CRF 30.05.23 Colorectal Cancer (Part 2), Dr Athula Withanage, Senior Lecturer General Surgery. BSS course Cardiff Medical Centre. Retired Consultant



This on-demand teaching session is relevant to medical professionals and will inform them of the unique characteristics of large bowel tumors compared to small bowel tumors. It will also cover the importance of screening, identifying risk factors, and the likelihood of detecting synchronous tumors. With this knowledge, medical professionals will be able to more effectively diagnose and treat colorectal cancers.
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Learning objectives

Learning Objectives: 1. Identify the differences between small bowel and large bowel tumors and carcinogenesis 2. Explain how environmental factors, such as diet, lead to an increased risk of tumors 3. Describe the ‘gatekeeper’ gene and its role in the tumor process 4. Explain the impact of mutations in tumor suppressor genes and proton co genes in colorectal cancer 5. Summarize the importance of regular screening to identify and prevent colorectal cancer.
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Computer generated transcript

The following transcript was generated automatically from the content and has not been checked or corrected manually.

Good afternoon. Um, everyone, uh, good morning or good evening wherever you are. Uh, we, um, did talk about uh uh small bowel tumors last time. And uh the, uh we also talked about uh why uh with so much uh mucosal and epithelial burden. Uh uh the uh bowel tumors, small bowel tumors are less. And the um uh because uh it's important for you to be able to talk across the table, uh uh about especially talking about very rapid transit time in uh in the, in small bowel tumors. And the liquid contains alkaline environment and the high level of benzopyrene hydroxylase, which will detoxify any, any carcinogens. Also the uh different types and the quality of the bacteria is different from the large bowel. Uh because the uh bacteria population is different and is small and the um metabolism uh reducing carcinogens is I uh is not uh uh common here. Um, and also high concentration of IG A uh in the small bowel. And uh they are, uh if a patient has, has got A I Ds um Crohn's disease, um immunosuppression on immunosuppression drugs or some um inherited uh imm uh immune deficiency syndromes. Like uh uh we why caught uh uh um that kind of syndrome IGA is very much less. So we are going to talk mainly about the large bowel tumors today. Um So it's there is a huge uh considerable geographical variation, the upper hemisphere of the world, the uh cancer of the colon is very much high. And the uh uh the they have the commonly uh population, high living standards, refined food, et cetera and ra in uh the southern hemisphere uh where there is a lot of fiber um and also uh more rapid transmit time because of that. So, uh the thing to remember is most of the majority of the tumors uh start from a uh arise from a benign adenoma. So, what, what does that tell us uh because it can be prevented and the screening is important here. Uh So the variation exists uh within the countries and within the communities and all seems to point out to the environmental factors uh uh coming through the uh Luminal of the uh of the colon. So, diet, you know, uh uh red meat and high output of basil uh bile acids and the uh and of course against the protective nature of the high fiber diet. So, uh uh all arising from the uh from the uh uh the uh benign uh adenoma, let's keep repeating. Um The uh the sporadic tumors. It's about uh 85% 85 to 95% So there is this uh conflict between the, between the uh proto oncogenes which favors tumor growth and also tumor suppressor genes. So, there is a uh uh when the tumor suppressor genes are damaged mutated and of course, that will help the uh the uh the uh proto oncogenes. So, mutational activation of the tumor suppressor genes are important and mutational activation of at least one proton oncogene I I is important is not one, it could be, it could be a few. Uh I'm giving you these things in order to be able to talk about cancer be because uh in any cancer uh not just uh colonic cancer. So about these uh environmental factors, the radiation, uh the diet and also then of course, the proton co genes and tumor suppressor genes uh becoming um inactivated. So this is a uh a diagram about uh a generation of tumors. So, sporadic tumors are much more. And the thing to remember is all these to begin with uh are benign adenomas. So, polyps, they are, they are benign. So, therefore, we got this golden opportunity to locate these tumors. So, uh uh by various screening methods, et cetera. And also then of course, going into the family history. Um and also uh uh if you take uh these GSIS syndromes, uh fa P uh which is only about 1% inflammatory bowel disease. And remember we talked about the uh change of a normal uh uh benign adenoma into uh carcinoma, the word gel stain model. So that's what I want you to remember that word gel stain model and uh sometimes