Characteristic findings on defecography according to reconstruction method and defecatory disorder following sphincter-saving surgery for rectal cancer

Abstract

This study used postoperative defecography to characterize morphological features of defecatory disorders in patients following rectal resection. We also evaluated differences in dynamic defecatory condition depending on reconstruction methods for sphincter-saving surgery. Subjects comprised 62 patients (male/female, 41/21; mean age, 61 years) who underwent defecography after sphincter-saving surgery for rectal cancer. Semisolid barium (100 ml) was introduced into the rectum, and images were taken in a sitting position. Characteristic dynamic findings in defecography were evaluated according to operative methods and were compared with symptoms of defecatory disorders. Defecographic findings closely associated with postoperative defecatory disorder were as follows: (1) low volume of neorectum in patients with worse incontinence grade (p < 0.05), (2) low evacuation fraction in patients with significantly impaired function such as soiling, urgency, and worsened incontinence score (p < 0.05), (3) minor alteration of anorectal angle at evacuation in patients with major soiling and worsened incontinence score (p < 0.05), and (4) barium shadow in the anal canal at rest in patients with urgency (p < 0.05). By reconstruction method, the J-pouch displayed a larger volume than straight anastomosis but a significantly wider anorectal angle than high anterior resection (HAR). Side-to-end anastomosis offered a moderate volume and a sharp anorectal angle as in HAR. Defecography is useful for visualizing and characterizing defecatory disorders following rectal resection. Based on defecography, J-pouch reconstruction offers advantageous volume, while side-to-end anastomosis provides a more acute anorectal angle for patients who have received rectal resection with low anastomosis. A new reconstruction method offering both advantages was discussed.