Prevalence of factor V Leiden mutation and other hereditary thrombophilic factors in Egyptian children with portal vein thrombosis: results of a single-center case-control study

Neonatal portal vein thrombosis: risk factors, diagnosis, treatment recommendations and review of the literature

BACKGROUND

Neonatal portal vein thrombosis (PVT) is currently more commonly encountered as a result of advances in diagnostic tools and increase in invasive interventions.

METHODS

In this study, 11 premature and 12 term infants diagnosed with PVT were retrospectively evaluated for clinical and laboratory characteristics, umbilical catheterization procedure, PVT location, risk factors, treatments, and long-term outcomes.

RESULTS

Median age of the patients at diagnosis was 10 days (range 3-90 days), and 69.6% of patients were girls. Of the 23 patients, 87% had left PVT and, 91.3% had at least one thrombosis risk factor, which was sepsis in 73.9% of patients, and presence of umbilical venous catheter in 87%. Totally, 59.1% of PVTs were completely resolved in a median follow-up of 7 months (1 month to 12 months), and 78.3% of these patients had no anticoagulant therapy (ACT). Partial thrombus resolution was achieved in 9 patients (40.9%). Five patients (%21) received ACT. Overall, 34.8% of patients had long-term complications. neonatal PVT is most commonly reported in the left portal vein and there is no evidence for the impact of ACT on reducing the short- or long-term complications. Well designed and larger studies are necessary to clarify this issue, which can facilitate developing appropriate management algorithms.

CONCLUSION

Neonatal PVT is most commonly reported in the left portal vein and there is no evidence for the impact of ACT on reducing the short- or long-term complications. Well designed and larger studies are necessary to clarify this issue, which can facilitate developing appropriate management algorithms.

Noncirrhotic Portal Hypertension: Current and Emerging Perspectives

Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are prototype noncirrhotic causes of portal hypertension (PHT), characterized by normal hepatic venous pressure gradient, variceal bleeds, and moderate to massive splenomegaly with preserved liver synthetic functions. Infections, toxins, and immunologic, prothrombotic and genetic disorders are possible causes in IPH, whereas prothrombotic and local factors around the portal vein lead to EHPVO. Growth failure, portal biliopathy, and minimal hepatic encephalopathy are long-term concerns in EHPVO. Surgical shunts and transjugular intrahepatic portosystemic shunt resolve the complications secondary to PHT. Meso-Rex shunt is now the standard-of-care surgery in children with EHPVO.

Outcomes following neonatal portal vein thrombosis: A descriptive, single-center study and review of anticoagulant therapy

BACKGROUND

Neonatal portal vein thrombosis (PVT) is uncommon with potentially serious complications that may manifest in infancy and childhood.

OBJECTIVE

The primary aim of our study was to describe the short-term and long-term outcomes of neonatal PVT.

METHODS

A retrospective chart review was conducted from 2008 to 2016 of neonates diagnosed with PVT. A systematic review was also performed from 2000 to 2018 to evaluate anticoagulant therapy (ACT) in neonatal PVT.

RESULTS

Forty-four premature and 30 term infants (mean gestational age 30.7 vs 39.1 weeks, respectively) had PVT. Sixty-eight involved the left portal vein, one involved only the main portal vein, and 5 involved ≥1 vein. PVT was catheter associated in 46 (62%); none of the 7 neonates tested had thrombophilia. Of 74 neonates, 19 (26%) received ACT and 55 (74%) were untreated. The mean follow-up duration was 16.6 months (SD = 17.62; range, 0-89.6); 59.5% were followed for ≥6 months. On last ultrasound examination, thrombus resolution was documented in treated (ACT; n = 19) and nontreated (n = 55) neonates: 12 (63%) versus 32 (58%) with complete resolution, 1 (5%) versus 6 (11%) partial, 0 versus 1 (2%) extension, and 6 (32%) versus 16 (29%) had nonprogressive lesions, respectively. Seventy-one (96%) had no complications. Seventy-one articles met inclusion criteria for the systematic review and 19 were retained for analysis after assessment.

