This research was supported by National Natural Science Foundation of China (Grant No. 81501382) and Zhejiang Provincial Natural Science Foundation of China (Grant No. LQ13H100003 and LQ16H100002).

<ol>
	<li>Yan, J. Q., Becker, T., Peng, C. H., Li, H. W., Klempnauer, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Split+liver+transplantation:+a+reliable+approach+to+expand+donor+pool.">Split liver transplantation: a reliable approach to expand donor pool.</a> Hepatobiliary Pancreat Dis Int. 4, 339-344 (2005).</li><li>Xia, R., Emond, 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=Orthotopic+partial+liver+transplantation+in+the+rat:+a+model+of+70%+hepatectomy+and+reduced+size+liver+transplantation.">Orthotopic partial liver transplantation in the rat: a model of 70% hepatectomy and reduced size liver transplantation.</a> Transplantation. 56, 1041-1043 (1993).</li><li>Omura, T., Ascher, N. L., Emond, 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=Fifty-percent+partial+liver+transplantation+in+the+rat.">Fifty-percent partial liver transplantation in the rat.</a> Transplantation. 62, 292-293 (1996).</li><li>Foss, 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=Function+of+reduced-size+liver+transplant+in+the+rat.">Function of reduced-size liver transplant in the rat.</a> Res Exp Med (Berl). 197, 91-99 (1997).</li><li>Nagai, K., Yagi, S., Uemoto, S., Tolba, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+procedures+for+a+rat+model+of+partial+orthotopic+liver+transplantation+with+hepatic+arterial+reconstruction.">Surgical procedures for a rat model of partial orthotopic liver transplantation with hepatic arterial reconstruction.</a> J Vis Exp. , e4376 (2013).</li><li>Sun, J., Qin, G., Wu, L., Wang, C., Sheil, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antigenic+load+and+peripheral+chimeric+levels+in+entire+and+partial+liver+allograft+recipients.">Antigenic load and peripheral chimeric levels in entire and partial liver allograft recipients.</a> Microsurgery. 21, 183-187 (2001).</li><li>Ninomiya, 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=Deceleration+of+regenerative+response+improves+the+outcome+of+rat+with+massive+hepatectomy.">Deceleration of regenerative response improves the outcome of rat with massive hepatectomy.</a> Am J Transplant. 10, 1580-1587 (2010).</li><li>Yamanaka, 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=Effect+of+olprinone+on+liver+microstructure+in+rat+partial+liver+transplantation.">Effect of olprinone on liver microstructure in rat partial liver transplantation.</a> J Surg Res. 183, 391-396 (2013).</li><li>Wang, 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=Mesenchymal+stem+cells+promote+liver+regeneration+and+prolong+survival+in+small-for-size+liver+grafts:+involvement+of+C-Jun+N-terminal+kinase,+cyclin+D1,+and+NF-kappaB.">Mesenchymal stem cells promote liver regeneration and prolong survival in small-for-size liver grafts: involvement of C-Jun N-terminal kinase, cyclin D1, and NF-kappaB.</a> PLoS One. 9, e112532 (2014).</li><li>Madrahimov, N., Dirsch, O., Broelsch, C., Dahmen, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Marginal+hepatectomy+in+the+rat:+from+anatomy+to+surgery.">Marginal hepatectomy in the rat: from anatomy to surgery.</a> Ann. Surg. 244, 89-98 (2006).</li><li>Martins, P. N., Theruvath, T. P., Neuhaus, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rodent+models+of+partial+hepatectomies.">Rodent models of partial hepatectomies.</a> Liver Int. 28, 3-11 (2008).</li><li>Kamada, N., Sumimoto, R., Kaneda, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+value+of+hepatic+artery+reconstruction+as+a+technique+in+rat+liver+transplantation.">The value of hepatic artery reconstruction as a technique in rat liver transplantation.</a> Surgery. 111, 195-200 (1992).</li><li>Steger, U., Sawitzki, B., Gassel, A. M., Gassel, H. J., Wood, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+hepatic+rearterialization+on+reperfusion+injury+and+outcome+after+mouse+liver+transplantation.">Impact of hepatic rearterialization on reperfusion injury and outcome after mouse liver transplantation.</a> Transplantation. 76, 327-332 (2003).</li><li>Huang, 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+novel+end-to-side+anastomosis+technique+for+hepatic+rearterialization+in+rat+orthotopic+liver+transplantation+to+accommodate+size+mismatches+between+vessels.">A novel end-to-side anastomosis technique for hepatic rearterialization in rat orthotopic liver transplantation to accommodate size mismatches between vessels.</a> Eur Surg Res. 47, 53-62 (2011).</li><li>Bernal, J., 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=Guidelines+for+rodent+survival+surgery.">Guidelines for rodent survival surgery.</a> J.Invest Surg. 22, 445-451 (2009).</li><li>Johnson, A. J., Stulting, R. D., Macsai, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Ophthalmic Microsurgical Suturing Techniques. , 21-28 (2007).</li><li>Delriviere, 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=Detailed+modified+technique+for+safer+harvesting+and+preparation+of+liver+graft+in+the+rat.">Detailed modified technique for safer harvesting and preparation of liver graft in the rat.</a> Microsurgery. 17, 690-696 (1996).</li><li>Oldani, G., Lacotte, S., Morel, P., Mentha, G., Toso, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orthotopic+liver+transplantation+in+rats.">Orthotopic liver transplantation in rats.</a> J Vis Exp. , (2012).</li><li>Delriviere, 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=Technical+details+for+safer+venous+and+biliary+anastomoses+for+liver+transplantation+in+the+rat.">Technical details for safer venous and biliary anastomoses for liver transplantation in the rat.</a> Microsurgery. 18, 12-18 (1998).</li><li>Jin, 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=Preliminary+experience+of+a+PDCA-cycle+and+quality+management+based+training+curriculum+for+rat+liver+transplantation.">Preliminary experience of a PDCA-cycle and quality management based training curriculum for rat liver transplantation.</a> J Surg Res. 176, 409-422 (2012).</li><li>Selzner, N., Selzner, M., Tian, Y., Kadry, Z., 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=Cold+ischemia+decreases+liver+regeneration+after+partial+liver+transplantation+in+the+rat:+A+TNF-alpha/IL-6-dependent+mechanism.">Cold ischemia decreases liver regeneration after partial liver transplantation in the rat: A TNF-alpha/IL-6-dependent mechanism.</a> Hepatology. 36, 812-818 (2002).</li><li>Tanaka, H., Hashizume, K., Enosawa, S., Suzuki, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Successful+transplantation+of+a+20%+partial+liver+graft+in+rats:+a+technical+innovation.">Successful transplantation of a 20% partial liver graft in rats: a technical innovation.</a> J Surg Res. 110, 409-412 (2003).</li><li>Bockhorn, 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=Erythropoietin+treatment+improves+liver+regeneration+and+survival+in+rat+models+of+extended+liver+resection+and+living+donor+liver+transplantation.">Erythropoietin treatment improves liver regeneration and survival in rat models of extended liver resection and living donor liver transplantation.</a> Transplantation. 86, 1578-1585 (2008).</li><li>Martins, P. N., Neuhaus, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+anatomy+of+the+liver,+hepatic+vasculature+and+bile+ducts+in+the+rat.">Surgical anatomy of the liver, hepatic vasculature and bile ducts in the rat.</a> Liver Int. 27, 384-392 (2007).</li><li>Kamada, N., Calne, R. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orthotopic+liver+transplantation+in+the+rat.+Technique+using+cuff+for+portal+vein+anastomosis+and+biliary+drainage.">Orthotopic liver transplantation in the rat. Technique using cuff for portal vein anastomosis and biliary drainage.</a> Transplantation. 28, 47-50 (1979).</li><li>Kashfi, 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=A+review+of+various+techniques+of+orthotopic+liver+transplantation+in+the+rat.">A review of various techniques of orthotopic liver transplantation in the rat.</a> Transplant.Proc. 37, 185-188 (2005).</li><li>Wain, R. A. J., Hammond, D., McPhillips, M., Whitty, J. P. M., Ahmed, W., Ahmed, W., Jackson, M. 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> Surgical Tools and Medical Devices. , 545-562 (2016).</li><li>Huang, 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=Hepatic+arterial+perfusion+is+essential+for+the+spontaneous+recovery+from+focal+hepatic+venous+outflow+obstruction+in+rats.">Hepatic arterial perfusion is essential for the spontaneous recovery from focal hepatic venous outflow obstruction in rats.</a> Am J Transplant. 11, 2342-2352 (2011).</li><li>Czigany, Z., 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=Improving+Research+Practice+in+Rat+Orthotopic+and+Partial+Orthotopic+Liver+Transplantation:+A+Review,+Recommendation,+and+Publication+Guide.">Improving Research Practice in Rat Orthotopic and Partial Orthotopic Liver Transplantation: A Review, Recommendation, and Publication Guide.</a> Eur Surg Res. 55, 119-138 (2015).</li></ol>

