Right hepatic artery originated from the superior mesenteric artery : What is the standard anatomic position ?

1 Universidade Federal Fronteira Sul, Medicina Passo Fundo RS Brasil. 2 Universidade de Passo Fundo, Medicina Passo Fundo RS Brasil. 3 Hospital de Clínicas de Passo Fundo, Cirurgia do Aparelho Digestivo Passo Fundo RS Brasil. 4 Hospital de Clínicas de Passo Fundo, Radiologia Passo Fundo RS Brasil. Vivian Right hepatic artery originated from the superior mesenteric artery: What is the standard anatomic position? 2 Rev Col Bras Cir 47:e20202379 Quantitative variables were presented as mean ± standard deviation and qualitative variables as frequency and percentage. We did not perform any statistical analysis hypothesis tests. The CTs were performed by 16-channel or 80-channel multiple detector CT scanners (both Aquilion, Toshiba Medical Systems, Tokyo, Japan), with intravenous injection of non-ionic watersoluble iodinated contrast media with an iodine concentration of 300 mg/mL. A radiologist with six years of experience in abdominal radiology evaluated the CT scans. We considered as the normal anatomy, the origin of the celiac trunk from the aorta, branching into the left gastric artery, the splenic artery, and the common hepatic artery. The latter, after the emergence of the gastroduodenal artery, continues as the proper hepatic artery, and branches into the RHA and left hepatic artery in the hepatic hilum (Figure 1). This was considered the typical anatomic position, and when different, it was treated as an anatomic variation, regarding its position with the pancreas, the portal vein, the common bile duct and the distance from the superior mesenteric artery and the right hepatic artery.


INTRODUCTION
A ccording to the anatomists Testut, Moore, Sobotta, and Netter, the most common right hepatic artery anatomic position is as a brunch of the celiac trunk which arises from the aorta. The aorta is the origin of the left gastric artery, splenic artery, and common hepatic artery. The latter is the origin of the gastroduodenal artery and the proper hepatic artery, which is divided into the right and left hepatic arteries, in the hepatic hilum¹. However, variations in the hepatic arterial supply may be seen in 25% to 42% of the cases. Therefore, considering the various common hepatic artery anatomy, it is of utmost importance to be aware of its variations since these may impact procedures in the region. A significant number of complications can be prevented while performing any hepatobiliopancreatic procedure².
Thus, we aimed to describe the Right Hepatic Artery (RHA) anatomical position when arising from the superior mesenteric artery (SMA).

Original Article
Right hepatic artery originated from the superior mesenteric artery: What is the standard anatomic position?

Artéria hepática direita originada da artéria mesentérica superior: Qual seu real trajeto anatômico?
Patricia aline Ferri ViVian 1 ; iVana loraine lindemann 1 ; Fernanda marcante carlotto 2 ; marcos dal Vesco neto 2 ; lucas duda schmitz 3 ; Juarez antonio dal-Vesco 3 ; robson rottenFusser 4 ; Jorge roberto marcante carlotto, tcbc-rs 3 Objective: Liver arterial irrigation is characterized by a high frequency of variations in its anatomy. The aim of the study was to describe the anatomic position of the right hepatic artery as a brunch of the superior mesenteric artery. Methods: A total of 5147 intravenous contrast-enhanced computed tomography scans of patients seen at the Radiology Service of the Passo Fundo Clinical Hospital (RS), from October 2016 to December 2017, were selected. 125 patients with anatomic variation of the right hepatic artery were selected. The findings were categorized by the variation of the vascular position, emergence from the superior mesenteric artery and the relationship with other structures. Results: The most frequent position was retropancreatic (88.8%), retroportal (76.8%) and post-choledocian (75.2%), emerging about 2.33 cm from the superior mesenteric artery. Conclusion: We have shown that most common variant of the right hepatic artery presents its posterior origin from the pancreatic and hepatic pedicle, and arises close to the origin of the superior mesenteric artery.
Headings: Anatomy. Liver. Hepatic Artery. Quantitative variables were presented as mean ± standard deviation and qualitative variables as frequency and percentage. We did not perform any statistical analysis hypothesis tests. We considered as the normal anatomy, the origin of the celiac trunk from the aorta, branching into the left gastric artery, the splenic artery, and the common hepatic artery. The latter, after the emergence of the gastroduodenal artery, continues as the proper hepatic artery, and branches into the RHA and left hepatic artery in the hepatic hilum ( Figure 1). This was considered the typical anatomic position, and when different, it was treated as an anatomic variation, regarding its position with the pancreas, the portal vein, the common bile duct and the distance from the superior mesenteric artery and the right hepatic artery.

RESULTS
A total of 5147 CT scans were analyzed.
The patients' average age was 57 ± 16.1 years, and 54.4% were men. Of those, 125 patients (2.42%) showed an anatomical variation in which RHA originated from the SMA.
In the literature, there have been reports for this variation from 8% to 18% 2,5 . We believe that this variation is more relevant both for its frequency, as well as for its impact on surgical procedures in the hepatic, biliary, and pancreatic regions 8,9 . The arterial pathway near the inferior vena cava and the portal vein is associated with the risk of inadvertent injuries while performing hepatectomies and pancreatoduodenectomies [8][9][10][11] .Therefore, to identify and understand the most common course variation preoperatively is essential for those procedures.