a smaller number of tumors like if you have arthritic colitis, uh Crohn's colitis, uh it is dysplasia cancer sequence. There are two types of cancer sequence, adenoma carcinoma sequence, which is the one projected by roel ST and also dysplasia cancer sequence. Therefore, if somebody has got uh ulcerative colitis, early onset, uh uh frequently relapsing uh ulcerative ulcerative colitis. After about uh 20 years, there's a 10% chance of cancer. So you have to take multiple biopsies and if there is dysplasia, uh severe dysplasia, then of course, it's almost equivalent to cancer. Uh So, uh so the, another thing is that why you want to catch these uh tumors early. Uh The, the, it begins with the uh the gatekeeper gene, which is a PC, which is a, which is a good gene, which is a tumor suppressor gene. And when that mutates, uh it's mostly about 80% of the tumors when that mutates. That is the time that the uh uh beginning to uh cause uh carcinoma. So, uh a PC genes, then, of course, you have this Kras model, uh Kras which uh stops the, which induce uh uh growth factor signal. So it will transform it further further down uh towards the malignancy. And of course DC C gene, uh the uh uh the uh uh the the, this one will further change and stop the uh stop the apoptosis. When you stop the a apoptosis, it start growing. And of course, then you get the three p 53 genes. So it is an accumulation of genetic change. So that's what. So uh once it comes, that becomes more invasive. So once p 53 mutated, it becomes more invasive. So if you can catch the uh not just the adenoma before it becomes a cancer, even after it becomes a cancer early. Uh If you can catch it early, obviously, it will, you can prevent metastatic disease to lungs, the liver, the bones, uh et cetera. So it is important to catch uh catch it in the adenoma stage or uh you should be able to uh prevent it become more invasive, more virulent cancers. Because as I said, the last lecture, the when in the cancer, the cohesion goes, it starts spreading, going, going through uh going into uh uh the lymphatics, the direct spread, then you, you will know all the all that hematogenous spread, transom spread, et cetera, right? So this is the same thing about model. If you can remember the spelling, it's nice to be able to tell these things in the exam because the examiner will, we will consider you very knowledgeable. Uh instead of saying adenoma uh converts into a carcinoma. So I think about the 5th, 6th decade, if you get an adenoma, it is uh 67 de de, you get that carcinoma. So that's why you have to, uh, catch it before it becomes a carcinoma. That's why the screening is for, again, the same thing. Uh, the gatekeeper gene A PC Kras, uh which is the worst gene, uh, that is a proton cogen. And there is another proton cogen we'll talk about called C MYC, uh P 53. After P 53 mutation takes place within that tumor, these are not kind of inherited ones. This happens in the, excuse me, right? So, uh so there are proton co genes. Uh just remember the word proton cogen and tumor suppressor genes. So, uh what happened to tumor suppressor genes is that it becomes inactivated. Uh So uh uh the main two genes, uh mostly 80% of the colon in cancer. There is uh Kras genes, Kryten rat sarcoma genes. We are not going to ask you that. But uh Kras is the one that uh uh uh as mentioned. So, cm is not relevant to colonic cancer that much. But uh bladder cancer uh uh then uh uh the prostate cancer, uh the uh these are more responsible so C I can car us mutations, right? So, a PC is a good gene as that's the gatekeeper. That is when it really starts. So, so, uh and then the other one is DC C and P 53. So, I uh if you just know the names, that's enough, I don't think anybody is going to ask you what uh what uh chromosome, it's, it is on um um A PC. Some may, somebody may ask is the long arm of chromosome five. Um So, right. So colonic uh colorectal cancer is the second most common cause of death in United Kingdom, um possibly worldwide as well. And 20,000 new cases a year in UK. And uh most of them are 40% colonic cancer. Uh sorry, 60% colonic cancer, 40 40% rectal cancer. Uh that uh that, that doesn't mean that which half uh the, the, the, the left half colonic cancer is uh I is, is, is more uh colon uh the descending colon and the rectum. Therefore, uh for screening purposes or even quick examination purposes uh because you don't need bowel prep, you can do a le left colonic uh right uh in investigation, descending colon, sigmoid colon and the rectum. And uh you can do a without bowel prep, just a couple of EMR and uh the, the get it done almost uh soon after the clinic uh or the following day, you don't have to wait for admit the patient bowel preparation, et cetera. And uh the uh why we do need to do colon uh full colonoscopy or barium and M I examination. Uh even if you find a rectal tumor is because about 4% there are synchronous tumors. This will be asked from you, why you do it because you have to do the organized investigation. Why if you had seen and biopsied the correct cancer, why do