Decreased lung ischemia-reperfusion injury in rats after preoperative administration of cyclosporine and tacrolimus.

OBJECTIVES: Calcineurin inhibitors reduce experimental reperfusion injury in the liver, brain, heart, kidney, and small bowel. These studies were undertaken to determine whether these agents are similarly protective against lung ischemia-reperfusion injury. METHODS: Left lungs of male rats were rendered ischemic for 90 minutes and reperfused for as long as 4 hours. Treated animals received cyclosporine A (INN: ciclosporin; 1 or 5 mg/kg) or tacrolimus (0.2 mg/kg) 6 hours before ischemia, at reperfusion, or 2 hours after reperfusion. Injury was quantitated in terms of tissue polymorphonuclear leukocyte accumulation (myeloperoxidase content), vascular permeability (iodine 125-labeled bovine serum albumin extravasation), and bronchoalveolar lavage leukocyte content. Separate tissue samples were processed for nuclear protein and cytokine messenger RNA. RESULTS: Treatment with cyclosporine (5 mg/kg) or tacrolimus (0.2 mg/kg) 6 hours before reperfusion reduced lung vascular permeability by 54% and 56% relative to control animals (P <.03). The protective effects of cyclosporine and tacrolimus treatment before reperfusion correlated with 42% and 43% reductions in tissue polymorphonuclear leukocyte (myeloperoxidase) content (P <.008) and marked reductions in bronchoalveolar lavage leukocyte accumulation (P <.01). Administration of cyclosporine or tacrolimus at the time of reperfusion or 2 hours into the reperfusion period offered little or no protection. Animals treated before reperfusion also demonstrated marked reductions in nuclear factor kappaB activation and expression of proinflammatory cytokine messenger RNA. CONCLUSION: Cyclosporine and tacrolimus treatment before reperfusion was protective against lung ischemia-reperfusion injury in rats. The mechanism of these protective effects may involve the inhibition of nuclear factor kappaB, a central transcription factor mediating inflammatory injury. The decreased expression of cytokine messenger RNA indicates that both cyclosporine and tacrolimus may exert their protective effects at the pretranscriptional level.

Surgical management of lung gangrene.

OBJECTIVE: To review the outcomes of five cases of pulmonary resection for lung gangrene. DESIGN: A retrospective chart review. SETTING: A tertiary referral centre. POPULATION STUDIED: Five patients who underwent pulmonary resection for lung gangrene between April and December 1999. MAIN RESULTS: Pathological confirmation of lung gangrene was obtained in all cases. Three patients were ventilator dependent. All five patients had ongoing sepsis despite antibiotic therapy. Additional indications for resection included bronchopleural fistula (two patients), empyema (three patients) and hemoptysis (one patient). In two cases, there was evidence of bilateral, diffuse necrotizing pneumonia, while in three cases the process was localized to one side. Computed tomography revealed cavitation in four cases and the absence of blood supply to the affected lung in one case. Surgical resection included wedge resection (one patient), lobectomy (two patients), bilobectomy (one patient) and pneumonectomy (one patient). In all cases, the bronchial stump was reinforced with an intercostal flap. Postoperative empyema occurred in two cases, one treated by thoracoscopic decortication, the other by percutaneous drainage. There were no instances of stump leak and no deaths. One patient remains ventilator dependent. CONCLUSIONS: Resection for lung gangrene is possible even in the setting of diffuse parenchymal changes and ventilator dependency. A computed tomography scan of the chest is important to make the diagnosis of lung gangrene and to plan operative management. Reinforcement of the bronchial stump is critical.

Biliary obstruction in infants with cystic fibrosis requiring Kasai portoenterostomy.

Cystic fibrosis is associated with an inspissated bile syndrome producing cholestasis secondary to plugging of macroscopically normal bile ducts. In extreme neonatal forms, with early profound intrahepatic cholestasis, the process can be associated with a marked decrease in ductal diameter, varying from hypoplasia to atresia. From 1990 to 1995 three infants were identified with cystic fibrosis, persistent jaundice, and complete absence of biliary excretion despite expectant and conservative treatment including choleretics and surgical biliary irrigation. Abdominal ultrasounds showed contracted gallbladders and no evidence of dilated ducts. Liver biopsy results in two infants showed portal fibrosis, paucity of bile ducts, and minimal inflammation. The third infant had moderate inflammation, bile duct replication, and plugging. Two infants had undergone intestinal resection followed by hyperalimenation for complications of meconium ileus in the newborn period. Surgical exploration was undertaken at 7 to 12 weeks of age. Gross findings were typical of biliary atresia with microgallbladders and nonpatency of the cystic duct. Cholangiograms failed to document ductal patency in two patients who were then treated with a Kasai portoenterostomy. The third infant had patent hypoplastic ducts and underwent only biliary irrigation. Although bile flow was transiently achieved, jaundice recurred, and at reexploration at 16 weeks of age a Kasai poroenterostomy was performed. Histological review of the biliary specimens showed microscopically patent ducts in two patients and proximal patency and distal atresia in the third. All the ducts had mural fibrosis with cystic changes. Bile drainage was achieved in each instance, although in one patient with hypoplastic ducts scant output of highly concentrated bile proved insufficient to arrest progressive liver failure. The subsequent two patients responded with resolution of hyperbilirubinemia and normalization of liver function. They remain free of biliary complications at 30 and 40 months postoperatively. This manifestation of cystic fibrosis in infants is suggested by prolonged jaundice unresponsive to choleretics, nondilated bile ducts and gallbladder on ultrasound, absent biliary excretion on nuclear scan, and characteristic liver biopsy. Exploration is warranted, and discovery of atrophic bile ducts may be best managed with reconstruction.