Advanced technical tips and recent insights in ERCP using balloon-assisted endoscopy

Pancreatobiliary endoscopic interventions using balloon-assisted endoscopes have been widely acknowledged as the first-line therapy for pancreatobiliary diseases in postoperative patients with reconstructed gastrointestinal anatomy (excluding the Billroth I procedure). However, there are many technical difficulties, and the procedural completion rates vary in a wide range among institutions, indicating the procedural technique is yet to be standardized. This article aims to provide technical tips of procedures and insights into the advanced aspects, including the management of extremely difficult cases and troubleshooting of endoscopic retrograde cholangiopancreatography using balloon endoscopy, along with a review of recent advancements in this field.

Perforation-free removal of gastric gastrointestinal stromal tumors: Endoscopic inversion and strangulation of muscle layer and resection (EISMR)

Endoscopic resection for GIST has become more widespread in recent years because it is less invasive than surgery. However, when endoscopic resection is performed, a full-layer resection of the gastric wall is often necessary, and extensive suturing is required if perforation occurs, which is a technically challenging procedure. Recently, we reported a new method called endoscopic inversion and strangulation of the muscle layer and resection (EISMR), which consists of endoscopically inverting the muscle layer into the gastric lumen and strangulating the muscle layer with a detachable snare, followed by resection. The study comprised five consecutive patients with gastric GIST ≤50 mm in diameter who underwent EISMR procedures. The main outcomes of the study were en bloc resection rate, R0 resection rate, procedure time, and complications. The results showed that all five patients successfully underwent complete resection without perforation, and the en bloc resection and R0 resection rates were 100%. The median procedure time was 93 min (range, 58-120 min), and there were no major complications. We concluded that EISMR would be a safe and effective technique for endoscopic resection of gastric GISTs and may be an alternative to surgery or endoscopic submucosal dissection.

Viral Infection in Esophageal, Gastric, and Colorectal Cancer

The human gastrointestinal tract, which constitutes the digestive system, contains a large number of virus particles that maintain organizational homeostasis and health. Conversely, viral pathogens have also attracted attention for their involvement in the pathogenesis of certain cancers, including gastrointestinal cancers. To aid prevention and treatment of these cancers, the relevance of gastrointestinal viral factors as potential risk factors needs to be carefully investigated. This review summarizes and discusses the available literature on the relationship between the development of esophageal, gastric, and colorectal cancers and their corresponding viruses. This review reveals that research on the association between colorectal cancer and viruses, in particular, is still in its infancy compared to the association between HPV and esophageal cancer and between EBV and gastric cancer.

Esophageal Large-Cell Neuroendocrine Carcinoma with Inconsistent Response to Treatment in the Primary and Metastatic Lesions

Esophageal large-cell neuroendocrine carcinoma (NEC) is a rare malignant tumor that is characterized by high-grade malignancy and a poor prognosis. However, the rarity of esophageal NEC has prevented the development of an established treatment, and no reports have described a discrepancy in the effectiveness of cisplatin plus irinotecan between primary and metastatic lesions. A 43-year-old Japanese man was referred to our hospital with refractory epigastralgia. A previous gastrointestinal endoscopy had revealed a 50-mm type 2 tumor in the abdominal esophagus. The pathological findings indicated poorly differentiated squamous cell carcinoma. Contrast-enhanced computed tomography revealed a metastatic liver tumor. One cycle of fluorouracil and cisplatin was not effective, and endoscopy was repeatedly performed. The pathological findings indicated a large-cell malignant tumor with tumor cells that were positive for CD56, synaptophysin, and Ki-67 (> 80%). Based on a diagnosis of esophageal large-cell NEC with a metastatic liver tumor, the patient received cisplatin plus irinotecan biweekly. After 4 months, computed tomography revealed marked shrinkage of the metastatic tumor, but the patient complained of dysphagia. Endoscopy revealed enlargement of the primary tumor, which was then treated using radiotherapy plus fluorouracil and cisplatin. The primary tumor subsequently shrank, and the patient's symptoms were relieved, but the metastatic tumor grew. Thus, chemoradiotherapy could be an option for managing a primary esophageal large-cell NEC that does not respond to chemotherapy alone. However, the possibility of an inconsistent response to therapy in primary and metastatic lesions should be considered.

[Combination chemotherapy with etoposide, ADM, and CDDP (EAP) for advanced gastric cancer]

EAP therapy has been performed on 50 cases of advanced gastric cancer from January 1988 to September 1989. Adriamycin 20 mg/m2, Cisplatin 40 mg/m2 and Etoposide 100 mg/m2 were administered on day 1 and 7, 2 and 8, and 4, 5 and 6, respectively, with not less than 2 courses every 3 to 4 weeks. Complete success, PR, NC and PD were obtained in 48, 21, 20 and 7 cases, respectively, the rate of effectiveness being 43.8% with a confidence interval 95% of 30-58%. The rate of effectiveness by lesions for evaluation was high (30.4, 100, and 50% for primary lesion, Virchow's lymphnodal metastasis and liver metastasis, respectively). MST was 5.1 months for EAP therapy, which was highly effective but led to no prolonged survival period. Thus, it is thought that good control of leukopenia, a dose limiting factor remains to be examined.