Bleeding
Per-Olof Nyström
“It’s not bleeding until you can hear it bleeding.”
(Gail Waldby)
“Massive bleeding” is defined as “exsanguinating” or hemodynamically significant bleeding, which persists and requires at least 4 units of blood over a period of 24 hours.Fortunately, truly massive bleeding from the colon and rectum is unusual. The vast majority of episodes of lower gastrointestinal bleeding (LGIB) are self-limiting and not hemodynamically significant. As with all types of gastro- intestinal bleeding, never neglect it or think it is trivial until a period of vigilant observation tells you whether the bleeding is minor or major, whether it is likely to have ceased or is protracted.
Sources of Bleeding
Probably, many episodes of overt colonic bleeding never have the precise site and cause established. Often the bleeding is assumed to originate from an already known pathology. Later, when the bleeding episode is over, a diagnostic workup may reveal a previously unknown pathology as the cause or suggest, in retrospect, a lesion that may have been the source.> Table 27.1 shows the most common causes (without ranking their relative frequency).
Table 27.1. Causes of colorectal bleeding
Neoplasm
Inflammatory bowel disease
Diverticulosis – diverticulitis
Ischemic colitis
Vascular malformation – angiodysplasia
Hemorrhoids
Postoperative – anastomotic
Meckel’s diverticulum
Infectious
A short comment about the causes mentioned in the table may help you to choose the most likely cause in your next patient with colonic bleeding. Neoplasms, whether cancer or benign polyp, rarely bleed massively but often have occult bleed- ing that can produce significant anemia.Rectal cancer commonly bleeds overtly and if associated with anemia it can at first suggest a massive bleed until rectoscopy is performed.The patient with rectal cancer will give a history of tenesmus and usually there will have been episodic minor bleeding with the stools for some time. Bleed- ing in inflammatory bowel disease (IBD) is almost never the first symptom of the disease and is rarely massive (> Chap. 24). The diagnosis will be known in most such patients and the bleeding is associated with an exacerbation, where diarrhea precedes the bleeding by several days. The exception is proctitis, which may present with bleeding, again easily identified at rectoscopy. The differential diagnosis of proctitis includes infections such as Campylobacter or amebiasis. The onset is then more sudden, with diarrhea and bleeding beginning together just a few days pre- viously. Radiation proctitis may bleed significantly but here the history is obvious.
Diverticulaof the sigmoid colon are assumed to be the commonest cause of acute major LGIB.By nature it occurs more often in elderly patients, and particu- larly in those taking non-steroidal anti-inflammatory drugs (NSAIDs) or anti-coa- gulants. In middle-aged patients and also elderly patients, with an unknown reason for hemorrhage you must consider mucosal angiodysplasia as the possible expla- nation. The bleeding can be massive and recurrent. In elderly patients ischemic co- litiscan rarely present with massive bleeding. Postoperative bleeding from colonic anastomoses,polypectomy site,or after anal surgery,should be easily identified.And finally, do not forget that internal hemorrhoids may bleed copiously: you do not want to diagnose an anal source at laparotomy.
Diagnosis
We find it very annoying to consult on bleeding patients where the referral note simply states: “Patient has melena”. Anything can hide behind such a note. It tells us that not a lot of thought was invested in this request.There are two very pow- erful tools to help you: the patient’s history and the rectoscope. First, find out whether the blood is pink-fresh blood, or maroon-almost-fresh blood. These two represent hematochezia (bloody stools) and signify a colonic (common) or small bowel (rare) source. We must not remind you that tarry black stools of melena signify an upper gastrointestinal (UGI) source above the ligament of Treitz
(> Chap. 16). Remember that with massive UGI hemorrhage, and rapid intestinal
transit, unaltered fresh blood may appear in the rectum. Insertion of a nasogastric tube with gastric irrigation may quickly direct you to a gastric bleed but remember that bleeding duodenal ulcers may not show blood in the stomach (> Chap. 16).
Rectoscopy
For all cases of hematochezia rectoscopy is the first step. It is amazing how often this step is omitted in “modern” practice – how often we see patients im- mediately referred instead for a “panendoscopy”.Use a rigid rectoscope because the flexible instrument will be coated rapidly with blood and you will see nothing. Have a good suction device available. It is not unusual to discover that there is simply too much blood to really see anything (> Fig. 27.1). If blood can be aspirated and you do get to see the rectum, simple things like a rectal cancer or proctitis should be obvious. Do not decide on a diagnosis of proctitis too lightly because the mucosa may look all red from the fresh blood. The mucosa should be swollen and there should be no visible mucosal blood vessels. The proctitis is often so distal that the margin between inflamed and normal mucosa can be seen. The redder the blood is, the closer to the anus is the source.Bleeding from the upper anal canal and lower rectum will reflux at least to the recto-sigmoid junction, so do not be fooled by finding fresh blood at that level.If you have a good view, when there is not too much bleeding, fresh blood may be seen flowing on the wall or dripping from above – in which case bleeding from a more proximal source is likely. Quite frankly, in patients with active bleeding you won’t be able to see much at rectoscopy.But at least you have the opportunity to exclude an anal source and to observe personally the character and magnitude of the bleeding.
