pediatrics in review 1994 ross 338 47 gastro

7/27/2019 Pediatrics in Review 1994 Ross 338 47 Gastro

1/12

DOI: 10.1542/pir.15-9-3381994;15;338Pediatrics in Review

Arthur J. Ross IIIIntestinal Obstruction in the Newborn

http://pedsinreview.aappublications.org/content/15/9/338the World Wide Web at:

The online version of this article, along with updated information and services, is located on

Print ISSN: 0191-9601.Village, Illinois, 60007. Copyright 1994 by the American Academy of Pediatrics. All rights reserved.

trademarked by the American Academy of Pediatrics, 141 Northwest Point Boulevard, Elk Groveandpublication, it has been published continuously since 1979. Pediatrics in Review is owned, published,

Pediatrics in Review is the official journal of the American Academy of Pediatrics. A monthly

at Indonesia:AAP Sponsored on September 4, 2013http://pedsinreview.aappublications.org/ Downloaded from
http://pedsinreview.aappublications.org/content/15/9/338http://pedsinreview.aappublications.org/content/15/9/338http://pedsinreview.aappublications.org/content/15/9/338http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/content/15/9/338


2/12

FO CU S Q UE STIO NS

1. W ha t Is th e significance o f b il io usvomit ing In Infancy and ch ild -

hood?

2 . W hat a re t h e d i st in g u is h in g clini-cal s igns and sym p tom s o f co ng en -

ita l upper sm aU b ow e l o bs tr uc ti onversus those o f congenital largeb ow el o bs tr uc tio n?

3. W hat are the com m on and the

uncom mon presen ting sym ptom s

o f m a l ro t at lo n ?4 . Exp la in the p athophyslolo gy o f

com plicating vo lvulu s , thebasisfo r urgency In diagnosis, and theapprop ria te stud ies needed fo rdiagnosis .

5 . W h at is the sIgnificance of theradiographic finding ofpneumato-si s intestinalls?

6 . W hat a re m ajo r cau se s o fpartialo r com ple te la rg e bow l ob struc -

tion occu rring in the n eo na tal

period?

F IG U R E 1. The m ost com m on type ofe so ph ag ea l a tr es ia /t ra ch eo es op ha ge al

fistu la . N ote the b lindproximalesophageal pouch and the distaltr ac he oe so ph ag ea l fis tu la .

33 8 Pedia trics in R eview VoL 15 N o. 9 Sep tem ber1994

L A RC

In testinal O bstruction in theNewbornArthur J . R oss Ill, M D *

O bstruction of an infants gastrointes-t inal (G I) tract can occur anywhere

from the esophagus to the anus. Forpurposes of th is rev iew , the new bornin fan t w ill be defined as an in fan tfrom birth to 30 days of age. B oth

congen ital and acquired obstructionsw ill be addressed . In each instance,the epidem io logy, pathogenesis, clin-

ical aspects, and m anagem ent of thedisorder w ill be considered .

Esoph ag eal A tres ia

E P I D E M I O L O G Y A N DPAT H O G E N E S I S

Esophageal atresia , or in terruption ofthe esophagus, generally occurs inassociation w ith a tracheoesophageal

fistula (E A - T EF). The m ost com -m on anatom ic arrangem ent is a blindproxim al esophageal pouch that has adistal tracheoesophageal fistula (F ig-ure 1). This is seen in85 % to 90%of infants w ho have this anom aly .Seen less com m only is pure esopha-

C linic al P ro fes sor of Surgery and P ediatr ics ,

U nive rsiily ofW isconsin-M adison M edical

School, D irecto r o f Medica l Educat ioni

Attending P ed ia tric S urg eo n, Gundersen

C linic , Ltd , LaC rosse, W I.

geal atresia that does not have atracheoesophageal fistu la and trach-eoesophageal fistula that does no thave an esophageal atresia (H -typetracheoesophageal fistula). These lat-ter tw o conditions occur in approx i-m ately 10% of new borns w ho havethese types of anom alies. O ther ana-tom ic arrangem ents, such as anesophageal atresia that has a fistulabetw een the upper pouch and tracheaor esophageal atresia that has a fis-tu la to bo th pouches, are seen in on lya tiny fraction of these infants.

EA - TEF occurs in approx im ately1 in 4000 live births. T here have

been num erous reports o f siblingsw ho have EA - TEF as w ell as re-ports o f the anom aly in iden ticaltw ins. A lso reported , how ever, arem any instances of identical tw ins inw hich one has the anom aly and theother has been spared . It is w ell rec-ogn ized that esophageal atresia is afrequent com ponen t of the V A TERassociation as w ell as o ther m alfor-m ations, suggesting that the anom alyalso m ight resu lt from a specific tera-togen in the developing fetus.

It com m only is believed that inter-ruption of the events responsible for

the elongation and separation of theesophageal and tracheal tubes duringthe fourth w eek of developm ent leadsto the developm ent of th is anom aly.

PRESENTATION

Infants w ho have EA- TEF com -m only w ill p resent in the nurseryhav ing an excessive am #{231}untf sa-liva. T he saliva poo ls in the blindprox im al esophageal pouch and iseither regurgitated or continuously

dribb led from the infants m outh.The in fan ts first feed ing w ill no t betolerated ; the form ula, w hich is, o fcourse, not bile-stained, w ill beregurgitated im mediately . B ecausethese infants m ost com m only have adistal tracheoesophageal fistula, airen ters their G I tracts through the fis-tu la, and the abdom en w ill not bescaphoid. Indeed , the in fan t w ho isven tilated m ay w ell have air forcedin to his or her G I tract via the fis-tu la, causing distension. S uch an in-

fan ts respirato ry difficu lty, thus,m ay be com pounded by the gastricdistention lead ing to d iaphragm aticelevation . In pure esophageal atresiathat has no fistula, no air w ill enterthe G I tract, and the in fan t w ill havea scaphoid abdom en.

D I A G N O S I S

T he diagnosis of esophageal atresia

can be m ade by attem pting to pass afirm catheter th rough the m outh andin to the esophagus. O bstruction topassage of the catheter, w hich shou ldnot be forced , suggests the anom -aly , and a chest rad iograph usuallyw ill confirm the d iagnosis via thepresence of the co iled catheter sittingw ith in the proxim al esophagealpouch. A ir injected in to the catheterp rovides an excellent contrastagent to help confirm the diagnosis.The use of a true con trast agent gen-erally is not recom m ended becausethe in fan t w ill be at risk of asp iratingthe agen t and acquiring a chem icalpneum onitis. In the rare instance inw hich contrast is requ ired , 1m L or

less of a w ater-so luble agent can bein jected in to the pouch and thenw ithdraw n im m ediately once the d i-agnosis has been confirm ed . A ir inthe G I tract confirm s the presence ofthe distal tracheoesophageal fistu la.

http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/http://pedsinreview.aappublications.org/


3/12

Babies w ho have py lori c stenosi s f eed eagerlybut lose weight and

m ay become dehydr ated and then develop hypochlor emic-

hyp ok alem ic m etab olic alk alosis.

