From the Guidelines
Large bowel obstruction (LBO) due to colorectal cancer is a life-threatening condition that requires prompt diagnosis and treatment to minimize morbidity, mortality, and improve quality of life. The most common cause of LBO is colorectal cancer, accounting for approximately 50-60% of all cases, typically occurring in the sigmoid colon or rectum 1. Patients with LBO present with abdominal pain, distension, constipation, and sometimes nausea and vomiting, which often develop gradually over days to weeks.
Diagnosis and Initial Management
Diagnosis involves physical examination, abdominal X-rays showing dilated colon with air-fluid levels, and CT scans which can identify the location and cause of obstruction 1. Initial management includes bowel rest, intravenous fluids, nasogastric tube decompression, and correction of electrolyte imbalances. Antibiotics such as piperacillin-tazobactam 3.375g IV every 6 hours or ceftriaxone 1g daily plus metronidazole 500mg every 8 hours are recommended if perforation or infection is suspected.
Treatment Options
For cancer-related LBO, treatment depends on the patient's condition and cancer stage. Emergency options include:
- Colonic stenting as a bridge to surgery, which can provide immediate relief while allowing time for proper cancer staging and patient optimization before definitive surgery 1.
- Immediate surgical intervention, which may involve resection with primary anastomosis or, in high-risk patients, resection with colostomy (Hartmann's procedure) 1.
- Self-expanding metal stents can be used as a non-invasive technique to relieve left-sided MBO, allowing surgical resection to be performed on an elective rather than emergency basis 1.
Surgical Options
Surgical options for complicated colorectal cancer depend primarily on the location of the tumor, comorbidities of the patient, and degree of their clinical status derangement at presentation 1. For left-sided lesions in unstable patients, a single-stage procedure represents a time-consuming intervention, at high risk of anastomotic leak, due to fecal loading and impaired microcirculation induced by sepsis and by the premorbid status of the patient.
Long-term Management
Long-term management involves cancer treatment with chemotherapy regimens like FOLFOX (leucovorin, 5-fluorouracil, oxaliplatin) or FOLFIRI (leucovorin, 5-fluorouracil, irinotecan), often combined with targeted therapies based on tumor genetics. Early detection through screening colonoscopy beginning at age 45 for average-risk individuals is crucial for preventing cancer-related LBO.
Key Recommendations
- Colonic stenting as a bridge to surgery is a valid option for left-sided MBO, allowing for elective resection and reducing the risk of anastomotic leak and mortality 1.
- Hartmann's procedure is a suitable option for patients who are too unwell to tolerate time-consuming procedures, such as an anastomosis 1.
- Loop colostomy should be reserved for unresectable disease or if neoadjuvant therapy is planned 1.
From the Research
Definition and Causes of Large Bowel Obstruction
- Large bowel obstruction (LBO) is a common surgical emergency that can be caused by various factors, including colonic cancer 2.
- Malignant bowel obstruction is a common complication of advanced gastrointestinal, gynecologic, and genitourinary tumors, presenting with symptoms such as nausea, vomiting, abdominal pain, and constipation 3.
Diagnosis and Management of Large Bowel Obstruction
- Cross-sectional imaging is essential for diagnosing bowel obstruction, and initial management is often conservative, involving fluid replacement, electrolyte replacement, bowel rest, and sometimes nasogastric decompression 3.
- Surgical options for LBO caused by cancer include resection and anastomosis, which can be performed as a one-stage or two-stage operation, depending on the patient's condition and the location of the obstruction 2, 4.
- Colonic stents can be used as a palliative measure for patients with recurrent gynecologic cancer, allowing for decompression and relief of symptoms without the need for major surgery 5.
Surgical Treatment and Outcomes
- The decision to perform primary resection and anastomosis or a two-stage operation depends on various factors, including the patient's condition, the location of the obstruction, and the presence of complications such as perforation or peritonitis 4.
- Studies have shown that primary resection and anastomosis can be a safe and feasible option for selected patients, with acceptable morbidity and mortality rates 2, 4.
- The overall prognosis for patients with malignant bowel obstruction is poor, with median survival ranging from 26 to 192 days, and treatment is often focused on palliation and symptom management 3.
Palliative Care and Symptom Management
- Palliative care and hospice should be discussed with patients who have advanced malignancy and present with peritoneal carcinomatosis or multiple levels of obstruction 3.
- Home parenteral nutrition can provide symptomatic palliation for patients who are not amenable to surgical relief, and can help to improve quality of life 6.
- The entire intestinal tract should be evaluated in all patients with bowel obstruction, as concurrent small- and large-bowel obstructions can occur 6.