CONCLUSIONS

PVT resolution rate was similar to previous reports. Although a low complication rate was detected, longer follow-up is necessary to determine the need for early treatment and the precise incidence of outcomes such as portal hypertension.

Idiopathic portal hypertension and extrahepatic portal venous obstruction

BACKGROUND

Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are non-cirrhotic vascular causes of portal hypertension (PHT). Variceal bleed and splenomegaly are the commonest presentations.

AIM

The present review is intended to provide the existing literature on etiopathogenesis, clinical profile, diagnosis, natural history and management of IPH and EHPVO.

RESULTS

IPH and EHPVO are both characterized by normal hepatic venous pressure gradient, moderate to massive splenomegaly with preserved liver synthetic functions. While the level of block in IPH is presinusoidal, in EHPVO it is at prehepatic level. Infections, autoimmunity, drugs, immunodeficiency and prothrombotic states are possible etiological agents in IPH. Contrastingly in EHPVO, prothrombotic disorders and local factors around the portal vein are the incriminating factors. Diagnosis is often clinical, supported by simple radiological tools. Natural history is defined by episodes of variceal bleed and symptoms related to enlarged spleen. Growth failure, portal biliopathy and minimal hepatic encephalopathy are additional concerns in EHPVO. Long-term survival is reasonably good with endoscopic surveillance; however, parenchymal extinction leading to decompensation is seen in a minority of patients in both the disorders. Surgical shunts revert the complications secondary to PHT. Meso-Rex shunt has become the standard surgery in children with EHPVO.

CONCLUSION

This review gives a detailed summary of these two vascular conditions of liver-IPH and EHPVO. Further research is needed to understand the pathogenesis and natural history of these disorders.

Impact of Prothrombotic Risk Factors in a Cohort of Egyptian Hemophilia A Patients

INTRODUCTION

Hemophilias are a group of related bleeding disorders that show an X-linked pattern of inheritance. The clinical phenotype of severe hemophilia may vary markedly among patients as a result of many factors, including genetic prothrombotic risk factors.

OBJECTIVES

Our objective was to study the incidence of the most common prothrombotic risk factors for additive effects among Egyptian patients with hemophilia A and their impact on clinical phenotype; annual bleeding frequency and severity of hemophilic arthropathy, as well as the effect of a single variation in these patients.

METHODS

This study was carried out in 100 patients with hemophilia A. Genotyping for factor V Leiden (FVL) G1691A, prothrombin G20210A, MTHFR C677T, and A1298C mutations was conducted using a real time-polymerase chain reaction (RT-PCR) assay.

RESULTS

Our study revealed mutations in hemophilia patients as follows: prothrombin G20210A (3 %), FVL (14 %), MTHFR C677T (42 %), and A1298C (59 %). Despite a lack of statistical significance when each gene was analysed separately, heterozygosity of prothrombin G20210A or FVL was always associated with either a mild or moderate, but never a severe, clinical presentation. The lowest bleeding frequency (less than once per month) was identified among patients with two heterozygous variants irrespective of the involved genes. In addition, the incidence of hemarthrosis was significantly higher among patients with a wild genotype of the prothrombin gene and FVL, and the average number of affected joints was significantly higher among patients with wild-type prothrombin and FVL genes than among heterozygous patients.

CONCLUSION

These prothrombotic mutations have a cumulative effect in amelioration of the severity of bleeding in hemophiliacs. The most prominent effect is that of prothrombin G20210A and FVL, while MTHFR C677A and A1298C gene mutations are less conclusive.

Skin Necrosis in a Patient with Factor V Leiden Mutation following Nipple Sparing Mastectomy

Nipple-sparing mastectomy (NSM) and immediate breast reconstruction have replaced radical surgical interventions for the treatment of selected patients with breast cancer undergoing prophylactic mastectomy. NSM is technically a difficult procedure. After dissection, the remaining breast skin and nipple-areola complex (NAC) must be thin enough to be free of tumor tissue and thick enough to preserve tissue perfusion. Factor V Leiden mutation is the most common cause of hereditary thrombophilia; thrombosis almost always develops in the venous system. The literature includes only a few case series of arterial thrombosis. The present study aimed to describe for the first time a patient with Factor V Leiden mutation that developed nipple-areola complex and skin necrosis, and multiple embolisms in the upper extremity arteries following NSM.