Pedia trics in R eview VoL 15 No. 9 Sep tem ber1994 33 9

M A N A G E M E N T

A ppropriate management of these ba-bies begins at the time of diagnosis.A significant r isk to the infants is thepotential for gastric juice to pass up-w ard in the distal esophagus andtraverse the tracheoesophageal f istula

w here i t may be aspirated, resul tingin the development of chemical pneu-monitis. These infants need to have asum p catheter placed im mediatelyinto the upper pouch and into thehead up position at an angie of atleast 45 degrees. This w i ll help mini-mize the aspiration of sal iva and thechance of gastric juice soi ling thelungs.

A s a general rule, all new bornswhose GI tracts are obstructed shouldhave intravenous f luids insti tuted andantibiotics begun. I f the neonate is

not at a surgical center, transportneeds to be arranged as soon aspossible.

In infants w ho have EA- TEF,immediate primary repair generally isundertaken in those w eighing as li ttleas 1200 g. A n infant presenting wi thsignif icant pneumonia or other majorcongenital anomal ies w ill requi re amore indiv idual ized approach; astaged repair v ia an initial gastros-tomy may be performed in an infantw ho has EA - TEF and is il l . Theinfant can be allow ed to improve or

to be evaluated for other anomaliesprior to performing def initive repair.

Infants w ho have pure esophagealatresia generally are unable to have aprimary repair performed in the new -born period because the distance be-tw een the tw o ends of the esophagusis too great. These infants requi re agastrostom y and ei ther ex teri ori zati onof the esophagus w ith a later esopha-geal substi tution procedure (reversegastric tube, colon interposition) orserial attempts at dilatation of thetw o ends of the esophagus w ith a

later attempt at a primary anastomo-sis. A lthough conceptually more at-tractive, the latter option requires aprolonged initial hospitalization andhas an attendant ongoing risk ofaspiration.

The prognosis for most babies isexcellent; only a few sick infantswho have ser ious coexisting anom-alies, ar e of extreme low bir thweight, and have persistent pulmo-nary disease have a diminished

chance for survival. It i s not at alluncommon for the infant to developa relative narrow ing or stricturing atthe anastomotic site, w hich does notbecome evident until the child is ad-vanced to solid foods. Generally , thisproblem is managed easily w ithesophageal dilatation. T he infantsalso may have problems w ith esopha-geal motil i ty that mimics a stricture.This is determined easily by a con-trast sw al low radi ograph.

P y lo r ic A tre s ia /S te n o s is

E P I D E M I O L O G Y A N DPATHOGENESIS

W hereas congenital obstructions ofthe gastric outlet are uncommon, in-fantile hypertrophic pyloric stenosis,an acquired condition, is one of the

most commonly encountered surgicalproblems of infants. Studies havefound an incidence of pyloric steno-

sis in about 1 of every 500 livebirths, and i t is well recognized thatmale infants are af fected more of tenthan females. Pyloric stenosis is seenmore often in caucasian children, andinterestingly, many authors havenoted that the f irst-born infant is af -fected most of ten. H ereditary andfamilial predisposi tion also exist inthis condition, w i th as many as 7%of infants of affected parents alsohaving pyloric stenosis. The chancesan infant w ill have pyloric stenosisare greater i f the mother is the parent

who had the condition.A ctual atresia of the pylor ic or an-

tral areas is relatively uncommon,whereas membranes or diaphragms inthis region, although also rare, areseen w ith more frequency. Theantral/pyloric membranes and dia-phragms are thought to result f romso me en dod er mal redundancy duringdevelopm ent. Pylor ic stenosis, how-ever , r esults from hyper trophy of themuscularis of the pyloric channel, es-

GASTROENTEROLOGYln t# {1 4 9 }s tln a lO b s tru c tio n , N w bo m

pecially the circular muscle. Becausepyloric stenosis has not been knownto occur earlier than the fourth orf if th day of life and usually developsat 3 or 4 w eeks of age, i t is not atrue congenital defect. I ts pathogen-esi s rem ai ns unex pl ai ned.

PRESENTATION

Infants w ho have an antral/pyloricdiaphragm generally present w i thcomplete gastric obstruction, even ifthe diaphragm is perforate. These in-fants of ten are thought mistakenly tohave esophageal atresia because theysal ivate ex cessively and f requentl yhave respiratory problems due to gas-tric distention. The abdomen, how -ever, is scaphoid, and the emesisrarely is bilious. This problem gener-ally is manifested w ithin the f irst day

of life. In contrast to the early pre-sentation of infants having an antral/pyloric diaphragm, children w ho

have hypertrophic pyloric stenosishave the onset of symptoms, on theaverage, at 3weeks of age.

The initial presenting symptom ofpyloric stenosis is vomiting; thevomitus is not bile-stained. A lthoughoccasionally mistaken for gastro-esophageal reflux, usually one is ableto elicit a history of absolutely no re-flux-type symptoms until the f irst ep-isode of emesis, which then becomesmore frequent. A s the obstruction in-creases, the vomiting becomes moreconstant and projecti le. I t occa-

sionally can have a coffee ground ap-pearance or blood streaking w ithin i t.The babies continue to feed eagerlybut lose weight and may become de-hydrated. Should the problem con-tinue, they develop a hypochloremic-hypokalemic metabolic alkalosis.

The abdominal examination ofthose w ho have pyloric stenosis al-most alw ays is remarkable for thepresence of a f irm, small , movablemass that sits w i thin the right upper



4/12

O bstr uctions of the duodenum ar e caused by congenital

anomalies, including atr esia/stenosis, annular pancr eas, and a

preduodenal portal vein.

34 0Pediatrics in

ReviewVoL 15 No. 9 Septem ber 1994

F G A S T R O E N T E R O L O G YIn te s tin al O bs tru ctio n, Nwbomquadrant. Gastric decompression w itha nasogastric tube (NG) tube maymake this physical f inding more eas-ily demonstrable. Of ten times, v isiblew aves of gastric peristalsis can beseen, and for reasons that are notclearly understood, jaundice is asso-ciated in a smal l percentage of theinfants. This jaundice resolves fol-low ing an operation.

D I A G N O S I S

The pyloric mass or olive vir-tual ly is pathognomonic, and no fur-ther studies need be performed if it isa def inite, reproducible f inding madeby an experienced examiner. Shouldthere be any doubt as to the diagno-sis, abdominal ultrasonography and/or an upper GI series can conf irm thediagnosis.

M A N A G E M E N T

Once diagnosed, these infants are ad-mitted to the hospital and given intra-

venous f luid rehydration. Themetabolic alkalosis, due to chlorideloss in the vomitus and renal com-pensation, must be corrected. Thebabies do not require emergency sur-gery and can be returned to normalmetabolic balance before pyloromy-otomy. These infants general ly re-cover rapidly and then live acomplete and normal life. They occa-sionally w ill have some ref lexvomiting for several days fol low ingthe operation, but this w i ll subsiderapidly . Similarly, infants who have

pyloric/antral w ebs are expected torecover rapidly and do well followingsurgery.

