Complications of Liver Transplantation: Multimodality Imaging Approach - SD

Introduction

My name is Antonio Sergio Marino.

I'm from San Paulo, Brazil.

I work as a radiologist, specialize in ultrasound.

I will talk a little bit about complications of liver transplants, normal and pathologic findings and mood modality, imaging approach, complications of liver transplantation, mood modality, imaging approach.

I will talk and we're gonna see some usual and unusual case of complications of liver transplantation learning objectives.

Learning Objectives

We describe the main complications of liver transplantations, demonstrate different examples of these complications and the main ultrasound doppler criteria for vascular complications with multimodality correlation.

Identify the appropriate indications for the use of contrast enhanced ultrasound for liver transplantations and this case the use of ultrasound in this scenario and perspectives for contrast enhanced ultrasound.

Liver Transplantation Overview

In summary, the liver transplants is indicated it with in patients with end stage acute or chronic liver disease that are at least three kinds of transplants.

The whole liver, the split liver and living donor liver transplantations for adults and children.

Ultrasound as Imaging Modality

Ultrasound. Ultrasound is the a imaging modality it can be performed in bedside scenario.

In our hospital we developed a protocol studying the patients in the first, third and fifth post respiratory day of liver transplants and with it we can perform the detection and the follow up of early and delayed complications.

Normal Findings

Normal findings of liver transplantations portal vein, the flow in the portal vein can bepi flow, continuous flow or with respiratory variations.

This is a continuous flow of portal vein ah Flow with respiratory variation.

The patchy veins and IVC, the flow is multiphasic in some cases and we can be um, attempted to loss of phasic flow or when you find continuous flow in some situations because these findings can uh, be present in some cases of osis of the EPA veins.

How you can see later EPA 3 45 0.6% of patients presents with right resistance flow up to seven two hour post transplantation.

It there is a relation with prolonged cardio interval and donor age.

There are no relation with early or latest survival rates in five years.

This is a flow with right resistance flow in the first post operator period and a normal flow three days of follow up complication.

Complications Overview

There are many complications such as a patch artery thrombosis stenosis in the portal vein a pet veins and in the inferior vena cavan biliary three rejection neoplasia and reinfection by varis B and C.

When is suspect of biliary complications we can perform MRI or conventional cholangiography In upper ultrasound screening.

If you have a suspicion of portal of or a palliative vein, complications MRI CT or conventional angiography can be performed.

If we don't identify no flow at doppler and we have a suspicion of thrombosis or a pet character stenosis, the contrasting has to ultrasound, um, Can be used to identify the epi ery in these cases if you find a normal arterial flow.

The follow up we do the follow up of these patients.

If you can't identify the arterial flow we can do the angiography or MRI angiography or CT angiography.

If normal it uh, this patient go to the follow up and if abnormal it can be performed at treatment.

Portal Vein Complications

Part of in complications the port of stenosis, the instance vary from one to 19%.

It can be as symptomatic atic dysfunction or a portal hypertension.

The diagnosis of ultrasound doppler an increased velocity flow on the stenosis.

Three to fourfold increased velocity related to preo site, a post anastomotic dilation portal hypertension signs.

In this case we can see a high velocity at an asmatic site on doppler, a velocity about um, almost 20 3,000 and on Doppler and you can see an ASTO port vein is stricter here on MRI and geography we can see the stricter of the portal vein, the dilation of poster stenotic site, some varis and in this case we can see the stent inside the port vein case.

One of Porto vein stenosis.

It's a 8-year-old boy with A 19 day follow up of liver transplant and we can identify a Porto vein lung stricture at grade scale and doper.

Here is the gray scale lung stricter of port vein and at Doppler the stenosis lung stenosis of the Porto vein.

There are many collaterals from portal vein at coronary vein site here and collaterals at coronary vein site and communications with Porto vein branch.

In this case, as you can see here, it's a video showing the collaterals from portal vein at Corona vein site and here the communication with portal vein branch.

This is the treatment developed by Carne Valley and it's a mini laboratory approach.

This is our, these are the collaterals at coronary vein site, the portal vein stenosis, the balloon inserted in the portal vein with the stent and the treatment with the stent in the main portal vein the follow up three day post stent, we can identify the stent in the main portal vein.

There are no restrictors now normal velocity at post stent portal vein.

The collaterals identified there are no flow in this collaterals.

Now an A post patient, the ined is from corona vein with no flow two And it's a little bit faster, but here it can identify normal flow at the portal vein and no collateral flow At coronary vein side.

Here we can see the main portal vein the stent inside the main portal vein and the left branch of port vein.

Yeah, hepatic vein complications.

Hepatic Vein Complications

The incidence is l less than 1% of transplants.

It's more common in living donor liver transplants in children.

Early stenosis can be caused by liver rotation and asto size discrepancy and the latest stenosis can be caused by fibrosis thrombosis and natal hyperplasia.

On a gray scale ultrasound we can identify pre anto structure thrombus, ascites, hepatomegaly and increased caliber of the tic veins.

Narrowing of the IVC on upper pre and post eno gradient three to four fold reverse or monophasic flow in the tic veins and portal vein intermittent reverse it flow.

This is an important sign as you can see later.

This is an adult with a first day post-transplant with a right heed vein thrombosis.

Confirm it on doppler and the correlation with CT study.

In this case we can identify low ity flow and the ined portion of middle edic vein here and height velocity at anastomotic side of the pad vein Almost 200 close to the anastomosis on MRA is studied.