Extrahepatic portal vein obstruction in Egyptian children

BACKGROUND AND AIM

Extrahepatic portal vein obstruction (EHPVO) is an important cause of portal hypertension in children. The aim of this study was to describe the clinical presentation, possible risk factors, upper gastrointestinal endoscopic findings, and treatment modalities of children with EHPVO.

METHODS

After ethical approval of our study protocol by our institution review board, we analyzed available data from medical records of patients with EHPVO presenting to the Pediatric Hepatology Unit, Cairo University Pediatric Hospital, Egypt, for a period of 15 years from January 1996 to December 2010.

RESULTS

The study included 169 patients. Their ages at presentation ranged from 1 month to 12 years (median 2.5 years, interquartile range 5); 101 were boys. Hematemesis was a presenting symptom in 58%, splenomegaly was present in 87%, esophageal varices were present in 94%, and fundal varices were present in 23%. Possible risk factors, in the form of umbilical catheterization, umbilical sepsis, and exchange transfusion, were elicited in 18%. Propranolol was associated with reduction in bleeding episodes (P < 0.001), but was associated with increased chest symptoms (P < 0.01). Both injection sclerotherapy and band ligation were effective in the management of bleeding varices and for primary and secondary prophylaxis; however, injection sclerotherapy was associated with the development of secondary gastric varices (P = 0.03).

CONCLUSIONS

This large study of children with EHPVO demonstrates the efficacy of propranolol in the reduction of gastrointestinal bleeding in children with EHPVO. Both injection sclerotherapy and band ligation were effective in the management of esophageal varices, although the former was associated with the development of secondary gastric varices. Randomized clinical trials to choose the best modalities for the management of portal hypertension in children are still lacking.

Associations of coagulation factor V Leiden and prothrombin G20210A mutations with Budd-Chiari syndrome and portal vein thrombosis: a systematic review and meta-analysis

BACKGROUND & AIMS

We conducted a systematic review and meta-analysis to evaluate the associations of the coagulation factor V (encoded by F5) Leiden (FVL) or prothrombin (encoded by F2) G20210A mutation with Budd-Chiari syndrome or portal vein thrombosis (PVT).

METHODS

Relevant articles were identified in searches of the PubMed, EMBASE, Cochrane Library, and ScienceDirect databases. The prevalence of the FVL and prothrombin G20210A mutations were compared between patients with Budd-Chiari syndrome or PVT without cirrhosis and healthy individuals (controls) and between patients with cirrhosis, with and without PVT. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

RESULTS

We initially identified 869 articles, and included 27 in our final analysis. Compared with controls, patients with Budd-Chiari syndrome had a significantly higher prevalence of the FVL mutation (OR, 6.21; 95% CI, 3.93-9.79) and a similar prevalence of the prothrombin G20210A mutation (OR, 1.90; 95% CI, 0.69-5.23); patients with PVT without cirrhosis had a significantly higher prevalence of the FVL mutation (OR, 1.85; 95% CI, 1.09-3.13) or the prothrombin G20210A mutation (OR, 5.01; 95% CI, 3.03-8.30). Compared with patients with cirrhosis without PVT, patients with cirrhosis and PVT had a significantly higher prevalence of the FVL mutation (OR, 2.55; 95% CI, 1.29-5.07). We observed a trend toward a higher prevalence of the prothrombin G20210A mutation in patients with cirrhosis and PVT, but the difference was not statistically significant (OR, 2.93; 95% CI, 0.94-9.07).

