Mechanical Bowel Preparation Does Not Affect Clinical Severity of Anastomotic Leakage in Rectal Cancer Surgery. World J Surg. 2017;41:1366-1374. [PMID: 28008456 DOI: 10.1007/s00268-016-3839-9]

The effect of preoperative mechanical bowel preparation in paediatric bowel surgery on postoperative wound related complications: A meta-analysis

Mechanical bowel preparation (MBP), a routine nursing procedure before paediatric bowel surgery, is widely should in clinical practice, but its necessity remains controversial. In a systematic review and meta-analysis, we evaluated the effect of preoperative MBP in paediatric bowel surgery on postoperative wound-related complications in order to analyse the clinical application value of MBP in paediatric bowel surgery. As of November 2023, we searched four online databases: the Cochrane Library, Embase, PubMed, and Web of Science. Two investigators screened the collected studies against inclusion and exclusion criteria, and ROBINS-I was used to evaluate the quality of studies. Using RevMan5.3, a meta-analysis of the collected data was performed, and a fixed-effect model or a random-effect model was used to analyse OR, 95% CI, SMD, and MD. A total of 11 studies with 2556 patients were included. Most of studies had moderate-to-severe quality bias. The results of meta-analysis showed no statistically significant difference in the incidence of complications related to postoperative infections in children with MBP before bowel surgery versus those with No MBP, wound infection (OR 1.11, 95% CI:0.76 ~ 1.61, p = 0.59, I2 = 5%), intra-abdominal infection (OR 1.26, 95% CI:0.58 ~ 2.77, p = 0.56, I2 = 9%). There was no significant difference in the risk of postoperative bowel anastomotic leak (OR 1.07, 95% CI:0.68 ~ 1.68, p = 0.78, I2 = 12%), and anastomotic dehiscence (OR 1.67, 95% CI:0.13 ~ 22.20, p = 0.70, I2 = 73%). Patients' intestinal obstruction did not show an advantage of undergoing MBP preoperatively, with an incidence of intestinal obstruction (OR 1.95, 95% CI:0.55 ~ 6.93, p = 0.30, I2 = 0%). Based on existing evidence that preoperative MBP in paediatric bowel surgery did not reduce the risk of postoperative wound complications, we cautiously assume that MBP before surgery is unnecessary for children undergoing elective bowel surgery. However, due to the limited number of study participants selected for this study and the overall low quality of evidence, the results need to be interpreted with caution. It is suggested that more high quality, large-sample, multicenter clinical trials are required to validate our findings.

High-intensity mechanical bowel preparation before curative colorectal surgery is associated with poor long-term prognosis

PURPOSE

Mechanical bowel preparation (MBP) has been widely used to reduce intestinal feces and bacteria and is considered necessary to prevent surgical infections. However, it is still controversial which intensity level of MBP is the most beneficial for patients before colorectal surgery. Our study aimed to determine the impact of different intensity levels of MBP on the progression-free survival (PFS) and overall survival (OS) for colorectal cancer (CRC) patients.

METHODS

We evaluated 694 patients pathologically diagnosed with CRC and underwent MBP before surgery at 4 general hospitals from January 2011 to December 2015. The survival status of patients, the disease progression, and the time of death or progression were obtained through telephone follow-up at the deadline October 10, 2018. Hazard ratios were estimated by Cox proportional hazard models. Survival was assessed using the Kaplan-Meier method followed by the log-rank test.

RESULTS

Of 694 patients included, 462 received low-intensity MBP and 232 received high-intensity MBP. A significantly higher PFS in low-intensity MBP was observed (p = 0.009). PFS at 2000 days was 69.331% in the low-intensity arm and 58.717% in the high-intensity arm. Patients who underwent low-intensity MBP also showed higher OS (p = 0.009). Nine patients in the low-intensity MBP group received secondary surgery, and two patients in the high-intensity MBP group received secondary surgery.

CONCLUSIONS

In this retrospective cohort, low-intensity MBP was associated with better PFS and OS, which could provide a reference for doctors when choosing the intensity of MBP.

