William Chapman, JR., MD, MPHS, discusses anatomic and functional changes for common colorectal resections.
I'm a colorectal surgeon here at Washington University. Um uh Here, our practice is a mix of both benign and malignant disease. And um, as N Nikki uh illustrated we take care of, you know, everything from bowel obstructions. Um Crohn's disease, you know, all the way through the lower G I tract down to the anus. Um you know, and include things like hemorrhoids and fissures and, and lots of other benign uh interactive disease. So, um I'm just gonna buzz through a few common um uh things that come up in our office from time to time. I'm gonna review anatomy and function of the lower G I tract very briefly and then just talk about some of the an atomic and functional changes that happen predominantly around some of the common uh surgeries that we perform. Um because I often will get calls uh, or questions from some of the um primary care folks outside of our institution when I'm especially returning a patient and uh they're wanting to know, you know, what might be normal versus abnormal and, and generate a call back to me. Um Also happy to talk about any other topics that, that people have questions on. Um And so why don't we jump right into our anatomy and function discussion? So, you know, as everyone on this call knows, um, there are multiple components of the digestive tract. Um, from the colorectal surgeon, our work really begins with the small bowel. So we typically are not doing any work with the esophagus, uh stomach, uh or any of the hepatobiliary uh organs. But, um, but we often will work with gastroenterology in, in the setting of inflammatory bowel disease to do surgery related to um, uh abnormality within the small intestine, um the large bowel and then obviously the recommend anus. I think there are a couple of key an atomic points to remember. And I always review these with patients when we're talking about surgery because it helps anticipate functional impacts after uh after our procedures. So, you know, obviously the main function of the stomach is to store food. And for me, some mechanical digestion as well as um, uh hormones related to hunger and feeding the small bowel is really the place where electrolytes and nutrients are absorbed. So when we have patients, uh such as those with significant Crohn's disease, who have had lots of their small bowel resected for one reason or another, um, we can run into uh nutritional issues and electrolyte abnormalities that can be very difficult to manage. Um, in opposition to that the large intestine or colon really only has one main job which is water, uh resorption from suckers and stool. So, in general, you know, folks can live without a colon with relatively limited impact in their function though they're gonna be having more frequent and looser bowel movements. Um The rectum is a stool storage container. Uh and the anus obviously is the main controller of continence. And any changes or surgeries related to the anus can have very big functional impacts in terms of um uh patient post operative continence. When we start thinking about um different types of surgeries that can impact the colon, I think it's really important to lump these together in a couple broad categories. So the first is uh any kind of segmental colectomy and there are a few of those pictured across the top there. Um The segment of the colon that we resect really doesn't matter so much from a functional standpoint. It does have some impact in terms of how we put things back together. Um But whether I'm taking out the right colon or the left colon or the sigmoid colon in general, patients in the short term will have some uh increased frequency of bowel movements and maybe some um diarrhea associated with that. But over the long term, and by that, I mean, 2 to 3 months out from surgery, they're gonna have relatively normal bowel function and most patients return to their preoperative, normal state. That's very different when you're considering either a subtotal colectomy or a total abdominal colectomy. Uh So for subtotal colectomies, that's a bit of a nebulous term. And different surgeons will use that term differently. So I personally try to stay away from it. But, but that essentially is used when we're removing the majority of the colon, typically leaving behind the sigmoid. Uh and a total colectomy is where we remove everything from the terminal ilium to the top of the rectum. Um that shakes away all of your water resortive capacity in the bowel and results in um even if someone has a connection from their small intestine to the rectum results in somewhere around 5 to 10 bowel movements a day. And most of of those are gonna be liquid or near liquid. This is just a another diagram depicting what a subtotal colectomy can contain and there's various indications for this. But in general, it's someone that either has multiple cancers in the colon or comes into the hospital, very sick with an obstructing cancer where all of the colon above that cancer is dilated and not healthy. And in those emergent situations, we have to take out the majority of the colon. Um Again, like I mentioned before that the comparator to that is the total colectomy where you can see pictured in part A here, the resection or removal of the entire colon from the ilium down to the rectum. And then if we can restoring continuity with an ilio anastomosis or not pictured here, um giving them an end ileostomy. Um This is a