Type II Abernethy Malformation with Hepatopulmonary Syndrome: Single-Stage Endovascular Occlusion of an SMV–IVC Communication — A Case Report

Q: What is the clinical evidence from this study?

Study design: Case Report. Population: Type II Abernethy malformation with hepatopulmonary syndrome and hyperammonemia (n=1). Intervention: Single-stage endovascular occlusion with a 12-mm Amplatzer Vascular Plug II and adjunctive gelfoam embolisation. Primary outcome: Room-air oxygen saturation (SpO2) at 3 months.

Q: What does this research mean for the field?

Single-stage endovascular occlusion of a Type II Abernethy malformation restores intrahepatic portal blood flow and resolves hypoxemia secondary to hepatopulmonary syndrome. Novelty: ClaimNovelty.CONFIRMATORY. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

Rajakumar Ramar; Babu Peter Sathyanathan; Shivashankar Kumaresan; Kirubakaran Balu; Benin Reejan; Sibi Elango

doi:10.59667/sjoranm.v36i2.14

November 8, 2026Swiss Journal of Radiology and Nuclear MedicineOpen Access

Type II Abernethy Malformation with Hepatopulmonary Syndrome: Single-Stage Endovascular Occlusion of an SMV–IVC Communication — A Case Report

View Full Paper

Ask AI

Bookmark

Share

Key result

Endovascular Abernethy shunt occlusion improves room-air SpO2 from 74% to 94% at 3 months.

n=1

Why the study?

Congenital extrahepatic portosystemic shunts (Abernethy malformations) can cause hyperammonemia and hepatopulmonary syndrome, and endovascular closure requires careful assessment of shunt anatomy and portal venous drainage.

Does single-stage endovascular plug occlusion with adjunctive gelfoam embolisation improve oxygenation and reduce hyperammonemia in a pediatric patient with Type II Abernethy malformation and hepatopulmonary syndrome?

Key Points

To describe the diagnosis and single-stage endovascular occlusion of a congenital portosystemic shunt causing hepatopulmonary syndrome and hyperammonemia in a pediatric patient.
A 12-year-old girl underwent echocardiography, CT pulmonary angiography, abdominal CT angiography, and temporary balloon occlusion testing to assess vascular anatomy and portal hemodynamics.
The side-to-side superior mesenteric vein to inferior vena cava communication was occluded in a single stage using a 12-mm Amplatzer Vascular Plug II with adjunctive gelfoam embolisation of collateral vessels.
During balloon occlusion, portal pressure rose from 7 to 17 mmHg while contrast demonstrated patent intrahepatic portal branches and hepatic perfusion.
At 3 months post-procedure, room-air SpO₂ increased from 74% to 94%, central cyanosis resolved, and serum ammonia decreased from 103 µmol/L to 46.8 µmol/L.

Study Design

Type

Case Report (n=1)

Multicenter

No

Structured PICO

Does single-stage endovascular plug occlusion with adjunctive gelfoam embolisation improve oxygenation and reduce hyperammonemia in a pediatric patient with Type II Abernethy malformation and hepatopulmonary syndrome?

P

Population

1 12-year-old female with Type II Abernethy malformation, hepatopulmonary syndrome, and hyperammonemia, followed for 3 months after endovascular closure.

I

Intervention

Single-stage transjugular endovascular shunt occlusion using a 12-mm Amplatzer Vascular Plug II deployed across the primary SMV–infrarenal IVC communication, supplemented by adjunctive gelfoam embolisation of tortuous collateral channels, followed by prophylactic anticoagulation (enoxaparin 40 mg subcutaneously once daily for 3 days, overlapping on day 3 with apixaban 2.5 mg oral twice daily for 3 months).

O

Outcome

Shunt occlusion, restoration of hepatopetal portal flow, and resolution of hypoxemia (room-air SpO₂ and arterial blood gas normalization) and central cyanosis at 3 months.surrogate

This case report demonstrates that single-stage endovascular closure of a Type II Abernethy malformation after temporary balloon occlusion testing can resolve severe hepatopulmonary syndrome-induced hypoxemia and reduce hyperammonemia at 3 months.

