What is the optimal surgical approach for a patient with obstructive colon cancer, considering a two-stage vs three-stage procedure with or without the use of self-expandable metallic stents (SEMS)?

Optimal Surgical Approach for Obstructive Colon Cancer

For patients with obstructive left-sided colon cancer who are candidates for resection, SEMS placement as a bridge to one-stage elective surgery is a reasonable option, though emergency resection remains acceptable; however, for right-sided obstructions, proceed directly to emergency resection with primary anastomosis rather than stenting. 1

Left-Sided Obstructive Colon Cancer

Resectable Disease - Bridge to Surgery Strategy

SEMS as bridge to surgery allows one-stage elective resection with lower stoma rates compared to emergency surgery, though long-term oncologic outcomes remain comparable. 1 The 2021 AGA guidelines explicitly state that SEMS insertion is reasonable to allow for one-stage, elective resection in surgical candidates. 1

However, critical caveats exist:

• SEMS should only be used when surgery is scheduled shortly after insertion (within days to weeks), as late complications including migration (22%), obstruction (17%), and perforation (7%) occur in up to 51% of patients. 2
• Avoid SEMS in patients receiving bevacizumab-based chemotherapy due to increased perforation risk; oncologist involvement in decision-making is mandatory. 1
• Perforation after SEMS carries 100% mortality in some series, occurring 3-34 days post-insertion. 2

Emergency Surgery Options (Two-Stage vs Three-Stage)

When SEMS is not feasible or contraindicated:

Hartmann's procedure (two-stage) should be preferred over simple loop colostomy (three-stage) for left-sided obstruction, as loop colostomy requires multiple operations without reducing perioperative morbidity. 1

Resection with primary anastomosis (one-stage) is preferred over Hartmann's procedure in patients without high surgical risk factors (no severe malnutrition, no perforating disease, hemodynamically stable). 1 The 2007 systematic review of 2,286 patients consistently showed one-stage procedures reduced mortality by 2-27% compared to multi-stage approaches. 3

A covering stoma with primary anastomosis does not reduce anastomotic leak rates and should not be routinely performed. 1

Right-Sided Obstructive Colon Cancer

Right colectomy with primary anastomosis is the preferred single-stage option for right-sided obstruction. 1

SEMS as bridge to surgery for right-sided obstruction is NOT recommended except in high-risk patients, as it is technically challenging with variable success rates. 1 However, SEMS remains reasonable in the palliative setting for right-sided lesions. 1

For unresectable right-sided cancer, perform side-to-side ileotransverse anastomosis (internal bypass) rather than loop ileostomy; decompressive cecostomy should be abandoned due to high malfunction rates. 1

Rectal Cancer Obstruction - Special Considerations

For obstructing extraperitoneal rectal cancer, create a transverse loop colostomy (not sigmoid colostomy) and avoid resection of the primary tumor. 4, 5, 6 This allows proper staging and timely initiation of neoadjuvant chemoradiotherapy, which is essential for locally advanced rectal cancers. 4, 5

SEMS is contraindicated in rectal cancer obstruction due to chronic pain, tenesmus, worsening quality of life, and risk of perforation during subsequent chemoradiotherapy. 5, 6

Transverse colostomy is preferred over sigmoid colostomy because it: 5

• Avoids damage to the marginal arcade (preserving blood supply)
• Provides greater mobility for easier creation
• Preserves the left abdomen for potential future permanent end colostomy after abdominoperineal resection

Palliative Setting (Non-Resectable Disease)

For non-resectable left-sided obstruction, SEMS placement is preferred over diverting colostomy in patients with good functional status (ECOG 0-1), as it allows earlier oral intake and shorter hospital stay. 1 However, for patients with ECOG 2-3, palliative surgery may provide better overall survival. 1

SEMS in extracolonic malignancy has lower clinical success rates (20% in early studies), higher symptom persistence, and increased complications including migration, though more recent data show improved outcomes. 1

Critical Pitfalls to Avoid

• Never use SEMS in patients with multiple luminal obstructions or severely impaired gastric motility - clinical benefit is limited. 1
• Avoid total colectomy for left-sided obstruction unless cecal perforation, bowel ischemia, or synchronous right colon cancer exists - it increases morbidity without reducing mortality. 1
• Do not perform emergency resection of obstructing rectal cancer - this prevents proper staging and eliminates neoadjuvant therapy opportunity. 4, 5, 6
• Recognize damage control surgery indications: pH <7.2, temperature <35°C, base excess <-8, coagulopathy, or septic shock requiring inotropes. 1

Decision Algorithm Summary

1. Determine location: Left colon vs right colon vs rectum
2. Assess resectability and surgical risk: High-risk patients (malnutrition, perforation, hemodynamic instability) favor staged approaches
3. Left-sided resectable: SEMS bridge to one-stage surgery vs emergency Hartmann's vs emergency resection with primary anastomosis (if low-risk)
4. Right-sided resectable: Emergency right colectomy with primary anastomosis (SEMS only if high-risk)
5. Rectal obstruction: Transverse loop colostomy, never SEMS
6. Palliative: SEMS preferred if ECOG 0-1 and no bevacizumab therapy planned