Welcome to First Incision, the podcast about preparing for the General Surgery Fellowship exam. I'm your host, Amanda Nikolic. Let's get right into it with our team timeout. Our patient today is the colorectal module from the general surgical curriculum and our operation or the topic we'll be covering today is Crohn's disease.
So after our last episode on ulcerative colitis, we better finish off the inflammatory bowel disease topic by talking about Crohn's disease. So a little bit of background. Crohn's disease... affects approximately 50 to 200 per 100,000 people in Western countries. The peak age of onset is in the 20 to 30 year old age brackets. and females are affected more commonly than men. Crohn's disease is a chronic transmural inflammatory process that can affect the entire gastrointestinal tract.
from the mouth to the anus, and it can also be associated with extra intestinal manifestations. Some key buzzwords are that the hallmark of this disease is that it's chronic, relapsing and remitting. inflammatory, and it can cause infectious, obstructive, hemorrhagic, fistulous, or neoplastic complications. In terms of the location of disease,
40% of patients just have isolated ileal Crohn's disease and 30% have just colonic disease. Patients can have mixed small bowel and colonic, which is usually ileocolic disease. 5% to 10% will have proximal small bowel disease. This is relatively rare. And 30% to 50% of patients with Crohn's disease will have some perianal disease as well. And this can include skin tags. fistulas, hydroadenitis, fissures, and anal stenosis. The cause of Crohn's disease is unknown.
but it's thought to be related to an interplay between environmental and genetic factors. And in the same way that ulcerative colitis is associated with potentially a hygiene hypothesis, the same has been talked about with Crohn's disease. And so this is the concept that a lack of exposure to infectious organisms early in life leads to a sort of hyper inflammatory response to organisms encountered later in life.
There are some risk factors for Crohn's disease. Smoking is a risk factor, which is different to ulcerative colitis where it's protective. There's a small increased risk with the oral contraceptive pill. And there is a genetic... risk factor where patients with first degree relatives with patients with inflammatory bowel disease have a 5% to 20% increased risk of developing Crohn's disease. And there's 50% to 60% of monozygotic twins will get Crohn's disease.
There's also a number of genetic chromosomal loci that have been identified that are related to IVD. I don't know whether or not we'd need to know this, but one of them is the NOD2 slash CARD15, which was identified as the first known susceptibility gene, and patients who are homozygous for this gene abnormality are 20 times more likely to develop.
Crohn's disease, and this is on chromosome 16. It's mostly associated with ileal disease as well as fibrous genotic stricturing and penetrating disease. The pathophysiology of Crohn's disease is related to an exaggerated inflammatory response at the level of the gastrointestinal tract. This includes... dysregulation of pro-inflammatory response to normal gut flora, dietary, and other antigens, and this leads to a local and systemic inflammatory response.
Dysregulation of the pro-inflammatory response at the gut level involves defects in the innate immunity related to excessive activation of T cells. Macrophages then release cytokines, especially interleukin 1, 6, 8, and TNF-alpha, and this stimulates T-cell infiltration and the release of chemokines, which then perpetuates the cycle of inflammation.
This results in that local and systemic inflammatory response, as I mentioned, which can include fevers, acute phase response and release of CRP and ESR, hypoalbinemia, weight loss, increased mucosal permeability, endothelial damage and collagen synthesis. So how do patients with Crohn's disease
So they can present with both gastrointestinal symptoms, systemic symptoms, and extraintestinal manifestations. So some gastrointestinal symptoms include abdominal pain, diarrhea, which can be caused by a number of factors, including the impaired fluid reabsorption due to mucosal inflammation, bile salt malabsorption in the terminal ileum,
short bowel if patients had previous surgery, and also small bowel bacterial overgrowth. They can present with rectal bleeding and active disease, perianal disease, as I've mentioned. intra-abdominal fistulas, strictures from fibrotic scarring as a response to inflammation and healing, terminal ileitis, and 3% to 5% of patients over their lifetime of the disease will develop an adenocarcinoma. Systemic symptoms of Crohn's disease include weight loss, which can be related to anorexia,
food fear as it causes pain, diarrhea or malabsorption. They can have fat-soluble vitamin deficiency. This is mostly related to ileal disease, which leads to a loss of bile salt. reabsorption, and this causes decreased absorption of the fat-soluble vitamins A, D, E, and K. Vitamin K deficiency can lead to bleeding tendency and vitamin D to osteomalacia. The decreased bile salt absorption can also lead to cholesterol stone formation, steatorrhea,
And then also the steatorrhea promotes the absorption of oxalate, which increases the incidence of oxalate renal stones. And patients can also present with a low-grade fever. Some extraintestinal manifestations of Crohn's disease do slightly overlap with ulcerative colitis. 50% of patients with Crohn's will experience these and they can actually precede their gastrointestinal symptoms and can also be independent of the activity of their Crohn's disease.
