© 2010 by the American Institute of Ultrasound in Medicine
J Ultrasound Med 29:87-93 • 0278-4297
Sonographic Anatomy of the Gastrohepatic Ligament
Gaurav Desai, MD and
Roy A. Filly, MD
Department of Radiology and Biomedical Imaging, University of California, San Francisco, California USA.
Address correspondence to Roy A. Filly, MD, Department of Radiology, University of California, 505 Parnassus Ave, L374, San Francisco, CA 94143-0628 USA. E-mail: roy.filly{at}radiology.ucsf.edu
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Abstract
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Objective. The purpose of this presentation is to illustrate anatomic and pathologic features of the gastrohepatic ligament (GHL) and to show its usefulness for precise localization of abnormalities, particularly in relation to the lesser peritoneal cavity and diseases occurring within the confines of the ligament itself. Methods. Cases were selected that illustrate the objectives above. Results. Illustrations show various anatomic and pathologic features meant to enhance interpretation of left upper quadrant sonograms. Conclusions. Illustrations seen in the sonographic literature vaguely interpret the relationships of the GHL. Misunderstanding has led not only to improper nomenclature but also to the use of inappropriate indicators of lesser omental diseases. With a clear understanding of the anatomy of the GHL and its use as a pivotal marker for structures around and within it, one can avoid these pitfalls and better evaluate adult and pediatric lesser omental anatomy.
Key Words: gastrohepatic ligament • hepatogastric ligament • lesser omentun Abbreviations: GHL, gastrohepatic ligament • HDL, hepatoduodenal ligament • LPV, left portal vein • LV, ligamentum venosum
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Introduction
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The gastrohepatic ligament (GHL) is an important landmark for diseases and variants of anatomy alike. Knowledge of the anatomy of this structure is useful for precise localization of abnormalities, particularly in relation to the lesser peritoneal cavity and to diseases that occur within the confines of the ligament itself.
The sonographic finding of abnormalities in the region of the lesser sac (lesser peritoneal cavity) causes concern for serious diseases, including nodal involvement from metastatic tumors and contiguous spread of primary gastric neoplasia.1 Also important is contiguous inflammation from pancreatitis and peptic ulcer disease, which can extend to involve the liver through this ligament.2 Recognition of the locations of abnormalities assists in differential diagnosis and planning of surgical therapy. Clues to diagnoses frequently can be assembled from careful scrutiny of the anatomy. This presentation aims to provide a comprehensive review of the sonographic features of the GHL, its use in sorting out anatomic structures in the left upper quadrant, and its value in identifying and localizing abnormalities.
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Relevant Anatomy and Embryology
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The lesser omentum, a derivative of the ventral midline mesentery of the embryonic primitive gut, is formed from two layers of peritoneum separated by variable amounts of connective tissue, principally fat.3 It is composed of two ligaments: the GHL and hepatoduodenal ligament (HDL), which are attachments from the esophagus and stomach to the liver (GHL) and from the duodenum to the liver (HDL). These ligaments constitute a continuous sheet even though the names imply two distinct ligaments (Figure 1 ). The GHL contains the right and left gastric vessels, branches of the vagus nerve, and the left gastric chain of lymph nodes, whereas the HDL contains the portal vein, the common hepatic artery (Figure 1), and the common bile duct. The major portion of the lesser omentum originating from the lesser gastric curvature passes in the coronal plane to reach the base of the increasingly deep groove formed for the ductus venosus on the hepatic dorsum as the liver volume increases.4 When fully developed, the fissure of the ligamentum venosum (LV) is a deep cleft extending from the porta hepatis inferiorly to the inferior vena cava superiorly. Although it contains the LV, the vestige of the ductus venosus for which it is named, one would need to perform a detailed dissection to find the LV. By contrast, the structure that is easily noted within the fissure on sonograms is the GHL. Thus, from a practical anatomic perspective, it would have been preferable to name it "the fissure of the GHL."
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Figure 1. The anatomy of the lesser omentum is illustrated in the drawing on the left. Note that it is a continuous sheet extending from the intra-abdominal esophagus, lesser curvature of the stomach, and duodenum to the liver. The GHL and HDL constitute a continuous sheet, despite the fact that the names imply two distinct ligaments. The red line illustrates the plane of section for the drawing on the right. The drawing on the right shows a longitudinal plane of section illustrating that the GHL precisely divides the caudate lobe from the lateral segment of the left hepatic lobe. It also serves as an anatomic arrow pointing to the common hepatic artery and main portal vein. Reproduced with permission from Filly RA. Upper Abdominal Sonographic Anatomy [CD-ROM]. Philadelphia, PA: Lippincott-Raven Publishers; 1997.
