Colon EPA
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[00:00:00] Hi, all UBTK fans. It's Scott here, and welcome back to the EPA Playbook, the podcast where we dig into the entrustable professional activities that shape surgical training. So with me today are two of our BTK Surgical Education Fellows, Agnes Prem Kumar from Creighton, and Emma Burke from Baylor.

So today we're going to delve a little bit into the benign and malignant colon EPA. Now, this activity requires us to handle everything from elective cancer staging to emergent resections for perforation or obstruction.

To recap EPAs matter because they translate the abstract language of competencies into the real work you do every day as a surgical resident. Each EPA defines a professional activity. You must eventually be trusted to perform independently.

EPAs may also make feedback more meaningful by increasing objectivity and providing more data points across time, specialty case type, and case complexity when you demonstrate consistent entrustment on EPAs. It [00:01:00] accelerates your progression toward independent operating and decision making, and that's why we've created this series.

It's the perfect way for junior residents to dominate EPAs. So let's frame this entire topic with a scenario. So Mr. C is a 65-year-old man who is referred to the clinic after a screening Colonoscopy, unfortunately revealed the biopsy proven adenocarcinoma, the sigmoid colon. He was asymptomatic. He does have a 40 pack year history of smoking.

He's got well controlled hypertension. So what's the initial plan for his malignancy and what does this workup entail? The first priority here is to get a complete oncologic staging. That includes getting a CT chest, abdomen, pelvis with contrast to evaluate for metastatic disease. And you wanna review the colonoscopy report to confirm where exactly the tumor is, if they place a tattoo there and any other synchronous lesions. In addition, it's important to note on the colonoscopy if the lesion is obstructing or if the endoscopist was able to get past the lesion and [00:02:00] evaluate the colon fully.

Be sure to get also a baseline ca, which can help us in keeping track of his response to therapy and recurrence.

Before we get too ahead of ourselves, we should get a good history and physical exam. It's important to ask questions about weight loss, blood in the stool, and anemia related symptoms. We also wanna discuss his bowel movements. We wanna make sure that he's not clinically obstructed, which might warrant a more urgent intervention.

Also be sure to ask about family history of colorectal cancer, polyposis syndromes, or IBD. All of these will change his cancer risk and subsequently the type of surgery that we will have to think about and offer. And specifically for colorectal surgery, it's important to understand what his baseline continence is since some of our procedures such as an LAR can impact this.

And also just like any other patient, you wanna understand his prior surgeries, medical comorbidities, and his overall functional status to see if he's able to undertake and recover from a cancer operation. And just to [00:03:00] jump in here, I would also ask you about any prior use of biologics or steroids that might interfere with wound healing, especially in those patients who have a history of IBD that was comprehensive.

Great job. So what are you looking for in physical exam? I wanna do a focus but complete exam. That means looking at a, doing a good abdominal exam for masses or distension, and also a rectal exam to rule out any distal disease and evaluate his sphincter function. And also palpate his inguinal nodal basins to see if he might have any,, bulky nodes there.

So the patient tells you that he's been feeling good overall. No bloody bowel movements or recent changes in bowel habits. This was his first colonoscopy. He has no other medical comorbidities, no family history of colon or recal cancer, and only a vague discomfort in the left abdomen. At times that resolves spontaneously.

His abdomen is soft on examination. It's non-tender and you [00:04:00] cannot palpate any nodal disease in his inguinal basins. When you review his colonoscopy, it shows that he has a four centimeter fungating mass in the sigmoid colon. That was positive for adenocarcinoma. They did MSI testing on it, and it was MSI low.

The GI team has tattooed the location as well. They were able to get the, cecum and no other lesions were identified. Baseline, CEA is elevated at five. And imaging does not reveal any other synchronous tumors or metastatic deposits. What is this stage and how do we do neoadjuvant therapy or go straight into surgery?

So staging in colon cancer is dependent on the extent of tumor invasion and lymph node involvement. The tumor is graded on depth of invasion. TIS is carcinoma in situ two, where the Lamin propria is the only layer involved. T one invades the Submucosa T two invades the muscularis propria and T three invades through the muscularis propria to the peric colorectal tissues.

