Experiences of Percutaneous Endoscopic Approach for the Mastoid Lesions: A Novel Minimally Invasive Ear Surgery.

OBJECTIVES: We developed a novel keyhole surgery, named "percutaneous endoscopic ear surgery" (PEES), with the aim of further reducing the invasiveness of otologic surgery. We reported the cases we encountered and retrospectively analyzed the invasiveness of PEES. METHODS: We analyzed the ears of eight patients who underwent PEES for mastoid lesions that could not be manipulated with transcanal endoscopic ear surgery (TEES) at our hospital between July 2021 and November 2022. We performed PEES alone in three patients, including one case of type A (preauricular incision) and two cases of type B (retroauricular incision). The last five patients underwent combined endoscopic ear surgery, which is simultaneous PEES and TEES. In these cases, one patient underwent type A PEES, and four patients underwent type B PEES. RESULTS: PEES was performed in all patients without converting to conventional microscopic mastoidectomy. The mean length of skin incisions was 19.1 ± 4.5 mm, which was smaller than that in conventional mastoidectomy. In all cases, the average length of the major axis of the keyhole was <10 mm, indicating that sufficient minimally invasive surgery was achieved. The average depth from the keyhole to the deepest site was 21.6 ± 8.9 mm. There was no change in the mean hearing level before and after the surgery. CONCLUSION: PEES is a minimally invasive procedure for manipulating lesions in the mastoid. In addition, the combination of PEES and TEES is an ideal, minimally invasive procedure that can be used to treat all regions of the temporal bone.

Factors affecting the incidence of chorda tympani nerve transection in middle ear surgery.

Objective: To reveal the factors affecting the incidence of chorda tympani nerve (CTN) transection during middle ear surgery. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: We analyzed 232 ears (117 ears with cholesteatoma, 101 ears with chronic otitis media, and 14 ears with otosclerosis) that underwent tympanoplasty or stapes surgery during 2017-2020. Intervention: Eighty-four ears underwent transcanal endoscopic ear surgery (TEES), 103 ears underwent microscopic ear surgery (MES), and 45 ears underwent surgery using both endoscopy and microscopy (Dual). Main Outcome Measure: To confirm CTN transection, intraoperative endoscopic/microscopic video images were evaluated. We used the same video images to determine the anatomical variation of the CTN course in the middle ear. Results: In 18 ears (7.8%: 6/84 TEES ears [7.1%], 6/103 MES ears [5.8%], and 6/45 Dual ears [13.3%]), the CTN was cut during middle ear surgery. There was no significant difference in CTN transection among groups. In cholesteatoma patients, stapes involvement resulted in a significantly higher CTN transection incidence. CTN anatomical variants such as the "Attached Short type" and "Ultrashort type" showed a significantly higher CTN transection incidence. Conclusion: Although endoscopic surgery did not reduce the incidence of CTN transection during middle ear surgery, pathological involvement of the stapes and CTN anatomical variants, such as the "Attached Short type" and "Ultrashort type," may increase this incidence. Preoperative evaluation of stapes involvement and anatomical location of the CTN course could help identify patients at greater risk for iatrogenic CTN transection. Level of Evidence: 4.

Patency of Anterior Epitympanic Space and Surgical Outcomes After Endoscopic Ear Surgery for the Attic Cholesteatoma.

