松本 志郎

Abstract The advent of Artificial Intelligence (AI)-based object detection technology has made identification of position coordinates of surgical instruments from videos possible. This study aimed to find kinematic differences by surgical skill level. An AI algorithm was developed to identify X and Y coordinates of surgical instrument tips accurately from video. Kinematic analysis including fluctuation analysis was performed on 18 laparoscopic distal gastrectomy videos from three expert and three novice surgeons (3 videos/surgeon, 11.6 h, 1,254,010 frames). Analysis showed the expert surgeon cohort moved more efficiently and regularly, with significantly less operation time and total travel distance. Instrument tip movement did not differ in velocity, acceleration, or jerk between skill levels. The evaluation index of fluctuation β was significantly higher in experts. ROC curve cutoff value at 1.4 determined sensitivity and specificity of 77.8% for experts and novices. Despite the small sample, this study suggests AI-based object detection with fluctuation analysis is promising because skill evaluation can be calculated in real time with potential for peri-operational evaluation.

INTRODUCTION: An eyeglass gaze camera and a skeletal coordinate camera without sensors attached to the operator's body were used to monitor gaze and movement during a simulated surgical procedure. These new devices have the potential to change skill assessment for laparoscopic surgery. The suitability of these devices for skill assessment was investigated. MATERIAL AND METHODS: Six medical students, six intermediate surgeons, and four experts performed suturing tasks in a dry box. The tip positions of the instruments were identified from video recordings. Performance was evaluated based on instrument movement, gaze, and skeletal coordination. RESULTS: Task performance time and skeletal coordinates were not significantly different among skill levels. The total movement distance of the right instrument was significantly different depending on the skill level. The SD of the gaze coordinates was significantly different depending on skill level and was less for experts. The expert's gaze stayed in a small area with little blurring. CONCLUSIONS: The SD of gaze point coordinates correlates with laparoscopic surgical skill level. These devices may facilitate objective intraoperative skill evaluation in future studies.

Gastrointestinal stromal tumors (GIST) in patients under 18 years of age are classified as pediatric GIST. Pediatric GIST are extremely rare, and there are no reports of laparoscopic-endoscopic cooperative surgery for these lesions. We report the use of non-exposed endoscopic wall-inversion surgery as a laparoscopic-endoscopic cooperative surgery-related procedure for the treatment of a pediatric GIST. The case involved a 17-year-old male patient who presented with anemia and was found to have a bleeding gastric tumor. The tumor was resected transorally using the non-exposed endoscopic wall-inversion surgery technique. No gene mutation of c-Kit or Platelet-Derived Growth Factor Receptor α (PDGFRα) was found, and the final pathological diagnosis was epithelial-type GIST due to a succinate dehydrogenase abnormality. Follow-up included a CT scan every 4 months. No recurrence has occurred to date.

INTRODUCTION: Black adrenal adenoma (BAA) is a rare, benign adrenal lesion with a black or brown appearance. This is the first report of this lesion in a patient with a synchronous esophageal cancer and highlights the importance of considering a false positive finding on a Positron Emission Tomography (PET) scan, which might otherwise preclude resection. PRESENTATION OF CASE: A 73-year-old male was diagnosed with mid-esophagus carcinoma. Computed tomography scan revealed an enlarged left adrenal gland. Plasma adrenocorticotropic hormones levels were normal. To characterize the adrenal lesion, a PET scan was obtained which showed high uptake of 18F-fluoro-2-deoxy-d-glucose (FDG), consistent with a metastasis, suggesting T3N2M1, clinical stage IV esophageal cancer. After two courses of neo-adjuvant therapy, sub-total esophagectomy and left adrenalectomy were performed. The adrenal tumor was soft, and black in color, diagnosed as a BAA on histology. The pathologic stage of the esophageal cancer was T3N0M0, Stage II. Six months after surgery, he is alive without recurrence. DISCUSSION: High FDG uptake by an adrenal lesion on PET scan, as in this patient, usually suggests a metastatic lesion. Although rare, patients with esophageal cancer and adrenal metastases have been reported to have long-term survival, so it is important to characterize an adrenal lesion when found. CONCLUSION: Most adrenal lesions with high FDG uptake are malignant, but BAA is also positive on PET scan. Although rare, BAA should be considered in patients with solitary adrenal lesions with high uptake on PET scan, even in the presence of a malignancy.

We present three patients with T2 acinar cell carcinomas (ACC) (two of which were small) and discuss their clinical and pathological features. Case 1: A 34 year-old woman had a 2.6 cm iso- or hyperdense tumor. Enucleation was performed but final diagnosis was ACC and a pylorus preserving pancreaticoduodenectomy was performed. Case 2: A 35 year-old woman was found to have a 4.5 cm hypervascular tumor in the tail of the pancreas. Distal pancreatectomy was performed. Case 3: A 61 year-old man suffered from acute pancreatitis and was found to have an encapsulated 2.5 cm hypervascular tumor in the head of pancreas. Pylorus-preserving pancreaticoduodenectomy was performed. These three patients with T2 ACCs had common characteristics including well-demarcated exophytic tumors with slow and limited progress, distinctively different from large ACCs and pancreatic ductal adenocarcinomas. ACCs are important in the differential diagnosis of homogeneously or heterogeneously enhancing small pancreatic tumors.