Digestive System
Online Learning Platform

This is a healthy patient wihout history of mental health illness or impaired cognitive issues.  Age and sex may suggest EoE or peptic stricture as possible etiology.

As there is no suspicion of intentional multiple foreing body ingestions, x ray would not be necessary. (Xray can be very useful to guide us when radiopaque objects have been ingested, to see whereabouts in the GI tract they may be lying)  As there is no subcutaneous emphysema or abdominal pain or guarding to suggest any perforation , a CT scan would not be needed.

As per the timing, ASGE  recommends emergent endoscopy for complete esophageal obstruction. ESGE   recommends emergent (preferably within 2 hours, but at the latest within 6 hours) gastroduodenoscopy for foreign bodies inducing complete esophageal obstruction, and for sharp-pointed objects or batteries in the esophagus. The cough and sialorrhaea suggest a complete obstruction.

They recommend urgent (within 24 hours)  for other esophageal foreign bodies without complete obstruction 

AGA-For patients with suspected non bony food bolus impaction without complications (eg,no evidence of perforation or respiratory distress),endoscopy may be performed without obtaining radiographs.

Glucagon 1mg iv can be given to induce esophageal relaxation and try and avoid urgent endoscopy, however it should not delay endoscopy and definetely we do not need 6-10 hours to see if it works.

It has always been agreed that High grade dysplasia should merit ablation, however clasically LGD would be offered endoscopic surveillance until progressed to HGD. This approach has changed over the last years to the point that Both ESGE and AGA suggest eradication with ablation to prevent progression to HGD/cancer. BSG recommends repeating endoscopy in 6 months and if confirmed again, offering eradication vs 6 -monthly surveillance.  The AGA 2024 guidelines favous ablation over surveillance.

All societies agree that he biopsies should be reviewed by an expert pathologist (ESGE suggest 2 experts) before embarking into eradication.  Remember that the incidence of progression (to HGD or adenoca) is estimated around   9.1%/year  with reported incidence of adenocarcinoma of 0.54% per year. The overall yearly incidence of Eosphageal adenocarcinoma is 0.3% (0.19 in short segment )

High Amplitude propagating contractions (HAPC)

• HAPC, Defined by high amplitude (variable threshold among studies) and presence of propagation; amplitude is higher in the prepped than unprepped colon
•  from 50-100, can reach up  to 200 mm Hg, they last 20 to 30 seconds, approximately 6 times a day, with a range of 2 to 24 daily.
• Occur spontaneously, in response to pharmacological agents or colonic distention
• Increase upon awakening, are much more common during the day, and increase after meals
• A majority originate in the proximal colon; most do not propagate beyond the midcolon and fewer than 5% reach the rectum
• Can transfer colonic contents over long distances, can be associated with internal anal sphincter relaxation, and can precede defecation

Low amplitude (Haustral Contractions)

• Slow, segmenting movements that further mix chyme.
• About every 30 minutes.
• (5 to 40 mm Hg) 3 seconds
• Occur in haustra: small pouches caused by the teniae coli (longitudinal smooth muscle ribbons that run along outside the entire length of the colon). Because they are shorter than the large intestine, the large intestine tucks between the teniae and form sacs
• Primarily occur in ascending and transverse colons.
• Produced by contractions of smooth muscle layer

Both the low- and high-amplitude contractions are promoted by physical exercise as well as by emotional stress.

It is known that HAPC reduce  over time in elderly patients, and also are notoriously reduced in frequency in those wih chronic constipation. Opposingly they are increased in diarrhoea type IBS.  Low amplitude are worse understood, and despite increasing with age, they do not usually change the transit time.

Source

Source 2

Anatomy and Physiology of the Pelvic Digestive Organs
Ursula Szmulowicz MD, in
Posterior Pelvic Floor Abnormalities
, 2011

-MRCP does not usually require contrast.  The technique enhances any fluid  (the normal fluid which is present in the biliary and pancreatic ducts) as an intrinsic contrast medium by using heavily T2-weighted sequences. T2 potentiate water , therefore this structures will appear hyperintense against the surrounding non-fluid-containing tissues. We can see structures like stomach or duodenum being also bright due to the fluid content.

-Gadolinum is the typical MRI contrast causing brigher T1-weighted images , helping detection of focal lesions (e.g. tumor, abscess, metastasis) venography or calculating MR perfusion parameters.

-Omnipaque® is a low-osmolar iodinated contrast media is indicated for intravenous, intra-arterial or  oral use. Iodine-based contrast are often used in CT scan.

-SonoVue ® is a constrast based on sulphur hexafluoride microbubbles , which used is mainly on contrast-enhanced ultrasound imaging. Bubbles are extremely small—smaller than a red blood cell—and have a high degree of "echogenicity", reflecting ultrasound waves. Structures with higher echogenicity will be brighter on ultrasound.  The microbubbles dissolve, usually within 10 to 15 minutes, and the gas within them is cleared from the body through exhalation.

Andexanet is factor Xa inhibitor which is approved to reverse Rivaroxaban and Apixaban. However, it has not being proved to be efficacious against Edoxaban. Dabigatran is  a direct thrombin (factor IIa) inhibitor, not a Xa inhibitor.

Kudo II (asteroid or stellate pits) which are star or cross-shaped.  This is very typical of hyperplastic polyps (non neoplastic)  or serrated lesions.

The proportion of AST to ALT in hepatocytes is about 2.5:1, but because AST is removed from serum by the liver sinusoidal cells twice as quickly (serum half-life t1/2 = 18 hr) compared to ALT (t1/2 = 36 hr), so the resulting serum levels of AST and ALT are about equal in healthy individuals, resulting in a normal AST/ALT ratio around 1. See here.

B6 is more essencial for ALT synthesis than AST, that is why in chronic alcohol (low B6) we will see a reduction of ALT in proportion to AST, increasing the AST/ALT ratio>2

Underwater EMR is a technique in which instead of gas, the colon is insuflated with liquid (usually water, less common saline). The water makes the mucosa 'float' by reducing the wall tension and this separates the layers of the mucosa-submucosa naturally without injecting lifting solution.  This makes flat polyps easy to get grasped. Scar appears small after resection, but when water is aspirated and air insuflatted, one can see the scars are usually much bigger than they appear with water.  See this image from Spadaccini et al 

This is likely a lower GI bleed, however, the fact that is so abrupt and has caused   haemorrhagic shock makes us wonder if he is not having a severe upper GI bleed – frail patient taking clopidogrel - Severe upper GI bleed sometimes can be so brisk and profuse that blood travels the intestine fast wihtout being digested, so patient passes per rectum red bright blood instead of black melaena. (Blood is laxative too) As many as 10–15% of patients suspected initially to have lower GI bleed are ultimately found to have an UGI source.

Once OGD is done and clear, the next step should be depending on the clinical and hemodinamic status. Either prepare the patient for colonoscopy/ video capsule (If clinically stable)  or repeat CT angio (If clinically worse)-->If bleeding point is located and there is no access to IR (interventional radiology) the surgeons may want to proceed with exploration and colectomy but this is the last resource as obviously this is an elderly patient with cardiovascular factors (Clopidogrel) whose surgery would be high risk of mortality and morbidity.