Gas leakages from gastrointestinal endoscopy system-its visualization and semi-quantification utilizing schlieren optical system in the swine models.

BACKGROUND AND AIMS: With the global epidemic of SARS-CoV-2, there has been a growing concern regarding the risk of aerosol exposure to healthcare workers and patients during medical/surgical interventions. The Schlieren device is capable of visualizing fine gas-flows by using refractive index differences in the medium. We aimed to reveal the existence of gas leakage from gastro-intestinal endoscopy system by utilizing Schlieren device and to clarify the factors which relates to the amount of gas leakage. METHODS: The experiments were performed on the excised swine stomach while maintaining a constant pressure environment in the stomach. The System Schlieren (SS100,KatoKoken) was used to visualize possible gas leakages from forceps plugs of endoscopy. We attempted to semi-quantify the leakage by referring to the image of the gas from the forceps plug and by measuring the initial velocity and diffusion area of the leakage. RESULTS: Regardless of the type of forceps plugs, a certain amount of leakage was detected during both insertion and removal of forceps. The initial velocity and the diffusion area of the leakage increased with the increase in intragastric pressure. Semi-quantitative comparison showed that there was a difference in the amount of gas leakage among various forceps plugs. Furthermore, the amount of gas leakage was significantly greater in the forceps plugs that were used repeatedly. CONCLUSION: It was possible to visualize gas leakages from the gastrointestinal endoscope system using the Schlieren optical device. Avoiding too high intragastric pressure and not using deteriorated plugs may reduce the risk of aerosol exposure.

[A Case of Long-Term Survival after Multimodal Therapy against Gastric GIST with Multiple Hepatic Metastasis].

A male in his forties experiencing epigastric pain visited our hospital and was diagnosed with a large gastric gastrointestinal stromal tumor(GIST)invading pancreatic tail with synchronous multiple liver metastases. We diagnosed as unresectable and started imatinib. Two weeks later, tumor necrosis and penetration were occurred. We performed partial gastrectomy with pancreatic tail resection and splenectomy. During the surgery, we also performed radiofrequency ablation(RFA)on all the liver metastases. After surgery, we immediately resumed imatinib. Four years after surgery, metastatic lesion in liver S4/8 was detected, RFA was performed and Imatinib was continued. Eight years after surgery, a recurrent metastatic lesion of the liver coincident with the previous RFA site was detected. We performed a right hepatic lobectomy and he continued imatinib, Currently, 16 years after the first operation, he is alive under the imatinib continuation. This case demonstrates that the combination of surgery, RFA and imatinib can be effective for prolonging survival in patients with advanced gastric GIST with synchronous multiple liver metastases.

Laparoscopic resection for imatinib-resistant recurrent tumors of gastric gastrointestinal stromal tumors: A case report.

An 82-year-old woman underwent laparoscopic partial gastrectomy for fundal gastrointestinal stromal tumor (GIST) in a previous hospital. She visited our hospital for the treatment of recurrence, because two nodules, one each on the gastric suture line and in the peritoneum of the left diaphragm, were pointed out. Imatinib therapy was immediately initiated, and the size of both nodules decreased. However, the one on the gastric suture line showed regrowth after 4 years, which was eventually diagnosed as imatinib-resistant GIST. Hence, laparoscopic partial gastrectomy with peritoneal imatinib-sensitive nodule resection was subsequently performed. Pathologically, the nodule on the gastric suture line was confirmed as a GIST, whereas the other was diagnosed as a hyaline-degenerated GIST. Surgical intervention for imatinib-resistant GISTs has been reported to improve the outcomes of recurrent GISTs. Laparoscopic resection of localized imatinib-resistant GISTs could safely and less invasively be performed in this case; however, caution should be paid to the indication of the approach.

[Long-Term Survival with Multidisciplinary Treatment and Nutritional Therapy for Thoracic Esophageal Cancer with Multiple Liver Metastases-A Case Report].

The patient was a 63-year-old man with a chief complaint. Upper endoscopic examination revealed a semicircular type 2 lesion, sized 24-28 cm, on the incisor teeth and a 3 cm sized elevated lesion directly above the EGJ. When biopsy was performed, squamous cell carcinoma(SCC)was detected. In this case, lymph node metastasis and multiple liver metastases were observed, and diagnosis at the first examination was cT3N2M1(HEP), Stage Ⅳ. After 7 months of chemotherapy, he underwent right thoracic esophageal subtotal resection, 3-field lymph node dissection, posterior mediastinal gastric tube reconstruction, and partial hepatectomy. Despite receiving postoperative chemotherapy, he showed recurrence in the liver(S8). Four additional courses of chemotherapy were administered and partial hepatectomy(S8)was performed, without the appearance of new lesions. He was considered to be cured 1 year and 6months after starting the treatment and was followed- up without chemotherapy. However, 4 months later, chemotherapy was resumed when right adrenal and abdominal wall metastases and liver recurrence(S3)were found. After that, the regimen was modified, and he continued treatment. More than 4 years have passed since the start of treatment, but the treatment has been continued without a decline in ADL.