Transoral CO2 laser microsurgery (TLM) - Vula - University of Cape ...

OPEN ACCESS ATLAS OF OTOLARYNGOLOGY, HEAD &NECK OPERATIVE SURGERYTRANSORAL LASER MICROSURGERY (TLM) OF CANCERS & OTHERPATHOLOGY OF THE UPPER AERODIGESTIVE TRACTJohan Fagan, Wolfgang SteinerCO 2 laser is used to resect or vaporisebenign and malignant lesions of the upperaerodigestive tract. This chapter focuses ontransoral CO 2 laser technique using amicromanipulator attached to an operatingmicroscope. The advantages of using CO 2laser with an operating microscope aremicrosurgical precision, excellent intraoperativedetail, and a dry surgical field; thefunctional outcomes in terms of swallowingand speech exceed that of traditionalexternal surgical approaches.Surgeons must familiarise themselves withthe laser machine, its settings and deliverysystems, and its tissue effects prior toattempting to use it clinically.1aArticulated armControl panelEmergency stopCO 2 laser machine (Figure 1)Surgical lasers convert radiation energyinto heat at the point of contact of thefocused radiation with the tissue. The laserbeam is generated in a gas-containingdischarge tube. The light beam is collimated(coherent), is of a single wave-length(monochromatic), and can be reflected andhence manipulated by mirrors, and focusedby passing it through lenses. Because CO 2laser falls outside the visible light spectrumand is therefore invisible, the lasermachine generates a red diode laser aimingbeam that is focused at the same workingdistance as the microscope to indicate tothe surgeon where the beam is directed.The laser beam is directed along a springloadedarticulated arm which connects to abeam applicator. The articulated arm hasmirrors at each articulation; therefore onehas to handle the articulated arm with greatcare so as not to disturb the alignment ofthe mirrors. The laser is fired when the footpedal is depressed.1bFigures 1a, b: CO 2 laser: Wet drapesprotect the patientSafety glassesFoot pedal

ightness of the aiming beam; power(Watts); and “Laser standby” or “Laserready” settings. Spot size is set with thefocus setting of the micromanipulator.Spot size0.2mm 0,4mm 0.8mm 1,4mm5 watts 16000 4000 1000 30010 watts 32000 8000 2000 60015 watts 48000 12000 3000 90020 watts 64000 16000 4000 1200Table 2: PD according to spot size andwatts 1Power (Watts)Figure 6: Example of laser control panelLaser Power Density (PD)Laser Power Density (PD) is a keysurgical parameter. It is affected by thedistance from the tissue, the diameter ofthe beam (laser spot size), and the numberof Watts (Joules/sec); all these parameterscan be controlled by the surgeon.Key formulae to remember are:Power Density (PD) = Watts (W)/cm 2Watts (W) = Joules/secBy controlling PD the surgeon canmaximise the benefits of CO 2 laser surgery(Table 1).Power Effect on tissuesdensity0-500 Heating500-1500 Contracture, denaturing1500-5000 Ablation, partial vaporisation5000-20000 Incision, complete vaporisation20000-100000 Rapid deep incisionTable 1: Relationship between PD andtissue effects 1To achieve complete vaporisation, thesurgeon should aim for 4500 PD at thetissue interface. Table 2 illustrates howcritical the number of Watts and laser spotsize are to PD.This is selected by the surgeon every timethe laser machine is used, and can be preprogrammedfor different types of surgery.A laser machine with power settings of upto 40W is recommended for head and necksurgery.Laser spot sizeThe smaller the spot size, the less the rangeof depth of focus at which the laser cutseffectively and the more accurately thelaser has to be focussed. Spot sizes of 0.5-0.8mm provide a comfortable compromisebetween depth of focus and cutting ability.To coagulate bleeding vessels, PD has tobe adjusted to a level at which tissue is nolonger vaporised, but is only heated andblood vessels are coagulated (Table 1);Tables 2 illustrates how increasing spotsize by defocusing the laser beam reducesthe PD.Total duty cycleThe total duty cycle is the total time thatlaser energy interacts with target tissues.This can be regulated in a number of ways(Figure 6):Continuous wave (CW): Continuousemittance of laser energy while the footpedal is depressedPulsed settings: Energy emitted asdiscrete pulses; the lengths, frequencies3

and time intervals between pulses canbe selected by the surgeono Single pulse: Single energy burstemitted every time the foot pedal isdepressedo Repeat pulse: Repeated energybursts emitted while the foot pedalis depressedo Super pulse (SP): Several thousandenergy bursts of very high peakpower laser pulses emitted persecond while the foot pedal isdepressed. The peak power of thebursts may be a few hundred watts,but the wattage shown on the lasermachine reflects the average powertransferred over time. The burstsare spaced far enough apart forefficient tissue cooling to occurbetween pulses; this reducesthermal damage to surroundingtissue and minimises charring. Formore coagulation, switch from SPto CW.Laser/tissue interactionCO 2 laser is absorbed almost completelyby intracellular water and causesvaporisation of water and cells. Because99% of heat that is generated is lost in thevapour that is released, peripheral tissueinjury and necrosis are limited to

