1. The Road Less Traveled: The Often Ignored
Lesser Branches of the Celiac Axis
Aram Lee, MD
Justin McWilliams, MD
UCLA Radiology

2. The Road Less Traveled: The Often Ignored Lesser
Branches of the Celiac Axis
Learning Objectives: To highlight the clinical relevance of less
commonly encountered vascular branches of the celiac
axis, specifically in liver-directed interventional treatment.
Organization:
Part 1: Review of classic hepatic arterial anatomy and common
hepatic arterial variants
Part 2: Extrahepatic collateral vessels originating from the celiac
axis which can be parasitized by liver tumors
Part 3: Extrahepatic branches arising from the hepatic arterial
circulation to recognize in liver embolotherapy

3. Part 1:
CLASSIC HEPATIC ARTERIAL ANATOMY
AND COMMON ARTERIAL VARIANTS

4. Conventional hepatic arterial anatomy
RHA LHA
PHA CHA
GDA
61%
Conventional hepatic artery anatomy; the CHA gives off the GDA and continues as the PHA, which splits into RHA and
LHA. In the surgical literature, 55-70% of the population has this configuration; in the largest DSA study, 61%.
Michels et al. Blood supply and antaomy of the upper abdominal organs with a descriptive atlas. Philadelphia, PA: Lippincott, 1955.
Hiatt et al. Surgical anatomy of the hepatic arteries in 1000 cases. Ann Surg 1994; 220: 50-52.
Covey et al. Variant hepatic arterial anatomy revisited: DSA performed in 600 patients. Radiology 2002; 224: 542-547.

5. Left hepatic artery
Origin
-Proper hepatic artery
-Left gastric artery (5%)
-Celiac trunk (rare, double hepatic
artery)
Supplies
-Segments 2 and 3, and sometimes 4
Recognized by
-Arch over L portal vein
-Distribution to L lobe of liver
Covey et al. Variant Hepatic Arterial Anatomy Revisited: DSA Performed in 600 Patients. Radiology. August 2002. 224: 542-547.

6. Right hepatic artery
Origin
Proper hepatic artery
SMA (12%)
Celiac trunk (double hepatic artery)
Destination
Segments 5-8
Recognized by
Distribution to right lobe of liver
Covey et al. Variant Hepatic Arterial Anatomy Revisited: DSA Performed in 600 Patients. Radiology. August 2002. 224: 542-547.

7. Replaced or accessory right
hepatic artery
Replaced right hepatic artery (12%)
-No right hepatic artery from PHA
-Instead originates from the SMA,
or rarely the right phrenic artery or
other
Accessory right hepatic artery (5.5%)
-Right hepatic artery from PHA
-Second right hepatic artery from
elsewhere
-Usually SMA
Replaced RHA from SMA
-Also GDA, LGA, celiac axis,
right phrenic artery
Hiatt et al. Surgical Anatomy of the Hepatic Arteries in 1000 Cases. Annals of Surgery. July 1994. 220: 50-52.
Covey et al. Variant Hepatic Arterial Anatomy Revisited: DSA Performed in 600 Patients. Radiology. August 2002. 224: 542-547

8. Replaced or accessory left hepatic
artery
Replaced left hepatic artery
-Entire left hepatic artery originates
elsewhere other than the PHA (4.5 %)
-Commonly originates from the left
gastric artery
Accessory left hepatic
- Part (but not all) of the left hepatic
artery has an anomalous origin (15%)
- Almost always originates from left Replaced left hepatic artery arising from left gastric
gastric artery, very rarely from RHA artery. Left gastric branches (arrowheads) can mimic
segment 2 or 3 branches; true left hepatic branches
take off beyond the umbilical point (arrow).
Hiatt et al. Surgical Anatomy of the Hepatic Arteries in 1000 Cases. Annals of Surgery. July 1994. 220: 50-52.
Covey et al. Variant Hepatic Arterial Anatomy Revisited: DSA Performed in 600 Patients. Radiology. August 2002. 224: 542-547

