Archives of Disease in Childhood 1993; 69: 533-537

PERSONAL PRACTICE

Therapeutic bronchoscopy in ventilated neonates

Isi Dab, Anne Malfroot, Anita Goossens

In the past bronchial endoscopy needed rigidhollow bronchoscopes and until recently thetechnique was rarely used by paediatricians.Thin and ultrathin fibreoptic flexible broncho-scopes (FFBs) are now available and endo-scopy is likely to be increasingly used. Despitethe expected exponential expansion of endo-scopies using FFB at any age for a growingnumber of indications, some conditions willcontinue to need rigid bronchoscopy.

Instruments available for babies andchildrenRIGID BRONCHOSCOPESRigid bronchoscopes are rigid hollow stainlesssteel tubes. There are a variety of differentlengths and widths in accordance with thechildren's age and size. The smallest one has aninner diameter of 2-5 mm and a length of 20cm. The upper or proximal part is T shaped (figIA) with one central channel and two lateralchannels. In the central channel one can insertvarious kinds of telescopes (fig 1B), either for astraightforward view, or for some more lateralviews (30°, 70°, or 900 depending on howmuch the distal lens is tilted). The centralchannel allows various kinds of forceps (fig 1 C)for biopsy or the removal of a foreign body.Unfortunately for the small baby rigid broncho-scope optical forceps are not available (smalltetescopes within the shaft of the forceps, thejaws of the latter being in front of the distal

AcademischKinderziekenhuis,Vrije UniversiteitBrussel, Brussels,Belgium, Departmentof Paediatrics,PaediatricPulmonology, andCystic Fibrosis ClinicIsi DabAnne Malfroot

Department ofPathologyAnita Goossens

Correspondence and reprintrequests to: Professor I Dab,Department of Paediatrics,Respiratory and CysticFibrosis Clinic, AcademischKinderziekenhuis, VrijeUniversiteit Brussel (VUB),Laabeeklaan 101, B-1090Brussels, Belgium.

Figure I Rigid bronchoscope with the Tshaped proximalpart and a central channel and two lateral channels (A).Telescope in the central channel (B); forceps (C); onelateral channelfor ventilation with a bag or with amechanical ventilator and perhaps gas anaesthesia (D).The other lateral channel is aimedfor the prism thatprojects the light into the airways through the lumen of thebronchoscope (E). Y shaped cable that conducts the lightfrom an external source onto the prism and onto thetelescope (F).

lens). An aspiration catheter can also beinserted for the removal of secretions, tenaciousmucus, or pus. One lateral channel is designedfor ventilation and perhaps gas anaesthesia (fig1D), the other for a prism (fig 1E) whichprojects light enabling inspection with thenaked eye and without a telescope. To avoidbums the light source is at distance and light istransmitted through a Y shaped cable (fig 1F)consisting of large bundles of optical fibres: oneproximal tip is connected to the lateral prismfor proximal light projection and the other tothe telescope for distal light projection.The diameter of the telescope needs to be

smaller than the inner diameter of the rigidbronchoscope used and they should never beshorter than the total length of the broncho-scope, though they may be longer. A large rigidbronchoscope will not pass through a smallglottis and a small one will be too short toreach the bronchi in a larger child. Severalbronchoscopes are thus needed and for eachlength at least two or three telescopes.The only way to insert the rigid broncho-

scope is through the mouth. The jaws need tobe opened with a retractor or a laryngoscope.As this would be rather painful, even after localanaesthesia, narcosis is the rule. The broncho-scope progresses through the pharynx and theglottis, whether or not the telescope is con-nected. As stainless steel tubes are not flexiblethey can enter into the trachea, into the twomain bronchi and into the lower lobe bronchi,and in general not into the upper orifices andonly with difficulty into the middle lobe orifice.Another limitation is that the rigid broncho-scope cannot pass beyond the level where itsouter diameter reaches that of the bronchiallumen, and this might be short after the carinain small premature babies. If, however, thetelescope is some centimetres longer thanthe bronchoscope deeper inspection remainsfeasible. The lateral inaccessible large orificescan be partly inspected because of the rela-tively large field of vision of the straightforwardtelescopes and very clearly with telescopes withthe more laterally tilted distal lenses.

