醫(yī)科大學(xué)精品課件：病例1

1、Case 1Patient Presentation A 24-month-old male came to the emergency room with a 12 hour history of colicky abdominal pain every 15-20 minutes. He is normal between episodes but has decreased overall intake. He has non-bilious emesis during some of these episodes.He has had several normal stools whi

2、ch do not contain mucous or blood. The rest of his history is unremarkable.The pertinent physical exam shows a healthy boy with normal growth parameters. His abdomen shows no distension, nor is tympanetic. He has normal bowel sounds. His abdomen is soft, without pain and with no organomegaly or mass

3、es palpable. His genitourinary examination is normal.At this time the differential diagnosis that was discussed was gastroenteritis versus intussusception.His radiologic evaluation began with a plain film of his abdomen which showed a non-obstructed gas pattern and a suspicious soft tissue mass in t

4、he right lower quadrant.The ultrasound confirmed the diagnosis of intussusception at the level of the cecum just below the hepatic flexure. During the examination he was noted to draw-up his legs to his abdomen in episodic pain.The intussusception was easily reduced by air contrast enema. He was adm

5、itted for 20 hours of follow-up and was eating and drinking normally at discharge.Figures Figure 19 - Supine AP radiograph of the abdomen showing an unremarkable bowel gas pattern and suggests a mass in the right lower quadrant. Figure 20 - Ultrasound image of the right lower quadrant, obtained tran

6、sversely through the colon, showing a colonic mass in the ascending colon, the so-called “target sign” representing intussusception.Figure 21 - Ultrasound image of the right lower quadrant, obtained longitudinally through the colon, showing a colonic mass in the ascending colon, the so-called “pseud

7、o-kidney sign” representing intussusception.Figure 22 - Fluoroscopic spot film obtained during an air enema showing an intussusception near the hepatic flexure. The “coiled-spring” appearance of the intussusception can be seen.DiscussionIntussusception happens when one segment of the gastrointestina

8、l tract telescopes into an adjacent segment. The outer receiving segment of bowel is known as the intussuscipiens and the inner inverting segment is known as the intussusceptum.It occurs most often in children between 2 months to 5 years, with a peak incidence between 4-10 months. Males are more oft

9、en affected than females by 3:2. It also occurs more often after abdominal operations.It is the second most common acute abdominal emergency in children after appendicitis. in adults 80% have an underlying cause or lead point such as a polyp, tumor, fibrosis, endometriosis, etc. The cause is usually

10、 idiopathic in children (95%) but it is hypothesized that In children is caused by a viral induced edema of the Peyers patches in the ileum that serves as a lead point, but this hypothesis has not been confirmed. It commonly occurs near the ileocecal valve.Unequal longitudinal forces in the bowel th

11、en cause the bowel wall to invaginate into the lumen. The intussusceptum is propelled onwards by peristalsis with more bowel becoming involved. Blood vessels and mesentery also become involved with resulting edema, all of which results in intestinal obstruction.Pressure in the bowel wall increases w

12、ith impedence of venous outflow and followed by arterial inflow, which again leads to edema and more intestinal obstruction.Early diagnosis and treatment is necessary to prevent these physiologic changes from progressing to bowel infarction and perforation.If not treated, intussusception can be fata

13、l in 2-5 days. In the radiology suite, diagnosis and definitive treatment often occur concurrently. Plain film was first used to diagnose intussusception in 1941. Early on there are few radiological changes seen. With time, soft tissue densities or absence of air in the right upper and lower quadran

14、ts can be seen.Small bowel dilitation and air fluid levels may also be seen in more advanced cases. If the intussusception has progressed to perforation, then free air may be seen.Although plain films are useful, they lack sensitivity and many false negatives can occur. Ultrasound was first used to

15、diagnose intussusception in the 1980s.Ultrasound is fast, non-invasive, easy to perform and reproducible, with a high rate of sensitivity and specificity in experienced hands. The classic findings are a doughnut or target sign with concentric rings formed by the intussusceptum.The pseudo-kidney sign

16、 on longitudinal imaging shows multiple thin parallel stripes of varrying echogenitiy . Barium or air enema is one of the most reliable tests for intussusception in children. It is both diagnositic and therapeutic.The pediatrician must work with the radiologist and surgeon, to clinically stabilize t

17、he child before the procedure and to plan for treatment of possible problems such as perforation.Radiologic reduction should be attempted unless there are signs of peritoneal irritation and is successful in 90% of cases.The procedure involves placing a catheter without balloon inflation into the rec

18、tum and taping the buttocks together. Barium in introduced via a reservoir suspended 3 feet over the child.Traditionally 3 attempt, each lasting 3 minutes are made to reduce the intussusception.Fluoroscopy confirms the intusccusception and monitors the reduction. The intussusception is reduced when

19、there is free flow of barium or air into the terminal ileum.Air can be used instead of barium by introducing air up to a pressure of 120 centimeters of water.If air is used, the pressure can be maintained for 3 minutes before being released. The air enema reduction is also attempted 3 times before s

20、urgery is indicated.Some centers will attempt more than 3 times to reduce the intussusception if progress is being made as the patient will be going to the operating room if the enema fails.The main risk of the procedure is causing perforation of the bowel or unmasking a pre-existing perforation of

21、bowel and subsequent barium peritonitis or tension pneumoperitoneum. Air has less risk of perforation than barium and is less messy. Computed tomography and magnetic resonance imaging are not often used in children as the diagnosis is often made by ultrasound or enema. These modalities are often use

22、d in adults to diagnose the underlying pathology of the intussusception. After reduction, the children are monitored for several hours for reoccurrance (3-10%) and then are dischaged home. Reoccurence after the peri-reduction period is uncommon.Children with reoccurence or who are older than the typical age should be evaluated for possible underlying pathology.Causes in descending order are: Meckels diverticulum, polyp, gastrointestinal duplication, hemangioma, suture line, appendix, tumors and ecto