During this 20-25 minute pre-recorded lecture, Dr. Steven Naymagon discusses the topic of occult GI bleeding. This in-depth review will provide an update on this topic for your clinical practice as well as supplement your learning for the ABIM Gastroenterology and Hepatology boards.
Hi everybody welcome to this session of the Mount Sinai intensive review and gastroenterology and hepatology uh session will focus on obscure G. I. Bleeding. Let's get started. The second session will be case based. We'll talk about several cases pertaining to the definitions differential diagnosis diagnosis of small bowel bleeding and management of small bowel. So case one A 75 year old man with diabetes, hypertension, coronary artery disease on aspirin is noted to have anemia on a routine annual examination. His work up reveals normal physical exam but positive occult blood. I am a little bit of 10.5 on MTV of 72 and a very 10 of eight. He has a normal colonoscopy and E. G. D. He has a capsule endoscopy which is also normal and he also undergoes cT and choreography which is normal. So what is the best way to classify this patient's presentation? Is it an upper gi bleed? Lower gi bleed. An obscure occult G. I bleed or an obscure overt G. I. This patient has an obscure occult gi bleed. So let's go over the answers. An upper gi bleed classically is defined as bleeding with a source identified above the ligament of traits. Whereas lower Gi bleeding is classically defined as coming from a site distal to the ligament of traits obscure Occult Gi bleeding as in this case has no identifiable source and no visible gi bleeding and presents with iron deficiency anemia or occult blood positive, stool, obscure overt gi bleeding has no identifiable source with visible bleeding such as melon. A hermetic asia. So the terminology has changed a bit in the last few years because the advent of new technologies such as capsule endoscopy, ct, entire ah graffiti and device assistant and torre Skopje has really allowed us to visualize all of this of all of the all of the belt. And the proposed definitions in the latest A CG guidelines are that upper gi bleeding should really be bleeding that's within the reach of an upper endoscope. And Kalanick bleeding should really be defined as bleeding. This within the reach of a kaleidoscope and small bowel bleeding um should be everything in between. Uh and that can be of course overt or a cult and obscure Gi bleeding should really be reserved for cases where a source cannot be identified despite complete visualization of the entire Gi tract and obscure Gi bleeding can of course be overt or occult as we saw in this case. So how common is small about bleeding? It's actually very rare E. G. D. And colonoscopy will identify that ideology of Gi bleeding in 90 to 95% of cases. So small bowel bleeding accounts for certainly less than 10% of all Gi bleeds. And a small bowel sources identified in 70 about 75% of cases of normal uh eight cases where there's a normally G. D. N. Colonoscopy so that really less than around 2.5% of cases will be classified as a true obscure G. I bleed. So just to sum up this case uh the term obscura Gi bleeding should really be reserved for patients not found to have a source of bleeding. After performing an E. G. D. Colonoscopy and small val evaluation and small bowel bleeding represents under 10% of all Gi bleeds. Moving on to Case two, A 42 year old man with no significant medical history presents with three days of Melania. On probing, he notes frequent episodes axis Starting in his teenage years, he denies use of an sets, He denies weight loss or other associated gi symptoms. His father also has frequent nosebleeds but there is no history of GI disease in the family. On exam, his vital signs are stable and abdomen is benign examination of his lips reveals several. Arab feminist molecules. Labs on presentation are notable for a hemoglobin of 9.2 and m. c. b. of 78. Which of the following is true regarding this patient's condition. It is caused by a mutation in the STK 11 gene. The most common ideology of anemia in this condition is chronic obscure G. I. Bleeding. It affects multiple systems including the G. I tract, lungs, liver and brain. It usually manifests in early childhood. The best answer here is it affects multiple systems including the Gi tract lungs, liver and brain. So let's go over the answers. The STK 11 gene usually is associated with fatigue syndrome. Whereas H. H. T. Which is what this patient has is caused by mutations in the E. N. G. A. C. V. R. L. One gene and smith for jean. The most common ideology of anemia in patients with H. H. T. Is actually chronic recurrent episode axis, not gI bleeding. Uh H. H. T. Mutations in vascular endothelial cells leads to tell