Otology & Neurotology 35:635Y638 Ó 2014, Otology & Neurotology, Inc.
Computed Tomography Before Balloon Eustachian TuboplastyYA True Necessity? *Tarek Abdel-Aziz, *Stefanie Schro¨der, *Martin Lehmann, †Hans-Bjo¨rn Gehl, *Jo¨rg Ebmeyer, and *Holger Sudhoff *Department of Otorhinolaryngology, Head and Neck Surgery, and ÞDepartment of Radiology, Klinikum Bielefeld, Academic Teaching Hospital University of Mu¨nster University, Bielefeld, Germany
Objective: Since the introduction of balloon Eustachian tuboplasty the necessity of preoperative high-resolution CT scans of the temporal bone has been a topic of debate. This study investigated the informative value of preoperative CT scanning in predicting intraoperative or postoperative difficulties and complications. Special focus was laid on the existence of carotid canal dehiscences for fear of intraprocedural injury. Study Design: Retrospective. Setting: Tertiary referral center. Patients and Interventions: Approximately 284 patients (510 Eustachian tubes) with intractable Eustachian tube dysfunction undergoing unilateral or bilateral balloon Eustachian tuboplasty with preoperative high-resolution CT scans of the temporal bone from January 1, 2009, to December 31, 2012. Results: Carotid canal dehiscences were found in 18 patients (6.3%). In 3 patients (4 Eustachian tubes, 1.1% of patients) balloon dilatation could not be performed because of difficulties advancing the balloon catheter. Of these 3 patients, one had bilateral carotid canal dehiscences, whereas the other two had
unremarkable CT scans. Postoperative complications occurred in 3 patients (1.1%): 2 soft tissue emphysemas and 1 unilateral hypoglossal paresis. All 3 patients had unremarkable CT scans, and all complications resolved completely without further sequelae. Conclusion: Preoperative high-resolution CT scan of the temporal bone does not seem to be suitable to predict intraoperative or postoperative difficulties of balloon Eustachian tuboplasty. Being extremely cautious during balloon catheter insertion into the Eustachian tube and using a device that is designed with a built-in stop mechanism preventing too deep insertion, the data presented suggest that fear of injury to the internal carotid artery during balloon dilatation might be disproportionate. Nevertheless, for inexperienced surgeons, HR-CT scans of the temporal bone may help to understand the relation between internal carotid artery and the Eustachian tube. Key Words: Balloon dilatationVCarotid canal dehiscenceVComputed tomographyV Eustachian tube dysfunction. Otol Neurotol 35:635Y638, 2014.
Chronic Eustachian tube (ET) dysfunction has been a recognized cause of recurrent ear diseases for many years. Several attempts have been made to improve ET function but have been abandoned because of lack of long-term success or high potential for lethal carotid artery injury (1Y8). Within the past few years, several minimally invasive and effective treatment options to improve ET function have been developed. Poe et al. (9) could identify an approximately 5-mm-long segment of the tubal lumen,
just inferior to the bony cartilaginous isthmus as the crucial cause for obstructive ET dysfunction. Consequently, focus was laid on improvement of the opening of the cartilaginous portion of the ET (10). In 2010, Sudhoff et al. and Poe et al. in 2011 first published studies using a flexible balloon catheter to temporarily dilate the cartilaginous portion of the Eustachian tube (11,12). After positioning of the balloon catheter within the cartilaginous portion of the ET via its pharyngeal orifice, the balloon is inflated and the ET dilated. The balloon catheter used at our institution has the following specifications: length of 20 mm and diameter of 600 Hm when deflated and 3.28 mm when inflated to 10 bar. Additionally, the balloon catheter possesses a design that limits depth of insertion into the ET and therefore prevents unintended insertion into the bony part of the ET. Duration of inflation is 2 minutes at a pressure of 10 bar (7.501 mm Hg) (Spiggle & Theis, Overath, Germany) (11,13).
