Endoscopic procedures overview

🔭 Core concept - The Inner Tube

• Endoscopy: Visualizing internal organs using an endoscope, a tube with a light source and camera.
• Purpose: Diagnostic (e.g., biopsy) and therapeutic (e.g., polypectomy, stenting).
• Types:
  • Flexible: Navigates tortuous lumens (GI tract, bronchi).
  • Rigid: Superior optics, larger working channels for straight-access procedures (laparoscopy, arthroscopy).
• Key Components:
  • Light source & camera/lens system.
  • Working channel(s) for instruments.
  • Insufflation/irrigation channels.

⭐ Perforation is a feared complication of any endoscopic procedure, especially during therapeutic interventions. It often presents with acute pain, fever, and signs of peritonitis.

🩺 Clinical manifestations - Scope on Demand

Endoscopy is performed for both diagnostic evaluation and therapeutic intervention based on clinical presentation. The decision pathway often follows initial assessment of symptoms and risk factors.

⭐ In patients with new-onset dyspepsia, endoscopy is indicated for age >60 or presence of alarm features: unintentional weight loss, persistent vomiting, dysphagia, odynophagia, palpable mass, or iron deficiency anemia.

🔧 Management - Fix-It Flex

• Gastrointestinal (GI) Interventions:
  • EGD: Banding esophageal varices, dilating strictures, placing stents for malignancy, percutaneous endoscopic gastrostomy (PEG) for feeding.
  • Colonoscopy: Polypectomy prevents colorectal cancer. Hemostasis via clips, thermal coagulation (e.g., APC), or injection.
  • ERCP: Biliary sphincterotomy, stone extraction from CBD, stenting for benign/malignant strictures.
• Other Systems:
  • Bronchoscopy: Airway stenting, foreign body removal, tumor ablation.
  • Cystoscopy: Ureteral stenting, lithotripsy/stone removal, transurethral resection of bladder tumor (TURBT).

⭐ Post-ERCP pancreatitis is the most common complication. Prophylactic rectal NSAIDs (e.g., indomethacin) can significantly decrease incidence.

🕵️ Diagnosis - The Inside Scoop

• Direct Visualization: Real-time assessment of mucosal surfaces for inflammation, ulcers, polyps, and masses.
• Tissue Sampling (Definitive Dx):
  • Biopsy: Forceps obtain tissue for histopathology (e.g., cancer, H. pylori, celiac disease). The gold standard for many conditions.
  • Cytology: Brushings collect cells for analysis.
• Advanced Imaging Modalities:
  • Narrow-Band Imaging (NBI): Enhances mucosal and vascular patterns to better identify dysplasia.
  • Endoscopic Ultrasound (EUS): Assesses depth of tumor invasion and evaluates adjacent lymph nodes.

⭐ EUS is critical for locoregional staging (T & N stages) of esophageal, gastric, and rectal cancers, guiding neoadjuvant therapy.

⚠️ Complications - Perilous Probes

• Perforation: Most feared. Risk ↑ with therapeutic interventions. Presents with acute pain, fever, peritonitis, subcutaneous emphysema.
• Bleeding: Immediate or delayed (up to 2 weeks). Manage with endoscopic clips, cautery, or angiography.
• Infection: Transient bacteremia is common; sepsis is rare. Prophylaxis for high-risk cases.
• Sedation-related: Aspiration, hypotension, hypoxia.
• Post-polypectomy Syndrome: Transmural burn without frank perforation; manage conservatively with bowel rest and antibiotics.

⭐ Perforation of retroperitoneal structures (e.g., duodenum) may cause back/flank pain and retroperitoneal air on CT, lacking classic peritonitis.

⚡ Biggest Takeaways

• Endoscopy has dual roles: diagnostic (visualization, biopsy) and therapeutic (polypectomy, stenting, hemostasis).
• Key procedures: EGD (upper GI), colonoscopy (lower GI), ERCP (biliary/pancreatic), bronchoscopy (airways).
• Major complications are perforation, bleeding, infection, and sedation-related cardiopulmonary events.
• Post-ERCP pancreatitis is a classic, high-yield complication.
• Adequate bowel preparation is critical for a successful colonoscopy.
• Pre-procedure management of anticoagulants is vital to mitigate bleeding risk.