Some of the ones that are related to disease activity include apthos ulceration, erythema nodosum, pyoderma gangrenosum, arthropathy. eye complications, and amyloidosis. And some extraintestinal manifestations not related to disease activity include sacroiliitis, ankylosing spondylitis, PSC, chronic hepatitis, cirrhosis, gallstones, and renal stones, as I've mentioned. On examination,
Patients can present in a number of ways. They can be systemically very well if their disease is well controlled or minimal. General findings could include evidence of cachexia, anemia, clubbing. proximal myopathy, easy bruising with vitamin K deficiency. They can have fevers or tachycardia, peripheral edema, and evidence of those extra intestinal manifestations.
On abdominal examination, they may be tender depending on where the disease is. There may be a mass palpable, especially if there's an inflammatory mass. They may have a psoas sign or other intra-abdominal signs of if there's abscess or transmural inflammation. They can have fistula formation, including enterocutaneous fistula.
And they may have evidence of a bowel obstruction if there's stricturing disease with abdominal distension. And perianal disease, on examination you may see skin tags, fissures, fistulas, anal stenosis. anal cancers or ulceration. The workup of Crohn's disease, similar to ulcerative colitis, is complex. There is no single test and it is a combination of the patient's history. examination, blood results, stool tests, endoscopic imaging, and biopsy that's going to determine the diagnosis.
And it's important to be thinking about ruling out other differential diagnoses with these tests. So in terms of lab tests, you can send an anti-saccharomyces cervicia antibody, ASCA, which has higher sensitivity for Crohn's than for ulcerative colitis. If you remember in the UC talk, we said we would send... anti-neutrophil cytoplasmic antibodies or ANCAS, which is more sensitive for ulcerative colitis. ASCA is a positive in 35 to 50% of Crohn's and in less than 1% of ulcerative colitis.
You can send a fecal calprotectin, which is a marker of disease activity. Fecal calprotectin is a protein that's found in neutrophils, so it demonstrates whether there's neutrophilic infiltration into the bowel lumen. And you can also send the fecal test for culture to rule out other infections as a cause of this presentation. General bloods may also be abnormal in Crohn's disease.
Full blood count may demonstrate anemia and also leukocytosis if the disease is active or there's an infectious complication. Urea electrolyte creatinine can be sent and their electrolytes may be low. LFTs should also be sent to screen for PSC and you also may find a low albumin. Iron studies may show a low transfer and saturation. CRP and ESR markers of inflammation.
do correlate with disease severity and active inflammation. Celiac antibodies should be sent to exclude celiac. And you can also send a quantifier on gold if you're thinking about starting. immunomodulators or biologic agents. Endoscopy is the gold standard test to have a look at the bowel. Colonoscopy and ileoscopy with multiple biopsies is first line in establishing a diagnosis as well as determining the extent of disease.
It gives you a macroscopic view of the bowel and allows you to do biopsies, obviously. And it's also helpful in monitoring disease activity as well as reassessing mucosal healing during therapy. Some of the endoscopic appearances you may find in Crohn's disease include longitudinal ulcers, a cobblestone appearance, and abscess ulcers, usually a longitudinal array.
In upper gastrointestinal Crohn's disease, like gastroduodenal Crohn's disease, you can just see nonspecific lesions such as erosions, erythema or ulcers. Given this can be a disease that affects the entire gastrointestinal tract, these patients can also undergo upper GI endoscopy, especially if there are upper GI symptoms. They may also require push.
enteroscopy to have a look at more of the small bowel, or capsule endoscopy to assess for the presence, extent, and severity of any small bowel involvement. An alternative to this could be an MRE, an MRI enterography, and this would be preferred if there was any evidence of stricturing because the capsule can get stuck if you do a capsule endoscopy.