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The GHL: How We See It on Sonograms
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The relative ease of seeing the GHL as it lies in the fissure of the LV on sonograms is related to the amount of fat contained between the peritoneal leaves of the ligament. As such, it is seen as a brightly reflective structure. The less fat contained within the ligament, the less obvious it is on sonograms (Figure 2A). As the amount of contained fat increases, the GHL becomes more obvious (Figure 2B). On longitudinally oriented scans, it is easily seen as the bright line dividing the caudate lobe from the lateral segment of the left hepatic lobe (Figures 1 and 2). Indeed, the GHL shows the precise division between the lateral segment of the left hepatic lobe and the caudate lobe (Figures 1 and 2). Thus, in parasagittal planes of section, when the GHL is seen, the plane necessarily is through the lateral segment of the left lobe. On transversely oriented sonograms, in planes of section near the diaphragm, the GHL again separates the caudate lobe from the lateral segment of the left hepatic lobe (Figure 3).
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Figure 2. A, Longitudinal sonogram as illustrated in Figure 1. Note that in this ectomorphic patient, the ligament (GHL) is not seen as a continuous sheet. B, Longitudinal sonogram as illustrated in Figure 1 in a mesomorphic patient. With a somewhat greater amount of fat in the GHL, the ligament is more easily seen. When viewed in a parasagittal plane, one can see two vessels at the inferior end of the fissure. The fissure points to them like an arrow (compare with Figure 1). These vessels necessarily must be the common hepatic artery (CHA) and the main portal vein (MPV). Although the splenic artery and splenic vein could have a similar configuration and relationship to the pancreas, we can be confident that our anatomic arrow has discriminated these two possibilities. Only the main portal vein and common hepatic artery enter the lesser omentum en route to the liver via the HDL. This configuration also tells us that we are in a plane of section to the right of the aorta near the midline. To find the common bile duct, one would need to move the transducer a centimeter or two to the right. To find the origin of the superior mesenteric artery from the aorta, would need to move the transducer a centimeter or two to the left. Thus, this simple observation both clarifies the anatomy in the plane of section under observation and orients us as to our position within the abdomen. Importantly, the GHL precisely divides the caudate lobe (CL) from the lateral segment of the left hepatic lobe (LS).
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The GHL: An Anatomic Arrow
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What is an anatomic "arrow"? Simply, it is a standard anatomic arrangement that is easily recognizable and serves to immediately orient one in the upper abdomen. After a while, one can recognize it instantly like an old friend. The fissure for the LV (ie, the GHL) is an excellent example. In the parasagittal plane, the GHL "points" to the common hepatic artery and portal vein (Figures 1 and 2). In the transverse axial plane near the level of the diaphragm, the GHL points to the intra-abdominal esophagus (Figure 3). Recall that the GHL (lesser omentum) begins at the abdominal esophagus. At the end of our anatomic arrow is a "bull’s eye" (how appropriate; Video 1). The bull’s eye is made up of the various wall components of the esophagus. At the opposite end, the GHL points to the left portal vein (LPV). Indeed, it does more than simply point to the LPV; it precisely divides the LPV into its two major segments (the pars transversa and umbilical segments; Figure 3B).3,5
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The Fat Is in the GHL, Not the Retroperitoneum
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Recall that the ease of seeing the GHL is related to the amount of fat contained between the peritoneal leaves of the ligament. On transverse axial sonograms at the level of the pancreas, lying between the liver and the pancreas, the GHL (or, more specifically, the fat in the GHL) is commonly mistaken to be retroperitoneal fat. That the fat is in the ligament is recognizable because the fatty tissue can be easily seen to spread both anteriorly and posteriorly around the stomach (for renal masses, the "claw sign"; Figure 4 and Video 2). Often sonologists mistakenly assume that all of the fat lying anterior to the pancreas is retroperitoneal fat. Most of the fat is in the GHL and not the retroperitoneum (Video 2). In this digital video clip, the fatty tissue lying posterior to the liver and anterior to the pancreas is in the GHL, not the retroperitoneum. Note that the fatty tissue spans the apparent "gap" between the gastric body and antrum.
