Establishment of a Novel Simplified Surgical Model of Acute Liver Failure in the Cynomolgus Monkey

Abstract

Models using large animals that are suitable for studying artificial liver support system (ALSS) are urgently needed. Presently available acute liver failure (ALF) models mainly involve pigs or dogs. Establishment of current surgical ALF models (hepatectomy/devascularization) requires either very good surgical skills or multistep processes-even multiple stages of surgery. Therefore, it is necessary to develop a simplified surgical method. Here we report a novel simplified surgical ALF model using cynomolgus monkeys. Six monkeys underwent portal-right renal venous shunt combined with common bile duct ligation and transection (PRRS + CBDLT). Postoperatively, the monkeys had progressively increased listlessness, loss of appetite, and obvious jaundice. Blood biochemistry levels (Amm, ALT, AST, TBiL, DBiL, ALP, LDH, CK, and Cr) and prothrombin time (PT) were significantly increased (all P < 0.01) and albumin (ALB) was markedly reduced (P < 0.01) compared with baseline values. Histological examination of liver specimens on postoperative day 10 revealed cholestasis and inflammation. PRRS + CBDLT produced ALF that closely correlated with clinical situations. Compared with other surgical or drug ALF models, ours was simplified and animals were hemodynamically stable. This model could provide a good platform for further research on ALSS, especially regarding their detoxification functions.

Figure 1

Simple surgical procedures for portal-right renal venous shunt combined with common bile duct ligation and transection. (a) Identification of the porta hepatis and dissection, ligation, and transection of common bile duct. (b) Identification of the right renal hilum and ligation of right renal artery. (c) PVC-gel catheter (about 11 cm × 0.5 cm) from a disposable sterile blood transfusion set. (d) Completion of right renal vein and portal vein intubation. RRV, right renal vein; RRA, right renal artery; RU, right ureter; SBV, small branch vein; IVC, inferior vena cava; CBD, common bile duct; PV, portal vein; L, Liver; RK, right kidney; GB, gall bladder; PVC-GC, PVC-gel catheter.

Figure 2

Changes of HR (a), BP (SBP/DBP) (b), CVP (c), and SpO₂ (d) during surgery. Mean ± SD, n = 6. HR: heart rate; SBP: systolic blood pressure; DBP: diastolic blood pressure; CVP: central venous pressure; SpO₂: oxygen saturation.

Figure 3

Changes in levels of Amm (a), ALB (b), TBiL (c), DBiL (c), ALT (d), AST (d), CK (e), LDH (e), ALP (f), Cr (g), BUN (h), and PT (i) prior to operation (baseline) and at 0 h, 8 h, 1 d, 2 d, 3 d, 7 d, and 10 d after operation. Mean ± SD. ^∗ P < 0.01 versus baseline, ^# P > 0.05 versus baseline. Amm: ammonia; ALB: albumin; TBiL: total bilirubin; DBiL: direct bilirubin; ALT: alanine aminotransferase; AST: aspartate aminotransferase; CK: creatine phosphate kinase; LDH: lactate dehydrogenase; ALP: alkaline phosphatase; Cr: creatinine; BUN: blood urea nitrogen; PT: prothrombin time.

Figure 4

Pathological hepatic features of experimental monkey. (a) Representative preoperative specimen. (b) Representative specimen from postoperative day 10. Hematoxylin-eosin stain, ×20.

Figure 5

TUNEL staining in liver of the experimental monkey. (a) Preoperative liver section showed no evidence of apoptosis (×10). (b) A number of apoptotic cells were detected in the liver section from postoperative day 10 (×10). High magnification (×20) images are shown in the lower right corner.

Figure 6

Masson trichrome staining in liver of the experimental monkey. Fibrotic change did not appear in preoperative liver section (a) and liver section from postoperative day 10 (b) (×10). High magnification (×20) images are shown in the lower right corner.

Figure 7

Ki-67 staining of proliferating hepatocytes in liver of the experimental monkey. (a) Preoperative liver section showed a negative expression. (b) Liver section from postoperative day 10 revealed a few positively stained nuclei (×10). High magnification (×20) images are shown in the lower right corner.