Comprehensive surgical management for lower cranial nerve palsies, including hypopharyngeal pharyngoplasty with ePTFE mesh, based on detailed swallowing CT evaluation: a case report

Comprehensive surgical management for lower cranial nerve palsies, including hypopharyngeal pharyngoplasty with ePTFE mesh, based on detailed swallowing CT evaluation: a case report | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Comprehensive surgical management for lower cranial nerve palsies, including hypopharyngeal pharyngoplasty with ePTFE mesh, based on detailed swallowing CT evaluation: a case report Rumi Ueha, Maria Angela Dealino, Kaoru Yamakawa, Miguel Limbert Ramos, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6750134/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Introduction Lower cranial nerve (LCN) palsy may develop following tumor resection in the cerebellopontine angle or jugular foramen, often resulting in dysphagia and dysphonia. Although many patients recover with rehabilitation, some exhibit persistent functional deficits. In such cases, detailed pathophysiologic evaluation can guide surgical intervention to improve outcomes. Case Presentation A 77-year-old woman presented with severe dysphagia and hoarseness after resection of a right cerebellopontine angle meningioma, which caused glossopharyngeal, vagus, and accessory nerve palsies. Despite initial recovery, she experienced repeated aspiration pneumonia and malnutrition. Comprehensive reassessment using high-resolution manometry and dynamic swallowing computed tomography revealed right-sided velopharyngeal insufficiency, pharyngeal constrictor dysfunction, vocal fold paralysis with fixation at the paramedian position, and impaired upper esophageal sphincter (UES) relaxation. A tailored multi-procedural surgical approach was adopted, including right pharyngeal flap, right hypopharyngeal pharyngoplasty with expanded polytetrafluoroethylene mesh reinforcement, right cricopharyngeal myotomy, arytenoid adduction, and tracheostomy. Postoperatively, swallowing and phonation improved markedly. The patient resumed oral intake, and tracheostoma closure was achieved by postoperative day (POD) 25. By POD 32, maximum phonation time improved sevenfold, and she was discharged on a regular diet. Conclusions Intractable dysphagia due to complex LCN dysfunction requires individualized surgical strategies. Advanced diagnostic modalities, including dynamic swallowing CT and HRM, enable precise localization of dysfunction and guide effective, function-preserving surgical interventions that can significantly improve quality of life. Lower cranial nerve palsies swallowing improvement surgery dysphagia swallowing CT virtual reality high-resolution pharyngeal manometry Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Lower cranial nerve (LCN) palsied may develop after tumor resection involving the cerebellopontine angle or jugular foramen. While the degree of impairment differs among individuals, dysphagia and dysphonia are the predominant clinical manifestations. In more severe cases, interventions such as tracheostomy or tube feeding may be necessary [ 1 – 3 ]. Although most patients improve within several months, a subset continues to suffer from severe dysphagia or dysphonia despite dedicated rehabilitation [ 3 ]. When conservative management is ineffective, thorough evaluation of the LCN-related pathology may support the use of surgical intervention to improve outcomes. However, few reports have addressed the surgical approach to these impairments from a practical standpoint. This case report describes the application of advanced diagnostic tools, such as dynamic swallowing computed tomography (CT), alongside standard assessments to precisely evaluate the site and nature of dysphagia-related dysfunctions. A personalized surgical strategy was developed accordingly, leading to significant improvements in the patient’s quality of life (QOL). Of particular note is the successful use of expanded polytetrafluoroethylene (ePTFE) for targeted reinforcement of the hypopharyngeal wall in managing unilateral pharyngeal constrictor dysfunction. Case presentation A 77-year-old woman presented to our institution with breathy hoarseness and dysphagia. Fiberoptic laryngoscopy demonstrated right vocal fold paralysis with fixation at the paramedian position. Further detailed examination also revealed right-sided velopharyngeal insufficiency, right pharyngeal paralysis, decreased right pharyngolaryngeal sensation, and marked atrophy of the right sternocleidomastoid muscle, corresponding to multiple ipsilateral LCN impairments (glossopharyngeal nerve, vagus nerve, and accessory nerve). At that point, her oral intake status was scored as 6 on the Functional Oral Intake Scale (FOIS). Subsequent contrast-enhanced magnetic resonance imaging of the brain identified a tumor in the right cerebellopontine angle as the causative lesion (Fig. 1A). Most of the tumor was surgically removed by the neurosurgery team, and histopathological examination confirmed the diagnosis of fibrous meningioma. Following surgery, her swallowing function deteriorated, necessitating placement of a gastrostomy tube for nutritional support. Swallowing rehabilitation commenced on postoperative day (POD) 5. At one-month post-surgery, the patient's swallowing function had improved to the point where she was able to consume uniformly textured foods and thickened liquids (FOIS 5), while assuming a right-neck rotation posture for swallowing, which allowed bolus passage through the left pharynx. Consequently, the nasogastric tube was removed, and the patient was discharged. Despite initial improvement, she suffered multiple episodes of aspiration pneumonia, requiring treatment with antibiotics. At six months postoperatively, she exhibited a 10-kg weight loss and persistent severe dysphagia and hoarseness, prompting her to return to our institution with a request for surgical treatment. Her oral intake was at FOIS level 5 at this stage, but with a very limited intake. On re-assessment, the patient showed no signs of tongue atrophy or impaired tongue movement. However, marked atrophy of the left sternocleidomastoid muscle and absence of the right pharyngeal reflex were noted. During phonation, the curtain sign was observed, characterized by retraction of the posterior pharyngeal wall to the left, and laryngeal elevation was more pronounced on the left side. The patient’s maximum phonation time (MPT) was measured at 2.3 seconds, and her mean flow rate (MFR) was 725.9 mL/s. Flexible endoscopic examination demonstrated right-sided velopharyngeal insufficiency during both phonation and swallowing, with nasal regurgitation of saliva during swallowing (Fig. 1B). In addition, a large amount of saliva pooling was observed in the vallecula and bilateral piriform sinuses, along with salivary penetration into the larynx (Fig. 1C), paramedian fixation of the right vocal fold (Fig. 1D), and impaired right-sided laryngeal sensation. Nevertheless, the patient was generally able to expectorate accumulated saliva spontaneously. Videofluoroscopic swallowing study (VFSS, Supplemental movie 1) showed immediate regurgitation of contrast material into the nasal cavity before reaching the hypopharynx on the first swallow for 3 mL of moderately thickened contrast agent (200 mPa·s) (Fig. 1E). After contrast medium had entered the hypopharynx, a subsequent swallow resulted in