While T [00:05:00] four invades the visceral peritoneum and even can adhere to adjacent organs. So our end stage depends on lymph node number with N zero being no lymph node involvement, N one being one to three positive lymph nodes and n. Two is four or more positive lymph nodes. And then for our M component, it's a one if there is a metastasis to a distal site or if you have peritoneal metastases.

And unlike rectal cancer, colon cancer does not usually get neoadjuvant therapy for early stage cancers. If the tumor is locally advanced, such as a. T three or four with positive nodes or has high risk features like the mismatch repair deficient tumors. So MSI high patients might benefit from neoadjuvant therapy to downstage the tumor and improve your resection margins.

This includes an emerging body of literature that has demonstrated improved outcomes for neoadjuvant immunotherapy for MSI high tumors. As a recap, microsatellite instability is where [00:06:00] cancer cells have many DNA errors because their DNA repair system, MMR or mismatch repair is not working correctly, that leads to unstable short repeating DNA sequences and the instability makes tumor cells prone to accumulating even more mutations.

This is also the basis of hereditary syndrome, such as Lynch syndrome. That instability makes these cells good candidates for immunotherapy or chemotherapy based on specific mutation targeted approaches. Our patient here doesn't seem to have any high risk features, so we can schedule surgery.

Preoperative optimization for these patients is similar to other surgeries you wanna advocate for things like smoking cessation and doing a good cardiac risk stratification. Another important component is nutritional assessment. We wanna see if our cancer patients are tolerating their food currently and will they be able to deal with the insults of surgery.

Be sure to also think about getting an albumin level and examine for physical [00:07:00] signs of cachexia like temporal wasting. So our patient is well nourished as no signs of a cachexia and he does not smoke and has had no issues with his heart. He really overall seems ready for surgery. But before we go into surgery, another important thing to discuss here is the preoperative planning stage, and that's aris or enhanced recovery after surgery, which truly was kind of pioneered in colorectal surgery.

So Emma, what is it and how does it apply for our patient here? The ERA RAS pathway is designed to help improve recovery by optimizing care before, during, and after surgery. And it's truly something that, especially as an intern, you're going to really get a good handle on for your patients.

The first guideline was published all the way back in 2005, and the main goals were to emphasize nutrition, minimally invasive procedures as possible, early mobilization and pain control, using techniques such as regional anesthesia. The benefits are a reduced hospital length of [00:08:00] stay and a faster return to normal function for the patient.

I would talk to our patient about this protocol in the office so that he's aware of the plan to encourage regional anesthesia such as a tap block or spinal anesthesia, ambulating as soon as possible post-surgery, and then resuming his normal diet as soon as possible. And I can't emphasize that enough.

What you're trying to do here is manage expectations to a certain degree. So what are some of the other important things to mention during the consenting process and specifically for colorectal cancer surgery?

Consent include a discussion of the performance of an oncologic resection, and that includes a lymphadenectomy so that we can get adequate staging information. And as always, we should mention that we'll start with a minimally invasive approach, but we might need to convert to open if that's what's safer for the patient.

However, the trickier thing to discuss is the potential need for an ostomy creation. The nuances of ostomy creation will depend on the nature of the dissection, how stuck or inflamed the mass and the surrounding colon is. [00:09:00] And how the tension looks on the two ends of the resected colon that we are going to try to sew back together.

We'll also need to consider if the patient can heal on anastomosis or if it's better to do a diverting ostomy, and then later take that down. Sometimes we'll do a diverting ostomy if we're concerned that the patient will develop an anastomotic leak, and this diverting ostomy will help reduce the risk of pelvic sepsis.

And other complications that you should mention are bleeding, ureteral injury, anastomotic leaks, and sexual or urinary dysfunction. Because we're dissecting really in the pelvic region.

So as a recap, Mr. C has a four centimeter sigmoid adenocarcinoma with no identifiable notable metastases or metastatic disease on imaging, and he has no MSI high features. So what operation do you wanna offer? Yeah, so we have a lot of options here. For a good oncologic resection, we can either do an open or a minimally invasive based approach.

Since he's had a small tumor that doesn't really [00:10:00] have any invasion of surrounding areas, I would advocate that we would start with a minimally invasive approach for a sigmoid colectomy with a primary anastomosis and a flexible sigmoidoscopy, if we have any difficulty locating the tumor.