D u o d e n a l O b s tru c t io n

E PI D E M I O L O G Y A N DPATHOGENESIS

M ost obstructions of the duodenumare congenital anomalies, includingatresi a/stenosi s, annul ar pancreas,and a preduodenal portal vein.

M alrotation also can cause obstruc-tion of the duodenum, w hich is ad-dressed later in this review .

Congenital duodenal obstruction isseen in approximately 1 of every10 000 births. There f requently is ahistory of polyhydramnios, and theseinfants of ten are either preterm orsmall for gestational age. There is asignif icant coincidence of otheranomal ies, including a 30% mci-dence of D own syndrome. Childrenw hose duodenal obstruction is a re-sult of an annular pancreas have asmuch as a 70% incidence of otheranomalies.

The most common causes of duo-denal obstruction in the newborn areduodenal atresia and stenosis.W hereas atresia produces symptomsshortly fol low ing birth, duodenal ste-

nosis may take several w eeks beforeits presence becomes obvious. D uo-denal mucosal proliferation beginsabout the fourth week of gestation,and the cel lular proliferation is soabundant that by5 to 6 w eeks ofgestation, the duodenum occludescompletely . I f the lumen does not re-form, an atresia of the duodenumw ill result. These atresias commonlyoccur in the second or thi rd portionof the duodenum, w ith the site of theatresia located just distal to the open-ing of the bile duct. I f the recanal iza-tion is incomplete, a duodenalstenosis may result. Obstruction inthis area may present as a partial orcomplete w eb.

A nnular pancreas, another com-mon obstruction, results f rom an ab-erration in the rotation of the ventralanlage of the pancreas, which nor-mally fuses w ith the dorsal anlage.The resul t is a 270-degree (orgreater) ring of pancreas aroundthe duodenum. The duodenum alsomay be obstructed by a preduodenalportal vein that is a result of an ab-normal development of vitell ine veinanastomoses. U sually this phenome-

jnon is found in association wi th otherserious malformations of a rotationalvariety . A preduodenal portal veinof ten is encountered in situs anom-alies, w here it may be associatedw ith duodenal obstructi on.

D I A G N O SI S A N D PR E SE N T A T I O N

A duodenal obstruction may be diag-nosed by prenatal ul trasonography ,w hich w il l demonstrate a dilatedstomach and proximal duodenum as alarge, f luid-f i l led, cystic mass.

Because absorption of the amnioticf luid by the fetus is impeded if theduodenum is obstructed, many ofthese fetuses w ill have polyhydram-nios. The typical presentation of duo-denal obstruction is an infant w hohas bilious vomiting shortly af terbi rth. N onbi lious emesis, however,does not rule out the diagnosis ofduodenal obstruction. A f lat anderect (or lateral decubi tus) abdominalradiograph is suff icient to diagnosethe duodenal obstruction because thetypical double-bubble sign of duo-denal atresia is diagnostic. Infantswho have complete duodenal obstruc-tion general ly have a scaphoid abdo-men due to the absence of gas in theintestine. I t is possible, how ever, thatthe abdomen w ill appear distendedinitial ly due to the greatly di latedstomach. Passage of an N G tubeshould decompress the dilated stom-ach and leave the infant w i th a sca-phoi d abdom en.

Should the chi ld have a duodenalstenosis that is not high grade, thediagnosis may not be made duringi nf ancy. T hese children occasional lycan present w ith long-term feedingproblems and not have signif icantsymptoms until later in childhood.A lthough the double-bubble usuallyis pathognomonic of duodenal ob-struction, occasionally one is notseen on a preliminary radiograph.

W e find that insti l l ing 50 mL of airof ten wi ll provide a suff icient amountof contrast to establish the diagno-sis. Should there be any question, aradiopaque agent contrast study canbe performed. W e believe that thereis li ttle role for a contrast study,though, unless one sees the sugges-tion of distal air w ithin the GI tract.A lthough this f inding could be due toa duodenal stenosis, the possibil i tyexists that mairotation is present, andthis diagnosis must be established (or



5/12

FIGU RE 24. Normal complete rotation

of the bowel with fixation of theduodenojejunal junction (ligament of

Treitz) in the left upper quadrant and

fixation of the cecum in the right lowerquadrant. The fixation results in a broad-

based mesente?y. The potential of amidgut volvulus developing is very

unlikely.

FIGURE 2B. M alrotation. The lack offixation results in the potential for midgut

volvulus. Note Ladd bands covering

par tial duodenal obstr uction.

FIGU RE 2C. M idgut volvulus. The entire

distribution of the superior mesenteric

a r te ry (duodenal -j ej unal junction to mid-transverse colon) is at ,isk. Operative

r eduction is i n a counter clockwise

direction.

Pediatrics in Review Vol. 15 No. 9 September 1994 341

- G A S T R OIntestinal 0

E N T E R O L O G Ybstructlon, Newborn

ruled out) im m ediately because thepotential p rob lem of m idgut v olv ulusi s l i f e- th rea ten ing.

M A N A G E M E N T

If the infant w hose duodenum is ob-structed has no sign if ican t respirato ry

or m etabolic problem s or o ther lif e-th reatening anom alies, he or she is acand idate fo r im m ediate operativ ecorrection. O n the o ther hand , in thepresence of any of these com plicatingfactors, the in fan t shou ld undergo ap-propriate ev aluation , stab iliz ation , o r

bo th before transport to the operatingroom . T he m ajor ex ception to thisrule is the in fan t in w hom the ev alua-tion determ ines that the duodenal ob-struction is due to m alro tation ; thisrepresents an em ergency because ofthe potential fo r v o lv u lus, and no un-

due delay s in transport to the operat-ing room are acceptable.

G enerally , eith er d uo deno du od en -ostom y or duodenojejunostom y is theprocedure of choice for duodenalatresia/stenosis and annular pancreas.C hildren w hose duodenum s are ob-

structed of ten are slow to open upand tolerate full enteral feeds. T his isw hy som e place gastrostom y tubes atthe tim e of operation , especially insm all, sick infants w ho tend to tak elonger to progress to fu ll feeds.O therw ise, their p rognosis generallyis ex cellent unless they hav e associ-ated congen ital anom alies of a lim it-in g n atu re .

Mairo ta t ion

E P I D E M I O L O G Y A N D

PAT H O G E N E S I S

A nom alies of in testinal ro tation m ay

be life-threaten ing or d iscov ered inci-dental to other conditions. T heseanom alies resu lt f rom disruption ofthe norm al rotational p rocess of them idgut during its retu rn f rom its ex -

tracoelom ic phase of dev elopm ent tothe abdom inal cav ity during thefourth to tenth w eek of em bry ogene-sis (Figure 2). In fan ts w ho hav e m al-ro tation of ten w ill hav e incom pleteduodenal obstruction created by peri-toneal (L add) bands com pressing the

duodenum . B ecause the m esentery isno t broadly fix ed and attached, theseinfants are at risk for dev elop ing am id gu t v olv ulus.