some contrast material passing through the esophagus, but partially entering the larynx as well (Fig. 1F). Although the cough reflex was elicited, contrast agent that had entered the airway was not sufficiently cleared. Maneuvers such as left and right neck rotation did not improve swallowing in terms of the degree of aspiration or esophageal passage. As observed throughout the entire length of the esophagus, there was immediate esophageal relaxation following passage of the contrast agent, indicating impaired esophageal motility. Comprehensive investigation of the background pathophysiology and three-dimensional dynamics of swallowing dysfunction High-resolution manometry (HRM) was conducted to evaluate the pressure dynamics from the velopharynx to the cervical esophagus during swallowing. The pharyngeal contraction pressure between the velopharynx and mesopharynx was reduced, and there was no relaxation of the upper esophageal sphincter (UES) during swallowing. Furthermore, abnormal pressure was observed in the hypopharynx, 2 cm above the UES during swallowing. No contractile pressure was observed in the cervical esophagus following swallowing (Fig. 2A). To further investigate the dynamics of swallowing in three dimensions, dynamic swallowing computed tomography (CT) was performed (Supplemental movie 2). At the nasopharyngeal level, right-sided velopharyngeal insufficiency was noted, and the anteroposterior distance of the right velopharynx was measured as 14.0 mm at rest via a virtual reality (VR) system (Fig. 2B). During swallowing, the contrast agent regurgitated from the oropharynx into the nasal cavity (Fig. 2C). Pharyngeal contraction on the right was inadequate, and pressure from pharyngeal contraction on the contralateral side displaced the right hypopharynx laterally. Normally, the hypopharynx contracts at maximum laryngeal elevation, and right hypopharyngeal volume typically reduces to approximately 0 mL. However, in this patient, right hypopharyngeal volume was 6.80 mL at rest (Fig. 2D) and 2.70 mL at maximum laryngeal elevation (Fig. 2E). Thus, although present, contraction of the right hypopharynx was insufficient, and pressure from pharyngeal contraction on the left caused lateral displacement of the right hypopharynx. Based on these findings, a diagnosis of further deterioration of complex lower cranial nerve dysfunction (cranial nerves IX-XI) in a patient with primary brain tumor who had undergone neurosurgical intervention was made. Tailored surgical management for patients with complex pathophysiology Given the repeated episodes of aspiration pneumonia and the lack of significant improvement at six months following surgery, it was determined that further improvement with swallowing rehabilitation alone was unlikely. Thus, surgical intervention was deemed necessary. The strategic approach in selecting the most appropriate procedure from the various swallowing improvement surgeries that address distinct functional impairments is shown in Fig. 3. Accordingly, the following procedures were performed: right pharyngeal flap was constructed for right-sided velopharyngeal insufficiency, right hypopharyngeal pharyngoplasty with pharyngeal wall reinforcement for reduced pharyngeal contraction, right cricopharyngeal myotomy (CPM) for impaired UES passage, right arytenoid adduction for right vocal cord paralysis, and tracheostomy to establish a suction route to manage silent aspiration. Before arytenoid adduction, the thyropharyngeal muscle was separated from the thyroid cartilage and preserved laterally. A portion of the lateral thyroid ala measuring 1-cm was excised. After arytenoid adduction, hypopharyngeal pharyngoplasty was performed by suturing the hypopharyngeal mucosa to the thyroid cartilage anteriorly, followed by suturing of the thyropharyngeal muscle to the anterior thyroid cartilage for reinforcement (Fig. 4A). A trimmed 0.4-mm-thick expanded polytetrafluoroethylene (ePTFE, Gore-Tex ® ) sheet was additionally applied to bolster the thyropharyngeal muscle (Fig. 4B). With regard to selecting which side to perform CPM, given the patient's esophageal motility disorder and the associated risk of pharyngoesophageal reflux, CPM was performed exclusively on the right. If UES passage continues to prove inadequate postoperatively, the option of further intervening on the left side remains. Despite the presence of reduced laryngeal elevation, laryngeal suspension was deferred, as impairment was limited to one side. Additional procedures may be offered depending on the postoperative course. Postoperatively, a cuffed tracheostomy tube (inner diameter 7.0 mm, outer diameter (OD) 9.6 mm) was inserted through the tracheostoma. Nutritional support was provided through total parenteral nutrition administered via a peripherally inserted central catheter. Postoperative clinical course and functional outcomes Mucosal swelling around the right arytenoid and hypopharynx developed postoperatively but had improved by POD 10. On POD 11, partial suture dehiscence of the pharyngeal flap occurred and repair was done by placing three additional sutures (3-0 synthetic, absorbable monofilament sutures). The tracheostomy tube was exchanged for a cuffed speech-type tracheostomy tube on POD 13, and voice training was initiated. By POD 18, the frequency of tracheal suctioning had decreased. VFSS demonstrated that 5 mL of mildly thickened liquid (100 mPa·s) flowed into the pharynx without nasal regurgitation (Supplemental movie 3). There was absence of aspiration as contrast agent passed through the UES (predominantly on the right side) while the patient adapted the chin-tuck posture (Fig. 5A, 5B). Jelly-based oral intake training was then started on POD 18. In addition, the tracheostomy tube was exchanged for a smaller tracheal opening retainer (OD 9.0 mm, length 14.0 mm). The patient progressed to taking pureed meals on POD 19 and to diced soft food the day after, completing each meal in about 60 minutes. As no further tracheal suctioning was needed by POD 25, the tracheal opening retainer was removed and the tracheostoma was closed surgically. By POD 32, the pharyngeal mucosa was fully epithelialized, though the pharyngeal flap was not visible in the oral cavity (Fig. 5C). Flexible endoscopy demonstrated that the pharyngeal flap had formed on the right side of the nasopharynx (Fig. 5D), with no retrograde flow of saliva into the nasal cavity during swallowing (Fig. 5E). Pharyngeal saliva residue was markedly reduced, and there was complete glottic closure during phonation (Fig. 5F). MPT increased to 15.2 seconds, about seven times the preoperative value, and MFR improved significantly to 139.8 mL/s. Although abnormal pharyngeal pressure during swallowing was still observed in the hypopharyngeal region 2 cm cranial to the UES on HRM, velopharyngeal pressure was significantly increased, and UES relaxation during swallowing was satisfactory (Fig. 6A). Following the combined swallowing improvement surgeries, the patient showed marked amelioration of swallowing function and was discharged on POD 33. Three-dimensional dynamic swallowing CT performed three months postoperatively revealed that, at the level of the pharyngeal flap, the anteroposterior diameter of the right velopharynx at rest measured 6.9 cm, and the flap width was 7.2 mm (Fig. 6B). In addition, there was no nasal regurgitation of contrast agent during swallowing (Fig. 6C). The lateral hypopharyngeal wall