced portal hypertension.</a> J Hepatol. 65 (4), 692-699 (2016).</li><li>Schwabl, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interferon-free+regimens+improve+portal+hypertension+and+histological+necroinflammation+in+HIV/HCV+patients+with+advanced+liver+disease.">Interferon-free regimens improve portal hypertension and histological necroinflammation in HIV/HCV patients with advanced liver disease.</a> Aliment Pharmacol Ther. 45 (1), 139-149 (2017).</li><li>Reiberger, T., Mandorfer, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beta+adrenergic+blockade+and+decompensated+cirrhosis.">Beta adrenergic blockade and decompensated cirrhosis.</a> Journal of Hepatology. 66 (4), 849-859 (2017).</li><li>Reiberger, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carvedilol+for+primary+prophylaxis+of+variceal+bleeding+in+cirrhotic+patients+with+haemodynamic+non-response+to+propranolol.">Carvedilol for primary prophylaxis of variceal bleeding in cirrhotic patients with haemodynamic non-response to propranolol.</a> Gut. 62 (11), 1634-1641 (2013).</li><li>Reiberger, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Austrian+consensus+guidelines+on+the+management+and+treatment+of+portal+hypertension+(Billroth+III).">Austrian consensus guidelines on the management and treatment of portal hypertension (Billroth III).</a> Wiener klinische Wochenschrift. 129 (3), 135-158 (2017).</li><li>de Franchis, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expanding+consensus+in+portal+hypertension.">Expanding consensus in portal hypertension.</a> Journal of Hepatology. 63 (3), 743-752 (2015).</li><li>Pinter, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+sorafenib+on+the+portal+hypertensive+syndrome+in+patients+with+liver+cirrhosis+and+hepatocellular+carcinoma+-+a+pilot+study.">The effects of sorafenib on the portal hypertensive syndrome in patients with liver cirrhosis and hepatocellular carcinoma - a pilot study.</a> Alimentary Pharmacology &amp; Therapeutics. 35 (1), 83-91 (2012).</li><li>Schwabl, P., Laleman, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+treatment+options+for+portal+hypertension.">Novel treatment options for portal hypertension.</a> Gastroenterol Rep (Oxf). 5 (2), 90-103 (2017).</li><li>Klein, S., Schierwagen, R., Uschner, F., Trebicka, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Mouse and Rat Models of Induction of Hepatic Fibrosis and Assessment of Portal Hypertension. , (2017).</li><li>Russell, W. M. S., Burch, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Principles of Humane Experimental Technique. , (1959).</li><li>Langhans, W., Myrtha, A., Riediger, T., Lutz, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Routine animal use procedures. , (2016).</li><li>Animal Care and Use Program. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Rat and Mouse anesthesia and analgesia: Formulary and General Drug Information. , (2016).</li><li>Davis, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Current Protocols in Neuroscience. , (2001).</li><li>Albrecht, M., Henke, J., Tacke, S., Markert, M., Guth, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+isoflurane,+ketamine-xylazine+and+a+combination+of+medetomidine,+midazolam+and+fentanyl+on+physiological+variables+continuously+measured+by+telemetry+in+Wistar+rats.">Effects of isoflurane, ketamine-xylazine and a combination of medetomidine, midazolam and fentanyl on physiological variables continuously measured by telemetry in Wistar rats.</a> BMC Veterinary Research. 10 (1), 198 (2014).</li><li>Redfors, B., Shao, Y., Omerovic, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+anesthetic+agent,+depth+of+anesthesia+and+body+temperature+on+cardiovascular+functional+parameters+in+the+rat.">Influence of anesthetic agent, depth of anesthesia and body temperature on cardiovascular functional parameters in the rat.</a> Laboratory Animals. 48 (1), 6-14 (2014).</li><li>Becker, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Statement on anesthesia methodologies: Recommondations on anaesthesia methodologies for animal experimentation in rodents and rabbits. , (2016).</li></ol>

The authors have nothing to disclose.