All authors have no conflicting interests to disclose.

Rat PLTx is a sophisticated microsurgical procedure with a training program that is high in cost and long in duration20. The complexity of the rat PLTx protocol has prevented researchers from using this animal model. Compared with full-size rat LTx, rat PLTx presents the microsurgeon not only with the challenge of a transplantation procedure but also with the challenge of liver resection in a small animal. Therefore, a visualized microsurgical protocol describing the whole procedure in detail is essential for establishing this complex model. A previously visualized article reported by Nagai et al. presented a protocol of 50% partial orthotopic LTx with hepatic arterial reconstruction in rats5 (Table 2). This protocol used an ex vivo hepatectomy, which is clinically similar to the procedure of split LTx. 
Compared with split LTx, living donor LTx resects the partial liver graft from the living donor rather than splitting the liver in the back-table operation. The in vivo liver resection may lead to more surgical manipulations, longer portal hypertension, and even more warm ischemia injuries to the partial liver graft. Hence, several rat PLTx models utilizing in vivo hepatectomy have been established in relevant studies6,8,21,22. Many protocols involve resection of the liver lobes after simple ligation at the pedicle or base2,3,6,8,21,23. However, different liver lobes are of different shapes. The ML of the rat has a wide base that semi-surrounds the vena cava10,24. Placing a simple ligation at the base of the ML easily constricts the inferior vena. To avoid the constriction of the vena cava, Madrahimov et al. developed a parenchyma-preserving vessel-oriented hepatectomy to remove the ML in 2 steps after four piercing sutures in the parenchyma were made, leaving the remnant stump of the ML flat10. However, the PVs of the liver lobes ligated by the piercing sutures were hidden in the parenchyma. Bleeding in the remnant stump caused by missing or injuring the small branches of the PV could not be completely avoided 11. In our protocol, the corresponding PVs and hepatic arteries were further dissected first. Then, the blood supply of the resected liver lobes was individually occluded by ligations before the resection. Therefore, the rate of bleeding in the remnant stump was lowered using our protocol (Figure 10). The technique of placing four piercing sutures in the stump of the ML was also employed in our protocol to ligate the hepatic veins but not the PV and hepatic arteries. With these ligations using multiple piercing sutures and a step-wise resection, the flat shape of the remnant liver stump was maintained, which avoided the constriction of the vena cava. 
For the IHVC reconstruction, a slight modification was made to the cuff anastomosis described by Kamada et al.25. The inferior vena cava of the recipient was transected in the parenchyma of the right inferior lobe, rather than on the IHVC vessel, which left a circumferential liver parenchyma around the vena cava. The liver parenchyma around the vena cava helped maintain a cylindrical shape of the vascular end of the IHVC of the recipient rather than a flat shape. Hence, the lumen of the IHVC was naturally opened without the help of stay sutures and forceps. This modification helped save the step of placing stay sutures and facilitated the insertion of the IHVC cuff into the vascular lumen of the recipient. Moreover, this modification prolonged the vascular length of the IHVC, thereby reducing the tension between the two ends during the cuff anastomosis. 
With the advantage of fast vascular anastomosis, the two-cuff technique is frequently used in the rat orthotopic LTx for anastomosing the PV and IHVC. Miyata et al. even proposed a protocol involving a three-cuff technique to anastomose the PV, IHVC and SHVC. However, the cuff technique also has its disadvantages. First, a cuff with a fixed size cannot perfectly fit the size of the corresponding vessel. In addition, the cuff technique disturbs blood flow, resulting in a higher incidence of thrombosis and foreign body reaction to the cuff26. The SHVC, a main vessel in the rat, shows high blood flow. Any constriction or thrombosis in this vessel may cause severe postoperative complications. Therefore, in our PLTx protocol, we choose to use the hand suture technique to reconstruct the SHVC, which allows for the adjustment of the anastomosis as close as possible to the physical setting. However, high-quality SHVC anastomosis completed by the hand suture technique requires high microsurgical skill. For beginners, Carrel's triangulation technique is recommended for anastomosing vessels 27. By using this technique, three stay sutures are placed at regular intervals around the circumference of the SHVC. The 3D shape of the SHVC is maintained by retracting these three stay sutures along three directions, which can prevent the SHVC from stenosis during anastomosis.
Re-arterialization of the liver graft is a controversial topic. In our opinion, re-arterialization is not the key step for ensuring a high survival rate of the recipient, but it might be the key step for ensuring a high-quality liver graft. In the traditional protocol of the rat LTx involving the two-cuff technique, the hepatic artery was not reconstructed, as the lack of perfusion of the hepatic artery did not affect the outcome of the rat LTx12. Moreover, a previous study on mouse LTx was conducted to investigate the effect of re-arterialization on long-term graft survival, histological alterations, ischemic liver damage and early immunologic activation pathways13. The researchers concluded that the re-arterialization of liver grafts did not have a major effect on the survival rate or the degree of immunologic activation. However, a recent study reported by Huang et al. suggests that re-arterialization is important for the recovery of liver parenchyma subjected to hepatectomy, especially with the obstruction of outflow28. Non-arterialization of the partial liver graft aggravated liver damage and delayed the recovery from focal necrosis. Therefore, re-arterialization of the partial liver graft is recommended. As illustrated here, an end-to-side anastomosis technique was used to reconstruct the hepatic artery, which was described previously by one of our authors 14. The advantage of this technique is the choice to anastomose two thick arteries, the CHA and GDA, rather than the thin PHA, which reduces the difficulty of reconstructing the hepatic artery and maintains a high rate of patency of anastomosis. 
The classical rat LTx protocol proposed by Kamada et al. suggests controlling the anhepatic phase such that it is less than 26 min, as no animal survived when the anhepatic phase lasted longer than 26 min25. Our experience is consistent with this suggestion, although we previously observed several survival cases with an anhepatic phase time longer than 26 min. In our opinion, a stable anhepatic phase takes priority over a shorter anhepatic phase in surgical research. In our group, the anhepatic phase is precisely controlled to within a specific time. The anhepatic phase is not stopped until the preset anhepatic time is reached, although the anastomosis of the SHVC and PV could be completed much earlier. However, in a training project, a shorter anhepatic phase is encouraged. 
Although many improvements have been made to shorten the training phase and eliminate unnecessary operations, rat LTx and PLTx are still complex microsurgical operations20. Therefore, in addition to a visualized protocol, a step-wise training protocol based on the Plan-Do-Check-Action cycle is important for achieving a high survival rate and high operation quality. Our preliminary experience in using this training protocol showed that 40-73 operations were required to master the rat orthotopic LTx. An additional 9-13 operations were required to master the rat re-arterialized PLTx. The training protocol proposed by Czig&#225;ny et al. claims that 50-60 LTxs are sufficient to master the orthotopic LTx and the PLTx29.
In our Plan-Do-Check-Action training protocol, quality control at each training step and in each individual manipulation must be emphasized, especially in such a complex model. A high survival rate is not tantamount to a high-quality procedure. In the representative results, several criteria for evaluating the quality of the microsurgery were listed, including histology, liver enzyme, body weight recovery, jaundice (serum bilirubin and yellow urine), duration of the anhepatic phase, and patency of the hepatic artery. High quality is achieved only when all of the criteria are met.