was reinforced by the ePTFE sheet (Fig. 6D), and hypopharyngeal volume during swallowing had significantly decreased to 1.27 mL (Fig. 6E). At this point, the patient had regained the ability to consume both thin liquids and a regular diet, though some foods remained difficult to eat. Discussion Patients with LCN impairments typically present with multifaceted and severe disturbances in both swallowing function and voice, necessitating comprehensive assessment and multidisciplinary management [ 1 – 3 ]. The present case exhibited right-sided velopharyngeal insufficiency, pharyngeal and vocal fold paralysis, reduced laryngeal elevation, and impaired UES passage. Based on the identified deficits, we hypothesized the following: Achieving velopharyngeal closure during swallowing would help generate effective pressure to propel the bolus toward the esophagus. Reinforcement of the hypopharyngeal wall could enhance its resistance to contralateral contraction pressure, thus facilitating bolus propulsion. Facilitating UES opening through CPM would be expected to increase the amount of bolus passing into the esophagus. Additionally, medialization of the paralyzed vocal fold might enhance glottic closure during swallowing, thereby reducing the risk of aspiration. Therefore, to address the multiple impairments, we performed a single-stage combination of surgical procedures: right-sided lateral pharyngeal flap, CPM, hypopharyngeal wall reinforcement, arytenoid adduction, and tracheostomy. Predictably, bolus transit from the right hypopharynx into the esophagus was facilitated, resulting in a marked improvement in the patient's swallowing function, and consequently, her quality of life. Pharyngeal flap surgery is a widely accepted treatment for velopharyngeal insufficiency, with the median-focused flap being the conventional technique [ 4 ]. In this patient, unilateral pharyngeal paralysis warranted the use of a lateral pharyngeal flap to reinforce the weakened side [ 5 , 6 ]. Hypopharyngeal pharyngoplasty was developed to improve swallowing in patients with dysphagia caused by unilateral pharyngeal paralysis, often due to cranial nerve injuries or skull base surgery [ 7 , 8 ]. It focuses on reshaping the hypopharynx to reduce aspiration risk and enhance pharyngeal transit [ 9 ]. The procedure can be performed through the same surgical field as arytenoid adduction. It is often combined with medialization laryngoplasty and/or arytenoid adduction to address both pharyngeal and glottic insufficiencies [ 7 , 8 ]. Cricopharyngeal myotomy is not a standard component of hypopharyngeal pharyngoplasty, but it may be incorporated when significant cricopharyngeal dysfunction is identified [ 8 ]. Reinforcement of the pharyngeal constrictor muscles with polypropylene mesh during hypopharyngeal pharyngoplasty has been reported to reduce postoperative pharyngeal dilatation and pooling in the pyriform sinus [ 10 ]. To the best of our knowledge, this is the first case to report the use of ePTFE mesh for this purpose. The said material, characterized by micropores smaller than 10 µm, is widely used in vascular and cardiac surgeries, offering superior flexibility and moldability compared to polypropylene mesh [ 11 ]. Despite its relative softness, ePTFE mesh provided sufficient reinforcement to the weakened pharyngeal wall in this patient. Recently, with advances in diagnostic technology, HRM, swallowing CT, and swallowing VR have emerged as powerful tools for the comprehensive evaluation of swallowing dysfunction [ 9 , 12 – 19 ]. HRM is highly effective for assessing the pathophysiology of velopharyngeal insufficiency and UES passage disorders. Even when VFSS suggests impaired UES passage that may imply cricopharyngeal dysfunction, HRM enables direct evaluation of cricopharyngeal muscle relaxation. Swallowing CT and VR imaging provide superior insights into dynamic three-dimensional structural changes during swallowing [ 17 , 20 , 21 ]. These valuable modalities are expected to be adopted more widely for the evaluation of dysphagia pathophysiology. Conclusion In the present case, comprehensive multimodal swallowing assessment, including laryngoscopy, VFSS, HRM, and swallowing CT allowed for precise evaluation of dysphagia. Based on the detailed pathophysiological findings, appropriate surgical interventions were performed, resulting in an excellent postoperative course. Reinforcement of the hypopharyngeal wall with ePTFE mesh contributed to the favorable outcome. Declarations Acknowledgments We gratefully acknowledge Ms. Mika Imamura for her kind cooperation in development of a program for measurement in three-dimensional reconstruction images of swallowing CT. Fundings: None Conflicts of interest/Competing interests: On behalf of all the authors, the corresponding author states that there are no conflicts of interest. Ethics: This case report was approved by the Ethics Committee of the University of Tokyo (No. 2487, 2022179NI). Written consent for publication: Written informed consent was obtained from the patient. Availability of datal: Data are available on a reasonable request. Author contributions: RU: conceived a treatment strategy, performed swallowing CT and VR, contributed to patient care, drew the figures, and drafted the work. MAD: contributed to patient care, reviewed and edited the manuscript. KY: contributed to patient care and reviewed the manuscript. MLR: contributed to patient care, reviewed and edited the manuscript. MT: performed swallowing CT and reviewed the manuscript. HK: contributed to patient care and reviewed the manuscript. AK: contributed to patient care and reviewed the manuscript. TG: contributed to patient care and reviewed the manuscript. KK: contributed to patient care and critically revised the work. All authors reviewed and approved the final version of the manuscript for publication. References Peterson KL, Fenn J: Treatment of dysphagia and dysphonia following skull base surgery. Otolaryngol Clin North Am 2005, 38(4):809-817, xi. Finsterer J, Grisold W: Disorders of the lower cranial nerves. J Neurosci Rural Pract 2015, 6(3):377-391. Niu Y, Chen C, Jin X, Huo H, Cui T, Wang J: Management of Severe Dysphonia and Dysphagia Following Lateral Skull Base Surgery. J Voice 2024. Gart MS, Gosain AK: Surgical management of velopharyngeal insufficiency. Clin Plast Surg 2014, 41(2):253-270. Abdel-Aziz M, Rashed M, Naguib N, Shawky A: Lateralization of the Pharyngeal Flap for Treatment of Lateral Velopharyngeal Gap. J Craniofac Surg 2016, 27(1):101-104. 