When Development Goes Wrong, A Clinical Perspective PDF

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Summary

Describes multitude of anatomical disorders, mostly occurring at the fetal, and the causation of those disorders...

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When Development Goes Wrong: A Clinical Perspective Dr Julia Phillips General Paediatrician; Clayton and Paediatric Emergency Department, Monash Medical Centre

Talk Outline and Objectives • Definitions • General principles of disease origins • Understand how development can go wrong; what this means for the patient and her family through specific clinical examples • Skeletal • Thorax • Cardiac

• Questions???

Definitions • Pathology – the study of disease • Acute – referring to a disease process of recent or sudden onset • Chronic – referring to a disease of longer duration (often > 6 weeks) • Aetiology – the cause of (e.g.) a disease • Idiopathic – a disease that has not had a cause identified • Congenital – a condition affecting an individual from birth (or during fetal life) • Acquired – a condition that affects a person later in their life • Neonatal – “newborn” period; Day 1-28 of life

How to humans develop diseases and disorders? • Genetic mutations • Originate in germ cells (spermatozoa or ova) • Or develop during cell division or early embryogenesis

• Abnormal growth during fetal development • Due to uterine environment; blood flow, maternal ill-health, infections, toxins • Cause often not identified

• Natural ageing and decline in physiological processes and DNA repair • Environmental influences • Infective agents • Trauma • Chemical – food, air-borne pollutants, drug-related • Exposure – sun, weather etc. • Lifestyle – nutrition, activity levels, substance use, stress

Disease aetiology and time of presentation • Mutations in significant genes and/or abnormal fetal development • More likely to present early in life • The more significant the abnormality on the organ/system affected, the earlier it will present • Some may be recognised before the baby is born!

• Medical conditions that arise as a result of an accumulation of risk factors • More likely to present in adulthood as this accumulation takes time • Especially if dependent upon the presence of environmental exposures

Osteogenesis Imperfecta Skeletal system

Osteogenesis Imperfecta • Also known as “brittle bone disease”; there are a number of subtypes with varying severity • Caused by a small number of mutations in genes that code for Type I procollagen •  •  • 

• Results in bones that break easily, often from minimal trauma

Osteogenesis Imperfecta • May also be associated with • Short stature • Hearing loss • Easy bruising • Fragile rib cage and breathing abnormalities

• And…….

OI – Blue sclera

OI – Bowing of limbs

Case courtesy of Dr Prashant Mudgal, Radiopaedia.org, rID: 23717

Curvature of the spine Gradual reduction in lung function Impairment of cardiac function Chronic pain and mobility limitations

OI – Lax (“loose”) ligaments

At risk of (recurrent) joint dislocations

OI – Abnormal dentition

Discoloured, deformed teeth – cosmetic concern Risk of dental decay and fracture

Osteogenesis Imperfecta – Type II • Most severe form • Fetal bones may appear abnormal on pregnancy scans (ultrasound) and may break during in utero or during the birth • Expectant parents and medical staff are therefore, usually, aware of the condition before birth and can prepare • Often have abnormal rib cage and underdeveloped lungs • May die at or soon after birth

Normal child

OI Type II

• Rib cage smaller • Lungs grossly under-developed • Born with significant breathing difficulties • Often not compatible with life

Question: Which of these children have OI?

Answer: they all do!

What’s life like for those affected with OI? • Depends upon the severity • A life of regular and emergency medical visits • Miss lots of school • Social isolation

• The pain, stress and inconvenience of repeated fractures • Although tend to have high pain threshold

• Multiple operations and procedures – bones/teeth/spine • More severe types - living with daily risk of life-threatening bony injury (skull fracture, atlanto-axial instability and possible resultant spinal cord injury) • More severe types – premature death from respiratory or cardiac failure

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What’s life like for those affected with OI

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• Living with disability – physical/mobility/hearing loss • Simple tasks become challenging • Much of society does not support the independence of individuals with a disability • Discrimination • Physical appearance – deformity/difference • The public often assume physical disability = intellectual disability

• A life wrapped in “cotton wool” • Families – may be under severe financial/emotional/social/marital strain • Family planning – 1:2 risk of affected individual passing it on to their offspring

OI - Resources • https://ghr.nlm.nih.gov/condition/osteogenesis-imperfecta • https://www.oiaustralia.org.au/ • https://www.oiaustralia.org.au/wpcontent/uploads/2016/06/OI_Book_2nd_ed_Complete.pdf

Congenital Diaphragmatic Hernia Thorax

Congenital Diaphragmatic Hernia (CDH) • Failure of diaphragm to close during development • Small number of variants, according to where in the diaphragm the defect is

• Occurs in ~1 in every 2-3000 live births • Herniation of some of the abdominal structures through the defect into the chest cavity • Hernia = “bulging” of structures from one compartment into an adjacent one, where they are not expected to normally lie

• Resulting small lungs (“pulmonary hypoplasia“) • Persistently high blood pressure in the pulmonary circulation (“pulmonary hypertension”) • Puts strain on the heart

• 50% of cases are detected antenatally • Or the baby may become unwell soon after birth • Occasionally the patient may not develop significant symptoms until a few months or years later

Left sided CDH

Normal fetal thorax (28 weeks)

← Baby’s legs

Baby’s head 

CDH on Antenatal Scans

Case courtesy of Dr Laughlin Dawes , Radiopaedia.org, rID: 36006

When a baby with CDH arrives… • The birth will be planned and take place in a hospital with a neonatal intensive care (NICU). Paediatric team will be at the birth. • Most develop breathing problems after delivery • Many will have a breathing tube inserted soon after and be placed on a ventilator

• They will be stabilised in the NICU…..

