Serial Endoscopic Surveillance & Direct Topical Antibiotics to Define the Role of Microbes in Anastomotic Healing

Rationale: The surgical complication of intestinal anastomotic leak remains a clear and present danger to patients despite advances in surgical technique and ever more powerful antibiotics. No surgeon is immune from this complication and leak rates have not changed in decades. The consequences of a leak (peritonitis, sepsis, death) can be so severe that in the case of rectal cancer, diverting ileostomies are routinely performed to divert the fecal stream away from the healing anastomosis. We have recently discovered that certain intestinal bacteria, with the capacity to express collagenase and cleave MMP9 (Matrix metallopeptidase 9) to its active collagen degrading form, play a key and causative role in anastomotic leak. These bacteria often escape elimination due to the failure of current antibiotic regimens and their delivery methods to remain functionally durable at anastomotic tissue sites. Purpose: This phase II clinical trial will track, in real time, the process of anastomotic healing and its associated microbiome by performing serial endoscopic surveillance (SES) following rectal cancer resection. By capturing anastomotic images and the associated microbial and inflammatory mediators from anastomotic fluids via SES performed at three time points following rectal cancer resection, we will correlate healing to microbial composition and inflammatory mediator status. Patients will be randomized and, at each time point, will receive lavage of their anastomosis with either saline or a triple antibiotic solution (ciprofloxacin, metronidazole, neomycin). An anastomotic healing score captured during SES will be compared between the two treatment arms and correlated to microbial and inflammatory mediator analyses of fluid samples to determine how intestinal microbes influence the process of anastomotic healing.