Recently, Self-expandable metallic stents as a bridge to surgery in obstructive right- and left-sided colorectal cancer: a multicenter cohort study was published in Scientific Reports, and it’s relevant to some patients with colorectal cancer in cases where an obstructing cancer is found. Carmen Fong, MD, FACS, explains stents as a bridge to surgery for colorectal cancer patients.

Carmen Fong, MD, FACS

When to Stent

A colorectal cancer patient generally needs a stent when the tumor has grown to such a large size that it causes an obstruction, or blockage, of the intestines.

When a near-complete blockage occurs, there are usually two options—the current standard of care, which is surgery, or a stent. Surgery can be minimally invasive or open (traditional large incision) and serves to remove the portion of the colon with the tumor in it and to relieve the obstruction. Sometimes this may involve a temporary ostomy

A stent is an expandable tube that is passed through the lumen (which is the hollow part of a tube) of the tumor that serves to keep the lumen open. This is important because if the lumen is completely blocked, nothing can pass through. Without either surgery or stenting, the danger is that the colon (bowel) may perforate, or burst, which can make the person very sick and be life-threatening.

Why Stent?

The purpose of the stent is to keep the bowel open, so that stool can continue to pass through. Note, in a complete blockage, sometimes a wire cannot be passed through the tumor, and therefore, surgery is the only option. Also note, generally advanced endoscopists perform stenting procedures, and these are usually gastroenterologists, though some colorectal surgeons perform this procedure. Either way, the gastroenterologist and the colorectal surgeon work closely together to decide how to proceed in these cases. 

Benefits of a Stent

A stent is usually a temporizing measure so that the person can be optimized prior to surgery. Optimization can mean decompression of the bowel, because surgery with decompressed bowel carries lower risks—less chance of an ostomy, less likely to damage adjacent organs, less likely to have problems with wound closure and surgical site infections, and less likely to have respiratory issues post-operatively. 

So if a person comes in with a near-obstructing tumor, the goal would be stent immediately, then operation on the same admission (though after a few days). Again, it is unlikely that a completely obstructing tumor can be stented. The other reason to stent is if the person has distant metastases (tumor deposits) on organs other than the colon, most commonly the liver. 

In some cases, a stent is used to get the patient through neoadjuvant therapy (chemotherapy) and then a combined surgery for both the liver and colon can be performed at the same time. 

Lastly, a stent can be performed as means of palliation—that is, there is no planned surgery for the person, if the person does not want surgery or surgery is futile because the tumor is “inoperable,” but a stent allows the person to eat and pass stool and gas and be comfortable in the meantime. There are also certain areas of the colon where a stent may not be possible—for example, places where the colon bends and turns. 

Risks of a Stent

The main risk is perforation during the procedure or afterward. There is a chance of bleeding and infection due to the procedure. Also, there is a risk of stent migration— that is, the stent slides up and down and either causes a blockage, a perforation, or doesn't do its job.

Can I Avoid an Ostomy with a Stent?

Can stenting prevent a patient from needing an ostomy? Perhaps. A stent is often touted as an “alternative to an ostomy,” but the only instance where that is true is if the person never gets surgery, as in the palliative situation above. In this case, the person gets a stent instead of a permanent colostomy. 

In situations where the stent is a bridge, or temporizing measure, until surgery, then the stent reduces the chance of an ostomy in the final surgery (in some studies, by 12%–30%). Note, a stent prevents an initial ostomy surgery where the standard sequence was colostomy--> definitive resection--> colostomy reversal. Most ostomies performed in this scenario are reversed via a reversal surgery.

Summing Up the Research

This study, Self-expandable metal stents as a bridge to surgery in obstructive right- and left-sided colorectal cancer: A multicenter cohort study, is important to the colorectal cancer community so that patients know about stenting as an option in select obstructing cancers.

The authors' goals were to compare post-operative and oncologic outcomes between stented patients and those who underwent emergency surgery. The study confirms what we already know: Stents can decrease the need for a stoma, decrease length of stay, with similar oncologic outcomes as patients who undergo initial colostomy surgery.

“Would I have a stent if I needed one? Yes. Would I transfer for one? Not necessarily.”

– Dr. Carmen Fong

What this means for patients is that asking for a stent is an option in select tumors: if the surgeon/GI agrees; if a facility is not equipped or does not have an advanced endoscopist; if the patient is stable, it may be an option to transfer to a facility that does stent.

4 thoughts on “Stents as a Bridge to Surgery for Colorectal Cancer Patients

    1. Hi Luke: We reached out to Dr. Fong with your question, and she so graciously answered it as follows. (Thank you so much, Dr. Fong!)

      “The reasons for this are a few: The ileocecal valve is the connection between the small bowel and the right colon. ‘Pre’ IC valve (proximal in surgical terms) is small bowel. Small bowel is thin and floppy and can’t get stented because of the risk of perforation. The IC valve itself is a common place for malignancy, and again can’t be stented because of the small bowel proximal to it. ‘Post’ IC valve (distal in surgical terms) is colon and can be stented but it depends on the distance between the IC valve, the obstructing tumor, and the hepatic flexure. Flexures, or where the colon turn a corner, happens at the liver (hepatic), the spleen (splenic), and the sigmoid. The flexures are also difficult to stent because of the angle and the risk of perforation, migration, and stent kinking. If the tumor is in the cecum, which is right colon immediately ‘post’ IC valve, also tends to be thin, prone to perforation, and difficult to deploy a stent in. Therefore, stents really need an ideal, straight segment of colon to work. Hopefully this will change, and we will someday be able to do more with stenting to prevent additional surgeries and ostomies.

      When the tumor is on the right side, at or near the IC valve, the standard of care is to proceed with surgery, a right hemicolectomy, with or without an ostomy. The success rate is good and the known complications are less than attempting to stent on the right side.”

  1. Does taking Avastin present a greater risk of perforation ?1
    If yas how long after stopping Avastin would that risk be resuced?

    1. Hi Jay, Unfortunately, we cannot provide individual medical advice. Please reach out to your health care team, since they know you and are equipped to handle your questions. Thanks!

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