very common procedure used in the management of either ulcerative colitis or in chronic inertia or constipation that's refractory to medical interventions. Um There are also some cases uh especially in patients with heritable um uh disease processes that can increase risk for developing malignancies where we might prophylactically remove the colon. Sometimes we're also prophylactically removing the rectum and there's some nuance there, which probably isn't relevant here, but this includes patients um that have FA P for example. Uh and then sometimes we end up having to do this procedure if patients are having recurrent gastrointestinal bleeds, and we have a lot of difficulty figuring out exactly where the source of that bleed is, but we know it's somewhere distal to the A. So that's all colon related resections. Once we start talking about rectal resections, it's a very different consideration and very different conversation. And I think that, you know, that distinction is um obvious to colorectal surgeons, but it's missed by lots of general surgeons and certainly uh the broader medical community. And there are some particular uh considerations and reasons why we really think of a rectal resection as a very different type of operation with very different preoperative considerations, the colon resection. And in general, what I would say is that the fact that we have to operate deep in the bony pelvis really changes our capabilities in terms of dealing with whatever pathology we're dealing with and it significantly increases the morbidity of that operation for the patient. Not only are we potentially looking at giving people um you know, permanent colostomies uh after a rectal resection, but we can also impact um the nerves that um allow for sexual and bladder function. Um There's also the pelvic vasculature that um can be impacted or affected and lead to, you know, very significant uh limb ischemia if there's injuries there. Um And so, in general, uh you know, within the surgical community, we really believe that rectal resections uh should be performed by high volume providers. You know, either a general surgeon who's doing a lot of rectal surgery or a colorectal specialist. Um There are a number of different types of rectal resections out there. There are a few that are pictured here um that I'm just gonna touch on briefly. You know, the low anterior resection is a common procedure that you'll see performed for rectal cancer. Um What is uh different between a low anterior resection and an anterior or a high interior section. It's just the amount of rectum that is left behind after the resection. Sometimes in cases of bad diverticulitis, we have to do a low interior resection, but typically the rectum is spared in that type of operation. Abdominal perineal resections involve the removal of the rectum as well as the entire anal complex. So that procedure leaves the patient with no anus and we sew uh the gluteal cleft closed at the end of that operation. Um those are typically performed for cancers of either the anus itself or the very low rectum or in cases where um patients have significant anal pathology, like a very bad ulcerative colitis case where there's not enough preserved function to reconnect a person. Um The total proctocolectomy is a removal of the colon and the rectum all together at one time, often performed in the setting of um pin uh colitis um or sometimes in patients who, you know, are not gonna have good post operative functional outcomes and have a history of IBD or a very high risk of developing a malignancy in the rectum. And in those cases, we remove everything and give them an end iost toy. And then finally, the, you know, performance of AJ pouch or creation of AJ pouch in say the ulcerative colitis patient um requires a, a proctectomy, but that's usually done in a stage fashion and I'll touch on that a little bit later. Um You may, if you're taking care of folks that have a rectal cancer diagnosis, you may hear this term TME or total meso rectal excision really that just talks about the type of rectal resection that we do. And when we do this, it's important to remove, not just the rectum but also all of the surrounding fat, the mesorectum. And you can see that picture here. This is a schematic from uh the 19 eighties. But the black um tumor that you can see speculated and invading the mes ectal fat um demonstrates that these rectal cancers often do not stay confined to the rectal wall itself. And um in the pre TME era, rectal resections typically resulted in a 30% rate of local recurrence. Whereas in today's era, with the use of TME, as well as preoperative treatment, the local recurrence rate in the pelvis is somewhere in the order of 1 to 3%. Uh I mentioned this a little bit earlier, but when we create a AJ pouch or, you know, reconstruct someone with a ileoanal pouch, um anastomosis, um that's typically done for ulcerative colitis patients or those with a pre-cancerous heritable um mutation that increases the risk of developing malignancy. Uh We often do that operation in a series of stages. Again, why we do that is probably not in the um you know, confines of this discussion, but essentially when we create that J pouch, when we take the small bowel and reconfigure it into a capacitance organ to mirror the rectum, it's a very high risk um uh operation that leads to creation of this 15 to 20 centimeter pouch, but that can have lots of functional uh problems if it doesn't heal appropriately. So