Pediatric abdominal emergencies In the first year of life

Common Pediatric abdominal emergencies In the first year of life Kristian Stien Thomassen Section of Pediatric Radiology Dept. of Radiology and Nuclear Medicine Oslo University Hospital

Understand the age distribution of common pediatric abdominal emergencies Describe the most common clinical presentation of these emergencies Choose the most appropriate imaging Interpret the most common imaging findings Finish in time for lunch :)

References «Barnekirurgi» / «Pediatric surgery» - dr. Sigvald Refsum «Caffey s - Pediatric Diagnostic imaging» - Briand D. Coley «Essential diagnosis of abdominal emergencies in the first year of life» - Louie et al. Emerg Med Clin North Am. 2007 Nov;25(4):1009-40 «Emergent Pediatric US: What Every Radiologist Should Know» - Cogley et al. Radiographics. 2012 May-Jun;32(3):651-65. doi: 10.1148/rg.323115111. If not otherwise stated, all radiological images from Dept. of Radiology and Nuclear medicine, Oslo University Hospital

Pediatric abdominal emergencies Age - definitions Pre-term neonate Full-term neonate Infant GA 23/24w - 36w 6d GA 37w - 42w 31 days of age 31d - 12 months

Common Pediatric abdominal emergencies Neonates Infants Malrotation with volvolus Necrotizing enterocolitis Omphalitis Hirschprung s Disease Hypertrophic pyloric stenosis Incarcerated inguinal hernia Intussusception Appendicitis

Malrotation ) Failure of the midgut to undergo appropriate rotation and retroperitoneal fixation during early fetal life. Malrotation Normally there is a 270º counterclockwise rotation «Midgut» = Duodenum (distal to ampulla vateri) to distal 2/3 of transverse colon Supplied by superior mesenteric artery

Malrotation with volvolus Varying degrees of malrotation giving a wide spectrum of symptoms: Asymptomatic, incidental finding Approximation of duodenum and coecum Chronic (partial/intermittent) volvolus Acute volvolus Suspension from a narrow mesenteric pedicle

Malrotation with volvolus Venous congestion, ischemia, necrosis

Malrotation with volvolus Epidemiology 1 in 5000 live births 80% of cases presents within 1st month of life Males 2:1 Females Clinical presentation Bilious vomiting Hematochezia Abdominal distension Pain Shock Differential diagnosis Meconium ileus Gradual, but rapid progression of symptoms Hirschprung s disease Duodenal atresia NEC

Malrotation with volvolus - Imaging Plain abdominal radiograph Upper GI series Ultrasound

Malrotation with volvolus - Imaging Plain abdominal radiograph: Bowel distention Lack of bowel gas distal to stomach Markedly dilated 2 day old infant with bilious vomiting stomach Separation of bowel loops (mural thickening/ ascites) Tubular appearance of bowel loops Distended abdomen Normal/equivocal findings in 20% Findings not specific for volvolus «Caffey s pediatric diagnostic imaging»

Malrotation with volvolus - Imaging Plain abdominal radiograph: Bowel distention 7 day old infant with bilous vomiting Lack of bowel gas distal to stomach Markedly dilated stomach Separation of bowel loops (mural thickening/ ascites) Tubular appearance of bowel loops Distended abdomen Normal/equivocal findings in 20% Findings not specific for volvolus «Caffey s pediatric diagnostic imaging»

Malrotation with volvolus - Imaging Plain abdominal radiograph: Bowel distention Lack of bowel gas distal to stomach Markedly dilated stomach Separation of bowel loops (mural thickening/ ascites) Tubular appearance of bowel loops Distended abdomen Normal/equivocal findings in 20% Findings not specific for volvolus

Malrotation with volvolus - Imaging Plain abdominal radiograph: Bowel distention Lack of bowel gas distal 2 week old infant with bilous vomiting for several days to stomach Markedly dilated stomach Separation of bowel loops (mural thickening/ ascites) Tubular appearance of bowel loops Distended abdomen Normal/equivocal findings in 20% Findings not specific for volvolus «Caffey s pediatric diagnostic imaging»

Malrotation with volvolus - Imaging Ultrasound Inversion of the SMA and SMV Duodenal wall thickening (>2mm) Dilated distal SMV (compared to proximal part) «Whirlpool sign» Ascites Dilated, distally tapering duodenum SMA SMV «Caffey s pediatric diagnostic imaging»

Malrotation with volvolus Imaging Upper GI series Gold standard Low osmolality Normalfunn water soluble contrast Enteric tube First bolus of contrast important (duodenum often obscured later)

