Emergency management of malignant large bowel obstruction (COLMNG5)
Malignant large bowel obstruction occurs in up to 20% of patients with colorectal cancer. It is a significant cause of mortality among patients with colorectal cancer; up to 25% of all postoperative deaths are associated with malignant bowel obstruction. It is also associated with significant morbidity, including a high probability of receiving a stoma.
Patients with malignant large bowel obstruction may be candidates for curative treatment or palliative treatment. Due to the increased availability of computed tomography (CT), patients’ status is often known prior to therapeutic intervention.
Given that this malignant large bowel obstruction is common, patients with this problem can present to any hospital that has emergency admissions. There has been a long debate over the best approach to left-sided malignant large bowel obstruction, predominantly focused on restorative procedures, versus non-restorative procedures which result in an end colostomy. The advent of self-expanding metallic stents (SEMS) has added a further management option to the mix.
Systematic review evidence[edit source]
In patients diagnosed with colorectal cancer and acute obstruction, does stenting or colostomy achieve equivalent or better outcomes, compared to acute resection with primary anastomosis? (COLMNG5)
A systematic review was undertaken to evaluate outcomes following stenting or colostomy in patients with acute large bowel obstruction, compared with acute resection plus primary anastomosis. Two randomised controlled trials (RCTs) were identified that compared (1) the use of temporary stents, followed by an elective surgery with (2) acute resection with primary anastomosis. All participants were patients who presented with left-sided colonic cancer as confirmed by CT. Acute resections consisted of either a colectomy or a left hemicolectomy, sigmoid colectomy or a high anterior resection. The median follow-up period in these RCTs ranged from 18 months to 37.6 months.
Both trials were at high risk of bias, as the blinding processes were not reported. The first provided minimal description of the randomisation process, and the trial was terminated early due to a high rate of complications in the comparator group.
The studies are heterogeneous, small in sample size and empirical results vary in significance. Outcomes reported varied between trials. Overall, RCT evidence on which to evaluate the use of stents in curative obstructive colorectal patients is limited.
Two RCTs comparing preoperative stenting versus emergency surgery for acute left sided obstruction were prematurely closed because of adverse outcomes in the stenting group, namely tumour perforation, in the stent group. These RCTs were therefore excluded from the systematic review.
The search strategy, inclusion and exclusion criteria, and quality assessment are described in detail in the Technical report.
Perioperative morbidity and adverse events[edit source]
Overall morbidity[edit source]
A Spanish RCT (n = 28) reported that stenting was associated with a significant (p=0.042) benefit for overall morbidity.
An Egyptian RCT (n = 60) also reported that stenting was associated with a significant reduction in morbidity. Stenting patients lost less blood (p = 0.010) and required fewer blood transfusions (p = 0.035) and fewer fresh frozen plasma infusions (p = 0.010) intraoperatively. The stenting group also showed significantly fewer median bowel motions per day (p = 0.013) at 3 months’ follow-up, but this was no longer significant at 6 months’ follow-up.
Anastomotic leakage[edit source]
In both studies, patients who received stents did not experience any anastomotic leakage within the trial period. In the smaller study, the rate of anastomotic dehiscence was significantly lower (p=0.035) in the stenting group than the emergency primary anastomosis group, but in the larger study there was no statistically significant difference in the rate of anastomotic leakage between groups.
Wound infections[edit source]
The larger study reported that significantly fewer patients presented with wound infections in the stenting group, compared with the acute resection group (10% versus 30%; p = 0.022). The smaller study reported a numerically lower rate of surgical space infections in the stenting group than the resection and anastomosis group, but the difference was not statistically significant overall. The variation of significance may be due to small sample sizes.
Other morbidity[edit source]
Neither study reported stent-related technical complications such as perforation, bleeding or stent migration. The clinical implications of this is unknown, as it was not analysed further in either trial.
The larger study reported that chest infections occurred less frequently in those with stents than those with acute resection and anastomosis, but this difference was not statistically significant (p = 0.098). The smaller study reported a significantly higher rate of reoperations within the overall follow-up period among those who underwent acute resection, compared with those who received stents (approximately 31% versus zero; p = 0.035).
Length of hospital stay[edit source]
Both trials reported longer hospital stays for those in the stenting group than the acute resection and anastomosis group, although this difference was not statistically significant. The smaller study reported that mean postoperative stay was significantly shorter for the stenting group.
Perioperative mortality[edit source]
Both trials reported no mortality as a result of the stenting procedure. However, the statistical significance of this was either not reported on or found to be not statistically significant.
Overall survival[edit source]
The smaller study reported that approximately 58% of patients who received stents, and approximately 70% of those who received acute resections, survived at the end of 59 months of follow up. However, this difference was not statistically significant (p = 0.843).
Evidence summary and recommendations[edit source]
|Patients who received stents before an elective surgery showed reduced perioperative morbidity than those who underwent emergency resection and anastomosis.||II||, |
|Two RCTs were prematurely closed because of adverse outcomes, namely tumour perforation, in the stent group.||N/A||, |
|The benefits of stenting on perioperative mortality rates and length of hospital stays were inconclusive.||II||, |
|There is weak evidence that the use of stents may reduce the risk of adverse events in colorectal cancer patients with cases of curative obstruction.||II||, |
|The trials did not report complications of stent migration, perforation or bleeding.||N/A||, |
|The studies did not report 5-year survival, cancer-specific survival, stoma rate or quality of life as outcomes.||N/A||, |
If stenting is considered, it should be discussed by the multidisciplinary team and implications for anti-VEGF systemic therapy should be assessed.
