The authors have no acknowledgements.

All experiments in this protocol were approved by the Veterinary Authorities of the Canton of Z&#252;rich, Switzerland (number 60/2014). Furthermore, all experimental steps were performed in strict compliance with the Guidelines on Experiments with Animals by the Swiss Academy of Medical Sciences (SAMS) and Guidelines of the Federation of European Laboratory Animal Science Associations (FELASA).
1. Animal Husbandry, Operating Room Equipment and Instruments, Anesthesia
<ol>
	<li>Keep male Wis...

<ol>
	<li>She, W. H., Chok, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strategies+to+increase+the+resectability+of+hepatocellular+carcinoma.">Strategies to increase the resectability of hepatocellular carcinoma.</a> World J Hepatol. 7 (18), 2147-2154 (2015).</li><li>Vauthey, J. N., 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=Standardized+measurement+of+the+future+liver+remnant+prior+to+extended+liver+resection:+methodology+and+clinical+associations.">Standardized measurement of the future liver remnant prior to extended liver resection: methodology and clinical associations.</a> Surgery. 127 (5), 512-519 (2000).</li><li>Kinoshita, H., 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=Preoperative+portal+vein+embolization+for+hepatocellular+carcinoma.">Preoperative portal vein embolization for hepatocellular carcinoma.</a> World J Surg. 10 (5), 803-808 (1986).</li><li>van Lienden, K. 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=Portal+Vein+Embolization+Before+Liver+Resection:+A+Systematic+Review.">Portal Vein Embolization Before Liver Resection: A Systematic Review.</a> Cardiovasc Intervent Radiol. , (2012).</li><li>Kianmanesh, R., 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=Right+portal+vein+ligation:+a+new+planned+two-step+all-surgical+approach+for+complete+resection+of+primary+gastrointestinal+tumors+with+multiple+bilateral+liver+metastases.">Right portal vein ligation: a new planned two-step all-surgical approach for complete resection of primary gastrointestinal tumors with multiple bilateral liver metastases.</a> J Am Coll Surg. 197 (1), 164-170 (2003).</li><li>Nadalin, S., 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=Volumetric+and+functional+recovery+of+the+liver+after+right+hepatectomy+for+living+donation.">Volumetric and functional recovery of the liver after right hepatectomy for living donation.</a> Liver Transpl. 10 (8), 1024-1029 (2004).</li><li>Michalopoulos, G. K., DeFrances, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liver+regeneration.">Liver regeneration.</a> Science. 276 (5309), 60-66 (1997).</li><li>Fulop, A., 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=Alterations+in+hepatic+lobar+function+in+regenerating+rat+liver.">Alterations in hepatic lobar function in regenerating rat liver.</a> J Surg Res. 197 (2), 307-317 (2015).</li><li>Schnitzbauer, A. A., 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=Right+portal+vein+ligation+combined+with+in+situ+splitting+induces+rapid+left+lateral+liver+lobe+hypertrophy+enabling+2-staged+extended+right+hepatic+resection+in+small-for-size+settings.">Right portal vein ligation combined with in situ splitting induces rapid left lateral liver lobe hypertrophy enabling 2-staged extended right hepatic resection in small-for-size settings.</a> Ann Surg. 255 (3), 405-414 (2012).</li><li>de Santibanes, E., Clavien, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Playing+Play-Doh+to+prevent+postoperative+liver+failure:+the+&amp;#34;ALPPS&amp;#34;+approach.">Playing Play-Doh to prevent postoperative liver failure: the &amp;#34;ALPPS&amp;#34; approach.</a> Ann Surg. 255 (3), 415-417 (2012).</li><li>Schadde, E., 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=Monosegment+ALPPS+hepatectomy:+extending+resectability+by+rapid+hypertrophy.">Monosegment ALPPS hepatectomy: extending resectability by rapid hypertrophy.</a> Surgery. 157 (4), 676-689 (2015).</li><li>Dokmak, S., Belghiti, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Which+limits+to+the+&amp;#34;ALPPS&amp;#34;+approach?.">Which limits to the &amp;#34;ALPPS&amp;#34; approach?.</a> Ann Surg. 256 (3), e6 (2012).</li><li>Aloia, T. A., Vauthey, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Associating+liver+partition+and+portal+vein+ligation+for+staged+hepatectomy+(ALPPS):+what+is+gained+and+what+is+lost?.">Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS): what is gained and what is lost?.</a> Ann Surg. 256 (3), e9 (2012).</li><li>Yao, L., 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=Establishment+of+a+rat+model+of+portal+vein+ligation+combined+with+in+situ+splitting.">Establishment of a rat model of portal vein ligation combined with in situ splitting.</a> PLoS One. 9 (8), e105511 (2014).</li><li>Schlegel, A., 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=ALPPS:+from+human+to+mice+highlighting+accelerated+and+novel+mechanisms+of+liver+regeneration.">ALPPS: from human to mice highlighting accelerated and novel mechanisms of liver regeneration.</a> Ann Surg. 260 (5), 839-846 (2014).</li><li>Croome, K. 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=Characterization+of+a+porcine+model+for+associating+liver+partition+and+portal+vein+ligation+for+a+staged+hepatectomy.">Characterization of a porcine model for associating liver partition and portal vein ligation for a staged hepatectomy.