Endoscopic Hydroxyapatite Augmentation for Patulous Eustachian Tube

Transcription

1 The Laryngoscope VC 2013 The American Laryngological, Rhinological and Otological Society, Inc. Endoscopic Hydroxyapatite Augmentation for Patulous Eustachian Tube Reza Vaezeafshar, MD; Justin H. Turner, MD, PhD; Gang Li, MD, PhD; Peter H. Hwang, MD Objectives/Hypothesis: To evaluate the safety and efficacy of endoscopic calcium hydroxyapatite injection in patients with patulous Eustachian tube. Study Design: Retrospective case series. Methods: Fourteen patients diagnosed with patulous Eustachian tube (PET) underwent endoscopic hydroxyapatite injection under general anesthesia. All patients had at least two of three major PET symptoms including voice autophony, breathing autophony, or aural fullness/pressure. Patients were evaluated postoperatively with nasal endoscopy and a symptom questionnaire. Results: Endoscopic Eustachian tube injection was performed in a total of 23 sides in 14 patients with an average volume of 2.1 cc injected per side. Mean follow-up was 17.5 months. The most common symptoms reported preoperatively were voice autophony (96%), breathing autophony (91%), and ear fullness (83%). A complete or significant response to treatment was noted in 13/22 sides with voice autophony (59%), 12/21 sides with breathing autophony (57%), and 12/19 sides with ear fullness (63%). All complete or significant symptom improvements remained durable through the entirety of the follow-up period. Four sides that had temporary or no improvement with treatment underwent repeat injection but did not achieve additional improvement. No intraoperative or postoperative complications were observed. Conclusion: Endoscopic hydroxyapatite injection of the Eustachian tube is a minimally invasive procedure that provided significant or complete relief of autophony and ear fullness in 57% to 63% of sides treated. The procedure is well tolerated and can be performed safely under endoscopic visualization. Hydroxyapatite injection may be a satisfactory alternative to more invasive treatments for PET. Key Words: Patulous Eustachian tube, hydroxyapatite, injection, augmentation, Eustachian tube. Level of Evidence: 4. Laryngoscope, 124:62 66, 2014 INTRODUCTION The Eustachian tube is normally a closed structure that opens temporarily during yawning and swallowing, typically for less than one-half second. 1 It has several functions, including equalizing middle ear pressure, maintaining middle ear gas exchange, and protecting the ear from nasopharyngeal secretions. Patulous Eustachian tube, first described by Schwartz in 1864, 2 typically presents with vocal autophony, breathing autophony, and aural fullness; 3 other symptoms such as tinnitus, hearing loss, and vertigo are reported less commonly. 4 6 Several conditions are thought to predispose to PET, including weight loss and pregnancy; 7,8 however, up to one-third of cases have no readily identifiable cause. Postulated etiologies of PET include From the Department of Otolaryngology Head and Neck Surgery (R.V., G.L., P.H.H.), Stanford University School of Medicine, Stanford, California; and the Department of Otolaryngology Head and Neck Surgery (J.H.T.), Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A Editor s Note: This Manuscript was accepted for publication May 21, The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Peter H. Hwang, MD, Department of Otolaryngology Head and Neck Surgery, Stanford University School of Medicine, 801 Welch Road, Stanford, CA phwang@ohns.stanford.edu DOI: /lary atrophy of peritubal fat tissue (Ostmann s fat pad), dysfunctional contraction of the peritubal musculature, and loss of venous tone of the pterygoid venous plexus. 9 Although symptoms are intermittent in many cases, patients with severe PET symptoms often experience interference with activities of daily living and impaired quality of life. Diagnosis of PET is primarily based on history, but this can be supported by otoscopic findings of hypermobility of the tympanic membrane with regular or forced nasal breathing. Tympanometry may also indicate tympanic membrane hypermobility. On nasopharyngeal endoscopy, a concave longitudinal defect will often be seen along the anterolateral wall of the tubal valve. 10 There is currently no standard treatment for PET. A variety of nonsurgical treatments have been described with only temporary effectiveness, including orally administered tranquilizers, topical estrogen drops, insufflation of salicylic acid-boric acid powder, and mucus thickening agents. 5,11 13 Surgical procedures have in general shown variable results. These procedures include myringotomy with ventilation tube placement, 11,13,14 cauterization of the ET orifice 15 or lumen, 16 fat grafting, 17 transposition of the tensor veli palatini muscle, 18 endoscopic ligation of the ET orifice, 19 transtympanic plug insertion, 20 tubal reconstruction with autologous cartilage and human acellular dermis 62

