Manifestation and Diagnosis of Pediatric Laryngopharyngeal Reflux:</= title> <o:SmartTagType namespaceuri=3D"urn:schemas-microsoft-com:office:smarttags" name=3D"country-region"/> <o:SmartTagType namespaceuri=3D"urn:schemas-microsoft-com:office:smarttags" name=3D"place"/>  <style>  </style>  </head> <body lang=3DEN-US link=3D"#0033CC" vlink=3Dpurple style=3D'tab-interval:36= .0pt'> <div class=3DSection1> TITLE: Manifestation and Diagnosis of Pediatric Laryngopharyngeal Reflux SOURCE: Grand Rounds Presentation, UTMB, Dept. of Otolaryngology DATE: June 13, 2007 RESIDENT PHYSICIAN: Kevin Ho, M.D. FACULTY PHYSICIAN: Seckin Ulualp, M.D. SERIES EDITORS: Francis B. Quinn, Jr., MD <div class=3DMsoNormal align=3Dcenter style=3D'text-align:center'> <hr size=3D2 width=3D"100%" align=3Dcenter> </div> "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program = of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purp= ose of stimulating group discussion in a conference setting. No warranties, eit= her express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes= of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." <o:p></o:p> <div class=3DMsoNormal align=3Dcenter style=3D'text-align:center'> <hr size=3D2 width=3D"100%" align=3Dcenter> </div> <o:p> </o:p> Introduction: Gastroesophageal reflux (GER) is a common physio= logic condition in children; larygopharyngeal reflux (LPR) has gained increasing recognition over the past few years as a distinct pediatric condition. The former refers to retrograde flow gastric content into the esophagus, while = the refluxate passes through the upper esophageal sphincter to reach the pharyn= x in the latter condition. Clinical Manifestation: Although the prevalence of LPR in children is not known, it is estimated that up to 10% of adult patients present to otolaryngologists with symptoms related to reflux. It occurs more commonly = in the upright position and during daytime. Unlike GER, esophageal motility is thought to be normal in LPR. Laryngeal and pharyngeal symptoms are more com= mon in LPR than GER, which tends to present with heartburn and/or abdominal complaints. Symptoms of LPR are non-specific, thus making accurate diagnosis difficult. Infants may present with vomiting, regurgitation, failure to thr= ive, irritability, chronic respiratory disorder; while children may present with dysphagia, globus sensation, otalgia, dental pain, nasal congestion, chronic cough. Reflux has been implicated in a number of otolaryngologic conditions, including: Chronic rhinosinusitis: Phipps et al. reported a higher incidence of GER= in patients with sinusitis and their symptomatic improvement after acid suppressive therapy. Bothwell et al. reviewed the records of 28 patients who met the criteria for endoscopic sinus surgery and 25 of them (89%) showed improvement and avoided surgery after GER treatment. Though it is possible = that refluxate might reach the nasopharynx and cause inflammatory changes, there= is no prospective controlled trial to support that reflux contributes to sinusitis. Otitis media: A recent prospective non-randomized study by Cra= pko et al. demonstrated that pepsin is present in 60% of middle ear effusion sampl= es of children who underwent myringotomy for chronic otitis media with effusion (OME). A possible mechanism is reflux-induced nasopharyngeal inflammation a= nd Eustachian tube dysfunction. Further investigation is underway to establish the relationship between LPR and otitis media in children. Chronic cough: Holinger and Sanders retrospectively studied 72 infants and children who had cough for at least 1 month and found that GER = was present in 15% of the cases. However, there is no prospective data to date = on the causal relationship between LPR and chronic cough. Asthma: Several studies have tried to demonstrate the relationship between asthma and GER. Debley et al. performed a cross-sectio= nal study of 2397 adolescents and found that GER was eight times more prevalent= in the asthma group than non-asthma group. The study also showed that morbidity associated with asthma, such as the number of visits to ER and clinic, is higher among those with <st1:country-region w:st=3D"on"><st1:place w:st=3D"= on">GER.</st1:place></st1:country-region> Reflux-induced bronchospasm and reduction of peak flow are possible mechanisms to explain the association. = Reflux-induced stridor: In contrast to laryngomalacia, reflux-induced st= ridor is intermittent and not affected by change in position. Stridor might be a result of acid-induced laryngospasm or rapid breathing associated with esophageal irritation. Bouchard et al. reported 61 of 105 (58%) children presented with stridor and pH study-proven GERD; 83% of those improved with acid suppressive therapy. Flexible laryngoscopy is recommended to distingui= sh this condition from laryngomalacia. Laryngomalacia: Laryngomalacia is the most common cause of strid= or in infants, who present with inspiratory stridor