Because CO 2 laser is absorbed and“neutralised” by water, wet swabs andpatties are used and the cuff of theendotracheal tube may be filled withsaline. To reduce the risk of airway fire, itis critical that the anaesthetist keeps theFiO 2 at a minimum (+/- 30%) to avoid ablow-torch effect if the oxygen in theairways is ignited. It is advisable that anopen bowl of water/saline be kept at handto douse a laser fire.Anaesthesia for CO 2 laser surgeryThe principal anaesthetic challenges are touse endotracheal tubes that permit thesurgeon to work in the confined space ofthe larynx and pharynx, and to eliminatethe risk of laser fire (Table 3).Gases: Avoid nitrous oxide if possible andmaintain inspired oxygen FiO 2 as low as isclinically feasible; this requires continuousmonitoring of the patient’s oxygenation bypulse oximetry. The surgeon must notifythe anaesthetist before activating the laserand give the anaesthetist enough time toreduce the delivered oxygen concentrationto a minimum, to stop using nitrous oxide,and then to wait a few minutes for theoxygen concentration in the airways todrop to a safe concentration.Airway: The airway may be maintained ina number of ways:Endotracheal intubation (nasal or oral)Intermittent jet ventilation; lasering isdone during apnoeic intervalsIntermittent extubation with laseringdone during apnoeic intervals (2 ndauthor’s preference over jet ventilation)Open airwayo Spontaneous breathing of anaestheticgases administered throughthe suction port of the laryngoscopeo Intravenous anaesthesiaTracheostomy (rarely)It is important that the surgeon discusseswith the anaesthetist the optimal method ofmaintaining an airway for the specificpatient e.g. nasotracheal intubation may bebest for base of tongue cancer, but isproblematic for an endolaryngeal tumouras it fixes the position of the endotrachealtube.Endotracheal tubes: All tubes areflammable; no tube is therefore “safe”. Theproblem is not the type of tube, but perforatingthe tube when the O 2 concentrationin the tube is too high. The authors useregular PVC tubes, but take special care toprotect them with a strip of wet cloth cutfrom e.g. surgical drapes (Figure 7), orwith neuro patties.Figure 7: Tube protected by strip of wetclothThe drawbacks of “laser tubes” are thatthey have thicker walls and are expensive.PVC tubes with 5mm inner diameter aremore flexible, less expensive and pose noincreased risk for fire as long as the FiO 2 is

into the bronchi when a fluid-filled cuff isperforated.Surgical InstrumentationTo prevent reflection of the laser beam,instruments with beaded or mat surfacesare used (Figure 8). Adequate tumourexposure is critical to TLM; an integratedsuction channel to remove smoke isessential. It is therefore crucial that avariety of laryngoscopes and pharyngoscopesis available (Figure 8).Distending oropharyngoscope: Toaccess lesions in the tongue base,vallecula and lingual epiglottis; notethe side-flaps that keep the endotrachealtube and soft tissues out of thesurgical field (Figures 8b, 10)abcgFigure 9: Distending laryngopharyngoscopedeeijhkflFigure 8: Laryngopharyngoscope (a), oropharyngoscope(b), laryngoscopes (c, d),light carrier (e), laryngoscope holder (f),graspers (g), insulated suckers (h), microforceps(i), coagulation forceps (j), diathermylead (k), and ligaclip applicators toleft and right (l) (Karl Storz)Distending laryngopharyngoscope: Toaccess lesions in the hypopharynx andsupraglottic larynx (Figures 8a, 9)Figure 10: Distending oropharyngoscopeLarge laryngoscope: To access endolaryngeal,upper tracheal and hypopharyngeallesions (Figures 8c, 11)Small laryngoscope: Laryngoscope issmaller and longer; used for difficultexposures such as anterior commissure,subglottis and upper trachea (Figures8d, 11)6

Figure 11: Larger & small laryngoscopesLight carrier (Figure 8e)Laryngoscope holder: (Figure 8f)Grasping forceps: Different sizes(Figure 8g)Suction tubes: insulated for monopolardiathermy (Figure 8h)Microforceps (for small vocal foldlesions): (Figure 8i)Coagulation forceps (Figure 8j)Diathermy cable: (Figure 8k)Liga clip applicators (left & right):(Figure 8l)Weerda diverticuloscope: For Zenker’sdiverticulum and for carcinoma of thehypopharynx extending to the upperoesophagus (Figure 12)Figure 13: Adjustable supporting plate forlaryngoscope holderOperating room setup (Figure 14)Figure 14: Typical operating room setupFigure 12: Weerda diverticuloscopeAdjustable supporting plate forlaryngoscope holder: This avoidsplacing pressure on the patient’s chest;the support can be moved away fromthe midline so as to angulate thelaryngoscope if necessary (Figure 13)A typical setup has the anaestheticmachine placed at the patient’s feet; thisrequires extensions for anaesthetic tubingand intravenous lines. A camera is attachedto the microscope so that the assistant andnurses can follow the procedure on amonitor. Two suction systems are required,one attached to the laryngoscope to extractsmoke from the surgical field and the otherattached to the hand-held suction tube.Monopolar diathermy should be availablefor laser procedures other than mid-cord T 1glottic carcinomas.7

