Acta Oto-Laryngologica. 2014; 134: 429–432
ORIGINAL ARTICLE
Delayed facial nerve palsy after surgery for the EsteemÒ fully implantable middle ear hearing device
MAURIZIO BARBARA, LUIGI VOLPINI & SIMONETTA MONINI Otolaryngology Clinic, NESMOS Department, Sapienza Rome, Sant’Andrea University Hospital, Rome, Italy
Abstract Conclusion: Delayed facial nerve (FN) impairment was shown to occur after EsteemÒ surgery, and taste disturbances were found in a limited number of subjects. Thus, when this type of active middle ear implant (AMEI) is to be implanted, these specific complications need to be shared with the candidate. Objectives: To report on FN involvement in EsteemÒ AMEI surgery. Methods: A total of 23 males and 11 females, who presented with sensorineural hearing loss of varying severity, underwent surgical implantation of the EsteemÒ AMEI. FN function was assessed according to the House-Brackmann (HB) grading system. A specific question regarding taste impairment was administered to each patient on the first day and 3 months after surgery. Results: None of the patients presented with a FN deficit in the first postoperative days. In three patients (8.8%), FN palsy developed after 7 days (two patients) and 10 days (one patient), and the severities were HB 4 (two cases) and HB 5 (one case). All patients fully recovered (HB 1) after 6–8 weeks. In 10 of the 34 implanted subjects (29.4%), taste disturbances were found on postoperative day 1, and these impairments remained in only 6 (17.6%) patients at the 3-month postoperative follow-up.
Keywords: Active middle ear implant, taste, chorda tympani nerve
Introduction Active middle ear implants (AMEIs) are gradually becoming an option for the rehabilitation of conductive, mixed or purely sensorineural hearing loss. Regarding their different assembly, they are commonly named fully or partially implantable AMEIs, the former being completely inserted into the body and consequently invisible from the outside. The EsteemÒ is a fully implantable AMEI that is indicated for cases of purely sensorineural hearing loss and has been implanted in Europe, Asia and, beginning with FDA (Food and Drug Administration) clearance in March 2010, the USA [1]. In addition to being invisible, the EsteemÒ device has some unique features, such as the absence of a microphone and a non-rechargeable battery that needs to be replaced after a certain number of years of usage. For the above-mentioned reasons, the EsteemÒ device may
be considered an appealing device for hearingimpaired individuals with unsatisfactory hearing aid performances, stenosing diseases of the external ear canal or cosmetic issues with the wearing of conventional hearing aids. Surgical implantation of the EsteemÒ device shares some common steps with the routine surgical procedures that are used for chronic otitis media, such as mastoidectomy and posterior tympanotomy. Therefore, the EsteemÒ surgery carries some risks of complications that include taste disturbances and facial nerve (FN) palsy, both of which are clearly related to damage of the VII cranial nerve [2]. The occurrence of transient palsy has been previously reported to range from 5% to 33% [2–5], while permanent deficits have been reported to occur in 2% of cases [2]. The aims of the present paper were to report on FN involvement after EsteemÒ surgery in a series of subjects who were implanted at a single center and
Correspondence: Prof. Maurizio Barbara MD PhD, Chairman of Otorhinolaryngology, Sant’Andrea Hospital, via di Grottarossa 1035, 00189 Rome, Italy. E-mail: [email protected]
(Received 18 September 2013; accepted 13 November 2013) ISSN 0001-6489 print/ISSN 1651-2251 online Ó 2014 Informa Healthcare DOI: 10.3109/00016489.2013.868602
430
M. Barbara et al.
to discuss the possible factors that caused this unpleasant complication. Material and methods From July 2007 to July 2013, 34 subjects (23 men, 11 females) were implanted with an EsteemÒ device (Envoy Medical, St Paul, MN, USA) at a tertiary university hospital by the same surgeon. Surgical and postoperative functional details have been reported previously [6,7]. Following the recommended best practice protocol, the main surgical steps are as follows: . . .
. .
. .
. .