you want to see the whole colon? And this is the answer I want to know, make sure that there are no synchronous tumors. Um The uh remember there are synchronous polyps as well. Uh That uh that is if you are treating polyps, you need to know that as well. At least 10 to 20% cases you have synchronous polyps as well. But once you find the cancer, you have to exclude a cancer somewhere that is known as the synchronous tumor and different tumors is not the recurrence. It is, the recurrence may come on the uh anastomotic site or somewhere else. Metastatic disease, which had been there that you may not have uh come to light at the time of surgery. Uh especially sometimes you get uh hepatic cancer uh at the time when you go to do the uh uh laparotomy or laparoscopy, you don't see any cancers. But uh that's why after the first three months, at least you must get do the lift is and the uh whether the left is normal or abnormal, you need to get ultrasound scan of the liver done and to make sure there are no micro uh metastatic disease has uh has uh has come to light. So, metachronous tumor is uh something totally different. That's why we are doing uh colonoscopies after uh uh every uh every six, every, every one year. So at the end of the first year, you have to organize a colonoscopy. Then after that, every three years, uh up to the age of 75 that is what we do in United Kingdom, right? So, uh as I said, that, you know, the adenoma decayed the, the sixth deca and the cancer decay is the seventh dede that itself tell you that it is the benign adenoma which converts into uh cancer because of the accumulation of various genetic abnormalities. Uh diet. I think we already talked about this one. familial adenomatous polyposis. That's why we are doing uh um colectomies for those. And the past medical history is important. Past history of uh uh cancer of the colon ulcerative colitis. Crohn's disease are important and the family history of H and PC C hereditary nonpolyposis Coli coli syndromes. And these are the Lynch Syndrome. I I forgot to type it here. There is Lynch Syndrome one and li limb syndrome, two limb syndrome. One is it is it is they come at the age of 45 or so, both limb syndrome and, and N PC. And also uh the uh uh the uh the, the, the, the, the, the, the Lynch Syndrome, one will produce only colonic cancer. Lym syndrome. Two produce uh cancer of the uh uh bowel. Uh uh uh an addition to that uh cancer of the breast, um uh uterine cancers um and gastric cancers, et cetera. So, it is important to know what is the Lynch syndrome at least know that. And the um although it says that hereditary nonpolyposis, uh when you say polyposis, the you are talking about more than 100 polyps, you cannot say familial adenomatous polyposis. Uh if there are no less than 100 polyps. So it may be synchronous poly polyps in various parts of the colon. Um And the uh but uh by uh although they say there is no polyposis, there are polyps so that you have to remember that. Uh uh well, they could be upper git polyps, uh Duodenal polyps, gastric polyps. That's why you have to follow up those patients with various endoscopies, et cetera fiber. I think I, I uh it's my favorite because uh my boss uh Mister Neil is painter from Royal Free. Uh He, he used to um uh promote this theory with Goller who wrote the book on the famous book on colonic cancer. And the uh so it is important to talk about the fiber. I think uh remember the conditions I talked to you about er in the last lecture and in the diverticular disease as well. So, diverticular disease, constipation, hemorrhoids and colonic cancer almost can be taken in a high fiber syndrome. So if you get one, make sure you do not miss a cancer, don't treat the patient with hemorrhoids and send him home without, without really going into his details. And following up because the patient after the hemorrhoid treatment may still bleed because of a cancer, right. So uh uh this 1 72% of the cancers are in the left colon. That is why uh a flexible sigmoidoscopy. Uh The is is important because it is easy to do. And there are poor people who can do it rather than going all the way to the colon. Of course, if you find the cancer, you have to do the other side as well, or at least get a barium, doub double contrast barium in done. So, personal history is important. Uh symptoms of blood mucus pr change of bowel habits, uh loss of weight, uh write all the three in the nose at the same time. Uh uh blood pr and you have to say, is it mixed or coming fro uh coming uh uh to the commode at the beginning or at the end? Uh So, uh uh if it is mixed, obviously, it is serious problem. And so, uh uh past history of polyps, we already talked about past history of cancer, past history of previous surgery for cancer is important. The family history is important and the uh uh risk factors, family history, ulcerative colitis again, uh dysplasia, cancer sequence is important. Um uh in ulcerative colitis and Crohn's disease, ureterosigmoidostomy for bladder cancer, you take the bladder out, it is not done anymore. We nowadays do