Currently, there is a large discrepancy between the number of donated liver organs and the number of patients waiting for a donated liver. The shortage of liver organs is a global problem. To expand the donor pool, split liver transplantation (LTx) and living donor LTx were developed to use a partial liver as a graft1.
To further investigate the mechanism behind partial liver transplantation (PLTx), relevant animal models have been established2,3,4,5. In rat PLTx, the liver lobes are resected in vivo and ex vivo to mimic the conditions of the living donor LTx and split LTx, respectively, in human. A paper published in the Journal of Visualized Experiments presented a detailed protocol involving a 50% rat PLTx using an ex vivo hepatectomy5. However, a rat PLTx with an in vivo hepatectomy has not yet been reported in the visualized literature.
In addition to the difference between in vivo and ex vivo hepatectomies, the technique of performing a hepatectomy itself also plays an important role in determining the outcome of PLTx. Currently, in many surgical studies using the rat PTLx model, the liver lobes were resected after placing a simple ligation at the pedicle of the liver lobe2,3,6,7,8,9. However, placing a simple ligation before resection is not suitable for all liver lobes, as different liver lobes have different shapes and sizes. A simple ligation at the base of the median lobe carries a high risk of causing a constriction of the vena cava, which might eventually affect the outflow of the partial liver graft10,11. Therefore, an update hepatectomy technique based on knowledge of the rat hepatic anatomy is required in the field of rat PTLx.
In the protocol described in this study, an updated vessel-oriented 70% hepatectomy was incorporated into the procedure of the rat PLTx. The portal veins and hepatic arteries of the left lateral lobe (LLL) and median lobe (ML) were dissected and divided individually before removal of the liver parenchyma. Then, the hepatic veins of the LLL and ML were ligated by piercing sutures. By using individual ligations and multiple piercing sutures rather than placing a simple ligation, the remnant stump of the ML was able to spread over the vena cava. Hence, the constriction of the infrahepatic vena cava caused by a surgical ligation was avoided. Additionally, occlusion of the blood supply of the LLL and ML by individual ligations before removal of the liver parenchyma decreased the rate of bleeding in the remnant liver stump, thereby minimizing the influence of blood loss on the experiments11.
For microsurgeons, it is a significant challenge to reconstruct the proper hepatic artery (PHA) of a liver graft because of the extremely small diameter of this vessel. Although the question of whether re-arterialization in LTx is truly necessary is still under debate12,13,14, numerous microsurgical techniques for reconstructing the hepatic artery have been proposed14. Here, we introduce a novel technique for re-arterialization of the liver graft, which anastomoses the common hepatic artery (CHA) to the enlarged PHA in an end-to-side manner. By using this end-to-side technique, two hepatic arteries are connected with an anastomosis of a larger diameter. The larger the diameter of the anastomosis is, the easier hand suturing is to perform and the greater the improvement in the patency of the anastomosis becomes.

