Case Presentation: Antenatal USS significance? By Thomas Cromarty ST2

Transcription

1 Case Presentation: Antenatal USS significance? By Thomas Cromarty ST2

2 Introduction Case Presentation South Africa bites to break it up Topic learning Summary

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5 Background 35+3, Primigravida SROM 36hrs Steroids (bethamthosone) 2 nd dose Grade I Meconium

6 Background No maternal High Temp/Tacchycardia Mat WCC 21.6, CRP 49. (Erythromycin PO x2) CMV and CF negative A/N Bloods Rubella susceptible (otherwise NAD) Mum non smoker, no alcohol Asthma Surestart

7 Antenatal Scans 25week Dilated loop of bowel with maximum diameter of 14mm Some echogenic bowel noted 31week Normal growth No polyhydramnios Bowel dilation 10.9mm Some areas of echogenic bowel EDF +ve Due to see the surgeons on Monday and fetal 36 weeks

8 Delivery Born by SVD in a good condition No resus required HR>100 throghout Regular Respiration <1min Normal palate, anus, spine PREM, PROM, Raised Mat CRP IV ABX for presumed sepsis LBW and Mec obs

9 GI Management Neonatal and SHO & Reg reviewed Hx No documentation of FU/Mx Reg discussed with Surgical Reg ~ Continue with normal neonatal care Feed early as per usual No dysmorphic features

10 Transitional Care Unit Day 1 Feeding well via bottle, some small vomits PU Otherwise examines well systemically Soft, non distended, non tender, BS +ve R/v at 24 hours old Completed hypoglycaemia protocol 3 hourly bottle feeds, few small vomits NBO Normal examination

11 TCU Day 2 (36 hours of age) NBO 1x green vomit Vomiting after each feed (milky) Abdo exam?tinkling bowel sounds? 37 hours age

12 There is gross dilatation of the stomach, duodenum and proximal jejunum. There is no gas seen distally. Appearances are in keeping with Jejunal atresia. No evidence of perforation. Referred to Surgical Team

13 Day 2 Admitted to 40 hours of age. NBM NGT on free drainage Surgical r/v Day 3 - Surgical r/v 2x mucous plugs passed following PR Testes descended bilaterally?small Bowel Atresia Repeat Xray (no change)

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15 on (62 hours of age) Fresh blood in abdomen (15-20ml) Very Dilated twisted duodenojejunal loop (blind ending) Apple peel atresia with nonviable (proximal part) Absent Right & Transverse colon/appedix/ic valve Descending (Left)colon patent but curled Ladd s band twisting the D2-D3 creating a blind end.

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17 Non viable bowel removed Bowel untwisted & straightened Anastomoses A-B & C-D.

18 Small bowel length 55cm No Ileo-caecal valve

19 Post op complication Not passed urine since operation (12 hrs) Catheter passed, balloon inflated but?not in bladder. Balloon deflated and fresh blood into catheter. Catheter removed.

20 Post op information Operation D3 Triple ABX (Gent, Co-Amox, Metroni) TPN initiated (Standard initially) PICC Day 5 (Prescribed TPN Day 6) Extubated Day 7 to SVIA Day 9 completed 5/7 triple ABX Trophic feeds 1ml hourly initiated Day 11 BO with Meconium on Day 12 Day 14 Up to 3ml hourly 2x Vomits with green aspirates (up to 8mls) Day 15 Returned to low reflux

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22 Echogenic Bowel First described in 1985 Poorly understood, Consequences for parents, obstetricians, radiologists, neonatologists and paediatric surgeons. Definition: Foetal bowel with homogenous areas of echogenicity equal to or greater than surrounding bone. It can be focal or multifocal. There is associated considerable debate as there is much intraobserver variability. Difficult to introduce objective measures

23 Echogenic Bowel Timing Physiological midgut herniation in the first trimester precludes assessment of foetal bowel in the first trimester. In normal foetuses, it is a rare finding in T2 and resolves with no adverse sequelae. <20/40 usually transient, disappearing on serial scans during the next few weeks Foetal bowel is often echogenic in the third trimester and is not considered to be clinically significant. It is often considered a soft sign for aneuploidic anomalies.

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28 Incidence Echogenic bowel is present in 0-6% to 1-4% of all second trimester foetuses. Foetal small bowel becomes progressively more visible by ultrasound scan during the second trimester as relatively bright meconium accumulates within its lumen from about 16 weeks gestation. Persistently hyper echogenic small bowel in the third trimester is more likely to reflect underlying pathology even though a normal outcome is still possible.