Preparation of operative siteWound scrubs and paints should beaqueous or non-flammableEnsure that surgical prep solution doesnot puddle on or around the patientUse draping and gown material that isflame retardant or non-flammable, orwet it with waterSurround the scope with moistenedtowels, sponges or cotton to reduce thepossibility of fire or burns to thepatient’s facenot to disrupt the anterior commissure(Figure 16)Surgical exposureSurgical exposure is a critical element ofTLM. It may prove sometimes impossibleto proceed with TLM due to inadequateaccessPlace patient in supine position withneck extendedCheck that the head is resting on thebed and not suspended in mid-airCheck for loose or crowned teethInsert gum guardDo panendoscopy to exclude synchronousmalignanciesInsert laryngoscope / laryngopharyngoscope/ oropharyngoscope and exposethe tumourA number of different scopes may haveto be used to best visualise the tumourduring the course of an operationSuspend scope with the laryngoscopeholderIt may be necessary for the assistant topress on the larynx, or to place tapesattached to the theatre table across theneck to displace the larynx posteriorlyRarely an external approach is requiredfor access. This may be achieved bypassing the laryngoscope through asuprahyoid approach into the vallecula(Figure 15); or by doing a partiallaryngofissure, cutting only through theupper half of the thyroid cartilage so asFigure 15: Suprahyoid approach to thevalleculaFigure 16: View of glottic cancer via apartial laryngofissurePrinciples of CO 2 laser surgeryCO 2 laser may be used to incise, excise orvaporise (ablate) tissue. Novices shouldstart by operating on simpler cases e.g.smaller tumours of the aryepiglottic fold,supraglottis, or medial wall of piriformfossa. Important principles of CO 2 lasersurgery include:1. Correct laser settings: Selecting spotsize, focus, power, and superpulse/pulsed/continuous mode, are importantin order to achieve the desired effects,and may have to be altered during the8

course of an operation for differenttissues, or to achieve coagulation,cutting or vaporisation effects etc.2. Tension: Constant traction must beapplied to the tissue to expose thedissection plane, maintain goodexposure and facilitate dissection3. Hand speed: The surgeon shouldmaintain a relatively slow, smoothhand speed4. Haemostasis:o Laser does not cut through blood;keep the field dry with suction /suction cautery / coagulation forceps/ liga clipso Use ligaclips, not suction diathermy,for large vessels to avoidpostoperative bleeding5. Charring: Charring is reduced bygenerating less heat by using the superpulsesetting. Wipe carbon off thesurgical field with a wet cotton ball tomaximise the vaporisation effect ontarget tissue6. Minimise peripheral tissue injury:(Super)pulse as opposed to CW settingavoids excessive heating of tissue7. Avoid desiccation of tissues: Usenormal saline or water to wet tissues tobe lasered as CO 2 laser interaction isimproved if tissue is well hydrated8. Test the alignment of the aiming beamwith that of the laser beam: This isimportant especially when using CO 2laser in otology as the margin for erroris much more critical; direct the laser ata wet, wooden tongue depressor tocheck the alignment9. Past-pointing: Avoid the possibility ofpast-pointing of the laser beam as thismay burn tissue or cause laser fires. Beaware of reflection of the laser beamoff instruments and scopes, and ensurethat the backstop e.g. neuro patty iscorrectly positioned to protect theendotracheal tube10. Resecting structures for improvedaccess: Resecting suprahyoid epiglottisimproves access to the pre-epiglotticspace and to tumours on the laryngealsurface of the epiglottis. Althoughresecting the false vocal cord improvesaccess to the laryngeal ventricle bothfor resection and follow-up, the benefitof improved access has to be weighedagainst possible functional deficits asthe preserved false vocal cord can beused to produce a good voice afterglottectomy. A small laryngoscopeintroduced from laterally will in mostcases adequately expose the ventricle;only with tumours spreading up tocartilage (T3) may it therefore benecessary to sacrifice the false vocalcord11. Debulking: This is a key TLM techniqueand allows the surgeon to createspace within which to move tissuesaround and to apply traction to tissue,or to resect a bulky tumour through anendoscope (Figure 17). The debulkedtissue is discarded, and only the deepertissue along the tumour margins aresent for histology to determine theadequacy of the resectionFigure 17: Example of tumour that hasto be debulked before oncologic resectioncan commence12. Hydrodissection: Water can be used asa barrier to penetration of the laserbeam. Dissecting in the plane of Reinke’sspace or around nerves and vesselscan be facilitated by infiltrating salinesolution into Reinke’s space or intotissue planes around nerves and ves-9

sels. Haemostasis can be promoted byinjecting a solution containing epinephrine13. Interface between tumour and normaltissue (Figure 18): The surgeon distinguishestumour from normal tissuewhen transecting tumour by checkingthe pliability of the tissues (tumour isrigid), and by the colours of the tissues(tumour chars and is brown / blackwhen transected with laser)the patient. Specimens are pinned tosmall cut-outs of cork floor tiles thatare placed in formaldehyde so that thepathologist can orientate the specimen(Figure 20).Figure 19: Bread slicing the tumour toevaluate tumour depth and guide depthof resectionFigure 18: Note clear demarcationbetween dark brown transected tumourand pale-coloured normal tissue ofparaglottic space14. Bread slicing: (Figure 19) In order toensure an adequate oncological deepmargin, but to minimise impairment ofvoice quality by not resecting too muchtissue, the surgeon needs to preciselydetermine the tumour depth and toresect along the deep aspect of thetumour under high magnification. Thisis achieved by serially sectioning(bread slicing) the tumour. This isapplicable to all tumours other thanvery superficial (T is or T 1 ) tumourswhich are simply peeled off the vocalligament staying in Reinke’s space15. Orientating specimens: Take specialcare not to lose the orientation ofspecimens when removing them fromFigure 20: Specimens are pinned tocut-outs of cork floor tiles so thatpathologist can orientate the specimen16. Tumour topography: Include adetailed drawing on the pathology formand in the patient’s notes of the preciselocation of all the resected specimensWhat is an adequate resection margin?This is a controversial topic, and one thatmay cause surgeons a great deal of anxietyas to whether the patient should be returnedto the operating room for an additionalresection, whether simply to advise closesurveillance, or whether to recommendadjuvant irradiation. Factors that play arole in reaching such a decision include10