B ecause there are so m any ty pesof rotational anom alies, it is d if f icu ltto k now their ex act f requency in liv ebirths. H ow ev er, the m ajority of pa-tients w ho dev elop m idgut v olv u lusas a resu lt o f m alro tation do sow ith in the f irst y ear of lif e; indeed ,50% of such patien ts present w ithinthe f irst m onth of lif e. Incom plete ro-tation is seen in association w ith con-genital diaphragm atic hern ia as w ellas abdom inal w all anom alies such as

om phalocele and gastrosch isis. M al-ro tation also has been noted inci-dentally in m any ch ild ren beingtreated for H irschsprung disease andin tussusception. T here does not seemto be a hereditary /fam ilial fo rm ofmalrotation.

P R E S E N T AT I O N

B ecause the m ajority of sy m ptom aticch ild ren presen t before 1 m onth ofage and m anifest b ilious v om iting ,



6/12

Bilious vomiting in the neonate is an indication of malr otation

un til p roven other wise.

342 Pedi atr ics in Review VoL 15 No. 9 September 1994

G A S T R O E N T E R O L O G YIn te s t in a l O b s tru c tio n , Newborn

w e m aintain a rule that biliousv om iting in the neonate is m alrota-tion un til p rov en o therw ise. T hesy m ptom s of m alro tation m ay appearin sev eral d if ferent w ay s, and the pa-tien t m ay presen t hav ing either inter-m ittent abdom inal pain , v om iting, o ran ex trem e abdom inal em ergency re-lated to the dev elopm ent of a m idgutv o lv u lus. T he m ost com m on presen-tation is that of interm ittent duodenalobstruction by [add bands occurringas b ilious v om iting in the otherw isenorm al infan t. A f lat and uprigh t ab-dom inal f ilm m ay dem onstrate ev i-dence of an incom plete duodenal

obstruction w ith an en larged duo-denum . O f ten the d istribu tion ofintestinal gas is seen to be m ostly inthe right half o f the abdom en; gas isseen in the d istal in testine. T h is f ind-ing represen ts a v ery im portant dis-tinction betw een the radiographic

m ent on the part of the paren ts, re-

ferring phy sician , and surgeon m aym ak e the dif ference betw een a condi-tion that is com pletely rev ersib le andone that, in a few hours, results inloss of a large segm ent of intestine.Precious tim e should no t be lost intry ing to correct a m etabo lic im bal-ance that is not correctable un til thev olv u lus has been addressed .

M A N A G E M E N T

T he procedure of choice in infantsw ho hav e m alrotation is the [addprocedure. T h is operation consists ofd iv iding the peritoneal ([add) bands,w hich partially obstruct the duo-

denum , and then placing the colonon the infan ts lef t and the duodenum

and jejunum on the righ t so as tobroaden the m esentery . A n appen-dectom y alw ay s is perfo rm ed to

-ipercentage of neonates w ho hav e in -testinal obstruction . A tresia, or acom plete congenital obstruction, isfar m ore com m on than is stenosis ora partial occlusion . R eports o f its in-cidence w ould seem to be on theav erage of 1 in 750 liv e births. C o-ex isting anom alies and fam ilial tend-encies are uncom mon; the incidence

of associated ex train testinal anom -alies is thought to be only about5% .W hereas atresia and stenosis in them ore prox im al duodenum has beenattributed to the failure of recanaliz a-tion of the prox im al sm all bow el,

atresias and stenoses of the jejuno-ileal reg ion lik ely are due to late in-trau terine m esen teric v ascular

accidents. Jejuno ileal atresia is seenin association w ith m alro tation , m e-

conium ileus, and gastrosch isis; eachof these could hav e led to a late in-trauterine m esenteric v ascu lar acci-

den t fo llow ed by atresia.

P R E S E N TAT I O N

appearance of a ch ild w ho has m alro-tation and the ch ild w ho has duo-denal obstruction due to ano ther

enti ty.

D I A G N O S I S

A fair cav eat is that the baby w hohas green v om itus and duodenal ob-struction w ill need an operation andshould be referred im m ediately . T hechild shou ld be m ade nothing per os(N PO ), w ith the p lacem ent of an N Gtube and adm in istration of intrav e-nous f lu ids and antib iotics. C ontraststudies of ten are em ploy ed to helpm ak e the diagnosis of m alro tation ;

som e pediatric radio log ists p refer anupper G I series, others a bariumenem a. W e, and m ost others, preferthe upper G I series to docum entw hether the ligam ent of T reitz is po-sitioned properly in the left upperquadran t and w hether the duodenumis obstructed . In any ch ild w ho hasb ilious em esis and ev idence of a ro-tational anom aly , the possib ility ofv olv ulus accentuates the urgency ofthe diagnosis; ex peditious m anage-

av o id future confusion w hen thech ild has abdom inal pain.

T he return of intestinal function

can be delay ed in those w ho hav ehad a sev ere ischem ic insult f rom am idgut v o lv ulus. O n the o ther hand,those w ho hav e few presen ting sy m p-tom s and undergo m anagem ent be-fore the appearance of a v o lv u lus dow ell and generally retu rn to norm alfunction w ith in a few day s. From aprognostic standpoint, these childrenshould do w ell un less they hav e hada v olv ulus that has required a m as-siv e resection of sm all bow el. S uch

children require long-term intrav e-nous nu trition. O ccasionally , the v o l-

v u lus results in the irrev ersib le lossof such a large segm ent of bow el that

the ch ild s prognosis is hopeless.

J e ju n a l/Ile a l A t re s la a n dS t e n o s i s

E PI D E M I O L O G Y A N DPAT H O G E N E S I S

A tresia or stenosis o f the jejunoilealarea is the d iagnosis in a sign if ican t

A card inal sign of jejuno ileal atresiais abdom inal distention , bu t it israrely , if ev er, presen t im m ediatelyat b irth. D isten tion in the infant w hohas jejuno ileal atresia w ill dev elop 12to 24 hours af ter birth, fo llow ing thein itiation of feedings. T he in fan t w hopresents w ith abdom inal distentionim m ediately at b irth is m ore lik ely to

hav e m econium periton itis. O thercom m on f ind ings in those w ho hav ejejunoileal atresia are po ly hy dram -nios, bilious v om iting, and failure topass m econ ium .

D I A G N O S I S

T he diagnosis generally is im plied byf lat and erect (o r lateral decubitus)abdom inal rad iographs. L arge dilatedloops of bow el w ith air f luid lev elsgenerally are noted; the low er theatresia, the greater the num ber ofsuch distended loops. A dif ferential

d iagnosis of m alrotation w ith orw ithout v olv ulus, m econium ileus,and H irschsprung disease ex ists. Abarium enem a can by helpfu l by al-low ing one to determ ine w hether theco lon is used or unused (ie, m icro-co lon) as w ell as by locating the po-sition of the cecum . A dditionally , thebarium enem a w ill be ab le to dif fer-entiate betw een sm all bow el andcolon d istention. T his w ill help dif -feren tiate cond itions in need of sur-



7/12

GASTROENTEROLOGYIn testina l O bstruction , N sw born

Pn eu m atosis in t est in a lis is t h e h allm ar k o f n ecr ot iz in g

enterocol i t i s .

