American College Of Surgeons - Inspiring Quality: Highest Standards, Better Outcomes

On the Prevention, Detection, and Evaluation of Anastomotic Leaks

OCTOBER 29, 2019
Clinical Congress Daily Highlights, Tuesday Second Edition

Anastomotic leaks are the bane of gastrointestinal surgery. Occurring at rates ranging from 2 to 20 percent following gastrointestinal procedures, they cause high rates of mortality (up to 20 percent), and require surgical intervention. Causes of anastomotic leaks include patient, surgeon, and environmental factors such as the state of the patient’s microbiome.

Matthew F. Kalady, MD, Cleveland Clinic, Cleveland, OH, discussed surgical factors contributing to anastomotic leaks, chief among which is low tissue perfusion during surgery. Dr. Kalady offered technical tips to avoid tissue injury and ensure adequate blood supply in two common anastomosis scenarios, colorectal and ileocolic.

Andrew A. Shelton, MD, Stanford University School of Medicine, Palo Alto, CA, reviewed novel devices that aim to prevent anastomotic leaks. These include the ColonRing (which holds the two ends of the bowel together while they heal), a fecal diversion device, and Bioabsorbable Staple Line Reinforcement (BSLR). Only the ColonRing received a thumbs-up from Dr. Shelto with respect to possible efficacy.

Anuradha R. Bhama, MD, Rush University School of Medicine, Chicago, IL, discussed methods for evaluating anastomoses. Real-time imaging of tissue perfusion during surgery can be done using the fluorescent dye indocyanine green (ICG). Air leak testing by flexible sigmoidoscopy is recommended and can help prevent adverse outcomes.

John C. Alverdy, MD, The University of Chicago Medical School, IL, discussed the role of the microbiome in anastomotic leaks. “Anastomotic leak is not a problem of physics,” he said, “it is a problem of biology.” Studies in rodent models and humans supports the hypothesis that anastomotic leaks result from infections at the surgical site with common bacteria like Enterococcus faecalis. These bacteria in turn induce hyper-activation of host tissue proteases and tissue breakdown.

The microbiome is strongly influenced by diet. Dr. Alverdy presented evidence from his laboratory that feeding mice with a Western diet shifts their microbiome toward a more antibiotic-resistant profile, and that these mice are more susceptible to anastomotic leaks.

Emily V. Finlayson, MD, MS, University of California, San Francisco, CA, discussed other patient factors affecting risk of anastomotic leak. The top two non-modifiable risk factors are male sex and renal disease. Modifiable risk factors include tobacco use and high alcohol intake (>21 units/week); these factors increase risk of anastomotic leaks by up to 4-fold and 7-fold, respectively. For patients with high modifiable risk factors and whose surgery can be delayed, doctors should take advantage of “teachable moments” to encourage patients to change to healthier lifestyles.

Justin A. Maykel, MD, University of Massachusetts Medical School, Worcester, MA, reviewed methods for detecting anastomotic leaks. Endoscopy can be used during surgery to inspect the integrity of the staple line and health of the mucosa. C-reactive protein (CRP) levels of 150 mmol/liter have been associated with anastomotic leaks; the sensitivity and specificity of CRP tests are not terribly good, but they have good negative predictive value.

CT scans and water‐soluble contrast enema (WSCE) can detect leaks, but neither method is very sensitive. Therefore Dr. Maykel recommends getting as much imaging information as possible in cases of suspected anastomotic leaks, including endoscopy as well as CT and WSCE.

Additional Information:
The Panel Session, Anastomotic Leaks: Are We Getting Closer to Understanding and Preventing Them?, was held Tuesday, October 29 at the American College of Surgeons Clinical Congress 2019 in San Francisco (program, webcast and audio information).