that worsens with crying or supine position. The prolapse of supraglottic structures during inspiration= is thought to create negative pressure that induces upward flow of refluxate i= nto the larynx. Incidence of GER in laryngomalacia has been reported to range f= rom 50-80%. Direct laryngoscopy and bronchoscopy may be indicated in prolonged symptomatic cases because the incidence of a second synchronous lesion is reported to be 15-30%. Subglottic stenosis: Evidence linking reflux and subglottic stenosis = is limited to animal studies and uncontrolled human studies. Numerous animal studies w= ere able to demonstrate acid could induce ulceration, basilar hyperplasia, and edema of the subglottic mucosa. Yellon et al. reported that 80% of 26 child= ren who underwent laryngotracheal reconstruction were diagnosed of GER either by barium esophagram, pH monitoring, nuclear scintiscan, or esophageal biopsy. Diagnosis: Because of its intermittent pattern, the diagnos= is of LPR in children is often difficult. Given the limitations of the diagnostic tests discussed below, it remains controversial which test is optimal for detecting LPR. Barium esophagram: It is used frequently to diagnose associated anatomical anomalies such as web and stricture. However, its poor sensitivi= ty (20-60%) as a result of short sampling time makes it less useful for diagnosing LPR.= Nuclear scintigraphy: It has the advantage of detecting aspiration, non-acidic reflux episodes, and gastric emptying. Like barium esophagram, it only has a short sampling time and sensitivity is low (15-59 %). In additio= n, the correlation of scintigraphy with pH monitoring is poor. Direct Laryngoscopy and bronchoscopy (DLB): There is limited data evaluating DLB as a diagno= stic tool in pediatric LPR. Carr et al. reported a prospective uncontrolled tria= l on 77 children who underwent DLB for complete airway evaluation. Endoscopic examination was graded based on laryngeal (eg. post-glottic edema, arytenoid edema) and cricotracheal (eg. cobblestoning, blunting of carina) findings. Those diagnosed with GERD were found to have significantly higher scores th= an those without GERD. The subjective nature of DLB in diagnosing LPR w= as evaluated in Branski’s prospective randomized trial. 120 adult stroboscopic findings were graded by 5 otolaryngologists based on criteria = such as edema, erythema, and pachydermia of the larynx. The study found that both inter-rater and intra-rater reliability were poor especially in arytenoids measurements. In another study, McMurray et al. also found a poor correlati= on between laryngoscopic findings and pH probe. 24-hour pH monitoring: Considered the gold standard for diagnosing GER,= it is one of the most commonly used techniques to document LPR. The double probe (pharyngeal, esophageal) design allows for simultaneous detection of pH cha= nge in both the hypopharynx and esophagus. Manometry has been used in the past = to confirm positioning of the distal probe, which is usually 3-5 cm above the lower esophageal sphincter. Ulualp et al. recently reported a new technique= using flexible laryngoscopy to guide the placement of the dual-probe. The criteria for what constitutes a reflux episo= de are not standardized but usually require 1) a decrease in pH below 4 and 2) pha= ryngeal event following an esophageal event. The total amount of time of acid expos= ure in 24 hours has also been suggested as a useful criterion. There are several limitations regarding the use = of pH monitoring for LPR. It is invasive, time consuming, and generally not well tolerated by children. Brief, non-acidic, and gaseous reflux episodes might= be missed by this technique. In addition, the criteria for a significant LPR episode are not well defined and vary among studies. Furthermore, pharyngeal reflux events do not correlate well with symptoms of laryngitis, as Joniau = et al. pointed out in an adult study. Multichannel Intraluminal Impedance (MII) Monitoring:= This technique measures the change in impedance = between two electrodes during the passage of food bolus. Impedance, a measure of electrical resistance, decreases as bolus passes through measuring segments= . It has the advantage of measuring the direction and speed of bolus, as well as detecting non-acidic and gaseous reflux episodes. Although there is no stud= y to date using MII to diagnose pediatric LPR, preliminary results on GER are encouraging. Rosen et al. compared MII and pH monitoring in 50 children and found that sensitivity of MII (80%) is significantly higher than pH monitor= ing (47%) in the group treated with proton pump inhibitor. Conclusions: Manifestation and diagnosis of pediatric laryngopharyngeal reflux remain controversial. Despite increasing effort to establish an association between reflux and otolaryngological manifestation= s, conclusive evidence is lacking. In addition, well-designed controlled studi= es are needed to evaluate the optimal diagnostic tool for pediatric LPR. <span style=3D'font-size:14.0pt; mso-bidi-font-size:10.0pt;font-family:Arial;mso-fareast-font-family:"Times = New Roman"; mso-bidi-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-= language: EN-US;mso-bidi-language:AR-SA'> References: <ol style=3D'margin-top:0pt' start=3D1 type=3D1> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Carr MM et al. Arch Otolaryngol Head Neck Surg. 2001 Apr;127(4):369-74. <o:p>= </o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Stavroulaki P. Int J Pediatr Otorhinolaryng= ol. 2006 Apr;70(4):579-90.