FIBREOPTIC FLEXIBLE BRONCHOSCOPESFFBs became available at the end of the 1 960s,however the size of the first ones were not suit-able for paediatric use. Subsequently, smallerFFBs with a diameter of 3-5 mm and anaspiration channel of 1 2 mm were designedthat could be used even in small children.

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More recently ultrathin FFBs with a diameterof only 2-2 mm and provided with a dirigibledistal tip became available. They are for verysmall premature babies or small children withvery severe stenoses through which a standardFFB would not pass. They lack, however, anaspiration channel.FFBs are closed tubes in contrast to hollow

rigid bronchoscopes. The diameter of a paedi-atric FFB is smaller than the outer diameter ofany rigid bronchoscope. FFBs can be insertedthrough the nose or mouth. Because the 3-5mm FFB, except for a small aspirationchannel, has no passage dyspnoea may occurin small babies when the size approaches thediameter of the glottis channel; time availablefor inspection is then rather restricted andoxygen saturation needs to be continuouslymonitored. Because of its flexibility and itsdirigible tip, once in the airways, the FFB canbe directed deep into many bronchi even inmore laterally situated ones.The 1 2 mm wide aspiration channel of the

3.5 FFB is enough for the removal of not toosticky secretions but insufficient for the inser-tion of forceps. When the distal lens is blottedwith secretions and hinder inspection, simpleaspiration through this channel, or rinsing firstwith a few instilled drops of saline, will restorethe vision immediately. The channel can alsobe used for the instillation of drugs.

Another advantage of FFBs is that in experthands narcosis is rarely needed. In olderchildren bronchoscopy can be performed whilethe child is sitting and only local anaesthesia isneeded after the procedure has been explained.Smaller children need to be recumbent andslight and short sedation together with localanaesthesia are enough.With only one 3*5 mm sized and one 2 2

mm sized FFB, one can perform endoscopiesat any age as their length is suitable even foradults. Thorough inspection ofmany deep andsmall orifices and even very lateral ones arefeasible, but the removal of solid materialremains impossible.

Proposal for bronchoscopy in ventilatedneonates and methodology(A) FLEXIBLE BRONCHOSCOPYSmall premature babies are prone to variouskinds of severe respiratory complications suchas, for example, large areas of consolidationsometimes associated with uncontrollablesevere hypoxaemia. When this occurs one caneasily first inspect the airways with the smallest2-2 mm FFB, without interrupting the mechan-ical ventilation and without the infant leavingthe incubator. For this purpose one has to con-nect the endotracheal tube with the distal part ofthe ventilation tube using a swivel Y connector(fig 2) for uninterrupted bronchoscopy (Vygon,Ecouen, France code 526.01). Inspection canthen be made comfortably without a time limitand it will indicate whether sticky mucus orsolid material occlude a large airway. When theinspection is hindered by secretions the FFBcan be replaced momentarily with a suctioncatheter. If sticky dried secretions, tumoral

Figure 2 A 2-2 mm FFB (A) passing through a Yswivel(B) connected to an endotracheal tube size 3 (C). Theoblique lateral orifice (D) is for the connection with either aventilation bag (E) or a mechanical ventilator.

processes, or stenoses are present these need tobe removed for the patency of the airways andthis can only be achieved by rigid bronchoscopywith adapted forceps.

(B) RIGID BRONCHOSCOPYMany ventilated premature infants will besedated anyway to facilitate mechanical ventila-tion. This also meets the requirements for rigidbronchoscopy. In addition, and before startingrigid bronchoscopy, one can hyperventilate theinfant for a while to improve oxygenation andto try to produce hypocapnia. In small prema-ture babies or neonates rigid bronchoscopy canbe performed without general anaesthesia inthe neonatal unit itself, the baby being outsidethe incubator under a radiant heater. Artificialventilation with selected concentrations of oxy-gen can easily be applied, either with a balloonor with the ventilator connected to one of theproximal lateral channels (fig 1D). Dependingon the size of the baby you can select a2-5 mm or a 3 mm bronchoscope and intro-duce it together with the telescope. As soon asthe abnormality is encountered therapeuticmanoeuvres are implemented.

