Portal Vein Thrombosis: Recent Advance

Efficacy and safety of thrombolytic therapy for portal venous system thrombosis: A systematic review and meta-analysis

BACKGROUND AND AIMS

The role of thrombolytic therapy in patients with portal venous system thrombosis (PVST) remains ambiguous. This study aimed to systematically collect available evidence and evaluate the efficacy and safety of thrombolysis for PVST.

METHODS

Eligible studies were searched via PubMed, EMBASE, and Cochrane Library databases. Among the cohort studies, meta-analyses were performed to assess the outcomes of PVST patients receiving thrombolysis. Pooled proportions were calculated. Among the case reports and case series, logistic regression analyses were performed to identify the risk factors for outcomes of PVST patients receiving thrombolysis. Odds ratios (ORs) were calculated.

RESULTS

Among the 2134 papers initially identified, 29 cohort studies and 131 case reports or case series were included. Based on the cohort studies, the pooled rates of overall response to thrombolytic therapy, complete recanalization of PVST, bleeding events during thrombolysis, further bowel resection, thrombosis recurrence, and 30-day mortality were 93%, 58%, 18%, 3%, 1%, and 4%, respectively. Based on the case reports and case series, acute pancreatitis (OR = 0.084), history of liver transplantation (OR = 13.346), and interval between onset of symptoms and initiation of thrombolysis ≤14 days (OR = 3.105) were significantly associated with complete recanalization of PVST; acute pancreatitis (OR = 6.556) was significantly associated with further bowel resection; but no factors associated with the overall response to thrombolytic therapy, bleeding events during thrombolysis, thrombosis recurrence, and 30-day mortality were identified or could be calculated.

CONCLUSION

Early initiation of thrombolysis should be effective for the treatment of PVST. But its benefits for PVST secondary to acute pancreatitis are weakened.

Trombose de veia porta não associada à cirrose – desafio terapêutico

Portal vein thrombosis (PVT) is a disease in which thrombosis occurs from the intrahepatic branches of the portal vein, and may extend to the splenic vein and/or superior mesenteric vein. It is most often associated with liver cirrhosis. PVT not associated with cirrhosis is rare. The aim of this article is to report two cases of PVT in which it was not associated with cirrhosis. Both were treated with anticoagulation and clinical progress afterwards was good.

Natural history and predictors associated with the evolution of portal venous system thrombosis in liver cirrhosis

BACKGROUND

Portal venous system thrombosis (PVST) will progress in some cases, indicating worse outcome and the necessity of antithrombotic treatment, but will spontaneously improve in others. It is crucial to understand the natural history of PVST in liver cirrhosis. However, the knowledge regarding how to predict the evolution of PVST in cirrhotic patients is very scant.

METHODS

Sixty-nine cirrhotic patients without malignancy, who had undergone repeated contrast-enhanced computed tomography or MRI to evaluate the severity of PVST at the first and last admissions, were included. Logistic regression analysis was performed to identify the risk factors for the evolution of PVST in liver cirrhosis. Odds ratios (ORs) were calculated.

RESULTS

Among 42 patients without PVST at the first admission, 10 (23.8%) developed PVST at the last admission. Serum albumin level (OR = 0.873), prothrombin time (OR = 1.619), activated partial thromboplastin time (OR = 1.169), Child-Pugh score (OR = 1.560) and model for end-stage liver disease (MELD) score (OR = 1.292) at the last admission were significant risk factors associated with the development of PVST. Among 27 patients with PVST at the first admission, 11 (40.7%), 4 (14.8%) and 12 (44.4%) had improvement, stabilization and progression of PVST at the last admission, respectively. ΔMELD score (OR = 0.714) was the only significant risk factor associated with the improvement of PVST; additionally, serum albumin level at the first admission (OR = 1.236) was the only significant risk factor associated with the progression of PVST.

CONCLUSION

Aggravation and amelioration of liver dysfunction may predict the development and improvement of PVST in liver cirrhosis, respectively.

Idiopathic portal vein thrombosis not related to hepatic disease or malignancy

Acute portal vein thrombosis (PVT) is a rare disorder defined by the sudden occlusion of the portal vein, which could be partial or complete. Prothrombotic states, inherited or acquired, are thought to be the cause in patients without cirrhosis or malignancy. However, the aetiology of some cases remains idiopathic despite a multidisciplinary diagnostic approach. The initial diagnostic modality to confirm PVT is either contrast-enhanced abdominal (CT) or MRI; as it can identify predisposing factors, and detect evidence of complications. Eliciting the underlying aetiology is critical to guide overall management and prevent future recurrence. The purpose of treatment is to stop thrombus extension and achieve portal vein patency by anticoagulation to optimise outcomes. Herein, we present an unusual case of spontaneous PVT in a young woman. We will also discuss the evaluation of patients without obvious aetiology.