</a> HPB (Oxford). 17 (12), 1130-1136 (2015).</li><li>Schadde, E., 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=Hypoxia+of+the+growing+liver+accelerates+regeneration.">Hypoxia of the growing liver accelerates regeneration.</a> Surgery. 161 (3), 666-679 (2017).</li><li>Moris, D., 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=Mechanistic+insights+of+rapid+liver+regeneration+after+associating+liver+partition+and+portal+vein+ligation+for+stage+hepatectomy.">Mechanistic insights of rapid liver regeneration after associating liver partition and portal vein ligation for stage hepatectomy.</a> World J Gastroenterol. 22 (33), 7613-7624 (2016).</li><li>Garcia-Perez, R., 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=Associated+Liver+Partition+and+Portal+Vein+Ligation+(ALPPS)+vs+Selective+Portal+Vein+Ligation+(PVL)+for+Staged+Hepatectomy+in+a+Rat+Model.+Similar+Regenerative+Response?.">Associated Liver Partition and Portal Vein Ligation (ALPPS) vs Selective Portal Vein Ligation (PVL) for Staged Hepatectomy in a Rat Model. Similar Regenerative Response?.</a> PLoS One. 10 (12), e0144096 (2015).</li><li>Shi, H., 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+preliminary+study+of+ALPPS+procedure+in+a+rat+model.">A preliminary study of ALPPS procedure in a rat model.</a> Sci Rep. 5, 17567 (2015).</li><li>Almau Trenard, H. 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=Development+of+an+experimental+model+of+portal+vein+ligation+associated+with+parenchymal+transection+(ALPPS)+in+rats.">Development of an experimental model of portal vein ligation associated with parenchymal transection (ALPPS) in rats.</a> Cir Esp. 92 (10), 676-681 (2014).</li><li>Dhar, D. K., Mohammad, G. H., Vyas, S., Broering, D. C., Malago, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+rat+model+of+liver+regeneration:+possible+role+of+cytokine+induced+neutrophil+chemoattractant-1+in+augmented+liver+regeneration.">A novel rat model of liver regeneration: possible role of cytokine induced neutrophil chemoattractant-1 in augmented liver regeneration.</a> Ann Surg Innov Res. 9, 11 (2015).</li><li>Wei, W., 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=Establishment+of+a+rat+model:+Associating+liver+partition+with+portal+vein+ligation+for+staged+hepatectomy.">Establishment of a rat model: Associating liver partition with portal vein ligation for staged hepatectomy.</a> Surgery. 159 (5), 1299-1307 (2016).</li><li>Tschuor, 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=Salvage+parenchymal+liver+transection+for+patients+with+insufficient+volume+increase+after+portal+vein+occlusion+-+an+extension+of+the+ALPPS+approach.">Salvage parenchymal liver transection for patients with insufficient volume increase after portal vein occlusion - an extension of the ALPPS approach.</a> Eur J Surg Oncol. 39 (11), 1230-1235 (2013).</li><li>Schadde, E., 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=Early+survival+and+safety+of+ALPPS:+first+report+of+the+International+ALPPS+Registry.">Early survival and safety of ALPPS: first report of the International ALPPS Registry.</a> Ann Surg. 260 (5), 829-836 (2014).</li><li>Harnoss, J. 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=Prolyl+Hydroxylase+Inhibition+Enhances+Liver+Regeneration+Without+Induction+of+Tumor+Growth.">Prolyl Hydroxylase Inhibition Enhances Liver Regeneration Without Induction of Tumor Growth.</a> Ann Surg. , (2016).</li><li>Olthof, P. B., 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=Comparable+liver+function+and+volume+increase+after+portal+vein+embolization+in+rabbits+and+humans.">Comparable liver function and volume increase after portal vein embolization in rabbits and humans.</a> Surgery. 161 (3), 658-665 (2017).</li><li>Olthof, P. B., van Gulik, T. M., Bennink, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimal+use+of+hepatobiliary+scintigraphy+before+liver+resection.">Optimal use of hepatobiliary scintigraphy before liver resection.</a> HPB (Oxford). 18 (10), 870 (2016).</li><li>Lau, L., Christophi, C., Muralidharan, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+functional+liver+remnant+assessment+with+indocyanine+green+clearance:+another+toehold+for+climbing+the+&amp;#34;ALPPS&amp;#34;.">Intraoperative functional liver remnant assessment with indocyanine green clearance: another toehold for climbing the &amp;#34;ALPPS&amp;#34;.</a> Ann Surg. 261 (2), e43-e45 (2015).</li><li>Cieslak, K. 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=Assessment+of+Liver+Function+Using+(99m)Tc-Mebrofenin+Hepatobiliary+Scintigraphy+in+ALPPS+(Associating+Liver+Partition+and+Portal+Vein+Ligation+for+Staged+Hepatectomy).">Assessment of Liver Function Using (99m)Tc-Mebrofenin Hepatobiliary Scintigraphy in ALPPS (Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy).</a> Case Rep Gastroenterol. 9 (3), 353-360 (2015).</li><li>Truant, S., 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=Drop+of+Total+Liver+Function+in+the+Interstages+of+the+New+Associating+Liver+Partition+and+Portal+Vein+Ligation+for+Staged+Hepatectomy+Technique:+Analysis+of+the+&amp;#34;Auxiliary+Liver&amp;#34;+by+HIDA+Scintigraphy.">Drop of Total Liver Function in the Interstages of the New Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy Technique: Analysis of the &amp;#34;Auxiliary Liver&amp;#34; by HIDA Scintigraphy.</a> Ann Surg. 263 (3), e33-e34 (2016).</li></ol>

