Artery aberrant hepatic

An aberrant hepatic artery refers to a branch that does not arise from its usual source (i.e. proper hepatic artery from the celiac trunk). This type of artery may be a substitute for the usual hepatic artery that is absent, in which case it is referred to as an aberrant replaced hepatic artery. In other cases there may be an additional artery to the one normally present hence the term aberrant accessory artery. 

The first published description of aberrant hepatic arteries is attributed to Haller in 1756. The data necessary for the study of such variations may be obtained from direct observation of large autopsies, surgical series or from radiological studies, initially by conventional angiography including DSA or more recently from CT or MR angiography. 

Fig. 4.2. Aberrant replaced right hepatic artery coming of the superior mesenteric artery (arrow) and aberrant accessory left hepatic artery (arrowhead) coming of the left gastric artery...

Quite often the hepatic artery has an incomplete set of branches because one or the other of its usual branches arises from a source other than the proper hepatic artery from the celiac trunk. Such a vessel if from an outside source is spoken of as aberrant ... 

Fig.7.9a,b. A 52-year-old woman with a recent history of gall stone pancreatitis was admitted with further abdominal pain. A CECT scan suggested an aneurysm of uncertain origin. Angiography revealed a true (Type la) aneurysm of an aberrant right hepatic artery (a). CECT had revealed a patent portal vein and so proximal and distal coil embolization was performed (b). There were no further complications and the patient is alive and well at 36 months... 

Michels classic autopsy series of200 dissections, published in 1966, defined the basic anatomic variations in hepatic arterial supply, and has served as the benchmark for all subsequent contributions in this area (Table 20.1). Variant patterns occurred in 45% of cases, and the commonest arterial variant has been shown to be an aberrant right hepatic supply, which is seen in 13%-18% of patients (Coinaud 1986). Michels motivation was to maximize the database of the surgeon performing procedures in and around the porta hepatis, so as to avoid injury to vascular and ductal structures. A modification of the Michels classification was developed to reflect the presence of vessels that were either accessory or replaced, so that Michels original ten groups could be reduced to five major types and a most rare sixth variant (Hiatt et al. 1994) (Table 20.2) (Fig. 20.3). 

Among various patterns, Michels type IX anatomy or Hiatt s type 5 can potentially change the surgical approach during liver transplantation. In this anatomic variant, there is complete replacement of the hepatic trunk to the superior mesenteric artery. The aberrant course of this artery deep to the portal vein may necessitate altering the sequence of the vascular anastomoses so that the hepatic arterial reconstruction is performed prior to portal vein anastomoses (Nghiem et al. 1999). 

Fig. 2.7.5. Actinic, hemorrhagic, ulcerative gastritis (arrows) due to aberrant microparticle embolization via angio-graphically unidentifiable collaterals, presumably from the left hepatic artery to gastric or duodenal arteries...

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