Differences in demographics, medical expertise, and patient healthcare resources across countries have led to significant variations in guidelines. In light of these differences, in this review, we aimed to explore and compare the most recent updates to gastric cancer treatment from five guidelines that are available in English. These English-version guidelines, which have been recently published and updated for journal publication, include those published in South Korea in 2024, Japan in 2021, China in 2023, the United States in 2024, and Europe in 2024. The South Korean and Japanese guidelines provide a higher proportion of content to endoscopic and surgical treatments, reflecting their focus on minimally invasive techniques, function-preserving surgeries, and systemic therapy. The Chinese guidelines provide recommendations addressing not only surgical approaches but also perioperative chemotherapy and palliative systemic therapy. Meanwhile, in the United States and European guidelines, a higher proportion of the content is dedicated to perioperative and palliative systemic therapy, aligning with their approaches to advanced-stage disease management.All guidelines address surgical and systemic chemotherapy treatments; however, the proportion and emphasis of content vary based on the patient distribution and treatment approaches specific to each country. With emerging research findings on gastric cancer treatment worldwide, the national guidelines are being progressively revised and updated.Understanding the commonalities and differences among national guidelines, along with the underlying evidence, can provide valuable insights into the treatment of gastric cancer.

Differences in demographics, medical expertise, and patient healthcare resources across countries have led to significant variations in guidelines. In light of these differences, in this review, we aimed to explore and compare the most recent updates to gastric cancer treatment from five guidelines that are available in English. These English-version guidelines, which have been recently published and updated for journal publication, include those published in South Korea in 2024, Japan in 2021, China in 2023, the United States in 2024, and Europe in 2024. The South Korean and Japanese guidelines provide a higher proportion of content to endoscopic and surgical treatments, reflecting their focus on minimally invasive techniques, function-preserving surgeries, and systemic therapy. The Chinese guidelines provide recommendations addressing not only surgical approaches but also perioperative chemotherapy and palliative systemic therapy. Meanwhile, in the United States and European guidelines, a higher proportion of the content is dedicated to perioperative and palliative systemic therapy, aligning with their approaches to advanced-stage disease management.All guidelines address surgical and systemic chemotherapy treatments; however, the proportion and emphasis of content vary based on the patient distribution and treatment approaches specific to each country. With emerging research findings on gastric cancer treatment worldwide, the national guidelines are being progressively revised and updated.Understanding the commonalities and differences among national guidelines, along with the underlying evidence, can provide valuable insights into the treatment of gastric cancer.

Differences in demographics, medical expertise, and patient healthcare resources across countries have led to significant variations in guidelines. In light of these differences, in this review, we aimed to explore and compare the most recent updates to gastric cancer treatment from five guidelines that are available in English. These English-version guidelines, which have been recently published and updated for journal publication, include those published in South Korea in 2024, Japan in 2021, China in 2023, the United States in 2024, and Europe in 2024. The South Korean and Japanese guidelines provide a higher proportion of content to endoscopic and surgical treatments, reflecting their focus on minimally invasive techniques, function-preserving surgeries, and systemic therapy. The Chinese guidelines provide recommendations addressing not only surgical approaches but also perioperative chemotherapy and palliative systemic therapy. Meanwhile, in the United States and European guidelines, a higher proportion of the content is dedicated to perioperative and palliative systemic therapy, aligning with their approaches to advanced-stage disease management.All guidelines address surgical and systemic chemotherapy treatments; however, the proportion and emphasis of content vary based on the patient distribution and treatment approaches specific to each country. With emerging research findings on gastric cancer treatment worldwide, the national guidelines are being progressively revised and updated.Understanding the commonalities and differences among national guidelines, along with the underlying evidence, can provide valuable insights into the treatment of gastric cancer.

Objectives: . Balloon dilation of the Eustachian tube (BDET) is widely recognized as a minimally invasive treatment for obstructive Eustachian tube dysfunction (ETD). We employed a Delphi consensus methodology to develop recommendations for the clinical management of BDET in cases of obstructive ETD. Methods: . A Delphi panel consisting of 26 expert physicians specializing in otology participated in two rounds of anonymous, iterative questionnaires. Consensus was defined as agreement from ≥70% of the panelists on a recommendation, while disagreement was defined as <70% agreement. The responses from the Delphi study were analyzed using both the content validity ratio and Kendall’s coefficient of concordance. Results: . The panel finally evaluated 26 topics, reaching agreement on 9 and failing to reach consensus on 17 after two rounds. While consensus was not achieved regarding the postoperative follow-up period, a duration of 12 months was most commonly adopted. The Valsalva maneuver and questionnaire responses were identified as the most agreed-upon postoperative assessment tools following BDET. Conclusion . Consensus was reached on several recommendations for managing BEDT in obstructive ETD. This agreement will guide future research aimed at defining standard postoperative management for BEDT.

Objectives: . Balloon dilation of the Eustachian tube (BDET) is widely recognized as a minimally invasive treatment for obstructive Eustachian tube dysfunction (ETD). We employed a Delphi consensus methodology to develop recommendations for the clinical management of BDET in cases of obstructive ETD. Methods: . A Delphi panel consisting of 26 expert physicians specializing in otology participated in two rounds of anonymous, iterative questionnaires. Consensus was defined as agreement from ≥70% of the panelists on a recommendation, while disagreement was defined as <70% agreement. The responses from the Delphi study were analyzed using both the content validity ratio and Kendall’s coefficient of concordance. Results: . The panel finally evaluated 26 topics, reaching agreement on 9 and failing to reach consensus on 17 after two rounds. While consensus was not achieved regarding the postoperative follow-up period, a duration of 12 months was most commonly adopted. The Valsalva maneuver and questionnaire responses were identified as the most agreed-upon postoperative assessment tools following BDET. Conclusion . Consensus was reached on several recommendations for managing BEDT in obstructive ETD. This agreement will guide future research aimed at defining standard postoperative management for BEDT.