Mechanical bowel preparation with or without oral antibiotics for rectal resection for cancer (REPCA trial): a study protocol for a multicenter randomized controlled trial

BACKGROUND

There is still a lack of randomized trials assessing the clinical value of mechanical bowel preparation (MBP) and oral antibiotics (OA) before rectal surgery. Existing studies are inconsistent regarding OA. The aim of this study is to examine the role of MBP with or without OA (using Alfa Normix^®) on postoperative complications in patients undergoing rectal resection for cancer.

METHODS

We are conducting a prospective multicenter randomized controlled trial comparing MBP (Moviprep^®) with OA (Alfa Normix^®) versus MBP alone in patients undergoing elective rectal resection for cancer. Patients with rectal or rectosigmoid cancer are randomized in a 1:1 allocation ratio. The primary endpoint is incisional surgical site infection (SSI) assessed within 30 days after surgery. Secondary endpoints are anastomotic leakage (AL), organ/space SSI, other postoperative complications, intraoperative complications, operation time, bowel preparation quality, bowel preparation adherence. Intention-to-treat and per protocol analyses will be performed.

CONCLUSIONS

The results of the REPCA trial will demonstrate whether MBP + OA is superior to MBP alone in rectal cancer surgery. This trial might influence current preoperative practice and improve postoperative outcomes.

Intraoperative Colonic Irrigation for Low Rectal Resections With Primary Anastomosis: A Fail-Safe Surgical Model

Aim

Regardless the technological developments in surgery, the anastomotic leakage (AL) rate of low rectal anastomosis remains high. Though various perioperative protocols have been tested to reduce the risk for AL, there is no standard peri-operative management approach in rectal surgery. We aim to assess the short-term outcome of a multidisciplinary approach to reduce the rates of ALs using a fail-safe-model using preoperative and intraoperative colonic irrigation in low rectal resections with primary anastomosis.

Methods

Between January 2015 and December 2020, 92 patients received low rectal resections for rectal cancer with primary anastomosis and diverting ileostomy. All these patients received pre-operative mechanical bowel preparation (MBP) without antibiotics as well as intraoperative colonic irrigation. The intraoperative colonic irrigation was performed via the efferent loop of the ileostomy. All data were analyzed by SPSS for descriptive and inferential analyses.

Results

In the study period, 1.987 colorectal surgical procedures were performed. This study reports AL in 3 (3.3%) of 92 recruited patients. Other postoperative complications (Dindo-Clavien I-IV) were reported in 25 patients (27.2%), which occurred mainly due to non-surgical reasons such as renal dysfunction and sepsis. According to the fail-safe model, AL was treated by endoscopic or re-do surgery. The median postoperative length of hospitalization was 8 days (4–45) days.

Conclusion

This study validates the effectiveness of a multi-disciplinary fail-safe model with a pre-operative MBP and an intraoperative colonic irrigation in reducing AL rates. Intraoperative colonic irrigation is a feasible approach that lowers the AL rates by reducing fecal load and by decontamination of the colon and anastomotic region. Our study does not recommend a pre-operative administration of oral antibiotics for colorectal decontamination.