<table><tbody><tr><td>Surgical microscope</td><td>M&amp;ouml;ller-Wedel, Germany</td><td>654359</td><td></td></tr><tr><td>Light source</td><td>OSRAM (China) Lighting Co., Ltd</td><td>64627</td><td></td></tr><tr><td>Isoflurane Vaporizer</td><td>MIDMARK Corporation</td><td>VIP3000</td><td></td></tr><tr><td>Isoflurane</td><td>Baxter Healthcare Corporation</td><td>40032609</td><td>For Inhalation anesthesia</td></tr><tr><td>Normal Saline</td><td>Zhejiang Tianrui Pharmaceutical Co., Ltd.</td><td>716092103</td><td></td></tr><tr><td>Povidone Iodine Solution</td><td>HANGZHOU MINSHENG PHARMACEUTICAL</td><td>H33021567</td><td>For disinfection</td></tr><tr><td>Hemostatic forceps</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>J31020</td><td></td></tr><tr><td>Surgical scissors</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>JC2116</td><td></td></tr><tr><td>Needle-holder</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>J32030</td><td></td></tr><tr><td>Dressing Forceps</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>J42020</td><td></td></tr><tr><td>Mosquito hemostatic forceps</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>W40340</td><td>For liver resection; For retracting the stay sutures.&amp;nbsp;</td></tr><tr><td>Micro-scissors</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>WA1040</td><td></td></tr><tr><td>Micro needle-holder</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>WA2060</td><td></td></tr><tr><td>Curved micro typing forceps</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>WA3061</td><td></td></tr><tr><td>straight micro typing forceps</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>WA3060</td><td></td></tr><tr><td>Micro hemostatic forceps</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>WA3020</td><td></td></tr><tr><td>Bulldog clamp</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>XEC350</td><td></td></tr><tr><td>Vessel clamps</td><td>Shanghai Medical Instruments(Group) Ltd</td><td>W40160</td><td></td></tr><tr><td>Micro Serrefine-curved</td><td>&amp;nbsp;Fine Science Tools, Inc</td><td>18055-05</td><td></td></tr><tr><td>Dacryosyrinx</td><td>Shi Zhuo medical instruments Co., Ltd.</td><td>5# curve</td><td>Use as the curved needle for forcing out the air bubbles in the vascular lumen</td></tr><tr><td>Sterilized gauze swabs</td><td>Fuqing Health &amp;amp; Integral Medical</td><td>20230R</td><td></td></tr><tr><td>5mL syringe</td><td>Zhejiang Yusheng Medical Instrument Co.,Ltd</td><td>811932416</td><td></td></tr><tr><td>18G needles</td><td>Shanghai Kindly Enterprise Development Group Co., Ltd</td><td>01-014</td><td>For fixing the upper abdomen wall</td></tr><tr><td>Intima II 22G intraveous catheter</td><td>Becton Dickinson Medical Devices (Shanghai) Co Ltd.</td><td>383207y</td><td>For making biliary stent; For infusing perfusate</td></tr><tr><td>7-0 polypropylene sutures</td><td>Ningbo Medical Needle Co., Ltd</td><td>151026</td><td>For SHVC anastomsis</td></tr><tr><td>6-0 silk suture</td><td>Shanghai Pudong Jinhuan Medical Products Co., Ltd</td><td>2650182</td><td>For ligation</td></tr><tr><td>Culture dish (100mm)</td><td>Corning Incorporated</td><td>430165</td><td>used in back table for storage ice. The back table dish was placed on it.&amp;nbsp;</td></tr><tr><td>Culture dish (30 mm)</td><td>Corning Incorporated</td><td>3296</td><td>As a vessel for organ preservation</td></tr><tr><td>Angiocath 12G intravenous catheter</td><td>Becton Dickinson Medical Devices (Shanghai) Co Ltd.</td><td>382277</td><td>For making a IHVC cuff</td></tr><tr><td>Angiocath 14G intravenous catheter</td><td>Becton Dickinson Medical Devices (Shanghai) Co Ltd.</td><td>382269</td><td>For making a PV cuff</td></tr><tr><td>Buprenorphine (hydrochloride)</td><td>Tianjin Institute of Pharmaceutical Research Pharmaceutical Co., Ltd</td><td>H12020275</td><td>For analgesic</td></tr><tr><td>Cefuroxime sodium for injection</td><td>Esseti FarmaceuticiS.r.l</td><td>H20160013</td><td>As an antibiotics</td></tr></tbody></table>

re-arterialized rat partial liver transplantation with an in vivo vessel-oriented 70% hepatectomy

Split liver transplantation and living liver donor liver transplantation were developed in the clinic to utilize liver organs in a more efficient manner. To better understand the mechanism behind these surgical procedures, a rat partial liver transplantation (PLTx) model was established for relevant surgical studies. Because of the complexity of the rat PLTx model, a protocol with detailed descriptions is required. An article published previously reported a protocol in which ex vivo hepatectomy was used to achieve 50% rat PLTx. In contrast to this protocol, we introduced a re-arterialized PLTx with an in vivo 70% hepatectomy. An updated vessel-oriented hepatectomy was incorporated into the rat PLTx to refine the microsurgical procedure. The portal veins and hepatic arteries of the left lateral lobe and the median lobe were individually dissected and ligated before removal of the liver parenchyma, thereby decreasing the probability of bleeding in the remnant liver stump. Furthermore, an end-to-side vessel anastomosis between the common hepatic artery and the enlarged proper hepatic artery was introduced to re-arterialize the hepatic artery. By using this end-to-side vessel anastomosis technique, the diameter of the anastomosis was enlarged, thereby decreasing the difficulty of hand suture and maintaining a high rate of anastomotic patency. Moreover, the cuff anastomosis of the infrahepatic vena cava was slightly modified. A section of circumferential liver parenchyma around the vena cava of a recipient was preserved during cuff anastomosis to maintain the three-dimensional shape of the vascular lumen. This section of liver parenchyma was removed after completing the anastomosis. With this modification, the step involving placement of stay sutures was omitted, thereby further shortening the cuff anastomosis time. By using this protocol of rat PLTx, a low liver enzyme level, an intact liver lobular architecture and a high survival rate were achieved after microsurgery.