typically, uh especially if a patient is sick in the hospital, we would first remove their colon, let their disease resolve, let their symptoms improve, get them through whatever medical um you know, acute medical issues. They have uh with an ileostomy and then we bring them back in 3 to 6 months, remove the rectum and create the pouch. But at that time, we also create a proximal diversion to allow the pouch to heal without stool passing through it and then bring them back for a third operation. At which time we uh reverse their ileostomy and they're fully reconnected. Um There are some, you know, unique considerations with these J pouches. I think, you know, broadly speaking about 90% of patients who get AJ pouch have great function afterwards. Um but 10% don't. And there are, you know, many different potential issues that can arise from these pouches, whether there's an atomic considerations like a twist in the pouch or um a kinking uh of the pouch. Uh There can also be a stenosis at any of the anastomosis that we have to create in order to construct these. And there's three different staple lines that interact in different ways. I mean, any stenosis at those points can um lead to problems like any anastomosis. There can also be leaks associated with it. Um And I didn't mention it here in the bullets, but you know, when we're creating these for inflammatory bowel disease, there's always the chance that uh you can have recurrence of the inflammatory bowel disease within the pouch. And there's a whole line of uh research that's being performed currently to try and understand how that progression happens. How can somebody who had disease only in their colon Briers who gets a pouch then develop the same disease in the pouch, which had previously been unaffected. And lots of different theories around that. Um But it does happen, uh you know, treatment of problems with pouches typically is gonna be handled by a gastroenterologist, um at least in a chronic setting. Um, but I think that it is important to remember that for any patient that has a pouch, you know, though their anatomy is altered and though there are certainly lots of potential problems, most of these patients, we can get through these issues and they actually have very good function. And for the most part, um patients are very, very happy with their continent and with pouches, even though they're not back to what life was like before their inflammatory bowel disease diagnosis. Um it also, you know, has some minor implications in terms of absorptive capacity. But as long as a patient has adequate small intestine, the presence of a pouch does not really change their nutritional um uh uh or their ability to maintain their own nutritional needs through a, you know, well balanced and varied diet. So sure we do sometimes have to put some patients on vitamins. But for the most part, you know, this is not like a bariatric patient or uh a bypass patient who um needs lots of continued follow up and who has significant absorptive or nutritional issues. I'm gonna move now into Thomas. And um you know, my, my purpose in reviewing this a little bit is just to revisit some of the different types of stom that we create and what they mean and what they might look like externally. Um when you're examining these patients, um you know, the question about when to divert or when to create a stoma is obviously influenced by lots of different, uh, characteristics and patient factors. Um, when we're doing surgery, one of the main reasons that we would divert somebody, um, is if we're concerned that a bowel anastomosis is gonna be high risk for a week and there's multiple reasons for that, um, related to tension or ischemia. Um, but in general, um, that is an intraoperative decision that's made based on what you're looking at, uh, in front of you. Um, there are several scenarios in which patients who are chronically ill need a stoma. And we know that going into surgery that's not really influenced by their uh intraoperative anatomy, but, you know, when patients are malnourished or they're a lot on lots of steroids, um, or they have a significant number of medical comorbidities that would make them very high risk for, um, you know, severe abnormalities or, or death, uh, if they were to have a leak from an anastomosis. Um, and then for patients with cancer, if there is need for them to get quickly to chemotherapy after surgery. And we do sometimes create stoma so that there's no potential delays in chemo from the healing of an anastomosis or the unfortunate um anastomotic leak, which may occur. Um Obviously, there's also patients who are just generally unhealthy and may have things like uh refractory colitis or prior radiation, which we know changes the underlying ability of the bowel to heal itself. Um And then finally, if we're operating on someone for whatever cause, and we know that they already have poor um continent, um or poor anal sphincter function, then we sometimes, you know, use that opportunity to just go ahead and give them a permanent stoma to relieve issues related um to, to their continents. And I guess one other point I'd make here is that we are from time to time asked to divert patients who have bad infections um related to a spinal cord injury or, uh you know, a diabetes related infection or whatever the perineum. Um And, you know, for the most part, those patients are able ultimately to be reversed, but it's critical to assess their sphincter function once they've