â– LECTURE OVERVIEW: Inflammatory Bowel Disease (IBD) is a chronic, relapsing inflammatory disorder of the GI tract, classically divided into Crohn's Disease and Ulcerative Colitis (UC).
â– MORPHOLOGIC AND HISTOPATHOLOGIC PROFILES:
1. Crohn's Disease (Transmural, Patchy):
- Distribution: Can affect any part of the gastrointestinal tract from mouth to anus, characteristically displaying 'skip lesions' (normal mucosa separating inflamed areas).
- Depth: Transmural inflammation (invading the entire bowel wall), leading to fistulas, stricture-induced obstructions, and deep aphthous ulcers.
- Histology: Characterized by non-caseating granulomas and mucosal cobblestoning.
2. Ulcerative Colitis (Mucosal, Continuous):
- Distribution: Confined strictly to the colon and rectum, spreading continuously proximally from the rectum.
- Depth: Confined strictly to the mucosa and submucosa.
- Histology: Shows crypt abscesses with neutrophils and pseudo-polyps.
â– SURGICAL LANDMARKS & ANATOMICAL BOUNDARIES:
Intraoperative access requires meticulous dissection along defined tissue planes. Avoid excessive traction near neurovascular bundles and look for key bony landmarks or fascial reflections to secure margins.
â– COMPENSATORY HORMONAL & VASCULAR FEEDBACK:
Acute systemic shifts trigger immediate neural and hormonal reflexes to preserve blood flow to vital organs like the brain and kidneys.
[HY-BOARD-1393]
🌟 Dynamic Clinical Key:
On radiography, chronic Ulcerative Colitis presents with a loss of haustra, creating a classic 'lead-pipe' colon. Crohn's disease presents with a 'string sign of Kantor' on barium swallow due to stricture-induced narrowing of the terminal ileum. Never divide or ligate any vessel before clearly isolating and confirming its origin and termination. Carefully evaluate the underlying cause of high blood pressure before aggressively suppressing compensatory vasoconstriction.