BOWEL AND MESENTERIC INJURIES IN BLUNT TRAUMA
USE OF ORAL CONTRAST MEDIUM IN CT EXAMS FOR TRAUMA
Discussion and references from HOT TOPICS – TRAUMA RADIOLOGY WORKSHOP 2001/Bertil Leidner, HS; Mats Beckman, KS
Pros and cons for using oral contrast medium:
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Excluding bowel injury is becoming more important as many solid organ injuries are managed conservatively. When surgery was the rule, the concomitant
bowel injury was found by laparatomy, but now the bowel injury is at risk for delayed presentation if it is not recognized by the CT- exam. Delayed diagnosis (even as little as 6-8 h) carries an increased morbidity and even an increased mortality rate! (ref 9)
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Early CT experience had low sensitivity for bowel and mesenteric injuries, but spiral CT state of the art scanning shows a very sensitivity and high negative predictive value (ref 1).
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No solid scientific evidence proves oral contrast favourable (one is negative, ref 7).
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Dedicated USA trauma radiologists are convinced of the benefit of oral contrast from their everyday practice (Drs Mirvis, Shanmuganathan, Federle and Halvorsen), although only half of USA centers do use oral contrast.
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Few Scandinavian hospitals use oral contrast. Our own (BL-MB) experience includes only few positive preoperative exams of bowel/mesenteric injuries as compared to our Danish collegue Henrik Teisen, who showed us numerous cases.
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Oral contrast makes it possible to find contrast leakage but also the thickening of the injured bowel wall, directing the focus to a specific area to scrutinize for signs of complete bowel wall injury = indication for laparatomy.
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Oral contrast is safe to administer (ref 4).
Conclusion:
We recommend the introduction of oral contrast usage in the Scandinavian trauma scene as a mean to focus on GI injury. The feasibility of a scientific study will be examined at KS aimed to include the cooperation of as many Scandinavian centers as possible.
Strategy to introduce oral contrast use in our hospitals
Educational
Radiologists
-evidence of oral contrast usefulness
-image bank
Surgeons
-visit their internal meetings
-by correct CT readings
Organizational
-trauma committee consensus
-emergency room – contrast administration procedure is to be trained
AD EDUCATIONAL
Diagnostic features for BOWEL INJURY
Specific CT signs
Free extra intestinal air
Oral contrast/intestinal content extraluminally
Discontinuity of bowel wall
Air within bowel wall
Nonspecific CT signs
Bowel wall thickening
Free intraperitoneal fluid with no source
Image examples see ref 1 and 8
How to give oral contrast:
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Procedure: 400 ml of 2-3 % Gastrografin (mix 20-30 ml of Gastrografin in 1000 ml water – alternatively Omnipaque 300 mg I/ml) is given to the patient as soon as possible in the trauma admitting room. If possible the patient drinks this with a straw; if not it is given by a nasogastric tube.
The CT exam is NOT to be delayed in waiting for the contrast to pass distally. An additional 200 ml of 2-3 % Gastrografin is given to the patient on the CT table.
References and selected abstracts:
Helical computed tomography of bowel and mesenteric injuries.
Killeen KL, Shanmuganathan K, Poletti PA, Cooper C, Mirvis SE.
Department of Diagnostic Radiology, University of Maryland Medical System and Shock Trauma Center, Baltimore, Maryland 21201-1595, USA.
BACKGROUND: The role of computed tomography in diagnosing hollow viscus injury after blunt abdominal trauma remains controversial, with previous studies reporting both high accuracy and poor results. This study was performed to determine the diagnostic accuracy of helical computed tomography in detecting bowel and mesenteric injuries after blunt
abdominal trauma in a large cohort of patients. METHODS: One hundred fifty patients were admitted to our Level I trauma center over a 4-year period with computed tomographic (CT) scan or surgical diagnosis of bowel or mesenteric injury. CT scan findings were retrospectively graded as negative, nonsurgical, or surgical bowel or mesenteric injury.
