Eur Arch Otorhinolaryngol DOI 10.1007/s00405-013-2789-1
OTOLOGY
Fallopian canal dehiscence at pediatric cholesteatoma surgery Akihiro Shinnabe • Hiroki Yamamoto • Mariko Hara • Masayo Hasegawa • Shingo Matsuzawa • Hiromi Kanazawa Naohiro Yoshida • Yukiko Iino
•
Received: 6 September 2013 / Accepted: 16 October 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract The objectives of the study were to investigate the characteristics of ears with dehiscence of the fallopian canal at the time of cholesteatoma surgery and the relationship between dehiscence and age, and to consider the reasons why the fallopian canal tends to be preserved in pediatric patients. This study included 37 ears with cholesteatoma in pediatric patients (mean age 9.2 years, age range 4–14 years) and 273 ears with cholesteatoma in nonpediatric patients (mean age 45 years, age range 15–84 years). Patients were treated between January 2006 and April 2012. All patients had undergone prior tympanoplasty under general anesthesia at our institution. Facial canal dehiscence was evaluated by inspection and through palpation by blunt picking after the pathological tissues had been removed. The size of fallopian canal dehiscence was not investigated in this study. The frequency of dehiscence of the fallopian canal according to the type of cholesteatoma and coexisting pathological conditions, including destruction of the stapes, presence of a labyrinthine fistula, and dural exposure, were compared between the pediatric and non-pediatric groups. The frequency of dehiscence in cases with destruction of the stapes was also compared between the pediatric and non-pediatric groups. Dehiscence of the fallopian canal occurred in 6 of 37 ears (16.8 %) in the pediatric group and 91 of 273 ears (33.3 %) in the non-pediatric group (p \ 0.05). In congenital cholesteatoma, the frequency of dehiscence was lower in the pediatric group than in the non-pediatric group (p \ 0.05).
A. Shinnabe (&) H. Yamamoto M. Hara M. Hasegawa S. Matsuzawa H. Kanazawa N. Yoshida Y. Iino Department of Otolaryngology, Saitama Medical Center, Jichi Medical University, 1-847 Amanuma-cho, Omiya-ku, Saitama 330-8503, Japan e-mail: [email protected]
However, in other types of cholesteatoma there was no statistically difference between the two types of cholesteatoma. The frequency of the destruction of the stapes was higher in the pediatric group than in the non-pediatric group (43.2 vs. 16.5 %, p \ 0.001). In patients with severe destruction of the stapes, the fallopian canal was preserved more frequently in the pediatric group than in the nonpediatric group (p \ 0.05). The frequency of dehiscence of the fallopian canal at the time of cholesteatoma surgery was lower in the ears of pediatric patients than in the ears of non-pediatric patients. This is probably due to the difference in types of cholesteatoma between the two groups and other unknown mechanisms. Keywords Pediatric cholesteatoma Tympanoplasty Fallopian canal Dehiscence Stapes superstructure
Introduction Dehiscence of the fallopian canal is encountered commonly especially during cholesteatoma surgery [1, 2], and preoperative evaluation of the fallopian canal by temporal bone computed tomography (CT) is necessary for safe surgical management [3]. Previous studies have also reported that labyrinthine fistulas and intracranial complications are associated with dehiscence of the fallopian canal [4–6], which means that dehiscence tends to be encountered frequently in progressive cases. Ozbek et al. [5] and Magliulo et al. [7] reported that dehiscence of the fallopian canal was less frequent in pediatric patients than adult patients with cholesteatoma (pediatric dehiscence 10.3 % vs. adult dehiscence 24.9 %, and pediatric dehiscence 7.8 % vs. adult dehiscence 29.5 %, respectively). In
123
Eur Arch Otorhinolaryngol Fig. 1 Frequencies of the types of cholesteatoma in the pediatric and non-pediatric groups
this study, we focused on pediatric cases to consider why the fallopian canal tends to be preserved in pediatric patients and investigated differences in the frequencies of dehiscence between pediatric and non-pediatric patients according to the type of cholesteatoma, including patients with severe destruction of the stapes. No similar study has previously been reported in the English literature.
