Spectrum of hepatofugal collateral pathways in portal hypertension: an illustrated radiological review

Abstract

The purpose of this article is to describe the various portosystemic collateral pathways pertinent to portal hypertension on multi-detector row computed tomography (MDCT) and their clinical relevance, with special emphasis on the uncommon ones. The knowledge and understanding of the various patterns of portosystemic collateral channels has important implications both for the clinician and the interventionist. MDCT with its advanced post processing capabilities can exquisitely demonstrate these vascular pathways to help in therapeutic decision making. Teaching points • Portosystemic collaterals are an important cause of bleeding and hepatic encephalopathy. • Radiologists should be familiar with the imaging findings to effectively identify them. • Pre-operative knowledge of portosystemic collaterals is essential to avoid inadvertent vascular injury.

Keywords: Collateral pathways; Multi-detector row computed tomography; Portal hypertension; Shunt; Varices.

Fig. 1

Portosystemic collateral pathways described in English-language medical literature

Fig. 2

Coronal-oblique maximum intensity projection (MIP) contrast-enhanced CT (CECT) image demonstrating multiple collaterals in the oesophageal mucosa (solid arrows) and para-oesophageal region (interrupted arrow). Asterisk denotes the gastro-oesophageal junction

Fig. 3

.Coronal MIP image showing a bunch of para-oesophageal collaterals (asterisk) being supplied by a dilated left gastric vein (arrows)

Fig. 4

Sagittal MIP image from another patient demonstrating multiple oesophageal and para-oesophageal collaterals (arrows and asterisk, respectively) drained via dilated azygous vein (arrowheads)

Fig. 5

Axial CECT image showing multiple collaterals in the gastric mucosa (arrowhead) and perigastric region (arrow). The patient also had a right lobe hepatocellular carcinoma (asterisk)

Fig. 6

Graphic illustration of the Kiyosue classification of GV [21]. a Classification based on the inflow pathway(s). Type 1 (i) refers to a single afferent vein for the varices, while type 2 (ii) refers to multiple afferent vessels contributing to the varix. Type 3 is like type 2 with the addition of small afferent vein(s) in direct continuity with the outflow tract. b Classification based on drainage pathway. Type A consists of a gastrorenal shunt as the sole drainage. Type B describes the additional presence of small portosystemic collaterals; type C describes the presence of both a gastrorenal and direct gastrocaval shunt; type D consists of multiple small portosystemic collaterals as the drainage pathways without any recognisable shunt

Fig. 7

Axial CECT image showing multiple submucosal as well as paraduodenal collaterals along the third part of duodenum (arrows)

Fig. 8

Axial CECT image showing multiple jejunal collaterals (arrow)

Fig. 9

Coronal MIP image demonstrating multiple pericolonic collaterals (arrowheads) deriving their afferent supply from the superior mesenteric vein (arrow)

Fig. 10

Axial CECT image showing collaterals in the pancreatic parenchyma (arrow) in a patient with portal vein thrombosis

Fig. 11

Sagittal MIP image showing multiple uterine and vaginal collaterals (arrows and arrowheads, respectively)

Fig. 12

Sagittal MIP image showing multiple collaterals in the wall of the urinary bladder (arrows)

Fig. 13

Axial CECT image showing multiple pericholecystic varices (arrows)

Fig. 14

Coronal MIP image showing multiple retroperitoneal and paravertebral collaterals (arrows in a and b, respectively)

Fig. 15

Axial MIP image showing multiple omental collaterals (arrows)

Fig. 16

Axial MIP image showing stomal collaterals (arrows)

Fig. 17

Sagittal MIP image showing multiple rectal collaterals (arrows) deriving their afferent supply from the IMV (interrupted arrow)

Fig. 18

Sagittal MIP image showing an intrahepatic shunt (arrow) between the right portal vein (black arrowhead) and IVC (white arrowhead)

Fig. 19

Coronal MIP image showing a dilated and tortuous recanalised paraumbilical vein (solid arrows) arising from the left portal vein (interrupted arrow) and draining into the right common iliac vein (arrowhead)

Fig. 20

A giant recanalised paraumbilical vein draining via a large tuft of periumbilical varices (interrupted arrow) into the ipsilateral internal thoracic vein (solid arrow) as well as contralateral superficial epigastric vein (white arrowhead)

Fig. 21

Left infradiaphragmatic shunt. A transhepatic shunt (interrupted arrow) wherein the collateral vein from the peripheral portal branch of the left lateral segment communicates with the left inferior phrenic vein at (solid arrow) the left triangular ligament

Fig. 22

Bare area shunt. An intrahepatic shunt (white arrow) is seen arising from a peripheral branch of right portal vein (black arrow) and draining into the intercostal veins (arrowhead)

Fig. 23

Aberrant left gastric vein (arrow) draining into the portal vein (arrowhead)

Fig. 24

Coronal MIP image demonstrating a dilated and tortuous splenorenal shunt (arrowheads) communicating between the splenic vein (interrupted arrow) and the left renal vein (asterisk)

Fig. 25

Coronal MIP image showing a mesocaval shunt (interrupted arrow) communicating between the SMV (arrow) and IVC (arrowhead) with a bunch of mesenteric collaterals (asterisk)

Fig. 26

Coronal oblique MIP image showing a trans-splenic shunt (interrupted arrow) draining into the intercostal vein (arrowhead)