Yutaka Saito

Diagnostic accuracy of narrow-band imaging and pit pattern analysis significantly improved for less-experienced endoscopists after an expanded training program

BACKGROUNDnPrevious reports assessing diagnostic skill using narrow-band imaging (NBI) and pit pattern analysis for colorectal polyps involved only highly experienced endoscopists.nnnOBJECTIVEnTo evaluate diagnostic skills of less-experienced endoscopists (LEE group) for differentiation of diminutive colorectal polyps by using NBI and pit pattern analysis with and without magnification after an expanded training program.nnnDESIGNnProspective study.nnnPATIENTSnThis study involved 32 patients with 44 colorectal polyps (27 adenomas and 17 hyperplastic polyps) of < or =5 mm that were identified and analyzed by using conventional colonoscopy as well as non-magnification and magnification NBI and chromoendoscopy followed by endoscopic removal for histopathological analysis.nnnINTERVENTIONnBefore a training course, 220 endoscopic images were distributed in randomized order to residents with no prior endoscopy experience (NEE group) and to the LEE group, who had performed colonoscopies for more than 5 years but had never used NBI. The 220 images were also distributed to highly experienced endoscopists (HEE group) who had routinely used NBI for more than 5 years. The images were distributed to the NEE and LEE groups again after a training class. Magnification NBI and chromoendoscopy images were assessed by using the Sano and Kudo classification systems, respectively.nnnMAIN OUTCOME MEASUREMENTSnDiagnostic accuracy and interobserver agreement for each endoscopic modality in each group.nnnRESULTSnDiagnostic accuracy was significantly higher, and kappa (kappa) values improved in the LEE group for NBI with high magnification after expanded training. Diagnostic accuracy and kappa values when using high-magnification NBI were highest among endoscopic techniques for the LEE group after such training and the HEE group (accuracy 90% vs 93%; kappa = 0.79 vs 0.85, respectively).nnnLIMITATIONSnStudy involved only polyps of < or =5 mm.nnnCONCLUSIONnUsing high-magnification NBI increased the differential diagnostic skill of the LEE group after expanded training so that it was equivalent to that of the HEE group.

Diagnosis and Treatment of Superficial Gastric Neoplasms

Abstract Gastric cancer is the third leading cause of cancer-related death in both sexes worldwide. However, the incidence and mortality of gastric cancer is decreasing due to the recent reduction of Helicobacter pylori infection and the widespread use of eradication therapy for H. pylori. Although the prognosis of advanced gastric cancer is poor, the long-term outcome of early gastric cancer (EGC) is favorable; therefore it is very important to endoscopically detect EGC and neoplastic lesions. As a first step, it is important to motivate even asymptomatic individuals to undergo an endoscopy screening examination. Next, a fundamental understanding of EGC and proper endoscopic techniques such as adequate preparation, systematic examination and use of chromoendoscopy, optical image-enhanced endoscopy, and targeted biopsy are essential for early detection. Finally, accurate endoscopic estimation of invasion depth for EGC is required for making proper decisions on treatment strategy. Endoscopic resection is indicated for EGCs with a negligible risk of lymph node metastasis. The technique of endoscopic resection has been improved from endoscopic mucosal resection to endoscopic submucosal dissection (ESD). ESD offers the advantage of achieving en bloc resection. Step-by-step training is important for training in ESD techniques. The technique employed for ESD depends on which type of device (IT-type or needle-type knife) is used during the procedure. ESD is associated with a relatively high risk of complications. Endoscopists must be aware of not only the incidence and risk factors for complications, but must also know how to effectively manage these complications.

News in ESD

Endoscopic submucosal dissection (ESD) is now becoming a standard treatment for early-stage, large, gastrointestinal (GI) tumors. Although ESD is one of the more difficult procedures in GI therapeutic endoscopy, new devices and strategies have been invented to make it easier and safer. Understanding new methods for ESD may help endoscopists perform safer and more time-saving ESD procedures.

Endoscopic Submucosal Dissection: Upper Gastrointestinal Tract

Endoscopic submucosal dissection (ESD) is an advanced endoscopic resection technique for the treatment of superficial cancers of the esophagus and stomach. Its advantages over traditional endoscopic mucosal resection techniques are higher curative resection rates and lower local recurrence. While ESD has become the standard of care in Japan for early gastric cancer, its initial adoption in the West was slow. However, as many of the barriers to Western adoption have now been overcome, we are seeing increasing interest and practice of this technique. ESD is indicated for early cancerous lesions of the esophagus and stomach with a negligible risk of lymph node metastasis. It has the potential for curative resection of these cancers while avoiding the morbidity and mortality associated with traditional surgery and allowing preservation of the native organ.

