Rational classification of portal vein thrombosis and its clinical significance

Portal vein thrombosis: diagnosis, management, and endpoints for future clinical studies

Portal vein thrombosis (PVT) refers to the development of a non-malignant obstruction of the portal vein, its branches, its radicles, or a combination. This Review first provides a comprehensive overview of all aspects of PVT, namely the specifics of the portal venous system, the risk factors for PVT, the pathophysiology of portal hypertension in PVT, the interest in non-invasive tests, as well as therapeutic approaches including the effect of treating risk factors for PVT or cause of cirrhosis, anticoagulation, portal vein recanalisation by interventional radiology, and prevention and management of variceal bleeding in patients with PVT. Specific issues are also addressed including portal cholangiopathy, mesenteric ischaemia and intestinal necrosis, quality of life, fertility, contraception and pregnancy, and PVT in children. This Review will then present endpoints for future clinical studies in PVT, both in patients with and without cirrhosis, agreed by a large panel of experts through a Delphi consensus process. These endpoints include classification of portal vein thrombus extension, classification of PVT evolution, timing of assessment of PVT, and global endpoints for studies on PVT including clinical outcomes. These endpoints will help homogenise studies on PVT and thus facilitate reporting, comparison between studies, and validation of future studies and trials on PVT.

Prevalence and Risk Factors for Portal Cavernoma in Adult Patients with Portal Vein Thrombosis

Portal vein thrombosis (PVT) represents a restriction or occlusion of the portal vein by a blood clot, which can appear in liver cirrhosis, inherited or acquired thrombophilia, malignancies, abdominal infection, abdominal inflammation, and injury to the portal vein; it can evolve to local venous extension, recanalization, or portal cavernoma (PC). This research represents an observational study of patients admitted with a diagnosis of PVT between January 2018 and December 2022. We assessed the rate of and risk factors for PC. In total, 189 patients with PVT were included; the rate of PC was 14.8%. In univariate and multivariate analysis, the main risk factors for the presence of PC were etiology (thrombophilia, myeloproliferative disorders, local inflammatory diseases, and idiopathic causes), prior PVT, and complete versus incomplete or single-branch portal obstruction. In patients with superior mesenteric vein (SMV) thrombosis, distal obstruction was more prone to PC than proximal obstruction. The main predictive factors were etiology, prior PVT, complete PVT obstruction, and no prior non-selective beta-blocker (NSBB) use; in patients with SMV thrombosis, the distal extension was more significantly associated with the risk of PC. We propose a composite score for the prediction of PC which includes etiology, prior diagnosis of PVT, prior NSBB use, complete versus incomplete PVT, and distal versus proximal SMV thrombosis, with good accuracy (AUC 0.822) and an estimated sensitivity of 76.92% and specificity of 82.39% at a cut-off value of 4.

Current concepts in the management of non-cirrhotic non-malignant portal vein thrombosis

Non-cirrhotic non-malignant portal vein thrombosis (NCPVT) is an uncommon condition characterised by thrombosis of the portal vein, with or without extension into other mesenteric veins, in the absence of cirrhosis or intra-abdominal malignancy. Complications can include intestinal infarction, variceal bleeding and portal biliopathy. In this article, we address current concepts in the management of NCPVT including identification of risk factors, classification and treatment, and review the latest evidence on medical and interventional management options.

An unusual case of severe gastrointestinal bleeding

We present the case of a 58-year-old female with a history of a bleeding duodenal peptic ulcer. Endoscopic hemostasis was unsuccessful; therefore, a transcatheter arterial embolization of a culprit vessel was performed. She was admitted to the hospital two months later because of obstruction of the common bile duct with cholangitis. Attempts to endoscopically place a biliary stent failed. The treating medical team opted for a surgical choledocho-jejunostomy. After 20 months, she presented with a melena and a severe anemia. Diagnostic work-up revealed portal vein thrombosis with portal cavernoma and bleeding choledocho-jejunostomy varices. The case presents and discusses rare complications of duodenal ulcer disease, as well as possible causes and treatment options.