Examples ofrigid bronchoscopy inventilated neonatesPATIENTS AND METHODSTwenty neonates (18 premature and twonearly term babies) were selected for rigidbronchoscopy over a three year period. All 20had severe bronchial abnormalities and sevenofthem suffered more than one abnormality incombination (table) that could not be removedby blind catheter suction. Gestational agevaried from 27 to 40 weeks and their birthweight from 810 to 3000 g. Ventilation wasstill in progress and lasted for five to 43 days.All had suffered moderate or severe respiratorydistress syndrome at birth. All procedures wereperformed because the babies had suddenlydeveloped one or both of the followingconditions: (i) uncontrollable blood gas deteri-oration despite 100% oxygen administrationand high ventilator settings and/or (ii) suspi-cion of mechanical airway obstruction onradiography.

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Therapeutic bronchoscopy in ventilated neonates

Endoscopic abnormalities and therapeutic procedures

Abnormality*

Sticky mucous plugsTracheal masses

Bronchial masses

Bronchial stenosis

No Procedure

10 Selective bronchial lavage with mesna3 Total resection

Local hydrocortisone7 Resection

Local hydrocortisone7 Local hydrocortisone

Dilatation

No Success Failure

10 102 21 11 16 27 33 3

0000440

*Seven patients had more than one abnormality.

The babies were extubated and the rigidbronchoscope was inserted at once. Thepatency of the extubated endotracheal tubewas examined by an assistant. Assisted ventila-tion with 100% oxygen was continued eithermanually with the bag or with the mechanicalventilator connected onto the lateral channel ofthe rigid bronchoscope. Heart rate and trans-cutaneous oxygen saturation were monitoredduring bronchoscopy. At the end of thebronchoscopy the patient was reintubated witha new sterile transnasal endotracheal tube.Rigid bronchoscopes size 3 or 2-5 mm wereused (Karl Storz GmbH, Tuttlingen,Germany) together with the smallest Hopkintelescope. The following instruments werealways within arm's reach: (1) Various Storzgrasping forceps for cutting masses or granula-tion tissue. (2) Suction catheters (De Leetype, Vygon) to instil precisely either mesna(Mistabron, UCB-Pharma, Brussels, Belgium),a mucolytic substance that was diluted with thesame amount of a saline solution, or 1 ml of a5% solution ofhydrocortisone. (3) Angioplastyballoon catheters (coronary dilation catheterwith a balloon diameter of 3 mm, MonorailBonzel, Schneider-Shiley AG EuropeanDivision, Zurich, Switzerland) for dilatingbronchial stenoses.

Manipulations of the forceps and the suctioncatheter was performed mainly with naked eyecontrol with the light coming from the lateralprism (fig 1E). Occasionally the forceps andthe telescope were introduced simultaneouslyfor improved precision. This, however, pro-duced occlusion of an important part of thelumen of the bronchoscope and hindered theventilation. Instruments then needed to be'repeatedly removed because of deterioratingtranscutaneous blood gas measurements orbecause of falls in the heart rate. Manipu-lations with the balloon catheter were alwaysperformed by simultaneously inserting theoptic telescope to steer the former with the tipof the latter and adjust it correctly.

RESULTSAltogether 48 rigid bronchoscopies were per-formed and in each patient the procedure wasachieved between one to 10 times with amedian of two per patient. If more than onebronchoscopy was needed on the same day,they were counted as a single examination.Occasional oxygen desaturation during themanoeuvre was reduced by removing thetelescope and other instruments until the con-dition improved by ventilating through thelumen of the bronchoscope. Oral bleeding

occurred rarely and never exceeded a fewdrops. No other adverse effects were noticed.

Th7erapeutic proceduresMethods were adapted to the observed abnor-malities and to their location (table). Clinicallyand radiologically the immediate results of thedifferent applied therapeutic procedures werefair to excellent in 15 of the 20 patients andhad little or no desirable effect in five patients(table).