and palpation by blunt picking after the pathological tissues had been removed. The size of fallopian canal dehiscence was not investigated in this study. Frequencies and locations of dehiscence of the fallopian canal and coexisting pathological conditions The location of the dehiscence is classified simply into the following three groups:
Methods
(1)
Patients A total of 37 ears with middle ear cholesteatoma in pediatric patients with a mean age of 9.2 years (range 4–14 years) and 273 ears with middle ear cholesteatoma in non-pediatric patients with a mean age of 45 years (range 15–84 years) were included in this study. All patients had undergone prior tympanoplasty under general anesthesia at our institution between January 2006 and April 2012. Figure 1 shows the frequencies of different types of cholesteatoma in pediatric and non-pediatric patients. In pediatric patients with congenital cholesteatoma, 11 of 18 ears (61.1 %) had disease extension beyond the attic. Surgical procedure and method to determine dehiscence of the fallopian canal The surgical procedure for cholesteatoma removal comprises retroauricular incision with a transcanal approach and atticotomy or attico-mastoidectomy. We try to preserve the middle ear mucosa as much as possible and to confirm middle ear ventilation especially anterior to the cochleariform process (i.e., the most anterior area) and the eustachian tube. The canal wall is reconstructed with tragal or conchal cartilage and a cortical bone graft. If necessary, the ossicular chain is reconstructed with cartilage. The surgical records of patients were retrospectively reviewed to determine the frequency of dehiscence of the fallopian canal. Facial canal dehiscence was evaluated by inspection
123
(2)
(3)
If the dehiscence is between the geniculate ganglion and the cochleariform process, it is classified as anterior to the cochleariform process (CP) dehiscence. If the dehiscence is between the CP and the second genu, it is classified as posterior to the CP dehiscence. If the dehiscence is after the lower level of the oval window at the mastoid or vertical segment, it is classified as mastoid segment dehiscence.
These locations were compared between the pediatric and non-pediatric groups. Coexisting pathological conditions were recorded, including destruction of the stapes superstructure (including partial destruction), presence of a labyrinthine fistula, and dural exposure. Comparison of the frequency of dehiscence in ears with destruction of the stapes The frequency of dehiscence in patients with destruction of the stapes was compared between the pediatric and nonpediatric groups using bivariate analysis, and odds ratios with 95 % confidence intervals were calculated. A value of p \ 0.05 was considered to be statistically significant.
Results Six of the 37 ears (16.8 %) in the pediatric group and 91 of the 273 ears (33.3 %) in the non-pediatric group had
Eur Arch Otorhinolaryngol Table 1 Comparisons of the frequencies of dehiscence of the fallopian canal in pediatric and non-pediatric patients according to the type of cholesteatoma
Congenital Pars flaccida Pars tensa Secondary
Pediatric group N = 37 ears
Non-pediatric group N = 273 ears
p value
5.26 %
100 %
\0.05
(1/18)
(2/2)
8.33 %
27.5 %
(1/12)
(49/178)
100 %
53.3 %
(4/4)
(32/60)
0%
24.2 %
(0/2)
(8/33)
0.17 0.17
Table 2 Coexisting pathological conditions in the pediatric and nonpediatric groups Pediatric group N = 37 ears
Non-pediatric group N = 273 ears
p value
Destruction of the stapes
43.2 %
16.5 %
\0.001
(16/37)
(45/273)
Labyrinthine fistula
0%
7%
(0/37)
(19/273)
Dural exposure
5.4 %
7%
(2/37)
(19/273)
NS NS
NS
dehiscence of the fallopian canal, which was a significant difference between the two groups (p \ 0.05). Table 1 shows the frequency of dehiscence of the fallopian canal according to the type of cholesteatoma. In ears with congenital cholesteatoma, the frequency of dehiscence was lower in the pediatric group than in the non-pediatric group (p \ 0.05). However, in ears with other types of cholesteatoma there were no statistical significances in the frequency of dehiscence. Figure 2 shows the locations of dehiscence of the fallopian canal in the pediatric and non-pediatric groups. The tympanic portion was the most frequent location of dehiscence, especially anterior and posterior to the CP in both groups. There were no significant differences in the locations of dehiscence between the two groups. Table 2 shows the coexisting pathological conditions in the pediatric and non-pediatric groups. The frequency of destruction of the stapes was statistically higher in the pediatric group than in the non-pediatric group (43.2 vs. 16.5 %, p \ 0.001). Labyrinthine fistula and dural exposure were rare in the pediatric group, but there were no significant differences in the frequencies of these conditions between the two groups.
