A Feasibility Study Investigating the Relationship between Ankle Brachial Pressure Index and Colorectal Anastomotic Leak


Following large bowel surgery, the surgical complication with the greatest threat to life is from disruption of colonic anastomosis; this is known as an anastomotic leak. Its occurrence varies from 3-25% in different patient groups. The key to healing of a colorectal anastomosis is the blood supply to the bowel during recovery. Identifying patients with a poor blood supply to the bowel prior to surgery would allow us to recognise a group of patients at high risk of an anastomotic leak. Better stratification of these patients would improve pre-operative patient counselling and enable surgeons to protect high-risk anastomoses by a temporary stoma, or in appropriate cases to advise against anastomosis altogether.


We intend to investigate whether the ankle-brachial pressure index (ABPI), a marker of both peripheral and central vascular disease, may serve as a simple non-invasive, reproducible test to identify those at highest risk of anastomotic failure.

This feasibility study is intended to evaluate whether the ABPI has sufficient specificity and a low enough false positive rate to warrant its use in the prediction of anastomotic leak. This will guide whether or not we proceed to a second phase study to evaluate the sensitivity and positive predictive value of the test.

Primary Outcome

Obtain sufficient data to calculate a false positive rate and estimate a specificity of the ABPI as a marker for anastomotic leak.  This will allow us to evaluate the feasibility of proceeding to a second phase study.

Secondary Outcome

  • To inform the power calculation for a second phase study
  • To evaluate whether the current data collection pathway is deliverable
  • To evaluate ABPI inter-observer error
  • To evaluate whether routinely performed pre-operative CT scans of the abdomen and pelvis can be used to assess the calcification of major pelvic blood vessels. This may identify patients at a higher leak risk. The findings will guide whether this warrants parallel investigation in the second phase study.


A prospective cohort study, of 150 patients in 3 trusts within the West Midlands. click here

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