Malrotation with volvolus Upper GI series 7-day old infant Duodenojejunal junction Malrotationwithout volvolus positioned low and to the right of the midline «Corkscrew» - sign «Caffey s pediatric diagnostic imaging»

Malrotation with volvolus Imaging Upper GI series 7-day old infant Malrotation with volvolus Completely obstructed duodenum «Beak» like configuration Anterior position of duodenum relative to vertebral column «Caffey s pediatric diagnostic imaging»

Malrotation with volvolus Imaging Upper GI series Infant with malrotation with volvolus Incomplete obstruction of duodenum Dilated stomach and proximal duodenum Duodenojejunal junction low and to the right «Caffey s pediatric diagnostic imaging»

Necrotizing enterocolitis The most common newborn surgical emergency Inflammatory and infectious condition affecting the gastrointestinal tract - precise pathophysiology not know Several NEC-mimics (Feeding Intolerance of Prematurity, Spontaneous Intestinal Perforation, Viral enteritis of infancy) Varying degree of disease severity - «Modified Bell s Staging»

Necrotizing enterocolitis Epidemiology Clinical presentation Incidence inversely related to GA 750g = 11,5% 1250-1500g = 4% Term infants = 0.07% Mean time of presentation is 10th day of life Differential diagnosis Hirschprung s disease Malrotation with volvolus Overfeeding Pyelonephritis Meningitis Feeding intolerance Emesis Abdominal distention Fever Cofee ground/bilous vomiting (ileus) Bloody stools Abdominal cellulitis Peritonitis Sepsis Feeding intolerance of prematurity Spontaneous intestinal perforation Viral enteritis of infancy

NEC - Pathophysiology

Necrotizing enterocolitis

NEC - Staging Radiological findings (Abdominal radiographs) IA/B Normal IIIA Ascites Reduced intestinal air Intestinal dilatation Mild ileus IIA Intramural air IIIA Pneumoperitoneum Ileus IIB Portal venous gas

IA/B Normal IA/B Reduced intestinal air Intestinal dilatation Mild ileus

IIA Intramural air Ileus IIA «Caffey s pediatric diagnostic imaging»

IIA Intramural air Ileus IIA

IIB Portal venous gas IIB

IIB Portal venous gas

IIIA Ascites IIIA

IIIA Pneumoperitoneum IIIB

Necrotizing enterocolitis - Management Initial treatment is medical Fluid resuscitation/supportive therapy Antibiotics Total parental nutrition Surgical management Remove gangrenous bowel, while preserving bowel length Optimal time for surgery is when the bowel is gangrenous, but has not yet perforated «Radiological» management Poor surgical candidates may undergo initial peritoneal drainage Only 60% of patients with surgically proven perforation had proven pneumoperitoneum on abdominal radiographs

Omphalitis Infection of the umbilical stump Occurs in 7/1000 live births May progress to necrotizing fasciitis of the abdominal wall, having 50-60% mortality. Treated with broad spectrum antibiotics Surgical debridement

Omphalitis - necrotizing fasciitis - imaging Diagnosis is made clinically Ultrasound/(CT) may show fluid/air in abdominal wall, thickening of fascial layers Take home message: CT/Ultrasound cannot exclude nec. fasciitis

Pathophysiology Hirschprung s Disease Variable length of distal bowel lacks parasympathetic plexuses ( Auerbach=intermuscular, Meissner=submucosal) Failure of relaxation of the affected bowel, functional obstruction Aganglionic segment is limited to the rectosigmoid in 75% of cases Epidemiology 1/5000 live births Responsible for 15-20% of cases of neonatal bowel obstruction H. Disease presents in the newborn period in 80% of cases.

Hirschprung s Disease Clinical presentation Neonate: Infants/children: Constipation Failure to thrive Distal obstruction/ileus Failure to pass meconium within the first 48 hours Vomiting Abdominal distension Hirshcprung ass. enterocolitis/toxic megacolon Diarrhea Fever Abdominal distension Sepsis

Hirschprung disease - Imaging 2 week old newborn, Abdominal radiograph Abdominal distention Dilated bowels inability to pass stools and abdominal distention Gas in distal bowels

Hirschprung Disease - Imaging Contrast enema newborn, 2w Radiological diagnosis Identification of the transition zone Small catheter placed close to the external sphincter, without inflating balloon Water soluble contrast preferred in neonates Distal aganglionic segment usually normal caliber

Hirschprung Disease - Imaging

Hirschprung Disease - Imaging Dilated small intestine Total aganglionic colon http://www.radrounds.com