OBJECTIVE: To reveal the patency of the anterior epitympanic space (AES) and the surgical outcomes after transcanal endoscopic ear surgery (TEES) for attic cholesteatoma with a classification of anatomical variation of the AES. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Seventy-four ears (72 patients with early-stage (I or II) attic cholesteatoma) aged between 16 and 85 years (mean: 48.9 yr) who underwent TEES between 2015 and 2017 were analyzed. INTERVENTION: Tympanoplasty with atticoantrotomy was performed with TEES. TEES was performed using a rigid endoscope with an outer diameter of 2.7 mm. MAIN OUTCOME MEASURE: The tensor fold in the AES anatomical classification, the postoperative patency of the AES evaluated by computer tomography images, and hearing outcomes based on the American Academy of Otolaryngology and Head and Neck Surgery criteria were evaluated after TEES for early-stage attic cholesteatoma. RESULTS: There were 14 (18.9%) ears with a vertical tensor fold orientation, 29 (39.2%) ears with an oblique orientation, and 29 (39.2%) ears with a horizontal orientation. The total postoperative patency rate in the AES was 81.0%, without any significant difference in the anatomical variation in the AES, whereas the rate of preoperative complete tensor fold was 90.5%. Cholesteatoma recurrence was observed in three cases (4.1%), and all recurrent cases had obstructed AES. No significant difference was found in the postoperative air-bone gap regardless of the patency of the AES. CONCLUSION: Our findings indicate that TEES is useful in restoring ventilation in the AES, resulting in favorable management of cholesteatoma.

Risk factors of post-tonsillectomy hemorrhage in adults.

OBJECTIVE: Tonsillectomy is an essential surgery and is conducted on both children and adults. However, the risk factors of post-tonsillectomy hemorrhage for adult patients remain unclear. In this study, we analyzed post-tonsillectomy hemorrhage in adult patients. METHODS: We retrospectively analyzed 325 adult patients who underwent a tonsillectomy between 2014 and 2018 in our facilities. RESULTS: The average age of this study's population was 31.7 ± 10.5 years (range: 19-70 years), and 250 (76.9%) patients were male. Overall, post-tonsillectomy hemorrhage occurred in 71 (21.8%) patients and 5 (1.5%) patients required a second surgery for hemostasis. Post-tonsillectomy hemorrhage often occurred on postoperative day zero or six. Using multiple logistic regression analysis, current smoking status (odds ratio 3.491; 95% confidence interval 1.813-6.723), male sex (odds ratio 3.924; 95% confidence interval 1.548-9.944), and perioperative non-steroidal anti-inflammatory drug administration (odds ratio 7.930; 95% confidence interval 1.004-62.64) were revealed as overall post-tonsillectomy hemorrhage risk factors. To analyze the hemorrhage period after tonsillectomy, we categorized the post-tonsillectomy hemorrhage patients into the primary (bleeding within postoperative day one) and secondary hemorrhage (bleeding on or after postoperative day two) groups. The current smoking status and older age were risk factors for primary hemorrhage and the current smoking status and sex (male) were risk factors for secondary hemorrhage. CONCLUSIONS: In this study, smoking status, sex, and perioperative non-steroidal anti-inflammatory drug administration were the clinical risk factors for adult post-tonsillectomy hemorrhage. Thus, smoking cessation is, at least, mandatory for patients who receive tonsillectomy to avoid post-tonsillectomy hemorrhage. LEVEL OF EVIDENCE: 4.

Update on treatment options for blast-induced hearing loss.

PURPOSE OF REVIEW: The incidence of blast injuries has increased, and the ear is the highest risk organ. Ear injury induced by blast exposure is important in both military and civilian conditions. The permanent hearing loss caused by blast exposure is associated with a decline in the quality of life. In this review, I describe recent therapeutic strategies for each of the ear pathologies caused by blast exposure. RECENT FINDINGS: For tympanic membrane perforation after blast exposure, basic fibroblast growth factor (bFGF) has been used as a less invasive treatment to repair the tympanic membrane. The closure rates of tympanic membrane perforations treated with bFGF were reported to be comparable to those following conventional tympanoplasty.For sensorineural hearing loss after blast exposure, treatment with neurotrophic factors, such as nerve growth factor (NGF) or neurotrophin-3, antioxidants, and Atoh1 induction have recently been applied, and some of them were considered for clinical application. SUMMARY: Recent advances of therapeutics for blast-induced hearing loss, based on their pathologies, have been outlined. There are several promising therapeutic approaches for both middle and inner ear disorders after blast exposure; however, further research is needed to establish new treatments for blast-induced hearing dysfunction.