Table 3 Comparisons of the frequencies of dehiscence of the fallopian canal in patients with destruction of the stapes in the pediatric and non-pediatric groups Pediatric N = 16 ears Congenital Pars flaccida Pars tensa Secondary
Non-pediatric N = 45 ears
10 %
100 %
(1/10)
(2/2)
0%
62.5 %
(0/2)
(5/8)
100 %
57.1 %
(4/4)
(16/28)
–
71.4 %
p value 0.052 0.2 0.2 –
(5/7) Total
31.3 %
62.2 %
(5/16)
(28/45)
\0.05
Table 3 shows comparisons of the frequencies of dehiscence in the pediatric and non-pediatric groups with destruction of the stapes. In the pediatric group, 16 of 37 ears had destruction of the stapes, of which 5 (31.3 %) had dehiscence of the fallopian canal. In the non-pediatric group, 45 of 273 ears had destruction of the stapes, of which 28 (62.2 %) had dehiscence of the fallopian canal. In cases with destruction of the stapes, the fallopian canal was
Fig. 2 Locations of dehiscence in the pediatric and nonpediatric groups
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Eur Arch Otorhinolaryngol
more frequently preserved in the pediatric group than in the non-pediatric group (p \ 0.05).
of the pediatric fallopian canal under conditions of disease such as cholesteatoma.
Discussion
Conclusions
In this study, the frequency of dehiscence of the fallopian canal was significantly lower in pediatric patients with cholesteatoma than in non-pediatric patients with cholesteatoma, which is consistent with previously reported findings [5, 7–9]. In pediatric patients, the frequency of dehiscence was influenced by the type of cholesteatoma. In ears with pars tensa cholesteatoma, the frequency of dehiscence was high, which means that cholesteatoma progressed directly to the fallopian canal around the stapes even in pediatric cases. However, the small number of pars tensa cholesteatoma has a minor influence on the overall comparison between the pediatric and non-pediatric groups, as the proportion of ears with pars tensa cholesteatoma was lower in the pediatric group than in the nonpediatric group (10 vs. 22 %). The data comparing the frequencies of dehiscence in patients with destruction of the stapes are also important. As the stapes is very close to the fallopian canal, there is extensive cholesteatoma around the fallopian canal in such cases. In our series, destruction of the stapes was more frequent in the pediatric group, but the fallopian canal was more frequently preserved in the pediatric group than in the non-pediatric group. This indicated that the stapes superstructure was more fragile than the fallopian canal, but we have not found the reason why fallopian canal tends to be preserved even in such a progressive case. Spector et al. [10] investigated temporal bones in the fetus and neonates and reported that normal ossification of the lateral wall of the fallopian canal started at 21 weeks of gestation, anteriorly from the apical otic ossification centers near the CP, and at 26 weeks from the canalicular ossification centers near the stapedius muscle and was completed during the neonatal period. The lateral wall of the fallopian canal gradually thins with growth due to temporal bone pneumatization. The pediatric temporal bone has high water content and is more vascular than the non-pediatric temporal bone. Further investigation is necessary to clarify the mechanisms including defense systems
Except in cases of pars tensa cholesteatoma, the frequency of dehiscence of the fallopian canal at the time of cholesteatoma surgery was lower in the ears of pediatric patients than in the ears of non-pediatric patients. This is probably due to the difference in types of cholesteatoma between the two groups and other unknown mechanisms.