9. Middle hepatic artery
Middle hepatic artery from RHA Middle hepatic artery from Proper Hepatic Artery (trifurcation)
A “middle hepatic artery” supplying segment 4 can arise from PHA as a
trifurcation, or from the right hepatic artery

10. Double replaced hepatic artery
Celiac injection demonstrates absence of
RHA and LHA. Expected course of CHA
(arrow) terminates in GDA and RGA.
0.5%
Replaced LHA from LGA Replaced RHA from SMA
Covey et al. Variant hepatic arterial anatomy revisited: DSA performed in 600 patients. Radiology 2002; 224: 542-547.

11. Replaced common hepatic artery
2%
Injection of celiac axis demonstrates splenic and left Common hepatic artery arises from the superior mesenteric
gastric arteries, but no common hepatic artery. artery.
Hiatt et al. Surgical Anatomy of the Hepatic Arteries in 1000 Cases. Annals of Surgery. July 1994. 220: 50-52.

12. Part 2:
EXTRAHEPATIC COLLATERAL VESSELS
ORIGINATING FROM THE CELIAC AXIS
WHICH CAN BE PARASITIZED BY LIVER
TUMORS

13. Extrahepatic collaterals in liver
tumor therapy
 Only tumors with surface location
 17% overall likelihood of extrahepatic supply at initial presentation
 3% for tumors <4 cm
 63% for tumors >6 cm
 Likelihood of extrahepatic supply increases with repeated embolizations
Chung et al. Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma: Prevalence and Causative Factors of Extrahepatic Collateral
Arteries in 479 Patients. Korean J Radiol. 2006 Oct; 7(4): 257-266.

14. Extrahepatic collaterals to
consider
 Where to look based on tumor location
 Bare area of liver (seg 7/8): R phrenic and R adrenal
 Superior-anterior liver (cardiophrenic area): R internal mammary
 Exophytic toward kidney: R renal and R adrenal
 Any peritoneal surface: Omental branches from R gastroepiploic
 Contacts chest wall: Lower intercostal
 Left lateral segment: L gastric
 Contacts colon: Colic branches of SMA
 Gallbladder fossa: Cystic Bare area = Posterior surface
of segment 7 and posterior
half of the diaphragmatic
surface of segment 8 .
Chung et al. Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma: Prevalence and Causative Factors of Extrahepatic Collateral
Arteries in 479 Patients. Korean J Radiol. 2006 Oct; 7(4): 257-266.

15. Right inferior phrenic artery
Origin
Aorta 50% (12% as common trunk with LIPA)
Celiac trunk 40% (16% as common trunk with LIPA)
Right renal artery 5%
Left gastric artery 4%
Rarely other
Supplies
Right hemidiaphragm
Suspect HCC supply for tumors in segment 7 abutting the diaphragm
50%
of collateral supply
Effects of embolization
Usually well-tolerated
Shoulder pain
Pleural effusion
Basal atelectasis
Transient hemoptysis
Diaphragmatic weakness (usually asymptomatic)
Basile A et al. MDCT anatomic assessment of right inferior phrenic artery origin related to potential supply to hepatocellular carcinoma and its
embolization. CVIR 2008.

16. HCC involvement of the right inferior phrenic artery
Replaced RHA angiogram demonstrates tumor supply. DEB-
Infiltrative HCC of the right lobe
TACE was performed.
1 month post-TACE, tumor necrosis is seen, but persistent Right phrenic angiography demonstrates copious
enhancement is seen at the posterior diaphragmatic margin. tumor supply. DEB-TACE was performed from this
location.