Hirschprung s Disease - Imaging Hirschprung associated enterocolitis Irregular, ulcerated mucosa «Caffey s pediatric diagnostic imaging»

Hirschprung Disease - Management Definitive diagnosis is made by biopsy «Duhamel» procedure Management is surgical with removal of the aganglionic segment

Hirschprung Disease - Management «Duhamel» procedure

Hypertrophic pyloric stenosis Pathophysiology Idiopathic thickening of gastric pyloric muscle Partial or complete pyloric obstruction Epidemiology 3/1000 live births 4x more common in boys Clinical presentation Intermittent nonbilous vomiting (often mistaken for GERD) Projectile nonbilous vomiting Dehydration x5 incidence among 1st degree relatives 90% occurs 3w-12w age DDx: Midgut volvolus, duodenal stenosis/atresia, http://pedsurg.ucsf.edu/ annular pancreas

Hypertrophic pyloric stenosis Management Supportive therapy/ fluid resuscitation Pyloromyotomy

Hypertrophic pyloric stenosis - imaging Ultrasound Sensitivity and specificity almost 100% Linear high freq. transducer Liver used as acoustic window Supine/Right anterior oblique position Stomach should be partly filled (milk, water) Pitfall Overdistention of stomach displaces antrum and pylorus posteriorly and may lead to a false negative result

Hypertrophic pyloric stenosis - imaging Ultrasound findings Single muscle layer thickness 3-4mm Pyloric length >14mm Passage of gastric contents? «Cervix» sign http://www.ohsu.edu/xd/education/schools/school-of-medicine/departments/clinicaldepartments/diagnostic-radiology/pediatric-radiology-normal-measurements/

Hypertrophic pyloric stenosis - imaging http://www.ohsu.edu/xd/education/schools/school-of-medicine/departments/clinicaldepartments/diagnostic-radiology/pediatric-radiology-normal-measurements/

Hypertrophic pyloric stenosis - imaging «Cervix» sign http://www.ohsu.edu/xd/education/schools/school-of-medicine/departments/clinicaldepartments/diagnostic-radiology/pediatric-radiology-normal-measurements/

Pathophysiology Intussusception Involution of one part of the intestine into another Ilecolic intussusception most common - 90% Idiopathic URI Rotavirus vaccine IIleo-ileocolic intussuception 4% Ileoileal/appendicocolic/ cecocolic/colocolic/ jejunojejunal/ Bowel obstruction and ischemia Epidemiology Occurs in children btw. 3months -6years, peak incidence btw. Lead points Appendix Lipoma Polyp Meckel s diverticulum Lymph nodes Duplication cyst Tumor 5-12months Occurs in 1:2000 children The most common cause of bowel obstruction in children < 2 years. Punnoose AR, Kasturia S, Golub RM. Intussusception. JAMA. 2012;307(6): 628. doi:10.1001/jama.2012.45.

Intussusception Clinical presentation Classic clinical triad Colicky abdominal pain «currant jelly» / bloody stools Vomiting or palbable abd. mass - only 30% will have all of these symptoms Lethargy following abdominal pain and vomiting - 75% 20% may be pain-free (but otherwise ill) Distention Pain Vomiting 60-70% of cases with suspicious clinical findings does not have the condition http://www.memrise.com/

Intussusception - imaging Enema reduction Ultrasound Primary diagnostic tool Air/Hydrostatic Water soluble contrast Sensitivity 98% Specificity 98% Neg. predictive value 99.7% Abdominal radiograph Low sensitivity/specificity Exclude pneumoperitoneum

Intussusception - Ultrasound «Emergent Pediatric US: What Every Radiologist Should Know» - Cogley et al. Radiographics. 2012 May-Jun;32(3):651-65. doi: 10.1148/rg.323115111.

Intussusception - Ultrasound 6 months old boy, long ileocolic intussuception extending to sigmoid colon

Intussusception - Radiography 6 months old boy, long ileocolic intussuception extending to sigmoid colon

Intussusception - Nonoperative reduction Therapeutic enema Pneumatic Hydrostatic Air innsuflation Saline Fluoroscopy Fluoroscopy 400ml Omnipaque 20F Foley Ultrasound 140mg/mL - isotonic 20mL balloon 200ml Saline Water soluble contrast Pressure btw 100-150 cmh2o Safe (perforation <1%) Effective (Success >80-90%) Absolute contraindications Peritonitis Pneumoperitoneum

Intussusception - Nonoperative reduction 6 months old boy long ileocolic intussuception Success? Passage of contrast to ileum Clinical improvement w/o passage of contrast to ileum

Intussusception - Nonoperative reduction

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