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The Nodes Are in the GHL
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The sonographic finding of a mass within the region of the lesser sac raises concern for a practicing radiologist. Noteworthy diseases associated with the GHL include nodal involvement from local neoplasms and inflammation.4 Contiguous spread of gastric carcinoma and inflammation from pancreatitis and peptic ulcer disease can reach the liver through this ligament.2 The nodes visualized commonly reside in the lesser omentum, either within the GHL or the HDL rather than the retroperitoneum (Video 3).
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The GHL Helps Us See Accessory and Replaced Left Hepatic Arteries
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Typically, the proper hepatic artery reaches the liver through the HDL traveling with the portal vein (Figure 5). On reaching the porta hepatis, it divides into the left and right hepatic arteries. Replaced and accessory arteries to both the left and right hepatic lobes are not uncommon. An accessory or replaced left hepatic artery, seen in 8% to 10% of individuals,6 may arise from the left gastric artery, superior mesenteric artery, or aorta. However, on its path to the liver, it passes through the GHL (Figure 5). The clinical importance of this artery is its impact during gastrectomy7,8 and liver transplantation.9,10 It has been reported previously in the literature11 that this artery travels through the LV when in fact it travels though the GHL (Figure 5). The left gastric artery and vein enter the GHL and distribute to the lesser curvature of the stomach (Figure 6 and Video 4). On observing an artery, or in some cases a notch within this fissure, one must consider a replaced or accessory left hepatic artery (Figure 7).
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Figure 5. Illustration of the "routes" that the left hepatic arterial blood takes when going to the liver. The typical route is through the HDL, traveling in contiguity with the portal vein. However, not uncommonly, the left hepatic artery (a replaced left hepatic artery or an accessory left hepatic artery) originates from the left gastric artery and reaches the liver through the GHL. Reproduced with permission from Filly RA. Upper Abdominal Sonographic Anatomy [CD-ROM]. Philadelphia, PA: Lippincott-Raven Publishers; 1997.
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Figure 6. Longitudinal sonogram of the GHL (arrowheads). Within the GHL travels the left gastric artery and vein (LGA/V). SA indicates splenic artery.
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Figure 7. A, Longitudinal color Doppler image of an accessory left hepatic artery (LHAa). B, Transverse axial color Doppler image of an accessory left hepatic artery. The easiest way to identify a replaced or accessory LHA is on the longitudinal plane. A very tiny accessory LHA is shown in Video 4. Can you see it? CHA indicates common hepatic artery in the HDL; and LHV, left hepatic vein.
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The Varices Are in the GHL
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In patients with cirrhosis, it is important to make a determination as accurately as possible regarding the coexistence of portal hypertension. The most definitive sonographic feature of portal hypertension is the depiction of varices. One of the most common pathways for portosystemic communications to occur is through the left gastric vein to the esophageal veins (so-called esophageal varices). The variceal pathways are in the GHL because, of course, the left gastric vein travels in the GHL (Figure 8).
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Figure 8. Longitudinal sonogram of the GHL (arrowheads) in a patient with cirrhosis and portal hypertension. Note the markedly enlarged and tortuous left gastric varices (V). These continue to anastomose with esophageal veins. Compare with Figure 6 and Video 4.
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The GHL Shows Us Fluid in the Superior and Splenic Recesses
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The omental bursa or lesser sac is composed of a series of pouches or recesses: the vestibule, superior omental recess, lienal or splenic omental recess, and inferior omental recess.4 The superior recess is situated between the caudate lobe of the liver and the diaphragm, is continuous over the inferior vena cava to the right of the midline, and extends to the level of the diaphragm. The splenic recess is positioned between the spleen and pancreas and the stomach. The lesser sac is connected to the greater sac (greater peritoneal cavity) via the epiploic foramen (also known as the foramen of Winslow). Lesser sac collections constitute 50% to 60% of extrapancreatic fluid collections (Figure 9 and Video 5).12,13 Sterile or infective inflammation of surrounding structures such as the pancreas and surgery on the stomach or biliary tree may cause fluid to collect in either the splenic recess (Figure 9 and Video 5) or superior recess of the lesser sac (Video 6).14
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Figure 9. Transverse axial sonogram in a patient with ascites. The lesser omentum (LO) is easily seen because fluid surrounds it. (In this section we see the GHL.). The lesser omentum divides the greater peritoneal cavity (GPC) from the lesser peritoneal cavity (LPC). The portion of the lesser peritoneal cavity seen here is the splenic recess. Note again that the fat is in the GHL, not in the retroperitoneum overlying the pancreas (Pa). LL indicates left hepatic lobe.