Portal Vein Thrombosis in Patients with Liver Cirrhosis: What Went Wrong?

Purpose

This study aimed to explore inflammatory biomarkers, stool's functional bacterial groups and their possible link to portal vein thrombosis (PVT) in patients with liver cirrhosis (LC).

Materials and Methods

An observational study of 300 participants: 200 inhospital cirrhotic patients, who met inclusion criteria, equally assigned into two groups, based on the presence or absence of PVT and 100 healthy controls was carried out.

Results

The PVT group displayed significant differences related to older age, cigarettes smoking history, emergency admission, higher Child-Pugh score, metabolic related disorders and nonalcoholic fatty liver disease, as well as non-obstructive aspects, with chronic thrombi. The PVT group exhibited significant differences related to biomarkers such as tumor necrosis factor (TNF)-alpha, C-reactive protein (CRP), D-dimers (D-D), as well as gut overall dysbiosis (DB) and alteration of different functional bacterial groups of the gut microbiota. Strong positive correlations were observed between PVT severity, and TNF-alpha, CRP, D-D as well as lipopolysaccharide (LPS) positive bacteria. Esophageal varices, age and abdominal pain were independent predictors for PVT severity as well as CRP, TNF-alpha and D-D.

Conclusion

Patients with LC and PVT displayed elevation of TNF-alpha, CRP, D-D alterations of the functional gut microbiota, as well as several morphological and clinical particularities. Although the LPS positive gut microbiota was linked to inflammatory biomarkers and PVT severity, it was not proven to be an independent predictor of the PVT severity like CRP, TNF-alpha and D-D.

Natural History and Outcomes of Cavernous Transformation of the Portal Vein in Cirrhosis

BACKGROUND AND AIMS

Cavernous transformation of the portal vein can occur after portal vein thrombosis (PVT). In this study, we investigated clinical complications associated with cavernous transformation in the context of cirrhosis and PVT.

METHODS

In this retrospective cohort analysis, 204 patients with cirrhosis and PVT with or without cavernous transformation were identified using MUSC's Clinical Data Warehouse between January 1, 2013, through December 31, 2019. Complete demographic data, clinical history, and laboratory tests were abstracted from the electronic medical record.

RESULTS

Of 204 patients, 41 (20%) had cavernous transformation. MELD, Child-Pugh, and Charlson Comorbidity Index scores were similar among groups. There were no significant differences in the prevalence of esophageal varices (with or without bleeding), splenomegaly, or hepatic encephalopathy in patients with and without cavernous transformation, although ascites tended to be lower in patients with cavernous transformation (31/41 (76%) vs 142/163 (87%), p = 0.06). Patients with cavernous transformation were significantly less likely to have hepatocellular carcinoma (HCC) (13/41 (32%) vs 81/163 (50%), p < 0.05) and had significantly lower APRI (1.4 vs 2.0, p < 0.05) and Fib-4 (4.7 vs 6.5, p < 0.05). Patients with cavernous transformation had lower 5-year mortality (12/41 (29%) vs 81/163 (49%) died, p = 0.06). The 10-year mortality of patients with cavernous transformation without HCC was significantly lower than in those without cavernous transformation (8/28 (29%) vs 46/82 (56%), respectively, p < 0.05).

CONCLUSIONS

Patients with cavernous transformation appeared to have better outcomes than those without cavernous transformation.

Alternative forms of portal vein revascularization in liver transplant recipients with complex portal vein thrombosis

BACKGROUND & AIMS

Complex portal vein thrombosis (PVT) is a challenge in liver transplantation (LT). Extra-anatomical approaches to portal revascularization, including renoportal (RPA), left gastric vein (LGA), pericholedochal vein (PCA), and cavoportal (CPA) anastomoses, have been described in case reports and series. The RP4LT Collaborative was created to record cases of alternative portal revascularization performed for complex PVT.

METHODS

An international, observational web registry was launched in 2020. Cases of complex PVT undergoing first LT performed with RPA, LGA, PCA, or CPA were recorded and updated through 12/2021.

