Splanchnic Vein Thrombosis Due To Severe Acute Pancreatitis:A Single-center Experience

Splanchnic vein thrombosis is a well-recognized complication of severe acute pancreatitis.The incidence of splanchnic vein thrombosis varies from 1%to 24%in different studies depending on the study population and also on the imaging technique used.In recent studies,the occurrence was found to be related to pancreatic necrosis.Splanchnic vein thrombosis involves the portal vein,splenic vein,and superior mesenteric vein,either in combination or separately.Symptoms depend on the locations of thrombus.including life-threating complications such as variceal bleeding,intestinal ischemic and liver failure.The literature on this important complication is very sparse and how to prevent and treat this complication remains unclear.Our study concerned the following aspects:diagnosis,clinical metrics,prevention and treatment.Firstly,computed tomographic venography and digital subtraction angiography were compared to clarify the most effective examination for splanchnic vein thrombosis detection.Secondly,clinical data was retrospectively collected to explore clinical characteristics and potential risk factors for the development of splanchnic vein thrombosis in this setting.Thirdly,a prospective cohort study was performed in high-risk thrombus severe acute pancreatitis patients to discuss the effective and safety of antithrombotic drugs in prevention of thrombus.Finally,we retrospectively analyzed the effectiveness of systematic or regional anticoagulation in the prevention of thrombus.This essay was divided into five parts:PART 1:Splanchnic vein thrombosis secondary to severe acute pancreatitis:Detection by computed tomographic venographyObjective:To assess the diagnostic accuracy of CT venography for splanchnic vein thrombosis detection in severe acute pancreatitis patients.Methods:We reviewed data from patients diagnosed with severe acute pancreatitis in our center from 2011 to 2013.Those who underwent both CT venography and DSA within 3 days were included in this study.The sensitivity and specificity and positive and negative predictive values of CT venography were analyzed according to the golden standard DSA diagnostic criteria.Results:According to the DSA results,17(39.5%)of the total 43 patients included had splanchnic vein thrombosis.The sensitivity,specificity,positive and negative predictive values of CTV for SVT detection were 100%(95%CI:77.1%-100%),92.3%(95%CI:73.4%-98.7%),89.5%(95%CI:65.5%-98.2%)and 100%(95%CI:82.8%-100%),respectively.Conclusions:CTV is an effective examination for splanchnic vein thrombosis detection in severe acute pancreatitis patients with high positive and negative predictive values.PART 2:Clinical characteristics,risk factors and follow-up of splanchnic vein thrombosis due to severe acute pancreatitisObjective:The aim of the study was to explore clinical characteristics,potential risk factors and nature history of splanchnic vein thrombosis due to severe acute pancreatitis.Methods:Data of severe acute pancreatitis patients admitted in our center among January,2012 to Augest,2014 were reviewed.The presence and location of splanchnic vein thrombosis or narrowing were detected by CT venography.Results:The incidence of splanchnic vein thrombosis was 16.5%in the setting of severe acute pancreatitis,while the incidence of splanchnic vein narrowing was 15.2%.97.1%splanchnic vein thrombosis patients had pancreatic necrosis.Either splanchnic vein thrombosis or narrowing,the splenic vein was most commonly involved.The incidence of splenomegaly,varication,ascites and enteral nutrition intolerance in thrombosis patients was significantly higher than that in splanchnic vein narrowing patients.The result of risk factors analysis showed only CT score was the risk factor of development of splanchnic vein thrombosis.The mortality of patients with splanchnic vein thrombosis and narrowing was 16.3%and 10.3%,respectively.During the 6 months follow-up,71.8%thrombus vessels resulted in recanalization,2 splanchnic vein thrombosis patients occurred gastrointestinal hemorrhage,3 narrowing patients developed splanchnic vein thrombosis due to persistent effect from walled-off necrosis or infected pancreatic or peripancreatic necrosis.Conclusions:The incidence of splanchnic vein thrombosis is 16.5%in the setting of severe acute pancreatitis and those with pancreatic necrosis has higher incidence.Splenic vein is the most commonly involved vessel.The development of splanchnic vein thrombosis is associated with local effect rather than systemic