the ileal conduit but in underdeveloped countries or developing countries, they may be still doing. It's an easy operation. We, we used to do as, as the, uh, the, uh, second part of the operation after cystectomy to put these ureters into the sigmoid and the, um, acromegaly. And, uh, uh, we already talked about that. So history is important, altered bowel habits. I took it from a book, uh, bleeding mucus pr and tenesmus and urgency, constant anal pain. It's not very common actually. That's the problem. Uh and continence issues uh already due to tumor invading onto the sphincters, et cetera. Uh It, we talked about digital rectal examination. There's three stages to it. Uh uh We look at around the anus, around the anal word, not to miss an anal carcinoma or fungating rectal carcinoma. And uh it happens so often to the medical world, we go to see patients and nobody has done APR and then we open the, uh open the uh uh cur o open the curtain and ask the patient. Uh and you inspect it sometimes you see a fungating carcinoma. It's an embarrassment for the whole team. So don't do that. Sphincter assessment initially is important because the sphincter may be damaged due to due to uh difficult labor in the past. And you, uh so after surgery, you won't be blamed for that. So, uh accurate measurement of the tumor distance from the anal word is important to decide whether you can do an anterior resection or you may have to do a, do an abdominal peroneal resection with two surgeons involved uh from lap, from the anterior method, as well as the uh uh peroneal supra levator, uh uh uh extra levator exertion of the, of the rectum. So, ct thorax is a staging thing and MRI is important uh especially for low rectal uh uh tumors. And endo anal ultrasound is also important to see uh to almost get the T staging. Uh Because you can see and also looking at the sphincter is important because after the reflection peritoneal reflection, there is no point of doing endo anal ultrasound, but you can still go with MRI higher up. So you have to decide how far the tumor is from the anal but, and decide whether to do uh endo uh anal ultrasound or do an MRI examination. Um uh We talked about carcinoembryonic antigen. Uh if it is negative, it is not diagnostic, you cannot tell the patient that uh and also the lab usually warns you uh uh every lab says that this is not diagnostic. Uh So, uh if it is high, of course, that will positive. And uh uh you are doing that still because you need to follow up because in the follow up it will be positive. Um So, so preoperative discussion at MDT that is uh normally done in all hospitals. Um So you have to have assessment optimization of the comorbidities. You may have to get the medical doctors to come in to look at the chest. If the patient has the COPD cardiac problem, you have to see whether the patient is fitness for, for surgery. So, uh the in recovery program now is, is, is, is uh in place in UK and fast track surgery. Um, antibiotic prophylaxis. I'll be talking about that in a minute and deep thrombosis, prophylaxis. Very important. OK. So I put this one this morning for you because this is the most important slide for medical students. Uh because we'll be asking these questions from you. So, antibiotics, antibiotics uh are important and it, you have to really target the colonic bacteria. So uh I will d dwell on this slide for a bit. Uh because even if I finish the lecture after this, that will be enough. So uh antibiotics, uh we started late as well. Uh Antibiotics are important and usually you are looking for and we will be asking that question from you. Why you give metroNIDAZOLE? So you give metroNIDAZOLE to attack the, the uh the most common bacteria waiting in the wings of the colon which is bactero frags. So broad spectrum antibiotics is important. Uh uh And the uh Closin third generation uh is the one we give maybe 1.5 mg IV uh preoperatively uh and the uh the uh the uh and then continue with 750. Uh because I think the dose will be asked, you look at, look at the look at the do dose, uh, using the means and the, um, uh, you have to decide whether you are giving perioperative antibiotics or the, uh, or you are going to continue with the antibiotic. That depends on the contamination. You know, you have already learned this, the, the, the four classes of contamination. One is clean. Uh, if you are just talking about surgery in general, uh, that means clean surgery like a hernia. Um The, the taking a lipoma out that is clean surgery. Uh You don't give any, you don't need to give any antibiotics. And the uh occasionally there may, could be an argument uh whether you, we are putting a, a prosthesis to a hernia in the groin, maybe you perioperative antibiotics. But uh the, so other one is clean contaminated. Uh that means uh uh you are cutting through and uh your bile duct uh without spilling. So that is a clean contaminated. And uh uh you can give uh give three doses perioperative antibiotics. I think that should, that should be enough. If you did not spill it, then of course contaminated during