PP is the main outcome parameter for evaluation of the portal hypertensive syndrome and reflects the severity of underlying cirrhosis. Both matrix deposition (i.e., fibrosis) and sinusoidal vasoconstriction (due to increased hepatic expression of vasoconstrictors and decreased responsiveness to vasodilators) cause increased IHVR. The importance of PP and its impact on chronic liver disease has been shown in multiple preclinical11,12,<sup class...

PHT is defined as pathologically increased blood pressure in the portal venous system that can cause severe complications in patients with cirrhosis such as variceal bleeding and ascites1. While pre-hepatic (e.g., portal vein thrombosis) and post-hepatic (e.g., Budd-Chiari Syndrome) PHT are rare, intrahepatic PHT due to liver cirrhosis represents the most common cause of PHT2.
In liver cirrhosis, PP is primarily increased as a consequence of elevated IHVR3. In advanced stages, PHT is aggravated by the increased PVBF due to increased cardiac output and decreased systemic and splanchnic vascular resistance &#8212; defining the portal hypertensive syndrome4. Ohm&#39;s law (&#916;P = Q * R) implies that the IHVR and blood flow are proportional to PP5. In patients, direct measurement of PP is risky and not routinely performed; instead, the hepatic venous pressure gradient (HVPG) is used as an indirect measure of PP6,7. The HVPG is calculated by subtracting the free hepatic venous pressure (FHVP) from the wedged hepatic venous pressure (WHVP), which are measured using a balloon catheter placed in a hepatic vein8. The physiological HVPG ranges between 1&#8211;5 mmHg, while an HVPG &#8805;10 mmHg defines clinically significant portal hypertension (CSPH) and indicates increased risk for PHT-related complications, such as variceal bleeding, ascites, and hepatic encephalopathy9. Although PP (i.e., HVPG) is the most relevant parameter for PHT severity, information about other components of PHT, including the severity of hyperdynamic circulation (HR, MAP), splanchnic/mesenteric arterial blood flow, and IHVR, are critical to obtain a comprehensive understanding of the distinct underlying mechanism of PHT.
Thus, in contrast to indirect measurements of PP in humans, the introduced methodology for rats offers the advantage of a direct measurement of PP and allows the recording of additional hemodynamic parameters characterizing the portal hypertensive syndrome. In addition, the direct measurement of PP is an excellent integrative readout of the amount of liver fibrosis (a major determinant of IHVR) and overcomes certain limitations of fibrosis quantification related to liver tissue sampling errors.
The most commonly used rodent models of cirrhotic PHT include surgical bile duct ligation (BDL), toxin-induced liver injury (i.e., by carbon tetrachloride, thioacetamide, or dimethylnitrosamine administration), and diet-induced metabolic liver disease models. Prehepatic (non-cirrhotic) PHT can be induced by partial portal vein ligation (PPVL)10.
Small rodents are well suited for the presented method, including mice, hamsters, rats, or rabbits, and are associated with relatively low maintenance costs. Despite that all the hemodynamic assessments are feasible to perform in mice, better accuracy and reproducibility of results are seen with rats or larger rodents due to the obvious advantage of animal size. In addition, specific micro-instruments and devices are needed to obtain similar hemodynamic parameters in mice. Finally, rats are more robust with lower associated morbidity and mortality and thus, the drop-out rates are likely lower in rats than in mice.
The presented methodology is well-suited for evaluating specific treatments of liver disease (i.e., anti-fibrotic or anti-inflammatory drugs) or novel pharmacological approaches that influence vascular tone and/or endothelial biology; and thus, likely effect hemodynamic parameters in PHT.