RESULTS

A total of 140 cases were available for analysis: 74 RPA, 18 LGA, 20 PCA, and 28 CPA. Transplants were primarily performed with whole livers (98%) in recipients with median (IQR) age 58 (49-63) years, model for end-stage liver disease score 17 (14-24), and cold ischemia 431 (360-505) minutes. Post-operatively, 49% of recipients developed acute kidney injury, 16% diuretic-responsive ascites, 9% refractory ascites (29% with CPA, p <0.001), and 10% variceal hemorrhage (25% with CPA, p = 0.002). After a median follow-up of 22 (4-67) months, patient and graft 1-/3-/5-year survival rates were 71/67/61% and 69/63/57%, respectively. On multivariate Cox proportional hazards analysis, the only factor significantly and independently associated with all-cause graft loss was non-physiological portal vein reconstruction in which all graft portal inflow arose from recipient systemic circulation (hazard ratio 6.639, 95% CI 2.159-20.422, p = 0.001).

CONCLUSIONS

Alternative forms of portal vein anastomosis achieving physiological portal inflow (i.e., at least some recipient splanchnic blood flow reaching transplant graft) offer acceptable post-transplant results in LT candidates with complex PVT. On the contrary, non-physiological portal vein anastomoses fail to resolve portal hypertension and should not be performed.

IMPACT AND IMPLICATIONS

Complex portal vein thrombosis (PVT) is a challenge in liver transplantation. Results of this international, multicenter analysis may be used to guide clinical decisions in transplant candidates with complex PVT. Extra-anatomical portal vein anastomoses that allow for at least some recipient splanchnic blood flow to the transplant allograft offer acceptable results. On the other hand, anastomoses that deliver only systemic blood flow to the allograft fail to resolve portal hypertension and should not be performed.

Portal Vein Thrombosis Extending to the Superior Mesenteric and Splenic Veins Secondary to a Hypercoagulable State Due to Prior Abdominal Surgery, Hormonal Replacement Therapy, and Flaxseed Consumption

Herein is a case of a 50-year-old male diagnosed with a non-cirrhotic acute portal vein thrombosis (PVT). Acute PVT is a rare condition usually presenting in cirrhotic patients. This patient had no past medical history of cirrhosis or hypercoagulable status and no past family history of a hypercoagulable disorder. However, the patient, who has been on testosterone replacement therapy (TRT) along with over-the-counter flax seeds (commonly known to contain phytoestrogens), recently underwent an abdominal surgery essentially placing him in a hypercoagulable state which could contribute to the development of acute PVT. This case showed the importance of being aware of possible contributors to hypercoagulable states which can lead to the occurrence of these events.

Portal vein-variceal anastomosis for portal vein inflow reconstruction in orthotopic liver transplantation: A case report and review of literature

BACKGROUND

Portal vein thrombosis (PVT) is a frequent complication occurring in 5% to 26% of cirrhotic patients candidates for liver transplantation (LT). In cases of extensive portal and or mesenteric vein thrombosis, complex vascular reconstruction of the portal inflow may become necessary for a successful orthotopic LT (OLT).

CASE SUMMARY

A 54-year-old male with history of cirrhosis secondary to schistosomiasis complicated with extensive portal and mesenteric vein thrombosis and severe portal hypertension who underwent OLT with portal vein-left gastric vein anastomosis.

CONCLUSION

We review the various types of PVT, the portal venous inflow reconstruction techniques.