Which does take us to imaging. There are a number of imaging scans that can be done for Crohn's disease. Most of these are not specific for a diagnosis but may help you determine the extent of disease. An abdo x-ray can rule out toxic megacolon and also rule out perforation or complications in an acute setting. It may also demonstrate a bowel obstruction and you can sometimes see colitis as well. An MRI enterography, which is the MRE I mentioned, is a good scan for looking at
small bowel especially looking for small bowel thickening can also determine whether or not there's edema in the bowel wall or in the mesenteric fat. It may demonstrate increase in fat adjacent to the bowel, which is one of the macroscopic features we'll be talking about later. It can demonstrate increased vascularity. It may help you to determine if a stricture is inflammatory or fibrotic. And it can also help you characterize any sinuses or fistulas that may be present.
CT scans are often done to investigate abdominal pain or acute presentations with Crohn's disease, but obviously these patients are quite young and you want to be avoiding recurrent scans if you can. This may demonstrate thick and small bowel, could demonstrate abscesses, dilated segments, fistulas, perforations, and it is good for those acute presentations, as I mentioned.
I guess imaging modality, which is sometimes used, is high resolution intestinal ultrasound. This is used to detect inflamed bowel and can demonstrate many of the features of Crohn's disease. I have come across this in a specialized center where it's done relatively routinely by the gastroenterology teams. And it is an emerging technique, but it's obviously operator dependent as with most ultrasound modalities.
And an MRI pelvis is the gold standard for assessing perianal sepsis or for characterizing perianal Crohn's disease. Before we go into treatment, I just wanted to briefly talk about disease severity assessment as well as talking about the different... diagnoses that you need to consider when a patient presents with symptoms of inflammatory bowel disease and briefly the macroscopic and microscopic features of Crohn's disease. So firstly staging of
disease activity or severity of disease. There is a thing called the Crohn's Disease Activity Index, CDAI. This is mostly used in research and can also be used to gain access to funding and monitor response to treatment, especially treatment with biological agents that need special funding by the government.
It's basically a scoring system that looks at a different number of variables, including clinical features like the number of stools, abdominal pain, and general wellbeing, as well as... other complications of the disease like erythema nodosum, ulcers, abscesses, how much analgesia they're requiring, whether or not they have an abdominal mass. their weight and the normal hematocrit and how different their normal hematocrit is from baseline.
Different scores will group patients into mild, moderate or severe disease. And also if patients have a score of less than 150 for 12 months, they're considered to be in remission.
The other thing to know, and I don't know whether again this is relevant, but is that there's a Montreal classification in the same way there is for ulcerative colitis that looks at... the age at diagnosis, location of disease, whether it's ileocolonic, ileocolic or isolated upper disease, and the behaviour of the disease, so whether it's stricturing or not stricturing, which is...
used mainly for research and also that this concept that the different phenotypes may be associated with different genetic abnormalities so to help try and identify those the next thing i wanted to talk about was differential diagnoses for symptoms or patients presenting with symptoms of inflammatory bowel disease. There can be multiple differentials depending on the location of bowel or the gastrointestinal tract that's involved.
their presenting symptom and whether there are any other associated features. The ones that you should think about and exclude include irritable bowel syndrome. And the differentiating feature here is that inflammatory bowel disease will usually have a positive or elevated fecal calprotectin, which is a highly accurate and sensitive way of differentiating between the two.
Irritable bowel syndrome is typically long-standing, will have fluctuating severity, will not have any red flag symptoms such as PR bleeding, weight loss, anorexia, and will have normal bloods typically. Celiac disease should also be excluded. Patients can present with diarrhea and with or without evidence of iron, vitamin D and folate deficiency.
Other normal abdominal pathology needs to be excluded, such as appendicitis, diverticulitis, pelvic inflammatory disease, etc. And there are some random sort of diagnoses that especially can mimic. inflammatory bowel disease in the ileum. These include things such as Yersinia and TB infections, small bowel lymphoma, eosinophilic gastroenteritis, actinomycosis, Bechet's disease and other systemic vasculitises which can affect the small bowel and also radiation enteritis.
