Gastric endoscopy

Endoscopic examination of the esophagus, stomach, and duodenum is performed using a flexible device with a high-definition camera. Modern systems allow for detailed examination of the mucosa, targeted biopsies, treatment of bleeding, removal of small polyps, and dilation of stenosis. The quality of the examination directly impacts the detection rate of early cancer and precancerous changes, so special attention is now paid to the quality standards of the procedure and photographic documentation of key landmarks. [1]

The purposes of gastroscopy are divided into diagnostic and therapeutic. Diagnostic purposes include identifying the causes of pain, heartburn, dysphagia, and anemia; identifying ulcers, erosions, and foci of intestinal metaplasia; and assessing the consequences of Helicobacter pylori infection. Therapeutic goals include stopping non-variceal bleeding, clipping vessels, coagulation, injections of adrenaline-containing solutions, use of hemostatic powders, dilation of strictures, and removal of foreign bodies. Early interventions reduce the risk of complications and rehospitalizations. [2]

An important concept in recent years is "examination, not just performance." This means sufficient time for inspection of all areas and mandatory photographic documentation. For initial diagnostic gastroscopy, a minimum of 7 minutes of pure examination time is recommended, and for monitoring intestinal metaplasia and Barrett's esophagus, even longer, with step-by-step image capture. This increases the detection of small and flat lesions. [3]

Additionally, the role of enhanced imaging technologies is growing. Narrow-spectrum imaging, digital texture and contrast enhancement, and, if necessary, solution staining allow for more precise differentiation between benign and suspicious areas and the selection of biopsy sites, improving diagnostic accuracy without significantly increasing procedure time. [4]

When is gastroscopy really indicated?

Common indications include dysphagia and odynophagia, "red flags" of dyspepsia, upper gastrointestinal bleeding, unexplained iron deficiency anemia, weight loss, recurrent vomiting, persistent heartburn with proton pump inhibitor-resistant heartburn, suspected celiac disease based on laboratory tests, monitoring of precancerous conditions, and post-endoscopic tumor treatment. The threshold for referral depends on age, risk factors, and noninvasive Helicobacter pylori testing results. [5]

For uncomplicated dyspepsia in individuals under 60 years of age without red flags, initial management typically includes a test-and-treat strategy for Helicobacter pylori infection or a trial course of a proton pump inhibitor; endoscopy is deferred until this strategy is ineffective or warning signs develop. In older age groups and in patients from high-risk families, endoscopy is indicated earlier. [6]

Monitoring of precancerous conditions of the stomach is a separate priority. When atrophic gastritis and intestinal metaplasia are detected, the frequency of follow-up endoscopies is determined based on the histological stages according to the OLGA and OLGIM systems, which correlate well with the risk of gastric cancer and help plan monitoring. [7]

Finally, gastroscopy is indispensable in acute non-variceal bleeding from the upper gastrointestinal tract. Early endoscopy within the first 24 hours, and even earlier in unstable cases, reduces the risk of rebleeding, allows for risk stratification, and allows for treatment decisions. [8]

Table 1. Frequent indications for gastroscopy and the level of practical urgency

Clinical situation	Approximate timeframes
Suspected acute upper bleeding	In the first 24 hours, if unstable - urgently
Dysphagia, odynophagia	In the coming days
Dyspepsia with "red flags"	In the coming weeks
Persistent heartburn with ineffective therapy	As planned
Iron deficiency anemia of unknown origin	Planned with biopsies
Monitoring for intestinal metaplasia or atrophy	According to an individual schedule

[9]

Contraindications and risk assessment

There are few absolute contraindications: patient refusal, high risk of perforation with an unstable wall, and severe hemodynamic instability before stabilization. Most situations are relative and require preparation: severe respiratory failure, severe uncorrected coagulopathy, incomplete fasting, high risk of aspiration, and pregnancy with threatened miscarriage. The decision is made by a multidisciplinary team, taking into account the balance of benefits and risks. [10]

Particular attention is paid to the use of antiplatelet and anticoagulant medications. For low-risk procedures, including diagnostic gastroscopy and biopsies, continuation of most antiplatelet medications and warfarin is generally acceptable. However, for high-risk interventions, temporary discontinuation is preferable in consultation with a cardiologist. Decisions are individualized based on thrombotic risk. [11]

Patients with obesity, sleep apnea, or severe comorbidities more often require enhanced monitoring and a well-thought-out sedation strategy. Current standards emphasize the importance of assessing respiratory risks and being prepared to immediately manage them. [12]

In recent years, the effect of glucagon-like peptide 1 receptor agonists on gastric emptying delay and the risk of aspiration has been debated. A 2024 consensus of professional societies indicated that most patients can continue therapy with risk-reducing measures, such as a liquid diet the day before and fasting. The final decision is made jointly by the anesthesiologist and endoscopy team. [13]

Preparation for the study: fasting, medications, cleansing the mucous membrane

Standard fasting intervals before a scheduled gastroscopy are at least 2 hours for clear liquids and at least 6 hours for light solid foods. These intervals reduce the risk of aspiration and improve visualization. In children, fasting intervals may vary and are determined by individual protocols. [14]