Optimal Treatment for Patients With Cavernous Transformation of the Portal Vein

Cavernous transformation of the portal vein (CTPV) is a sequela of extrahepatic and/or intrahepatic portal vein obstruction caused by a combination of local and risk factors. It was ever taken as a relatively rare disease due to its scant literature, which was mainly based on clinical series and case reports. CTPV often manifests as gastroesophageal variceal bleeding, splenomegaly, and portal biliopathy after the long-term insidious presentation. It is unable for CTPV to be recanalized with anticoagulation because it is a complete obstruction of the mesentericoportal axis. Endoscopic therapy is mainly used for temporary hemostasis in acute variceal bleeding. Meso-Rex shunting characterized by portal-flow-preserving shunts has been widely performed in children with CTPV. The multitude of complications associated with CTPV in adults can be effectively addressed by various interventional vascular therapies. With the ubiquity of radiological examinations, optimal treatment for patients with CTPV becomes important. Multivisceral transplantation, such as liver-small intestinal transplantation, may be lifesaving and should be considered for patients with diffuse mesenteric venous thrombosis.

Transjugular Intrahepatic Portosystemic Shunt for Portal Vein Cavernous Transformation: A Systematic Review and Single-Arm Meta-Analysis

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) is technically challenging in the treatment of portal vein cavernous transformation (PVCT), and there is no high-quality evidence regarding whether it is an option for patients with PVCT. We carried out a systematic review and meta-analysis to assess the feasibility and safety of TIPS for PVCT.

METHODS

Systematic search of PubMed, Chinese National Knowledge Infrastructure (CNKI) database, Cochrane Library, Embase, and Wanfang database through December 2021 for appropriate studies reporting efficacy and safety in patients with PVCT undergoing TIPS. The main outcome included the technical success rate, postoperative rebleeding rate, postoperative hepatic encephalopathy rate, stent patency rate, preoperative, and postoperative portal pressure.

RESULTS

Ten studies, including 292 patients were included. Our results showed that TIPS was technically successful in 82.97% (95% confidence interval [CI]: 77.14%-88.41%, p = 0.297) with low heterogeneity (I2 = 18.39%, p = 0.279). Postoperative rebleeding occurred in 9.56% (95% CI: 4.55%-16.77%, p = 0.073) with moderate heterogeneity (I2 = 46.45%, p = 0.06). Postoperative hepatic encephalopathy occurred in 18.55% (95% CI: 9.23%-27.05%, p = 0.343) with moderate heterogeneity (I2 = 48.62%, p = 0.049). Stent patency during follow-up was in 78.43% (95% CI: 70.74%-85.20%, p = 0.805) with low heterogeneity (I2 = 0%, p = 0.654). Postoperative portal pressure significantly reduced (WMD = 12.79 mm Hg, 95% CI: 12.09-13.48 mm Hg, p < 0.00001) with high heterogeneity (I2 = 61.4%, p = 0.02). Both Begg test and funnel plot showed that there was no significant publication bias.

CONCLUSIONS

TIPS is feasible and safe in patients with PVCT and PVCT should not be considered an absolute contraindication to TIPS.

The Pathophysiology of Portal Vein Thrombosis in Cirrhosis: Getting Deeper into Virchow's Triad

Portal vein thrombosis (PVT) is a common complication among patients with cirrhosis. However, its pathophysiology is not well established and there are currently very few predictive factors, none of which are actually useful, from a clinical perspective. The contribution of each of the vertices of Virchow’s triad, e.g., blood hypercoagulability, blood flow, and portal vein endothelial damage in the development of PVT is not clear. In this review, we aim to recapitulate the latest studies on the field of PVT development in order to understand its mechanisms and discuss some of the future directions in the study of this important complication of cirrhosis.

Liver transplantation in patients with non-neoplastic portal vein thrombosis: 20 years of experience in a single center

BACKGROUND

The Yerdel classification is widely used for describing the severity of portal vein thrombosis (PVT) in liver transplant (LT) candidates, but might not accurately predict transplant outcome.

METHODS

We retrospectively analyzed data regarding 97 adult patients with PVT who underwent LT, investigating whether the complexity of portal reconstruction could better correlate with transplant outcome than the site and extent of the thrombosis.