We can confirm the, the findings of the doppler with strictures on the right median and left hepatic veins venous outflow occlusion in pediatric liver transplant.

We can treat these cases with percutaneous endovascular treatment and the angioplasty is the first option.

The stent is the second option that can be performed when we, we have found recurrent osis post angioplasty and or in a failure of percutaneous transluminal angioplasty case one, we can identify hepatic vein stenosis, a high velocity at the site of the stenosis and low velocity at pre stenotic site and phasic flow.

These are the velocity in a post stenotic site, pre stenotic site and post stenotic site.

Here in this video you can see the occlusion of the medial branch of the pet vein.

Here the left one is okay and we can identify short iPath shunts from middle to left branch in this case a different short iPath shunts from middle to left hepatic branch vein.

This is the appearance on angiography study.

Short inter shunt from middle to left hepatic branch, the left hepatic branch, the middle hepa branch, the occlusion is here.

As you can see on doppler ultrasound and the short shunts between middle and left Hepatic vein.

It was treated with an stent in the hepatic vein.

This is the appearance of post stent left epe vein and here this is the inferior venava and in the first day post stent a normal velocity flow with postal flow in inside the stent in the smal middle extension of the stent case two, a patto and ugal flow in the main and Porto vein branch.

Uh, this is a reverse it inter intermittent flow of the portal vein.

We have an inspiration.

The flow is reverse it and in a aspiration the flow is in flow.

A petal flow to deliver a hypo flow in the main portal.

Vein can be identifi identified in this case low velocity in HEPA vein and a high grade stenosis in HEPA vein in the left branch, this is the high grade stenosis and here we can see the stent in the pad vein close to the right side of her.

This is the four day post follow up.

He petal flow in the main and port of branch during the inspiration and expiration.

Normal velocity flow in the main part of vein almost 40 centimeters per second and normal velocity flow in the stented atic vein.

Hepatic Artery Complications

Hepatic artery complications, the incidence is up to 11% of transplants in adults.

There are some risk factors related to surgical techniques.

Symptoms can be neg negative is related in symmatic abnormalities, graft loss, ischemia, thrombosis and can cause rejection.

The importance of early diagnosis is termin amenable to treatment angiopathy and vascular re reconstruction do diagnostic criteria.

Peak velocity more than 200 tardis parvos aspect of the flow acceleration time more than 0.08 seconds.

And in cases of inconclusive doppler we can follow with angio MRI or CT hepatic artery thrombosis.

The incidence is 60% of the acute vascular complications, three to 10% in adults and eight to 19% in children.

The main risk factors are code interval and mismatch between vessels.

Calibers the pet charactery thrombosis is the second leading cause of earth.

Early graft failure, early diagnosis can decrease biliary complications.

The routine doppler follow up decrease severe complications and prevents re transplantations ultrasound dopper specificity is 92% in this cases of hepatic art artery thrombosis.

This is a case of a pet charactery thrombosis in a B mode.

We can see here the pet charactery, the portal vein and the IVC on doppler.

There are no flow. There is no flow in the pet charactery confirmed by MRI angiography and with conventional angiography.

False negatives of a atory thrombosis.

It can cause it by some situations of market reduction of an arterial flow in cases of liver edema, systemic hypotension, severe stenosis rejection and exam conditions.

In bedside scenario and in this case contrast enhanced ultrasound can be used to identify the, the flow of the path artery.

Contrast Enhanced Ultrasound

The ENS contrast agents in this paper the outdoors, uh, the comparison of conventional and micro bubble contrast enhanced ultrasound and in conclusion contrast enhanced ultrasound help it improve flow visualization in a pet character and portal vein, decreasing scanning time and correctly different between thrombosis and a patent artery in patients with do petica flow at conventional doppler ultrasound, Brazilian experience with contrast enhanced ultrasound, the preferred carbon expose TROs albumin called pesa is available since November of 24.

Is sterly manipulation of this contrast for different studies.

Pancreas, liver, kidney transplants, focal liver lesions and carotid studies.

Definitive was approved by Avis for liver, kidney and echocardiography studies.

In 27 we performed about almost 20, sorry, 2,250 exams and re and but it was removed from Brazilian market in November of 2008.

The complications are mine complications such as red egg, lumbar pain, cough and dyspenia.

This is a case of a petica and the cross-sectional view of Porto vein and the petica main petica with contrasting ute ultrasound, the left branch of a ery, the portal vein, again, we can see the main path charact three in a cross-section view and the branch of the left lobe, the branch of the four segment of segment four.

In this case, there are no enhancement of pep path, cerial, early phase and late phase enhancement of collaterals.

Here we can see the time, the lapse time of uh, injection 25 seconds and later.

With contrast enhanced ultrasound, we identified enteropathic arterial collateral with du parvos flow in the left branch of hepato artery.

This is the portal vein and there is no flow in the arterial branch of hepato charactery.

Summary

In summary, ultrasound is the first imaging modality for follow-up liver transplantations.

It's an important tool to determine the most appropriate imaging method or management.

Uh, for complications it can detect early and delayed vascular complications.

Contrast enhanced ultrasound is a useful tool and improve flow flow visualization of a atory in patients with dot flow.

At DOR ultrasound studies suspected of thrombosis or stenosis.

Acknowledgements

My acknowledgement and thanks to Professor Bert Goldberg, Flemming Frostberg, Jimmy Lou, Dan Merton, Giovanni Che Maria, Christina Schama, Roberto made TE and Francisco Carnival for these materials.

Thank you.