The CT scan diagnosis was then compared with surgical findings, which were also graded as negative, nonsurgical, or surgical. RESULTS: Computed tomography had an overall sensitivity of 94% in detecting bowel injury and 96% in detecting mesenteric injury. Surgical bowel cases were correctly differentiated in 64 of 74 cases (86%), and surgical
mesenteric cases were correctly differentiated from nonsurgical in 57 of 76 cases (75%). CONCLUSION: Helical CT scanning is very accurate in detecting bowel and mesenteric injuries, as well as in determining the need for surgical exploration in bowel injuries. However, it is less accurate in predicting the need for surgical exploration in
mesenteric injuries alone.
Performance of CT in detection of bowel injury.
Butela ST, Federle MP, Chang PJ, Thaete FL, Peterson MS, Dorvault CJ, Hari AK, Soni S, Branstetter BF, Paisley KJ, Huang LF.
Department of Radiology, University of Pittsburgh Medical Center-Presbyterian Hospital, 200 Lothrop St., Pittsburgh, PA 15213, USA.
OBJECTIVE. The objective of our study was to identify relevant and reliable CT signs of bowel injury, to determine the overall performance of CT in detection of bowel injuries, and to establish the effect of the training level of radiologists on this performance. MATERIALS AND METHODS. Abdominal CT scans of 112 patients with blunt abdominal trauma
were prospectively and retrospectively reviewed. Fifty patients had proven bowel injuries (with or without other visceral injuries), whereas 62 patients had no bowel injury and comprised the comparison or control group. Thirty-one of the 62 patients in the comparison group had surgical proof of abdominal but not bowel or mesenteric injuries. The
retrospective review of the 112 CT scans was performed randomly and individually by nine radiologists unaware of the diagnosis, including three faculty abdominal radiologists, three senior residents in training, and three junior residents in training. Individual performance and group performance were evaluated by receiver operating characteristic
analysis, and interobserver agreement was tested. Individual CT signs as relevant predictors of bowel injury were identified by logistic regression. RESULTS. Relevant predictors of bowel injury included mesenteric infiltration, bowel wall thickening, extravasation of vascular or enteric contrast agent, and the presence free air. In the
retrospective blinded review, CT showed good to excellent interobserver reliability for individual CT signs as well as for diagnosis of bowel and visceral injuries. Faculty radiologists tended to diagnose injuries with greater accuracy and confidence, but they showed significantly better performance than residents only in diagnosing duodenal
perforation. For the prospective CT diagnosis of bowel injury, CT had a sensitivity of 64%, an accuracy of 82%, and a specificity of 97%. CONCLUSION. Bowel injuries are challenging to diagnose on CT. Radiologists with various levels of experience and expertise can achieve accurate and reproducible results using a variety of CT criteria.
Blunt bowel and mesenteric injuries: the role of screening computed tomography.
Malhotra AK, Fabian TC, Katsis SB, Gavant ML, Croce MA.
Department of Surgery, University of Tennessee, Memphis 38163, USA.
BACKGROUND: Early generation scanners have demonstrated poor sensitivity detecting blunt bowel/mesenteric injuries (BBMI). This study was aimed at determining the accuracy and role of helical scanners in BBMI. METHODS: Retrospective chart review of patients with BBMI, or computed tomographic scans suspicious of BBMI, from August of 1995 to
December of 1998. RESULTS: One hundred of 8,112 scans (1.2%) were suspicious of BBMI. Of these suspicious scans, 53 patients had BBMI (true positive-TP) and 47 patients did not (false positive-FP). Seven patients with negative scans had BBMI (false negative-FN). Computed tomography contributed toward early surgery in 77% of patients who may have
been delayed. Six patients developed intra-abdominal abscess. The abscess group had a significantly longer time interval from injury to surgery. Multiple findings were seen in 57% of true positive scans, whereas in 13% of false positive scans (p < 0.0001). An algorithm for management of BBMI is presented. CONCLUSION: Helical scanners have high
accuracy in detecting BBMI. Single versus multiple findings are useful in managing these injuries.