RESULTS

79/97 (80%) patients underwent thrombectomy and anatomical anastomosis (TAA), 18/97 (20%) patients underwent non-anatomical physiological reconstructions (non-TAA). PVT Yerdel grade was 1-2 in 72/97 (74%) patients, and 3-4 in 25/97 (26%) patients. Univariate analysis revealed higher 30-day mortality, 90-day mortality, 1-year mortality, and a higher rate of severe early complications in the non-TAA group than in the TAA group (p = .018, .001, .014, .009, respectively). In the model adjusted for PVT Yerdel grade, non-TAA remained independently associated with higher 30-day, 90-day, and 1-year mortality (p = .021, .007, and .015, respectively). The portal vein re-thrombosis and overall patient and graft survival rates were similar.

DISCUSSION

In our experience, the complexity of portal reconstruction better correlated with transplant outcome than the Yerdel classification, which did not even appear to be a reliable predictor of the surgical complexity and technique.

Evolution of Nonmalignant Portal Vein Thrombosis in Liver Cirrhosis: A Pictorial Review

Portal vein thrombosis (PVT) is a common complication in liver cirrhosis, especially in advanced cirrhosis. It may be related to a higher risk of liver-related events and liver function deterioration. Imaging examinations can not only provide an accurate diagnosis of PVT, such as the extent of thrombus involvement and the degree of lumen occupied, but also identify the nature of thrombus (i.e., benign/malignant and acute/chronic). Evolution of PVT, mainly including development, recanalization, progression, stability, and recurrence, could also be assessed based on the imaging examinations. This article briefly reviews the pathophysiology, diagnosis, classification, and evolution of PVT with an emphasis on their computed tomography imaging features.

Clinical characteristics of cirrhosis patients with umbilical vein recanalization: A retrospective analysis

Umbilical Vein Recanalization (UVR) may occur in patients with long-standing portal hypertension and liver cirrhosis. This study aimed to investigate the clinical significance of UVR.Medical records of a cohort of patients with cirrhosis (n = 247) who were hospitalized at the Digestive Medicine Center of the Second Affiliated Hospital of Nanchang University from January 2012 to October 2015 were accessed. The UVR diagnosis was made by ultrasound examination and was confirmed by computerized tomography scan.The UVR incidence was 20.2% (50/247) in the cohort. The size of UVR was 9.9 ± 4.7 mm (range: 5-26.5 mm) in diameter. The UVR and non-UVR groups showed no difference in grades of hepatic encephalopathy (P = .496), Child-Pugh classification (P = .401), the incidence of moderately severe ascites (26% vs 26%, P = 1), the esophageal variceal bleeding rate (32% vs 39%, P = .402), or portal vein thrombosis (8% vs 12%, P = .580). However, the incidence of cavernous transformation of the portal vein was statistically different, that there was 0 case in the UVR group and 8 cases in the non-UVR group (P < .05).Our results suggested that UVR had little impact on the clinical manifestations of patients with liver cirrhosis, the significance of UVR as an intervention method requires further studies.

Clinical application of liver stiffness measurement in patients with cavernous transformation of portal vein

The clinical outcomes differ between patients with cavernous transformation of the portal vein (CTPV) with and without cirrhosis. Therefore, invasive liver biopsy may be needed for the differential diagnosis of patients with CTPV with or without cirrhosis. The present study aimed to investigate the diagnostic efficacy of liver stiffness measurements (LSM) for the prediction of cirrhosis in patients with CTPV. A total of 20 patients with CTPV, 34 with chronic hepatitis B (CHB)-related cirrhosis and 20 healthy volunteers, were retrospectively recruited in the study. CTPV was diagnosed with contrast-enhanced computed tomography (CT) and ultrasound for the abdomen. LSM values were detected for each patient, while liver biopsy was performed in each patient in the CTPV and cirrhosis groups. The results demonstrated that LSM values were significantly lower in the CTPV group (12.5 kPa; range, 6.8-21.5 kPa) compared with the CHB-related cirrhosis group (21.0 kPa; range, 15.5-27.2 kPa; P=0.017). However, this was still higher compared with healthy volunteers (4.9 kPa; range 4.0-5.8 kPa; P<0.001). In addition, CTPV patients with cirrhosis (17.7 kPa; range, 13.9-30.8 kPa) exhibited significantly increased LSM values compared with those without cirrhosis (6.4 kPa; range, 5.7-7.8 kPa; P<0.001). Furthermore, LSM values in CTPV patients without cirrhosis were slightly higher compared with those of healthy volunteers (P=0.003), while no statistically significant difference was observed in LSM between CTPV patients with cirrhosis and CHB-related cirrhosis group. These findings indicated that LSM values could be used for the differential diagnosis of CTPV patients with or without cirrhosis. However, further validation studies are needed.