Wide, lazy-C retroauricular incision; Enlarged mastoidectomy, extending to the sinodural angle and to the mastoid tip; Posterior epitympanectomy with full visualization of the incus body, the incudo-malleolar joint and the malleus head; Wide posterior tympanotomy with systematic resection of the chorda tympani nerve (CTN); Removal of the long process of the incus with a diode laser (Medilas D fibertom, Dornier MedTech Europe GmbH, Wessling, Germany) set at 7 W, using intermittent pulses of 0.5 ms duration; Precoating of the stapes head with Bioglass cement (EnvoyCemÒ, Envoy Medical); Stabilization of the transducer’s body with hydroxyapatite cement (MedCemÒ, Envoy Medical) within the mastoidectomy cavity; Cementing of the sensor tip onto the incus body with EnvoyCemÒ followed by neojoint creation; Cementing of the driver tip around the precoated stapes head with EnvoyCemÒ.
All surgeries were performed under EMG-based intraoperative FN monitoring (Nerve Integrity Monitor System; Medtronic, Inc., Minneapolis, MN, USA) as recommended by the company’s best practice protocol. Results Neither abnormal FN courses nor dehiscence from the fallopian canal were observed in any surgery. In all cases, while paying particular attention to widening the facial recess approach up to its lateral side, both the fibrous annulus and the CTN were exposed from the bony wall; the latter was regularly avulsed in close proximity to its branching point from the vertical FN segment. FN function at the postoperative awakening was normal (House-Brackmann score 1: HB 1) [8] in all patients. The postoperative course was devoid of complications for all but three patients (8.8%) who,
on days 7, 8, and 10, displayed facial weakness on the operated side. The FN deficit was graded as HB 4 for two patients and HB 5 for the other patient. These three patients were immediately treated with steroids, antiviral drugs, and physical rehabilitation, and they all fully recovered (HB 1) within 4–7 weeks after the onset of FN palsy. Taste disturbances on the ipsilateral side were reported on the day after surgery in 10 patients (29.4%): 8 patients spontaneously, and 2 only when specifically asked. These symptoms remained persistent in six patients (17.6%). Discussion Postoperative FN palsy occurring 1 or 2 days after surgery is commonly considered to be one of the more worrying complications after both major and minor surgical procedures on the ear. When FN palsy occurs days after the surgery, its nosology changes, as indicated mainly by the timing of FN palsy onset and it is referred to as delayed FN palsy (DFNP). DFNP is not rare. Several reports have described the occurrence of DFNP after skull base fractures [9], after the removal of vestibular schwannomas [10], after tympanomastoidectomies [11], after stapes surgery [12], and after cochlear implantation [11]. This clinical entity is generally considered to have a benign and favorable outcome in terms of functional recovery; however, when DFNP occurs, it creates a stressful situation for both the patient and the surgeon. DFNP is thought to derive from viral (herpes simplex) reactivation due to situations that create local immunosuppression, which can occur after any surgical procedure of the ear [13]; however, in the case of the EsteemÒ surgery, other causes should be discussed. Primarily, thermal damage is worth mentioning for the use of a rotating bur in close proximity to the FN to create the facial recess approach [14] and the use of the laser for the resection of the long process of the incus [15]. Both steps may theoretically induce intra-osseous FN swelling, but the clinical manifestation of this swelling should occur 1–2 days after surgery at the latest, and is unlikely after a week, which is the time-frame in which FN disturbances in our patients were observed. An additional reason regards the use of cements of different compositions. One type of cement (MedCemÒ) is made of hydroxyapatite, which, once amalgamated, is poured with a syringe into the mastoidectomy cavity to stabilize the bodies of the two transducers after they have been positioned in contact with the ossicles. The other cement is a Bioglass type (EnvoyCemÒ); small amounts are used to precoat the denuded stapes head and then on the ossicular chain.