The next thing I wanted to chat about was just the different macroscopic appearances of Crohn's disease. This is a favored... exam topic, it's pretty easy for them to show you a operative specimen of a piece of bowel with evidence of Crohn's disease. So it's worth having a look at some pictures online of this. But in general, obviously there needs to be skip lesions, so it's usually not contiguous disease. The bowel will look inflamed and edematous. There's this...
concept of mesenteric fat wrapping, which is where the mesenteric fat kind of creeps around the bowel wall surface. It's good to look at a picture of that. Obviously, there's ulceration and it can be full thickness disease in Crohn's. You may see a fistula and fistula can either be sinuses with no real other... organ that the fistulas tract is extending to, or can involve other loops of bowel, the bladder, vagina, sigmoid, or even through to the skin as an enterocutaneous fistula.
They can be strictures, which can be very long in length, and they can be stiff and edematous, or they can be fibrotic, and they can be prominent lymph nodes in the mesentery. Some microscopic features of Crohn's disease. We did talk about these for ulcerative colitis. So for Crohn's disease, you're going to see full thickness inflammation. So you're going to see neutrophils all the way through the mucosa in the base of the crypts.
progression through the submucosa and into the muscularis mucosa. There are three sort of diagnostic hallmarks of Crohn's disease on histopathology. These include non-caseating granulomas, which are present in 60% to 70% of patients, intralymphatic granulomas, and granulomatous vasculitis.
And some of the differences between the histopathology in Crohn's and ulcerative colitis. So in Crohn's disease, there's usually a normal number of goblet cells, but these are typically depleted in ulcerative colitis. There's usually not many crypt abscesses in Crohn's disease, but these are common in ulcerative colitis.
The glandular architecture in the mucosa is usually preserved in Crohn's but often distorted and atrophic in UC. There's a lymphocytic... infiltrate in both but in Crohn's this is usually patchy versus it's uniformly heavy and you see granulomas as I mentioned are present in Crohn's but not in ulcerative colitis The muscularis mucosa is usually thickened in ulcerative colitis but normal in Crohn's.
And the submucosal inflammation is usually very heavy in Crohn's and there's minimal UC because as we mentioned, Crohn's is a transmural inflammatory process. So after all those random bits of knowledge about Crohn's, let's get back on track and talk about the management of Crohn's disease. The goals of treatment in Crohn's disease are to treat acute disease improve and maintain patients' quality of life, correct nutritional deficiencies, to try and maintain steroid-free remissions.
and to prevent complications, hospitalizations, and surgery. This disease there's no cure for. We can only control their disease. And so the aims are really to try to... minimize the effects of the disease on that patient's life. Medical management of Crohn's depends on the location of disease, the degree of involvement and inflammation, severity of symptoms. whether or not there's any extra intestinal manifestations, and their response or lack of response to previous treatments.
You might hear the term step-up approach to treatment. This is kind of the traditional approach to management of Crohn's disease, which starts with some mild sort of anti-inflammatory therapy and then progresses to immunomodulating. agents and then to biologics and then to surgery. There is some evidence now though that actually treating till there is mucosal healing which is able to be sustained may be a more effective long-term plan for these patients.
That's a little bit complicated in Australia because of the funding for biologic agents. And part of that involves having failed treatment with other modalities prior to getting funding for that. But it's good to know about those two. approaches. In terms of medical treatment of Crohn's disease if you listen back to my episode on ulcerative colitis I go through all the different drug types and how they work and basically when you would and wouldn't use them.
So just briefly, talking about medical management of Crohn's, amino salicylates like mesalazine and sulfasalazine are usually not used in Crohn's disease. They're mostly used in ulcerative colitis.
Corticosteroids are typically used for disease flares, not for maintenance therapy. So patients who present with their first episode of Crohn's disease or who have a flare of disease may be put on corticosteroids, but it's also important that they're then started on an immunomodulator or a biologic early to then be able to wean the steroids off. The immunomodulators commonly used are thiopurine. So this includes azathioprine and 6-mecaptopurines, which are purine analogs.
