Gross Anatomical Studies on the Portal Vein, Hepatic Artery and Bile Duct in the Liver of the Pig

Surgical Models of Liver Regeneration in Pigs: A Practical Review of the Literature for Researchers

The remarkable capacity of regeneration of the liver is well known, although the involved mechanisms are far from being understood. Furthermore, limits concerning the residual functional mass of the liver remain critical in both fields of hepatic resection and transplantation. The aim of the present study was to review the surgical experiments regarding liver regeneration in pigs to promote experimental methodological standardization. The Pubmed, Medline, Scopus, and Cochrane Library databases were searched. Studies evaluating liver regeneration through surgical experiments performed on pigs were included. A total of 139 titles were screened, and 41 articles were included in the study, with 689 pigs in total. A total of 29 studies (71% of all) had a survival design, with an average study duration of 13 days. Overall, 36 studies (88%) considered partial hepatectomy, of which four were an associating liver partition and portal vein ligation for staged hepatectomy (ALPPS). Remnant liver volume ranged from 10% to 60%. Only 2 studies considered a hepatotoxic pre-treatment, while 25 studies evaluated additional liver procedures, such as stem cell application, ischemia/reperfusion injury, portal vein modulation, liver scaffold application, bio-artificial, and pharmacological liver treatment. Only nine authors analysed how cytokines and growth factors changed in response to liver resection. The most used imaging system to evaluate liver volume was CT-scan volumetry, even if performed only by nine authors. The pig represents one of the best animal models for the study of liver regeneration. However, it remains a mostly unexplored field due to the lack of experiments reproducing the chronic pathological aspects of the liver and the heterogeneity of existing studies.

Anatomical and radiographic distribution of hepatic artery and biliary duct system applied to biochemical parameters indicative to hepatobiliary disease in Egyptian donkey (Equus asinus)

The current study was performed on ten adult Egyptian donkeys of both sexes for anatomical and radiographic studies in addition to six other donkeys for enzymatic, biochemical and statistical analysis. The aim was to illustrate the normal hepatic arterial and biliary distribution using different anatomic techniques and radiographic imaging besides, establishing an accurate laboratory profile specific for donkeys that used as standard indicators for hepatobiliary dysfunction. The right branch of the hepatic artery in donkey forms a curved arch erupting five branches, unlike the left branch that erupts six branches, being the direct continuation of the main hepatic artery. The caudate lobe artery either originated from the hepatic artery or its right division. The common hepatic duct represented a very clear enlargement called 'gall tank' at its terminal pouring intestinal end and compensating absence of gall bladder, cystic and common bile ducts. The intrahepatic biliary distribution is characterized by a segmental ramification into dorsal, intermediate, and ventral branches of bile ductules especially noticed in the undivided right lobe and left lateral lobe. The quadrate lobe is divided according to its biliary drainage into right and left parts where the former is drained by the left hepatic duct while the latter is drained through a branch from R. lobi medialis sinistri. The serum enzymatic activity was slightly similar to that of the horse while some biochemical parameters differentiating the donkey from the horse such as lowered total bilirubin, serum bile acids, and higher triglycerides, blood urea and prolonged prothrombin time.

Variations and some clinically relevant relations of A. cystica in pigs - a corrosion cast study

The aim of this study was to investigate the variations as well as the length of A. cystica and its branches in pigs using corrosion casting method with the self-polymerising resin Duracryl® Plus. The method included several steps: hepatectomy, precasting treatment, injection of Duracryl, polymerisation of casting medium, corrosive treatment, cleaning of the corrosion casts, air-drying and preservation of casts. The livers were collected from 12 male 6-month-old pigs (crossbred Landrace×Danube White). With regards to the beginning of A. cystica, 4 variations were observed and grouped as follows: variation A  A. cystica detached from R. dexter medialis, together with R. quadratus (variation A1), or alone (variation A2); variation B1 – A. cystica originated from A. gastroduodenalis, or was a branch of the common trunk (R. dexter) (variation B2). The metric data were processed by GraphPad Prism 6 for Windows. Clinically relevant relations between А. сystica, Ductus cysticus, A. celiaca and R. sinister also were described. The new information re-ceived about the blood supply of the gallbladder would contribute to the understanding of the etiology of postoperative complications as a result of surgical interventions in this location and for their prevention.

Experimental Hepatocyte Transplantation in Pigs

Technical issues of experimental hepatocyte transplantation in pigs, i.e., selection of animals, anesthesia, route of transplantation, and segment-specific transplantation have described.

Importance Rat Liver Morphology and Vasculature in Surgical Research

BACKGROUND The laboratory rat is one of the most popular experimental models for the experimental surgery of the liver. The objective of this study was to investigate the morphometric parameters, physiological data, differences in configuration of liver lobes, biliary system, and vasculature (arteries, veins, and lymphatic vessels) of the liver in laboratory rats. In addition, this study supports the anatomic literature and identified similarities and differences with human and other mammals. MATERIAL AND METHODS Forty laboratory rats were dissected to prepare corrosion casts of vascular system specimens (n=20), determine the lymph vessels and lymph nodes (n=10), and for macroscopic anatomical dissection (n=10) of the rat liver. The results are listed in percentages. The anatomical nomenclature of the liver morphology, its arteries, veins, lymph nodes, and lymphatic vessels are in accordance with Nomina Anatomica Veterinaria. RESULTS We found many variations in origin, direction, and division of the arterial, venous, and lymphatic systems in rat livers, and found differences in morphometric parameters compared to results reported by other authors. The portal vein was formed by 4 tributaries in 23%, by 3 branches in 64%, and by 2 tributaries in 13%. The liver lymph was drained to the 2 different lymph nodes. The nomenclature and morphological characteristics of the rat liver vary among authors. CONCLUSIONS Our results may be useful for the planing of experimental surgery and for cooperation with other investigation methods to help fight liver diseases in human populations.

Characterization of a porcine model for associating liver partition and portal vein ligation for a staged hepatectomy

BACKGROUND

Publications using the ALPPS (associating liver partition and portal vein ligation for a staged hepatectomy) procedure have demonstrated a future liver remnant growth of 40-160% in only 6-9 days. The present study aimed to develop and describe the first large animal model of ALPPS that can be used for future studies.

METHODS

A total of 13 female domestic pigs underwent ALPPS stage 1 (portal vein division and parenchymal transection) followed by ALPPS stage 2 (completion left-extended hepatectomy) 7 days later. An abdominal computed tomography (CT) scan was performed immediately prior to ALPPS stage 1 surgery and again 7 days later to assess hypertrophy immediately prior to ALPPS stage 2 surgery. Blood samples, as well as tissue analysis for Ki-67, were performed.

RESULTS

On CT volumetric analysis, the mean size of the future liver remnant (FLR) prior to ALPPS stage 1 was 21 ± 2% and 40 ± 6% prior to ALPPS stage 2. The median degree of growth was 75% with a mean kinetic growth rate of 11% per day. Liver weights at autopsy correlated well with CT volumetric analysis (r = 0.87). There was no significant difference in mean lab values [asparate aminotransferase (AST), alanine aminotransferase (ALT), ammonia, International Normalized Ratio (INR) or bilirubin] from baseline until immediately prior to ALPPS stage 2. Post ALPPS stage 2 there was a significant increase in INR from baseline 1.1 to 1.6 (P = 0.012). No post-operative deaths secondary to liver failure were observed.

CONCLUSION

The present study describes the first reproducible large animal model of the ALPPS procedure. The degree of liver growth and the kinetic rate of growth were similar to that which has been demonstrated in human publications. This model will be valuable as future laboratory studies are performed.