Hepatic Pedicle Clamping Research Articles

Liver resections with or without pedicle clamping

Background: Decreasing operative bleeding during liver resection, and thus extent of transfusions, has become a main criterion to evaluate operative results of hepatectomies. Hepatic pedicle clamping (HPC) is widely used for this purpose. The aim of the study was to evaluate safety, efficacy, technique, and contraindications of HPC during liver resections, comparing results of resections performed with or without HPC. Methods: Data from 245 liver resections were analyzed. In all, 125 resections were performed with HPC (group A), continuous in 100 cases and intermittent in 25 cases. The average duration of ischemia in group A was 39 ± 20 minutes (range 7 to 107). In 20 cases (16%) ischemia was prolonged for 60 minutes or more. A total of 120 resections were performed without HPC (group B). Major resections were 53.6% in group A (67 cases) and 38.3% in group B (46 cases). Cirrhosis was present in 36 cases, 19 in group A and 17 in group B. Results: Operative mortality was nil. Postoperative mortality was 2.9%, morbidity 22.4%. Percentage of transfused cases (34.4% versus 60.0%; P <0.001) and number of blood units per transfused case (2 ± 1 versus 4 ± 3; P <0.001) were lower in group A versus group B. Similar figures were found by considering only major resections. Postoperative blood chemistries did not show important differences between the two groups, and postoperative alterations were related more to extent and complexity of the operation than to length of HPC. Conclusions: HPC during liver resection is a safe and effective technique. This is demonstrated in a context where HPC is used continuously in most cases, intermittently in cases with impaired liver function and for more prolonged ischemia, and avoided in cases with limited bleeding, jaundice, and simultaneous bowel anastomoses.

Prolonged continuous or intermittent vascular inflow occlusion during hemihepatectomy in pigs.

To assess ischemia and reperfusion (I/R) injury in a hemihepatectomy model in pigs after prolonged continuous or intermittent vascular inflow occlusion in the liver. Massive intraoperative blood loss during liver resections can be prevented by temporary vascular inflow occlusion, consequently leading to ischemia and reperfusion injury in the remnant liver. Previously, in a pig liver resection model in which only limited I/R injury was induced during brief (90 min) vascular inflow occlusion, the authors demonstrated reduced I/R injury after continuous (CNT) occlusion, compared to intermittent (INT). This liver resection study on pigs was undertaken to assess I/R injury after prolonged (120 min) CNT or INT occlusion. In pigs (37.0 +/- 1.5 kg), liver ischemia during 2 hours was CNT (n = 6) or INT (n = 6) (eight subsequent periods of 12 min ischemia and 3 min recirculation), followed by 6 hours of reperfusion. A left hemihepatectomy (45.5% +/- 1.4%) was performed within the first 12 minutes of ischemia. No hepatic pedicle clamping or liver resection was performed in control experiments (n = 6). Microvascular damage was assessed by hyaluronic acid (HA) uptake capacity of the liver (parameter of early sinusoidal endothelial cell damage) and restoration of intrahepatic tissue pO2 during reperfusion. Hepatocellular damage was tested by plasma concentrations of aspartate aminotransferase (AST), alanine aminotransferase, and lactate dehydrogenase (LDH). Hyaluronic acid uptake after 6 hours of reperfusion, compared to preischemic uptake, was unaltered in the control group, but was significantly reduced in both resection groups. However, more HA was taken up after INT occlusion, compared to CNT (60.4% +/- 5.6% and 39.5% +/- 3.7%, respectively; ANOVA: p = 0.001). Intrahepatic tissue pO2 distribution after 6 hours of reperfusion more closely returned to preischemic configuration in the INT group than in the CNT group, indicating reduced microcirculatory disturbances after INT occlusion. Release of AST and LDH after 6 hours of reperfusion was significantly increased in both CNT and INT groups. Lower AST levels, however, were found after INT occlusion than after CNT occlusion (267.0 +/- 74.7 U/l and 603.3 +/- 132.4 U/l, respectively; p = 0.06). Intermittent hepatic vascular inflow occlusion during prolonged liver ischemia in pigs resulted in less microcirculatory and hepatocellular injury, compared to continuous occlusion. Intermittent clamping is preferable when prolonged periods of vascular inflow occlusion are applied during liver resections.

Effect of intermittent hepatic pedicle clamping on free radical generation in the rat liver

Background: Intermittent hepatic pedicle clamping is thought to cause less hepatic reperfusion injury compared with continuous clamping. The mechanisms underlying this difference are unknown. We examined the relationship between intermittent ischemia/reperfusion and the production of free radicals using electron spin resonance spectrometry. Methods: Alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone was administered to rats as a spin trap agent. Continuous clamping (15, 30, or 60 minutes) or intermittent clamping (four cycles of 15-minute ischemia and 5 or 15 minutes of reperfusion) of hepatic pedicle was carried out. After reperfusion, free radical production in the liver was measured by an electron spin resonance spectrometer, and the level of hepatic injury was evaluated by measuring liver enzyme. Results: Longer periods of ischemia increased free radical production after reperfusion. There was no significant increase in free radical production or liver enzymes when the duration of ischemia was 15 minutes. Free radical production and liver damage were significantly less severe in intermittent pedicle clamping than in continuous clamping for 60 minutes, especially when the duration of the reperfusion between four cycles of ischemia was 15 minutes. Conclusions: These results indicate that intermittent pedicle clamping lessens free radical production when compared with continuous clamping, although many free radicals are produced. (Surgery 1998;124:49-56.)

