Presentation on theme: "The Pediatric Abdomen: Intussusception"— Presentation transcript:
1 The Pediatric Abdomen: Intussusception Mark Y. WahbaX-ray roundsOctober 9th, 2003
2 Intussusceptionmost common cause of intestinal obstruction between 3 mo and 6 yr of age60% per cent of patients are younger than 1 yr80% of the cases occur before 24 morare in neonatesincidence 1-4/1,000 live birthsmale:female ratio is 4:1
3 Clinical Presentation “sudden onset, in a previously well child, of severe paroxysmal colicky pain that recurs at frequent intervals and is accompanied by straining efforts with legs and knees flexed and loud cries”Vomiting in most cases and is usually more frequent earlyIn the later phase, the vomitus becomes bile stainedStools of normal appearance may occur during the first few hours of symptomsthen fecal excretions are small or more often do not occur, and little or no flatus is passedInfant May be comfortable and play normally between the paroxysms of pain, but if the intussusception is not reduced, the infant becomes progressively weaker and lethargicIt is common for these infants to have a history of severe intermittent abdominal pain every 20 to 30 minutes, with periods of relief lasting 10 to 20 minutes, during which they can appear calm and healthlethargy may be out of proportion to the abdominal signs
4 Clinical Presentation Blood generally is passed in the first 12 hr but at times not for 1-2 days and infrequently not at all60% of infants pass a stool containing red blood and mucus, the currant jelly stoolSome patients have only irritability and alternating or progressive lethargyEventually a shock-like state may develop, with an elevation of body temperature to as high as 41°C (106°F)classic currant jelly stool is a late manifestation of the diseasepulse becomes weak and thready, the respirations become shallow and grunting, and the pain may be manifested only by moaning sounds
5 Clinical Presentation palpation usually reveals a slightly tender sausage-shaped massoften in the right upper quadrantabout 30% of patients do not have a palpable masspresence of bloody mucus on the finger after DRE supports the diagnosisabdominal distention and tenderness develop as intestinal obstruction becomes more acute
7 Gas Distribution: There are pockets of gas scattered in several areas of the abdomen. There is gas in the small bowel, colon, and rectum.Bowel Dilatation: No excessively dilated bowel. The bowel walls are not smooth. Haustra and plicae are preserved.Air-Fluid Levels: None.Arrangement of Loops: Large loops are not present.Impression: Within normal limits.
8 Case 12 month old femaleAll of these patients are vomiting with varying degrees of abdominal pain
10 Radiographic signs of Intussusception target signcrescent signabsent liver edge sign (also called absence of the subhepatic angle)bowel obstructionBut Normal abdominal radiographs do not rule out intussusception
11 plain abdominal films cannot be used to rule out intussusception Keep in mind…plain abdominal films cannot be used to rule out intussusception
12 Target sign a mass in the right upper quadrant sometimes does not have a target appearancemay just resemble a solid mass“pseudokidney” sign because it may have the shape of an oval mass in the RUQ
13 Crescent Signcaused by the intussuscepting lead point protruding into a gas filled pocketif the pocket is large, it may not be crescent shapeddirection of the crescent always points in the direction of normal colon transitThus, it should be more generically called the intussusceptum protruding into a gas filled pocket sign, but this is too long and it is not nearly as catchy as the "crescent" sign.superiorly if found in the ascending colon, right to left if found in the transverse colon, and inferiorly if found in the descending colon
14 Absent Liver Edge Sign Failure to see inferior edge of liver Caused by mass in RUQSilhouetting of the liver edge
15 Bowel Obstruction gas distribution bowel dilation air-fluid levels poor: not much gas over most of the abdomenbowel dilationnot a measured diameter of the bowel, but rather the loss of plications such that a smooth hose-like or sausage-like appearance resultsair-fluid levelsclassic candy cane (or upside down J) appearance where the level in one half of the loop is different from the level in the other half of the looporderlinessdoes view resembles a bag of sausages (obstruction) or a bag of popcorn (ileus)?
24 is a crescent sign in the right upper quadrant, which is definitely not crescent shaped. The intussuscepting lead point is pointing cephalad at the hepatic flexure. The colonicair pocket is large in this case, so the classic crescentshape is not seen. This is why it should more accurately be called the intussusceptum protruding into a gas filled pocket sign, but this is too long to say. Note again that the intusscepting lead point always points in the direction of normal colon transit
31 This is an 8 month old male. supine This is an 8 month old male. supine. The inferior liver margin is not visible. Now look carefully for a target sign. There is a target sign in the right upper quadrant.
