Impact of mechanical bowel preparation on survival after colonic cancer resection

Gut microbiome influences on anastomotic leak and recurrence rates following colorectal cancer surgery

BACKGROUND

The pathogenesis of colorectal cancer recurrence after a curative resection remains poorly understood. A yet-to-be accounted for variable is the composition and function of the microbiome adjacent to the tumour and its influence on the margins of resection following surgery.

METHODS

PubMed was searched for historical as well as current manuscripts dated between 1970 and 2017 using the following keywords: 'colorectal cancer recurrence', 'microbiome', 'anastomotic leak', 'anastomotic failure' and 'mechanical bowel preparation'.

RESULTS

There is a substantial and growing body of literature to demonstrate the various mechanisms by which environmental factors act on the microbiome to alter its composition and function with the net result of adversely affecting oncological outcomes following surgery. Some of these environmental factors include diet, antibiotic use, the methods used to prepare the colon for surgery and the physiological stress of the operation itself.

CONCLUSION

Interrogating the intestinal microbiome using next-generation sequencing technology has the potential to influence cancer outcomes following colonic resection.

A European survey of bowel preparation in colorectal surgery

AIM

Meta-analysis has shown that mechanical bowel preparation (MBP) does not improve outcomes in colonic surgery; however, there is uncertainty regarding MBP use in laparoscopic and rectal surgery and the addition of oral antibiotic regimens. The aim of this study was to assess current use of bowel preparation among European surgeons.

METHOD

An online survey was circulated to members of the European Society of Coloproctology. Chi-squared analysis was used to compare subgroups.

RESULTS

A total of 426 surgeons responded to the survey. MBP is routinely prescribed by 29.6% of respondents prior to colonic surgery and in 77.0% prior to rectal surgery. In the cohort performing > 30% of colorectal operations laparoscopically (n = 294), routine use of MBP in colonic surgery was significantly lower (19.7% vs 51.5%, P < 0.01). Less than 10% prescribe oral antibiotic bowel preparation whereas 96% prescribe perioperative intravenous antibiotics.

CONCLUSION

Among the majority of respondents to this survey, MBP is used routinely for rectal operations. For colonic surgery, laparoscopic surgeons have a significantly lower use of MBP. Use of oral antibiotic bowel preparation remains uncommon.

Bowel Preparation Is Associated with Reduced Morbidity in Elderly Patients Undergoing Elective Colectomy

BACKGROUND

Bowel preparation in elderly patients is associated with physiologic derangements that may result in postoperative complications. The aim of this study is to determine the impact of bowel preparation on postoperative outcomes in elderly patients.

METHODS

Patients age 75 years and older who underwent elective colectomy were identified from the 2012-2014 American College of National Surgical Quality Improvement Program (ACS-NSQIP database). Patients were grouped into no bowel preparation, mechanical bowel preparation (MBP), oral antibiotic preparation (OABP), or combined MBP + OABP. Logistic regression modeling was conducted to calculate risk-adjusted 30-day outcomes.

RESULTS

There were 4829 patients included in the analysis. Morbidity was 34.3% in no bowel prep, 32.4% in MBP, 24.8% in OABP, and 24.6% in MBP + OABP groups (p < 0.001). The MBP + OABP group compared with no bowel prep was associated with reduced rates of anastomotic leak, ileus, superficial surgical site infection (SSI), organ space SSI, respiratory compromise, and reduced length of stay. There was no difference in the rate of acute kidney injury between the groups.

CONCLUSION

MBP + OABP was associated with reduced morbidity compared with no bowel preparation in elderly patients undergoing elective colorectal resection. MBP alone was not associated with differences in outcomes compared with no bowel preparation. The use of MBP + OABP is safe and effective in elderly patients undergoing elective colectomy.

Preoperative, intraoperative and postoperative risk factors for anastomotic leakage after laparoscopic low anterior resection with double stapling technique anastomosis

Anastomotic leakage (AL) is one of the most devastating complications after rectal cancer surgery. The double stapling technique has greatly facilitated intestinal reconstruction especially for anastomosis after low anterior resection (LAR). Risk factor analyses for AL after open LAR have been widely reported. However, a few studies have analyzed the risk factors for AL after laparoscopic LAR. Laparoscopic rectal surgery provides an excellent operative field in a narrow pelvic space, and enables total mesorectal excision surgery and preservation of the autonomic nervous system with greater precision. However, rectal transection using a laparoscopic linear stapler is relatively difficult compared with open surgery because of the width and limited performance of the linear stapler. Moreover, laparoscopic LAR exhibits a different postoperative course compared with open LAR, which suggests that the risk factors for AL after laparoscopic LAR may also differ from those after open LAR. In this review, we will discuss the risk factors for AL after laparoscopic LAR.