5 sphincter pharyngoplasty

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*Presented at the 22nd

annual meeting of Egypt ian Pediatric Surgical Association (EPSA) 14-16 December 2006

Correspondence to: Amir Elbarbary, MD, Plastic & Reconstructive Surgery Department, Faculty of Medicine,Ain-Sham University, Phone: + 20 12 228 7582, Email: [email protected]

Original Article

Annals of Pediatric Surgery, Vol 4, No 1,2, January-April, 2008 PP 22-36

Sphincter Pharyngoplasty: the One Procedure That Fits All Patterns of Closure in

Velopharyngeal Insufficiencies*

Amir Elbarbary, MD, Hassan Ghandour, MD

Plastic & Reconstructive Surgery Department & Phoniatric Unit, ENT Department, Faculty of Medicine,Ain-Shams University

Abstract

Background/ Purpose: Velopharyngeal insufficiency occurs in a considerable number of patients following cleft palaterepair. It disrupts speech intelligibility leading to breakdown of the ability to communicate verbally. Substantial uncertaintyoccurs in choosing between sphincter pharyngoplasty and pharyngeal flap in restoring the velopharyngeal function. This

prospective study aimed to assess the treatment outcome of modified sphincter pharyngoplasty applied to patients withresidual velopharyngeal insufficiency following palatal repair regardless of their pattern of velopharyngeal closure.

Materials & Methods: Preoperatively, patients underwent in-depth speech and endoscopic evaluations for symptoms ofvelopharngeal insufficiency. Six to twelve weeks following the surgical procedure they underwent the same thoroughevaluation prior to receiving any speech therapy. Speech evaluation was carried out using the protocol of assessment that isapplied in the phoniatric unit, Ain-Shams University which included auditory perceptual assessment (APA),nasopharyngeal videofibroscopy and nasometry.

Results: Forty three patients were included in this study. Statistical analysis of the results documented a significantreduction in the degree of open nasality, glottal articulation and pharyngalization following a modified sphincter

pharyngoplasty. A significant increase in the overall intelligibility was delineated regardless of the pattern of velopharyngealclosure. Postoperatively, velopharyngeal port achieved functional closure in the majority of patients as detected bynasopharyngeal videofibroscopy and was categorized as circular in thirty patients and coronal in thirteen.

Conclusion: The results of this study demonstrated that sphincter pharyngoplasty could be applied effectively to patientswith velopharyngeal insufficiency following cleft palate repair regardless of their velopharyngeal pattern of closure.

Index Word:Velopharyngeal inefficiency, sphincter pharyngoplasty, closure pattern.

INTRODUCTION

elopharyngeal insufficiency (VPI) refers toexcessive nasal resonance or hypernasality as

the consequence of anatomical abnormalities andfailure of the velum and the pharyngeal muscles to

produce optimal sphincter-like closure between theoro- and nasopharynx.1 It occurs in a substantialnumber of patients after cleft palate repair2-5 and canbe attributed to a variety of factors: scarring as a

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El Barbary & Ghandour

23 Vol 4, No 1,2, January-April, 2008

result of the initial palatoplasty can shorten thevelum; making it impossible for the velum to reachthe posterior pharyngeal wall "target" during speech;a deep nasopharynx relative to the position of thevelum; a poor velar movement despite an adequatelength resulting from insufficient restoration of thepalatal muscle sling at the time of primary repair.6Velopharyngeal insufficiency results in the inabilityof the cleft patients to communicate coherently and isconsidered the most disabling and devastating resultamong the various secondary problems that mayfollow cleft lip/palate repair.7

When surgical management is indicated forrestoration of the velopharyngeal function, thepharyngeal flap and the sphincter pharyngoplasty areamong the most commonly used surgicalprocedures8. Considerable uncertainty of choice existsboth within variations of flap and sphincter

pharyngoplasty and between the two approaches.Authorities such as Riski9 agree that if surgicalintervention is needed, the procedure should betailored to the size and nature of the velopharyngealdefect. However, reports of morbidity and mortalityassociated with pharyngeal flap surgery10-16 have leda lot of operators to adopt sphincterplasty instead.Several publications have advocated sphincterpharyngoplasties17-19 citing their additionaladvantages as (1) technical ease of execution, (2)superior speech results, (3) low complication rate, (4)reduced anaesthesia time, (5) non-obstruction of the

nasal airway.