laparoscopic surgery, you, you spill a lot of bile and uh spill bile contains those needs at least five days of antibiotic. Some people say 33 days. But I think uh as, as old fashioned surgeons, we like to give at least five days of antibiotics. So the fourth class will be fecal contaminated. You may have to give antibiotics maybe, uh, 5 to 7 days. So that is, that depends on, on, on your contamination class. So, uh, you will be asked about those four classes. So, so remember that and then of course, bowel preparation. Now, of course, if you are doing enhance recovery program, uh, and also doing laparoscopic surgery or even open surgery, uh, uh, we are trying not to prepare bowel unless it's an ultra low anastomosis. So, uh, uh even there is no decision about that, but bowel preparation is not done. And we usually use, uh uh just for as for colonoscopy, we use picosulfate. Uh uh, the uh is the one we normally use with magnesium citrate, uh Pcox. I think people call it. Uh, but you, you have to know what is, what is pila as well because simple things you have to be able to give. So the, uh, so the other b is the blood transfusion, are you going to give a blood transfusion? But if you are giving blood transfusion, make sure you give it at least 48 hours before surgery, not after 48 hours. I think, you know about that, you know, about C prep cycle, you know about uh went may have pathway and 2 3D PG. That's what we will be. Uh, we will be normally like to ask as our jargon. So 2 3D PG is depleted in, in, in stored blood. Therefore, oxygen dissociation curve uh will be, um, uh will be difficult, it will be moving on to the, on to the right. So, uh, uh, so be careful. Some people may ask you though if it is 10, I think I will just cross match blood for the surgery. Uh I just leave that only if it is about seven, which is the critical point there. Uh, you may have to transfuse and bring it up to about 10. That's, that's more than enough. And then of course, the C will be the consent informed consent. Uh Now, this is a difficult one for um junior doctors because, er, in our hospital here, the how the University Trust hospital here with the Bush General, we, we don't really get the house officers to get consent because they cannot really, although I uh we are trying to do uh educate you with these various types of surgery we do. Uh it is uh uh it is important, uh uh somebody who knows about it can give an informed consent whether the patient needs a, needs a colostomy. So, if you are doing a right hemicolectomy, you don't need a, need a uh a colostomy, you should know that. And of course, uh if you are doing a low anterior resection, you will need a loop ileostomy. So, uh so, uh and of course, if you are doing a palliative surgery uh in uh emergency surgery, you may doing a heart men's operation, then you, you need the left eye fossa and colostomy. So, so you have to know about loop and the end it's important and you have to sign this in the on the board. There is a colostomy sister or maybe just the house offices, stay away from, away from all the scars away from uh the rib cage, away from midline and uh uh away from my uh crest uh et cetera. So and also uh it should be on a summit of the patient's abdomen because if, if it is below the summit of the abdomen, patient cannot see that's why it's important to uh uh important to decide exactly and mark it with, with the permanent thing uh in order to do that. So, uh so you, so that's why the DVT prophylaxis. Uh there are various protocols uh and oxy we give and the uh important for you to remember is that uh usually if they are doing an epidural, uh they don't like you give two hours before surgery. So, um make sure that uh uh uh the, you have to ask the anesthetist when to give it. Now, in our hospital will give 12 hours before or don't give it at all until surgery is done. So, uh but that possibly may not be acceptable because all the clot formation may happen during the patient lying there. Although we can put uh compression, stockings, um uh and continue compression uh uh during surgery as well. So uh uh ask the anesthetist if, if the patient usually have an epidural, not for a right hemic colectomy. That's why you need to know the surgery but left-sided colonic surgery. Anterior resection, you will be, uh, you will be doing an epidural and then of course, the epidural, uh somebody may ask you why you are doing an epidural. Uh if you say pain control, well, answer is correct, but that's not what we are expecting you to answer. Uh uh I I in a final medical examination, we wanted to tell that this is to, this is to reduce the uh metabolic uh metabolic uh response to surgery because you cut off the pathway to the hypothalamus. And you should have another lecture for that metabolic response to trauma because I cannot do that in this one. So make sure when you go home, look at the metabolic response to trauma. So that, that is why we epidural, once you do epidural, you cannot manage the patient on the ward. So your patient is going to it. So book the ICU well in advance. So, epidural