<table>
	<tbody>
		<tr>
			<td>Instruments</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>LabChart 7 Pro software</td>
			<td>ADInstruments, Colorado Springs, CO, USA</td>
			<td>&#160;-</td>
			<td>Software</td>
		</tr>
		<tr>
			<td>ML870 PowerLab 8/30</td>
			<td>ADInstruments, Colorado Springs, CO, USA</td>
			<td>&#160;-</td>
			<td>Electronic multichannel recorder</td>
		</tr>
		<tr>
			<td>MLT0380/D</td>
			<td>ADInstruments, Colorado Springs, CO, USA</td>
			<td>&#160;-</td>
			<td>Pressure transducer (x2: for Portal Pressure and Arterial Pressure)</td>
		</tr>
		<tr>
			<td>ML112 Quad Bridge Amplifier</td>
			<td>ADInstruments, Colorado Springs, CO, USA</td>
			<td>&#160;-</td>
			<td>Bridge amplifier</td>
		</tr>
		<tr>
			<td>TS420</td>
			<td>Transonic Systems Inc., Ithaca, NY, USA</td>
			<td>&#160;-</td>
			<td>Flowmeter module</td>
		</tr>
		<tr>
			<td>Biological Research Apparatus 7025</td>
			<td>UGO BASILE S.R.L., Comerio, Italy</td>
			<td>&#160;-</td>
			<td>Ventilator</td>
		</tr>
		<tr>
			<td>Vapor 2000</td>
			<td>Dr&#228;ger Medical AG &#38; Co. KG, L&#252;beck, Germany</td>
			<td>&#160;-</td>
			<td>Isofluran Vaporizer</td>
		</tr>
		<tr>
			<td>Perivascular probes (rat) for Transonic systems (Superior Mesenteric Artery)</td>
			<td>Transonic Systems Inc., Ithaca, NY, USA</td>
			<td>#MA1PRB</td>
			<td>Ultrasonic flow probe (1mm)</td>
		</tr>
		<tr>
			<td>Perivascular probes (rat) for Transonic systems (Portal Vein)</td>
			<td>Transonic Systems Inc., Ithaca, NY, USA</td>
			<td>#MA2PSB</td>
			<td>Ultrasonic flow probe (2mm)</td>
		</tr>
		<tr>
			<td>1st for intubation &#38; 2nd for clean skin incisions</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>Mayo scissor [x2]</td>
		</tr>
		<tr>
			<td>Metzenbaum scissor</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>Cuticle scissor</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>e.g. Adson Brown tissue forceps</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>Tissue Forceps</td>
		</tr>
		<tr>
			<td>High precision 45&#176; angle broad point forceps [x2]</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>Hemostat [x4]</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>e.g. Mikulicz peritoneal clamp</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>Curved clamp</td>
		</tr>
		<tr>
			<td>e.g. Dieffenbach clamp</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>Micro clamp</td>
		</tr>
		<tr>
			<td>e.g. micro spatula with flat ends, width 4 mm,</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>Micro metal spatula</td>
		</tr>
		<tr>
			<td>for transbuccal suture at intubation</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>Needle holder</td>
		</tr>
		<tr>
			<td>Scalpel grip</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>selfmade</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>Intubation desk</td>
		</tr>
		<tr>
			<td>blut, flexible and with a suitable diameter for arterial cannula and venflow</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>Blunt steel wire</td>
		</tr>
		<tr>
			<td>modified arterial line 20G with Flowstich</td>
			<td>Becton Dickinson, Farady Road, Swindon, UK</td>
			<td>#682245</td>
			<td>Arterial line</td>
		</tr>
		<tr>
			<td>Heating pad</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>Rectal temerature probe</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>Saline heater</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>Laryngoscope (specific for animal size, e.g. rat)</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>Inductionbox for inhalation anesthesia</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>Scale (able to measure mg)</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>Hair clipper</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
			<td>&#160;-</td>
		</tr>
		<tr>
			<td>Name </td>
			<td>Company </td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Consumables </td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>e.g. modified BD Venflon Pro Safety 14GA</td>
