Rsna final 2

34
The Road Less Traveled: The Often Ignored Lesser Branches of the Celiac Axis Aram Lee, MD Justin McWilliams, MD UCLA Radiology

Transcript of Rsna final 2

The Road Less Traveled: The Often Ignored Lesser Branches of the Celiac Axis

Aram Lee, MD Justin McWilliams, MD UCLA Radiology

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

CLASSIC HEPATIC ARTERIAL ANATOMY AND COMMON ARTERIAL VARIANTS

Part 1:

CHA

GDA

PHA

RHA LHA

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%.

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.

Conventional hepatic arterial anatomy

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.

Right hepatic artery

OriginProper hepatic arterySMA (12%)Celiac trunk (double hepatic artery)

DestinationSegments 5-8

Recognized byDistribution to right lobe of liver

Covey et al. Variant Hepatic Arterial Anatomy Revisited: DSA Performed in 600 Patients. Radiology. August 2002. 224: 542-547.

Replaced or accessory right hepatic arteryReplaced 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-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

Replaced RHA from SMA

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 gastric artery, very rarely from RHA

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

Replaced left hepatic artery arising from left gastric artery. Left gastric branches (arrowheads) can mimic segment 2 or 3 branches; true left hepatic branches take off beyond the umbilical point (arrow).

Middle hepatic artery

A “middle hepatic artery” supplying segment 4 can arise from PHA as a trifurcation, or from the right hepatic artery

Middle hepatic artery from RHA Middle hepatic artery from Proper Hepatic Artery (trifurcation)

Double replaced hepatic artery

Celiac injection demonstrates absence of RHA and LHA. Expected course of CHA (arrow) terminates in GDA and RGA.

Replaced LHA from LGA

0.5%

Replaced RHA from SMA

Covey et al. Variant hepatic arterial anatomy revisited: DSA performed in 600 patients. Radiology 2002; 224: 542-547.

Replaced common hepatic artery

2 %

Hiatt et al. Surgical Anatomy of the Hepatic Arteries in 1000 Cases. Annals of Surgery. July 1994. 220: 50-52.

Injection of celiac axis demonstrates splenic and left gastric arteries, but no common hepatic artery.

Common hepatic artery arises from the superior mesenteric artery.

EXTRAHEPATIC COLLATERAL VESSELS ORIGINATING FROM THE CELIAC AXIS WHICH CAN BE PARASITIZED BY LIVER TUMORS

Part 2:

Extrahepatic collaterals in liver tumor therapy

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.

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

Extrahepatic collaterals to consider

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.

Bare area = Posterior surface of segment 7 and posterior half of the diaphragmatic surface of segment 8 .

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

Right inferior phrenic arteryOrigin

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

SuppliesRight hemidiaphragmSuspect HCC supply for tumors in segment 7 abutting the diaphragm

Effects of embolizationUsually well-toleratedShoulder painPleural effusionBasal atelectasisTransient hemoptysisDiaphragmatic 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.

50%of collateral supply

Infiltrative HCC of the right lobe Replaced RHA angiogram demonstrates tumor supply. DEB-TACE was performed.

HCC involvement of the right inferior phrenic artery

1 month post-TACE, tumor necrosis is seen, but persistent enhancement is seen at the posterior diaphragmatic margin.

Right phrenic angiography demonstrates copious tumor supply. DEB-TACE was performed from this location.

Omental arteries

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.

OriginRight or left gastroepiploic artery

SuppliesGreater omentum (mobile!)Can supply tumors on almost any surface of the liver

Effects of embolizationUsually 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).

OriginUsually first branch of right hepatic artery

SuppliesGallbladderHCC in gallbladder fossa

Recognized byProximal bifurcationCurved shape outlining viscus

Effects of embolizationCholecystitis/gallbladder infarctionOften asymptomatic 9%

of collateral supply

Cystic artery injection demonstrates parasitic 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.

Cystic Artery

Right adrenal arteryOrigin

Superior adrenal artery from right inferior phrenic arteryMiddle adrenal artery from lateral aorta between the celiac and renal arteriesInferior adrenal artery from superior aspect of right renal artery

SuppliesRight adrenal glandMay supply tumor which extends inferomedially

Effects of embolizationUsually well-tolerated

Kim HC et al. Recognizing extrahepatic collateral vessels that supply hepatocellular carcinoma to avoid complications of transcatheter arterial chemoembolization. Radiographics 2005.

6%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%)

Kim HC et al. Recognizing extrahepatic collateral vessels that supply hepatocellular carcinoma to avoid complications of transcatheter arterial chemoembolization. Radiographics 2005.

