MRI-enema for the assessment of pelvic intestinal anastomotic integrity

Considerations in case of suspected anastomotic leakage in the lower GI tract

Colorectal anastomotic leakage (CAL) remains a feared complication after colorectal surgery and requires prompt detection and proper treatment. With the upswing of fast-track recovery programs in recent years this challenge has increased, as clinical features may only arise after discharge. Therefore, identification of the best diagnostic tools is of utmost importance, also since early treatment is associated with high success rates. Diagnostic tools range from general screening tools to invasive procedures to assess the severity of the leak. Laboratory tests, in particular the inflammation biomarkers C-reactive protein and procalcitonin, have a significant role in the detection of CAL after colorectal surgery. As these biomarkers are unspecific for CAL, additional imaging should be performed when blood levels are elevated. The golden standard for the detection of AL after colonic resections is a computed tomography (CT-scan). If tolerated, a contrast medium should be administered rectally to enhance diagnostic accuracy. When suspicion of CAL remains high despite negative previous tests, further endoscopy examination should be conducted. However, endoscopic examinations become more suitable for the early diagnostic work-up after rectal resections. This review aims to provide an overview of current diagnostics for the screening and assessment of the severity of CAL after colorectal surgery.

MRI diagnose post-operative anastomotic leak in patients with rectal cancer: preliminary experience

BACKGROUND

Anastomotic leakage (AL) is one of the most serious postoperative complications after colorectal anastomosis. This study aims to evaluate the feasibility and diagnostic accuracy of magnetic resonance imaging (MRI) in the early detection of AL in patients with clinically suspected AL after rectal anterior resection.

METHODS

This was a prospective study including patients who underwent anterior resection and postoperative MRI examination. AL was diagnosed by comprehensive indictors, which were mainly confirmed by clinical signs, symptoms, and retrograde contrast enema (RCE) radiography. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of diagnosing AL with MRI were calculated.

RESULTS

In total, 347 patients received anterior resection for rectal cancer, and 28 patients were suspected to have AL. Finally, 23 patients were included and received MRI examination. The median time interval from surgery to MRI was 10 days (3-21 days). The median distance from anastomosis to anal verge was 4.0 cm (2.0-10 cm), and 11 patients underwent diverted ileostomy. Eighteen patients had an anastomotic leak, including one patient who had a pelvic abscess and five patients who had no evidence of AL in the MRI examination. The overall sensitivity and specificity were 94.4% (95% CI 70.6% to 99.7%) and 80% (95% CI 29.8% to 98.9%), respectively. The PPV was 0.94 (95% CI 0.71 to 0.99) and the NPV was 0.80 (95% CI 0.29 to 0.99). For patients who had anastomosis less than 5 cm, the diagnostic accuracy of MRI was 93.7% (15/16). T2-weighted imaging with fat suppression can effectively reveal the leak track.

CONCLUSIONS

The accuracy of plain MRI examination in diagnosing AL was favorable for patients with a suspected AL. T2-weighted imaging with fat suppression was the best imaging modality to diagnose AL. A multicenter prospective study with more samples is needed to further determine the safety and feasibility of MRI in the diagnosis of AL.