What instruments and techniques are used for biopsies and foreign body removal in the upper (UGI) and lower (LGI) gastrointestinal tracts?

Endoscopic Instruments and Techniques for GI Biopsies and Foreign Body Removal

Biopsy Forceps and Techniques

For diagnostic upper and lower GI endoscopy, standard biopsy forceps should obtain multiple specimens (6-8 biopsies for UGI, minimum 2 from each of 6 segments for LGI) to ensure adequate tissue sampling for histopathological diagnosis 1.

Upper GI Biopsy Protocols

Single-bite vs. Multiple-bite Forceps:

• Standard-size endoscopy forceps are recommended for routine diagnostic biopsies, with 6-8 specimens obtained during upper endoscopy 1
• Larger forceps may be used during surveillance endoscopy of Barrett's esophagus to provide more tissue for histologic interpretation 1
• Multiple biopsies from both abnormal and normal-appearing mucosa are essential to document disease distribution and skip lesions 1

Specific UGI Biopsy Indications:

• Esophagus: Two biopsies from different regions when evaluating dysphagia/food bolus obstruction to rule out eosinophilic esophagitis 1
• Barrett's esophagus: Biopsies taken according to Seattle protocol when no lesions detected (>90% compliance standard) 1
• Gastric sampling: Separate biopsies from antrum and body when investigating gastric atrophy, intestinal metaplasia, or iron deficiency anemia 1
• Duodenum: Minimum of 4 biopsies from second part of duodenum including duodenal bulb when celiac disease suspected 1, 2

Lower GI Biopsy Protocols

Standard Colonoscopy Biopsy Protocol:

• Minimum of 2 representative samples from each of 6 segments: terminal ileum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum 1
• Biopsies must include both inflamed areas and normal-appearing mucosa to establish diagnosis and document disease extent 1
• Targeted biopsies from ulcer edges and aphthous erosions maximize granuloma detection in Crohn's disease 1

Four-Quadrant Biopsy Technique:

• While the Seattle protocol is specifically mentioned for Barrett's esophagus surveillance 1, the principle of systematic four-quadrant sampling applies to surveillance of any segment requiring comprehensive mucosal assessment
• This systematic approach ensures adequate sampling of circumferential disease and reduces sampling error 1

Foreign Body Removal Accessories

Emergent endoscopic removal (within 2-6 hours) is required for complete esophageal obstruction, sharp-pointed objects, or batteries in the esophagus 3.

Retrieval Devices

Snares:

• Used for removing large, blunt foreign bodies and food boluses 3
• Polypectomy snares can retrieve medium-sized objects from stomach 3

Rat-Tooth (Alligator) Forceps:

• Effective for grasping sharp or irregular objects 4, 3
• Provides secure grip on difficult-to-grasp foreign bodies 4

Roth Net (Retrieval Net):

• Basket-type device for capturing and extracting multiple small objects or fragmented foreign bodies 4, 3
• Particularly useful when objects are difficult to grasp with standard forceps 4

Protective Devices (Hoods/Caps/Overtube):

• Mandatory use when extracting sharp-pointed objects to prevent esophagogastric/pharyngeal damage and aspiration 3
• Protective hoods shield mucosa during withdrawal of sharp objects through esophagus 3
• Endotracheal intubation should be considered when aspiration risk is high 3

Foreign Body Management Algorithm

Timing of Intervention:

• Emergent (<6 hours): Complete esophageal obstruction, sharp objects in esophagus, batteries in esophagus 3
• Urgent (24 hours): Other esophageal foreign bodies, sharp objects/magnets/batteries in stomach 3
• Non-urgent (72 hours): Medium-sized blunt objects in stomach 3
• Observation only: Asymptomatic patients with small blunt objects (except batteries/magnets) 3

Technique Selection:

• Food bolus impaction: Gently push into stomach; if unsuccessful, retrieve 3
• Sharp objects: Use protective device and appropriate grasping forceps 3
• Multiple small objects: Consider Roth net for efficient retrieval 4, 3

Critical Technical Considerations

Photo documentation of lesions and anatomical landmarks should achieve >90% compliance, with targeted biopsies using Paris classification for lesion description 1.

Common Pitfalls to Avoid

• Inadequate number of biopsies reduces diagnostic accuracy—always obtain minimum recommended specimens 1
• Failing to biopsy normal-appearing mucosa misses patchy disease distribution in inflammatory bowel disease 1
• Attempting endoscopic retrieval of drug packets in body packers is contraindicated; surgical referral required if complications occur 3
• Delaying endoscopy for medical treatment of food bolus impaction worsens outcomes 3
• Using barium swallow before endoscopy increases aspiration risk and impairs visualization 3