tumour location, size, function (voice andswallowing), patient fitness, extent of theinitial resection e.g. onto cartilage orcarotid, not knowing precisely where thepositive or close margin is located, and thereliability of regular follow-up. Frozen sectionmay be useful with larger resectionse.g. base of tongue and hypopharynx; yetpathologists are reticent to do frozen sectionson small resections e.g. T 1 glotticcancers, as it makes it difficult to commentdefinitively on adequacy of margins. Thesurgeon’s impression of the adequacy of aresection as seen through the microscope isalso important; he/she may elect to adopt awatchful waiting approach even whentumour is reported to be “present at themargin”, with the knowledge that cells aredenatured and killed adjacent to theincision during laser excision; such awatchful waiting approach applies especiallyto small mid-vocal fold carcinomasthat can be carefully monitored and reoperatedon timeously without adversely affectingprognosis.Glottic CarcinomaThe challenge for the laser surgeon is tostrike the correct compromise between anoncologically adequate resection and preservationof voice quality. The new lasersurgeon should initially select smallertumours and progress to larger tumoursonly once he/she has gained a goodunderstanding of the endoscopic “insideout”surgical anatomy of the larynx, andhas become proficient with laser surgerytechnique. We do not advise voice restafter surgery except for superficial defectsof the membranous cord.Classification of laser cordectomyThe European Laryngological Societyproposed a useful classification of endoscopiccordectomy in 2000 (Table 3,Figure 21) 2 .Cordectomy Type Resected tissueSubepithelial I EpitheliumSubligamental II Epithelium, Reinke's space,vocal ligamentTransmuscular III Through vocalis muscleTotalIVExtended Va Contralateral vocal fold,anterior commissureVb ArytenoidVc SubglottisVd VentricleTable 3: European Laryngological Societyclassification of endoscopic cordectomy 2Figure 21: Classification of cordectomy 2One can anticipate an excellent speakingvoice following Type I or subepithelialresection of T 1s and T 1 cancers of themembranous vocal fold (Figures 22, 23).Figure 22: Type I cordectomy; note intactvocal ligament11

Figure 23: Type I cordectomy: Pre- andpostoperativelyFigures 24 & 25 illustrate T1 glotticcancers that required Type II cordectomyand subsequent “new cord” formation dueto a scar band; such patients can beexpected to have a good, though not quitenormal quality voice.Figure 26: Type III cordectomyWith Type IV cordectomy the resectionextends onto thyroid cartilage with loss ofvolume of the hemilarynx and less predicttablevoice outcome (Figure 27).Figure 24: Type II cordectomyFigure 27: Type IV cordectomyThis applies to patients who undergo completeresection of the paraglottic space forT3 glottic carcinoma. Such patients mayhave to phonate using the false vocal cordsand may produce a good voice; hence thevalue of preserving the false vocal cords ifpossible.Figure 25: T1 glottic carcinoma requiredType II cordectomy; final resultFigure 26 illustrates transmuscular or TypeIII cordectomy for T 2 glottic carcinoma.This defect is subsequently filled by a scarband leading to a very adequate speakingvoice.Superficial lesions of membranous cordThe objective is to do a Type 1 resection,and to restore a normal speaking voice.Resection margins of

dissection with minimum lateral thermalinjury to the tissues. Surgery is done underhigh magnification. The initial incision ismade only through epithelium (Figure 28).thermal injury. Surgery is done under highmagnification. It is imperative to breadslicethe tumour in order to determine thedepth of the tumour and the deep resectionplane, and to remove it in sections (Figures18, 19, 30, 31).Figure 28: Initial incision for Type 1cordectomyThe cut edge of the epithelium is picked upwith microforceps and the tumour isdissected off the vocal ligament, takingcare to remove and pin the tumour to thecork without losing spatial orientation(Figure 20).Figure 30: Example of sequence of incisionsfor a partial cordectomyDeeper lesions of membranous cordWith deeper tumours requiring Types II-IVresections the objective is to do an adequateresection (>1mm margin), and tomaintain an adequate speaking voice(Figure 29).Figure 31: Tumour has been transected todetermine depth of invasionFigure 29: Example of margins requiredSet the laser at its smallest spot size, powerof 3-5 W and superpulse mode; this allowsa very precise dissection with minor lateralIt is generally easiest to 1 st remove theposterior segment, especially if access tothe anterior commissure if poor (Figure32).13

