. Diaphragmatic Hernia

8/11/2019 . Diaphragmatic Hernia

1/11

Diaphragmatic Hernia

Incidence

1.Congenital diaphragmatic hernia (CDH) refers to acongenital defect in the posterolateral diaphragm at theforamen of Bochdalek.It is a relatively common case of neonatal respiratorydistress !ith an overall incidence "et!een 1#$%%% and1#&%%% live "irths. CDH acconts for a"ot '% ofcongenital diaphragmatic defects.ighty to ninety percent of congenital diaphragmatic

hernias occr on the left side. * hernia sac is only present$% of the time.

$.+etrosternal hernias (,orgagni) are mch lesscommon and only accont for $- of congenitaldiaphragmatic defects. /.Diaphragmatic eventrationis even rarer "t is a postoperative complication in 1-$of children ndergoing srgery to repair congenital heartdefects.

Etiology0he specic etiology of CDH is nkno!n "t it is "elievedto reslt from a defective formation of thepleroperitoneal mem"rane.In the early !eeks of development2 the pleral andperitoneal cavities commnicate via the pairedpleroperitoneal canals. Dring the 3th !eek2 the pleralcavity "ecomes separated

from the peritoneal cavity "y the developingpleroperitoneal mem"rane.If the pleroperitoneal mem"rane fails to develop2closre of the pleroperitoneal canal is incomplete and aposterolateral diaphragmatic defect reslts.


2/11

* ne!er hypothesis has arisen from the nitrofen ratmodel of CDH.lectron microscopy of these nitrofen e4posed ratem"ryos sggests that CDH reslts from a defective

development of theposthepatic mesenchymal plate !hich also contri"testo closre of the pleroperitoneal canal.*lthogh familial cases are reported2 most cases of CDHare sporadic.CDH is associated !ith trisomies 132 $12 and $/ "t aspecic genetic etiology has yet to "e identied.,orgagni hernias reslt from failre of the sternal and

crral portions of the diaphragm to fse at the site !herethe sperior epigastric artery traverses the diaphragm.,orgagni hernias are associated !ith congenital heartdisease and trisomy* variant of the retrosternal hernia is associated !ith thepentalogy of Cantrell !hich incldes# omphalocoele2inferior sternal cleft2 severe cardiac defects (incldingectopia cordis)2 diaphragmatic hernia and pericardial

defects.0he diaphragmatic defect reslts !hen the septmtransversm fails to develop in the em"ryo.ventration of the diaphragm may "e either a congenitalor ac5ired lesion.6eonatal eventration may "e de to defective centraldevelopment or enervation of the diaphragm. It may alsoreslt from a traction in7ry to the nerve roots of the

phrenic nerve dring tramatic delivery. ventration mostoften reslts from iatrogenic phrenic nerve in7rycomplicating cardiac or mediastinal srgery.DefnitionsThe diaphragm develops largely rom threestructures:


3/11

1 the pleuroperitoneal membrane;2 the septum transversum; the marginal ingro!ths rom the muscles o thebody !all"

#ongenital diaphragmatic hernia results romailure o ormation or usion o the components othe diaphragm$ such that abdominal contents canmove through a deect into the chest"%ometimes$ ailure o muscularisation may producea thin$ !ea& diaphragm$ reerred to as aneventration o the diaphragm"The 'ochdale& type is the most common variety o

congenital diaphragmatic hernia and results roma deect in the posterolateral part o thediaphragm" During intra(uterine development$ thesmall bo!el$ stomach$ spleen and let lobe o theliver pass through the deect in the diaphragm intothe chest$ limiting the space available or thedeveloping lung" This causes lung hypoplasia$!hich in many inants is severe enough to produce

severe respiratory distress !ithin minutes o birth$and may not be compatible !ith lie"The )orgagni *retrosternal+ type o diaphragmatichernia is rare$ and results rom a deect in theanterior midline$ ,ust behind the sternum -.ig/" Itusually contains part o the colon or small bo!el$and less commonly$ part o the liver" 0ccasionally$a hernia may occur through the ape o the cupola

or at the periphery ad,acent to the costal margin"0esophageal hiatal hernias also occur and usuallyproduce symptoms o gastro(oesophageal re u"#linical eatures3ntenatal diagnosis


4/11

)ost congenital diaphragmatic hernias arediagnosed !ell beore birth$ on antenatalultrasonography" .actors that may indicate a !orseprognosis on antenatal scanning *summarised in

Table + may inuence counselling o the parents(to(be" 3ntenatal ultrasonographic diagnosis odiaphragmatic hernias also allo!s the mother(to(be to be transerred to a tertiary paediatricsurgical centre beore birth" %uccessul in uterocorrection o diaphragmatic hernia and etoscopictracheal occlusion has been achieved in researchsetting$ but the techni4ues are comple and the

indications are still being ref ned" To date$ theyhave not resulted in improved survival or reducedmorbidity compared !ith modern postnataltechni4ues"Table " 5ossible antenatal mar&ers o severity Early gestational age at diagnosis onultrasonography 6ung(to(head ratio *6H7+ at 2892(!ee&s

gestation


5/11

5ostnatal diagnosis

The ma,ority o inants born !ith a 'ochdale&*posterolateral+ diaphragmatic hernia becomesymptomatic at or shortly ater birth" herepulmonary hypoplasia is severe$ the inantbecomes cyanosed !ith severe respiratory distress!ithin minutes o birth" In other patients there istachypnoea$ increased respiratory eort$ hyperinated chest and scaphoid abdomen$ and heart

sounds are on the right side" This is because F?@o posterolateral hernias involve the lethemidiaphragm" The remainder are rightsided*12@+ or bilateral *@+" 3ssociated anomaliesoccur in up to 8=@$ but most are minor and do notaect survival$ or eample$ undescended testes"