CONCLUSIONS

Based on a meta-analysis, the FVL mutation is associated with an increased risk of Budd-Chiari syndrome, PVT without cirrhosis, and PVT in cirrhosis. The prothrombin G20210A mutation is associated with PVT, but not Budd-Chiari syndrome. Studies are needed to confirm these findings in different racial and ethnic groups.

Risk factors for thrombosis in an african population

SUMMARY

Little is known about the biological, epidemiological, and clinical risk factors for thrombosis and venous thromboembolism (VTE) among Black Africans. We undertook a study of the prevalence of VTE risk factors for thrombosis in a Senegalese population.

A three-year cross-sectional and case–control study involving 105 cases and 200 controls was conducted in various hospitals in Dakar (Senegal). Our results demonstrate that oral contraception, immobilization by casts, surgery, and blood group were significantly associated with VTE occurrence. Additionally, 16 cases and 2 controls had protein S (PS) values of less than 48.4% (M-2SD), exhibiting a highly significant difference (P < 1 × 10⁻⁴). The number of cases with a low protein C (PC) level was significantly higher than the respective number of controls. Using logistic regression methods, we established a correlation between significantly associated variables and deep venous thrombosis (DVT) occurrence. Age, obesity, sickle cell disease, and PC deficiency were not significantly associated with thrombosis. In contrast, gender, PS deficiency, varicose veins, surgery, non-O blood type, and the presence of antiphospholipid antibodies were significantly and independently associated with DVT.

These findings are extremely useful for clinical management of patients suffering from DVT and can help to reduce the high recurrence rate observed in our study.

Non-cirrhotic portal hypertension - diagnosis and management

NCPH is a heterogeneous group of liver disorders of vascular origin, leading to PHT with near normal HVPG. NCPF/IPH is a disorder of young adults or middle aged women, whereas EHPVO is a disorder of childhood. Early age acute or recurrent infections in an individual with thrombotic predisposition constitute the likely pathogenesis. Both disorders present with clinically significant PHT with preserved liver functions. Diagnosis is easy and can often be made clinically with support from imaging modalities. Management centers on control and prophylaxis of variceal bleeding. In EHPVO, there are additional concerns of growth faltering, portal biliopathy, MHE and parenchymal dysfunction. Surgical shunts are indicated in patients with failure of endotherapy, bleeding from sites not amenable to endotherapy, symptomatic hypersplenism or symptomatic biliopathy. Persistent growth failure, symptomatic and recurrent hepatic encephalopathy, impaired quality of life or massive splenomegaly that interferes with daily activities are other surgical indications. Rex-shunt or MLPVB is the recommended shunt for EHPVO, but needs proper pre-operative radiological assessment and surgical expertise. Both disorders have otherwise a fairly good prognosis, but need regular and careful surveillance. Hepatic schistosomiasis, CHF and NRH have similar presentation and comparable prognosis.

Perioperative strategies and thrombophilia in children with extrahepatic portal vein obstruction undergoing the meso-Rex bypass

BACKGROUND/PURPOSE

Extrahepatic portal vein obstruction (EHPVO) is an important cause of chronic portal hypertension in children. Although usually idiopathic in etiology, genetic and acquired thrombophilia have been implicated in EHPVO. Meso-Rex bypass is increasingly used to treat EHPVO in children.

OBJECTIVE

The objective of this study is to assess the relationship of postoperative anticoagulation strategies and thrombophilic risk factors to the development of bypass thrombosis following the meso-Rex bypass.

METHODS

Records of children who underwent meso-Rex bypass for EHPVO at a single institution from 1999 to 2009 were reviewed, and preoperative thrombophilia testing, perioperative anticoagulation strategies, and postoperative bypass patency based on imaging at last follow-up were examined.

RESULTS

Sixty-five children with EHPVO underwent a first time meso-Rex bypass during the study period, and 9 of 65 (14 %) developed bypass thrombosis. The use of warfarin in the postoperative period was more common among children with thrombosed shunts than among those with open shunts [63 % vs. 20 %; OR, 6.5 (95 % CI, 1.3-31.5), p = 0.022]. The contribution of genetic or acquired thrombophilia to shunt thrombosis was inconclusive given variability in testing.