P ediatrics in Review Vol. 15 No. 9 S eptember 1994 343

gi cal i nterventi on ( mal rotati on,H i rschsprung di sease, atresi a/ steno-sis) from meconium ileus, whichoften can be managed nonoperatively(see section on meconium ileus).

M A N A G E M E N T

Babies who have atresia/stenosis aremanaged best with placement of anN G tube and initiation of intravenousfluid therapy and antibiotics. Theatresia may be corrected immedi-ately, provided that no other life-threatening anomalies exist. M ostchildren have not had severe fluidand electrolyte losses and can be pre-pared rapidly for the operating room.Occasionally, however, childrenpresent with prolonged vomiting andmarked electrolyte losses. Theyshould have adequate fluid replace-

ment provided and normal urine out-put restored before surgery.Postoperative management includes

conti nued i ntesti nal decompressionand administration of appropriate in-travenous nutrition until the infanthas recovered from his or her periodof postoperative ileus and anasto-motic dysfunction. This often willlast as long as 2 to 3 weeks and, oc-casionally, longer. T hese childrenotherwise tend to do well. Occasion-ally, those who have small bowelatresi as have m arkedly foreshortened

lengths of small bowel due to the inutero vascular accident; they willbe limited by their short gutsyndrome.

N e c ro tiz in g E n te ro c o lit is

E P I D E M I O L O G Y A N DPAT H O G E N E S I S

N eonatal necroti zi ng enterocol iti s(N EC) is a problem that affects pre-term infants predominantly. I t is un-clear why some children are affectedand others are spared, but it may berelated to compromise of the sick,stressed preterm infants m esentericblood flow w ith an ischem ia-reperfu-sion type of injury sustained by thegut. Epidemiologic data suggest thatthe presence of enteric feeds has arole in the pathogenesis of necrotiz-ing enterocolitis; in most studies, theaffected patients were fed by mouthprior to the onset of the disease. A d-ditional workers have shown thatnecrotizing enterocolitis has occurred

in clustered epidemics, implicatingan infectious agent. The most signifi-cant risk factor for children to de-velop necrotizing enterocolitis isprematurity. I t is believed by mostthat in such infants the coexistence ofcirculatory instability, enteral feed-ing, and infection in some combina-tion plus the presence of inflam-matory mediators function as asufficient inciting event to create mu-cosal injury, with bacterial over-growth and translocation allowing thepresence of endotoxin and gas pro-duction by bacteria within the gutwall.

The most common site of involve-ment of necrotizing enterocolitis isthe terminal ileum; the colon is thesecond most common location. Thedisease can involve single or multiplesegments of intestine, although occa-sionally a fulminating form of necro-

tizing enterocolitis is characterized bynecrosis of the entire gut.


Children who have necrotizing enter-ocolitis generally will present havingabdominal distention and either amarked gastric residual or vomiting.Occult positive or even grosslybloody stools may become apparentas the abdominal distention increases.Early on, the abdomen is soft, but asthe necrotizing enterocolitis pro-gresses, the abdomen tends to be-come more firm; occasionally,visible loops of bowel are present.Erythema of the abdominal wall oc-

casionally may be noted, suggestingunderlying peritonitis. Often, thesebabies have nonspecific signs of sep-sis, such as lethargy and temperatureinstability, along with some abdomi-nal distention, which suggests N EC.

D I A G N O S I S

The diagnosis of necrotizing entero-colitis often can be made via abdomi-nal radiographs. T he gas-formingorganisms within the bowel wall pro-

duce pneumotosis intestinalis orintramural gas; gas within the portalvenous system also may be seen. Thepresence of intramural gas may bethe most important radiologic featureof necrotizing enterocolitis, and it isseen commonly, but not always.Some believe that the presence ofportal venous gas portends a morevirulent form of the disease, but wehave not found this always to betrue. L ateral decubitus radi ographsmay reveal the presence of a pneu-moperitoneum, and serial radiographsmay demonstrate the presence of afi xed, persi stently dilated intestinalloop.

M A N A G E M E N T

The initial management of necrotiz-ing enterocoliti s is nonoperativeunless there is good evidence of in-

testinal necrosis or perforation. A llchildren need to have NG decom-pression and broad-spectrum antibiot-ics instituted immediately. Thechildren are monitored by followingtheir white blood cell and plateletcounts carefully. Persistent and/orprogressive thrombocytopenia corn-monly is associated with severe casesof necrotizing enterocolitis. Simi-larly, progressive acidosis suggestssi gni fi cant di sease.

Aside from pneumoperitoneum,there is no single criterion that canpredict the presence of bowel necro-sis invariably. Thus, children sus-pected of having NEC who develop

pneurnoperitoneum are operated onwithout hesitation, but it is difficultto know which children have devel-oped full-thickness necrosis of a seg-ment of bowel but no perforation.Children who have necrotic intestine,which serves as their ongoing sourceof sepsis, require operation. M anystudies have been undertaken to de-termine how to diagnose intestinalnecrosis prior to perforation; the pos-itive findings on abdominal paracen-tesis have been used by many. W e



8/12

Children w ho have sim ple m econium ileus dem onstr ate distended

intestinal loops without air fluid levels.

344 P ediatr ics in Review VoL 15 No. 9 Septem ber1994

G A S T R O E N T E R O L O G YIn te s t in a l O b s tru c tio n , Newborn

have felt that infants suspected ofhaving N EC w ho continue to deterio-rate cl inically despi te adequate sup-portive therapy are managed bestw ith an early operation. W e alsohave been reasonably aggressiv eabout operating on children who havesignif icant abdominal wall ery themaand a progressi ve throm bocy topeni a.M ore than many other problems ofthe new born, N EC requires early sur-gical consultation and a tremendousamount of judgment as to the appro-priate time of operative intervention.

The ultimate outcome of childrenwho have had N EC seems to dependon the severity of disease. The lateoutcome parallels the late outcome ofotherw ise sick, stressed, pretermnew borns in terms of growth and de-velopmental parameters, but thesechildren w ill have GI sequelae thatdepend greatly on the extent of dis-

body s exocrine gland secretions areabnormal in CF. A pproximately 10%to 15 % of such infants w ill developmeconium ileus, w ith obstruction ofvarying lengths of their distal i leumand colon by inspissated meconium.CF almost exclusively is a caucasiandisease that presents in approxim atel y1 in every 2000 live caucasian births.


M econium ileus is classif ied as eithersimple or compl icated. In simple me-conium ileus one f inds that the distali leum and proximal colon are im-pacted w ith inspissated meconiumand that a resultant obstruction is inthe mid-ileum, which is markedly di-lated and f il led wi th a thick, tena-cious, dark green, tarry -likemeconium. The w all of the smallbowel can be congested and hyper-

tinal obstruction. A n important dif -ferential diagnostic feature ofmeconium ileus is that af fected in-fants of ten are born having markedabdominal distention (as comparedw ith children w ho have jejunoi lealatresia w ho develop distention) andmay vomit biliously, fail to pass me-conium, or both. The impacted intra-luminal meconium usually is palpableas a doughy, rubbery substance, andthe distended abdomen w ill have acharacteristic feel to it.

