Laryngopharyngeal Reflux (LPR) Play A Role In Pathogenesis Of Vocal Cord Polyps

ObjectiveHoarseness (Dysphonia) was defined as a disorder characterized by altered vocal quality, pitch, loudness, or vocal effort that impairs communication or reduces voice-related QOL. It was reported that hoarseness has a prevalence of30percent in adults and more than half of teachers. Hoarseness may affect all age groups, women especially. Among children, prevalence rates vary from15percent to24percent. Hoarseness has significant public health implications. Patients suffer social isolation, depression, and reduced disease-specific and general QOL.Survery had demonstrated that about25～35%hoarseness patients with vocal cord polyps/nodules. Vocal cords polyp is one of the common diseases in otorhinol-aryngological department, frequently-occurring disease, patients often complained of clinic for hoarseness, and for vocal fatigue, globus pharyngeus, chronic throat clearing and so on. The cause of vocal cord polyp formation is not very clear. Surgical remove it to improve the vocal cord vibration, when conventional conserva-tive treatment is invalid. However hoarseness, globus, dysphonia were still remain in some part of postoperative patients.Hormones, antibiotics widely used and even abused may cause heavy economic burden of patients but with no expected treatment effect, thus has become a common problem in both clinical doctors and patients.Pharyngeal reflux was considered to be one of risk factors of hoarseness. It is estimated that50%of hoarseness related to the laryngopharyngeal reflux. Martins et al reported that61%of vocal oversue,47%of gastroesophageal and nasosinusal symptoms32%were found be associated with76cases of vocal polyps by questionnaires.Although academics have a preliminary understanding to the laryngopharyngeal reflux and the correlation of vocal cord polyps, but rare studies had objective evaluation laryngopharyngeal and esophagus reflux dynamic condition of vocal cord polyps,and also lack of reports research on reflux mechanism in vocal cord polyps formation.Based on the above background, this study proposed by high resolution esophageal pressure (HRM) evaluation esophageal dynamic characteristics,24hour multichannel intraluminal impedance-pH monitoring (24hMⅡ-pH) assessment gastroesophageal reflux and laryngopharyngeal reflux condition; by detection pepsin concentration of saliva and pepsin expression in vocal polyps’tissues,to discuss the correlation between laryngopharyngeal reflux with histopathological and clinical classification of vocal polyps, so as to provide guidance for vocal polyps treatment.Methods1. SubjectsVocal polyp patients:Prospectively,complain of hoarseness, patients with polyps of vocal cord diagnosed by electronic laryngoscopy were picked in the ENT department of Nanfang Hospital from October2011to May2012.Routine conservative therapy effect is poor,surgical indications,the patient agree with surgical to remove vocal polyps. Postoperative pathological diagnosis was accordance with the clinical diagnosis.Control group:Selected healthy volunteers (normal) as the control group. Volunteers were all asked to have no voice disorders, no long drinking or smoking history, without laryngeal diseases and through the guidance of physician subjects since the RSI scale, electronic laryngoscope check for normal laryngeal structures and for RFS scores, qualifier ones pass to at the same time satisfy the RSI<13points, RFS<7points.All patients and healthy volunteers were voluntary and informed consent to participate in the study signed a consent form. 2. Study DesignReflux Scales The vocal polyps and healthy subjects were asked to complete the self-administered nine-item RSI questionnaire and were examined by videolaryngoscopy to reveal any laryngeal mucosal abnormalities.The video recordings were evaluated using RFS by two otolaryngologists, with more than five years of experience in the field, who worked indepently and were blind to the patient data.The mean score for the subjects was used for analysis of the results.When satisfied both RSI≥13and RFS>7points the subjects sufferred from laryngopharyngeal reflux.Esophageal dynamic monitoring By36channels ManoScan360TM solid-state high-resolution esophageal pressure system, pressure catheter is placed through the participants’ nose in the recumbent position of the process.With swallowing food and water for10times, esophageal dynamic parameters transform into into a "3d color pressure relief map" by the software. With the computerization and graphic data presentation, intuitive image can see catheter passes through from the pharynx to the stomach esophagus movement function.A new criteria of the Chicago classification (second edition)was based on asystematic analysis of motility patterns by HRM.Multichannel intraluminal impedance-pH monitoring (MII-pH) Zephr multichannel intraluminal impedance-pH monitoring portable system (Sandhill Scientific Inc, USA) and model ZAI-BL-48E single root bifurcation type electrode were adopted. Participants fasting water and food at least8hours before monitoring, nasal catheter insertion according to the position the LES esophageal dynamic monitoring, chest fixed external reference electrode, adjust the portable data recorder records laryngopharyngeal reflux and gastroesophageal reflux, guarantee24hours monitoring dismantling equipment, end inspection. Reference to the data of24hMII-pH monitoring healthy volunteers such as Wang’s, take the number2times of acid laryngopharyngeal reflux as LPR positive standard. According to Johnson and DeMeester standards define DeMeester acuity14.7divided into gastroesophageal reflux positive standard.Pepsin concentration The subjects were asked to spit into a container at least3.0mL of sputum to be used for enzyme-linked immunosorbent assay (ELISA).According to the enzyme standard instrument under the450±620nm wavelength determination of absorbance (O.D value) computing the actual concentration of the sample. Experiment to choose the kits pepsin concentration range is4.94ng/ml-400ng/ml (1ng/ml=1000ng/ul), less