The sphincter pharyngoplasty operation is designedto form a ridge on the posterior pharyngeal wall,narrow the pharynx from side to side, and to producea sphincteric type of closure.20 The objective of theprocedure is to create a muscular valve capable ofisolating the nasal cavity from the remainder of thevocal tract during appropriate speech tasks. This isnecessary to eliminate hypernasality and to allow oralpressure to build in the oral cavity for the productionof many consonant phonemes.21 Severalmodifications of sphincter pharyngoplasty have been

described since it was first introduced by Hynes22-24who used superiorly based flaps from thesalpingopharyngeus. Orticochea25 usedpalatopharyngeus instead and sutured them to aninferiorly based pharyngeal flap to below the palatalplane. Jackson & Silverston26 replaced the inferiorlybased flap by a superiorly based posterior wall flap inan attempt to raise the flap insertion and improve theoutcome. Despite the reported high success rate

following sphincter pharyngoplasty,27 a number ofpatients have persistent unacceptable vocal resonanceand residual air escape postoperatively.21,28 Advancesin patient selection and surgical technique to enhancesuccessful valving of sphincter pharyngoplasty havebeen reported.8,28

In an attempt to enhance the success of the sphincterpalatoplasty and further improve the outcome, amodified sphincter pharyngoplasty is presented. Itincluded the elevation of bilateral superiorly basedpalatopharyngeus muscle with overlying mucosa thatare sutured overlapped to each another and to atransverse incision on the posterior pharyngeal wallat the level of attempted velopharyngeal closure.

The aim of this prospective study is to assess thetreatment outcome for patients with residualvelopharyngeal insufficiency after palatal repair

undergoing a modified technique of sphincterpharyngoplasty regardless of the pattern ofvelopharyngeal closure.

PATIENTS AND METHODS

Patients diagnosed with residual velopharyngealinsufficiency after cleft palate repair presenting to theoutpatient cleft palate clinic at Ain-Shams UniversityHospital from January of 2004 to December of 2006had been considered potentially eligible for the study.

Similar to other studies,8,29 the patients had to meetthe following criteria to qualify for the study: (1)undergone a primary repair of the palate (with orwithout a cleft lip or alveolus), (2) chronological agebetween 4 and 16 years with apparent VPI diagnosedby an experienced speech specialist, (3) had at least75% of normal language development for their age.Exclusion criteria comprised patients with: (1) size ofthe velopharyngeal gap exceeding 2 cm inanteroposterior dimension which necessitated alengthening procedure, (2) hearing impairment, (3)

the cleft being part of a syndrome, (4) any preexistingpalatal fistulae, (5) obstructive sleep apnea syndrome.

The surgical procedure and study methods werecarefully explained to all parents. Patients underwentin-depth speech and endoscopic evaluations forsymptoms of velopharyngeal insufficiency. Six totwelve weeks, with a mean of two months, followingthe surgical procedure they underwent the samethorough evaluation prior to receiving any speech


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Annals of Pediatric Surgery 24

therapy if they needed any. Evaluation was carriedout using the protocol of assessment that is applied inthe phoniatric unit, Ain-Shams University whichincludes subjective as well as quasi-objectivemeasures of evaluation30.This protocol includes:

I-Preliminary Diagnostic Procedures:

Auditory Perceptual Assessment (APA) was usedas a subjective tool for evaluation of patients'language, speech and voice through listening toevery patient in a free conversation and a recordedspeech sample. Passive and active aspects oflanguage were investigated including semantic,syntactic and pragmatic aspects. Speech evaluationincluded the type and degree of open nasality,consonant precision, the compensatory articulatorymechanisms (glottal articulation, pharyngealizationof fricatives, and facial grimace), audible nasal airescape and overall unintelligibility of speech. All

these elements are graded along a 5-point scale inwhich 0 = normal and 4 = severe affection.

II-Clinical Diagnostic Aids:

(A) Nasopharyngeal videofibroscopy:

All patients were examined using nasopharyngealvideo-fibroscopy Henke-Sass-Wolf, type 10,connected to a Lemke video camera (MC 204) andPanasonic video cassette recorder 357. Thenasofibroscope was introduced through the nasalcavity to a position superior to the soft palate. Thevelopharyngeal valve movement was recordedwhile the patient repeated the speech samplesapplied in the protocol of assessment of VPI in thephoniatric unit, Ain-Shams University.30Movements of the velum, lateral, and posteriorpharyngeal walls were traced on the monitor. Themovement of each component was given a scorefrom 0 to 4 as follow: 0 = the resting (breathing)position or no movement, 2 = half the distance tothe corresponding wall, 4 = the maximummovement reaching and touching the oppositewall. Also,the pattern of closure of thevelopharyngeal port, whether coronal, sagittal,

circular or others were specified and recorded.

