Superior Mesenteric-Portal Vein Thrombosis: Animal Experimental Study And Clinical Investigation

Background:SMV-PV thrombosis is an uncommon form of intestinal ischemia.Morbility and mortality rates can be significant because of delay in diagnosis resulting from the unspecific clinical presentation.The traditional treatment of SMV-PV thrombosis include anticoagulation,thrombolysis and surgery.In recent years,endovascular interventional techniques are a promising new alternative for treatment of SMV-PV thrombosis.Objective:â… .To assess the feasibility of establishment of the SMV-PV thrombosis animal model using interventional techniques.â…¡.To investigate the CT and MRI manifestations and dynamic changes of the SMV-PV thrombosis.â…¢.To evaluate the efficacy and safety of the interventional radiological techniques with TIPS approach for management of acute and subacute SMV-PV thrombosis.Materials and methods:Partâ… .Establishment of animal models of SMV-PV thrombosis.Nine miniature pigs were treated with percutaneous transhepatic portal venous approach.After access to the PV,a balloon catheter was put in the main trunk of PV to block the portal flow and then the autologous thrombosis was injected into the SMV.Venography was performed to confirm the extent of the thrombosis at 30 minutes after blocked the PV by the balloon.Partâ…¡.Imaging investigation of the animal models.CT and MRI scan were performed at once,12 hours,24 hours,72 hours,7 days,and 14 days after the establishment of the SMV-PV thrombosis.The study was focused on the imaging manifestations and dynamic changes of the thrombosis.Partâ…¢.Clinical evaluation.Twelve patients with thrombosis of the SMV and PV were treated by the interventional procedure,using transjugular intrahepatic portosystemic shunt(TIPS)approach.The patients consisted of 8 men and 4 women with age range of 28-68 years.All patients present with abdominal pain,distention,and diarrhea, associated with a small amount of ascites in 5 cases.Results:Partâ… .The result of the animal model of SMV-PV thrombosis.The technical success was achieved in 6 of 9 animals.Three pigs were died in 3 hours after SMV-PV thrombosis established.The remain six pigs were successfully formed SMV-PV thrombosis model,and were feed 14 days.Partâ…¡.Imaging investigation of the animal SMV-PV thrombosis.Because of the residual iodine contrast in the thrombosis,the acute SMV-PV thrombosis was highdensity on the CT scan.On MRI,the acute PVT demonstrated hypointensity on T1WI and hyperintensity on T2WI.At 72 hours after the model establishment,the PVT was highdensity on CT scan,however MRI was not useful to evaluate the changes of the PVT due to the artifacts from intestinal gas and respiratory motion.At 7～14 days after the model establishment,the subacute PVT was low-density on the CT scan.On MRI,the subacute PVT demonstrated hypointensity on both T1WI and T2WI.On the enhanced CT scan,the subacute PVT recanalized but had no enhancement.Partâ…¢.With TIPS approach,the technical success was achieved in 11 of 12 cases. No complications related to the procedure occurred.The majority of the thrombosis in PV and SMV was cleared with flow restoration in the 11 patients on the completion angiograms.One patient died of intra-abdominal sepsis and multiple organs failure.10 patients who stayed in hospital for 3 weeks to 2 months have no relapse.Conclusion:â… .The establishment of SMV-PV thrombosis by interventional techno-logy was successful and effective.â…¡.The imaging of the SMV-PV thrombosis is regularly.On MRI,the acute SMV-PV thrombosis was demonstrated hypointensity on T1WI and hyperintensity on T2WI due to the Fe²⁺of the deoxyhemoglobin.The subacute PVT was hyperintense on both T1WI and T2WI due to the Fe³⁺of the metaemoglobin.On the enhanceed CT scan the low-density subacute PVT was recanalized,but the PVT had no enhacement.â…¢.The TIPS interventional technology is effective in the treatment of acute and subacute SMV-PV thrombosis.