And you need to remember to test the thiopurine methyltransferase, TPMT, prior to starting these drugs to make sure that they have their metabolite to be able to break them down. If these don't work, then the next step are biologic agents, which are types of monoclonal antibodies that target mediators of the inflammatory response, and this includes TNF-alpha inhibitors such as infliximab or adalimumab, anti-integrine therapies like vetalizumab and rarely ustacunumab.
And then there's also calcine urine inhibitors, which from what I understand aren't used that often, such as cyclosporine and tacrolimus. And for Crohn's disease... Patients are often started on metronidazole or ciprofloxacin, especially after they've had an ileal resection because this can reduce... recurrent disease and also has been demonstrated in some small studies to help induce remission of disease. The other thing that I came across is this concept of exclusive enteral nutrition.
which is where patients are exclusively enterally fed, as their name suggests, which can help induce remission of disease. There's some data that says that's better than steroids, but I've never seen this used in practice. And I do work at a IBD center. So I'm not sure that that's something I would bring up in the exam. In terms of surgery for Crohn's disease, indications for surgery include failed medical management and disease-associated complications.
So failed medical management includes ongoing symptoms despite medical therapy, as well as poor compliance or intolerance of medications and adverse side effects of medications.
Disease-associated complications can include both acute complications and chronic complications. Acute complications include development of an abscess or perforation, hemorrhage, obstruction especially with a fibrotic stricture and if there's colonic disease there's a small chance of toxic megacolon or toxic dilatation of the colon. Chronic disease-associated complications include growth retardation in children, fistulas, the development of neoplasia or cancer and obstruction again.
There's quite a lot to talk about when we talk about surgery and Crohn's disease, mainly because it can present in so many different areas of the gastrointestinal tract. It can present in so many different ways, such as inflammation. obstruction, strictures, fistulas, and abscesses. And also because it depends so much on the reason you're doing the surgery and the general state of the patient.
To start with, I think I might focus just on some pre-operative principles and then just some general principles of surgery for Crohn's disease, as well as some post-op. treatment pearls. And then we'll go into a little bit more detail about some specific scenarios in Crohn's disease and how you might approach those. So to start with some pre-operative
principles when thinking about surgery for Crohn's disease. So firstly, nutrition is a major consideration in patients with Crohn's disease who are potentially undergoing surgery. often malnourished due to the gastrointestinal effects of their disease, as well as just the sort of catabolic effects of having a chronic inflammatory condition.
You need to do a nutritional assessment and also consider preoperative enteral or parenteral nutrition to try to make them as nutritionally replete as you can preoperatively. In my institution, I've seen some patients have their operation delayed when safe to stay in hospital for a period of TPN preoperatively. The consequences of a malnourished patient undergoing resectional
bowel surgery is obviously that they won't heal and that they'll have anastomotic or other infectious complications from the surgery. Patients' bloods should be checked. And often these patients are anemic. So if they can have an iron transfusion, if it's not too bad, that's preferable. But they may also require a transfusion if their HP is less than 70.
and you should replace any electrolyte abnormalities. Patients should be encouraged to stop smoking. Firstly, this will make the disease worse, and secondly, obviously contributes to issues with respiratory. complications around the time of surgery and also with healing and rates of infection. If a patient is having surgery for Crohn's disease, they definitely need preoperative stoma marking. These patients have a much higher incidence of requiring stoma.
due to their nutritional status, steroid use, other immunomodulators, and the fact that they have active bowel inflammation and they will often require a stoma for a period of time. You definitely want to go through that patient's history and find out what previous treatment and where the previous disease that they have had is. You want to know if they have any perianal disease, small bowel, if there are other sites.
And if you have time, you should try an image with MRI preoperatively in order to identify the full extent of disease. These patients are also at higher risk of... DVTs and PEs, and so do require DVT prophylaxis. If possible, you should try and control any sepsis preoperatively. And this may include treating a patient with antibiotics and percutaneous drainage and deferring surgery to a more elective setting.
Because obviously, if you have active sepsis, they're definitely going to need a stoma and you can't do a join there, as well as them having a higher rates of complications from the surgery. You should review all available imaging and try to have a pre-operative plan. And you can also have a talk to the gastroenterologists about their immunosuppressive drugs.
it may be best to try and schedule an elective operation before the patient is due their next dose of a biologic in order to maximize their time off the drug preoperatively to help with healing. In terms of some general principles of operative surgery for Crohn's disease, these principles include draining any sepsis, identifying diseased areas
which includes an examination of the entire bowel in order to stage the disease. Resecting the least amount of bowel that's required to be removed, mainly because these patients... often require further resections in the future, and also because there's good evidence that leaving microscopic disease doesn't influence disease recurrence. It's a good idea to measure the length of bowel that's left at the end of the surgery and to document this.