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Footnotes
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We thank Christine Gralapp, who prepared the original illustrations for the CD-ROM Upper Abdominal Sonographic Anatomy by Roy A. Filly, MD (Lippincott-Raven Publishers, Philadelphia, PA), and Wolters Kluwer Health Medical Research, Lippincott Williams & Wilkins, for granting us permission to use the illustrations in this article.
Received June 16, 2009, from the Department of Radiology and Biomedical Imaging, University of California, San Francisco, California USA. Revision requested June 29, 2009. Revised manuscript accepted for publication July 9, 2009.
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References
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- Filly RA, Marglin S, Castellino RA. The ultrasonographic spectrum of abdominal and pelvic Hodgkin’s disease and non-Hodgkin’s lymphoma. Cancer 1976; 38:2143–2148.[Medline]
- Vikram R, Balachandran A, Bhosale PR, Tamm EP, Marcal LP, Charnsangavej C. Pancreas: peritoneal reflections, ligamentous connections, and pathways of disease spread. Radiographics 2009; 29:e34.[Abstract/Free Full Text]
- Schoenwolf GC, Bleyl SB, Brauer PR, Francis-West PH. Development of the gastrointestinal tract. In: Larsen WJ (ed). Human Embryology. 4th ed. Philadelphia, PA: Churchill Livingstone; 2009:435–477.
- Borley NR, Collins P, Healy J. Development of the peritoneal cavity, gastrointestinal tract and its adnexae. In: Standring S. Gray H (eds). The Anatomical Basis of Clinical Practice. 40th ed. London, England: Churchill Livingstone; 2008: 1214–1215.
- Chinn DH, Filly RA, Callen PW. Ultrasonic evaluation of umbilical and hepatic fetal vascular anatomy. Radiology 1982; 144:153–157.[Free Full Text]
- Hiatt JR, Gabbay J, Busuttil RW. Surgical anatomy of the hepatic arteries in 1000 cases. Ann Surg 1994; 220:50–52.[Medline]
- Okano S, Sawai K, Taniguchi H, Takahashi T. Aberrant left hepatic artery arising from the left gastric artery and liver function after radical gastrectomy for gastric cancer. World J Surg 1993; 17:70–73.[Medline]
- Lurie AS. The significance of the variant left accessory hepatic artery in surgery for proximal gastric cancer. Arch Surg 1987; 122:725–728.[Abstract/Free Full Text]
- Gruttadauria S, Foglieni CS, Doria C, Luca A, Lauro A, Marino IR. The hepatic artery in liver transplantation and surgery: vascular anomalies in 701 cases. Clin Transplant 2001; 15:359–363.[Medline]
- Co
 kun M, Kayahan EM, Ozbek O, Cakir B, Dalgiç A, Haberal M. Imaging of hepatic arterial anatomy for depicting vascular variations in living related liver transplant donor candidates with multidetector computed tomography: comparison with conventional angiography [references and further reading therein]. Transplant Proc 2005; 37:1070–1073.[Medline] - 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. AJR Am J Roentgenol 2006; 187:1002–1009.[Abstract/Free Full Text]
- Siegelman SS, Copeland BE, Saba CP, Cameron JL, Sanders RC, Zerhouni EA. CT of fluid collections associated with pancreatitis. AJR Am J Roentgenol 1980; 134:1121–1132.[Abstract]
- King LR, Siegel MJ, Balfe DM. Acute pancreatitis in children: CT findings of intra- and extrapancreatic fluid collections. Radiology 1995; 195:196–200.[Abstract/Free Full Text]
- Mueller PR, Ferrucci JT Jr, Simeone JF, et al. Lesser sac abscesses and fluid collections: drainage by transhepatic approach. Radiology 1985; 155:615–618.[Abstract/Free Full Text]
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Abstract
Introduction