healed from whatever interventions they have related to the perineal infection um prior to reversing them. I I have certainly seen patients that had, you know, significant surgical debridements related to bad infections got diverted healed, ultimately got reversed and then had significant incontinence issues related to sphincter changes. Um you know, during the time of their infection, uh treatment. So that, that's another thing that we're always uh keeping a close eye on. It's really important um to differentiate an ileostomy from a colostomy. And oftentimes that can be hard for the non surgical team because these words may be interchanged intermittently throughout the medical record. Um You can't necessarily look at a stoma and differentiate it. You know, whether it's an ilium or colon that you're looking at, there can be very big ileostomies and very small colostomies and vice versa. Um But the reason that differentiating them is so important is because of the considerations about water absorption from the stool in the colon. So with a colostomy, you're creating that at some point distal to some segment of colon. In other words, there is preserved colonic function in the patient's G I tract in ileostomy, you are above the colon or proximal to the colon. And so there is no water resorption that's happening from the time of ingestion to the time that the SCU is coming out of the stoma. And because of that, um patients with ileostomies are at significant risk of dehydration. Um There can also be some pouching issues that are specific to um ileostomies. Um and there can be a lot more skin irritation or erosion because the suck is coming out of the ilium is very acidic um and it um uh erodes the skin if it's in prolonged contact. So, uh what we commonly refer to as an end stoma or an end class Mios toy is just that, it means that the stoma that you see at the skin level is the end of the part of the G I tract that's in circuit. Now, it doesn't necessarily mean that there's not some distal colon or rectum left behind in the patient. And it's always important to sort that out, especially in the chronic setting because if someone has say an IND ostomy or an end colostomy, but they still have a rectum, that rectum is still at risk for developing a cancer. And that rectum still needs to be surveyed with intermittent endoscopies, especially in a patient, say with um uh inflammatory bowel disease. So the best way to differentiate that, I mean, on a physical exam, you can look and see if there's an anus or not. Um But oftentimes getting some axial imaging, if there's no, um you know, medical or surgical reports available, uh is the best way to determine what kind of internal anatomy still exists in the present of an end stoma. In contrast, when you have a loop stoma, um when you look at it on physical exam, you typically will see two holes. Um And when we form these, most of the time, they're not always, this is a sign that there is in fact distal um bowel that's still inside the patient and most likely still connected, we formed these loop stoma for lots of different reasons. Um you know, one reason is to protect a distal connection or anastomosis. And that's pictured in the upper right of the slide. Here, you can see that the patient has had a, a low interior section and their colon is reconnected to the top of the rectum. But a proximal stoma has been created. This is a lube ostomy in order to divert stool contents out of the abdomen before it comes in contact with the colon or especially that colorectal anastomosis. Um This is typically used in the setting where we're trying to allow an anastomosis to heal. But we know there's some underlying changes that make that a high risk connection. Um, for almost all of our rectal cancer patients who get radiation prior to surgery. If we end up taking out their rectum, they, uh, even if they have room to get things reconnected, they will still end up with a diverting lil ostomy because we know that rectal tissue that we're connecting to is not normal since it's been radiated prior to, to their operation. There are some other considerations in other times where we use loops in the form of, uh, or in the setting of anastomoses, mostly related to inflammatory bowel disease. Um, there's also times where we'll create a loop ileostomy to help with a condition that just needs a quick bypass. We just need a way to get the stool diverted from something going on distal. Um, in young patients with significant constipation issues who may not be ready uh to commit to say a total colectomy, but who are absolutely miserable with their, um you know, severe colonic inertia. We sometimes create these just as a way to get them through their current stage of life. Um We also create these stoma sometimes in the setting of distal obstructions. Though in general, we try not to do that because uh this type of an ostomy does not decompress the colon. And again, there's some nuance there, uh, which I won't get into. There are sometimes that what we create, what's called an in the loop stoma and I won't get into all of this. But essentially, you can sometimes look at a stoma and see only one hole, but there may be another one tucked underneath there. This is a more classic, uh type of stoma that's created in the, in the time of an obstruction. Um But again, I, I, that's pretty unusual. I'm gonna, I had to pause for questions here, but I'm gonna go ahead and finish the presentation and then we'll come back to questions