The authors have nothing to disclose.

This protocol presents an animal model of ALPPS with its rapid hypertrophy induced by PVL+T, that roughly doubles volume increase within 3 days compared to PVL alone.17 The right middle hepatic lobe is used as a model for the growing liver lobe because the middle hepatic lobe is one contiguous parenchymal mass supplied by two separate portal veins to its left and to its right side, as shown in Figure 1 in a recently published work.17 Compared t...

The size of the liver remnant limits the resectability of liver tumors.1 In general, when less than 25% liver tissue is left behind, the patient is at increased risk of death from acute liver failure due to the lack of metabolic function for the entire organism (&#34;too small for size syndrome&#34;).2 This post-hepatectomy liver failure is the most devastating complication after liver resection. Therefore clinicians have tried to induce liver regeneration prior to resection of the liver by manipulating the flow of the portal vein.3 It was found that, once the portal vein is occluded, the remaining part with portal vein flow starts to grow at a slow rate, and can thereby increase up to 60% in size.4 Surgical ligation5 or interventional portal vein occlusion have both been clinically established.4 The increase in volume and function of the liver is reliable, but the growth rate of the liver after portal occlusion is only about one fifth compared to the growth of the remnant liver after partial hepatectomy.6
The time necessary for the liver to grow is weeks to months even though the liver can regenerate at a much faster rate after resection. As such, the liver is the only organ that grows back to normal function after removal of a part of it.7 A novel procedure inducing liver regeneration at a similar pace as after partial hepactectomy was developed by a group of surgeons who discovered that adding a transection between the occluded and the non-occluded part of the liver induces liver hypertrophy at the same growth rate as after liver resection, but prior to resection.9 The procedure initiates rapid hypertrophy of 80% within a week in the future liver remnant, which allows the resection of extensive, primarily unresectable, liver tumors within a week. The procedure was called &#34;Associating Liver Partition and Portal vein ligation for Staged hepatectomy = ALPPS&#34; and became rapidly popular across the world.10 Multiple reports supported an expansion of the resectability of borderline resectable liver tumors achieved by the new technique,11 while the complex surgical procedure was also criticized for its high complication rate.12,13
The development of a rodent and also large animal models of slow and rapid hypertrophy has been attempted since the publication of ALPPS in 2012 to allow a better histological characterization and understanding of the mechanisms and to test drug effects on the different growth rates of liver tissue in animals. The first animal model developed was a rat model. In this model, rapid hypertrophy after parenchymal transection between the right and the left part of the median lobe accelerated regeneration of the right median lobe.14 A different model was introduced later in the mouse. In this model the left lateral lobe was resected and the portal vein branches to every lobe of the liver except the left median lobe were tied.15 In the meantime, large animal models of ALPPS in pigs have been described as well.16
For the study of physiological mechanisms like flow changes and pressure in the portal vein, perfusion and oxygenation of liver tissue, the rat model is superior to the model of ALPPS in mice. Another advantage of the rat over the murine model is that in the rat model there is no necessity for a resection of the left lateral lobe,15 which may contaminate the effects of liver resection with those of ALPPS. The rat model in contrast does not reduce the liver cell mass. A pig model uses the right posterior lobe as the growing lobe, but the pig liver is highly lobulated. Therefore, it is difficult to create a transection plane in the already thin tissue bridge between the right posterior and the right anterior lobe. In contrast, the median lobe in rats consist of two parts that are separately supplied by a portal vein each and a parenchymal transection plane can easily be created between the two using microsurgical techniques. The availability of small animal computer tomography (CT) and/or magnet resonance imaging (MRI) allows the very exact quantification of volumetric growth between portal vein ligation alone and portal vein ligation and the added transection, which is important for the validation of any rapid liver hypertrophy model.
The protocol presented here describes the surgical technique and procedures used for volumetric validation and physiological characterization of the model of slow and rapid hypertrophy after portal vein ligation and portal vein ligation with transection, respectively, in rats.

