Lessons learned from anatomic variants of the hepatic artery in 1,081 transplanted livers

Abstract

The aim of this study is to contribute our experience to the knowledge of the anatomic variations of the hepatic arterial supply. The surgical anatomy of the extrahepatic arterial vascularization was investigated prospectively in 1,081 donor cadaveric livers, transplanted at La Fe University Hospital from January 1991 to August 2004. The vascular anatomy of the hepatic grafts was classified according to Michels description (Am J Surg 1966;112:337-347) plus 2 variations. Anatomical variants of the classical pattern were detected in 30% of the livers (n ϭ 320). The most common variant was a replaced left artery arising from the left gastric artery (9.7%) followed by a replaced right hepatic artery arising from the superior mesenteric artery (7.8%). In conclusion, the information about the different hepatic arterial patterns can help in reducing the risks of iatrogenic complications, which in turn may result in better outcomes not only following surgical interventions but also in the context of radiological treatments. Knowledge of hepatic arterial vascularization has a significant relevance for the daily practice of a wide range of practitioners including not only surgeons specialized in the hepato-biliary-pancreatic area, but also general surgeons and radiologists, mainly those who are dedicated to interventional radiologic treatments.In the last few years, substantial improvements have been achieved in the surgical and/or radiological treatment of benign and malignant liver, pancreatic, and biliary diseases. With laparoscopic surgery the need has arisen for exact descriptions of the hepatic vascularization to avoid iatrogenic vascular lesions.In the setting of liver transplantation, the most effective approach to reduce the dropout rate on the waiting lists is to expand the number of available livers. Several strategies including living donors and split livers have been developed for this purpose. These are extremely complex techniques in which the exact knowledge of the arterial anatomy is a required step to plan the best resection as well as to minimize the risks of morbidity.The patterns of hepatic arterial supply are not constant. The usual anatomy of the hepatic arterial vascularization is a common hepatic artery arising from the celiac axis, accounting for 25 to 75% of the cases. 1 In the variant patterns, the hepatic lobes receive arterial flow through branches coming from the superior mesenteric artery, left gastric artery, or, rarely, from other arterial trunks. 2 Since Michels 3 published his first report, several studies have reported not only common and rare hepatic artery variants, but also different classifications. These studies are based on angiographic data and autopsy dissections, and mainly derive from surgery and transplantation literature. [4][5][6][7][8][9][10][11][12][13][14] The large sample size of transplanted livers is one of the major interests of this study. Indeed, harvested livers offer an excellent opportunity to describe, in situ, the anatomic variants of the arteries since all e...

Clinical Implications of an Aberrant Right Hepatic Artery in Patients Undergoing Pancreaticoduodenectomy

“…Therefore, surgeons should be familiar with these variants so that they can avoid various surgical complications [8]. Although Suzuki and Nakayasu [9] classified hepatic arterial variations, Michel's classification is more useful because it established the differences between ''an accessory'' and ''a replaced'' artery [3,7]. The incidence of CHA originating from the SMA, the so-called hepatomesenteric (HM) trunk-type CHA, is 1.5-4% [1].…”

Ring-shaped variation of the coeliac trunk branches

“…Michels [7] was the first who suggested an extensive classification proposal of 10 different types of hepatic artery variations modified by Hiatt et al [3] 28 years later. In a review on 1081 liver transplantations, 30% of the livers exhibited variations in the arterial supply, and 12 different patterns/types were described [6]. In 9.7% of cases, the left hepatic artery was replaced by the gastric artery (type II).…”

“…The 2 vessels together form a hepato-hepatic trunk and surround the caudate lobe of the liver. Lopez-Andujar et al [6], highlight the concept that aberrant hepa- tic vessels should be classified either as "accessory" or "replaced" because hepatic arteries are terminal vessels. We disagree with this description as the diameter and course of a vessel should also be taken into consideration.…”

“…Due to the high clinical significance of these branches many studies have documented the arterial variations of the major unpaired arteries that originate from the aorta. Some studies offer classifications with the types and frequency of these variations, in an effort to illustrate the extensive variety [1,3,[5][6][7][8]14]. In a review of the literature, on 2141 cadavers, 87.6% of coeliac trunks had the classical trifurcation, 12.2% presented an incomplete bifurcated coeliac trunk and in 0.2% was absent [14].…”

“…It seems there is a prevalence of Korean and Japanese populations presenting coeliac trunk variations more frequently than Caucasians [8]. In rare cases, the coeliac branches may arise independently from the anterior wall of the abdominal aorta [4,6,14]. Knowledge of such variations has important clinical significance especially in regards to certain abdominal, invasive arterial, and radiological procedures.…”