Correlation between Radiotherapy and Suture Fistulas following Colo-anal Anastomosis for Carcinoma of the Rectum Evaluation of 152 Consecutive Patients

Post-treatment fistulas in patients with rectal cancer: MRI with rectal superparamagnetic contrast agent

MRI is the standard modality in the pre- and post-treatment evaluation of patients with rectal cancer, particularly in those cases with locally advanced disease. We routinely employ a superparamagnetic iron oxide (SPIO) contrast enema to distend the rectal lumen and achieve maximal tumor-to-lumen contrast gradient. This practice also allowed the identification of a fistula in 24% of patients treated for rectal cancer. Contrast agent-related low intensity signal could be seen filling the tract and eventually opacifying surrounding organs (i.e., vagina) or collections (i.e., presacral abscess). Fistula formation after radiochemotherapy and surgery for rectal cancer is not uncommon. MRI with dark lumen contrast enema allows an effective demonstration of this complication in a high number of patients.

Digital rectal examination compares favourably with conventional water-soluble contrast enema in the assessment of anastomotic healing after low rectal excision: a cohort study

BACKGROUND

Assessment of healing after low colorectal, colo-anal or ileo-pouch anal anastomosis is routinely performed with a water-soluble contrast enema (WSCE) prior to the reversal of the defunctioning stoma. Interpretation of these radiographs is sometimes difficult and imprecise. As these anastomoses are within the reach of a simple digital rectal examination (DRE), this approach is proposed as an effective and accurate adjunct.

PATIENTS AND METHODS

This is a prospective cohort study recruiting patients who had undergone a low colorectal, colo-anal or ileo-pouch anal anastomosis with a diversion stoma. Anastomotic healing was assessed with a DRE in the clinic followed by the conventional WSCE. Anastomotic defects on digital examination and leaks on WSCEs were studied.

RESULTS

There were 195 patients recruited with a total of 202 paired assessments from 182 patients over 45 months. Six months after closure of the study, 174 patients had their stomas reversed. Thirteen examinations with WSCE showed pathology but were normal on digital examination (false positive rate of 6.4% for WSCE). These patients had their stomas reversed with no subsequent problems. Seven patients had an abnormal DRE but had a normal enema study (false negative rate of 3.5% for WSCE). These were large defects with pus and allowed the tip of the examining finger through. Delayed reversal of the stomas in these patients probably avoided continuing pelvic sepsis. The DRE was accurate in all instances except in the detection of a minor fistula in three patients. The sensitivity of the DRE in the detection of anastomotic pathology was 98.4%.

CONCLUSION

The DRE yields additional and reliable information compared with the conventional water-soluble enema study in the assessment of anastomotic healing prior to stoma closure. In the experienced surgeon, it yielded more useful clinical information than the enema study.