Question about colorectal surgeries and ostomies

[GoPelicans]

Hey I'm a first year rads resident trying to understand rationale behind forming ostomies since I am having a lot of trouble understanding imaging of postsurgical patients.. Anyone have a resource that explains why some patients get ilesotomies, colostomies, why some are permanent, some are temporary, the rationale for doign ostomies vs an anastamosis, etc for diff types of colorectal cancer?

---

Members don't see this ad.

 

[HighwayVagabond]

There is not a simple, straightforward answer for this, but for some basics:

In general, ostomies are created to either protect a more distal anastomosis, to allow for a functional GI tract when a more distal anastomosis is not safely possible in an acute setting, or to all for a functional GI tract permanently in someone who doesn't have an option left for restoration of GI continuity.

Most patients undergoing emergent colectomy (ie for diverticulitis or acute obstruction) will get an ostomy. This is usually a situation where the GI tract is left entirely in discontinuity due to severe inflammation in the affected area. The ostomy (often colostomy unless the resection is proximal) is placed temporarily and the distal stump stapled off such that the inflammation has several months to die down and you can return to the abdomen to reconnect the GI tract at a later date. Or in case of obstruction, often the upstream bowel is so dilated you can't successfully/safely make an anastomosis to the normal caliber bowel more distally in the acute setting.

In case of very low anastomoses, we often create a diverting loop ileostomy more proximally, as the main feared complication of this is a leak, and the main cause of a leak is tension on an anastomosis. As you can imagine, anastomoses down in the pelvis tend to be more difficult, including in terms of reaching without tension, and therefore a diverting ostomy gives that anastomosis time to heal. Then the DLI is reversed at a later date when healing is complete. Often for right hemicolectomies, or sigmoid colectomies in the elective setting, we will not create an ostomy as there is less likelihood of leak.

Some patients have Total proctocolectomies or APRs and have no distal options for anastomosis. Total proctocolectomies technically can get a J-pouch, and coloanal anastomoses are also possible in general, but as you can imaging, these can be lifestyle limiting in that patients may have multiple bowel movements throughout the day, issues with poor continence, etc. Some people find it easier to continue to live their normal lives with an ostomy, and elect to have a permanent ostomy. Or in cases where we have exhausted all distal anastomotic options, a permanent ostomy would be placed.

This is a very, very general answer to your question but hopefully it gives you a foundation to work with.

 

[TraumaLlamaMD]

Just a few more thoughts:

You can think of ostomies in a few categories - small bowel vs. colon, and end vs. loop.

In general, we prefer as distal an ostomy as is feasible, to leave the patient with more functional GI tract. This means we will typically choose a colostomy over an ileostomy when possible, and a descending colostomy over a transverse or ascending colostomy. Sometimes this isn’t possible, because the patient has no colon left, or because the process necessitating the ostomy (cancer, obstruction) is in the proximal colon.

In terms of end vs. loop, note that loop ostomies are much easier to reverse, because both ends of the bowel are right there at the surface - we don’t have to go digging in the abdomen/pelvis for our stump. So in general, if we anticipate reversing an ostomy (usually in cases where the ostomy is created to protect a distal anastomosis, or we anticipate conditions in the abdomen will be more hospitable in the future) we try to make a loop.

Of course there are exceptions, most notably the Hartmann procedure where your ostomy is made from very distal colon. An alternative to the Hartmann procedure is a primary colorectal anastomosis with a loop ileostomy which protects the patient by diverting the fecal stream away from a new, possibly tenuous anastomosis.

There are some downsides to a loop ostomy though - mainly, it requires a bigger hole in the fascia, and the ostomy itself is larger because it has two limbs. Therefore, if we are anticipating a permanent ostomy, we often choose an end ostomy to make it easier for the patient to manage. If there is no/little downstream bowel left, as with an end descending colostomy, there is also no need for the second limb.

That was longer than I intended, hope it was helpful!