Mesenteric Vein Access for OPVT-Related Recurrent Variceal Bleeding: An Ambispective Cohort

Official title

Percutaneous Mesenteric Vein Access for Interventional Management of Recurrent Variceal Bleeding in Occlusive Portal Vein Thrombosis: An Ambispective Cohort Study

Overview

Occlusive portal vein thrombosis (OPVT) is defined as complete thrombosis of the main portal vein trunk, resulting in total interruption of portal venous inflow and representing the most severe form of portal vein thrombosis. A small proportion of patients may remain asymptomatic for prolonged periods because of sufficient collateral compensation; however, most develop complications of portal hypertension when collateral flow is inadequate, including gastroesophageal variceal bleeding and ascites. Among these, gastroesophageal variceal bleeding is the most life-threatening, and its management is more challenging-with a higher risk of rebleeding-than in patients without portal vein thrombosis. Occlusive portal vein thrombosis (OPVT) is defined as complete thrombosis of the main portal vein trunk, resulting in total interruption of portal venous inflow and representing the most severe form of portal vein thrombosis. A small proportion of patients may remain asymptomatic for prolonged periods because of sufficient collateral compensation; however, most develop complications of portal hypertension when collateral flow is inadequate, including gastroesophageal variceal bleeding and ascites. Among these, gastroesophageal variceal bleeding is the most life-threatening, and its management is more challenging-with a higher risk of rebleeding-than in patients without portal vein thrombosis. Transjugular intrahepatic portosystemic shunt (TIPS) is an effective minimally invasive therapy for portal hypertension-related complications; however, in OPVT, technical feasibility largely depends on successful portal vein recanalization. To improve TIPS success in OPVT, our group-together with domestic and international investigators-has explored several adjunctive access routes and technical modifications, including percutaneous transhepatic or transsplenic portal vein recanalization TIPS (PVR-TIPS); transjugular portal cavernous collateral-caval shunt (TCCS); transjugular mesenteric-caval shunt (TMCS); transjugular spleno-caval shunt (TSCS); and surgically assisted hybrid procedures. Although these strategies have improved technical success rates to some extent, their applicability remains limited. In patients with extensive thrombosis involving intrahepatic portal vein branches, in those without a feasible splenic venous puncture route, or in patients with prior splenectomy, percutaneous transhepatic and transsplenic approaches are often not possible. Moreover, in patients with poor hepatic reserve and/or ascites, laparotomy-assisted hybrid procedures substantially increase invasiveness and perioperative risk. In this context, the present project aims to systematically investigate and evaluate ultrasound-guided percutaneous mesenteric vein (MV) puncture as an adjunctive access strategy for interventional treatment of OPVT. This technique uses ultrasound-guided percutaneous puncture of the MV to establish antegrade portal venous access, thereby facilitating subsequent portal vein recanalization and/or shunt creation.

Detailed description

Occlusive portal vein thrombosis (OPVT) is defined as complete thrombosis of the main portal vein trunk, resulting in interruption of portal venous inflow and representing a severe form of portal vein thrombosis. Although some patients may remain asymptomatic for prolonged periods because of collateral compensation, many develop clinically significant portal hypertension when collateral flow is inadequate-most notably gastroesophageal variceal bleeding and ascites. Gastroesophageal variceal bleeding is a major cause of morbidity and mortality and is often more difficult to control, with a higher risk of rebleeding, than variceal bleeding in patients without portal vein thrombosis.

Transjugular intrahepatic portosystemic shunt (TIPS) is an established minimally invasive therapy for complications of portal hypertension. In OPVT, however, technical feasibility often hinges on successful portal vein recanalization. Multiple adjunctive techniques have been developed to improve feasibility in selected patients, including percutaneous transhepatic or transsplenic portal vein recanalization TIPS (PVR-TIPS), portal cavernous collateral-caval shunt procedures, mesenteric-caval or spleno-caval shunts, and surgically assisted hybrid approaches. Despite these advances, a meaningful subset of patients remain poor candidates because of extensive intrahepatic portal branch thrombosis, absence of a feasible splenic puncture route, prior splenectomy, or prohibitive risk for laparotomy-assisted hybrid procedures (e.g., in patients with limited hepatic reserve and/or ascites).