Address correspondence and reprint requests to Holger Sudhoff, F.R.C.S. (Lon), F.R.C.Path, Department of Otorhinolaryngology, Head and Neck Surgery, Klinikum Bielefeld, Teutoburger Str. 50, 33604 Bielefeld, Germany; E-mail: [email protected] Competing interests: Martin Lehmann, Jo¨rg Ebmeyer, and Holger Sudhoff receive speaker honoraria and financial support for research purposes from Spiggle & Theis GmbH, Overath, Germany. No funding was supplied for this research project. Supplemental digital content is available in the text.
635
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
636
T. ABDEL-AZIZ ET AL.
At our institution, preoperative diagnostics comprise a thorough medical history, microscopic evaluation of the tympanic membrane including Valsalva’s and Toynbee’s maneuver. Furthermore, tympanometry and pure tone audiogram are obtained and measurement of ET function by tubomanometry as modified by Este`ve (11,14Y17). In terms of preoperative imaging, high-resolution computed tomography (HR-CT) scans of the temporal bones are obtained. Here, special attention is focused on the bony canal of the internal carotid artery to identify carotid canal dehiscences (CCDs) neighboring the bony part of the Eustachian tube for fear of intraoperative injury to the internal carotid artery (Fig. 1). The necessity of preinterventional HR-CT scans of the temporal bone has been a controversy ever since the introduction of balloon Eustachian tuboplasty (BET). The rationale for preoperative CT scans of the temporal bone is to gain information on the relation between the ET and the bony canal of the internal carotid artery. It is feared that the dilation, although performed within the cartilaginous part of the ET, might inadvertently affect the bony part of the ET, possibly leading to plaque mobilization, fractures of the thin bony canal with spearing of fragments into the internal carotid artery leading to potentially fatal bleeding or even rupture because of penetration of a dehiscent artery (18).
OBJECTIVE The present retrospective study was performed to investigate the necessity and value of preoperative HR-CT examination of the relation between the ET and internal carotid artery and its bony canal. Furthermore, it was investigated whether the CT scan may be of value to anticipate possible intraoperative or postoperative difficulties in BET.
FIG. 1. HR-CT scan of the temporal bone. Right-sided carotid canal dehiscence (thin arrow). Left-sided carotid canal intact (thick arrow).
TABLE 1. Distribution of bony canal dehiscences in 284 patients with high-resolution computed tomographic scans of the temporal bone performed at our institution before balloon Eustachian tuboplasty
Patients with CCD
Righta
Lefta
Bilaterala
Totala
6 (2.1%)
4 (1.4%)
8 (2.8%)
18 (6.3%)
CCD indicates carotid canal dehiscence. a Percentage listing in reference to all CT scans and BET performed at our institution.
MATERIALS AND METHODS Between January 1, 2009, and December 31, 2012, approximately 319 patients (569 ET) underwent endoscopic BET at our institution (revisions excluded); 284 preoperative HR-CT scans were obtained at our institution (See Supplemental Digital Content for description, http://links.lww.com/MAO/A184), and 35 CT scans were performed elsewhere. For study purposes, only CT scans performed at our institution were analyzed. Patients undergoing revision BET were only examined once. Altogether, 284 patients (510 ET) were investigated.
RESULTS Carotid canal dehiscences next to the Eustachian tube were diagnosed in 18 patients (6.3%) (Table 1). In 3 patients (1.1% of patients; 4 ET, 0.8% of ET), BET could not be performed because of difficulties introducing the balloon catheter. Of these patients, one had bilateral carotid canal dehiscences, and the other 2 patients had unremarkable CT scans (Table 2). Intraoperative or postoperative complications occurred in 3 patients (1.1%). Observed complications were postoperative unilateral soft tissue emphysema after Valsalva’s maneuver in 2 cases and 1 case of unilateral hypoglossal paresis, which improved markedly within 4 days and had resolved completely by the time of 2 months’ follow-up. No complications occurred in the group of patients with radiologically diagnosed CCD. All complications observed occurred in patients with completely normal HR-CT morphologic findings (Table 2, Fig. 2). As a cause for postoperative soft tissue emphysema, intraoperative kinking of the catheter within the ET with mucosal injury during dilatation was hypothesized. The hypoglossal paresis was believed to be a sequel of the transoral approach with extensive pressure applied to the tongue via the McIvor retractor. All complications resolved completely without sequelae under conservative treatment. Because of the low number of failed BET attempts in the investigated collective, we also retrospectively investigated the patients with failed ET dilations and CT scans from outside facilities to look for possible CT morphologic predictors of intraoperative complications or difficulties. CT scans were reevaluated by our senior radiologic staff. This way, additional 2 patients (2 ET) with failed BET attempts were identified. Altogether, BET could not be performed in a total of 5 of 319 patients (6 of 569 ET). Retrospectively looking at these patients’
Otology & Neurotology, Vol. 35, No. 4, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
COMPUTED TOMOGRAPHY BEFORE BET TABLE 2.
