AIM: To evaluate the surface microvascular patterns of early colorectal cancer (ECC) using narrow-band imaging (NBI) with magnification and its effectiveness for invasion depth diagnosis.

Background/Aims: Recently, postendoscopic submucosal dissection electrocoagulation syndrome (PEECS) has attracted attention. However, the criteria for computed tomography (CT) scanning following esophageal endoscopic submucosal dissection (ESD) are unclear. In this study, we aimed to identify the predictive factors of PEECS and the usefulness of CT scanning after esophageal ESD. Methods: A total of 245 lesions in 223 patients who underwent esophageal ESD between February 2008 and October 2018 were retrospectively analyzed. Patients with double cancers, those who experienced procedural accidents, such as aspiration pneumonitis or perforation, and those who were unable to undergo CT were excluded from the study. PEECS evaluation items included body temperature (≤37.7°C = 1 point, ≥37.8°C = 2 points), white blood cell count (<10,800/μL = 1 point, ≥10,800/μL = 2 points), and chest pain (numerical rating scale [NRS] ≤4 = 1 point, NRS ≥5 = 2 points). Scores of ≥5 points were categorized as the PEECS-positive group, and scores of ≤4 points were categorized as the PEECS-negative group. The degree of mediastinal emphysema on CT was stratified into 5 grades, in which grades 0 and 1 were considered as the “low-grade” group, and grades 2, 3, and 4 were considered as the “high-grade” group. We analyzed the prognostic factors of high-grade mediastinal emphysema, including the presence or absence of PEECS. Results: The PEECS-positive group comprised 18 out of the 163 patients (11.0%), and mediastinal emphysema was stratified into grades 0 (94), 1 (51), 2 (12), 3 (5), and 4 (1 patient). Three independent risk factors for the onset of PEECS were identified, as follows: resected area ≥750 mm² (OR 7.28, 95% CI 1.42–37.33, p = 0.017), treatment duration ≥75 min (OR 10.26, 95% CI 1.20–87.77, p = 0.034), and muscle layer exposure (OR 10.92, 95% CI 2.22–53.74, p = 0.003). Two independent predictive factors of high-grade mediastinal emphysema were identified, which were PEECS positivity (OR 4.31, 95% CI 1.29–14.41, p = 0.018), and muscle layer exposure (OR 4.08, 95% CI 1.18–14.06, p = 0.026). Conclusions: A large resected area, prolonged treatment duration, and muscle layer exposure are risk factors for the onset of PEECS. Mediastinal emphysema was observed in 43% of patients following ESD. When marked clinical symptoms of PEECS appear, high-grade mediastinal emphysema may be observed, and therefore CT should be performed in these cases.

Objective This study aims to elucidate the association between the clinical characteristics of postcolonoscopy colorectal cancer (PCCRC) and quality indicators (QIs) of colonoscopy. Methods Patients with PCCRC who underwent total colonoscopy (TCS) and were histologically diagnosed with adenocarcinoma within six months to five years of the last examination were included in this study. PCCRC and normally detected cancer (NDC) identified within the same period were compared in terms of their clinicopathological characteristics. Furthermore, the QIs at PCCRC detection were compared to those at the last examination. Results Patients with PCCRC had a significantly higher rate of colon surgery history than those with NDC (PCCRC: 25/76, 32.9%; NDC: 31/1,437, 2.2%; p<0.001), but the invasion depth in these patients was significantly shallower (PCCRC: <= Tis/>= T1, 37/39; NDC: <= Tis/>= T1, 416/1,021; p<0.001). Among patients with PCCRC, the T1b group had significantly more non-polypoid growth (NPG)-type cases than PG-type CRC cases (p=0.018). The adenoma detection rate (ADR) of colonoscopists performing TCS was 30.2-52.8%. Furthermore, the ADR of colonoscopists at the time of PCCRC detection (36.7%+/- 5.9%) was significantly higher than that of colonoscopists who performed the last examination (34.9%+/- 4.4%; p=0.034). The withdrawal time for negative colonoscopy (WT-NC) at detection was significantly longer than that at the last examination (at detection: 494.3 +/- 253.8 s; at last examination: 579.5 +/- 243.6 s; p=0.010). Conclusion Given that these PCCRC cases were post-colon surgery cases, had a long WT-NC, and were detected by colonoscopists with a high ADR, most cases showed lesions that were missed during the previous colonoscopy. Caution should be practiced in order to avoid missing flat, NPG-type tumors.

Background/Aims: Hybrid endoscopic submucosal dissection (ESD), in which an incision is made around a lesion and snaring is performed after submucosal dissection, has some advantages in colorectal surgery, including shorter procedure time and preventing perforation. However, its value for rescue resection in difficult colorectal ESD cases remains unclear. This study evaluated the utility of rescue hybrid ESD (RH-ESD).Methods: We divided 364 colorectal ESD procedures into the conventional ESD group (C-ESD, n=260), scheduled hybrid ESD group (SH-ESD, n=69), and RH-ESD group (n=35) and compared their clinical outcomes.Results: Resection time was significantly shorter in the following order: RH-ESD (149 [90–197] minutes) >C-ESD (90 [60–140] minutes) >SH-ESD (52 [29–80] minutes). The en bloc resection rate increased significantly in the following order: RH-ESD (48.6%), SH-ESD (78.3%), and C-ESD (97.7%). An analysis of factors related to piecemeal resection of RH-ESD revealed that the submucosal dissection rate was significantly lower in the piecemeal resection group (25% [20%–30%]) than in the en bloc resection group (40% [20%–60%]).Conclusions: RH-ESD was ineffective in terms of curative resection because of the low en bloc resection rate, but was useful for avoiding surgery.

We report the case of a patient with a giant Brunner's gland hamartoma that was pathologically diagnosed by endoscopic mucosal resection. A 69‐year‐old woman presented with intermittent abdominal pain, and imaging revealed a smooth saccular submucosal tumor, 40 mm in diameter, on the anterior wall of the duodenal bulb. Brunner's gland and smooth muscle tissue were observed on endoscopic ultrasound‐guided fine‐needle aspiration biopsy, which resulted in the preoperative diagnosis of a duplication cyst. However, subsequent endoscopic mucosal resection established a final histopathological diagnosis of Brunner's gland hamartoma.