Considerations in making these recommendations[edit source]
Randomised controlled trials demonstrate no specific benefit from stenting as compared to primary surgery. There is a recognised incidence of local tumour perforation from stenting, which may convert a curative case to a potentially palliative case. Whilst this has not demonstrated reduced long-term survival, two large randomised controlled trials were closed early as a result of this. Hence, insertion of a stent as a bridge to surgery cannot be recommended in curative cases unless the patient is considered unfit for major surgery.
There does appear to be a role for insertion of a stent to relieve obstruction as a palliative procedure, if the technical skill is available. This approach might reduce the incidence of stoma formation and avoid the requirement of surgery in a proportion of cases in which metastatic colorectal cancer is incurable or where patients considered unfit for major surgery. However, the use of anti-VEGF systemic therapy may be contraindicated in the presence of a stent, as there is evidence that the risk of perforation is increased. Balancing the potential long term benefits on survival of anti-VEGF agents versus stenting or surgery, the later removing the risk of perforation and allowing anti-VEGF therapy to subsequently proceed, should therefore be discussed in this situation.
Health system implications[edit source]
Clinical practice[edit source]
These recommendations would potentially necessitate the increased availability of the expertise to insert SEMS. However, this expertise is already established in clinical practice, so the recommendation would not require a change to the way that care is currently organised.
Increased application of stenting will require increased availability of personnel with the technical ability to insert a colonic stent, particularly if it is to be used out of routine hours. This could be colorectal surgeons or gastroenterologists. However, it may be challenging in smaller centres.
Barriers to implementation[edit source]
No barriers to the implementation of these recommendations are envisaged.
Unresolved issues[edit source]
Currently, there are no RCTs comparing outcomes of colostomies or Hartmann’s Procedure with those of resections, or comparing colectomies with anastomosis.
In patients with curative obstructive colorectal cancer, the use of stents as an alternative to primary resection remains undecided. More evidence is required to demonstrate a concrete benefit over acute resection with primary anastomosis.
Studies currently underway[edit source]
No relevant major RCTs are awaited. Publication of findings from the CReST study, the largest multicentre cohort study yet completed, may address endpoints other than survival, such as avoidance of a permanent stoma.
Future research priorities[edit source]
Further evidence is required to determine the role of stenting in palliative cases.
- Irvin TT, Greaney MG. The treatment of colonic cancer presenting with intestinal obstruction. Br J Surg 1977 Oct;64(10):741-4 Available from: http://www.ncbi.nlm.nih.gov/pubmed/922296.
- Mella J, Biffin A, Radcliffe AG, Stamatakis JD, Steele RJ. Population-based audit of colorectal cancer management in two UK health regions. Colorectal Cancer Working Group, Royal College of Surgeons of England Clinical Epidemiology and Audit Unit. Br J Surg 1997 Dec;84(12):1731-6 Available from: http://www.ncbi.nlm.nih.gov/pubmed/9448628.
- Ghazal AH, El-Shazly WG, Bessa SS, El-Riwini MT, Hussein AM. Colonic endolumenal stenting devices and elective surgery versus emergency subtotal/total colectomy in the management of malignant obstructed left colon carcinoma. J Gastrointest Surg 2013 Jun;17(6):1123-9 Available from: http://www.ncbi.nlm.nih.gov/pubmed/23358847.
- Pirlet IA, Slim K, Kwiatkowski F, Michot F, Millat BL. Emergency preoperative stenting versus surgery for acute left-sided malignant colonic obstruction: a multicenter randomized controlled trial. Surg Endosc 2011 Jun;25(6):1814-21 Available from: http://www.ncbi.nlm.nih.gov/pubmed/21170659.
- van Hooft JE, Bemelman WA, Oldenburg B, Marinelli AW, Lutke Holzik MF, Grubben MJ, et al. Colonic stenting versus emergency surgery for acute left-sided malignant colonic obstruction: a multicentre randomised trial. Lancet Oncol 2011 Apr;12(4):344-52 Available from: http://www.ncbi.nlm.nih.gov/pubmed/21398178.
- van Halsema EE, van Hooft JE, Small AJ, Baron TH, García-Cano J, Cheon JH, et al. Perforation in colorectal stenting: a meta-analysis and a search for risk factors. Gastrointest Endosc 2014 Jun;79(6):970-82.e7; quiz 983.e2, 983.e5 Available from: http://www.ncbi.nlm.nih.gov/pubmed/24650852.
- Imbulgoda A, MacLean A, Heine J, Drolet S, Vickers MM. Colonic perforation with intraluminal stents and bevacizumab in advanced colorectal cancer: retrospective case series and literature review. Can J Surg 2015 Jun;58(3):167-71 Available from: http://www.ncbi.nlm.nih.gov/pubmed/25799132.
- Hill J KC, Morton D, Magill L, Handley K, Gray RG, et al. CREST: Randomised phase III study of stenting as a bridge to surgery in obstructing colorectal cancer—Results of the UK ColoRectal Endoscopic Stenting Trial (CREST). Proceedings of the American Society of Clinical Oncology Annual Meeting; 2016 Jun 3-7. Chicago (IL).;.