Herein, we delineate and describe some of the most common issues encountered by clinicians caring for hospitalized patients with gastrointestinal cancers. These issues arise from the cancers themselves or as complications of the oncologic treatment.
MALIGNANT BOWEL OBSTRUCTION
Malignant bowel obstruction in patients with gastrointestinal malignancies is a common problem and is most commonly due to peritoneal carcinomatosis. Other etiologies include obstruction from the primary malignancy, or metastatic lesions other than peritoneal carcinomatosis. Patients with a history of prior abdominal surgery may also develop obstruction from surgical adhesions. Bowel obstruction may also be the presenting symptom of a gastrointestinal malignancy and is not uncommonly diagnosed at surgical resection. Management is dependent on the etiology of obstruction, severity of obstruction, and the patient’s overall prognosis.
Small bowel obstruction generally presents with symptoms of abdominal distension, nausea, vomiting, and occasionally with hiccups or belching. Signs can include high-pitched, “tinkling” bowel sounds and a distended and/or tympanic abdomen on examination. Laboratory abnormalities may include hypochloremic hypokalemic metabolic alkalosis from repeated vomiting and increased blood urea nitrogen (BUN) and creatinine from dehydration. An elevated serum lactic acid or peritoneal signs on abdominal examination should raise concern for bowel strangulation or perforation, and the patient should receive immediate surgical evaluation (see Chapter 162 [Small Bowel Disorders]).
Small bowel obstruction may be diagnosed on abdominal imaging, most commonly by plain radiograph or abdominal computed tomography (CT). Plain radiograph will likely diagnose the obstruction, and CT may be useful in further characterizing the obstruction, such as in determining whether the obstruction is due to primary malignancy or peritoneal disease (see Chapter 116 [Basic Abdominal Imaging] and Chapter 117 [Advanced Abdominal Imaging]).
Initial management should include bowel rest and bowel decompression with placement of nasogastric tube (NGT), particularly if the patient has nausea and vomiting. Intravenous (IV) fluids should be administered and adjusted accordingly if electrolyte abnormalities exist from persistent vomiting. In the absence of signs of bowel strangulation or perforation, it is reasonable to continue with conservative management for 48 to 72 hours. After this time, if the obstruction does not resolve with conservative management, surgical evaluation is warranted.
Whether surgical intervention is warranted depends on several factors, including the patient’s overall prognosis and goals of care, medical suitability for surgery, and location and type of obstruction. Obstruction due to peritoneal carcinomatosis often results in multifocal obstruction, which is not amenable to surgical resection. If the obstruction is due to primary malignancy or a single metastatic site, a surgical bypass procedure, or resection of that site may provide symptomatic relief. In patients with obstruction from primary malignancy who are not surgical candidates, radiation therapy may be an option.
In patients for whom surgical intervention is not indicated, interventional procedures by interventional radiology or endoscopy may provide relief of symptoms. In certain instances, stenting may provide ...