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Diver EM, Regan J: Use of Pharyngeal High-Resolution Manometry to Evaluate Dysphagia in Adults with Motor Neurone Disease: A Scoping Review. Dysphagia 2022, 37(6):1697-1714. Ueha R, Koyama M, Seto A, Sato T, Goto T, Orimo K, Mitsui J, Yamasoba T: Esophageal Dysmotility in Multiple System Atrophy: A Retrospective Cross-Sectional Study. J Clin Med 2024, 13(17). Katsuno T, Ueha R, Nanjo K, Matsuda K, Miura C, Sato T, Goto T, Kondo K: Clinical Conundrum: Swallowing Virtual Reality as a Novel Diagnostic Tool for Severe Dysphagia after Deep Neck Infection. Dysphagia 2025, 40(1):305-309. Ueha R, Dealino MA, Koyama M, Yamakawa K, Matsumoto N, Sato T, Goto T, Mizukami A, Kondo K: Improved Pharyngeal Contraction and Oral Intake Status After Modified Central-Part Laryngectomy for Late-Stage ALS. Otolaryngol Head Neck Surg 2025. Cotaoco C, Goto T, Koyama M, Sato T, Kondo K, Ueha R: Severe Dysphagia in a Patient with Wallenberg Syndrome and Killian Jamieson Diverticulum: A Case Report. SN Comprehensive Clinical Medicine 2024, 6(1):81. Suto A, Ueha R, Ogura T, Maeda E, Tatebayashi M, Shimada D, Koyama M, Sato T, Goto T, Yamauchi A et al : Swallowing computed tomography and virtual reality as novel imaging modalities for the diagnosis of clicking larynx: Two case reports. Auris Nasus Larynx 2023, 50(3):468-472. Inamoto Y, Ueha R, Gonzalez-Fernandez M: Emerging Dysphagia Technologies: Swallowing CT. Current Otorhinolaryngology Reports 2023, 11(2):154-160. Additional Declarations No competing interests reported. Supplementary Files Supplementalmovie1.mp4 Supplemental movie 1. Preoperative videofluoroscopic swallowing study. Supplementalmovie2.mp4 Supplemental movie 2. An anterior-posterior view of preoperative swallowing CT. Supplementalmovie3.mp4 Supplemental movie 3. Postoperative videofluoroscopic swallowing study. 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06:49:23","extension":"html","order_by":26,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":77041,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/94c5c41bdd585adec25e7dfb.html"},{"id":94762996,"identity":"fb5bd8c8-cffb-403f-8a10-97f808a14390","added_by":"auto","created_at":"2025-10-30 12:17:06","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":2541459,"visible":true,"origin":"","legend":"\u003cp\u003eClinical and radiological findings.\u003c/p\u003e\n\u003cp\u003eA: Magnetic resonance imaging showing an enhancing tumor in the right cerebellopontine angle (yellow arrowhead). B-D: Flexible endoscopy revealed nasal regurgitation of saliva (B), copious saliva pooling in the vallecula and piriform sinuses with laryngeal penetration (C), and paramedian fixation of the right vocal fold (D). E, F: Videofluoroscopic swallowing study with 3 mL of moderately thickened contrast agent showing nasal regurgitation of contrast agent (yellow arrow) before reaching the hypopharynx (E) and partial esophageal passage with laryngeal aspiration (yellow arrowhead) (F)\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/25e3cf2d50e3af7c3ab0f414.png"},{"id":94762995,"identity":"05841119-25d7-43b0-bf0b-793d06752111","added_by":"auto","created_at":"2025-10-30 12:17:06","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":2050151,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative high-resolution manometry (HRM), dynamic swallowing computed tomographic (CT) and virtual reality (VR) findings.\u003c/p\u003e\n\u003cp\u003eA: HRM showing reduced pharyngeal contraction pressure, absent upper esophageal sphincter (UES) relaxation, abnormal pressure above the UES, and no contractile activity in the cervical esophagus post-swallow. B: Swallowing VR showing the measured baseline anteroposterior distance at rest (14.0 mm). C-E: Dynamic swallowing CT showing nasal regurgitation of contrast agent during swallowing (yellow arrow) (C), and residual right hypopharyngeal volume (shown in yellow) of 6.80 mL at rest (D) and 2.70 mL at peak laryngeal elevation (E)\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/5908e756d5c5406836a4a8c5.png"},{"id":94762994,"identity":"ab46ed41-6b0c-45b6-a601-e053c373a863","added_by":"auto","created_at":"2025-10-30 12:17:06","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":222072,"visible":true,"origin":"","legend":"\u003cp\u003eStrategic approach for selection of swallowing improvement surgeries based on identified impairments\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/f378f1e9ec14528cb28b2e24.jpg"},{"id":94763004,"identity":"55200084-8217-4cf1-871a-8c237e7c30a6","added_by":"auto","created_at":"2025-10-30 12:17:06","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":3232050,"visible":true,"origin":"","legend":"\u003cp\u003eIntraoperative views.\u003c/p\u003e\n\u003cp\u003eA: Hypopharyngeal pharyngoplasty with anterior suspension of the hypopharyngeal mucosa, reinforced by suturing the thyropharyngeal muscle (star) to the thyroid cartilage. B: Additional reinforcement using 0.4-mm expanded polytetrafluoroethylene sheet (arrow) over the muscle\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/41d8d7a294289f78b90b3694.png"},{"id":94823642,"identity":"d16bd4dc-a68f-45e5-8016-415cb49ecca3","added_by":"auto","created_at":"2025-10-31 06:47:42","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":2659803,"visible":true,"origin":"","legend":"\u003cp\u003ePostoperative findings.\u003c/p\u003e\n\u003cp\u003eA, B: Videofluoroscopic swallowing study showing absence of nasal regurgitation and aspiration of contrast medium with effective upper esophageal sphincter passage (yellow arrow) while assuming the chin-tuck posture. C–F: Flexible endoscopy revealing epithelialized pharyngeal mucosa with the pharyngeal flap not visible intraorally (C), intact right pharyngeal flap (yellow arrowhead) formed in the nasopharynx (D), absence of retrograde salivary flow into the nasal cavity during swallowing (E), and reduced pharyngeal residue with complete glottic closure during phonation (F)\u003c/p\u003e","description":"","filename":"Figure5.png","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/16cf9939c419671d2b05d094.png"},{"id":94763002,"identity":"11ce6fe2-abd1-4194-8e9d-a502edf4a15e","added_by":"auto","created_at":"2025-10-30 12:17:06","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":2217834,"visible":true,"origin":"","legend":"\u003cp\u003ePostoperative high-resolution manometry (HRM), dynamic swallowing computed tomographic (CT) and virtual reality (VR) findings.\u003c/p\u003e\n\u003cp\u003eA: HRM showing increased velopharyngeal pressure and adequate upper esophageal sphincterrelaxation. B: Swallowing VR revealing decreased anteroposterior distance of the right velopharynx at rest (6.9-mm) and pharyngeal flap (star) with a width of 7.2 mm (shortest distance between dotted lines). C-E: Dynamic swallowing CT demonstrating absence of nasal regurgitation of contrast agent during swallowing (C), expanded polytetrafluoroethylene sheet reinforcing the lateral hypopharyngeal wall (yellow arrow) (D), and reduced hypopharyngeal volume during swallowing (shown in yellow, 1.27 mL) (E)\u003c/p\u003e","description":"","filename":"Figure6.png","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/582101b4a2856a4431e8f53b.png"},{"id":99307246,"identity":"a85cefc7-afa2-4a7e-9f44-4c12dbdef46d","added_by":"auto","created_at":"2025-12-31 16:05:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":12792711,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/4c539179-836d-46bd-9d6e-63eeb6934d26.pdf"},{"id":94763030,"identity":"170df907-c71a-47a1-831d-59abae8da9be","added_by":"auto","created_at":"2025-10-30 12:17:07","extension":"mp4","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":25185931,"visible":true,"origin":"","legend":"\u003cp\u003eSupplemental movie 1. Preoperative videofluoroscopic swallowing study.\u003c/p\u003e","description":"","filename":"Supplementalmovie1.mp4","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/314e8af2a017e1144d2e7fc4.mp4"},{"id":94762998,"identity":"fad31925-d2fe-4d17-914b-b77244efd4bf","added_by":"auto","created_at":"2025-10-30 12:17:06","extension":"mp4","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":770802,"visible":true,"origin":"","legend":"\u003cp\u003eSupplemental movie 2. An anterior-posterior view of preoperative swallowing CT.