Neonatal intestinal obstruction: how to make etiological diagnosis?

Transcription

1 Neonatal intestinal obstruction: how to make etiological diagnosis? Poster No.: C-1414 Congress: ECR 2013 Type: Educational Exhibit Authors: W. Mnari, M. Zguidi, A. Zrig, M. Maatouk, B. Hmida, R. Salem, M. Golli; Monastir/TN Keywords: Abdomen, Paediatric, Gastrointestinal tract, Conventional radiography, Ultrasound, Contrast agent-other, Surgery, Acute, Obstruction / Occlusion, Volvulus DOI: /ecr2013/C-1414 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 30

2 Learning objectives To report and illustrate the contribution of different imaging modalities in diagnosis of neonatal digestive obstruction. To develop an approach to the management of bowel neonatal obstruction involving clinical and imaging data. Page 2 of 30

3 Background Background Bowel obstruction is one of the most common surgical emergencies in newborns. The diagnosis can be evoked in prenatal period using fetal ultrasonography or within the first 30 days of life based on clinical signs of occlusion. It is due to either an anatomical lesion (eg:atresia) or functional disorders such as Hirschsprung's disease. Diagnosis : Prenatally: By ultrasonography (polyhydramnios, intestinal expansion ) Family history (cystic fibrosis ) Aassociated abnormalities Signs of bowel obstruction can include Vomiting with or without bile stained material Gastric residuals before feedings Failure to pas meconium in the first 24 hours of life Abdominal distension The diagnosis is based on history and physical examination The role of imaging is to confirm the obstruction syndrome and to clarify the level and the nature of the obstacle. Imaging is based on the triad: plain X-Ray,water-soluble contrast enema and ultrasonographie with doppler. After birth, air progresses through the gastrointestinal truct: - H1: stomach and duodenum - H6: cæcum - H12: rectum Normally, the same timeline is followed on abdominal radiograph. False-positives bowel obstruction on abdominal radiograph: Page 3 of 30

4 Infection : entérocolitis. Mask ventilation. Incessant crying. Page 4 of 30

5 Imaging findings OR Procedure details Etiological diagnosis A. Organic intraluminal obstruction Gastrointestinal atresia : Atresia types : (fig.1) Type I = mucosal web Type II = fibrous cord Type III = complete separation Duodenal atresia Bilious vomiting in 90% cases. The abdomen is flat except in the epigastric region. Failure to pass meconium. Associated abnormalities. X-Ray usually shows a characteristic «double-bubble» appearance (fig.2 and fig.3). Contrast enema is useless and even dangerous. Other parts of abdomen do not contain gas in complete form of duodenal atresia. Antro-pyloric atresia Exceptional Isolated gastric dilatation Early feedinf vomiting (H1) Respiratory distress: inhalation Plain X-ray: gastric distension without air in the other parts of abdomen (single bubble image) (fig.4) Page 5 of 30

6 Ultrasonography : associated abnormalities Small intestinal atresia Small intestinal atresia is usually caused by the loss of blood supply at the part of the intestine that closes off. The diagnosis is established later than for duodenal atrasia. Bilious vomiting with early abdominal distention. Failure to pas meconium. Plain X-ray : variable distension depending on the seat of atresia with air-fluid levels without gaz in large intestine area (fig.5). Water-soluble contrast enema is usually useless, if it is done it shows a non-functional micro colon with an interrupted small intestine (fig.6). Calcifications on the plain X-ray can be related to a meconium peritonitis. Large intestinal atresia Rare congenital conditions of the lower gastro-intestinal tract It is due to a mucosal web. Image from a barium enema study (fig.7) demonstrates microcolon with complete obstruction to the retrograde flow of barium in the transverse portion of the colon. 2. Gastrointestinal duplications (fig.8) Rarely obstructive in the neonatal period. They may be spherical or tubular in appearance. Sonography revealed an anechoic double-walled cystic lesion. B. Organic extraluminal obstruction Malrotation of the intestine occurs when the two-part rotational process does not proceed normally. The duodenojejunal junction remains right of midline and the cecum remains in the upper left abdomen. The mesentery still attaches to the retroperitoneum. The attachment is very narrow. This «omega» configuration predisposes postnatal rotation about the narrow vascular mesenteric axis, leading to midgut volvulus with subsequent intestinal ischemia and necrosis. Page 6 of 30

7 Ladd's bands is a fibrous stalk of peritoneal tissue that attaches the cecum to the abdominal wall. This condition is found in malrotation of the intestine. (fig.9 and 10). Intestinal malrotation may be complicated by volvulus and intestinal necrosis. Small intestinal volvulus Initially flat abdomen with vomiting, then abdominal distension and signs of severity in relation to intestinal distress. Plain X-ray:Gastroduodenal distension, rare gaz underlying (fig.11) Ultrasonography: Reversal of mesenteric pedicle (fig.12), «Whirlpool sign» (fig.13) Upper gastro-intestinal truct contrast: Turns of twist (fig.14), pre duodenal bar, topographic abnormality C. Functional obstruction 1. Abnormal intestinal contents Meconium Ileus Cystic fibrosis ++ Failure to pas meconium in the first 24 hours of life Abdominal distension Vomiting without then with bile stained material Plain X-ray: multiple dilated bowel loops The classic finding on water-soluble contrast enema (fig.15) is a small colon filled with pellet-like meconium when contrast material goes back into last part of the small intestine. Carefully repeated enema can sometimes raise the intra luminal obstruction. Left microcolon (fig.16) Left colon obstruction in the neonate results from meconium plug syndrome in which there is a failure to pass meconium in the first 24 hours of life, caused by blockage of the distal colon by meconium Flat abdomen immediately after birth, then obstruction syndrome. Digital rectal examination can sometimes eliminate a long meconium plug. Page 7 of 30

