Right renal artery arising from the celiac artery - A rare anatomical variation.

Variations in origin and number of renal artery are common. We present a very rare anatomical variation where superior right renal artery was arising from celiac artery. This variation has important surgical implication. Copyright:

CASE

A 45-year-old female voluntary kidney donor was evaluated with computed tomography angiography (CTA) as a part of the preoperative workup. On CTA [Figures 1 and 2], both kidneys were normal in size, outline, shape, and position. Two renal arteries were seen supplying the right kidney, with the superior one supplying the upper half while the inferior artery supplied the lower segment of the right kidney. The superior right renal artery was arising from the celiac artery. Extra hilar branching was seen at its distal end, with the most prominent branch entering the kidney through the hilum while the rest entered through the capsule. The inferior right renal artery was from the abdominal aorta, just proximal to aortic bifurcation at the L4 vertebral level. The superior right renal artery and the right inferior renal artery diameter were 4 mm and 3.3 mm, respectively, at their origin. Two renal veins were present on the right side, draining into the inferior vena cava.

Figure 1

Computed tomography angiography, volume rendered (a), image demonstrates two renal arteries supplying the right kidney. Superior, dominant right renal artery (blue arrow) originated from the celiac artery (green arrow) while inferior right renal artery (white arrow) was arising from the right anterolateral aspect of the lower aorta just proximal to its bifurcation The inferior artery was coursing superolaterally, running anterior to the inferior vena cava, closely abutting pelvic-ureteric junction near the renal hilum. Computed tomography angiography coronal image (b) showing two renal veins on the right side and single renal veins on the left side (orange arrows in b)

Figure 2

Computed tomography angiography, maximum intensity projection images in axial cuts (a-c) demonstrate superior, dominant right renal artery (blue arrows) originating from celiac artery and coursing inferiorly toward right lying posterior to inferior vena cava and the right superior renal vein to enter into the right renal hilum finally

DISCUSSION

Kidneys are usually supplied by arteries arising from the abdominal aorta at L1 to L2 vertebral levels. The accessory renal artery is seen in up to 30% of the population.[1] When two or more arteries have a separate origin, the vessel with the greatest diameter is considered the main renal artery, and the rest are named accessory arteries.[1] Depending on how the accessory renal artery enters into renal parenchyma, they are classified as accessory hilar (entering through hilum) and polar/aberrant (entering the poles directly through renal capsule).[1] Accessory artery most commonly arises from the abdominal aorta and iliac arteries, but there are a few case reports of their origin from mesenteric arteries, lumbar artery, median sacral artery, lower thoracic aorta, inferior phrenic artery, and splenic artery. In our case, the superior main renal artery (larger in diameter) arose from the celiac artery, while the inferior accessory artery was from the lower abdominal aorta at the L4 level. This variation is very rare and has been described in very few case reports. Nachiappan and Garti and Meiraz have described a single ectopic main renal artery arising from the celiac axis.[23] Gillaspie et al. reported the upper polar accessory artery arising from the celiac axis.[4]

A possible explanation for this rare variation is the presence of periaortal and subperitoneal plexus.[5] Failure of regression of these plexuses may be responsible for developing arterial supply to the kidney from the celiac artery.

There are several theoretical disadvantages of renal transplant with donor kidneys having multiple arterial supplies such as acute tubular necrosis, rejection episodes, and decreased graft function.[12] However, no significant differences in graft and patient survival were seen between multiple and single renal artery allografts in most of the recent studies.[6] Knowledge of such rare variation of branching of renal and celiac artery is crucial before doing renal transplantation, liver, or pancreatic surgeries and for the interventional radiologist to prevent injury to the renal artery.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent.