Colorectal cancer (CRC) is a common disease in the worldwide population. Unfortunately, even in western countries with screening programs for CRC, there are still patients resorting to the emergency departments with bowel obstruction. Worldwide, one in six patients presents with an obstructive CRC needing emergent treatment. Classically, surgery is the first line option with stoma formation with or without cancer resection. Because of the patient's instability and lack of bowel preparation, anastomosis is frequently not conducted.
Self-expanding metal stents (SEMS) can relieve bowel obstruction in left-sided cancers. However, due to increased complications like perforation, failure in relieving the obstruction, and potential tumor dissemination from stent insertion, SEMS is not usually used. The European guidelines recommend SEMS for palliation, but for a potentially curative disease, SEMS is only an option to consider. The CReST trial published in 2022 can change this idea.
This randomized trial included 245 patients with left-sided colonic obstruction from 39 NHS hospitals. Patients were randomized into two groups: 123 allocated for stenting and 122 allocated for emergency surgery. If stenting was successful, the patient would be operated on within the next 1-4 weeks. Stenting relieved obstruction in 82,4% of patients (78.2% of potentially curative patients, and 92.3% of palliative patients). Cases of stenting failure were treated with emergency surgery.
Comparing the potentially curative patients operated on in both groups (stenting vs. emergency surgery), 70 patients in the stenting group (70.7%) and 60 patients in the emergency surgery group (56.6%) had anastomosis (p=0.04). A stoma (including loop stoma with anastomosis) was constructed during index surgery in 47.5% and 67.9% of patients in the stenting and emergency surgery groups, respectively (0.003). In the stenting group, 28 patients had an end stoma without anastomosis, contrasting with 44 patients in the emergency surgery group (p=0.047). Additionally, of all patients submitted to potentially curative treatment, 44.5% in the stenting group and 66.4% in the emergency surgery group had a stoma at 1 year of follow-up (p=0.001) These data from the CReST study support that the risk/need of a stoma formation is significantly lower if a SEMS is inserted. This is in contrast with previous studies.
Perforations due to stent insertion occurred only in four patients, and the stent treated one. The duration of hospital stays for patients who received potentially curative treatment was similar in both groups. The 30-day mortality was also identical (p=0.48). Although the anastomotic leak rate was lower in the stenting group (3,5% vs. 7.4%), there was no statistical significance (p=0.35). Global morbidity was identical. The CReST study also states that the quality of life (QoL) at 3 and 12 months was the same in both groups. Well, this I cannot agree with or understand. Does having a stoma decrease QoL? I think it does. No one enjoys having a stoma and a bag full of stools while at a party dinner or social event. I believe that by decreasing the risk of stoma formation, SEMS insertion can give the patient a better QoL than emergency surgery.
The CReST trial seems to demystify some negative aspects of colonic stenting in left-sided colonic obstruction. The European guidelines do not recommend stenting as a bridge for surgery in potentially curative patients because of the risks of stenting failure and patient safety, and concerns that stents can increase the local and metastatic spread. In the CReST study, the rate of stenting success and relief of obstruction was higher than in previous reports for potentially curative patients. Additionally, SEMS insertion had a low number of complications (easily treated), and morbidity was identical to emergency surgery. At three years of follow-up, the CReST trial showed no difference in recurrence. So, there seems to be no increased risk of recurrent malignancy from colonic stenting. We must highlight that SEMS insertion avoided stoma formation in a significantly higher number of patients submitted to potentially curative treatment, than emergency surgery. Avoiding stomas is a huge advantage of stenting, I think. It also allows for patient stabilization (potential impact on the surgical outcome) and accurate preoperative staging (impact on treatment strategy).
As the authors state, “stenting as a bridge to surgery should therefore be considered as a standard option for patients with obstructing but potentially curative cancer (…)”.
Link to PubMed:
Dr. Carlos Eduardo Costa Almeida
General Surgeon