CONCLUSIONS

Choice of anticoagulation following meso-Rex bypass may affect postoperative incidence of bypass thrombosis. Role of thrombophilic risk factors in the development of shunt thrombosis remains unclear.

Guidelines for the diagnosis and treatment of extrahepatic portal vein obstruction (EHPVO) in children

INTRODUCTION

Extrahepatic portal vein obstruction is an important cause of portal hypertension among children. The etiology is heterogeneous and there are few evidences related to the optimal treatment.

AIM AND METHODS

To establish guidelines for the diagnosis and treatment of EHPVO in children, a group of gastroenterologists and pediatric surgery experts reviewed and analyzed data reported in the literature and issued evidence-based recommendations.

RESULTS

Pediatric EHPVO is idiopathic in most of the cases. Digestive hemorrhage and/or hypersplenism are the main symptoms. Doppler ultrasound is a non-invasive technique with a high degree of accuracy for the diagnosis. Morbidity is related to variceal bleeding, recurrent thrombosis, portal biliopathy and hypersplenism. Endoscopic therapy is effective in controlling acute variceal hemorrhage and it seems that vasoactive drug therapy can be helpful. For primary prophylaxis of variceal bleeding, there are insufficient data for the use of beta blockers or endoscopic therapy. For secondary prophylaxis, sclerotherapy or variceal band ligation is effective; there is scare evidence to recommend beta-blockers. Surgery shunt is indicated in children with variceal bleeding who fail endoscopic therapy and for symptomatic hypersplenism; spleno-renal or meso-ilio-cava shunting is the alternative when Mesorex bypass is not feasible due to anatomic problems or in centers with no experience.

CONCLUSIONS

Prospective control studies are required for a better knowledge of the natural history of EHPVO, etiology identification including prothrombotic states, efficacy of beta-blockers and comparison with endoscopic therapy on primary and secondary prophylaxis.

Evaluation of the presence of hereditary and acquired thrombophilias in Brazilian children and adolescents with diagnoses of portal vein thrombosis

OBJECTIVE

The aim of this study was to describe the prevalence of main hereditary thrombophilias, Janus kinase 2 (JAK2) V617F mutation, antiphospholipid antibody syndrome (APS), and hyperhomocysteinemia in Brazilian children and adolescents diagnosed with portal vein thrombosis (PVT) without associated hepatic disease.

METHODS

A cross-sectional study was carried out with 32 children with PVT in accompaniment at Hospital das Clínicas of the Universidade Federal de Minas Gerais from January 1990 to July 2011. Laboratory evaluation of thrombophilias was performed from September 2010 to July 2011.

RESULTS

Thirty-two patients were evaluated; 59% were boys. Median age at diagnosis was 2.4 years. Mean time of patients' accompaniment was between 4.7 and 5.2 years. The presence of hereditary and acquired thrombophilias occurred in 34.4% of patients, and 9 of them also showed other risk factors in the previous history evaluation. Risk factors were absent in the previous history of 18 patients (56.3%). Two patients showed persistent high titres of anticardiolipin antibodies. Hyperhomocysteinemia was not observed. One patient was heterozygous for factor V Leiden and prothrombin G20210A mutation (3.1%). Eleven patients (34.4%) showed heterozygous methylenetetrahydrofolate reductase (MTHFR) C677T, and no patient had the JAK2V617F mutation.

CONCLUSIONS

Even after investigation of main hereditary and acquired thrombophilia, PVT remains without apparent cause in most patients. Nevertheless, association of local and systemic risk factors seems to be important also in the pediatric age group. Therefore, despite the low prevalence, a complete investigation, which includes both hereditary and acquired thrombophilias, may be necessary.

Portal vein thrombosis in children and adolescents: 20 years experience of a pediatric hepatology reference center

CONTEXT

Portal vein thrombosis refers to a total or partial obstruction of the blood flow in this vein due to a thrombus formation. It is an important cause of portal hypertension in the pediatric age group with high morbidity rates due to its main complication - the upper gastrointestinal bleeding.