2 Fig. 1. Nasopharyngeal endoscopic view of the right Eustachian tube orifice. A) Preoperative image showing an atrophic and abnormally open ET. B) Injection of hydroxyapatite is performed at three separate locations around the torus tubarius at 3, 9, and 12 o clock positions (white arrows). C) Intraoperative image of the same patient after 2 cc hydroxyapatite injection of the torus tubarius. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.] implantation, 10 and the curvature inversion technique. 21 In addition, different injectable materials have been used to augment the ET orifice, including paraffin, 22 absorbable gelatin, 23 and polytetrafluoroethylene (Teflon paste). 3 Most recently, injection of autologous fat 17 or cartilage 24 has been described in case reports, with some apparent initial success. As the primary mineral constituent of bones and teeth, hydroxyapatite is generally considered to be biocompatible and has been used for more than 20 years in medicine. Hydroxyapatite has been approved by the Food and Drug Administration for vocal fold augmentation in the form of synthetic calcium hydroxyl apatite microspheres suspended in a gel; this form of hydroxyapatite was used for ET augmentation in this study. The use of hydroxyapatite injection for PET was first reported by Poe in 2007 as a salvage procedure for a single patient with persistent symptoms after peritubal cartilage implantation. 10 Asubsequent case report likewise described the successful use of hydroxyapatite injection for recalcitrant otorrhea due to a patulous Eustachian tube. 25 In the current study, we report our outcomes of a case series of hydroxyapatite injections for PET in 14 patients, with a total of 23 treated sides. MATERIALS AND METHODS This study was performed with approval from the Stanford University Institutional Review Board. A retrospective review of patients who underwent ET injection with hydroxyapatite between December 2009 and March 2012 was performed. Patients were included in the study if they were diagnosed with PET and underwent hydroxyapatite injection with at least 6 months of postoperative follow-up at the time of the review, and if adequate follow-up documentation was available. Patients were excluded if they could not be reached via telephone to assess postoperative symptom improvement, or if adequate follow-up documentation was not available. Diagnosis of PET required the presence of at least two PET-related symptoms: voice autophony, breathing autophony, and/or ear fullness/ pressure. Diagnosis was confirmed by examination with otoscopic findings of tympanic membrane hypermobility upon regular or forced nasal breathing and nasal endoscopic findings of torus tubarius atrophy. Other parameters recorded included patient demographics, comorbid medical conditions, previous surgical procedures, intraoperative findings, and intraoperative or postoperative complications. Postoperative symptom improvement was assessed via telephone using a PET-specific questionnaire for the following symptoms: voice autophony, breathing autophony, ear fullness, ear pain, vertigo, and ear popping/clicking. The scoring system described by Poe 10 was adapted to score postoperative outcomes as 1) complete relief; 2) significant improvement, satisfied; 3) significant improvement, dissatisfied; 4) unchanged; or 5) worse. Surgical Technique ET injection was performed as an outpatient procedure under general anesthesia using an endoscopic endonasal approach. A 1 cc syringe loaded with Radiesse voice paste (Merz Aesthetics, Inc.; Franksville, WI) was attached to a 22-gauge spinal needle bent 45 degrees at 1 cm from the distal tip. The needle was placed into the submucosal space of the torus tubarius, parallel to the lumen of the Eustachian tube and directed toward the isthmus. Injection of hydroxyapatite was performed at three separate locations around the torus tubarius at the 3, 9, and 12 o clock positions (Fig. 1). At each subsite, hydroxyapatite was injected until no additional material could be placed without reflux of the injected material. Adequacy of injection was assessed by palpating the Eustachian tube orifice and torus tubarius with a maxillary seeker probe. Patients were discharged on the same day of surgery. Preoperative, site of injections, and intraoperative postinjection views of the Eustachian tube orifice are shown in Figure 1. RESULTS Fourteen patients had 23 ears treated for patulous Eustachian tube (5 unilateral, 9 bilateral). A total of 27 augmentation procedures were performed; two patients underwent a repeat bilateral augmentation for persistence of symptoms after the first treatment. There were four men and 10 women, with a mean age of 53 years (range 14 83). The most common symptoms reported preoperatively were voice autophony (96%), breathing autophony (91%), and aural fullness (82%). A summary of patient-reported symptoms is presented in Table I. The preoperative duration of symptoms ranged from 6 to 40 months, with a mean of 15 months. Preoperative comorbidities based on history are presented in Table II. The most commonly associated comorbidity was 63

