Perihilar branching patterns of renal artery and extrarenal length of arterial branches and tumour-feeding arteries on multidetector CT angiography

Objective: The purpose of our study was to assess the extrarenal length of renal arterial branches and tumour-feeding arteries on multidetector CT (MDCT) angiography, in addition to the perihilar branching patterns, with relevance to segmental artery clamping. Methods: MDCT angiograms of 64 patients with renal masses ,4 cm were retrospectively reviewed by 2 radiologists. The perihilar branching patterns of the single main renal artery were assessed according to the number of pre-segmental and segmental arteries. The extrarenal lengths of segmental plus pre-segmental arteries and the tumourfeeding arteries, measured on volumerendered images, were compared according to the vascular segmentation and the tumour location, respectively. Results: In the 116 kidneys, 1 pre-segmental plus 5 segmental arteries (n548) was the most common branching pattern. The mean extrarenal length of the inferior segmental plus pre-segmental arteries (33.05mm) and the posterior segmental plus pre-segmental arteries (32.30mm) was longer than any of the other segmental plus pre-segmental arteries (apical, 23.87mm, superior, 26.80mm, middle, 29.23mm) (p,0.05). The mean extrarenal length of the lower pole tumour-feeding arteries (35.94mm) was longer than those of the upper and mid-pole tumour-feeding arteries (24.95mm, 29.62mm), with significant difference between the lower and the upper pole tumour-feeding arteries (p,0.05). Conclusion: Tumours in the lower pole, supplied by the inferior or posterior segmentalartery, may be more amenable to segmental artery clamping. Advances in knowledge: MDCT angiography with volume rendering can demonstrate the extrarenal length of tumour-feeding arteries and may help in determining the accessibility for segmental artery clamping.