637
Correlation of findings of high-resolution computed tomographic scans obtained at our institution to intraoperative and postoperative complications and ability to perform balloon Eustachian tuboplasty
High-resolution computed tomographic scan/BET complications/failed CCDa a
No CCD Totalb
No complications BET successful
Complications
Failed BET
Pt 17 (94.4%) ET 24 (92.3%) Pt 261 (98.1%) ET 480 (99.2%)c Pt 278 (97.9%) ET 504 (98.8%)
Pt 0 (0%) ET 0 (0%) Pt 3 (1.1%)c ET 2 (0.4%)c Pt 3 (1.1%) ET 2 (0.4%)
Pt 1 ET 2 Pt 2 ET 2 Pt 3 ET 4
(5.6%) (7.7%) (0.8%) (0.4%) (1.1%) (0.8%)
Totalb Pt 18 (6.3%) ET 26 (5.1%) Pt 266 (93.7%) ET 484 (94.9%) Pt 284 (100%) ET 510 (100%)
CCD indicates carotid canal dehiscence; BET, balloon Eustachian tuboplasty; Pt, patient; ET, Eustachian tube. a Percentage listing for the groups with CCD respective without CCD. b Percentage listing in reference to all CT scans and BET performed at our institution. c As for complications, although 3 patients had complications, only the soft tissue emphysemas where attributed directly to manipulation within the Eustachian tube. The hypoglossal paresis was therefore listed within the complications column under patient but not under ET.
histories and reevaluating their CT scans, the following observations were made: One HR-CT scan conducted at our institution yielded bilateral CCD, whereas the other 2 scans yielded normal results. No pathology was observed in preoperative transnasal epipharyngoscopy. One of the patients with CT scans performed at an outside institution displayed a right-sided epipharyngeal mass consistent with the long lasting history of right-sided chronic otitis media with effusion (Fig. 3, A and B). Biopsy revealed a petroclival meningeoma. The CT scan showed signs of chronic sinusitis within the ethmoid and sphenoid sinus (as suspected by the outside radiologist) with additional blurring of the bony border in the area of the anterior and middle cranial fossa (Fig. 3B, C). This lesion, however, could have very well been missed and was probably only diagnosed because of the retrospective approach used here. The other patient was a 14-year-old boy who had undergone adenoidectomy and revision-adenoidectomy resulting in extensive epipharyngeal scarring with impaired middle ear ventilation. Because of a long history of recurrent cholesteatoma requiring 8 surgical interventions, BET was attempted. Despite the extensive scar formation, it could be performed on the right side while catheter insertion failed on the left side. The CT scans at the very most showed a hypoplastic torus tubarius, whereas the ET on both sides seemed to be, at least in part, opened at the time of the investigation. It must be emphasized that in the case with the epipharyngeal mass, suspicion was raised during initial epipharyngoscopy and would have resulted in further imaging studies despite the performance of BET!
The patient with the bilateral failed BET attempts had bilateral CCD, whereas the remaining 2 had unremarkable CT scans. In the other 3 patients (1.1% of 284 patients), complications such as postoperative soft tissue emphysema (2 patients, 0.7%) or temporary hypoglossal paresis (1 patient, 0.4%) occurred despite completely normal CT scans. Carotid artery injury occurred in none of the treated patients. According to these data, routine preoperative HR-CT scan of the temporal bone seems not predictive of intraoperative or postoperative difficulties or complications in BET. Furthermore, the data suggest that fear of injury to the internal carotid artery during BET might be disproportionate. To our knowledge, no report of intraoperative injury to the internal carotid artery has been neither published nor reported on meetings. In our opinion, BET can therefore be performed despite CCD as long as dilation is restricted to the cartilaginous portion of the Eustachian
DISCUSSION In this investigation, 284 HR-CT scans were conducted before BET, evaluating 510 temporal bones for carotid canal dehiscences (Table 2). Eighteen patients (6.3%) showed unilateral or bilateral CCD, yielding comparable rates as reported by Moreano et al. (7.7%) (19). BET was performed without any complications in 278 patients (97.9%). Of the remaining 6 patients, in 3 patients, 4 of 6 BET (0.8% of total of 510 ET) could not be performed.
