Debugging Data Transfers in CMS

The CMS experiment at CERN is preparing for LHC data taking in severalcomputing preparation activities. In early 2007 a traffic load generator infrastructure for distributed data transfer tests was designed and deployed to equip the WLCG tiers which support the CMS virtual organization with a means for debugging, load-testing and commissioning data transfer routes among CMS computing centres. The LoadTest is based upon PhEDEx as a reliable, scalable data set replication system. The Debugging Data Transfers (DDT) task force was created to coordinate the debugging of the data transfer links. The task force aimed to commission most crucial transfer routes among CMS tiers by designing and enforcing a clear procedure to debug problematic links. Such procedure aimed to move a link from a debugging phase in a separate and independent environment to a production environment when a set of agreed conditions are achieved for that link. The goal was to deliver one by one working transfer routes to the CMS data operations team. The preparation, activities and experience of the DDT task force within the CMS experiment are discussed. Common technical problems and challenges encountered during the lifetime of the taskforce in debugging data transfer links in CMS are explained and summarized

Preoperative selective portal vein embolization (PSPVE) before major hepatic resection. Effectiveness of Doppler estimation of hepatic blood flow to predict the hypertrophy rate of non-embolized liver segments.

Hepatocellular carcinoma may be unresectable for volumetric reasons. The future remaining liver after hepatectomy might be too small to ensure survival. Preoperative selective portal vein embolization of the tumorous lobe can induce hypertrophy of the future remaining liver and enable safer surgery. A 76-year-old patient with hepatocellular carcinoma needed right lobectomy however, the future remaining liver was judged insufficient to ensure an uneventful postoperative course. The left lobe to whole liver volumetric ratio was to small (29.7%) and a preoperative selective portal vein embolization of the right portal branch via a percutaneous, transhepatic, contralateral approach was performed without side effects. A Doppler estimation of left branch portal blood flow and velocity was carried out before and after preoperative selective portal vein embolization. After 21 days the left lobe volume increased by about 44.2% with a safe left lobe/whole liver ratio of 40.8%. The portal blood flow and portal blood flow velocity showed an increase of 253% and 122%, respectively. A right lobectomy was performed without complications. Three months later, computed tomography scan showed no hepatocellular carcinoma recurrence. Preoperative selective portal vein embolization is a safe technique which can enable major hepatectomy to be performed in situations otherwise judged unresectable for a life-threatening volumetric insufficiency. The portal blood flow and portal blood flow velocity evaluations can easily predict the hypertrophy rate of non-embolized liver segment

CAVOPORTAL HEMITRANSPOSITION : A SUCCESSFULL WAY TO OVERCOME THE PROBLEM OF TOTAL PORTOMESENTERIC THROMBOSIS IN LIVER TRANSPLANTATION

Orthotopic liver transplantation (OLT) may be feasible even in the presence of diffuse portal vein thrombosis (PVT) in the recipient, providing hepatopetal portal flow to the graft can be ensured. Cavoportal hemitransposition was used in selected cases in which no other salvage solutions were technically possible. We report our experience of two patients with diffuse thrombosis of the entire portal system. One patient also had thrombosis of a previous portacaval shunt with a synthetic interposition graft. Portal pedicle dissection and native hepatectomy (with or without vena cava removal) appeared difficult. Bleeding from the exposed area was severe, and in one case, a new laparotomy was necessary to stop the abdominal hemorrhage. The postoperative course was complicated by severe ascites (with fluid infection and surgically drained suprahepatic abscess in one case), renal insufficiency (requiring dialysis in one case), esophagogastric variceal bleeding (needing several sessions of endoscopic treatment), and bronchopneumonic infections (in one case, superinfection with Aspergillus fumigatus despite amphotericin B lipid complex therapy led to the patient's death from multiorgan failure). Our experience was compared with 17 other cases in the literature. Etiologic factors, preoperative diagnostics, surgical problems, and postoperative complications are focused on and discussed. Diffuse PVT no longer appears to be an absolute contraindication to OLT, although cavoportal hemitransposition needs further experience and long-term follow-up