Bronchial lavage with mesna instilled selec-tively was successful in all 10 patients withmucus plugs or casts. The complete resectionwith forceps of an obstructive mass (fig 3) waspossible in three patients and resulted in animmediate restoration of the blood gases. Inthe remaining seven patients the masses werenot within the reach of the forceps, eitherbecause they were deep in the right mainbronchus or lateral in the upper rightbronchus, or because the jaws of the forcepscould not be opened sufficiently in the narrowbronchial lumen. In the latter situation 50 mgof hydrocortisone was locally instilled througha catheter pointed on the obstructive mass. Inthree of these seven patients both the bloodgases and the chest radiograph showed animprovement within 24 hours and on subse-quent bronchoscopy the granulation tissue haddisappeared. Altogether six of the 10 patientswith an endobronchial mass improved afterendoscopy. Of the remaining patients three

Figure 3 (A) Endoscopic view showing how severelyintraluminal granulation tissue can hinder the ventilation.This lesion is located in the right main bronchus. (B) Thesame view immediately after partial resection of thegranulation tissue showing a residual stenosis. Completepatency was ultimately restored after local instillation ofhydrocortisone. (These pictures were taken under veryuncomfortable conditions and the semilunar shadowsobscuring a part of these are due to the lean of the cameralevering the very thin shaft of the Hopkins rod transientlyoff centre.)

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one had hepatised lungs and signs of severecardiac failure with organ congestion, one hadmultiple malformations including cerebralabnormalities, and two had generalised haem-orrhages with thrombosis of the vena cava andof the right atrium in one patient.

Figure 4 Resected specimen with preservation of thenormal respiratory epithelium at the margins (arrows),formation ofgranulation tissue with absence of theepithelium (arrowheads), and a scar lesion in the depth ofthe specimen (star).

died between three and 40 days later and one

survived with a persisting atelectasis of theright upper lobe one year later. The local instil-lation of hydrocortisone, as described above,was successful in three of the seven patientswith bronchial stenosis.

Angioplasty balloon catheter dilation couldbe performed in three infants with a main stemstenosis (fig 3B). They underwent respectivelythree, seven, and 10 bronchoscopies on differ-ent days, that is, increasing the pressure of theballoon each time until the lumen of the orificeremained sufficiently patent. The chest radio-graph and blood gases showed improvement inall three patients. Ultimately six of the seven

stenoses were successfully and completelyrelieved. The complete stenosis of the rightupper bronchus in the fourth patient was out ofreach ofthe catheter because of its lateral local-isation in an already small lumen. He survivedwith a complete and permanent atelectasis ofthe right upper lobe.

PathologyMicroscopic examination of the resectedspecimens showed granulation tissue without a

covering respiratory epithelium (fig 4). Thisgranulation tissue was already organised andcontained many plump fibroblasts but fewinflammatory cells. In the depth of the lesion,collagen was lying as bundles in a parallelarrangement, as a resolving scar lesion.

Postmortem examinationsAltogether eight of 20 patients died betweenthree weeks and six months after birth andbetween three and 372 days after the lastbronchoscopy. Postmortem findings were

available for two boys and two girls. Theweight at death varied from 1275 g to 2330 gand the age from 27 days to 3 months. In one

patient in whom a granuloma was resected andwho died 21 days after the endoscopy, a smallscar was present at the resection site withoutulceration. In none of the others could anysequelae be observed that could be attributedto the bronchoscopy. No residual materialremained in any bronchus. The fatal outcomescould be explained by the following findings:

DISCUSSIONRigid bronchoscopy has always been used inpaediatrics for the removal of foreign bodies, 14though it has rarely been performed by paedia-tricians themselves. In the future broncho-scopy will become one of the basic tools inpaediatric pulmonology with an increasingspectrum of indications even in neonates.5-9Our experience confirms that even in neonatol-ogy an FFB is an excellent and safe diagnostictool. Ultrathin FFBs can pass through an

