Background/Aims: Sufficient sedation is important when performing an endoscopic submucosal dissection (ESD) for an esophageal squamous cell carcinoma (ESCC), and dexmedetomidine (DEX) is being increasingly used. ESD is often performed in elderly patients and those with comorbidities. Therefore, adverse events (AEs) in the circulatory and respiratory systems remain a clinical concern.Despite this, limited data exist on these AEs, so this study was conducted to investigate this issue. Methods: This single-center retrospective study included 526 patients who underwent ESD for ESCC under DEX-based sedation from 2016 to 2023. The study assessed the incidence of AEs in circulatory and respiratory systems, as well as the risk factors associated with these events. Various clinical factors, including the Prognostic Nutritional Index (PNI), were analyzed as candidates. Results: Circulatory AEs occurred in 55 cases (10.5%), including bradycardia (7.2%) and hypotension (4.2%). Univariate and multivariate analyses revealed significant associations of lower PNI (<45) and prolonged procedure time with circulatory AEs (p=0.023 and p=0.008, respectively). Respiratory AEs occurred in 12 cases (2.3%), including respiratory depression (1.0 %) and post-ESD pneumonia (1.5 %) with one fatal case (0.2 %). An analysis of respiratory AEs showed that the elderly (≥80 years) and lower PNI were significant in univariate analysis but not in multivariate analysis (both p=0.07). Conclusions When performing ESD for ESCC under DEX-based sedation, special caution is needed for patients with lower PNI and the elderly, who are more likely to experience circulatory or respiratory complications.

Tirzepatide has demonstrated greater efficacy than semaglutide in improving glycemic control and reducing body weight in patients with type 2 diabetes mellitus (T2DM). However, the optimal tirzepatide dose following a switch from 1.0 mg of semaglutide remains unclear. This retrospective study included 15 T2DM patients who switched to tirzepatide due to inadequate weight loss. All patients started tirzepatide at 2.5 mg, with escalation to either 7.5 mg (n=10) or 10 mg (n=5). Changes in glycated hemoglobin (HbA1c) and body weight were assessed over a 3-month period. The 10 mg group experienced a significant reduction in HbA1c (−0.7%±0.3%, P<0.01) and a non-significant trend toward weight loss (−6.6±5.4 kg, P=0.07). In contrast, no significant changes were observed in the 7.5 mg group. There were no statistically significant differences between groups. Since 10 mg of tirzepatide significantly improved glycemic control after switching from 1.0 mg of semaglutide, early escalation to 10 mg may be beneficial for patients who respond inadequately to semaglutide.

Background: The posterior interosseous nerve (PIN) is at risk of iatrogenic nerve injury during elbow surgery when using a lateral or posterolateral approach. Results of cadaveric studies indicated that maintaining forearm pronation throughout the surgery can help move the PIN away from the surgical window. However, in vivo dynamic migration of the PIN in response to changes in the elbow and forearm position is unclear. This study aimed to clarify the in vivo dynamic migration pattern of the PIN in response to changes in the elbow and forearm position using ultrasound imaging. Methods: This study included 43 upper extremities of 22 healthy volunteers (16 females; mean age, 29 years). Using ultrasound imaging, we measured the shortest distance from the radial head (RH) to the point where the PIN crossed the lateral aspect of the radial axis in six positions of the elbow and forearm: 90° forearm supination, 90° pronation, and neutral forearm position, each at 135° of elbow flexion and 0° of elbow extension. Results: The RH-to-nerve distance was greater during elbow extension than during elbow flexion regardless of the forearm position. However, the maximum migration distance was 3.5 mm when transitioning from elbow extension and forearm pronation (25.1 mm) to elbow flexion and forearm supination (21.6 mm). Conclusions Although forearm pronation may help move the PIN away from the surgical window, care should be taken not to injure the nerve when performing elbow surgery using a lateral or posterolateral approach.Level of evidence: III.

Background: The posterior interosseous nerve (PIN) is at risk of iatrogenic nerve injury during elbow surgery when using a lateral or posterolateral approach. Results of cadaveric studies indicated that maintaining forearm pronation throughout the surgery can help move the PIN away from the surgical window. However, in vivo dynamic migration of the PIN in response to changes in the elbow and forearm position is unclear. This study aimed to clarify the in vivo dynamic migration pattern of the PIN in response to changes in the elbow and forearm position using ultrasound imaging. Methods: This study included 43 upper extremities of 22 healthy volunteers (16 females; mean age, 29 years). Using ultrasound imaging, we measured the shortest distance from the radial head (RH) to the point where the PIN crossed the lateral aspect of the radial axis in six positions of the elbow and forearm: 90° forearm supination, 90° pronation, and neutral forearm position, each at 135° of elbow flexion and 0° of elbow extension. Results: The RH-to-nerve distance was greater during elbow extension than during elbow flexion regardless of the forearm position. However, the maximum migration distance was 3.5 mm when transitioning from elbow extension and forearm pronation (25.1 mm) to elbow flexion and forearm supination (21.6 mm). Conclusions Although forearm pronation may help move the PIN away from the surgical window, care should be taken not to injure the nerve when performing elbow surgery using a lateral or posterolateral approach.Level of evidence: III.