\u003c/p\u003e","description":"","filename":"Supplementalmovie2.mp4","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/4a463a2797f4b08b46f4678b.mp4"},{"id":94823756,"identity":"17012423-99cd-41f9-b3d1-5b9eaa18035c","added_by":"auto","created_at":"2025-10-31 06:47:57","extension":"mp4","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":14430304,"visible":true,"origin":"","legend":"\u003cp\u003eSupplemental movie 3. Postoperative videofluoroscopic swallowing study.\u003c/p\u003e","description":"","filename":"Supplementalmovie3.mp4","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/a4a943b1563a9f245b513689.mp4"},{"id":94824540,"identity":"326a4526-4b34-4a5e-9815-1c062952ac6f","added_by":"auto","created_at":"2025-10-31 06:49:05","extension":"pdf","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":677006,"visible":true,"origin":"","legend":"","description":"","filename":"CAREchecklistEnglish2013.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6750134/v1/14159668b758f58245c3bfe8.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comprehensive surgical management for lower cranial nerve palsies, including hypopharyngeal pharyngoplasty with ePTFE mesh, based on detailed swallowing CT evaluation: a case report","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLower cranial nerve (LCN) palsied may develop after tumor resection involving the cerebellopontine angle or jugular foramen. While the degree of impairment differs among individuals, dysphagia and dysphonia are the predominant clinical manifestations. In more severe cases, interventions such as tracheostomy or tube feeding may be necessary [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Although most patients improve within several months, a subset continues to suffer from severe dysphagia or dysphonia despite dedicated rehabilitation [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. When conservative management is ineffective, thorough evaluation of the LCN-related pathology may support the use of surgical intervention to improve outcomes. However, few reports have addressed the surgical approach to these impairments from a practical standpoint.\u003c/p\u003e\u003cp\u003eThis case report describes the application of advanced diagnostic tools, such as dynamic swallowing computed tomography (CT), alongside standard assessments to precisely evaluate the site and nature of dysphagia-related dysfunctions. A personalized surgical strategy was developed accordingly, leading to significant improvements in the patient\u0026rsquo;s quality of life (QOL). Of particular note is the successful use of expanded polytetrafluoroethylene (ePTFE) for targeted reinforcement of the hypopharyngeal wall in managing unilateral pharyngeal constrictor dysfunction.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 77-year-old woman presented to our institution with breathy hoarseness and dysphagia. Fiberoptic laryngoscopy demonstrated right vocal fold paralysis with fixation at the paramedian position. Further detailed examination also revealed right-sided velopharyngeal insufficiency, right pharyngeal paralysis, decreased right pharyngolaryngeal sensation, and marked atrophy of the right sternocleidomastoid muscle, corresponding to multiple ipsilateral LCN impairments (glossopharyngeal nerve, vagus nerve, and accessory nerve). At that point, her oral intake status was scored as 6 on the Functional Oral Intake Scale (FOIS). Subsequent contrast-enhanced magnetic resonance imaging of the brain identified a tumor in the right cerebellopontine angle as the causative lesion (Fig. 1A).\u003c/p\u003e\n\u003cp\u003eMost of the tumor was surgically removed by the neurosurgery team, and histopathological examination confirmed the diagnosis of fibrous meningioma. Following surgery, her swallowing function deteriorated, necessitating placement of a gastrostomy tube for nutritional support. Swallowing rehabilitation commenced on postoperative day (POD) 5. At one-month post-surgery, the patient\u0026apos;s swallowing function had improved to the point where she was able to consume uniformly textured foods and thickened liquids (FOIS 5), while assuming a right-neck rotation posture for swallowing, which allowed bolus passage through the left pharynx. Consequently, the nasogastric tube was removed, and the patient was discharged.\u003c/p\u003e\n\u003cp\u003eDespite initial improvement, she suffered multiple episodes of aspiration pneumonia, requiring treatment with antibiotics. At six months postoperatively, she exhibited a 10-kg weight loss and persistent severe dysphagia and hoarseness, prompting her to return to our institution with a request for surgical treatment. Her oral intake was at FOIS level 5 at this stage, but with a very limited intake.\u003c/p\u003e\n\u003cp\u003eOn re-assessment, the patient showed no signs of tongue atrophy or impaired tongue movement. However, marked atrophy of the left sternocleidomastoid muscle and absence of the right pharyngeal reflex were noted. During phonation, the curtain sign was observed, characterized by retraction of the posterior pharyngeal wall to the left, and laryngeal elevation was more pronounced on the left side. The patient\u0026rsquo;s maximum phonation time (MPT) was measured at 2.3 seconds, and her mean flow rate (MFR) was 725.9 mL/s. Flexible endoscopic examination demonstrated right-sided velopharyngeal insufficiency during both phonation and swallowing, with nasal regurgitation of saliva during swallowing (Fig. 1B). In addition, a large amount of saliva pooling was observed in the vallecula and bilateral piriform sinuses, along with salivary penetration into the larynx (Fig. 1C), paramedian fixation of the right vocal fold (Fig. 1D), and impaired right-sided laryngeal sensation. Nevertheless, the patient was generally able to expectorate accumulated saliva spontaneously. Videofluoroscopic swallowing study (VFSS, Supplemental movie 1) showed immediate regurgitation of contrast material into the nasal cavity before reaching the hypopharynx on the first swallow for 3 mL of moderately thickened contrast agent (200\u0026nbsp;mPa\u0026middot;s) (Fig. 1E). After contrast medium had entered the hypopharynx, a subsequent swallow resulted in some contrast material passing through the esophagus, but partially entering the larynx as well (Fig. 1F). Although the cough reflex was elicited, contrast agent that had entered the airway was not sufficiently cleared.\u0026nbsp;Maneuvers such as\u0026nbsp;left and right neck rotation did not improve swallowing in terms of the degree of aspiration or esophageal passage. As observed throughout the entire length of the esophagus, there was immediate esophageal relaxation following passage of the contrast agent, indicating impaired esophageal motility.\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eComprehensive investigation of the background pathophysiology and three-dimensional dynamics of swallowing dysfunction\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eHigh-resolution manometry (HRM) was conducted to evaluate the pressure dynamics from the velopharynx to the cervical esophagus during swallowing. The pharyngeal contraction pressure between the velopharynx and mesopharynx was reduced, and there was no relaxation of the upper esophageal sphincter (UES) during swallowing. Furthermore, abnormal pressure was observed in the hypopharynx, 2 cm above the UES during swallowing. No contractile pressure was observed in the cervical esophagus following swallowing (Fig. 2A).