Hemorheological Alteration in Patients with Cirrhosis Clinically Diagnosed with Portal Vein System Thrombosis After Splenectomy

Background

Portal vein system thrombosis (PVST) is a common and serious complication after splenectomy. Key factors, including wider diameters of the portal vein, decreased liver function, and high flow volume of portosystemic collateral vessel, are recognized PVST risks. Relationships between PVST and altered hemorheology, including increased plasma viscosity, remain unclear. We investigated hemorheological alterations and explored risk factors of PVST in patients with cirrhosis after splenectomy.

Material/Methods

Data on patients with cirrhosis who underwent splenectomy were collected retrospectively from January 2018 to June 2020. Color Doppler ultrasonography was performed after splenectomy. Hemorheological indexes were compared between groups. Receiver operating characteristic (ROC) analysis was conducted to analyze risk factor cutoff values. Univariate and multivariate analyses were conducted to explore risk factors of PVST.

Results

A total of 50 patients were divided into a PVST group (n=30) and control group (n=20). Hemorheological indexes of activated partial thromboplastin time, fibrinogen degradation products (FDP), D-dimer, middle shear rates 50 and 30, low shear rates 5 and 1, and hematocrit in the PVST group were significantly higher than those of the control group (P<0.05). FDP and low shear rate 1 were found to be risk factors of PVST after splenectomy by multivariate analysis. ROC analysis showed that the cutoff points for FDP and low shear rate 1 were ≥38.6 ug/mL and ≥16.855 mPa.s, respectively.

Conclusions

PVST after splenectomy is closely related to hemorheological alteration. FDP and low shear rate 1 may be valuable markers of PVST.

Association of portal venous system thrombosis with endoscopic variceal treatment: a systematic review and meta-analysis

The association of endoscopic variceal treatment (EVT) with the development of portal venous system thrombosis (PVST) in liver cirrhosis remains uncertain. A systematic review and meta-analysis aimed to investigate the incidence of PVST after EVT and to explore the association of EVT with the development of PVST in liver cirrhosis. All relevant studies were searched via the PubMed, EMBASE, and Cochrane Library databases. The incidence of PVST in patients treated with and without EVT was pooled. Risk ratios with 95% confidence intervals (CIs) were calculated. Heterogeneity among studies was calculated. Meta-regression, sensitivity, and subgroup analyses were used to analyze the source of heterogeneity. Thirteen studies involving a total of 833 patients were included. The pooled incidence of PVST after EVT was 10.4% (95% CI, 4.9-17.7%). There was a statistically significant heterogeneity (I2 = 83.3%, P < 0.0001). Meta-regression, sensitivity, and subgroup analyses did not find the source of heterogeneity. Four studies compared the incidence of PVST between patients treated with and without EVT. The incidence of PVST was significantly higher in the EVT group than that in the no-EVT group (risk ratio: 2.23; 95% CI, 1.11-4.49; P = 0.02). The heterogeneity was not statistically significant (I2 = 0%, P = 0.43). In conclusion, PVST after EVT may not be scare, and EVT may increase the risk of PVST in liver cirrhosis.

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

BACKGROUND

Patients 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.

METHODS

PubMed, 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.

RESULTS

A 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).

CONCLUSION

PVST 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 REGISTRATION

Registered on PROSPERO, Identifier: CRD42020159579.

No Association of Homocysteine, Anticardiolipin Antibody, and Anti-β2 Glycoprotein I Antibody With Portal Venous System Thrombosis in Liver Cirrhosis