Abdominal trauma: use of oral contrast material for CT is safe.
Federle MP, Yagan N, Peitzman AB, Krugh J.
Department of Radiology, University of Pittsburgh Medical Center, PA 15213, USA.
PURPOSE: To determine the potential risk of aspiration pneumonitis associated with use of oral contrast material in computed tomography (CT) performed for evaluation of abdominal trauma. MATERIALS AND METHODS: In 510 consecutive adult patients, a dilute 2.5% solution of diatrizoate meglumine and sodium was administered orally or by means of a
nasogastric tube as part of a routine protocol for CT evaluation of acute abdominal trauma. A retrospective review of medical records was performed to determine evidence of aspiration pneumonitis occurring before or after CT. RESULTS: None of the patients had aspiration of contrast material or gastric contents attributable to the CT examination.
CONCLUSION: Use of contrast material for stomach and bowel opacification during CT for evaluation of abdominal trauma appears to be safe. Proper preparation and administration of contrast material and control of the patient's airway are essential to ensure the safety of this procedure.
CT findings of mesenteric injury after blunt trauma: implications for surgical intervention.
Dowe MF, Shanmuganathan K, Mirvis SE, Steiner RC, Cooper C.
Department of Diagnostic Radiology, University of Maryland Medical Center, Baltimore 21201, USA.
OBJECTIVE: The purposes of this study were to determine the spectrum of CT findings of mesenteric injury, to compare CT findings of mesenteric injury with surgical observations, and to assess the potential of CT to predict which patients with mesenteric injury require laparotomy. MATERIALS AND METHODS: Blunt trauma patients admitted to our
facility during a 5-year 4-month period with a CT or surgical diagnosis of mesenteric injury were identified from a radiology database and trauma registry. Patients with CT findings of full-thickness bowel injury associated with mesenteric injury or diagnostic peritoneal lavage performed before CT were excluded. CT scans of all patients were
retrospectively reviewed both with and without knowledge of surgical results. Medical records of all study patients were reviewed to ascertain admission physical findings and surgical results. RESULTS: Twenty-seven of 29 patients meeting the study criteria underwent laparotomy, and two others were managed conservatively. Among the 27 patients who
had surgery. 24 (89%) had CT findings of mesenteric injury confirmed. Surgical findings showed CT scans to be falsely negative in two other patients and falsely positive in one other patient. No major discrepancies were found between retrospective CT review done with and without knowledge of the surgical findings. Two CT findings unique to
patients whose injuries, in the judgment of the surgical team, required surgical repair were active extravasation of IV contrast material and bowel wall thickening associated with mesenteric findings. Physical findings did not correlate well with the type and clinical significance of the mesenteric injury. CONCLUSION: The CT finding of mesenteric
bleeding or bowel wall thickening associated with mesenteric hematoma or infiltration in the blunt trauma patient indicates a high likelihood of a mesenteric or bowel injury requiring surgery. The finding of focal mesenteric hematoma or infiltration without adjacent bowel wall thickening is nonspecific and can occur both in mesenteric or bowel
lesions that require surgery and those that do not.
Rupture of the bowel after blunt abdominal trauma: diagnosis with CT.
Mirvis SE, Gens DR, Shanmuganathan K.
Department of Diagnostic Radiology, University of Maryland Medical Center, Baltimore 21201.