And it's important to remember as well that Crohn's disease is not curable. So your focus is only on returning that patient's quality of life by managing their current disease that is linked to the symptom that you're doing the surgery for. So asymptomatic disease should be ignored. You want to restore continuity if possible or otherwise have temporary or permanent diversion.
I'd say in the exam, if there's anything with a Crohn's patient that makes them unwell or any red flags about performing an anastomosis, you should take the safe decision and do not do an anastomosis. And the other principle that's really important is to definitively deal with any sepsis that you come across and to perform a thorough washout. You want to have that patient treated with adjuvant.
therapies including immunosuppressants to try and reduce the risk of disease recurrence and another tip is that division of the mesentery can be very difficult in Crohn's disease it's often quite thick and edematous, and the vascular pedicles can often be difficult to control with normal sort of clamping and tying. So you want to consider double suture ligation of the mesentery for Crohn's patients.
And then also consider nutrition. So if this patient's not going to be able to have adequate nutrition because of what you're doing with your surgery, considering feeding tubes at the time of operation is important. Performing a stoma may be indicated in inflammatory bowel disease in the setting of a seriously unwell patient on inotropes, patients who are coagulopathic, who have severe comorbidities.
Patients who are on high-dose steroids, and I've always found this difficult to find a clear cutoff for, but I did find something that said if they've been on more than 20 milligrams a day for more than six weeks, if the patient's severely malnourished. if there's any sepsis, especially purulent or feculent peritonitis, or if there's excessive blood loss. But that should be an individual decision based on patient and bowel and pathology factors.
Some general post-operative tips or considerations include considering nutrition, which I've mentioned a few times now. If you haven't picked up, that's very important. In addition, you want to monitor these patients for complications.
high risk of complications such as sepsis, leaks, PEs, DVTs, and other things such as bowel obstructions and hemorrhage. You want to reduce the risk of recurrence in patients. So consider... recommending that they see smoking if they haven't already, metronidazole as an antibiotic for low-risk patients post-operatively, and typically these patients will have adjuvant treatment.
But there is a concept that it can be difficult to know whether to treat a patient who's had all of their disease resected. So if they just have ileal disease and you've resected that and they have no evidence of disease elsewhere. Do they still need to be on ongoing immunosuppressants? It is a bit of a balance of the side effects of the medications against the benefit of prophylactic medications, and this does need to be considered on a case-by-case basis.
Endoscopic recurrence usually precedes the clinical recurrence, so it's important that these patients are followed up and monitored. So next I wanted to talk about some different scenarios in Crohn's disease and some surgical approaches to these. The first thing I wanted to mention is a tip that I was told by one of my consultants, which said to always put Crohn's patients in lithotomy.
Because any part of the bowel can be involved. And you may think you're dealing with a terminal ileal phlegmon and you find that there's a fistula to the distal sigmoid. So that's a nice tip I thought I'd share with you. So the next thing I thought I'd talk about is... Operative options for strictures. Crohn's strictures can be inflammatory or fibrotic. If they're inflammatory, often they're treated initially with steroids and then medical management. But once they're fibrotic...
There's a few approaches. The first thing is there are endoscopic options where gastroenterologists typically will try and access the stricture and perform a dilation of the stricture. This is good for strictures that are less than 5cm in length and up to 50% of patients will avoid surgery over a 5-year period with endoscopic dilation. There obviously is a risk of...
perforation and bleeding which is approximately three to five percent for these strictures. If it's a long stricture or dilation isn't working then often it becomes a surgical problem. The aims of surgery for Crohn's strictures is to try and do the limited amount required to remove the stricture or unblock the problem, whilst also trying to maintain bowel length. So the options include bypass, which isn't usually used routinely anymore for small bowel strictures.
