Role of MRI in evaluation of patients with anorectal malformations

ABSTRACT

The goal of surgical correction of anorectal anomalies is to establish socially acceptable function and to avoid undesirable effects sequelae such as fecal incontinence, urinary incontinence, and sexual inadequacy. The goal of this study was to review the various findings on pelvic MRI in postoperative anorectal malformation [ARM] patients with complications, to see how far these findings can explain the patients condition and to help the surgeon's planning for proper management regimen for each patient, either surgically or medically. This study included 41 children [31 post-operative anorectal malformation patients and 10 controls]. They were 28 boys [21 patients and 7 controls], and 13 girls [10 patients and 3 controls].Their age ranged between 5 months and 16 years. The patients were subjected to the followings 1]-Full history taking and clinical examination. 2]-Imaging modalities including a]-Pelvic MRI. b]-Spinal MRI for 17 patients. c]-Radiographs of the abdomen and pelvis. d]-Voiding cystourethrogram [VCUG] for 8 patients. e]-Water soluble contrast enema for 26 patients. f]-Ultrasonography of the urinary tract for 16 patients. The mean age of the studied children was 5 years and 6 months. The most common clinical presentation encountered after repair was incontinence in 18 cases, followed by constipation in 8 patients. The most common complication noticed on MRI was misplaced rectum in relation to the levator sling in 11 cases, and the commonest associated congenital anomaly was urinary bladder involvement seen in 8 patients [neurogenic bladder in 4 patients, atrophic bladder in 2 patients, and hemibladder remnant in the remaining 2 patients]. Patients with high anomalies [18 cases] had an equal chance of having either good, air, or poor sphincter mechanism muscle development on MRI. Also fair sphincter mechanism muscle development was common in patients with incontinence, and good muscle quality was common in patients with constipation. There was a good correlation between the sphincter quality and the degree of sacral development [7/12 patients with dysplastic sacrum showed poor sphincter quality, and 12/14 cases with normal sacrum showed good and fair sphincter quality]. Pelvic MRI could be used in adjunction with other imaging modalities in assessment of post operative anorectal malformations patients with complications. Pelvic MRI is the method of choice to show details of their initial repair and to detect any anatomical abnormalities which could relate to their condition. Information collected by different imaging modalities could help the surgeon in decision taking concerning the best management plan for the patient, either surgically or medically