Collaterals in portal hypertension: anatomy and clinical relevance

Abstract

Portal hypertension is a key pathophysiology of chronic liver diseases typified with cirrhosis or noncirrhotic portal hypertension. The development of collateral vessels is a characteristic feature of impaired portal hemodynamics. The paraumbilical vein (PUV), left gastric vein (LGV), posterior gastric vein (PGV), short gastric vein (SGV), splenorenal shunt (SRS), and inferior mesenteric vein (IMV) are major collaterals, and there are some rare collaterals. The degree and hemodynamics of collateral may affect the portal venous circulation and may compensate for the balance between inflow and outflow volume of the liver. Additionally, the development of collateral shows a relation with the liver function reserve and clinical manifestations such as esophageal varices (EV), gastric varices, rectal varices and the other ectopic varices, hepatic encephalopathy, and prognosis. Furthermore, there may be an interrelationship in the development between different collaterals, showing additional influences on the clinical presentations. Thus, the assessment of collaterals may enhance the understanding of the underlying pathophysiology of the condition of patients with portal hypertension. This review article concluded that each collateral has a specific function depending on the anatomy and hemodynamics and is linked with the relative clinical presentation in patients with portal hypertension. Imaging modalities may be essential for the detection, grading and evaluation of the role of collaterals and may help to understand the pathophysiology of the patient condition. Further investigation in a large-scale study would elucidate the basic and clinical significance of collaterals in patients with portal hypertension and may provide information on how to manage them to improve the prognosis as well as quality of life.

Keywords: Doppler; Portal hypertension; cirrhosis; collateral; ectopic varices; esophageal varices (EV); gastric varices; hepatic encephalopathy; hepatic venous pressure gradient (HVPG); shunt; ultrasound (US).

Figure 1

Schematic presentation of collaterals. *, shunt from SMV to right renal vein, duodenal varices, or stomal varices. PUV, paraumbilical vein; LGV, left gastric vein; PGV, posterior gastric vein; SGV, short gastric vein (with creating gastric varices); SRS, splenoreal shunt (without creating gastric varices); IMV, inferior mesenteric vein; PV, portal vein; SV, splenic vein; SMV, superior mesenteric vein.

Figure 2

Seventy-one-year-old male; HCV-related cirrhosis. (A) CT image showed PUV (arrows). (B) Percutaneous transhepatic portogram demonstrated development of PUV (arrows). HCV, hepatitis C virus; CT, computed tomography; PUV, paraumbilical vein.

Figure 3

Seventy-five-year-old male, nonBnonC cirrhosis with EV. (A) Moderate-degree of EV. (B) Ultrasonic microprobe (12 MHz) demonstrated submucosal vessels (arrows) corresponding to EV. (C) Pulsed Doppler sonography demonstrated LGV with hepatofugal flow direction (arrow). EV, esophageal varices; LGV, left gastric vein.

Figure 4

Seventy-seven-year-old female, nonBnonC cirrhosis (A) CT image showed development of paraesophageal vein (arrows) around the esophagus (arrow head). (B) Ultrasonic microprobe (12 MHz) demonstrated paraesophageal vein (arrows) around the esophagus. (C) Percutaneous transhepatic portogram demonstrated development of paraesophageal vein (arrows). CT, computed tomography.

Figure 5

Doppler sonogram (normal subject, 42-year-old male) demonstrated LGV (arrow) with hepatopetal flow direction. Arrow heads, left gastric artery. LGV, left gastric vein.

Figure 6

Sixty-nine-year-old male, HBV-related cirrhosis with gastric varices. Transjugular retrograde venography by using balloon catheter (arrow heads) demonstrated gastric varices (circle) and three inflow routes, LGV, PGV and SGV. The PGV originates from the middle of splenic vein. HBV, hepatitis B virus; LGV, left gastric vein; PGV, posterior gastric vein; SGV, short gastric vein.

Figure 7

Sixty-two-year-old female, alcoholic cirrhosis with gastric varices. (A) Moderate-degree of gastric fundal varices. (B) Gastric fundal varices (arrow heads). (C) SGV as the inflow route to gastric varices (arrows). SGV, short gastric vein.

Figure 8

Sixty-seven-year-old female, HCV-related cirrhosis with hepatic encephalopathy. Transfemoral retrograde venography by using balloon catheter (arrow heads) demonstrated IMV (arrows). Splenic vein is the route for which the IMV drains. HCV, hepatitis C virus; IMV, inferior mesenteric vein.

Figure 9

Fifty-eight-year-old male, HCV-related cirrhosis. (A) Duodenal varices. (B) Transjugular venogram demonstrated inferior pancreaticoduodenal vein (arrow) as inflow route, and the outflow route (arrow heads) which connects to inferior vena cava. Thick arrows, catheter in the inferior vena cava. HCV, hepatitis C virus.

Figure 10

Eighty-eight-year-old male, nonalcoholic steatohepatitis, cirrhosis. (A) Collateral (arrows) which originates from superior mesenteric vein. (B) Shunt showing tortuous shape. (C) Outflow route (arrows) which connects with RRV. SMV, superior mesenteric vein; RRV, right renal vein.