FIG. 2. A, HR-CT scan of the temporal bone. Status before BET. B, Same patient, postoperative CT scan of the paranasal sinuses, bone window. Soft tissue emphysema extending from the soft tissue around the Eustachian tube to the cheek. Otology & Neurotology, Vol. 35, No. 4, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
638
T. ABDEL-AZIZ ET AL.
FIG. 3. A, Transnasal endoscopic view of the right epipharynx. Mass (white arrow) adjacent to the torus tubarius (asterisk) B, Same patient, HR-CT scan of the temporal bone. Right-sided posterior ethmoid as well as sphenoid sinus opacified with radiopaque tissue, possible newly formed bone (asterisk). Temporal bone with blurred border (white arrow). C, Same patient, MRI scan, T1w with gadolinium, depicting the actual dimensions of the meningioma (white arrow).
tube as ensured by the built-in insertion stop of the balloon catheter used at our institution. Although HR-CT scans may help the inexperienced surgeon in appreciating the relation between carotid canal and Eustachian tube, the given radiation exposure of the patients and low predictive value let us come to the conclusion that HR-CT scans of the temporal bone should not be used as a routine screening tool in patients undergoing BET. However, in patients with failed BET attempts, imaging studies may be useful in search of underlying pathology. Furthermore, in patients with lesions in the epipharynx in the context of impaired middle ear ventilation and absence of hypertrophic adenoid tissue, imaging studies should still be performed to rule out malignancies. REFERENCES 1. Gluth MB, McDonald DR, Weaver AL, et al. Management of Eustachian tube dysfunction with nasal steroid spray: a prospective, randomized, placebo-controlled trial. Arch Otolaryngol Head Neck Surg 2011;137:449Y55. 2. Zollner F. Surgery of the sound conducting apparatus. J Laryngol 1955;69:637Y52. 3. Zollner F. Therapy of the Eustachian tube. Arch Otolaryngol 1963;78:394Y9. 4. Schrom T, Kla¨ring S, Sedlmaier B. Treatment of chronic tube dysfunction. Use of the tube conductor [in German]. HNO 2007;55:871Y5. 5. Wullstein H. Eustachian tube in tympanoplasty. AMA Arch Otolaryngol 1960;71:408Y10. 6. House WF, Glasscock ME 3rd, Miles J. Eustachian tuboplasty. Laryngoscope 1969;79:1765Y82.
7. Misury VK. Eustachian tuboplasty. J Laryngol Otol 1975;89: 807Y13. 8. Poe DS, Metson RB, Kujawski O. Laser Eustachian tuboplasty: a preliminary report. Laryngoscope 2003;113:583Y91. 9. Poe DS, Grimmer JF, Metson R. Laser Eustachian tuboplasty: two-year results. Laryngoscope 2007;117:231Y7. 10. Metson R, Pletcher SD, Poe DS. Microdebrider Eustachian tuboplasty: a preliminary report. Otolaryngol Head Neck Surg 2007;136:422Y7. 11. Ockermann T, Reineke U, Upile T, et al. Balloon dilatation Eustachian tuboplasty: a clinical study. Laryngoscope 2010;120: 1411Y6. 12. Poe DS, Silvola J, Pyykko¨ I. Balloon dilation of the cartilaginous Eustachian tube. Otolaryngol Head Neck Surg 2011;144:563Y9. 13. Ockermann T, Reineke U, Upile T, et al. Balloon dilation Eustachian tuboplasty: a feasibility study. Otol Neurotol 2010;31: 1100Y3. 14. Esteve D. Tubomanometry and pathology. In: Ars B, ed. Fibrocartilaginous Eustachian TubeYMiddle Ear Cleft. The Hague, The Netherlands: Kugler, 2003;159Y76. 15. Esteve D, Dubreuil C, Della Vedova C, et al. Tympanometric evaluation of the opening of the Eustachian tube in normal subjects and cases with chronic otitis media [in French]. J Fr ORL 2001;50:223Y31 16. Ars B, Dirckx JJ. Tubomanometry. The Hague, The Netherlands: Kugler, 2003. 17. Sudhoff H, Ockermann T, Mikolajczyk R, et al. Clinical and experimental considerations for evaluation of Eustachian tube physiology [in German]. HNO 2009;57:428Y35. 18. Poe D. In reference to Balloon dilatation Eustachian tuboplasty: a clinical study. Comment on Balloon dilatation Eustachian tuboplasty: a clinical study. [Laryngoscope. 2010]. Laryngoscope 2011;121:908. 19. Moreano EH, Paparella MM, Zelterman D, et al. Prevalence of carotid canal dehiscence in the human middle ear: a report of 1000 temporal bones. Laryngoscope 1994;104(5 Pt 1):612Y8.