17. Omental arteries
Origin
Right or left gastroepiploic artery
Supplies
Greater omentum (mobile!)
Can supply tumors on almost any surface of the
liver
Effects of embolization
Usually well-tolerated
15%
of collateral supply
After multiple TACEs, common hepatic injection demonstrates multiple
omental branches (arrows) from the R gastroepiploic artery supplying
right lobe HCC (arrowheads).
Kim HC et al. Recognizing extrahepatic collateral vessels that supply hepatocellular carcinoma to avoid complications of transcatheter arterial
chemoembolization. Radiographics 2005.
Image courtesy of Antoinette Gomes, MD.

18. Cystic Artery
Origin
Usually first branch of right hepatic artery
Supplies
Gallbladder
HCC in gallbladder fossa
Recognized by
Proximal bifurcation
Curved shape outlining viscus
Effects of embolization Cystic artery injection demonstrates parasitic
Cholecystitis/gallbladder infarction
Often asymptomatic
9%
of collateral supply
supply to HCC (arrow).
Kim HC et al. Recognizing extrahepatic collateral vessels that supply hepatocellular carcinoma to avoid complications of transcatheter arterial
chemoembolization. Radiographics 2005.
Image courtesy of David Liu, MD.

19. Right adrenal artery
Origin
Superior adrenal artery from right inferior phrenic artery
Middle adrenal artery from lateral aorta between the celiac and
renal arteries
6%
of collateral supply
Inferior adrenal artery from superior aspect of right renal artery
Supplies
Right adrenal gland
May supply tumor which extends inferomedially
Effects of embolization
Usually well-tolerated
Kim HC et al. Recognizing extrahepatic collateral vessels that supply hepatocellular carcinoma to avoid complications of transcatheter arterial
chemoembolization. Radiographics 2005.

20. Uncommon sources of collateral supply
Right adrenal artery (6%)
Right intercostal arteries (5%)
Right or left gastric artery (3%)
Right internal mammary artery (3%)
Superior mesenteric artery (2%)
Right renal capsular artery (2%)
Left inferior phrenic artery (2%)
Right adrenal artery
Kim HC et al. Recognizing extrahepatic collateral vessels that supply hepatocellular carcinoma to avoid complications of transcatheter arterial chemoembolization.
Radiographics 2005.

21. Part 3:
EXTRAHEPATIC BRANCHES ARISING
FROM THE HEPATIC ARTERIAL
CIRCULATION TO RECOGNIZE IN LIVER
EMBOLOTHERAPY

22. Vascular optimization
Protective coil embolization of extrahepatic branches arising from the hepatic
circulation prior to embolotherapy
1. Gastroduodenal artery
2. Right gastric artery
3. Accessory left gastric artery
Other vessels to consider:
4. Retroduodenal artery -Dorsal pancreatic artery
5. Supraduodenal artery -Left phrenic artery
-Esophageal branches
6. Falciform artery
7. Cystic artery
Coil embolization of these vessels (when necessary) prevents passage of particles
(DEB or Y90) into sensitive structures

23. Accessory left gastric
Right gastric
Falciform
Left phrenic
Cystic
Supraduodenal
Retroduodenal
Right gastric
Supraduodenal
Retroduodenal
Dorsal pancreatic

24. Gastroduodenal Artery
Origin
Common hepatic artery
Supplies
Pylorus of stomach
Proximal duodenum
Pancreatic head (via pancreaticoduodenals)
Greater curvature of stomach (via R gastroepiploic)
Anatomic Clues
Near constant origin from CHA
Characteristic branching pattern
The gastroduodenal artery arises from the CHA. It typically gives
off the posterior superior pancreaticoduodenal artery (curved
arrow), then bifurcates into the anterior superior
pancreaticoduodenal artery (arrow) and the right gastroepiploic
artery (arrowhead).

25. Gastroduodenal Artery
Considerations for optimization:
-Should be coil embolized in almost all cases
-High flow, need lots of coils to occlude (usually 5-7
mm coils)
-Coil all the way back to origin to avoid hypertrophy
of small proximal vessels
-Look for accessory hepatic arteries and parasitized
tumor supply
-GDA flow reversed?
If due to low hepatic artery resistance, best to coil
If due to celiac stenosis, probably OK not to coil
GDA with reversed flow. Depending on the etiology, this
may or may not require coil embolization.