than4.94ng/ml for saliva samples pepsin test negative.Pathological morphological changes Surgery to remove vocal cord lesions under topical anaesthesia electronic laryngoscope or laryngoscope under general anesthesia in nanfang hospital otolaryngology.Biopsies from the corpus of the stomach were fixed in formalin for histopathologic analysis.All vocal polyps’tissue samples were routine HE staining to observe pathological morphological changes and pepsin expression by immunohistochemical method.Under electronic laryngoscope images polyps should be divided into with or without pedicle2kind of clinical classification.According to the polyp tissue pathological morphological changes would be divided into edematous type, vascular type and fibrous type.3. Statistical analysisMetering and continuity data with mean+/-standard deviation (Mean±SD), counting and non continuous data expressed in the median and the25th and percentile is M (P25, P75).Measurement data comparison with Independent Samples t test, discontinuity data of two. The Studentrs/-test, non-parametric test and Independent Samples nonparametric tests were used. Bivariate correlation analysis, Pearson correlation coefficient and Spearman correlation coefficient were used.Single box diagram were plotted for comparison results between measured data. A P value of less than0.05was taken as indicating statistical significance.The statistical analyses were done with SPSS computer software (version13.0; SPSS).Results1. Selected32patients with vocal cord polyp group, of which the male17, female15cases; The average age of32+/-9.4years, range9～60years old; with an average of19.9+/-21.1months hoarseness history from1month to84months. Control group within a hospital healthy volunteers,16cases of recruiting staff12cases and4cases of medical students, male8cases, female8cases, mean age26.6+/-8.5years old, and distribution of20to49years.2. Satisfied both the RSI acuity13points and RFS>7points in vocal cord polyp patients was12cases (12/32,37.5%), and in the controls none case satisfied the RSI acuity13points or RFS>7points.3. Compaired with the new criteria of the Chicago classification (second edition) was based on asystematic analysis of motility patterns by HRM.There were70.0%(21/30) patients with vocal cord polyps and25%(4/16) in normal control group exist in abnormal esophageal dynamics. Upper esophageal sphincter (UES)relaxation duration, UES relaxation recovery time,lower esophageal sphincter (LES) average length were all shorten and intrabolus pressure (average maximum) in vocal polyps than the controls (P<0.05).4. LPR positive rate in vocal cords polyp group (40.6%) was higher than the control group (12.5%)(Z=2.481, P=2.481). Number of laryngopharyngeal acid reflux in vocal cord polyp group with more than once in16cases,13cases (13/32,40.6%) with2or more times,8cases with more than3times. Median number of laryngopharyngeal acid reflux was0.5[0;3.5]; one case of laryngopharyngeal acid reflux was2times, and one case was3times (12.5%,2/16).Median number of laryngopharyngeal acid reflux was0[0;0] in control group respectively.DeMeester was on an average of25.2±37.0points (distribution of0.8～113.8) in vocal polyps, compared with the controls of4.0±6.4(0.8～27points). Total number of reflux had statistical significance difference in polyps group and the control group (Z=1.980, P=0.048).5. Pepsin detection test of the saliva was positive (>4940ng/ul) for17cases (60.7%) in polyps group,1case (7.1%) positive in the controls. Pepsin concentration of saliva was9169.1±6865.9ng/ul in vocal polyps, and2329.7±1118.2ng/ul in the control group, there was a statistical significance difference in the two groups (t=5.14,P=0.000) 6. Laryngoscopic photographs were reviewed. The vocal cord polyps with pedicles were found in5cases, without pedicles in23cases.The vocal cord polyps were classified into3types according to the pathological features:edematous type in14cases(50%),vascular type in6cases (21.4%),and fibrous type in8cases(28.6%).7. Pepsin expression strong positive was5cases (17.8%), positive for12cases (42.8%),11cases(39.3%)negetive in polyps group.There were one case with strong positive pepsin,2cases with positive, and2cases negetive in the pedicles type;4cases,10cases, and9cases in the type of polyps without pedicles, respectively.There were2cases with strong positive pepsin expression,8cases with positive, and4cases with negetive in the edematous type; one case of strong positive,2cases of positive,3cases of negetive in the vascular type;2cases of strong positive,2cases of positive,4cases of negetive in the vascular type, respectively.The clinical courses among the the types of vocal polyps had no satistic significance (P>0.05).Conclusions1. With24hMII-pH monitoring method diagnose laryngeal reflux in vocal cord polyp patients, there was a higher rate of LPR accurance in vocal polyps(40.6%) than that of the controls(12.5%), which showed that LPR may play a role in the mechanism of vocal polyps developing.2.24hMⅡ-pH monitoring the impedance analysis showed that the reflux event features of vocal polyps was:reflux material properties is given priority to acid reflux in withstand position; reflux content composition is given priority to acidic and weak acidic, alkaline reflux accounts for a relatively small proportion.3. Through high resolution esophageal pressure evaluation vocal cord polyp patients in control group and normal esophageal dynamic characteristics, reference standard data analysis of Chicago, found that UES dysfunction and esophageal peristalsis function decline.The esophageal dynamic obstaclesled led to laryngopharyngeal reflux. 4. There were60.7%(17/28) positive pepsin concentration of saliva and pepsin expression in vocal polyps tissues in vocal polyp patients.There was no statistical significance difference of pepsin expression in different clinical types or pathological types of vocal polyps. Pepsin played an important role in in the mechanism of vocal cord polyps formation and with no selection on different clinical and pathological types (pedunculated or not) of vocal polyps at all.