Otology & Neurotology, Vol. 35, No. 4, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
Computed Tomography Before Balloon Eustachian TuboplastyYA True Necessity? *Tarek Abdel-Aziz, *Stefanie Schro¨der, *Martin Lehmann, †Hans-Bjo¨rn Gehl, *Jo¨rg Ebmeyer, and *Holger Sudhoff *Department of Otorhinolaryngology, Head and Neck Surgery, and ÞDepartment of Radiology, Klinikum Bielefeld, Academic Teaching Hospital University of Mu¨nster University, Bielefeld, Germany
Objective: Since the introduction of balloon Eustachian tuboplasty the necessity of preoperative high-resolution CT scans of the temporal bone has been a topic of debate. This study investigated the informative value of preoperative CT scanning in predicting intraoperative or postoperative difficulties and complications. Special focus was laid on the existence of carotid canal dehiscences for fear of intraprocedural injury. Study Design: Retrospective. Setting: Tertiary referral center. Patients and Interventions: Approximately 284 patients (510 Eustachian tubes) with intractable Eustachian tube dysfunction undergoing unilateral or bilateral balloon Eustachian tuboplasty with preoperative high-resolution CT scans of the temporal bone from January 1, 2009, to December 31, 2012. Results: Carotid canal dehiscences were found in 18 patients (6.3%). In 3 patients (4 Eustachian tubes, 1.1% of patients) balloon dilatation could not be performed because of difficulties advancing the balloon catheter. Of these 3 patients, one had bilateral carotid canal dehiscences, whereas the other two had
unremarkable CT scans. Postoperative complications occurred in 3 patients (1.1%): 2 soft tissue emphysemas and 1 unilateral hypoglossal paresis. All 3 patients had unremarkable CT scans, and all complications resolved completely without further sequelae. Conclusion: Preoperative high-resolution CT scan of the temporal bone does not seem to be suitable to predict intraoperative or postoperative difficulties of balloon Eustachian tuboplasty. Being extremely cautious during balloon catheter insertion into the Eustachian tube and using a device that is designed with a built-in stop mechanism preventing too deep insertion, the data presented suggest that fear of injury to the internal carotid artery during balloon dilatation might be disproportionate. Nevertheless, for inexperienced surgeons, HR-CT scans of the temporal bone may help to understand the relation between internal carotid artery and the Eustachian tube. Key Words: Balloon dilatationVCarotid canal dehiscenceVComputed tomographyV Eustachian tube dysfunction. Otol Neurotol 35:635Y638, 2014.