			<td>Becton Dickinson Infusion Therapy, AB, SE251 06 Helsingborg, Sweden</td>
			<td>#393230</td>
			<td>Peripheral venous catheter (14G)</td>
		</tr>
		<tr>
			<td>Fine-Bore Polyethylene Tubing, ID 0.58mm, OD 0.96mm, Portex,</td>
			<td>Smiths Medical International Ltd., Kent, UK</td>
			<td>#800/100/200</td>
			<td>Catheter tube (PE-50)</td>
		</tr>
		<tr>
			<td>e.g. Omnifix-F Solo</td>
			<td>B. Braun Melsungen AG, Melsungen, Germany</td>
			<td>#9161406V</td>
			<td>Syringe 1mL</td>
		</tr>
		<tr>
			<td>e.g. Injekt Solo</td>
			<td>B. Braun Melsungen AG, Melsungen, Germany</td>
			<td>#4606051V</td>
			<td>Syringe 5mL</td>
		</tr>
		<tr>
			<td>e.g. Injekt Solo</td>
			<td>B. Braun Melsungen AG, Melsungen, Germany</td>
			<td>#4606205V</td>
			<td>Syringe 20mL</td>
		</tr>
		<tr>
			<td>e.g. BD Microlance 3, 18G - 1 1/2&#34;</td>
			<td>Becton Dickinson S.A., Fraga, Spain</td>
			<td>#304622</td>
			<td>Cannula (18G)</td>
		</tr>
		<tr>
			<td>e.g. BD Microlance 3, 23G - 1&#34;</td>
			<td>Becton Dickinson S.A., Fraga, Spain</td>
			<td>#300800</td>
			<td>Cannula (23G)</td>
		</tr>
		<tr>
			<td>e.g. BD Microlance 3, 30G - 1/2&#34;</td>
			<td>Becton Dickinson S.A., Fraga, Spain</td>
			<td>#304000</td>
			<td>Cannula (30G) </td>
		</tr>
		<tr>
			<td>e.g. Leukoplast S</td>
			<td>BSN medical GmbH, Hamburg,&#160; Germany</td>
			<td>#47619-00</td>
			<td>Adhesive tape</td>
		</tr>
		<tr>
			<td>e.g. Gazin RK Mullkompressen (18x8cm)</td>
			<td>Lohmann &#38; Rauscher, Vienna, Austria</td>
			<td>#10972</td>
			<td>Gauze compress (small)</td>
		</tr>
		<tr>
			<td>e.g. Gazin RK Mullkompressen (5x5cm)</td>
			<td>Lohmann &#38; Rauscher, Vienna, Austria</td>
			<td>#10961</td>
			<td>Gauze compress (big)</td>
		</tr>
		<tr>
			<td>Silk Braided black, USP 4/0, EP 1.5</td>
			<td>SMI AG, St. Vith, Belgium</td>
			<td>#2021-04</td>
			<td>Suture (Silk 4/0, EP 1.5)</td>
		</tr>
		<tr>
			<td>e.g. Mersilk, 2-0 (3 Ph. Eur.), PS-1 Prime</td>
			<td>Johnson &#38; Johnson Medical GmbH - Ethicon Deutschland, Germany</td>
			<td>#EH7552</td>
			<td>Transbuccal suture</td>
		</tr>
		<tr>
			<td>e.g. Cottonbuds (2.2mm, 15cm)</td>
			<td>Paul Hartmann AG, Heidenheim, Germany</td>
			<td>#967936</td>
			<td>Cotton buds</td>
		</tr>
		<tr>
			<td>e.g. Vue Ultrasoundgel</td>
			<td>Optimum Medical Limited, UK</td>
			<td>#1157</td>
			<td>Ultrasound gel</td>
		</tr>
		<tr>
			<td>e.g. Glubran 2</td>
			<td>Gem srl, Viareggio, Italy</td>
			<td>#G-NB2-50</td>
			<td>Tissue glue</td>
		</tr>
		<tr>
			<td>e.g. Surgical scalpell knife Nr. 10 - carbon steel</td>
			<td>Swann-Morton, England, B.S.</td>
			<td>#202</td>
			<td>Scalpel Knife</td>
		</tr>
		<tr>
			<td>Heparin, 5000 i.E./mL (Natriumheparin)</td>
			<td>Medicamentum Pharma GmbH, Allerheiligen im M&#252;rztal, Austria</td>
			<td>&#160;-</td>
			<td>Heparin</td>
		</tr>
		<tr>
			<td>Florane</td>
			<td>Aesica Queenborough Ltd., Queenborough, UK</td>
			<td>&#160;-</td>
			<td>Isoflurane</td>
		</tr>
		<tr>
			<td>OeloVital (5g)</td>
			<td>Fresenius Kabi Austira Gmbh, Graz, Austria</td>
			<td>&#160;-</td>
			<td>Eye gel</td>
		</tr>
		<tr>
			<td>Ketasol</td>
			<td>aniMedica GmbH, Senden-B&#246;sensell, Germany</td>
			<td>&#160;-</td>
			<td>Ketamine</td>
		</tr>
		<tr>
			<td>Rompun</td>
			<td>Bayer Austria Ges.m.b.H., Vienna, Austria</td>
			<td>&#160;-</td>
			<td>Xylazine</td>
		</tr>
		<tr>
			<td>Xylocain 10% Pumpspray</td>
			<td>AstraZeneca &#214;sterreich GmbH, Vienna, Austria</td>
			<td>&#160;-</td>
			<td>Lidocaine pump spray</td>
		</tr>
		<tr>
			<td>Dipidolor</td>
			<td>Jansen-Cilag Pharma GmbH, Vienna, Austria</td>
			<td>&#160;-</td>
			<td>Piritramide</td>
		</tr>
		<tr>
			<td>NaCl 0.9% Fresenius, 1L</td>
			<td>Fresenius Kabi Austira GmbH, Graz, Austria</td>
			<td>#13LIP132</td>
			<td>Physiological saline solution</td>
		</tr>
	</tbody>
</table>

