Diagnosis
Proximal jejunal transection
Findings
CT examination of the abdomen and pelvis with oral and
intravenous contrast demonstrated a left rectus sheath hematoma.
The subjacent small bowel showed wall thickening with intramural
low attenuation regions thought to represent hematoma (figure 1A).
A small amount of free fluid was present in the pelvis (figure 1B).
No free air was observed. Due to fat stranding of the left
lateroconal fascia adjacent to the descending colon (figure 1A), a
gastrograffin enema was performed to rule out colonic injury. No
colonic abnormality was seen, and the patient was admitted for
observation.
Due to continued patient complaints of abdominal pain and
vomiting, a gastrograffin upper gastrointestinal series was
performed. Initial images showed gastroesophageal reflux.
Subse-quent imaging showed contrast to flow promptly through a
dilated duodenum and come to an abrupt halt in the proximal jejunum
with a "beaked" appearance (figure 2). Scant amounts of contrast
extending from this "beak" were seen to outline a mass. A diagnosis
of traumatic obstruction was made.
The patient was taken to the operating room where a proximal
jejunal transection was found. The mass outlined by contrast was
omentum wrapped around and sealing off the transected jejunum.
Three liters of fluid were removed from the peritoneal cavity, the
injured bowel was resected, and a primary small bowel anastomosis
was performed. After a 1-week stay in the intensive care unit and
drainage of residual pelvic fluid collections, the patient
recovered well without complication.
Discussion
Small bowel laceration/perforation occurs in 3% to 5% of cases
of blunt abdominal trauma.1-3 The classic triad of small bowel
injury (rigid abdomen, tenderness, absent bowel sounds) occurs in
only one-third of patients.1 The detection of this subset of trauma
patients has improved markedly with CT, which has led to a decrease
in the number of negative laparotomies performed in the setting of
blunt abdominal trauma.4
In the setting of blunt abdominal trauma, CT has a sensitivity
of 92%, a specificity of 94%, a positive predictive accuracy of
30%, and a negative predictive accuracy of 100% for the diagnosis
of small-bowel laceration/contusion.2 Common CT signs of small
bowel perforation in order of decreasing frequency include:
peritoneal free fluid (80%), bowel wall thickening (60%), free air
(40%), and contrast extravasation (15%).1,2 Hemoperitoneum can be
diagnosed when the free fluid collections measure >30 HU, with
an average of 45 HU if <48 hours old.5 Free air and contrast
extravasation are found in only half of patients with small-bowel
perforation, but are each nearly 100% specific for bowel
perforation.1 One other sign of small bowel rupture is the streaky
mesentery sign. In one series, this was found in 70% of patients
with small-bowel perforation on the mesenteric side.3 Although no
one sign is 100% sensitive, the presence of multiple signs carry a
90% sensitivity and 95% specificity.2
When small bowel, particularly duodenal, injury is present,
there is a high association of solid organ injury. These include
pancreas (45%), liver (30%), spleen (25%), and kidney (10%).5,6
There is also a 15% incidence of colonic injury.7 The presence of
these other injuries may delay diagnosis of small bowel injury; to
avoid this a thorough examination of the small bowel should be
performed when these injuries are present.3 Extraperitoneal
injuries may also mask small bowel injury, particularly
retroperitoneal and rectus sheath hematomas, as in this case.6 If
treatment of small bowel perforation is delayed, mortality rises
dramatically from 5% to 65%.1,8
If abdominal complaints persist after an initial CT shows no
bowel injury, continued surveillance is warranted. A surgical
series from Canada has reported delayed intestinal perfor-ation
after blunt abdominal trauma.9 All patients had persistent
complaints of abdominal pain. Three-quarters of the patients had
spinal injury. All had either direct insult to the bowel or the
mesenteric vessels, with 75% showing adjacent mesenteric hematoma.9
Continued surveillance with CT is widely accepted.8 The role of
other contrast studies such as UGI series is not yet clearly
defined.l,8
REFERENCES
1. Rizzo MJ, Federle MP, Griffiths BG: Bowel and mesenteric
injury following blunt abdominal trauma: Evaluation with CT.
Radiology 173:143-148, 1989.
2. Sherck J, Shatney C, Sensaki K, Selivanov V: The accuracy of
computed tomography in the diagnosis of blunt small bowel
perforation. Am J Surg 168:670-675, 1994.
3. Hagiwara A, Yukioka T, Satou M, et al: Early diagnosis of
small intestine rupture from blunt abdominal trauma using computed
tomography: Significance of the streaky density within the
mesentery. J Trauma 38:630-633, 1995.
4. Wing VW, Federle MP, Morris JA Jr, et al: The clinical impact
of CT for blunt abdominal trauma. AJR 145:1191-1194, 1985.
5. Wolfman NT, Bechtold RE, Scharling ES, Meredith JW: Blunt
upper abdominal trauma: Evaluation by CT. AJR 158:493-501,
1991.
6. Federle MP, Goldberg HI, Kaiser JA, et al: Evaluation of
abdominal trauma by computed tomography. Radiology 138:637-644,
1981.
7. Weissleder R, Rieumont MJ, Wittenberg J: Primer of Diagnostic
Imaging, 2nd ed, p. 167. St Louis, Mosby, 1997.
8. Cone JB, Eidt JF: Delayed diagnosis of duodenal rupture. Am J
Surg 168:676-679, 1994.
9. Winton TL, Girotti MJ, Manley PN, Sterns EE: Delayed
intestinal perforation after nonpenetrating abdominal trauma. Can J
Surg 28:437-439, 1985.
- Rizzo MJ, Federle MP, Griffiths BG: Bowel and
mesenteric injury following blunt abdominal trauma: Evaluation with
CT. Radiology 173:143-148, 1989.
- Sherck J, Shatney C, Sensaki K, Selivanov V:
The accuracy of computed tomography in the diagnosis of blunt small
bowel perforation. Am J Surg 168:670-675, 1994.
- Hagiwara A, Yukioka T, Satou M, et al: Early
diagnosis of small intestine rupture from blunt abdominal trauma
using computed tomography: Significance of the streaky density
within the mesentery. J Trauma 38:630-633, 1995.
- Wing VW, Federle MP, Morris JA Jr, et al: The
clinical impact of CT for blunt abdominal trauma. AJR
145:1191-1194, 1985.
- Wolfman NT, Bechtold RE, Scharling ES, Meredith
JW: Blunt upper abdominal trauma: Evaluation by CT. AJR
158:493-501, 1991.
- Federle MP, Goldberg HI, Kaiser JA, et al:
Evaluation of abdominal trauma by computed tomography. Radiology
138:637-644, 1981.
- Weissleder R, Rieumont MJ, Wittenberg J:
Primer of Diagnostic Imaging, 2nd ed, p. 167. St Louis, Mosby,
1997.
- Cone JB, Eidt JF:Delayed diagnosis of duodenal
rupture. Am J Surg 168:676-679, 1994.
- Winton TL, Girotti MJ, Manley PN, Sterns EE:
Delayed intestinal perforation after nonpenetrating abdominal
trauma. Can J Surg 28:437-439, 1985.