Anticoagulation Prevents Portal Vein Thrombosis And Hepatic Decompensation In Cirrhotic Patients Awaiting Liver Transplantation

Background Portal vein thrombosis(PVT)is a relatively common event occurring in cirrhotic patients who are waiting for liver transplantation(LT)and is no longer considered as an absolute contraindication for LT.There are more PVT cases accidentally diagnosed during LT operation.In addition,PVT in cirrhosis has a negative effect on the outcome of the transplantation,especially on early post-LT mortality.Anticoagulation is a major noninvasive treatment strategy for the patients with PVT awaiting LT and it improve the survival after LT.This case report highlights the safety and efficacy of anticoagulation therapy for PVT in candidate for LT.We also review recent literatures about the anticoagulation therapy of PVT in cirrhotic patients in order to explore any possible practical guidelines for the clinical treatment.Case report On Oct.2014,A 51 year old gentleman complaining of abdominal distention for two weeks with a history of hematemesis,hematochezia and one time blood transfusion since 4 years ago.On Dec 22,2014,he was admitted to our hospital and no history of hepatitis or exposure to infected areas.There was no family history and smoking or alcohol history.No surgical history was reported.The patient denied any allergies.On examination he was conscious,oriented with normal vital signs.There were spider nevi and palmarerythema sings with no jaundice was noted in the eyes or on the skin.There were splenomegaly about three fingers in the left subcostal margin and positive abdominal shifting dullness and no evidence of encephalopathy.The lungs were clear to auscultation.No murmurs or additional heart sounds were noted.No edema was noted in the extremities and the pulses were present.Laboratory test results were as follows: hemoglobin 123g/L(130-175),Hct 35.50 %(40-50),white blood cell3.1×109/L(3.5-9.5);platelets 69×109/L(125-350);prothrombin time 13.80s(8.8-13.8);international normalized ratio 1.21(0.80-1.2);activated partial thromboplastin time 33.2s(26-42);aspartate aminotransferase 21.4U/L(15-40);alanine aminotransferase 24.2U/L(9-50);alkaline phosphatase 91.1U/L(45-125);?-glutamyltransferase 43.5U/L(10-60);bilirubin 15.69 ?mol/L(0-17.1);albumin 42.7g/L(40-55);BUN 5.53mmol/L(2.9-8.2);urea 552.4 ?mol/L(208-428);creatinine 96.1 ?mol/L(44-115);potassium 3.92mmol/L(3.5-5.3);sodium 142.9 mmol/L(137-147);glucose 5.62mmol/L(3.9-6.1)and alphafetaprotein 3.13ng/ml(0-20).HBs Ag,anti-HBs,and anti-HCV were negative.Endoscopy showed severe esophageal varices.Abdominal computed tomography(CT)showed a partially obstructive thrombus of the portal vein trunk and the splenoportal confluence(Fig.1).On Jan 1,2015,subcutaneous injection of enoxaparin(1 mg/kg,twice daily)was started.After 1 month,the PVT almost disappeared by CT images(Fig.2).On May 19,2015,the patient presented with epigastric pain.Doppler ultrasound revealed the presence of common bile duct calculus.After performing endoscopy,there was no evidence of variceal bleeding.Endoscopic retrograde cholangiopancreatography(ERCP)was done after discontinuation of anticoagulation treatment.On May 29,2015,Doppler ultrasound demonstrated the presence of PVT.On Jun 5,2015,anticoagulation treatment with enoxaparin started again(Fig.3).CT images on Jun 17,2015 displayed that PVT was significantly decreased(Fig.4).Furosemide and albumin were given in order to control ascites,however the patient condition deteriorated as he had fatigue and the ascites increased.In addition,the albumin decreased and the liver function with coagulation parameters got worse.So liver transplantation was indicated.On July 23,2015,orthotropic liver transplantation(OLT)was performed.During the operation,we follow our center routine to perform simplethrombectomy as the following: We fully liberate the porta hepatis,divide the hepatic artery to the origin of the common hepatic artery then we ligate and disconnect the common bile duct and hepatic artery.After that we fully expose the portal vein to the superior border of the splenic vein,and ligate to embolize the gastric coronary vein to avoid laceration of the portal vein during the process of removing the thrombus.The main portal vein trunk was clamped then the left and right portal vein branches are tied.The operator uses his left index finger and thumb to block blood flow in the portal vein on the superior border of pancreas.Consequently we incise the anterior wall of the portal vein for 0.5 cm below the level of the ligature.After dissecting the intima of the portal vein,we strip and disconnect the wall of portal vein circularly along the thrombus.After that,the operator pulls the trunk of the portal vein with his left hand,everting the portal vein wall,slowly separating it from the PVT with his right hand using a right angle forceps,until we have exposed the conjoint section between the splenic and superior mesenteric vein thrombi;we keep on separating it until the PVT is removed completely.After the PVT is removed and blood flow in the portal vein has recovered,we then observe its volume and it was satisfactory,30 m L of heparin solution is infused and an end to end anastomosis was performed quickly between the donor and recipient portal veins.Before completing the anastomosis,blood flow in the recipient portal vein is confirmed by removing the clamp.The portal vein is washed out with blood to remove remaining or newly formed clots.The explant showed a patent portal vein.During the operation,palpation of the portal vein showed that PVT was soft and the liver is shrunken with macronodular cirrhoisis.2000 ml of Fresh frozen plasma(FFP)and 10 unites of RBC were given.The blood loss was 1000 m L and ascetic fluid volume was 6000 ml,the operation lasted 6 hours(Fig.7,8).Post-OLT course passed routinely without any vascular complications.Depending on one week coagulation parameters monitoring results,subcutaneous injection of enoxaparin 8000 U q12hrs was prescribed.Two weeks later,liver function returned to normal and postoperative blood flow of the transplanted liver was smooth,and there was no portal vein thrombosis as shown by ultrasound(Fig 5,6)and aspirin was added after three months.Conclusion In conclusion,cirrhotic patients with PVT on the waiting list for LT should be treated with anticoagulation therapy.Careful use of anticoagulation is safe and effective in patients with PVT.Early initiation of anticoagulation therapy might be associated with a high rate of portal vein recanalization after anticoagulation.Long-term use of anticoagulation therapy might prevent recurrence of thrombosis.However,at present still there is no a consensus about anticoagulation therapy,initiation of medicine taking,duration of treatment and monitoring to patients.So,further randomized clinical trials needed in order to verify the reasonable use of anticoagulation therapy and to harmonize the adverse events in accordance with the desired efficacy of anticoagulation therapy in these patients group.