Shin-ichi Ishimoto

Hearing Levels in Patients With Microtia: Correlation With Temporal Bone Malformation

Objective: To evaluate the relationship between hearing level and temporal bone abnormalities in patients with microtia.

Induction of KGF, Basic FGF, and TGFa mRNA Expression During Healing of Experimental TM Perforations

KGF (KGF), synthesized and secreted exclusively by stromal cells in epithelialized organs, specifically promotes proliferation of cells of epithelial origin, including keratinocytes. A related peptide, basic fibroblast growth factor (bFGF), has mitogenic properties for fibroblasts and endothelial cells. KGF expression is stimulated markedly in the skin during wound healing. To investigate the physiologic action of KGF in the healing of TM (TM) perforations, we examined KGF and KGF receptor (KGFR) mRNA transcript levels as well as those of bFGF and transforming growth factor-alpha (TGFalpha) in normal and wounded rat TM at varying intervals, using a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). We found KGF and TGFalpha mRNA expression to be induced rapidly, peaking 3 days after wounding and then declining. Expression of bFGF was induced gradually and remained increased until 7 days. In contrast, we found KGFR to be expressed in normal TM, remaining unchanged during TM repair. These results indicate that KGF and TGFalpha may mediate migration and proliferation of epithelial cells of the outer layer in the early stage of TM repair while bFGF may mediate the connective tissue reaction in the middle layer in a subsequent stage.

Induction of Growth Factor Expression is Reduced during Healing of Tympanic Membrane Perforations in Glucocorticoid-Treated Rats

The participation of growth factors in wound healing of tympanic membranes (TMs) is established. To determine the possible role of these growth factors in normal healing, we examined the regulation of keratinocyte growth factor (KGF), transforming growth factor–α (TGF-α), and basic fibroblast growth factor (bFGF) messenger RNA (mRNA) expression in wounded TMs of glucocorticoid-treated rats; these rats have severe wound healing abnormalities. Induction of KGF, TGF-α, and bFGF mRNA expression after TM injury was significantly reduced in these rats. Moreover, we found that the average number of bromodeoxyundine-positive cells in a glucocorticoid-treated group was significantly lower than that in controls. The data suggest that reduced expression of these genes might be partially responsible for the wound healing defects seen in these animals. These results provide a possible explanation for the beneficial effect of exogenous KGF, TGF-α, or bFGF in treatment of wound healing disorders of the TM.

Fungal mastoiditis in an immunocompetent adult.

Abstract Manifest fungal infection of the middle ear, fungal mastoiditis, is a very rare entity, which is almost exclusively seen in immunocompromised patients. The authors present a case of fungal mastoiditis in a 52-year-old woman without immunocompromise. The patient presented with acutely progressing symptoms of hearing loss and dysequilibrium. Bony fistula of the semicircular canal was noted on CT scans and a marginal perforation of the tympanic membrane was also seen. Her hearing recovered following the surgery, which revealed massive granulations and proliferation of fungi but no cholesteatoma in the mastoid cavity. Fungal infection of the middle ear is rare, but can cause serious complications. The possibility should be considered even in immunocompetent patients.

Keratinocyte Growth Factor and its Receptor Messenger RNA Expression in Nasal Mucosa and Nasal Polyps

To examine the potential biologic role of fibroblast growth factors (FGFs) in nasal polyps and nasal mucosa during chronic inflammatory conditions, we investigated messenger RNA (mRNA) expression of three members of the FGF family — Acidic FGF, basic FGF, and keratinocyte growth factor (KGF) — in nasal polyp tissues, as well as in hyperplastic nasal mucosa. Using the sensitive method reverse transcription-polymerase chain reaction (RT-PCR), we demonstrated that of the examined FGFs, KGF had the most abundant mRNA expression in nasal polyps and nasal mucosa. We also found that significantly higher levels of KGF mRNA were expressed in nasal polyps than in nasal mucosa, whereas mRNA expression of acidic FGF and basic FGF was relatively low in these tissues. In addition, we showed that KGF receptor mRNA was present in most of the nasal mucosa; however, none or little was expressed in nasal polyps. These results suggest that KGF might play an important role in nasal epithelial proliferation and that excessive synthesis of KGF in nasal polyp stroma may contribute to hypertrophy of the nasal mucosa in patients with chronic sinusitis associated with nasal polyposis.