(B) Nasometry:

Nasometery was performed to all patients usingKay nasometer model 6200-2 with a softwareversion 1.5. It is composed of a head set,microprocessor and a printed circuit board. Everypatient was asked to repeat (with a normalconversational loudness, while sitting comfortably

on a chair) a nasal loaded sentence /mamabetnajem mana:l/ and an oral sentence devoid of

nasal sounds / ali rah jel ab korah/ according tothe protocol of assessment of VPI in the phoniatricunit, Ain-Shams University.30 The nasometercalculates the nasalance which is the ratio of thenasal to the nasal plus oral acoustic energymultiplied by 100. The degree of hypernasalitydepends on the percent nasalance.31 Similar toAbyholm et al,8 the nasalance results were reportedas an overall measure of preoperative andpostoperative mean changes as opposed tocomparing each patient with the norm.

All patients included in the study received amodified sphincter pharyngoplasty regardless ofthe pattern of velopharyngeal closure or theseverity of the symptoms. The retractor and tongueblade were adjusted to completely expose the

palatopharyngeus folds in the operating field. Thesoft palate was retracted supoeriorly to expose theposterior pharyngeal wall as high as the adenoid. Asubmucous injection of 1:200,000 adrenaline wasinjected into the operative field. Vertical incisionswere made in front of and behind the posteriortonsillar pillar starting from the upper limit of thetonsillar recess. With a Metzenbaum scissor, thepalatopharyngeous muscle was elevated with itsoverlying mucosa. After obtaining as much verticallength as possible, the superiorly basedmyomucosal flap was divided inferiorly and

elevated with a right-angled scissor. The donor sitewas closed. The same steps were repeated toelevate the contralateral flap. A transverse incisiondown to the prevertebral fascia is placedapproximately 2 mm below the adenoidal pad towhich the flaps are rotated 90 degrees. The flapswere interdigitated and sutured together tip-to-base and to the posterior pharyngeal wall withoutleaving any lateral ports. During recovery fromgeneral anaesthesia, the patients were placed in acompulsory posture with the head turned to oneside. They were encouraged to start liquid diet onthe first day of operation as soon as they were fullyrecovered. Any perioperative complications inrecovery or any later complications includingairway complications, readmission to hospital andreoperation were recorded.

Statistical analysis was done using paired t-testwith P>0.05 indicating no significance. P


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significance, and P


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A BFig 2. (A) Improvement in glottal articulation as a compensatory mechanism in scale points from preoperative to the

postoperative condition.(B) Comparison between preoperative and postoperative glottal articulation. A highly significant increase in thenumber of patients with grade 1 and a significant increase in the number of patients with grades 0 & 2. A highlysignificant decrease in the number of patients with grade 3, and a ver highly significant decrease in the number of

patients with grade 4 glottal articulation.

A BFig 3. (A)Improvement in pharyngalization as a compensatory mechanism in scale points from preoperative to the

postoperative condition.(B) Comparison between preoperative and postoperative degree of pharyngalization. There was a significant increasein the number of patients with grade 0 and a very highly significant increase in the number of patients with grade 1.

No statistical significance was found among the increase in number of patients with grade 2. A highly significantdecrease in the number of patients with grades 3 & 4 pharyngalization was detected.


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A BFig 4. (A) Overall speech intelligibility was rated on a 6-point scale. Ratings showed improvement from preoperative to the

postoperative condition in 86% of patients.(B) Comparison between the preoperative and postoperative grade revealed that there was a significant decrease in the

number of patients with grade 0, and a very high significance decrease in the number of patients with grade 1. Therewas a significant increase in the number of patients with grades 2 & 4, and a very high significant increase in thenumber of patients with grade 3 overall intelligibility.

A B CFig 5. Nasofiboscopic view of one of the cases classified with excellent postoperative overall intelligibility. (A) Preoperativeview demonstrating the gap at rest. (B) postoperative view demonstrating an open sphincter in repose and during

pronunciation of nasal phonemes (C) sphincter with circular pattern of closure upon pronunciations of oral phonemes.(* asterisk denotes posterior pharyngeal wall, and the arrow refers to the area of velopharyngeal port.