Facial involvement in AMEI surgery While curing of the EnvoyCemÒ takes approximately 10 min, the MedCemÒ begins to cure in approximately 20 min, but curing continues for several days. Thus, postoperative sustained elevations in middle ear temperature cannot be ruled out. An additional explanation for local overheating conditions is related to the fact that multilayer piezoelectric components, when oscillating at high frequencies, emit heat [16]. This source of heat could possibly cause side effects, but it is unlikely that such highfrequency oscillations would be required because the vibrations needed for the piezoelectric transducers of the EsteemÒ are of the order of a few micrometers. Taste disturbances are a well-known complication after middle ear surgery and can occur after simple manipulations or stretching of the CTN. Taste disturbances apparently occur more often when surgery is performed on a non-infected ear (e.g. surgery for otosclerosis [17] or cochlear implantation [18]). However, the impairment is usually temporary even if the CTN is severed; thus, the rather favorable data from our EsteemÒ patients are not surprising. The unavoidable resection of the CTN during EsteemÒ surgery may be a possible concurrent cause of DFNP. A few previous reports have hypothesized that FN palsy could be a secondary effect of the primary involvement of the CTN [19,20]. As previously mentioned, during the EsteemÒ surgery, the CTN is regularly sacrificed and avulsed by the rotating bur near its branching from the FN mastoid segment. Differently from a radical mastoidectomy, where CTN function could be already compromised by the pathology, one may hypothesize that this maneuver may jeopardize the FN function in a non-infected ear. Although it may be argued that experienced surgeons should be able to isolate and spare the CTN during this maneuver, the preservation of the CTN is discouraged because, being loose in the facial recess area, it may eventually touch the driver transducer and cause the device to malfunction due to mechanical feedback. The recent advent of smaller transducers could eventually eliminate the need to transect the CTN and rule this out as a possible cause of DFNP after EsteemÒ surgery. Based on the literature and the present data, EsteemÒ surgery seems to carry greater risks of FN involvement than the implantation surgery for other AMEI devices (e.g. Vibrant Soundbridge or Carina). This complication most frequently manifests with a delayed onset and, therefore, full recovery is normally achieved. Nevertheless, the risk of FN involvement should certainly be included in the information that the candidate must consent to before undergoing surgery and should be given the same importance
431
as other device-related issues, such as the duration of battery life and the possibility of postoperative hearing loss due to ossicular interruption. Despite these possible complications, the functional results of EsteemÒ surgery prompt us to keep using the EsteemÒ device as a rehabilitation tool for subjects with sensorineural hearing loss and poor hearing aid performance. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
References [1] Kraus EM, Shohet JA, Catalano PJ. Envoy Esteem totally implantable hearing system: phase 2 trial, 1-year hearing results. Otolaryngol Head Neck Surg 2011;145:100–9. [2] Klein K, Nardelli A, Stafinski T. A systematic review of the safety and effectiveness of fully implantable middle ear hearing devices: the carina and esteem systems. Otol Neurotol 2012;33:916–21. [3] Memari F, Asghari A, Daneshi A, Jalali A. Safety and patient selection of totally implantable hearing aid surgery: envoy system, Esteem. Eur Arch Otorhinolaryngol 2011;268: 1421–5. [4] Gerard JM, Thill MP, Chantrain G, Gersdorff M, Deggouj N. Esteem 2 middle ear implant: our experience. Audiol Neurotol 2012;17:267–74. [5] Murali S, Krishnan PV, Bansal T, Karthikeyan K, Natarajan K, Kameswaran M. Totally implantable hearing aid surgical technique and the first Indian experience with Envoy system. Indian J Otolaryngol Head Neck Surg 2009; 61:245–51. [6] Barbara M, Biagini M, Monini S. The totally implantable middle ear device ‘Esteem’ for rehabilitation of severe sensorineural hearing loss. Acta Otolaryngol 2011;131:399–404. [7] Monini S, Biagini M, Atturo F, Barbara M. Esteem(Ò) middle ear device versus conventional hearing aids for rehabilitation of bilateral sensorineural hearing loss. Eur Arch Otorhinolaryngol 2013;270:2027–33. [8] House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg 1985;93:146–7. [9] Baumann BM, Jarecki J. Posttraumatic delayed facial nerve palsy. Am J Emerg Med 2008;26:115.e1–2. [10] Arriaga MA, Luxford WM, Atkins JS Jr, Kwartler JA. Predicting long term facial nerve outcome after acoustic neuroma surgery. Otolaryngol Head Neck Surg 1993;108:220–4. [11] Kitahara T, Kubo T, Doi K, Mishiro Y, Kondoh K, Horii A, et al. Delayed facial nerve palsy after otologic surgery. Nihon Jibiinkoka Gakkai Kaiho 2006;109:600–5. [12] Althaus SR, House HP. Delayed post-stapedectomy facial paralysis: a report of five cases. Laryngoscope 1973;83: 1234–40. [13] Gianoli GJ. Viral titers and delayed facial palsy after acoustic neuroma surgery. Otolaryngol Head Neck Surg 2002;127: 427–31. [14] Eskander A, Holler T, Papsin BC. Delayed facial nerve paresis after using the KTP laser in the treatment of cholesteatoma despite inter-operative facial nerve monitoring. Int J Pediatr Otorhinolaryngol 2010;74:823–4.