<table border="0" cellpadding="0" cellspacing="0" width="1220">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:225px;">Isoflurane, 250ml bottles</td>
			<td style="width:400px;">Attane, Piramal, Mumbai, India</td>
			<td style="width:255px;">LDNI 22098</td>
			<td style="width:340px;">Standard vet. equipment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tec-3 Isofluorane Vaporizer</td>
			<td>Ohmeda, GE-Healthcare, Chicago, IL</td>
			<td>not available anymore</td>
			<td>Standard vet. equipment&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Buprenorphine (Temgesic)</td>
			<td>Indivior, Baar, Switzerland</td>
			<td>7680419310353</td>
			<td>GTIN-number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vitamine A ointment</td>
			<td>Bausch&#38;Lomp, Zug, Switzerland</td>
			<td>7680223980247</td>
			<td>GTIN-number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Atropine sulfate 0.5mg/ml</td>
			<td>Sintetica SA, Mendrisio, Switzerland</td>
			<td>7680565330045</td>
			<td>GTIN-number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microsurgery microscope</td>
			<td>Olympus, Tokio, Japan</td>
			<td>SZX10</td>
			<td>Standard vet. equipment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Betadine</td>
			<td>Mundipharma, Basel, Switzerland</td>
			<td>7680342821377</td>
			<td>GTIN-number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sponges</td>
			<td>Carl Roth GmbH, Karlsruhe, Germany</td>
			<td>NK83.1</td>
			<td>Mini-sponges</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Abdominal Wall retractors</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Self-made from paper clips and Q-Tips</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">3-0 silk&#160;</td>
			<td>Ethicon, Sommerville, NJ</td>
			<td>K872H</td>
			<td>Standard surgical</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Scissors&#160;</td>
			<td>World precision instruments (WPI), Sarasota, FL</td>
			<td>503371</td>
			<td>Standard microsurgical</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Adson forceps</td>
			<td>World precision instruments (WPI), Sarasota, FL</td>
			<td>501244-G</td>
			<td>Standard microsurgical</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fine tips microforceps</td>
			<td>World precision instruments (WPI), Sarasota, FL</td>
			<td>501976</td>
			<td>Tips need to be polished regularly</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Curved fine tips microforceps</td>
			<td>World precision instruments (WPI), Sarasota, FL</td>
			<td>504513</td>
			<td>Essential to go around the portal vein branches&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">6-0 LOOK black braided silk</td>
			<td>Surgical Specalities Corporation, Wyomissing, PA&#160;</td>
			<td>SP114</td>
			<td>Spool, precut prior to the procedure</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2-0 silk sutures</td>
			<td>Ethicon, Sommerville, NJ</td>
			<td>K833</td>
			<td>Standard surgical</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">5-0 maxon sutures</td>
			<td>Covidien, Dublin, Ireland</td>
			<td>6608-21</td>
			<td>Standard surgical</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Bipolar microforceps</td>
			<td>Sutter, Freiburg, Germany</td>
			<td>780148SGS</td>
			<td>Essential for parenchymal transection</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Q-tips small</td>
			<td>Carl Roth GmbH, Karlsruhe, Germany</td>
			<td>EH11.1</td>
			<td>Standard surgical</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Q-tips big</td>
			<td>Carl Roth GmbH, Karlsruhe, Germany</td>
			<td>XL54.1</td>
			<td>Standard surgical</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">G30 needle&#160;</td>
			<td>Terumo, Tokyo, Japan</td>
			<td>NN-3013R&#160;</td>
			<td>Standard anesthesia equipment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2mm volume flow probe&#160;</td>
			<td>Transonic Systems, Ithaca, NY</td>
			<td>MA-2PS</td>
			<td>Smallest available probe for HAT-311 flow meter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Transonic flow meter</td>
			<td>Transonic Systems, Ithaca, NY</td>
			<td>HAT-311 Transsonic flow QC meter</td>
			<td>One of the&#160; first generation flow flow meters for surgery</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ExiTron nano 12,000&#160;</td>
			<td>Miltenyi Biotech, Bergisch Gladbach, Germany</td>
			<td>130-095-698</td>
			<td>Nanomoloecular contrast medium that opacifies liver and spleen</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">G26 intravenous catheter</td>
			<td>Becton Dickinson, Franklin Lakes, NJ</td>
			<td>391349</td>
			<td>Standard anesthesia equipment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Quantum FX MicroCT&#160;</td>
			<td>Perkin Elmer, Waltham, MA</td>
			<td>N/A</td>
			<td>Standard small animal CT scanner at the institute of physiology, University of Z&#252;rich</td>
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			<td height="21" style="height:21px;">OsiriX 8.0</td>
			<td>Pixmeo Sarl, Geneva, Switzerland</td>
			<td>N/A</td>
			<td>Public domain software : www.pixmeo.com</td>
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rat model of the associating liver partition and portal vein ligation for staged hepatectomy (alpps) procedure

