Figure 1
Coeliac trunk arteriogram
Digital subtraction arteriogram (DSA) of coeliac trunk. The left gastric artery is not opacified.
Work-up before radioembolization: anatomic variants
SectionInterventional radiology
Case TypeAnatomy and Functional Imaging
AuthorsJaimin Shah, Christopher Moosavi, Bertrand Janne d'Othée
Connected authors
70 years, male
Clinical History
Multifocal, bilobar hepatocellular carcinoma. Recurrence after chemoembolization, multidisciplinary team recommended radioembolization. Patient comes now for pre-radioembolization arteriographic evaluation +/- coiling as needed and intra-arterial infusion of macroaggregated albumin particles.
Superior mesenteric arteriogram shows normal anatomy and patent portal vein with antegrade flow.
Coeliac arteriogram shows no left gastric artery.
Superior mesenteric arteriogram shows normal anatomy and patent portal vein with antegrade flow.
Coeliac arteriogram shows no left gastric artery.
Imaging Findings
1. Aberrant left gastric artery coming off the aorta (common trunk with the right inferior phrenic artery). The coeliac trunk supplies the left inferior phrenic, the splenic, the common hepatic and the dorsal pancreatic arteries.
2. Replaced hepatic artery to the left lateral segment, arising from the aberrant left gastric artery.
3. After coiling of this replaced artery, redistribution of arterial inflow to the lateral segment of the left hepatic lobe occurs immediately via collaterals from the segment IV artery (i.e., modal left hepatic artery, which supplied only segment IV prior to coiling). Coiling allowed safe radioembolization therapy of the left hepatic lobe via this route by preventing non-target embolization of Yttrium 90-loaded microspheres to the stomach.
2. Replaced hepatic artery to the left lateral segment, arising from the aberrant left gastric artery.
3. After coiling of this replaced artery, redistribution of arterial inflow to the lateral segment of the left hepatic lobe occurs immediately via collaterals from the segment IV artery (i.e., modal left hepatic artery, which supplied only segment IV prior to coiling). Coiling allowed safe radioembolization therapy of the left hepatic lobe via this route by preventing non-target embolization of Yttrium 90-loaded microspheres to the stomach.
Discussion
BACKGROUND
Prior to treating liver malignancies with selective internal (intra-arterial) radiation therapy (SIRT) with Yttrium 90 (Y90) loaded microspheres (also known as radioembolization), an outpatient arteriographic mapping is performed (a) to rule out communications between hepatic arteries and gastrointestinal (GI) arteries. Such communications must be coiled prior to radioembolization [1] to prevent reflux of microspheres to the GI tract and severe, transmural GI ulcerations ('skeletonization' of the hepatic arterial tree).
(b) In addition, at the end of this mapping procedure, radioactive (99mTc) macro-aggregated albumin (MAA) particles are infused in the hepatic arteries to quantify lung shunting. Significant (>10-20%) liver-to-lung shunting via the hepatic veins may cause lung radiation injury (so called 'radiation pneumonitis'). To prevent this complication, Y90 dose reduction during treatment may be needed; sometimes excessive lung shunting may even preclude administration of this therapy.
IMAGING FINDINGS
The initial coeliac arteriogram (Fig. 1) in this case shows opacification of all usual branches of the coeliac trunk except the left gastric artery.
The right gastric artery may originate from various vessels, including the common, proper or left hepatic arteries and the gastroduodenal arteries among others; in this case, it came off the common hepatic artery (Fig. 2). The right gastric artery follows the lesser curvature of the stomach to join the left gastric artery, as commonly found.
The microcatheter tip has been advanced farther in the right up to the left gastric artery. Arteriogram at this level shows a branch going towards the left lobe of the liver (Fig. 3); cone beam CT (Fig. 4) confirms this artery to be a replaced artery feeding the left lateral segment of the liver (II-III) and its multiple hypervascular lesions. It is 'replaced' and not 'accessory' because no other branch coming from the normal hepatic arterial tree supplies this left lateral segment.
OUTCOME
Fig. 5 shows that the left lateral segment artery has been coiled via the right gastric artery [1] approach, to prevent non-target embolization of the stomach during future radioembolization therapy. Redistribution of arterial flow to the left lateral segment of the liver was immediate and can increase further during the next 2-4 weeks [2]. Post coiling arteriogram (Fig. 6) shows that the origin of the left gastric artery, which supplied the replaced left lateral segment hepatic artery, is now visible and is aberrant, coming directly off the aorta (with a common trunk with the right inferior phrenic artery).
Prior to treating liver malignancies with selective internal (intra-arterial) radiation therapy (SIRT) with Yttrium 90 (Y90) loaded microspheres (also known as radioembolization), an outpatient arteriographic mapping is performed (a) to rule out communications between hepatic arteries and gastrointestinal (GI) arteries. Such communications must be coiled prior to radioembolization [1] to prevent reflux of microspheres to the GI tract and severe, transmural GI ulcerations ('skeletonization' of the hepatic arterial tree).
(b) In addition, at the end of this mapping procedure, radioactive (99mTc) macro-aggregated albumin (MAA) particles are infused in the hepatic arteries to quantify lung shunting. Significant (>10-20%) liver-to-lung shunting via the hepatic veins may cause lung radiation injury (so called 'radiation pneumonitis'). To prevent this complication, Y90 dose reduction during treatment may be needed; sometimes excessive lung shunting may even preclude administration of this therapy.