In total, 31 cases of syngeneic arterialized rat PLTx were completed using this protocol. All of the recipients survived until the end of the observation time. The body weight of the recipients began to recover after postoperative day (POD) 4. The slope of the body weight was close to that of a normal Lewis rat after POD 6 (Figure 8), which indirectly implied the recovery of the recipient. Histologically, a slight proliferation of the bile duct was observed in the recipients, and the liver lobular architecture of the recipients was intact. No necrosis or obvious sinusoidal dilatation was observed (Figure 9). The serum level of alanine aminotransferase (ALT) was within the normal range at POD 30 (Figure 10). No cases of yellow urine caused by jaundice were observed in these recipients, which was indicated by checking the cage bedding daily, indicating the patency of the biliary stent. The normal serum level of bilirubin on POD 30 further confirmed the successful reconstruction of the bile duct (Figure 11). The patency of the hepatic artery was checked by transecting the PHA on the proximal side of the anastomosis during sacrifice. Bleeding from the PHA was observed in all of the recipients, implying the patency of the anastomosis. All of these results suggested that the liver grafts functioned well.
The average duration of the anhepatic phase was 23.03 &#177; 2.3 min. The cuff anastomosis of the PV took 4.68 &#177; 0.77 min, while the cuff anastomosis of the IHVC only took 2.05 &#177; 0.71 min. Compared with the cuff anastomosis of the PV, the cuff anastomosis of the IHVC saved the step of placing stay sutures and thereby further shortened the anastomosis time (Table 1).
Two cases of bleeding in the remnant stump of the ML during the 70% hepatectomy were observed among the 31 cases of vessel-oriented hepatectomy. In a previous experiment, bleeding in the remnant stump of the ML was observed in 8 out of 18 cases of parenchyma-preserving vessel-oriented hepatectomy (Figure 12). This result indicated a lower rate of bleeding in the remnant liver stump of the ML after using vessel-oriented 70% hepatectomy.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56392/56392fig1.jpg" /> 
Figure 1. The cuffs and biliary stent. 
(A,C) The size of cuffs. (B) The fillister on the cuff. (D) The body part and handle part of the cuff. (E) (a) IHVC cuff; ( b) PV cuff. (F) Biliary stent. Scale bar = 5 mm. <a href="/files/ftp_upload/56392/56392fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56392/56392fig2v2.jpg" /> 
Figure 2. To occlude the blood supply of LLL and ML. 
(A)The common trunk of the PV, hepatic artery and bile duct of the LLL and LML. 
(B)The discoloration of the LLL and LML after transecting the common trunk. 
(C)The portal vein of the RML. 
(D)All PVs, hepatic arteries and bile ducts of the LLL and the ML were transected. 
Scale bar = 5 mm. Abbreviations: LLL left lateral lobe, ML median lobe, LML left median lobe, RML right median lobe, RSL right superior lobe, RIL right inferior lobe, SCL superior caudate lobe. <a href="/files/ftp_upload/56392/56392fig2v2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/56392/56392fig3.jpg" /> 
Figure 3. To resect the left median lobe. 
(A) Resect the liver mass of the LML immediately above the forceps. 
(B) Place three piercing sutures on the incision. (<img alt="Image 1" src="/files/ftp_upload/56392/56392img1.jpg" />) 
Scale bar = 5 mm. Abbreviations: RML right median lobe, RSL right superior lobe, RIL right inferior lobe, SCL superior caudate lobe. <a href="/files/ftp_upload/56392/56392fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/56392/56392fig4.jpg" /> 
Figure 4. To resect the right median lobe (RML). 
(A)The base of the RML. 
(B)Place mosquito hemostasis forceps around the base of RML. 
(C)Resect the liver parenchyma of RML immediately above the forceps. 
(D)Leave a plain and thin layer of the remnant liver tissue on the SHVC. 
Scale bar = 5 mm. Abbreviations: ML median lobe, RSL right superior lobe. <a href="/files/ftp_upload/56392/56392fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/56392/56392fig5.jpg" /> 
Figure 5. To install the cuff. 
(A) Pull the PV through the lumen of a cuff. 
(B) Fix the cuff handle and PV together by a vessel clamp. 
(C) Evert the PV vascular wall to cover the outside surface of the cuff. 
(D) Secure the vascular wall and the cuff in position. 
Scale bar = 5 mm. <a href="/files/ftp_upload/56392/56392fig5large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/56392/56392fig6.jpg" /> 
Figure 6. To reconstruct the SHVC. 
(A&#38;B) Pull two stay sutures to the right and left, respectively. 
(C) Anastomose the posterior wall of the SHVC by a running suture in the vascular lumen. 
(D) Anastomose the anterior wall of the SHVC out of the vascular lumen. 
Scale bar = 5 mm. <a href="/files/ftp_upload/56392/56392fig6large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/56392/56392fig7.jpg" /> 
Figure 7. To reconstruct the IHVC. 
(A) A cylindrical vascular lumen of the IHVC in the recipient. 
(B) Secure the cuff anastomosis of the IHVC. 
(C) Start the reperfusion. 
(D) Trim off the surrounding liver parenchyma above the circumferential silk suture. 
Scale bar = 5 mm. Abbreviations: PV portal vein, IHVC inferior infrahepatic vena cava, RIL right inferior lobe. <a href="/files/ftp_upload/56392/56392fig7large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 8" class="xfigimg" src="/files/ftp_upload/56392/56392fig10v4.jpg" /> 
Figure 8. Postoperative body weight recovery. 
The body weight of recipients began to recover after postoperative day 4. The slope of the body weight was close to that of a normal Lewis rat after postoperative day 6, which indirectly implied the recovery of the recipient.
<img alt="Figure 9" class="xfigimg" src="/files/ftp_upload/56392/56392fig9.jpg" /> 
Figure 9. Histology of liver graft after 30 days. 
In histology, a slight proliferation of the bile duct was observed in recipients, and the liver lobular architecture of recipients was intact. No necrosis or obvious sinusoidal dilatation was observed (400X). Scale bar = 20 um <a href="/files/ftp_upload/56392/56392fig9large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 10" class="xfigimg" src="/files/ftp_upload/56392/56392fig8v4.jpg" /> 
Figure 10. Serum level of ALT. 
The serum level of ALT was within the normal range on POD 30. (**, P&#60;0.05).
<img alt="Figure 11" class="xfigimg" src="/files/ftp_upload/56392/56392fig11v2.jpg" /> 
Figure 11. Serum Level of bilirubin. 
The serum level of bilirubin on POD 30 was comparable to that of a normal Lewis rat ( P&#62;0.05).
<img alt="Figure 12" class="xfigimg" src="/files/ftp_upload/56392/56392fig12v2.jpg" /> 
Figure 12. Bleeding rates of different methods of hepatectomy. 
A lower rate of bleeding in the remnant liver stump of the ML was observed in the method using the vessel-oriented 70% hepatectomy.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Procedures</td>
			<td>Removal of liver&#160;</td>
			<td>SHVC anastomosis&#160;</td>
			<td>PV anastomosis&#160;</td>
			<td>IHVC anastomosis&#160;</td>
			<td>Anhepatic time&#160;</td>
		</tr>
		<tr>
			<td>Time (minutes)&#160;</td>
			<td>2.62&#177;0.46&#160;</td>
			<td>15.73&#177;2.05&#160;</td>
			<td>4.68&#177;0.77&#160;</td>
			<td>2.05&#177;0.71&#160;</td>
			<td>23.03&#177;2.30&#160;</td>
		</tr>
		<tr>
			<td colspan="6">Data were expressed in Mean&#177;SD</td>
		</tr>
	</tbody>
</table>
Table 1. Time of individual surgical procedures during anhepatic phase
<img alt="Table 2" src="/files/ftp_upload/56392/56392tbl2.jpg" /> 
Table 2. Difference between two visualized protocols of the rat PLTx. <a href="/files/ftp_upload/56392/56392tbl2large.jpg" target="_blank">Please click here to view a larger version of this table.</a>

<img src="/files/ftp_upload/56392/SUPPLEMENTARY_MATERIAL.jpg" /> 
Supplementary Materials

Watch this Scientific Journal Video about Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy at JoVE.com

Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Here, a protocol involving re-arterialized rat partial liver transplantation is presented. Specifically, 70% liver was resected in vivo by using an updated technique of vessel-oriented hepatectomy. The hepatic artery was reconstructed in an end-to-side manner. The cuff technique was modified to shorten the anastomosis time of the infrahepatic vena cava.

Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Split liver transplantation and living liver donor liver transplantation were developed in the clinic to utilize liver organs in a more efficient manner. ...

re-arterialized-rat-partial-liver-transplantation-with-an-vivo-vessel

Universidad San Sebastian

Research

JoVE Journal

Medicine

11.5K Views.  The First Affiliated Hospital of Wenzhou Medical University. Here, a protocol involving re-arterialized rat partial liver transplantation is presented. Specifically, 70% liver was resected in vivo by using an updated technique of vessel-oriented hepatectomy. The hepatic artery was reconstructed in an end-to-side manner. The cuff technique was modified to shorten the anastomosis time of the infrahepatic vena cava.

Video: Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Orthotopic Liver Transplantation in Rats

Clinical progress in the field of liver transplantation has been largely supported by animal models1,2. Since the publication of the first orthotopic rat liver transplantation in 1979 by Kamada et al.3, this model has remained the gold standard despite various proposed alternative techniques4. Nevertheless, its broader use is limited by its steep learning curve5.
In this video paper, we show a simple and easy-to-establish revision of Kamada's two-cuff technique. The suprahepatic vena cava anastomosis is performed manually with a running suture, and the vena porta and infrahepatic vena cava anastomoses are performed utilizing a quick-linker cuff system6. Manufacturing the quick-linker kit is shown in a separate video paper.

We present an easy-to-establish revision of the classical two-cuff technique for orthotopic liver transplantation in rat.

Clinical progress in the field of liver transplantation has been largely supported by animal models1,2. Since the publication of the first orthotopic rat ...

Surgical Procedures for a Rat Model of Partial Orthotopic Liver Transplantation with Hepatic Arterial Reconstruction

Orthotopic liver transplantation (OLT) in rats using a whole or partial graft is an indispensable experimental model for transplantation research, such as studies on graft preservation and ischemia-reperfusion injury 1,2, immunological responses 3,4, hemodynamics 5,6, and small-for-size syndrome 7. The rat OLT is among the most difficult animal models in experimental surgery and demands advanced microsurgical skills that take a long time to learn. Consequently, the use of this model has been limited. Since the reliability and reproducibility of results are key components of the experiments in which such complex animal models are used, it is essential for surgeons who are involved in rat OLT to be trained in well-standardized and sophisticated procedures for this model.
While various techniques and modifications of OLT in rats have been reported 8 since the first model was described by Lee et al. 9 in 1973, the elimination of the hepatic arterial reconstruction 10 and the introduction of the cuff anastomosis technique by Kamada et al. 11 were a major advancement in this model, because they simplified the reconstruction procedures to a great degree. In the model by Kamada et al., the hepatic rearterialization was also eliminated. Since rats could survive without hepatic arterial flow after liver transplantation, there was considerable controversy over the value of hepatic arterialization. However, the physiological superiority of the arterialized model has been increasingly acknowledged, especially in terms of preserving the bile duct system 8,12 and the liver integrity 8,13,14.
In this article, we present detailed surgical procedures for a rat model of OLT with hepatic arterial reconstruction using a 50% partial graft after ex vivo liver resection. The reconstruction procedures for each vessel and the bile duct are performed by the following methods: a 7-0 polypropylene continuous suture for the supra- and infrahepatic vena cava; a cuff technique for the portal vein; and a stent technique for the hepatic artery and the bile duct.

Orthotopic liver transplantation in rats is an indispensable experimental model for biomedical research. Here we present our surgical procedures for orthotopic rat liver transplantation with hepatic arterial reconstruction using a 50% partial graft.

Orthotopic liver transplantation (OLT) in rats using a whole or partial graft is an indispensable experimental model for transplantation research, such as ...

Heterotopic Auxiliary Rat Liver Transplantation With Flow-regulated Portal Vein Arterialization in Acute Hepatic Failure

In acute hepatic failure auxiliary liver transplantation is an interesting alternative approach. The aim is to provide a temporary support until the failing native liver has regenerated.1-3 The APOLT-method, the orthotopic implantation of auxiliary segments- averts most of the technical problems. However this method necessitates extensive resections of both the native liver and the graft.4 In 1998, Erhard developed the heterotopic auxiliary liver transplantation (HALT) utilizing portal vein arterialization (PVA) (Figure 1). This technique showed promising initial clinical results.5-6 We developed a HALT-technique with flow-regulated PVA in the rat to examine the influence of flow-regulated PVA on graft morphology and function (Figure 2).
A liver graft reduced to 30 % of its original size, was heterotopically implanted in the right renal region of the recipient after explantation of the right kidney.&#160; The infra-hepatic caval vein of the graft was anastomosed with the infrahepatic caval vein of the recipient. The arterialization of the donor&#8217;s portal vein was carried out via the recipient&#8217;s right renal artery with the stent technique. The blood-flow regulation of the arterialized portal vein was achieved with the use of a stent with an internal diameter of 0.3 mm. The celiac trunk of the graft was end-to-side anastomosed with the recipient&#8217;s aorta and the bile duct was implanted into the duodenum. A subtotal resection of the native liver was performed to induce acute hepatic failure. 7
In this manner 112 transplantations were performed. The perioperative survival rate was 90% and the 6-week survival rate was 80%. Six weeks after operation, the native liver regenerated, showing an increase in weight from 2.3&#177;0.8 g to 9.8&#177;1 g. At this time, the graft&#8217;s weight decreased from 3.3&#177;0.8 g to 2.3&#177;0.8 g.
We were able to obtain promising long-term results in terms of graft morphology and function. HALT with flow-regulated PVA reliably bridges acute hepatic failure until the native liver regenerates.

