Epidemiology and Risk Factors of Portal Venous System Thrombosis in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BackgroundPatients with inflammatory bowel disease (IBD) may be at risk of developing portal venous system thrombosis (PVST) with worse outcomes. This study aims to explore the prevalence, incidence, and risk factors of PVST among patients with IBD.MethodsPubMed, Embase, and Cochrane Library databases were searched. All the eligible studies were divided according to the history of colorectal surgery. Only the prevalence of PVST in patients with IBD was pooled if the history of colorectal surgery was unclear. The incidence of PVST in patients with IBD after colorectal surgery was pooled if the history of colorectal surgery was clear. Prevalence, incidence, and risk factors of PVST were pooled by only a random-effects model. Subgroup analyses were performed in patients undergoing imaging examinations. Odds ratios (ORs) with 95% CIs were calculated.ResultsA total of 36 studies with 143,659 patients with IBD were included. Among the studies where the history of colorectal surgery was unclear, the prevalence of PVST was 0.99, 1.45, and 0.40% in ulcerative colitis (UC), Crohn's disease (CD), and unclassified IBD, respectively. Among the studies where all the patients underwent colorectal surgery, the incidence of PVST was 6.95, 2.55, and 3.95% in UC, CD, and unclassified IBD after colorectal surgery, respectively. Both the prevalence and incidence of PVST became higher in patients with IBD undergoing imaging examinations. Preoperative corticosteroids therapy (OR = 3.112, 95% CI: 1.017–9.525; p = 0.047) and urgent surgery (OR = 1.799, 95% CI: 1.079–2.998; p = 0.024) are significant risk factors of PVST in patients with IBD after colorectal surgery. The mortality of patients with IBD with PVST after colorectal surgery was 4.31% (34/789).ConclusionPVST is not rare, but potentially lethal in patients with IBD after colorectal surgery. More severe IBD, indicated by preoperative corticosteroids and urgent surgery, is associated with a higher risk of PVST after colorectal surgery. Therefore, screening for PVST by imaging examinations and antithrombotic prophylaxis in high-risk patients should be actively considered.Systematic Review RegistrationRegistered on PROSPERO, Identifier: CRD42020159579.

Features of morphometric parameters of vessels in the human portal venous system identified by multislice computed tomography

The aim of this study was to identify the morphometric features of the human portal venous system by means of multislice computed tomography (MSCT).Materials and methods. A contrast X-ray study of the portal vein was carried out in 53 men who were treated in the surgical departments of the Krasnoyarsk Regional Hospital No. 1. The average age of the patients was 54.9 ± 1.7 years (36–71 years). Measurements were performed on 3D models of the vascular bed in the portal venous system (GE Advantage Workstation and Siemens singo.via workstations). Branching patterns, length, diameter, angle of the portal vein formation relative to the midline of the human body, and angles of formation of the vessels forming the portal vein in the frontal plane were evaluated.Results. Variations in the morphometric parameters of the intrahepatic vessels of the portal vein are obvious, although the branching patterns are not diverse and are reduced to one type – the magistral pattern (according to V.N. Shevkunenko). The veins that form the portal vein are represented by three systems, each of which has a stem and tributaries that differ in branching patterns and other morphological characteristics.Conclusion. The findings of the study made it possible to supplement the scientific materials regarding branching patterns and morphological characteristics of the portal vein and its tributaries as well as to use the morphometric characteristics of the superior and inferior mesenteric and splenic veins to resolve the issues of surgical intervention on the abdominal organs.

Rebalanced hemostasis in liver disease: a misunderstood coagulopathy

The combination of frequently abnormal hemostatic markers and catastrophic bleeding as seen with variceal hemorrhage has contributed to the longstanding misperception that chronic liver disease (CLD) constitutes a bleeding diathesis. Laboratory studies of hemostasis in liver disease consistently challenge this with global coagulation assays incorporating activation of the protein C pathway demonstrating rebalanced hemostasis. It is now recognized that bleeding in CLD is predominantly secondary to portal hypertension (rather than a coagulopathy) and additionally that these patients are at increased risk of venous thrombosis, particularly in the portal venous system. This narrative review describes the current understanding of hemostasis in liver disease, as well as the periprocedural management of hemostasis and anticoagulation for management of venous thromboembolism in patients with CLD.

Portal Vein Thrombosis: Diagnosis and Endovascular Management

Background Portal vein thrombosis (PVT) is a rare but severe entity that can cause clinically significant sequela such as worsening portal hypertension or mesenteric ischemia. Those cases refractory to medical management may be referred for endovascular intervention. Several technical considerations have been described in the literature, but a cohesive comparison of these multiple techniques is lacking. Methods The purpose of this article is to review the diagnosis and endovascular management of PVT, including areas in which further research is warranted. Results Cases of PVT can be readily diagnosed using ultrasound, computed tomography, or magnetic resonance imaging. Treatment often begins with systemic anticoagulation and endovascular interventions may be used in selected cases. Determining the optimal approach to accessing the portal venous system depends on the underlying disease and chronicity of the thrombus and the degree of occlusion. Once access to the portal venous system is established, catheter-directed therapy may be performed to achieve recanalization. Conclusion Despite the heterogeneity in patient presentation, cases of PVT can be readily diagnosed across several imaging modalities. Strategizing interventional approaches involves evaluation of the underlying disease and the chronicity of the thrombus. Key Points: Citation Format

Imaging of Portal Gastroduodenopathy

Portal hypertension is characterized by elevated pressure in portal venous system due to portal resistance due to various causes. The etiologies are either pre-hepatic, hepatic, or post-hepatic. Elevated portal pressure results in varices at various sites some of which are difficult to identify on endoscopy alone. Other manifestations of elevated portal pressure include portal gastropathy, enteropathy, colopathy, gastric antral vascular ectasia, and ascites. Imaging plays an essential role in diagnosis and imaging of various manifestations of portal hypertension by determining the locations of varices and plan the management for same. Endoscopy helps in visualizing mucosal varices but newer imaging modalities give a panoramic extent of the disease in the entire gastrointestinal tract with great specificity and sensitivity. Initially, Barium study was used to determine esophageal or gastric varices, computed tomography provides detailed anatomic information which can be used to plan management. Due to advancement in imaging and interventional techniques, treatment for varices has seen advent of multiple minimally invasive interventional radiological techniques. A brief outlook on anatomical aspect of varices and various recent advances in management of the same has been provided. Overall knowledge of the various imaging manifestations of portal hypertension can be helpful to evaluate prognosis and plan proper management.