Anastomotic leakage in colorectal cancer surgery

The safety of colorectal surgery for oncological disease is steadily improving, but anastomotic leakage is still the most feared and devastating complication from both a surgical and oncological point of view. Anastomotic leakage affects the outcome of the surgery, increases the times and costs of hospitalization, and worsens the prognosis in terms of short- and long-term outcomes. Anastomotic leakage has a wide range of clinical features ranging from radiological only finding to peritonitis and sepsis with multi-organ failure. C-reactive protein and procalcitonin have been identified as early predictors of anastomotic leakage starting from postoperative day 2-3, but abdominal-pelvic computed tomography scan is still the gold standard for the diagnosis. Several treatments can be adopted for anastomotic leakage. However, there is not a universally accepted flowchart for the management, which should be individualized based on patient's general condition, anastomotic defect size and location, indication for primary resection and presence of the proximal stoma. Non-operative management is usually preferred in patients who underwent proximal faecal diversion at the initial operation. Laparoscopy can be attempted after minimal invasive surgery and can reduce surgical stress in patients allowing a definitive treatment. Reoperation for sepsis control is rarely necessary in those patients who already have a diverting stoma at the time of the leak, especially in extraperitoneal anastomoses. In patients without a stoma who do not require abdominal reoperation for a contained pelvic leak, there are several treatment options, including laparoscopic diverting ileostomy combined with trans-anal anastomotic tube drainage, percutaneous drainage or recently developed endoscopic procedures, such as stent or clip placement or endoluminal vacuum-assisted therapy. We describe the current approaches to treat this complication, as well as the clinical tests necessary to diagnose and provide an effective therapy.

Risk Factors and Preventive Measures for Anastomotic Leak in Colorectal Cancer

Anastomotic leak (AL) represents one of the most detrimental complications after colorectal surgery. The patient-related factors and surgery-related factors leading to AL have been identified in previous studies. Through early identification and timely adjustment of risk factors, preventive measures can be taken to reduce potential AL. However, there are still many problems associated with AL. The debate about preventive measures such as preoperative mechanical bowel preparation (MBP), intraoperative drainage, and surgical scope also continues. Recently, the gut microbiota has received more attention due to its important role in various diseases. Although the underlying mechanisms of gut microbiota on AL have not been validated completely, new strategies that manipulate intrinsic mechanisms are expected to prevent and treat AL. Moreover, laboratory examinations for AL prediction and methods for blood perfusion assessment are likely to be promoted in clinical practice. This review outlines possible risk factors for AL and suggests some preventive measures in terms of patient, surgery, and gut microbiota.

Updates of Risk Factors for Anastomotic Leakage after Colorectal Surgery

Anastomotic leakage is a potentially severe complication occurring after colorectal surgery and can lead to increased morbidity and mortality, permanent stoma formation, and cancer recurrence. Multiple risk factors for anastomotic leak have been identified, and these can allow for better prevention and an earlier diagnosis of this significant complication. There are nonmodifiable factors such as male gender, comorbidities and distance of tumor from anal verge, and modifiable risk factors, including smoking and alcohol consumption, obesity, preoperative radiotherapy and preoperative use of steroids or non-steroidal anti-inflammatory drugs. Perioperative blood transfusion was shown to be an important risk factor for anastomotic failure. Recent studies on the laparoscopic approach in colorectal surgery found no statistical difference in anastomotic leakage rate compared with open surgery. A diverting stoma at the time of primary surgery does not appear to reduce the leak rate but may reduce its clinical consequences and the need for additional surgery if anastomotic leakage does occur. It is still debatable if preoperative bowel preparation should be used, especially for left colon and rectal resections, but studies have shown similar incidence of postoperative leak rate.

Does Intracorporeal Anastomosis Decrease the Rate of Surgical Site Infection in Laparoscopic Colon Cancer Surgery?

Objective

This study aimed to compare the surgical site infection (SSI) rates between intracorporeal anastomosis (ICA) and extracorporeal anastomosis (ECA).

Summary of background data

Laparoscopic surgery is recommended for colonic malignancies because of its superior clinical outcomes and comparable oncologic results. Laparoscopic colectomy with ICA has the advantages of incision length and free extraction site choice. However, ICA may be associated with a risk of SSI due to enterotomy inside the abdominal cavity.

Methods

We retrospectively analyzed patients with colon cancer who underwent radical surgery at Korea University Ansan Hospital between January 2017 and June 2020. We compared the SSI rates and other clinical variables between the ICA and ECA groups.

Results

Of the 502 patients who underwent radical surgery for colorectal cancer during the study period, 234 were eligible for inclusion. ECA and ICA were performed in 62.4% and 37.6% of patients, respectively. There were no statistically significant intergroup differences in clinicopathologic variables. The overall SSI rate did not differ between the groups (P = 0.801), but organ/space SSIs were more common in the ICA group than in the ECA group (P = 0.048).