OBJECTIVE

To describe a group of patients with portal vein thrombosis without associated hepatic disease of the Pediatric Hepatology Clinic of the Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil with emphasis on diagnosis, presentation form and clinical complications, and the treatment of portal hypertension.

METHODS

This is a descriptive study of a series of children and adolescents cases assisted from January 1990 to December 2010. The portal vein thrombosis diagnosis was established by ultrasound.

RESULTS

Of the 55 studied patients, 30 (54.5%) were male. In 29 patients (52.7%), none of the risk factors for portal vein thrombosis was observed. The predominant form of presentation was the upper gastrointestinal bleeding (52.7%). In 20 patients (36.4%), the initial manifestation was splenomegaly. During the whole following period of the study, 39 patients (70.9%) showed at least one episode of upper gastrointestinal bleeding. The mean age of patients in the first episode was 4.6 ± 3.4 years old. The endoscopic procedure carried out in the urgency or electively for search of esophageal varices showed its presence in 84.9% of the evaluated patients. The prophylactic endoscopic treatment was performed with endoscopic band ligation of varices in 31.3% of patients. Only one died due to refractory bleeding.

CONCLUSIONS

The portal vein thrombosis is one of the most important causes of upper gastrointestinal bleeding in children. In all non febrile children with splenomegaly and/or hematemesis and without hepatomegaly and with normal hepatic function tests, it should be suspect of portal vein thrombosis. Thus, an appropriate diagnostic and treatment approach is desirable in an attempt to reduce morbidity and mortality.

Thrombophilia testing in neonates and infants with thrombosis

In neonates and infants with idiopathic venous thrombosis (VTE) and in pediatric populations in which thromboses were associated with medical diseases, inherited thrombophilia (IT) have been described as risk factors. Follow-up data for VTE recurrence in neonates suggest a recurrence rate between 3% in provoked and 21% in idiopathic VTE. Apart from underlying medical conditions, recently reported systematic reviews on pediatric VTE have shown significant associations between factor V G1691A, factor II G20210A, and deficiencies of protein C, protein S and antithrombin, even more pronounced when combined IT were involved. Independent from the age at first VTE onset, the pooled odds ratios (OR: single IT) for VTE ranged from 2.4 for the factor II G20210A mutation to 9.4 in neonates and infants with antithrombin deficiency. The pooled OR for persistent antiphospholipid antibodies/lupus anticoagulants was 4.9 for pediatric patients with venous VTE. The factor II G20210A mutation (OR: 2.1), and deficiencies of protein C (OR: 2.4), S (OR: 3.1) and antithrombin (OR: 3.0) also played a significant role at recurrence. Based on these data, screening and treatment algorithms must be discussed.

Neonatal portal vein thrombosis: diagnosis and management

Neonatal portal vein thrombosis (PVT) is an increasingly recognized event. Patients are generally asymptomatic in the neonatal period. The diagnosis is made with Doppler ultrasound. Umbilical catheterization, exchange transfusion and sepsis are risk factors for neonatal PVT. Thrombophilia is possibly a contributing risk factor. Although there are potential serious acute complications such as hepatic necrosis, the outcome is good in the majority of cases, followed up to 8 years of age. Thrombus resolution occurs in 30-70% in days to months. Liver lobe atrophy may occur following PVT, and does not appear to be associated with any impairment of liver function. Non-occlusive thrombosis is more likely to resolve than non-occlusive thrombosis. A subset of patients without resolution is at risk for developing portal hypertension over the next decade of life. There are no current defining features present during the neonatal period to enable identification of neonates at risk for portal hypertension. There is no evidence that anticoagulation therapy improves time to resolution or decreases the likelihood of portal hypertension. Anticoagulation therapy may be considered. A management algorithm is proposed.