Recent clinical data support an aggressive surgical approach to both primary and metastatic liver tumors. For some indications, like colorectal liver metastases, the amount of liver tissue left behind after liver resection has become the main limiting factor of resectability of large or multiple liver tumors. A minimal amount of functional tissue is required to avoid the severe complication of post-hepatectomy liver failure, which has high morbidity and mortality. Inducing liver growth of the prospective remnant prior to resection has become more established in liver surgery, either in the form of portal vein embolization by interventional radiologists or in the form of portal vein ligation several weeks prior to resection. Recently, it was shown that liver regeneration is more extensive and rapid, when the parenchymal transection is added to portal vein ligation in a first stage and then, after only one week of waiting, resection performed in a second stage (Associating Liver Partition and Portal vein ligation for Staged hepatectomy = ALPPS). ALPPS has rapidly become popular across the world, but has been criticized for its high perioperative mortality. The mechanism of accelerated and extensive growth induced by this procedure has not been well understood. Animal models have been developed to explore both the physiological and molecular mechanisms of accelerated liver regeneration in ALPPS. This protocol presents a rat model that allows mechanistic exploration of accelerated regeneration.

The two different surgical procedures portal vein ligation (PVL) and PVL with transection (PVL+T) result in distinctly different growth kinetics. PVL induces moderate volume increase within 3 days, whereas in PVL+T a much larger right median lobe (RML) can be seen (Figure 5). This can be verified by daily volumetry. The volume of the RML roughly doubles within 3 days in PVL, while it triples in PVL+T.17
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Watch this Scientific Journal Video about Rat Model of the Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy ALPPS Procedure at JoVE.com

Rat Model of the Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy ALPPS Procedure

Inducing rapid liver hypertrophy using Associating Liver Partition and Portal vein ligation for a Staged hepatectomy (ALPPS) has been proposed for resection of borderline resectable liver tumors. This model may elucidate mechanisms involved in rapid hypertrophy and allows testing of drugs that promote or block the acceleration of regeneration.

Rat Model of the Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) Procedure

Recent clinical data support an aggressive surgical approach to both primary and metastatic liver tumors. For some indications, like colorectal liver ...