432
M. Barbara et al.
[15] Ator GA, Coker NJ, Jenkins HA. Thermal injury to the intratemporal facial nerve following CO2 laser application. Am J Otolaryngol 1985;6:437–42. [16] Ronkanen P, Kallio P, Villko M, Koivo HN. Self-heating of piezoelectric actuators: measurement and compensation. Micro-Nanomechatronics and Human Science 2004. 313–18. [17] Guder E, Böttcher A, Pau HW, Just T. Taste function after stapes surgery. Auris Nasus Larynx 2012;39:562–6.
[18] Alzhrani F, Lenarz T, Teschner M. Taste sensation following cochlear implantation surgery. Cochlear Implants Int 2013; 14:200–6. [19] May M, Schlaepfer WM. Bell’s palsy and the chorda tympani nerve: a clinical and electron microscopic study. Laryngoscope 1975;85:1957–75. [20] Gussen R. Pathogenesis of Bell’s palsy. Retrograde epineurial edema and postedematous fibrous compression neuropathy of the facial nerve. Ann Otol Rhinol Laryngol 1977;86:549–58.
Copyright of Acta Oto-Laryngologica is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
ORIGINAL ARTICLE
Delayed facial nerve palsy after surgery for the EsteemÒ fully implantable middle ear hearing device
MAURIZIO BARBARA, LUIGI VOLPINI & SIMONETTA MONINI Otolaryngology Clinic, NESMOS Department, Sapienza Rome, Sant’Andrea University Hospital, Rome, Italy
Abstract Conclusion: Delayed facial nerve (FN) impairment was shown to occur after EsteemÒ surgery, and taste disturbances were found in a limited number of subjects. Thus, when this type of active middle ear implant (AMEI) is to be implanted, these specific complications need to be shared with the candidate. Objectives: To report on FN involvement in EsteemÒ AMEI surgery. Methods: A total of 23 males and 11 females, who presented with sensorineural hearing loss of varying severity, underwent surgical implantation of the EsteemÒ AMEI. FN function was assessed according to the House-Brackmann (HB) grading system. A specific question regarding taste impairment was administered to each patient on the first day and 3 months after surgery. Results: None of the patients presented with a FN deficit in the first postoperative days. In three patients (8.8%), FN palsy developed after 7 days (two patients) and 10 days (one patient), and the severities were HB 4 (two cases) and HB 5 (one case). All patients fully recovered (HB 1) after 6–8 weeks. In 10 of the 34 implanted subjects (29.4%), taste disturbances were found on postoperative day 1, and these impairments remained in only 6 (17.6%) patients at the 3-month postoperative follow-up.