uh uh so uh the uh uh uh and also entry method uh uh I'll put another one that means how do you enter the abdomen? So either it is laparoscopy or laparotomy. So, uh the, so the when you say laparotomy, what does it mean? It may, it, it's not me, it does not mean you just cut from uh from the kei sternum to the symphysis pubis and open up the abdomen. No, it is only the first part of it. So, uh once you do a labor toy, you have to do a full laparoscopy like examination, look at every place. Uh Yeah, then of course, are they are disseminated disease with the liver is clear. Uh Are the loops adhered? Is it operable? Is it resectable, et cetera? So, uh uh you need to know that. Uh So that is the laboratory means all that. So if you, if you think about laparoscopy, you will understand what Lao toy means. Of course, F is the fluid and electrolytes. And of course, every patient uh uh uh must go to the theater with normoglycemia and normothermia, normal beta blockade and nomia. That means oxygen levels, oxygen saturation should be normal. So glucose should be normal. Otherwise hold on to the uh uh uh because the our n studies will not accept the patient if somebody's got a temperature. So you need to sort this out before you send the patient to the patient to theater. Of course HDU is you have to book HDU. And IC uhdu means that you will be doing all the follow up investigation everything IC, of course, the intensivist and his team will take over, but the intensivist will come and help you through the high dependency unit. We got only 15 minutes. I don't know how to finish this. Of course, there are what kind of surgery. So, minimal access therapy for uh, various colonic surgery, which is, uh, taking a, taking uh se polyp out doing, uh, doing a polypectomy, sle loop polypectomy, et cetera, uh endoscopic method of treatment. So, endoscopy is for diagnosis and treatment and the um prophylactic surgery. That's what we are doing for uh, um hereditary polyposis syndromes that we take the colon out and in the right aid you follow up and the, uh, uh, then of course, emergency surgery, patient come with obstruction and the uh uh you're allowed to carry emergency surgery. Um, and then elective surgery. Uh That's the one you should uh know quite well and also palliative surgery because it is inoperable cancer. You try and resect and debug the tumor but you cannot take uh the metastatic deposit, et cetera. Uh You just have to relieve the patients. Uh uh ok. So lo polypectomy and also il polyp you inject something underneath uh, something like uh saline. Um uh So flat lesion can be excised using either laser or, or, or various methods uh of endoscopic surgery. And of course, metabolic response trauma, please, uh make sure that you, uh get another lecture from somewhere, uh, or uh the, uh, know quite well about it because that is what we are laparoscopically. We're trying to minimize the signal. So the whole thing is the loop signal, uh detect uh processor and negative feedback. So that is the loop and the uh great of the signal greater the response. Therefore, therefore you give an epidural block, the, uh, uh, nociceptive, uh, uh, impulse into the going, uh, through the spinal cord into the hypothalamus. And also, uh, uh, give a less painful surgery with laparoscopic surgery, uh, uh, uh, in order to cut down the, uh, the, the, uh, the signal, the, the trauma, the, and of course, uh, the, uh, I, uh, he has a, uh, block the pathway that is why you give a epidural and the uh uh because the response starts because the patient is excited about surgery and the response and the all the uh uh uh all the uh uh the response starts even before starting the surgery. That's why you reassure the patient, you premed et cetera. And of course, the, during the first uh phase you have aldosterone, uh I'm running out of time. That's the problem here. Aldosterone and a DH you have to know that because you try and give less fluid. That's why uh the enhanced recovery program and the laparoscopic surgery all now we are trying to give less saline and also a DH antidiuretic hoon is liberated and aldosterone is liberated uh conserving sodium and water. So, during the perioperative period, you give uh just enough uh enough fluids. So, uh as I said, uh you need to really go through this, the uh carefully in recovery program is a new thing. Now, we, we try to feed the patient up to two hours before surgery, we give a lactose, uh uh drink, uh ch or drink two hours before, uh, and stop the saline ex uh excess for the reasons I just mentioned, right, uh, laparoscopic, uh why you give a new pneumoperitoneum, uh the uh for the patient to get to create space. And of course, ports are important and the uh the direct uh with, uh uh you have to see all the other ports coming through. We put the camera port through the umbilicus uh because it is a single layer. And uh so there are various way or ways of doing it. Uh introduce gas, carbon dioxide, more physiological, non inflammable gas. So, uh uh that is to again, to create, create space and you see the other ports