A 72-year-old man with chronic kidney disease (eGFR 28 mL/min) and hypertension on aspirin and amlodipine presents with acute onset of bright red blood per rectum and dizziness. Vital signs: HR 108/min, BP 102/68 mmHg, RR 22/min. Hemoglobin is 7.2 g/dL (baseline 10.5 g/dL). Rectal examination reveals bright red blood on the glove but no hemorrhoids or masses. Colonoscopy shows a 6 mm sessile polyp in the ascending colon with active arterial bleeding at its base. What is the most appropriate management of this bleeding lesion?

Explanation

## Hemostasis and Polypectomy for Bleeding Colonic Polyps **Key Point:** Active arterial bleeding from a colonic polyp requires dual hemostasis: injection of dilute epinephrine followed by mechanical removal (snare polypectomy) to achieve definitive hemostasis and tissue diagnosis. ### Pathophysiology of Polyp Bleeding Bleeding occurs when a polyp's feeding vessel is exposed during or after polypectomy. Risk factors include: - Large polyp size (>10 mm) - Sessile morphology (higher risk than pedunculated) - Antiplatelet/anticoagulant use - Chronic kidney disease (uremic platelet dysfunction) - Location in right colon (larger vessels) ### Hemostasis Techniques for Bleeding Polyps | Technique | Mechanism | Indications | Limitations | |-----------|-----------|-------------|-------------| | **Epinephrine injection (1:10,000)** | Vasoconstriction + tamponade | Active bleeding, high-risk polyps | Temporary; must combine with mechanical method | | **Snare polypectomy** | Mechanical removal + coagulation | Sessile/pedunculated polyps <20 mm | Risk of delayed bleeding if not combined with injection | | **Argon plasma coagulation (APC)** | Thermal coagulation | Flat lesions, bleeding after polypectomy | Cannot remove tissue; incomplete hemostasis if used alone | | **Endoscopic mucosal resection (EMR)** | Submucosal injection + snare removal | Large sessile polyps (10–20 mm) | Requires hemostasis measures; not for active bleeding | | **Clip placement** | Mechanical compression | Post-polypectomy bleeding | Difficult on polyp base; better for post-polypectomy syndrome | **High-Yield:** For active arterial bleeding from a polyp, the sequence is: 1. **Inject epinephrine** (1:10,000) around the base to achieve hemostasis 2. **Wait 1–2 minutes** for vasoconstriction 3. **Perform snare polypectomy** to remove the lesion and achieve definitive hemostasis ### Why Epinephrine + Snare Polypectomy Is Correct - **Active bleeding present** → requires immediate hemostasis - **Epinephrine injection** achieves temporary vasoconstriction and allows visualization - **Snare polypectomy** provides: - Mechanical hemostasis (electrocautery during snaring) - Tissue diagnosis (histology to exclude malignancy) - Definitive treatment (polyp removal) - **Dual approach** reduces rebleeding risk from 10–15% (snare alone) to <2% **Clinical Pearl:** In patients with CKD, uremic platelet dysfunction increases bleeding risk; aggressive hemostasis (injection + mechanical method) is essential. ```mermaid flowchart TD A[Colonic polyp with active arterial bleeding]:::outcome --> B{Polyp size?}:::decision B -->|<20 mm, sessile| C[Inject epinephrine 1:10,000]:::action B -->|>20 mm, sessile| D[EMR with epinephrine injection]:::action C --> E[Wait 1-2 minutes]:::action E --> F[Perform snare polypectomy]:::action D --> F F --> G{Hemostasis achieved?}:::decision G -->|Yes| H[Tissue diagnosis + definitive treatment]:::outcome G -->|No| I[Apply clip or APC]:::action I --> J[Repeat endoscopy in 2 weeks]:::action ``` **Warning:** Do not use APC or thermal methods alone for active arterial bleeding — they do not remove the polyp and carry high rebleeding risk. Do not perform cold snare polypectomy on actively bleeding polyps in high-risk patients (antiplatelet use, CKD, large polyps). [cite:Harrison 21e Ch 297]