Low-Molecular-Weight Heparin in the Initial Treatment of Proximal Deep Vein Thrombosis

Intravenous unfractionated heparin followed by oral warfarin is the current standard of care for the treatment of acute venous thrombosis. More recently, several low-molecular-weight heparin preparations have been shown to be as effective and safe as unfractionated heparin for the initial therapy of acute proximal vein thrombosis. These drugs have a number of advantages over unfractionated heparin, and will undoubtedly replace the current standard for the initial treatment of venous thromboembolism.     

Low-Molecular-Weight Heparin Should Replace Unfractionated Heparin for Treatment of Venous Thrombosis and Unstable Angina

Journal of Thrombosis and Thrombolysis -     

Portal Vein Thrombosis

Portal vein thrombosis is a condition not infrequently encountered by clinicians. It results from a combination of local and systemic prothrombotic risk factors. The presentation of acute thrombosis varies widely from an asymptomatic state to presence of life-threatening intestinal ischemia and infarction. In the chronic stage, patients typically present with variceal bleeding or other complications of portal hypertension. Abdominal ultrasound color Doppler imaging has a 98% negative predictive value, and is considered the imaging modality of choice in diagnosing portal vein thrombosis. Controlled clinical trials to assist with clinical decision-making are lacking in both acute and chronic portal vein thrombosis. Oral anticoagulant therapy is initiated if the risks of bleeding are low, but long-term anticoagulation is generally not recommended in patients with concomitant hepatic cirrhosis. The roles of invasive therapeutic approaches such as thrombolysis and transjugular intrahepatic portosystemic shunt continue to evolve. This review conflates dissenting views into a rational approach of managing patients with portal vein thrombosis for the general internist.     

低分子肝素钙预防心力衰竭患者深静脉血栓观察

目的观察低分子肝素钙对慢性心力衰竭患者深静脉血栓形成的预防效果。方法将未检出深静脉血栓的慢性心力衰竭患者随机分为试验组(95例)和对照组(91例)。在常规治疗基础上,试验组应用低分子肝素钙5 000 U,每日一次皮下注射。对照组应用安慰剂,连续应用2周。于2周及4周后复查下肢深静脉多普勒超声,计算两组深静脉血栓的发生率。结果治疗2周后试验组静脉血栓的发生率为3.1%,对照组为10.9%,两组比较有统计学意义(P<0.0 5);治疗4周后试验组静脉血栓的发生率为4.4%,对照组为13.3%,两组比较有统计学意义(P<0.05)。两组均无严重不良反应。结论应用低分子肝素钙预防慢性心力衰竭患者深静脉血栓形成效果确切,安全性及耐受性良好。     

Nontumoral Portal Vein Thrombosis: A Challenging Consequence of Liver Cirrhosis

Nontumoral portal vein thrombosis (PVT) is an increasingly recognized complication in patients with cirrhosis. Substantial evidence shows that portal flow stasis, complex thrombophilic disorders, and exogenous factors leading to endothelial dysfunction have emerged as key factors in the pathogenesis of PVT. The contribution of PVT to hepatic decompensation and mortality in cirrhosis is debatable; however, the presence of an advanced PVT increases operative complexity and decreases survival after transplantation. The therapeutic decision for PVT is often determined by the duration and extent of thrombosis, the presence of symptoms, and liver transplant eligibility. Evidence from several cohorts has demonstrated that anticoagulation treatment with vitamin K antagonist or low molecular weight heparin can achieve recanalization of the portal vein, which is associated with a reduction in portal hypertension-related events and improved survival in cirrhotic patients with PVT. Consequently, interest in direct oral anticoagulants for PVT is increasing, but clinical data in cirrhosis are limited. Although the most feared consequence of anticoagulation is bleeding, most studies indicate that anticoagulation therapy for PVT in cirrhosis appears relatively safe. Interestingly, the data showed that transjugular intrahepatic portosystemic shunt represents an effective adjunctive therapy for PVT in cirrhotic patients with symptomatic portal hypertension if anticoagulation is ineffective. Insufficient evidence regarding the optimal timing, modality, and duration of therapy makes nontumoral PVT a challenging consequence of cirrhosis. In this review, we summarize the current literature and provide a potential algorithm for the management of PVT in patients with cirrhosis.     

Altered Liver Morphology After Portal Vein Thrombosis: Not Always Cirrhosis

The macroscopic appearance of the liver after primary portal vein thrombosis often mimics cirrhosis, despite the absence of bridging fibrosis at histology. The purpose of this study was to describe unique morphologic changes of the liver after portal venous thrombosis. A retrospective review was performed to find patients with portal vein thrombosis and a corresponding noncirrhotic liver biopsy. The CT appearance of the liver was then evaluated, and the liver was categorized as having either peripheral or central hepatic atrophy. Of 15 patients included in this study, 12 had peripheral atrophy of the liver, while the remaining three had central atrophy. We concluded that maintenance of central portal venous blood flow and resultant relative peripheral atrophy of the liver may account for a distinctive rounded configuration of the liver after acute portal vein thrombosis. Awareness of this appearance after primary portal vein thrombosis may prevent an erroneous diagnosis of cirrhosis.     

