A 72-year-old man with chronic kidney disease (eGFR 28 mL/min/1.73m²) and hypertension on aspirin and atenolol presents with 3 episodes of bright red blood per rectum over the past 6 hours. He denies abdominal pain, weight loss, or change in bowel habits. Vital signs are stable (BP 138/82, HR 76/min). Digital rectal examination reveals bright red blood on the glove but no palpable mass. Hemoglobin is 12.2 g/dL (baseline 13.5 g/dL). Flexible sigmoidoscopy reveals a 1.5 cm sessile polyp in the sigmoid colon with active oozing from its tip. The polyp is removed by cold snare polypectomy. Histopathology shows tubular adenoma with low-grade dysplasia. What is the next step in management?

Explanation

## Post-Polypectomy Surveillance Strategy **Key Point:** Surveillance intervals after polypectomy depend on polyp characteristics (size, histology, morphology) and the completeness of resection. A single tubular adenoma <2 cm with low-grade dysplasia requires surveillance at 5–10 years. ### Polyp Risk Stratification | Risk Category | Polyp Features | Surveillance Interval | |---------------|----------------|----------------------| | **Low risk** | 1–2 adenomas, <1 cm, tubular, LGD | 10 years | | **Intermediate risk** | 3–4 adenomas OR ≥1 cm OR HGD | 5–10 years | | **High risk** | ≥5 adenomas OR ≥3 cm OR villous/tubulovillous OR HGD/cancer | 3 years | | **Very high risk** | Sessile serrated polyps ≥1 cm OR traditional serrated adenomas | 3 years | **High-Yield:** This patient has a **single sessile adenoma 1.5 cm with low-grade dysplasia** — intermediate-risk features. The interval is 5–10 years, not 3 months or 10 years alone. ### Why This Patient Is Intermediate Risk - **Size:** 1.5 cm (≥1 cm threshold) - **Histology:** Tubular adenoma with low-grade dysplasia (not high-grade) - **Number:** Single polyp (not multiple) - **Morphology:** Sessile (higher risk than pedunculated, but not villous) ### Rationale for 5–10 Year Interval The 2021 USPSTF and ASGE guidelines recommend: - **10 years** for small (<1 cm), tubular adenomas with low-grade dysplasia - **5–10 years** for adenomas 1–2 cm with low-grade dysplasia (individualize based on patient age, comorbidities, and adenoma burden) **Clinical Pearl:** In a 72-year-old with CKD, consider the shorter interval (5 years) if life expectancy is >5 years and the patient is willing to undergo repeat colonoscopy. ### Why NOT 3 Months? 3-month surveillance is reserved for: - Incomplete resection (visible remnant or piecemeal resection of large sessile polyps) - Perforation or significant bleeding requiring intervention - This patient had complete resection by cold snare and no complications. ### Why NOT 10 Years Alone? The polyp size (1.5 cm) and sessile morphology push this into intermediate risk, warranting closer follow-up than 10 years. ### Why NOT CT Colonography? CT colonography is not indicated for post-polypectomy surveillance. It has lower sensitivity for small polyps (<6 mm) and is reserved for patients who cannot tolerate optical colonoscopy. [cite:ASGE 2021 Colorectal Polyp Surveillance Guidelines; Harrison 21e Ch 283]