IMAGING FINDINGS
The initial coeliac arteriogram (Fig. 1) in this case shows opacification of all usual branches of the coeliac trunk except the left gastric artery.
The right gastric artery may originate from various vessels, including the common, proper or left hepatic arteries and the gastroduodenal arteries among others; in this case, it came off the common hepatic artery (Fig. 2). The right gastric artery follows the lesser curvature of the stomach to join the left gastric artery, as commonly found.
The microcatheter tip has been advanced farther in the right up to the left gastric artery. Arteriogram at this level shows a branch going towards the left lobe of the liver (Fig. 3); cone beam CT (Fig. 4) confirms this artery to be a replaced artery feeding the left lateral segment of the liver (II-III) and its multiple hypervascular lesions. It is 'replaced' and not 'accessory' because no other branch coming from the normal hepatic arterial tree supplies this left lateral segment.
OUTCOME
Fig. 5 shows that the left lateral segment artery has been coiled via the right gastric artery [1] approach, to prevent non-target embolization of the stomach during future radioembolization therapy. Redistribution of arterial flow to the left lateral segment of the liver was immediate and can increase further during the next 2-4 weeks [2]. Post coiling arteriogram (Fig. 6) shows that the origin of the left gastric artery, which supplied the replaced left lateral segment hepatic artery, is now visible and is aberrant, coming directly off the aorta (with a common trunk with the right inferior phrenic artery).
Differential Diagnosis List
Aberrant left gastric artery. Replaced left lateral segment hepatic artery.
Left gastric artery
Replaced left hepatic artery
Aberrant left gastric artery
Final Diagnosis
Aberrant left gastric artery. Replaced left lateral segment hepatic artery.
References
[1] Cosin O, Bilbao JI, Alvarez S, de Luis E, Alonso A, Martinez-Cuesta A. (2007) Right gastric artery embolization prior to treatment with yttrium-90 microspheres. Cardiovasc Intervent Radiol 30(1):98-103. (PMID: 17031727)
[2] Bilbao JI, Garrastachu P, Herráiz MJ, Rodríguez M, Iñarrairaegui M, Rodríguez J, Hernández C, de la Cuesta AM, Arbizu J, Sangro B. (2010) Safety and efficacy assessment of flow redistribution by occlusion of intrahepatic vessels prior to radioembolization in the treatment of liver tumors. Cardiovasc Intervent Radiol 33(3):523-31. (PMID: 19841973)
Case information
| URL: | https://www.eurorad.org/case/11809 |
| DOI: | 10.1594/EURORAD/CASE.11809 |
| ISSN: | 1563-4086 |
Figure 2
Right gastric arteriogram.
A 5 French carrier catheter tip is in the common hepatic artery; injection done via a coaxial microcatheter inserted in the right gastric artery (branch of the common hepatic artery in this case).
Figure 3
Follow-up common hepatic arteriogram 2 weeks later
Common hepatic DSA two weeks later (at time of right lobe Yttrium 90 radioembolization) shows redistribution of left lateral segment branches (II and III) via branches of the middle/left hepatic artery (supplying segment IV originally).
Figure 4
Arteriogram post coiling
The replaced left lateral segment artery was coiled to prevent non-target radioembolization.
Post-coiling DSA shows opacification of the left gastric artery.
Figure 5
Cone beam CT arteriogram
Cone beam CT shows opacification of a replaced left lateral segment (II-III) hepatic artery (in which the microcatheter tip was advanced). Multiple hypervascular liver masses opacified. Right lobe and segment IV not opacified.
Figure 6
Left gastric arteriogram performed via a right gastric artery approach
The microcatheter tip has been advanced into the left gastric artery, which itself supplies a replaced hepatic artery that supplies segments II and III of the liver (i.e., left lateral segment).
Figure 7
Left gastric arteriogram
Left gastric arteriogram: this artery has aberrant origin directly from the aorta (shared with the right inferior phrenic artery).
Coeliac trunk arteriogram
Digital subtraction arteriogram (DSA) of coeliac trunk. The left gastric artery is not opacified.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Right gastric arteriogram.
A 5 French carrier catheter tip is in the common hepatic artery; injection done via a coaxial microcatheter inserted in the right gastric artery (branch of the common hepatic artery in this case).
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Follow-up common hepatic arteriogram 2 weeks later
Common hepatic DSA two weeks later (at time of right lobe Yttrium 90 radioembolization) shows redistribution of left lateral segment branches (II and III) via branches of the middle/left hepatic artery (supplying segment IV originally).
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Arteriogram post coiling
The replaced left lateral segment artery was coiled to prevent non-target radioembolization.
Post-coiling DSA shows opacification of the left gastric artery.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Cone beam CT arteriogram
Cone beam CT shows opacification of a replaced left lateral segment (II-III) hepatic artery (in which the microcatheter tip was advanced). Multiple hypervascular liver masses opacified. Right lobe and segment IV not opacified.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Left gastric arteriogram performed via a right gastric artery approach
The microcatheter tip has been advanced into the left gastric artery, which itself supplies a replaced hepatic artery that supplies segments II and III of the liver (i.e., left lateral segment).
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Left gastric arteriogram
Left gastric arteriogram: this artery has aberrant origin directly from the aorta (shared with the right inferior phrenic artery).
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.
Dept. of Diagnostic Radiology & Nuclear Medicine, University of Maryland Medical Center, Baltimore, MD, USA.