For evaluation and diagnosis bowel obstruction in infants can be divided into:
1.
HIGH BOWEL OBSTRUCTION
- occuring proximal to ileum
- 3 or fewer dilated bowel loops
- various combination of gastric,
duodenal and jejunal dilatation
2.
LOW BOWEL OBSTRUCTION
- diffuse dilatation of small bowel loops
- more than 3 dilated bowel loops
- involve distal ileum or colon
HIGH BOWEL OBSTRUCTION
1.
Hypertrophic Pyloric Stenosis
- more common in first born male child
- 2-6 weeks after birth
- Plain radiograph: single bubble sign (dilated stomach) Fig. 3
- Ultrasonography: Pyloric muscle thickness 3-4mm,
Pyloric canal length 14-20mm,
target sign of pylorus on axial scan Fig. 5 Fig. 6
Fig. 4: Diagrammatic representation of pyloric muscle in IHPS
References: A.D.A.M. atlas of anatomy
2.
Duodenal atresia
- can be divided into 3 types
Fig. 7: Diagrammatic representation - Duodenal atresia
References: Skandalakis' surgical anatomy
A- mucosal web/ diaphragm between proximal and distal ends
B- fibrous cord between both ends
C- complete separation of both ends with absent mesentry in between
- recurrent episodes of bilious emesis
- abdominal distension maybe seen in the epigastric region
- Plain radiograph: Double bubble (stomach & duodenum) Fig. 8
- no gas distal to duodenum- complete atresia
- gas distal to duodenum- incomplete atresia/ type A
- Prenatal diagnosis: fetal USG showing double bubble sign Fig. 9
Fig. 10: Duodenal Stenosis: plain. 15min, 1hr & 3hr delayed film with oral contrast
References: Department of Radiology, L.H.M.C. Delhi/IN
3.
Malrotation and Midgut volvulus
- repeated vomiting ( bile stained in most cases)
- abdominal distension
- Plain radiograph: upper GI obstruction Fig. 11
- UGI contrast study: "Right"sided DJ; corkscrew jejunum Fig. 12
- USG: Fig. 13
- 1. altered SMA & SMV relationship with SMA on the right;
- 2. whirlpool sign on color doppler;
- 3. mesentric vein twisting around the artery
Fig. 15: Malrotation with midgut volvulus: UGI contrast series with oral contrast
References: Department of Radiology, L.H.M.C. Delhi/IN
Fig. 14: Malrotation with midgut volvulus: mesentric vein twisting around the artery
References: Department of Radiology, L.H.M.C. Delhi/IN
4.
Jejunal atresia
- Neonate presents with emesis and abdominal distension
- Radiograph: characterisic "triple bubble" sign with dilated stomach,
duodenum and proximal jejunum
- UGI contrast study: dilated duodenum and proximal jejunum both filled with contrast
Fig. 16: Jejunal atresia: Plain, 0, 15mins & 2hr delayed film with oral contrast and per-operative confirmation
References: Department of Radiology, L.H.M.C. Delhi/IN
Fig. 17: Jejuno-Ileal atresia : diagrammatic representation
References: Department of Pediatric surgery, L.H.M.C. Delhi/IN
LOW BOWEL OBSTRUCTION
1.
Ileal atresia
- Plain radiograph: air filled dilated proximal small bowel loops
- Contrast enema: functional microcolon with dilated small bowel
- Fig. 18
2.
Intussusception
- ileocolic > ileoileal in the infantile age group
- presents with vomiting,
abdominal pain( incessant crying) and "red currant" jelly stools
- Plain radiograph: LGI obstruction,
prominent bowel loops with gas distal to duodenum.
- USG: axial - Doughnut( target sign), longitudinal - sandwich/ Pseudokidney sign
Fig. 19: Ileo-colic intussusception in a 6 month old child : USG and Perop findings
References: Department of Radiology, L.H.M.C. Delhi/IN
3.
Hirschsprung's Disease
- failed migration of colonic ganglion cells during gestation
- according to the length of aganglionic(non-relaxing) segment:
1.
Short segment (only rectum and sigmoid colon); 75% cases
2.
Long segment (till hepatic flexure); 15% cases
3.
Total colonic agangliosis (till caecum +/- distal ileum); 5% cases
4.
Only distal 3-4 cm of rectum near anal sphincter; very rare
- Newborn presents with failure to pass stools within first 48 hours
- Contrast enema: abnormal rectosigmoid ratio ( <1),
transition zone of rectal narrowing,
retained contrast in delayed radiograph
- Fig. 20 Fig. 21
- Rectal biopsy required for definitive diagnosis
Fig. 22: 10 day old child with Total Colonic Agangliosis
References: Department of Radiology, L.H.M.C. Delhi/IN