The velopharyngeal port, as revealed by thenasopharyngeal videofibroscopy was categorizedpreoperatively as coronal in 28 patients, sagittal in 8,and circular in 7 patients. Postoperatively,velopharyngeal port achieved functional closure in

the majority of patients and was categorized ascircular in thirty patients and coronal in 13. Out of the8 sagittal closures preoperatively, 6 became coronalwhile the remaining two became circular. The gradeof movement in attempting closure improved in all


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except for one of the two that became circular withmovement judged as remaining similar to thepreoperative grade of movement. All preoperativecircular closures remained as such except for one thatbecame coronal. It was only in this one that thedegree of movement remained as preoperative, whileimproving in the rest. The majority of coronalclosures (n=22) became circular and only 6 remainedas coronal in the postoperative evaluation. Two of the22 that became circular were judged as deterioratingin the degree of movement as opposed to animprovement in the remaining 20. All of the 6 thatremained coronal showed an improvement in thedegree of movement except for one that remainedwith the same grade as preoperatively. Thenasopharyngeal sphincter showed remarkablecontraction during speech, but not to the extent ofclosing the velopharyngeal port completely in allpatients (Fig. 5)

DISCUSSION

The sphincter pharyngoplasty described here is avariation of older concepts. Even thoughreconstruction of the velopharyngeal sphincteranatomically was attempted in 1935 by Browne32through placing a constricting suture around theentire oronasal port at the level of Passavant's ridge,Hynes22 was, undoubtedly, the first to introduce the"lateral" pharyngoplasty as a method of treatment ofvelopharyngeal insufficiency in 1950. He raised flapsfrom the lateral pharyngeal walls then closed thedonor defects to narrow the pharynx. Medialinterpolation and crosslapping of the two flapsproduced a horizontal shelf above Passavant's ridgeto bring the posterior pharyngeal target closer to thevelum. He believed that his technique would be morefunctional since the nerve supply to the lateralpharyngeal muscles comes from a superior origin.Any flap lifted laterally would contain neuromuscularelements and would contract. In his first paper,Hynes23 described the flaps containing the

salpingopharyngeus muscles but in his Hunterianlecture in 1953 he made it clear that he also raised thepalatopharyngeus and the fibers of the underlyingsuperior constrictor. Further observations on this typeof operation were made by Hynes24 in 1967 and theresults were later reviewed by Pigott.20 Moore33 alsoraised the salpigopharyngeus muscle but rather usedit to augment the posterior margin of the soft palate.

In 1968 Orticochea25 described the construction of a"dynamic" pharyngeal muscle sphincter in cleft palatepatients by suturing the tips of the lateral flaps,containing palatopharyngeus, onto the superior endof a third low inferiorly based posterior pharyngealflap. The flaps were not sutured to the posteriorpharyngeal wall laterally. A modification of the latterthat has gained so much popularity was introducedby Jackson & Silverton in 1977.26 They felt that theterm "sphincter" was more appropriate for this type offunctional pharyngoplasy. A superiorly based midlineflap, raised high on the posterior pharyngeal wall,substituted for the low inferiorly based flap ofOrticochea. Further modifications of the techniquehave been made. Most have centered on obtaining asuperior placement and covering raw tissue areas.34Ren & Wang35 Sutured half of the wounds on thepalatopharyngeus flaps to form a tubed pedicled flapand left only distal free ends. These ends were

sutured together in a "lateral to lateral" way, thenjoined the raw surface of the superiorly basedposterior pharyngeal flap.

The modification in the technique presented takes intoaccount the evolution and advantages of each of thesphincter procedures and simplifies them. It avoidedsome of the intrinsic deficiencies that were presentthrough eliminating all raw areas of the earlierprocedures and raising the level of inset bydiscontinuing the use of the pharyngeal flap thatcomplemented earlier modifications of all sphincterprocedure. The palatopharyngeal flaps were suturedoverlapped tip-to-base similar to the originaldescription by Hynes to further narrow thevelopharyngeal valve in a static manner. In agreementwith Sie et al17 and Witt et al36, the width, length, andlevel of insertion of the palatopharyngeal flaps, aswell as the degree of overlap of the transposed flaps,can be modified to suit the requirements of anyindividual patient. The degree of tightness andclosure of the sphincter is therefore determined by allthese factors.

Reid37 and Abyholm38 suggested that large fistulas

might be detrimental to speech. Cosman & Falk39

reported on general speech effects associated withpalatal fistulas. Isberg & Henningsson40 studied theinfluence of palatal fistulas on velopharyngealmovements and found a statistically significantcorrelation between the fistula size and the degree oflateral wall movement but not with the velarmovement. Furthermore, they demonstrated animprovement in velopharyngeal movements when


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the fistula was covered and concluded that even smallfistulas impair the velopharyngeal activity. Therefore,any preexisting palatal fistula/fistulae was repairedfirst before the patient was included in this study.This is similar to the designs of other studies.8,29