123
Conflict of interest
None.
References 1. Di Martino E, Sellhause B, Haensel J, Schlegel JG, Westhofen M, Prescher A (2005) Fallopian canal dehiscence: a survey of clinical and anatomical findings. Eur Arch Otorhinolaryngol 262:120–126 2. Selesnick SH, Lynn-Macrae AG (2001) The incidence of facial nerve dehiscence at surgery for cholesteatoma. Otol Neurotol 22:129–132 3. Yu Z, Wang Z, Yang B, Han D, Zhang L (2011) The value of preoperative CT scan of tympanic facial nerve canal in tympanomastoid surgery. Acta Otolaryngol 131:774–778 4. Jaswal A, Jana AK, Sikder B, Sadhukhan SK, Jana U, Nandi TK (2008) Fallopian canal dehiscence: can it be predicted. Indian J Otolaryngol Head Neck Surg 60:11–15 5. Ozbek C, Tuna E, Ciftci O, Yazkan O, Ozdem C (2009) Incidence of fallopian canal dehiscence at surgery for chronic otitis media. Eur Arch Otorhinolaryngol 266:357–362 6. Bayazit YA, Ozer E, Kanlikama M (2002) Gross dehiscence of the bone covering the facial nerve in the light of otological surgery. J Laryngol Otol 116:800–803 7. Magliulo G, Colicchio MG, Appiani MC (2011) Facial nerve dehiscence and cholesteatoma. Ann Otol Rhinol Laryngol 120:261–267 8. Moody MW, Lambert PR (2007) Incidence of dehiscence of the facial nerve in 416 cases of cholesteatoma. Otol Neurotol 28:400–404 9. Perez B, Campos ME, Rivero J, Lopez Campos D, Lo´pez-Aguado D (1997) Incidence of dehiscences in the fallopian canal. Int J Pediatr Otorhinolaryngol 40:51–60 10. Spector JG, Ge X (1993) Ossification patterns of the tympanic facial canal in the human fetus and neonate. Laryngoscope 103:1052–1065
OTOLOGY
Fallopian canal dehiscence at pediatric cholesteatoma surgery Akihiro Shinnabe • Hiroki Yamamoto • Mariko Hara • Masayo Hasegawa • Shingo Matsuzawa • Hiromi Kanazawa Naohiro Yoshida • Yukiko Iino
•
Received: 6 September 2013 / Accepted: 16 October 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract The objectives of the study were to investigate the characteristics of ears with dehiscence of the fallopian canal at the time of cholesteatoma surgery and the relationship between dehiscence and age, and to consider the reasons why the fallopian canal tends to be preserved in pediatric patients. This study included 37 ears with cholesteatoma in pediatric patients (mean age 9.2 years, age range 4–14 years) and 273 ears with cholesteatoma in nonpediatric patients (mean age 45 years, age range 15–84 years). Patients were treated between January 2006 and April 2012. All patients had undergone prior tympanoplasty under general anesthesia at our institution. Facial canal dehiscence was evaluated by inspection and through palpation by blunt picking after the pathological tissues had been removed. The size of fallopian canal dehiscence was not investigated in this study. The frequency of dehiscence of the fallopian canal according to the type of cholesteatoma and coexisting pathological conditions, including destruction of the stapes, presence of a labyrinthine fistula, and dural exposure, were compared between the pediatric and non-pediatric groups. The frequency of dehiscence in cases with destruction of the stapes was also compared between the pediatric and non-pediatric groups. Dehiscence of the fallopian canal occurred in 6 of 37 ears (16.8 %) in the pediatric group and 91 of 273 ears (33.3 %) in the non-pediatric group (p \ 0.05). In congenital cholesteatoma, the frequency of dehiscence was lower in the pediatric group than in the non-pediatric group (p \ 0.05).
