Multiple in vivo liver biopsies using a freeze-clamping technique

A multiple in vivo liver biopsy technique was developed to measure labile metabolites (creative phosphate [CP], ATP, lactate) without interfering with normal perfusion and metabolism. Anesthetized rats (n = 7) had a midline abdominal incision done to expose the liver. Four biopsies were taken across 20 min. Bleeding was controlled by a small, nontraumatic clamp proximal to the biopsy. Prefrozen dressing forceps grasped the liver and scissors cut the biopsy, which was frozen in liquid nitrogen. Bleeding was minimal and hemodynamic stability was preserved. This technique has few complications, bleeding is easily controlled, and it allows for large multiple biopsies, which give reliable metabolic data and can be consistently taught.