While several studies have compared posterior

pharyngeal flap and sphincter pharyngoplasty interms of speech outcome or complications, there isnot, as yet, a consensus regarding the specific choiceof one versus the other for surgical management ofvelopharyngeal insufficiency. Several reports havesuggested that there cannot be one single approachbecause velopharyngeal physiology varies from oneindividual to another. Thus, a single operation is notlikely to correct all cases of velopharyngealinsufficiency because closure defects at thevelopharyngeal sphincter have been noted to vary insize, position, shape, and consistency.5,28,29,41,42 Other

reports have demonstrated superior results of oneapproach over the other.17-19 The evidence for all thesecontradicting views is generally weak and difficult toresolve. Even the reliability of the few randomizedtrials that has been performed and found no statisticaldifference between the different procedures29,43,44 isinevitably prejudiced by important sources of bias.8These could include small number of patients andhomogenecity of sample included in the studies45 aswell as comparisons among groups of cases withoutbaseline equivalence in the degree of VPI, age of thepatients, ability of patients to modify the learnedspeech abnormalities, variables in closure defects,secondary deformity, or among cases that receivedsurgery from operators with different levels of skill. Inaddition, false conclusions may arise from groupdifferences in follow-up, diagnostic measurement,and reporting.46 Having these limitations in mind, thisstudy was designed to evaluate one surgicaltechnique in different patterns of closure rather thancomparing different techniques in the presence of a lotof variables. It should be noted though that unlikeother studies, cases in this study were not confined tothose whom received their primary repair at ourinstitution but rather included a heterogeneous group

of patients to increase the sample size and to furthervalidate the outcomes.

Choosing sphincter pharyngoplasty was based on itsincreasing popularity and its numerous advantagescited in literature. The velopharyngeal sphincter asdescribed by Passavant in 186247 is formed bilaterallyby the superior constrictor muscles, thepalatopharyngeal muscle, and the levator veli

palatine. Its function is to distribute the column of airleaving the pharynx during speech and direct itthrough the nose or mouth. Orticochea48 believes thatmovements and functions of the Passavant sphincterare represented in the brain rather than the muscles.Therefore, the palatopharyngeal muscle that iselevated and relocated into a transverse incision at theposterior pharyngeal wall is considered morephysiological in substituting the Passavant sphincterbecause it will have the similar cerebral representationand mimics the same pattern of closure.

Supporters of the sphincter pharyngoplasty foundthat the pharyngeal flap divides the velopharyngealarea into two lateral ports. They believe that itdisturbs the superior constrictor function, disruptingthe palatopharyngeus superior constrictor sphincterwith loss of its mechanical advantage. Ultimately, thepharyngeal flap weakens the posterior and lateral

pharyngeal wall movement49

. Shprintzen et al50

foundthat unless the pharyngeal flaps are tailored to thesize of the gap, the velopharyngeal insufficiency andhypernasality are likely to persist. They demonstratedthat, most often, the lateral wall movement does notadapt to the presence of this new structure in thepharynx. To the contrary, surgeons who prefer thepharyngeal flap believe that the sphincter mechanismis not disrupted since the posterior pharyngeal wall isalways repaired after raising the flap. In agreement,Karling et al51 found that the magnitude and characterof change in pharyngeal wall adduction wassignificantly correlated with the degree ofpreoperative adduction and with the width of theflap. Although they verified an increase in lateral wallactivity when narrow pharyngeal flaps were elevated,they also documented a decrease in the lateral wallactivity when the flaps were wide. They attributedthis to the mechanical hindrance by the large flap,which proves in a way the argument of thesphincterpharyngoplasty advocates. Moreover, theystated51 in their conclusion, that their results cannot beinterpreted as generally applicable because of thestrict selection of patients. Regardless of theseconflicting reports, it doesn't seem logical to base the

surgical plan of a patient on his lateral wall mobilitywhen this postoperative movement is uncertain andcould be affected in any form or degree following thepharyngeal flap elevation; it simply defeats thepurpose. Especially when there is a morephysiological option; namely the sphincterpharyngoplasty that is known to preserve thesphincter with minimal interference of the pharyngealwall anatomy,49 advance the posterior wall and


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reduce the lateral recess thus narrowing thecircumference with resultant decrease invelopharyngeal port area.20The size and shape of the residual velopharyngeal gaphave been determinant factors in implementing thedifferent surgical modalities for the correction of

velopharyngeal insufficiency.52 Pharyngeal flaps havebeen recommended when the residualvelopharyngeal gap is sagittal indicating a stronglateral wall movement and weak palatal mobility,while sphincter pharyngoplasty is indicated when theresidual velopharyngeal gap is coronal indicatingpoor lateral wall movement and a strong velarmovement53-56. Armour and colleagues19 furtheremphasized on this and confirmed that pharyngealflaps are less effective in treating velopharyngealinsufficiency in patients with coronal closure.Consequently, they changed the historic pattern of

