Radiologic management of small bowel obstruction: A practical approach

ACR Appropriateness Criteria® Suspected Small-Bowel Obstruction

Small-bowel obstruction is a common cause of abdominal pain and accounts for a significant proportion of hospital admissions. Radiologic imaging plays the key role in the diagnosis and management of small-bowel obstruction as neither patient presentation, the clinical examination, nor laboratory testing are sufficiently sensitive or specific enough to diagnose or guide management. This document focuses on the imaging evaluation of the two most commonly encountered clinical scenarios related to small-bowel obstruction: the acute presentation and the more indolent, low-grade, or intermittent presentation. This document hopes to clarify the appropriate utilization of the many imaging procedures that are available and commonly employed in these clinical settings. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Emergency Medicine Evaluation and Management of Small Bowel Obstruction: Evidence-Based Recommendations

BACKGROUND

Small bowel obstruction (SBO) is a commonly diagnosed disease in the emergency department (ED). Recent literature has evaluated the ED investigation and management of SBO.

OBJECTIVE

This review evaluates the ED investigation and management of adult SBO based on the current literature.

DISCUSSION

SBO is most commonly due to occlusion of the small intestine, resulting in fluid and gas accumulation. This may progress to mucosal ischemia, necrosis, and perforation. A variety of etiologies are present, but in adults, adhesions are the most common cause. Several classification systems are present. However, the most important distinction is complete vs. partial and complicated vs. simple obstruction, as complete complicated SBO more commonly requires surgical intervention. History and physical examination can vary, but the most reliable findings include prior abdominal surgery, history of constipation, abdominal distension, and abnormal bowel sounds. Signs of strangulation include fever, hypotension, diffuse abdominal pain, peritonitis, and several others. Diagnosis typically requires imaging, and though plain radiographs are often ordered, they cannot exclude the diagnosis. Computed tomography and ultrasound are reliable diagnostic methods. Management includes intravenous fluid resuscitation, analgesia, and determining need for operative vs. nonoperative therapy. Nasogastric tube is useful for patients with significant distension and vomiting by removing contents proximal to the site of obstruction. Surgery is needed for strangulation and those that fail nonoperative therapy. Surgical service evaluation and admission are recommended.

CONCLUSION

SBO is a common reason for admission from the ED. Knowledge of recent literature can optimize diagnosis and management.

A 73-year-old man with long-term immobility presenting with abdominal pain

Salomone Di Saverio and colleagues discuss the diagnosis and management of a man presenting with symptoms of partial intestinal obstruction.

Small bowel obstruction: what to look for

Small bowel obstruction (SBO) is a common clinical syndrome for which effective treatment depends on a rapid and accurate diagnosis. Despite advances in imaging and a better understanding of small bowel pathophysiology, SBO is often diagnosed late or misdiagnosed, resulting in significant morbidity and mortality. A comprehensive approach that includes clinical findings, patient history, and triage examinations such as plain abdominal radiography will help the clinician develop an individualized treatment plan. When an SBO is accompanied by signs of strangulation, emergent surgical treatment is advised. If surgery cannot be performed immediately or if a partial obstruction is suspected, then a more detailed radiologic work-up is needed. The imaging techniques used subsequently vary according to the initial findings. If a low-grade partial obstruction is suspected, volume-challenge enteral examinations such as enteroclysis and computed tomographic (CT) enteroclysis are preferred. If a complete or high-grade obstruction is suspected, cross-sectional studies such as ultrasonography or multidetector CT are used to exclude strangulation. An algorithmic approach to imaging is proposed for the management of SBO to achieve accurate diagnosis of the obstruction; determine its severity, site, and cause; and assess the presence of strangulation. Radiologists have a pivotal role in clinical decision making in cases of SBO by providing answers to specific questions that significantly affect management.

Small-bowel obstruction: state-of-the-art imaging and its role in clinical management

Small-bowel obstruction (SBO) is a common clinical condition with signs and symptoms similar to other acute abdominal disorders. The radiologic investigation of patients with SBO as well as the indications and timing of surgical intervention have changed over the past 2 decades. This review focuses on modern imaging techniques and their role in both the diagnosis and treatment of patients with SBO.

ACR Appropriateness Criteria® on Suspected Small-Bowel Obstruction

With no one generally accepted approach to evaluate patients with suspected small-bowel obstruction (SBO), standard CT has emerged as the preeminent imaging modality and should be considered in the initial evaluation of patients with suspected high-grade SBO. Playing less significant roles in the diagnosis of acute SBO are barium enemas and the small-bowel examination.

Radiology of small bowel obstruction: contemporary approach and controversies

The radiologic workup of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this complex situation have undergone considerable changes over the past two decades. The diagnosis and treatment of small bowel obstruction, a common clinical condition often associated with signs and symptoms similar to those seen in other acute abdominal disorders, continue to evolve. This article examines the changes related to the use of imaging in the diagnosis and management of patients with this potentially dangerous problem and revisits pertinent controversies.

Current concepts in imaging of small bowel obstruction

The diagnosis and treatment of small bowel obstruction continue to evolve. The imaging approach in the work-up of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this disease have undergone considerable changes over the past two decades. This article examines the current concepts related to the use of imaging technology in the diagnosis and management of patients with small bowel obstruction. The meaning of frequently used but poorly defined terms in describing intestinal obstruction is clarified and illustrated.

Small Bowel Obstruction

The optimal treatment of patients with small bowel obstruction should be predicated upon answering the following diagnostic questions in each patient: 1) does the patient have mechanical bowel obstruction or an ileus?, 2) could the patient have colonic obstruction or a cause of obstruction other than adhesions (eg, hernia, cancer, Crohn's disease)?, 3) is the obstruction partial or complete?, and 4) is strangulation present, and hence immediate operation necessary, or is a period of observation appropriate? The most efficient way to answer these questions in many patients is by performing a careful history and physical examination, laboratory tests, and CT scanning. Surgical intervention should occur within 48 hours of admission in the vast majority of patients with complete small bowel obstruction due to adhesions. The chance for durable endoscopic treatment of any patient with SBO, in our opinion, is remote.

Targeted helical CT of the acute abdomen: appendicitis, diverticulitis, and small bowel obstruction

CT, especially helical CT, provides a fast and reliable modality for evaluation of the patient presenting with acute abdominal pain. Helical CT can provide an accurate diagnosis in the majority of patients and has found great utility in the evaluation of acute gastrointestinal emergencies, including acute appendicitis, diverticulitis, and small bowel obstruction. This article reviews proper helical CT technique, diagnostic imaging findings, and pitfalls of interpretation in evaluation of these acute abdominal disorders.