invasive hemodynamic characterization of the portal-hypertensive syndrome in cirrhotic rats

This is a detailed protocol describing invasive hemodynamic measurements in cirrhotic rats for the characterization of portal hypertensive syndrome. Portal hypertension (PHT) due to cirrhosis is responsible for the most severe complications in patients with liver disease. The full picture of the portal hypertensive syndrome is characterized by increased portal pressure (PP) due to the increased intrahepatic vascular resistance (IHVR), hyperdynamic circulation, and increased splanchnic blood flow. Progressive splanchnic arterial vasodilation and increased cardiac output with elevated heart rate (HR) but low arterial pressure characterizes the portal hypertensive syndrome.
Novel therapies are currently being developed that aim to decrease PP by either targeting IHVR or increased splanchnic blood flow &#8212; but side effects on systemic hemodynamics may occur. Thus, a detailed characterization of portal venous, splanchnic, and systemic hemodynamic parameters, including measurement of PP, portal venous blood flow (PVBF), mesenteric arterial blood flow, mean arterial pressure (MAP), and HR is needed for preclinical evaluation of the efficacy of novel treatments for PHT. Our video article provides the reader with a structured protocol for performing invasive hemodynamic measurements in cirrhotic rats. In particular, we describe the catheterization of the femoral artery and the portal vein via an ileocolic vein and the measurement of portal venous and splanchnic blood flow via perivascular Doppler-ultrasound flow probes. Representative results of different rat models of PHT are shown.

Depending on the animal model and the severity of liver disease, the degree of PHT and severity of the portal hypertensive syndrome is different (Figure 7).
The BDL model causes biliary cirrhosis due to cholestasis. Accordingly, PP increases over time and a hyperdynamic circulation develops, as seen by an increase of HR and decrease of MAP. In cirrhotic animals, SMABF, PVBF and IHVR also increase co...