coming through and the uh and you should really convert it if you cannot do it due to adhesions, a battle scarred abdomen, you may have to decide not to do uh laparoscopic surgery as well. Uh Prophylactic surgery, as I said is for uh uh gen PCC lymph syndrome and uh uh familial adenomatous polyposis. Uh uh this is the thing that uh they are definitely going to be converted into carcinoma. And of course, uh they have some desmoid tumors in the abdomen. You have to remove that as well. Uh uh maybe in the same sitting as well. So, Pete uh Pets Syndrome, um I did go through that. Uh and of course, uh uh this syndrome. You make sure that when you, during the follow up, you look into the breast as well. So a left-sided colon that is where you get, uh, go, got to do emergency surgery. Uh, I think we dis did discuss that last time and the, uh, when the patient come, you, uh, do APR, it must be done. Sometimes I see my registrars, there's nobody else in the team has done APR, uh, and the uh so they lift all the clothes and then try to do APR to see whether they missed the because they can't find the tumor inside the abdomen. So don't just take the patient uh without proper examination. Erect, chest is important. I will talk to you on Thursday about that and also plain film abdomen, not any erected abdomen. And we'll say why? Because our hospital won't love you to do uh uh ere just erect abdominal x-ray. Although in many parts of the world, they do still do that. So, uh co uh co contrast and, and CT scan should be done if you have time, I'm sure and never operate uh uh uh during the night because the whole team must be here. And that is uh very important. We stick to that. Uh Unless some fecal contamination is, you suspect uh preferably operation should be done during the daylight hours and the um the Harman's operation, uh we can talk about that uh uh when we do uh bowel obstruction um, so what we do in the surgery, lymphatic distribution of large bowel conforms with the arterial supply. You must take the whole of the, uh meso colon. Uh, the, the, this is a problem again, with junior doctors doing surgery, you must have at least 12 nodes in the specimen that we insist. Uh, because if you don't take enough notes, the patient will automatically have chemotherapy and sometimes unnecessarily and you will be blamed for that. So when you do that, make sure that uh you take enough adequate exertion of the uh mesocolon, same reason. Uh there is a rec there is a miso mesorectum just like the mesocolon, you got to remove that. So now we call it, we have to excise total mesorectum. Exertion tmetme is a, is a huge jargon nowadays. Um And the you must remove that. Now we used to put uh you may have seen the old surgeon still putting the hand behind the rectum and destroying the meso rectum and leaving most most of the tumor behind. And it's a disaster and almost it is now become criminal to leave the do that kind of. You just put your hand behind the rectum and just free it. So you should not do that. Now, we are even abolishing the coning. You can't cut sideways into the mesorectum. You go 10 around it and remove that. So, excision of the meso colon or mesorectum is very, very important and also not to damage the uh autonomic nerve, the hypogastric plexus superior or inferior in order to preserve sexual bowel sphincter uh pun functions. And that is why uh this part of surgery should be done with experienced people. Uh not to put patients into difficulties, right. Uh The nearly come to time and this is why MRI is important because uh this is the mis or rectum and this may have gone through. Uh then of course, you have to give neoadjuvant chemo radiotherapy uh in the, you may improve. Uh otherwise you will be having difficulties uh in the uh during surgery. So, uh due classification, you will be asked about that. It is in the wall and the er in through or just under the uh serosa and of course, going through the wall. So that is what is due classification if you want to describe it carefully. And of course, remember now, uh in your countries, the entry will be still in the books which is not there anymore. Uh Entry is taken off the list that used to be the epical epical node. We used to play with that in our registrar is uh looking for the epical node. We are not doing anymore because uh uh taking uh the inferior meric a artery flush does not improve the survival. So that's why we are not trying not to go after that and you have serious problems with vascularity. Uh And uh we have already spoken about that. So, um. Right. OK. Anyway, we have already done that. Uh, this is the barium enema appearance I showed you last time Apple co appearance and the core is the, is the colon and this is the tumor on either side, you can see that. And, uh, then of course, uh, we'll talk about this in the, uh, uh, lecture on, uh, Thursday again. Um, uh, this is what you see and it's important that you uh because if you are doing laparoscopically, you can't feel it and, and hold it in your hand. Therefore, it is important that the House Officer, Junior doctor