Laparoscopic ultrasound enhances standard laparoscopy in the staging of pancreatic cancer.

OBJECTIVE: To define the role of laparoscopic ultrasound (LUS) in the staging of pancreatic tumors. SUMMARY BACKGROUND DATA: Laparoscopy has recently been established as a valuable tool in the staging of pancreatic cancer. It has been suggested that the addition of LUS to standard laparoscopy could improve the accuracy of this procedure. METHODS: A prospective evaluation of 90 patients with pancreatic tumors undergoing laparoscopy and LUS was performed over a 27-month period. LUS equipped with an articulated curved and linear array transducer (6 to 10 MHz) was used. All patients underwent rigorous laparoscopic examination. Clinical, surgical, and pathologic data were collected. RESULTS: The median age was 65 years (range 43 to 85 years). Sixty-four patients had tumors in the head, 19 in the body, and 3 in the tail of the pancreas. Four patients had ampullary tumors. LUS was able to image the primary tumor (98%), portal vein (97%), superior mesenteric vein (94%), hepatic artery (93%), and superior mesenteric artery (93%) in these patients. LUS was particularly helpful in determining venous involvement (42%) and arterial involvement (38%) by the tumor. This resulted in a change in surgical treatment for 13 (14%) of the 90 patients in whom standard laparoscopic examination was equivocal. CONCLUSIONS: LUS is useful in evaluating the primary tumor and peripancreatic vascular anatomy. When standard laparoscopic findings are equivocal, LUS allowed accurate determination of resectability. Supplementing laparoscopy with LUS offers improved assessment and preoperative staging of pancreatic cancer.

Inhibition of nitric oxide synthesis is detrimental during endotoxemia.

BACKGROUND: Increased production of nitric oxide has been implicated as a mediator during septic shock and sepsis syndrome. Inhibition of nitric oxide production could be beneficial during endotoxemia to improve the individual's hemodynamic status and possibly outcome. OBJECTIVE: To evaluate the effects of nitric oxide inhibition on macrophage function and survival in a murine sepsis model. DESIGN: Sixty-eight female Swiss-Webster (ND4) mice were injected with a sublethal dose of Escherichia coli lipopolysaccharide (25 mg/kg). INTERVENTION: The treated group (n = 34) received 10 mg/kg of NG-nitro-L-arginine methyl ester at the time of lipopolysaccharide injection. MAIN OUTCOME MEASURES: Blood samples and peritoneal macrophages were obtained at baseline and at 2, 4, and 8 hours after injection. Nitrite levels were measured in 36 mice from plasma and supernatant samples of cultured peritoneal macrophages stimulated with interferon gamma (100 micrograms/mL) for 48 hours. Thirty-two animals were observed for survival. RESULTS: Administration of N-nitro-L-arginine methyl ester after lipopolysaccharide injection caused significant reductions in macrophage mean nitrite production from 13 and 15 mumol/L to 7 and 11 mumol/L (P < .05) and reduced mean plasma nitrite concentrations from 100 and 118 mumol/L to 46 and 108 mumol/L (P < .05) at 2 and 4 hours, respectively. The rate of survival was significantly decreased to 0% in the group receiving N-nitro-L-arginine methyl ester after septic challenge compared with 87.5% in controls (P < .005). CONCLUSIONS: Inhibition of nitric oxide production is detrimental in this murine model of endotoxemia.

Total parenteral nutrition, bacterial translocation, and host immune function.

Total parenteral nutrition (TPN) is associated with increased infectious complications in trauma and perioperative patients compared with enteral nutrition support. This study evaluated the effects of TPN on splenocyte and peritoneal macrophage (PM phi) function and intestinal bacterial translocation. Male Wistar rats underwent central vein cannulation and were randomized to isocaloric feeding of a regular chow diet (RD) plus saline infusion or TPN for 7 days. Splenocytes and PM phi were harvested to assess concanavalin A mitogenesis, superoxide production, and Candida albicans phagocytosis. Bacteria-positive mesenteric lymph nodes (MLNs) were found in 77% (10 of 13) of TPN-fed rats compared with 17% (2 of 12) of RD-fed rats (p < 0.05). Splenocyte mitogenesis, PM phi superoxide production, and C. albicans phagocytosis were significantly decreased in the TPN group compared with results in the RD group. In a second study, rats received RD, TPN, and parenteral nutrition (PN) with 10% or 20% of calories given as oral chow (PN and 10% chow and PN and 20% chow) for 7 days. PN and 10% chow reversed the TPN-induced suppression of C. albicans phagocytosis. PN + 20% chow significantly increased splenocyte mitogenesis, PM phi superoxide production, and C. albicans phagocytosis and killing to normal levels and was associated with a decreased incidence of bacteria-positive MLN. Thus, administration of TPN is associated with impaired PM phi microbicidal and splenocyte proliferative function. These defective cellular functions were reversed with a small amount of oral feeding.