8 Plain X-ray: small intestine, right and transverse colon distension. Enema is useful for the diagnosis and for treatment. It shows a left colon with a reduced size. Always think of Hirschsprung's disease (biopsy) and cystic fibrosis. 2. Abnormal peristaltis Hirschsprung's Disease Hirschsprung's disease is a blockage of the large intestine due to improper muscle movement in the bowel. It is a congenital condition. The nerves are missing from a part of the bowel. Areas without such nerves cannot push material through. This causes a blockage. Intestinal contents build up behind the blockage, causing the bowel and abdomen to become swollen. - Rectal or rectosigmoid form (80% of cases) - Long form involving the left colon - Total form reaching the last ileal loop (poor prognosis) - Short form juxta-anal. Hirschsprung's disease is revealed in 90% in the neonatal period. Its diagnosis is histological. Symptoms are variable with complete or incomplete obstruction or failure to pas meconium. Water-soluble contrast enema (fig.17 and 18): abrupt transition++ D. Necrotising enterocolitis Necrosis, ulceration and parietal pneumatosis of the large and small intestine. Mechanisms: ischemia and infection, severe prematurity, perinatal distress. Possible complications: Perforation and peritonitis (early), Bowel obstruction (late). Imaging : diffuse bowel distension, parietal and portal pneumatosis, pneumoperitoneum DIAGNOSTIC STRATEGY AND CHOICE OF RADIOLOGICAL INVESTIGATIONS The choice of imaging explorations depends primarily on the clinical presentation (expanded or flat abdomen, bilious or feeding vomiting...). The goal is to: Page 8 of 30

9 Confirm the diagnosis of occlusion Specify the seat (high or low) Type (complete or incomplete) Start the etiological survey (associated abnormalities, family background, mother's diseases...) A. Plain X-ray is the first examination to be conducted While standing: air-fluid levels While lying down: Complete obstruction: no gaz downstream Incomplete obstruction: gaz downstream (rectum particularly) Questions : Is there an obstacle? If yes, area? Complet ou incomplet? Is there air out of the gastrointestinal tract? Is there calcifications? Systematic analysis the bone? B. Contrast enema Complete obstacle: No indication++ (surgery immediately) Incomplete obstacle : water-soluble upper gastro intestinal contrast Doubt between high and low obstruction :lower intestinal tract enema C. Doppler ultrasound Modality of choice in: Obstruction by volvulus (Whirlpool sign) Intestinal rotation abnormalities (abnormal position of the mesenteric vessels) Intestinal duplications D. Diagrams: Page 9 of 30

10 High neonatal bowel obstruction (fig.19) Lower GI tract obstruction (fig.20) Page 10 of 30

11 Images for this section: Fig. 6 Page 11 of 30

12 Fig. 1 Page 12 of 30

13 Fig. 2: Incomplete duodenal atresia Page 13 of 30

14 Fig. 3: Complete duodenal atresia Page 14 of 30

15 Fig. 4: Antro-pyloric atresia Page 15 of 30

16 Fig. 5: Small intestine atresia : small intestine distension without gaz in large intestine area Page 16 of 30

17 Fig. 7: Small intestine atresia : non functional micro colon with small intestine distension Page 17 of 30

18 Fig. 8: Obstruction in the neonatal period : duplication of the distal small intestine (arrow) responsible for intussusception (open arrow) and bowel obstruction upstream. Fig. 9: Normal rotation of the intestine: note the normal appearance of the root of the mesentery (blue) Page 18 of 30

19 Fig. 10: Malrotation of the intestine: short mesentery leading to volvulus Page 19 of 30

20 Fig. 11 Page 20 of 30

21 Fig. 12 Page 21 of 30

22 Fig. 13 Fig. 14 Page 22 of 30

23 Fig. 15: Meconium ileus : a small colon filled with pellet-like meconium Page 23 of 30

24 Fig. 16: Left microcolon: enema and laparotomy findings Page 24 of 30

25 Fig. 17 Page 25 of 30

26 Fig. 18 Page 26 of 30

27 Fig. 19 Page 27 of 30

28 Fig. 20 Page 28 of 30

29 Conclusion Imaging plays a major role in neonatal bowel obstruction. It is helpful, with clinical symptoms, to establish a diagnosis. Successful management depends on timely diagnosis and appropriate intervention. Page 29 of 30

30 References Juan D, Snyder CL. Neonatalbowelobstruction. SurgClinNorthAm ;92(3): Page 30 of 30