An Experimental Model Of Reproducible Major Hepatic Trauma In Miniature Swine And Its Surgical Treatment With "Absorbable Abdominal Solid Organ Bandage"

Background It can be mainly ascribed to the fact that only a few ideal reproducible animal model are available that clinical management of major hepatic truama learned little from experimental study. Documentations described "Crush-clamping" method for the penetrating heptatic trauma or developing "Outer impact" for the blunt. The defeats of them include being relatively mild severity, bad correlation with the clinical pattern, high mortality, and poor reproducibility. Therefore, creating a new animal model of major hepatic trauma is important.Despite advances in diagnosis and treatment, major hepatic trauma still presents serious medical problem. We have designed "absorbale abdominal solid organ bandage" aiming to wrap directly the ruptured liver for selected patients, with a bandage form dramatically different from the rectangle-shap Vicryl mesh which was most frequently used for wraping nowadays. Although the use of the "bandage" is believed as a promising way for certain patients, with lower risk of ACS, infections and hemodymical disturbance than gauze packing and lower risk of developing post-operative hepatic function insufficiency than anatomical resection, a hypothesis-test experimental study is still necessary. In this chapter, a game between "bandage" and "anatomical resection" based on the new animal model is reported.Objective To establish a standarded, reproducible major hepatic trauma (large) animal model, and on the basis of which, to study whether the "bandage" has superiority to the "anatomical resection".Methods A "MT-1 remote-control explosive device" including controller unit and bomb unit was firstly invented, with the latter placed on the diaphragmatic surface of target hepatic lobe when the miniature swine had received celiotomy, followed by the protective isolation for adjacent structure, and then "fire". The MAP and the blood losswere recorded and the photographs from above of the liver injuries and the rule placed nearby, for the sake of measuring the area (cm~2) of parenchymal destroyed extent, were obtained. Severioty and reproducibility of the model is appraised with the above parameters.Eight miniature swines developed AAST IV injury of left lateral lobe by the formerly established approach, were assigned randomly into two groups: Group B receiving "bandage" and Group R receiving "resection". Time for hemostasis, blood loss after resuscitation were recorded and hepatic function at point of pre-, post-op and day 1, 4, 7, 10, 14 were investigated, and at last the values were compared between two groups.Results 1. MAP of each animal presents linear decline from 2 min to 7 min post injuries with the coefficient of regression (representing the MAP trends) lies between -3.94 and -9.91. The area (cm~2) of parenchymal destroyed extent is 12.19 ± 2.28 with the 95% confidence interval of 10.66 and 13.71. 2. Blood loss after resuscitation (ml) of Group B is statistically less than that of Group R (86.3± 25.0 vs. 136.3 ± 29.3, P=0.0407). AST (IU) at post-op/day 1 and ALT (IU) at day 1 of Group B elevates higher respectively than those of the control group (308.7±92.25 vs. 162.7±39.50, P=0.0270/400.6 ± 10726 vs 181.7 ± 75.50 , P=0.0157/1193 ± 32.01 vs 67.8 ± 16.55, P=0.0289). While no difference for time of hemostasis, as well as TB at each point, between two groups is displayed.Conclusions A new reproducible experimental animal model of major hepatic trauma has been successfully established, which corresponds with grade IV (AAST) and is charactered with, to some extent, "blunt injury". For those with extensive hepatic satellite fracture whereas without parenchymal devitalization, the "absorbalbe abdominal solid organ bandage" appears to be a better choice than "anatomical resection".