Another Brick in the Wall of an Ongoing DiscussionReduction of Anastomotic Leaks after Colorectal Resection by Preoperative Mechanical Bowel Preparation in Combination with Oral and Parenteral Antibiotics? A Clinical Retrospective Single Center Study

Research Article

Austin J Clin Case Rep. 2021; 8(5): 1211.

Another Brick in the Wall of an Ongoing Discussion– Reduction of Anastomotic Leaks after Colorectal Resection by Preoperative Mechanical Bowel Preparation in Combination with Oral and Parenteral Antibiotics?–A Clinical Retrospective Single Center Study

Safia O¹*, Tallbot SR², Kuebler S¹ and Mall JW¹

¹Department of General-Visceral and Minimally Invasive Surgery; KRH Siloah, Academic Teaching Hospital of the Hannover Medical School, Germany

²Department of Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Germany

*Corresponding author: Safia O, Department of General- Visceral and Minimally Invasive Surgery; KRH Siloah, Academic Teaching Hospital of the Hannover Medical School, Stadionbruecke 4, 30459 Hannover, Germany

Received: April 29, 2021; Accepted: May 19, 2021; Published: May 26, 2021


Background: In colorectal surgery, postoperative Anastomotic Leak (AL) is a serious complication. Besides the surgeon`s experience, bowel preparation may have an impact on AL, but the published data are still inconclusive. The purpose of this retrospective single center study was to investigate the role of preoperative Mechanical Bowel Preparation (MBP) in combination with Oral Antibiotic Bowel Preparation (OBP) and parenteral antibiotics in a certified highvolume colorectal center.

Methods: In the period of January 2017 to December 2019, all colon and rectal surgeries were recorded and separated into emergency and elective surgeries. Patients in the elective surgery group were further divided into two groups: patients with Bowel Preparation (BP) and patients without BP and were evaluated concerning to AL, postoperative hospital length of stay and mortality.

Results: Between 2017 to 2019, 625 patients underwent colorectal surgery. 262 patients had emergency operations and were therefore excluded from the study. 363 patients underwent colorectal elective surgery (197men, 166 women). 44.0% received Combined Bowel Preparation (CBP), 46.8% received no BP, 3.3% received OBP only, 4.1% received MBP only, and for 1.1% nothing was documented. CBP was not only associated with a reduction in the rate of AL (P=0.038) (14.1% vs. 4.4%), but also with reduction in mortality (P=0.032) (7.6% vs. 1.2%) and length of stay (P=0.016) (14 vs. 11 days).

Conclusion: Our retrospective data showed a significant impact of preoperative intestinal preparation with MBP in combination with OBP and parenteral antibiotics on AL, length of stay and mortality. Therefore we strongly recommend the use of this regimen of preoperative BP in elective colorectal surgery.

Keywords: Anastomotic insufficiency; Preoperative bowel preparation; Anastomotic leak; Elective colorectal resection


In colorectal surgery, postoperative AL is considered one of the most serious complications, which can have multiple causes and whose genesis has not been conclusively clarified to date [1]. Until today we do not know how significant the role of BP is in reducing the rate of postoperative AL. In particular, the effect of combined intravenous and oral antibiotic prophylaxis together with MBP has not yet been adequately studied [2].

Many studies show a reduction in postoperative complications by combining MBP with OBP before colorectal surgical procedures. In 2017 Klinger and colleagues suggested that combined bowel preparation should be used before any elective colorectal resection unless contraindications exist” [3]. Nevertheless, it is still not common practice in Germany to use a combination of MBP with OBP as well as intravenous antibiosis in elective colorectal surgery. Zmora et al. found that elective colorectal surgery was safer without MBP. Accordingly, preoperative MBP should be performed selectively, e.g., in cases where intraoperative colonoscopy would likely be required [4].

Atkinson et al. suggested that preoperative antibiotic administration alone results in a decrease in Surgical Site Infections (SSI) and advised against MBP [5]. Particularly with the proliferation of fast-track surgery, selective BP and preoperative antibiotic preparation of the bowel was increasingly criticized [6].

Overall, findings are inconsistent. Further studies demonstrate that CBP alone can reduce the incidence of postoperative AL. No effect has been demonstrated with the use of MBP alone or OBP alone [7,8]. The effectiveness of CBP is based on the massive reduction of bowel contents and the resulting significant reduction of gram-negative germs. These are usually considered to be the source of infectious pathogens in anastomotic infections. Accordingly, the local dilution of oral antibiotics in the intestine is lower and there is a faster and easier reduction of the bacterial load in the intestine [9].

According to the changing recommendations in the past years we applied different regimens to our elective colorectal surgery patients. Whereas from Jan 2017 to Feb. 2018 no routine bowel preparation was administered, we changed the regimen to strict bowel preparation with administration of oral antibiotics in the following period after. Therefore it was feasible to compare the two groups of patients. The aim of this retrospective study was to investigate whether the standardized administration of CBP (MBP + OBP) had an impact on the incidence of AL in elective colorectal surgery compared to no BP in a certified high-volume bowel center. A standardized antibiotic regimen and MBP was used.

Materials and Methods

Study design

Between January 2017 and December 2019, all consecutive colon and rectal surgery files were recorded and initially separated into emergency and elective surgery retrospectively. There were 625 patients enrolled in the study. In elective surgeries, patients received CBP one day before the scheduled surgery. A standard protocol for oral antibiotics and mechanical bowel preparation was used. This consists of 3x1g Neomycin, 3x500mg Metronidazole, 2000 ml Moviprep® (Macrogol), 2000 ml clear liquid.

All patients who were ventilated preoperatively or were septic were excluded. Emergency surgeries did not receive standard BP and were therefore not included in the study. Also excluded were all elective surgeries with discontinuity resection, as AL could not occur in those patients. Furthermore, patients with other main oncologic diagnoses such as hematological or lymphatic cancer were excluded. Undocumented or unknown procedures were also excluded. Thus, 363 patients remained for evaluation in the study (Figure 1).