Relationship between MRI findings after laparoscopic-assisted anorectal pull-through for anorectal malformations and the functional outcomes

Abstract

Objective To explore the relationship between MRI findings and defecation function after laparoscopic-assisted anorectal pull-through for anorectal malformations. Methods A retrospective cohort study focused on the findings of MRI performed after laparoscopic-assisted anorectal pull-through for anorectal malformations and no spinal deformity was present in all patients who are currently older than 3 years. Forty-two patients aged from 3 to 16 years (median age was 4 years), whom accepted operation at 3 months to 13 years old(median age was 5 months), and MRI was carried out in 2 to 5 months after operation(median time was 3 months). The MRI manifestations including the relationship between the anorect and the high muscle complex(RAHMC), anorectal angle(AA);the relationship between the anorect and the low muscle complex(RALMC), the rectal maximum diameter(RMD), the fat tissue interposition(FTI) and the development of pelvic floor muscle(PFM) were reviewed and summarized. Statistically, the differences of MRI manifestations in different defecation function index, including the degree of voluntary bowel movements, soiling, constipation and Krickenbeck score were evaluated respectively with Chi-square test or rank sum test. Results statistically, There was significant differences among the groups with different degree of voluntary bowel movements, soiling and Krickenbeck score in the RAHMC (P 0.05) . Conclusions The deviation of the anorect from the high muscle complex which showed in the postoperative MRI pictures suggested the poor prognosis, and well-developed pelvic floor muscles which indicated in the MRI was not the sufficient predictor for good outcome. Postoperative anorectal angle obtained in the MRI can be used as an objective indicator of prognosis. Key words: Rectum; Anus diseases; Laparoscopes; Magnetic resonance imaging