inject asia's in the Gi tract, the lungs, the brain and the liver. So it's true that multiple systems are involved and most patients with HHC actually manifest with apis taxes in their teenage years rather than a child. So let's delve a little bit deeper into a hereditary hemorrhagic contact AsIA or Osler Weber randy syndrome is an autism most dominant disorder. There are several variants H. H. T. One H. H. T. Two and J. P. H. T. Which are caused by mutations in the genes listed here. Um It results from mutations in uh the end Oakland and Elk one proteins which are trans membrane glycoprotein expressed abundantly on vascular endothelial cells and mutations lead to the formation of vascular lesions in a variety of vascular beds. It's a rare disease but it is thought that it is under recognized and under reported the clinical manifestations are variable. So a lot of patients can have episode axis. Um You go cutaneous subject ASIA's and iron deficiency anemia patients can have severe nosebleeds. They can have Gi bleeding. They can have transfusion dependence, pulmonary BMS can lead to paradoxical, symbolic strokes and migrants cerebral A VMS can lead to hemorrhagic strokes and hepatic A VMS can lead to high output cardiac failure and liver failure. Okay this is usually not apparent at birth and A VM start to develop As the patient ages. With 70% of individuals manifesting symptoms by age 16 and 90% manifesting symptoms by age 40. In terms of gi manifestations. Recurrent gi bleeding occurs in up to one third of patients with H. H. T. Most commonly they present with iron deficiency anemia and less often with a cube Gi bleeding. And typically bleeding occurs in patients over the age of 40. A. B. M. S. Can occur throughout the G. I. Tract, although most commonly occur in the stomach and duodenum. The diagnosis is made using an international consensus diagnostic criteria which include spontaneous and recurrent tempest axis, multiple nico cutaneous subject. Asia's a characteristic sites visceral involvement in a first degree relative with H. H. T. If you meet three or more criteria. That is a definitive diagnosis, confirmation via genetic testing is possible, although it's not required to make the diagnosis and while this disease can cause potential morbidity, life expectancy is very good and there is interestingly a relative protection from certain cancers and a reduced risk of myocardial infarction in these patients in terms of managing Gi bleeding in these patients. The main state really is iron supplementation. Treatment of GHB Ems is not required in the majority of cases bleeding. A BMS may be treated endoscopic lee, although recurrence is essentially inevitable. Embolization surgery may be used in emergent situations but overall these have limited success due to recurrent disease. And there are also a number of medical therapies that are being investigated for bleeding in these cases. So one of the things I wanted to demonstrate with this um with this case was the differential diagnosis of small bowel bleeding and one of the best ways to classify this is by the age of the patients. So for young patients, the most common causes of small bowel bleeding are actually inflammatory bowel disease. To the file lesions cancers, Michael's diverticular and halitosis syndrome in older patients Or patients over 40 angelo dysplasia is and dual coalitions are most common. No pleasure and insert ulcers follow. And of course there's a long laundry list of rare causes of small bowel bleeding, including as a robber Rhonda, which we just discussed. Moving on to case No three, A 68 year old woman with hypertension is noted to have microscopic anemia on routine blood work. She denies noting frankly bloody or black stool. She denies associated gi symptoms. Weight loss, vaginal bleeding Hugh materia or any dietary restrictions. Her exam is only notable for pallor and chemical positive stool. Her iron panel is consistent with her deficiency. She undergoes E. G. D. And colonoscopy, which are normal. She is referred for further evaluation of her anemia, which diagnostic study is the next best step in evaluating this patient's iron deficiency anemia. And the best choice here is small bowel capsule endoscopy. So let's go over the answers. Push Honora Skopje has a far lower sensitivity than capsule endoscopy. And it's not the best choice here. Capsule endoscopy is usually the initial test of choice in the assessment of suspected small bowel bleeding. The diagnostic yield of over 60 radiologic studies are typically reserved for patients with acute active Gi bleeding. And the patients in this vignette had iron deficiency anemia and Occult G. I. Bill, device assisted an arthroscopy has a diagnostic yield that is very similar to capsule