Anastomotic leak following mesorectal excision for rectal cancer: true incidence and diagnostic challenges

Anastomotic leakage is a potentially serious complication of low anterior resection which may be accompanied by clinical symptoms (clinical leak) or may be silent (subclinical leak). In this study the true incidence of the complication was evaluated, and the diagnostic accuracy of clinical symptoms, conventional rectal radiography (CRR) and computed tomography (CT) was compared.

Fifty-six consecutive patients were included in a prospective trial. Clinical parameters were recorded and CRR and CT performed 6-10 days postoperatively or earlier if a leak was suspected. Endoscopy was performed three months postoperatively.

Based on all available information including late endoscopy, 5 (9%) patients had clinical leak and five a leak that was asymptomatic during the hospital stay. Clinical assessment, CRR and CT during the hospital stay had an accuracy of 82%, 93% and 94%, respectively, and a sensitivity of 50%, 60% and 57%, respectively. The specificity of clinical assessment was 89%, whereas both CRR and CT had a specificity of 100%.

The incidence of anastomotic leakage seemed acceptable when compared with other series. Fifty per cent of the leaks were silent. CRR and CT may be false negative and immediate treatment should be started if clinical signs are highly suggestive of leak, irrespective of radiological findings CT was not more accurate than CRR in detecting anastomotic leak.