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.

A prospective, multicentre study in acute non-cirrhotic, non-malignant portal vein thrombosis: comparison of medical and interventional treatment

BACKGROUND

To evaluate medical versus interventional treatment (transjugular thrombus fragmentation, local thrombolysis with or without stent implantation) in patients with acute non-cirrhotic, non-malignant portal vein thrombosis (PVT).

METHODS

This prospective, observational study enrolled 65 patients with acute (<28 days since begin of symptoms, no cavernoma) PVT in nine centres. Thirty patients received medical treatment and 35 patients received interventional treatment. PVT was graded into grade 1: short thrombosis and incomplete occlusion of the vessel lumen and grade 2: extended thrombosis or complete occlusion. Treatment response was classified as partial or complete, if thrombosis was reduced by one grade or to <25% of the vessel diameter respectively.

RESULTS

Partial and complete response rates were 7% and 30% in the medical compared to 17% and 54% (P < 0.001) in the interventional treatment group. In the multivariate analysis, interventional treatment showed a strong positive (OR 4.32, P < 0.016) and a myeloproliferative aetiology a negative (OR 0.09, P = 0.006) prediction of complete response. Complications were rare in the medical group and consisted of septicaemia and upper gastrointestinal bleeding of unknown origin in one patient each. Interventional treatment was accompanied by mild and self-limiting bleeding complications in nine patients, moderate intra-abdominal bleeding requiring transfusions (2 units) in one patient and peritoneal bleeding requiring surgical rescue in one patient. Four patients in each group developed intestinal gangrene requiring surgery. One patient died 52 days after unsuccessful interventional treatment.

CONCLUSIONS

Compared to medical treatment alone, interventional treatment doubled response rates at the cost of increased bleeding complications.

Diagnostic challenges in non-cirrhotic portal hypertension - porto sinusoidal vascular disease

Non-cirrhotic portal hypertension consists of a group of diseases characterized by signs and complications of portal hypertension, which differ from cirrhosis through histological alterations, hemodynamic characterization and, clinical outcome. Because of the similarities in clinical presentation and imaging signs, frequently these patients, and particularly those with porto-sinusoidal vascular disease (PSVD), are misdiagnosed as having liver cirrhosis and thus raising difficulties in their diagnosis. The most challenging differentiation to be considered is between PSVD and cirrhosis and, although not pathognomonic, liver biopsy is still the standard of diagnosis. Although they still require extended validation before being broadly used, new non-invasive methods for the diagnosis of porto-sinusoidal vascular disease, like transient elastography, contrast-enhanced ultrasound or metabolomic profiling, have shown promising results. Another issue is the differentiation between PSVD and chronic extrahepatic portal vein obstruction, especially now when it is known that 40% of patients suffering from PSVD develop portal vein thrombosis. In this particular case, once the portal vein thrombosis occurred, the diagnosis of PSVD is impossible according to the current guidelines. Moreover, so far, the differentiation between PSVD and sinusoidal obstruction syndrome has not been clear so far in particular circumstances. In this review we highlighted the diagnostic challenges regarding the PSVD, as well as the current techniques used in the evaluation of these patients.