29 Differential Diagnosis 35% of foetuses with echogenic bowel will have underlying pathology (65% Normal) 1. Foetal aneuploidy Most commonly Trisomy 21: (bowel hypotonia) Includes Trisomy 13,18 and the sex chromosomes Isolated finding in 9% of foetuses with aneuploidy.

30 Differential Diagnosis 2. Non chromosomal Cystic fibrosis risk 2%: (meconium) Congenital infection: CMV, Toxoplasmosis, Parvovirus Intra-amniotic bleeding: swallowing of blood Congenital malformations of the bowel: atresia, perforation, meconium. 3. IUGR and increased risk perinatal morbidity and mortality: (mesenteric ischemia) 4. Other: foetal alcohol syndrome, alpha thalassaemia homozygous

31 Relevant PMHx Past obstetric history and any anomalies Any family history of note. In particular cystic fibrosis, aneuploidy, syndromes History of bleeding (swallowed blood) Viral/bacterial illness A prior risk for aneuploidy

32 Scanning: Isolated or Other Structural Anomalies Detailed review of anatomy, growth and placenta Assess markers for aneuploidy Other major structural abnormality Nuchal thickening Short femur / humerus Intracardiac echogenic foci Hypoplastic/absent nasal bone Mild foetal pyelectasis Choroid plexus cyst

33 Scanning: Isolated or Other Structural Anomalies Assess markers of infection Microcephaly, ventriculomegaly, calcifications Hydrops IUGR

34 Investigation Amniocentesis Karyotype PCR for virology: Toxoplasma, Rubella, Parvovirus, CMV DNA analysis: Cystic fibrosis Maternal factors Virology screen : Toxoplasma, Rubella, Parvovirus, CMV Maternal AFP (associated IUGR) Parental cystic fibrosis carrier status screening detects 80% of carriers. Not all mutations can be identified and this does not exclude the possibility.

35 Main Causes (5) Mechanism: Hypoperistalsis and/or decreased fluid content of the meconium. Foetal aneuploidy mostly Trisomy 21 (trisomy 18/13, Turner s syndrome and triploidy) It is thought to be due to decreased bowel motility with increased water absorption from the meconium. There appears to be decreased microvillar enzymes activity in the amniotic fluid of aneuploid fetuses.

36 Causes Small bowel obstruction proximally (especially duodenal atresia) can produce hyper echogenic bowel by reducing the meconium fluid content. Oligohydramnios. due to decreased amniotic fluid content of meconium.

37 Causes Hirschsprung s disease (increased frequency in foetuses with Down syndrome) due to hypoperistalsis. Intra-amniotic haemorrhage Swallowed blood products result in a hypercellular meconium, probably with small clots within the bowel lumen which is very echogenic. Bowel atresia. Decreased amniotic fluid content of the meconium.

38 Causes Cystic Fibrosis 0.8% % of foetuses with echogenic CF Echogenic bowel in 50% to 78% Abnormalities in pancreatic enzyme secretion changes in meconium consistency. Focal echogenic bowel with calcifications A hyper echoic mass Bowel dilation.

39 Causes - IUGR IUGR Most don t have echogenic bowel. The suggested mechanism is bowel ischemia due to haemodynamic redistribution and subsequent mesenteric ischemia. The presence of IUGR or elevated maternal serum alpha-fetoprotein in the second trimester in association with echogenic bowel seems to be associated with a particularly poor foetal prognosis.

40 Other Rarer Causes Viral Infections 0% to 10% Cytomegalovirus (Most common) Toxoplasmosis Parvovirus Mechanism is unclear,?caused by direct intestinal damage from inflammation or meconium peritonitis or indirectly by ascites, anaemia, or growth restriction Thalassemia

41 Outcomes 5 large North American Studies combined 60% had no abnormalities Aneuploidy (3-27%) IUGR in 15% Rare mechanical associations Congenital infections Antenatal haemorrhage CF

42 Management Detailed parental history?links with karyotype anomalies, intrauterine infection, and CF. Complete USS to exclude associated structural problems Serial ultrasound assessments Persistently hyper echogenic bowel Especially those with IUGR and/or documented abnormalities of umbilical artery blood flow are at risk of functional neonatal intestinal obstruction.

43 Prognosis Usually resolves but still requires investigation Better prognosis if does resolve but underlying disease still present in 15% Outcome in those with no prenatal diagnosis probably normal, no clear evidence long-term bowel problems

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48 Summary Algorithm Main causes 1. Intra-amniotic bleeding 2. Cystic Fibrosis 3. Aneuploidy 4. Congenital Infection 5. Primary GI pathology?associated with IUGR