</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Ulualp SO et al. Laryngoscope. 2007 Apr;117(4):577-80.</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Mandell DL et al. Arch Otolaryngol Head Neck Surg. 2004 Nov;130(11):1293-7</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Branski RC et al. Laryngoscope. 2002 Jun;112(6):1019-24.</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Karkos PD et al. Int J Pediatr Otorhinolary= ngol. 2006 Apr;70(4):757-8</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Wenzl TG et al. J Pediatr Gastroenterol Nut= r. 2002 May;34(5):519-23</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Phipps CD et al. Arch Otolaryngol Head Neck= Surg. 2000 Jul;126(7):831-6</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Bothwell MR et al. Otolaryngol Head Neck Su= rg. 1999 Sep;121(3):255-62</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Crapko M et al. Laryngoscope. 2007 Aug;117(8):1419-23<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Holinger LD et al. Laryngoscope. 1991 Jun;1= 01(6 Pt 1):596-605<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Debley JS. Pediatr Pulmonol. 2006 May;41(5):475-81<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Bouchard S et al. J Pediatr Surg. 1999 Jul;34(7):1053-6<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Yellon RF et al. Am J Med. 2000 Mar 6;108 S= uppl 4a:131S-138S. Review<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Joniau S et al. Otolaryngol Head Neck Surg.= 2007 May;136(5):686-92. Review<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Tutuian R et al. J Clin Gastroenterol. 2003 Sep;37(3):206-15. Review.<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Rosen R et al. Clin Gastroenterol Hepatol. = 2006 Feb;4(2):167-72<o:p></o:p></li> </ol> <= /p> </div> </body> </html>

MIME-Version: 1.0 Content-Location: file:///C:/A388DE53/pedi-LPR-070613.htm Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii" Manifestation and Diagnosis of Pediatric Laryngopharyngeal Reflux:</= title> <o:SmartTagType namespaceuri=3D"urn:schemas-microsoft-com:office:smarttags" name=3D"country-region"/> <o:SmartTagType namespaceuri=3D"urn:schemas-microsoft-com:office:smarttags" name=3D"place"/>  <style>  </style>  </head> <body lang=3DEN-US link=3D"#0033CC" vlink=3Dpurple style=3D'tab-interval:36= .0pt'> <div class=3DSection1> TITLE: Manifestation and Diagnosis of Pediatric Laryngopharyngeal Reflux SOURCE: Grand Rounds Presentation, UTMB, Dept. of Otolaryngology DATE: June 13, 2007 RESIDENT PHYSICIAN: Kevin Ho, M.D. FACULTY PHYSICIAN: Seckin Ulualp, M.D. SERIES EDITORS: Francis B. Quinn, Jr., MD <div class=3DMsoNormal align=3Dcenter style=3D'text-align:center'> <hr size=3D2 width=3D"100%" align=3Dcenter> </div> "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program = of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purp= ose of stimulating group discussion in a conference setting. No warranties, eit= her express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes= of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." <o:p></o:p> <div class=3DMsoNormal align=3Dcenter style=3D'text-align:center'> <hr size=3D2 width=3D"100%" align=3Dcenter> </div> <o:p> </o:p> Introduction: Gastroesophageal reflux (GER) is a common physio= logic condition in children; larygopharyngeal reflux (LPR) has gained increasing recognition over the past few years as a distinct pediatric condition. The former refers to retrograde flow gastric content into the esophagus, while = the refluxate passes through the upper esophageal sphincter to reach the pharyn= x in the latter condition. Clinical Manifestation: Although the prevalence of LPR in children is not known, it is estimated that up to 10% of adult patients present to otolaryngologists with symptoms related to reflux. It occurs more commonly = in the upright position and during daytime. Unlike GER, esophageal motility is thought to be normal in LPR. Laryngeal and pharyngeal symptoms are more com= mon in LPR than GER, which tends to present with heartburn and/or abdominal complaints. Symptoms of LPR are non-specific, thus making accurate diagnosis difficult. Infants may present with vomiting, regurgitation, failure to thr= ive, irritability, chronic respiratory disorder; while children may present with dysphagia, globus sensation, otalgia, dental pain, nasal congestion, chronic cough. Reflux