山原 康平

A 62-year-old woman with poorly controlled type 2 diabetes mellitus presented with a fever and altered consciousness. The patient was diagnosed with diabetic ketoacidosis (DKA) with a positive blood culture for group A Streptococcus. Although the source of infection was initially unclear, contrast-enhanced CT revealed a retropharyngeal abscess (RPA) and descending necrotizing mediastinitis (DNM) that required surgical drainage. RPA with DNM is rare and potentially fatal in adults and is often missed without high clinical suspicion. In severe DKA, altered mental status and hemodynamic instability may obscure the underlying infection, emphasizing the importance of a thorough evaluation.

OBJECTIVE: To evaluate the safety and feasibility of transaxillary robotic thyroidectomy (TART) in Japan by comparing early cases with video-assisted neck surgery (VANS). METHODS: Single-center retrospective review of 31 consecutive thyroid lobectomies: 16 VANS (Nov 2020-Feb 2025) and 15 TART (Mar 2022-Feb 2025). TART used da Vinci Surgical system (da Vinci) Xi for early cases and predominantly da Vinci SP thereafter. Indications included differentiated cancer ≤4 cm, cN0, unilateral disease without extrathyroidal invasion, or follicular tumors 3-5 cm. Operative time, blood loss, hospital stay, complications, and cosmetic outcomes were evaluated and compared with statistical analysis. RESULTS: All procedures were completed without conversion to open surgery. Blood loss (16.5 g vs 25.8 g) and length of stay (6.3 vs 6.1 days) were comparable. Complications included two transient recurrent laryngeal nerve palsies after VANS and, after TART, one axillary bleed controlled under local anesthesia and one lymphatic leak; overall rates were similar. High cosmetic satisfaction was reported in both cohorts. CONCLUSION: Early experience shows TART is feasible and safe in Japan, achieving perioperative outcomes comparable to VANS with excellent cosmetic results.

This article describes an extremely rare case of pediatric congenital external auditory canal cholesteatoma (EACC) that extended beyond the external auditory canal. A five-year-old girl presented with progressive swelling in the posterior wall of the left external auditory canal. Computed tomography of the temporal bone revealed a well-defined round mass that compressed and eroded the posterior canal wall without invasion of the mastoid tegmen, sigmoid sinus, or tympanic membrane. Surgical exploration via a retroauricular approach confirmed the presence of a cholesteatoma extending from the external auditory canal to the mastoid cavity; furthermore, complete excision was achieved. There has been a recent increase in the number of reported EACC pediatric cases, especially in East Asia. However, few studies have clearly distinguished congenital and acquired forms, which could be largely attributed to challenges in differential diagnosis, particularly when lesions extend beyond the canal. Based on our findings, we propose radiological and clinical features that may facilitate differentiation between congenital and acquired EACC, even in advanced-stage cases. This article highlights the importance of accurate classification for elucidation of the pathogenesis of EACC and optimization of surgical decision-making in pediatric patients with EACC.

Stapediovestibular luxations are often caused by trauma to the external ear canal. Sealing the oval window while leaving the stapes in the vestibule is a safer procedure than stapedectomy, considering the risk of additional inner ear damage, but it risks recurrence. We report a rare case of oval window rupture recurrence 25 years after initial surgery and introduce a new method using cartilage to seal the oval window. A 37-year-old woman experienced a recurrence of oval window rupture after nasal blowing. She had a history of left ear ossicular chain dislocations and oval window rupture caused by an ear pick 25 years earlier, initially treated by sealing the oval window with soft tissues while leaving the depressed stapes in place. In the current surgery, a stapedectomy was performed, the oval window was sealed with cartilage, and an incus columella was placed on the cartilage. Complete resolution of vestibular symptoms and improvement in air conduction thresholds were observed. Postoperatively, no recurrence of oval window rupture was observed. Patients with stapediovestibular luxations face a long-term risk of oval window rupture recurrence if sealed only with soft tissues. Cartilage may offer a promising alternative for oval window sealing after stapedectomy due to its flexibility and durability.

Cisplatin, an effective anti-neoplastic drug widely used in oncology protocols, has an adverse effect such as ototoxicity, for which no current treatment exists. Histological lesions in the cochlea after cisplatin administration are most prominent in outer hair cells in the organ of Corti. We have previously reported that insulin-like growth factor 1 (IGF1) protects cochlear hair cells (HCs) against several types of damage to the cochlea, including noise exposure, ischemia, surgical trauma, and aminoglycoside, resulting in hearing recovery. In the present study, we investigated the efficacy of IGF1 as a molecule to protect inner ear auditory sensory HCs against cisplatin using cochlear explant culture systems of postnatal day 2 mice. Administration of IGF1 to the explants grown in the medium containing cisplatin markedly protected outer HCs from cisplatin-induced damage. Pharmacological inhibition of IGF1 receptor (IGF1R) using an IGF1R antagonist or inhibitor markedly attenuated the protective activity of IGF1, indicating that IGF1R is specifically required for IGF1 effects in HCs against cisplatin. As a protective mechanism against cisplatin, we found that the administration of IGF1 reduces cisplatin-induced oxidative stress. IGF1 effects on the maintenance of HC numbers are achieved by inhibiting the apoptosis of HCs, not by inducing the proliferation of HCs or supporting cells (SCs). We conclude that treatment with IGF1 could be an efficient and safe approach to treat cisplatin-induced ototoxicity.