Current management of portal vein thrombosis in liver transplantation

Nontumoral portal vein thrombosis (PVT) is present at liver transplantation (LT) in 5-26% of cirrhotic patients, and is known to affect post LT outcomes. Up to 31% of patients who are found to have PVT at the time of LT, would have had PVT at the time of initial listing, but others develop PVT during the waiting period. Adequate screening and treatment of the PVT on the waiting list for LT is thus essential so that a portoportal anastomoses can be performed at the time of LT. Early PVT (Yerdel Grade I/II) can be usually managed by thrombectomy, whereas Grade III PVT may require a jump graft from the superior mesenteric vein to the graft PV. Complete portomesenteric thrombosis is a huge challenge, and sometimes a cause for denying a LT in these patients, with multivisceral transplant being the only alternative. The presence of spontaneous, or previously surgically created portosytemic shunts like the leinorenal shunt, may serve as a good inflow option (renoportal anastomosis) in these patients to establish a physiological reconstruction. Although challenging, good outcomes are possible in patients with complex PVT if the appropriate surgical technique is chosen to ensure portal inflow and resolution of PHT post LT.

Novel classification of non-malignant portal vein thrombosis: A guide to surgical decision-making during liver transplantation

Non-tumoral portal vein thrombosis (PVT) is present at liver transplantation in 5% to 26% of cirrhotic patients, and the prevalence of complex PVT as defined here (grade 4 Yerdel, and grade 3,4 Jamieson and Charco) has been reported in 0% to 2.2%. Adequate portal inflow is mandatory to ensure graft and patient survival after liver transplantation. With time, the proposed classifications of non-tumoral chronic PVT have evolved from being anatomy-based, to also incorporating functional parameters. However, none of the currently proposed classifications are directed towards decision-making, regarding the choice of inflow to the graft during transplantation and the outcomes thereof. The present scoping review i) addresses the limits of the currently available classifications in terms of surgical decisiveness, ii) clarifies the concept of physiological or non-physiological portal inflow reconstruction, and subsequently, iii) proposes a new classification of non-tumoral PVT in candidates for liver transplantation; to help tailor the surgical strategy to an individual patient, in order to provide portal inflow to the graft together with control of prehepatic portal hypertension whenever feasible.

Incidence of Splanchnic Vein Thrombosis After Abdominal Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Abdominal surgery may increase the risk of splanchnic vein thrombosis (SVT). We determined the incidence of SVT after abdominal surgery and identified groups at highest risk.

MATERIALS AND METHODS

MEDLINE and Embase were searched for clinical studies evaluating the incidence of postoperative SVT after abdominopelvic surgery. Study selection, data abstraction, and risk of bias assessment were carried out independently by two reviewers. Clinical heterogeneity was explored by subgroup analyses (i.e., type of intra-abdominal procedure and organ group).

RESULTS

Of 5549 abstracts screened, 48 were analyzed. Pooled incidence of SVT (n = 50,267) was 2.68% [95% confidence interval (CI), 2.24 to 3.11] (1347 events), I² = 96%. Pooled incidence of SVT in high-risk procedures were splenectomy with devascularization (24%), hepatectomy in patients with cirrhosis (9%), and pancreatectomy with venous resection (5%). Pooled incidence of symptomatic and asymptomatic SVT was 1.02% (95% CI: 0.97% to 1.07%) and 0.98% (95% CI 0.88% to 1.07%), respectively. Most common causes of SVT-related mortality were irreversible thrombosis, bowel ischemia, liver failure, and gastrointestinal bleed. Most studies included were at a high risk of bias due to lack of prospective data collection and lack of SVT screening for all participants.

CONCLUSIONS

Incidence of SVT after abdominal surgery is low but remains a relevant complication. Patients undergoing procedures involving surgical manipulation of the venous system and splenectomy are at the highest risk. Given the life-threatening risks associated with SVT, there is a need for larger prospective studies on the incidence and impact of SVT after abdominal surgery.