make sure the colon lower end has been tattooed with the blue dye and a uh because you cannot really catch it, you can't feel it. So that's why uh I think I should have told you in that slide, the ABC D slide that you need to make sure that the colon is tattooed somewhere here so that you can take the because you cannot see. Sometimes the inside the tumor may spread this far, you see. So you need to make sure that it is tattooed clearly uh where the tumor ends. So you take about five centimeters clearance. Uh So um screening, I think I just talked a little bit about it already and this is the slide that I need you to remember. And of course, the screening main thing is the uh flexible sigmoidoscopy and also F four B uh uh fecal local blood and also nowadays, fecal immune, they do fecal immunological test called fit that may not be available in the developing country. So F four B and fit fecal immunological test. We are doing all the uh if, if they are positive two out of three, we do ba enema and colonoscopy. So uh uh don't need to go through that. So, right hemicolectomy uh is you take that colon uh uh because for a tumor like this and if it is tumor into transverse colon, we take it extended right hemicolectomy from, from here to here. So, because uh you must not do it here because of the uh of the terminal artery is incomplete here. You should not do that here. So, uh so you have to do an extended ectomy, colectomy. If the tumor is higher up lefty colectomy means that you take the, the middle colic, the, the left side artery and uh uh based on the, based on the right side artery for your vascularity, you take this side and do a anastomosis here. Uh Sigmoid Colectomy, it, it itself tells you what to do. OK. Um Harman's operation, we talked about that in uh uh resect the tumor, do an end. I first colostomy, close it come back and uh reanastomosis. So, so this is, this is a loop, ileostomy or loop colostomy. We don't do anymore except for anal carcinoma. We may do a little loop in the uh in the left eye at fossa. Uh but mostly it's done now, loop ileostomy for ultra low anastomosis. So this is an end, end ileostomy or end colostomy. OK. So, uh uh anterior resection you, you do from above uh you resect the, the, you remember those 12 centimeters of the, of the rectum and you take the uh upper one is high and anterior resection, low waist, uh low anterior resection. Not much low available, only about three centimeters available because we have to leave the last three centimeters of the rectum uh in order to uh uh in order to uh uh preserve the bowel function. So, uh so total mesal excision. This is the endo ultrasound. I talked to you about um and the uh the whole thing of colon should 10 taking out and you must never do coning higher, higher level, you can translate that higher, higher tumors but lower tumors. You have to take this, this, this plane. Now, we call it Holy Plane named after uh uh the surgeon Mister Hild. So coning must never be done because you may miss a carcinoma uh metastatic deposit. So, uh that's my daughter did this uh uh slide. So I don't know what you meant. OK. Anyway, so I think uh I managed to cover most of it is a loop in your stomach. And thank you. Any questions, we'll talk about a little bit more about bowel surgery during the uh uh during the uh uh uh uh intestinal obstruction on Thursday, isn't it? Yeah. Um You said the pr exam pr is divided into three parts. The first part is you look around the anus for fungus carcino all carcinomas. Then then was the second. No, you, you, you basically looked around to see whether there is any other pathology look for. You cannot miss any pathology, whether, whether you are going to look for a tumor or not, there may be fistulas, scars and all that, that should be all recorded down. Then you test the sphincter and, and then go in uh round and also uh then you get the patient to strain. Uh so that higher tumors even up to 89 centimeters may hit your tip of the finger like a little bit of grapes. So uh so it is important all the three stages followed for any, any pr examination and make sure please don't push it sideways. It's caused so painful when I was the registrar. The, the, the the most of the rectal uh patients usually come to me because they know that uh uh you have to give an informed consent to reassure them and then apologize at the end. This is a, is a nice thing to do. Ok. Thank you very much professor. Um Can I just have everyone to fill out the form sent in the feedback? And I'm so sorry that the lecture is just finished. We need to catch up on the next one. So thank you again for such an amazing lecture and I hope you have a lovely evening. The next lecture is very important and many people for us, I will show you some x-rays as well because that, that lecture, I think the questions are coming from that, uh especially looking at the xrays in the distal obstruction. OK. Thank you very much. Thank you very much again, everyone. Just please fill out the form again and I hope to see you in the next lecture. All right. Bye bye. Sorry.