Percutaneous transhepatic treatment of a unique portal vein malformation with portal hypertension in a pediatric patient

Background Anomalies of the portal venous system can be congenital or acquired, the latter being related to spontaneous thrombosis or iatrogenic alterations such as complications of perinatal catheterization of the umbilical vein. These conditions can be clinically silent for years and then manifest abruptly causing severe clinical emergencies. Case presentation This case report describes the diagnosis and interventional management of a singular abnormality in the portal venous system of an 8-year-old female that led to severe portal hypertension and acute variceal bleeding. Peculiar imaging findings were not pathognomonic for any of the known congenital and acquired portal vein anomalies: absence of a normal extrahepatic portal vein; splenic and mesenteric veins merging into a dilated left gastric vein; presence of an aberrant mesenteric venous collateral with a stenotic connection with the intrahepatic right portal branch; and absence of porto-systemic shunt. The case was successfully managed with percutaneous transhepatic portography and angioplasty. Conclusions Prompt non-invasive imaging characterization allowed to understand the singular vascular abnormality and mini-invasive interventional radiology management resolved portal hypertension and variceal bleeding.

Association of thromboelastography profile with severity of liver cirrhosis and portal venous system thrombosis

Background and aim Hemostasis profile is often complicated in liver cirrhosis. Thromboelastography is a global viscoelastic test recommended by the current practice guideline and consensus. This cross-sectional study aimed to evaluate the association of thromboelastography profile with severity of liver cirrhosis and presence of portal venous system thrombosis (PVST). Methods Overall, 116 and 50 cirrhotic patients were included in the Shenyang and Xi’an cohorts, respectively. Thromboelastography parameters were compared between cirrhotic patients with Child–Pugh class A and B/C, those with and without decompensated events, and those with and without PVST. Hypercoagulability would be considered if at least two of the following thromboelastography parameters were met: shortened reactive time (R), shortened coagulation time (K), increased angle, and increased maximum amplitude (MA). Results In the Shenyang cohort, 16 patients had shortened R, of whom seven (43.75%) had prolonged K and 11 (68.75%) decreased MA. In the Xi’an cohort, 24 patients had shortened R, of whom seven (29.17%) had prolonged K and 15 (62.50%) decreased MA. In the Shenyang cohort, the prevalence of hypercoagulability was not significantly different between cirrhotic patients with Child–Pugh class A and B/C (3.85% vs. 6.25%, P = 0.873), those with and without decompensated events (5.49% vs. 4.00%, P = 1.000), and those with and without PVST (4.17% vs. 5.88%, P = 1.000), which were similar to the results obtained in the Xi’an cohort. Conclusion There is a high rate of discordance between R and other thromboelastography parameters. In addition, hypercoagulability may not be related to more advanced stage of liver cirrhosis or presence of PVST.

Influences of Anatomorphological Features of the Portal Venous System on Postsplenectomy Hemodynamic Characteristics in Patients With Portal Hypertension: A Computational Model-Based Study

Splenectomy, as an effective surgery for relieving complications caused by portal hypertension, is often accompanied by a significantly increased incidence of postoperative thrombosis in the portal venous system (PVS). While the underlying mechanisms remain insufficiently understood, the marked changes in hemodynamic conditions in the PVS following splenectomy have been suggested to be a potential contributing factor. The aim of this study was to investigate the influences of the anatomorphological features of the PVS on hemodynamic characteristics before and after splenectomy, with emphasis on identifying the specific anatomorphological features that make postoperative hemodynamic conditions more clot-promoting. For this purpose, idealized computational hemodynamics models of the PVS were constructed based on general anatomical structures and population-averaged geometrical parameters of the PVS. In the models, we incorporated various anatomorphological variations to represent inter-patient variability. The analyses of hemodynamic data were focused on the spatial distribution of wall shear stress (WSS) and the area ratio of wall regions exposed to low WSS (ALS). Obtained results showed that preoperative hemodynamic conditions were comparable among different models in terms of space-averaged WSS and ALS (all were small) irrespective of the considerable differences in spatial distribution of WSS, whereas, the inter-model differences in ALS were significantly augmented after splenectomy, with the value of ALS reaching up to over 30% in some models, while being smaller than 15% in some other models. Postoperative ALS was mainly determined by the anatomical structure of the PVS, followed by some morphogeometrical parameters, such as the diameter and curvature of the splenic vein, and the distance between the inferior mesenteric vein and splenoportal junction. Relatively, the angles between tributary veins and trunk veins only had mild influences on ALS. In addition, a marked increase in blood viscosity was predicted after splenectomy, especially in regions with low WSS, which may play an additive role to low WSS in initiating thrombosis. These findings suggest that the anatomical structure and some morphogeometrical features of the PVS are important determinants of hemodynamic conditions following splenectomy, which may provide useful clues to assessing the risk of postsplenectomy thrombosis based on medical imaging data.