Original article Assessment of haemorrhoidal artery network using colour duplex imaging and clinical implications C. Ratto, A. Parello, L. Donisi, F. Litta, G. Zaccone and G. B. Doglietto Department of Surgical Sciences, Catholic University, Largo A. Gemelli, 8, 00168, Rome, Italy Correspondence to: Dr C. Ratto (e-mail: carloratto@tiscali.it) Background: Dearterialization should reduce arterial overﬂow to haemorrhoids. The purpose of this study was to assess the topography of haemorrhoidal arteries. Methods: Fifty patients with haemorrhoidal disease were studied. Using endorectal ultrasonography, six sectors were identiﬁed within the lower rectal circumference. Starting from the highest level (6 cm above the anorectal junction), the same procedure was repeated every 1 cm until the lowest level was reached (1 cm above the anorectal junction). Colour duplex imaging examinations identiﬁed haemorrhoidal arteries related to the rectal wall layers, and the arterial depth was calculated. Results: Haemorrhoidal arteries were detected in 64·3, 66·0, 66·0, 98·3, 99·3 and 99·7 per cent of the sectors 6, 5, 4, 3, 2 and 1 cm above the anorectal junction respectively (P < 0·001). Most of the haemorrhoidal arteries were external to the rectal wall at 6 and 5 cm (97·9 and 90·9 per cent), intramuscular at 4 cm (55·0 per cent), and within the submucosa at 3, 2 and 1 cm above the anorectal junction (67·1, 96·6 and 100 per cent) (P < 0·001). The mean arterial depth decreased signiﬁcantly from 8 3 mm at 6 cm to 1·9 mm at 1 cm above the anorectal junction (P < 0·001). · Conclusion: This study demonstrated that the vast majority of haemorrhoidal arteries lie within the rectal submucosa at the lowest 2 cm above the anorectal junction. This should therefore be the best site for performing haemorrhoidal dearterialization. Presented in part to the Annual Meeting of the American Society of Colon and Rectal Surgeons, Minneapolis, Minnesota, USA, May 2010, and published in abstract form as Dis Colon Rectum 2010; 53: 578 Paper accepted 4 August 2011 Published online 21 October 2011 in Wiley Online Library (www.bjs.co.uk). DOI: 10.1002/bjs.7700 Introduction The anatomical and physiological characteristics of haem- orrhoids have not been elucidated fully. Microscopically, haemorrhoidal piles are sinusoids (vascular structures with- out a muscular wall)1. Direct arteriovenous communica- tions have been demonstrated histologically and radiolog- ically, and some authors have noted a resemblance to erec- tile tissue2. Traditionally, haemorrhoidal piles frequently appear to be localized to the left lateral, right posterolateral and right anterolateral sites in the anal canal circumference with the patient in the lithotomy position; however, this conﬁguration is demonstrated in less than 20 per cent of patients3. In reality, a wider network of arterial and venous vessels has been described4, although the distribution and relationship to rectal and anal layers is unclear. Re-use of this article is permitted is accordance with the Terms and Conditions set out at http://wileyonlinelibrary.com/onlineopen# OnlineOpen_Terms  2011 British Journal of Surgery Society Ltd Published by John Wiley & Sons Ltd Recently, haemorrhoidal disease (HD) has often been treated using non-excisional procedures. Some surgical techniques address the reduction of arterial inﬂow to haemorrhoids. Transanal haemorrhoidal dearterialization (THD) and Doppler-guided haemorrhoidal artery ligation (DG-HAL) are the main surgical procedures with this aim, and use speciﬁcally designed devices for arterial ligation in the lower rectum guided by a Doppler signal5. Stapled haem- orrhoidopexy (SH) divides the haemorrhoidal arteries in the suture line6. Assessment of the optimal site for these surgical approaches should improve the clinical efﬁcacy. The pur- pose of this study was to localize precisely the arteries running into the rectum and directed to haemorrhoids. Methods The local institutional review board approved this study. Patients with HD were enrolled prospectively. Each patient British Journal of Surgery 2012; 99: 112–118