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• Records of 11 patients undergoing biliary reconstruction after laparoscopic cholecystectomy are reviewed. Ductal injuries resulted from failure to define the anatomy of Calot's triangle. Risk factors include scarring, acute cholecystitis, and obesity. Presenting findings included anorexia, ileus, failure to thrive, pain, ascites, and jaundice. All patients required hepaticojejunostomies, which were multiple and above the hepatic bifurcation in four patients. Given the extensive nature of these injuries and the frequent need for intrahepatic anastomosis and early stenosis of repairs by referring physicians, we recommend reconstruction be undertaken by an experienced hepatobiliary surgeon. To avoid injuries, a greater appreciation of risk factors and anatomic distortion and variance and strict adherence to principles of dissection and identification of anatomic structures are suggested. The use of cholangiography and a low threshold for conversion to the open procedure are advised.(Arch Surg. 1992;127:596-602)

• Tumor necrosis factor (TNF) is a macrophage-derived peptide mediator released during endotoxemia and sepsis. We examined the systemic and visceral hemodynamic response to low doses of human recombinant TNF in rats. Each animal received a 30-minute intravenous infusion of either saline solution (n=8) or TNF (n=8) in a dose of 0.25 mg/kg or 1.0 mg/kg. Thermodilution cardiac output, blood pressure, pulse, vascular resistance, effective hepatic blood flow (galactose clearance), and effective renal plasma flow (p-aminohippurate clearance) were determined at time=2 hours. The 0.25-mg/kg dose had no apparent effect on systemic hemodynamics. The 1.0-mg/kg dose produced a hyperdynamic systemic circulatory response with an elevated cardiac output, tachycardia, and a diminished systemic vascular resistance. Effective hepatic blood flow was exquisitely sensitive to even the lowest dose of TNF, with a 29% reduction despite the normal cardiac output. Renal flow was unaffected by either dose. Tumor necrosis factor–induced systemic and visceral hemodynamic changes are remarkably similar to those seen in gram-negative sepsis, suggesting that TNF may occupy a proximal position in the pathogenesis of overwhelming infection.(Arch Surg 1989;124:445-448)

• To study hepatic blood flow with clearance techniques during sepsis, it is essential to work within the limitations of the test being applied. Based on galactose elimination kinetics, this study validates galactose clearance at low concentrations as an estimate of effective hepatic blood flow in a rat peritonitis model of cecal ligation and puncture. Hepatic function as determined by galactose elimination capacity fell 25% at ten hours after induction of peritonitis, which correlated closely with the 20% reduction in effective hepatic blood flow at the same time point despite a normal cardiac output. The pattern of reduced flow and reduced function is consistent with intrahepatic flow redistribution. Inadequate flow at the microvascular level with secondary cellular injury may explain the liver dysfunction observed during sepsis.(Arch Surg 1987;122:349-354)

• Whether acute renal failure following overwhelming bacterial septicemia is initially a consequence primarily of a cytotoxic insult or a perfusion insufficiency remains unclear. To assess the effects of intra-abdominal sepsis on the distribution of renal blood flow and renal cell bioenergy status, the glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and energy-charge ratios were measured in rats following cecal ligation/puncture (CLP) or sham laparotomies. The CLP animals demonstrated a decrease in ERPF of 42% and 58% from sham groups at ten and 20 hours, respectively. The GFR showed similar but more severe impairments of 53% and 71% at ten and 20 hours, respectively, following insult despite moderate increases in cardiac output. The disproportionate decrease in GFR over ERPF supports the hypothesis of a corticomedullary redistribution of renal blood flow in sepsis. Renal energy charge, unchanged at ten hours, decreased significantly at 20 hours. Diminished renal perfusion and the redistribution of renal blood flow precedes and may contribute to the renal cell bioenergy derangements in septic acute renal failure.(Arch Surg 1987;122:328-331)

• Clinical studies demonstrate that early débridement and operative fixation of femur fractures in multiply injured patients lowers both the incidence and severity of hepatic failure. Perhaps the single most important determinant of hepatic function is nutrient hepatic perfusion. This study compares systemic and hepatic blood flow in rats that have sustained femur fractures with or without associated soft-tissue injury. Femur fracture without soft-tissue trauma resulted in a hyperdynamic state with normal blood flow distribution at 24 hours after injury and normal hemodynamics at 48 hours. When femur fracture was associated with soft-tissue trauma, the elevated cardiac output at 24 hours was not matched by a proportionately elevated hepatic blood flow. In this latter group, the cardiac output was normal at 48 hours, but the hepatic perfusion defect remained. Retained fracture fragments, hematoma, and injured and necrotic soft tissue may serve as a stimulus leading to a pathologic reduction in hepatic perfusion.(Arch Surg 1988;123:412-415)

• Zymosan was administered intravenously in graded doses to Sprague-Dawley rats to investigate the hemodynamic effects of systemic complement activation. At two hours, thermodilution cardiac output, mean arterial pressure, heart rate, systemic vascular resistance, hematocrit, effective hepatic and renal blood flows, and percent change in total hemolytic complement activity were measured on all animals. Progressively increasing doses of zymosan produced characteristic hemodynamic changes of progressively deteriorating stages of hyperdynamic sepsis. In addition, complement activation resulted in a redistribution of systemic blood flow with hepatic hypoperfusion similar to that seen in sepsis. Renal blood flow was unaffected early after complement activation. Additional rats were studied from the control and a representative zymosan-treated group at 24 and 48 hours to determine if the hemodynamic changes observed at two hours persisted or resolved. All systemic hemodynamic measures returned to normal at both 24 and 48 hours. Liver blood flow, however, remained depressed and actually deteriorated overtime. Renal perfusion, which was stable at both two and 24 hours, fell below control values in the zymosan-treated group at 48 hours. We conclude that complement may be a mediator of both systemic and visceral flow abnormalities that precede, and perhaps precipitate, organ failure in trauma and sepsis.(Arch Surg 1988;123:316-321)

• Hepatic dysfunction following cardiopulmonary bypass (CPB) is a relatively frequent finding, and jaundice occurring after CPB is associated with an increased mortality rate. PostCPB jaundice may be a consequence of inadequate liver perfusion during CPB. To evaluate the potential impact of CPB on effective hepatic blood flow, 10 patients undergoing CPB for cardiac procedures were studied. Effective hepatic blood flow was measured in each patient during the operative procedure but before institution of CPB and during CPB as well. Effective hepatic blood flow was measured by the galactose clearance technique. Blood lactate and pyruvate levels were also measured before and during CPB. During CPB, effective hepatic blood flow was consistently reduced by an average of 19%. Although for most patients this reduction seems well tolerated, in a minority of patients it may contribute to postoperative hepatic dysfunction.(Arch Surg. 1989;124:458-459)