endoscopy. And since video capsule endoscopy is non invasive, it is the initial test of choice in this set in the senate. So what are the diagnostic options for assessing small bowel bleeding? And there are many, thankfully the american college of Gastroenterology put together a very nice guideline to help us uh choose the right modality. So the patient has suspected small bowel bleeding. Whether the occult or overt. The first decision to make is whether a repeat endoscopy is warranted and this will depend on clinical judgment and uh the quality and the timing of the prior exam. Once this is completed, uh we then proceed to a small bowel evaluation and the majority of the time this will be using capsule endoscopy. If there is no suspicion for bowel obstruction, absolute tosca P has a high diagnostic yield ranging from 40 to 80%. in various studies. A meta analysis of 10 studies found the pool diagnostic yield of 62%. In a systematic review of over 200 original articles involving almost 23,000 procedures Found a diagnostic field of 61%. However, if the capsule endoscopy is non diagnostic, a small bowel and choreography is recommended. So while it has been shown on multiple occasions that small bowel and choreography has a lower diagnostic yield overall than capsule endoscopy and devices that dangerous copy or small bowel bleeding. There is a setting in which it is superior and that is in the detection of small bowel tumors. In a admittedly small study of patients with known small bowel tumours, ct angiography detected 94% of lesions, whereas capsule endoscopy detected only 35% of legions. Thus a CG recommends that C. T. V. Should be performed in patients with suspected small bowel bleeding and negative capsule endoscopy because of higher sensitivity for the detection of mural based small bowel masses. Once your capsule endoscopy and enter an entire biography are done, specific management can be taken. However, if both studies are negative, the question is whether further evaluation is work. If the answer is no, it is very reasonable to observe the patients and treat them with iron supplements. If the answer is yes, one can consider repeat endoscopy, repeat capsule radiographic studies such as a medical scan or even proceeding to surgery in the appropriate clinical center. So to sum up case # three. In most cases of suspected small bowel bleeding, capsule endoscopy should be considered the first line diagnostic modality. Ct angiography should be performed in patients with suspected small bowel bleeding and negative capsule endoscopy. Because of higher sensitivity for the detection of mural based small bowel masses. Case for 84 year old man with a history of diabetes and stage renal disease and dialysis and coronary disease requiring drug eluting stents presents the emergency department with weakness and dark stool for the past week. His medications include aspirin and clopidogrel Admission, vital signs or blood pressure of 100 over 60 and a heart rate of 80. He has Melania on rectal exam. His hemoglobin is eight from a baseline of 10.5. The patient is stabilized and taken to the endoscopy suite. His E. G. D. Reveals gastric erosions with no clear source of bleeding. His colonoscopy is normal Over the next 24 hours, the patient remains stable but his blood counts continue to drift down slowly. A capsule endoscopy is performed revealing the following. In the mid to distill juna. What is the best modality for managing this patient's G. I bleed. The best answer here is device assisted and Terra Skopje. So let's go over the responses. Push arthroscopy would probably not reach the site of bleeding as identified. Be a capsule endoscopy in this case. Uh embolization requires a brisk bleed and has the potential for significant complications. So it would not be the best case and this is the best choice in this case device. Assistant Antara Skopje is the preferred modality for managing sub acute small bowel bleeding, identified on capitol and basketball. As as in this case an intra operative and to rosco p carries significant morbidity and mortality is reserved for factory cases not amenable to endoscopic or an geographic intervention. So when a patient has sub acute ongoing small valve bleeding, as in this case, the first step is of course to stabilize the patient. And then you can consider either a capsule endoscopy or radiographic study to try and identify the source of. And capsule endoscopy is actually a very good choice and has been shown to be very very sensitive in cases of uh of acute G. I. Bleeding in the emergent or urgent setting. The diagnostic yellow capsule endoscopy is quite high, device assisted and horoscope. You can also be considered in this case and as you can see, the diagnostic yield is