commissure with laser resection:Figure 32: Type 3 resection of posteriorhalf of tumourBleeding may be encountered especiallywhen dissecting adjacent to, or below, theanterior commissure and lateral to thevocal process of the arytenoid. Smallvessels may be coagulated by defocusingthe laser beam. More brisk bleeding iscontrolled using monopolar or bipolarcoagulation forceps. Avoid using suctiondiathermy on the vocal fold. Take care toremove and pin the tumour segments to thecork without losing spatial orientation, andto make a detailed drawing of theorientation of the segments in the patientrecords and on the pathology request form.It is also useful to paint the basal area(deep margin) blue, and to ask of thepathologist to determine whether thepainted area is free of tumour.Proximity to thyroid cartilage: Thismakes it difficult to obtain widemargins and raises the possibility ofcartilage invasion (Figure 33). Theauthors do not routinely obtainimaging, but follow the tumour duringthe resection and may resect cartilagewith CO 2 laser if necessary. Once thevocal ligaments have been severedfrom the cartilage with the laser, thesurgeon can strip the tissues in a planedeep to perichondrium up to theinferior margin of the cartilage, andthen defocuses the laser and “sterilises”the cartilage of any residual cancercells (Figure 34).Figure 33: Extension through thyroidcartilageAnterior commissureThe authors do not consider anteriorcommissure cancer to be a contraindicationto laser resection. However some surgeonsconsider involvement of the anteriorcommissure to be a contraindication forlaser resection and advocate vertical,supracricoid or even total laryngectomy.The following needs to be consideredwhen managing cancers of the anteriorFigure 34: Tissues stripped in subperichondrialplane and cartilage “sterilised”of cancer cells14

Subglottic tumour extension belowthyroid cartilage and through cricothyroidmembrane (Figures 35, 36):Webbing of anterior commissure causingpoor voice (Figure 37): Webbingoccurs when the anterior ends of bothvocal cords are denuded or resected(Figure 38). This can be avoided bydoing a two-stage resection, initiallyresecting only up to the midline, andcompleting the resection of the 2 ndvocal cord tumour about a month later(Figure 39).Figure 35: Subglottic extensionthrough cricothyroid membrane; endoscopicresection (red line)The surgeon follows the tumourendoscopically. Thyroid cartilage mayhave to be resected with laser to improveexposure and for resection ofextralaryngeal tumour; resection mayextend to just deep to the skin of theneck if needed (Figure 36)Figure 37: Webbing of commissureFigure 38: Denuding both vocal cordsmakes webbing likelyFigure 36: Tumour escaping betweenthyroid and cricoid cartilagesIt may be difficult correct a web.Simply dividing the web with laserinvariably leads to a new web. Anoption is to divide the web andendoscopic placement of a silastic keelfor 3 weeks (Figure 40) 3 , or to applyMitomycin C after excising of the scartissue with laser.15

Figure 39: Typical sequence of initial(blue) and 2 nd stage (red) resections ofanterior commissure tumour to avoidwebbingFigure 41: Suture passed around vocalcord to lateralising the cordFigure 40: Silastic keel with holdingsutures 3An alternative which has beensuccessful in the 1 st author’s hands is todivide the anterior commissure and totemporarily lateralise the vocal cord(s).Two injection needles are passed fromthe outside of the neck through thyroidcartilage above and below the vocalcord. A suture is fed in and out of thelarynx through the needles, and thecord is lateralised by tying the suturestogether outside the neck for 3 weeks(Figure 41, 42).Supraglottic carcinomaSupraglottic carcinoma is resected using adistending laryngopharyngoscope (Figure9), graspers, and liga clip applicators toclip the superior laryngeal vessels that tra-Figure 42: Lateralised vocal cordverse the pharyngoepiglottic folds. Becausethe vocal cords are not beingoperated on, the surgeon sets the laser at ahigher power (>5W), slightly larger spotsize, and on superpulse mode so as to bothcut and coagulate. Surgery is done underhigh magnification, maintaining a distanceof >5mm from the edge of the tumour.Provided a neck dissection is not donesimultaneously, antibiotics are notgenerally required.Cancer of suprahyoid epiglottisThe suprahyoid epiglottis can be resectedwith only transient and relatively minordifficulty with swallowing (aspiration) thatsettles once postoperative pain resolves.16

Cancer of infrahyoid epiglottis and falsevocal cordsPostoperative aspiration is minor whencompared to open supraglottic laryngectomy;the nasogastric tube is usually removedwithin a few days. The resection isadapted to the tumour and may e.g. involveonly removing one half of the epiglottisInsert a distending laryngopharyngoscopewith the anterior blade in thevallecula, and open it widelyDetermine the extent of the tumour andplan the resectionRemove the suprahyoid epiglottis forexposure and to remove the suprahyoidcomponent of the tumouro Make a curved incision in the vallecula(Figures 43, 44)o Bisect the suprahyoid epiglottis in asagittal plane, cutting throughtumour if need be (require higherpower setting to cut through epiglottis(Figure 43)o Cut transversely across theepiglottis at the level of the hyoid(Figure 44)o Remove the left and/or right segmentsof the suprahyoid epiglottisFigure 43: Initial incision in thevallecula and though the epiglottisReadjust the position of the distendinglaryngopharyngoscope to improveaccess to the infrahyoid component ofthe tumourFigure 44: Suprahyoid (blue) andinfrahyoid (red) incisions for lasersupra-glottic laryngectomy; preepiglotticfat (yellow)Incise the pharyngoepiglottic folds,taking care to identify the branches ofthe superior laryngeal vessels. Althoughsmall vessels can be coagulatedwith the angled grasping coagulationforceps, resist the temptation to coagulatethe superior laryngeal artery withelectrocautery; rather apply 2 ligaclipsto the artery before dividing it withlaserPreepiglottic dissection (Figure 44)o Cut transversely into the avascularpreepiglottic fat, preserving a layerof fat on the anterior aspect of thespecimen as a resection margino Palpate with the sucker to determinethe position of the hyoid boneand the superior edge of the thyroidcartilageo Cut down onto and expose thethyroid cartilageBisect the infrahyoid epiglottis in asagittal plane, cutting through tumourif need be (require higher power settingto cut through epiglottis)17

