Development of surgical support robots began in the 1980s as a navigation and auxiliary device for endoscopic surgery. For remote surgery on the battlefield, a master-slave-type surgical support robot was developed, in which a console surgeon operates the robot at will. The da Vinci surgical system, which currently dominates the global robotic surgery market, received United States Food and Drug Administration and regulatory approval in Japan in 2000 and 2009 respectively. The latest, fourth generation, da Vinci Xi has a good field of view via a three-dimensional monitor, highly operable forceps, a motion scale function, and a tremor-filtered articulated function. Gastroenterological tract robotic surgery is safe and minimally invasive when accessing and operating on the esophagus, stomach, colon, and rectum. The learning curve is said to be short, and robotic surgery will likely be standardized soon. Therefore, robotic surgery training should be systematized for young surgeons so that it can be further standardized and later adapted to a wider range of surgeries. This article reviews current trends and potential developments in robotic surgery.

Background: Endoscopic retrograde cholangiopancreatography (ERCP) is essential for diagnosing and treating biliopancreatic disease. Because ERCP-related perforation can result in death, therapeutic decisions are important. The aim of this study was to determine the cause of ERCP-related perforation and suggest appropriate management. Methods: Between January 1999 and August 2022, 7,896 ERCPs were performed in our hospital. We experienced 15 cases (0.18%) of ERCP-related perforation and conducted a retrospective review. Results: Of the 15 patients, 6 were female and 9 were male, and the mean age was 77.1 years. According to Stapfer's classification, the 15 cases of ERCP-related perforation comprised 3 type I (duodenum), 3 type II (periampullary), 9 type III (distal bile duct or pancreatic duct), and no type IV cases. Fourteen of 15 (92.6%) were diagnosed during ERCP. The main cause of perforation was scope-induced damage, endoscopic sphincterotomy, and instrumentation penetration in type I, II, and III cases, respectively. Four patients with severe abdominal pain and extraluminal fluid collection underwent emergency surgery for repair and drainage. One type III patient with distal bile duct cancer underwent pancreaticoduodenectomy on day 6. Three type III patients with only retroperitoneal gas on computed tomography (CT) performed immediately after ERCP had no symptoms and needed no additional treatment. Seven of the 15 patents were treated by endoscopic nasobiliary drainage (n=5) or CT-guided drainage (n=2). There were no deaths, and all patients were discharged after treatment. Conclusions: Early diagnosis and appropriate treatment are important in managing ERCP-related perforation.

Background: Bone metastases can cause severe pain, pathological fractures, and spinal cord paralysis, which interrupt treatment for tumors and cause patients to be bedridden. In this study, we aimed to clarify therapists' problems in the rehabilitation of patients with bone metastases and their countermeasures using the results of questionnaires to therapists and recommend safer and more rational rehabilitation. Methods: Questionnaire forms were sent to 21 therapists in our department. The questionnaire was conducted anonymously about problems during the rehabilitation procedure such as the risk of pathological fractures and paralysis. Results: All of the therapists had strong anxiety (43%) or some anxiety (57%) about the risk of pathological fractures or paralysis during a procedure. However, no therapist responded that this had ever occurred. Many of the respondents had changed a procedure to a milder one (81%) or interrupted a procedure (48%) due to the patient's condition on the day. Therapists chose many options to reduce the risk of pathological fractures and paralysis during the procedure. Among them, "pre-rehabilitation referral to orthopedic surgeon" (86%), "consultation with a doctor about changes in patient's symptoms and findings" (86%), and "regular cooperation between multiple occupations" (67%) were frequently selected. Conclusions: Our questionnaire survey of therapists regarding the treatment of patients with bone metastases found that there was considerable anxiety about the risk of pathological fractures and paralysis during treatment. Our findings suggest that it is necessary to strengthen cooperation with multiple occupations, especially those in the orthopedic field.