A Case of Gastric Meningeal Carcinomatosis Involving Bilateral Hearing Loss: The Difference between Clinical Images and Autopsy Findings.

We describe a rare case of meningeal carcinomatosis (MC) in a 66-year-old man who presented with bilateral deafness and vertigo, initially presumed to be neurofibromatosis type-2. Brain magnetic resonance imaging (MRI) of the patient revealed bilateral gadolinium enhanced masses at the cerebellopontine angle. However, multiple central nervous system symptoms, including loss of consciousness, gradually appeared. He had a history of gastric cancer; therefore, a lumbar puncture was performed. Cytological examination of the cerebrospinal fluid confirmed the presence of adenocarcinoma cells. The general condition of this patient worsened, and he died 46 days after the first onset of hearing loss. An autopsy was performed, and multiple infiltrations of adenocarcinoma cells in the brain were confirmed, though undetected by MRI. The prognosis of MC is extremely poor; therefore, rapid diagnosis is important to prevent mortality. Retrospectively, a lumbar puncture could have been conducted earlier to identify MC, especially in consideration of the clinical history of this patient.

Recovery of endocochlear potential after severe damage to lateral wall fibrocytes following acute cochlear energy failure.

Reduction of endocochlear potential (EP) is one of the main causes of sensorineural hearing loss. In this study, we investigated changes in the EP using a mouse model of acute cochlear energy failure, which comprised severe cochlear lateral wall damage induced by the local administration of 3-nitropropionic acid to the inner ear. We also analyzed the correlation between EP changes and histological findings in the cochlear lateral wall. We detected the recovery of the EP and hearing function at lower frequencies after severe damage of the cochlear lateral wall fibrocytes at the corresponding region. Remodeling of the cochlear lateral wall was associated with EP recovery, including the re-expression of ion transporters or gap junctions (i.e. Na/K/ATPase-ß1 and connexin 26). These results indicate a mechanism for late-phase hearing recovery after severe deafness, which is frequently observed in clinical settings.

NRF2 Is a Key Target for Prevention of Noise-Induced Hearing Loss by Reducing Oxidative Damage of Cochlea.

Noise-induced hearing loss (NIHL) is one of the most common sensorineural hearing deficits. Recent studies have demonstrated that the pathogenesis of NIHL is closely related to ischemia-reperfusion injury of cochlea, which is caused by blood flow decrease and free radical production due to excessive noise. This suggests that protecting the cochlea from oxidative stress is an effective therapeutic approach for NIHL. NRF2 is a transcriptional activator playing an essential role in the defense mechanism against oxidative stress. To clarify the contribution of NRF2 to cochlear protection, we examined Nrf2(-/-) mice for susceptibility to NIHL. Threshold shifts of the auditory brainstem response at 7 days post-exposure were significantly larger in Nrf2(-/-) mice than wild-type mice. Treatment with CDDO-Im, a potent NRF2-activating drug, before but not after the noise exposure preserved the integrity of hair cells and improved post-exposure hearing levels in wild-type mice, but not in Nrf2(-/-) mice. Therefore, NRF2 activation is effective for NIHL prevention. Consistently, a human NRF2 SNP was significantly associated with impaired sensorineural hearing levels in a cohort subjected to occupational noise exposure. Thus, high NRF2 activity is advantageous for cochlear protection from noise-induced injury, and NRF2 is a promising target for NIHL prevention.

Cricopharyngeal achalasia treated with myectomy and post-operative high-resolution manometry.

Cricopharyngeal achalasia is an uncommon cause of dysphagia in neonates or children. A nine-year-old female patient was referred to us with a long history of dysphagia, recurrent pulmonary infection and growth stunting. A gastrostomy was introduced to improve her nutritional condition and to minimize potential inflammation in the pharynx. Subsequently, cervical cricopharyngeal myectomy was conducted. The surgical intervention allowed prompt resolution of symptoms without complications. High-resolution manometry post myectomy demonstrated a significant reduction in upper esophageal pressure together with proper relaxation at deglutition. The patient was able to consume solid food and liquid normally, and remained asymptomatic without medications six months after the surgery.