26. Right gastric artery
Origin
-Proper hepatic artery (55%)
-Left hepatic artery (20%)
-Common hepatic artery (5%)
-Gastroduodenal artery (5%)
-Right or middle hepatic artery (rare)
Right gastric artery (arrow) arising from the origin of the gastro-
duodenal artery. Note anastomoses with the left gastric artery.
Destination
-Gastric antrum and pylorus
-Proximal duodenal bulb
Anatomic Clues
-Leftward course along lesser
curvature of stomach
-Anastomoses with left gastric artery
Right gastric artery (arrow) arising from the left hepatic artery.
VanDamme JP, Bonte J. Vascular anatomy in abdominal surgery. New York: Thieme, 1990.
Yamagami et al. Embolization of the right gastric artery before he- patic arterial infusion chemotherapy to prevent gastric mucosal lesions: approach
through the hepatic artery versus the left gastric artery. AJR Am J Roentgenol 2002; 179:1605�1610.

27. Right gastric artery
Considerations for optimization
Should be coil embolized in almost all patients
-Unnecessary if RGA origin is very proximal (CHA)
May have acute angle, difficult to catheterize
Options for difficult cannulation
-Shaped microcatheter
-Ultra-floppy wire (Synchro)
-Retrograde access via left gastric artery
-“Jail” right gastric by coiling left hepatic artery
-If all else fails, can deliver particles distal to origin
Right gastric artery accessed retrograde from the left gastric artery,
followed by coil embolization. Image courtesy of David Liu, MD.
Yamagami et al. Embolization of the right gastric artery before he- patic arterial infusion chemotherapy to prevent gastric mucosal lesions: approach through the
hepatic artery versus the left gastric artery. AJR Am J Roentgenol 2002; 179:1605-1610.

28. Dorsal Pancreatic Artery
Origin Considerations for Vascular Optimization
- Splenic artery (60%) - No, in most cases
- Common hepatic artery (15%) - Sufficiently proximal (splenic/celiac) origin
- SMA (10%)
to avoid collateral damage
- Celiac (10%)
- Rarely others - Yes, in a few cases
- Common hepatic or more distal origin
- Copious pancreatic collaterals allow safe coiling
Destination
- Pancreatic head
- Pancreatic body (via transverse pancreatic
artery)
Anatomic Clues
- Usual origin within 2 cm of the celiac terminus
- Courses down and right if from splenic; down and left if
from CHA; up if from SMA
- Characteristic branching pattern
-Leftward branch into transverse pancreatic
artery
-Rightward branches collateralize with superior
pancreaticoduodenal arcade
Dorsal pancreatic artery arising from the celiac artery terminus.
Bertelli et al. The arterial blood supply of the pancreas: a review. V. The dorsal pancreatic artery. An anatomic review and a radiologic study. Surgical
Radiologic Anatomy. 1998;20(6):445-52.

29. Accessory left gastric artery
Prevalence 3-21% (high in Asian populations)
Origin
Left hepatic artery in proximal portion – 60%
Left hepatic artery in distal portion – 40%
Destination
Gastric cardia and fundus
Anatomic Clues
Runs in the fissure of the ligamentum venosum (same
place as a replaced left hepatic artery) on CT
Considerations for optimization
Should be coil embolized if present
Often difficult to identify on angio
Proximal-type accessory left gastric artery (arrow) arises from
Tips for identification the LHA prior to the umbilical point and courses to the gastric
-Gastric mucosal enhancement fundus (arrowheads).
-Delayed-phase coronary vein filling
-Use cone beam CT
Ishigami K, Yoshimitsu K, Irie H, et al. Accessory left gastric artery from left hepatic artery shown on MDCT and conventional angiography: correlation with CT
hepatic arteriography. Am J Roentgenol 2006;187:1002-1009.