It may be indicated if there's a duodenal or a distal gastric stricture where you can't perform a resection and in which case you may perform a gastrogegenostomy type procedure. The next option is resection. which is where you remove the strictured segment. The principles here are try to remove only the stricture with about a two centimetre margin of grossly normal bowel.
And then to perform an anastomosis, which there is some controversy around this, but whether it's end to end or side to side anastomosis.
The reason I say it's controversial is because some proponents of the side-to-side think that end-to-end anastomosis and Crohn's have a higher stricture rate. But then on the flip side of that, Some people think that if you do an end-to-end anastomosis, then it's more easily accessible and transversible by the endoscopists to be able to then potentially dilate an anastomotic stricture.
Not really good data on either of those as yet, but at my institution for all of these, we do an end-to-end hand-sewn anastomosis. The last option for Crohn's strictures is a stricture row. plasty and there's three main types of strictureplasty techniques which are basically determined by the length of the stricture. These are typically done in small bowel strictures the concept being that you're going to
not resect a large area of bowel so that you're potentially going to be preserving length. It's not indicated if there's perforation, abscess, if there's a fistula or malignancy associated with the stricture. But it is good for rapidly recurring disease if the patient's got impending short gut syndrome and if it's a non-phlegminous stricture or there's multiple strictures in a long segment.
So the three main types of stricturoplasty include the Heineken Michalitz stricturoplasty, the Finney or Jabile stricturoplasty, and the Michalassi stricturoplasty. So the Heineken Michalitz is good for strictures that are less than 10 centimeters in length. And it involves incising along the anti-mesenteric border of the bowel. which should be extended one to two centimetres proximal and distal to the stricture.
The opening that you've made, the longitudinal incision, is then closed transversely, usually in two layers, to then basically open up that area of stricture. The Finney stricturoplasty is used for strictures that are 10 to 20 centimeters in length. This again involves an incision along the anti-mesenteric border along the stricture. And you then basically fold the bowel in half and you then close your enterotomy in two layers to perform a... side-to-side antiperistaltic anastomosis.
The Jabalay stricturoplasty is sort of a variation in the finny where you don't open the entire length of the stricture. You only open the proximal and distal part of the stricture and again you fold it on itself. and perform your anastomosis. So you are bypassing a short section of that stricture. And the last one to talk about is the Michelassie stricturoplasty, which is good for strictures that are more than 20 centimeters in length.
This involves dividing the strictured segment into two portions and dividing the bowel and then laying them side by side in an isoperistaltic fashion. performing a longitudinal enterotomy on the anti-mesenteric border and performing an anastomosis along the length of the strictured area. It's worth looking at a picture of that to get an idea in your head of what it actually looks like.
Moving on from strictures there are a few other scenarios I wanted to talk about. The first is abscess formation. An abscess in Crohn's disease can be managed the same as abscesses from other disease, initially with percutaneous drainage and intravenous antibiotics. Some of these patients will require surgery because they're obviously very unwell or septic or peritonetic.
And up to a third of patients will fail conservative management and require surgery. But you can still attempt percutaneous drainage and antibiotic conservative treatment in the first instance. Free perforation obviously requires surgery with resection of the perforated bowel and the macroscopically diseased or involved segment with creation of an end.
stoma or a diverted anastomosis depending on the location of disease. Hemorrhage can occur in Crohn's disease. It's typically caused from small bowel mucosal ulceration. In these patients, angiography is usually first line with embolization. Obviously, you have to localize the source of bleeding in the first instance. But recurrent bleeding may require... further interventions such as laparotomy and intraoperative enteroscopy and a resection of the involved segment once it's identified.
Fistulus disease is obviously a common complicating feature of Crohn's disease. Intra-abdominal fistulas, I'm not talking about perianal Crohn's at the moment. can often be associated with complications, perforation, obstruction, phlegmons. It can also involve a number of different organs, including the bowel, bladder, vagina.
and the skin as an enterocutaneous fistula. Principles of operative management of fistulas in Crohn's disease is that if the fistula is going from and to a diseased segment of bowel, that you remove both. sites of disease, so a resection and either anastomosis or diversion as required. If the fistula goes from a diseased segment to a non-diseased segment, typically this will be to the sigmoid colon or to the bladder, then you can just
pinch off the fistula at that site or excise locally and close that area. And as long as it's not diseased, then this should heal up, okay? I guess exception to this rule is if the fistula is going to the duodenum. This is really rare and pretty complex. I don't think we'll be given this sort of scenario in the exam, but if it's going to the duodenum, that may require a patch. or reconstruction rather than primary closure, which is likely to break down.