3 TABLE I. Prevalence of PET Symptoms (n 5 23 sides, 14 patients). Symptoms Number of Sides Affected * Percentage Voice autophony 22/23 96% Breathing autophony 21/23 91% Aural fullness 19/23 83% Ear popping/clicking 16/23 69% Ear pain 10/23 43% Vertigo 4/14 28% *Symptoms reported separately for each affected side, except vertigo. PET 5 patulous Eustachian tube. recent weight loss, which was observed in seven of 14 patients. Median percentage weight loss in these seven patients was 21% of body weight (absolute range lbs.). Five patients had undergone prior surgical treatment for PET without improvement: four patients had undergone previous ventilation tube placement, and one patient had undergone electrocautery of the ET orifice. One patient was concurrently diagnosed with palatal myoclonus and received botulinum toxin injections prior to ET injection. The botulinum injections improved ear clicking symptoms but did not improve autophony; therefore, the patient proceeded to ET injection. Four patients had a history of endoscopic sinus surgery for chronic rhinosinusitis prior to experiencing PET symptoms. Patients received an average injection volume of 2.1 cc per side (range ). No intraoperative or postoperative complications were observed. The mean follow-up period was 17.5 months (range 9 36 months). No patients were lost to follow-up. Patient outcomes, based on the Poe scoring system, are detailed in Table III and IV. The three symptoms that were most responsive to ET injection were voice autophony, breathing autophony, and ear fullness with complete or significant improvement noted in 57% to 63% of patients, and with sustained symptomatic improvement noted throughout the follow-up period. For voice autophony, the most common symptom, 9/22 treated sides (41%) did not show significant improvement. Of these nine nonresponding sides, four had a temporary improvement lasting less than 2 months, while five sides had either no improvement or improvement lasting less than 1 week. Four sides (two with initial temporary improvement, two with no improvement after injection) TABLE II. Comorbid Medical Conditions in PET Patients (N 5 14 Patients). Medical Condition No. Percentage Weight loss 7 50% Hypothyroidism 2 14% Wegener s granulomatosis 1 7% Palatal myoclonus 1 7% Hemifacial microsomia 1 7% PET 5 patulous Eustachian tube. TABLE III. Final Postoperative Outcomes by Symptom After Eustachian Tube Injection Procedure. Rate of Improvement Complete Significant, Satisfied Significant, Dissatisfied Unchanged Worse Voice 27% 23% 9% 41% 0 autophony Breathing 28% 10% 19% 43% 0 autophony Ear fullness 21% 16% 26% 37% 0 Ear popping/ 12% 31% 7% 50% 0 clicking Ear pain 20% 30% 0 50% 0 Vertigo 0 50% 0 50% 0 underwent repeated injection; however, again no appreciable long-term improvement in symptoms was observed. Overall rates of patient satisfaction generally lagged behind the rates of symptomatic improvement. Whereas the range of rates of complete/significant symptom improvement was 50% to 63%, the range of satisfaction rates was 36% to 50% (Table IV). No patients reported worsening symptoms as a result of the ET injection. DISCUSSION In the current study we have demonstrated the feasibility of Eustachian tube augmentation with injectable hydroxyapatite, achieving moderately successful rates of long-term improvement. In comparison with other recently introduced procedures for patulous Eustachian tube, such as patulous Eustachian tube reconstruction (PETR) 10 and the curvature inversion technique (CIT), 21 hydroxyapatite augmentation is less invasive and has the potential for reversibility (due to natural resorption TABLE IV. Final Improvement Rate Versus Satisfaction Rate After Eustachian Tube Injection (23 sides total, 19 sides injected once; 4 sides injected twice * ). Symptoms Total Number of Sides With Symptom (out of 23 total sides) Total Improvement Rate (score of 1, 2, or 3) Total Satisfaction Rate (score of 1or2) Voice autophony 22 59% 50% Breathing autophony 21 57% 38% Ear fullness 19 63% 36% Ear popping/clicking 16 50% 43% Ear pain 10 50% 50% Vertigo 4 50% 50% Scores (adapted from Poe): 1 5 complete relief; 2 5 significant improvement, satisfied; 3 5 significant improvement, dissatisfied; 4 5 unchanged; 5 5worse. *4 sides (2 patients) were reinjected after having temporary or no improvement (score 5 4). All 4 sides showed no additional improvement after the 2nd Eustachian tube injection. 64