Atlas of Neoplastic Lesions

These lesions refer to multiple areas of the esophagus not staining with iodine when sprayed with iodine stain. Lesions that do not stain with iodine include areas of inflammation, atypical epithelium, intraepithelial cancers, and invasive cancers, whereas squamous cell carcinoma is extremely likely with a positive pink color sign, a pink color change following iodine staining. Multiple Lugol-voiding lesions are seen in individuals with ALDH2 deficiency who habitually consume alcohol, and they are at an increased risk of multiple cancers of the esophagus and laryngopharyngeal region.

The Diagnosis and Treatment of Early-Stage Colorectal Cancer

The introduction of colorectal endoscopic submucosal dissection (ESD) has expanded the applications for endoscopic treatment; as a result, lesions with low metastatic potential can be treated endoscopically regardless of the lesion size. The most attractive feature of ESD is the achievement of en bloc resection with a lower local recurrence rate in comparison to that of endoscopic piecemeal mucosal resection. However, in case of gastric cancers, ESD is not as widely applied to the treatment of colorectal neoplasms because of its technical difficulty, longer procedural time, and increased perforation risk. In the movement toward diversified endoscopic treatment strategies for superficial colorectal neoplasms, endoscopists who begin to perform ESD need to recognize the indications of ESD, as well as the technical issues and associated complications of this procedure.

Augmented Endoscopy Imaging in the Study of Digestive Anastomosis: Does It Really Work and How?

Digestive anastomotic sites are often exposed to several mechanical stimuli. Therefore, erosions or hyperplastic changes often occur on there. In contrast, neoplastic lesions, both benign and malignant, sometimes occur on the anastomotic site. In the cases which the previous surgery was performed for a nonneoplastic disease, the neoplastic lesion on the anastomotic site occurs incidentally or partly due to the increased stimulus after surgery. In the cases which the previous surgery was due to a neoplastic lesion, anastomotic recurrence, metachronous cancer, and previously overlooked neoplasm are considered as the causes of anastomotic neoplasm. The augmented endoscopy (e.g., magnifying chromoendoscopy , narrow band imaging) may be useful to distinguish the anastomotic recurrence from benign erosion or hyperplastic change. In this chapter, we would like to introduce such advanced endoscopic modalities in the study of digestive anastomosis .

Neoplastic Disease of the Ileocecal Region

Relative to the length and surface area of the small intestine, malignancies at this site account for only 3% of all gastrointestinal tract cancers and less than 0.5% of all cancers in the United States [1]. However, the incidence of malignancies in the small intestine appears to be increasing [2]. With recent developments in the technology of digestive endoscopy, such as double-balloon enteroscopy and capsule endoscopy, the detection rate of small intestinal neoplasms is expected to increase further. Therefore, state-of-the-art knowledge of neoplastic diseases in this anatomical area is of utmost importance.

The Importance of Complete Colonoscopy and Exploration of the Cecal Region

Examination of the left colon alone misses right-sided lesions. Colonoscopy is the most sensitive colonic imaging test for adenomas. An additional advantage of colonoscopy is the ability to remove precancerous polyps at the time of their detection. A right-sided shift of initial and recurrent adenoma with aging and female gender has been reported. Therefore, total colonoscopy is needed for screening and surveillance. Clinically, right-sided cancer is likely to be detected at a more advanced stage, with severe symptoms, such as passage trouble or abdominal mass. Morphologically, flat-type tumors are significantly encountered in right-sided colon, while polypoid-type ones are substantially more dominant in the left colon. Histologically, poorly differentiated, mucinous and signet-ring cell tumors are frequently seen in the right colon. From the molecular aspect, both colorectal cancers (CRC) with a high frequency of CpG island methylation and those with microsatellite instability, have been frequently detected in the right-sided colon of elderly people. Moreover, sessile serrated adenomas or polyps (SSAP) are more prevalent in the proximal colon. The presence of large SSAPs (10 mm or larger in size) is also reported to be a risk factor for CRC, particularly CRC of the proximal colon.