Watch this Scientific Journal Video about Invasive Hemodynamic Characterization of the Portal-hypertensive Syndrome in Cirrhotic Rats at JoVE.com

Invasive Hemodynamic Characterization of the Portal-hypertensive Syndrome in Cirrhotic Rats

Here we describe a detailed protocol for invasive measurements of hemodynamic parameters including portal pressure, splanchnic blood flow, and systemic hemodynamics in order to characterize the portal hypertensive syndrome in rats.

This is a detailed protocol describing invasive hemodynamic measurements in cirrhotic rats for the characterization of portal hypertensive syndrome. ...

This method can help answer key questions in the field of advanced liver fibrosis and portal hypertension. It offers a unique opportunity to evaluate pharmacological approaches that target vascular tone, fibrogenesis, or endothelial dysfunction in rats with portal-hypertensive syndrome. The main advantages of this technique include the direct measurement of portal pressure and the opportunity to obtain additional hemodynamic parameters in contrast to the indirect measurement of portal pressure by hepatic venous pressure gradient, HVPG, in patients.Begin by sedating the rat, using short-time isoflurane anesthesia and optionally additional anesthetics. Quickly proceed to intubation, using a suitable self-made endotracheal tube. Use two fingers to grab the tongue, and gently pull it.Then, carefully moisten the laryngeal area with a cotton swab soaked in lidocaine spray. Next, gently insert the endotracheal tube between the vocal folds and into the trachea. Fix the endotracheal loop by a transbuccal suture through the cheek and the adhesive tape loop of the tube.After administering analgesia and injectable anesthesia, apply eye ointment. Then, clip the body hair at the abdominal region and both inner thighs, and disinfect the skin. Assess the anesthesia depth by lid-closure reflex and toe-pinch test prior to any intervention or surgery.Use tissue forceps to lift the skin on one of the shaved thighs above the presumed location of the femoral artery. Use Mayo scissors to remove a two-centimeter area of skin. Then, use a hemostat to blunt dissect the artery-vein-nerve complex from the connective tissue.For better visibility of the artery-vein-nerve complex, the cuticle scissor can be used to remove parts of fat tissue. Next, use two high-precision, 45-degree angle, broad-point forceps to separate the femoral artery from the femoral vein and nerve. The femoral vein is the most medial structure, and the femoral artery is located more lateral.Place a ligature on the femoral artery as distal as possible, and use a curved clamp on the suture to apply gentle longitudinal traction to the femoral artery. Then, place a second, loosely pre-knotted suture on the femoral artery as proximal as possible. Compress the femoral artery at the proximal end of the exposed section, using a micro clamp to temporarily stop the arterial blood flow.Then, place a supporting micro metal spatula underneath the femoral artery, and use a bent 23-gauge cannula to perforate the anterior arterial wall distal to the occluded section. Carefully catheterize the femoral artery through the perforation with the slanted tip of the catheter facing upward. Advance the catheter until it reaches the micro clamp.Fix the catheter in its intraluminal location by closing the prepared proximal ligature around the femoral artery and its introduced catheter. Then, open the micro clamp, and check for pulsatile arterial blood flow into the catheter. Fix the catheter position along the vessel, using the ends of the distal ligature to prevent dislocation and to ensure a longitudinal position of the catheter.Use the digital interface to start recording the heart rate and mean atrial pressure. Begin by performing a median laparotomy. First, lift the skin layer with tissue forceps five to six centimeters below the xiphoid, and use a Mayo scissor to remove a thin strip of skin, using above the linea alba until the xiphoid is reached.Then, use tissue forceps to lift the muscular layer at the center of the linea alba to create distance between the abdominal wall and the splanchnic organs. Open the peritoneal cavity by incising the abdominal wall with a scalpel at the linea alba. Extend the incision along the linea alba, over the same distance as the skin layer.Next, carefully excavate the intestine using wet cotton buds. Start with the caecum, and lay it on a large gauze compress, soaked in sterile physiological saline solution