Follow the tumour e.g. through thethyrohyoid membrane; thyroid cartilagemay also be resectedRemove tumour in as many segmentsas is required, taking care to maintaintheir orientation for the pathologistFrozen section may be used to directthe extent of the resectionSecure haemostasis with monopolarsuction cautery or coagulation forceps,preferably bipolarFigures 45a-d & 46a-c illustrate supraglotticcancers, their excision and recovery.Figure 45c: Completed resectionFigure 45a: (L) supragottic cancerFigure 45d: Following healingaFigure 45b: Resecting the 1 st segment;note endotracheal tube has been displacedanteriorly to improve visibility for theposterior resectionFigures 46 a: Supraglottic cancer extendingonto right aryepiglottic andpharyngoepiglottic folds18

Figures 46 b: Completed resectionbWhether lateral wall tumour extendsbehind thyroid lamina (Figures 47, 48)o Proximity of carotid sheatho Need to delay neck dissections by a2 weeks to avoid thru’-and-thru’fistula into the neckThe distal extent of tumour as oneshould attempt to avoid a circumferentialresection at the narrow cricopharyngeusregion as this may cause astricturecFigures 46 c: Following healingHypopharyngeal carcinomaCancers of the piriform fossa may extendmedially into paraglottic space, cricoid andcricoarytenoid joint; anteriorly into preepiglotticspace; and laterally to invadethyroid cartilage, and behind thyroidlamina, to the soft tissues of the neck andthe carotid sheath (Figure 47).Figure 47: Extension of piriform fossacancer: red arrows indicate higher riskresection due to proximity to carotidAt diagnostic endoscopy assessDepth and mobility of tumouro Tumours clearly limited to mucosaare easily resectedo Deeply invasive tumours of thelateral wall need additional CT +/MRI imaging as deeply invasivetumours infiltrating soft tissuearound the carotid artery are notamenable to laser excisionFigure 48: Posterior edges of thyroidlaminae19

Resection techniqueSurgery is done under high magnificationthrough laryngoscopes and a distendinglaryngopharyngoscope (Figure 9) usinggraspers, and liga clip applicators to clipthe superior laryngeal vessels that traversethe pharyngoepiglottic folds. Maintain adistance of 5-10mm from the mucosal edgeof the tumour. Because the vocal folds arenot being operated on, the surgeon sets thelaser at a higher power (>5W), slightlylarger spot size, and on CW mode so as toboth cut and coagulate tissue. Reduce thepower when dissecting posterior to thethyroid lamina in the region of the carotidsheath. Both authors have on occasionexposed the carotid artery during resectionfor hypopharyngeal cancers without anyadverse effects; the vessel was either leftuncovered or sealed with fibrin tissue glue.The tumour is excised in segments, takingcare to orientate the specimens relevant forhistology of the deep margins for the pathologist.With major resections insert anasogastric feeding tube under directvision to avoid the tube transgressing thetumour bed and entering the soft tissues ofthe neck, or arrange for a PEG. Provided aneck dissection is not done simultaneously,antibiotics are not required.Figure 49: Postcricoid cancer with extensionto piriform fossa (a) and followingresection and healing (b)babFigures 49 and 50 show examples ofpiriform fossa and postcricoid cancers bothbefore resection and after healing haveoccurred.aFigure 50: Piriform fossa cancer withextension to postcricoid area beforeresection (a) and following healing (b)20

Base of tongue (BOT) (Figures 51, 52)abFunctional outcomes are superior toexternal surgical resections. Depending onanatomical factors, accessing BOTtumours for laser excision may be veryeasy or impossible (other than in the handsof the expert using small scopes.Figure 51: Cancer of BOT (a) and followingresection and healing (b)Key issues relating to BOT cancerresection:Obtain a CT, or preferably an MRIscan, both in axial and sagittal planesto assesso Tumour deptho Anterior deep extension of tumouro Involvement of preepiglottic fatInsert a nasotracheal tube to improveaccess and protect it with a wet cloth ora neuro pattyApply anterior traction to the tonguewith a suture passed through the tongueaOral and oropharyngeal lesions may beexcised with CO 2 laser using the microbFigure 52: Preoperative (a) andpostoperative scan showing absentepiglottis and reduced volume of BOT (b)Use a distending oropharyngoscope(Figures 10a, b) +/ large laryngoscope+/ tonsil gag for accessWith long procedures, relieve pressureof the scope from time-to-time torestore blood circulation to the tongueDo not sacrifice both lingual arteries asthe tongue may infarctDo not sacrifice both hypoglossal nervesas the patient will then be an oralcripple (dysphagia and dysarthria)Resect the tumour in multiple segmentsFrozen section is used to guide the surgeryas margins may not be as clearlyvisible as with laryngeal cancerOrientate the resected segments accuratelyfor the pathologist to commenton marginsNo flaps are required, as the defectheals spontaneouslyTracheostomy is generally not requiredWith big resections that include resectingthe epiglottis, a nasogastric tube isinserted for feedingWhen expecting persistent deglutitionproblems e.g. with extended resectionsfor large tumours requiring adjuvantradiotherapy, a PEG should be consideredearlyOral cavity and oropharynx21