6/11

The most common serious abnormalities are heartdeects" Gnli&e posterolateral hernias$ mostanterior *retrosternal+ hernias are symptomlessunless strangulation occurs"

ery rarely the hernia may protrude into thepericardial cavity rather than into the ineriormediastinum and cause cardiac tamponade$presenting as cardiorespiratory distress in theneonatal period"

(ray o congenital diaphragmatic hernia*'ochdale& type+" )ultiple bo!el loops f ll the let

pleural cavity$ and the heart is displaced to theright"

Investigation


7/11

Diagnosis o a posterolateral hernia is confrmedby a chest (ray -.ig" ?"2/" In let(sided deects$loops o bo!el can be seen in the let chest" Theheart is deviated to the right" 6ittle room is let or

the lungs$ particularly the let lung !hich ismar&edly compressed" %ometimes$ the appearancemay be diCcult to distinguish rom basal lungcysts$ in !hich case a repeat chest (ray isperormed ater a nasogastric tube has beeninserted$ the tip o !hich can be seen in the chest"3lternatively$ a barium study !ill sho! bo!el!ithin the thoracic cavity !hen there is a

diaphragmatic hernia"

Treatment5osterolateral *'ochdale&+ herniahere an antenatal ultrasound eamination hasidentiy ed a diaphragmatic hernia$ the bestoutcomes are achieved i the inant is transerredto a tertiary paediatric surgical centre prior tobirth" This is because these inants may developsevere pulmonary distress very 4uic&ly ater birth$ma&ing subse4uent transer diCcult andpotentially dangerous" Initial treatment involvesintensive cardiorespiratory support and insertiono a nasogastric tube to prevent bo!el dilatation!ithin the chest" #are must be ta&en to avoidhyperin ation and barotrauma o the small

hypoplastic lungs" High(re4uency oscillatoryventilation in combination !ith nitric oide hasimproved survival rates"entilation !ith a ace mas& *Bbagging+ should beavoided as this may orce air into the stomach$increasing its volume at the epense o the already


8/11

compromised lungs" igorous endotrachealventilation should also be avoided because o theris& o causing barotrauma and a tensionpneumothora$ !hich can lead to the rapid demise

o the inant" Eogenous suractant provides nospecifc beneft in ne!borns !ith diaphragmatichernia" The &ey to success is careul gentleventilation that minimiJes in,ury to the hypoplasticlungs" %udden deterioration o the inantscondition during initial resuscitation or duringtransport suggests the development o a tensionpneumothora$ and this may necessitate prompt

drainage by needle aspiration or insertion o anintercostal drain".ortunately$ strict avoidance o hyperventilationand limited in ation pressures have made thiscomplication rare" %urgery to return the bo!el tothe abdominal cavity and to repair the deect inthe diaphragm is perormed !hen the inantscondition is stable" This may be any!here bet!een

12 h and K or more days ater birth" In let(sideddeects$ a let transverse or subcostal abdominalincision is used" The management o the inant!ith severe hypoplastic lungs is diC cult and mayinvolve highre4uency oscillation or etracorporealmembrane oygenation" The ma,or cause o deathremains pulmonary hypoplasia and pulmonaryhypertension" 5ulmonary hypertension is due to

the small pulmonary vascular bed and to thechanging resistance o the pulmonary arterioles: itresolves in most patients !ith time$ providedventilation does not produce additional lung in,ury"%urvival rates o about F=@ are no! beingreported"


9/11

Diagram o the diaphragm and its attachment tothe sternum$ sho!ing the site o an anteriordiaphragmatic hernia"

3nterior diaphragmatic hernia3nterior diaphragmatic *)orgagni+ hernias areoten diagnosed on an incidental (ray o the chest

in a symptomless patient$ but repair is stilladvisable because o the ris& o strangulation othe bo!el that protrudes through the deect" Thisis usually perormed as a laparoscopic procedure-.ig" ?"/" The results are ecellent"

Ley 5oints Diaphragmatic hernia is diagnosed antenatally

or by chest (ray in a baby !ith a barrelchest$scaphoid abdomen and respiratorydistress"

entilatory support$ especially duringtransport$ should be the minimum re4uired to


10/11

prevent deterioration$ as hyperin ation !ith2M barotraumas is a signif cant complication"

%udden deterioration is usually caused bytension pneumothora"

((((((((((((((((((((((((((((((((NNNNNNNNNNNNNNNNNNN((((((((((((((((((((((((((

#ase 1ithin minutes o birth$ a ull(term inant boydevelops increasing respiratory distress andbecomes cyanosed" He ails to improve !ith upperair!ay suctioning" The pregnancy !as uneventul"He loo&s barrel(chested and his abdomen is

scaphoid"O 1"1 hat is the diagnosisPO 1"2 hat investigation !ill conf rm thediagnosisPO 1" hat actors determine the outcome in thesesituationsP

#ase 2

3 ne!born inant !ith a recently diagnosed let(sided congenital diaphragmatic hernia is about tobe transerred to a paediatric surgical institutionby air" He is currently being ventilated through anendotracheal tube and ,ust maintaining ade4uateblood gas levels"O 2"1 %hould his ventilation be increased duringtransportP

O 2"2 %hould any other manoeuvre be perormed toreduce the li&elihood o problems duringtransportPO 2" I he suddenly deteriorates$ !hat

complication may have happenedP


11/11

than&s

. Diaphragmatic Hernia

Documents

Transcript of . Diaphragmatic Hernia