OBJECTIVE. The accuracy of CT in the detection of injuries of the solid viscera after blunt trauma is well established, but the value of CT in diagnosing bowel rupture resulting from blunt trauma is controversial. This study was conducted to determine the sensitivity of CT in diagnosing posttraumatic bowel rupture. SUBJECTS AND METHODS. During a
51-month period, 17 preoperative CT scans were obtained in 16 patients who subsequently had bowel ruptures verified surgically. Both preoperative (prospective) and retrospective CT findings were analyzed in these patients. Retrospective interpretation was made by consensus of two radiologists. RESULTS. Surgically confirmed bowel ruptures occurred
in the duodenum (five), ileum (four), jejunum (four), colon (four), and stomach (two). CT findings considered diagnostic of bowel perforation were detected prospectively on 10 (59%) of 17 scans; these included pneumoperitoneum without prior peritoneal lavage (six), mesenteric, intramural, or retroperitoneal free air (six), or direct visualization
of discontinuity of the bowel wall or extravasation of luminal contents (four). Prospective CT findings considered suggestive of bowel rupture were present on five (29%) of the 17 scans; these included intraperitoneal fluid of unknown source (three), thickened (> 4-5 mm) bowel wall (two), gross anterior pararenal fluid without a recognized
source (one), and a mesenteric-bowel wall hematoma (one). On two of 17 scans, findings were seen in retrospect only; these included free intraperitoneal blood without a source (findings on a second CT scan were diagnostic) and pneumoperitoneum. CT findings diagnostic or suggestive of bowel injury were detected prospectively on 15 (88%) of 17 scans
and were noted in all retrospectively. CONCLUSION. CT is sensitive for the diagnosis of bowel rupture resulting from blunt trauma, but careful inspection and technique are required to detect often subtle findings.
PMID: 1442385 [PubMed - indexed for MEDLINE]
Oral contrast solution and computed tomography for blunt abdominal trauma: a randomized study.
Stafford RE, McGonigal MD, Weigelt JA, Johnson TJ.
University of Minnesota, St Paul, USA.
HYPOTHESIS: Oral contrast solution (OC) is unnecessary in the acute computed tomographic (CT) evaluation of the patient with blunt abdominal trauma. DESIGN: Randomized controlled clinical trial. SETTING: Level I trauma center at a university-affiliated teaching hospital. PATIENTS: Five hundred adult patients sustaining blunt abdominal trauma and
requiring urgent resuscitation and CT evaluation of the abdomen were eligible for the study. Those patients who were younger than 18 years, pregnant, or in police custody were excluded. One hundred six patients were excluded from the analysis (15 for inappropriate enrollment, 9 because a CT scan had not been performed, 1 owing to inability to
accept a nasogastric tube, and 81 owing to missing or incomplete records). Three hundred ninety-four patients with an average age of 36 years, an average Revised Trauma Score of 10, and an average Glasgow Coma Scale score of 12 are included in the analysis. INTERVENTIONS: Patients were randomized via computer-generated assignment to 1 of 2 groups
either receiving OC or not receiving OC (no OC) after placement of a nasogastric tube. All patients received intravenous contrast solution and then underwent helical CT scan of the abdomen and pelvis using the GE HiSpeed Advantage CT scanner (GE Medical Systems, Milwaukee, Wis). MAIN OUTCOME MEASURES: Abnormal CT results, need for laparotomy,
missed gastrointestinal tract and solid organ injuries, nausea, and vomiting. RESULTS: There were 199 patients in the OC group and 195 patients in the no OC group. Vomiting occurred in 12.9% of patients and the incidence was not different between groups. One hundred five abnormal scans (50 OC and 55 no OC) were obtained and 33 patients with
abnormal scans (19 OC and 14 no OC) underwent laparotomy. There was 1 nontherapeutic laparotomy in each group. There was 1 missed small-bowel injury in the OC group (sensitivity, 86%) and no missed small-bowel injuries in the no OC group (sensitivity, 100%). Six bowel injuries were identified at laparotomy in the OC group. Two of the injuries were
perforations without contrast extravasation but with pneumoperitoneum in 1. Three bowel injuries were identified in the no OC group, none of which were perforations. Seven of the 9 patients with bowel injury at laparotomy had associated intra-abdominal injury. Specificity for solid organ injury was 94% in the OC group and 57.1% in the no OC group.