32 There is also strong evidence for a bowel obstruction There is also strong evidence for a bowel obstruction. There is an overallpaucity of gas which is poorly distributed. There is evidence of bowel dilation, especially on the upright view (right image). Note that most of the bowel issmooth, resembling hoses. The smooth bowel wall appearance results when excessive bowel dilation results in the loss of haustration and plication. Therearen't many air fluid levels, but the degree of orderliness resembles a bag of sausages more so than a bag of popcorn. This type of bowel obstruction with a paucity of bowel gas in an infant or young child is frequenty associated with intussusception
35 there is a mass appearance in the right upper quadrant of the supine view on the left. This might be a target sign. I’m not convincedBowel obstr:1) gas distribution: paucity of gas in abdomen2) bowel dilation: dilated, smooth loops, no plica circularis3) air-fluid levels: classic candy cane (or upside down J) appearance where the level in one half of the loop is different from the level in the other half of the loop4) orderliness: looks like sausages, not popcorn
36 You think Intussusception, What next? Alert surgery that you are sending someone for imaging to rule out intussusceptionGet plain filmsIf Hx, Phy and plain films convincing:Air/Contrast EnemaIf Hx, Phy and plain films not completely convincing:Ultrasound followed by Air/Contrast enema if necessary
37 Air/Contrast Enema diagnostic and therapeutic shows a filling defect in the head of contrast where its advance is obstructed by the intussusceptum“contrast material between the intussusceptum and the intussuscipiens is responsible for the coil-spring appearance”
38 Ultrasonography a sensitive diagnostic tool see a tubular mass in longitudinal views and a doughnut or target appearance in transverse imagesin the diagnosis of intussusceptionused in conjunction with hydrostatic or air reduction techniques but not here
39 Why Ultrasonography if Enema is diagnostic and therapeutic? Fast (if operator available)No radiationCan rule in/out other pathologyeg. appendicitis
40 Summary Radiographic signs of Intussusception: target sign crescent signabsent liver edge sign (also called absence of the subhepatic angle)bowel obstructionMay have a normal x-ray!
41 ReferencesFind the Intussusception Target and Crescent Signs Radiology Cases in Pediatric Emergency Medicine Volume 7, Case 18 Loren G. Yamamoto, MD, MPH University of Hawaii John A. Burns School of MedicineBehrman: Nelson Textbook of Pediatrics, 16th ed., 2000 W. B. Saunders CompanyIndex of suspicion. Case 2. Diagnosis: intussusception, Muhammad Waseem MD, Orlando Perales MD, Pediatrics in Review, Volume 22 • Number 4 • April 2001James D'Agostino MD, COMMON ABDOMINAL EMERGENCIES IN CHILDREN Emergency Medicine Clinics of North America Volume 20 • Number 1 • February 2002 W. B. Saunders CompanyDr. M. HodsmanPeter the radiiology resident and unknown Radiologist at Alberta Children’s Hospital
43 Intussusception cause of most intussusceptions is unknown seasonal incidence has peaks in spring and autumncorrelation with adenovirus infections has been notedpostulated that swollen Peyer’s patches in the ileum may stimulate intestinal peristalsis in an attempt to extrude the mass, thus causing an intussusception
44 PathopysiologyIntussusceptions are most often ileocolic and ileoileocolic, less commonly cecocolic, and rarely exclusively ilealVery rarely, the appendix forms the apex of an intussusceptionThe upper portion of bowel, the intussusceptum, invaginates into the lower, the intussuscipiens, dragging its mesentery along with it into the enveloping loop.Constriction of the mesentery obstructs venous return; engorgement of the intussusceptum follows, with edema, and bleeding from the mucosa leads to a bloody stool, sometimes containing mucusThe apex of the intussusception may extend into the transverse, descending, or sigmoid colon--even to and through the anus in neglected cases. This presentation must be distinguished from rectal prolapseMost intussusceptions do not strangulate the bowel within the first 24 hr but may later eventuate in intestinal gangrene and shock
45 Clinical Presentation Intussusception should be considered strongly in the presence of a distinctive triad of factors: vomiting without diarrhea; colicky, intermittent abdominal pain; and heme-positive stool. It is important to remember that only 20% of infants who have ileocolic intussusception have this typical triad.A definite anatomic lead point can be recognized in up to 10% of cases. Lead points are more common in neonates, older children, and adults than in infants between 5 and 24 months of age. The typical lead points include Meckel diverticulum, intestinal polyps, intestinal duplications, appendix, and neoplastic lesions. Lead points also occur more frequently in patients who have certain conditions, such as cystic fibrosis, Henoch-Schönlein purpura, Peutz-Jeghers syndrome, and hemolytic-uremic syndrome.Some children who have this condition become very still, listless, and pale and appear to be in shock due to the visceral pain. Lethargy may be the only presenting sign of intussusception in up to 10% of cases. The mechanism causing lethargy is unknown, although it is possible that endorphins or intestinal hormones resulting from the gastrointestinal insult are responsible.
46 TreatmentReduction of an acute intussusception is an emergency procedure and performed immediately after diagnosis in preparation for possible surgeryIn patients with prolonged intussusception with signs of shock, peritoneal irritation, intestinal perforation, or pneumatosis intestinalis, hydrostatic reduction should not be attemptedsuccess rate of hydrostatic reduction under fluoroscopic or ultrasonic guidance is approximately 50% if symptoms are present longer than 48 hr and 75-80% if reduction is done within the first 48 hrBowel perforations occur in % of attempted barium reductions. The perforation rate with air reduction ranges from %