Effect of intermittent hepatic pedicle clamping on free radical generation in the rat liver

Background: Intermittent hepatic pedicle clamping is thought to cause less hepatic reperfusion injury compared with continuous clamping. The mechanisms underlying this difference are unknown. We examined the relationship between intermittent ischemia/reperfusion and the production of free radicals using electron spin resonance spectrometry. Methods: Alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone was administered to rats as a spin trap agent. Continuous clamping (15, 30, or 60 minutes) or intermittent clamping (four cycles of 15-minute ischemia and 5 or 15 minutes of reperfusion) of hepatic pedicle was carried out. After reperfusion, free radical production in the liver was measured by an electron spin resonance spectrometer, and the level of hepatic injury was evaluated by measuring liver enzyme. Results: Longer periods of ischemia increased free radical production after reperfusion. There was no significant increase in free radical production or liver enzymes when the duration of ischemia was 15 minutes. Free radical production and liver damage were significantly less severe in intermittent pedicle clamping than in continuous clamping for 60 minutes, especially when the duration of the reperfusion between four cycles of ischemia was 15 minutes. Conclusions: These results indicate that intermittent pedicle clamping lessens free radical production when compared with continuous clamping, although many free radicals are produced. (Surgery 1998;124:49-56.)

Intermittent Hepatic Pedicle Clamping Reduces Liver and Lung Injury

Background.Temporary occlusion of the hepatic hilum is used to control hemorrhage during liver resection, but can result in widespread organ dysfunction.Materials and methods.Adult male Sprague-Dawley rats were subjected to either continuous (Group C) or intermittent (Group R) hepatic ischemia. The total ischemia time (60 min) was divided into four 15-min periods in Group R. Blood and lung tissue specimens were collected 2 h after the induction of ischemia (early phase), and 24 h after the termination of ischemia (late phase). Plasma lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) concentrations were measured. Histologic sections were studied using hematoxylin and eosin, as well as naphthol AS-D chloroacetate esterase techniques.Results.In the early phase, LDH, ALT, TNF-α, and IL-6 concentrations were significantly higher in Group C than in Group R. Pulmonary septal thickening and polymorphonuclear leukocyte infiltration were less severe in Group R than in Group C. These differences were significant in the late phase.Conclusions.Intermittent hepatic pedicle clamping reduces the ischemia-reperfusion injury not only to the liver but also to the lungs. This technique may improve the outcome in patients undergoing liver resection.

Is simultaneous hepatectomy and intestinal anastomosis safe?

To assess the safety of simultaneous, "one-stage," hepatectomy and intestinal anastomosis, we retrospectively studied 53 patients who underwent such a procedure, with 76 digestive tract sutures. They represented 80% of all the cases eligible for one-stage procedures among 332 liver resections for malignant tumors. The medical records of the patients were retrospectively analyzed to assess details of the surgical procedures, postoperative mortality and morbidity, and postoperative liver function, with special attention being paid to the prothrombin time and the bilirubin value on days 1, 2, 3, and 7. No postoperative mortality occurred and the postoperative morbidity rate was 19%. Only 2 cases of digestive tract anastomotic leakage occurred, which led to reoperation. Hepatectomy-related complications were noted in 5 patients (3 biliary fistulas, 1 hemorrhage and 1 transient liver failure), and pulmonary infections occurred 3 times. The technical difficulties of the one-stage procedure are discussed, focusing on the choice of the incision, the risk of sepsis for the liver if there is an intestinal aperture, possible repercussions of liver impairment and hepatic pedicle clamping on bowel suture healing, and the risk of digestive fistula according to the location of the bowel suture. It appears that this one-stage procedure is safe if the bowel is systematically cleaned before the operation, if an appropriate Rio-Branco incision is used, and if the risk of postoperative liver failure is low. It seems preferable to use intermittent hepatic pedicle clamping rather than continuous clamping (when feasible), and to temporarily protect a low rectal anastomosis with a colostomy.

Portosystemic Shunt for Orthotopic Liver Transplantation in the Rat

Despite several technical improvements, orthotopic liver transplantation (OLT) in the rat remains the most difficult experimental microsurgical transplant to perform. The short anhepatic phase tolerated by the rat makes it difficult for beginners to perform the suprahepatic and portal vein anastomoses in the limited time available. To overcome this obstacle, we examined the ability of a portosystemic shunt, induced previously by subcutaneous transposition of the spleen (STS), to decompress the portal system during hepatic pedicle clamping and thus prolong the anhepatic phase of OLT in the rat. Effective drainage was shown by the ability of rats subjected to STS 3 weeks previously to survive portal pedicle clamping of 120 min, while normal rats all died after 90 min of clamping. We demonstrated that, in STS rats, OLT performed with an anhepatic phase of 1 hr had 100% survival at 1 week, while this procedure caused 100% death in normal rats. The ablation in STS rats of the drastic pH decrease and appearance of endotoxins seen in the portal blood of normal rats subjected to "OLT-like" clamping corroborated these results. This application of the STS model to the field of OLT bas already proved in our laboratory to be extremely useful during the surgical learning phase of liver transplantation in the rat.