Objectives: . Balloon dilation of the Eustachian tube (BDET) is widely recognized as a minimally invasive treatment for obstructive Eustachian tube dysfunction (ETD). We employed a Delphi consensus methodology to develop recommendations for the clinical management of BDET in cases of obstructive ETD. Methods: . A Delphi panel consisting of 26 expert physicians specializing in otology participated in two rounds of anonymous, iterative questionnaires. Consensus was defined as agreement from ≥70% of the panelists on a recommendation, while disagreement was defined as <70% agreement. The responses from the Delphi study were analyzed using both the content validity ratio and Kendall’s coefficient of concordance. Results: . The panel finally evaluated 26 topics, reaching agreement on 9 and failing to reach consensus on 17 after two rounds. While consensus was not achieved regarding the postoperative follow-up period, a duration of 12 months was most commonly adopted. The Valsalva maneuver and questionnaire responses were identified as the most agreed-upon postoperative assessment tools following BDET. Conclusion . Consensus was reached on several recommendations for managing BEDT in obstructive ETD. This agreement will guide future research aimed at defining standard postoperative management for BEDT.

Objectives: . Particulate matter (PM) is a risk factor for various diseases. Recent studies have established an association between otitis media (OM) and PM exposure. To confirm this relationship, we developed a novel exposure model designed to control the concentration of PM, and we observed the effects of PM exposure on the Eustachian tube (ET) and middle ear mucosa of rats. Methods: . Forty healthy, 10-week-old, male Sprague-Dawley rats were divided into 3-day, 7-day, 14-day exposure, and control groups (each, n=10). The rats were exposed to incense smoke as the PM source for 3 hours per day. After exposure, bilateral ETs and mastoid bullae were harvested, and histopathological findings were compared using microscopy and transmission electron microscopy (TEM). The expression levels of interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and vascular endothelial growth factor (VEGF) in the middle ear mucosa of each group were compared using real-time reverse transcription polymerase chain reaction (RT-PCR). Results: . In the ET mucosa of the exposure group, the goblet cell count significantly increased after PM exposure (P=0.032). In the middle ear mucosa, subepithelial space thickening, increased angio-capillary tissue, and inflammatory cell infiltration were observed. Moreover, the thickness of the middle ear mucosa in the exposure groups increased compared to the control group (P<0.01). The TEM findings showed PM particles on the surface of the ET and middle ear mucosa, and RT-PCR revealed that messenger RNA (mRNA) expression of IL-1β significantly increased in the 3-day and 7-day exposure groups compared to the control group (P=0.035). VEGF expression significantly increased in the 7-day exposure group compared to the control and 3-day exposure groups (P<0.01). Conclusion . The ET and middle ear mucosa of rats showed histopathologic changes after acute exposure to PM that directly reached the ET and middle ear mucosa. Therefore, acute exposure to PM may play a role in the development of OM.

Objectives: . Endoscopic tympanoplasty (ET) provides minimally invasive transcanal access to the middle ear and improves middle ear visibility for the treatment of tympanic membrane (TM) perforations. However, the literature on surgical outcomes for large TM perforations is lacking and limited to small series. This study aimed to evaluate the clinical benefits of ET for large TM perforations. Methods: . This retrospective cohort study was conducted at nine tertiary referral hospitals in South Korea, where 252 patients who underwent ET as primary surgery from September 2019 to August 2021 were included. The outcome measures included the graft success rate and pre- and postoperative audiometric data. Results: . In 239 patients, the graft success rate of ET for large or subtotal perforations was 86.2% (206 patients), while the graft failure rate was 13.8% (33 patients). The graft failure rate was directly correlated with surgical techniques, including overlay and medial or lateral underlay tympanoplasty (P=0.027). Lateral underlay tympanoplasty showed the most favorable results. Sex, laterality, etiology, site and size of perforation, operation time, and graft materials did not vary significantly between the graft success and failure groups (P>0.05). The mean air-bone gap (ABG) improved significantly in both groups (graft success group: 10.0±0.6 dB and graft failure group: 7.7±0.3 dB; P<0.001). However, the ABG improvement did not significantly differ between the groups. Analysis of covariance revealed that the postoperative 500-Hz bone conduction threshold improved after successful ET (adjusted coefficient, –11.351; 95% confidence interval, –21.491 to –1.212; P=0.028). Conclusion . This study involved the largest population to date of large TM perforations treated by ET. The study findings suggest that ET is feasible and effective in treating large TM perforations.

Bilateral internal auditory canal (IAC) tumors are usually pathognomonic for vestibular schwannomas in the setting of neurofibromatosis type 2 (NF2). Descriptions of bilateral nonschwannomatous IAC tumors, such as metastasis that may mimic NF2, are limited to case reports. Here, we report a case of unusual metastatic bilateral IAC tumor originating from the ovary with a rapidly progressive pattern, which we initially suspected to be NF2.