This study will evaluate ultrasound-guided percutaneous mesenteric vein (MV) puncture as an adjunctive access strategy to enable interventional decompression of the portal venous system in OPVT. Using real-time ultrasound, percutaneous MV access is obtained to establish an antegrade working channel. This channel is then used to facilitate portal vein recanalization and/or shunt creation when standard access routes are not feasible or have failed.

Study design and setting: Ambispective, exploratory, single-center clinical study.

Population: Patients with imaging-confirmed OPVT and recurrent gastroesophageal variceal bleeding, particularly those in whom conventional interventional access routes (e.g., transjugular-only approaches, percutaneous transhepatic access, or transsplenic access) are limited, infeasible, or have been unsuccessful.

Intervention (Stepwise Intra-procedural Strategy)

After establishing MV access under ultrasound guidance, operators will follow a predefined escalation algorithm based on intra-procedural anatomy and technical feasibility:

MV-assisted PVR-TIPS (preferred): Antegrade catheter/guidewire manipulation via MV access to attempt recanalization of the occluded main portal vein trunk. A catheter or balloon may be positioned as a target to facilitate completion of a standard TIPS via the transjugular route.

MV-assisted collateral-to-caval shunt (secondary): If main portal vein recanalization is not achievable, selective catheterization of an eligible collateral (e.g., diameter ≥6 mm) may be performed, with target-marker assistance to create a collateral-to-inferior vena cava shunt via the transjugular route.

Extrahepatic MV-to-caval shunt (backup): If neither main portal vein recanalization nor a suitable collateral is available, an extrahepatic MV-to-inferior vena cava shunt tract may be created through the established MV access as an alternative portal decompression strategy.

Outcomes (Overview) The study will assess: (1) technical feasibility (e.g., successful MV access; successful creation of a functioning shunt via any pathway), (2) procedural safety (peri-procedural and follow-up complications), and (3) clinical effectiveness, including control of portal hypertension-related bleeding (e.g., rebleeding during follow-up) and other manifestations of portal hypertension, as applicable.

Interventions

• Procedure Percutaneous mesenteric vein-assisted interventional treatment
  Intervention (stepwise intra-procedural strategy). After MV access is established under ultrasound guidance, operators will follow a predefined escalation algorithm based on anatomy and feasibility: MV-assisted PVR-TIPS (preferred): Using antegrade catheter/guidewire manipulation via MV access, attempt recanalization of the occluded main portal vein trunk. A catheter or balloon may be positioned as a target to complete standard TIPS via the transjugular route. MV-assisted collateral-to-caval s

Primary outcome measures

• Technical success of the index procedure (overall) [Time frame: During the procedure (index hospitalization)]
• Safety-major procedure-related adverse events [Time frame: From procedure through 30 days post-procedure.]

Secondary outcome measures (4)

• Variceal rebleeding [Time frame: 6 months post-procedure.]
• Shunt patency (primary patency) [Time frame: 6 months post-procedure.]
• Hepatic encephalopathy (new onset or worsening) [Time frame: From procedure through 6 months post-procedure.]
• Overall survival [Time frame: 6 months post-procedure]

Eligibility criteria

Inclusion criteria

• Confirmed OPVT, as demonstrated by contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI).
• History of at least two episodes of esophagogastric variceal bleeding.
• Ineligible for, or have previously failed, conventional transjugular intrahepatic portosystemic shunt (TIPS) or percutaneous transhepatic/transsplenic access approaches, including but not limited to extensive thrombosis of intrahepatic portal vein branches, prior splenectomy, or previous unsuccessful attempts.
• Child-Pugh score ≤12, with anticipated tolerance of the interventional procedure.

Exclusion criteria

• Thrombosis or severe stenosis of the superior mesenteric vein (SMV), precluding its use as a percutaneous access route.
• Severe cardiac, pulmonary, or renal insufficiency that precludes tolerance of the procedure.
• Uncorrectable coagulopathy.
• Life expectancy <3 months, or inability to comply with scheduled follow-up visits.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

China · 1 center

• Air Force Medical University — Xi'an

Identifiers

NCT: NCT07666256 · KY20262173-F-1

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