\u003c/p\u003e\n\u003cp\u003eTo further investigate the dynamics of swallowing in three dimensions, dynamic swallowing computed tomography (CT) was performed (Supplemental movie 2). At the nasopharyngeal level, right-sided velopharyngeal insufficiency was noted, and the anteroposterior distance of the right velopharynx was measured as 14.0 mm at rest via a virtual reality (VR) system (Fig. 2B). During swallowing, the contrast agent regurgitated from the oropharynx into the nasal cavity (Fig. 2C). Pharyngeal contraction on the right was inadequate, and pressure from pharyngeal contraction on the contralateral side displaced the right hypopharynx laterally. Normally, the hypopharynx contracts at maximum laryngeal elevation, and right hypopharyngeal volume typically reduces to approximately 0 mL. However, in this patient, right hypopharyngeal volume was 6.80 mL at rest (Fig. 2D) and 2.70 mL at maximum laryngeal elevation (Fig. 2E). Thus, although present, contraction of the right hypopharynx was insufficient, and pressure from pharyngeal contraction on the left caused lateral displacement of the right hypopharynx.\u003c/p\u003e\n\u003cp\u003eBased on these findings, a diagnosis of further deterioration of complex lower cranial nerve dysfunction (cranial nerves IX-XI) in a patient with primary brain tumor who had undergone neurosurgical intervention was made.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eTailored surgical management for patients with complex pathophysiology\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eGiven the repeated episodes of aspiration pneumonia and the lack of significant improvement at six months following surgery, it was determined that further improvement with swallowing rehabilitation alone was unlikely. Thus, surgical intervention was deemed necessary. The strategic approach in selecting the most appropriate procedure from the various swallowing improvement surgeries that address distinct functional impairments is shown in Fig. 3. Accordingly, the following procedures were performed: right pharyngeal flap was constructed for right-sided velopharyngeal insufficiency, right hypopharyngeal pharyngoplasty with pharyngeal wall reinforcement for reduced pharyngeal contraction, right cricopharyngeal myotomy (CPM) for impaired UES passage, right arytenoid adduction for right vocal cord paralysis, and tracheostomy to establish a suction route to manage silent aspiration. Before arytenoid adduction, the thyropharyngeal muscle was separated from the thyroid cartilage and preserved laterally. A portion of the lateral thyroid ala measuring 1-cm was excised. After arytenoid adduction, hypopharyngeal pharyngoplasty was performed by suturing the hypopharyngeal mucosa to the thyroid cartilage anteriorly, followed by suturing of the thyropharyngeal muscle to the anterior thyroid cartilage for reinforcement (Fig. 4A). A trimmed 0.4-mm-thick expanded polytetrafluoroethylene (ePTFE, Gore-Tex\u003csup\u003e\u0026reg;\u003c/sup\u003e) sheet was additionally applied to bolster the thyropharyngeal muscle (Fig. 4B).\u003c/p\u003e\n\u003cp\u003eWith regard to selecting which side to perform CPM, given the patient\u0026apos;s esophageal motility disorder and the associated risk of pharyngoesophageal reflux, CPM was performed exclusively on the right. If UES passage continues to prove inadequate postoperatively, the option of further intervening on the left side remains. Despite the presence of reduced laryngeal elevation, laryngeal suspension was deferred, as impairment was limited to one side. Additional procedures may be offered depending on the postoperative course. Postoperatively, a cuffed tracheostomy tube (inner diameter 7.0 mm, outer diameter (OD) 9.6 mm) was inserted through the tracheostoma. Nutritional support was provided through total parenteral nutrition administered via a peripherally inserted central catheter.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003ePostoperative\u003c/em\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003cem\u003eclinical course and functional outcomes\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eMucosal swelling around the right arytenoid and hypopharynx developed postoperatively but had improved by POD 10. On POD 11, partial suture dehiscence of the pharyngeal flap occurred and repair was done by placing three additional sutures (3-0 synthetic, absorbable monofilament sutures). The tracheostomy tube was exchanged for a cuffed speech-type tracheostomy tube on POD 13, and voice training was initiated. By POD 18, the frequency of tracheal suctioning had decreased. VFSS demonstrated that 5 mL of mildly thickened liquid (100 mPa\u0026middot;s) flowed into the pharynx without nasal regurgitation (Supplemental movie 3). There was absence of aspiration as contrast agent passed through the UES (predominantly on the right side) while the patient adapted the chin-tuck posture (Fig. 5A, 5B). Jelly-based oral intake training was then started on POD 18. In addition, the tracheostomy tube was exchanged for a smaller tracheal opening retainer (OD 9.0 mm, length 14.0 mm). The patient progressed to taking pureed meals on POD 19 and to diced soft food the day after, completing each meal in about 60 minutes. As no further tracheal suctioning was needed by POD 25, the tracheal opening retainer was removed and the tracheostoma was closed surgically.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eBy POD 32, the pharyngeal mucosa was fully epithelialized, though the pharyngeal flap was not visible in the oral cavity (Fig. 5C). Flexible endoscopy demonstrated that the pharyngeal flap had formed on the right side of the nasopharynx (Fig. 5D), with no retrograde flow of saliva into the nasal cavity during swallowing (Fig. 5E). Pharyngeal saliva residue was markedly reduced, and there was complete glottic closure during phonation (Fig. 5F). MPT increased to 15.2 seconds, about seven times the preoperative value, and MFR improved significantly to 139.8 mL/s. Although abnormal pharyngeal pressure during swallowing was still observed in the hypopharyngeal region 2 cm cranial to the UES on HRM, velopharyngeal pressure was significantly increased, and UES relaxation during swallowing was satisfactory (Fig. 6A). Following the combined swallowing improvement surgeries, the patient showed marked amelioration of swallowing function and was discharged on POD 33.\u003c/p\u003e\n\u003cp\u003eThree-dimensional dynamic swallowing CT performed three months postoperatively revealed that, at the level of the pharyngeal flap, the anteroposterior diameter of the right velopharynx at rest measured 6.9 cm, and the flap width was 7.2 mm (Fig. 6B). In addition, there was no nasal regurgitation of contrast agent during swallowing (Fig. 6C). The lateral hypopharyngeal wall was reinforced by the ePTFE sheet (Fig. 6D), and hypopharyngeal volume during swallowing had significantly decreased to 1.27 mL (Fig. 6E). At this point, the patient had regained the ability to consume both thin liquids and a regular diet, though some foods remained difficult to eat.