The overall goal of this surgical intervention is to achieve rapid hypertrophy of the rat liver by ligation of the portal vein and transection of the parenchyma. This model allows for details physiological and molecular assessments of rapid liver regeneration. The liver regenerates after portal vein ligation.We found a way of transecting the parenchyma additionally to the portal vein ligation to accelerate that regeneration. This method provides a model for accelerated liver regeneration. It's a method that's used in human surgery for patients with borderline resectable liver tumors.Once the animal is fully anesthetized and prepared for surgery, shave the abdomen along the midline from the xiphoid to the genitals using small animal hair clippers. Thoroughly remove the hair within two centimeters of the midline. After disinfecting the skin, make an incision through the abdominal wall.Then retract both walls and the xiphoid with 3-0 silk stay sutures. Next using self-made small wire retractors, retract the stomach, colon and small bowel away from the hepatoduodenal ligament. Thus access the portal vein.Now dissect the portal vein bluntly. Lift the peritoneum with the micro forceps and slowly peel it medially. Dissect out the portal vein branches in the following sequence.First, the right posterior branch. Second, the left lateral and left median branch together. And third, the caudate branch.Next carefully peel off the peritoneum using small movements to avoid tearing the small arterial branches to the liver lobes that run directly below. Once the main portal vein is denuded, encircle the branches with slow forward pushing and spreading movements. Avoid pushing against resistance to prevent tearing an artery or vein.This is an essential part of the procedure. You have to avoid pushing against resistance. But usually once you've taken the peritoneal surface off, the microsurgical right angles slide quite easily around the portal vein branches.In case of bleeding apply pressure for at least one minute with a sterile cotton swab, and then reassess. Repeat this maneuver several times, if necessary. If the bleeding does not stop, then sacrifice the animal.Next, dissect the right posterior lobe branch. First carefully move the artery that runs directly across the lobe branch. Then using curved micro forceps, pull the artery cranially together with the peritoneum to expose the right portal vein branch.Now ligate the right posterior lobe branch using 6-0 silk. Observe the right posterior lobe. It will go pale after the ligation.Next, dissect the LLL and LML branches. They share a common trunk. Avoid injuring the arteries that run within the peritoneal layer leading to these branches.Peel the peritoneum back carefully to keep those arteries intact. Then dissect the somewhat separate caudate lobe branch. The portal vein leading to it takes off from the main portal vein distally and medial to the right lobe branch.This is unlike larger animals where the branches are strictly inferior. Lift the hepatoduodenal ligament with bile duct and the arteries from the main portal vein to dissect out and encircle the caudate lobe branch. Use curved micro forceps and approach the lobe laterally.Then ligate using 6-0 silk. This lobe will also turn pale after the ligation. Now observe the appearance of a distinct demarcation between the right and left median lobe.This forms due to exclusive portal vein profusion of only the RML. The surgery can be stopped here for the portal vein ligation model. To proceed with the transection, use a non-sticking bipolar silver forceps with a very fine neurosurgical tip.First, pre-cauterize the tissue by creating a short cauterization strip along the demarcation line. Next use scissors to carefully cut the pre-cauterized tissue. Cut deep enough to be as close to the vena cava as possible, which runs intrahepatically.Damaging the vena cava usually results in sacrificing the animal, so be extra careful. Different techniques have been used to transect the parenchyma. We found that using a silver forceps with fine tips, pre-cauterizing the liver tissue, then followed by the scissors to cut through it works the best for minimal blood loss.After the transection, pat the abdomen dry and make sure that there is no bleeding. Before closing the animal, make sure that the small bowel is repositioned correctly. Then close the peritoneum and the abdominal wall by placing 3-0 silk sutures using SH-1 needles.Lastly, use 5-0 Maxon to suture the skin. Post surgery there are distinctly different growth kinetics associated with the PVL without transection and the PVL with transection, which is also known as ALPPS. Daily volumetric measurements of the liver show that by day three there is only a 100%increase in volume after PVL, but there is a 200%increase in volume after ALPPS.After watching this video you should have a pretty good idea on how to perform a ligation of 75%of the portal inflow into the parenchyma, plus a transection. Once mastered, the procedure should not take longer than 45 minutes. While attempting this procedure it's important to have both an anesthesiologist and a surgeon experienced with volatile anesthesia present.Following along the general lines of this procedure you can attempt other types of transection techniques. For example, partial transection or ligation or radio frequency oblation to figure out how important the amount or type of transection is to induce rapid hypertrophy. Don't forget that after surgery in rodents, it's important to assess them for pain and provide sufficient analgesia.

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14.5K visualizações.  University of Zurich. The overall goal of this surgical intervention is to achieve rapid hypertrophy of the rat liver by ligation of the portal vein and transection of the parenchyma. This model allows for details physiological and molecular assessments of rapid liver regeneration. The liver regenerates after portal vein ligation.We found a way of transecting the parenchyma additionally to the portal vein ligation to accelerate that regeneration. This method provides a model for accelerated liver regenerati...