endotracheal tube as small as 3 mm. They offerthe possibility of rapid inspection of the air-ways thereby avoiding the risk of extubationand reintubation.5 Ultrathin FFBs may beroutinely used in the future in all ventilatedneonates as a part of the daily monitoring. Itshould help neonatologists to anticipate theoccurrence of airway obstruction before itbecomes too severe. On the other hand rigidbronchoscopy remains the method of choicefor therapeutic manoeuvres even if it is pre-

ceded by an FFB for rapid diagnosis.Obstructive tracheal injury and necrotising

tracheobronchitis, the extreme form of thisinjury, have been described as potential com-

plications of prolonged endotracheal intu-bation and ventilation.10-12 Multiple aetio-logical factors have been incriminated such as

high ambient oxygen concentrations, lackof adequate humidification, ventilatory fre-quency, and suction method.'2 Whatever theorigin of the accumulation of necrotic debris or

other forms of bronchial obstruction, they can

be observed only by endoscopy, and airwaypatency must be achieved as soon as possible.If one does not succeed with blind suction rigidbronchoscopy will be mandatory.

Obstructive masses yield best results byresection at the time that they are within thereach of the forceps. One can try with some

hope of success local and selective instillationofhydrocortisone in order to reduce inflamma-tion and mucosal oedema of the inaccessiblemass, as pathological examination shows that itcan be due to a non-specific inflammatoryreaction. Steroid treatment is not new as pro-longed parenteral corticoid treatment has beenused before in respirator dependent prematureinfants with acquired lobar emphysema'3 andwith other sequelae of bronchodysplasia.14However, topical treatment might have fewerside effects.For the most severe circular stenoses local

hydrocortisone is less effective. In thesecircumstances frequent bronchoscopies are

needed to perform stepwise balloon catheterdilations, that is increasing the pressure of theballoon during each new bronchoscopy to

restore airway patency. No comparativestudies have been performed to determinewhether the same result could be achieved with

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Therapeutic bronchoscopy in ventilated neonates

Figure S (A) Chest radiograph of the baby with the most severe stenosis of the right mainbronchus. Stenosis reappeared immediately after each balloon catheter dilation, so that theinflated balloon catheter was left in place during 24 hours (arrow). Intermittent injection ofoxygen or air through the central channel across the balloon prevented pulmonary collapse.(B) After 24 hours the ventilation of the right lung was permanently restored and thecatheter could be removed.

maximal dilation during one session. Catheterballoon dilations are usually performed todilate narrowing in arteries, in ureters or in thegastrointestinal tract, and were found by us tobe also effective for the relief of bronchialstenoses. A major advantage of angioplastycatheters is that these have a central channelthrough which air or oxygen can enter andreinflate the collapsed lobe or lung while dila-tion is still in process (fig 5).Cohen et al 15 and Grylack and Anderson'6

in 1984 and Groff and Allenl7 in 1985 were

the first to report single cases of tracheo-bronchial stenosis relieved successfully byballoon dilation. Cohen used fluoroscopy afterinjection of contrast to display the stenosis anddid not use rigid bronchoscopy or an FFB.However, bronchography with contrast is notrecommended in the very ill premature infantfor safety reasons. Furthermore, in all threereported cases therapeutic manoeuvres neededto be postponed until the age of 3 to 6 months.Hauft et al in 1988 were the first to reporttracheal stenosis in six premature babies andwere also the first to use rigid bronchoscopy forits diagnosis shortly after birth.'8 An attempt todilate the acquired tracheal stenosis was madein three infants by forcing the rigid broncho-scope through the stenosis or by tracheoplastyin the other three. Only two of the six survivedthese aggressive procedures. The use of a

balloon is safer than rigid bronchoscopy alonefor dilation, the former is less aggressive andmore selective and can be applied immediatelyin the neonatal period.

ConclusionThis study corroborated the therapeuticadvantages offered by rigid bronchoscopy inventilated neonates and premature infants whodeveloped sudden obstructive hypoxaemia.Immediate results of therapeutic procedureson blood gas values and on radiographs werevery encouraging on 15 of 20 patients withabnormal endoscopic findings. Tolerance andsafety are excellent, as confirmed by the post-mortem analyses.Parts of this article were presented at the 1990 Meeting of theEuropean Paediatric Respiratory Society (EPRS), September1990, London.

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