Acute Abdomen, Bowel/Biliary Obstruction, and Fistula
Summary of Key Points
Gastrointestinal Perforation
• Perforation affects approximately 20% of patients with acute abdominal emergencies.
• Bowel perforation can be due to spontaneous tumor rupture, tumor necrosis secondary to chemotherapy, radiation therapy, drugs (e.g., steroids), or inflammatory conditions.
• Operative intervention is mandated unless the patient’s overall prognosis is poor.
Gastrointestinal Bleeding
Neutropenic Enterocolitis
• Also termed necrotizing enterocolitis, neutropenic enterocolitis typically affects the terminal ileum, cecum, and ascending colon in patients with chemotherapy-induced neutropenia.
• Most patients respond to conservative management with broad-spectrum antibiotics and bowel rest.
• Surgical intervention should be considered for perforation, uncontrolled sepsis, or persistence of symptoms despite correction of neutropenia.
Bowel and Biliary Obstruction
• Obstruction affects approximately 40% of patients with cancer who experience acute abdominal emergencies.
• One fourth to one third of patients who require surgical intervention have a benign cause of their obstruction.
• Partial bowel obstruction can initially be treated nonoperatively, which is successful 25% of the time.
• Cross-sectional imaging gives valuable information about the location and etiology of malignant biliary obstruction and resectability of tumor.
Fistulae
• Manifesting symptoms rarely match those of intraabdominal malignancy and more commonly represent complications after surgery or radiation therapy or both.
• Medical management consisting of nutritional support and bowel rest allows spontaneous closure of most enterocutaneous fistulas.
• Causes for persistence of a fistula include undrained infection, luminal obstruction distal to the fistula, prior radiation, epithelialization of the fistulous tract, cancer within the tract, presence of a foreign body, and malnutrition.
A Gastrointestinal (GI) perforation associated with colon cancer is localized at the tumor site.
B Surgical treatment for gastrointestinal perforation usually requires resection with anastomosis.
C Approximately 1% to 2% of patients treated with bevacizumab (Avastin) experience bowel perforation during treatment.
D Bevacizumab (Avastin) is the only targeted molecular agent associated with bowel perforation or GI bleeding.
A GI bleeding during chemotherapy usually requires exploratory surgery.
B During treatment for a GI stromal tumor (GIST) while being treated with imatinib or sunitinib, bleeding complications are less common in patients who show an objective response than in those who don’t show an objective response.
C Neutropenic enterocolitis typically affects the right colon and could cause perforation.
D Appendicitis is more common among pediatric patients with leukemia or other malignancies than in the general population.
E Pancreatitis is common in patients with primary pancreatic cancer or metastases to the pancreas.
A Intestinal obstruction associated with recurrence of cancer is common and responds to the treatment well.
B Small bowel obstruction in the setting of intraluminal primary or secondary tumors usually respond with conservative management.
C Endoscopy with colonic stenting for obstructive rectal cancer offers an alternative to surgical diversion with no difference in long-term survival rates compared with an emergent operation.
D Bowel obstruction in a patient with end-stage cancer usually requires surgical resection and/or a bypass procedure.
A For suspected malignant biliary obstruction, endoscopic retrograde cholangiopancreatography (ERCP) and stent placement would be the first diagnostic and therapeutic modality of choice.
B The most common indication for abdominal surgery in patients with graft-versus-host disease (GVHD) is perforation of the bowel.
C One of the intraabdominal complications of hematopoietic stem-cell transplantation (HSCT), venoocclusive disease (VOD) of the liver, requires a liver biopsy to make the diagnosis.
D High-output enterocutaneous fistulae (>1 L/day) tend to originate more proximally in the GI tract and tend to cause dehydration and electrolyte and acid-base imbalances.
1. Answer: C. Perforation associated with colon cancer could occur proximal to the tumor site, such as at the cecum (the law of Laplace). Although small bowel perforations should be resected with primary anastomosis, colonic perforations, especially in the setting of the unprepped bowel and in the immunosuppressed patient, should be treated with resection and diversion. One-stage procedures to include primary anastomosis in these situations must be used cautiously and are generally not advised. Small-molecule tyrosine kinase inhibitors including Imatinib and sunitinib are also reported to be associated with bowel perforation or GI bleeding.
2. Answer: C. Treatment of upper GI tract bleeding requires defining its source. Endoscopic examination would be diagnostic as well as therapeutic. In most patients, nonoperative treatment is successful. GI bleeding or intraabdominal hemorrhage in patients with GIST has been reported to be 3% to 5% with imatinib and 3% to 9% with sunitinib therapy. Close follow-up would be recommended, especially for patients with necrotic or cystic degeneration shown on imaging studies during treatment. The incidence of appendicitis has been reported to be between 0.2% and 2%, which is equivalent to the incidence in the general pediatric population. Pancreatitis is rare in patients with primary pancreatic cancer or metastases to the pancreas.
3. Answer: C. A contrast study of the large bowel would be useful to determine the location of the obstruction in patients with suspected carcinomatosis. Recurrence of cancer, either locally or as diffuse peritoneal disease, is a more common problem and, unfortunately, is more difficult to treat. However, small bowel obstruction in the setting of intraluminal primary or secondary tumors almost never resolves by conservative treatment, and surgical intervention is indicated. Surgical resection and/or bypass to treat bowel obstruction in a patient with end-stage cancer might not yield durable palliation. Recent series have reported effective palliation in up to 80% of patients with obstruction. A decompressive gastrostomy tube in conjunction with either enteral or parenteral fluids might be the procedure of choice. Management of malignant bowel obstruction must be coordinated with end-of-life care in some patients.
4. Answer: D. For suspected malignant biliary obstruction, computed tomography (CT) would give you more valuable information about the location and etiology of a malignant biliary obstruction. Routine use of preoperative ERCP for resectable pancreaticobiliary disease is debated. Several studies have shown that it increases perioperative infectious complications. The most common indications for abdominal surgery in patients with GVHD are GI bleeding and obstruction. Perforation of the bowel is uncommon. The diagnosis of VOD can usually be made on the basis of clinical signs, with liver biopsy being reserved for patients for whom the diagnosis is not certain.