Case courtesy of Dr Laughlin Dawes , Radiopaedia.org, rID: 35858

CDH Management • Medical care • Ventilated – can be challenging and at risk of lung damage from the pressures generated by the ventilator • Feeding tube placed to deflate the stomach/small intestine • May initially receive nutrition via the blood and later, via feeding tube • Often critically unwell • Vulnerable to infection which can be overwhelming

• Surgical care • Surgical closure of defect (+/- a patch) and return of gut to abdominal contents • Performed within 7-10 days of delivery, once baby stable

….Reality.

Parental dream……

CDH Outlook

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• It is estimated that nearly 33% of fetuses with CDH are electively terminated; most of these are associated with other major abnormalities • Mortality of liveborns with CDH is 40-60%; especially if associated with other major anomalies • Death is often due to respiratory and/or cardiac failure

• Chronic lung problems • May have ongoing need for oxygen which can be given at home • Vulnerable to viral and bacterial chest infections which can put them back in intensive care

• Poor growth • Risk of brain insult and hearing loss from surgery/being critically unwell/low oxygen levels so will need regular development and health/hearing checks with a paediatrician for first few years

CDH Impact on Family • Impaired bonding at time of delivery • Baby needs immediate medical support and admission to NICU • This interferes with time-critical bonding with caregiver(s) and can have long lasting impact on temperament and behaviour as well as relationship with parents and their own mental health • Even basic parental jobs – such as feeding and bathing – are not possible for sometime

• Stress and worry of having critically ill child • Feeling utterly helpless and disempowered • No control over their baby’s course • Dependent upon medical staff to care for their baby

• Parents may blame themselves for passing on faulty genes etc. • Siblings end up taking a backseat whilst their parents’ attention is on the baby

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CDH - Resources • http://cdh.org.au/what-is-cdh/ • http://emedicine.medscape.com/article/978118-overview (warning: contains medical jargon!) • http://www.cdhgenetics.com/congential-diaphragmatic-hernia.cfm

Coarctation of the aorta Cardiac

Coarctation of the aorta (CoA) • Prevalence of 4 per 10,000 live births • Accounts for 4-6% of all congenital heart defects • Boys affected more commonly than girls • Perhaps Caucasian/European children > Asian • A narrowing of the descending aorta around the site of the insertion of the ductus arteriosus • But, rarely, can occur at other sites in the aorta

• Wide variability in severity and age of presentation

CoA

CoA – classic examination findings • Difference in blood pressure between upper and lower limbs • Weakened or absent femoral pulses • Part of newborn baby check

• Delayed brachial-femoral pulse • Bruit (“murmur”) heard between scapulae

CoA - Presentation • Hugely variable • From a collapsed neonate to a child with hypertension (high blood pressure) to an incidental finding later in life…..

Severe CoA – critical neonatal presentations • May present in first few days of life when patent ductus arteriosus closes • Critical reduction in blood flow to lower body (including kidneys, gut, legs) • Acute heart failure and circulatory collapse (“shock”): heart pumping against severe resistance in systemic circulation

• This baby will likely • Be grey and mottled • Have poor peripheral circulation • Show laboured breathing • Have a history of poor feeding and lethargy

Severe CoA – critical neonatal presentations • This baby will die without appropriate treatment • Immediate infusion of prostaglandin (PGE2) – reopens the duct plus breathing support via a ventilator • Urgent echocardiogram – identifies the problem • Surgical correction as soon as stable

• Some babies, without duct-dependent circulation, will present later in infancy with congestive heart failure • = failure of the right side of the heart • Fluid collects in the lungs and periphery (e.g. swollen legs) • Liver enlarges • Poor feeding, poor growth, lethargy, increasing breathing problems

CoA – Later presentations • CoA may be found when a child is investigated for hypertension • High blood pressure in children is much more likely to be due to a pathological process than in adults • Investigation should include 4-limb BP, femoral pulses check and echocardiogram • If CoA is found; surgical correction is standard treatment

• Or….CoA may be incidentally suspected/diagnosed when a chest Xray is taken for any number of reasons (e.g. for chest infection)…..

Chest Xray findings in CoA

Case courtesy of A.Prof Frank Gaillard, Radiopaedia.org, rID: 6274Case courtesy of A.Prof Frank Gaillard, Radiopaedia.org, rID: 6274

CoA – “Figure of 3” Sign on Chest Xray A: Ductal coarctation, B: Preductal coarctation, C: Postductal coarctation.

1: Ascending Aorta, 2: Pulmonary Artery, 3: Ductus arteriosus, 4: Descending Aorta, 5: Brachiocephalic Artery, 6: Common Carotid Artery, 7: Subclavian Artery

CoA – Other Xray signs

Inferior rib notching

CoA - Aortogram

CoA – Surgical correction

CoA – Surgical correction

COA – Life after correction • Blood pressure • Usually normalises after surgery and antihypertensives (medications to lower BP) can be weaned and stopped • A small proportion continue to have high BP needing treatment

• Late complications of surgical repair • Recurrent coarctation at site of surgery • Aneurysm formation

• If untreated; life expectancy is 30-45 years, so everyone is treated! • Quality of life, daily activities and life expectancy can be normal (if treated) unless associated with other cardiac defects

Coarctation - References • https://thoracickey.com/coarctation-of-the-aorta-5/ (discusses morphology and embryology too) • https://radiopaedia.org/articles/coarctation-of-the-aorta

Closing • Small deviances from normal fetal development – even if confined to one small area/system – can have devastating and lifelong consequences for the affected individual and their whole family • Medical teams are getting better at detecting these abnormalities before the baby is born which allows for adequate birth preparations and realistic parental expectations • Management – surgical and medical – of these babies is improving in many cases and fetal surgery is an area of advancing expertise • Decades ago, many of these babies would have died soon after birth but now many are surviving and living well

Questions or comments?...