actually similar to that of capsule endoscopy. However, the diagnostic yield goes up significantly if a patient has a previously positive capsule endoscopy, which is why capsule endoscopy is usually done before a small ballot Interros copy to help guide the intervention. So once you've done your capsule. If it's positive, you can proceed to enter a Skopje and hopefully treat the underlying lesion. And if the study is negative, one can then do radiographic studies or again consider surgery. In extreme cases Small Bell and Ross Copy has a diagnostic yield. As we mentioned, approximately 55%. And successful intervention can be performed between 40 and 70% of the time. It's a safe procedure with an overall complication rate of approximately one person. And as with capsule endoscopy and most things in life timing is of the essence. A study looking at 100 and 20 patients who underwent urgent versus non urgent capital and excuse me, device Assistant Honora Skopje found that an urgent exam yielded um more diagnoses was led to more endoscopic therapy. Also led to a higher overall therapeutic yield and a lower re bleeding. Right? The problem is, is durability. Most patients who undergo these treatments specifically for a VMS have a very high re bleeding rate with a lot of what some studies showing uh re bleeding rates of up to 50% within a few years. So to sum up case number four in a patient with suspected active small bowel bleeding capsule endoscopy should be considered prior to device. Assistant endoscopy. To increase diagnostic yield of the procedure and capsule endoscopy and devices insisted Antara Skopje to be performed as soon as possible. To maximize diagnostic yield. Case five, a 75 year old woman with coronary artery disease and atrial fibrillation presents with precinct p and Humenik Asia. Her medications include aspirin and warfarin Her vital science. Our blood pressure of 80 or 50 and a pulse of 110. Her abdomen is benign and she has a maroon stool and the rectal balls for hemoglobin is seven and I and our is 3.1. She's stabilized, receives a rapid bowel prep and undergoes E. G. D. And colonoscopy, revealing maroon and red blood throughout the colon and millions. No source of bleeding is identity. The patient continues to pass red blood and requires four units of blood over the next 24 hours. A. C. T. Angiogram is performed revealing the following what is the best modality for managing this patient's G. I bleed. And the best choice here is conventional angiography. Let's go over the answers again. Embolization pushing horoscope would not be a good choice here. Globalization is more effective in the case of a patient who has a positive bleed identified radio graphically and he would dynamically stable patients with acute active gi bleeding. C. T. Angiogram. Angiography is is indicated to guide further management and a positive C. T. Angiogram should be followed by conventional angiography with embolization and the embolization is more effective than endoscopy for managing active bleeding, identified radiographic and as we have mentioned before. Inter operative fonterra Skopje carries significant morbidity and mortality and it's really reserved for cases uh not amenable to endoscopic or and geographic concerns. So this patient has a brisk massive suspected small bowel bleed. The first step of course is to stabilize the patient and the next step is usually some sort of radiologic study. If this is positive patient can go on to a conventional angiography with embolization. In cases where a patient is truly unstable one can consider going directly to Andriana and of course if these studies are negative we can then consider and tyrus copy or surgery. T. T. I. Geography is actually a very sensitive and very specific modality for identifying small bowel bleeding. A negative CT angiogram implies cessation of bleeding or very slow bleeding with a negative predictive value of 88%. And watchful waiting may be a reasonable approach. In patients with a negative cT angiogram. The incidence of a positive angiography after a negative C. T. A. Is very low. So a negative C. T. A. Can spare patient and unnecessary angiography. So to sum up case five in hemo dynamically stable patients with evidence of active bleeding. Ct angiography should be strongly considered to identify the site of bleeding and further guide management. A positive cT angiography should be followed by conventional angiography and conventional angiography should not be used as a primary diagnostic mortality in the absence of significant bleeding. So to sum up in this section we've gone through five cases dealing with the management of obscure and small bala gi bleeding. Hope you found this helpful. Thank you for your attention and I wish you good luck