I f abdominal radiographs are per-formed, the chi ldren who have sim-ple meconium ileus demonstratedistended intestinal loops w ithout airf luid levels and with a markedly dis-parate degree of distention. A lso, thepresence of the meconium gives theradiograph a coarse, granular, soapbubble appearance, which may aidin the diagnosis. Patients w ho havecomplicated meconium ileus of tenw ill have scattered cal cif icationsevident on abdomi nal radiographs,w hich ref lect the presence of mecon-ium peritonitis f rom in utero intes-t inal per for at ion.

M A N A G E M E N T

ease and especially on the amount ofbowel resected. A child w ho has se-vere N EC and resection may havegreat dif f iculty wi th the short gut

syndrome and its nutri tional seque-lae. Some children w ho did not re-quire operative intervention wil ldevelop strictures at their site of dis-ease and subsequently may require ani nt est in al resect io n.

Me c o n lu m b u s

E PI D E M I O L O G Y A N DPAT H O G E N E S I S

M econium ileus is an intestinal ob-struction in the new born due to thepresence of mucoviscidosis (cystic f i-brosis), w hich is inherited as an auto-somal recessive trait. The geneticdefect responsible for cystic f ibrosis(CF) has been identif ied recentlyw ith the gene located on the longarm of chromosome 7. W hereas thediagnosis of CF previously w as es-tablished via sweat tests and stooltrypsin analysis, i ts diagnosis now ispossible prenatally via the use of re-striction fragment length polymor-phism analysis of amniotic f luid. The

trophied; the amount of distention asone proceeds proximally becomesprogressively less. D istal to the ob-struction the ileum is narrow , w ith

the inspissated meconium appearingas pel lets of gray , beaded putty .M ost of the colon is narrow andempty, presenting as a microcolon.The meconium ileus may becomecomplicated by having the di latedproximal intestinal segment undergoa volvulus in utero such that the isch-emic segment resorbs, resulting inthe formation of an intestinal atresia.I f volvulus and intestinal necrosis oc-cur late enough in gestation, mecon-ium perforation occurs wi th thepresence of meconium peritoniti s; oc-

casionally , the abdomen is f i l led w itha large pseudocyst. A ll of these complications are mechanical innature and occur before birth, soevaluation and management of thenew born w ho has meconium ileus re-quires a distinction betw een the sim-ple and complicated varieties.

D I A G N O S I S

M econium ileus is the most commoncause of neonatal intraluminal intes-

M anagement of these infants dependsinitially on w hether the meconiumileus is simple or complicated. In-fants w ho have a simple obstructionmay be both diagnosed and treatedby performing a contrast enema un-der f luoroscopic control , using gas-trograf in. This hyperosmolar enemaof ten can relieve the obstruction ofthe meconium ileus by drawing f luidinto the intestinal lumen and allowingthe mass of meconium to becomesof tened and disimpacted. These chil-dren w il l requi re N G decompressionand intravenous f luids because thehyperosmolar contrast agent w ill de-plete their intravascular space as thef luid shi f ts into the intestine. Successof the gastrograf in enema is gaugedby free ref lux of the contrast agentinto the proximal dilated smallbow el. Occasionally , two to threesuch enemas are needed before suc-cess is achieved. In infants in whomthe contrast enema fails to relieve theobstruction or in those whose mecon-ium ileus is complicated, an opera-tion should be undertaken.

Once recovered from meconiumileus, the infant s long-term outlook



9/12

H irschsprung disease isthree t im es m or e com m on in m ales th an

i n f em a les.

Pediatrics in Review VoL 15 No. 9 Sep tem ber199434 5

- G A S T R O E N T E R O L O G Y

intestinal Obstruct ion, Newborn

will depend on the severity and rateo f progression of the CF. The degreeof pulmonary disease is likely to bethe most limiting factor in his or herprospect for long-term survival.

C o b o n ic A tr e s ia /S te n o s is

E PI D E M I O L O G Y A N D

PAT H O G E N E S I S

A tresia or stenosis of the colon is arare anomaly occurring in approxi-mately 1 of every 20 000 live births;only gastric atresia is rarer than co-ionic atresia. W hen encountered, co-ionic atresia frequently is associatedwith skeletal anomalies such as syn-dactly, polydactly, absent radius, andclub foot. There also is an associa-tion of ocular and cardiac anomalies.A s with the jejunoileal forms, co-

lonic atresia and stenosis are widelyconsidered to be due to in utero vas-cular compromise.

anomaly, but it seems that reporteddeaths in modern times have oc-curred primarily from critical associ-ated anomalies or prolonged delaysin recognizing the problem. These in-fants should fare well once surgicallycorrected.

Me c o n iu m P lu g S y n d r o m e /S m a ll L e ft C o lo n S y n d r o m e

From a clinical standpoint, these twoentities are distinct, but they seem torepresent a continuum of transientneonatal colonic dysfunction. Chil-dren who have meconium plug syn-drome will present with evidence ofa low intestinal obstruction. Follow-ing administration of a contrastenema and passage of a large mecon-ium stool, they seem to be relievedo f difficulties. This problem com-monly is seen in preterm infants. Re-gardless of the age of presentation,should the children have further

intestinal obstruction in the newborn.I nterestingly, though, H irschsprungdisease seems to have varying de-grees of severity, and it is not un-common for the diagnosis not to bemade until the child is older and cx-periencing severe problems of consti-pation.

H irschsprung di sease is character-ized by a congenital absence of gan-glion cells in the myenteric andsubmucosal plexuses of the bowel.I ts exact etiology is unknown, but itis suggested that the migration ofneuroblasts during their cranial cau-dad descent in the intestine hasceased. T he length of aganglionicbowel varies according to the time ofthe arrest of the migration. A pproxi-mately 80% of H irschsprung diseasecases involve only the rectosigmoidregion; 3% of cases involve the en-tire colon, and even fewer have beenreported to have total intestinal agan-giionosis.


I n colonic atresia/stenosis, the chil-dren present in the early newborn pe-nod having findings of a very distalintestinal obstruction. T he infantswill develop marked abdominal dis-tention with bilious vomiting. Stoolsusually are absent, making much oftheir initial presentation not greatlydissimilar from those children whohave jejunoileal atresia. H owever, inchildren who have colonic atresia,the abdominal radiograph may dem-onstrate more and larger dilated loopsthan are seen in a small bowel ob-struction. I t is not uncommon forchildren who have colonic atresia topresent having col oni c perforationand pneumoperitoneum. A definitivediagnosis of colonic atresia can beestablished via a barium enema,which reveals a microcolon withincomplete colonic filling.

M A N A G E M E N T

These infants are managed via N Gdecompression, intravenous fluids,and antibiotics prior to surgery. Oncethe diagnosis has been establishedand the i ntestines are decompressed,the operation can be timed accordingto the infants well being and needfor other evaluati ons.

Because colonic atresia/stenosis isso rare, there are no large series toprovide a full prognosis of this

stooling abnormalities after theenema, they need to be evaluated forH i rschsprung di sease.