Limitations

Single case report unable to establish causation
Unresolved discrepancy between simultaneous baseline SpO2 (74%) and PaO2 (62 mmHg)
Systemic venous pressure was not recorded during the procedure, preventing calculation of a portosystemic pressure gradient
Post-treatment portal pressure and follow-up liver biochemistry values were not measured or reported
No laboratory assessment of anticoagulant intensity and unavailable details on anticoagulation dosing rationale
Short 3-month follow-up duration does not establish long-term resolution of pulmonary vascular changes or exclude portal hypertension
Single case report, so causation cannot be established and findings are limited to this patient
Short follow-up duration of 3 months; longer-term pulmonary vascular outcomes and long-term exclusion of portal hypertension are not yet available
Unresolved discrepancy between baseline simultaneous room-air SpO₂ (74%) and PaO₂ (62 mmHg)
Systemic venous pressure was not recorded during temporary balloon occlusion, preventing calculation of a portosystemic pressure gradient, and post-treatment portal pressure was not measured
No laboratory assessment of anticoagulant intensity was documented, and independent assessment of the anticoagulation dosing rationale was unavailable in the records

Ask about this paper

Answers are grounded in this paper and cite their sources.

Implication

Supports feasibility of single-stage endovascular closure after balloon testing in rare pediatric shunts; hypothesis-generating and leaves open need for prospective data.

Abstract

Background: Congenital extrahepatic portosystemic shunts (Abernethy malformations) can be associated with hyperammonemia and hepatopulmonary syndrome (HPS). Endovascular closure requires careful assessment of shunt anatomy and portal venous drainage. Case presentation: A 12-year-old girl presented with progressive exertional dyspnea, central cyanosis, clubbing, and room-air SpO₂ of 74%. Serum ammonia was 103 µmol/L, while liver biochemistry was within the reference ranges. Echocardiography showed no structural cardiac cause for the cyanosis and agitated saline bubble echocardiography showed delayed appearance (6 cardiac cycles) of bubbles in the left atrium. CT pulmonary angiography demonstrated distal pulmonary vascular dilatation and subpleural telangiectatic vessels, consistent with HPS. The preprocedural ABG on room air showed pH 7.45, PaCO₂ 31 mmHg, PaO₂ 62 mmHg, HCO₃⁻ 22 mEq/L, and A–a oxygen gradient of 49 mmHg; the follow-up ABG normalized. The baseline SpO₂/PaO₂ discrepancy remained unresolved. Abdominal CT angiography showed a side-to-side communication between the superior mesenteric vein (SMV) and infrarenal inferior vena cava (IVC), with tortuous collateral channels and normal, patent intrahepatic portal branches. During temporary balloon occlusion, portal pressure rose from 7 to 17 mmHg, and contrast opacified the intrahepatic portal branches and hepatic parenchyma. The primary communication was occluded with a 12-mm Amplatzer Vascular Plug II, with adjunctive gelfoam embolisation of collateral channels. Outcome: Doppler ultrasound demonstrated hepatopetal portal flow during early follow-up. At 3 months, room-air SpO₂ was 94%, central cyanosis had resolved, serum ammonia had decreased to 46.8 µmol/L, and the follow-up ABG normalized. Conclusion: This case highlights the role of cross-sectional vascular mapping and temporary balloon occlusion assessment before single-stage endovascular closure of a congenital portosystemic shunt.

Discussion

No takes yet. Share an insight, caveat, or question.

Cite This Study

Ramar et al. (2026) conducted a case report in Type II Abernethy malformation with hepatopulmonary syndrome and hyperammonemia (n=1). Single-stage endovascular occlusion with a 12-mm Amplatzer Vascular Plug II and adjunctive gelfoam embolisation was evaluated on Room-air oxygen saturation (SpO2) at 3 months. Single-stage endovascular occlusion of a Type II Abernethy shunt improved room-air SpO2 from 74% to 94% and reduced serum ammonia from 103 to 46.8 µmol/L at 3 months.

synapsesocial.com/papers/6af1d893f9a8addd138b1ceb https://doi.org/10.59667/sjoranm.v36i2.14

View Full Paper

Ask AI

Bookmark

Share

Type II Abernethy Malformation with Hepatopulmonary Syndrome: Single-Stage Endovascular Occlusion of an SMV–IVC Communication — A Case Report

Key Points

Study Design

Structured PICO

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Type II Abernethy Malformation with Hepatopulmonary Syndrome: Single-Stage Endovascular Occlusion of an SMV–IVC Communication — A Case Report

Key Points

Study Design

Structured PICO

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Keep reading

Keep reading