Keywords: Active middle ear implant, taste, chorda tympani nerve
Introduction Active middle ear implants (AMEIs) are gradually becoming an option for the rehabilitation of conductive, mixed or purely sensorineural hearing loss. Regarding their different assembly, they are commonly named fully or partially implantable AMEIs, the former being completely inserted into the body and consequently invisible from the outside. The EsteemÒ is a fully implantable AMEI that is indicated for cases of purely sensorineural hearing loss and has been implanted in Europe, Asia and, beginning with FDA (Food and Drug Administration) clearance in March 2010, the USA [1]. In addition to being invisible, the EsteemÒ device has some unique features, such as the absence of a microphone and a non-rechargeable battery that needs to be replaced after a certain number of years of usage. For the above-mentioned reasons, the EsteemÒ device may
be considered an appealing device for hearingimpaired individuals with unsatisfactory hearing aid performances, stenosing diseases of the external ear canal or cosmetic issues with the wearing of conventional hearing aids. Surgical implantation of the EsteemÒ device shares some common steps with the routine surgical procedures that are used for chronic otitis media, such as mastoidectomy and posterior tympanotomy. Therefore, the EsteemÒ surgery carries some risks of complications that include taste disturbances and facial nerve (FN) palsy, both of which are clearly related to damage of the VII cranial nerve [2]. The occurrence of transient palsy has been previously reported to range from 5% to 33% [2–5], while permanent deficits have been reported to occur in 2% of cases [2]. The aims of the present paper were to report on FN involvement after EsteemÒ surgery in a series of subjects who were implanted at a single center and
Correspondence: Prof. Maurizio Barbara MD PhD, Chairman of Otorhinolaryngology, Sant’Andrea Hospital, via di Grottarossa 1035, 00189 Rome, Italy. E-mail: [email protected]
(Received 18 September 2013; accepted 13 November 2013) ISSN 0001-6489 print/ISSN 1651-2251 online Ó 2014 Informa Healthcare DOI: 10.3109/00016489.2013.868602
430
M. Barbara et al.
to discuss the possible factors that caused this unpleasant complication. Material and methods From July 2007 to July 2013, 34 subjects (23 men, 11 females) were implanted with an EsteemÒ device (Envoy Medical, St Paul, MN, USA) at a tertiary university hospital by the same surgeon. Surgical and postoperative functional details have been reported previously [6,7]. Following the recommended best practice protocol, the main surgical steps are as follows: . . .
. .
. .
. .
Wide, lazy-C retroauricular incision; Enlarged mastoidectomy, extending to the sinodural angle and to the mastoid tip; Posterior epitympanectomy with full visualization of the incus body, the incudo-malleolar joint and the malleus head; Wide posterior tympanotomy with systematic resection of the chorda tympani nerve (CTN); Removal of the long process of the incus with a diode laser (Medilas D fibertom, Dornier MedTech Europe GmbH, Wessling, Germany) set at 7 W, using intermittent pulses of 0.5 ms duration; Precoating of the stapes head with Bioglass cement (EnvoyCemÒ, Envoy Medical); Stabilization of the transducer’s body with hydroxyapatite cement (MedCemÒ, Envoy Medical) within the mastoidectomy cavity; Cementing of the sensor tip onto the incus body with EnvoyCemÒ followed by neojoint creation; Cementing of the driver tip around the precoated stapes head with EnvoyCemÒ.
All surgeries were performed under EMG-based intraoperative FN monitoring (Nerve Integrity Monitor System; Medtronic, Inc., Minneapolis, MN, USA) as recommended by the company’s best practice protocol. Results Neither abnormal FN courses nor dehiscence from the fallopian canal were observed in any surgery. In all cases, while paying particular attention to widening the facial recess approach up to its lateral side, both the fibrous annulus and the CTN were exposed from the bony wall; the latter was regularly avulsed in close proximity to its branching point from the vertical FN segment. FN function at the postoperative awakening was normal (House-Brackmann score 1: HB 1) [8] in all patients. The postoperative course was devoid of complications for all but three patients (8.8%) who,
