What happens in stapled transanal rectum resection?

Abstract

Stapled transanal rectum resection is becoming increasingly popular as a surgical option for the treatment of obstructive defecation syndrome. However, details about the anatomical changes produced by stapled transanal rectum resection and its correlation with success or failure is poorly understood. The aim of this study was to correlate the defecographical and clinical patterns in patients treated with stapled transanal rectum resection. Based on a multi-institutional stapled transanal rectum resection registry composed of a total of 182 patients, correlation analysis of clinical and radiological parameters was prospectively obtained from 51 patients with a completed 12-month follow-up. Postoperative defecography shows significant changes in the following parameters: intussusception (89%-19%; P < .0001), enterocele (38%-18%; P = .038), rectocele (mean ± SD: 27.1 ± 7.4 mm to 16.5 ± 9.7 mm; P < .0001), rectal lumen (mean ± SD: 46 ± 11.4 mm to 35 ± 9.9 mm; P < .0001), anorectal angle (mean ± SD: 146.4 ± 10.6° to 132.4 ± 11.1°; P = .002), pelvic floor descent (mean ± SD: 59 ± 18 mm to 47 ± 1.3 mm; P = .0001), and, as a dynamic parameter, dynamic pelvic floor descent (mean ± SD: 30 ± 0.8 mm to 17 ± 0.4 mm; P < .0001). Of these parameters, reduction of intussusception (r = 0.433, 95% CI 0.15-0.61; P = .003), rectocele (r = 0.507, 95% CI 0.26-0.67; P = .001), and dynamic pelvic floor descent (r = 0.427, 95% CI 0.31-0.64; P = .001) correlated with a significant improvement in constipation. Reduction of intussusception positively affected postoperative continence (r = 0.524, 95% CI 0.29-0.70; P = .001), whereas reduced rectal lumen size correlated with incontinence and fecal urgency (r = -0.557, 95% CI -0.69 to -0.28; P = .001). Improved constipation after stapled transanal rectum resection is associated with improvement of intussusception, rectocele, and dynamic pelvic floor descent. Postoperative continence is determined by 2 parameters, reduction of intussusception and rectal lumen size, which have opposing effects. Reduction of rectal lumen size may be responsible for new-onset fecal urgency, which is occasionally seen after stapled transanal rectum resection.