later unless Nicky, there's anything burning out there. I don't see anything yet. So perfect. All right. Thank you. So, I'm just gonna touch briefly on um surgical platforms. Again, I, I don't think this would affect your day to day um work, but just so that when you're getting operative notes, um, you understand what has been done or what we might have been thinking about um in general. Um you know, nowadays, I think most surgeons, uh most abdominal surgeons would agree that when possible, a minimally invasive or mis approach um is, is preferable over open surgery. Um There are obviously caveats to all of this. But what a minimally invasive approach allows us to do is uh you know, perform the same quality operation through smaller incisions in the abdominal wall, which significantly reduces patient recovery time. It also reduces risk of infection as well as DVT formation. Um and longer term, it significantly reduces the risk of hernias. And when you think about a lot of the work that we do in colorectal, um you know, there's significant morbidity from hernias that we create. Now, sometimes we have to make a hernia say in the setting of an ileostomy or colostomy. Um You know, by definition, bringing a stoma through the abdominal wall, uh creates a hernia. Um But where we can, we really try to, to reduce the size of our incisions. Um With that being said, there's several different mis type approaches. So there's laparoscopic robotic and then transanal minimally invasive surgery. Um, laparoscopic surgery. I mean, this is an old picture, but it, it hasn't changed much since the nineties. Some of the equipment has changed. But essentially you're putting a series of ports into the abdominal wall. Uh But you're still standing at the patient bedside, you're using instruments that you manually control they're not electric or have any other special function. You're holding them outside the patient's body. But the effect of the instrument is um uh is transmitted just through the port into the inside of the patient. And you have a camera, various other devices. Usually it takes a couple of folks at the bedside, a surgeon and one or two assistants to do this type of operation. And we can do most colorectal operations, uh laparoscopically. So long as the patient doesn't have uh extreme obesity or significant um adhesions from prior surgery, etcetera, robotic surgery is very different. We're still accomplishing the surgery um in the same uh theoretic manner where um we make small incisions, we put in ports and we use instruments through those ports to affect uh our procedure. But rather than standing at the bedside, the surgical team for the most part is away from the bedside, sitting at a console. Um There are wires or in some cases, wireless connections from the console to the surgical uh to the bedside which control the arms of the surgical robot. Um Some of the advantages of robotics are that um you have a much better visualization, the primary surgeon can, can at the same time control all instruments and the camera uh which is one of my favorite parts about that type of operation. Um And you have much improved dexterity. So there's no tremor. Uh the robot is completely still and um uh you know, we can now achieve especially in the pelvis where we're working in a very confined space. Um very, very good outcomes. Of course, you know, there are some patients that you just can't do a minimally invasive surgery. And in that setting, uh we have to do open operations and we can still do, you know, highly effective surgeries through those large incisions, but the recovery is longer. Uh and you know, we do expose the patient to risk of hernias and infections. Uh postoperatively, I won't dwell on this for too long. But you know, there is an evolving area of interest within transanal surgery. Um This is typically not something that can be done for a cancer, but there are several different platforms out there uh which also include robotics too that allow for uh inflation of the rectum or creation of a, a pneumo rectum and then resection of various um pathology uh from the inside of the rectum and saving the patient, the morbidity of a proctectomy that I mentioned earlier. Um Pictured here is like some kind of an adenoma or something. And these are typically, these types of procedures are typically used for pre-cancerous lesions, um like significant adenoma that are too big to be resected via a um uh endoscopic approach. So for example, here's a, a polypoid mass um that uh that we removed trans anally. Um six months later, the mucosa has completely healed. In general, we're not going full thickness on these resections. We're just taking off the mucosa and some underlying se mucosa leaving behind just this nice white scar. Um, you know, and just a few years ago, these types of lesions, even though they are pre-cancerous or benign were having to be removed through, you know, large proctectomy with significant surgical morbidity, et cetera. Um We're very, you know, excited here about some of the new avenues for, for transanal surgery And I'm certainly looking to develop that more into the future. Um, so I didn't go into much about anorectal stuff if there are people with anorectal questions or hemorrhoid related topics. I know that tends to be popular and I'm happy to, uh, address those now or, um, we can open up the floor for any other topics of discussion related to colorectal disease.
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