CONCLUSION: LCVP is easily achievable in technique.Maintenance of CVP ≤ 4 mmHg can help reduce blood loss during hepatectomy, shorten the length of hospital stay, and has no detrimental effects on hepatic or renal function. INTRODUCTIONHepatectomy remains as the treatment of choice for hepatocellular carcinoma (HCC). Intra-operative blood loss is one of the major causes for post-operative morbidity and mortality. Various techniques, such as Pringle's maneuver and unilateral hepatic hilum occlusion, have been used to control bleeding from hepatic arterial and portal venous systems during hepatectomy in clinical settings. However, for excision of HCC adjacent to major blood vessels, hepatic system could be the major source of hemorrhage, especially after the application of Pringle's maneuver. Hence, effective control of hepatic venous hemorrhage is crucial to minimize intraoperative blood loss. This prospective randomized clinical trial aims at evaluating the role of low central venous pressure (LCVP) in reducing blood loss during hepatectomy for HCC. MATERIALS AND METHODS Patients'data and groupingFrom June 2002 to December 2003, a total of 50 consecutive patients with HCC (40 men and 10 women) underwent hepatectomy by the same group of surgeons at our hospital. By the sealed envelope method, the patients were blindly randomized into LCVP group (n = 25) and control group (n = 27) at the beginning of the operation. Two patients in the control group were excluded from the study because hepatectomy was given up due to cardiac arrest in one and unclear tumor demarcation in the other. Eventually, there were 25 patients in each group. The demographic data of the patients are shown in Table 1

Background: Holmium laser lithotripsy is the most common technique for the management of ureteral stone. Studies founded that holmium laser firing can produce heat which will cause thermal injury towards ureter. The aim of our current study is to explore factors affecting thermal effect of holmium laser during ureteroscopic lithotripsy. Methods: An in vitro experimental model is design to simulate the ureteroscopic lithotripsy procedure. Different laser power settings (10w (0.5JX20Hz, 1.0 JX10Hz), 20w (1.0 JX20Hz, 2.0 JX10Hz), 30w (1.5JX20Hz, 3.0 JX10Hz)) with various firing time (3 s, 5 s, 10s) and irrigation flow rates(10 ml/min, 15 ml/min, 20 ml/min and 30 ml/min) were employed in the experiment. The temperature around the laser tip was recorded by thermometer. Results: The temperature in the "ureter" rises significantly with the increasing laser power, prolonging firing time and reducing irrigation flow. The highest regional temperature is 78.0°C at the experimental setup , and the lowest temperature is 23.5°C. Higher frequency setting produces more heat at the same power. Laser power < =10w, irrigation flow> = 30 ml/min and "high-energy with low-frequency" can permit a safe working temperature. Conclusion: We clarify that the thermal effect of holmium laser is related with both laser working parameters and irrigation flow. The proper setting is the key factor to ensure the safety during ureteroscopic holmium laser lithotripsy.