Anatomical variations of hepatic artery using the multidetector computed tomography angiography

The frequency of normal and aberrant hepatic arteries differs among ethnicities. The aim of our work was to study the frequency of normal and aberrant hepatic arteries among Egyptians using multidetector computed tomography (MDCT) and to compare our prevalence with the prevalence of other nationalities. In addition, the gender differences of such variations were clarified. Moreover, the arterial feeding of hepatic segment IV was determined.

The present study was carried out on 500 patients (409 males and 91 females). Abdominal CT was performed using two MDCT systems, a 64-row, and a 256-slice system.

According to Michel's classification, the normal anatomy (type I) was observed in 369 (73.8%) cases, while anomalous hepatic arterial pattern was detected in 131 (26.2%) cases. These anomalies were distributed as follows: type II in 36 (7.2%) cases, type III in 60 (12%) cases, types IV and V in 5 cases for each (1% each), type VI in 14 (2.8%) and types VIII and IX in a single case for each (0.2% each). Neither type VII nor type X was detected. Nine (1.8%) unclassified cases were observed. According to Hiaat's classification, the anomalies were distributed as follows: type II in 41 (8.2%) cases, type III in 74 (14.8%) cases, type IV in 6 (1.2%) cases, type V in a single case (0.2%) and type VI in 2 (0.4%) cases. Finally, 7 (1.4%) unclassified cases were observed. Common hepatic artery (CHA) originated from coeliac trunk in 98% (79.8% males and 18.2% females). It originated from the abdominal aorta in 0.4% and from the superior mesenteric artery (SMA) in 0.4%. It was absent in 1.2%. Right hepatic artery (RHA) originated from the CHA in 86.6% (69.8% males and 16.8% females) and from the SMA in 13.2% (11.8% males and 1.4% females) and from the abdominal aorta in 0.2% (a single male case). Left hepatic artery (LHA) originated from the CHA in 91.2% and from the left gastric artery (LGA) in 8.8%. The most common origin of the segment IV blood supply was the LHA in 60.8%, followed by the RHA in 35%. Less commonly, blood supply derived from the hepatic artery proper (HAP) in 1%. Combined supply derived from RHA and LHA in 0.8%, from the LHA and HAP in 2% and the least encountered was from the RHA and HAP in 0.4%.

Hepatic artery variations among Egyptians have a different distribution when compared to such variations among other species. The normal hepatic arterial pattern was observed in 73.8%, while the anomalous was detected in 26.2%. The CHA originated from the coeliac trunk in 98%, the RHA originated from the CHA in 86.6% and the LHA originated from the CHA in 91.2%. The most common arterial supply of the hepatic segment IV is derived from the LHA (60.2%).