on days 7, 8, and 10, displayed facial weakness on the operated side. The FN deficit was graded as HB 4 for two patients and HB 5 for the other patient. These three patients were immediately treated with steroids, antiviral drugs, and physical rehabilitation, and they all fully recovered (HB 1) within 4–7 weeks after the onset of FN palsy. Taste disturbances on the ipsilateral side were reported on the day after surgery in 10 patients (29.4%): 8 patients spontaneously, and 2 only when specifically asked. These symptoms remained persistent in six patients (17.6%). Discussion Postoperative FN palsy occurring 1 or 2 days after surgery is commonly considered to be one of the more worrying complications after both major and minor surgical procedures on the ear. When FN palsy occurs days after the surgery, its nosology changes, as indicated mainly by the timing of FN palsy onset and it is referred to as delayed FN palsy (DFNP). DFNP is not rare. Several reports have described the occurrence of DFNP after skull base fractures [9], after the removal of vestibular schwannomas [10], after tympanomastoidectomies [11], after stapes surgery [12], and after cochlear implantation [11]. This clinical entity is generally considered to have a benign and favorable outcome in terms of functional recovery; however, when DFNP occurs, it creates a stressful situation for both the patient and the surgeon. DFNP is thought to derive from viral (herpes simplex) reactivation due to situations that create local immunosuppression, which can occur after any surgical procedure of the ear [13]; however, in the case of the EsteemÒ surgery, other causes should be discussed. Primarily, thermal damage is worth mentioning for the use of a rotating bur in close proximity to the FN to create the facial recess approach [14] and the use of the laser for the resection of the long process of the incus [15]. Both steps may theoretically induce intra-osseous FN swelling, but the clinical manifestation of this swelling should occur 1–2 days after surgery at the latest, and is unlikely after a week, which is the time-frame in which FN disturbances in our patients were observed. An additional reason regards the use of cements of different compositions. One type of cement (MedCemÒ) is made of hydroxyapatite, which, once amalgamated, is poured with a syringe into the mastoidectomy cavity to stabilize the bodies of the two transducers after they have been positioned in contact with the ossicles. The other cement is a Bioglass type (EnvoyCemÒ); small amounts are used to precoat the denuded stapes head and then on the ossicular chain.
Facial involvement in AMEI surgery While curing of the EnvoyCemÒ takes approximately 10 min, the MedCemÒ begins to cure in approximately 20 min, but curing continues for several days. Thus, postoperative sustained elevations in middle ear temperature cannot be ruled out. An additional explanation for local overheating conditions is related to the fact that multilayer piezoelectric components, when oscillating at high frequencies, emit heat [16]. This source of heat could possibly cause side effects, but it is unlikely that such highfrequency oscillations would be required because the vibrations needed for the piezoelectric transducers of the EsteemÒ are of the order of a few micrometers. Taste disturbances are a well-known complication after middle ear surgery and can occur after simple manipulations or stretching of the CTN. Taste disturbances apparently occur more often when surgery is performed on a non-infected ear (e.g. surgery for otosclerosis [17] or cochlear implantation [18]). However, the impairment is usually temporary even if the CTN is severed; thus, the rather favorable data from our EsteemÒ patients are not surprising. The unavoidable resection of the CTN during EsteemÒ surgery may be a possible concurrent cause of DFNP. A few previous reports have hypothesized that FN palsy could be a secondary effect of the primary involvement of the CTN [19,20]. As previously mentioned, during the EsteemÒ surgery, the CTN is regularly sacrificed and avulsed by the rotating bur near its branching from the FN mastoid segment. Differently from a radical mastoidectomy, where CTN function could be already compromised by the pathology, one may hypothesize that this maneuver may jeopardize the FN function in a non-infected ear. Although it may be argued that experienced surgeons should be able to isolate and spare the CTN during this maneuver, the preservation of the CTN is discouraged because, being loose in the facial recess area, it may eventually touch the driver transducer and