Chronic Eustachian tube (ET) dysfunction has been a recognized cause of recurrent ear diseases for many years. Several attempts have been made to improve ET function but have been abandoned because of lack of long-term success or high potential for lethal carotid artery injury (1Y8). Within the past few years, several minimally invasive and effective treatment options to improve ET function have been developed. Poe et al. (9) could identify an approximately 5-mm-long segment of the tubal lumen,
just inferior to the bony cartilaginous isthmus as the crucial cause for obstructive ET dysfunction. Consequently, focus was laid on improvement of the opening of the cartilaginous portion of the ET (10). In 2010, Sudhoff et al. and Poe et al. in 2011 first published studies using a flexible balloon catheter to temporarily dilate the cartilaginous portion of the Eustachian tube (11,12). After positioning of the balloon catheter within the cartilaginous portion of the ET via its pharyngeal orifice, the balloon is inflated and the ET dilated. The balloon catheter used at our institution has the following specifications: length of 20 mm and diameter of 600 Hm when deflated and 3.28 mm when inflated to 10 bar. Additionally, the balloon catheter possesses a design that limits depth of insertion into the ET and therefore prevents unintended insertion into the bony part of the ET. Duration of inflation is 2 minutes at a pressure of 10 bar (7.501 mm Hg) (Spiggle & Theis, Overath, Germany) (11,13).
Address correspondence and reprint requests to Holger Sudhoff, F.R.C.S. (Lon), F.R.C.Path, Department of Otorhinolaryngology, Head and Neck Surgery, Klinikum Bielefeld, Teutoburger Str. 50, 33604 Bielefeld, Germany; E-mail: [email protected] Competing interests: Martin Lehmann, Jo¨rg Ebmeyer, and Holger Sudhoff receive speaker honoraria and financial support for research purposes from Spiggle & Theis GmbH, Overath, Germany. No funding was supplied for this research project. Supplemental digital content is available in the text.
635
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
636
T. ABDEL-AZIZ ET AL.
At our institution, preoperative diagnostics comprise a thorough medical history, microscopic evaluation of the tympanic membrane including Valsalva’s and Toynbee’s maneuver. Furthermore, tympanometry and pure tone audiogram are obtained and measurement of ET function by tubomanometry as modified by Este`ve (11,14Y17). In terms of preoperative imaging, high-resolution computed tomography (HR-CT) scans of the temporal bones are obtained. Here, special attention is focused on the bony canal of the internal carotid artery to identify carotid canal dehiscences (CCDs) neighboring the bony part of the Eustachian tube for fear of intraoperative injury to the internal carotid artery (Fig. 1). The necessity of preinterventional HR-CT scans of the temporal bone has been a controversy ever since the introduction of balloon Eustachian tuboplasty (BET). The rationale for preoperative CT scans of the temporal bone is to gain information on the relation between the ET and the bony canal of the internal carotid artery. It is feared that the dilation, although performed within the cartilaginous part of the ET, might inadvertently affect the bony part of the ET, possibly leading to plaque mobilization, fractures of the thin bony canal with spearing of fragments into the internal carotid artery leading to potentially fatal bleeding or even rupture because of penetration of a dehiscent artery (18).
OBJECTIVE The present retrospective study was performed to investigate the necessity and value of preoperative HR-CT examination of the relation between the ET and internal carotid artery and its bony canal. Furthermore, it was investigated whether the CT scan may be of value to anticipate possible intraoperative or postoperative difficulties in BET.
FIG. 1. HR-CT scan of the temporal bone. Right-sided carotid canal dehiscence (thin arrow). Left-sided carotid canal intact (thick arrow).
TABLE 1. Distribution of bony canal dehiscences in 284 patients with high-resolution computed tomographic scans of the temporal bone performed at our institution before balloon Eustachian tuboplasty
Patients with CCD
Righta
Lefta
Bilaterala
Totala
6 (2.1%)
4 (1.4%)
8 (2.8%)
18 (6.3%)
CCD indicates carotid canal dehiscence. a Percentage listing in reference to all CT scans and BET performed at our institution.
MATERIALS AND METHODS Between January 1, 2009, and December 31, 2012, approximately 319 patients (569 ET) underwent endoscopic BET at our institution (revisions excluded); 284 preoperative HR-CT scans were obtained at our institution (See Supplemental Digital Content for description, http://links.lww.com/MAO/A184), and 35 CT scans were performed elsewhere. For study purposes, only CT scans performed at our institution were analyzed. Patients undergoing revision BET were only examined once. Altogether, 284 patients (510 ET) were investigated.