Late-phase recovery in the cochlear lateral wall following severe degeneration by acute energy failure.

We previously reported a model of acute cochlear energy failure using a mitochondrial toxin, 3-nitropropionic acid (3-NP), to study mechanisms of inner ear disorders such as inner ear ischemia. In this model, the main cause of hearing loss is apoptosis of fibrocytes in the cochlear lateral wall. Here, we analyzed the time course of structural and hearing level changes in the cochlea from the acute phase to the chronic phase up to 2 months after surgery. Hearing levels as determined by auditory brainstem response (ABR) thresholds exceeded the maximum acoustic output (>87 dBSPL) of the system at all frequencies 1 day after 3-NP treatment. Histology showed nearly complete loss of fibrocytes 2 weeks after 3-NP treatment. However, after 2 months, ABR showed significant recovery at low frequency (8 kHz) in four of five rats treated with 3-NP. ABR thresholds at 20 kHz occasionally showed some recovery. At 40 kHz, recovery of ABR thresholds was not observed. Histology of 3-NP-treated rats revealed partial recovery of the lateral wall and the regenerated fibrocytes in the spiral ligament expressed Na/K-ATPase in the cochlear basal turn 2 months after 3-NP treatment. These results indicate that ABR recovery is caused by regeneration of the cochlear lateral wall. Our findings demonstrate the recoverable capacity of the cochlear lateral wall that leads to functional recovery after severe damage.

Caspase inhibitor facilitates recovery of hearing by protecting the cochlear lateral wall from acute cochlear mitochondrial dysfunction.

We recently showed that acute energy failure in the rat cochlea induced by local administration of the mitochondrial toxin 3-nitropropionic acid (3-NP) causes hearing loss mainly due to degeneration of cochlear lateral-wall fibrocytes. In the present study, we analyzed the effect of the pan-caspase inhibitor z-Val-Ala-Asp(Ome)-fluoromethylketone (Z-VAD-FMK) on 3-NP-induced hearing loss in a model showing temporary threshold shifts at low frequencies and permanent threshold shifts at high frequencies. The model rats received an intraperitoneal injection of either Z-VAD-FMK or vehicle for 3 days starting 1 day prior to 3-NP treatment. One day after the administration of 3-NP, the auditory brain-stem response (ABR) threshold at 20 kHz was elevated to 70 dB in the Z-VAD-FMK group and to 85 dB in controls. The Z-VAD-FMK group completely recovered to the preoperative level within 14 days, whereas in the controls, the ABR threshold remained elevated at 50 dB even 28 days after the administration of 3-NP. Treatment with Z-VAD-FMK also improved recovery of hearing at 8 kHz but did not change recovery at 40 kHz. Histological examination demonstrated that treatment with Z-VAD-FMK inhibited progressive degeneration of the lateral-wall fibrocytes in the cochlear basal turn, as well as apoptosis of these fibrocytes. These results clearly indicate that caspase-dependent apoptosis of fibrocytes in the cochlear lateral wall plays an important role in hearing loss in the present animal model. Moreover, the results of the present study suggest that systemic administration of a caspase inhibitor may be an effective therapy for sensorineural hearing loss caused by acute energy failure such as that observed in cochlear ischemia.

Pulse-oximetery is useful in determining the indications for adeno-tonsillectomy in pediatric sleep-disordered breathing.