Infants of diabetic mothers alsomay present having the appearance ofa distal GI obstruction, and they mayhave abdominal distention, biliousemesis, and no stool in the immedi-ate newborn period. Such infants aremanaged w ith N G decompressionand control of hypoglycemia. Theuse of a contrast enema will docu-ment the presence of a small leftcolon and a dilated proximal colonfilled with meconium. Generally,these infants are relieved withadministration of the contrast enema,but it may need to be repeated. M anyclinicians, even in the presence of aclassic history, will obtain a suc-tion rectal biopsy to be sure thatH irschsprung disease is not present.

H lr s c h s p r u n g D is e a s e

E PI D E M I O L O G Y A N D

PATHOGENESIS

H irschsprung disease is a congenitalanomaly that can present as complete

The incidence of H irschsprung dis-ease seems to be approximately 1 in5000 live births and is three timesmore common in males than in fe-males; a pronounced difference insex incidence occurs in the long seg-ment disorder. Some familial occur-rences of H irschsprung disease havebeen reported, especially where longsegment involvement is present.

Peristalsis is abnormal or absent inthe aganglionic segment of thechilds colon. Failure of the involvedbowel and the internal anal sphincterto relax produce the intestinal ob-struction and/or constipation found inH irschsprung disease. T he intestineproximal to the aganglionic segmentbecomes dilated and hypertrophied.When H irschsprung disease presentsin the newborn, there often is cvi-dence of complete intestinal obstruc-tion, with abdominal distention andabsence of passage of meconium.


The presentation may vary frombeing mildly constipated to having aninitial, fulmi nant toxic enterocolitis,



10/12

FIGURE 3.I mper for ate anus. Rectalpouch 1 (RP ) sits above thepubococcygeal line (PC) and would be

classified as a high type anomaly.Rectal pouch 2 (RP2) sitsbelow the PCline and represents a low typeanomaly. The level of the rectal pouch iscrucial in decisions of management. B!i ndi ca tes the bladder.

346 Pediatrics inReview VoL 15 No. 9 September 1994

GASTROENTEROLOGYIn te s tin a l O b s tru c t io n , N e w b o rn

w hich occasionally can be fatal . Suchseverely affected children developtense abdominal distention over afew hours and vomit profusely w hilepassing large amounts of foul-smell-ing gas and putrid loose stools. Thespectrum of presentation ranges f romcomplete obstruction at birth, w ithvomiting, abdominal distention, andfailure to pass meconium, to delayedpassage of meconium and repeatedepisodes of constipation. One mustalw ays be suspicious of the diagnosiso f Hirschsprung disease in the babyw ho has evidence of a partial orcom plete distal bow el obstruction.

DIAGNOSIS

The dif ferential diagnosis includesmeconium ileus, jejunoileal atresia,meconium plug syndrome, and smalllef t colon syndrome as w el l as non-surgical sources such as neonatal sep-sis, adrenal insuff iciency, andhypothyroidism. The obstruction canbe ascertained as mechanical and notfunctional by the performance of abarium enema, w hich should demon-strate a transi tion zone at the junctionof agangli onic and ganglionatedbow el . A ny child w ho presents hay-ing colonic distention and theabsence of rectal air on a plain ab-dominal radiograph, therefore, shouldbe examined .

The diagnosis may be dif f icult tomake in the new born because thetransition zone betw een the agan-gl ionic segment and the proximal di -lated colon may be subtle or absent.In this instance, obtaining fol low -upradiographs 24 and 48 hours af ter thestudy can be helpful because if bar-ium is being retained, this can be in-terpreted as a relatively positivediagnostic sign. A lthough some haveused manometric studies of the colontv diagnose H irschsprung disease,these rarely are useful in the neonate.The best and most def initive meansof diagnosis is a rectal biopsy, w hichw ill conf irm aganglionosis histologi-cally . A lthough a preoperative biopsymay not be necessary if the child shistory and f indings from the bariumenema are convincing, even in thesmallest of babies, suction rectalbiopsy can be performed at thebedside.

M A N A G E M E N T

M anagement of these children, as

any child w ho evidences distal bow elobstruction, should include the place-ment of an intravenous catheter asw el l as NG decompression and theuse of intravenous antibiotics. I t isimportant that cleansing enemas andrectal examinations not be done priorto the performance of the contraststudy because the characteristic con-f iguration of the bow el could be lostif the colon is evacuated. Once thediagnosis of H irschsprung disease hasbeen established, prompt colostomyshould be undertaken and the level ofganglionosis is establi shed. The co-lostomy then is placed in a segmentof bowel that i s ganglionated, andthe infant i s al low ed to grow andthrive. The child may be managedfurther via a definitive pul l-throughprocedure at approximately 8 to 10months of age.

Im p e rfo ra te A n u s

E PID EM IO LO G Y A ND

PATHOGENESIS

The term imperforate anus encompas-ses a broad spectrum of anorectalmalformations that occur in 1 in5000 live births, w ith a slight pre-ponderance in males. This is a disor-der of embryogenesis involving thehind gut and results f rom the abnor-mal development of the urorectalseptum, w ith incomplete separationof the cloaca into i ts urogenital andanorectal components (Figure 3). A sa result of this abnormal develop-ment, the anal canal may end blindlyor there may be an ectopic openingon the perineum that virtual ly alw aysis directed anteriorly. This canal mayterminate in the vulva/vagina or inthe m ale urethra.

Imperforate anus generally is cate-gorized as either low or high; thisclassi fication is determined bywhether the blind end of the rectumends above or below the level of thelevator musculature. A high type oflesion is more common than the lowtype and, in general, is more com-plex; rectourinary and rectov aginalf istulas com monly are associated.T here is a greater m al e-to-f em alepredominance in patients w ho havethe high type of lesions, and morethan 80% of such patients w ill dem-onstrate such f istulas. The male-to-female ratio in low imperforate anus

is closer to 1 : 1, and in most of thesechildren, a discernible external pen-neal f i stula is noted at on shortly fol-low ing birth. There does not seem tobe a strong genetic predisposition,but reports of fami lial cases do exist.

DIAGNOSIS

The distinction betw een low and highimperfonate anus occasionally can behard even for experts to make. Ingeneral, though, the distinction isbest made by using the combinationof physical and radiographic exami-nations. W hether the child is male orfemale, a visible f istula throughw hich meconium is passed verylikely has a low lying rectal pouch.I f there is any doubt, how ever, acontrast injection through the fistulacan determine the diagnosis w ith cer-

tainty . A helpful means of diagnos-ing the level of the rectal pouch isthe so-called invertogram, f irst de-scribed by W angenstein and Rice,which w hen properly performed,of ten can show the level of the pouchrelativ e to the levator m usculature.Some currently are employing ultra-sonography to help determine thelevel of the bl ind rectal pouch. M ostbelieve that it can take as long as 24hours for air to descend far enough



11/12

G A S T R O E N T E R O L O G Y

Pediatr ics in Review VoL 15 No. 9 September1994 347

dow n in the pelv ic colon to deter-m ine the depth of descen t of the nec-tal pouch accurately . C hild rengenerally are studied at th is poin t un-less they becom e distended or dem -

onstnate the presence of a pen inealf istu la. S uch patients shou ld be m adeN PO and beg in in trav enous an tibiot-ics. A lthough N G tubes are no tp laced routinely , if the child needs tobe transferred to a referral cen ter forappropriate diagnosis and m anage-m ent, w e believ e that the N G tubeshould be used during transport.