treatment at The Hospital for Sick Children in Torontothat implied the pharyngeal flap for allvelopharyngeal insufficiencies regardless of theirclosure patterns; and became more inclined to treatcoronal pattern velopharyngeal insufficiencies withsphincter pharyngoplasty. Similarly, de Serres et al18

examined their experience with the sphincterpharyngoplasty and pharyngeal flap procedures aftertheir results seemed to indicate that less than optimalresults were being obtained with the pharyngeal flapprocedure. They found Sphincter pharyngoplasty tohave a higher success rate and tended to recommendit more liberally while abandoning the pharyngealflap procedure at their institution, although they stillconsider it as a management option depending onoperator preference. It is well documented1,57,58 thatcoronal closure is the commonest pattern of closureaccounting for 55% while sagittal closure accounts foronly 10-15%. This was comparable with the findingsin this study; coronal closure represented 65% of thecases while sagittal 18.5%.

Therefore, having the coronal closure as thecommonest pattern together with the hazard ofpotential impairment of the lateral wall movement

when elevating a pharyngeal flap,49

offers thesphincter pharyngoplasty, which interferes less withthe pharyngeal wall anatomy and is indicated in thecoronal pattern of closure, a better chance of outcomein all circumstances. Jackson59 once said that "as soonas surgeons become experienced and comfortablewith sphincter pharyngoplasty, they will find it themost common rehabilitative measure employed". Thisshould be because properly repaired palates should

have good mobility (coronal pattern of closure), andtherefore one shrinks from placing anything in thesoft palate that might in any way interfere with thismuch valued movement. When the palate is notfunctioning properly (sagittal pattern of closure), aninitial reconstruction of the soft palate levatormechanism should be carried out. If a degree ofvelopharyngeal insufficiency is still present, thenpatients can be very well rehabilitated with sphincterpharyngoplasty. Although this approach involves twooperations, it is certainly more anatomically andphysiologically sounds than opting immediately for apharyngeal flap.

It seems logical that when the soft palate isfunctioning adequately but is short and there is noviable way to make the palate longer, then the answeris to maintain the good palatal function and reducethe dimensions of the velopharyngeal mechanism by

performing a sphincter pharyngoplasty. This becomeseven more logic if we add to it the furtherimprovement in the palatal elevation that has beenconsidered to be one of the additional advantages ofthe sphincter pharyngoplasty.26,60 Georgantopoulouand coworkers61 studied in detail the effect on velarmobility and demonstrated a significant increase inthe range of movement of the soft palate followingdifferent types of sphincter pharyngoplasty. Theyexplained their findings based on the fact thatelevating the superiorly based posterior tonsillarpillar flaps divided the palatopharyngeous muscle.This in turn liberated the levator palati from itsantagonist, the palatopharyngeous, to actunopposed62 resulting in an increased velar elevation.Although, their explanation might have been asimplistic view to a very complex interaction betweenthe muscles of the soft palate63, it still holds logic andvalidates their findings. Some of the closure patternsin this study changed into coronal postoperatively,indicating a stronger velar mobility. Out of 8 sagittalclosures preoperatively, 6 became coronal whichconcurs Georgantopoulou's et al61 explanation.

The concept of dynamic pharyngoplasty arose from

Orticochea's25,64

observations of the process ofdeglutition. He speculated that the posterior tonsillarpillars with enclosed palatopharyngeus muscle whichacts during the gag reflex could be engaged for speechproduction. Hence, sphincter pharyngoplasty wasdesigned to change the lower insertion of theposterior pillars from the lateral walls to the posteriorwall on the pharynx. Witt et al65 tested this theoreticaladvantage of dynamic activity of the


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neovelopharyngeal port. They evaluated 58 patientswho underwent sphincter pharyngoplasty by speechvideofluroscopicy. Their results indicated aquantifiable and statistically significant excursion ofsphincteric closure concluding that sphincterpharyngoplasty works in a dynamic and activemanner. In another study, they66 found little evidenceto suggest that preexisting posterior pharyngeal wallmotion caused the sphincteric movement. To thecontrary, Ysunza et al42 and Ysunza67 suggested thatneither the lateral pharyngeal flaps in cases ofsphincter pharyngoplasties nor the central pharyngealflap in cases of pharyngeal flaps created newsphincters for velopharyngeal closure by usingselective electromyography and simultaneousvideonasopharyngoscopy. The participation of thesestructures is passive, increasing tissue volume inspecific areas, whereas their movements are caused bythe contraction of the superior constrictor pharyngeus