OBJECTIVE: Although first line therapy of sleep-disordered breathing (SDB) in children is adeno-tonsillectomy, the indications for this operation have not yet been clearly established. We investigated whether pulse-oximetry is useful for determining the optional treatment modality for pediatric SDB. METHOD: Two hundred and thirty-two children presenting with snoring and gasping had their oxygen saturation levels examined during sleep. Among them, 86 underwent on adeno-tonsillectomy and were evaluated pre- and post-surgery. We also examined 25 healthy children as controls. RESULTS: Little desaturation was observed in healthy children. The difference in oxygen saturation levels of the patients between pre- and post-surgery was closely correlated with the pre-surgery levels. We examined the reaction operation characteristics and concluded that children with an oxygen desaturation index of 4% or more (ODI4) of more than 1.5 and/or ODI3 of more than 3.5 should undergo surgery. CONCLUSION: Pulse-oximetry is useful in determining the indications for adeno-tonsillectomy.

Hypothyroidism after radiotherapy for patients with head and neck cancer.

We report on 2 cases of hypothyroidism presenting clinical symptoms that occurred after radiotherapy for cancer of the head and neck and on the results of estimating thyroid function in patients with head and neck cancer who received radiotherapy. The first patient underwent total laryngectomy for laryngeal cancer without sacrificing the thyroid gland and partial gastrectomy for gastric cancer. Radiotherapy of the neck was carried out postoperatively. Two years later, the patient developed chest pain; pericardial effusion was detected, leading to a diagnosis of myxedema caused by hypothyroidism. The second patient received radiotherapy alone for laryngeal cancer. Two months later, low serum sodium concentration and anemia were detected in this patient. The cause of these changes was subsequently found to be hypothyroidism. Based on our experience with these 2 cases, we measured thyroid function in 35 patients who had undergone neck radiation for head and neck cancer at our hospital over the past 10 years. Hypothyroidism was observed in 13 of the 35 patients (37%). The prevalence of hypothyroidism was 46% (6/13) for patients treated with both radiation and surgery, as compared with 32% (7/22) for those who received radiation alone. The risk factors responsible for hypothyroidism were not evident from the statistical analysis of these cases. We believe that thyroid function should be evaluated periodically in patients who have undergone neck radiation because it is often difficult to diagnose hypothyroidism only from clinical symptoms.

Aphonia and dysphagia after gastrectomy.

A 67-year-old male was referred to our otolaryngological clinic because of aphonia and dysphagia. His voice was breathy and he could not even swallow saliva following a total gastrectomy for gastric carcinoma performed 2 weeks previously. Laryngeal fiberscopy revealed major glottal incompetence when he tried to phonate. However, both vocal folds abducted over the full range during inhalation. The patient could not swallow saliva because of a huge glottal chink, even during phonation. Based on these findings, he was diagnosed as having bilateral incomplete cricoarytenoid dislocation after intubation. The patient underwent speech therapy; within 1 min his vocal fold movement recovered dramatically and he was able to phonate and swallow. There have been few case reports of bilateral cricoarytenoid dislocation, and no effective rehabilitation has been reported. We believe that our method of vocal rehabilitation serves as a useful reference for physicians and surgeons worldwide.

Oncocytic carcinoma in the submandibular gland: report of a case based on anti-mitochondrial immunohistochemical observations.

Oncocytic carcinoma arising in the submandibular gland is a very rare tumor that has only previously been reported in nine cases. This paper describes an additional case of oncocytic carcinoma in the right submandibular gland. The patient was a 55-year-old Japanese male who was presented with a 3 cm right submandibular mass. Both radical resection of the tumor and right supraomohyoid neck dissection were performed. Histologically, the tumor cells exhibited an abundant eosinophilic cytoplasm, which appeared to be finely granular, and invaded the surrounding tissues. In addition, perineural invasion was also observed. Electron microscopy demonstrated the presence of an abundance mitochondria in the cytoplasm of the tumor cells. However, since the fine structure of cytoplasm was destroyed by fixation and embedding of the tissue for the light microscopy, the cytoplasm of the tumor could not be observed clearly. Immunohistochemically, anti-mitochondrial antibody positivity was evident in the cytoplasm of the tumor cells. Consequently, we diagnosed the mass as oncocytic carcinoma. Usually, electron microscopy is necessary to diagnose oncocytic lesions, but the paraffin-embedded tissue was not suitable for electron microscopy. Immunohistochemistry using an anti-mitochondrial antibody was found to be useful and helpful for the diagnosis of oncocytic lesions.

