A 62-year-old woman from Delhi presents with a 3-month history of left-sided abdominal pain and a palpable mass in the left iliac fossa. Colonoscopy reveals a circumferential, ulcerated lesion at the sigmoid colon 25 cm from the anal verge. Biopsy confirms moderately differentiated adenocarcinoma. CT abdomen shows the tumour invading into the pericolonic fat but not breaching the serosa. No regional lymph nodes are enlarged (>1 cm), and there is no evidence of metastatic disease. The patient is otherwise fit with normal renal function. What is the most appropriate surgical approach for this patient?

Explanation

## Clinical Assessment This patient has a sigmoid colon adenocarcinoma at 25 cm from the anal verge (well within the sigmoid colon territory) with invasion into pericolonic fat (T3 stage) but no radiological evidence of lymph node involvement (N0 stage) and no distant metastasis (M0) — classified as Stage IIB colorectal cancer. ## Sigmoid Colectomy Principles **Key Point:** Sigmoid colon cancers (located 15–40 cm from anal verge) are managed by sigmoid colectomy with adequate lymphadenectomy (D3 resection) and primary anastomosis. Laparoscopic approach is preferred in fit patients without contraindications [cite:ESMO Colorectal Cancer Guidelines 2020]. **High-Yield:** The sigmoid colon has a distinct blood supply (sigmoid arteries from inferior mesenteric artery) and lymphatic drainage, making sigmoid colectomy the anatomically appropriate resection. ## Why Laparoscopic Sigmoid Colectomy with D3 Resection is Optimal 1. **Tumour location:** Sigmoid colon (25 cm from anal verge) requires sigmoid colectomy, not left hemicolectomy 2. **Staging:** T3N0M0 (Stage IIB) is resectable with curative intent 3. **Laparoscopic approach:** Equivalent oncological outcomes to open surgery with reduced morbidity in fit patients 4. **D3 lymphadenectomy:** Essential for accurate staging and therapeutic benefit in Stage II disease 5. **Primary anastomosis:** Safe in sigmoid colectomy with adequate blood supply and no contraindications ## Extent of Resection ```mermaid flowchart TD A[Colorectal Cancer Location]:::outcome --> B{Anatomical Site?}:::decision B -->|Caecum to Splenic Flexure| C[Right Hemicolectomy]:::action B -->|Splenic Flexure to Mid-Sigmoid| D[Left Hemicolectomy]:::action B -->|Sigmoid Colon| E[Sigmoid Colectomy]:::action B -->|Upper Rectum| F[Anterior Resection]:::action B -->|Lower Rectum| G[Abdominoperineal Resection]:::action E --> H[Resect 5-10 cm margins]:::action H --> I[D3 Lymphadenectomy]:::action I --> J[Primary Anastomosis]:::action ``` **Clinical Pearl:** Sigmoid colectomy removes the sigmoid colon and proximal rectum with ligation of sigmoid arteries at their origin from the inferior mesenteric artery, ensuring adequate lymph node harvest. ## Staging and Prognosis | Stage | TNM | Adjuvant Chemo | 5-Year Survival | |-------|-----|---|----------------| | IIA | T3N0M0 | Not standard | 75–80% | | IIB | T4aN0M0 | Consider | 65–75% | | IIIA | T2N1M0 | Yes | 65–75% | **Mnemonic: SLAM** — Sigmoid colectomy, Lymphadenectomy (D3), Anastomosis, Minimally invasive (laparoscopic) when feasible. ## Why Laparoscopic Over Open? **Key Point:** Laparoscopic colectomy offers: - Equivalent 5-year survival and recurrence rates - Reduced postoperative pain and hospital stay - Faster return to bowel function - Lower wound infection rates - Cost-effectiveness in fit patients