Auxiliary liver transplantation provides a temporary support in acute hepatic failure, until regeneration of the failing liver. The heterotopic auxiliary liver transplantation (HALT) with portal vein arterialization (PVA) renders sufficient liver function. We developed an analogous technique in the rat, to examine the influence of the portal vein arterialization on the morphology and function of the graft.

In acute hepatic failure auxiliary liver transplantation is an interesting alternative approach. The aim is to provide a temporary support until the ...

A Novel Surgical Technique As a Foundation for In Vivo Partial Liver Engineering in Rat

Organ engineering is a novel strategy to generate liver organ substitutes that can potentially be used in transplantation. Recently, in vivo liver engineering, including in vivo organ decellularization followed by repopulation, has emerged as a promising approach over ex vivo liver engineering. However, postoperative survival was not achieved. The aim of this study is to develop a novel surgical technique of in vivo selective liver lobe perfusion in rats as a prerequisite for in vivo liver engineering. We generate a circuit bypass only through the left lateral lobe. Then, the left lateral lobe is perfused with heparinized saline. The experiment is performed with 4 groups (n = 3 rats per group) based on different perfusion times of 20 min, 2 h, 3 h, and 4 h. Survival, as well as the macroscopically visible change of color and the histologically determined absence of blood cells in the portal triad and the sinusoids, is taken as an indicator for a successful model establishment. After selective perfusion of the left lateral lobe, we observe that the left lateral lobe, indeed, turned from red to faint yellow. In a histological assessment, no blood cells are visible in the branch of the portal vein, the central vein, and the sinusoids. The left lateral lobe turns red after reopening the blocked vessels. 12/12 rats survived the procedure for more than one week. We are the first to report a surgical model for in vivo single liver lobe perfusion with a long survival period of more than one week. In contrast to the previously published report, the most important advantage of the technique presented here is that perfusion of 70% of the liver is maintained throughout the whole procedure. The establishment of this technique provides a foundation for in vivo partial liver engineering in rats, including decellularization and recellularization.

A Novel Surgical Technique As a Foundation for In Vivo Partial Liver Engineering in Rat

We establish a novel surgical technique for an in vivo single liver lobe perfusion model in rat as a prerequisite for further studying in vivo partial liver engineering in the future.

Organ engineering is a novel strategy to generate liver organ substitutes that can potentially be used in transplantation. Recently, in vivo liver ...

Bioengineering

Visualization of Vascular and Parenchymal Regeneration after 70% Partial Hepatectomy in Normal Mice

A modified silicone injection procedure was used for visualization of the hepatic vascular tree. This procedure consisted of in-vivo injection of the silicone compound, via a 26 G catheter, into the portal or hepatic vein. After silicone injection, organs were explanted and prepared for ex-vivo micro-CT (&#181;CT) scanning. The silicone injection procedure is technically challenging. Achieving a successful outcome requires extensive microsurgical experience from the surgeon. One of the challenges of this procedure involves determining the adequate perfusion rate for the silicone compound. The perfusion rate for the silicone compound needs to be defined based on the hemodynamic of the vascular system of interest. Inappropriate perfusion rate can lead to an incomplete perfusion, artificial dilation and rupturing of vascular trees.
The 3D reconstruction of the vascular system was based on CT scans and was achieved using preclinical software such as HepaVision. The quality of the reconstructed vascular tree was directly related to the quality of silicone perfusion. Subsequently computed vascular parameters indicative of vascular growth, such as total vascular volume, were calculated based on the vascular reconstructions. Contrasting the vascular tree with silicone allowed for subsequent histological work-up of the specimen after &#181;CT scanning. The specimen can be subjected to serial sectioning, histological analysis and whole slide scanning, and thereafter to 3D reconstruction of the vascular trees based on histological images. This is the prerequisite for the detection of molecular events and their distribution with respect to the vascular tree. This modified silicone injection procedure can also be used to visualize and reconstruct the vascular systems of other organs. This technique has the potential to be extensively applied to studies concerning vascular anatomy and growth in various animal and disease models.

Tools used for visualizing vascular regeneration require methods for contrasting the vascular trees. This film demonstrated a delicate injection technique used to achieve optimal contrasting of the vascular trees and illustrate the potential benefits resulting from a detailed analysis of the resulting specimen using &#181;CT and histological serial sections.

A modified silicone injection procedure was used for visualization of the hepatic vascular tree. This procedure consisted of in-vivo injection of the ...

A Rat Model of Orthotopic Liver Transplantation Using a Novel Magnetic Anastomosis Technique for Suprahepatic Vena Cava Reconstruction

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep learning curve. The introduction of the cuff technique for anastomosis of the portal vein (PV) and infrahepatic vena cava (IHVC) has significantly simplified the transplant procedure in rats. However, due to the short anterior wall of the recipients' suprahepatic vena cava (SHVC), the cuff technique is very difficult to use for the reconstruction of the SHVC. Most researchers in this field still use the hand-suture technique for SHVC reconstruction, which makes it the bottleneck step in rat orthotopic liver transplantation. The magnetic anastomosis technique (i.e., magnamosis) is a method of connecting two vessels using the attractive force between two magnets. Our recent study has shown that the magnetic anastomosis technique is superior to the hand-suture technique for SHVC reconstruction in rats. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using the novel magnetic anastomosis technique. In this model, the reconstruction of the PV and IHVC was performed by the standard cuff technique, while the reconstruction of the bile duct (BD) was performed by a stent technique. The hepatic re-arterialization was not performed. The magnetic anastomosis technique made SHVC reconstruction much easier and significantly shortened the anphepatic phase. After a reasonable learning curve, even researchers without advanced microsurgical skills can produce reliable and reproducible results using this rat model of OLT.

The reconstruction of the suprahepatic vena cava (SHVC) remains a difficult step in rat orthotopic liver transplantation. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using a novel magnetic anastomosis technique.

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep ...

Reduced Complications after Arterial Reconnection in a Rat Model of Orthotopic Liver Transplantation

The rat orthotopic liver transplantation (OLT) model is a powerful tool to study acute and chronic rejection. However, it is not a complete representation of human liver transplantation due to the absence of arterial reconnection. Described here is a modified transplantation procedure that includes the incorporation of hepatic artery (HA) reconnection, leading to a marked improvement in transplant outcomes. With a mean anhepatic time of 12 min and 14 s, HA reconnection results in improved perfusion of the transplanted liver and an increase in long-term recipient survival from 37.5% to 88.2%. This protocol includes the use of 3D-printed cuffs and holders to connect the portal vein and infrahepatic inferior vena cava. It can be implemented for studying multiple aspects of liver transplantation, from immune response and infection to technical aspects of the procedure. By incorporating a simple and practical method for arterial reconnection using a microvascular technique, this modified rat OLT protocol closely mimics aspects of human liver transplantation and will serve as a valuable and clinically relevant research model.