Cortical Activation Shortly after Cochlear Implantation

We evaluated the cortical activations in postlingually deaf cochlear implant (CI) users in the early period (0–2 months) of CI usage. The subjects were 8 early CI users and 8 normal subjects. With tone burst stimuli (1 kHz) delivered to the right side, strong and broad activation of the ipsilateral (right) primary auditory cortex with 2 peaks and weaker activation of the contralateral (left) temporal lobe were observed in early CI users, in a clear contrast with the normal subjects in whom activation was observed in a small area of the contralateral (left) primary cortex. With word stimuli, activation of the superior frontomedian cortex presumably including the supplementary motor area and the neighboring cingulate gyri was observed in early CI users, which was absent in normal subjects. The activation in the immediate association cortices near the primary area was lower in early CI users, while the periphery of the association cortex seemed to be more mobilized.

An effective management regimen for laryngeal granuloma caused by gastro-esophageal reflux: combination therapy with suggestions for lifestyle modifications

According to our previous study, lifestyle modification in combination with drug therapy is much more effective than drug therapy alone in cases of laryngopharyngeal reflux (LPR). Most patients with LPR will have chronic gastro-esophageal reflux diseases (GERD) and require long-term medical therapy for control, resulting in high total expenditure on pharmacologic agents. We combined pharmacologic management with lifestyle modifications for the management of GERD with successful outcomes in patients with GERD-related laryngeal granulomas. Although further studies are needed, guidance concerning lifestyle modifications in combination with PPI therapy may be not only a clinically effective but also a cost-effective method for the management of laryngeal granulomas caused by gastro-esophageal reflux.

Neuro-otologic Findings in Unilateral Isolated Narrow Internal Auditory Meatus

Objective: To report neuro-otologic findings concerning the four nerves in the internal auditory meatus (IAM) in patients with isolated congenitally narrow IAM and explore the implications regarding ontogeny of the nerves in the IAM. Design: Retrospective case series study. Setting: University hospital. Subjects: Five consecutive patients between 1997 and 2002 with unilateral isolated narrow IAM demonstrated by high-resolution computed tomography whose chief complaint was hearing loss (1 male and 4 females, 4 right sides and 1 left; age range 5-37 years, mean 20 years; IAM diameter at the porus: 26-33% of that on the normal side). Main Outcome Measures: Functional studies concerning the VIIth cranial nerve and the three branches of the VIIIth cranial nerve. Results: In all ears, auditory brain stem responses were absent, the speech discrimination score was 0%, and otoacoustic emissions were absent or markedly reduced compared with those on the normal side. Caloric responses were absent in two ears, reduced in two ears, and normal in one ear. Galvanic body sway tests showed no responses in the two ears in which caloric responses were absent. Inferior vestibular nerve function was estimated as normal in all ears on the basis of vestibular evoked myogenic potential recordings. Facial nerve functions were normal in all patients. Conclusions: In isolated congenital stenosis of IAM, dysfunction of each nerve in the IAM can occur independently. In the ontogeny of the VIIIth cranial nerve, the cochlear and superior vestibular nerves tended to be involved together, whereas the cochlear and inferior vestibular nerves appeared independent of each other.

Hoarseness after cardiac surgery: Possible contribution of low temperature to the recurrent nerve paralysis