placed next to the incision. Wrap the intestine with the gauze compress, and make sure it is moistened with sterile physiological saline solution.The cirrhotic liver should now be visible. Then, dissect the superior mesenteric artery with two self-made blunt Schwabl hooks, lift the artery with the first hook, and place the second one through the tissue tunnel. Expose the superior mesenteric artery along a five-millimeter distance to ensure the flow probe can be placed around it.Next, apply ultrasound gel to the ultrasonic flow probe sensor. Attach the sensor to the splanchnic mesenteric artery so that it is aligned to the natural route of the superior mesenteric artery. Measure the superior mesenteric artery blood flow, and assess the accordance of the pulsatile flow signal to the systolic peaks of the femoral artery recording.To measure portal vein blood flow, first locate and expose the portal vein at the dorsal face of the mesentery that is close to the liver hilum. Then, use high-precision, 45-degree angle, broad-point forceps to gently dissect the portal vein from the surrounding tissue. Enlarge the tissue tunnel, and expose the portal vein along a distance of five to six millimeters to allow the placement of the perivascular flow probe.Apply ultrasound gel to the ultrasonic flow probe sensor, and attach it to the portal vein aligned with its natural route. Then, close the flow probe, and start recording the portal vein blood flow. To measure portal pressure, wet gloves with physiological saline, and spread the intestine across the fingers.Optimize the view of the mesenteric vascular bed close to the small intestine. Insert the catheter into the mesenteric tissue by perforating the visceral peritoneum of the mesentery close to the vascular junction chosen for catheterization. Then, carefully advance the slanted tip of the catheter closer to a junction of the ileocolic vein until a slight impression of the vessel junction is seen.Finally, catheterize the venous system in line with the joining vessel route by perforating the vascular wall at the crossing angle of the vessels. Record all hemodynamic parameters simultaneously under stable conditions for several minutes before euthanizing the animal. The bile duct ligation model causes biliary cirrhosis due to cholestasis.Accordingly, portal pressure increases over time, and a hyperdynamic circulation develops, as evident by an increased heart rate and decrease of mean arterial pressure. In cirrhotic animals, intrahepatic vascular resistance and superior mesenteric arterial blood flow increase, while subsequently portal venous blow flow rises, depending on the amount of portosystemic collateralization. In contrast, partial portal vein ligation causes prehepatic, non-cirrhotic portal hypertension, which is characterized by an immediate increase in portal pressure.However, during the time course, portosystemic collaterals develop that may lower portal pressure. In addition, we see corresponding changes in mean arterial pressure and heart rate. For healthy, sham-operated animals, their hemodynamic values remain at physiological levels and do not significantly change over time.The portal pressure in healthy, SO animals is at maximum five to six millimeters of mercury. Once mastered, these techniques can be performed within 40 to 50 minutes, depending on the animal model, need for troubleshooting, and optimal pre-surgical preparations. While performing the surgical procedure, it's very important to monitor the temperature of the animal, as well as the heart rate and the arterial pressure in order to assess the level of anesthesia.After watching this video, you should have a good understanding of how to cannulate the femoral artery and the portal vein and how to attach ultrasound flow probes to splanchnic blood vessels in a safe way that will guarantee accurate and reproducible results.

invasive-hemodynamic-characterization-portal-hypertensive-syndrome

Research

JoVE Journal

Medicine

14.9K ビュー.  Medical University of Vienna, Vienna, Austria. This method can help answer key questions in the field of advanced liver fibrosis and portal hypertension. It offers a unique opportunity to evaluate pharmacological approaches that target vascular tone, fibrogenesis, or endothelial dysfunction in rats with portal-hypertensive syndrome. The main advantages of this technique include the direct measurement of portal pressure and the opportunity to obtain additional hemodynamic parameters in contrast to the indirect measurement of portal pressur...