scope. All lesions should be excised forhistological evaluation i.e. not vaporised.Figures 53a & b illustrate the excellentfunctional outcome after leaving a tumourbed to heal following laser excision.Figures 54a & b illustrate resection ofcancer of the soft palate.baFigures 54a, b: Cancer of soft palate, tonsilsand posterior pharyngeal wall before(a) and after resection and healing (b)bCO 2 LASER FOR BENIGN DISEASELaryngocoeles and saccular cystsInternal laryngocoeles and saccular cystsdo very well with wide marsupialisationwith CO 2 laser and removing the contentsof the cyst with a sucker (Figure 55, 56).Figure 53: Cancer tongue before (a) andafter resection and healing (b)aFigure 55: Saccular cyst suited to CO 2laser marsupialisation22

Papillomata at the anterior commissurepresent a challenge in terms of avoidingwebbing and a poor voice. One may electto stage the treatment at the anteriorcommissure by ablating only one side at atime to avoid webbing. Tracheal papillomatacan be ablated using the microscopeby advancing a smaller and longer laryngoscopebetween the vocal cords; or by usinga laser bronchoscope (Figure 3).Intubation granulomaFigure 56: Inside surface of large internallaryngopyocoele following marsupialisationwith laserIntubation granulomas originate on thetraumatised vocal process of the arytenoid(Figure 58).Viral papillomatosis (Figure 57)The objectives of surgery for viralpapillomatosis are not to eradicate allvirally infected tissue, but to maintainairway and voice. The most populartechniques are CO 2 laser and microdebriders.Ablation of papillomata is donewith CO 2 laser on a low power setting andby slightly defocusing the beam to create alarger spot size. Surgery should beconservative to preserve voice.Figure 58: Intubation granulomaFigure 57: Viral papillomataFigure 59: Excised granuloma23

Only if they do not resorb after a fewmonths and remain symptomatic are theyremoved, taking care not to expose thecartilage so as to reduce the likelihood ofrecurrence (Figure 59).Paralysed vocal cordsWith surgery done to relieve airwayobstruction due to bilateral vocal foldparalysis, the patient has to be forewarnedabout the trade-off of airway vs. voicequality, and that a 2 nd operation may berequired should the airway still not beadequate. While some surgeons prefer initiallyto do unilateral posterior cordectomy,the 2 nd author routinely does bilateralposterior cordectomy as in his experiencethis yields a good outcome both in terms ofairway and voice.The surgery is done around a small (5mm)endotracheal tube with the laryngoscopeplaced behind the tube so as to expose theposterior larynx. CO 2 laser is used to exciseonly the vocal process of the arytenoid(posterior 1/3 of vocal fold) and a variableamount of tissue lateral to the vocalprocess (Figure 60). It is important that theanterior 2/3 (vibrating part) of the vocalfold be preserved to optimise voice quality.The final result is only apparent monthsafter the surgery once fibrosis and healinghave matured. The voice quality is usuallyvery adequate as there is improved airflowthrough the larynx due to the larger airway,and because surgery is limited to theposterior glottis (Figure 61).Figure 61: Final result of unilateralposterior cordectomySubglottic and tracheal stenosisCO 2 laser is best suited to thin webs. Thesurgery is done by passing the smaller,longer laryngoscope past the vocal folds.Anaesthesia is done with an open airway,either having the patient breathing spontaneouslywith intravenous anaesthesia, orwith intermittent jet ventilation; the 2 ndauthor prefers using intermittent extubationwith the surgery done during apnoeicintervals. The stricture is incised in a radialfashion, preserving mucosal bridgesbetween the cuts (Figures 62).Figure 60: Bilateral posterior cordectomyFigure 62: Tracheal stenosis; preservedmucosal bridges24

Pharyngeal pouch (Zenker’s diverticulum)Endoscopic diverticulotomy involves dividingthe “party wall” between the oesophagusand the diverticulum, as well as thecricopharyngeus muscle which is locatedwithin the superior part of the “party wall”(Figure 63). It may be performed with astapler (Figure 64) or with CO 2 laser. The2 nd author (W.S) has preferred CO 2 laserendoscopic diverticulotomy for the past 30years. Both techniques have proven to beeffective and safe.Figure 63: Party wall that contains cricopharyngeusmuscle separates oesophagus(anterior) from pouch (posterior)Figure 65: Large and small diverticulaCO 2 laser is particularly useful for pouchesof

