Contrast-free endoscopic stent insertion in malignant biliary obstruction

AIM： To present a case series of MRCP-guided endoscopic biliary stent placement, performed entirely without contrast injection. METHODS： Contrast-free endoscopic biliary drainage was attempted in 20 patients with malignant obstruction, unsuitable for resection on the basis of tumor extent or medical illness. MRCP images were used to confirm the diagnosis of tumor, to exclude other biliary diseases and to demonstrate the stenoses as well as dilation of proximal liver segments. The procedure was carried out under conscious sedation. Patients were placed in the left lateral decubitus position. The endoscope was inserted, the papilla identified and cannulated by a papiUotome. A guide wire was inserted and guided deeply into the biliary tree, above the stenosis, by fluoroscopy. A papillotomy approximately 1 cm. long was performed and the papillotome was exchanged with a guiding-catheter. A 10 Fr＇ Amsterdam-type plastic stent, 7 to 15 cm long, was finally inserted over the guide wire/ guiding catheter by a pusher tube system.
RESULTS： Successful stent insertion was achieved in all patients. There were no major complications. Successful drainage, with substantial reduction in bilirubin levels, was achieved in all patients.
CONCLUSION： This new method of contrast-free endoscopic stenting in malignant biliary obstruction is a safe and effective method of palliation. However＇ a larger, randomized study comparing this new approach with the standard procedure is needed to confirm the findings of the present study.     

Endoscopic approach to malignant strictures at the hepatic hilum

Hilar tumors have proven to be a challenge to treat and manage because of their poor sensitivity to conventional therapies and our inability to prevent or to detect early tumor formation. Endoscopic stent drainage has been proposed as an alternative to biliary-enteric bypass surgery and percutaneous drainage to palliate malignant biliary obstruction. Prosthetic palliation of patients with malignant hilar stenoses poses particular difficulties, especially in advanced lesions （type Ⅱ lesions or higher）. The risk of cholangitis after contrast injection into the biliary tree in cases where incomplete drainage is achieved is well known. The success rate of plastic stent insertion is around 80% in patients with proximal tumors. Relief of symptoms can be achieved in nearly all patients successfully stented.     

N-acetyl cysteine attenuates the inflammatory response in warm ischemic pig lungs

BACKGROUND: Lungs donated after cardiac death (DCD) may significantly reduce current organ shortage. However, the warm ischemic period following circulatory arrest may enhance ischemia-reperfusion injury (IRI). We investigated the possible therapeutic effect of N-acetyl cysteine (NAC), a potent anti-oxidative agent on IRI in a porcine ex vivo lung reperfusion model. MATERIALS AND METHODS: NAC (50 mg/kg) was nebulized to pigs (n = 6/group) prior to sacrifice (NAC-DCD). In DCD-NAC, animals received NAC 15 min after death. Control animals did not receive an aerosol (DCD). Interleukin (IL)-1beta, tumor necrosis factor-alpha, IL-8, lactate dehydrogenase activity and thiobarbituric acid reactive substances were measured and cells were counted in broncho-alveolar lavage from the right lung after a 3-h warm plus 1-h cold ischemic interval. RESULTS: There were no differences in cells between groups, however cell death was lower in NAC-DCD (10.3 +/- 1.5%) and DCD-NAC (7.83 +/- 1.8%) compared to DCD (18.0 +/- 3.8%). IL-1beta levels (111.5 +/- 28.8 pg/mL and 92.2 +/- 51.0 pg/mL versus 250.3 +/- 56.6 pg/mL) and lactate dehydrogenase activity (1258.0 +/- 440.9 U/L and 1606.0 +/- 289.0 U/L versus 2848.0 +/- 760.9 U/L) were significantly lower in NAC-DCD and DCD-NAC compared with DCD, respectively. These postischemic inflammatory markers correlated with functional parameters upon reperfusion of the left lung, reported in a previous study. CONCLUSIONS: Administration of NAC prior to or shortly after circulatory arrest results in a marked reduction of inflammation during the warm ischemic phase.     

Natural orifices transluminal endoscopic surgery (NOTES): an overview of technical challenges and complications of transgastric procedures in anesthetized pigs

AIM: Natural orifice transluminal endoscopic surgery (NOTES) is a new reality that is progressively gaining popularity in the scientific community. The aim of this study was to report the authors' experience with various peroral transgastric procedures performed on the porcine model. The technical difficulties and challenges that arose were also analyzed. METHODS: Ten anesthetized pigs, divided into an acute (3) and a survival group (7) underwent the following procedures using a double channel endoscope: peritoneoscopy (10), cholecystectomy (6),splenectomy (3), and gastrojejunostomy (3). \RESULTS: All the procedures were completed successfully. There was one complication related to the gastric wall incision. In the survival experiment group all pigs (4) submitted to biliare procedures made an uncomplicated recovery after a follow-up period of 2 weeks. Gastrojejunostomies (3) were instead graved by one technical failure (anastomosis disruption at post-mortem examination) and one case of mortality (premature euthanasia for evidences of sepsis). Complete gastric cleansing was impossible to achieve and overinflation was a common problem. The creation of gastro-enteric anastomoses was technically difficult with the current available devices.\CONCLUSION: Transgastric endoscopic surgery is technically feasible in a porcine model. A new instrumentation is needed and could strongly help to overcome the technical difficulties highlighted. More extensive animal studies are mandatory in order to evaluate the benefits and the limitations of this new technique.