cause the device to malfunction due to mechanical feedback. The recent advent of smaller transducers could eventually eliminate the need to transect the CTN and rule this out as a possible cause of DFNP after EsteemÒ surgery. Based on the literature and the present data, EsteemÒ surgery seems to carry greater risks of FN involvement than the implantation surgery for other AMEI devices (e.g. Vibrant Soundbridge or Carina). This complication most frequently manifests with a delayed onset and, therefore, full recovery is normally achieved. Nevertheless, the risk of FN involvement should certainly be included in the information that the candidate must consent to before undergoing surgery and should be given the same importance
431
as other device-related issues, such as the duration of battery life and the possibility of postoperative hearing loss due to ossicular interruption. Despite these possible complications, the functional results of EsteemÒ surgery prompt us to keep using the EsteemÒ device as a rehabilitation tool for subjects with sensorineural hearing loss and poor hearing aid performance. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
References [1] Kraus EM, Shohet JA, Catalano PJ. Envoy Esteem totally implantable hearing system: phase 2 trial, 1-year hearing results. Otolaryngol Head Neck Surg 2011;145:100–9. [2] Klein K, Nardelli A, Stafinski T. A systematic review of the safety and effectiveness of fully implantable middle ear hearing devices: the carina and esteem systems. Otol Neurotol 2012;33:916–21. [3] Memari F, Asghari A, Daneshi A, Jalali A. Safety and patient selection of totally implantable hearing aid surgery: envoy system, Esteem. Eur Arch Otorhinolaryngol 2011;268: 1421–5. [4] Gerard JM, Thill MP, Chantrain G, Gersdorff M, Deggouj N. Esteem 2 middle ear implant: our experience. Audiol Neurotol 2012;17:267–74. [5] Murali S, Krishnan PV, Bansal T, Karthikeyan K, Natarajan K, Kameswaran M. Totally implantable hearing aid surgical technique and the first Indian experience with Envoy system. Indian J Otolaryngol Head Neck Surg 2009; 61:245–51. [6] Barbara M, Biagini M, Monini S. The totally implantable middle ear device ‘Esteem’ for rehabilitation of severe sensorineural hearing loss. Acta Otolaryngol 2011;131:399–404. [7] Monini S, Biagini M, Atturo F, Barbara M. Esteem(Ò) middle ear device versus conventional hearing aids for rehabilitation of bilateral sensorineural hearing loss. Eur Arch Otorhinolaryngol 2013;270:2027–33. [8] House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg 1985;93:146–7. [9] Baumann BM, Jarecki J. Posttraumatic delayed facial nerve palsy. Am J Emerg Med 2008;26:115.e1–2. [10] Arriaga MA, Luxford WM, Atkins JS Jr, Kwartler JA. Predicting long term facial nerve outcome after acoustic neuroma surgery. Otolaryngol Head Neck Surg 1993;108:220–4. [11] Kitahara T, Kubo T, Doi K, Mishiro Y, Kondoh K, Horii A, et al. Delayed facial nerve palsy after otologic surgery. Nihon Jibiinkoka Gakkai Kaiho 2006;109:600–5. [12] Althaus SR, House HP. Delayed post-stapedectomy facial paralysis: a report of five cases. Laryngoscope 1973;83: 1234–40. [13] Gianoli GJ. Viral titers and delayed facial palsy after acoustic neuroma surgery. Otolaryngol Head Neck Surg 2002;127: 427–31. [14] Eskander A, Holler T, Papsin BC. Delayed facial nerve paresis after using the KTP laser in the treatment of cholesteatoma despite inter-operative facial nerve monitoring. Int J Pediatr Otorhinolaryngol 2010;74:823–4.
432
M. Barbara et al.
[15] Ator GA, Coker NJ, Jenkins HA. Thermal injury to the intratemporal facial nerve following CO2 laser application. Am J Otolaryngol 1985;6:437–42. [16] Ronkanen P, Kallio P, Villko M, Koivo HN. Self-heating of piezoelectric actuators: measurement and compensation. Micro-Nanomechatronics and Human Science 2004. 313–18. [17] Guder E, Böttcher A, Pau HW, Just T. Taste function after stapes surgery. Auris Nasus Larynx 2012;39:562–6.
[18] Alzhrani F, Lenarz T, Teschner M. Taste sensation following cochlear implantation surgery. Cochlear Implants Int 2013; 14:200–6. [19] May M, Schlaepfer WM. Bell’s palsy and the chorda tympani nerve: a clinical and electron microscopic study. Laryngoscope 1975;85:1957–75. [20] Gussen R. Pathogenesis of Bell’s palsy. Retrograde epineurial edema and postedematous fibrous compression neuropathy of the facial nerve. Ann Otol Rhinol Laryngol 1977;86:549–58.
Copyright of Acta Oto-Laryngologica is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