A portion of patients presenting with Crohn's disease will have primary colonic Crohn's. If patients present with toxic dilatation, hemorrhage, perforation, or severe colitis not responding to medical therapy, then these patients will require surgery. The choice of colonic resection in these patients depends on the extent of disease, the presence of symptoms, their bowel function, and how unwell the patient is. you can consider a segmental resection and primary anastomosis in isolated...
colonic Crohn's disease. So unlike in UC where you would remove all of the colon which could be involved in UC, in Crohn's because of the segmental nature of the disease you can do a segmental resection. This is slightly controversial, and you'd only consider it if there really was just one segment of colon involved, and especially if there's extensive small bowel disease and potential issues with gut length.
Other options for surgery in Crohn's are pretty varied. So options include a subtotal colectomy and ileostomy, which is the procedure of choice in the emergency setting and in patients who are really ill. A total colectomy with an ileorectal anastomosis, which is possible if there's minimal rectal disease, and it can be done at an initial operation or to restore continuity after you've needed to do an emergency case.
The function for those patients will end up with about five loose bowel motions a day. So they need to have good continence preoperatively. So patients with severe perianal Crohn's may not be considered for this. Patients can have a pan proctocolectomy and an end ileostomy, which is a well-established operation in inflammatory bowel disease. It can improve quality of life.
Because this isn't for a malignant cause, you can do dissection closer to the rectal wall rather than a TME, which can help avoid damage to pelvic nerves and function. And it can eliminate obviously the risk of colorectal cancer in the future.
Other options include restorative proctocolectomy, which involves a pouch, such as an ileal pouch. Traditionally, Crohn's disease has thought to be a contraindication to the... formation of a pouch because obviously Crohn's can involve the small bowel and lead to poor pouch functioning.
In patients who've had, I guess, a pouch formed because maybe they were thought initially to have UC and subsequently found to have Crohn's disease, the rates of requiring an excision of the pouch is between 10% to 45%. But some studies also show up to a 70% functioning pouch at 10 years. So it's not a complete contraindication, but obviously if they had severe small bowel disease as well, you'd definitely be thinking twice about forming a pouch.
gosh once again there is way more to talk about than i had expected The last thing I think I'll cover today just briefly is cancer surveillance for Crohn's disease. So Crohn's colitis is associated with an increased risk of colorectal cancer. And in the same way as ulcerative colitis, you should be starting colonoscopy
eight years post the first symptoms of inflammatory bowel disease, or 10 years before the age of the youngest relative they have with colorectal cancer. It really will depend on the disease. severity activity whether there's any dysplasia and family history as to how frequently you're going to surveil the colon
For Crohn's disease, you have to surveil if there's more than a third of the colon that's affected by Crohn's. In patients that have no Crohn's colitis, they may not need this intensive surveillance. But for patients who have... Crohn's colitis affecting more than a third of the colon and no high risk features. You need to do a colonoscopy every five years if the previous two colonoscopies have been normal. You need to be doing it three yearly if they have any active.
Crohn's if they have a family history of colorectal cancer in a first degree relative at more than 50 years old. And you have to be doing it every year for patients with Crohn's affecting the colon who have active disease. who have concomitant diagnosis of PSC, who have a family history of colorectal cancer in a first-degree relative diagnosed at less than 50 years old, who have any colonic strictures or inflammatory polyposis.
and any previous dysplasia. And for patients who get a diagnosis of PSC, they need to have annual surveillance from the time the PSC is diagnosed. I think that's enough for today. I'll do another episode to talk about perianal Crohn's disease, as well as some special populations such as pregnant patients with Crohn's or ulcerative colitis, and to talk about
indeterminate colitis. Thanks so much for hanging out with me today. Remember to rate, review and subscribe so that other people can find this podcast. It's time to close up. Thanks for listening to First Incision. If you have any comments or feedback, send us a message at firstincisionpodcast at gmail.com or follow us on Instagram at firstincision. Happy studying!