Portal and Mesenteric Venous Calcication in Patients with Advanced Cirrhosis: Two Case Reports and Literature

The incidence of portal and mesenteric venous calcications in patients with cirrhosis has rarely been reported. It is also very dicult to determine the vascular lesions in preoperative imaging examination. The liver cirrhosis patients associated with portal venous calcication have high postoperative complications and mortality, but poor prognosis. We present the case of two patients (45-year-old male, case 1; 50-year-old male, case 2). Both patients were admitted to the hospital with liver cirrhosis and portal hypertension associated symptoms. The cases and review of published reports suggest that, calcication in the portal vein system is extremely rare, and always occurs in patients with long-standing liver cirrhosis with portal hypertension gastroesophageal varices and splenomegaly. The presence of portal vein calcication on CT may be a sign of portal vein thrombosis, which may result in a dicult transplantation, and poor prognosis. 56U/L, TB 68.8umol/L, DB 43.7umol/L; PT 14.6s, INR 1.26, APTT 25.4s; blood ammonia: 112umol/L (hyperammonemia); Tumor marker: CA19-9 248.78U/L, CA12-5 412.50U/L;


Introduction
The incidence of portal and mesenteric venous calci cations in patients with cirrhosis has rarely been reported. It is also very di cult to determine the vascular lesions in preoperative imaging examination.
The liver cirrhosis patients associated with portal venous calci cation have high postoperative complications and mortality, but poor prognosis. Here, we reported two recent cases with evidence of calci cations in the portal venous system con rmed by computer tomography.
Case Report Case 1 A 45-years-old man was admitted for fever of 3 days duration and was diagnosed with acute cholangitis, biliary cirrhosis. He has congenital cystic dilatation of the intrahepatic bile duct but has not been examined and treated. 30 years ago, he underwent splenectomy and venous devascularization due to upper gastrointestinal bleeding caused by portal hypertension-related liver cirrhosis. In the past 20 years, he had repeated gastrointestinal bleedings and underwent endoscopic varicose ligation combined with embolization for hemostasis. In the past 1 year, the patient has repeatedly had fever with chills, abdominal pain, diarrhea, jaundice, and other symptoms. He denied smoking and alcohol abuse. Physical examination was essentially negative except for body temperature as high as 38.7℃. Lab-examination  Fig. 1A, B), and calci cations in the portal and superior mesenteric were detected (Fig. 1C, D), liver cirrhosis with portal hypertension. His liver function was Child-Pugh A grade and MELD 6 points. Based on comprehensive considerations, the patient met the indications for liver transplantation, and was reviewed and approved by the hospital ethics committee to undergo the allogeneic modi ed piggyback liver transplantation on January 23, 2021. The surgical procedure was complicated and took 25 hours, including 7 hours in the anhepatic phase. The cold ischemia-time of the donor liver was 16.5 hours. After a di cult hepatectomy, the portal vein was found to be calci ed and thrombosed. Attempted at direct intraluminal dissection and thrombectomy failed to reestablished patency. Finally, the portal vein stent was placed, and portal ow was reestablished. Intraoperative blood loss is estimated to be 16000ml, 6500ml autologous blood transfusion, 3600ml suspended red blood cells, and 2400ml fresh frozen plasma. Postoperative ultrasound of the transplanted liver vessels showed that the inner diameter of the portal vein was 1.0cm and the ow rate was 18.0cm/s. With long operation time, excessive bleeding, long cold ischemia time of the donor liver, and poor portal vein condition, the patient died of transplanted liver failure, kidney failure, and heart failure 2 days after surgery.

Case 2
A 50-years-old man was diagnosed as having liver cirrhosis twenty years prior to his present admission.  (Fig. 2A), the presence of calci cations of full-length in the portal vein and superior mesenteric vein (Fig. 2B, C, D). His liver function was Child-Pugh C grade and MELD 24 points, was in end-stage liver disease. Based on comprehensive considerations, the patient met the indications for liver transplantation, and was reviewed and approved by the hospital ethics committee to undergo the allogeneic modi ed piggyback liver transplantation, but the patient and his family refused to be treated by surgery and decided to be discharged.

Discussion
Calci cation in the portal vein system is extremely rare, and always occurs in patients with long-standing liver cirrhosis with portal hypertension gastroesophageal varices and splenomegaly 1 . For revealing portal vein and its tributaries, abdominal enhanced CT could improve the positive rate, and is the most sensitive examination, and showed the location and direction of portal venous calci cation 2, 3 . The distinctive radiographic feature of portal venous calci cation is the presence of radiodensity which correspond to the course of the vein 4 . Minimal calci cation may be frequently neglected on plain lm radiography and pathological examination.
Calcium could be deposited either in thrombus or as in the vessel wall. The mechanical stress may result in sclerosis and calci cation with the thickened and media of the vein. Since 1943, Moberg 5 reported the rst case of portal vein calci cation, less than 50 documented cases have been described in the Englishlanguage literature. The calci ed lesions occurred in the portal vein in 100% of patients, the splenic vein in 62%, the superior mesenteric vein in 33%, and the inferior mesenteric vein in 0 6 . Repeated thrombus formation and recanalization may be the main etiologic factor in the formation of calci cation. The predisposing factors for the deposition of calci ed thrombus in the portal vein well, included visceral infections affected by pancreatitis and cholangitis, history of abdominal surgery, malignant diseases, and hematological abnormalities 7 . It was found by Verma 4 a high operative mortality associated with calci cations in portal venous system in patients during liver transplantation because of preoperatively undiagnosed thrombosis of the portal venous system. And the presence of portal vein calci cation on CT may be a sign of portal vein thrombosis, which may result in a di cult transplantation. The calci cation of portal venous system with associated thrombosis is a signi cant nding and more attention should be devoted to detecting in patients undergoing liver transplantation. Identi cation of patients at high risk may provide information for prospective planning, rational distribution of organs, and a safer operation.

Declarations
The experimental protocol was established, according to the ethical guidelines of the Helsinki Declaration and was approved by the Human Ethics Committee of Beijing Chaoyang Hospital.
The authors do not have any possible con icts of interest.  The contrast-enhanced CT of the abdomen of patient 1. A and B, the enhanced CT of the abdomen suggests multiple dilation of the intrahepatic bile ducts because of Caroli's Disease, and liver cirrhosis and portal hypertension. C and D showed multiple calci cations in the running area of the portal vein and superior mesenteric vein.

Figure 2
The Abdominal vascular CT and magnetic resonance cholangiopancreatography (MRCP) of patient 2. A, the abdominal vascular CT showed liver cirrhosis, ascites, portal hypertension with formation of collateral circulation. B, C and D, the magnetic resonance cholangiopancreatography showed full length of portal vein and superior mesenteric vein calci cation.