RESULTS Carotid canal dehiscences next to the Eustachian tube were diagnosed in 18 patients (6.3%) (Table 1). In 3 patients (1.1% of patients; 4 ET, 0.8% of ET), BET could not be performed because of difficulties introducing the balloon catheter. Of these patients, one had bilateral carotid canal dehiscences, and the other 2 patients had unremarkable CT scans (Table 2). Intraoperative or postoperative complications occurred in 3 patients (1.1%). Observed complications were postoperative unilateral soft tissue emphysema after Valsalva’s maneuver in 2 cases and 1 case of unilateral hypoglossal paresis, which improved markedly within 4 days and had resolved completely by the time of 2 months’ follow-up. No complications occurred in the group of patients with radiologically diagnosed CCD. All complications observed occurred in patients with completely normal HR-CT morphologic findings (Table 2, Fig. 2). As a cause for postoperative soft tissue emphysema, intraoperative kinking of the catheter within the ET with mucosal injury during dilatation was hypothesized. The hypoglossal paresis was believed to be a sequel of the transoral approach with extensive pressure applied to the tongue via the McIvor retractor. All complications resolved completely without sequelae under conservative treatment. Because of the low number of failed BET attempts in the investigated collective, we also retrospectively investigated the patients with failed ET dilations and CT scans from outside facilities to look for possible CT morphologic predictors of intraoperative complications or difficulties. CT scans were reevaluated by our senior radiologic staff. This way, additional 2 patients (2 ET) with failed BET attempts were identified. Altogether, BET could not be performed in a total of 5 of 319 patients (6 of 569 ET). Retrospectively looking at these patients’
Otology & Neurotology, Vol. 35, No. 4, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
COMPUTED TOMOGRAPHY BEFORE BET TABLE 2.
637
Correlation of findings of high-resolution computed tomographic scans obtained at our institution to intraoperative and postoperative complications and ability to perform balloon Eustachian tuboplasty
High-resolution computed tomographic scan/BET complications/failed CCDa a
No CCD Totalb
No complications BET successful
Complications
Failed BET
Pt 17 (94.4%) ET 24 (92.3%) Pt 261 (98.1%) ET 480 (99.2%)c Pt 278 (97.9%) ET 504 (98.8%)
Pt 0 (0%) ET 0 (0%) Pt 3 (1.1%)c ET 2 (0.4%)c Pt 3 (1.1%) ET 2 (0.4%)
Pt 1 ET 2 Pt 2 ET 2 Pt 3 ET 4
(5.6%) (7.7%) (0.8%) (0.4%) (1.1%) (0.8%)
Totalb Pt 18 (6.3%) ET 26 (5.1%) Pt 266 (93.7%) ET 484 (94.9%) Pt 284 (100%) ET 510 (100%)
CCD indicates carotid canal dehiscence; BET, balloon Eustachian tuboplasty; Pt, patient; ET, Eustachian tube. a Percentage listing for the groups with CCD respective without CCD. b Percentage listing in reference to all CT scans and BET performed at our institution. c As for complications, although 3 patients had complications, only the soft tissue emphysemas where attributed directly to manipulation within the Eustachian tube. The hypoglossal paresis was therefore listed within the complications column under patient but not under ET.
histories and reevaluating their CT scans, the following observations were made: One HR-CT scan conducted at our institution yielded bilateral CCD, whereas the other 2 scans yielded normal results. No pathology was observed in preoperative transnasal epipharyngoscopy. One of the patients with CT scans performed at an outside institution displayed a right-sided epipharyngeal mass consistent with the long lasting history of right-sided chronic otitis media with effusion (Fig. 3, A and B). Biopsy revealed a petroclival meningeoma. The CT scan showed signs of chronic sinusitis within the ethmoid and sphenoid sinus (as suspected by the outside radiologist) with additional blurring of the bony border in the area of the anterior and middle cranial fossa (Fig. 3B, C). This lesion, however, could have very well been missed and was probably only diagnosed because of the retrospective approach used here. The other patient was a 14-year-old boy who had undergone adenoidectomy and revision-adenoidectomy resulting in extensive epipharyngeal scarring with impaired middle ear ventilation. Because of a long history of recurrent cholesteatoma requiring 8 surgical interventions, BET was attempted. Despite the extensive scar formation, it could be performed on the right side while catheter insertion failed on the left side. The CT scans at the very most showed a hypoplastic torus tubarius, whereas the ET on both sides seemed to be, at least in part, opened at the time of the investigation. It must be emphasized that in the case with the epipharyngeal mass, suspicion was raised during initial epipharyngoscopy and would have resulted in further imaging studies despite the performance of BET!
