PreOp Antibiotics Cut Left-Colon Surgery Infection Risk

Patients undergoing surgery of the left colon or rectum have significantly fewer surgical site infections (SSIs) if they received prophylactic antibiotics, according to a new study.

Researchers at Baylor College of Medicine (Houston, TX, USA) and the Houston Veterans Affairs (VA) Medical Center (TX, USA) conducted a retrospective study of 89 patients who underwent left colon and rectal cancer resections from October 1, 2013, to December 31, 2016, in order to determine the association of the addition of oral antibiotics to mechanical bowel preparation (MBP) in preventing post-surgical SSIs. The main outcomes and measures were SSI within 30 days of the index procedure and time to adjuvant therapy.

The results revealed that of the 89 patients in the study, 49 underwent surgery with MBP but without oral antibiotics, and 40 underwent surgery with MBP and oral antibiotics. The patients who received oral antibiotics and MBP were younger, but otherwise similar in baseline demographic, clinical, and cancer characteristics. Overall SSI rate was lower for patients who received oral antibiotics and MBP than for patients who received MBP only, with no deep or organ space SSIs or anastomotic leaks in the patients who received oral antibiotics and MBP, compared with nine organ space SSIs and five anastomotic leaks in patients who received MBP alone.

Oral antibiotics resulted in a trend toward quicker time to initiation of adjuvant chemotherapy (at a median of 60 days versus 72). Oral antibiotics were also associated with a longer median operative time (391 versus 348 minutes, respectively). Oral antibiotics and MBP, and minimally invasive surgery (MIS) were independently associated with reduced odds of SSIs. An analysis of the few patients who had right-colon surgery revealed that the SSI rate was marginally lower in patients who received antibiotics (8% versus 13%). The study was published on October 18, 2017, in JAMA Surgery.

“Use of oral antibiotics and mechanical bowel preparation was associated with an almost 90% reduced odds of having an SSI,” concluded senior author Samir Awad, MD, MPH, and colleagues. “However, even with the significant decrease in SSIs with oral antibiotics and mechanical bowel preparation, there was no significant difference in the number of patients receiving timely adjuvant therapy, suggesting that there may be other factors affecting this outcome.”

A left hemicolectomy is designed to remove the descending colon, approximately half of the large intestine; it is necessary to remove such a large section of the bowel due to blood supply distribution, rather than considerations of disease extent. After removal of the diseased portion the two free ends are joined in an anastomosis. Occasionally, if the sections are inflamed, it is necessary to create a temporary stoma to divert the bowel contents.

Related Links:
Baylor College of Medicine
Houston Veterans Affairs Medical Center