Ischemia/reperfusion injury after continuous or intermittent hepatic pedicle clamping in rabbits

Abstract

Background: The control of bleeding in hepatectomy is a challenge for surgeons. The hepatic pedicle clamping is a surgical maneuver that can provide reduction in bleeding, but it provokes a hepatocellular suffering. This, along with reperfusion after the clamping finishes, leads to an injury known as ischemia/reperfusion injury.

Aim: To examine the effects of the ischemia/reperfusion injury on the liver after continuous and intermittent hepatic pedicle clamping in an animal model, using the quantification of apoptosis for evaluation.

Method: Twenty New Zealand rabbits were assigned to groups 1 (control), 2 (60 minutes of continuous ischemia) and 3 (60 minutes of intermittent ischemia alternating 12 minutes of ischemia and three minutes of reperfusion). Liver biopsies were collected before ischemia, at its end and after six hours of reperfusion, when the animals were killed. The liver fragments were subjected to histological analysis (paraffinization and hematoxilin-eosin staining) and histochemical (Tunel reaction). Microscope fields of view were scanned for characterization and quantification of apoptosis.

Results: Ischemia led to an increased apoptotic index in both experimental groups in comparison to controls, but similarly between them. After the reperfusion, the indexes returned to baseline values.

Conclusion: Clamping of the hepatic pedicle, either continuous or intermittent, induces apoptosis in liver cells in a similar way.