Conclusions

There was no significant difference in overall SSI or anastomotic leakage (AL) rates between the ICA and ECA groups, but the organ/space SSI rate was higher in the ICA group when AL cases were excluded. Further high-quality studies are needed to assess the risk of organ/space SSIs in the ICA after colon cancer surgery.

[Role of Mechanical Bowel Preparation for Elective Colorectal Surgery]

The presence of bowel contents during colorectal surgery has been related to surgical site infections (SSI), anastomotic leakage (AL) and postoperative complications theologically. Mechanical bowel preparation (MBP) for elective colorectal surgery aims to reduce fecal materials and bacterial count with the objective to decrease SSI rate, including AL. Based on many observational data, meta-analysis and multicenter randomized control trials (RTC), non-MBP did not increase AL rates or SSI and other complications in colon and even rectal surgery. In 2011 Cochrane review, there is no significant benefit MBP compared with non-MBP in colon surgery and also no better benefit MBP compared with rectal enemas in rectal surgery. However, in surgeon's perspectives, MBP is still in widespread surgical practice, despite the discomfort caused in patients, and general targeting of the colon microflora with antibiotics continues to gain popularity despite the lack of understanding of the role of the microbiome in anastomotic healing. Recently, there are many evidence suggesting that MBP+oral antibiotics (OA) should be the growing gold standard for colorectal surgery. However, there are rare RCT studies and still no solid evidences in OA preparation, so further studies need results in both MBP and OA and only OA for colorectal surgery. Also, MBP studies in patients with having minimally invasive surgery (MIS; laparoscopic or robotics) colorectal surgery are still warranted. Further RCT on patients having elective left side colon and rectal surgery with primary anastomosis in whom sphincter saving surgery without MBP in these MIS and microbiome era.

The Role of Bowel Preparation in Open, Minimally Invasive, and Converted-to-Open Colectomy

BACKGROUND

Bowel preparation before colectomy is considered an effective strategy to decrease postoperative complications. However, data regarding the effect of bowel preparation in patients undergoing minimally invasive colectomy are limited. The aim of this study was to investigate the role of different bowel preparation strategies in patients undergoing open, minimally invasive, and converted-to-open elective colectomies.

METHODS

We identified 39,355 patients who underwent elective colectomy from the American College of Surgeons National Surgical Quality Improvement Program colectomy-targeted database (2012-2016). Multivariate logistic regression models were used to assess the impact of different bowel preparation strategies on postoperative complications and mortality in three subapproach groups: open (n = 12,141), minimally invasive (n = 23,057), and converted to open (n = 4157).

RESULTS

Overall, a total of 10,066 (25.6%) patients received no preparation (NP), 11,646 (29.5%) mechanical bowel preparation (MBP) alone, 1664 (4.2%) antibiotic bowel preparation (ABP) alone, and 15,979 (40.6%) MBP + ABP. Compared with NP, MBP + ABP showed the strongest protective effects. MBP + ABP was associated with reduced risk of major complications (odds ratio [OR] = 0.60, 95% confidence interval [CI]: 0.55-0.66), infectious complications (OR = 0.50, 95% CI: 0.46-0.54), any complications (OR = 0.55, 95% CI: 0.51-0.60), 30-d mortality (OR = 0.68, 95% CI: 0.48-0.96), anastomotic leak (OR = 0.50, 95% CI: 0.43-0.58), and length of stay ≥ 4 d (OR = 0.64, 95% CI: 0.61-0.67) in overall population. These protective effects, except for 30-d mortality, were observed in open, minimally invasive, and converted-to-open groups. When the analysis was limited to robotic surgery only, MBP + ABP was only associated with reduced risk of major complications (OR = 0.61, 95% CI: 0.38-0.97) compared with NP. The protective effects remained similar over the study time period.