The patient with the bilateral failed BET attempts had bilateral CCD, whereas the remaining 2 had unremarkable CT scans. In the other 3 patients (1.1% of 284 patients), complications such as postoperative soft tissue emphysema (2 patients, 0.7%) or temporary hypoglossal paresis (1 patient, 0.4%) occurred despite completely normal CT scans. Carotid artery injury occurred in none of the treated patients. According to these data, routine preoperative HR-CT scan of the temporal bone seems not predictive of intraoperative or postoperative difficulties or complications in BET. Furthermore, the data suggest that fear of injury to the internal carotid artery during BET might be disproportionate. To our knowledge, no report of intraoperative injury to the internal carotid artery has been neither published nor reported on meetings. In our opinion, BET can therefore be performed despite CCD as long as dilation is restricted to the cartilaginous portion of the Eustachian
DISCUSSION In this investigation, 284 HR-CT scans were conducted before BET, evaluating 510 temporal bones for carotid canal dehiscences (Table 2). Eighteen patients (6.3%) showed unilateral or bilateral CCD, yielding comparable rates as reported by Moreano et al. (7.7%) (19). BET was performed without any complications in 278 patients (97.9%). Of the remaining 6 patients, in 3 patients, 4 of 6 BET (0.8% of total of 510 ET) could not be performed.
FIG. 2. A, HR-CT scan of the temporal bone. Status before BET. B, Same patient, postoperative CT scan of the paranasal sinuses, bone window. Soft tissue emphysema extending from the soft tissue around the Eustachian tube to the cheek. Otology & Neurotology, Vol. 35, No. 4, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
638
T. ABDEL-AZIZ ET AL.
FIG. 3. A, Transnasal endoscopic view of the right epipharynx. Mass (white arrow) adjacent to the torus tubarius (asterisk) B, Same patient, HR-CT scan of the temporal bone. Right-sided posterior ethmoid as well as sphenoid sinus opacified with radiopaque tissue, possible newly formed bone (asterisk). Temporal bone with blurred border (white arrow). C, Same patient, MRI scan, T1w with gadolinium, depicting the actual dimensions of the meningioma (white arrow).
tube as ensured by the built-in insertion stop of the balloon catheter used at our institution. Although HR-CT scans may help the inexperienced surgeon in appreciating the relation between carotid canal and Eustachian tube, the given radiation exposure of the patients and low predictive value let us come to the conclusion that HR-CT scans of the temporal bone should not be used as a routine screening tool in patients undergoing BET. However, in patients with failed BET attempts, imaging studies may be useful in search of underlying pathology. Furthermore, in patients with lesions in the epipharynx in the context of impaired middle ear ventilation and absence of hypertrophic adenoid tissue, imaging studies should still be performed to rule out malignancies. REFERENCES 1. Gluth MB, McDonald DR, Weaver AL, et al. Management of Eustachian tube dysfunction with nasal steroid spray: a prospective, randomized, placebo-controlled trial. Arch Otolaryngol Head Neck Surg 2011;137:449Y55. 2. Zollner F. Surgery of the sound conducting apparatus. J Laryngol 1955;69:637Y52. 3. Zollner F. Therapy of the Eustachian tube. Arch Otolaryngol 1963;78:394Y9. 4. Schrom T, Kla¨ring S, Sedlmaier B. Treatment of chronic tube dysfunction. Use of the tube conductor [in German]. HNO 2007;55:871Y5. 5. Wullstein H. Eustachian tube in tympanoplasty. AMA Arch Otolaryngol 1960;71:408Y10. 6. House WF, Glasscock ME 3rd, Miles J. Eustachian tuboplasty. Laryngoscope 1969;79:1765Y82.
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Otology & Neurotology, Vol. 35, No. 4, 2014
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