Tolerance of the liver to intermittent Pringle maneuver in hepatectomy forliver tumors

Background: Hepatectomy can be performed with a low mortality rate, but mas sive hemorrhage during the operation remains a potentially lethal problem. The Pringle maneuver is traditionally used during hepatectomy to reduce blo od loss, but the effect on the metabolic function of hepatocytes is potenti ally harmful. Although our randomized study showed that an intermittent Pri ngle maneuver is safe and effective during hepatectomy, the upper limit of the duration of the Pringle maneuver is not known. Hypothesis: The liver can tolerate intermittent Pringle maneuver if the dur ation is not excessive. Design: From July 20, 1995, to November 25, 1997, 112 patients undewent hep atectomy for liver tumors. The data of 50 patients who had hepatectomy with out the Pringle maneuver were compared with those of 62 patients who had a liver transection using a Pringle maneuver for 20 minutes and a S-minute cl amp-free interval. The data were collected prospectively. Main Outcome Measures: The surface area of liver transection was measured, and blood loss during liver transection per centimeter square of transectio n area was calculated. Routine liver biochemical tests, arterial ketone bod y ratio (AKBR), and plasma cytokine-interleukin (IL) 1 alpha, 1 beta, 2, an d 6, and tumor necrosis factor alpha-levels were measured before and after the operation. The morbidity and hospital, mortality rates were also compar ed among the patients with different ischemic durations and those without a n intermittent Pringle maneuver. Setting: Tertiary referral center. Results: The cutoff point of accumulated ischemic time that induced substan tial liver damage, as shown by the postoperative recovery rate of the AKBR, was found to be 120 minutes. Compared with the control group, the patients whose accumulated ischemic time was shorter than 120 minutes had less bloo d loss related to transection area (10 mL/cm(2) vs 22 mL/cm(2); P<.001),les s blood transfused (0 L vs 0.6 L; P=.004), a shorter transection time relat ed to transection area (2.0 min/cm(2) vs 2.8 min/cm(2); P=.002), a signific antly higher AKBR in the first 2 hours after liver transection, an equal re covery rate of the AKBR, and a comparable increase of the plasma level of I L-6 postoperatively. For the patients whose accumulated ischemic time was l onger than 120 minutes, blood loss from the transection area was less than for the control group (14 mL/cm(2) vs 22 mL/cm(2); P<.05); but the transect ion time related to the transection area and the blood transfusion volume d id not differ from those of the control group. Furthermore, they had a sign ificantly lower recovery rate of the AKBR and higher plasma levels of IL-6 postoperatively than the control group. Conclusion: The upper limit of tolerance of the liver to intermittent Pring le maneuver is 120 minutes.