The goal of this study is to modify the rat orthotopic liver transplant model to better represent human liver transplantation and improve recipient survival. The presented method reestablishes hepatic arterial inflow by connecting the donor liver&#39;s common hepatic artery to the recipient liver&#39;s proper hepatic artery.

The rat orthotopic liver transplantation (OLT) model is a powerful tool to study acute and chronic rejection. However, it is not a complete representation ...

Organ Ischemia-Reperfusion Injury by Simulating Hemodynamic Changes in Rat Liver Transplant Model

Orthotopic liver transplantation (OLT) in rats is a tried and proven animal model used for preoperative, intraoperative, and postoperative studies, including ischemia-reperfusion injury (IRI) of extrahepatic organs. This model requires numerous experiments and devices. The duration of anhepatic phase is closely related to the time to develop IRI after transplantation. In this experiment, we used hemodynamic changes to induce extrahepatic organ damage in rats and determined the maximum tolerance time. The time until the most severe organ injury varied for different organs. This method can easily be replicated and can also be used to study IRI of the extrahepatic organs after liver transplantation.

This paper provides a detailed description of how to build an animal model of the anhepatic phase (liver ischemia) in rats to facilitate basic research into ischemia-reperfusion injury after liver transplantation.

Orthotopic liver transplantation (OLT) in rats is a tried and proven animal model used for preoperative, intraoperative, and postoperative studies, ...

Strategies for Efficient Vascular Anastomosis in Mouse Liver Transplantation

Vascular Reconstruction with the Cuff Technique in Mouse Orthotopic Liver Transplantation

Mouse orthotopic liver transplantation is an effective methodology for investigating the underlying mechanisms of liver ischemia and reperfusion injury. However, the technical challenges pose a barrier to utilizing this valuable experimental model and passing on these skills to the next generation. The most challenging aspect of this procedure is vascular reconstruction, including the portal vein (PV), infrahepatic inferior vena cava (IHIVC), and suprahepatic inferior vena cava. The use of plastic cuffs, rather than sutures, allows for smoother PV and IHIVC reconstruction. Vessels are reconstructed by attaching a cuff made from an intravenous catheter to the tip of the graft vessel and interposing the cuff into the recipient vessel. The two most crucial aspects are properly visualizing the inner lumen of the vessel and avoiding the use of excessive force. Our aim is to provide a technical overview of vascular reconstructions using the cuff technique in recipient surgery. These technical tips for the cuff technique are expected to help microsurgeons facilitate vascular reconstruction and advance their research.

Author Spotlight: Exploring Cold Ischemia and Warm Reperfusion Injury in Fatty Liver Transplantation

This protocol provides technical information for vessel reconstruction using the cuff technique in mouse orthotopic liver transplantation.

Mouse orthotopic liver transplantation is an effective methodology for investigating the underlying mechanisms of liver ischemia and reperfusion injury. ...

Liver Transplantation in Rats and Analyzing Allograft Patency

Heterotopic Auxiliary Whole Liver Rat Transplant Model Utilizing a Hepaticoureterostomy for Allograft Rejection Studies

Small animal transplant models are indispensable for organ tolerance studies investigating feasible therapeutic interventions in preclinical studies. Rat liver transplantation (LTx) protocols typically use an orthotopic model where the recipients&#39; native liver is removed and replaced with a donor liver. This technically demanding surgical procedure requires advanced micro-surgical skills and is further complicated by lengthy anhepatic and lower body ischemia times. This prompted the development of a less complicated heterotopic method that can be performed faster with no anhepatic or lower body ischemia time, reducing post-surgery stress for the recipient animal.
This heterotopic LTx protocol includes two main steps: excising the liver from the donor rat and transplanting the whole liver into the recipient rat. During the excision of the donor liver, the surgeon ligates the supra-hepatic vena cava (SHVC) and hepatic artery (HA). On the recipient side, the surgeon removes the left kidney and positions the donor liver with the portal vein (PV), infra-hepatic vena cava (IHVC), and bile duct facing the renal vessels. Further, the surgeon anastomoses the recipient&#39;s renal vein end to end with the IHVC of the liver and arterializes the PV with the renal artery using a stent. A hepaticoureterostomy is utilized for biliary drainage by anastomosing the bile duct to the recipient&#39;s ureter, permitting the discharge of bile via the bladder.
The average duration of the transplantation was 130 min, cold ischemia duration was around 35 min, and warm ischemia duration was less than 25 min. Hematoxylin and eosin histology of the auxiliary liver from syngeneic transplants showed normal hepatocyte structure with no significant parenchymal alterations 30 days post-transplant. In contrast, 8-day post-transplant allogeneic graft specimens demonstrated extensive lymphocytic infiltration with a Banff Schema rejection activity index score of 9. Therefore, this LTx method facilitates a low morbidity rejection model alternative to orthotopic LTx.

The rat heterotopic auxiliary liver transplant protocol described here offers a practical investigational tool for exploring mechanisms of hepatic allograft rejection. This model helps to alleviate the surgical hurdles and animal stress of orthotopic liver transplantation in rats.

Small animal transplant models are indispensable for organ tolerance studies investigating feasible therapeutic interventions in preclinical studies. Rat ...

Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Summary

Explore More Videos

Chapters in this video

Orthotopic Liver Transplantation in Rats

Surgical Procedures for a Rat Model of Partial Orthotopic Liver Transplantation with Hepatic Arterial Reconstruction

Heterotopic Auxiliary Rat Liver Transplantation With Flow-regulated Portal Vein Arterialization in Acute Hepatic Failure

A Novel Surgical Technique As a Foundation for In Vivo Partial Liver Engineering in Rat

Visualization of Vascular and Parenchymal Regeneration after 70% Partial Hepatectomy in Normal Mice

A Rat Model of Orthotopic Liver Transplantation Using a Novel Magnetic Anastomosis Technique for Suprahepatic Vena Cava Reconstruction

Reduced Complications after Arterial Reconnection in a Rat Model of Orthotopic Liver Transplantation

Organ Ischemia-Reperfusion Injury by Simulating Hemodynamic Changes in Rat Liver Transplant Model

Vascular Reconstruction with the Cuff Technique in Mouse Orthotopic Liver Transplantation

Heterotopic Auxiliary Whole Liver Rat Transplant Model Utilizing a Hepaticoureterostomy for Allograft Rejection Studies