4 of the injected material). The surgical technique for PETR involves raising a submucosal flap along the anterolateral wall of the tubal lumen up to the level of the valve and filling the pocket with autologous cartilage or human acellular dermis. 10 The objective of PETR is to restore the convexity and competence of the mucosal luminal valve. Poe reported that approximately 50% of patients with PETR experienced complete relief or significant improvement with satisfaction. 10 The CIT uses a KTP laser to crosshatch the medial and lateral laminae of the tube in order to modify curvature and alter the elasticity of the posterior cushion. 21 It has been postulated that this technique can promote full closure of the patulous gap without interfering with the tube s muscular activity. A success rate of 81% was reported by Yanez et al. 21 A more recent report by Rotenberg et al. also highlighted good results using a composite closure method using cautery and fat plugging. 26 We achieved a rate of improvement with satisfaction by ET injection that was comparable to that of Poe s PETR series. A failure analysis in our series of nonresponders is inconclusive, primarily because the site of therapeutic interest is not readily examined. The cartilaginous portion of the adult ET has a valvular function at the midportion segment, with the mucosal surfaces in this segment maintaining closure in the resting position and generally requiring muscular activity of the tensor veli palatini for dilation. Although most PET patients demonstrate a lack of lateral cartilaginous lamina and a lack of soft tissue volume in the anterolateral wall, others may develop symptoms from hypertonic basal tone of the tensor veli palatini muscle, which results in reduced movement and increased dilatory activity. 27,28 While it is possible that our augmentation failures were due to inadequate replacement of lost tissue volume, it is also possible that some patients had a primary tensor muscle dysfunction that could not be overcome by soft tissue augmentation. Our study group was too small to identify clear predictors for success with augmentation. One patient in the current series who did not respond to injection was also suspected of having superior semicircular canal dehiscence (SSCD). Although CT imaging did not clearly identify a dehiscence, vestibularevoked myogenic potential (VEMP) testing was consistent with the diagnosis. This result suggests that this patient may not have had PET in the first place, and highlights the overlap of symptoms between these two diagnoses and the potential difficulty of making a definitive diagnosis. 10,29 Temporal bone CT and/or VEMP testing is therefore advised to rule out SSCD in suspicious cases prior to the consideration of ET augmentation. We did not routinely assess patients with audiogram or tympanometry after surgery. However, no patients experienced new-onset hearing loss or aural fullness after the injection, and none developed a serous effusion postoperatively. Unlike some other ET occlusion procedures, hydroxyapatite injection does not appear to require placement of a ventilation tube, based on our preliminary experience. While a previous animal study showed that injection of as little as 0.5 cc of Teflon into the posterior cushion could produce a serous otitis media, 30 this result may have been related to the proinflammatory characteristics of Teflon. In contrast to Teflon, hydroxyapatite injection appears to be well tolerated and does not appear to cause significant local inflammation. A serious historical complication of ET injection that was described in the nonendoscopic surgical era was the inadvertent injection of filler material (Teflon) into the internal carotid artery. 3 The gravity of this complication halted progress in the historical development of ET injection techniques. Although the circumstances surrounding this catastrophic complication were not well described, one can surmise that poor visualization in the deep recess of the nasal cavity contributed to the malpositioning of injected material. With the clear illuminated views currently afforded by endoscopic techniques, injection of the Eustachian tube can be performed with a high level of precision and control. Still, it is our routine to inform patients of the very small potential risk of the intravascular injection of hydroxyapatite. Relative weaknesses of the current study include its retrospective study design, which is subject to recall bias, small cohort size, and the use of nonvalidated symptom measures. The nonvalidated scoring system adapted from Poe was chosen for this study in order to enable more direct outcome comparisons with the surgical techniques previously published by Poe and others. 10 Future studies would benefit from the development and implementation of disease-specific validated outcomes measures for PET. Nevertheless, this series represents one of the larger series of hydroxyapatite injection in patulous Eustachian tube patients. Prospective studies are currently underway to gauge the long-term efficacy of this technique. With appropriate preoperative counseling, hydroxyapatite injection may be considered as a first-line surgical treatment for patulous Eustachian tube. CONCLUSION Hydroxyapatite injection appears to be a promising option for treating PET. 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