30. Supraduodenal Artery (of Wilkie)
Origin
Gastroduodenal artery – 26%
Common or proper hepatic artery – 20%
Left hepatic artery – 20%
Right hepatic artery – 13%
Cystic artery – 10%
Right gastric artery – 8%
Destination
Proximal duodenum
Anatomic Clues
Extremely variable origin
Small branch
Distribution to duodenal bulb area
Considerations for optimization
Often not visualized (though almost always present)
Be suspicious if branch from hepatic artery passes
inferomedially toward duodenum
Coil embolize if originating from hepatic circulation
(about 50%) Supraduodenal artery (arrows) arises from the proper hepatic
artery and passes toward the proximal duodenum.
Bianchi et al. The supraduodenal artery, Surg Radiol Anat 11 ( 1989), pp. 37-40.
Image courtesy of David Liu, MD

31. Retroduodenal Artery
Also known as the posterior superior
pancreaticoduodenal artery
Origin
Gastroduodenal artery – 78%
Hepatic artery (proper or right) – 15%
Superior mesenteric artery – 5%
Destination
Head of pancreas
Uncinate process
Duodenal bulb
Anatomic Clues
Runs along common hepatic duct
Parallels 2nd segment of duodenum
Considerations for optimization
No need to coil embolize in most cases The retroduodenal artery (arrows) typically arises as the first branch of
the gastroduodenal artery.
Coil embolize if originating from the hepatic artery
VanDamme JP, Van der Schueren G, Bonte J. Vascularisation du pancreas: proposition de nomenclature PNA et angioarchitecture des ilots. C R Assoc Anat 1968;
139:1184 –1192.

32. Falciform Artery
Origin
Middle hepatic artery – 56%
Left hepatic artery – 44%
Destination
Anterior abdominal wall, umbilical region
Anatomic Clues
Courses anteriorly and diagonally toward the Falciform artery (arrow) arising from the left hepatic
artery, early phase.
midline (paralleling the falciform ligament)
Considerations for optimization
Coil embolize if present (2%)
Lack of protection can result in abdominal wall
injury, pain, and/or rash
Late phase confirms typical course of falciform artery
Baba et al. HEPATIC FALCIFORM ARTERY: Angiographic findings in 25 patients. Acta Radiologica. Volume 41:4 July 2000 , pages 329 - 333.
Williams et al. Hepatic falciform artery: anatomy, angiographic appearance, and clinical significance. Radiology 1985. 156: 339-340.

33. Cystic Artery
Origin
Right hepatic artery – 90%
Left hepatic artery – 7%
Common hepatic artery – 3%
Gastroduodenal artery – 1%
Destination
Gallbladder
Anatomic Clues
Typically the first branch of right hepatic
artery
Bifurcation into superficial and deep
branches
Network of vessels outlining viscus
Considerations for optimization
Coil embolization can rarely lead to
ischemic cholecystitis
Lack of coil embolization can rarely lead to Cystic artery (arrow) arising from the anterior division branch of the
chemical or radiation cholecystitis right hepatic artery
Daseler EH, Anson BA, Hambley WC, Reimann AF. The cystic artery and constituents of the hepatic pedicle. A study of 500 specimens. Surg Gynecol
Obstet 1947: 85: 47–63

34. Summary
-Extrahepatic collaterals originating from the celiac axis
should be considered in hepatic tumor treatment including
the inferior phrenic, omental, and adrenal arteries.
- “Lesser” branches of the celiac axis specifically arising
from the hepatic circulation should be recognized in
vascular optimization of liver-directed therapy. These
branches include the gastroduodenal, right gastric,
accessory gastric, dorsal pancreatic, supraduodenal,
retroduodenal, falciform, and cystic arteries.