and the levator veli palatini. It is interesting to sightthat they were cautious about their observation andstated that the small number of their study does notallow definite conclusions. In all circumstances, thesphincter pharyngoplasty will work as described byPigott20 in any of three ways: as an active sphincter, orat least by advancing the posterior wall and byreducing the lateral recess in a static manner. Thenasopharyngoscopic findings of this study concurredwith Witt et al65,66 results and demonstrated adynamic neosphincter in all cases. However, theorigin of this activity was not tested for since no

electomyographic study was conducted. The majorityof the cases demonstrated a circular pattern of closureindicating participation of velum and pharyngeal wallin the movement. While in the remaining cases, thevelar movement was more significant than thepharyngeal wall and was accounted in as coronalpattern of closure. It is interesting to observe from theresults of this study that the five patients whomoverall speech intelligibility were judged asunsatisfactory following surgery were distributedover the different patterns of closure. In three of thepatients whom had the same preoperative and

postoperative overall speech intelligibility, one was asagittal that became circular, the second was circularand became coronal, while the last was the coronalthat remained as such postoperatively. Speechintelligibility was reviewed as showing deteriorationonly in two patients out of the 22 patients thatchanged from coronal preoperatively into circularpostoperatively. Therefore, these few unsatisfactory

results could be rather explained by factors other thanthe pattern of closure.

Huang et al68 examined the blood supply of the entirevelopharyngeal complex. They described thepharyngeal flap, from a vascular standpoint and inagreement with Mercer & MacCarthy69 as being

random in nature. The lateral incisions for superiorlyor inferiorly based flaps invariably divide theperforators from the ascending pharyngeal artery thatsupplies the superior constrictor as these vessels runtransversely. Although this certainly does notpreclude flap viability, it could be a contributingfactor to the common sequel of unpredictable flapshrinkage. On the other hand, the pattern of bloodsupply to the faucial portion of the palatopharyngeuswas observed to be segmental, with a number ofbranches of the ascending palatine artery entering themuscle throughout the length of the tonsilar pillar.

Therefore, even if the flaps were raised up to orbeyond the superior pole of the tonsil, the base of eachflap would probably contain at least the hamularbranch of the ascending palatine artery, ensuring anadequate axial blood supply to the flap. This concuredwith the opinions of Boorman & Freedlander70 andprobably explains why flap necrosis in this procedureis a rare phenomenon. An intraoperative finding offlap retraction following its elevation was observed inall cases of this study indicating the preservation of itsneurovascular supply.

Although healing around the orifice of the

velopharyngeal sphincter is not totally controllablefollowing sphincter pharyngoplasty, it is still muchmore controllable than healing around the lateralports of the pharyngeal flap. Jackson59 emphasizesthat only one posterior vertical suture line isincorporated in the recreated sphincter and thereforecontracture of the sphincter due to scarring is unlikelyto occur. In the modification presented here, even thisposterior scar has been eliminated. The fact that thevelopharyngeal aperture does not retract by scarring,in this modification, because of the lack of raw areasand circumferential incisions is significant.

There have been several reports of disastrous totalclosure of the velopharyngeal area, airwayobstruction and death associated with posteriorpharyngeal flap surgery.10-16 Valnicek et al14 revieweda 7-year experience with superiorly based pharyngealflap in a total of 219 children at The Hospital for SickChildren in Toronto. Complications included 18children (8.2%) with bleeding, of whom 5 requiredtransfusion; 20 children (9.1%) with airway


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obstruction; and 9 (4.1%) with sleep apnea afterdischarge from the hospital. Three patients requiredreintubation in the early postoperative period, and 11required eventual surgical revision, includingcomplete takedown of the flap in four patients. To thecontrary, Jackson59 stated that he has never seen a caseof sleep apnea with sphincter pharyngoplasty andattribute this to the fact that scarring is minimal andoccurs in a vertical rather than a horizontal direction.Obstructive sleep apnea seems to be more frequent, ifnot almost exclusively, associated with posteriorpharyngeal flap surgery.62 The literature does notcontain as many reports of airway problems withsphincter pharyngoplasty as with pharyngeal flap.Extraordinarily, Witt et al71 demonstrated that airwaydysfunction can occur following sphincterpharyngoplasty. They reported perioperative and/orpostoperative airway dysfunction in a minority oftheir patients. However, these patients had either

Pierre Robin sequence, micrognathia, or histories ofperinatal respiratory and/or feeding problems. In allof them, airway dysfunction resolved within 3 dayspostoperatively without the need for a surgicaltakedown of the sphincter pharyngoplasty to relievethe airway problems. In this study none of thepatients suffered airway dysfunction nor sleep apnea;only snoring at night that persisted for three monthsin some cases.