inflammation or coagulation.In 6 months,the recanalization rate of thrombus vessels is relatively high with a low gastrointestinal hemorrhage rate.PART 3:Prevent splanchnic vein thrombosis due to severe acute pancreatitis by antithrombotic drugsObjective:The aim of this study was to evaluate the efficacy and safety of antithrombotic therapy for preventing the development of splanchnic vein thrombosis in high-risk splanchnic vein thrombus acute pancreatitis patients.Methods:Severe acute pancreatitis patients admitted to our department from Sep 2014 to Jan 2015,those with pancreatic necrosis and without splanchnic vein thrombosis assessed by initial CT venography were considered eligible for the study and then randomly allocated to the intervention group or the control group.Study group received LMWH 4100/day during hospitalization following aspirin 100mg/d for 3months after discharge.The presence and location of splanchnic vein thrombosis was screened by CT venography.Results:A total of 39 patients with severe acute pancreatitis were involved in this study,of which 18 patients received antithrombotic therapy.All these patients finished follow-up without significant bleeding complication.Study group patients did not results in significantly lower rates of splanchnic vein thrombosis(1/18 vs.2/21 p = 0.64)and infected pancreatic or peripancreatic necrosis as well as hospital and ICU stay.Conclusions:Antithrombotic therapy in this study did not decrease the rate of splanchnic vein thrombosis,but it was safe in preventing splanchnic vein thrombosis in severe acute pancreatitis patients.PART 4:Splanchnic vein thrombosis secondary to severe acute pancreatitis treated with regional anticoagulation via transjugular intrahepatic portosystem stent-shuntObjective:To evaluate the efficacy and safety of regional anticoagulation via transjugular intrahepatic portosystem stent-shunt for treating splanchnic vein thrombus acute pancreatitis patients.Methods:Severe acute pancreatitis patients admitted in our center among January,2013 to December,2014,those with splanchnic vein thrombosis treated by with regional anticoagulation via transjugular intrahepatic portosystem stent-shunt were included in this study.Their clinical characteristics and outcomes were reviewed for efficacy and safety assess.Results:5 severe acute pancreatitis patients with splanchnic vein thrombosis were involved in this study,of which all 5 patients had superior mesenteric vein thrombosis,4 patients was diagnosed with critical acute pancreatitis with persistent ascites and enteral nutrition intolerance.And their CT scores were all above 8 points.All 5 patients'thombus vessels resulted in recanalization,persistent ascites and enteral nutrition intolerance were solved after the regional therapy.One patient was complicated with intrahepatic hematoma.The other one patient died from septic shock and multiple organ dysfunction.Conclusions:Regional anticoagulation via transjugular intrahepatic portosystem stent-shunt is an effective therapy for severe acute pancreatitis patients with splanchnic vein thrombosis.However,its safety need further discussion.PART 5:The effects of anticoagulation in severe acute pancreatitis patients with splanchnic vein thrombosisObjective:Treatment recommendations for splanchnic vein thrombosis due to severe acute pancreatitis remained controversial.In this study we aim to evaluate the effects of anticoagulation in this setting.Methods:The 104 splanchnic vein thrombus acute pancreatitis patients collected from January,2012 to December,2014 were allocated to anticoagulation group or non-anticoagulation group according to whether they received anticoagulants or not.The rate of recanalization,hemorrhage complications,severity during the disease course and outcomes were analyzed.Results:38 of the 104 patients received anticoagulation therapy.17 patients died in the duration of ICU.Therefore,33 patients(54 thrombus vessels)in the AC group and 54 patients(56 thrombus vessels)in the non-AC group were undergo indexed CECT scan during systematically visit.Early anticoagulation resulted in recanalization in 46 of 54 vessels(85.2%)while the recanalization rate in non-AC group is only 33/56(58.9%)at the end of follow up(p=0.005).Additionally,the rates of varices or collaterals,hemorrhage complications and mortality did not differ significantly between two groups.Conclusions:Anticoagulation therapy is safe and effective in treating splanchnic vein thrombosis due to severe acute pancreatitis.It can increase the rate of recanalization without increasing the hemorrhage rate.