A. Shinnabe (&) H. Yamamoto M. Hara M. Hasegawa S. Matsuzawa H. Kanazawa N. Yoshida Y. Iino Department of Otolaryngology, Saitama Medical Center, Jichi Medical University, 1-847 Amanuma-cho, Omiya-ku, Saitama 330-8503, Japan e-mail: [email protected]
However, in other types of cholesteatoma there was no statistically difference between the two types of cholesteatoma. The frequency of the destruction of the stapes was higher in the pediatric group than in the non-pediatric group (43.2 vs. 16.5 %, p \ 0.001). In patients with severe destruction of the stapes, the fallopian canal was preserved more frequently in the pediatric group than in the nonpediatric group (p \ 0.05). The frequency of dehiscence of the fallopian canal at the time of cholesteatoma surgery was lower in the ears of pediatric patients than in the ears of non-pediatric patients. This is probably due to the difference in types of cholesteatoma between the two groups and other unknown mechanisms. Keywords Pediatric cholesteatoma Tympanoplasty Fallopian canal Dehiscence Stapes superstructure
Introduction Dehiscence of the fallopian canal is encountered commonly especially during cholesteatoma surgery [1, 2], and preoperative evaluation of the fallopian canal by temporal bone computed tomography (CT) is necessary for safe surgical management [3]. Previous studies have also reported that labyrinthine fistulas and intracranial complications are associated with dehiscence of the fallopian canal [4–6], which means that dehiscence tends to be encountered frequently in progressive cases. Ozbek et al. [5] and Magliulo et al. [7] reported that dehiscence of the fallopian canal was less frequent in pediatric patients than adult patients with cholesteatoma (pediatric dehiscence 10.3 % vs. adult dehiscence 24.9 %, and pediatric dehiscence 7.8 % vs. adult dehiscence 29.5 %, respectively). In
123
Eur Arch Otorhinolaryngol Fig. 1 Frequencies of the types of cholesteatoma in the pediatric and non-pediatric groups
this study, we focused on pediatric cases to consider why the fallopian canal tends to be preserved in pediatric patients and investigated differences in the frequencies of dehiscence between pediatric and non-pediatric patients according to the type of cholesteatoma, including patients with severe destruction of the stapes. No similar study has previously been reported in the English literature.
and palpation by blunt picking after the pathological tissues had been removed. The size of fallopian canal dehiscence was not investigated in this study. Frequencies and locations of dehiscence of the fallopian canal and coexisting pathological conditions The location of the dehiscence is classified simply into the following three groups:
Methods
(1)
Patients A total of 37 ears with middle ear cholesteatoma in pediatric patients with a mean age of 9.2 years (range 4–14 years) and 273 ears with middle ear cholesteatoma in non-pediatric patients with a mean age of 45 years (range 15–84 years) were included in this study. All patients had undergone prior tympanoplasty under general anesthesia at our institution between January 2006 and April 2012. Figure 1 shows the frequencies of different types of cholesteatoma in pediatric and non-pediatric patients. In pediatric patients with congenital cholesteatoma, 11 of 18 ears (61.1 %) had disease extension beyond the attic. Surgical procedure and method to determine dehiscence of the fallopian canal The surgical procedure for cholesteatoma removal comprises retroauricular incision with a transcanal approach and atticotomy or attico-mastoidectomy. We try to preserve the middle ear mucosa as much as possible and to confirm middle ear ventilation especially anterior to the cochleariform process (i.e., the most anterior area) and the eustachian tube. The canal wall is reconstructed with tragal or conchal cartilage and a cortical bone graft. If necessary, the ossicular chain is reconstructed with cartilage. The surgical records of patients were retrospectively reviewed to determine the frequency of dehiscence of the fallopian canal. Facial canal dehiscence was evaluated by inspection
123
(2)
(3)
If the dehiscence is between the geniculate ganglion and the cochleariform process, it is classified as anterior to the cochleariform process (CP) dehiscence. If the dehiscence is between the CP and the second genu, it is classified as posterior to the CP dehiscence. If the dehiscence is after the lower level of the oval window at the mastoid or vertical segment, it is classified as mastoid segment dehiscence.
