Computerized Tomography for Small Bowel Obstruction
Date First Published:
May 3, 2007
Last Updated:
October 24, 2007
Report by:
Usman Jaffer, Specialist Registrar (Peterborough District Hospital)
Search checked by:
Amin Alyas, Peterborough District Hospital
Three-Part Question:
In an [adult patient presenting with suspected SBO] is [CT] useful in [diagnosis of obstruction and strangulation].
Clinical Scenario:
A 65-year-old woman presents to the emergency department with signs and symptoms of SBO. She had previously had an abdominal hysterectomy. Plain abdominal radiograph (AXR) is non-specific. You wonder whether abdominal CT would be useful in the management of a patient with presumptive SBO.
Search Strategy:
Medline 1950 to March 2006 using the OVID interface, combined with a manual search of references in papers found.
Search Details:
(exp Intestinal obstruction/AND exp Intestine, Small/AND exp Tomography, X-Ray Computed/) AND ((intestinal adj obstruction) AND CT).mp. limit to (humans and English language).
Outcome:
A total of 491 papers were found of which 16 were relevant to the topic and one systematic review incorporating 11 of these papers
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Differentiation of simple and strangulated small-bowel obstructions: usefulness of known CT criteria. Ha HK, Kim JS, Lee MS, Lee HJ, Jeong YK, Kim PN, Lee MG, Kim KW, Kim MY, & Auh YH 1997 South Korea | 84 patients with previous laparotomy presenting with small bowel obstruction (SBO) (41 strangulated) undergoing computed tomography (CT) (intravenous (iv) contrast). Malignant/inflammatory obstruction excluded | Case series | CT diagnosis of strangulation | Sensitivity 85% | Retrospective case series |
| Comparative evaluation of plain films, ultrasound and CT in the diagnosis of intestinal obstruction. Suri S, Gupta S, Sudhakar PJ, Venkataramu NK, Sood B, & Wig JD 1999 India | 32 patients presenting with clinical suspicion of intestinal obstruction undergoing AXR, US and CT. | Cohort study | CT diagnosis of, level of and cause of SBO | Diagnosis: sensitivity 93%, specificity 100%, accuracy 94%.Level: sensitivity 93%.Cause: sensitivity 70% | Small numbers |
| Imaging bowel obstruction: a comparison between fast magnetic resonance imaging and helical computed tomography. Beall DP, Fortman BJ, Lawler BC, & Regan F 2002 USA | 44 patients with suspected bowel obstruction (28 obstructed) undergoing CT | Cohort study | CT diagnosis of SBO | Accuracy 71%, sensitivity 71%; specificity 71%; positive predictive value (PPV) 83% (n = 21) | Small numbers. |
| Frequency and relevance of the Lazarus DE, Slywotsky C, Bennett GL, Megibow AJ, & Macari M 2004 USA | 34 patients with CT findings of small bowel obstruction. | Prospective. | Presence of small bowel faeces sign (SBFS). Severity of obstruction. Localisation of obstruction. | SBFS present in 55.9%. Present in 16.6% patients with mild obstruction, 72.7% patients with moderate obstruction and 58.8% patients with high grade obstruction. In 94.7% with SBFS level of obstruction found | Small numbers. |
| Positive predictive value and negative predictive value of spiral CT in the diagnosis of closed loop obstruction Scaglione M, Grassi R, Pinto A, Giovine S, Gagliardi N, Stavolo C, & Romano L 2004 Italy | 120 cases of closed loop SBO who had undergone laparotomy within 6 h of CT (iv contrast) and plain abdominal x ray (AXR). | Retrospective analysis | Diagnosis of closed loop SBO and diagnosis of infarction | CT diagnosed closed loop obstruction in 78%. PPV for CT diagnosis of strangulation 100%, negative predictive value (NPV) 73% | Retrospective analysis. |
| Computed tomography diagnosis of ischemia and complete obstruction in small bowel obstruction: a systematic review. Mallo RD, Salem L, Lalani T, et al. 2005, USA | 11 studies reporting on diagnosis of ischaemia in SBO (743 patients).7 studies reporting on complete/high grade obstruction (408 patients) | Systematic review | Aggregated PPV, NPV, sensitivity and specificity for CT diagnosis of obstruction and infarction | For bowel ischaemia: PPV 79%, NPV 93%, sensitivity 83%, specificity 92%.For bowel obstruction: PPV 92%, NPV 93%, sensitivity 92%, specificity 94% |
Author Commentary:
Published literature supports the use of CT as a sensitive and specific test for small bowel obstruction. The evidence supports the proposal that CT provides reliable information regarding cause of the obstruction and presence of bowel strangulation.
Bottom Line:
CT is a useful investigation in patients presenting with suspected SBO.
References:
- Ha HK, Kim JS, Lee MS, Lee HJ, Jeong YK, Kim PN, Lee MG, Kim KW, Kim MY, & Auh YH. Differentiation of simple and strangulated small-bowel obstructions: usefulness of known CT criteria.
- Suri S, Gupta S, Sudhakar PJ, Venkataramu NK, Sood B, & Wig JD. Comparative evaluation of plain films, ultrasound and CT in the diagnosis of intestinal obstruction.
- Beall DP, Fortman BJ, Lawler BC, & Regan F. Imaging bowel obstruction: a comparison between fast magnetic resonance imaging and helical computed tomography.
- Lazarus DE, Slywotsky C, Bennett GL, Megibow AJ, & Macari M. Frequency and relevance of the
- Scaglione M, Grassi R, Pinto A, Giovine S, Gagliardi N, Stavolo C, & Romano L. Positive predictive value and negative predictive value of spiral CT in the diagnosis of closed loop obstruction
- Mallo RD, Salem L, Lalani T, et al.. Computed tomography diagnosis of ischemia and complete obstruction in small bowel obstruction: a systematic review.