And if we have any difficulty performing attention for anastomosis, we can really resort to that ostomy. And in the or, we wanna ensure proper positioning, often lithotomy with arms tucked to facilitate Flex Sig.

And as always, we wanna ensure safe abdominal access through thoughtful port placement. We always wanna be sure to confirm the ureter location before we fire the stapler to resect. And remember the ureters lie on the S sous muscle and cross medial to the gonadal vessels. Many surgeons often involve their urology colleagues to assist with placement of ureteral stents so that they can help avoid injuring the ureter.

So those are great things to keep in mind. What are the required margins and lymph node? We need at least 12 lymph nodes for an adequate lymph node harvest. [00:11:00] And the resection should be an N block removal with five centimeter margins, both proximally and distally. Make sure you see where the tumor is localized before you do a resection.

The tattoos that they do during colonoscopy can help identify, but there is any difficulty, or if you're unsure about where it is, you can always perform a flexible sigmoidoscopy intraoperatively to confirm where your tumor is. And I can't emphasize that. Last point is that understanding where the tattoo is in orientation to the lesion itself.

By nature, we tend to always tattoo distal to those lesions, but you never know who the gastroenterology colleague might do, and sometimes they tattoo it proximal and distal, or you can only see one tattoo and the report says there are two of them. So use that flexible sigmoidoscopy as needed to again, identify the location.

So. Do we always need to mobilize the splenic flexor for a sigmoid colon cancer? Not necessarily. It's optional and really depends on [00:12:00] how much tension you have on your anastomosis. If the tumor is in the proximal sigmoid colon, or if the patient has a four shortened colon, too much tension on the anastomosis will increase your risk for a leak.

Mobilizing the colon at the splenic flex can help with more length to ensure that tension-free anastomosis. Again, a good anastomosis should be tension-free, properly aligned, and well perfused. We should ensure that there's not twisting of the mesentary and that the color of the colon looks good. You can even use things such as immunofluorescence to check the blood supply and examination with leak testing where you provide air through the scope is the standard of care for left-sided resections.

Yeah, we talk about ICG being one test, but I like ICB, I see bleeding edges on the cut edge of the bowel itself. So we touched on this earlier, but when do you divert? Yeah, so consider diverting if the patient has poor tissue quality, if they're just having ongoing hemodynamic [00:13:00] instability, or if you feel that the patient is a high risk for healing and anastomosis, they might be on steroids or be malnourished.

Or if you're just. Worried about the profusion of your anastomosis? Think about diverting. Great. So let's go back to her case. Mr. C's surgery, thankfully went well and he completed a laparoscopic sigmoid colectomy and a primary anastomosis. He got the path back and revealed the 4.2 centimeter adenocarcinoma that had invaded the muscularis propria.

So he was a pathologic T two N zero M zero with no lymphovascular invasion. What are our postoperative priorities? So again, we're gonna go back to Thatas protocol, early mobilization, early feeding, and multimodal pain management with things like Tylenol NSAIDs, minimal narcotics, the use of gabapentinoids and local and regional anesthesia.

We'll send you a surveillance plan for his malignancy, which will include coordinating with oncology. This patient had a complete colonoscopy prior to his surgery, so he needs his next one at [00:14:00] a year after surgery. And if that colonoscopy looks good, then he can come back three years later and then five years subsequently, let's say that the patient had an obstructive cancer that was not able to be traversed preoperatively, so he wouldn't have screened the rest of his colon before the surgery.

You'll wanna get it. Colonoscopy three to six months after surgery to rule out any synchronous cancers, which are two or more colon cancers existing at the same time. Okay. Let's take us back and say that Mr. C is now on post update five. He was doing great and almost ready for discharge, but suddenly got fever, tachycardia, and new onset oliguria.

What are you worried about? Okay, so these symptoms, along with a timeframe of him being on postoperative day five, immediately makes me use his pictures for anastomotic leak or maybe an intraabdominal abscess. I wanna make sure that he has fluids running, antibiotics running, and then get an urgent CT scan, which will really evaluate the anastomosis.

You can get a CT scan with a rectal contrast as [00:15:00] well. If there are fluid collections, but they're relatively small, you could consider getting a percutaneous drain by IR to control the leak. But if he has a leak that's significant and he's clinically not doing well, he might have to go back to the OR for source control and maybe even a diverting ostomy.