Epidemiology of activated protein C resistance and factor v leiden mutation in the mediterranean region

Venous thromboembolic disorders (VTE) are serious disorders with high morbidity and mortality rates. Many genetic and acquired risk factors were identified to cause VTE. The most common genetic risk factor is Factor V Leiden mutation (FVL). FVL was found in high percentage of populations of Caucasian origin but was almost absent in non-Caucasians. It was also reported in populations living in North Africa and the Middle East. This review article briefly explains FVL and how it causes VTE, the distribution of FVL worldwide, and then it elaborates on the epidemiology of FVL in the Mediterranean Region and how this brought speculations that FVL might have originated in the Eastern Mediterranean area.

Splanchnic vein thrombosis in the mediterranean area in children

Abdominal venous thrombosis may present as splanchnic venous thrombosis (SVT) (occlusion of portal, splenic, superior or inferior mesenteric veins) or Budd- Chiari Syndrome (BCS) (thrombosis of inferior vena cava and/or hepatic veins). The aim of this review is to report the scanty data available for SVT in the South Mediterranean area. In one Egyptian study, the possible circumstantial risk factors for portal vein thrombosis (PVT) were found in 30% of cases: 19% neonatal sepsis, 8.7% umbilical catheterization, 6% severe gastroenteritis and dehydration. Another Egyptian study concluded that hereditary thrombophilia was common in children with PVT (62.5%), the commonest being factor V Leiden mutation (FVL) (30%). Concurrence of more than one hereditary thrombophilia was not uncommon (12.5%). The first international publication on hepatic veno-occlusive disease (VOD) in Egypt was in 1965 in children who rapidly develop abdominal distention with ascites and hepatomegaly. This disease was more frequent in malnourished children coming from rural areas; infusions given at home may contain noxious substances that were hepatotoxic and infections might play a role. VOD of childhood is rarely seen nowadays. Data from South Mediterranean area are deficient and this may be attributable to reporting in local medical journals that are difficult to access. Medical societies concerned with this topic could help distribute this information.

Etiology and long-term outcome of extrahepatic portal vein obstruction in children

AIM: To study the management and outcome of children with extrahepatic portal vein obstruction (EHPVO) in a whole country population.

METHODS: A nationwide multicenter retrospective case series of children with EHPVO was conducted. Data on demographics, radiographic studies, laboratory workup, endoscopic and surgical procedures, growth and development, were extracted from the patients’ charts. Characteristics of clinical presentation, etiology of EHPVO, management and outcome were analyzed.

RESULTS: Thirty patients, 13 males and 17 females, 19 (63.3%) Israeli and 11 (36.7%) Palestinians, were included in the analysis. Age at presentation was 4.8 ± 4.6 years, and mean follow-up was 4.9 ± 4.3 years. Associated anomalies were found in 4 patients. The incidence of EHPVO in Israeli children aged 0-14 years was 0.72/million. Risk factors for EHPVO were detected in 13 (43.3%) patients, including 9 patients (30%) with perinatal risk factors, and 4 patients (13.3%) with prothrombotic states: two had low levels of protein S and C, one had lupus anticoagulant, and one was homozygous for methyltetrahydrofolate reductase mutations. In 56.6% of patients, no predisposing factors were found. The most common presenting symptoms were an incidental finding of splenomegaly (43.3%), and upper gastrointestinal bleeding (40%). No differences were found between Israeli and Palestinian children with regard to age at presentation, etiology and clinical symptoms. Bleeding occurred in 18 patients (60%), at a median age of 3 years. Sclerotherapy or esophageal banding was performed in 20 patients. No sclerotherapy complications were reported. Portosystemic shunts were performed in 11 patients (36.6%), at a median age of 11 (range 3-17) years: splenorenal in 9, mesocaval in 1, and a meso-Rex shunt in 1 patient. One patient underwent splenectomy due to severe pancytopenia. Patients were followed up for a median of 3 (range 0.5-15) years. One patient died aged 3 years due to mucopolysaccharidase deficiency type III. None of the patients died due to gastrointestinal bleeding.

