Digestive System
Online Learning Platform

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 

In the guidelines they mention the increasing resistance of  Hpylori strains in the US to Clarithromycin (20-30%)  and Levofloxacin (approaching 40%) , therfore supporting antibiotics with much lower resistance rates (such as amoxicillin, tetracycline, and rifabutin that are all 5%)

That is why this guidelines say Clarithromycin- and levofloxacin-containing treatment regimens should be avoided in the absence of demonstrated macrolide and quinolone susceptibility, respectively.

Clarithromycin- and levofloxacincontaining treatment regimens remain an important option for selected patients, especially treatment-experienced patients with confirmed persistent H. pylori infection with strains that are known to be susceptible to these antibiotics

Vonoprazan is potassium-competitive acid blocker (PCAB) that inhibits the H⁺, K⁺-ATPase enzyme system in a potassium-competitive manner.    This is the same target as PPI but this class  of drugs  are acid-stable and thus do not require enteric coating or optimal dosing administration 30 minutes prior to meals , are more potent acid suppression, rapid onset of action, and long-lasting half-life.   Penicillin dual therapy was superior to lansoprazole-clarithromycin triple therapy among patients with clarithromycin-resistant H. pylori strains (70% vs 32%, P , 0.0001).

When treating with Vonoprazan + Amoxicillin, exceptionally we can add Clarithromycin as first line even in naive patients.

For standard colonoscopies,  ASGE  and ESGE  agree that it should be an overall > 25% (for men ≥30%, for women ≥20%)

The  BSG minimum standard is slightly lower to > 15% (aspirational 20%)

Based on this metanalysis of real life Colonoscopy findings in >3.5 million patients, this percentage are pooled to real life colonoscopies

This rate is for standard colonoscopies, does not take into account FIT/FOBT  positive patients (Positive faecal blood patients in bowel screening) in which the aspirational should be at least 40-50% of adenoma or cancer detection. (See report from bowel screening in the UK)

Even though only 10% of hep B infections will become chronic and we have an effective vaccination that can virtually prevent infection, the reality is that hepatitis B incidence and prevalence is very high.  WHO estimates that 254 million people were living with chronic hepatitis B infection in 2022, with 1.2 million new infections each year. Maternal-to-newborn perinatal transmission of the virus can be high (70 to 90% in HBeAg-positive-indicating high viral replication-, or 10% to 30% if the mother is HBeAg-negative )

Hepatitis C , despite easy to become chronic (80% of infections) and no effective vaccine, is less common, (Estimated 50 million worldwide) partly because the vertical transmission is low and also because the new  direct-acting antiviral (DAA) tablets are highly effective at clearing the infection in more than 90% , reducing transmission.

Misty mesentery refers to a non-specific radiological finding characterized by increased attenuation within the mesenteric fat on computed tomography  imaging.  It mimics mistiness as localised fat stranding in the mesentery.  Many processes can lead to the appearance including infiltration by inflammatory cells, oedema, lymphatic accumulation, haemorrhage, tumour infiltration, and fibrosis.  Tipically reflects mesentery panniculitis  ( rare  benign condition characterized by chronic inflammation  of adipose tissue mainly of the small bowel mesentery) But can be the results of any inflammatory or neoplasic process. That is why it is needed to consider also vasculitis, lymphomas, inflammatory process or GI neoplasia.

It is expected that up to 1 in 2 patients who are positive in faecal inmunochemistry test  (FIT) can have pathology (polyps or cancer) This can be seen in  results such as the QUALISCOPIA group or the UK bowel screening  report

The lower cutoff for FIB 4   >1.3.  Less than 1.3 rules out advanced fibrosis, and >1.3 needs further investigations.

In elderly patients (>65 yo) this threlsholds has low especificity (many false positive patients who do not really have advanced fibrosis) therefore the cutoff proposed in those is 2 (Fib 4 <2 rules out significant fibrosis)

>2.67 is the upper threshold for advanced fibrosis. Patients scoring this have high chance of advance fibrosis and should be referred to liver clinic

Audit C score has 3 questions and if score is 5 or more, should prompt the full AUDIT of 10 questions.  Most questions ask about the past year alcohol habits. In a full AUDIT , any 15 or above represents high risk of alcohol dependence.

Number 3 is correct but not universal. A standard drink in US contains 14g, 10g in many EU countries and 8g in the UK. EASL advices to standardise to 10g (1 unit) but this is down to the individual countries. https://auditscreen.org/

Difficult case with patient older than 65 and comorbidities with moderately to severely active ulcerative colitis.

Vedolizumab should be indicated in his case as it performs better than anti TNFs in ulcerative colitis, confirming the results of the Varsity study.   ( Over a 5 year period, drug persistence is higher in patients treated with vedolizumab as compared to anti-TNF therapies and loss of response is less frequent again in the vedolizumab group). Age or previous TIA /AV block are not contraindications for anti-TNF (only Moderate-severe heart failure, which is not the case) So even though Adalimumab would be a valid option, it should be ideally used if Vedolizumab fails.

JAK inhibitor (Tofacitinib) should not be prescribed in people with a history of cardiovascular disease (eg. heart attack or stroke) at increased risk of cardiovascular problems (eg. current or past long-time smokers) at increased risk of cancer or aged 65 years and over unless no suitable alternative

Ozanibod could be an oral alternative , however second-degree Mobitz type II atrioventricular (AV) bloc and TIA within the previous 6 months contraindicates its use.

Off the quizz options, another good one would be Ustekinumab (interleukin 12&23 antagonist drug ) as not contraindicated here and equally valid to Vedolizumab.