BACKGROUND: Portal vein thrombosis (PVT) used to be a contraindication for liver transplantation (LT). This obstacle has been delt with following the improvement of LT-related techniques and therapeutic approaches to ...BACKGROUND: Portal vein thrombosis (PVT) used to be a contraindication for liver transplantation (LT). This obstacle has been delt with following the improvement of LT-related techniques and therapeutic approaches to thrombosis. But the effect of PVT on LT outcomes is still controversial. We reviewed retrospectively the outcome of LT patients with PVT as well as risk factors and surgical management according to PVT grades. METHODS: A total of 465 adult LTs were performed from December 2002 through December 2006. Operative findings and the result of preoperative ultrasonography and imaging were reviewed for PVT grading (Yerdel grading). Comparison of risk factors, variables associated with perioperative period and prognosis between recipients with and without PVT is based on the grades. RESULTS: In the 465 LTs, 42 were operatively confirmed to have PVT (9.0%) (19 recipients with grade I, 14 with grade 2, 7 with grade 3, and 2 with grade 4). Increased age and treatment of portal hypertension were associated with PVT. Grade 1 or 2 PVT was treated by direct anastomosis or single thrombectomy. In grade 3 PVT patients, the donor PV was directly anastomosed to the dilated branch of the recipient portal venous system or to the distal open superior mesenteric vein through an interposition vein graft if needed. Grade 4 PVT was managed by our modified cavoportal hemitransposition technique. The comparison between PVT patients and controls showed no significant difference in operative duration and blood transfusion (P > 0.05). The flow rate of the PV was lower in the PVT patients (48.881 +/- 12.788 cm/s) than in the controls (57.172 +/- 21.715 cm/s, P < 0.05). The PVT patients had such postoperative complications as renal failure and PV rethrombosis (P < 0.05). The 1-year survival rates in PVT and non-PVT patients were 78.6% and 76.4% respectively (P > 0.05); the 3-year survival rates were 58.8% and 56.4% respectively (P > 0.05). CONCLUSIONS: PVT is not contraindicated for LT if it is graded. PVT recipients may have post-transplantation complications like renal failure and PV rethrombosis, and operative difficulty and patient survival are similar to those in recipients without PVT. Development of therapeutic approaches and accumulation of experience in dealing with PVT further improve the outcomes of LT in PVT recipients.展开更多
This paper presents a method for solving Lagrangian version of governing equations that allows boundary conditions at the free surface to be satisfied exactly, which is a three-dimensional generalization of a method f...This paper presents a method for solving Lagrangian version of governing equations that allows boundary conditions at the free surface to be satisfied exactly, which is a three-dimensional generalization of a method first put forward by Stoker. Analytical expressions of nonlinear hydrodynamic pressure up to the third order and of free surface displacement up to the fourth order of an accelerating cylindrical tank were obtained. Here only the motions of objects in their early stage after initial impulses was considered. As a justification of the method, the important special case when the ratio of tank diameter to fluid depth tends to infinity was taken as an example, which shows that the linear hydrodynamic pressure obtained agrees completely with Westergaard or von Karman's classical result.展开更多
文摘BACKGROUND: Portal vein thrombosis (PVT) used to be a contraindication for liver transplantation (LT). This obstacle has been delt with following the improvement of LT-related techniques and therapeutic approaches to thrombosis. But the effect of PVT on LT outcomes is still controversial. We reviewed retrospectively the outcome of LT patients with PVT as well as risk factors and surgical management according to PVT grades. METHODS: A total of 465 adult LTs were performed from December 2002 through December 2006. Operative findings and the result of preoperative ultrasonography and imaging were reviewed for PVT grading (Yerdel grading). Comparison of risk factors, variables associated with perioperative period and prognosis between recipients with and without PVT is based on the grades. RESULTS: In the 465 LTs, 42 were operatively confirmed to have PVT (9.0%) (19 recipients with grade I, 14 with grade 2, 7 with grade 3, and 2 with grade 4). Increased age and treatment of portal hypertension were associated with PVT. Grade 1 or 2 PVT was treated by direct anastomosis or single thrombectomy. In grade 3 PVT patients, the donor PV was directly anastomosed to the dilated branch of the recipient portal venous system or to the distal open superior mesenteric vein through an interposition vein graft if needed. Grade 4 PVT was managed by our modified cavoportal hemitransposition technique. The comparison between PVT patients and controls showed no significant difference in operative duration and blood transfusion (P > 0.05). The flow rate of the PV was lower in the PVT patients (48.881 +/- 12.788 cm/s) than in the controls (57.172 +/- 21.715 cm/s, P < 0.05). The PVT patients had such postoperative complications as renal failure and PV rethrombosis (P < 0.05). The 1-year survival rates in PVT and non-PVT patients were 78.6% and 76.4% respectively (P > 0.05); the 3-year survival rates were 58.8% and 56.4% respectively (P > 0.05). CONCLUSIONS: PVT is not contraindicated for LT if it is graded. PVT recipients may have post-transplantation complications like renal failure and PV rethrombosis, and operative difficulty and patient survival are similar to those in recipients without PVT. Development of therapeutic approaches and accumulation of experience in dealing with PVT further improve the outcomes of LT in PVT recipients.
文摘This paper presents a method for solving Lagrangian version of governing equations that allows boundary conditions at the free surface to be satisfied exactly, which is a three-dimensional generalization of a method first put forward by Stoker. Analytical expressions of nonlinear hydrodynamic pressure up to the third order and of free surface displacement up to the fourth order of an accelerating cylindrical tank were obtained. Here only the motions of objects in their early stage after initial impulses was considered. As a justification of the method, the important special case when the ratio of tank diameter to fluid depth tends to infinity was taken as an example, which shows that the linear hydrodynamic pressure obtained agrees completely with Westergaard or von Karman's classical result.