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003ePatients with LCN impairments typically present with multifaceted and severe disturbances in both swallowing function and voice, necessitating comprehensive assessment and multidisciplinary management [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. The present case exhibited right-sided velopharyngeal insufficiency, pharyngeal and vocal fold paralysis, reduced laryngeal elevation, and impaired UES passage. Based on the identified deficits, we hypothesized the following: Achieving velopharyngeal closure during swallowing would help generate effective pressure to propel the bolus toward the esophagus. Reinforcement of the hypopharyngeal wall could enhance its resistance to contralateral contraction pressure, thus facilitating bolus propulsion. Facilitating UES opening through CPM would be expected to increase the amount of bolus passing into the esophagus. Additionally, medialization of the paralyzed vocal fold might enhance glottic closure during swallowing, thereby reducing the risk of aspiration. Therefore, to address the multiple impairments, we performed a single-stage combination of surgical procedures: right-sided lateral pharyngeal flap, CPM, hypopharyngeal wall reinforcement, arytenoid adduction, and tracheostomy. Predictably, bolus transit from the right hypopharynx into the esophagus was facilitated, resulting in a marked improvement in the patient's swallowing function, and consequently, her quality of life.\u003c/p\u003e\u003cp\u003ePharyngeal flap surgery is a widely accepted treatment for velopharyngeal insufficiency, with the median-focused flap being the conventional technique [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. In this patient, unilateral pharyngeal paralysis warranted the use of a lateral pharyngeal flap to reinforce the weakened side [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Hypopharyngeal pharyngoplasty was developed to improve swallowing in patients with dysphagia caused by unilateral pharyngeal paralysis, often due to cranial nerve injuries or skull base surgery [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. It focuses on reshaping the hypopharynx to reduce aspiration risk and enhance pharyngeal transit [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. The procedure can be performed through the same surgical field as arytenoid adduction. It is often combined with medialization laryngoplasty and/or arytenoid adduction to address both pharyngeal and glottic insufficiencies [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Cricopharyngeal myotomy is not a standard component of hypopharyngeal pharyngoplasty, but it may be incorporated when significant cricopharyngeal dysfunction is identified [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Reinforcement of the pharyngeal constrictor muscles with polypropylene mesh during hypopharyngeal pharyngoplasty has been reported to reduce postoperative pharyngeal dilatation and pooling in the pyriform sinus [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. To the best of our knowledge, this is the first case to report the use of ePTFE mesh for this purpose. The said material, characterized by micropores smaller than 10 \u0026micro;m, is widely used in vascular and cardiac surgeries, offering superior flexibility and moldability compared to polypropylene mesh [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Despite its relative softness, ePTFE mesh provided sufficient reinforcement to the weakened pharyngeal wall in this patient.\u003c/p\u003e\u003cp\u003eRecently, with advances in diagnostic technology, HRM, swallowing CT, and swallowing VR have emerged as powerful tools for the comprehensive evaluation of swallowing dysfunction [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan additionalcitationids=\"CR13 CR14 CR15 CR16 CR17 CR18\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. HRM is highly effective for assessing the pathophysiology of velopharyngeal insufficiency and UES passage disorders. Even when VFSS suggests impaired UES passage that may imply cricopharyngeal dysfunction, HRM enables direct evaluation of cricopharyngeal muscle relaxation. Swallowing CT and VR imaging provide superior insights into dynamic three-dimensional structural changes during swallowing [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. These valuable modalities are expected to be adopted more widely for the evaluation of dysphagia pathophysiology.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn the present case, comprehensive multimodal swallowing assessment, including laryngoscopy, VFSS, HRM, and swallowing CT allowed for precise evaluation of dysphagia. Based on the detailed pathophysiological findings, appropriate surgical interventions were performed, resulting in an excellent postoperative course. Reinforcement of the hypopharyngeal wall with ePTFE mesh contributed to the favorable outcome.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe gratefully acknowledge Ms. Mika Imamura for her kind cooperation in development of a program for measurement in three-dimensional reconstruction images of swallowing CT.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFundings:\u003c/strong\u003e None\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest/Competing interests:\u003c/strong\u003e On behalf of all the authors, the corresponding author states that there are no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics: \u003c/strong\u003eThis case report was approved by the Ethics Committee of the University of Tokyo (No. 2487, 2022179NI).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWritten consent for publication:\u003c/strong\u003e Written informed consent was obtained from the patient.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of datal: \u003c/strong\u003eData are available on a reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRU: conceived a treatment strategy, performed swallowing CT and VR, contributed to patient care, drew the figures, and drafted the work.\u003c/p\u003e\n\u003cp\u003eMAD: contributed to patient care, reviewed and edited the manuscript.\u003c/p\u003e\n\u003cp\u003eKY: contributed to patient care and reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003eMLR: contributed to patient care, reviewed and edited the manuscript.\u003c/p\u003e\n\u003cp\u003eMT: performed swallowing CT and reviewed the manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHK: contributed to patient care and reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003eAK: contributed to patient care and reviewed the manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTG: contributed to patient care and reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003eKK: contributed to patient care and critically revised the work.\u003c/p\u003e\n\u003cp\u003eAll authors reviewed and approved the final version of the manuscript for publication.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003ePeterson KL, Fenn J: Treatment of dysphagia and dysphonia following skull base surgery. \u003cem\u003eOtolaryngol Clin North Am \u003c/em\u003e2005, 38(4):809-817, xi.\u003c/li\u003e\n\u003cli\u003eFinsterer J, Grisold W: Disorders of the lower cranial nerves. \u003cem\u003eJ Neurosci Rural Pract \u003c/em\u003e2015, 6(3):377-391.\u003c/li\u003e\n\u003cli\u003eNiu Y, Chen C, Jin X, Huo H, Cui T, Wang J: Management of Severe Dysphonia and Dysphagia Following Lateral Skull Base Surgery. \u003cem\u003eJ Voice \u003c/em\u003e2024.\u003c/li\u003e\n\u003cli\u003eGart MS, Gosain AK: Surgical management of velopharyngeal insufficiency. \u003cem\u003eClin Plast Surg \u003c/em\u003e2014, 41(2):253-270.