Great. So a colon cancer management is built on strong preoperative staging and good oncological resection anastomosis, and to be sure to counsel the patient on their postoperative surveillance. Let's shift gears now to another patient scenario. Mr. L is a 62-year-old man who presents to the emergency department with two days of progressively worsening left lower quadrant abdominal pain.

He describes it as constant, dull, and worse with movement. He's had subjective fevers, decreased appetite. And mild nausea, but no vomiting. He also reports constipation for the last three days, but doesn't have melanin and no hemato. Keysia. He's had no prior abdominal surgeries and his last colonoscopy was eight years ago and reportedly showed [00:16:00] diverticulosis.

What's our differential based on his history? So some diagnoses I'd wanna consider would be ischemic colitis, infectious colitis, IBD, nephrolithiasis, A UTI, or pyelonephritis, and a colonic malignancy in women too. We can add on some gynecologic causes, such as ovarian torsion, a ruptured ovarian cyst, or pelvic inflammatory disease, and I'd wanna get a good exam and take a look at his imaging and labs to kind of narrow down that list.

So on exam first is vitals. He's febrile the 38.3. His heart rate is 1 0 2 and his blood pressure is stable. On his abdominal exam, it's notable for localized tenderness in the left lower quadrant with mild guarding, but again, no diffuse peritonitis. He got his labs back and is significant for a white blood cell count of 14.5.

That's mildly left shifted. He's got a mildly elevated CRP and his lactate is normal. He did get a CT scan and it shows segmental sigmoid, colon wall thickening. [00:17:00] With Pericolic Fat Stranding, several Diverticula 2.5 centimeter pericolic fluid collection, consistent with a small abscess and no free air.

What's running through your mind now? So it seems to me like this is the diverticulitis flare. Diverticulitis is an infection of diverticula in the colon wall, and uncomplicated diverticulitis is when the inflammation is just localized to the colon wall. While complicated diverticulitis is when there's abscesses, fistulas, or obstructions from like a stricture, and perforations is a consequence of the diverticulitis.

So in our patient, this is complicated diverticulitis because he has an abscess. The main way really to talk about diverticulitis is with a hinchey classification. HIE one A is pericolic inflammation or phlegm mon, where one B is pericolic or mesenteric abscess and hinchey two is when you have pelvic intraabdominal or retroperitoneal abs.

Then HIE three is purulent peritonitis, which is free plus, but no fecal [00:18:00] contamination. And then HIE four is really fent peritonitis where you have gross stool spillage. Our patient has a small pericolic abscess, so he's now at a Hinchey one B, and oftentimes this matters because hinchey one and HIE two are usually non-operative, whereas Hinchey three and Hinchey four are often surgical emergencies.

So what are the treatment modalities, Emma, and what will you offer our patient? So for HIE one, we typically recommend IV antibiotics that are broad spectrum with some bowel rest and closed serial abdominal exams. Abscesses less than three to four centimeters are usually treated with antibiotics alone.

For a patient with HIE two diverticulitis, so an abscess greater than three or four centimeters, we'd recommend percutaneous drainage IV antibiotics. And close observation. And then lastly, for Hinchey three and four, we'd recommend an operation. So for our patient, I wanna start him on some ceftriaxone and Flagyl and give him some bowel rest.

Okay, so let's say that Mr. C is not really progressing with bowel rest. In fact, four [00:19:00] days later, his abdo exam seems to be getting worse and he's more symptom. Yeah, I'm worried that his diverticulitis is not responding and that he's just progressing. So if he's stable, I would re-scan him to see if he's developed more abscesses.

But if he's parasitic or unstable, I would counsel him on proceeding to the operating room for a washout sigmoid resection, and a possible heart risk procedure. Remember, the indications for an emergent operation is if he's peroney, if he has a free perforation, septic shock, and like our patient, if he fails non-operative management.

So let's just say he is paralytic and you decide to take him to the operating room. Historically, operative diverticulitis meant hartman's procedure with a sigmoid colectomy, which is an end colostomy in a hartman's stump. But nowadays it seems like it's a little bit more nuanced. So walk us through some of the operative options available now.