If possible, proton pump inhibitors should be discontinued two weeks before a scheduled Helicobacter pylori biopsy, and antibiotics and bismuth preparations should be discontinued four weeks beforehand, otherwise the risk of a false-negative result increases. After eradication, a urea breath test or a fecal antigen test should be used to confirm cure after four weeks or more. [15]

Simple premedication to improve visibility prior to examination is increasingly being used: simethicone as an antifoam and acetylcysteine as a mucolytic. Randomized trials and prospective cohorts have shown improved mucosal clarity scores without increasing adverse events, facilitating the detection of small lesions. [16]

On the day of the procedure, it is important to clarify medications, sedative tolerance, and any allergies. When using glucagon-like peptide 1 receptor agonists, the endoscopy service will discuss with the anesthesiologist the risk of delayed gastric emptying and possible precautions. [17]

Table 2. Fasting before gastroscopy

Product	Minimum interval
Clear liquids	2 hours or more
Light solid food	6 hours or more
Fatty foods or large portions	8 hours or more

[18]

Table 3. Medications and tests for Helicobacter pylori

Situation	What to do	Why
Biopsies for Helicobacter pylori are planned.	Discontinue proton pump inhibitors for 2 weeks	Reduce the risk of false negative results
Recent antibacterial therapy or bismuth	Wait 4 weeks for the follow-up test	The indicators are normalizing
Confirmation of eradication	Breath test or fecal antigen no earlier than 4 weeks	Reliability of control

[19]

How a Gastroscopy Works: Anesthesia, Sedation, Monitoring, and Quality Standards

The procedure is performed under local anesthesia of the oropharynx, with sedation as indicated for comfort and to reduce the gag reflex. Sedation options include benzodiazepines with opiates, propofol with monitoring, or without sedation as desired and appropriate for the task. Oxygen saturation, pulse, and blood pressure are monitored during and after the procedure. During deep sedation, respiration is monitored via capnography, and airway management is assessed. [20]

Minimum quality requirements include a minimum of 7 minutes of dedicated examination time, step-by-step photographic documentation of anatomical landmarks, mandatory documentation of the location and number of biopsies taken, and the inclusion of photographs in the report. These steps improve the completeness of documentation and the reproducibility of observations during subsequent follow-up. [21]

Enhanced imaging technologies—narrowband imaging, digital texture and contrast enhancement, and optical magnification—help visualize the vascular-superficial pattern, identify flat lesions, and refine their boundaries before endoscopic treatment. When suspicious areas are identified, targeted biopsies are performed using visual guidance. [22]

If necessary, the following therapeutic interventions are performed during a single session: injection therapy, thermocoagulation, clipping, application of hemostatic powder, and stricture dilation. The choice of method depends on the source of bleeding, the size of the lesion, and the availability of equipment. [23]

Table 4. Sedation levels and monitoring

Level	Main characteristics	Monitoring
Without sedation	Complete preservation of reflexes	Pulse oximetry according to indications
Light sedation	The answer to the voice has been saved.	Pulse oximetry, blood pressure monitoring
Moderate sedation	Reaction to handling and mild irritation	Pulse oximetry, pressure, readiness for respiratory support
Deep sedation	Reaction only to pain, risk of respiratory depression	Pulse oximetry, blood pressure, most often capnography and readiness for ventilation

[24]

Table 5. Quality control of gastric endoscopy

Parameter	Minimum
Net inspection time	7 minutes or more
Photographic recording of key points	Yes, in the report
Biopsy site marking	Required
Using the Picture Enhancement Mode	According to the readings
Informed consent and comfort assessment	Required

[25]

Biopsies: protocols, Helicobacter pylori, cancer risk stratification

If gastritis and precancerous changes are suspected, updated mucosal mapping principles are followed. The "Updated Sydney" system requires at least five biopsies: two from the antrum, two from the body of the stomach, and one from the angle. This increases sensitivity to focal changes and allows for the assessment of inflammatory activity, atrophy, and intestinal metaplasia. [26]

The OLGA and OLGIM scores, which summarize the degree of atrophy and intestinal metaplasia by region, are used to stratify cancer risk. High stages, especially III and IV, are associated with a significantly higher risk of progression, which justifies regular monitoring at specified intervals. In recent years, meta-analytic data have accumulated, confirming the prognostic value of staging. [27]

Diagnosis and eradication of Helicobacter pylori remain the cornerstone of peptic ulcer prevention and cancer risk reduction. The Maastricht Consensus emphasizes the importance of selecting regimens based on resistance and subsequent confirmation of eradication with a valid test. During endoscopy, biopsy tests are complemented by histology and can be combined with noninvasive tests. [28]

For unclear or focal changes, extended imaging and targeted biopsies are included, which reduces the risk of missing dysplasia. The report must include the exact location, number of fragments, and separate fixation of the material in jars to ensure the pathologist provides the most informative conclusion. [29]

Table 6. Sydney Renewal mapping and staging

Step	What to do	For what
Take 5 standard biopsies	2 antrum, 1 angle, 2 body	Basic assessment of gastritis
Evaluate Helicobacter pylori	Test and histology	Eradication tactics
Calculate OLGA and OLGIM	According to the pathologist's conclusion	Cancer risk stratification
Determine the observation interval	By stage and clinical presentation	Personalization of control

[30]

What can a gastroscopy show and how do they act upon its findings?