CONCLUSIONS

MBP + ABP is a preferred preoperative strategy in open, minimally invasive, and converted-to-open colectomy.

2017 WSES guidelines on colon and rectal cancer emergencies: obstruction and perforation

ᅟ

Obstruction and perforation due to colorectal cancer represent challenging matters in terms of diagnosis, life-saving strategies, obstruction resolution and oncologic challenge. The aims of the current paper are to update the previous WSES guidelines for the management of large bowel perforation and obstructive left colon carcinoma (OLCC) and to develop new guidelines on obstructive right colon carcinoma (ORCC).

Methods

The literature was extensively queried for focused publication until December 2017. Precise analysis and grading of the literature has been performed by a working group formed by a pool of experts: the statements and literature review were presented, discussed and voted at the Consensus Conference of the 4th Congress of the World Society of Emergency Surgery (WSES) held in Campinas in May 2017.

Results

CT scan is the best imaging technique to evaluate large bowel obstruction and perforation. For OLCC, self-expandable metallic stent (SEMS), when available, offers interesting advantages as compared to emergency surgery; however, the positioning of SEMS for surgically treatable causes carries some long-term oncologic disadvantages, which are still under analysis. In the context of emergency surgery, resection and primary anastomosis (RPA) is preferable to Hartmann’s procedure, whenever the characteristics of the patient and the surgeon are permissive. Right-sided loop colostomy is preferable in rectal cancer, when preoperative therapies are predicted.

With regards to the treatment of ORCC, right colectomy represents the procedure of choice; alternatives, such as internal bypass and loop ileostomy, are of limited value.

Clinical scenarios in the case of perforation might be dramatic, especially in case of free faecal peritonitis. The importance of an appropriate balance between life-saving surgical procedures and respect of oncologic caveats must be stressed. In selected cases, a damage control approach may be required.

Medical treatments including appropriate fluid resuscitation, early antibiotic treatment and management of co-existing medical conditions according to international guidelines must be delivered to all patients at presentation.

Conclusions

The current guidelines offer an extensive overview of available evidence and a qualitative consensus regarding management of large bowel obstruction and perforation due to colorectal cancer.

Impact of mechanical bowel preparation in elective colorectal surgery: A meta-analysis

AIM

To analyse the effect of mechanical bowel preparation vs no mechanical bowel preparation on outcome in patients undergoing elective colorectal surgery.

METHODS

Meta-analysis of randomised controlled trials and observational studies comparing adult patients receiving mechanical bowel preparation with those receiving no mechanical bowel preparation, subdivided into those receiving a single rectal enema and those who received no preparation at all prior to elective colorectal surgery.

RESULTS

A total of 36 studies (23 randomised controlled trials and 13 observational studies) including 21568 patients undergoing elective colorectal surgery were included. When all studies were considered, mechanical bowel preparation was not associated with any significant difference in anastomotic leak rates (OR = 0.90, 95%CI: 0.74 to 1.10, P = 0.32), surgical site infection (OR = 0.99, 95%CI: 0.80 to 1.24, P = 0.96), intra-abdominal collection (OR = 0.86, 95%CI: 0.63 to 1.17, P = 0.34), mortality (OR = 0.85, 95%CI: 0.57 to 1.27, P = 0.43), reoperation (OR = 0.91, 95%CI: 0.75 to 1.12, P = 0.38) or hospital length of stay (overall mean difference 0.11 d, 95%CI: -0.51 to 0.73, P = 0.72), when compared with no mechanical bowel preparation, nor when evidence from just randomized controlled trials was analysed. A sub-analysis of mechanical bowel preparation vs absolutely no preparation or a single rectal enema similarly revealed no differences in clinical outcome measures.

CONCLUSION

In the most comprehensive meta-analysis of mechanical bowel preparation in elective colorectal surgery to date, this study has suggested that the use of mechanical bowel preparation does not affect the incidence of postoperative complications when compared with no preparation. Hence, mechanical bowel preparation should not be administered routinely prior to elective colorectal surgery.