114 C. Ratto, A. Parello, L. Donisi, F. Litta, G. Zaccone and G. B. Doglietto a Perirectal fat b Perirectal fat c Perirectal fat–rectal muscle d Rectal muscle–submucosa e Rectal muscle–submucosa f Submucosa Fig. 2 Colour duplex imaging examples of different locations of arteries in relation to the rectal wall: a,b perirectal fat; c perirectal fat – rectal muscle; d,e rectal muscle – submucosa; e submucosa submucosa in the majority of sectors, whereas at 2 and 1 cm above the ARJ almost all of the arteries had a submucosal location (in 96·6 and 100 per cent of sectors respectively); the differences were statistically signiﬁcant (P < 0·001). No haemorrhoidal arteries were detected in the left and right anterolateral sectors at 6, 5 and 4 cm above the ARJ, whereas such arteries were identiﬁed in the other sectors. At the lower three levels (3, 2 and 1 cm above the  2011 British Journal of Surgery Society Ltd Published by John Wiley & Sons Ltd www.bjs.co.uk British Journal of Surgery 2012; 99: 112–118