Although the recurrent nerve can be directly damaged in cardiothoracic surgeries such as thoracic aortic arch (TAA) surgery, the bilateral recurrent nerves suffer only indirect damages during cardiac surgeries such as coronary artery bypass graft (CABG) and valve replacement (VR). However, we have the impression that vocal cord paralysis (VCP) is not a rare complication, even after such cardiac surgeries without the risk of direct injury. Although the causes for such VCP have been attributed to various indirect damages by retraction, injury at the time of internal jugular vein cannulation, injury by endotracheal intubation, and so forth, the incidence has not yet been established because of the paucity of reports, and the proposed risks are not supported by the data. Recently, three cases were reported suggesting that the extreme low temperature by the use of ice/saline slush in the pleural cavity during cardiac operations, which has long been recognized to provoke the phrenic nerve paralysis, was the most probable cause of VCP. We review retrospectively consecutive patients who underwent cardiac surgeries (CABG and VR) in a single institution, to show the incidence and prognosis of VCP and also to suggest possible influence of temporary low temperature on the recurrent nerve paralysis. Between 1989 and 2000, 1206 CABG surgeries and 267 VR surgeries (in all, 1473 cases [1056 men and 417 women; age range, 29 – 89 y; mean age, 64.5 y]) were performed at the Kameda Medical Center. Two patients who died after prolonged intubation were excluded from the study (therefore, n 1471). The left-side internal mammary artery graft was principally used for CABG. No patients complained of hoarseness before surgery. Endotracheal tube cuff pressure was monitored and optimized throughout the intubation period. Vocal cord movement was examined postoperatively by the otolaryngologists, using a fiberoptic laryngoscope, if hoarseness lasted for more than 1 week after extubation. Seventeen patients (1.2%) developed hoarseness attributable to VCP after surgery. The incidence was higher in VR (2.2%) than in CABG (0.9%), but the difference was not statistically significant. The paralysis observed was unilateral (left-sided in 11 cases and right-sided in 6 cases). The position of the paralyzed cord was median in 2 patients, paramedian in 13, and intermediate in 2. In the patients with median vocal cord fixation, hoarseness seemed to be due to a thin slit between bilateral cords. The paralysis recovered spontaneously within 6 months except in one patient with paramedian fixation. Ice/saline slush was used (mean duration, 1 h) during surgery in all cases before 1996 but was no longer used thereafter. Therefore, we divided the patients into the following groups: group A (earlier period, 939 patients with the use of ice/saline slush) and group B (later period, 532 patients without ice/saline slush). The parameters other than the use of ice/saline slush were not different between the two groups, including duration of surgery (5 h for CABG and 4.5 hours for VR), duration of cardiac arrest (1.5 h), mean intubation time (24 h), CABG/VR ratio (CABG:VR 8:2), indication of surgery, surgical methods, skill of surgeons (the same surgeons already fully experienced at the beginning), skill of anesthesiologists, methods of internal jugular vein cannulation, and so forth. The incidence of VCP in group A was higher than in group B, both in CABG patients (group A, 1.3%; group B, 0.2%) and in VR patients (group A, 2.7%; group B, 1.2%). In all (CABG VR), the incidences (group A, 1.6%; group B, 0.4%) showed significant difference (P .035, 2 test). From our experience with a large number of patients undergoing cardiac surgery (CABG and VR) without the risk of direct nerve injury, the incidence of hoarseness attributable to VCP is estimated to be 1% to 2%. The paralysis showed a tendency to recover spontaneously, in contrast to that caused by direct injury as in TAA surgery. Therefore, observation with repeated laryngoscopy should be the first choice. The recurrent nerve paralysis observed in this study could be caused by multiple factors described above. However, other conditions being equal between groups A and B, a possible contribution of intraoperative low temperature on the recurrent laryngeal nerve paralysis can be proposed, which is already established in the phrenic nerve paralysis after cardiac surgery. We look forward to other large-scale studies to verify this possibility.

Results of hearing tests after total middle ear reconstruction

Conclusions: Patients treated by mastoidectomy in the past often present with hearing loss and cavity problems such as pus discharge. Total middle ear reconstruction (TMER) improves the hearing of these patients by correcting cavity problems and resolution of ear discharge, which facilitates ossicular chain reconstruction such as type III or type IV tympanoplasty. Objective: To evaluate the effectiveness of TMER in improving hearing. Patients and methods: We reviewed the audiograms of 56 ears of 48 patients who underwent TMER in combination with either type III or type IV tympanoplasty. Audiometric pure tone thresholds averaged over three frequencies (500, 1000, and 2000, pure tone average) were measured and compared before and after surgery. Successful outcome was defined as improvement of 15 dB or more. The mean follow-up was 5.7 years (range 1.1–12.6). We also analyzed the relations between hearing improvement and factors such as type of tympanoplasty (types III and IV), choice between one-stage and two-stage operation, and the interval between original mastoidectomy and final operation. Results: The mean hearing gain was 13.6 (±11.9) dB. Twenty-seven procedures (48.2%) were considered successful, with improvement of 15 dB or more. The results of type III tympanoplasty group were significantly superior to those of type IV (p<0.05, Students t test). One- and two-stage surgery did not significantly influence outcome. The interval between the initial operation correlated weakly and negatively (r = − 0.266, p<0.05) with hearing gain.