Int J Colorectal Dis (2005) 20:33–37 DOI 10.1007/s00384-004-0620-6 ORIGINAL ARTICLE K. K. Y. Wong P. L. Khong S. C. L. Lin W. W. M. Lam L. C. L. Lan P. K. H. Tam Post-operative magnetic resonance evaluation of children after laparoscopic anorectoplasty for imperforate anus Accepted: 25 May 2004 Published online: 20 August 2004  Springer-Verlag 2004 K. K. Y. Wong · S. C. L. Lin · L. C. L. Lan · P. K. H. Tam ( ) ) Department of Surgery, Queen Mary Hospital, University of Hong Kong Medical Centre, Pokfulam Road, Hong Kong, China e-mail: paultam@hkucc.hku.hk Tel.: +852-28554850 Fax: +852-28173155 P. L. Khong · W. W. M. Lam Department of Diagnostic Radiology, Queen Mary Hospital, University of Hong Kong Medical Centre, Pokfulam Road, Hong Kong, China Abstract Background and aims: Laparoscopic anorectoplasty (LAR) is a relatively new procedure in the treatment of imperforate anus. Using magnetic resonance imaging (MRI), we evaluated the anatomical features of the anorectal region of children treated with LAR and compared this with conventional posterior sagittal anorectoplasty (PSARP). The find- ings were correlated with functional outcome. Patient/methods: A retro- spective review of ten children with the high/intermediate types of im- perforate anus underwent LAR be- tween May 2000 and December 2002. MRI of the pelvis was per- formed post-operatively and a semi- quantitative score was used to assess the degree of sphincter sym- metry, peri-rectal fibrosis, and the position of the pull-through rectum. The defecation status of these pa- tients was also recorded. Eight his- torical patients who had undergone PSARP served as a control group. Results/findings: When compared with PSARP patients, a significantly lower proportion of LAR patients had sphincter asymmetry (40 vs. 100%, p<0.05) and peri-rectal fibro- sis (40 vs. 87.5%, p<0.05). The po- sitioning of the rectum was, however, central for both groups (90 vs. 87.5%). No statistical correlation was found between defecation status and the degree of sphincter asymmetry or peri-rectal fibrosis. Interpretation/conclusion: LAR al- lows more optimal anatomical re- construction for patients with the high/intermediate types of imperfo- rate anus. However, additional fac- tors that are not correctable by sur- gery, such as intrinsic innervation deficiency, also influence the clini- cal outcome. Keywords Imperforate anus · Laparoscopic anorectoplasty · Magnetic resonance imaging · Defecation Introduction Anorectal malformations including imperforate anus af- fect approximately 1 in 5,000 live births. Single-stage ab- dominoperineal procedures had been performed for many years until the introduction of posterior sagittal anorec- toplasty (PSARP) by deVries and Peæa in 1982 [1–4]. The versatility and practicality of this technique has meant that it has become the gold standard for most paediatric centres. For the high/intermediate types of imperforate anus, poor functional outcome is a major problem for many patients, even after corrective surgery. When com- pared with the traditional abdominoperineal method, PSARP has been shown to be a superior technique in terms of defecation function [5–7]. It may be due to a more precise placement of the pull-through recto-colonic segment within the centre of the sphincteric complex. Despite this, it has been reported that many of the patients who underwent PSARP still suffer from some degree of faecal incontinence after repair [5]. Laparoscopic rectoanoplasty (LAR) is a relatively new technique that was first described by Georgeson et al. in