Introduction

At present, to perform hepatic surgery a precise preoperative and intraoperative study of liver vascular supply has to be considered mandatory. In fact, detecting vascular variations may have great importance on surgical strategy and outcome, and details of anatomy do not concern only academical knowledge but become deeply involved in practice. Anatomical variations of hepatic arterial blood supply are well known and they have been extensively described in the literature [1–3, 5, 7, 9]. Modal anatomy is usually characterized by a common hepatic artery originating from the celiac trunk, but in 12–19 % of patients, the right hepatic artery originates from the superior mesenteric artery, usually directed to the right liver [4]. In less than 2 % of cases the entire hepatic artery may arise from the superior mesenteric artery. These anatomical variations deeply influence surgical strategy.

Case report

We present a case of unusual blood supply of the liver; during the preoperative evaluation of a patient affected by colorectal liver metastasis of the right lobe (segment 4, 5, 6, 7, 8) an unusual arterial supply of the liver on the arterial phase of the abdominal computed tomography (CT) was observed. A double supply was present, the common hepatic artery, originating from the celiac trunk, was directed to the right liver (s5, s6, s7, s8) (Fig. 1c). A right hepatic artery originating from the superior mesenteric artery that was directed to the left liver (s2, s3, s4) was also present. The right hepatic artery crossed the common hepatic artery in the proximal part of the hepatic pedicle, anterior to the portal vein (Fig. 1a–c). Considering the left lobe future remnant liver the operation planned was a two-stage hepatectomy performing the Associating Liver Partition and Portal vein ligation for Staged hepatectomy (A.L.P.P.S). During dissection of the hepatic pedicle the radiological findings were confirmed, and in the post-operative CT scan (Fig. 1d) it was clearly evident that the common hepatic artery stump was crossed by the right hepatic artery in the mentioned region.

Fig. 1
figure 1

Arterial phase of CT scan: a origin of the right hepatic artery from the superior mesenteric artery (arrow); b crossing of the right hepatic artery and common hepatic artery (arrow), transversal plane; c crossing of the right hepatic artery and common hepatic artery, frontal plane; d post-operative CT scan, crossing of the right hepatic artery and common hepatic artery stump (arrow), frontal plane

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Discussion

To our knowledge this type of anatomical variation has not been described before and it represents a rare finding that has to be kept in mind, especially in case of major hepatectomies and more demanding splitting liver procedures such as A.L.P.P.S. [6], in situ split, ex situ split and living donor liver transplantation [8].

Conclusions

Precise preoperative evaluation of liver blood supply has great importance on surgical strategy and outcome. Details of anatomy do not concern only academical knowledge but are deeply involved in practice.