Background: The posterior interosseous nerve (PIN) is at risk of iatrogenic nerve injury during elbow surgery when using a lateral or posterolateral approach. Results of cadaveric studies indicated that maintaining forearm pronation throughout the surgery can help move the PIN away from the surgical window. However, in vivo dynamic migration of the PIN in response to changes in the elbow and forearm position is unclear. This study aimed to clarify the in vivo dynamic migration pattern of the PIN in response to changes in the elbow and forearm position using ultrasound imaging. Methods: This study included 43 upper extremities of 22 healthy volunteers (16 females; mean age, 29 years). Using ultrasound imaging, we measured the shortest distance from the radial head (RH) to the point where the PIN crossed the lateral aspect of the radial axis in six positions of the elbow and forearm: 90° forearm supination, 90° pronation, and neutral forearm position, each at 135° of elbow flexion and 0° of elbow extension. Results: The RH-to-nerve distance was greater during elbow extension than during elbow flexion regardless of the forearm position. However, the maximum migration distance was 3.5 mm when transitioning from elbow extension and forearm pronation (25.1 mm) to elbow flexion and forearm supination (21.6 mm). Conclusions Although forearm pronation may help move the PIN away from the surgical window, care should be taken not to injure the nerve when performing elbow surgery using a lateral or posterolateral approach.Level of evidence: III.

Background: The posterior interosseous nerve (PIN) is at risk of iatrogenic nerve injury during elbow surgery when using a lateral or posterolateral approach. Results of cadaveric studies indicated that maintaining forearm pronation throughout the surgery can help move the PIN away from the surgical window. However, in vivo dynamic migration of the PIN in response to changes in the elbow and forearm position is unclear. This study aimed to clarify the in vivo dynamic migration pattern of the PIN in response to changes in the elbow and forearm position using ultrasound imaging. Methods: This study included 43 upper extremities of 22 healthy volunteers (16 females; mean age, 29 years). Using ultrasound imaging, we measured the shortest distance from the radial head (RH) to the point where the PIN crossed the lateral aspect of the radial axis in six positions of the elbow and forearm: 90° forearm supination, 90° pronation, and neutral forearm position, each at 135° of elbow flexion and 0° of elbow extension. Results: The RH-to-nerve distance was greater during elbow extension than during elbow flexion regardless of the forearm position. However, the maximum migration distance was 3.5 mm when transitioning from elbow extension and forearm pronation (25.1 mm) to elbow flexion and forearm supination (21.6 mm). Conclusions Although forearm pronation may help move the PIN away from the surgical window, care should be taken not to injure the nerve when performing elbow surgery using a lateral or posterolateral approach.Level of evidence: III.

Background/Aims: The etiology of superficial non-ampullary duodenal epithelial tumors (SNADETs) remains unclear. Recent studies have reported conflicting associations between duodenal tumor development and Helicobacter pylori infection or endoscopic gastric mucosal atrophy. As such, the present study aimed to clarify the relationship between SNADETs and H. pylori infection and/or endoscopic gastric mucosal atrophy. Methods: This retrospective case-control study reviewed data from 177 consecutive patients with SNADETs who underwent endoscopic or surgical resection at seven institutions in Japan over a three-year period. The prevalence of endoscopic gastric mucosal atrophy and the status of H. pylori infection were compared in 531 sex- and age-matched controls selected from screening endoscopies at two of the seven participating institutions. Results: For H. pylori infection, 85 of 177 (48.0%) patients exhibited SNADETs and 112 of 531 (21.1%) control patients were non-infected (p<0.001). Non-atrophic mucosa (C0 to C1) was observed in 96 of 177 (54.2%) patients with SNADETs and 112 of 531 (21.1%) control patients (p<0.001). Conditional logistic regression analysis revealed that non-atrophic gastric mucosa was an independent risk factor for SNADETs (odds ratio, 5.10; 95% confidence interval, 2.44–8.40; p<0.001). Conclusions Non-atrophic gastric mucosa, regardless of H. pylori infection status, was a factor independently associated with SNADETs.