CONCLUSION: EHPVO is a rare disorder. The etiological factors are still mostly unknown, and the endoscopic and surgical treatment options ensure a good long-term prognosis.

Vascular disorders of the liver

This guideline has been approved by the American Association for the Study of Liver Diseases (AASLD) and represents the position of the association.

Portal vein thrombosis and budd-Chiari syndrome

Venous thrombosis results from the convergence of vessel wall injury and/or venous stasis, known as local triggering factors, and the occurrence of acquired and/or inherited thrombophilia, also known as systemic prothrombotic risk factors. Portal vein thrombosis (PVT) and Budd-Chiari syndrome (BCS) are caused by thrombosis and/or obstruction of the extrahepatic portal veins and the hepatic venous outflow tract, respectively. Several divergent prothrombotic disorders may underlie these distinct forms of large vessel thrombosis. While cirrhotic PVT is relatively common, especially in advanced liver disease, noncirrhotic and nontumoral PVT is rare and BCS is of intermediate incidence. In this article, we review pathogenic mechanisms and current concepts of patient management.

Impact of Inherited Thrombophilia on Venous Thromboembolism in Children

Background— The aim of the present study was to estimate the impact of inherited thrombophilia (IT) on the risk of venous thromboembolism (VTE) onset and recurrence in children by a meta-analysis of published observational studies.

Methods and Results— A systematic search of electronic databases (Medline, EMBASE, OVID, Web of Science, The Cochrane Library) for studies published from 1970 to 2007 was conducted using key words in combination as both MeSH terms and text words. Citations were independently screened by 2 authors, and those meeting the inclusion criteria defined a priori were retained. Data on year of publication, study design, country of origin, number of patients/controls, ethnicity, VTE type, and frequency of recurrence were abstracted. Heterogeneity across studies was evaluated, and summary odds ratios and 95% CIs were calculated with both fixed-effects and random-effects models. Thirty-five of 50 studies met inclusion criteria. No significant heterogeneity was discerned across studies. Although >70% of patients had at least 1 clinical risk factor for VTE, a statistically significant association with VTE onset was demonstrated for each IT trait evaluated (and for combined IT traits), with summary odds ratios ranging from 2.63 (95% CI, 1.61 to 4.29) for the factor II variant to 9.44 (95% CI, 3.34 to 26.66) for antithrombin deficiency. Furthermore, a significant association with recurrent VTE was found for all IT traits except the factor V variant and elevated lipoprotein(a).

Conclusions— The present meta-analysis indicates that detection of IT is clinically meaningful in children with, or at risk for, VTE and underscores the importance of pediatric thrombophilia screening programs.

Nonmalignant portal vein thrombosis in adults

Portal vein thrombosis (PVT) consists of two different entities: acute PVT and chronic PVT. Acute PVT usually presents as abdominal pain. When the thrombus extends to the mesenteric venous arches, intestinal infarction can occur. Chronic PVT is usually recognized after a fortuitous diagnosis of hypersplenism or portal hypertension, or when there are biliary symptoms related to portal cholangiopathy. Local risk factors for PVT, such as an abdominal inflammatory focus, can be identified in 30% of patients with acute PVT; 70% of patients with acute and chronic PVT have a general risk factor for PVT, most commonly myeloproliferative disease. Early initiation of anticoagulation therapy for acute PVT is associated with complete and partial success in 50% and 40% of patients, respectively. A minimum of 6 months' anticoagulation therapy is recommended for the treatment of acute PVT. For patients with either form of PVT, permanent anticoagulation therapy should be considered if they have a permanent risk factor. In patients with large varices, beta-adrenergic blockade or endoscopic therapy seems to prevent bleeding as a result of portal hypertension, even in patients on anticoagulation therapy. In patients with jaundice or recurrent biliary symptoms caused by cholangiopathy, insertion of a biliary endoprosthesis is the first treatment option. Overall, the long-term outcome for patients with PVT is good, but is jeopardized by cholangiopathy and transformation of underlying myeloproliferative disease into myelofibrosis or acute leukemia.