C h ild ren w ho hav e im perfonateanus of ten w ill m anifest the V A T ERassociations and need to be inv esti-gated carefully for other anom alies.A sign if ican t feature of this anom alyis the absence of sacnal v ertebral seg-m ents in som e children w ho hav ehigh ty pe defects; these child ren can

be pred icted to hav e som e def icien-cies in their neunologic con trol of de-fecation . A lm ost 50% of childrenw ho hav e high im perforate anus alsow ill hav e genitourinary m alfo rm a-tions; an ultrasonographic study ofthe k idney and early assessm ent ofthe renal ex creto ry status is im portan tin the preoperativ e ev aluation .

M A N A G E M E N T

In general, m ost low ty pe im penfor-ate anus prob lem s can be m anagedv ia a penineal anoplasty perfo rm ed

during in fancy . H igh im perforateanus, how ev er, requ ires a m ore cx -tensiv e operativ e repair as w ell as d i-v ision of the lik ely nectoun inaryf istu la. T herefore, these infants gen-enally are m anaged v ia a co lostom yin the new born period. In add ition tostool div ersion , the properly con-structed co lostom y w ill av oid urinarytract soiling v ia con tam ination of therectouninary f istu la. D ef in itiv e recon-structiv e pull-th rough surgery then isundertak en at abou t 8 m onths of age.

C hildren w ho hav e low ty pe im -perforate anus do v ery w ell; thosew ho hav e high ty pe im perforate anustend to hav e d if f iculty w ith fetal con-tinence, w hich can v ary in sev erity .T h is especially is true of infants w hohav e absen t sacral segm ents, so th isp rob lem should be iden tif ied earlyfor the fam ily . O ther lim itations ofch ild ren w ho hav e im perforate anus

depend greatly on the coassociationw ith other V A T ER anom alies.

S UG G E S TE D R E A D IN G

L ister J, Irv ing IM .N eonat al Sur ger y, 3rd ed .L ondon, U K : B utterw orths; 1990

Pena A . Su,gi cal M anagement ofAnorectalMalfonnations. N ew Y ork , N Y : S pringer-

P IR Q UIZ

1. A mong the f ollow ing , themost i m-portant s y m p t o m or f inding in aninfant that is suggestiv e of intestinalobstruction is:A . D istention of intestinal loops on

radiograph.B . H is to iy o f o li go hy dram n io s.C. H y peractiv ity of bow el sounds.D . Passage of bloody stoo ls.E. V om iting of bile.

2 . A m ajor dif ference in the clin icalpictu re of congen ital upper sm allbow el obstruction v ersus congen itallarge bow el obstruction is the f ind-ing of :A . A bsence of bow el sounds.B . B il io us v om i ti ng .C . Failure to pass m econium .D . G eneraliz ed abdom inal disten-

t ion.E . M e tab olic ac id os is .

3. A 2-day -old m ale inf an t has beentransferred f rom a com munity hospi-tal w ith the com plaint of repeatedem esis since f irst f eeding. H ism other is prim iparous w ith a historyof crack cocaine use in the thirdtrim ester. B irth w eight w as7 lb. A t

birth the abdom en w as noted to beunusually f ull. Findings on theadm ission phy sical ex am ination in-cluded a distended abdom en w ithhy peractiv e bow el sounds. O n rectalex am ination, the am pulla is em pty .O n rad iographic ex am ination, air isp resent in m ultip le loops of bow el,no air f luid lev els are seen , andf leck s of calcium are scatteredthroughout the abdom en. T hemostlikely diagnosis is:A . A nnular pancreas.B . B a ct eri al p eri to ni ti s.C. D ru g w i th draw al .D . M econium ileus.E . N eo natal to xo plas m osis .

4 . A 6-day -old fu ll-term f em ale infantdev elops repeated v om iting, abdom -inal distention , and cessation of pas-sage of stool. A ccording to herhistory , m econium passage w as de-lay ed. T em perature is norm al. R ec-tal ex am ination is follow ed by alarge quantity of liquid feces w ith

m uch gas. O fth e follow ing, themost appropriate nex t step in m an-agem ent is to:

V erlag; 1990R af fensperger JG , ed. S w enson s Pediatric

S urgery , 5 th ed. N orw alk , C onn: A ppleton& L ange; 1990

R oss A J III, ed. N eonatal S urgery : Post-graduate G eneral S w ge,y . A ustin , T ex : R GL andes C o; 1992

W elch JU , R andolph JO , R av itch M M , et al.Pediatric S urgery , 4th ed. C hicago, Ill:Y ear B ook M edical Publishers; 1986

A . O rder a gastrograf in (oil-basedc on trast) en em a.

B . O rder a barium enem a af tersaline cleansing enem a.

C . R efer for anorectal m anom etry .D . R ef er for suction rectal biopsy .

5 . A 10-day -old preterm f em ale infantdev elops repeated episodes of v om -iting w ith ab dom inal distention.B irthw eight w as 1400 g, and hercourse w as unev entful un til the

present sy m pto ms. N asojejunalfeed ings w ere w ell tolerated m i-tiaf ly . Platelet coun t and coagulatio nstudies are norm al. S too ls now areliqu id and guaiac positiv e. T he m ostcorrect statem ent regard ing thisclinical picture is:A . A prev iously unsuspected con-

gen ital anom aly of the gastro in -testinal tract is the basis for theproblem.

B . C ontinuation of norm al plateletcounts predicts a benign course.

C . Prom pt an tib io tic therapy is re-qu ired to av oid sev ere dehy dra-t io n f ro m e nt ero to xi ge ni cE scherichia coil in fection.

D . T he possibility of intussuscep-tion necessitates perform ing abarium enem a.

E . T he presence of pneum atosis in-testinalis on radiograph w ill m di-cate the und erly in g patholog y.

6. A 3-w eek -old m ale infant presentsw ith a 1-day history of recurrentem esis. T he v om itus is bile-stained.A sim ilar episode occurred at 5 day sof age and spon taneously resolv edin 1 day . Findings on phy sical cx -am ination include a norm al tem pera-triT e, f lat abdom en, and occasionalbow el sounds. O n rectal ex am ina-tion, norm al stool is present. T hem ost appropriate nex t step in m an-

agem ent is:A . Intrav enous f luid replacem ent

u ntil alk alo sis is c orre cte d.B . O bserv ation until prelim inary

results of sep tic ev aluation areavailable.

C . Prom pt upper 01 radiograph icstudy.

D . T rial of thick ened f eed ings w ithh yp oalle rg en ic f orm u la.



12/12

pediatrics in review 1994 ross 338 47 gastro

Documents