has been implicated in a number of otolaryngologic conditions, including: Chronic rhinosinusitis: Phipps et al. reported a higher incidence of GER= in patients with sinusitis and their symptomatic improvement after acid suppressive therapy. Bothwell et al. reviewed the records of 28 patients who met the criteria for endoscopic sinus surgery and 25 of them (89%) showed improvement and avoided surgery after GER treatment. Though it is possible = that refluxate might reach the nasopharynx and cause inflammatory changes, there= is no prospective controlled trial to support that reflux contributes to sinusitis. Otitis media: A recent prospective non-randomized study by Cra= pko et al. demonstrated that pepsin is present in 60% of middle ear effusion sampl= es of children who underwent myringotomy for chronic otitis media with effusion (OME). A possible mechanism is reflux-induced nasopharyngeal inflammation a= nd Eustachian tube dysfunction. Further investigation is underway to establish the relationship between LPR and otitis media in children. Chronic cough: Holinger and Sanders retrospectively studied 72 infants and children who had cough for at least 1 month and found that GER = was present in 15% of the cases. However, there is no prospective data to date = on the causal relationship between LPR and chronic cough. Asthma: Several studies have tried to demonstrate the relationship between asthma and GER. Debley et al. performed a cross-sectio= nal study of 2397 adolescents and found that GER was eight times more prevalent= in the asthma group than non-asthma group. The study also showed that morbidity associated with asthma, such as the number of visits to ER and clinic, is higher among those with <st1:country-region w:st=3D"on"><st1:place w:st=3D"= on">GER.</st1:place></st1:country-region> Reflux-induced bronchospasm and reduction of peak flow are possible mechanisms to explain the association. = Reflux-induced stridor: In contrast to laryngomalacia, reflux-induced st= ridor is intermittent and not affected by change in position. Stridor might be a result of acid-induced laryngospasm or rapid breathing associated with esophageal irritation. Bouchard et al. reported 61 of 105 (58%) children presented with stridor and pH study-proven GERD; 83% of those improved with acid suppressive therapy. Flexible laryngoscopy is recommended to distingui= sh this condition from laryngomalacia. Laryngomalacia: Laryngomalacia is the most common cause of strid= or in infants, who present with inspiratory stridor that worsens with crying or supine position. The prolapse of supraglottic structures during inspiration= is thought to create negative pressure that induces upward flow of refluxate i= nto the larynx. Incidence of GER in laryngomalacia has been reported to range f= rom 50-80%. Direct laryngoscopy and bronchoscopy may be indicated in prolonged symptomatic cases because the incidence of a second synchronous lesion is reported to be 15-30%. Subglottic stenosis: Evidence linking reflux and subglottic stenosis = is limited to animal studies and uncontrolled human studies. Numerous animal studies w= ere able to demonstrate acid could induce ulceration, basilar hyperplasia, and edema of the subglottic mucosa. Yellon et al. reported that 80% of 26 child= ren who underwent laryngotracheal reconstruction were diagnosed of GER either by barium esophagram, pH monitoring, nuclear scintiscan, or esophageal biopsy. Diagnosis: Because of its intermittent pattern, the diagnos= is of LPR in children is often difficult. Given the limitations of the diagnostic tests discussed below, it remains controversial which test is optimal for detecting LPR. Barium esophagram: It is used frequently to diagnose associated anatomical anomalies such as web and stricture. However, its poor sensitivi= ty (20-60%) as a result of short sampling time makes it less useful for diagnosing LPR.= Nuclear scintigraphy: It has the advantage of detecting aspiration, non-acidic reflux episodes, and gastric emptying. Like barium esophagram, it only has a short sampling time and sensitivity is low (15-59 %). In additio= n, the correlation of scintigraphy with pH monitoring is poor. Direct Laryngoscopy and bronchoscopy (DLB): There is limited data evaluating DLB as a diagno= stic tool in pediatric LPR. Carr et al. reported a prospective uncontrolled tria= l on 77 children who underwent DLB for complete airway evaluation. Endoscopic examination was graded based on laryngeal (eg. post-glottic edema, arytenoid edema) and cricotracheal (eg. cobblestoning, blunting of carina) findings. Those diagnosed with GERD were found to have significantly higher scores th= an those without GERD. The subjective nature of DLB in diagnosing LPR w= as evaluated in Branski’s prospective randomized trial. 