Update on Management of Portal Vein Thrombosis and the Role of Novel Anticoagulants

The clinical management of portal vein thrombosis (PVT) remains ambiguous due to its heterogeneous presentations and its associations with liver disease, malignancy, and hypercoagulable states. The natural history and clinical outcome of PVT are highly variable, dependent upon size, extent and degree of the thrombotic occlusion, as well as the physiological impact of patient comorbidities. While existing clinical guidelines consistently recommend low molecular weight heparin or vitamin K antagonist anticoagulation in cirrhotic patients with symptomatic acute PVT, management of asymptomatic and chronic PVT may need to be determined on a case-by-case basis, factoring in the state of underlying liver disease. In general, patients with PVT and underlying malignancy should be anticoagulated to alleviate symptoms and prevent recurrences that could disrupt the cancer management. However, existing clinical data does not support routine anticoagulation of cirrhotic patients with asymptomatic PVT in the absence of underlying cancer. While low molecular weight heparin and vitamin K antagonist remain the most commonly used agents in PVT, an emerging body of clinical evidence now suggests that direct-acting oral anticoagulants may be used safely and effectively in PVT. As such, direct-acting oral anticoagulants may offer a more convenient anticoagulation alternative for PVT management in future practice.

Portal Cavernoma Mimicking Pancreatic Malignancy

Portal cavernoma colangiopathy (PCC) is an uncommon cause of portal hypertension, and it is an important differential diagnosis of pancreatic malignancy given the expanded network of collateral vessels. On imaging studies, portal cavernoma can be seen as a hypoechoic mass, possibly associated with distal common bile duct obstruction. Most cases occur in non-cirrhotic patients. During the symptomatic phase, these patients carry a high-risk of complications related to sustained biliary obstruction. We report a unique patient with obstructive jaundice and a presumed pancreatic mass that proved to be a portal cavernoma complicated by PCC in the setting of nodular regenerative hyperplasia of the liver.

Portal vein thrombosis - a primer for the general physician

Portal vein thrombosis (PVT) is thrombosis of the portal -circulation, which may present with varied symptoms. However, increased use of abdominal imaging has noted a large number of incidental PVT. At the same time, PVT may be overlooked in the absence of the characteristic symptoms. More recently, a JAK2 mutation has been recognised as a cause of PVT. Anticoagulation is the mainstay of treatment, but can pose a dilemma because of the associated coagulopathy, the presence of varices and thrombocytopenia.

Portal vein thrombosis in patients with cirrhosis

Portal vein thrombosis (PVT) is frequent in patients with liver cirrhosis and possible severe complications such as mesenteric ischemia are rare, but can be life-threatening. However, different aspects of clinical relevance, diagnosis and management of PVT are still areas of uncertainty and investigation in international guidelines. In this article, we elaborate on PVT classification, geographical differences in clinical presentation and standards of diagnosis, and briefly on the current pathophysiological understanding and risk factors. This review considers and highlights the pitfalls of the various treatment approaches and prophylactic treatments. Finally, we review the controversial issue of clinical impact of PVT on prognosis, especially considering liver transplantation and future perspectives.

Nontumoral portal vein thrombosis in patients awaiting liver transplantation

Portal vein thrombosis (PVT) occurs in approximately 2%-26% of the patients awaiting liver transplantation (LT) and is no longer an absolute contraindication for LT. Nearly half of PVT cases are accidentally found during the LT procedure. The most important risk factor for PVT development in cirrhosis may be the severity of liver disease and reduced portal blood flow. Whether other inherited or acquired coagulation disorders also play a role is not yet clear. The development of PVT may have no effect on the liver disease progression, especially when it is nonocclusive. PVT may not increase the risk of wait-list mortality, but it is a risk factor for poor early post-LT mortality. Anticoagulation and transjugular intrahepatic portosystemic shunt (TIPS) are 2 major treatment strategies for patients with PVT on the waiting list. The complete recanalization rate after anticoagulation is approximately 40%. The role of TIPS to maintain PV patency for LT as the primary indication has been reported, but the safety and efficacy should be further evaluated. PVT extension and degree may determine the surgical technique to be used during LT. If a "conventional" end-to-end portal anastomotic technique is used, there is not a major impact on post-LT survival. Post-LT PVT can significantly reduce both graft and patient survival after LT and can preclude future options for re-LT.