A handlebar injury to the abdomen

A 14 year old boy presented at the emergency department with severe abdominal pain in the right upper quadrant. Two hours before he had lost control of his bicycle and landed heavily on the handlebar. He had vomited once since.

On examination there was bruising to the right upper quadrant. The abdomen was soft but diffusely tender throughout the right side. There were no signs of haemodynamic instability. His white cell count was raised at 19×10⁹/l (normal range 4-11×10⁹/l), but all other results of blood tests were normal. Figure ¹ shows the patient’s initial plain abdominal radiograph and figure ² the computerised tomogram that followed.

Fig 1 Plain abdominal radiograph

Fig 2 Axial contrast computed tomogram of the abdomen

Questions

(1) Describe the radiological findings in figures ¹ and ². What is shown at A, B, and C?

(2) What is the likely diagnosis?

(3) What is the definitive management in this patient?

Answers

(1) Both images show evidence of free retroperitoneal gas. On the abdominal radiograph, air is outlining the upper pole of the right kidney (A), and mottled gas bubbles are seen along the right psoas margin (B). On the computed tomogram², retroperitoneal air pockets are seen adjacent to the pancreas and the right lobe of the liver (C).

(2) These features indicate perforation of the retroperitoneal bowel. The duodenum, which becomes retroperitoneal in its descending second and transverse third part, is the likely site of injury.

(3) This patient needs an emergency laparotomy to identify the site of the perforation and repair it.

The boy was taken to theatre. The findings at laparotomy are shown in figure ³.

Fig 3 Intraoperative photograph during laparotomy for retroperitoneal bowel perforation

Questions

(1) Which organs are labelled A, B, and C in figure ³?

(2) What is the abnormality identified by the arrow? What are your concerns?

(2) How would you proceed?

Answers

(1) A duodenum; B stomach; C small bowel

(2) The wall of the duodenum has a large tear. Gastrointestinal content has spilled, contaminating the wound. Risk of infection after operation is high, including abscess formation, wound infection, and generalised sepsis.

(3) The injured area and surrounding organs must be inspected carefully. In particular, you should check for any damage to the pancreas, which is closely associated with the duodenum. In this case the duodenal tear was closed primarily with interrupted sutures. However, certain injuries may need some form of duodenal diversion. A thorough washout of the abdomen should be performed and a drain left in place. Intravenous antibiotics should be maintained after operation.

One week later the drain was noted to contain bile. A computed tomogram using oral contrast was performed (figs ⁴ and ⁵).

Fig 4 Axial oral contrast computed tomogram at the level of the duodenal repair

Fig 5 Axial oral contrast computed tomogram at the level of the intra-abdominal drain

Questions

(1) What is shown at A and B in figures ⁴ and ⁵?

(2) What has happened?

(3) How would you manage this patient now?

Answers

(1) Arrow A shows a leak of contrast contained in the region of the duodenum. The contrast can be seen leaving the abdominal cavity through the drain, B.

(2) The duodenal repair has broken down, probably because of local contamination or tissue ischaemia. Bowel contents are leaking from the duodenum.

(3) This is a contained leak, and the patient remains systemically well. He can, therefore, be managed conservatively with a period of total parenteral nutrition to allow the duodenum to heal. Should he start to display signs of sepsis or peritonism, however, further surgical intervention will be required.

The boy continued to be managed conservatively, and after eight weeks he was eating a normal diet and was well enough to be discharged from hospital.

Discussion

Handlebar injuries have been reported to account for 8-13% of cases of blunt abdominal trauma in children, second only to falls and road traffic crashes.^{w1 w2} After blunt abdominal trauma the spleen and liver are the most commonly injured organs, followed by the kidneys, pancreas, and duodenum.^{w3 w4}

Blunt force causes injury to intra-abdominal organs by three different mechanisms.^w5 Shear forces, created by rapid deceleration, can cause organs and vascular pedicles to tear. Alternatively, organs may be crushed between the anterior abdominal wall and the vertebral column or posterior thoracic cage. Solid viscera, such as the spleen, liver, and pancreas are particularly susceptible. And sudden external compression can result in a big rise in intraluminal pressures, causing hollow organs such as the duodenum to burst.

Presentation

A patient who has sustained blunt abdominal trauma may present with anything from abdominal tenderness to peritonitis with signs of shock. Children have a great ability for physiological compensation, and some signs, such as hypotension, may not occur until late.

The force of injury and the organs involved will in part determine severity when a patient presents. The liver and spleen are large, vascular, and relatively exposed organs. After injury the resulting blood loss and peritoneal irritation are more likely to show clinically. In contrast, retroperitoneal structures, such as the duodenum and kidneys, are relatively more protected, and damage often results in non-specific signs and symptoms. This can lead to a delay in diagnosis, resulting in more complications and admission to hospital.^w6

Imaging

Diagnosis after blunt abdominal trauma is from a combination of clinical findings and imaging. Changes on plain radiographs can be subtle. Haemoperitoneum should be suspected when the normal soft tissue silhouettes are obscured. Sufficient free intraperitoneal air so as to become visible under the diaphragm is rare, particularly early on. Specific findings of retroperitoneal duodenal perforation include air bubbles along the right margin of the psoas or the upper pole of the right kidney (fig 1¹).^w3

Ultrasound imaging in children has advantages in that it is non-invasive and non-irradiating. It can rapidly identify free intra-abdominal fluid, which correlates well with organ injury.^w7 Computed tomography is commonly the diagnostic test of choice because it can show specific organ injuries and allows detailed visualisation of the retroperitoneum.^{w2 w8}

The management of blunt abdominal trauma is naturally dependent on the severity of the injury. In general, stable patients without signs of evolving peritonitis can be managed conservatively. Patients who are haemodynamically unstable or have signs of bowel perforation require laparotomy.

This case reminds us to maintain a high index of suspicion when assessing children with blunt abdominal trauma. Initial clinical and radiological signs are often subtle and if missed can lead to delayed diagnosis. Computed tomography can provide important diagnostic information in these instances.

Competing interests: None declared.

Patient consent: Obtained.

Provenance and peer review: Not commissioned; externally peer reviewed.

References w1-w8 are on student.bmj.com.

1. w1 Canty TG Sr, Canty TG Jr, Brown C. Injuries of the gastrointestinal tract from blunt trauma in children: a twelve year experience at a designated paediatric trauma centre. J Trauma 1999;46:234-240.
2. w2 Desai KM, Dorward IG, Minkes RK, Dillon PA. Blunt duodenal injuries in children. J Trauma 2003;54:640-646
3. w3 Plancq MC, Villamizar J, Richard J, Canarelli JP. Management of pancreatic and duodenal injuries in paediatric patients. Paediatr Surg Int. 2000;16:35-39
4. w4 Cone JB, Eidt JF. Delayed diagnosis of duodenal rupture. Am J Surg. 1994;168:676-678
5. w5 Salomone JA. Blunt abdominal trauma. eMedicine.com (http://www.emedicine.com/EMERG/topic1.htm) August 2007.
6. w6 Clendenon JN, Meyers RL, Nance ML, Scaife ER. Management of duodenal injuries in children. J Paed Surg. 2004;39:964-968
7. w7 Rathaus V, Zissin R, Werner M, Erez I, Shapiro M, Grunebaum M, Konen O. Minimal pelvic fluid in blunt abdominal trauma: the significance of this sonographic finding. J Paed Surg. 2001;36:1387-9
8. w8 Rance CH, Singh SJ, Kimble R. Blunt Abdominal Trauma in Children. J. Paediatr. Child Health 2000;36:2-6.

       

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