These locations were compared between the pediatric and non-pediatric groups. Coexisting pathological conditions were recorded, including destruction of the stapes superstructure (including partial destruction), presence of a labyrinthine fistula, and dural exposure. Comparison of the frequency of dehiscence in ears with destruction of the stapes The frequency of dehiscence in patients with destruction of the stapes was compared between the pediatric and nonpediatric groups using bivariate analysis, and odds ratios with 95 % confidence intervals were calculated. A value of p \ 0.05 was considered to be statistically significant.
Results Six of the 37 ears (16.8 %) in the pediatric group and 91 of the 273 ears (33.3 %) in the non-pediatric group had
Eur Arch Otorhinolaryngol Table 1 Comparisons of the frequencies of dehiscence of the fallopian canal in pediatric and non-pediatric patients according to the type of cholesteatoma
Congenital Pars flaccida Pars tensa Secondary
Pediatric group N = 37 ears
Non-pediatric group N = 273 ears
p value
5.26 %
100 %
\0.05
(1/18)
(2/2)
8.33 %
27.5 %
(1/12)
(49/178)
100 %
53.3 %
(4/4)
(32/60)
0%
24.2 %
(0/2)
(8/33)
0.17 0.17
Table 2 Coexisting pathological conditions in the pediatric and nonpediatric groups Pediatric group N = 37 ears
Non-pediatric group N = 273 ears
p value
Destruction of the stapes
43.2 %
16.5 %
\0.001
(16/37)
(45/273)
Labyrinthine fistula
0%
7%
(0/37)
(19/273)
Dural exposure
5.4 %
7%
(2/37)
(19/273)
NS NS
NS
dehiscence of the fallopian canal, which was a significant difference between the two groups (p \ 0.05). Table 1 shows the frequency of dehiscence of the fallopian canal according to the type of cholesteatoma. In ears with congenital cholesteatoma, the frequency of dehiscence was lower in the pediatric group than in the non-pediatric group (p \ 0.05). However, in ears with other types of cholesteatoma there were no statistical significances in the frequency of dehiscence. Figure 2 shows the locations of dehiscence of the fallopian canal in the pediatric and non-pediatric groups. The tympanic portion was the most frequent location of dehiscence, especially anterior and posterior to the CP in both groups. There were no significant differences in the locations of dehiscence between the two groups. Table 2 shows the coexisting pathological conditions in the pediatric and non-pediatric groups. The frequency of destruction of the stapes was statistically higher in the pediatric group than in the non-pediatric group (43.2 vs. 16.5 %, p \ 0.001). Labyrinthine fistula and dural exposure were rare in the pediatric group, but there were no significant differences in the frequencies of these conditions between the two groups.
Table 3 Comparisons of the frequencies of dehiscence of the fallopian canal in patients with destruction of the stapes in the pediatric and non-pediatric groups Pediatric N = 16 ears Congenital Pars flaccida Pars tensa Secondary
Non-pediatric N = 45 ears
10 %
100 %
(1/10)
(2/2)
0%
62.5 %
(0/2)
(5/8)
100 %
57.1 %
(4/4)
(16/28)
–
71.4 %
p value 0.052 0.2 0.2 –
(5/7) Total
31.3 %
62.2 %
(5/16)
(28/45)
\0.05
Table 3 shows comparisons of the frequencies of dehiscence in the pediatric and non-pediatric groups with destruction of the stapes. In the pediatric group, 16 of 37 ears had destruction of the stapes, of which 5 (31.3 %) had dehiscence of the fallopian canal. In the non-pediatric group, 45 of 273 ears had destruction of the stapes, of which 28 (62.2 %) had dehiscence of the fallopian canal. In cases with destruction of the stapes, the fallopian canal was
Fig. 2 Locations of dehiscence in the pediatric and nonpediatric groups
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Eur Arch Otorhinolaryngol
more frequently preserved in the pediatric group than in the non-pediatric group (p \ 0.05).
of the pediatric fallopian canal under conditions of disease such as cholesteatoma.