Figure 67: Perforated pouchSurgical steps for laser diverticulotomyDetermine the anatomy of the pouchand the location of the opening of theoesophagus with rigid oesophagoscopyPass the closed end of the Weerdascope into the pouch taking care not toperforate the thin wall of the pouchOpen the blades, and retract the scopeuntil the oesophageal opening appearsanteriorly (A trick to make it easier tolocate the oesophageal opening is tofirst place a suction catheter in theoesophageal opening)Pass the anterior blade of the Weerdascope into the oesophagus and keep theposterior blade in the pouchDistract the blades further to bring theparty wall into view, and suspend thescopeClear the pouch of food debrisInsert a wet strip of cloth into theoesophagus to protect it from injurydue to past pointing of the laserSet the laser at 5W, CW mode andsmall spot sizeTransect mucosa and cricopharyngeusmuscle of the party wall (Figure 68)Stop the dissection 5mm from thefundus of the pouchBroad spectrum antibiotics are givenperioperativelyFigure 68: Divided party wallIntroduce free fluids on Day 1; progressto a soft and then solid diet overthe course of a week (Some surgeonselect to insert a nasogastric feedingtube for 2 days)Complications of laser surgeryPatients have surprisingly little painfollowing laser resections. They commonlymention having to clear their throats for afew weeks due to discharge from thehearing surgical bed.Early complicationsDental: Use a gum guard to protect theteeth, and check for crowns or implantsand explain the risks to the patientbefore surgeryOropharyngeal trauma: It is notuncommon to cause minor tears of thetonsillolingual mucosa when havingdifficulty with endoscopic accessLingual nerve: Prolonged upwardtraction on the base of the tongue cancause transient sensory change of theoral tongue due to traction injury to thelingual nerveBleeding: It is important to apply ligaclips, and not to cauterise, majorvessels. Though infrequent, this can be26

a catastrophic event, especially when itoriginates from the lingual, superiorlaryngeal or carotid arteriesSurgical emphysema: This occursmainly in the setting of surgery in thesubglottic region e.g. resection throughthe cricothyroid membrane, and istreated conservatively; it occurs withsmall defects, as air is then trapped inthe soft tissues. To avoid emphysemaone can press on the larynx duringextubation and subsequently apply abandage around the neckAirway obstruction: This is anuncommon event; hence prophylactictracheostomy is only rarely indicatedAspiration: This does not occur withcordectomies, but may complicatesupraglottic largyngectomy and BOTresections. It is rarely a persistentproblem, and occurs less frequentlythan with open resections. Initial managementmay include good paincontrol, thickened foods (rather thanliquids); and temporary nasogastrictube or PEG feedingLaser burns: This occurs when thetissues e.g. facial skin are not properlyprotected with wet drapesAirway fire: This is an extremely rareevent and is entirely preventableLate complicationsGranuloma (Figure 69): This occursespecially where cartilage has beenexposed e.g. at the anterior commissureand the vocal process of the arytenoid.It generally resolves with time, butmay require biopsy if it cannot bedistinguished from tumour recurrenceChondronecrosis: This rarely occurswhen cartilage has been exposed or excised,especially after salvage surgeryin a post chemoradiation setting. Thepatient is treated with antibiotics andmicrolaryngoscopy to remove mucusand sequestra, and by sterilizing theremaining cartilage with the laser toimprove healing and to excluderesidual tumour (Figure 70)Figure 69: Granuloma on arytenoidFigure 70: Chondronecrotic sequestraStricture: This occurs very rarely withtumour surgery. Figures 71a-c illustratea patient who developed a completestricture in the region of the cricopharyngeusfollowing circumferentialexcision of a tumour of the hypopharynx;the stricture was bypassedwith a jejunal free flap27

abSuggested ReadingEndoscopic Laser Surgery of the UpperAerodigestive Tract: With Special Emphasison Cancer Surgery. W Steiner, PAmbrosch (2000) ISBN-10: 08657-7996, ISBN-13: 978-0865779969Transoral Laser Microsurgery for Cancerof the Upper Aerodigestive Tract(incl. DVD): Steiner W. 2013 (Distributedat no charge by Karl Storz, Tuttlingen)American Society for Laser Medicineand Surgeryhttp://www.aslms.org/public/standardpsgs.shtmlApfelbaum JL et al. Practice advisoryfor the prevention and management ofoperating room fires: an updated reportby the American Society of AnesthesiologistsTask Force on OperatingRoom Fires. Anesthesiology. 2013Feb;118(2):271-90cReferences1. Peter H. Eeg. CO 2 Lasers: The FourKeys to Success. Veterinary PracticeNews Posted: May 23, 2011http://www.veterinarypracticenews.com/vet-dept/small-animal-dept/c02-lasers-the-four-keys-to-success.aspx2. Remacle M et al. Endoscopic cordectomy.A proposal for a classification bythe Working Committee, EuropeanLaryngological Society. Eur ArchOtorhinolaryngol. 2000;257(4):227-313. Lichtenberger G, Toohill RJ. New keelfixing technique for endoscopic repairof anterior commissure webs. Laryngoscope1994:104 (6):771–4Figures 71a-c: Stricture of hypopharynx(a); inset of jejunal free flap(b); and postoperative result (c)28

Author and EditorJohan Fagan MBChB, FCORL, MMedProfessor and ChairmanDivision of OtolaryngologyUniversity of Cape TownCape Town, South Africajohannes.fagan@uct.ac.zaAuthorWolfgang Steiner MD, Hon. FRCS (Engl)Professor em. & Past ChairmanDept of ENT, Head & Neck SurgeryUniversity of GoettingenGöttingen, Germanywolfgang.p.steiner@googlemail.comTHE OPEN ACCESS ATLAS OFOTOLARYNGOLOGY, HEAD &NECK OPERATIVE SURGERYwww.entdev.uct.ac.zaThe Open Access Atlas of Otolaryngology, Head &Neck Operative Surgery by Johan Fagan (Editor)johannes.fagan@uct.ac.za is licensed under a CreativeCommons Attribution - Non-Commercial 3.0 UnportedLicense29