Fig 1.
Simplified study design of the resection model.
Maximum liver function capacity (LiMAx) was tested on day -5, 0 (after resection), 3, 7 and 15 (grey bars), respectively. Therapy with 1g paromomycin and 15ml lactulose-syrup twice a day was started 4 days prior to resection until day 5 postoperatively. Straw was removed from the compound from day -4 until day 3 and at the same time pigs were set on a pellet-free diet. Animals fasted 24 hours prior to surgery with free access to water. Further laxative agents applied: Macrogol 6.75g, paraffin oil 20ml and Microlax enema 5ml as needed. (POD: Postoperative day).
Fig 2.
Portal venous catheter and liver resection.
(A) Segmental anatomy of the porcine liver. Caudate lobe: Segment (I). Left lateral lobe: Segments (II) and (III). Left medial lobe: Segment (IV). Right medial lobe: Segments (V) and (VIII). Right lateral lobe: Segments (VI) and (VII). The white area represents the resected extend of three liver lobes and the grey area defines the future liver remnant (FLR); (*) representing the additional partial resection area of the right lateral liver lobe in order to achieve a FLR of approx. 50% is marked with an asterix (*). (B) Anatomy of the porcine following major liver resection, the asterix (*) again marks the potential additional resection area. (C) Anatomic situs prior to and (D) after major liver resection in the minipig. (E) Presentation of the superior mesenteric vein/portal vein following implantation of a 4–6 F tapered portal venous catheter. (F) Liver with hypertrophic right liver lobe (marked **) 30 days after liver resection.
Fig 3.
Calculation of the total liver weight.
Diagram depicting total liver weight of 13 pigs following full hepatectomy in relation to bodyweight (black squares) as well as logistic regression curve (solid black line; LW = 491.86 *ln(BW)– 1249.6 (R2 = 0.807)) for estimation of the future liver remnant.
Fig 4.
Comparison of portal and central venous pressures.
Scatter plot depicting the portal venous (black arrows) and central venous (black squares) pressures before and after liver resection determined via the appropriate catheters. (Pre-Rx: Prior to liver resection; Post-Rx: After liver resection; data presented with mean ± standard error of mean; n = 7, * p < 0.05).
Fig 5.
Postoperative course of laboratory findings.
(A) Diagram depicting the courses of lactate (mmol/l; solid black line) and pH (dotted black line) determined in the blood gas analyses following major liver resection. (B) Diagram depicting course of INR (dotted black line) following major liver resection. (C) Diagram depicting the courses of AST (mmol/l; solid black line) and ALT (mmol/l; solid grey line) following major liver resection, respectively (Rx: Liver resection; POD: Postoperative day; Data presented as mean ± standard error of mean; n = 7).
Fig 6.
Development of ammonia and bilirubin levels after major liver resection.
(A) Diagram depicting the courses of ammonia (solid black line) and bilirubin (dotted black line) following major liver resection. (B) Bar chart depicting serum levels of ammonia before and after liver resection determined in the blood withdrawn from the portal vein (PV, grey bars) and the central vein (CV, white bars). Furthermore, the calculated ammonia clearance (CL, striped bars) before and after resection is shown. (POD: Postoperative day; Pre-Rx: Prior to liver resection; Post-Rx: After liver resection; Data presented as mean ± standard error of mean; n = 7, * p < 0.05).
Fig 7.
Development of maximum liver function capacity after liver resection.
(A) Diagram depicting the development of the maximum liver function capacity (LiMAx) on POD -5, 0, 3, 7 and 15 of liver resection for one representative subject (DOB: Delta over baseline; time-dependent changes in 13CO2/12CO2-ratio given in per mil (‰)). The LiMAx device (Flip 1.0) determined the DOB in one-minute-intervals, so results of measurements are illustrated as dotted lines. The individual LiMAx values are presented in brackets. (B) Diagram summarizing the course of the LiMAx value (μg/kg/h) prior to and after major liver resection for all animals. (POD: Postoperative day; Data presented as mean ± standard error of mean; n = 7).