Finally, a very important issue is the ability to salvagefailures with further surgery. Jackson59 stated thatsphincter pharyngoplasty can be used to rehabilitatethe patient who has failed a pharyngeal flap.Moreover, in patients requiring Le Fort I or Le Fort IIIadvancements, the sphincter has never caused anyobstruction to advancement. This problem occurredon several occasions with pharyngeal flaps, which,when tight and scarred, have required division. Eventhen, rehabilitation has been performed usingsphincter pharyngoplasty six months after themaxillary advancement. Advocates of sphincterpharyngoplasty have listed the ability to easily andsuccessfully revise port size as one of its advantagesover pharyngeal flap62. Revision surgeries were

described as being without difficulty72. The patientswhom required revisions because of persistenthypernasality were associated with flap dehiscence,low-lying flaps, and end-to-end (as opposed to end-to-tip) flap suturing72. In this study only one patientrequired revision because of flap dehiscence. This wasone of the patients that were operated upon early inthis series and the flaps were set high into the adenoidtissues were the sutures did not hold.

It should be emphasized that the results in this studywere evaluated early between 6 and 12 weekspostoperatively and prior to establishment of speechtherapy to assess the role of the surgical procedurealone. Abyholm et al8 demonstrated that the sphincterpharyngoplasty achieved correction more slowly andthat one year follow ups provided better outcomesthan at three months. The original design of this studywas to carry a second follow up evaluation at oneyear. However, because of the non compliance of themajority of patients, only a small sample size werefollowed up after one year and no conclusiveoutcomes could be withdrawn in this regard.

Nevertheless, the results of this study indicates that amodified sphincter pharyngoplasty improved speechoverall intelligibility significantly in 86%. This iscomparable with the 74% success rate of Ren &Wang,35 79% improvement of Witt et al,73 85% success

rate of Abyholm et al8

, 91% of Jackson & Silverton26

.Orticochea48 reported his observations accumulatedover 40 years in treating velopharyngeal insufficiency.He recognized a variety of factors that influenced thesuccess rate of dynamic sphincter pharyngoplastyoutcomes. He considered the age of the patient as oneof them; the older the patient, the more deeplyengraved will be the cerebral engram patterns of thematernal language spoken through the nose withvelopharyngeal incompetence. Also, he believed thatthe later the reconstruction, the less the mobility of thesphincter. Moreover, he cited the ability of eachpatient to modify the learned speech abnormalities ofchanging their nasal mother tongue to an oral mothertongue as one of the important factors. Any of thesefactors could have been a contributing source for thefew unsatisfactory results in this study. Jackson59cautioned about the wrong position of palatal musclesin the primary repairs and suggested an initialcorrection followed by sphincter pharyngoplasty ifthey ever needed it. The fact that our studypopulation was heterogeneous and included patientswith their primary repairs conducted elsewhere,might have contained some patients with wrongposition of palatal muscles and accounted for the few

unsatisfactory results.

Ideally the level of the sphincter should be placedwhere the velum is attempting contact with theposterior pharyngeal wall. However, some limitationsare encountered in the presence of a large or lowadenoid pad17. Abyholm et al8 reported a surgeonwho declined the procedure because he did not thinkthat he could adequately carry out the procedure in


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the presence of large adenoids. Some of the fewunsatisfactory results in this study could be explainedby the low level of placement of sphincter due to thepresence of large adenoid pad. The only patient in thisstudy that was reoperated upon for flap dehiscenceoccurred when attempting on insetting the sphincterinto a large adenoid pad to avoid its inset at a lowerposition. One of the future implications that could bedrawn from this work is to design a pilot study wereadenoidectomy is carried out on a selective group ofpatients prior to sphincter pharyngoplasty in order tohelp in insetting the sphincter at its ideal level.

CONCLUSION

Sphincter pharyngoplasty is a physiological andanatomical substitution of the velopharyngeal valve.Not only does it reduce the velopharyngeal port by

advancing the posterior pharyngeal wall anddecreasing the lateral recess, but it also offers adymanic sphincter in the majority of cases, andimproves velar elevation. It relies on an axial patternflap with fewer complications. When needed to besalvaged it can be easily revised. The modifiedsphincter pharyngoplasty that is presented hereineliminates the addition of pharyngeal flap as well asall raw surfaces and is sutured with overlap. Thesemodifications are more anatomically andphysiologically sound and take into account theevolution and advantages of the sphincter

pharyngoplasty. It is very easy and very quick toperform with minor postoperative symptoms. Theresults demonstrate a satisfactory improvement ofvelopharyngeal function when applied in all patternsof velopharyngeal closure following primary repair ofthe palate despite a heterogeneous population of thestudy. Caution should be practiced in patients withextremely large defects, those accompanied by palatalfistulae, and those with improper position of palatalmuscles following their primary repair.

.

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