I. For our patient, once he's in the operating room, depending on the tissue quality and his clinical stability, we can [00:20:00] perform either a primary resection with an anastomosis, with or without a diverting ileostomy. A heart men's procedure is more like a damage control surgery involving that resection of the diseased colon and getting that ostomy made to get out of there.

Quickly key here is that there's no anastomosis in the hartman's. You leave behind that hartman's stump and create an end colostomy. And during the colectomy, the resection should be carried out to healthy colon proximally and distally. And these are really your margins. So different from a cancer operation.

You also wanna wash out liberally and make sure that you evaluate that rectal stump to make sure that tissue quality is healthy and will heal if the colonic ends are well perfused, the patient is stable and he doesn't have a history of steroid use or immunosuppression that you're worried about, it's reasonable to perform an anastomosis.

So let's just say that you have considerable difficulty in dissecting out the sigmoid. You're able to resect the disease portion, but despite your best efforts in the proximal and distal ends of the colon do not appear to be the healthiest. [00:21:00] So you decide to do a hartman's. What do you need to do postoperatively?

So postoperatively, I'd continue his antibiotics for four more days from surgery as he has had source control at that time of surgery. And that's all based on the stop at trial. And now that he has an ostomy, I'd recommend closely monitoring the output to ensure that he doesn't get dehydrated. But this is typically more common with an ileostomy.

You can resume a diet once he has return of bowel function. And it's important, even like with our more elective cases, that he walks regularly and has a multimodal pain regimen, as well as all of the other components of the ERAS principles. After diverticulitis flare, everyone should receive a colonoscopy six to eight weeks later to rule out any concurrent malignancy.

Perfect. So the post flare colonoscopy is very important. Remember that perforation of a cancer could have been the inciting factor to what seemed initially like simple diverticulitis. And just as an aside, diverticulitis is also [00:22:00] definitely not an easier, simple disease for patients to have. Each episode can lead to significant financial and emotional burden with hospitalization.

Missed work and other things. Elective sigmoid ectomy can be considered for patients with recurrent complicated diverticulitis, fistula, stricture, immunocompromised patients to reduce the likelihood of future flares. So that impact on the quality of life is important to consider, not just the number of episodes they have alone.

Alright, Mr. C is recovering slowly after his heart's. Fast forward to post-op day three. The nurse calls you 'cause the ostomy looks dark and there's been minimal ostomy output for 24 hours. What do you do? I've definitely gotten this call before, so I would go to the bedside and assess the stoma. A black stoma indicates possible mucosal necrosis of that stoma, and in the worst case scenario, mucosal ischemia that extends beneath the fascia into the intraabdominal colon.

This is where the test tube test can come in handy. This is where you insert a clear plastic [00:23:00] test tube or a syringe barrel into the stoma lumen. The goal here is really to visualize that mucosa that's below the skin level to see if the ischemia is spreading into the intraabdominal colon. If the mucosa looks pink and it's viable below the fascia, you may be just dealing with a superficial ischemia, but if it's dusty or black below that fascial level, that's full thickness ischemia and that's a surgical emergency.

In this case, the mucosa is black and non-viable below the fascia, and unfortunately there's no bleeding even when you gently scratch it. Labs show the leukocytosis and a rising lactate. What are you gonna do next? Yeah, so unfortunately for Mr. C, this is a surgical emergency for his ischemic stoma.

Management includes taking the patient back to the OR for resection of any necrotic bowel and creation of a new end colostomy at a different site. Postoperatively, you'll want to provide broad spectrum antibiotics, perform serial abdominal exams, and closely monitor that stoma. Excellent. So there's a lot of things that can make a stoma [00:24:00] look less than ideal, such as stoma, retraction venous congestion.

But you certainly don't wanna miss a necrotic stoma. That is an urgent surgical intervention. Okay, so we covered a lot here. Colon surgery is about thinking longitudinally, diagnosing correctly, operating thoughtfully, and managing complications early. Thank you for listening. This is just one episode in the series entitled the EPA Playbook, where we delve into each of the EPAs that are outlined by the American Board of Surgery.

You can find more information about the EPA descriptions and the specific competencies for each topic on the A BS website. Hope you can join us for the next episode and as always, dominate the day.