Discussion
Conclusions
In this study, the frequency of dehiscence of the fallopian canal was significantly lower in pediatric patients with cholesteatoma than in non-pediatric patients with cholesteatoma, which is consistent with previously reported findings [5, 7–9]. In pediatric patients, the frequency of dehiscence was influenced by the type of cholesteatoma. In ears with pars tensa cholesteatoma, the frequency of dehiscence was high, which means that cholesteatoma progressed directly to the fallopian canal around the stapes even in pediatric cases. However, the small number of pars tensa cholesteatoma has a minor influence on the overall comparison between the pediatric and non-pediatric groups, as the proportion of ears with pars tensa cholesteatoma was lower in the pediatric group than in the nonpediatric group (10 vs. 22 %). The data comparing the frequencies of dehiscence in patients with destruction of the stapes are also important. As the stapes is very close to the fallopian canal, there is extensive cholesteatoma around the fallopian canal in such cases. In our series, destruction of the stapes was more frequent in the pediatric group, but the fallopian canal was more frequently preserved in the pediatric group than in the non-pediatric group. This indicated that the stapes superstructure was more fragile than the fallopian canal, but we have not found the reason why fallopian canal tends to be preserved even in such a progressive case. Spector et al. [10] investigated temporal bones in the fetus and neonates and reported that normal ossification of the lateral wall of the fallopian canal started at 21 weeks of gestation, anteriorly from the apical otic ossification centers near the CP, and at 26 weeks from the canalicular ossification centers near the stapedius muscle and was completed during the neonatal period. The lateral wall of the fallopian canal gradually thins with growth due to temporal bone pneumatization. The pediatric temporal bone has high water content and is more vascular than the non-pediatric temporal bone. Further investigation is necessary to clarify the mechanisms including defense systems
Except in cases of pars tensa cholesteatoma, the frequency of dehiscence of the fallopian canal at the time of cholesteatoma surgery was lower in the ears of pediatric patients than in the ears of non-pediatric patients. This is probably due to the difference in types of cholesteatoma between the two groups and other unknown mechanisms.
123
Conflict of interest
None.
References 1. Di Martino E, Sellhause B, Haensel J, Schlegel JG, Westhofen M, Prescher A (2005) Fallopian canal dehiscence: a survey of clinical and anatomical findings. Eur Arch Otorhinolaryngol 262:120–126 2. Selesnick SH, Lynn-Macrae AG (2001) The incidence of facial nerve dehiscence at surgery for cholesteatoma. Otol Neurotol 22:129–132 3. Yu Z, Wang Z, Yang B, Han D, Zhang L (2011) The value of preoperative CT scan of tympanic facial nerve canal in tympanomastoid surgery. Acta Otolaryngol 131:774–778 4. Jaswal A, Jana AK, Sikder B, Sadhukhan SK, Jana U, Nandi TK (2008) Fallopian canal dehiscence: can it be predicted. Indian J Otolaryngol Head Neck Surg 60:11–15 5. Ozbek C, Tuna E, Ciftci O, Yazkan O, Ozdem C (2009) Incidence of fallopian canal dehiscence at surgery for chronic otitis media. Eur Arch Otorhinolaryngol 266:357–362 6. Bayazit YA, Ozer E, Kanlikama M (2002) Gross dehiscence of the bone covering the facial nerve in the light of otological surgery. J Laryngol Otol 116:800–803 7. Magliulo G, Colicchio MG, Appiani MC (2011) Facial nerve dehiscence and cholesteatoma. Ann Otol Rhinol Laryngol 120:261–267 8. Moody MW, Lambert PR (2007) Incidence of dehiscence of the facial nerve in 416 cases of cholesteatoma. Otol Neurotol 28:400–404 9. Perez B, Campos ME, Rivero J, Lopez Campos D, Lo´pez-Aguado D (1997) Incidence of dehiscences in the fallopian canal. Int J Pediatr Otorhinolaryngol 40:51–60 10. Spector JG, Ge X (1993) Ossification patterns of the tympanic facial canal in the human fetus and neonate. Laryngoscope 103:1052–1065