For erosions and ulcers of the stomach and duodenum, endoscopy determines the depth of the defect, the presence of bleeding stigmata, the need for hemostasis, and subsequent antiulcer therapy. For active bleeding, combined methods are used, such as injection and mechanical clipping. Topical powders are considered a life-saving treatment when standard methods are ineffective. [31]

When foci of intestinal metaplasia and atrophy are detected, a surveillance plan is developed based on stages, including intervals for repeat endoscopies and targeted biopsies. The use of enhanced imaging improves the accuracy of detection of dysplasia and early cancer, which is important for timely endoscopic treatment. [32]

Small polyps can be removed during the same procedure with subsequent histological confirmation. If submucosal lesions are suspected, additional imaging techniques and biopsy are performed, taking into account the risk. In each case, detailed photographic documentation before and after the procedure is important. [33]

For non-variceal bleeding, timing before endoscopy, adequate preparation, and choice of hemostasis method determine outcomes. Pre-procedural erythromycin infusion, if indicated, endoscopy within the first 24 hours, and combination treatments for high-risk ulcers are recommended. [34]

Table 7. Non-variceal bleeding: endoscopic tactics

Situation	Recommended tactics
Active spurting bleeding or visible vessel	Combination of injection and mechanics or thermal application
Hemostatic success is questionable	Supplementation with hemostatic powder
The risk of rebleeding is high	Intensive surveillance, proton pump inhibitors, early control

[35]

Risks and complications: how to minimize them

Common adverse events include transient sore throat, bloating, and short-term nausea. Rare complications include aspiration, hypoxia due to sedation, bleeding after biopsy or polypectomy, and perforation. The risk is reduced by fasting, appropriate sedation, high-quality monitoring, and clear indications for the procedure. [36]

In patients on anticoagulants and antiplatelet agents, bleeding prevention involves individualizing the discontinuation or continuation of medications and meticulously stopping bleeding during interventions. When planning high-risk interventions, decisions are made in consultation with the attending physician, taking into account cardiac risks. [37]

In groups at increased risk of respiratory complications, including obesity and sleep apnea, preliminary airway assessment, supplemental oxygenation, use of capnography, and preparedness for respiratory support are helpful. This is reflected in current sedation guidelines. [38]

Transparent communication, informed consent, and discussion of alternatives help reduce anxiety and increase patient satisfaction, which also improves the tolerability and quality of the procedure. [39]

Table 8. Prevention of complications at each stage

Stage	Key measures
Before the procedure	Checking fasting, medications, risk factors
During	Adequate sedation, monitoring, sufficient examination time
After	Observation until stability, written recommendations
Special groups	Individual plan with an anesthesiologist and attending physician

[40]

What to do after a gastroscopy and when to seek help

Following a diagnostic gastroscopy without sedation, patients can usually immediately return to normal activity, avoiding hot drinks until throat sensitivity has returned. If sedation was used, supervision and activity restrictions are required on the day of the procedure. Final recommendations depend on the results and extent of the procedure. [41]

Red flags after the procedure include increasing abdominal pain, vomiting blood, black stools, severe dizziness, fever, and difficulty breathing. If these symptoms occur, contact your healthcare provider immediately. For scheduled biopsies, your doctor will explain the turnaround time for the histological results and any further follow-up. [42]

If atrophy or intestinal metaplasia is detected, the surveillance schedule is determined by the OLGA and OLGIM stages, family history, and comorbidities. Control of Helicobacter pylori and risk factor modification, including smoking cessation, are important. [43]

In case of peptic ulcer with bleeding after discharge, proton pump inhibitors are prescribed according to the regimen, hemoglobin monitoring if necessary and early monitoring to prevent relapse. [44]

Table 9. Patient information after gastroscopy

Situation	Recommendation
There was sedation	On this day, do not drive or sign important documents.
There is a feeling of discomfort in the throat	Warm drinks after 1-2 hours, soft food if necessary
Biopsies were taken	Minor discomfort is possible, but there should not be any heavy bleeding.
Alarming symptoms have appeared	Contact medical services immediately

[45]

Briefly about the main thing

1. The quality of gastroscopy is determined not only by the fact that it is performed, but also by the time of examination, photographic documentation, and accurate biopsy. A minimum of 7 minutes of inspection is required for the initial diagnostic examination. [46]
2. In uncomplicated dyspepsia in individuals under 60 years of age without “red flags”, non-invasive management is usually started, with endoscopy performed if ineffective or associated with risks. [47]
3. Monitoring of precancerous conditions relies on the Sydney Update mapping and OLGA and OLGIM staging, which predict cancer risk and dictate the frequency of follow-up examinations. [48]
4. In acute non-variceal bleeding, endoscopy in the first 24 hours and combined hemostatic methods improve outcomes. [49]
5. Preparation includes fasting, medication testing, and, if necessary, premedication with simethicone and acetylcysteine for better visibility.[50]