\u003c/li\u003e\n\u003cli\u003eAbdel-Aziz M, Rashed M, Naguib N, Shawky A: Lateralization of the Pharyngeal Flap for Treatment of Lateral Velopharyngeal Gap. \u003cem\u003eJ Craniofac Surg \u003c/em\u003e2016, 27(1):101-104.\u003c/li\u003e\n\u003cli\u003eChitose SI, Sato K, Fukahori M, Kurita T, Sato K, Sato F, Umeno H: Lateral pharyngeal flap with a double pedicle for repair of unilateral velopharyngeal insufficiency. \u003cem\u003eAuris Nasus Larynx \u003c/em\u003e2020, 47(2):245-249.\u003c/li\u003e\n\u003cli\u003eMok P, Woo P, Schaefer-Mojica J: Hypopharyngeal pharyngoplasty in the management of pharyngeal paralysis: a new procedure. \u003cem\u003eAnn Otol Rhinol Laryngol \u003c/em\u003e2003, 112(10):844-852.\u003c/li\u003e\n\u003cli\u003eFayoux P, Bonne NX, Hosana G: Hypopharyngeal pharyngoplasty in the treatment of severe aspiration following skull base tumor removal: experience in pediatric patients. \u003cem\u003eArch Otolaryngol Head Neck Surg \u003c/em\u003e2011, 137(1):60-64.\u003c/li\u003e\n\u003cli\u003eCotaoco C, Ueha R, Koyama M, Sato T, Goto T, Kondo K: Swallowing improvement surgeries. \u003cem\u003eEur Arch Otorhinolaryngol \u003c/em\u003e2024, 281(6):2807-2817.\u003c/li\u003e\n\u003cli\u003eKiyohara H, Umezaki T, Adachi K, Matsubara N, Matsuyama K, Komune S: Pharyngoplasty for the treatment of unilateral pharyngeal paralysis. \u003cem\u003eOTOLOGIA FUKUOKA \u003c/em\u003e2007, 53(6Supplement2):S94-S101.\u003c/li\u003e\n\u003cli\u003eBaylon K, Rodriguez-Camarillo P, Elias-Zuniga A, Diaz-Elizondo JA, Gilkerson R, Lozano K: Past, Present and Future of Surgical Meshes: A Review. \u003cem\u003eMembranes (Basel) \u003c/em\u003e2017, 7(3).\u003c/li\u003e\n\u003cli\u003eUeha R, Goto T, Sato T, Nativ-Zeltzer N, Shen SC, Nito T, Belafsky PC, Yamasoba T: High Resolution Manofluorographic Study in Patients With Multiple System Atrophy: Possible Early Detection of Upper Esophageal Sphincter and Proximal Esophageal Abnormality. \u003cem\u003eFront Med (Lausanne) \u003c/em\u003e2018, 5:286.\u003c/li\u003e\n\u003cli\u003eSuh JH, Park D, Kim IS, Kim H, Shin CM, Ryu JS: Feasibility of high-resolution manometry for decision of feeding methods in patients with amyotrophic lateral sclerosis. \u003cem\u003eMedicine (Baltimore) \u003c/em\u003e2019, 98(23):e15781.\u003c/li\u003e\n\u003cli\u003eKatoh M, Ueha R, Sato T, Sugasawa S, Goto T, Yamauchi A, Yamasoba T: Choice of Aspiration Prevention Surgery for Patients With Neuromuscular Disorders: Report of Three Cases. \u003cem\u003eFront Surg \u003c/em\u003e2019, 6:66.\u003c/li\u003e\n\u003cli\u003eDiver EM, Regan J: Use of Pharyngeal High-Resolution Manometry to Evaluate Dysphagia in Adults with Motor Neurone Disease: A Scoping Review. \u003cem\u003eDysphagia \u003c/em\u003e2022, 37(6):1697-1714.\u003c/li\u003e\n\u003cli\u003eUeha R, Koyama M, Seto A, Sato T, Goto T, Orimo K, Mitsui J, Yamasoba T: Esophageal Dysmotility in Multiple System Atrophy: A Retrospective Cross-Sectional Study. \u003cem\u003eJ Clin Med \u003c/em\u003e2024, 13(17).\u003c/li\u003e\n\u003cli\u003eKatsuno T, Ueha R, Nanjo K, Matsuda K, Miura C, Sato T, Goto T, Kondo K: Clinical Conundrum: Swallowing Virtual Reality as a Novel Diagnostic Tool for Severe Dysphagia after Deep Neck Infection. \u003cem\u003eDysphagia \u003c/em\u003e2025, 40(1):305-309.\u003c/li\u003e\n\u003cli\u003eUeha R, Dealino MA, Koyama M, Yamakawa K, Matsumoto N, Sato T, Goto T, Mizukami A, Kondo K: Improved Pharyngeal Contraction and Oral Intake Status After Modified Central-Part Laryngectomy for Late-Stage ALS. \u003cem\u003eOtolaryngol Head Neck Surg \u003c/em\u003e2025.\u003c/li\u003e\n\u003cli\u003eCotaoco C, Goto T, Koyama M, Sato T, Kondo K, Ueha R: Severe Dysphagia in a Patient with Wallenberg Syndrome and Killian Jamieson Diverticulum: A Case Report. \u003cem\u003eSN Comprehensive Clinical Medicine \u003c/em\u003e2024, 6(1):81.\u003c/li\u003e\n\u003cli\u003eSuto A, Ueha R, Ogura T, Maeda E, Tatebayashi M, Shimada D, Koyama M, Sato T, Goto T, Yamauchi A\u003cem\u003e et al\u003c/em\u003e: Swallowing computed tomography and virtual reality as novel imaging modalities for the diagnosis of clicking larynx: Two case reports. \u003cem\u003eAuris Nasus Larynx \u003c/em\u003e2023, 50(3):468-472.\u003c/li\u003e\n\u003cli\u003eInamoto Y, Ueha R, Gonzalez-Fernandez M: Emerging Dysphagia Technologies: Swallowing CT. \u003cem\u003eCurrent Otorhinolaryngology Reports \u003c/em\u003e2023, 11(2):154-160.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Lower cranial nerve palsies, swallowing improvement surgery, dysphagia, swallowing CT, virtual reality, high-resolution pharyngeal manometry","lastPublishedDoi":"10.21203/rs.3.rs-6750134/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6750134/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction\u003c/h2\u003e\u003cp\u003eLower cranial nerve (LCN) palsy may develop following tumor resection in the cerebellopontine angle or jugular foramen, often resulting in dysphagia and dysphonia. Although many patients recover with rehabilitation, some exhibit persistent functional deficits. In such cases, detailed pathophysiologic evaluation can guide surgical intervention to improve outcomes.\u003c/p\u003e\u003ch2\u003eCase Presentation\u003c/h2\u003e\u003cp\u003eA 77-year-old woman presented with severe dysphagia and hoarseness after resection of a right cerebellopontine angle meningioma, which caused glossopharyngeal, vagus, and accessory nerve palsies. Despite initial recovery, she experienced repeated aspiration pneumonia and malnutrition. Comprehensive reassessment using high-resolution manometry and dynamic swallowing computed tomography revealed right-sided velopharyngeal insufficiency, pharyngeal constrictor dysfunction, vocal fold paralysis with fixation at the paramedian position, and impaired upper esophageal sphincter (UES) relaxation. A tailored multi-procedural surgical approach was adopted, including right pharyngeal flap, right hypopharyngeal pharyngoplasty with expanded polytetrafluoroethylene mesh reinforcement, right cricopharyngeal myotomy, arytenoid adduction, and tracheostomy. Postoperatively, swallowing and phonation improved markedly. The patient resumed oral intake, and tracheostoma closure was achieved by postoperative day (POD) 25. By POD 32, maximum phonation time improved sevenfold, and she was discharged on a regular diet.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eIntractable dysphagia due to complex LCN dysfunction requires individualized surgical strategies. Advanced diagnostic modalities, including dynamic swallowing CT and HRM, enable precise localization of dysfunction and guide effective, function-preserving surgical interventions that can significantly improve quality of life.\u003c/p\u003e","manuscriptTitle":"Comprehensive surgical management for lower cranial nerve palsies, including hypopharyngeal pharyngoplasty with ePTFE mesh, based on detailed swallowing CT evaluation: a case report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-30 12:17:01","doi":"10.21203/rs.3.rs-6750134/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d700455b-7f1f-4775-a5b4-a94feddab937","owner":[],"postedDate":"October 30th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-22T16:15:05+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-30 12:17:01","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6750134","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6750134","identity":"rs-6750134","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}