120 adult stroboscopic findings were graded by 5 otolaryngologists based on criteria = such as edema, erythema, and pachydermia of the larynx. The study found that both inter-rater and intra-rater reliability were poor especially in arytenoids measurements. In another study, McMurray et al. also found a poor correlati= on between laryngoscopic findings and pH probe. 24-hour pH monitoring: Considered the gold standard for diagnosing GER,= it is one of the most commonly used techniques to document LPR. The double probe (pharyngeal, esophageal) design allows for simultaneous detection of pH cha= nge in both the hypopharynx and esophagus. Manometry has been used in the past = to confirm positioning of the distal probe, which is usually 3-5 cm above the lower esophageal sphincter. Ulualp et al. recently reported a new technique= using flexible laryngoscopy to guide the placement of the dual-probe. The criteria for what constitutes a reflux episo= de are not standardized but usually require 1) a decrease in pH below 4 and 2) pha= ryngeal event following an esophageal event. The total amount of time of acid expos= ure in 24 hours has also been suggested as a useful criterion. There are several limitations regarding the use = of pH monitoring for LPR. It is invasive, time consuming, and generally not well tolerated by children. Brief, non-acidic, and gaseous reflux episodes might= be missed by this technique. In addition, the criteria for a significant LPR episode are not well defined and vary among studies. Furthermore, pharyngeal reflux events do not correlate well with symptoms of laryngitis, as Joniau = et al. pointed out in an adult study. Multichannel Intraluminal Impedance (MII) Monitoring:= This technique measures the change in impedance = between two electrodes during the passage of food bolus. Impedance, a measure of electrical resistance, decreases as bolus passes through measuring segments= . It has the advantage of measuring the direction and speed of bolus, as well as detecting non-acidic and gaseous reflux episodes. Although there is no stud= y to date using MII to diagnose pediatric LPR, preliminary results on GER are encouraging. Rosen et al. compared MII and pH monitoring in 50 children and found that sensitivity of MII (80%) is significantly higher than pH monitor= ing (47%) in the group treated with proton pump inhibitor. Conclusions: Manifestation and diagnosis of pediatric laryngopharyngeal reflux remain controversial. Despite increasing effort to establish an association between reflux and otolaryngological manifestation= s, conclusive evidence is lacking. In addition, well-designed controlled studi= es are needed to evaluate the optimal diagnostic tool for pediatric LPR. <span style=3D'font-size:14.0pt; mso-bidi-font-size:10.0pt;font-family:Arial;mso-fareast-font-family:"Times = New Roman"; mso-bidi-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-= language: EN-US;mso-bidi-language:AR-SA'> References: <ol style=3D'margin-top:0pt' start=3D1 type=3D1> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Carr MM et al. Arch Otolaryngol Head Neck Surg. 2001 Apr;127(4):369-74. <o:p>= </o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Stavroulaki P. Int J Pediatr Otorhinolaryng= ol. 2006 Apr;70(4):579-90.</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Ulualp SO et al. Laryngoscope. 2007 Apr;117(4):577-80.</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Mandell DL et al. Arch Otolaryngol Head Neck Surg. 2004 Nov;130(11):1293-7</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Branski RC et al. Laryngoscope. 2002 Jun;112(6):1019-24.</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Karkos PD et al. Int J Pediatr Otorhinolary= ngol. 2006 Apr;70(4):757-8</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Wenzl TG et al. J Pediatr Gastroenterol Nut= r. 2002 May;34(5):519-23</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Phipps CD et al. Arch Otolaryngol Head Neck= Surg. 2000 Jul;126(7):831-6</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Bothwell MR et al. Otolaryngol Head Neck Su= rg. 1999 Sep;121(3):255-62</li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Crapko M et al. Laryngoscope. 2007 Aug;117(8):1419-23<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Holinger LD et al. Laryngoscope. 1991 Jun;1= 01(6 Pt 1):596-605<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Debley JS. Pediatr Pulmonol. 2006 May;41(5):475-81<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Bouchard S et al. J Pediatr Surg. 1999 Jul;34(7):1053-6<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Yellon RF et al. Am J Med. 2000 Mar 6;108 S= uppl 4a:131S-138S. Review<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Joniau S et al. Otolaryngol Head Neck Surg.= 2007 May;136(5):686-92. Review<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Tutuian R et al. J Clin Gastroenterol. 2003 Sep;37(3):206-15. Review.<o:p></o:p></li> <li class=3DMsoNormal style=3D'mso-list:l0 level1 lfo1;tab-stops:list 36.0= pt'>Rosen R et al. Clin Gastroenterol Hepatol. = 2006 Feb;4(2):167-72<o:p></o:p></li> </ol> <= /p> </div> </body> </html>