[Review of 26 patients operated on for primary hyperparathyroidism].

The traditional surgical approach for primary hyperparathyroidism (PHP) is routine bilateral neck exploration. At Saiseikai Utsunomiya Hospital, however, unilateral exploration, and the direct resection of one gland is performed if single gland enlargement is suspected, based on the findings of several preoperative localization procedures. Here, we reviewed 26 patients who underwent single gland operations for PHP at our institution between 1993 and 2001. The 26 patients (21 women and 5 men) ranged in age from 20 to 79 years (mean, 54.8 years). None of the patients had multiple endocrine neoplasia (MEN), familial hypercalcemia, or malignant tumors. At least three preoperative localization procedures, such as ultrasonography, computed tomography, thallium technetium scanning, 99mTc sestamibi scintigraphy, or magnetic resonance imaging, were performed in each patient. A parathyroidectomy was then performed under general anesthesia. Contralateral exploration was not routinely performed. In addition, an intraoperative biopsy of the other glands was not performed. The following data were retrospectively collected in all patients: serum calcium, and the HS-PTH at one month and 6 months after the parathyroidectomy. All patients were normocalcemic, and the serum HS-PTH concentration significantly decreased in all patients after this operation. Patients were divided into two groups (adenoma group, n = 16; hyperplasia group, n = 6) and the data was analyzed according to the histological and pathological diagnosis. In both pathological groups, all patients were normocalcemic and the serum HS-PTH concentration was significantly lower after surgery. The serum HS-PTH concentration showed no significant difference between the adenoma group and the hyperplasia group at 6 months after surgery. No complications, including recurrent laryngeal nerve palsy or permanent hypocalcemia, were observed after surgery. In conclusion, if a single gland disease is suspected based on the findings of multiple preoperative localization procedures, resection of the enlarged gland alone appears to provide good results for the treatment of either adenoma or hyperplasia resulting in PHP. In addition, this procedure also reduces the occurrence of postoperative hypocalcemia, because the normal glands are not injured by the biopsy procedures.

[Nocturnal pulse oximetry diagnosis for screening pediatric obstructive sleep apnea syndrome].

We evaluated the diagnostic value of pulse oximetry during sleep in pediatric obstructive sleep apnea syndrome (OSAS) caused by adenoid-tonsil hypertrophy. Subjects were 22 healthy children free of symptoms such as snoring, sleep apnea and oral breathing and 163 children suspected of OSAS with snoring or sleep apnea. Subjects were measured for percutaneous oxygen saturation (SpO2) during sleep. Of those with suspected OSAS, 69 underwent adenotonsillectomy and were measured for SpO2, both pre- and postoperatively, then pre- and postoperative measurements were compared. After measurement, we analyzed three parameters: lowest saturation (LSpO2), the desaturation index, and total desaturation duration under 95% (TDD95). Few abnormal findings were seen in healthy children. We calculated the mean and standard deviation (SD) of each parameter and set borderlines of mean-2SD for LSpO2 and mean + 2SD for ODI and TDD95. With these borderlines, 105 children for LSpO2, 75 for ODI and 76 for TDD 95 were judged to be normal among the 163 with suspected OSAS. Histograms showed that the mode of each parameter was situated near the borderline. Comparison between pre- and postoperative measurements showed that the effect of the surgery strongly correlated with preoperative measurement in patients undergoing surgery. Assuming that a patient with postoperative improvement is positive, we calculated sensitivity and specificity for each borderline measurement. We found that if success is 100%, the borderline should be 87% for LSpO2, 3.5 for ODI, and 30.0 for TDD95. If success exceeds 90%, the borderline should be 90% for LSpO2, 2.0 for ODI, and 7.0 for TDD95. We therefore conclude that measurement of SpO2 during sleep is useful in screening for pediatric OSAS.