Let us forget, at this stage, the majority of patients in whom the bleeding stops spontaneously. They will be further investigated with a colonoscopy performed in
Fig. 27.1. “Hey, are you sure that all of this is coming from above?”
a well-prepared bowel. Let us concentrate instead on that problematic minority of patients – those bleeding massively or continuing to bleed. In such patients more aggressive means will be needed to establish and treat the source of the bleeding.
The “Sophisticated” Means of Diagnosis
There are two means of diagnosis in this situation: technetium-labeled erythrocyte scanand mesenteric angiography. Which of the two should be chosen roughly depends on the intensity of the bleeding. The more profuse the bleeding, the better it is to start with angiography. Not only will it define the site of the bleeding but also the bleeding vessel may be treated by embolization through the angiographic catheter. Both investigations require that the patient is bleeding actively; do not waste the radiologist’s time with a non-bleeding patient.
The Operation
This is how to proceed if you elect to perform a laparotomy on a patient who fails to settle. Make a quick examination of the colon to exclude obvious pathology.
Then inspect the small bowel, which may contain blood even if the bleeding comes from the right colon, although it would be unusual for the blood to regurgitate throughout the entire small bowel. If you find blood in the upper small bowel, direct your investigation to the UGI tract. Blood in the right colon, but not small bowel, does not definitely identify the bleeding as being in the right colon because blood will regurgitate long distances in the colon. Make your guess based on what you find because now comes the really difficult part.Are you going to take a chance on a right or left colectomy? Do you trust the pre-operative localizing studies-if performed?
Or can you identify the bleeding spot with certainty? Not even if you open and clean the colon can you be sure to see the bleeding site. It is messy and takes time, which is a reason why traditional teaching proposed the “blind” right hemicolectomy (assuming angiodysplasia as the cause).There are instances when the colon is so full of blood that a total or subtotal colectomy is advisable. Temporary clamping of the three main vessels to the colon will reduce the bleeding while you mobilize the colon.
A Pathway to Reason
The experience with,and perception of,LGIB differs slightly from one surgeon to another. This is understandable if one realizes that all published data on this topic represent retrospective studies on poorly stratified patients. So this is what we think:
Let’s face it – in nine-tenths of patients with LGIB,the bleeding stops spontane- ously.Emergency localizing tests are unnecessary in this group; elective colonoscopy is indicated. Hysterical MDs tend, however, to over-investigate this group – jumping on them with isotope scans and angiograms – all useless when the hemorrhage is not active.
Each of us operates perhaps once or twice a year on “massive” lower LGIB (> 4–6 units bleed over 24 hours, which continues). Therefore, the collective experience of each hospital is small – not allowing any meaningful prospective studies. All that is published on this subject is therefore retrospective and biased by local dogma and facilities.
Reports by radiologists boasting about high accuracy rates of isotope scans and angiography are often meaningless, because such reports do not discuss the clinical benefit of such accuracy; i.e. did it change the management and how?
Most “massive” LGIB in elderly patients is either from colonic diverticula (in the left or, less commonly, the right colon) and angiodysplasia (usually of the right colon).True,angiodysplasia lesions are common but we do not know how often they bleed. It is our impression that colonoscopists often over-diagnose these lesions as the source after the hemorrhage has ceased,whereas the true source of bleeding was elsewhere (e.g. diverticular).
Based on the above considerations this is how we would approach a LGIB:
Start with supportive care. Exclude UGI bleeding. There is no need for a routine UGI endoscopy, as fresh blood per rectum in a stable patient means that the source is not in the UGI tract. Do a rectoscopy to rule out an anorectal source.
When the patient requires the second and third unit of blood it is time to get a little excited. Angiography at this stage is indicated – if it localizes the source of bleeding in the left or right colon so much the better. If it fails – not a big deal.
Isotope scan requires time and is clinically almost useless in actively bleeding patients. Blood migrates within the lumen of the colon and so does the extra- vasated isotope. We do not value this investigation. (Nuclear medicine = unclear medicine).
When the patient is on his fifth or sixth unit and blood is still dripping from his rectum – it is time to take him to the operating room. If angiography has local- ized the source in either the left or right colon we do a segmental colectomy – either right or left hemicolectomy. If angiography is not available or is non-localizing, we do a subtotal colectomy with ileo-rectal anastomosis.“Blind” segmental colectomy may produce a re-bleeder who won’t tolerate a major re-operation.
A few authors have described intra-operative colonoscopy after “on-table”
colonic lavage.Theoretically it appears attractive but practically it is messy and time consuming. If the hemorrhage has stopped it won’t show us much; try and see what an angiodysplasia is and what just some old clotted blood is.
There is no doubt that in practice we are over-investigating these patients and often waiting too long prior to operation. The bleeding either stops or continues;
when it continues you must operate – on a well-resuscitated patient who has not been allowed to deteriorate in a medical ward. A fast subtotal colectomy is a safe, definitive, and life-saving procedure.
Whether we are right or wrong depends on which papers you read, on what you believe,your local facilities and your own philosophy.We hope you’ll adopt ours.
Beware: in lower gastrointestinal bleeding, removing the wrong side of the colon is embarrassing. Removing any segment of the colon while the bleeding source is in the anorectum is shameful.