Uncommon sources of collateral supply

Right adrenal artery

EXTRAHEPATIC BRANCHES ARISING FROM THE HEPATIC ARTERIAL CIRCULATION TO RECOGNIZE IN LIVER EMBOLOTHERAPY

Part 3:

Vascular optimizationProtective coil embolization of extrahepatic branches arising from the hepatic

circulation prior to embolotherapy

1. Gastroduodenal artery2. Right gastric artery3. Accessory left gastric artery4. Retroduodenal artery5. Supraduodenal artery6. Falciform artery7. Cystic artery

Coil embolization of these vessels (when necessary) prevents passage of particles (DEB or Y90) into sensitive structures

Other vessels to consider:-Dorsal pancreatic artery-Left phrenic artery-Esophageal branches

Accessory left gastricRight gastricFalciformLeft phrenic

CysticSupraduodenalRetroduodenal

Right gastricSupraduodenalRetroduodenalDorsal pancreatic

Gastroduodenal Artery

OriginCommon hepatic artery

SuppliesPylorus of stomachProximal duodenumPancreatic head (via pancreaticoduodenals)Greater curvature of stomach (via R gastroepiploic)

Anatomic CluesNear constant origin from CHACharacteristic 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).

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

Gastroduodenal Artery

GDA with reversed flow. Depending on the etiology, this may or may not require coil embolization.

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)

Destination-Gastric antrum and pylorus-Proximal duodenal bulb

Anatomic Clues-Leftward course along lesser curvature of stomach-Anastomoses with left gastric 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.

Right gastric artery (arrow) arising from the origin of the gastro-duodenal artery. Note anastomoses with the left gastric artery.

Right gastric artery (arrow) arising from the left hepatic 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.

Right gastric artery

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.

Dorsal Pancreatic Artery

Origin- Splenic artery (60%)- Common hepatic artery (15%)- SMA (10%)- Celiac (10%)- Rarely others

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

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.

Considerations for Vascular Optimization- No, in most cases

- Sufficiently proximal (splenic/celiac) origin to avoid collateral damage

- Yes, in a few cases- Common hepatic or more distal origin

- Copious pancreatic collaterals allow safe coiling

Dorsal pancreatic artery arising from the celiac artery terminus.

Prevalence 3-21% (high in Asian populations)Origin

Left hepatic artery in proximal portion – 60%Left hepatic artery in distal portion – 40%

DestinationGastric cardia and fundus

Anatomic CluesRuns in the fissure of the ligamentum venosum (same place as a replaced left hepatic artery) on CT

Considerations for optimizationShould be coil embolized if presentOften difficult to identify on angioTips for identification-Gastric mucosal enhancement-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.

Proximal-type accessory left gastric artery (arrow) arises from the LHA prior to the umbilical point and courses to the gastric fundus (arrowheads).

Accessory left gastric artery

Supraduodenal Artery (of Wilkie)

Bianchi et al. The supraduodenal artery, Surg Radiol Anat 11 ( 1989), pp. 37-40.Image courtesy of David Liu, MD

Supraduodenal artery (arrows) arises from the proper hepatic artery and passes toward the proximal duodenum.

OriginGastroduodenal artery – 26%Common or proper hepatic artery – 20%Left hepatic artery – 20%Right hepatic artery – 13%Cystic artery – 10%Right gastric artery – 8%

DestinationProximal duodenum

Anatomic CluesExtremely variable originSmall branchDistribution to duodenal bulb area

Considerations for optimizationOften not visualized (though almost always present)Be suspicious if branch from hepatic artery passes inferomedially toward duodenumCoil embolize if originating from hepatic circulation (about 50%)

Also known as the posterior superior pancreaticoduodenal artery

OriginGastroduodenal artery – 78%Hepatic artery (proper or right) – 15%Superior mesenteric artery – 5%

DestinationHead of pancreasUncinate processDuodenal bulb

Anatomic CluesRuns along common hepatic ductParallels 2nd segment of duodenum

Considerations for optimizationNo need to coil embolize in most cases Coil embolize if originating from the hepatic artery

The retroduodenal artery (arrows) typically arises as the first branch of the gastroduodenal 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.

Retroduodenal Artery

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.

Falciform artery (arrow) arising from the left hepatic artery, early phase.

Late phase confirms typical course of falciform artery

OriginMiddle hepatic artery – 56%Left hepatic artery – 44%

DestinationAnterior abdominal wall, umbilical region

Anatomic CluesCourses anteriorly and diagonally toward the midline (paralleling the falciform ligament)

Considerations for optimizationCoil embolize if present (2%)Lack of protection can result in abdominal wall injury, pain, and/or rash

Cystic Artery

OriginRight hepatic artery – 90%Left hepatic artery – 7%Common hepatic artery – 3%Gastroduodenal artery – 1%

DestinationGallbladder

Anatomic CluesTypically the first branch of right hepatic arteryBifurcation into superficial and deep branchesNetwork of vessels outlining viscus

Considerations for optimizationCoil embolization can rarely lead to ischemic cholecystitisLack of coil embolization can rarely lead to chemical or radiation cholecystitis

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

Cystic artery (arrow) arising from the anterior division branch of the right hepatic artery

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.