Background: Gonadal hormones function in the retina; however, their targets have not yet been identified. Therefore, the present study examined the effects of progesterone and other gonadal hormones on glutamatergic circuits in the retina. Methods: Extracellular glutamate concentrations, which correspond to the amount of glutamate released, were examined using an enzyme-linked fluorescent assay system. The activity of glutamatergic synapses between bipolar cells and ganglion cells was investigated using a patch clamp technique. Changes in retinal thickness during pregnancy were assessed using optical coherence tomography (OCT) images. Results: Progesterone and pregnenolone sulfate increased extracellular glutamate concentrations, whereas estrogen and testosterone did not. Progesterone increased the activity of glutamatergic synapses between bipolar cells and ganglion cells. A temporal decrease in the thickness of the peripheral retina was observed in the 1^st trimester. Conclusions: Progesterone, but not estrogen or testosterone, activated glutamate release in the mouse retina. Increases in the concentration of progesterone during pregnancy did not induce any detectable change in retinal thickness.

Intracranial tumors are rare in persons with Down syndrome. Although germ cell tumors and gliomas have been reported in Down syndrome, primary central nervous system lymphoma (PCNSL) has not. We report a case of PCNSL in a 48-year-old man with Down syndrome and no history of malignant tumors. He visited our hospital for evaluation of left hemiparesis and gait disturbance. A thorough examination revealed brain tumors, and analysis of a biopsy specimen of the tumor confirmed a diagnosis of PCNSL. The final pathological diagnosis was diffuse large B-cell lymphoma of the central nervous system. Chemotherapy with rituximab, methotrexate, procarbazine, and vincristine was administered, and whole-brain irradiation was planned in conjunction with chemotherapy. It is unclear whether chromosomal abnormalities related to Down syndrome were involved in the development of PCNSL. Further molecular biological analysis may clarify the mechanism of combined Down syndrome and PCNSL.

Although necessary for hemodialysis (HD), arteriovenous grafts (AVG) frequently cause complications. Stenosis resulting in venous hypertension is a concern for physicians. Herein, we describe how venous hypertension was improved by using a Viabahn stent graft in an elderly HD patient. An 86-year-old woman started maintenance HD with a left-arm AVG. Two years later, she was referred to our hospital for treatment of juxta-graft-venous junction (GVJ) stenosis. Because of recurrence of stenosis at the juxta-GVJ, she underwent four percutaneous transluminal angioplasty (PTA) procedures during a period of 9 months. One month after the most recent PTA, the patient had redness, swelling, and pain in her left forearm. Venous hypertension was diagnosed on the basis of angiography findings showing regurgitation to the periphery of the basilic vein and juxta-GVJ stenosis. The stenosed juxta-GVJ was adequately expanded with a 7-mm balloon, and a 7-mm stent graft was inserted into the stenosis site. After successful treatment, there was no regurgitation to the periphery of the basilic vein and no symptoms. This complication should be considered when an AVG is created, because cutting off peripheral veins might prevent venous hypertension. Clinicians should perform regular postoperative monitoring.

Salivary gland carcinoma is a rare cancer and has more than 20 histopathological types. Although chemotherapy has been the mainstay of treatment for unresectable carcinomas such as multiple recurrence and distant metastasis, no standard regimen is available. In this article, we report a case of poorly differentiated salivary duct carcinoma of the submandibular gland with distant metastases that was successfully treated with pembrolizumab monotherapy. A 66-year-old man became aware of a left submandibular mass 2 months before his first visit to our department. A needle biopsy at a previous hospital revealed carcinoma, not otherwise specified. The combined positive score on a programmed death ligand-1 immunohistochemistry test was 1-10%. The patient was referred to our department for further treatment. Computed tomography revealed left level II and IV neck lymphadenopathy, bilateral lung shadowing, and osteolytic changes in the 12th thoracic vertebra. Needle biopsy showed poorly differentiated carcinoma, positive human epidermal growth factor receptor 2, and positive androgen receptor, which suggested salivary duct carcinoma. These findings indicated a diagnosis of submandibular carcinoma T4aN2bM1 stage IVC. Pembrolizumab monotherapy was started, and tumor shrinkage was observed after three courses of treatment. At 1 year, complete response was achieved without adverse events, and treatment is ongoing. Despite a lack of evidence for the efficacy of immune checkpoint inhibitors in salivary gland carcinoma, the present case suggests that some patients might respond to this treatment. Hence, clinical trials are warranted.