《肝硬化门静脉血栓管理专家共识》解读

该文对《肝硬化门静脉血栓管理专家共识》中门静脉血栓的流行病学,对肝硬化预后的影响、危险因素、影像学检查、诊断、病情评估和治疗策略等方面的推荐要点予以解读,以期能让医师更好地理解其内容并合理应用于临床.     

Portal Vein Thrombosis and Pancreatic Failure

Summary We report a case of a child with portal vein thrombosis presenting with protein losing enteropathy. He later developed exocrine and endocrine pancreatic failure. This association has not been reported before.     

Role of D-dimer in the Development of Portal Vein Thrombosis in Liver Cirrhosis: A Meta-analysis

Background and Aims:

A meta-analysis was performed to explore the role of the D-dimer in the development of portal vein thrombosis (PVT) in liver cirrhosis.

Methods:

All papers were searched via PubMed, EMBASE, China National Knowledge Infrastructure, Wan Fang, and VIP databases. A standardized mean difference (SMD) with 95% confidence interval (CI) was pooled.

Results:

Overall, 284 studies were initially identified, of which 21 were included. Cirrhotic patients with PVT had a significantly higher D-dimer concentration than those without PVT (pooled SMD = 1.249, 95%CI = 0.740–1.758). After the portal hypertension-related surgery, cirrhotic patients with PVT had a similar preoperative D-dimer concentration to those without PVT (pooled SMD = 0.820, 95%CI = −0.122–0.286), but a higher postoperative value of D-dimer concentration than those without PVT (pooled SMD = 2.505, 95%CI = 0.975–4.036). Notably, the D-dimer concentration at the 1^st postoperative day was similar between cirrhotic patients with and without PVT (pooled SMD = 0.137, 95%CI = −0.827–1.101), but that at the 7^th post-operative day was higher in cirrhotic patients with PVT than in those without PVT (pooled SMD = 1.224, 95%CI = 0.277–2.171).

Conclusion:

D-dimer might be regarded as a diagnostic marker for PVT in liver cirrhosis. In addition, postoperative D-dimer testing is worthwhile for the diagnosis of PVT after portal hypertension-related surgery.     

Metabolic Disorders and Risk of Portal Vein Thrombosis in Liver Cirrhosis: A Systematic Review and Meta-Analysis

Portal vein thrombosis is considered to be an indicator of worse outcomes in patients with hepatic cirrhosis. More and more evidence shows that metabolic disorders are noticeable pro-thrombotic factors. However, whether or not metabolic disorders increase the risk of cirrhotic portal vein thrombosis is controversial. We aim to quantify the magnitude of the association between metabolic disorders and the risk of cirrhotic portal vein thrombosis. Databases were searched for papers to identify studies in which metabolic disorders were compared in liver cirrhosis with or without portal vein thrombosis. Based on data from the eligible studies, metabolic disorders related to portal vein thrombosis included diabetes mellitus, nonalcoholic fatty liver disease, hypercholesterolemia, and body mass index. Pooled adjusted odds ratios with 95% CIs were calculated. Data for 22 studies with a total of 57 371 portal vein thrombosis cases and 3 979 015 participants were included. Statistically significant pooled odds ratios for portal vein thrombosis were obtained for diabetes mellitus (odds ratio 1.80, 95% CI 1.42-2.28), nonalcoholic fatty liver disease (odds ratio 1.61, 95% CI 1.34-1.95), and hypercholesterolemia (odds ratio 3.59, 95% CI 1.83-7.03). Body mass index was likely irrelevant with cirrhotic portal vein thrombosis (odds ratio 1.01, 95% CI 0.87-1.17), both in overall and subgroup meta-analyses. Significant heterogeneities among studies were observed, except for the hypercholesterolemia group. Metabolic disorders, such as diabetes mellitus, nonalcoholic fatty liver disease, and hypercholesterolemia, increased the risk of portal vein thrombosis in cirrhotic patients by 1.80-fold, 1.61-fold, and 3.59-fold, respectively. Body mass index did not appear to be a risk predictor of cirrhotic portal vein thrombosis. Further, well-designed clinical and mechanistic studies are required to strengthen the arguments, especially in obese patients.     

门静脉血栓形成的影像学表现及病因探讨

目的总结门静脉血栓形成的影像学表现及各种影像学检查的意义。方法选择2011年5月～2012年7月我院收治30例门静脉血栓形成患者,所有病例均经彩超、CT、CTA、MR、3DCE-MRA及间接法门静脉造影检查。结果对门静脉血栓进行Ⅰ～Ⅵ型分型,Ⅰ～Ⅲ型23例;Ⅳ型3例;Ⅴ、Ⅵ型各2例。结论超声可以作为首选检查和筛查,CTA和MRA为诊断的金标准,间接法门静脉造影可作为介入治疗的术前检查。分析病因,力求降低门静脉血栓的发病率。