Portal venous system thrombosis (PVST), a common complication of liver cirrhosis, is closely associated with thrombophilia. To explore the association of homocysteine (Hcy), anticardiolipin antibody (aCL), and anti-β2 glycoprotein I antibody (aβ₂GPI), which are possible thrombophilic factors, with PVST in liver cirrhosis. Overall, 654 non-malignant patients (219 with and 435 without liver cirrhosis) admitted between January 2016 and June 2020 were retrospectively evaluated. Presence of PVST, degree of main portal vein (MPV) thrombosis, and clinically significant PVST were identified. Hcy level, hyperhomocysteinemia (HHcy), aCL positivity, and aβ₂GPI positivity were compared according to the presence of liver cirrhosis and PVST. Positive aβ₂GPI was significantly more frequent in patients with liver cirrhosis than those without, but Hcy level and proportions of HHcy and positive aCL were not significantly different between them. PVST could be evaluated in 136 cirrhotic patients. Hcy level [10.57 μmol/L (2.71-56.82) versus 9.97 μmol/L (2.05-53.44); P = 0.796] and proportions of HHcy [4/44 (9.1%) versus 13/81 (16.0%); P = 0.413] and positive aCL [1/23 (4.3%) versus 10/52 (19.2%); P = 0.185] and aβ₂GPI [9/23 (39.1%) versus 21/52 (40.4%); P = 0.919] were not significantly different between cirrhotic patients with and without PVST. There was still no significant association of Hcy level, HHcy, aCL, or aβ₂GPI with PVST based on Child-Pugh classification, MPV thrombosis >50%, and clinically significant PVST. Hcy, aCL, and aβ₂GPI may not be associated with PVST in liver cirrhosis, suggesting that routine screening for Hcy, aCL, and aβ₂GPI should be unnecessary in such patients.

Practice guidance for diagnosis and treatment of pancreatitis-related splanchnic vein thrombosis (Shenyang, 2020)

Splanchnic vein thrombosis is a severe complication of pancreatitis. To date, no consensus over the management of pancreatitis-related splanchnic vein thrombosis has been established. Based on the consensus of multidisciplinary experts, this practice guidance systematically reviewed the epidemiology, anatomy, pathophysiology, risk assessment and clinical presentations of splanchnic vein thrombosis, and formulated a diagnosis and treatment strategy for providing guidance in clinical practice for this disease.

Portal vein thrombosis secondary to postoperative gastric cancer: Report of two cases

Few cases of portal vein thrombosis secondary to gastric cancer surgery have been reported. Here we report the diagnosis and management of two such cases. Case 1: Gastric carcinoma with acute hematemesis was detected by endoscopy in the gastric body of a 48-year-old woman. Histologic examination revealed signet-ring cell carcinoma with marked invasion of the vessels and nerves. Laparoscopic partial gastrectomy and Roux-en-Y gastrogastrostomy were performed. One month after surgery, imaging examination showed the formation of thrombi in the main portal vein and the right hepatic vein. Case 2: Gastric carcinoma with pyloric obstruction was clinically diagnosed in a 66-year-old woman. Laparoscopic partial gastrectomy and Billroth Roux-en-Y gastrogastrostomy were again performed. Two months after surgery, an abdominal imaging examination detected a thrombus in the right hepatic vein. Clinicians should consider portal vein thrombosis in patients with hyperthermia combined with an abnormal increase in procalcitonin.

Acute portal vein thrombosis after liver transplant presenting with subtle ultrasound abnormalities: A case report and literature review

BACKGROUND

Portal vein thrombosis (PVT) after liver transplantation (LT) is an uncommon complication with potential for significant morbidity and mortality that transplant providers should be cognizant of. Recognizing subtle changes in post-operative ultrasounds that could herald but do not definitively diagnose PVT is paramount.

CASE SUMMARY

A 30-year-old female with a history of alcohol-related cirrhosis presented with painless jaundice and received a deceased donor orthotopic liver transplant. On the first two days post-operatively, her liver Doppler ultrasounds showed a patent portal vein, increased hepatic arterial diastolic flows, and reduced hepatic arterial resistive indices. She was asymptomatic with improving labs. On post-operative day three, her resistive indices declined further, and computed tomography of the abdomen revealed a large extra-hepatic PVT. The patient then underwent emergent percutaneous venography with tissue plasminogen activator administration, angioplasty, and stent placement. Aspirin was started to prevent stent thrombosis. Follow-up ultrasounds showed a patent portal vein and improved hepatic arterial resistive indices. Her graft function improved to normal by discharge. Although decreased hepatic artery resistive indices and increased diastolic flows on ultrasound are often associated with hepatic arterial stenosis post-LT, PVT can also cause these findings.

CONCLUSION

Reduced hepatic arterial resistive indices on ultrasound can signify PVT post-LT, and thrombolysis, angioplasty, and stent placement are efficacious treatments.