Sensitivity for solid organ injury was 84.2% in the OC group and 88.9% in the no OC group. The average time to abdominal CT scanning after placement of a nasogastric tube was 39.02+/-18.73 minutes in the no OC group and 45.92+/-24.17 minutes in the OC group (P= .008). CONCLUSION: The addition of OC to the acute CT protocol for the evaluation of
the patient with blunt abdominal trauma is unnecessary and delays time to CT scanning.
PMID: 10367871 [PubMed - indexed for MEDLINE]
CT of blunt trauma bowel and mesenteric injury: typical findings and pitfalls in diagnosis.
Brody JM, Leighton DB, Murphy BL, Abbott GF, Vaccaro JP, Jagminas L, Cioffi WG.
Departments of Diagnostic Imaging, Brown University School of Medicine, Rhode Island Hospital, 593 Eddy St, Providence, RI 02903, USA. jbrody@lifespan.org
Detection of bowel and mesenteric injury can be challenging in patients after blunt abdominal trauma. Early diagnosis and treatment are critical to decrease patient morbidity and mortality. Computed tomography (CT) has become the primary modality for the imaging of these patients. Signs of
bowel perforation such as free air and contrast material are virtually pathognomonic. Bowel-wall thickening, free fluid, and mesenteric infiltration may be seen with this type of injury and partial thickness injuries. The authors present and discuss the range of CT findings seen with bowel and mesenteric injuries. Examples of observation and
interpretation errors are also provided to highlight pitfalls encountered in the evaluation of abdominopelvic CT scans in patients after blunt trauma.
Relatively short diagnostic delays (<8 hours) produce morbidity and mortality in blunt small bowel injury: an analysis of time to operative intervention in 198 patients from a multicenter
experience.
Fakhry SM, Brownstein M, Watts DD, Baker CC, Oller D.
Trauma Services, Inova Regional Trauma Center at Inova Fairfax Hospital, Falls Church, Virginia 22042, USA.
OBJECTIVE: Blunt small bowel injury (SBI) is uncommon, and its timely diagnosis may be difficult. The impact of operative delays on morbidity and mortality has been unclear. The purpose of this study was to determine the relationship of diagnostic delays to morbidity and mortality in blunt
SBI. METHODS: Patients with blunt SBI with perforation were identified from the registries of eight trauma centers (1989-1997). Patients with duodenal injuries were excluded. Data were extracted by individual chart review. Patients were classified as multi-trauma (group 1) or near-isolated SBI (group 2 with Abbreviated Injury Scale score < 2
for other body areas). Time to operation and its impact on mortality and morbidity was determined for each patient. RESULTS: A total of 198 patients met inclusion criteria: 66.2% were male, mean age was 35.2 years (range, 1-90 years) and mean Injury Severity Score was 16.7 (range, 9-47). 100 patients had multiple injuries (group 1). There were 21
deaths (10.6%) with 9 (4.5%) attributable to delay in operation for SBI. In patients with near-isolated SBI, the incidence of mortality increased with time to operative intervention (within 8 hours: 2%; 8-16 hours: 9.1%; 16-24 hours: 16.7%; greater than 24 hours: 30.8%, p = 0.009) as did the incidence of complications. Delays as short as 8 hours 5
minutes and 11 hours 15 minutes were associated with mortality attributable to SBI. The rates of delay in diagnosis were not significantly associated with age, gender, intoxication, transfer status, or presence of associated injuries. CONCLUSION: Delays in the diagnosis of SBI are directly responsible for almost half the deaths in this series.
Even relatively brief delays (as little as 8 hours) result in morbidity and mortality directly attributable to "missed" SBI. Further investigation into the prompt diagnosis of this injury is needed.